Simulation of Fragmentation Characteristics of Projectile Jacket Made of Tungsten Alloy after Penetrating Metal Target Plate using SPH Method

A smooth particle hydrodynamics (SPH) model was used to simulate the fragmentation process of the jacket during penetrator with lateral efficiency (PELE) penetrating the metal target plate to study the fragmentation characteristics of PELE jacket made of tungsten alloy. The validity of the SPH model was verified by experimental results. Then the SPH model was used to simulate the jacket fragmentation under different impact velocity and thickness of target plate. The influence of impact velocity and thickness of target plate on the jacket fragmentation was obtained by analysing the mass distribution and quantity distribution of the fragments formed by the jacket. The results show that the dynamic fragmentation of tungsten alloy can be simulated effectively using the SPH model, Johnson-Cook strength model, maximum tensile stress failure criterion and stochastic failure model. When the thickness of target plate is fixed, the greater the impact velocity, the greater the pressure produced by the projectile impacting the target plate; with the increase of impact velocity, the mass of residual projectile decreases, the number of fragments formed by fragmentation of jacket increases linearly, and the average mass of fragments decreases exponentially. When the impact velocity is constant, the greater the thickness of the target plate, the longer the pressure duration by the projectile impacting the target plate; with the increase of the thickness of target plate, the mass of residual projectile decreases, the number of fragments formed by fragmentation of jacket increases linearly, and the average mass of fragments decreases exponentially. The numerical calculation model and research method adopted in this paper can be used to study the impact fragmentation of solid materials effectively

Fragmentation Behaviour of Radial Layered PELE Impacting Thin Metal Target Plates

The fragmentation mechanism of the penetrator with lateral effect (PELE) after perforating a thin target plate has been summarised and analysed firstly. Then the fragmentation of radial layered PELE was analysed qualitatively and verified by experiment. In the experiment, the target plates were made of 45# steel and 2A12 aluminium respectively. Qualitative analysis and experimental results show that: for normal PELE without layered, after perforating the thin metal target plate, from the bottom to the head of the projectile, the number of fragments formed by the jacket gradually increases, and the mass of the fragment decreases correspondingly. Compared with the normal PELE without layered, the radial layered PELE is less likely to break into fragments, when impacting the thin metal target plate with the same material and thickness under the same impact velocity. However, from the mechanism of the PELE, when the resistance of the target plate is large enough, and the duration of pressure is long enough, the radial layered PELE also can break into fragments with transverse velocity component. The resistance of the target plate plays an important role in the fragmentation of radial layered PELE. The radial layered PELE produced massive fragments with transverse velocity component when impacting the 45# steel plate with5 mm thickness under the impact velocity of 657.2 m/s

Photocatalytic self-cleaning graphene oxide/ZnO hybrid membrane for ultrafast cyclic small organic molecule separation

Graphene oxide (GO) based membranes have attracted tremendous interest owing to their unique lamellar structure resulting in excellent molecular filtration. However, the expansion of interlayer spacing of GO nanoflakes in liquid solutions, particularly in aqueous solution, and the adsorption of foulants in the layered nanoconfinement as well as on the surface adversely affects the long-term performance of the membranes. In this work, one-dimensional zinc oxide (ZnO) nanorods were integrated with graphene oxide via in-situ crystallization. A fast thermal treatment was applied to partially reduce the graphene oxide nanoflakes and chemically ‘lock’ the newly formed ZnO nanorods during the final step of hybrid membrane fabrication. It was found that the partially reduced graphene oxide (rGO) provided excellent mechanical stability between the nanolayers and also very stable and efficient molecular sieving properties. Interestingly, the ZnO nanorods not only served as a space holder between neighbouring reduced graphene-oxide nanoflakes but also endowed the hybrid membrane with responsive photocatalytic self-cleaning properties, which has been considered one of the most promising approaches for energy-efficient environmental remediation. In water permeation tests, these graphene oxide-zinc oxides (P-rGO/ZnO) membranes exhibited ultrahigh permeance of 400 ± 21 L m−2 h−1 bar−1, more than an order of magnitude higher than the conventional rGO membranes. In the meantime, these membranes exhibited excellent small organic molecule separation efficiencies with &gt;98.8 ± 1.2% rejections toward direct red 80, rose bengal, reactive black 5, and trypan blue. More importantly, under ultraviolet–visible light irradiation, the membrane demonstrated highly efficient self-cleaning behaviour for fast organic dye decomposition, enabling excellent cyclic removal of pre-adsorbed dye molecules. Therefore, this intelligent self-cleaning hybrid membrane has great potential in wastewater purification, particularly for ultrafast small organic molecule removal.</p

Numerical simulation of hydraulic fracture propagation under energy supplement conditions

After the long-term production, due to the influence of low-pressure and low-stress fields in the near-well area, the reversion and propagation of new fractures after temporary plugging is short. It is difficult for the new fracture to extend to the remaining oil enrichment areas on both sides of the primary fractures, resulting in a low increase in the bandwidth of the fracture group after repeated fracturing, which affects the reservoir utilization. In the early stage of repeated fracturing, a large amount of pre-fracturing fluid is injected to supplement the energy of the fractures and rapidly increase the pore pressure in the local range, weakening rock strength and change the pore structure. In addition, the combination of energy replenishment and reservoir stimulation, coupled reconstruction of the seepage field and stress field, promotes the effective propagation of new fractures. However, in the process of increasing formation energy, the propagation law of hydraulic fractures and natural fractures is not clear. In this paper, the model of tight sandstone reservoir in the HQ block of Ordos Basin was established with the finite element software ABAQUS, based on the effective stress principle and the theoretical method of fluid-solid coupling numerical simulation. The propagation of a single hydraulic fracture and the interaction between hydraulic fracture and natural fracture under the condition of energy increase was investigated to better guide the field operation. The results show that for every 1 MPa pressure increase in a single hydraulic fracture, the fracture length increases by 0.62 m and the maximum fracture width decreases by 0.09 mm. When the formation energy increases by 6 MPa, the time for the hydraulic fracture to reach the intersection point with the natural fracture is shortened by 10 %, and the length of the natural fracture is 2.16 times compared with the case of 3 MPa energy increase

Complex 3D microfluidic architectures formed by mechanically guided compressive buckling.

Microfluidic technologies have wide-ranging applications in chemical analysis systems, drug delivery platforms, and artificial vascular networks. This latter area is particularly relevant to 3D cell cultures, engineered tissues, and artificial organs, where volumetric capabilities in fluid distribution are essential. Existing schemes for fabricating 3D microfluidic structures are constrained in realizing desired layout designs, producing physiologically relevant microvascular structures, and/or integrating active electronic/optoelectronic/microelectromechanical components for sensing and actuation. This paper presents a guided assembly approach that bypasses these limitations to yield complex 3D microvascular structures from 2D precursors that exploit the full sophistication of 2D fabrication methods. The capabilities extend to feature sizes <5 μm, in extended arrays and with various embedded sensors and actuators, across wide ranges of overall dimensions, in a parallel, high-throughput process. Examples include 3D microvascular networks with sophisticated layouts, deterministically designed and constructed to expand the geometries and operating features of artificial vascular networks

Functional genomics analysis of Leptin-Melanocortin system genes reveals candidate genes associated rapid growth and high carcass yield in sheep

The Leptin-Melanocortin System (LMS) is an important regulatory system involved in appetite and energy balance in many organisms, including sheep. Functional genomics analysis of LMS genes can provide insights into the genetic factors that influence rapid growth and high carcass yield in sheep. However, the genetic potential of sheep growth and reproduction has not been fully exploited. Therefore, identifying genes that regulate growth and reproduction would offer strategies for improving the yield and quality of sheep meat. In this study, to explore the possible molecular mechanisms underlying rapid growth and muscular high-yield carcass in sheep, we screened 14 genes, which were previously claimed to be associated with such traits in humans and rodents. The FST outlier approach implemented in LOSITAN detected the loci under selection. These candidate genes were connected to complicated biological processes, including the regulation of eating behavior, energy balance, and the positive regulation of the cAMP biosynthetic process, according to the gene ontology (GO) study. In addition, the 14 genes' re-sequence data revealed 7,226 SNPs. The MC4R, STAT3, BDNF, and TUB genes were discovered to be an outlier and significantly under positive selection using the fixation index (FST) based technique with the tentative combined allocation of mean heterozygosity and FST. Differentially expressed genes were found, and their functions were assigned using a functional genomics approach. Results showed that these genes are crucial in determining sheep features including size and meat quality. Insights are gained into the molecular mechanisms behind these phenotypic variations, and possible genes for future sheep breeding initiatives are provided. This research proves the value of functional genomics analysis in identifying the heritable components of valuable sheep agriculture traits.The authors extend their appreciation to the Researchers Supporting Project number (RSP2023R27) King Saud University, Riyadh, Saudi Arabia.Peer reviewe

Outcomes of elective liver surgery worldwide: a global, prospective, multicenter, cross-sectional study

Background: The outcomes of liver surgery worldwide remain unknown. The true population-based outcomes are likely different to those vastly reported that reflect the activity of highly specialized academic centers. The aim of this study was to measure the true worldwide practice of liver surgery and associated outcomes by recruiting from centers across the globe. The geographic distribution of liver surgery activity and complexity was also evaluated to further understand variations in outcomes. Methods: LiverGroup.org was an international, prospective, multicenter, cross-sectional study following the Global Surgery Collaborative Snapshot Research approach with a 3-month prospective, consecutive patient enrollment within January–December 2019. Each patient was followed up for 90 days postoperatively. All patients undergoing liver surgery at their respective centers were eligible for study inclusion. Basic demographics, patient and operation characteristics were collected. Morbidity was recorded according to the Clavien–Dindo Classification of Surgical Complications. Country-based and hospital-based data were collected, including the Human Development Index (HDI). (NCT03768141). Results: A total of 2159 patients were included from six continents. Surgery was performed for cancer in 1785 (83%) patients. Of all patients, 912 (42%) experienced a postoperative complication of any severity, while the major complication rate was 16% (341/2159). The overall 90-day mortality rate after liver surgery was 3.8% (82/2,159). The overall failure to rescue rate was 11% (82/ 722) ranging from 5 to 35% among the higher and lower HDI groups, respectively. Conclusions: This is the first to our knowledge global surgery study specifically designed and conducted for specialized liver surgery. The authors identified failure to rescue as a significant potentially modifiable factor for mortality after liver surgery, mostly related to lower Human Development Index countries. Members of the LiverGroup.org network could now work together to develop quality improvement collaboratives