Abstract: Lanthanide molybdates, with the general formula Ln5.4MoO11.1-δ, are materials known for their mixed proton-ionic conductivity. This study investigated the effects of Pr content and Nb-doping on the crystal structure and electrical properties of the La5.4-xPrxMo1-yNbyO12-δ (x= 0, 1.35, 2.7, 4.05, 5.4; y= 0, 0.1) series. The research focuses on two primary objectives: (i) enhancing the electronic conductivity through the use of Pr4+/Pr3+ redox pairs, and (ii) increasing the ionic conductivity through Nb5+ aliovalent doping. The materials were thoroughly characterized by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission and scanning electron microscopy (TEM and SEM), and complex impedance spectroscopy. The average crystal structure of the materials depends significantly on the Pr content. In general, compositions with higher Pr content crystallize in a cubic fluorite-type structure, whereas lower Pr content stabilizes a rhombohedral polymorph. However, detailed TEM studies reveal a more complex local crystal structure characterized by nanodomains and incommensurate modulations. The highest conductivity values are observed in a N2 atmosphere for compositions with elevated Pr content, attributed to electronic conduction mediated by the Pr4+/Pr3+ redox pair, as confirmed by XPS. These findings highlight the potential of tailored doping strategies to optimize the conducting properties of lanthanide molybdates for specific high-temperatures electrochemical applications.

Abstract: Bacterial growth on implant surfaces poses a significant problem to the long term success of dental and orthopedic implants. There is a need for implant surfaces which promote osseointegration, while at the same time decreasing or preventing bacterial growth. In this study, we adapted existing methods for measurement of bacterial biofilms, to be suitable for measuring the bacterial growth on implant surfaces. We used two different strains of bacteria, Pseudomonas aeruginosa and Staphylococcus epidermidis, and investigated the in vitro effect of bacterial growth on titanium surfaces coated with an ultrathin (20–40 nm thick) layer of nanosized hydroxyapatite (HA). We found that after 2 hours of biofilm growth, there was a 33% reduction of bacteria for both S. epidermidis and P. aeruginosa on nanosized HA compared to Ti. For a more mature 24 h biofilm, there was a 46% reduction for S. epidermidis and a 43% reduction for P. aeruginosa on nanosized HA compared to Ti. This shows that nanosized HA can be of benefit in reducing implant related infections, together with antimicrobial therapy.

Abstract: This study presents a method for the simultaneous determination of six acidic herbicides and their metabolites in various matrices, including fruits, vegetables, grains and edible oils. The method employs acidified acetonitrile extraction combined with dispersive solid-phase extraction cleanup(dSPE) using magnesium sulfatem, Florisil, and graphitized carbon black (GCB). The analysis was performed using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Acetonitrile and 2 mmol.L-1 ammonium formate aqueous solution with a volume ratio of 0.1%(v/v) formic acid were used as mobile phases, target pesticides were analyzed by HPLC-MS/MS in both positive and negative at an ESI ion source under multiple reaction monitoring(MRM). The mass concentrations of six herbicide pesticides and their metabolites showed good linearity with the corresponding peak area in the range of 0.5~50 μg/L, and the correlation coefficient was more than 0.993. The limits of method detection（LODs）ranged from 0.0001 to 0.008 mg/kg. The recovery rates of adding recovery experiments to cabbage, chives, pear, wheat flour and soybean oil were 69.8%~120%, and the relative standard deviation (RSD) was 0.6%~19.5%. The results indicate that this method is efficient and fast, and can be used for the detection of actual samples in various matrices.

Abstract: A viable alternative to fossil fuel diesel is biodiesel. Due to its high oxidation risk, low stability, and short storage life, biodiesel has significant downsides. We use biodiesel-compatible antioxidants to eliminate issues. Sustainable energy and biodiesel antioxidants impact the global economy and environment. Researchers built Schiff bases to examine biodiesel-diesel blends. Schiff bases deactivated metals and antioxidants. Compound structures were disclosed by TLC, MP, FT-IR, 1H–13C NMR, and elemental analysis. These compounds' antioxidant activities were investigated utilizing the DPPH• free radical trapping and ABTS•+ radical cation scavenging assays. The study utilized 30% biodiesel, 70% diesel. Mixtures of 3000 ppm Schiff bases were tested for oxifast. Comparison to BHT antioxidant. Sample names were D100, B30D70, B30D70BHT, B30D70_2, and B30D70_1. These samples were characterized by FT-IR, DSC, and TGA. The DSC measured sample crystallisation temperatures. Antioxidant-rich diesel was lower than D100. DSC testing indicated antioxidant strengths of -11.76, -11.87, -12.03, -12.73, and -13.97 °C at crystallization for samples D100, B30D70, B30D70BHT, B30D70_2, and B30D70_1. TGA values of 102.30, 118.06, 129.84, 131.75, and 137.01 indicate sample stability increases Tonset. Antioxidants clarify FT-IR spectrum antioxidant impact areas. The extra antioxidant works. In various dosages, Schiff bases increase biodiesel's oxidative stability.

Abstract: To study uranium transport by surface water from Sierra Peña Blanca to Laguna del Cuervo in the Chihuahuan Desert, sediments from intermittent streams and the lagoon have been extracted and studied. Two samples are sediments from the high area of ​​the Sierra, close to the uranium deposit “El Nopal.” Moreover, 23 segments of a sedimentary core were analyzed to study changes in the fine component concentrations. The techniques of scanning electron microscopy-energy dispersive X-ray spectroscopy, XRD in a conventional diffractometer, and high-resolution synchrotron XRD analysis were applied. The crystallographic objective has been to evaluate the functionality of various methodologies when applied to cases of detailed analysis of many polyphase samples with cryptocrystals. The methods for processing the experimental data have been the Rietveld method, in the current multi-pattern variant of the Fullprof program, and the Degree of Crystallinity method for rapid estimation of the proportion of cryptocrystals in a mixture. This last technique has been developed with an Ad-Hoc software package, which has been deposited in the public repository GitLab.

Abstract:

In this study, we have analysed the Amazonian variety EETP801 Cacao, grown under sustainable organic conditions, in comparison to CCN51 cacao grown on a neighbouring commercial farm using standard practices and an European commercial cacao powdered beverage. The overall metabolite profile was analysed by high performance TLC analyses (HPTLC), the volatile fraction by head-space gas chromatography–mass spectrometry (HS-GC-MS) and the xanthine alkaloids by quantitative liquid chromatography-UV photodiode array (HPLC-DAD) analyses. Total polyphenol content was determined by the Folin-Ciocalteu method. Despite the reduced production of cocoa by the EETP801 cultivar in comparison with the CCN51 cultivar, the obtained produce is significantly richer in theobromine (130 mg vs 170 mg per g of cacao) with CCN51 having double concentration of theophylline (12.6 vs 6.5 mg per g of cacao). Qualitatively, EETP-801 has the same polyphenolic composition (as per the HPTLC fingerprint) of the CCN51 cultivar but shows more traces of glycosylated flavonoids (rutin). The HS-GC-MS analyses revealed that the fragrance of both Amazonian cacao samples was superior to that of the commercial sample. The variability in the artisan fermentation and roasting processes influenced certain aspects of the volatile composition. The cultivar EETP801 is a viable option for a more ecologically conscious sector of the cocoa beverages consumer group.

Abstract:

In this work, the simple hydrothermal method was used to prepare a series of ZnO /r-GO (ZGO-x) catalysts. The obtained products were subjected by a series of characterization, which showed that The zinc oxide particles were encapsulated on r-GO and the crystal structure was not disrupted. In addition, due to the large specific surface area and the good electrical conductivity of r-GO, more photogenerated electrons are rapidly transferred to the r-GO surface to participate in the reaction, thus improving the photocatalytic performance. The degradation rate of sample ZGO-3 reached 100% for RhB after simulated sunlight irradiation for 150 min, whereas the pure ZnO degraded RhB by about 83% under the same environment. The ZGO-3 also showed the best photocatalytic degradation of methyl orange, with 100% degradation in 180 min, whereas pure ZnO degraded only 87.64% of methyl orange under solar irradiation.

Abstract: The Oxidative Coupling of Methane (OCM) is a promising process for converting methane directly into more valuable ethane and ethylene. In this work, high-time-resolution online mass spectrometry was employed to track the OCM reaction over a commercial La2O3 catalyst, focusing on the effects of methane to oxygen ratio, Gas Hourly Space Velocity (GHSV), and the presence of H2O and CO in the feed gas on methane conversion and C2 yield. The results demonstrated that an optimized GHSV (44640 to 93000 mL·g−1·h−1) and methane to oxygen ratio (CH4/O2= 3) would achieve the highest methane conversion and C2 yield at 740 °C. Furthermore, the introduction of 1% H2O into the reaction mixture resulted in a twofold increase in C2 yield at 650 °C, while the addition of 1% CO led to a threefold increase in C2 yield at 550 °C. A model in which only the front-end catalyst is active was also developed to show excellent agreement with the experimental data. The relationship between catalytic performance and the effective catalyst position in the catalyst bed provides important insights into optimizing reactor design and operating conditions to maximize C2 yield and selectivity in the OCM reaction.

Abstract:

Despite the development of nuclear and alternative energy, thermal power plants operating by burning fossil fuels (coal, petroleum products or natural gas) will retain a significant share in the energy balance for a long time. In this regard, it is of particular interest to reduce CO2 emissions from the combustion of organic fuels through its capture and subsequent use or burial. In our work, mathematical modeling of the two-stage process of membrane extraction of CO2 from the flue gases of a thermal power plant was carried out, taking into account the presence of water vapor and various operating modes of the membrane module. We used commercially available polymer membranes for gas separation in our simulations. The calculations showed: Taking into account the presence of water vapor makes it possible to reduce the required membrane area by 1.6 times; For the degree of CO2 extraction < 80% in one stage, cross-flow and counter-current modes provide equal indicators for the required membrane area, and the co-current mode turns out to be less advantageous already with a degree of CO2 extraction > 60%. In this regard, in the area of low CO2 extraction values at the first stage, any flow organization mode in the membrane module can be selected, and in the high area, a counter-current has a slight advantage over the cross-flow mode; An optimal combination of membrane areas in the first and second stages is shown to achieve the maximum CO2 concentration in the product stream; Polaris Gen-2 membranes provide the best performance after two-stage separation: the CO2 content in the product stream was > 85 mol% and > 90 mol% with a total recovery rate of 80 and 50%, respectively; PolyActive and PPO membranes provide equal indicators for the CO2 content in the product stream, but in the use of PolyActive, the required membrane area is 2.3 times less.

Abstract: High entropy alloys are being increasingly investigated for their excellent combination of properties like strength, ductility, and significant low temperature fracture toughness. In the present work, the quinary equiatomic FeNiCoCrCu alloy is studied for its sputter deposition over a [001] nickel substrate using molecular dynamics simulations, described by the embedded atom method. The influence of annealing on the mechanical properties of the HEA coating is studied using nanoindentation with a virtual spherical indenter of diameter 25Å to an indentation depth of 25Å. The alloy is observed to undergo Transformation Induced Plasticity (TRIP) deformation – with activation and annihilation of stacking faults.