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Journal of Hydrodynamics 2005年第2期17卷 209-215页

作者： AL-saif A.S.J. Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China

The problem of two-dimensional steady flow of an incompressible second-order viscoelastic fluid coupled with heat transfer between parallel plates was considered. A viscous dissipation function was included in the energy equation. When the elastic property of the fluid is weaker, the zeroth-order and first-order approximate governing equations were obtained by means of the perturbation method. To understand the behavior of flow near the tube wall, the half-domain was divided into two sub-domains, in which one is a thin layer near the wall called the inner domain and the remainder is called the outer domain. The governing equations in the inner domain and in the outer domain were discretized respectively by using the Differential Quadrature Method (DQM). The matching conditions at the interface between the inner and outer domains were presented. An iterative method for solving these discretized equations was given in this paper. The numerical results obtained agree with existing results.

关键词： momentum equations heat equation second-order viscoelastic fluid Differential Quadrature Method (DQM)

Assessment of BRRI Whole Feed Combine Harvester (Model BRRI WCH2021) for Mechanized Rice Harvesting in Bangladesh

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Agricultural Sciences 2024年第2期15卷 274-291页

作者： Arafat ullah Khan Akm saiful Islam Md. Kamruzzaman Pintu Subrata Paul Md. Durrul Huda Md. Anwar Hossen Md. Monirul Islam Md. Moudud Ahmmed Farm Machinery and Postharvest Technology Division Bangladesh Rice Research Institute Gazipur Bangladesh Workshop Machinery & Maintenance Division Bangladesh Rice Research Institute Gazipur Bangladesh

Agricultural mechanization plays a pivotal role in the transition from subsistence to commercial agriculture, with a particular focus on labour-intensive activities like harvesting. This study assesses the operational characteristics of the BRRI Whole Feed Combine Harvester (Model BRRI WCH2021) at the field level. Developed under the SFMRA project, the harvester’s technical performance and loss assessment were conducted during the Boro 2022 and Aman 2022 seasons in farmer fields in Bangladesh’s Rangpur region. The field efficiency of the harvester was determined to be 62.5% and 57.9% in the Boro and Aman seasons, respectively. Fuel consumption rates were recorded at 2.77 l/ha and 2.31 l/ha for the Boro and Aman seasons. The total harvesting losses, encompassing cutter bar, shatter, cylinder, and separation loss, averaged 0.56% and 0.48% in the Boro and Aman seasons, respectively. Mechanized harvesting with the BRRI Whole Feed Combine Harvester significantly reduced paddy losses by 5.81% compared to manual methods. The field evaluation results indicate the combine harvester’s satisfactory performance, highlighting its potential to alleviate labour demands during peak harvesting. The development of the BRRI WCH offers a sustainable solution for rice harvesting mechanization among progressive farmers. It paves the way for the broader adoption of advanced agricultural technology in Bangladesh.

关键词： BRRI Whole Feed Combine Harvester Field Efficiency Fuel Consumption Harvesting Loss

Lifetime Estimation Based on Surface Degradation and Characterization of HTV Silicone-rubber Based Composites for HVAC and HVDC Transmission

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CSEE Journal of Power and Energy Systems 2023年第2期9卷 751-758页

作者： Rahmat ullah Muhammad Akbar Faculty of Electrical Engineering GIK Institute of Engineering Sciences and TecnologyTopi23460 Pakistan

In this paper,six different types of silicone rubberbased composites were investigated for applications in high voltage insulation through multi-stress accelerated aging conducted for a period of 5000 h both under AC and DC *** main goal of this study was lifetime prediction of HTV-SR based composites at a typical multi-stress aging *** diagnostic techniques such as hydrophobicity assessment,leakage current measurement and FTIR were incorporated to assess the *** an outcome of this investigation,all the five hybrid samples were found as quite resistant to aging while the neat sample was comparatively,less resistant to the ***,among the studied samples,TS2 and TS4 appeared to have shown the highest resistance to aging giving a service life of 43.2 and 42 years,respectively under AC *** DC stress the order of merit of investigated samples was identical to that of AC stress but having marginally less life spans.

关键词： ATH hydrophobicity classification leakage current life time prediction multi-stress accelerated aging silica

Methanolic extract from Lespedeza bicolor： potential candidates for natural antioxidant and anticancer agent

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Journal of Traditional Chinese Medicine 2017年第4期37卷 444-451页

作者： Sami ullah Department of Botany University of PeshawarPeshawar 24420 Pakistan

OBJECTIVE: To evaluate the anticancer, antioxidant and antimicrobial activities along with total phenolic and flavonoids contents extracted from Lespedeza bicolor indigenous to Khyber Pukhtoonkhwa ***: Anticancer activity against human lung carcinoma(LU-1) and human prostate carcinoma(Ln Cap), antimicrobial against Aspergillus fumigates, Aspergillus niger, Fusarium solani, Mucor sp Klebsiella pneumonia and Enterococcus and antioxidant activity on 1,1-Diphenyl-2-picryl-hydrazy(DPPH) and Hydrogen peroxide radicals scavenging activity were assessed in methanol extract o Lespedeza ***: Lespedeza bicolor aerial parts and root extract showed IC_(50)value of 12.5 and 50 μg/m L against LU-1 whereas, ≤ 12.5 and 12 μg/m L were calculated against Ln Cap cell line. Minimum inhibition concentration(MIC) value of 20-35 μg/m L has been observed against Aspergillus fumigates, Aspergillus niger, Fusarium solani and Mucor sp in comparision with 1-2.5 μg/m L of Terbinafine used as a standard fungicide. MIC value of 20 and 35 μg/m L of Lespedeza bicolor aerial parts and root extract against bacterial pathogen Klebsiella pneumonia and 20-50 μg/m L against Enterococcus has been measured. DPPH radical scavenging activity of Lespedeza bicolor with IC_(50)values of ≤ 50 μg/m L and ≤ 200 μg/m L was observed whereas, hydrogen peroxide scavenging activity with IC_(50)values of ≤25 μg/m L for aerial parts and ≤ 50 μg/m L for the root extract of Lespedeza bicolor has been ***: These data suggested that the methanolic extract of Lespedeza bicolor could be potential candidates for natural antioxidants and anticancer.

关键词： Lespedeza Antineoplastic agents Antioxidants Anti-infective agents

Modification of the spectra of correlated charm-anticharm quark pairs in the quark-gluon plasma

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Chinese Physics C 2020年第5期44卷 56-62页

作者： Ismat ullah Min He Department of Applied Physics Nanjing University of Science and TechnologyNanjing 210094China

Heavy quarks play an important role in probing the properties of strongly interacting quark-gluon plasma(QGP)created in ultra-relativistic heavy-ion *** study the interactions of single heavy(charm)quarks and correlated charm and anticharm(ccˉ)quark pairs with the medium constituents of QGP by performing fireball+Langevin simulations of the pertinent Brownian motion with elastic *** studying the traditional observables,the nuclear modification factor and the elliptic flow of single heavy quarks in QGP for different thermal relaxation rates,we also study the broadening of the azimuthal correlations of charm and anticharm quark pairs in the QGP medium for different relaxation rates and transverse momenta *** quantified the smearing of ccˉpair azimuthal correlations with an increasing thermal relaxation rate:while the(nearly)back-to-back correlations among ccˉpairs are almost completely washed out at low transverse momentum(pT),these correlations at high pT largely survive the pair *** provides a novel observable for diagnosing the properties of QGP.

关键词： quark-gluon plasma heavy quarks Brownian motion Langevin simulation

Boron nitride-based electrocatalysts for HER,OER,and ORR:A mini-review

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Frontiers of Materials Science 2021年第4期15卷 543-552页

作者： Nabi ullah Rizwan ullah Saraf KHAN Yuanguo XU School of Materials Science and Engineering Jiangsu UniversityZhenjiang 212013China School of Chemistry and Chemical Engineering Jiangsu UniversityZhenjiang 212013China National Centre of Excellence in Physical Chemistry University of PeshawarPeshawar25120Pakistan Institute of Chemical Sciences University of PeshawarKhyber Pakhtunkhwa25120Pakistan

A reliable and efficient solution to the current energy crisis and its associated environmental issues is provided by fuel cells,metal-air batteries and overall water *** heart reactions for these technologies are oxygen reduction reaction(ORR),oxygen evolution reaction(OER)and hydrogen evolution reaction(HER).Different supporters such as graphene,carbon nanotube,and graphitic carbon nitride have been used to avoid agglomeration of active materials and provide maximum active surface for these *** all the supporters,boron nitride(BN)gains extensive research attention due to its analogue with graphene and excellent stability with good oxidation and chemical *** this mini-review,the well-known strategies(exfoliation,annealing,and CVD)used in the synthesis of BN with different morphologies for HER,OER and ORR applications have been briefly debated and *** comparative analysis determines that the performance and stability of state-of-the-art electrocatalysts can be further boosted if they are deposited on *** is revealed that BN-based catalysts for HER,OER and ORR are rarely studied yet especially with non-noble transition metals,and this research direction should be studied deeply in future for practical applications.

关键词： boron nitride electrocatalyst hydrogen evolution reaction oxygen evolution reaction oxygen reduction reaction

Moisture Transport over the Arabian Sea Associated with Summer Rainfall over Pakistan in 1994 and 2002

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Advances in Atmospheric Sciences 2012年第3期29卷 501-508页

作者： Kalim ullah 高守亭 Laboratory of Cloud-Precipitation Physics and Severe Storms Institute of Atmospheric Physics Chinese Academy of Sciences Graduate University of the Chinese Academy of Sciences Department of Meteorology COMSATS Institute of Information TechnologyIslamabadPakistan

In this study, we aimed to elucidate the critical role of moisture transport affecting monsoon activity in two contrasting summers over the Arabian Sea during the years 1994, a relatively wet year, and 2002, a relatively dry year. A comprehensive diagnostic evaluation and comparisons of the moisture fields were con- ducted; we focused on the precipitation and evaporation as well as the moisture transport and its divergence or convergence in the atmosphere. Monthly mean reanalysis data were obtained from the National Centers for Environmental Prediction （NCEP-I and -II）. A detailed evaluation of the moisture budgets over Pak- istan during these two years was made by calculating the latent energy flux at the surface （E - P） from the divergence of the total moisture transport. Our results confirm the moisture supply over the Arabian Sea to be the major source of rainfall in Pakistan and neighboring regions. In 1994, Pakistan received more rainfall compared to 2002 during the summer monsoon. Moisture flow deepens and strengthens over Arabian Sea during the peak summer monsoon months of July and August. Our analysis shows that vertically integrated moisture transport flux have a significant role in supplying moisture to the convective centers over Pakistan and neighboring regions from the divergent regions of the Arabian Sea and the Bay of Bengal. Moreover, in 1994, a deeper vertically integrated moisture convergence progression occurred over Pakistan compared to that in 2002. Perhaps that deeper convergence resulted in a more intense moisture depression over Pakistan and also caused more rainfall in 1994 during the summer monsoon. Finally, from the water budget analysis, it has been surmised that the water budget was larger in 1994 than in 2002 during the summer monsoon.

关键词： moisture flux moisture convergence convection heavy rainfall

Improved Software Implementation for Montgomery Elliptic Curve Cryptosystem

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Computers, Materials & Continua 2022年第3期70卷 4847-4865页

作者： Mohammad Al-Khatib Wafaa saif Computer Science Department College of Computer and Information SciencesImam Mohammad Ibn Saud Islamic University(IMSIU)RiyadhSaudi Arabia

The last decade witnessed rapid increase in multimedia and other applications that require transmitting and protecting huge amount of data streams *** such applications,a high-performance cryptosystem is compulsory to provide necessary security *** curve cryptosystem(ECC)has been introduced as a considerable ***,the usual sequential implementation of ECC and the standard elliptic curve(EC)form cannot achieve required performance ***,the widely used Hardware implementation of ECC is costly option and may be not *** research aims to develop a high-performance parallel software implementation for *** achieve this,many experiments were performed to examine several factors affecting ECC performance including the projective coordinates,the scalar multiplication algorithm,the elliptic curve(EC)form,and the parallel *** ECC performance was analyzed using the different factors to tune-up them and select the best choices to increase the speed of the *** results illustrated that parallel Montgomery ECC implementation using homogenous projection achieves the highest performance level,since it scored the shortest time delay for ECC *** addition,results showed thatNAF algorithm consumes less time to perform encryption and scalar multiplication operations in comparison withMontgomery ladder and *** multi-threading technique was adopted to implement ECC computations in *** proposed multithreaded Montgomery ECC implementation significantly improves the performance level compared to previously presented parallel and sequential implementations.

关键词： Elliptic curve cryptosystem parallel software implementation multi-threading scalar multiplication algorithms modular arithmetic

Curve25519 based lightweight end-to-end encryption in resource constrained autonomous 8-bit IoT devices

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Cybersecurity 2021年第1期4卷 147-159页

作者： Shafi ullah Raja Zahilah School of Computing Faculty of EngineeringUniversiti Teknologi Malaysia81310 Johor BahruJohorMalaysia

Robust encryption techniques require heavy computational capability and consume large amount of memory which are unaffordable for resource constrained IoT devices and Cyber-Physical Systems with an inclusion of general-purpose data manipulation *** encryption techniques have been introduced to address the inability of such devices,lacking in robust security provision at low *** article presents an encryption technique,implemented on a resource constrained IoT device(AVR ATmega2560)through utilizing fast execution and less memory consumption properties of curve25519 in a novel and efficient lightweight hash *** hash function utilizes GMP library for multi-precision arithmetic calculations and pre-calculated curve points to devise a good cipher block using ECDH based key exchange protocols and large random prime number generator function.

关键词： Cyber-physical systems IoT Resource constrained IoT devices Lightweight encryption End-to-end encryption Elliptic curve cryptography Curve25519

Structure-based discovery of *** phytochemicals as potential inhibitors against Monkeypox(mpox)viral protein

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Journal of Biosafety and Biosecurity 2024年第3期6卷 157-169页

作者： Ranjan K.Mohapatra Ahmed Mahal Pranab K.Mohapatra Ashish K.Sarangi Snehasish Mishra Meshari A.Alsuwat Nada N.Alshehri Sozan M.Abdelkhalig Mohammed Garout Mohammed Aljeldah Ahmad A.Alshehri Ahmed saif Mohammed Abdulrahman Alshahrani Ali S.Alqahtani Yahya A.Almutawif Hamza M.A.Eid Faisal M Albaqami Mohnad Abdalla Ali A.Rabaan Department of Chemistry Government College of EngineeringKeonjhar 758002OdishaIndia Department of Medical Biochemical Analysis College of Health TechnologyCihan University–ErbilErbilKurdistan RegionIraq Department of Chemistry CV Raman Global UniversityBhubaneswarOdishaIndia Department of Chemistry School of Applied SciencesCenturion University of Technology and ManagementBalangirOdishaIndia School of Biotechnology Campus-11KIIT Deemed-to-be-UniversityBhubaneswar 751024OdishaIndia Clinical Laboratory Sciences Department College of Applied Medical SciencesTaif UniversityAl-Taif 21974Saudi Arabia Internal Medicine Department King Khalid University Medical CityCollege of MedicineAbha 61481Saudi Arabia Department of Basic Medical Sciences College of MedicineAlMaarefa UniversityRiyadhSaudi Arabia Department of Community Medicine and Health Care for Pilgrims Faculty of MedicineUmm Al-Qura UniversityMakkah 21955Saudi Arabia Department of Clinical Laboratory Sciences College of Applied Medical SciencesUniversity of Hafr Al BatinHafr Al Batin 39831Saudi Arabia Department of Clinical Laboratory Sciences Faculty of Applied Medical SciencesNajran UniversityNajran 61441Saudi Arabia Department of Medical Laboratory Sciences Faculty of Applied Medical SciencesKing Khalid UniversityAbha 61481Saudi Arabia mDepartment of Medical Laboratories Technology College of Applied Medical SciencesTaibah UniversityMadinah 41411Saudi Arabia Biology Department College of ScienceIslamic University of MadinahMadinah 42351Saudi Arabia Pediatric Research Institute Children’s Hospital Affiliated to Shandong UniversityJinanShandong 250022China Molecular Diagnostic Laboratory Johns Hopkins Aramco HealthcareDhahran 31311Saudi Arabia College of Medicine Alfaisal UniversityRiyadh 11533Saudi Arabia Department of Public Health and Nutrition The University of HaripurHaripur 22610Pakistan

Outbreaks of Monkeypox(mpox)in over 100 non-endemic countries in 2022 represented a serious global health *** a neglected disease,mpox has become a global public health issue.A42R profilinlike protein from mpox(PDB ID:4QWO)represents a potential new lead for drug development and may interact with various synthetic and natural *** this report,the interaction of A42R profilinlike protein with six phytochemicals found in the medicinal plant Ficus religiosa(abundant in India)was *** on the predicted and compared protein–ligand binding energies,biological properties,IC_(50) values and toxicity,two compounds,kaempferol(C-1)and piperine(C-4),were *** characteristics and quantitative structure–activity relationship(QSAR)of these two compounds were determined,and molecular dynamics(MD)simulations were *** silico examination of the kaempferol(C-1)and piperine(C-4)interactions with A42R profilin-like protein gave best-pose ligandbinding energies of–6.98 and–5.57 kcal/mol,*** predicted IC_(50) of C-1 was 7.63 lM and 82 lM for *** data indicated that kaempferol and piperine are non-mutagenic,and the QSAR data revealed that piperlongumine(5.92)and piperine(5.25)had higher log P values than the other compounds *** simulations of A42R profilin-like protein in complex with C-1 and C-4 were performed to examine the stability of the ligand–protein ***/C and C-4 showed the highest affinity and activities,they may be suitable lead candidates for developing mpox therapeutic *** study should facilitate discovering and synthesizing innovative therapeutics to address other infectious diseases.

关键词： Monkeypox Mpox Phytochemical Molecular docking MD simulation ADMET QSAR