The search for higher energy efficiency of industrial-scale burners to attain low emission especially Nitrogen Oxide (NOx) has demanded experimental studies that are complemented with Computational Fluid Dynamics (CFD) simulations. While there exist numerous emission control techniques, the passive control technique was the main focus of the present review study. Biodiesel fuel crude palm oil (CPO) was found to reduce emission components, particularly carbon components and particulate matter (PM). Biodiesel CPO has the capability to mitigate cavitation inside the injector’s orifice which contributes to damage reduction on the orifice. Moreover, although cavitation can improve spray atomization and produce finer spray droplets, it also causes damage to the orifice of injectors. Orifice characteristics such as orifice’s diameter and pattern can also reduce cavitation inside the orifice. Orifice’s pattern is divided into cylindrical shape orifice and conical shape orifice. The conical orifice is found to reduce the cavitation inside the orifice while cylindrical orifice was indicated as a highly cavitating orifice. Alternatively, as rapid swirling motion is capable to enhance the fuel and air mixing, a new concept of swirling fuel-air premix inside the injector is invented and it is proven to reduce emissions. It was, however, learned that spray characteristics are still playing an important role in the prediction of combustion performance, particularly droplets Sauter Mean Diameter (SMD) which is a worldwide parameter that needs further investigations in order to predict the fineness of spray production and combustion.

The article contains the results of experimental studies for a multi-opening orifice with substitute constriction factor of β = 0.5 (m = 0.25), mounted in a DN50 hydraulic measuring flume. Flow measurements were taken for a progressing turbulent flow within Reynolds numbers (Re = 4700...19500). Based on experimental data, flow characteristics as well as discharge coefficient C characteristics were determined. Relative expanded uncertainty of determining a discharge coefficient C was estimated within the changes of volume flow qv from 0.35 dm3/s to 0.68 dm3/s. The value does not exceed 1.25% within the changes of Reynolds numbers 9800 ≤ Re ≤ 19500.

For our research on droplet deformation and breakup in scaled high-pressure homogenizing units we developed a pressure stable inline droplet generator. It consists of an optically accessible flow channel with a combination of stainless steel and glass capillaries and a 3D printed orifice. The droplet size is determined online by live image analysis. The influence of the orifice diameter, the mass flow of the continuous phase and the mass flow of the disperse phase on the droplet diameter was investigated. Furthermore, the droplet detachment mechanisms were identified. Droplet diameters with small diameter fluctuation between 175 µm and 500 µm could be realized, which allows a precise adjustment of the Ca and We Number in the subsequent scaled high pressure homogenizer disruption unit. The determined influence of geometry and process parameters on the resulting droplet size and droplet detachment mechanism agreed well with literature on microfluidics. Furthermore, droplet trajectories in an exemplary scaled high-pressure homogenizer disruption unit are presented which show that the droplets can be reinjected on a trajectory close to the center axis or close to the wall, which should result in different stresses on the droplets.

Performance of flow through orifices on a perforated distribution pipe between periods with and without partial clogging (submersion of part of the distribution pipe) was compared. The distribution pipe directly receives runoff and delivers it to an underground infiltration bed. Partial clogging appeared in winter but reduced in summer. Performance was defined as flow rate divided by l_eff (h_(d,mean)^0.5) where h_(d,mean) is the mean pressure head that drives flow and l_eff is the effective pipe length (length of water column with pipe water volume and the pipe cross-sectional area). ANCOVA (ANalysis of COVAriance) was adopted to examine the clogging effects with flow rate plotted against l_eff (h_(d,mean)^0.5) . Partial clogging had a significant effect on pipe performance during periods of low or no rainfall. However, if only data during larger storms was considered, little evidence showed that partial clogging had effects on pipe delivery performance. Partial clogging might be caused by leaves accumulated in the lower section of the pipe in winter, and its effect was insignificant when water level rose in the pipe, utilizing significantly more orifices on the distribution pipe, thus the effect from the clogged portion had negligible impact on system performance. Larger storms might also provide the required flow rate to move the debris block thus exposing the orifices. Partial clogging did not increase the tendency of overflow; therefore, current maintenance schedule was sufficient to keep the distribution pipe at satisfactory performance even though partial clogging can exist.

(1) Background: Sentinel lymph node (SLN) mapping represents an accurate and feasible technique for the surgical staging of endometrial and cervical cancer. This is commonly performed by conventional laparoscopy or robotic-assisted laparoscopy, but in recent years, a new retroperitoneal transvaginal natural orifice transluminal endoscopic surgery (vNOTES) approach has been described. This technique provides easy visualization of lymphatic afferent vessels and pelvic lymph nodes, early SLNs assessment, and a coherent mapping methodology following the lymphatic flow from caudal to cranial. However, only a few publications have reported it. Following the IDEAL (Idea Development Exploration Assessment Long-term follow-up) framework, research concerning this technique is at stage 2a, with only small case series as evidence of its feasibility. Its standardized description appears necessary to provide the surgical homogeneity required to move further. (2) Methods: description of a standardized approach for retroperitoneal pelvic SLN mapping by vNOTES. (3) Results: we described a 10-step approach to successfully perform retroperitoneal vNOTES SLN mapping, including pre-, intra-, and postoperative management. (4) Conclusions: This IDEAL stage 2a study could help other surgeons approach this new technique, and it proposes a common methodology necessary to evolve through future IDEAL stage 2b (multi-center studies) and stage 3 (randomized controlled trials) studies.

The article is devoted to the analytical and numerical study of the pattern of propagation and attenuation, due to Coulomb friction, of shear waves in an infinite thin elastic plate with a circular orifice of radius lying on a rough base. In the field of motion, an exact analytical solution of a nonlinear boundary value problem for tangential stresses and transversal velocities is obtained in quadratures by the method of Laplace transformations. It turned out that the complete exhaustion of the wave front of a strong rupture occurs at a finite distance from the center of the hole and an elementary formula is given for this distance (the case of tangential forces instantly applied to the orifice boundary, and then constant in time, is considered). For various ratios of the magnitude of the limiting friction force to the amplitude of the applied load, the trailing wave fronts are obtained, after which a state of static equilibrium between the elastic and friction forces with a nonlinear distribution of residual deformations is established in the region .

Surgical approaches for ovarian cancer have advanced significantly in recent years. Transvaginal natural orifice transluminal endoscopic surgery (vNOTES) is an emerging technique in gyneco-logical oncology, with limited reports of its use in ovarian cancer management. This study aimed to evaluate the feasibility and safety of vNOTES for the surgical staging of early-stage adnexal malignancies. Methods: We retrospectively reviewed all cases of borderline ovarian tumors (BOTs) and early-stage ovarian cancer surgically staged using vNOTES at our institution between October 2021 and August 2024. Results: Eleven patients were included, 7 with ear-ly-stage ovarian or tubal cancer and 4 with BOTs. The median age was 47 (27 – 81) years, and the median body mass index was 28.1 (22.4 – 39.2) Kg/m². Complete vNOTES staging was achieved in all cases, including peritoneal washing, unilateral/bilateral salpingo-oophorectomy, ab-dominal cavity inspection, peritoneal biopsies, infracolic omentectomy, and total hysterectomy when required. The median operating time was 70 (35 – 138) minutes, with a median blood loss of 50 (10 – 100) mL. No intraoperative complications occurred except for one case of minor ovar-ian spillage. No conversions to laparoscopy or laparotomy were needed. Postoperative compli-cations included one surgical site infection (9.1%) and two cases of postoperative cystitis (18.2%). No severe complications graded ≥3 on the Clavien-Dindo classification were observed. Conclu-sion: vNOTES appears to be a feasible and safe approach for the surgical staging of selected pa-tients with early stage adnexal malignancies. Further studies are needed to validate its long-term safety and oncological outcomes.