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Deuterium retention in chemically vapor deposited tungsten carbide coatings and hot-rolled tungsten exposed to low-energy deuterium plasma

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Tungsten 2022年第1期4卷 10-19页

作者： Vladimir kh.Alimov Joachim Roth Frumkin Institute of Physical Chemistry and Electrochemistry Russian Academy of SciencesMoscow 119071Russia Max-Planck-Institut fur Plasmaphysik 85748 GarchingGermany

Samples of chemically vapor deposited(CVD)coatings of tungsten carbides W_(45)C_(55)and W_(60)C_(40)and samples of hot-rolled tungsten were exposed to deuterium(D)plasma at sample temperatures ranging from 323 to 813 K,as a result of which the samples were irradiated with D ions with an energy of about 200 eV per D particle at a flux of D particles of about1.1×10^(21)D·m^(-2)·s^(-1)to a fluence of about 2×10^(24)D·m^(-2).The concentration of deuterium in these samples was examined by the D(3 He,p)4 He nuclear *** on the measured deuterium depth profiles and assuming that these profiles are determined by diffusing D atoms,the diffusion coefficients of deuterium in the CVD tungsten carbide coatings were *** these diffusion coefficients,an estimate of the Arrhenius relation for the diffusion coefficients of deuterium in CVD tungsten carbide coatings was obtained:D=2.5×10^(-3)exp(-1.12 eV/kT)m~2·s^(-1),where T is temperature expressed in Kelvin,and k is the Boltzmann *** concentration of trapped deuterium in the bulk of CVD tungsten carbide coatings is practically independent of the stoichiometry of the *** decreases from about 5×10^(-2)to about 7×10^(-4)D/(W+C)with an increase in the deuterium plasma exposure temperature from 373 to 813 *** concentration of trapped deuterium in hot-rolled tungsten,expressed in units of the D/W atomic ratio,is more than an order of magnitude lower than the concentration of deuterium in tungsten carbides,and also decreases with increasing plasma exposure temperature.

关键词： Chemically vapor deposited tungsten carbides Tungsten Deuterium plasma Deuterium depth profiles Deuterium diffusion coefficients

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Application of metal oxides-based nanofluids in PV/T systems: a review

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Frontiers in Energy 2022年第3期16卷 397-428页

作者： Shahriar Ahmed kh.Nazmul Ahshan MdNur Alam Mondal Shorab Hossain Department of Mechanical Engineering Hajee Mohammad Danesh Science and Technology UniversityDinajpur5200Bangladesh Department of Engineering BGMEA University of Fashion and TechnologyDhaka1230Bangladesh

Having the wide application of metal oxides in energy technologies, in recent years, many researchers tried to increase the performance of the PV/T system by using metal oxide-based nanofluids (NFs) as coolants or optical filters or both at the same time. This paper summarizes recent research activities on various metal oxides (Al2O3, TiO2, SiO2, Fe3O4, CuO, ZnO, MgO)-based NFs performance in the PV/T system regarding different significant parameters, e.g., thermal conductivity, volume fraction, mass flowrate, electrical, thermal and overall efficiency, etc. By conducting a comparative study among the metal oxide-based NFs, Al2O3/SiO2-water NFs are mostly used to achieve maximum performance. The Al2O3-water NF has a prominent heat transfer feature with a maximum electrical efficiency of 17%, and a maximum temperature reduction of PV module of up to 36.9°C can be achieved by using the Al2O3-water NF as a coolant. Additionally, studies suggest that the PV cell’s efficiency of up to 30% can be enhanced by using a solar tracking system. Besides, TiO2-water NFs have been proved to have the highest thermal efficiency of 86% in the PV/T system, but TiO2 nanoparticles could be hazardous for human health. As a spectral filter, SiO2-water NF at a size of 5 nm and a volume fraction of 2% seems to be very favorable for PV/T systems. Studies show that the combined use of NFs as coolants and spectral filters in the PV/T system could provide a higher overall efficiency at a cheaper rate. Finally, the opportunities and challenges of using NFs in PV/T systems are also discussed.

关键词： metal oxide nanofluids(NFs) nanoparticles(NPs) optical filter PV/T systems solar energy

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Secure and efficient implementation of facial emotion detection for smart patient monitoring system

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Quantitative Biology 2023年第2期11卷 175-182页

作者： kh Shahriya Zaman Md Mamun Bin Ibne Reaz Department of Electrical Electronic and Systems EngineeringUniversiti Kebangsaan Malaysia(UKM)Bangi 43600Malaysia

Background:Machine learning has enabled the automatic detection of facial expressions,which is particularly beneficial in smart monitoring and understanding the mental state of medical and psychological *** algorithms that attain high emotion classification accuracy require extensive computational resources,which either require bulky and inefficient devices or require the sensor data to be processed on cloud ***,there is always the risk of privacy invasion,data misuse,and data manipulation when the raw images are transferred to cloud servers for processing facical emotion recognition(FER)*** possible solution to this problem is to minimize the movement of such ***:In this research,we propose an efficient implementation of a convolutional neural network(CNN)based algorithm for on-device FER on a low-power field programmable gate array(FPGA)*** is done by encoding the CNN weights to approximated signed digits,which reduces the number of partial sums to be computed for multiply-accumulate(MAC)*** is advantageous for portable devices that lack full-fledged ***:We applied our approximation method on MobileNet-v2 and ResNet18 models,which were pretrained with the FER2013 *** implementations and simulations reduce the FPGA resource requirement by at least 22%compared to models with integer weight,with negligible loss in classification ***:The outcome of this research will help in the development of secure and low-power systems for FER and other biomedical *** approximation methods used in this research can also be extended to other imagebasedbiomedicalresearchfields.

关键词： facial expression detection emotion recognition FPGA implementation convolutional neural network signed digit approximation

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Reduced differential transform and Sumudu transform methods for solving fractional financial models of awareness

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Applied Mathematics(A Journal of Chinese Universities) 2023年第3期38卷 338-356页

作者： A.M.S.Mahdy K.A.Gepreel kh.Lotfy A.El-Bary Department of Mathematics and Statistics College of ScienceTaif UniversityP.O.Box 11099Taif21944Saudi Arabia Department of Mathematics Faculty of ScienceZagazig UniversityP.O.Box 44519ZagazigEgypt Arab Academy for Science Technology and Maritime Transport1029AlexandriaEgypt

In that paper,we new study has been carried out on previous studies of one of the most important mathematical models that describe the global economic movement,and that is described as a non-linear fractional financial model of awareness,where the studies are represented at the steps following:One:The schematic of the model is ***:The disease-free equilibrium point(DFE)and the stability of the equilibrium point are ***:The stability of the model is fulfilled by drawing the Lyapunov exponents and Poincare ***:The existence of uniformly stable solutions have ***:The Caputo is described as the fractional ***:Fractional optimal control for NFFMA is discussed by clarifying the fractional optimal control through drawing before and after ***:Reduced differential transform method(RDTM)and Sumudu Decomposition Method(SDM)are used to take the resolution of an ***,we display that SDM and RDTM are highly identical.

关键词： financial of awareness stability Lyapunov exponents Poincare map fractional optimal control Hamiltonian

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Fractionation and fixation of rare earth elements in soils:Effect of spiking with lanthanum,cerium,and neodymium chlorides

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Journal of Rare Earths 2022年第1期40卷 143-152页

作者： Olga B.Rogova Petr S.Fedotov Rustam kh.Dzhenloda Vasily K.Karandashev V.V.Dokuchaev Soil Science Institute Russian Academy of Sciences7 Building 2 Pyzhevskiy Side StreetMoscow119017Russia V.I.Vernadsky Institute of Geochemistry and Analytical Chemistry Russian Academy of Sciences19 Kosygin StreetMoscow119991 Russia National University of Science and Technology'MISiS' 4 Leninsky ProspectMoscow119049Russia The Institute of Microelectronics Technology and High-Purity Materials Russian Academy of Sciences6 Institution StreetChernogolovka142432Russia

Industrial and agricultural activities lead to the release of rare earth elements(REEs)in wastewater and aquatic ecosystems,and their accumulation in ***,the behavior of REEs in soils remains somewhat *** the present work the fractionation and fixation of REEs in soddy-podzolic and chernozem soils spiked with La,Ce,and Nd chlorides were studied using dynamic(continuous flow)extraction,which allows natural conditions to be mimicked and artefacts to be *** eluents applied are aimed to dissolve exchangeable,specifically sorbed,bound to Mn oxides,bound to metal-organic complexes,and bound to amorphous and poorly ordered Fe/Al oxides fractions extractable by 0.05 mol/L Ca(NO_(3))2,0.43 mol/L CH_(3)COOH,0.1 mol/L NH_(2)OH·HCl,0.1 mol/L K_(4)P_(2)O_(7) at pH 11,and 0.1 mol/L(NH4)_(2)C_(2)O_(4) at pH 3.2,*** is found that the fixations of added La,Ce,and Nd in the form of metal-organic complexes is predominant for both types of soils:35%-38%in soddy-podzolic soil and 50%-79%in *** fixation of added elements in the first three fractions(exchangeable,specifically sorbed,and bound to Mn oxides)is significant for soddy-podzolic soil(5%-25%).For chernozem,the relative contents of added Ce and Nd in these fractions are nearly *** the content of exchangeable La is notable,about 5%.Adding any of three elements(La,Ce,or Nd)at the level of100 mg/kg to an initial sample results in changing the fractionation and bioaccessibility of other REEs present in *** contents increase in the first three fractions and decrease in fifth(oxalate extractable)fraction for both soddy-podzolic soil and *** main difference is the behavior of REEs in pyrophosphate extractable *** soddy-podzolic soil,adding La,Ce,or Nd results in decreasing the contents of other REEs associated with organic *** chernozem,on the contrary,the contents of REEs in the form of metal-organic complexes slightly *** processes

关键词： Rare earth elements Soddy-podzolic soil Chernozem Fractionation Competitive binding

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Hydrothermal analysis of non-Newtonian fluid flow(blood)through the circular tube under prescrib e d non-uniform wall heat flux

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Theoretical & Applied Mechanics Letters 2022年第4期12卷 275-285页

作者： Shahin Faghiri Shahin Akbari Mohammad Behshad Shafii kh.Hosseinzadeh Department of Mechanical Engineering Sharif University of TechnologyTehranIran Sharif Energy Water and Environment Institute(SEWEI)TehranIran

The present article aims to investigate the Graetz-Nusselt problem for blood as a non-Newtonian fluid obeying the power-law constitutive equation and flowing inside the axisymmetric tube subjected to nonuniform surface heat *** the flow field is determined by solving the continuity and the momentum equations,the energy equation is handled by employing the separation of variables *** resulting Eigen functions and Eigen values are numerically calculated using MATLAB built-in solver *** analysis is first conducted for the situation of constant heat flux and subsequently generalized to apply to the case of sinusoidal variation of wall heat flux along the tube length,using Duhamel’s ***,an approximate analytic solution is determined,employing an integral approach to solve the boundary layer *** respect to the comparison,the results of approximate solution display acceptable congruence with those of exact solution with an average error of 7.4%.Interestingly,with decreasing the power-law index,the discrepancy between the two presented methods significantly ***,the influences of the controlling parameters such as surface heat flux and power-law index on the non-Newtonian fluid flow’s thermal characteristics and structure are elaborately *** is found that switching from constant wall heat flux to non-uniform wall heat flux that sinusoidally varies along the tube length significantly improves the simulation’s accuracy due to the better characterization of the heat transport phenomenon in non-Newtonian fluid flow through the *** the presence of sinusoidally varying wall heat flux with an amplitude of 200 W/m 2 and when the power-law index is 0.25,the maximum arterial wall temperature is found to be about 311.56 K.

关键词： Non-newtonian fluid Power-law model Non-uniform heat flux Analytical solution

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Discrete time dynamics of a SIRD reinfection model

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生物数学学报:英文版 2023年第5期16卷 49-70页

作者： F.F.Eshmatov U.U.Jamilov kh.O.khudoyberdiev 221 School 33Feruza Street 100124 TashkentUzbekistan V.I.Romanovskiy Institute of Mathematics Uzbekistan Academy of Sciences 9 University Street100174 TashkentUzbekistan AKFA University 264National Park Street Barkamol MFYYangiabad VillageQibray District 111221 Tashkent RegionUzbekistan National University of Uzbekistan 4 University Street100174 TashkentUzbekistan

This paper deals with a discrete-time dynamical system generated by a modified susceptible-infected-recovered-dead model(SIRD model;nonlinear operator)in threedimensional *** introduce a novel approach that incorporates the SIRD model with the quadratic stochastic operator(QSO)that allows for real-time *** basic reproductive number Ro is *** describe the set of fixed points of the operator and demonstrate that all fixed points are ***,we study the asymptotical behavior of the trajectories of this system and show that SIRD operators havea regularity property.

关键词： Modeling quadratic stochastic operator regular operator

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Hydrothermal analysis of hybrid nanofluid flow on a vertical plate byconsidering slip condition

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Theoretical & Applied Mechanics Letters 2022年第5期12卷 306-314页

作者： M.R.Zangooee kh.Hosseinzadeh D.D.Ganji Department of Mechanical Engineering Payamenoor University(PNU)TehranIran Department of Mechanical Engineering Babol Noshirvani University of TechnologyBabolIran

Hybrid nanofluids have attracted burgeoning attention owing to their outstanding capacity to improve heat *** influence of velocity and temperature slip parameter and nanoparticls’(NPs’)volume fraction on a vertical plate in the existence of suction has been explored in this *** investigation’s controlling partial differentiation equations were transformed into a conventional differential equation mechanism using resemblance *** were then solved employing the fifth-order Runge-Kutta *** skin coefficient of friction,temperature,and temperature gradient all rise when the volume percentage of NPs increases from 0 to 2%.Furthermore,a rise in the temperature slip variable was linked to a drop in the Nusselt number(heat transfer).The Nusselt number increased 0.15%and 5.63%respectively when the velocity slip parameter enhanced from 0 to 5 and the NPs volume percentage were increased from 0 to 1.5%.Furthermore,an increase in the temperature slip from 0 to 3 inflated the x-direction skin friction coefficient 8.2%,while inflation in the velocity slip from 0 to 5 was associated with a decline in the x-direction skin friction coefficient 95%.

关键词： Hybrid nanofluid Stagnation flow Velocity slip Temperature slip

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The effect of a magnetic field on a 2D problem of fibre-reinforced thermoelasticity rotation under three theories

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Chinese Physics B 2012年第6期21卷 264-275页

作者： kh.Lotfy Department of Mathematics Faculty of ScienceZagazig UniversityZagazigP.O.Box 44519Egypt Department of Mathematics Faculty of Science and ArtsAl-mithnabQassim UniversityP.O.Box 931Buridah 51931Al-mithnabKingdom of Saudi Arabia

In the present paper, we introduce the coupled theory （CD）, Lord-Schulman （LS） theory, and Green-Lindsay （GL） theory to study the influences of a magnetic field and rotation on a two-dimensional problem of fibre-reinforced thermoelasticity. The material is a homogeneous isotropic elastic half-space. The method applied here is to use normal mode analysis to solve a thermal shock problem. Some particular cases are also discussed in the context of the problem. Deformation of a body depends on the nature of the force applied as well as the type of boundary conditions. Numerical results for the temperature, displacement, and thermal stress components are given and illustrated graphically in the absence and the presence of the magnetic field and rotation.

关键词： Lord-Schulman theory Green-Lindsay theory coupled theory reinforcement rotation,magnetic field

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Spatio-temporal variation of cyclone intensity over the coastal region of Bangladesh using 134 years track analysis

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Tropical Cyclone Research and Review 2022年第1期11卷 16-25页

作者： Nm Refat Nasher kh Razimul Karim Md Yachin Islam Department of Geography and Environment Jagannath UniversityBangladesh Graduate School of Human Development and Environment Kobe UniversityJapan Center for Environmental and Geographic Information Services(CEGIS) DhakaBangladesh

The cyclone tracks from 1877 to 2020 were analyzed to detect the spatial and temporal *** tracks were gathered from previously published *** previous articles’tracks were digitized and converted to shape files for analysis in Arc-GIS.A total 126 cyclone tracks were used to detect monthly and seasonal cyclone intensity and spatial *** fluctuations were examined over a 30-year period,which is believed to be the climate of a particular *** cyclones hit the Bay of Bengal’s coast starting in May and lasting until *** May and October,the number of cyclones is at its peak(26 nos in each month).From June through September,the number of cyclones *** October and November,the number of cyclones increased *** number of cyclones substantially fell in December,and no cyclones were observed from January through *** 1939 through 1969,the highest number of cyclones(36)was *** the mid-and latetwentieth century,there were a higher number of *** coastal region of Bangladesh suffered the fewest cyclones in history over the recent era(2001–2020).The western shore was particularly vulnerable from 1877 to 1907,and the entire coastal region was dangerous from 1908 to *** the Post-monsoon(October to December)season,the number of cyclones is lower than in the Monsoon period(May to September).In the pre-monsoon season,71 cyclones strike,while in the Monsoon season,53 cyclones strike.

关键词： Digitize Tropical Seasonal Monthly Strike Coastal

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