Nowadays, in order to improve asphalt pavement performance, durability and reduce environmental pollution caused by asphalt binder, many researchers are studying to modify asphalt concrete (AC) and find alternative paving materials to extend service life of asphalt pavement. One of the successful materials used in a modification of AC are fibers. Different types of fibers have been reinforced in AC mixture and improvements have been observed. This research studies the performance of glass wool fiber reinforced in a dense-graded asphalt mixture. Generally, glass fibers are known to have excellent mechanical properties such as high tensile modulus, 100% elastic recovery and a very high tolerance to heat. The glass wool fibers are commonly used as a thermal insulation material. In this research to evaluate the performance of glass wool fiber in AC, laboratory tests Marshall mix design test, Indirect tensile strength (IDT), Tensile strength ratio (TSR) and Kim test were conducted to determine a proper mix design, tensile properties, moisture susceptibility, rutting and fatigue behaviors. Results show that addition of glass wool fibers does affect the properties of AC mixture. The use of glass wool fibers showed a positive consistence results, in which it improved the moisture susceptibility and rutting resistance of the AC. Also result showed addition of fiber increased tensile strength and toughness which indicates that fibers have a potential to resist distresses that occur on a surface of the road as a result of heavy traffic loading. The overall results showed that addition of glass wool fiber in AC mixture is beneficial in improving properties of AC pavements.

Cementitious materials exhibit excellent binding properties and micropore structures that support the stabilization of TiO2 nanoparticles within the matrix. Therefore, these materials are ideal for the development of functional construction products with TiO2 nanoparticles. This study investigated the degree of hydration, microstructure, and mechanical properties of cement-containing TiO2 nanoparticles. The experimental results demonstrated that TiO2 nanoparticles accelerated the hydration rate of cement, reducing the setting times. Moreover, TiO2 nanoparticles changed matrix microstructure, decreasing the porosity and improving early-age strength. Although TiO2 nanoparticles function as nucleation sites in the cement hydration reaction, the tendency of the particles to clump implies that proper dispersion should be ensured when mixing in large quantities. When developing new building materials incorporating TiO2 nanoparticles, considering the effect of TiO2 nanoparticles on the hydration reaction of cementitious materials is crucial.

Objective: The effect of long-term performance of one-bottle or two-bottle bonding agents on the shear bond strength to lithium disilicate ceramics (LDS) were to investigate, and the long-term performance of the bond strength of two-bottle bonding agent (Tokuyama Universal Bond II) was investigated under conditions without hydrofluoric acid solution (abbreviated as HF)-pretreatment of LDS. Methods: Nine resin cements (both self-adhesive and adhesive types) were used. It was investigated 1) the adhesion strength of various resin cements to LDS from the presence or absence of HF-treatment, 2) to determine the effect of the deterioration in three times [after one-day storage (abbreviated as Base), and after 5,000 & 20,000 thermocycles (abbreviated as TC 5k and TC 20k)] of one- and two-component bonding agents. And the difference in degradation between one- and two-component bonding gents consist of the silane coupling agent was performed by chemical analysis (High Performance Liquid Chromatography). Results: The trends of resin cements were statistically not very different for each cement 3 times with HF-conditions. Also ESTECEM II and Super-Bond Universal showed the significant greatest values in two conditions (TC 5k and TC 20k) without HF-condition. In TC 20k, ESTECEM II & Super-Bond Universal showed significantly better results than others when treated with the recommended bonding agents without HF-condition. In TC 20k, there was not much statistically significant difference if pretreated with Tokuyama Universal Bond II without HF-condition. Significance: When using LDS, it was found that long-term durability could be maintained by pretreating with Tokuyama Universal Bond II without pretreating with various hazardous HFs.

Improving performance and promoting sustainability in women's handball are key objectives to maximize the potential of female players and ensure the long-term viability of the sport. In this context, training with Olympic movements and their derivatives improves the development of strength, power, and speed, which are determinants of performance in team sports. The aim of this study was to determine if training with Olympic movements produces significant improvements in jumping, throwing, sprinting, and change of direction performance in women handball players. Twenty-one female handball players participated in the study (10 for the control group and 11 for the intervention group). Age ranged from 15 to 17 years. All participants performed four assessment tests (Abalakov Test, throw test, 20-meter Sprint and V-Cut Test) to determine jump height, throwing speed, running speed, and change of direction ability. Measurements were carried out before and after the intervention. For six weeks, the control group performed the strength work established by the club twice a week while the intervention group additionally performed training with Olympic movements. Significant differences (p <0.05) were found between the pre and post measurement of the control group and the intervention group in jump height, throwing speed and running speed, being higher in the intervention group. For the change of direction, no significant differences were found. Between groups, significant differences were observed at the end of the intervention for jump height and running speed. The conclusion of this study was that, by training with Olympic movements, in addition to regular training, could produce greater improvements in jumping performance, throwing speed and running speed in female handball players.

This research paper investigates the enhancement of strength and performance of self-compacting concrete (SCC) for integration in Department of Public Works and Highways (DPWH) projects using a value engineering approach. The study explores key elements of SCC's strength and performance, including mix design optimization, construction practices, and durability considerations. Strategies to optimize SCC's strength, durability, and workability are discussed, emphasizing the benefits of SCC in improving construction efficiency and quality control within DPW infrastructure. The study also identifies challenges and gaps in SCC utilization, such as standardized performance verification and cost considerations, and proposes future directions for advancing SCC technology in civil infrastructure development.

Predictive biomarkers for immune checkpoint inhibitors (ICI), such as PD-L1 expression (TPS), remain limited in clinical applications. Improved novel ICI predictive biomarkers are urgently needed. We evaluated a live single-cell functional liquid biopsy cytokine profiling platform to track immunotherapy treatment response and outcomes. Peripheral blood mononuclear cell samples of healthy donors and NSCLC patients undergoing ICI-based therapies were collected longitudinally pre-/post-treatment under IRB-approved protocols. Samples were enriched for CD4+ and CD8+ T-lymphocytes and analyzed on the IsoLight platform. The single T-cells were captured in microchambers on IsoCode chips for cytokines profiling. Functional polyfunctionality data from 55,775 single cells were analyzed using the IsoSpeak software, kappa coefficient, and Kaplan-Meier survival plots. We found a significant difference between responders and non-responders in CD8+ T-cells’ changes in overall polyfunctionality and polyfunctional strength index (ΔPSI). ΔPSI score in CD8+ T-cells performed better than PD-L1 TPS and, when combined with PD-L1 TPS, strongly correlated with early ICI treatment response with a kappa coefficient of 1.0 (p=0.003). High CD4+ T-cells ΔPSI predicted a strong trend of improved PFS (3.9-fold) and OS (3-fold). In conclusion, single peripheral T-cell polyfunctionality dynamics analysis is a promising liquid biopsy profiling platform as NSCLC ICI predictive biomarker regardless of oncogene-addiction status.

The oil and gas sector has recognised structural integrity assessment of ageing platform for prospective life extension as a rising concern, particularly in encountering the randomness of the harsh ocean environments. This condition leads to uncertainty in wave-in-deck load estimates and a high load level being imposed on offshore structures. This emphasises the necessity of enhanced reliability, as failure might result in inaccessibility because of the uncertainties related to long-distance services, such as accuracy of predictions of loads and responses. Even though the established guidelines present a fundamental assessment, additionally, comprehensive rules are required. This paper performed a reliability analysis incorporating practical approaches that can more accurately represent time-dependent structural deterioration. The following two procedures have been adopted by a majority of significant oil and gas operators to monitor the safety and integrity of these structures: a) Ultimate Strength Assessment (USA) method and b) Reliability Design Assessment (ReDA) method. A comparison of these two reliability approaches was performed on selected ageing jacket structures in the region of the Malaysian sea. The comparative findings, namely, reserve strength ratio (RSR) at various years of the return period (RP) and ratio value for risk of failure regarding the probability of failure (POF), provided a check and balance in strengthening confidence in the results. The findings showed that the structural components might safely survive either using the USA and ReDA method in such conditions, as the reliability indexes were determined to be satisfactory compared to allowable values from ISO 19902 design specifications. Therefore, these evaluations were determined to control the risk level of the structure during the remaining of its lifetime and undertake cost-effective inspections or mitigation strategies when necessary.

Background: Strength assessment is one of the main fields in sports performance, physical rehabilitation, physical activity and health. Purpose: To compare maximal voluntary isometric contractions (MVIC) and paired voluntary isometric contractions (VIC) of knee extensors between an isokinetic dynamometer (BIODEX) and a portable and lightweight device (DINABANG). Methods: From 19 volunteers (age: 28.7±7 y; body mass: 72±10 kg and height: 173±7 cm) we obtained 114 paired MVIC measures and, from the force-time curves of these repetitions, 22507 paired VIC measures of knee extensors. Results: We observed “excellent” repeatability for MVIC (ICC:1.00; p<0.001) between BIODEX (247±79.5 Nm) and DINABANG (247±74.8 Nm), with “trivial” effect (mean difference: 0.12 Nm (0.02%); 95%CI: -0.13 to 0.23 Nm; p=0.606; d=0.048). Bland-Altman plots revealed high accuracy for MVIC (bias: 0.12 Nm) and consistent distribution (precision) inside the limits of agreement (-4.81 to 5.06 Nm) and respective 95%CI. “Excellent” repeatability was also observed for VIC (ICC:1.00; p<0.001) between BIODEX (219±84.1 Nm) and DINABANG (218±84.0 Nm), with “trivial” effect (0.24 Nm (0.11%); 0.08 to 0.11 Nm; p<0.001; d=0.100). Bland-Altman plots revealed high accuracy for VIC (bias: 0.24 Nm) and consistent distribution (precision) inside the limits of agreement (-4.5 to 4.9 Nm) and respective 95%CI. Conclusion: DINABANG is accurate, precise and reliable for torque measurement.

Chitosan's favourable characteristics, such as biocompatibility, biodegradability, and bioactivity, have made it a popular biomaterial and the subject of numerous studies over the last years. This study investigates the enhancement of mechanical properties of chitosan fibres through wet impregnation using tripolyphosphate (TPP) as cross-linker. A 1% w/v solution of TPP was prepared and five separate chitosan fibre specimens were immersed individually in TPP solution for varying times (1, 2, 4, 6, and 8 hours). The specimens were then characterized using FTIR, SEM, and dynamometry to evaluate their physical, chemical, and mechanical properties. The FTIR results indicated successful interaction between the protonated amine groups of chitosan and TPP ions, with the crosslinking reaction reaching completion after 2 hours of immersion. SEM images showed that the surface of the fibres became rougher after the crosslinking reaction, suggesting the formation of new chemical bonds. Mechanical testing revealed a significant improvement in tensile strength for the treated samples compared to untreated ones, indicating successful strengthening through crosslinking. The fibres demonstrate significant potential for use in wound healing dressings.

The results of studying the effect of particles of few-layer graphene (FLG) synthesized by self-propagating high-temperature synthesis (SHS) on the complex of strength and thermo physical properties of polymer composite products obtained by DLP 3D printing are presented. It has been discovered to achieve an increase in thermo physical and strength parameters of polymers modified by FLG compared with samples made on the unmodified base resin. This result was achieved due to low defectiveness, namely the absence of Stone-Wales defects in the structure of FLG due to the homogeneous distribution of FLG over the volume of the polymer in the form of highly dispersed aggregates. It was possible to increase hardness by 120 %, bending strength by 102 %, Charpy impact strength by 205 %, and thermal conductivity at 25 °C by 572 % at concentrations of few-layer graphene of no more than 2 wt. %.

Enhancement in the strength of austenitic steels with a small content of carbon can be achieved by a limited number of methods, among which is the ultrafine-grained (UFG) structure formation, especially efficient with the use of severe plastic deformation (SPD) processing that enables increasing significantly the contribution of grain-boundary strengthening, and also involves a combination of other strengthening factors (work hardening, twins, etc.). In this paper, we demonstrate that the use of SPD processing combined with conventional methods of deformation treatment of metals, such as rolling, may lead to an additional strengthening of UFG steel. Analysis of the results of the study on the change of the microstructure and mechanical properties of the Cr-Ni stainless austenitic steel after a combined deformation reveals a substantial increase in the strength properties of this steel, resulting from a consecutive application of SPD processing via equal-channel angular pressing and rolling at a temperature of 400 С, yielding a strength more than 1.5 times higher that that produced by any of these two methods used separately.

The effect of contamination of polypropylene (PP) with selected polymers is studied to simulate the effect of mis-sorting in recycling streams. Polystyrene (PS), polyethylene terephthalate (PET), polycarbonate (PC), acrylonitrile-butadiene-styrene (ABS) and polylactic acid (PLA) were compounded with PP at different concentrations varying between 3 and 10%. Infrared spectroscopy proved the absence of chemical bonds between the constituents. The samples for mechanical testing were injection moulded and further tested for their tensile and impact properties. Critical behaviour was induced by the introduction of a weld line as a result of the application of multiple gating points during injection moulding. Results generally show the applicability of PP mixtures within the investigated range of inclusions, without much sacrifice in mechanical performance. However, in the case of ABS and PLA, more care should be taken when designing complex parts with weld lines, due to reduced toughness.

Alternative food sources are essential in both low-resource settings or during emergencies like abrupt sunlight reduction scenarios. Seaweed presents a promising option but requires investigation into the viability of unconventionally sourced ropes for harvesting. As such, a low-cost reliable method to test the tensile strength of rope is needed to validate alternative materials for use in harvesting seaweed. Unfortunately, commercial rope testing jigs alone range in price from several thousand to tens of thousands of dollars. To fill this need, this article reports on an open-source design for tensile strength rope testing hardware. The hardware design focuses on using readily available parts that can be both sourced from a hardware store and manufactured with simple tools to provide for the greatest geographic accessibility. The jig design, which can be fabricated for CAD$20 is two to three orders of magnitude less expensive than commercially available solutions. The jig was built and tested using a case study example investigating denim materials (of 1 5/8”, 3 1/4", 4 7/8”, 6 1/2", and 8 1/8” widths) as a potential alternative rope material for seaweed farming. Denim demonstrated strength up to 1.65kN for the widest sample and the jig demonstrated sufficient strength and stiffness for operating at forces below 4kN. The results are discussed and areas for future improvements are outlined to adapt the device to other circumstances and increase the strength of materials that can be tested.

The purpose of this study is to analyse the feasibility of using waste from granite gang saws (GCW-GS) to manufacture ultra-high performance, steel-fibre reinforced concrete (UHPFRC). These machines cut granite blocks by abrasion using a steel blade and slurry containing fine steel grit. The waste generated by gang saws (GCW-GS) contains up to 15% Fe2O3 and up to 5% CaO. This is the main difference from the waste produced by diamond saws (GCW-D). Consequently, the second objective of this study is to compare the results of the waste obtained with gang saws with that from diamond saws, in order to determine the influence of iron and calcium oxides. The waste from cutting granite with gang saws was used in different percentages to replace micronized quartz powder of natural origin in the manufacture of UHPRFC. All the test specimens were analysed to determine their compressive strength, elasticity modulus, flexural strength and indirect tensile strength. The final conclusion is that wastes from both gang saws and diamond saws can be used to manufacture UHPFRC with an improvement in the mechanical properties up to a 35% replacement. The results for GCW-GS are better, mainly due to the pozzolanic effect of the iron dioxide. For higher percentage replacements the mechanical properties are close to the control concrete with small decreases.

The objective was to assess the instrumental validity and the test-retest reliability of a low-cost hand-held push dynamometer adapted from a load-cell based hanging scale (tHHD) to collect compressive forces in different ranges of compressive forces. Three independent raters applied 50 pre-established compressions each on the tHHD centered on a force platform in 3 distinct ranges: ~70 N, ~160 N, ~250 N. Knee isometric strength was also assessed on 19 subjects in two sessions (48h apart) using the tHHD anchored by an inelastic adjustable strap. Knee extension and flexion were assessed with the participant seated on a chair with the feet resting on the floor, knees, and hips flexed at 90°. The isometric force peaks were recorded and compared. The ICC and the Cronbach’s α showed excellent consistency and agreement for both instrumental validity and test-retest reliability, as the correlation and determination coefficients. The SEM and the MDC analysis returned adequate low values with a coefficient of variation less than 5%. The Bland-Altman results showed consistency and high levels of agreement. The tHHD is a valid method to assess the knee isometric strength, showing portability, cost-effectiveness, and user-friendly interface to provide an effective form to assess the knee isometric strength.

Based on an in-depth analysis of the factors influencing the compressive strength of ultra-high performance concrete (UHPC), this study examined the impact of both single factors and combined factors on UHPC performance using experimental data. The correlation analysis indicates that cement content, water content, steel fiber, and fly ash significantly affect the strength of UHPC, whereas silica fume, superplasticizers, and slag powder have a relatively smaller influence. This analysis provides a scientific basis for model development. Furthermore, the support vector regression (SVR) model was optimized using the arithmetic optimization algorithm (AOA). The superior performance and computational efficiency of the AOA-SVR model in predicting UHPC compressive strength were validated. Compared to SVR, support vector machine（SVM）, and other single models, the AOA-SVR model achieves the highest R2 value and the lowest error rates. The results demonstrate that the optimized AOA-SVR model possesses excellent generalization ability and can more accurately predict the compressive strength of UHPC.

There are no studies that have investigated the characteristics of car use across THA patients, including those who do not drive. This study aimed to evaluate, in THA patients, (1) postoperative car usage, (2) comfort while entering and exiting a car, and (3) whether lower limb muscle strength affects action comfort. One hundred seventy-two post-THA patients completed the questionnaire in 2020, along with assessments of hip abductor and knee extensor muscle strength before surgery and at discharge. Patients whose overall comfort level was judged as “comfortable” were defined as the “comfort” group; others were placed in the “discomfort” group. Of the 172 patients, 161 reported car usage at a mean of 5.6 years after THA. Of these, 114 and 47 patients were placed in the "comfort" and "discomfort" groups, respectively. Patients in the "discomfort" group were three times more likely to experience discomfort using the contralateral side door than the surgical side door, and about twice as many patients experienced discomfort when entering as when exiting. Lower preoperative contralateral hip abductor muscle strength was the only independent predictor for discomfort. The take-home messages were that prevention of contralateral-side weakness may improve comfort during the action after THA.

In recent years, the production of cement has grown globally in a very rapid manner due to the modernization of the world we live in, and after fossil fuels and land-use change, cement production is the third-largest source of anthropogenic emissions of carbon dioxide, CO₂. Cement being the primary binding material for concrete and with the prospects for the concrete industry continues to grow so will the emissions of CO₂. Hence, a method to reduce the CO₂ production while keeping up with the progression of the concrete industry is very crucial in current times. This is where CO₂ sequestration comes in. It is a process where CO₂ is converted into a mineral which will then be trapped into the concrete forever. Required data to carry out the research between CO₂ sequestered concrete and concrete without CO₂ have been observed, obtained and tabulated as necessary. These data are then used to compare the concrete samples with one another and also prove the theoretical effects of CO₂ exposure to concrete. Hence, experimental results on the compressive strength of the concrete samples for 7, 14 and 28 days has also been tabulated, graphed and further disputed. The objective of this research is mainly to determine the compressive strength of CO₂ sequestered concrete in comparison with concrete without CO₂ in order to decrease the effects the concrete industry has on the environment. The compressive strength of concrete samples with sequestration of CO₂ gas is expected to be higher than of the concrete without CO₂.

In Geo Polymer bricks (GPB), fly ash content which is a waste from power plants is converted into bricks by chemical treatment. GPB can be dried by using appropriate curing methods. Conven-tionally electric oven curing is one of the prominent methods. Using solar dryer instead of elec-trical oven gives added advantage of saving high grade electrical energy. So in this work solar dryer with PCM (Phase Change materials) Paraffin Wax and without PCM is used for curing ap-plication. GPB are gaining added advantage when compared to conventional bricks like cement and sand bricks in terms of strength. GPB has been taken as specimen for comparing the com-pressive, tensile split strength and flexural strength by electrical energy based curing and solar energy based curing. It is experimentally observed that solar energy based curing with PCM and without PCM exhibits higher compressive strength, higher tensile split strength and flexural strength when compared to electrical energy based curing. Solar curing with PCM shows higher compressive strength, higher tensile split strength and flexural strength when compared to Solar curing without PCM. Open solar curing is a traditional technique but nowadays aggressive cli-matic conditions can lead to severe damage of Geo polymers. The novelty of this work is to suggest to study the effect of PCM like paraffin wax in solar drying on curing time, mechanical properties of GPB.

Player’s performance in an intense sport such as basketball is known to be related to attributes like speed, agility, and power. This study presents a comparative analysis of associations between anthropometric assessment and physical performance in different age-group elite youth basketball players, while simultaneously identifying the predictors for speed and agility in these players. U14 (n=44), U15 (n=45) and U16 (n=51) players were tested for anthropometry, lower body power, speed, and agility. U16 players were found to be taller, heavier, more muscular than U14 and U15 players. Also, the U16 group showed better performance in all performance tests. Age had a significant positive correlation with countermovement (CMJ) and drop jump (DJ) performance in U14 players, and a significant negative correlation with 10m and 20m sprint times in U15 group. CMJ and DJ emerged as the most significant predictors for sprint and agility variables, respectively. Body fat percentage was found to be a significant predictor for the speed and agility tests in all age groups, but a negative lower-body power predictor. Therefore, besides all sport-specific and fitness tests, it is essential to place emphasis on the percentage of body fat when designing players’ individualized training programs, and during team selection.

Worldwide the steel corrosion is one of the greatest deterioration problems for reinforced concrete structures. Comparing some literature experimental results with a complex FEM model, the present paper points out the principal aspects those characterize the static behavior of RC elements damaged by corrosion. Moreover, the non-dimensional abaci defined for some specific case studies finalized to the evaluation of the residual flexural strength of corroded elements highlight the dangerousness of the corrosion degradation if the failure of the element is governed by the steel

In India, particularly within its North-Eastern territories, the occurrence of landslides triggered by post-dry period rainfall events is a significant concern, with the phenomena persistently causing extensive damage to both life and infrastructure. Despite the inevitability of such natural disasters, it is understood that the impact they exert can be substantially mitigated through the implementation of pre-emptive measures. Critical to the endeavour of landslide prevention is the application of a spectrum of mitigation strategies, predicated upon a foundational analysis of slope stability to ascertain critical surfaces for intervention. This investigation delves into the dynamics of partially saturated soils, a condition commonly resultant from the prolonged dry periods preceding the monsoonal rains. The study's focal point is an experimental examination conducted on soil samples to assess parameters such as soil matric suction and unconfined compressive strength across varying degrees of saturation and density, alongside performing analyses of slope failure incidents after dry period during the 2017 monsoon in the Lunglei district, Mizoram based on some established data. The Soil-Water Characteristic Curve (SWCC), derived from soil suction measurements employing the ASTM D5298-10 standard, utilizes a contact filter paper method and serves to delineate the moisture transition phases of the slope. To replicate the desiccation of the soil slope after monsoonal rains, a microwave drying technique based on the ASTM standard was employed to prepare unsaturated soil samples for Unconfined Compressive Strength (UCS) testing. The integrity of the slope was evaluated in a temporal context, before and after rainfall events of varied intensities throughout the calendar year, utilizing a blend of numerical modeling and empirical laboratory investigations. The persistence of real onsite slope failures underscores the necessity for a numerical analysis approach to unravel the underlying factors causing slope instability, especially given the absence of prior stability assessments for the landslide in question. An evaluation of SWCC curves, UCS tests on partially saturated soil at different densities and saturation and the utilization of the benchmark data collected in 2017 on the shallow transitional landslide in Lunglei, Mizoram caused by intense monsoonal precipitation, are central key data and information used to carry out this research. Rainfall data for Lunglei, sourced from the Mizoram Meteorological Department, facilitated a real-time monsoonal data-driven numerical analysis. This analysis elucidated the pivotal role of rainfall in inducing slope failure, indicating a marked destabilization of the slope after precipitation events. The implications of these findings are far-reaching, suggesting a foundational basis for the development of an advanced landslide early warning system, thereby enhancing disaster preparedness, and mitigating potential damages.

The aim of this study was to using a lignin based resin (LB) to improve the performance of the soy flour based adhesive. Soy flour (SF), polyamidoamine-epichlorohydrin (PAE), LB was used to develop a plywood adhesive. The solid content and viscosity of the adhesive, functional groups, thermo-stability, and crystallinity of the cured adhesive were characterized and the performance of the resultant adhesive was evaluated by fabricating three-ply plywood. Results showed using LB and PAE mixture to modify SF adhesive improves dry and wet bond strength by 66.3 and 184.2%. PAE contributed more for the wet bond strength improvement and the LB contributed more for the dry bond strength. The improvement was attributed to: 1) LB/PAE reacted with the functions of the soy protein and form a cross-linking network; 2) Polycondensation reaction between LB molecules further improved crosslinking density of the adhesive and formed a interpenetration structure with crosslinked protein; 3)The easy penetration of LB on wood surface and formed more interlock with wood. The denser structure created by LB and PAE mixture improved the thermal stability and decreased the crystallinity of cured adhesive. The usage of the LB and PAE mixture increased solid content by 35.5%, meanwhile, makes its viscosity acceptable for the industrial application.

This paper discusses the theoretical and experimental correlations between fatigue and static strength statistical distributions. We use a two-parameter residual strength model that obeys the qualitative Strenght-Life Equal-Rank (SLERA) assumption for guidance. The modeling approach consists of recovering the model's parameters by best fitting the constant amplitude (CA) fatigue data at a given stress ratio, R, and the experimental Weibull parameters of the static strength distribution function. Once the model's parameters are fixed, its capabilities, potential, and limits are discussed by comparing its predictions with residual strength and fatigue data obtained at different stress ratios, R. Moreover, from a preliminary analysis, the theoretical extension of the model's capabilities to variable amplitude loadings is conceptualized. The application of Miner's rule is also discussed and compared with a new damage rule to analyze the fatigue responses under variable amplitude loadings.

Rigid pavements at military airfields experience surface deterioration within 6-18 months of construction. The cause of this degradation is mainly due to combined exposure to repeated heat shocks from jet engine exhaust and spilled aviation oils (hydrocarbons). Surface degradation occurs in the form of disintegration of aggregates and cement paste into small pieces that pose severe risks of physical injury to maintenance crews or damage to an aircraft engine. Since coarse aggregates typically occupy 60-80% of the concrete volume, aggregates' thermal properties and microstructure should play a crucial role in the degrading mechanism. At high temperatures, concrete with lightweight aggregates is reported to have better performance compared to concrete with normal-weight aggregate. Thus, the present study carried out a detailed investigation of the mechanical and thermal performance of lightweight aggregate concrete exposed to the combined effects of high temperature and hydrocarbon oils simultaneously. To identify the resistance of different concrete with various lightweight coarse aggregates, pumice, perlite, lytag (sintered fly ash), and crushed brick were used as lightweight coarse aggregates in concrete. Also, basalt aggregate concrete was used as a reference. After cyclic exposures, all specimens were tested for residual mechanical, thermal, chemical, and microstructural properties. Overall, concrete with crushed brick aggregate and LYTAG used in this study showed superior resistance to the simulated airfield conditions.

Extruded polystyrene (XPS) is frequently used in the construction of many different structures. It is therefore necessary to appropriately characterize its mechanical properties to ensure the safety of said structures. Among the available characterization tests, static bending tests are simple and easy to perform; owing to these characteristics, they should be performed more frequently than other tests. However, in static bending tests on XPS, there are several challenges owing to the high flexibility of XPS, and the chosen testing method and sample configuration affect the accuracy of characterization. In this study, three bending properties (Young’s modulus, proportional limit stress, and bending strength) of samples cut from an XPS panel were determined using three-point bending (TPB), four-point bending (FPB), and compression bending (CB) tests with varying sample span/depth ratios, and statistical analyses were performed to determine the relevance of the tests. The experimental results suggest that the TPB and CB tests were more feasible than the FPB test when the span/depth ratio was appropriately determined. However, clear differences were observed in the sample bending properties determined in these tests. In light of these findings, further studies should be conducted to elucidate these differences.

Large inconsistencies in the outcome of precise measurements of Newtonian gravitational ‘constant’ were identified throughout more than three hundred experiments conducted up to date. This paper illustrates the dependency of the Newtonian gravitational parameter on the curvature of the background and the associated field strength of vacuum energy. Additionally, the derived interaction field equations show that boundary interactions and spin-spin correlations of vacuum and conventional energy densities contribute to the emergence of mass. Experimental conditions are recommended to achieve consistent outcomes of the parameter precision measurements, which can directly falsify or provide confirmations to the presented field equations.

A robust methodology to simulate virtually the residual stresses pattern in welded steel plates is presented. The methodology is applied to the structural analysis of typical welded plates belonging to ship structures, and the effect of residual stresses on the elastoplastic behavior of plates loaded axially is analyzed in comparison to the residual stress free case, both for tension and compression and including initial imperfections. Residual stresses affect in different manner plates with different geometries; thus a parametric study is performed covering the usual range of variation of the most important plate parameters that control the strength of the plates, more precisely the slenderness and the aspect ratio. The results from finite elements analysis are compared with codes and most stablished formulations and recommendations of applicability in the prediction of load-shortening curves for hull’s bending strength evaluation, ultimate strength and ultimate strain of plate elements are made.

The CuCrSn alloy is promising as high-strength and high-conductivity Cu alloy due to its relative low smelting requirement, while thus far reports on the CuCrSn alloy is still quite lacked. In this study, the microstructure and properties of Cu-0.20Cr-0.25Sn (wt%) specimens prepared under different rolling and aging combinations were comprehensively characterized, in order to reveal the effects of cold rolling and aging on the CuCrSn alloy. The results show that increasing the aging temperature from 400 ºC to 450 ºC can obviously accelerates the precipitation, and the cold rolling before aging significantly increases the initial microhardness and promotes the precipitation. Whereas, the deformation hardening will be eliminated during the aging process, making the microhardness even decrease monotonically when the aging temperature and the rolling ratio before aging are high. Performing the cold rolling after the aging can maximize the effects of precipitation strengthening and deformation strengthening, and its adverse impact on the conductivity is not serious. A tensile strength of 506.5 MPa and a conductivity of 70.33% IACS were obtained with such a treatment, only the elongation decreases. Different strength-conductivity combinations of the CuCrSn alloy can be achieved through appropriate combinations of the aging and post aging cold rolling conditions.

The topic of modification of magnesium oxychloride cement (MOC) via specific functional additives is very much pronounced in the research of alternative building materials. This study deals with the co-doping of MOC by 1D and 2D carbon nanomaterials in order to improve its mechanical properties while using tannic acid (TA) as a surfactant. Furthermore, the effect of TA on MOC also covers the improvement of water resistance. As a filler, three size fractions of standard quartz sand are used. The proposed types of MOC-based composites show promising results considering their mechanical, macro- and microstructural, chemical, and hygric properties. The use of 1D and 2D nanoadditives and their mixture enables the improvement of the flexural strength and most of all softening coefficient, the durability parameter characterizing the resistance of the prepared materials to water. For samples immersed in water for 24 h, the compressive strength of all modified composites tested was higher than that of the reference composite. Quantitatively, the developed co-doped composite shows mechanical parameters comparable to or even better than those of commonly used Portland cement-based materials, while maintaining high environmental efficiency. This indicates its potential use as an environmentally friendly alternative to Portland cement-based products.

The use of Supplementary Cementitious Material (SCM) is widely used in production of sustainable concrete. Blended cements, incorporating SCM such as Pulverized Fly Ash (PFA) and Ground Granulated Blast Furnace Slag (GGBFS) have been widely used to reduce the cement contents and avoid adverse environmental impacts of CO2 produced during cement manufacturing. The analysis of various structural properties of concrete such as compressive strength, flexural strength and modulus of elasticity is important for its structural application. In this research, flexural strength of 100mmx100mmx500mm beams made from blended cement were tested under three curing conditions i.e. winter, summer and under water and the flexural strength was calculated using EN-12390-5 at the ages of 28 days and 56 days. For modulus of elasticity, concrete cylinders 150mmx300mm were tested as per procedure described in BS 1881-121(1983) at the age of 28 days. The compressive strength, flexural strength and modulus of elasticity for blended cement incorporating PFA and GGBFS has been increased under summer curing environment. The experimental values of Modulus of Elasticity are compared with the provision of BS 1881.

Aging is associated with muscle atrophy and fatty infiltration of skeletal muscle. The multifidus muscle stabilizes the lumbar spine and undergoes adipose accumulation with age, leading to functional decline in the elderly. Therefore, quantitative assessment of the multifidus muscle can be beneficial for the elderly when formulating treatment strategies and reducing future complications. Fifty-seven patients (mean age, 73.89 ± 6.09; 23 male patients) who underwent lumbar Magnetic resonance imaging (MRI) were prospectively recruited. The cross-sectional area (CSA) of the multifidus from the L2-S1 level and the CSA of the L4-5 level psoas muscle were measured. The functional CSA (fCSA) of the multifidus muscle was measured by excluding the fat infiltration area from the multifidus CSA. The CSA to fCSA ratio was obtained by multiplying 100 by the value obtained by dividing CSA by the fCSA. Pfrrmann classification was used to evaluate the degree of disc degeneration. The functional disability measurements were the Short Physical Performance Battery (SPPB), Berg Balance Scale (BBS), grip strength, and functional reach test (FRT). Pearson's correlation analysis was used to examine the relationship between the functional disability measurements and the multifidus muscle. The CSA to fCSA ratio value was relatively constant at each spine level and showed a significant correlation with the SPPB, grip strength, FRT, and psoas index (p<0.05). However, degree of disc and multifidus muscle degeneration were not statistically significant. So, age-related changes play a significant role in developing back muscle fatty infiltration than disc dgeneration. Moreover, Grip strength showed a stronger relationship with the quality of the multifidus muscle than other functional disability measurements.

The effects of various drawing parameters and annealing processes on the structure and properties of Cu-Ag wires, containing 1 wt% silver, were investigated using specialized equipment including fine wire drawing machines, very fine wire drawing machines, heat treatment equipment, tensile testing machines, microcomputer-controlled electronic universal testers, resistance testers, and scanning electron microscopes. The results revealed that continuous drawing of Cu-1%Ag alloy wires led to elongation of the grains, resulting in a uniform and tightly fibrous microstructure. Moreover, the tensile strength of the alloy wire increased from 670 MPa to 783.9 MPa after a single-pass with a deformation of 14%. Subsequently, when the wire was drawn at a speed of 500 m/min, the tensile strength further increased to 820.1 MPa. After annealing the Փ0.08 mm Cu-1% Ag alloy wire, an increase in annealing temperature up to 500°C resulted in the wire's tensile strength decreasing from 820.1 MPa to 377.5 MPa. Simultaneously, the elongation increased from 1.94% to 15.21%, and the resistivity decreased from 1.931×10-8Ω·m to 1.723×10-8Ω·m. Additionally, when annealing was conducted at a rate of 80 m/min, the wire resistivity dropped to 1.635×10-8Ω·m.

Background: Evidences on the effects of chemotherapy treatment cycles on measures of muscle, mental state, social and cognitive performance are scarce. Objective: To analyze the effects of chemotherapy cycles on muscle strength and activation, functional capacity, quality of life, fatigue and anxiety of women with breast cancer. Methods: Twenty-two women divided into a treatment group (n = 10; 46.6 ± 9.6 years) and control group (n = 12; 51.6 ± 7.0 years) participated in the study. Analysis of muscle performance, quality of life, fatigue and anxiety after the 2nd and 4th cycle of chemotherapy with anthracyclines and cyclophosphamide were performed in women with breast cancer (TRA) and compared to healthy women (CTR). Two-way ANOVA was used to compare the variance of the means and the significance level was set as p≤0.05. Results: Differences were found in the muscular activation of the vastus medialis between the groups at post time (p = 0.038), as well as in the sit and stand test in the baseline (p<0.001) and post moment (p<0.001). Functional capacity performance was different between baseline (p<0.001) and post-time (p<0.001) groups. Additionally, the TRA group worsened the quality of life in the domains of functional capacity (p<0.001) and limitation of physical aspects (p=0.002), besides presenting negative changes in fatigue. Conclusion: Anthracycline and cyclophosphamide chemotherapy cycles reduce muscular performance and affect biopsychosocial variables in women with breast cancer.

This study aims to formulate binary cementitious systems containing silica fume (SF) and micro quartz (MQ) to improve cementitious concrete's durability and mechanical properties. In this investigation, we examined the effects of different essential variables, such as the level of SF and MQ replacement and the ratio of the water-binder (w/b). In this study, the w/b ratios were 0.25, 0.3, 0.35, and 0.4. Replacement levels for SF were 8, 10, and 12%, while replacement levels for MQ were 5, 8, 10, 15, 25, and 35%. The porosity and permeability decreased with an increase in replacement levels, regardless of the type of fine material used or the amount of replacement. Meanwhile, the strength increased markedly with SF replacement, reaching its maximum MQ of 25% at the SF level. The strength of the SF mixing was the highest in all mixes, and it remained the highest until 15% of MQ was replaced. The ultrafine size of MQ particles contributes to the improvement of compressive strength, porosity, and permeability in a similar way to SF particles, despite their high crystalline structure. Furthermore, in this study, analysis of variance (ANOVA) was employed to verify the influence of each variable on the studied response.

In many developing countries, plastic waste management is left to citizens. This usually results in hazardous landfilling or open-air burning, leading to emissions that are harmful to human health and the environment. An easy, profitable, and clean method of processing and transforming the waste into value is required. In this context, this study provides an open-source methodology to transform low-density polyethylene drinking water sachets, into pavement blocks by using a streamlined do-it-yourself approach that requires only modest capital. Two different materials, sand, and ashes are evaluated as additives in plastic composites and the mechanical strength of the resulting blocks are tested for different proportion mix of plastic, sand, and ash. The best composite had an elastic modulus of 169MPa, a compressive strength of 29MPa, and a water absorptivity of 2.2%. The composite pavers can be sold at 100% profit while employing workers at 1.5X the minimum wage. In the West African region, this technology has the potential to produce 19 million pavement tiles from 28,000 tons of plastic water sachets annually in Ghana, Nigeria, and Liberia. This can contribute to waste management in the region while generating a gross revenue of 2.85 billion XOF (4.33 million USD).

Bamboo is considered a sustainable construction material due to its ability to grow quickly and its mechanical properties that are comparable to timber. Contributing to the current effort to establish the structural bamboo standards in the National Structural Code of the Philippines (NSCP), this study establishes the characteristic compressive strength of four bamboo species: Bambusa vulgaris (36 samples), Dendrocalamus asper (36 samples), Bambusa blumeana (94 samples), and Guadua angustifolia Kunth (30 samples). The samples were subjected to compressive loading following ISO 22157-1 (2017). The characteristic compressive strength values obtained, according to ISO 12122-1 (2014), were 40.35 MPa for B. vulgaris, 40.21 MPa for D. asper, 46.63 MPa for B. blumeana, and 36.99 MPa for G. angustifolia Kunth. Simple linear analysis, One-way ANOVA, and Welch’s t-Test were used to analyze the correlation models and establish a comparative analysis of the effect of nodes, and geometric and physical properties on the compressive strength of bamboos. Comparing the characteristic compressive strength obtained from this study to the strength of unseasoned structural timber of Philippine woods, all bamboo species showed higher strength values, and thus have great potential as an alternative construction material to timber.

Concrete is the most commonly used construction material due to its various advantages, such as versatility, familiarity, strength and durability and it will continue to be in demand far into the future. However, with today’s sensitivity to the environmental protection, this material is facing unprecedented challenges due to its high greenhouse gas emission mainly during cement production. This paper investigates one of the promising cement replacement materials, alkali activated cement (AAC) concrete. Being produced mainly from byproduct materials and having a comparable structural performance to conventional concrete, AAC concrete has a potential to transform the construction industry. Mechanical properties such as compressive and flexural strength and the relationship between them are studied. Different source materials such as fly ash (FA), ground granulated blast furnace slag (GGBS), silica fume (SF) and Metakaolin (MK) are used. The effect of the source materials and the activator solutions on the concrete performance is studied. Furthermore, the freeze-thaw resistance of the concrete is studied. The results of the study showed that the behavior of AAC depends highly on the source material combinations as well as type used. The effect of the alkaline solution is also dependent on the source material used. Mixes with higher GGBS content in general showed the highest strength while mixes with MK showed the highest flexural strength. The results from the freeze-thaw test showed that proper design of AAC concrete with a lower water content is critical to achieve a good resistance.

This study is focused on the mechanical properties of WC-Co composites obtained via Selective Laser Sintering using PA12 as a binder. The as-printed samples were thermally debonded, and sintered, first in vacuum, and then sinter-HIPed at 1400oC, using 50 bar Ar, which has led to relative densities up to 66 %. Optical metallographic images show a microstructure consisting of WC, with an average grain size in the range of 1.4 – 2.0 µm, with isolated large grains, in a well-distributed Co matrix. The shrinkage of the samples was 43 %, with no significant shape distortion. The printing direction of the samples has a great impact on the transversal rupture strength (TRS). Nevertheless, the bending strength was low, with a measured maximum of 612 MPa. SEM images of the fracture surface of TRS samples show the presence of defects that constitute the cause of the low measured values. The hardness values position the obtained composites in the range of medium coarse classical cemented carbides. The results were also related to the amount of free Co after sintering, close to the initial one, as assessed by magnetic measurements, indicating a low degree of interaction with PA12 decomposition products.

The interlaminar strength of mechanically interlocked polymer-metal-interfaces is strongly dependent on the surface structure of the metal component. Therefore, this contribution assesses the suitability of the fractal dimension for quantification of the surface structure as well as interlaminar strength prediction of aluminum/polyamide 6 polymer-metal-hybrids. Seven different surface structures, manufactured by blasting, combined blasting and etching, thermal spraying and laser ablation, are investigated. The experiments are carried out on a novel butt-bonded hollow cylinder testing method that allows shear and tensile strength determination with one specific specimen geometry. The fractal dimension of the metal surfaces is derived from cross-sectional images. For comparison, the surface roughness slope is determined and related to the interlaminar strength. Finally, a fracture analysis is conducted. For the investigated material combination, the experimental results indicate that the fractal dimension is an appropriate measure for predicting the interlaminar strength

In regions with low-temperature action transverse cracks can appear in asphalt pavements as a result of thermal stresses that exceed the fracture strength of materials used in asphalt layers. To better understand thermal cracking phenomenon, strength properties of different asphalt mixtures were investigated. Four test methods were used to assess the influence of bitumen type and mixture composition on tensile strength properties of asphalt mixtures: tensile strength using the Thermal Stress Restrained Specimen Test (TSRST) and the Uniaxial Tension Stress Test (UTST), flexural strength using the Bending Beam Test (BBT) and fracture toughness using the Semi-Circular Bending Test (SCB). The strength reserve behavior of tested asphalt mixtures was assessed as well. The influence of cooling rate on strength reserve was investigated and correlations between results from different test methods were also analyzed and discussed. It was observed that the type of bitumen is a factor of crucial importance to low-temperature properties of the tested asphalt concretes. This conclusion was proved by all test methods that were used. It was also observed that the level of cooling rate influences the strength reserve and, in consequence, resistance to low-temperature cracking. It was concluded that reasonably good correlations were observed between strength results for the UTST, BBT and SCB test methods.

This study addresses the critical issue of dowel-bearing strength in Bambusa blumeana, a key sus-tainable construction material crucial for climate change mitigation. Given the lack of bamboo connection standards, the research focuses on determining the dowel-bearing strength of Bambusa blumeana, emphasizing factors such as dowel diameter, node placements, and the physical prop-erties of bamboo. A predictive equation is derived, enhancing the practicality of bamboo in struc-tural design. The results underscore a notable correlation between dowel diameter and character-istic strength, with implications for engineering practices. Node placements significantly affect dowel-bearing capacity, while bamboo's physical attributes, including thickness, culm diameter, and moisture content, exhibit modest correlations with strength. The derived equation aims to assist in structural design, mitigating splitting and bearing failures in bamboo structures. This research establishes a foundation for optimizing the use of Bambusa blumeana in sustainable construction, advancing the understanding of its dowel-bearing strength for improved sustainability and resili-ence in the construction industry. Future research suggestions include exploring bamboo-mortar composites, additional node placements, and employing more comprehensive empirical equations and curve-fitting techniques. The study advocates for further investigations with more diverse and larger bamboo samples to bolster robustness. Additionally, delving into bamboo ductility may offer valuable insights.

The world’s population is growing at a rapid pace, thus increasing the need for shelter, which, because of increased carbon emissions, is making our planet less inhabitable. Thus, supplementary cementitious materials (SCMs) are used to reduce the embodied carbon emissions in the building sector. Wood ash, as a replacement for cement in soil treatment, seems to be a promising material. In this study, we considered the strength, stiffness, and microstructural behavior of marine clay treated with cement and wood ash as a cement replacement. Since clay is abundant in nature, it could help stabilize waste to improve the mechanical behavior of produced composites. Portland cement (7%, 10%, and 13%) was replaced with various amount of wood ash (5% and 10%) with two different dry densities (1400 and 1600 kg/m3) and three distinct curing periods (7, 28, and 60 days). Unconfined compressive strength, direct shear, porosity, pulse velocity, x-ray diffraction, and scanning electron microscopy tests were performed on selected specimens to evaluate the structural and microstructural effect of clay–wood ash–cement interaction. The results revealed that the replacement of cement with 5% of wood ash yielded superior performance. The microstructure investigation of wood ash–cement–clay blends further showed the formation of a densified matrix with stable bonds. Furthermore, the porosity and strength properties of blends developed unique relationships, which were further confirmed by other supplementary materials and soils.

Prolonged application (&gt; 20 minutes) of LV on muscles or tendons is known to reduce maximal isometric strength. However, the effect of short vibration durations (&lt; 6 minutes) is still unknown. In fourteen participants, the changes in maximal voluntary isometric contraction (MVIC) were measured after 1, 3, and 6 minutes of rest (CONT) or local vibration (LV) over the quadricipital tendon (frequency: 100 Hz; amplitude: 0.5mm). Before and after each condition, the amplitude of the twitch induced by a 100 Hz potentiated electrical doublet (PDPOT), relative electromyographic activity of the vastus medialis and rectus femoris muscle during the MVIC (RMSMVIC.M-1), the torque developed 50 ms after the onset of contraction (T50) and the voluntary activation level (VAL) were evaluated. None of the three LV durations significantly changed MVIC compared with the control condition (p = .379). Indices of central (i.e., VAL, T50, RMSMVIC.M-1) and peripheral (PDPOT) fatigue were unaffected (p &gt; .147). In conclusion, a short duration of LV (&lt;6min) on a voluminous muscle group, does not impair maximal force production nor induce any central or peripherical fatigue.

Solute decoration at grain boundaries (GB) leads to a number of phenomenon such as changes in interface structure, mobility, cohesion etc. Recent experimental investigations on interfacial segregation in steels are based on microstructural characterisation using two correlative methodologies, namely, Transmission Electron Microscopy-Atom Probe Tomography (APT) and Electron Backscatter Diffraction-APT. Considering the growing interest in this avenue, the present review is aimed at addressing the common adsorption isotherms used for quantifying interfacial segregation and providing an overview of the present state of experimental research in the area of GB segregation in steels. The areas where an understanding of GB segregation may be utilised have also been highlighted with a focus on the experimental challenges associated with understanding GB segregation in steels.

Magnesium matrix composites have attracted significant attention due to their lightweight nature and impressive mechanical properties. However, the fabrication process for these alloy compo-sites is often time-consuming, expensive, and labor-intensive. To overcome these challenges, this study employed machine learning (ML) techniques to predict the mechanical properties of magnesium matrix composites. Regression models were utilized to forecast the yield strength of magnesium alloy composites reinforced with various materials. The study incorporated previous research on matrix type, reinforcement type, heat treatment, and mechanical working. The re-gression models employed in this study included decision tree regression, random forest re-gression, extra tree regression, and XGBoost regression. Model performance was assessed using metrics such as RMSE and R2. The XGBoost Regression model out-performed others, exhibiting an R2 value of 0.94 and the lowest error rate. Feature importance analysis indicated that the rein-forcement particle form had the greatest influence on the mechanical properties. The study iden-tified the optimized parameters for achieving the highest yield strength, which was 186.99 MPa. Overall, this study successfully demonstrates the effectiveness of ML as a valuable tool for opti-mizing the production parameters of magnesium matrix composites.

This study evaluated the mechanical strengths of three types of orthodontic micro-implants by analyzing their structural configurations. Thirty micro-implants of three types (diameter 1.5 mm, Types A, B, C) were assessed. All micro-implants were manually driven into artificial bones at an 8-mm depth. The insertion torque (IT), pullout strength (PS), and gripping volume (GV) of each type were measured. Intergroup comparisons and intragroup correlation were investigated by statistical analysis. Type B had the greatest inner–outer diameter ratio (0.67), and Type A had the smallest (0.53). The IT of Type A (5.26 Ncm) was significantly (p = 0.038) lower than that of Type C (8.8 Ncm). There was no significant difference in the pullout strength (p = 0.868). The GV of Type A (9.7 mm3) was significant (p < 0.01) greater than Type C (8.4 mm3). Type C was significant (p < 0.01) greater than Type B (7.2 mm3). Spearman’s rho rank correlation test showed that PS of Type B was correlated significantly with GV. In conclusion, the design of thread and its GV were the important factors on the mechanical strengths of micro-implant.

This study investigated the effects of freeze-thaw cycles on the mechanical properties of hardened self-compacting concrete for varying column heights. A column (100×20×300 cm) was fabricated by C30 self-compacting concrete in the laboratory and 10 cube samples (10x10x10 cm) were taken from fresh concrete as the references. After a period of 28 days, 160 core specimens (Ø67 mm in diameter) were taken from different column heights. Unit weight, water absorption, compressive strength, and freeze-thaw tests were performed on these 170 (10 reference cubic and 160 core) samples. The mechanical properties of the core specimens before freeze-thaw and after 8-56 freeze-thaw cycles were reported for varying column heights. The average compressive strength value of the reference cubic samples was determined as 40.28 MPa, while the compressive strengths of the core specimens before freeze-thaw were ranged from 40.25 MPa to 49.62 MPa, impying an increase in compressive strength values up to 23.18% compared to the reference cubic samples. Compressive strengths of the specimens subjected to 8 and 56 freeze-thaw cycles varied between 38.71‒48.07 MPa and 31.72‒39.11 MPa, respectively. Statistical analysis revealed that the compressive strength of the concrete exposed to 56 freeze-thaw cycles was significantly different from that of the other specimens.

This study investigated the effects of freeze-thaw cycles on the mechanical properties of hardened self-compacting concrete for varying column heights. A column (100×20×300 cm) was fabricated by C30 self-compacting concrete in the laboratory and 10 cube samples (10x10x10 cm) were taken from fresh concrete as the references. After a period of 28 days, 160 core specimens (Ø67 mm in diameter) were taken from different column heights. Unit weight, water absorption, compressive strength, and freeze-thaw tests were performed on these 170 (10 reference cubic and 160 core) samples. The mechanical properties of the core specimens before freeze-thaw and after 8-56 freeze-thaw cycles were reported for varying column heights. The average compressive strength value of the reference cubic samples was determined as 40.28 MPa, while the compressive strengths of the core specimens before freeze-thaw were ranged from 40.25 MPa to 49.62 MPa, impying an increase in compressive strength values up to 23.18% compared to the reference cubic samples. Compressive strengths of the specimens subjected to 8 and 56 freeze-thaw cycles varied between 38.71‒48.07 MPa and 31.72‒39.11 MPa, respectively. Statistical analysis revealed that the compressive strength of the concrete exposed to 56 freeze-thaw cycles was significantly different from that of the other specimens.

The rehabilitation of the road embankments alongside the irrigation canal, which is constructed on a Bangkok soft clay foundation, has resulted from land use growth for several decades. As a result, the embankment is always confronted with the problem of instability. Numerous articles have demonstrated that rapid drawdown of the water level in the canal could be one of the most significant reasons, whereas vehicle cyclic loading may potentially contribute to some effect of the embankment failure. To explore and assess the effects of the influence factors, the finite element method (FEM) and conventional and dynamic triaxial approaches were employed. The study also investigated the consequences of varying thicknesses of soft clay and cyclic loading with different magnitudes and frequencies. Consequently, cyclic loading can lead to an augmentation in strain distribution and excess pore water pressure. Likewise, more significant deformation and excess pore water pressure were induced by a lower frequency and deeper thickness of soft clay compared to a higher frequency and thinner thickness. In brief, vehicle repetitive loading is one of the primary factors contributing to embankment failure, with the threshold stress being approximately three-fourths of the undrained shear strength. In contrast, threshold strain is approximately one to two-fold of the monotonic strain condition.

Flue gas desulfurization gypsum (FGD gypsum) is obtained from the desulphurization of combustion gases in fossil fuel power plants. FGD gypsum can be used to produce anhydrite binder. The effect of three independent variables such as the calcination temperature of FGD gypsum (500-800 oC), the hydration time (3-28 days) and the amount of activator (0-2 %) on the compressive strength of anhydrite binder were studied. K2SO4 and Na2SO4 were used as activators. The compressive strength of anhydrite binder was evaluated using a full factorial design. The multiple linear regression models were developed to correlate the significant variables to the compressive strength of anhydrite binder. The experimental results and statistical analysis showed that the hydration time had the biggest impact on the compressive strength of anhydrite binder using K2SO4 and Na2SO4. K2SO4 made a greater influence on the compressive strength than Na2SO4. The results of modeling indicated that the individual variables had a larger effect on the compressive strength of anhydrite binder than their interaction. The mean absolute percentage error between experimental and calculated values of compressive strength was less than 10 %.

This study deals with two different aspects of the high-strength low-alloyed 1100 MC steel. The first is associated with the remarkable heterogeneity in the surface state produced during sheet rolling with respect to the sheet width. The variable-thickness surface layer exhibits a microstructure different from that of the deeper bulk. Variation of the thickness of the thermally softened near-surface region strongly affects Barkhausen noise, as well. This technique can be considered a reliable tool for monitoring the aforementioned heterogeneity. It can also be reported that the opposite sides of the sheet are different with respect to the surface state, heterogeneity distribution, and corresponding Barkhausen noise. These aspects indicate the different conditions during hot rolling followed by rapid quenching on the upper and lower rollers. The second aspect is related to the remarkable asymmetry of Barkhausen noise emission with respect to two consecutive bursts. This asymmetry is due to the presence of remnant magnetisation in the sheet produced during manufacturing. The remnant magnetisation is coupled to the magnetic field produced by the excitation coil of the Barkhausen noise sensor and strongly contributes to the aforementioned asymmetry. As soon as sufficient removal of this remnant magnetisation is carried out in the vanishing magnetic field (demagnetisation), the aforementioned remarkable asymmetry is fully lost.

All over the world, externally bonded fiber-reinforced polymer systems used to strengthen concrete elements improve building sustainability. However, reports issued by the American Concrete Institute Committee 440 called for heavy scrutinizing before actual field implementation. The very limited number of proposed equations lacks reliability and accuracy. Thus, further investigation in this area is needed. In addition, machine learning techniques are being implemented successfully in developing strength models for complex problems. This study aims to provide a reliable machine learning model based on an experimental database. The proposed model was developed and validated against the experimental database and the very limited models in the literature. The model showed improved agreement with the experimental results compared to the previous models.

Automation of vegetable seedling transplanting has provided opportunities for saving labors and improving productivity. Some changes in seedling agronomy are necessary for efficient transplanting. In this study, the local nursery substrates were added with the herbaceous peat, the sphagnum peat and the coir peat, respectively. Effects of the new compound substrates were investigated on the seedling qualities and the root-substrate strength. In the results, we found that the addition of these horticultural mediums significantly affected the physiochemical properties of the original substrates. Under the same nursery conditions, some appropriate additions could promote the seedling growth. And the deficient or excessive additions were to inhibit the growing development of seedlings and their roots. The corresponding additions would also improve the structural characteristics of the root lumps. Generally, the nursery substrates added with the sphagnum peat were relatively optimized in contribution to the seedling qualities and the root-substrate strength. Especially as the commercial substrate and the sphagnum peat were mixed at the volume ratio of 2:1, the dry matter accumulation of seedlings was 2.18 times more than the original. Their root lumps had the best consolidation strength, which may be an effective application for the necessary qualities of seedlings for automatic transplanting.

Introduction:The high interest in sports among young people has contributed to the growing importance of the phenomenon of sports specialization in recent years. It refers to players who train a particular sport for more than 80h per month. This is particularly noticeable in the group of young soccer players, in whom such a high training volume, is an important factor predisposing to the development of injuries. An important risk factor is the common lower limb muscle imbalance in the soccer player population between the extensors and flexors of the knee joint, showing a maximum isometric force ratio as low as 1:2. To compensate for this imbalance, it is important that eccentric exercises have a positive effect by improving the strength of the knee joint flexor muscles, especially the well-studied Nordic hamstring exercise(NHE). However, many studies only evaluate the effect of modified NHE exercise training volume, without isolating the effects of performing a single exercise session. It is worth noting that, there are warm-up protocols that incorporate the aforementioned exercise and enjoy high utility and effectiveness for sports injury prevention. Objective: Given the emerging imbalance in the strength of the knee stabilizing muscles, the aim of the study was to determine whether performing a single NHE intervention would alter the isometric strength of the knee flexor muscles (HAM). Methods: A group of 56 players of a youth soccer team (age range 13-16), were recruited for the pilot study. In doing so, the players constituted a group of healthy, training soccer players at the central junior level. After meeting the inclusion criteria, 32 players were entered into the study. Participants were randomly assigned to a study group (A) and a control group (B). In the study group, the intervention consisted of a single NHE exercise in the form of two series of trunk slumps in a kneeling position, eight repetitions each. The control group performed one series of forward trunk bends, five repetitions each. Participants (group A and B) were tested on the ` platform before the experimental procedure and immediately after the intervention. Maximum isometric strength of the knee joint extensors (QUAD) and knee joint flexors (HAM) were measured. Results: Statistical analysis of the obtained results indicated that the maximum muscle strength of the HAM increased after the performed, single intervention NHE (p=0.04) relative to the control group. At the same time, no increase in the strength of the quadriceps muscles of the thigh (extensors of the knee joint) was shown after the intervention, relative to the control group. Conclusions:The results obtained indicate that a single performance of the NHE exercise has an effect on increasing the maximum isometric strength of the HAM muscles. This increase, although not statistically significant, correlated with no change in quadriceps muscle strength. The work is a pilot study and further research may benefit in maintaining the balance between the two muscle groups, namely HAM and QAD, which contributes to the prevention of joint-muscle injuries. At the same time, the study supports the previously stated thesis that a single performed Nordic Eccentric Exercise is an important element in the prevention of muscle injuries in the lower limb, thus confirming the effectiveness of its use in football warm-ups. Nonetheless, implementation of the exercise into long-term training is necessary to achieve significant effects of muscle balance compensation in the lower limb, as confirmed by numerous training protocols.

Flexible capacity applications demands to large energy storage density and high breakdown electric field strength of flexible films. Here, P(VDF-HFP) with ultra-thin Al2O3 nanosheets composite films were designed and fabricated through an electrospinning process followed by hot-pressing in sandwich structured. The results show that the insulating ultra-thin Al2O3 nanosheets and the sandwich structure can enhance the composites' breakdown field (by 24.8%) and energy density (by 30.6%) remarkedly to P(VDF-HFP) polymer matrix. An energy density of 23.5 J/cm3 at the ultrahigh breakdown field of 740kV/mm can be therefore realized. Insulating test and phase-field simulation results reveal that ultra-thin nanosheets insulating buffer layers can reduce the leakage current in composites, thus it effects the electric field spatial distribution to enhance breakdown strength. Our research provides a feasible method to increase the breakdown strength of ferroelectric polymers, which is comparable to those of non-ferroelectric polymers.

Dental polymers are often advertised and selected for use in restorations based upon the flexural strength of prefabricated discs, which may not accurately reflect their performance in dental applications. The objectives of this study were, therefore, to determine whether the three-point bending (3PB) test for flexural strength would be predictive of the “crunch-the-crown” CTC test for the failure load. Three brands of polymers (Trilor, Juvora, and Pekkton) were fabricated into rectangular bars and fully contoured crowns (10 specimens of each polymer brand, 30 specimens of each shape). Bars were tested in 3PB to determine flexural strength, and crowns were CTC tested to determine failure load after luting to resin abutments. Statistical significance was evaluated by one-way ANOVA ( = 0.05) and Pearson’s correlation coefficient. The fracture mechanisms were characterized by scanning electron microscopy (SEM). There were significant differences (p < 0.05) in the mean crown failure loads (Trilor [7,033 N] > Juvora [5,217 N] > Pekkton [3,023 N]) and mean flexural strengths of the bars (Trilor [468 MPa] > Juvora [197 MPa] = Pekkton [192 MPa]). There were no correlations between flexural strength and failure load. The mode of crown fracture was different between the polymers, and included deformation (Juvora), ductile-to-brittle fracture (Pekkton), and a combination of cracks and deformation (Trilor). The flexural strength was not correlated with the corresponding crown failure load. Dental practitioners should not rely on the value of flexural strength obtained from the three-point bending test, as advertised from the manufacturer, to predict the performance of polymeric crowns.

This study aimed to evaluate and compare the mechanical properties of three CAD-CAM monolithic esthetic zirconia (Ceramill® Zolid FX Multilayer (ZF), IPS e.max® ZirCAD MT Multi (ZM), and KATANATM STML (KS)) with a CAD-CAM lithium disilicate glass-ceramic (IPS e.max® CAD LT (MC)) as control. 80 samples (20/group) were milled, sintered, and subjected to a three-point bending test (3-PBT) to measure flexural strength and elastic modulus; Vickers indentations were used to measure microhardness. The numerical outcomes were analyzed using one-way ANOVA with a statistical significance set at <0.05. Zirconia showed superior mechanical properties compared with lithium disilicate (P<0.05). ZM had the highest values of flexural strength (P<0.05), KS and ZM showed significantly higher elastic modulus values than ZF (P<0.05), and ZF and KS microhardness values were significantly higher than ZM (P<0.05). Monolithic multi-layered zirconia had enhanced mechanical properties when compared with lithium disilicate and can be a predictable replacement in clinical applications.

The effect of rare earth Pr6O11 on the microstructure and mechanical properties of high-strength steel weld metal was investigated by optical microscopy, scanning electron microscopy and mechanical testing. Three different contents of Pr6O11 were added to the flux-cored wires. The results showed that the addition of 1% Pr6O11 can promote the refinement and spheroidization of inclusions, refine the grains, form acicular ferrites, and significantly improve the toughness of weld metal. The addition of Pr6O11 promoted the formation of rare earth composite inclusions and acicular ferrites in the weld metal, refined the lath microstructure, inhibited the formation of martensite and bainite. The crack formation mode changed from the boundary cracking of the bainite clusters caused by the surface shear stress to the surface shear stress-induced decohesion of inclusion. However, excessive addition of Pr6O11 will reduce the number of inclusion nucleation and deteriorate the mechanical properties. The wire No.2 with 1% Pr6O11 had the good comprehensive mechanical properties, and the corresponding values were 835MPa of tensile strength and 72 J of impact toughness. These findings suggest that the control of Pr6O11 can be an effective way to improve the impact toughness of weld metal.

The effect of Pr6O11 on the microstructure and mechanical properties of high-strength steel weld metal was investigated by optical microscopy, scanning electron microscopy and mechanical testing. Three different contents of Pr6O11 were added to the flux-cored wires. The results demonstrate that the addition of 1% Pr6O11 can promote the refinement and spheroidization of inclusions, refine the grains, form acicular ferrites in the weld metal, and significantly improve the toughness. The addition of Pr6O11 promoted the formation of rare earth composite inclusions and acicular ferrites in the weld metal, refined the lath microstructure, inhibited the formation of martensite and bainite. The crack formation mode changed from the boundary cracking of the bainite clusters caused by the surface shear stress to the surface shear stress-induced decohesion of inclusion. Excessive addition of Pr6O11 will reduce the number of inclusion nucleation and deteriorate the mechanical properties. The wire No.2 with 1% Pr6O11 had the good comprehensive mechanical properties.

A large amount of concrete waste is generated around the world and its recycling is an urgent issue. In this research, a new approach to recycle concrete waste with wooden waste was studied. Concrete and wooden wastes were crushed, mixed, and heat compacted to produce plates with different water contents and mix proportions at various temperatures, pressures, and durations of compaction. The bending strength of the plates was measured after compaction. The result indicated that with an increase in the percentage of wooden waste in the mixture, pressure, or temperature improved the bending strength. The increase in water content reduced the bending strength. Most of the products exhibited higher bending strength than that of ordinary concrete.

In recent years, it has been found in engineering practice that the service life of cemented carbide shield machine tools used in uneven soft and hard strata is substantially reduced. The study found that thermal stress is the main reason for the failure of cemented carbide shield tunneling tools when shield tunneling is carried out in uneven soft and hard soil. To maintain the hardness of cemented carbide, improving the thermal conductivity of the shield machine tool is of great importance for prolonging its service life and reducing engineering costs. In this paper, graphene and carbon nanotubes were mixed with WC-Co powder and sintered by SPS (Spark Plasma Sintering). The morphology was observed by using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). A Rockwell hardness tester and bending strength tester were used to test hardness, bending strength and thermal conductivity. The results show that adding trace graphene or carbon nanotubes can increase the bending strength of the cemented carbide by approximately 50% while keeping the hardness of the cemented carbide unchanged. The thermal conductivity of the cemented carbide can be increased by 10% with the addition of 0.12% graphene alone.

Adiposity is associated with adverse health conditions such as obesity, cardiovascular disease and type 2 diabetes. The combination of resistance exercise and creatine supplementation has been shown to decrease body fat % in adults ≥ 50 years of age. However, the effects in adults < 50 years of age is unknown. To address this limitation, we systematically reviewed the literature and performed several meta-analyses comparing studies that included resistance exercise and creatine supplementation to resistance exercise and placebo. Twelve studies were included involving 266 participants. Adults (< 50 years of age) that supplemented with creatine and performed resistance exercise experienced a significant reduction in body fat % (-1.19%, p=0.006) and a non-significant reduction in absolute fat mass (-0.09 kg, p=0.88). Collectively, the combination of resistance exercise and creatine supplementation produces a very small reduction in body fat % in adults < 50 years of age.

This study aimed to compare the flexural strength, surface roughness, and microhardness of a resin for three-dimensional (3D) printing and a conventional composite resin and to evaluate whether the printing orientation influences these properties. To evaluate the flexural resistance, test specimens were produced and divided into four groups: three groups of resins for 3D printing with inclinations of 0°, 45°, and 90°, and one group of conventional composite resin. Forty discs were produced and subjected to a sandpaper-polishing sequence, and the surface roughness was measured using a roughness meter. The Vickers microhardness test was performed at three different points, and the average was obtained. The results were subjected to ANOVA statistical analysis and Tukey's test. There were statistical differences in the flexural strength and microhardness between the conventional resin and the resin used for 3D printing. No statistical difference in surface roughness was observed. The resin for 3D printing exhibited lower flexural strength and microhardness than conventional composite resins. We concluded that the resin for 3D printing had lower flexural strength and hardness than the conventional composite resin but similar surface roughness. The printing orientation did not affect the flexural strength, whereas the hardness increased as the printing angle increased.

This paper aims to investigate the feasibility of strengthening the web opening in the shear zone of RC beams by using iron-based shape memory alloy (Fe-SMA) bars. To conduct this study, numerical analysis with ABAQUS software was employed. The research was divided into six groups of beams with web openings of different lengths (150, 300, and 450 mm), prestressing levels (0%, 30% and 60%), and reinforcement diameters (14, 18, and 22 mm) of Fe-SMA bars. The results show that the presence of web openings can cause a significant reduction in the cracking and ultimate loads of the beams, with reductions ranging from 11 to 50% and 36 to 48%, respectively. However, by adding pre-stressed Fe-SMA bars around small web openings (100×150 mm), the shear capacity of the beam is restored, and the beam exhibits behavior similar to solid beams. Additionally, activating the Fe-SMA bars by 30 and 60% resulted in almost similar cracking loads but improved load-carrying capacity of the beam with small openings by 12% and 9%, respectively, compared to the solid beam. The technique proposed for enhancing shear strength is most effective for beams with small (100×150 mm) and medium (100×300 mm) web openings as it can restore both the beam’s shear strength and stiffness. However, for beams with larger web openings (100×450 mm), the use of activated Fe-SMA beams can recover almost 90% of the solid beam's shear capacity. Furthermore, reinforcing small openings with Fe-SMA bars of different diameters enhances beam shear capacity and stiffness, while for larger openings, higher Fe-SMA reinforcement ratios could potentially restore the beam's full strength and stiffness. This study emphasizes the importance of strengthening web openings in RC beams, particularly in shear zones, and provides significant insights into how to strengthen beams with web openings, thereby contributing to developing safer structures. However, further laboratory experiments are recommended to validate, complement and extend the findings of this numerical study.

The aim of this research was to undertake laboratory testing to investigate the beneficial effects of epoxy resin grouts on the physical and mechanical properties of sands with a wide range of granulometric characteristics. Six sands, of different particle size and uniformity coefficients, were grouted using epoxy resin solutions with three ratios of epoxy resin to water (3.0, 2.0 and 1.5). A set of unconfined compressive strength tests were conducted on grouted samples at different curing periods and a set of long-term unconfined compressive creep tests in dry and wet conditions after 180 days of curing were also carried out, in order to evaluate the development of the mechanical properties of the sands, as well as, the impact of water on them. The findings of the investigation showed that epoxy resin resulted in appreciable strength values in the specimens, especially those of fine sands, grouted with the different epoxy resin grouts. In general, the compressive strength varied between 0.68 - 5.60 MPa and the modulus of elasticity between 75 - 480 MPa, after a curing period of 180 days. In terms of physical properties, the permeability and porosity (before and after the grouting process) were estimated. Grouts with an epoxy resin to water ratio of 3 decreased permeability by up to four orders of magnitude. Using laboratory results and regression analysis, three mathematical equations were developed that relate each of the dependent variables; compressive strength, elastic modulus, and coefficient of permeability, with particular explanatory variables.

Geopolymer concrete (GPC) represents an innovative green and low-carbon construction material, offering a viable alternative to ordinary Portland cement concrete in building applications. However, existing studies tend to overlook the recyclability aspect of GPC for future use. Various structural applications necessitate the use of concrete with distinct strength characteristics. The recyclability of the parent concrete is influenced by these varying strengths. This study examined the recycling potential of GPC across a spectrum of strength grades (40, 60, 80 and 100 MPa, marked as C40, C60, C80 and C100) when subjected to freeze-thaw conditions. The cementitious material comprised 60% metakaolin and 40% slag, with natural gravel serving as the coarse aggregate, and the alkali activator consisting of sodium hydroxide solution and sodium silicate solution. The strength of the GPC was modulated by altering the Na/Al ratio. After 350 freeze-thaw cycles, the GPC specimens underwent crushing, washing, and sieving to produce recycled geopolymer aggregates (RGAs). Subsequently, their physical properties and microstructure were thoroughly examined. The findings indicated that GPC with strength grades of C100, C80, and C60 were capable of enduring 350 freeze-thaw cycles, in contrast to C40, which did not withstand these conditions. RGAs derived from GPC of strength grades C100 and C80 complied with the criteria for Class II recycled aggregates, whereas RGAs produced from GPC of strength grade C60 aligned with the Class III level. A higher strength grade in the parent concrete correlated with enhanced performance characteristics in the resulting recycled aggregates.

There is evidence that Additive Manufacturing plays a crucial role in the fourth industrial revolution. The design freedom provided by this technology is disrupting limits and rules from the past enabling engineers to have new products otherwise unfeasible. Recent developments in the field of SLM have led to a renewed interest in lattice structures that can be produced non-stochastically in previously unfeasible dimensional scales. One of the primary applications is aerospace engineering where the need of lightweight and performance is urgent to reduce the carbon footprint of civil transport around the globe. Of particular concern is fatigue strength. Being able to predict fatigue life in both LCF (Low Cycle Fatigue) and HCF (High Cycle Fatigue) is crucial for a safe and reliable design in aerospace systems and structures. In the present work, an experimental evaluation of compressive-compressive fatigue behavior has been performed to evaluate the fatigue curves of different cells, varying sizes and relative density. A Design of Experiment approach has been adopted in order to maximize the information extractable in a reliable form.

The solid-state welding method known as friction stir welding (FSW) bonds two metallic work parts, whether the same or different, by plastically deforming the base metal. The frictional resistance between both metallic work pieces causes them to produce heat, which produces plastic deformation and welds them. However, the weldability and strength of FSW joints mainly depend on the FSW parameters. This review work highlights the previous research work on the FSW parameters and their effects on the weldability and quality of the aluminum alloys joined with similar and dissimilar metals through the FSW method. About 150 research studies were systematically reviewed, and the articles included data from peer-reviewed journals. It has been concluded that the key parameters, including welding speed, “rotational speed”, “plunge depth”, “spindle torque”, “shoulder design”, “base material”, “pin profile” and “tool type", significantly affect the weldability of the aluminum joint through the FSW method. Also, the selection of these parameters is important and fundamental as they directly affect the joint. It is recommended that future work focus on FSW for aluminum. Among these, the most essential is the application of artificial intelligence (AI) techniques to select the optimum FSW parameters for aluminum welding.

The objective of this article was to forecast the ultimate failure load laminate stacking sequence combination on bonding joints which are exposed to tensile strength by using artificial neural networks. We have glass fiber composite materials with three different sequence combinations ([0°/90°], [±45°], [0°/90°/±45°]). Various adherend thicknesses and also ductile type adhesive was used in the experiment. The bonding geometry is a single lap and has four types of overlap angles 30°, 45°, 60°, 75° respectively. The experimental results demonstrate that composite laminate stacking sequence profoundly affects the bonding joints of failure load. Taking experimental results into account, Levenberg–Marquardt learning algorithm model was used by preferring a three layer forward on ANN so as to discipline network. In order to procure a precise ANN tool, an integrate methodology of experimental method has been used. The outcomes are used to ensure the experimental data’s to the ANN. The method of ANN permits surveying much adequately the probabilities of composite laminate stacking sequence combination using the prevalent ones which are [0°/90°], [±45°] and [0°/90°/±45°]. Testing data and training results were quite well 0.998, 0.997 and 0.998 in turn. Consequences acquired can be used by engineers who are interested in the composite material design to enhance failure load.

China is facing the development requirements of the dual carbon goal and the construction needs of resilient cities. Currently, high-strength composite structural systems are a feasible solution, but their research and application in the construction field are insufficient, especially for the combination forms of concrete above C100 and steel above Q550. In response to this issue, this paper proposes a new high-performance structural system, namely the composite frame - high-strength steel plate wall core tube resilient structure system, which includes high-strength steel plate (Q550) - ultra-high strength concrete (C100) shear walls, replaceable energy dissipation coupling beams, and composite frames. Taking a 200 meter building as an example, this paper designs and establishes calculation models for a conventional reinforced concrete frame-core tube structure and a high-performance structure based on PKPM software, and establishes elastoplastic analysis models for both based on SAUSAGE software, and then conducts dynamic elastoplastic time history analysis and seismic resilience assessment of structures under design basis earthquakes (DBEs), maximum considered earthquake (MCEs) and extremely rare earthquakes (EREs). Research has shown that compared to conventional structures, new high-performance structures can effectively reduce the size of shear walls, reduce the self-weight of the structure, and enhance the space for building use; The story drift ratio has higher redundancy than specification limits, lower plastic damage and overall stiffness degradation of the structure, and better seismic performance; The seismic resilience has significantly improved, especially in the case of casualties, which can better ensure the safety of people's lives and property.

The corrosion of prestressing steel in prestressed concrete bridges is a critical issue for bridge maintenance. To assess structures with corroded strands, it is necessary to define the mechanical properties of the strands and their influence on the structural behavior. In this study, corroded strands are taken from external tendons in existing bridges and tested to define the effects of corrosion on the tensile properties of the strand. Empirical equations for the tensile strength and ductility of the corroded strand are proposed using test results. The most corroded wire governs the mechanical properties of the strand. Experiments on prestressed concrete beams with a single corroded strand are conducted to investigate the structural behavior. A reduction in the flexural strength and maximum deformation is observed from the experiment. According to the section loss of a wire in a strand and its location in a beam, the flexural capacity can be evaluated using the proposed equation. The reduced ultimate strain of the corroded strand can be the governing factor of the flexural strength.

Collapsibility is an inherent characteristic of loess, which is often treated by adding industrial materials such as cement and lime in engineering, it seriously damages the reclamation performance of soil. Degradable calcium lignosulfonate (CLS) has a good prospect in balancing soil stabilization and environmental protection. Therefore, this paper evaluates the collapsibility and mechanical characteristics of CLS improved loess based on the collapsibility test, grey correlation analysis, and unconfined compressive strength test. The results show that when the content is 3%, the stabilization effect is most obvious, and the collapsibility coefficient can be reduced by more than 95%. The order of grey correlation degree of collapsibility on each index is moisture content, void ratio, dry density, and CLS content from large to small. The unconfined compressive strength increases rapidly in the first 14 days and then decreases with the content. When the content is too high, the strength of improved loess is lower than that of plain loess. Combined with SEM, microstructure parameters, and X-ray diffraction analysis, the carbonate minerals can play the role of filling pores and connecting soil particles, which reduces the grain size of mineral composition and the thickness of the electric double layer and makes the structure more compact. The research results have scientific significance and application value for the ecological modification research and engineering application of soil.

(1) Background: The study aimed to investigate compressive strength for three computer-aided design/computer-aided manufacturing (CAD/CAM) dental materials: glassceramic IPS Empress CAD (IvoclarVivadent), hybrid ceramic Cerasmart (GC) and polymer-reinforced graphene G-CAM (Graphenano Dental). (2) Methods: 45 samples consisted of the molar crowns fabricated by three CAD/CAM materials were cemented adhesively on 3D printed abutments (Asiga DentalResin). The samples were divided into 3 groups (n=15) according to the crowns thickness; group 1 under the cusps/cervical margins - 0.6 mm/0.4 mm, group 2 - 1 mm/0.7 mm respectively, and group 3 - 1.5 mm/1 mm. Additionally, 20 cylindrical specimens fabricated by the three crowns and abutments material (n=5) were prepared by CAD/CAM technique. All samples and specimens were subjected to an axial compressive load by using a universal testing machine (Instron 3366-10kN, USA) until fracture. (3) Results: The compressive strength were for Empress CAD 1258 MPa, Cerasmart 501.3 MPa, G-CAM 435 MPa and Asiga resin 360 MPa. G-CAM crowns exhibited a higher maximum compressive load (1701.5-2011.8N) than both Cerasmart (1295.4-1642.9N) and Empress CAD (494.3-597.5N). (4) Conclusions: The CAD/CAM crown materials presented different mechanical behavior; Empress CAD and Cerasmart presented a fragile behavior, with a high compressive strength when compared to G-CAM and Asiga resins.

Polyalcohol liquefaction can be done by acid or basic catalysis producing polyols with different properties. This study compared the mechanical properties of foams produced using polyols from liquefied Cytisus scoparius obtained by acid and basic catalysis and using two different foam catalysts. The differences were monitored using FTIR analysis. Acid-catalyzed liquefaction yielded 95.1 %, with the resultant polyol having an OH index of 1081 mg KOH/g while basic catalysis yielded 82.5 %, with a similar OH index of 1070 mg KOH/g. Generally, compressive strength with dibutyltin dilaurate (DBTDL) ranged from 16 - 31 kPa (acid-liquefied polyol) and 12 -21 kPa (base-liquefied polyol), while with stannous octoate (TIN), it ranged from 17 - 42 kPa (acid) and 29 - 68 kPa (base). Increasing water content generally decreased the compressive modulus and strength of foams. Higher water content led to a higher absorption at 1670 cm-1 in the FTIR spectrum due to the formation of urea. Higher isocyanate indices generally improved compressive strength, but high amounts led to unreacted isocyanate that could be seen by a higher absorption at 2265 cm-1 and 3290 cm-1. DBTL was shown to be the best foam catalyst due to higher trimer conversion seen in the spectra by a higher absorption at 1410 cm-1. Acid and base-derived polyols lead to different polyurethane foams with different FTIR spectra, particularly with a higher absorption at 1670 cm-1 for foams from acid-derived liquefaction.

In this study, we present different methods of estimating fuzzy reliability of a two-parameter Rayleigh distribution via the maximum likelihood estimator, median first-order statistics estimator, quartile estimator, L-moment estimator, and mixed Thompson-type estimator. The mean-square error MSE as a measurement for comparing the considered methods using simulation through different values for the parameters and unalike sample sizes is used. The results of simulation show that the fuzziness values are better than the real values for all sample sizes, as well as the fuzzy reliability at the estimation of the Maximum

. (1) Background: The aim of this study was to verify the differences in body composition, power and lower limb muscle strength in futsal players from three competitive levels. (2) Methods: The study involved 68 players (24.26 ± 4.63 years), divided into three competitive levels: elite, sub-elite and amateur. To assess physical condition, we used the Inbody270, the ChronoJump and the Isokinetic Dynamometer and used the non-parametric Kruskal-Wallis test to compare the three independent variables. (3) Results: There were no differences in body composition between the players at the three competitive levels. With regard to lower limb muscle power and strength, the elite group showed, on average, better performance and capabilities, especially when compared to the amateur group, and all groups showed an H/Q ratio &gt; 60%. (4) Conclusions: We conclude that there are not many differences in physical condition between the three competitive levels of futsal, despite the unequal sporting demands between them. However, the elite group has greater power and muscle strength, and both groups showed a high probability of lower limb muscle injury at this stage of the sporting season, alerting sports training professionals to the importance of individualized analysis of physical condition and performance capacity.

Carbon dioxide, CO₂ accounts for most of the emission from all the types of greenhouse gasses in the world. The ability of CO₂ to remain longer than other greenhouse gases and the convenience of producing CO₂ has resulted in its high projection in a yearly manner. The prime factor for the emission of CO₂ are from the actions of human beings. One such human act is the concrete industry. Total emissions from the concrete industry could therefore contribute as much as 8% of global CO₂ emissions. Sequestered CO₂ in concrete can provide an impact on reducing the carbon footprint and is also able to improve the compressive strength of concrete. During this process, the sequestered carbon dioxide chemically reacts with cement to produce a mineral, trapping carbon dioxide gas in the concrete. Hence, sequestering carbon dioxide gas in concrete does not only on a bigger scale reduces carbon footprint, but it also reduces the impact the construction industry has on the environment. This paper presents a detailed review on the chemical reaction that takes place during the sequestration of carbon dioxide and the research published on the effects of carbon dioxide sequestered concrete on its properties. The impact this process has on the concrete industry and the environment is discussed in this paper.

This study aimed to examine the vitamin D status of professional volleyball athletes and to determine its correlation with shoulder muscle strength. We finally included 52 healthy male professional volleyball players (23.2 ± 4.5 years), who were categorized by vitamin D status (<20 ng/mL: deficiency, 20-30 ng/mL: insufficiency, and >30 ng/mL: sufficiency). We examined the strength of the internal rotator (IR) and external rotator (ER) muscles of the shoulder by using isokinetic dynamometer. Fourteen players (26.9%) had vitamin D deficiency, 24 players (46.2%) were vitamin D insufficient, and 14 players (26.9%) were vitamin D sufficient. There was no significant correlation between the vitamin D level and shoulder muscle strength at 60°/s (IR, r = 0.159, p = 0.26; ER, r = 0.245, p = 0.08), and at 180°/s (IR, r = - 0.093, p = 0.51; ER, r = - 0.037, p = 0.79). Moreover, the isokinetic shoulder strengths were not significantly different across the three groups in all settings. In conclusion, vitamin D insufficiency was common in elite volleyball players. Though not being associated with isokinetic muscle weakness, vitamin D should be regularly monitored and supplemented in young elite athletes, considering its importance on musculoskeletal health.

Polymer-derived SiC-polycrystalline fiber (Tyranno SA) shows excellent heat-resistance up to 2000^oC, and relatively high strength. Up to now, through our research, the relationship between the strength and residual defects of the fiber, which were formed during the production processes (degradation and sintering), has been clarified. In this paper, we addressed the relationship between the production condition and the surface roughness of the obtained SiC-polycrystalline fiber, using three different raw fibers (Elementary ratio: Si₁Al_0.01C_1.5O_0.4~0.5) and three different types of reactor (Open system, Partially-open system, and Closed system). With increase in the oxygen content in the raw fiber, the degradation during the production process easily proceeded. In this case, the degradation reactions (SiO+2C=SiC+CO and SiO₂+3C=SiC+2CO) in the inside of each filament become faster, and then the CO partial pressure on the surface of each filament is considered to be increased. In consequence, according to Le Chatelier’s principle, the surface degradation reaction and grain growth of formed SiC crystals would be considered to become slower. That is to say, using the raw fiber with higher oxygen content and closed system (highest CO content in the reactor), much smoother surface of the SiC-polycrystalline fiber could be achieved.

The present paper investigates flaw strength distributions established using various flexural tests on batches of SiC bar test specimens: 4-point bending as well as 3-point bending with different span lengths. Flaw strength is given by the elemental stress operating on the critical flaw at fracture of a test specimen. Fracture inducing flaws and their locations are identified by fractography. A single population of pores was found to dominate fracture. The construction of diagrams of p-quantile vs elemental strengths was aimed at assessing the Gaussian nature of flaw strengths. Then, empirical cumulative distributions of strengths were constructed using the normal distribution function. Weibull cumulative probability distributions were derived from the mean and the standard deviation using the first moment equation. Agreement was obtained between both Weibull and normal flaw strengths distributions. The cumulative distributions for the different bending tests were predicted satisfactorily from the flaw strength density function using the elemental strength model. Flaw strength distributions that include potential weaker flaws encountered in larger test pieces are extrapolated using the p-quantile diagrams. Implications are discussed about the pertinence of an intrinsically representative flaw strength distribution, about failure predictions, about size effects, and about the significance of flaw spatial distributions.

A simple undirected graph $\Gamma=(V_\Gamma,E_\Gamma)$ admits an $H$-covering if every edge in $E_\Gamma$ belongs to at least one subgraph of $\Gamma$ that isomorphic to a graph $H$. For any graph $\Gamma$ admitting $H$-covering, a total Labelling $\beta: V_\Gamma \cup E_\Gamma \longrightarrow \{1,2,\dots,p\}$ is called an $H$-irregular total $p$-labelling of $\Gamma$ if every two different subgraphs $H_1$ and $H_2$ of $\Gamma$ isomorphic to $H$ have distinct weights where the weight $w_\beta(K)$ of subgraph $K$ of $\Gamma$ is defined as $w_f(K):=\displaystyle \sum_{v\in V_K} f(v) + \sum_{e\in E_K} f(e)$. The smallest number $p$ for which a graph $\Gamma$ admits an $H$-irregular total $p$-labelling is called the total $H$-irregularity strength of $\Gamma$ and is denoted by $ths(\Gamma)$. In this paper, we determine the total $H$-irregularity strength of edge comb product of two graphs.

Raw earth bricks made from the soil of the Chalky Champagne region (France) have been used for at least two millennia in construction, a promising heritage in the context of reducing the carbon emissions of buildings. The present experimental study aims at measuring the physical, mechanical, thermal, and hydric properties of adobes collected from a local village barn. Results show a high chalk content estimated at 71%, and a clay content, acting as binder, at 14%. Despite limited load-bearing capacity, these lightweight adobes are suitable for current single-story constructions, while their hydrothermal properties classify them as excellent moisture regulators for occupants. In association with other bio-sourced materials such as starch-beet pulp bricks, Chalky Champagne adobes yield promising insulating properties, and meet the criteria defined by current energy standards.

Nonwoven fabrics have been widely used in textile manufacturing industry as a sheet or web structure because of soft, water-repellent, recycle, ecological and resilient functions. Ultrasonic welding method has been applied for bonding nonwoven fabrics due to clean, fast and reliable approach. In this work, the ultrasonic stepped horn is designed to generate uniform amplitudes on the working surface by using finite element analysis (FEA) simulation. Chromium carbon steels are utilized to produce ultrasonic horns due to high wear resistant and hardness. Isotactic polypropylene nonwoven fabrics fabricated by spunbond process were bonded by continuous ultrasonic sewing machine. Ultrasonic horn with 70 mm in diameter working at 20 kHz, polypropylene (PP) nonwoven density of 80 gsm and various design of welding joints were applied. A typical image in the case of number one was investigated by the scanning electron microscope (SEM) images of inter-facial micro-structure. However, welding joints of totally eight roller patterns was test the tensile strength of the ultrasonic welding joints on PP nonwoven fabrics. The tensile strength of the welding joints is proportional to the area ratio between the welding area and cycling area. The results showed that the melted zone without welding defects such as crack or blowhole can be seen. Furthermore, the tensile strength of welding joints in eight cases of roller patterns (No.1-No.8) was described in details. The ultrasonic welding joints with brick structures give higher tensile strength while the solid line in the pattern gave less strength.

Natural Fibre Reinforced Composites (NFRCs) represent a significant category of materials that has the capacity to contribute to the worldwide objectives of sustainability and environmental preservation. To maximise the potential of composite materials, it is essential to establish their high quality and cost-effective manufacture. While the basic production procedures for producing items based on NFRCs have reached a high level of development, more research efforts are needed to advance their secondary manufacturing processes, namely in the areas of machining and joining. The primary factor leading to the rejection of composite goods with holes is the damage generated during the drilling process. The present experimental study aims to examine the effectiveness of hole production during the moulding phase. A comparative analysis has been conducted to assess the mechanical characteristics of moulded and drilled holes in jute fibre reinforced epoxy composite. It was observed that the moulded holes exhibit superior performance compared to the drilled holes for jute/epoxy materials. Additionally, the load extension curves indicate that the moulded holes experience greater extension in comparison to the drilled holes.

Contract farming can reduce transaction costs and improve agricultural productivity. With the establishment of stable and effective contractual relationships, not only have agricultural products been provided with a stable market, but the standardization, refinement, and branding transformation of agricultural products can also be realized, thus further promoting the progress of agricultural modernization. The willingness of farmers to renew their contracts is a key factor in maintaining long-term, stable cooperative relationships. This research has empirically verified the impact model of tie strength between companies and farmers in contractual agriculture on the willingness of farmers to renew their contracts and revealed the working mechanism of tie strength on sustainable participation of farmers in contract farming. This study has utilized the survey data from 286 agricultural households in Inner Mongolia, China, and the method of structural equation modeling（SEM）, with the following results:(1)Interaction and reciprocity have a significant positive influence on trust. (2)Trust has a significant positive impact on farmers' willingness to renew their contracts. Also, reciprocity and interaction have an indirect impact on contract renewal willingness through trust .(3)Perception of economic value can significantly increase the contract renewal willingness of farmers and plays a mediating role between trust and contract renewal willingness.Overall, on the basis of tie strength, this research has provided a new perspective for the investigation of the sustainable stability of contract farming and empirical evidence for the sustainable development of the contract farming supply chain.

Artificial intelligence is increasingly used in various branches of engineering. In this article, artificial neural networks are used to predict the crush resistance of corrugated packaging. Among the analysed packages were boxes with ventilation openings, packages with perforations, and typical flap boxes, which makes the proposed estimation method very universal. Typical shallow feedforward networks were used, which are perfect for regression problems, mainly when the set of input and output parameters is small, so no complicated architecture or advanced learning techniques are required. The input parameters of the neural networks are selected so as to take into account not only the material used for the production of the packaging, but also the dimensions of the box and the impact of ventilation holes and perforations on the load capacity of individual walls of the packaging. In order to maximize the effectiveness of neural network training process, the group of input parameters was changed so as to eliminate those to which the sensitivity of the model was the lowest. This allowed the selection of the optimal configuration of training pairs for which the estimation error was on the acceptable level. Finally, models of neural networks were selected, for which the training and testing error did not exceed 10%. The demonstrated effectiveness allows to conclude that the proposed set of universal input parameters is suitable for efficient training of a single neural network model capable of predicting the compressive strength of various types of corrugated packaging.

In the modern world, all manufacturers strive for the optimal design of their products. This general trend is recently also observed in the corrugated board packaging industry. Colorful prints on displays, perforations in shelf-ready-packaging and various types of ventilation holes in trays, although extremely important for ergonomic or functional reasons, weaken the strength of the box. To meet the requirements of customers and recipients, packaging manufacturers outdo each other in new ideas for the construction of their products. Often the aesthetic qualities of the product become more important than the attention to maintaining the standards of the load capacity of the packaging (which, apart from their attention-grabbing functions, are also intended to protect transported products). The particular flaps design (both top and bottom) and their influence on the strength of the box is investigated in this study. The updated analytical-numerical approach is used here to predict the strength of the packaging with various flap’s offsets. Experimental results indicated a significant decrease in the static load-bearing capacity of packaging in the case of shifted flap creases. The simulation model proposed in our previous work has been modified and updated to take into account also this effect. The results obtained by the model presented in the paper are in satisfactory agreement with the experimental data.

In this work 144 reinforcing bars of high-ductility steel named B500SD were subjected to an accelerated corrosion treatment and then tested under tension at different loading speeds in order to assess the effect of corrosion on the ductility properties of the rebars. Results showed that the bars with a corrosion level as low as the one reducing the steel mass by 1% gave rise to a significant degradation on the ductility properties with strain-stress curves losing the yield plateau and behaving practically as cold deformed steel bars. This effect took place at every tested loading speed. Thus, the research significance relies on the assessment of the influence of the loading speed at which the tensile test is performed given that it affects the ductility properties of the reinforcement bars.

In order to effectively utilize red mud, an aluminum industrial waste, the stabilized soil material was developed using nano-SiO2 synergistically modified red mud, and the strength characteristics of the stabilized soil were analyzed to clarify the feasibility of such stabilized soil serves as a road base material. Through different combination schemes, the effects of different nano-SiO2 and cement contents on the strength of the stabilized materials were explored. The test results show that: in the synergistic modification of nano-SiO2 and cement, nano-SiO2 can significantly improve the early unconfined compressive strength of red mud-based stabilized soil; in the synergistic modification of nano-SiO2, gypsum and cement, the 7-d unconfined compressive strength of red mud-based stabilized soil is greater than 2 MPa, which meets the strength requirements of road base materials and shows the superiority of synergism. The nominal stress-strain curves are divided into five stages: compressed and compacted stage, elastic deformation stage, plastic deformation stage, damage deformation stage and residual deformation stage. The macroscopic compressive damage pattern of the specimens shows that the modified red mud-based stabilized soil mostly exhibits brittle damage.

Background: Blood flow restriction training (BFRT) uses occlusion during low-intensity resistance training (&lt;50% of repetition maximum, 1RM) to reduce arterial blood flow and venous return, imposing greater metabolic stress but similar muscular hypertrophy and strength gains as high-intensity resistance training (HIRT). However, no study, to date, has incorporated BFRT in a collegiate strength and conditioning setting to assess ecological validity. We aimed to investigate the effects of adding 6-weeks of accessory BFRT or HIRT to NCAA Division III soccer players prescribed resistance training regimen on muscle strength and hypertrophy. Methods: Male and female (n=17) athletes were randomly assigned to complete biceps curls 2x/week under BFRT or control (HIRT), following the regularly scheduled strength training. Bicep strength (1RM) and circumference (BC) were assessed at weeks 0, 3, and 6. Results: In men, no significant interaction between time and condition was observed for BC (p=0.861), though condition (BFRT vs Control, p=0.025) and time (p=0.024) were significant. For 1RM, there was no significant interaction between time and condition (BFRT vs HIRT, p=0.067) or of condition (p=0.598), but there was a significant effect of time (p=0.004). In women, there was no significant interaction between time and condition (p=0.765) or of condition (p=0.971) on BC, but time was significant (p=0.045). For 1RM, there was no significant interaction between time and condition (p=0.227) or of condition (p=0.741), but time was (p=0.018). Conclusion: BFRT induced similar increases in muscle strength and hypertrophy as HIRT in soccer players, suggesting that BFRT could be incorporated into collegiate athlete training.

The shear failure of surface methane capture borehole (SMCB) is the main cause of shortening life cycle of SMCB but lack of lithological analysis. In order to improve the stability of SMCB and improve efficient drainage period, it is of great significance to investigate the lithology performances for shear failure of SMCB. Based on the direct shear tests and geological method, the results shows that the shear displacement increases as the grain size decreases. Mechanical jump occurs at the lithological boundaries, which is mainly determined by the composition of rock specimens. The cohesion is the mainly possible reason for the step change of shear strength. Lithology with high quartz and low clay may effectively improve shear strength and failure resistance. Boreholes drilled into the weaker siltstone and mudstone sections may potentially experience preferential damage due to the larger shear displacement and shear strength. Protective measures at these sections may improve the stability of the borehole casing. The probing data where it was found that boreholes closure validated the prediction.

Currently, the design of the concrete mix is an important part of the environmental problem. In front of this question, engineers face a major challenge that is addressed in two ways. On one hand, how do they use its component materials to improve its mechanical properties, on the other hand how do they use less polluting materials? Hence, in an environmental and economical view, laboratory tests were carried out on samples of concrete reinforced with smooth steel fiber extracted from the waste tires, in order to assess its impact and to prove its mechanical feasibility for these purposes. Consequently, laboratory results have shown satisfactory improvement in the behavior of concrete under compression loads in the elastic stage and an increase in ductility and toughness of the matrix in the plastic stage. Besides, taking into account the discontinuity and the structural disturbances observed during the loading of samples in the post-elastic state, a method has been proposed to calculate "the effective toughness and toughness Index of fiber concrete; on the other hand, this method has helped to better optimize length and slenderness of fibers for better use of this recycled material

In this paper, an upper bound of the longitudinal elastic modulus of unidirectional fibrous composites is proposed according to strength of materials approach, on the premise that the fiber is much stiffer than the matrix. In the mathematical derivations, the concept of boundary interphase between fiber and matrix was also taken into account and the main objective of this work is the attainment of an upper bound for the interphase stiffness with respect to fiber concentration by volume. The novel element here is that the authors have not taken into consideration any specific variation law to approximate the interphase modulus. The theoretical results arising from the proposed formula were compared with those obtained from some reliable theoretical models as well as with experimental data found in the literature, and a satisfactory agreement was observed.

The Mann-Whitney effect is a measure for comparing survival distributions between two groups. The Mann-Whitney effect is interpreted as the probability that a randomly selected subject in a group survives longer than a randomly selected subject in the other group. Under the independence assumption of two groups, the Mann-Whitney effect can be expressed as the traditional integral formula of survival functions. However, when the survival times in two groups are not independent each other, the traditional expression of the Mann-Whitney effect has to be modified. In this article, we propose a copula-based approach to compute the Mann-Witney effect with parametric survival models under dependence of two groups, which may arise in the potential outcome framework. In addition, we develop a Shiny web app that can implement the proposed method via simple commands (https://nkosuke.shinyapps.io/shiny_survival/). Through a simulation study, we show the correctness of the proposed calculator. We apply the proposed methods to two real datasets.

Alloys based on TiNi are widely used in various fields of technology and medicine. In the present work, we report on preparation of TiNi-alloy based wire with the shape memory effect, which was used for compression clips for surgery. Composition and structure of the wire, and its martensitic and physical-chemical properties were studied using SEM, TEM, optic microscopy, profilometry, mechanical tests, etc. The TiNi alloy was found to consist of B2 and B19' and secondary-phase particles of Ti2Ni, TiNi3 and Ti3Ni4. Its matrix was slightly enriched in Ni (50.3 at. % of Ni). Homogeneous grain structure was revealed (an average grain size of 19±0.3 μm) with equal quantities of grain boundaries of special and general types. Surface oxide layer provide improved biocompatibility and promote adhesion of protein molecules. Overall, the obtained TiNi wire was concluded to exhibit martensitic, physical and mechanical properties suitable for its use as an implant material. The wire was then used for manufacturing compression clips with the shape memory effect and applied in surgery. The medical experiment that involved 46 children demonstrated that the use of such clips in children with double-barreled enterostomies permitted to improve the results of surgical treatment.

Printed oral splints are a therapeutic alternative in the treatment of functional disorders. Their mechanical properties are crucial to their clinical success and their performance can vary depending on cleaning, post-polymerization, or build orientation. This in vitro study aimed to compare the biaxial flexural strength of the chosen materials depending on the aforementioned parameters. 720 discs (n = 15 per group, 16 mm x 2 mm) were printed from splint materials. Printing was performed under 90°, 45°, or 0° orientation to the building platform with supporting structures. Specimens were either automatically or manually cleaned with isopropanol. Post-polymerization was performed with LED- or Xenon-light. Biaxial flexural strength (BFS) was determined with a piston-on-3-ball test after 24 hours or 60 days water storage (37°C). Test specimens were preloaded with 0.5 N and the load was applied by a piston of 1.6 mm in diameter at 1 mm/min crosshead speed. Statistics were performed by using descriptive statistics, ANOVA, and Levene-tests. Mean BFS after 24 hours of storage varied between 79 MPa and 157 MPa. After 60 hours the BFS significantly decreased and revealed values ranging from 72-127 MPa (mean24 113 MPa, mean60 97 MPa; p&lt;0.001). No significant differences could be determined between the materials (p=0.103) or between the different cleaning procedures (p=0.321). Post-polymerization yielded higher means with LED- (P1: 115 MPa) than with Xenon-light (P2: 95 MPa; p&lt;0.001). Regarding position, the mean values ranged from 101 MPa for 0°, 102 MPa for 45°, and 115 MPa for 90°, which was significantly different (p&lt;0.001). Build orientation of 90° and post-polymerization with LED-light provided significantly higher biaxial flexural strength and should be used to guarantee optimal strength of splint materials. Aging decreased the biaxial flexural strength of the tested specimens.

The objective of this work is to study the physical and mechanical behavior of concrete with the addition of 0.5% and 1.0% of coconut fibers subjected to two chemical treatments in order to reduce their degradation and optimize their use in the elaboration of concrete specimens, which must comply with the standards of the American Society for Testing of Materials (ASTM), the American Concrete Institute (ACI) and the Instituto Ecuatoriano de Normalización (INEN). The coconut fibers were obtained from the raw material by hand and cut to a length of 4 cm. Subsequently, the coconut fibers were subjected to two chemical treatments: The first treatment is the immersion of the coconut fibers in 4% sodium hydroxide (NaOH) solution and the second treatment, the coconut fibers were immersed in gum arabic to consequently coat them with silica fume. A particular dosage was carried out with a proportion of 0.5% and 1.0% volume of coconut fiber for the two chemical treatments, replacing the volume of coarse aggregate. Simple concrete joists were made without fiber and with the post-treatment coconut fibers, which were subjected to flexural tests. The results indicated that the best chemical treatment is sodium hydroxide with a concentration of 4% and 1.0% coconut fiber for strengths of 210 kg/cm² and 240 kg/cm². In general, the joists with coconut fiber treated with sodium hydroxide outperformed the fibers treated with gum arabic and silica fume.

This research aimed to determine the effect of alkaline treatment on zalacca midrib fiber (ZMF) concerning various aspects such as thermal stability, crystallinity index, interfacial bonding, interfacial shear strength, water absorption capacity, as well as conducting Scanning Electron Microscopy (SEM). This investigation extended to evaluating the mechanical properties of composites enriched with microcrystalline cellulose with prosthetic socket materials available on the market. Subsequently, ZMF was obtained by splitting and soaking zalacca midrib for 12 hours. Each of ZMF was removed from the midrib and soaked in 5% sodium hydroxide for 3, 6, 9, and 12 hours. The composite material was molded by mixing 10% microcrystalline cellulose with a rotational speed of 150 rpm, maintaining a temperature of 40°C, and continuing the mixing process for 30 minutes. As a result of the alkaline treatment, several positive effects were observed, including increased fiber density, improved particle bonding, increased thermal compatibility, and cleaner fiber surfaces, attributed to reduced levels of hemicellulose, lignin, pectin, and other impurities as confirmed by SEM analysis. The microcrystalline cellulose added to the composite increased the interfacial shear strength, and tensile strength increased by 56.74%, composite flexural strength increased by 76.43%. The SEM analysis results showed that the composite with ZMF on the base fiber broke during the tensile test because fiber experienced an increase in interfacial bonding between fiber and the matrix. The water absorption test showed that untreated fiber had a higher level of absorption

A frequent problem in Geotechnics is the soils with inadequate physical-mechanical properties before the efforts to which they will be subjected by the constructions, incurring cost overruns caused by their engineering improvement. The need to improve the engineering properties of soils is not recent, currently observing that the most common alternatives are binders such as cement and lime. The climate change observed in recent decades and the uncontrolled emission of greenhouse gases have motivated Geotechnical and Geoenvironmental researchers to seek mechanisms for soil reinforcement from a more sustainable and environmentally friendly approach by proposing the use of recycled and waste materials. An alternative is natural fibers, which can be obtained as waste from many agro-industrial processes, implying their high availability and low cost. Sawdust as a by-product of wood processing has a rough texture that can generate high friction between the fiber and the matrix of the soils, leading to a significant increase in its shearing strength and bearing capacity. This concept of improving the properties of soils using natural fibers distributed randomly is inspired by the natural phenomenon of grass and/or plants that when growing on a slope can effectively stabilize a said slope.