检索结果-南通市图书馆

Communications in Theoretical Physics 2010年第8期54卷 339-346页

作者： Mohammed H.E.Abu-Sei’leek mahmoud a.hasan Department of Physics Al-Jouf University Middle East University for Graduate Studies

The ground state properties of the spherical nucleus ^40Ca have been investigated by using constrained spherical Hartree Fock （CSHF） approximation at equilibrium and under high radial compression in a six major shells. The effective baryon-baryon interaction that includes the △（1236） resonance freedom degrees to calculate nuclear properties is used. The nucleon-nucleon （N-N） interaction is based on Reid soft core （RSC） potential. The results of calculations show that much of increase in the nuclear energy generated under compression is used to create the massive △ particles. The number of △ ＇s can be increased to about 2.1% of constituents of nucleus when nuclear density reaches about 1.34 times of normal density. The single particle energy levels are calculated and their behavior under compression is also examined. △ good agreement has been found between current calculations and phenomenological shell model for low lying single-particle spectra. The gap between shells is very clear and L-S coupling become stronger as increasing the static load on the nucleus. The results show a considerable reduction in compressibility when freedom degrees of △＇s are taken into account. It has been found that the total nuclear radial density becomes denser in the interior and less dense in the exterior region of nucleus. The surface of nucleus becomes more and more responsive to compression than outer region.

关键词： nuclear structure compressed finite nuclei △-resonance

Effect of the Arrangement of a New-Type of Turbulator Inserts on Heat Pipe Exchanger Performances

在线全文

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2023年第10期19卷 2749-2759页

作者： Ibtisam a.hasan Wafa Maki Department of Electromechanical Engineering The University of TechnologyBaghdadIraq

This research tests the effect of introducing turbulators of a new type into a circular tube heat exchanger under a constant and uniform longitudinal heatﬂux condition.A 45 mm diameter copper tube with a length of 1,350 mm is utilized with a solid disk being inserted inside the tube,which consists of three sections,each one containing two *** slot is cut at a 45 degree angle toward the inner tube surface,which results in diverging theﬂow toward the inner hot tube surface in order to enhance the heat transfer *** is considered as the workingﬂuid with Prandtl number *** Reynolds number spans the interval from 6,000–13,500,which indicates that the consideredﬂow is *** heat exchanger performance is studied and analyzed in terms of average Nusselt *** experimental results show that the Nusselt number value is directly proportional to the increase of the Reynolds number,and the number of turbulators *** the use of three novel turbulators,the heat transfer was about 3.15 times higher than that in the smooth tube and the friction factor was about 1.11.

关键词： Heat pipe exchanger heat transfer inserts(NT inserts) turbulators(novel turbulators) disk(solid disk)

Ru/NiMnB spherical cluster pillar for highly proficient green hydrogen electrocatalyst at high current density

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2025年第1期100卷 397-408页

作者： Md Ahasan Habib Shusen Lin Mehedi hasan Joni Sumiya Akter Dristy Rutuja Mandavkar Jae-Hun Jeong Jihoon Lee Department of Electronic Engineering College of Electronics and Information Kwangwoon University

Advanced OER/HER electrocatalytic alternatives are crucial for the wide adaptation of green hydrogen ***,Ru/NiMnB spherical cluster pillar （SCP）,denoted as Ru/NiMnB,is synthesized using a combination of electro-deposition and hydrothermal *** investigation of Ru doping in the NiMnB matrix revealed significant improvements in electrocatalytic *** Ru/NiMnB SCPs demonstrate superior OER/HER activity with low overpotentials of 150 and 103 mV at 50mA/cm2in 1 M KOH,making them highly competitive with state-of-the-art ***,the Ru/NiMnB SCPs exhibit a low 2-E cell voltage of 2.80 V at ultra-high current density of 2,000 m A/cm2in 1 M KOH,outperforming the standard benchmark electrodes of RuO2||Pt/C,thereby positioning Ru/NiMnB as one of the best bifunctional *** SCPs exhibit exceptional high-current characteristics,stability and corrosion resistance,as evidenced by continuous operation at 1,000 mA/cm2high-current density for over 150 h in 6 M KOH at elevated temperatures under harsh industrial *** a small amount of Ru incorporation significantly enhances the electrocatalytic performances of NiMnB,attributed to increased active sites and improved intrinsic properties such as conductivity,adsorption/desorption capability and reaction ***,Ru/NiMnB SCPs present a promising bi-functional electrode concept for efficient green H2production.

关键词： Advanced electrocatalyst High current Corrosion resistance Industrial requirement

Carbonate rocks resistivity determination using dual and triple porosity conductivity models

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Petroleum 2020年第1期6卷 35-42页

作者： Zeeshan Tariq Mohamed mahmoud hasan Al-Youssef Mohammad Rasheed Khan Department of Petroleum Engineering King Fahd University of Petroleum&MineralsDhahran31261Saudi Arabia

The rocks may be classified as Archie rocks or Non-Archie rocks,depending on the link between pore structure and resistivity of the *** carbonate rocks,keeping this factor in view,the applicability of Archie's law tends to be unreasonable and employing Archie's equation will ultimately lead to inaccurate estimates of the water *** investigators have reported models that forms a link between laboratory results and field well logs to determine water saturation in intricate pore *** case of complex systems,Archie's law fails to correctly define the resistivity-index *** addition,it is imperative to carry out investigations at lower saturation values in order to elaborate the non-Archie *** brings the dual and triple porosity conductivity models into the *** these models are essential in defining the considerable changes of the resistivity-index curves,both qualitatively and *** linkage between the two models is depicted electrically in series or in ***,it is possible to have a combination of the two *** a result,the experimental results can be modeled accurately using least *** work presents two models to determine water saturation in carbonate rocks,containing dual and triple porosity *** study also investigates the impact of different influential parameters such as saturation exponents,conductivity ratios,and pore volume fraction of each network systems,on the new ***,the effect of each parameter is individually studied and the sensitivity analysis on the RI curves is produced.A new approach to apply these models is also explained which requires the use of NMR log,mercury injection capillary pressure(MICP)measurement,and simple plotting techniques to determine the water *** proposed new models help petrophysicists to estimate water saturation in Non-Archie rocks,containing double and triple porosity network systems.

关键词： Dual porosity Triple porosity Carbonate rocks Water saturation models

Design,Analysis,and Torque and Induced Phase Voltage Improvement of an Axial-flux Permanent-magnet Synchronous Machine

在线全文

学校读者我要写书评

暂无评论

CES Transactions on Electrical Machines and Systems 2024年第4期8卷 404-413页

作者： mahmoud-Reza Kheiri Arash Kiyoumarsi hasan Zamani Department of Electrical Engineering University of IsfahanIsfahan ***Iran

In this manuscript,a new axial-flux permanentmagnet machine(AFPMM)is designed,analyzed,improved,and successfully tested.A double-sided AFPM generator with four layers of stator winding is initially designed using a well-known quasi-3D analytical ***,the designed machine is simulated using commercial *** is shown that modification techniques are required to improve the performance of both the torque ripple and the ratio of the third to the fundamental harmonics of the induced ***,a new improvement technique is proposed,in which the layers of the stator winding are shifted relative to each *** this new technique significantly improves the third harmonic problem,the design still has a high torque ripple and,thus,it is suggested to combine the proposed method with the conventional magnet shifting *** is revealed numerically that the resulting combination properly resolves both third harmonic and torque ripple ***,this design is considered the main design of the present *** the end,a prototype of the main design is manufactured and *** is shown that the measurement results are in good agreement with those of numerical software.

关键词： Axial-flux permanent-magnet(AFPM)machines Third-harmonic reduction Torque ripple reduction

Accelerating the elimination of hepatitis C in Kuwait: An expert opinion

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2020年第30期26卷 4415-4427页

作者： Fuad hasan Ahmad Alfadhli Abeer Al-Gharabally mahmoud Alkhaldi Massimo Colombo Jeffrey V Lazarus Department of Internal Medicine Faculty of MedicineKuwait UniversityKuwait 12037Kuwait Department of Gastroenterology Amiri HospitalKuwait 13041Kuwait Public Health Department Ministry of HealthKuwait 13110Kuwait Head Center of Translational Research in Hepatology Humanitas Clinical and Research CenterRozzano 20089Italy Barcelona Institute for Global Health Barcelona Institute for Global Health(ISGlobal)University of BarcelonaBarcelona 08036Spain

The hepatitis C virus(HCV)is estimated to affect 71 million people *** 2016,the World Health Organization adopted the first global health sector strategy to eliminate viral hepatitis as a public health threat by *** December 2018,the European Association for the Study of the Liver,International Liver Foundation convened an expert panel to address the elimination of HCV in *** steps have already been taken to eliminate HCV in Kuwait,including free HCV treatment for Kuwait’s citizens,high blood safety standards,and the implementation of screening and awareness *** expert panel made several recommendations aimed at accelerating the elimination of HCV in Kuwait:The development of a national strategy and action plan to guide all HCV elimination activities;the formation of a coordination mechanism to support collaboration between hepatitis working committees;the prioritization of microelimination at primary,secondary or tertiary facilities,in prisons and rehabilitation centers;and ensuring the involvement of multiple stakeholders–including relevant civil society groups–in all *** screening and linkage to care should be prioritized in Kuwait,with the expansion of the prescriber base to primary healthcare providers and nurse practitioners to be *** awareness and educating people about HCV infection also remain essential to achieve the goal of HCV ***,a national HCV registry should be developed to help monitor the implementation of viral hepatitis plans and progress towards achieving national and international targets.

关键词： Awareness Hepatitis C virus Kuwait Micro-elimination Registries Prescribers

Minimizing Buoyancy Factor of Metallic Pressure-Hull Subjected to Hydrostatic Pressure

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Intelligent Automation & Soft Computing 2023年第1期35卷 769-793页

作者： mahmoud Helal Elsayed Fathallah Abdulaziz H Alghtani Hussein Shawki Osman Jong Wan Hu hasan Eleashy Department of Mechanical Engineering Faculty of EngineeringTaif UniversityTaif 21944Saudi Arabia Production and Mechanical Design Department Faculty of EngineeringMansoura UniversityMansoura 35516Egypt Civil Engineering Department M.T.C.Kobry ElkobbaCairo 11865Egypt Ships and Submarines Engineering Department Military Technical CollegeCairo 11865Egypt Civil Engineering Department Sohag UniversitySohag 82524Egypt Department of Civil and Environmental Engineering Incheon National UniversityIncheon 22012Korea Incheon Disaster Prevention Research Center Incheon National UniversityIncheon 22012Korea Mechanical Engineering Department Faculty of Engineering&TechnologyFuture University in EgyptCairo 11835Egypt

To increase the payload,reduce energy consumption,improve work efficiency and therefore must accordingly reduce the total hull weight of the *** paper introduces a design optimization process for the pressurehull of submarines under uniform external hydrostatic pressure using bothfinite element analysis(FEA)and optimization tools.A comprehensive study about the optimum design of the pressure hull,to minimize the weight and increase the volume,to reach minimum buoyancy factor and maximum operating depth minimizing the buoyancy factor(B.F)is taken as an objective function with constraints of plate and frame yielding,general instability and *** optimization process contains many design variables such as pressure-hull plate thickness,unsupported spacing,dimensions of long and ring beams andfinally the elliptical submersible pressure-hull *** optimization process was conducted using ANSYS parametric design language(APDL)and *** Multi-Island Genetic Algorithm(G.A)is considered to conduct the optimization ***,parametric analysis is done on the pressure hull to examine the effect of different design variables on the pressure-hull *** a result,the B.F of the proposed optimal model is reduced by an average of 31.78%compared with Reference Model(RM).Maximum von Mises stress is reduced by 27%as *** results can be helpful for submarine pressure-hull designers.

关键词： Buoyancy factor pressure-hull material failure ANSYS ISIGHT general instability

Earthquake behavior of steel cushion-implemented reinforced concrete frames

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2018年第2期17卷 385-401页

作者： hasan Ozkaynak Beykent University Civil Engineering DepartmentIstanbulTurkey

The earthquake performance of vulnerable structures can be increased by the implementation of supplementary energy-dissipative metallic *** main aim of this paper is to describe the earthquake behavior of steel cushionimplemented reinforced concrete frames（SCI-RCFR）in terms of displacement demands and energy *** quasi-static experiments were performed on steel cushions（SC）installed in reinforced concrete（RC）*** test results served as the basis of the analytical models of SCs and a bare reinforced concrete frame（B-RCFR）.These models were integrated in order to obtain the resulting analytical model of the ***-time history analyses（NTHA）were performed on the SCI-RCFR under the effects of the selected earthquake data *** to the NTHA,SC application is an effective technique for increasing the seismic performance of RC *** main portion of the earthquake input energy was dissipated through *** succeeded in decreasing the plastic energy demand on structural elements by almost 50% at distinct drift levels.

关键词： steel cushion energy dissipation non-linear time history analysis seismic performance

Dynamic response of an alluvial valley consists of three types of soil

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2020年第2期19卷 289-305页

作者： hasan Faik Kara Civil Engineering Department Trakya UniversityTurkey

Dynamic response of an alluvial valley consisting of three different types of soil was *** the twodimensional model,the alluvial valley was assumed to have half-cylindrical *** alluvial valley contained three different types of soil with different *** valley was surrounded by a *** of the soil types and the half-space were assumed to be isotropic,homogeneous and linear *** half-space was excited by simple harmonic SH-waves radiated from a strike-slip *** fault was assumed to have circular-arc shape in the mathematical *** governing equations were solved by using wave function expansion method where boundary conditions were relatively *** the regions where boundary conditions were more complex,finite difference method was ***,the wave propagation problem was solved *** obtained numerical results showed that surface displacement amplitudes are significantly affected by the material properties of the different soil types of the alluvial *** was also observed that the shapes of the soil types in the alluvial valley played a considerable role in surface displacements.

关键词： cylindrical SH-waves alluvial valley strike-slip fault

Performance Comparison of Hyper-V and KVM for Cryptographic Tasks in Cloud Computing

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第2期78卷 2023-2045页

作者： Nader Abdel Karim Osama A.Khashan Waleed K.Abdulraheem Moutaz Alazab hasan Kanaker mahmoud E.Farfoura Mohammad Alshinwan Department of Intelligent Systems Faculty of Artificial IntelligenceAl-Balqa Applied UniversityAl-Salt1705Jordan Research and Innovation Centers Rabdan AcademyP.O.Box 114646Abu DhabiUnited Arab Emirates Department of Information Systems and Networks TheWorld Islamic Sciences and Education UniversityAmman11947Jordan Department of Cyber Security Isra UniversityAmman1162Jordan Faculty of Science and Information Technology Al-Zaytoonah University of JordanAmman11733Jordan Middle East University Research Unit Middle East UniversityAmman11831Jordan

As the extensive use of cloud computing raises questions about the security of any personal data stored there,cryptography is being used more frequently as a security tool to protect data confidentiality and privacy in the cloud environment.A hypervisor is a virtualization software used in cloud hosting to divide and allocate resources on various pieces of *** choice of hypervisor can significantly impact the performance of cryptographic operations in the cloud *** important issue that must be carefully examined is that no hypervisor is completely superior in terms of performance;Each hypervisor should be examined to meet specific *** main objective of this study is to provide accurate results to compare the performance of Hyper-V and Kernel-based Virtual Machine(KVM)while implementing different cryptographic algorithms to guide cloud service providers and end users in choosing the most suitable hypervisor for their cryptographic *** study evaluated the efficiency of two hypervisors,Hyper-V and KVM,in implementing six cryptographic algorithms:Rivest,Shamir,Adleman(RSA),Advanced Encryption Standard(AES),Triple Data Encryption Standard(TripleDES),Carlisle Adams and Stafford Tavares(CAST-128),BLOWFISH,and *** study’s findings show that KVM outperforms Hyper-V,with 12.2%less Central Processing Unit(CPU)use and 12.95%less time overall for encryption and decryption operations with various file *** study’s findings emphasize how crucial it is to pick a hypervisor that is appropriate for cryptographic needs in a cloud environment,which could assist both cloud service providers and end *** research may focus more on how various hypervisors perform while handling cryptographic workloads.

关键词： Cloud computing performance virtualization hypervisors Hyper-V KVM cryptographic algorithm