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KM2A is one of the main sub-arrays of LHAASO, working on gamma ray astronomy and cosmic ray physics at energies above 10 TeV. Detector simulation is the important foundation for estimating detector performance and data analysis. It is a big challenge to simulate the KM2A detector in the framework of Geant4 due to the need to track numerous photons from a large number of detector units (>6000) with large altitude difference (30 m) and huge coverage (1.3 km2). In this paper, the design of the KM2A simulation code G4KM2A based on Geant4 is introduced. The process of G4KM2A is optimized mainly in memory consumption to avoid memory overflow. Some simplifications are used to significantly speed up the execution of G4KM2A. The running time is reduced by at least 30 times compared to full detector simulation. The particle distributions and the core/angle resolution comparison between simulation and experimental data of the full KM2A array are also presented, which show good agreement.

Abstract: The physical, mechanical, and thermal properties of new nonwoven materials based on heat-resistant fibers were studied. An analysis of existing nonwoven materials of various fibrous compositions, as well as effective water-repellent compositions, was carried out. A technique has been developed for the production of hydrophobized nonwoven materials using solutions of fluorine-containing latex. Bulk density values of samples were determined, thermogravimetric analysis was carried out, mechanical properties (values of breaking load and elongation at break), water absorption, and other technical characteristics of the developed material were studied, and an experimental batch was manufactured.

The 5G‐enabled sensor network systems make it possible to connect cyber and real ‘things’ in many ways. Even so, the flow of data between 5G‐enabled sensor devices brings big data environment problems, such as huge amounts of data, duplicated data, a lack of scalability etc. Some of these problems are as follows. It is hard to keep an eye on 5G‐enabled sensor systems in a ‘big data’ environment. Cyberattacks that could put the safety of the sensor network systems at risk are hard to find, which make the situation even more complicated. The security challenges of 5G‐enabled Sensor Network Systems are studied and analyzed due to some constraints associated with the sensor nodes. The proposed advanced algorithm for securing the 5G‐enabled sensor systems is a Multidimensional big data environment using artificial intelligence/machine learning (AI/ML). Using a structure that depends on both geographical and temporal data, an improved clear point selection operation may get important information from multidimensional time series data that is spread across a wide range of sensor nodes. Therefore, the actions of the 5G‐enabled sensor network can be shown accurately and a complete model of its underlying data structure is built to analysis attacking, pattern on 5G‐enabled Sensor Network Systems using the AI/ML Algorithm. The 5G‐enabled sensor network systems make it possible to connect cyber and real ‘things’ in many ways. Even so, the flow of data between 5G‐enabled sensor devices brings big data environment problems, such as huge amounts of data, duplicated data, a lack of scalability etc. Some of these problems are as follows. It is hard to keep an eye on 5G‐enabled sensor systems in a ‘big data’ environment. Cyberattacks that could put the safety of the sensor network systems at risk are hard to find, which make the situation even more complicated. The security challenges of 5G‐enabled Sensor Network Systems are studied and analyzed due to some constraints associated with the sensor nodes. The proposed advanced algorithm for securing the 5G‐enabled sensor systems is a Multidimensional big data environment using artificial intelligence/machine learning.

Spherical pressure hull for manned submersible may experience extreme environmental conditions. Damage assessment of the spherical pressure hull subjected to an underwater explosion of a mine or a depth charge or a gas explosion in offshore industries is very much required. This study focuses on elastic and inelastic numerical analysis on the spherical pressure hull of 2100 mm internal diameter and 65 mm thickness subjected to a non-contact underwater explosion. Numerical analysis is carried out in finite element analysis software ANSYS. Explosion can be defined by its intensity, which is a function of the mass of the explosive and distance between the structure and the detonation point. The amount of shock energy delivered by the explosion is defined by scaled distance, whereas the energy absorbed by the structure is defined by effective shock factor. Numerical analyses under elastic and inelastic conditions are carried out for different stand-off distances. Initially, the analysis is carried out using stress–strain curve. If the structure undergoes permanent deformation, then Cowper–Symonds material model is introduced to consider the strain rate effect. At a shock factor of 3.98 and scaled distance of 0.15, the spherical pressure hull undergoes a permanent deformation of 0.7 mm. Non-contact underwater explosion damage is predicted by numerical analysis to understand the elasto-plastic behavior of the spherical pressure hull.

Hard coatings are used to improve the wear resistance of various engineering materials while maintaining the mechanical properties of the base material. In this work, the high-velocity oxy-fuel (HVOF) thermal spray process was used to deposit NiCrSiBCFe(65)-WC-Co(35) and NiCrSiBCFe(65)-Cr3C2-NiCr(35) coatings on SA213-T17 boiler steel to improve the erosion wear resistance of the base material. The erosion wear behaviours of the specimens were investigated using an air jet erosion tester at 30 and 90° impact angles and 400 ± 25 °C temperature. The surface morphologies of the as-deposited and eroded samples were examined using the Scanning electron microscope. The NiCrSiBCFe-WC-Co ceramic coating deposited on SA213-T17 boiler steel exhibited superior erosion resistance compared to NiCrSiBCFe-Cr3C2-NiCr coating and boiler steel under all the tested conditions. This enhanced performance can primarily be attributed to the higher hardness of the NiCrSiBCFe-WC-Co coating due to the presence of harder phases such as WC, W2C and NiCo2O4.

In developing nations such as Nigeria, the housing industry lacks appropriate and highquality housing. One of the housing development concepts and shelter delivery systems in practice in developing nations Nigeria inclusive are public, private and public–private. These three delivery strategies involves in mass housing production, although the bulk of these mass housing are not sustainable. This study examines at the conditions of mass housing delivered by the public, public–private, and private sectors in Ilorin, Nigeria. Quantitative and qualitative research approaches were employed for the study and both primary and secondary data were utilised. Multistage sampling technique was adopted to sample 27% of the 4166 households’ population. A set of questionnaire was administered to 1125 household heads, from 895 houses of the Public, 203 of public–private–partnership and 27 of private developers. Data were evaluated with descriptive statistics and multiple analyses of variance (MANOVA) to get the variation in housing elements condition based on the three-delivery strategy. According to the study, private had walls with highest percentage of very good (41.0%), good conditions (51.6%), and public had walls with 33.1% very good, 36.6% good conditions. However, 13.0% of PPP wall are in poor condition, and 80.1% of walls are only fair, comparisons of the condition of housing elements in the three strategies revealed that all the parameters of houses were found to have significant differences with p values reported for the comparison were observed to be less than 0.05 confidence level (p < 0.05). The study suggests among others that public–private partnership delivery strategy should be given more attention by the government to ensure good quality delivery and sustainability of mass housing.

Hypothalamic gonadotropin-releasing hormone (GnRH) neurons regulate fertility and integrate hormonal status with environmental cues to ensure reproductive success. Here we show that GnRH neurons in the olfactory bulb (GnRHOB) of adult mice can mediate social recognition. Specifically, we show that GnRHOBneurons extend neurites into the vomeronasal organ and olfactory epithelium and project to the median eminence. GnRHOBneurons in males express vomeronasal and olfactory receptors, are activated by female odors and mediate gonadotropin release in response to female urine. Male preference for female odors required the presence and activation of GnRHOBneurons, was impaired after genetic inhibition or ablation of these cells and relied on GnRH signaling in the posterodorsal medial amygdala. GnRH receptor expression in amygdala kisspeptin neurons appear to be required for GnRHOBneurons’ actions on male mounting behavior. Taken together, these results establish GnRHOBneurons as regulating fertility, sex recognition and mating in male mice.

Theoretical investigation on self-focusing of q-Gaussian laser beam propagating through underdense plasma has been presented. The optical nonlinearity of plasma has been modeled by the relativistic mass nonlinearity of plasma electrons in the field of laser beam. Using variational theory approach, semi-analytical solutions of the wave equations for the fields of main beam and that of ripple have been obtained. Emphasis has been put on the evolutions of the intensities of main beam and that of ripple.

This study addresses the research gap regarding using natural fibre-reinforced polymers (FRPs) to construct hybrid Double-Skin Tubular Columns (DSTCs). Experimental testing on twelve rectangular specimens revealed critical failure mechanisms primarily due to the rupture of FRP tubes under excessive stress. This rupture led to the loss of lateral support for the concrete, resulting in severe crushing and localized buckling of the inner steel tube. The experimental results also showed an 18% increase in axial stress and 18 times enhancement in axial strain within confined concrete specimens compared to unconfined concrete specimens because of the effective confinement provided by the outer natural FRP tube (hemp fibre). By integrating experimental and nonlinear finite element simulations, this study highlights the structural performance of these hybrid DSTCs under axial compression, with an average deviation of 1% at the peak axial load, demonstrating the effectiveness of the numerical simulation model. Additionally, a parametric study using validated nonlinear finite element analysis (NLFEA) models to investigate the influence of outer tube cross-sectional aspect ratio, inner steel tube shape, and outer FRP tube thickness on the confined concrete in rectangular DSTCs has been carried out. The finding highlighted that rectangular DSTCs with thicker FRP tubes exhibit higher ultimate axial stress and strain in the confined concrete. Moreover, rectangular DSTCs with square inner steel tubes showed notably lower ultimate axial stress and strain in the confined concrete than rectangular DSTCs with circular inner steel tubes. This comprehensive study emphasizes the importance of stress–strain models, offering valuable insights for the design and construction of hybrid rectangular DSTCs.

A strong π-donor, weak σ-donor pyridonate pincer complex of platinum is reported, a rare but important electronic ligand structure for promoting C–H activation in late transition metals. Protonation of the complex 2,6-bis(diethylaminomethyl)-4-pyridonate platinum(II) methyl occurs initially at oxygen, with a second proton equivalent affording methane. Methyl triflate similarly methylates initially with oxygen and then platinum. A computational study indicates that this terdentate pyridonate pincer greatly enhances the ability of late transition metals to cleave the C–H bond of methane compared to a classic NCN pincer. With iridium bound to this π-donor pincer, the oxidative addition of methane is computationally predicted to be thermodynamically favorable.

Aluminium has got a greater potential in wide range of applications due to its low weight, higher resistance to corrosion. But its low strength and less resistance to wear make it unsuitable for large number of the application. Therefore, these aluminium alloys are added with some of the reinforcements in order to create hybrid aluminium metal matrix composites (HAMCs). HAMCs are used in applications like automotive, aerospace, marine and specifically in preparations of gears. These HAMCs gears can be used in gear pumps, gear box, gear reducers, actuators, etc. Through simulation study, these HAMC gears can be analysed for their fatigue characteristics. Therefore, in this study, gears of Al 7075 with varying wt.% of SiC and fixed wt.% of Al2O3are considered for their fatigue characteristics. ANSYS Workbench is used as a simulation tool to predict the fatigue life of these gears. Simulation results indicated that with increase in wt.% of reinforcements, fatigue life increases.

A magnet has been developed to generate 30 T pulsed magnetic field with 100 ms flat-top at the Wuhan National High Magnetic Field Center (WHMFC). By adjusting the conductor height of each layer, this magnet has a typical bore with 20 mm diameter and a conical bore with 30 degree opening angle on the one side for X-ray diffraction and neutron scattering experiments. Fast cooling technique was used for better cooling performance, and eight stainless steel rods were placed in the cooling channel to resist the strong axial electromagnetic force. The magnet was connected in series with an auxiliary coil to extend the flat-top duration of the magnetic field, and energized with nineteen 1.25 MJ capacitor modules. The multiple capacitor modules are pre-charged to the set voltage, and then triggered in sequence. Peak field of 30 T with 90 ms flat-top and 1% flatness was obtained with optimized initial voltage and trigger time of each capacitor module.

Pseudomonas aeruginosaposes a significant threat to immunocompromised individuals and those with cystic fibrosis. Treatment relies on antibiotics, but persistent infections occur due to intrinsic and acquired resistance of P. aeruginosatowards multiple classes of antibiotics. To date, there are no licensed vaccines for this pathogen, prompting the urgent need for novel treatment approaches to combat P. aeruginosainfection and persistence. Here we validated AAV vectored immunoprophylaxis as a strategy to generate long-term plasma and mucosal expression of highly protective monoclonal antibodies (mAbs) targeting the exopolysaccharide Psl (Cam-003) and the PcrV (V2L2MD) component of the type-III secretion system injectosome either as single mAbs or together as a bispecific mAb (MEDI3902) in a mouse model. When administered intramuscularly, AAV-αPcrV, AAV-αPsl, and AAV-MEDI3902 significantly protected mice challenged intranasally with a lethal dose of P. aeruginosastrains PAO1 and PA14 and reduced bacterial burden and dissemination to other organs. While all AAV-mAbs provided protection, AAV-αPcrV and AAV-MEDI3902 provided 100% and 87.5% protection from a lethal challenge with 4.47 × 107CFU PAO1 and 87.5% and 75% protection from a lethal challenge with 3 × 107CFU PA14, respectively. Serum concentrations of MEDI3902 were ~10× lower than that of αPcrV, but mice treated with this vector showed a greater reduction in bacterial dissemination to the liver, lung, spleen, and blood compared to other AAV-mAbs. These results support further investigation into the use of AAV vectored immunoprophylaxis to prevent and treat P. aeruginosainfections and other bacterial pathogens of public health concern for which current treatment strategies are limited.

Abstract: The surface of monocrystalline silicon irradiated with a high-power pulsed beam of carbon ions and protons is studied using optical and scanning electron microscopy. The surface is irradiated using a TEMP-2 accelerator in a vacuum of ~10–3Pa. The ion beam consists of 70% carbon ions (C++ C+2) and 30% protons. The sample is irradiated with one pulse with a dose of 1.5 × 1013ions/cm2. Craters characterized by a hexagonal shape are obtained on the silicon surface. X-ray diffraction analysis shows the presence of carbon content inside the crater.

Abstract: The results of ablation experiments are given for the case for a scanning beam of nanosecond range pulsed laser radiation using targets made of high-carbon U13 and low-carbon St30 steel grades. The dependence of the depth and power efficiency of ablation on the power density is determined in the range q= 4 × 108–1010W/cm2. It is established that the maximum efficiency of removing the material is obtained when q= 4 × 109W/cm2for a target made of U13 steel and q= 7 × 108–5 × 109W/cm2for St30 steel. The size distribution is estimated for emitted microparticles. It is established that irradiation of high-carbon steel results in generating a flow of particles deposited on the target surface (back flow). The mechanism of this back flow is associated with formation of nanosized condensate particles. On the basis of the reflectivity measurements and on the studies of the microstructure of the irradiated surface using electron microscopy methods, a hypothesis is put forward that the higher ablation efficiency of high-carbon steel U13 compared to low-carbon steel St30 depends on the process of condensation of supersaturated carbon vapor on the target surface. This process can increase the absorption capacity of the irradiated target surface. As a result, the efficiency of material removal during the subsequent scanning pass is increased.

AbstractAn experimental study of a synthesis technique in which deuterium ions are implanted into thin films of erbium to form erbium deuterides is presented. Results from thermal desorption spectroscopy indicate the synthesis of multiple hydride phases has occurred, including ErD3and ErD2. The findings also indicate that, for erbium deuteride synthesis via ion beam bombardment, elevated substrate temperatures are not required to promote deuterium uptake in the film. Stoichiometries of up to ErD0.21were achieved for a 400-nm film exposed to a 1000-eV ion beam for 5 h at a deuterium ion fluence of 3.6 × 1022 m−2. Over the tested experimental conditions, deuterium uptake was found to scale proportionally with deuterium ion fluence and ion energy. The presence of deuterium in the film was confirmed by secondary ion mass spectrometry.

Additive manufacturing (AM) is a developing manufacturing technology, which provides excellent attributes compared to other manufacturing techniques. However, one of the critical challenges is the presence of defects that hinder the mechanical properties of the parts, particularly the fatigue life. Experimental understanding of fatigue is a cumbersome process. Therefore, numerical prediction based on specified conditions (such as porosity and applied load) can be an alternative to experimental analysis at the design stage of AM parts. In this study, elastic–plastic finite element analysis (FEA) is performed to obtain the stress distribution around pores, and their resultant effect on fatigue life for L-PBF (laser powder bed fusion) produced AlSi10Mg alloy samples. The stress field is calculated for both single and multiple pore models, where stress concentration is evaluated as a function of the pore’s location and its size. It is found that both pore location and size affect the stress field; however, location effects dominate over pore size. For the same remote applied stress level, the stress concentration around the pore increases with an increase in pore size, and the local maximum stress occurs near the pores that are closest to the surface. The current study also evaluates the relative effect of porosity fraction, average pore size, and location. It is found that the magnitude and sensitivity of stress concentration are hierarchically controlled by porosity location, pore size, and porosity density. A multi-scale finite element (FE) model is proposed based on inherent porosity data measured using Computed Tomography (CT) to predict overall fatigue life. The fatigue cycles are calculated using the rainflow counting algorithm in FE Safe using the stress–strain data obtained from the proposed FEA model. Using the proposed model, it is possible to generate S–N curves for any loading condition for a given porosity condition (porosity density and average pore size). The S–N curve results obtained from the FE model are compared to the experimental observations. The predicted fatigue life shows approximately 5% error with experimental results at high stress loading conditions. However, the proposed model overpredicts the fatigue life at low stress loading by almost 30%.