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Development of multi-physics numerical simulation model to investigate thermo-mechanical fatigue crack propagation in an autofrettaged gun barrel

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Defence Technology（防务技术） 2021年第5期17卷 1579-1591页

作者： Naveed Hussain Faisal Qayyum Riffat Asim Pasha masood shah Department of Mechanical Engineering University of Engineering and TechnologyTaxilaPakistan Institut für Metallformung Technische Universitat BeragakademieFreibergGermany

In this research,a detailed multi-physics study has been carried out by numerically simulating a solid fractured gun barrel for 20 thermo-mechanical *** numerical model is based on thermal effects,mechanical stress fields and fatigue crack ***-plastic material data of modified AISI 4340 at temperatures ranging from 25 to 1200℃and at strain rates of 4,16,32 and 48 s^(-1) was acquired from high-temperature compression *** was used as material property data in the simulation *** boundary conditions applied are kept similar to the working gun barrel during continuous firing.A methodology has been provided to define thermo-mechanically active surface-to-surface type interface between the crack faces for a better approximation of stresses at the crack *** of results from non-autofrettaged and autofrettaged simulation models provide useful information about the evolution of strains and stresses in the barrel at different points under combined thermo-mechanical loading cycles in both *** effect of thermal fatigue under already induced compressive yield due to autofrettage and the progressive degradation of the accumulated stresses due to thermo-mechanical cyclic loads on the internal surface of the gun barrel(mimicking the continuous firing scenario)has been *** between energy release rate at tips of varying crack lengths due to cyclic thermo-mechanical loading in the non-autofrettaged and autofrettaged gun has been carried out.

关键词： Steel Autofrettage Gun barrel Crack propagation Thermo-mechanical fatigue Numerical simulation Residual stress dissipation

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An estimation of stress intensity factor in a clamped SE(T) specimen through numerical simulation and experimental verification:case of FCGR of AISI H11 tool steel

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Acta Metallurgica Sinica(English Letters) 2012年第4期25卷 307-319页

作者： masood shah Catherine Mabru Farhad Rezai-Aria Ines Souki Riffat Asim Pasha Mechanical Engineering Department University of Engineering and TechnologyTaxilaPakistan Department of Mechanics of Structures and Materials University of Toulouse INSA UPSMines AlbiISA ICA(Institute Cl'ement Ader) DMSM F-31056 ToulouseFrance Research Group of Surfaces MachiningMaterials and ToolingUniversity of Toulouse INSA UPSMines AlbiISAE Campus Jarlard F-81013 Albi cedex 09France

A finite element analysis of stress intensity factors （KI） in clamped SE（T）c specimens （dog bone profile） is presented. A J-integral approach is used to calculate the values of stress intensity factors valid for 0.125≤a/W≤0.625. A detailed comparison is made with the work of other researchers on rectangular specimens. Different boundary conditions are explored to best describe the real conditions in the laboratory. A sensitivity study is also presented to explore the effects of variation in specimen position in the grips of the testing machine. Finally the numerically calculated SIF is used to determine an FCGR curve for AISI Hll tool steel on SE（T）c specimens and compared with C（T） specimen of the same material.

关键词： Fatigue crack propagation Stress intensity factor J-Integral Paris law

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Numerical Simulation and Experimental Verification of CMOD in SENT Specimen: Application on FCGR of Welded Tool Steel

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Acta Metallurgica Sinica(English Letters) 2013年第1期26卷 92-96页

作者： Amir SULTAN Riffat Asim PASHA Mifrah ALI Muhammad Zubair KHAN Muhammad Afzal KHAN Naeem Ullah DAR masood shah Department of Mechanical Engineering University of Engineering and Technology International Islamic University

Single-edged notched tension （SENT） specimen is used to study the fatigue crack growth rate （FCGR） behavior of AISI 50100 steel using MTS 810. Calibration tests are run to get plots of crack mouth opening displacement （CMOD） vs. load and CMOD vs. crack length-to-width ratio with the known crack lengths. Numerical simulation is also done to try to establish a relation between crack length and CMOD. FCGR of welded and un-welded specimens are plotted against stress intensity factor range to show the effect of welding on fatigue crack growth rate of AISI 50100 steel. The experimentally obtained CMOD values are compared with values obtained by numerical simulation using ABAQUS/StandardTM software package. Results show that numerical values are in good agreement with experimental data for small crack lengths and lower values of applied load,

关键词： Tool steel Weld Single-edged notched tension (SENT) CMOD Fatigue crackgrowth rate (FCGR)

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Introgression of Drought Tolerance into Elite Basmati Rice Variety through Marker-Assisted Backcrossing

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Phyton-International Journal of Experimental Botany 2023年第5期92卷 1421-1438页

作者： Muhammad Sabar shahzad Amir Naveed shahid masood shah Abdul Rehman Khan Muhammad Musaddiq shah Tahir Awan Muhammad Ramzan Khan Zaheer Abbas Muhammad Arif National Institute for Biotechnology and Genetic Engineering(NIBGE) Faisalabad38000Pakistan Rice Research Institute Kala Shah Kaku39020Pakistan National Institute for Genomics and Advanced Biotechnology(NIGAB) Islamabad44000Pakistan Institute of Crop Sciences Chinese Academy of Agricultural SciencesBeijing100081China Department of Biotechnology COMSATS University IslamabadAbbottabad22020Pakistan Department of Biotechnology University of SialkotSialkot51310Pakistan Pakistan Institute of Engineering and Applied Sciences Islamabad44000Pakistan

Drought is one of the major abiotic threat to rice production in the context of climate *** Basmati is an elite,fine grain basmati rice variety grown in Punjab,*** to drought sensitive in nature,its yield has been facing an alarming situation in production because of gradual decrease in irrigated water for a couple of *** reported novel QTLs for drought tolerance were selected for incorporation into Super Basmati by employing marker assisted selection ***55419-04 with novel QTLs was used as a donor *** selection was performed by applying PCR based QTL linked SSR markers followed by recombinant selection by using 2-4 flanking *** selection was exercised by using polymorphic SSR markers for maximum genome recovery of the Super *** individuals homozygous at the target QTLs and with maximum background of Super Basmati at the rest of the non-target genome was selected for evaluation of drought *** drought stress conditions,the yields of all introgressed lines(ILs)were 44.2%-125.7%higher than recurrent *** superior ILs that are drought tolerant and very similar to Super Basmati in terms of agronomic and grain quality traits are marked for release as drought-tolerant varieties in arid regions or for use in breeding programs of high grain quality and drought-tolerant parents.

关键词： Drought QTL SSR markers basmati rice drought marker assisted breeding

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Rice molecular markers and genetic mapping:Current status and prospects

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Journal of Integrative Agriculture 2017年第9期16卷 1879-1891页

作者： Ghulam Shabir Kashif Aslam Abdul Rehman Khan Muhammad shahid Hamid Manzoor Sibgha Noreen Mueen Alam Khan Muhammad Baber Muhammad Sabar shahid masood shah Muhammad Arif National Institute for Biotechnology and Genetic Engineering(NIBGE) Faisalabad 38000Pakistan Biotechnology Program Environmental SciencesCOMSA TS Institute of Information TechnologyAbbottabad 22010Pakistan Institute of Molecular Biology and Biotechnology Bahauddin Zakariya UniversityMultan 60000Pakistan Rice Research Institute Kala Shah Kaku 39020Pakistan Department of Bioinformatics and Biotechnology Government College UniversityFaisalabad 38000Pakistan Institute of Pure and Applied Biology Bahauddin Zakariya UniversityMultan 60000Pakistan Department of Plant Breeding and Genetics The Islamia University of BahawalpurBahawalpur 63100Pakistan National Center for Soybean Improvement Nanjing Agricultural UniversityNanjing 210095P.R.China

Dramatic changes in climatic conditions that supplement the biotic and abiotic stresses pose severe threat to the sustainable rice production and have made it a difficult task for rice molecular breeders to enhance production and productivity under these stress factors. The main focus of rice molecular breeders is to understand the fundamentals of molecular pathways involved in complex agronomic traits to increase the yield. The availability of complete rice genome sequence and recent improvements in rice genomics research has made it possible to detect and map accurately a large number of genes by using linkage to DNA markers. Linkage mapping is an effective approach to identify the genetic markers which are co-segregating with target traits within the family. The ideas of genetic diversity, quantitative trait locus（QTL） mapping, and marker-assisted selection（MAS） are evolving into more efficient concepts of linkage disequilibrium（LD） also called association mapping and genomic selection（GS）, respectively. The use of cost-effective DNA markers derived from the fine mapped position of the genes for important agronomic traits will provide opportunities for breeders to develop high-yielding, stress-resistant, and better quality rice cultivars. Here we focus on the progress of molecular marker technologies, their application in genetic mapping and evolution of association mapping techniques in rice.

关键词： genetic mapping molecular markers maker assisted selection Oryza sativa L quantitative trait loci

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Potential of Plant Growth Regulators on Modulating Rooting of <i>Rosa centifolia</i>

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American Journal of Plant Sciences 2015年第5期6卷 659-665页

作者： Gulzar Akhtar Ahsan Akram Yasar Sajjad Rashad Mukhtar Balal Muhammad Adnan shahid Hasan Sardar Kaleem Naseem shahid masood shah Department of Horticulture University College of Agriculture University of Sargodha Pakistan Department of Environmental Sciences COMSATS Institute of Information Technology Abbottabad Pakistan Institute of Horticultural Sciences University of Agriculture Faisalabad Pakistan

Rosa centifolia is grown for its flowers which are used for essential oil extraction. It is vegetatively propagated through its cuttings which are difficult to root. This study was designed to increase the rooting percentage of cuttings by applying plant growth regulators (PGRs) with different levels. In total 31 treatments with different concentrations (450 ppm, 700 ppm and 950 ppm) of indole butyric acid (IBA), indole acetic acid (IAA), naphthalene acetic acid (NAA) alone, in combination and with same concentrations of 6-benzylamino purine (BAP) were used. Healthy similar sized cutting of R. centifolia was treated in solution of PGRs by quick dip method and planted in polythene bags. The data for shoot length, shoot dry weight, number of roots, root length and root dry weight were recorded. All three levels (450 ppm, 700 ppm and 950 ppm) of IBA alone produced maximum results in case of all parameters as compared to all other treatments. Among three levels of IBA, 450 ppm concentration produced maximum shoot length (10.67 cm), shoot dry weight (3.02 g), number of roots (14.00), root length (11.90 cm) and root dry weight (0.50 g). Lower concentrations of plant growth regulators produced better results as compared to higher concentrations.

关键词： Growth Regulator Rosa centifolia Auxins Rooting Shooting

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Spectrum of venous thromboembolism in adult patients with ulcerative colitis in Pakistan:A single center retrospective study

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World Journal of Clinical Cases 2025年第6期13卷 9-13页

作者： masood Muhammad Karim Hafsa Shaikh Faisal Wasim Ismail Department of Medicine The Aga Khan University HospitalKarachi 74800Pakistan Department of General Surgery The Aga Khan University HospitalKarachi 74800Pakistan

BACKGROUND Patients with inflammatory bowel disease are at a 2-8-fold higher risk of deve-loping venous thromboembolism(VTE)as compared to the general *** the exact pathogenesis is unclear,the literature suggests that increased risk of thromboembolic events in such patients occurs as a result of increased coagulation factors,inflammatory cytokines,and reduction in anticoagulants leading to a prothrombotic *** To assess the prevalence,risk factors,management,and outcome of ulcerative colitis(UC)patients who develop *** This was a retrospective chart review done in The Gastroenterology Department of The Aga Khan University *** was collected from medical records for all patients admitted with a diagnosis of UC from January 2012 to December *** Seventy-four patients fulfilled the inclusion *** mean±SD of age at presentation of all UC patients was 45 years±10 years whereas for those who developed VTE,it was 47.6 years±14.7 *** and diabetes were the most common co-morbid seen among UC patients with a frequency of 17(22.9%)and 12(16.2%),respectively.A total of 5(6.7%)patients developed *** venous thrombosis was the most common thromboembolic phenomenon seen in 3(60%)*** the patients with UC and concomitant VTE were discharged home(5;100%).CONCLUSION The prevalence of VTE with UC in Pakistani patients corresponds with the international ***,multi-centric studies are required to further explore these results.

关键词： Deep venous thrombosis Inflammatory bowel disease Low-middle-income country Anticoagulation Protein C deficiency

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Alternative Strategy for Development of Dielectric Calcium Copper Titanate‑Based Electrolytes for Low‑Temperature Solid Oxide Fuel Cells

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Nano-Micro Letters 2025年第1期17卷 310-332页

作者： Sajid Rauf Muhammad Bilal Hanif Zuhra Tayyab Matej Veis MAKYousaf shah Naveed Mushtaq Dmitry Medvedev Yibin Tian Chen Xia Martin Motola Bin Zhu College of Mechatronics and Control Engineering Shenzhen UniversityShenzhen 518060People’s Republic of China Department of Inorganic Chemistry Faculty of Natural SciencesComenius University BratislavaIlkovicova684215 BratislavaSlovakia Energy Storage Joint Research Center School of Energy and EnvironmentSoutheast UniversityNanjing 210096People’s Republic of China Hydrogen Energy Laboratory Ural Federal University620002 EkaterinburgRussia Laboratory of Electrochemical Devices Based on Solid Oxide Proton Electrolytes Institute of High Temperature Electrochemistry620066 EkaterinburgRussia School of Microelectronics Hubei UniversityWuhan 430062People’s Republic of China

The development of low-temperature solid oxide fuel cells(LT-SOFCs)is of significant importance for realizing the widespread application of *** has stimulated a substantial materials research effort in developing high oxide-ion conductivity in the electrolyte layer of *** this context,for the first time,a dielectric material,CaCu_(3)Ti_(4)O_(12)(CCTO)is designed for LT-SOFCs electrolyte application in this *** individual CCTO and its heterostructure materials with a p-type Ni_(0.8)Co_(0.15)Al_(0.05)LiO_(2−δ)(NCAL)semiconductor are evaluated as alternative electrolytes in LT-SOFC at 450–550℃.The single cell with the individual CCTO electrolyte exhibits a power output of approximately 263 mW cm^(-2) and an open-circuit voltage(OCV)of 0.95 V at 550℃,while the cell with the CCTO–NCAL heterostructure electrolyte capably delivers an improved power output of approximately 605 mW cm^(-2) along with a higher OCV over 1.0 V,which indicates the introduction of high hole-conducting NCAL into the CCTO could enhance the cell performance rather than inducing any potential short-circuiting *** is found that these promising outcomes are due to the interplay of the dielectric material,its structure,and overall properties that led to improve electrochemical mechanism in CCTO–***,density functional theory calculations provide the detailed information about the electronic and structural properties of the CCTO and NCAL and their heterostructure CCTO–*** study thus provides a new approach for developing new advanced electrolytes for LT-SOFCs.

关键词： LT-SOFCs Dielectric CaCu_(3)Ti_(4)O_(12) Semiconductor Ni_(0.8)Co_(0.15)Al_(0.05)LiO_(2−δ) Ionic conductivity Heterostructure electrolyte

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Influence of Cu doping in Magnesium Hydroxide Nanoparticles for Bandgap Engineering

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Journal of Wuhan University of Technology(Materials Science) 2023年第3期38卷 485-489页

作者： SYED masood Raza S NASEEM shah ADEEL Tahir YASMEEN Bibi Department of Physics Federal Urdu University of ArtsScience&TechnologyKarachiPakistan Department of Chemistry Federal Urdu University of ArtsScience&TechnologyKarachiPakistan

Cu doped Mg(OH)_(2) nanoparticles were synthesized with varying concentrations from 0 to 10%by a chemical synthesis technique of coprecipitation.X-rays diffraction (XRD) of the samples confirms that all the samples acquire the hexagonal crystal *** results indicated the solubility limit of dopant in the host material and the secondary phase of CuO was observed beyond 3%Cu doping in Mg(OH)_(2).The reduction in the size of nanoparticles was observed from 166 to 103 nm for Mg(OH)_(2) and 10% Cu doped Mg(OH)_(2)samples,*** shift in absorption spectra exhibited the systematical enhancement in optical bandgap from 5.25 to 6.085 eV.A good correlation was observed between the bandgap energy and crystallite size of the nanocrystals which confirmed the size induced effect in the *** transformation in the sample morphology was observed from irregular spherical particles to sepals like shapes with increasing the Cu concentration in the host *** energy dispersive X-Ray (EDX) analysis confirmed the purity of mass percentage composition of the elements present in the samples.

关键词： Cu doped Mg(OH)_(2) nanoparticles phase purity optical band gap morphologies

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Restless head syndrome:A retrospective study

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World Journal of Methodology 2025年第1期15卷 51-59页

作者： Sanjay Prakash Varoon Vadodaria Niraj Chawda Chetsi S shah Anurag Prakash Department of Neurology Smt.B.K.Shah Medical Institute and Research CentreSumandeep VidyapeethVadodara 391760GujarātIndia Department of Medicine Smt.B.K.Shah Medical Institute and Research CentreSumandeep VidyapeethVadodara 391760GujarātIndia Department of Medicine Parul Institute of Medical Sciences and Research CentreParul University WaghodiaVadodara 391760India

BACKGROUND Restless legs syndrome(RLS)is characterized by an urge to move with an unpleasant sensation in the lower *** typically affects the ***,it can also affect several other body regions,such as the arms,abdomen,face,neck,head,and genital *** are only a few reports of the RLS variant affecting the *** To assess the epidemiological,clinical,and other aspects of the RLS variant affecting the *** We conducted a retrospective study of 17 adult patients(>18 years)who met the RLS criteria and simultaneously experienced RLS-like symptoms in the *** The median age at which symptoms appeared was 41.6 *** and females were equally affected(1.1:1).All 17 patients had uncomfortable sensations in the lower *** or disturbed sleep was the most common comorbidity(n=16,88.2%).However,headache was the most common presenting or primary symptom(n=10,70.5%).Dizziness or an abnormal sensation in the head was the second most common presenting symptom(5 patients,29.4%).Other presenting features were leg pain,backache,and generalized body *** patients responded favorably to dopaminergic *** If RLS-related unpleasant sensations and pain are felt in the head,they may be misinterpreted as headache,dizziness,or psychosomatic *** and headaches in a subset of patients may be two phenotypic manifestations of the same disorder.

关键词： Restless legs syndrome Restless head syndrome Dopamine Headache Migraine Tension-type headache

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