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Computational Fluid Dynamics Approach for Predicting Pipeline Response to Various Blast Scenarios: A Numerical Modeling Study

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Computer Modeling in Engineering & Sciences 2024年第9期140卷 2747-2777页

作者： Farman Saifi Mohd javaid Abid Haleem S.M.Anas Department of Mechanical Engineering Jamia Millia Islamia(A Central University)New Delhi110025India Department of Civil Engineering Jamia Millia Islamia(A Central University)New Delhi110025India

Recent industrial explosions globally have intensified the focus in mechanical engineering on designing infras-tructure systems and networks capable of withstanding blast *** centered on high-profile facilities such as embassies and petrochemical plants,this concern now extends to a wider array of infrastructures and *** and scholars increasingly prioritize structural safety against explosions,particularly to prevent disproportionate collapse and damage to nearby *** has further amplified the reliance on oil and gas pipelines,making them vital for urban life and prime targets for terrorist ***,there is a growing imperative for computational engineering solutions to tackle blast loading on pipelines and mitigate associated risks to avert *** this study,an empty pipe model was successfully validated under contact blast conditions using Abaqus software,a powerful tool in mechanical engineering for simulating blast effects on buried *** a Eulerian-Lagrangian computational fluid dynamics approach,the investigation extended to above-surface and below-surface blasts at standoff distances of 25 and 50 *** descriptions in the numerical model relied on Abaqus’default mechanical *** analysis revealed varying pipe performance,with deformation decreasing as explosion-to-pipe distance *** explosion’s location relative to the pipe surface notably influenced deformation levels,a key finding highlighted in the ***,quantitative findings indicated varying ratios of plastic dissipation energy(PDE)for different blast scenarios compared to the contact blast(P0).Specifically,P1(25 mm subsurface blast)and P2(50 mm subsurface blast)showed approximately 24.07%and 14.77%of P0’s PDE,respectively,while P3(25 mm above-surface blast)and P4(50 mm above-surface blast)exhibited lower PDE values,accounting for about 18.08%and 9.67%of P0’s PDE,***

关键词： Blast loading computational fluid dynamics computer modeling pipe networks response prediction structural safety

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Evolutionary Safe Padé Approximation Scheme for Dynamical Study of Nonlinear Cervical Human Papilloma Virus Infection Model

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Computer Modeling in Engineering & Sciences 2024年第9期140卷 2275-2296页

作者： javaid Ali Armando Ciancio Kashif Ali Khan Nauman Raza Haci Mehmet Baskonus Muhammad Luqman Zafar-Ullah Khan Department of Mathematics Govt.Graduate College TownshipLahore54770Pakistan Universitàdegli Studi di Messina Dipartimento di Scienze BiomedicheOdontoiatriche e delle Immagini Morfologiche e FunzionaliMessina98122Italy Department of Mathematics University of Engineering and TechnologyLahore54890Pakistan Department of Mathematics University of the PunjabLahore54590Pakistan Mathematics Research Center Near East University TRNCMersin 10Nicosia99138Turkey Department of Mathematics and Science Education Faculty of EducationHarran UniversitySanliurfa63190Turkey Department of Dermatology Rashid Latif Medical CollegeLahore54600Pakistan

This study proposes a structure-preserving evolutionary framework to find a semi-analytical approximate solution for a nonlinear cervical cancer epidemic(CCE)*** underlying CCE model lacks a closed-form exact *** solutions obtained through traditional finite difference schemes do not ensure the preservation of the model’s necessary properties,such as positivity,boundedness,and ***,the development of structure-preserving semi-analytical approaches is always *** research introduces an intelligently supervised computational paradigm to solve the underlying CCE model’s physical properties by formulating an equivalent unconstrained optimization ***-free safe Padérational functions approximate the mathematical shape of state variables,while the model’s physical requirements are treated as problem *** primary model of the governing differential equations is imposed to minimize the error between approximate *** evolutionary algorithm,the Genetic Algorithm with Multi-Parent Crossover(GA-MPC),executes the optimization *** resulting method is the Evolutionary Safe PadéApproximation(ESPA)*** proof of unconditional convergence of the ESPA scheme on the CCE model is supported by numerical *** performance of the ESPA scheme on the CCE model is thoroughly investigated by considering various orders of non-singular Padéapproximants.

关键词： Nonlinear cervical cancer epidemic non-singular Padéapproximants approximate solutions computational biology

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Phase Noise Quenching in a Four-Level Laser

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Chinese Physics Letters 2010年第3期27卷 184-187页

作者： javaid Anwar Department of Physics COMSATS Institute of Information Technology Islamabad Pakistan

In the presence of usual transmission losses, it is shown that phase noise in a four-level laser can be reduced below the Schawlow-Townes limit when lasing levels are coupled to a squeezed vacuum reservoir. The squeezed vacuum coupled to the lasing mode modifies the phase diffusion rate and dominates the contribution from transmission losses. It is predicted to obtain phase stability in the system and phase noise vanishes for larger squeezing. Gain of the laser remains positive under these conditions.

关键词： Optics quantum optics and lasers

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Progress in twin roll casting of magnesium alloys: A review

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Journal of Magnesium and Alloys 2021年第2期9卷 362-391页

作者： Amjad javaid Frank Czerwinski CanmetMATERIALS Natural Resources CanadaHamiltonOntarioL8P 0A5Canada

Twin roll casting was commercialized for a strip production from ferrous and non-ferrous alloys in the 1950 s;however,its application to magnesium has proven difficult and still creates major *** report describes global efforts in expanding manufacturing capabilities of magnesium sheet through twin roll casting path,offering many benefits,including a reduction in number of processing steps and energy *** addition to hardware design,alloy transformation during processing,product microstructure and properties,examples of successful solutions along with present technology and knowledge limitations are discussed.A particular attention is paid to developments at Canmet MATERIALS,having the only in North America pilot scale twin roll casting facility,devoted to *** are described that aim at design of new magnesium alloys,which could take advantage of unique processing conditions during twin roll casting and contribute to the overall progress in magnesium sheet manufacturing.

关键词： Twin roll casting Magnesium alloys Solidification Magnesium sheet

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A Novel Action Transformer Network for Hybrid Multimodal Sign Language Recognition

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Computers, Materials & Continua 2023年第1期74卷 523-537页

作者： Sameena javaid Safdar Rizvi Department of Computer Sciences School of Engineering and Applied SciencesBahria UniversityKarachi CampusKarachiPakistan

Sign language fills the communication gap for people with hearing and speaking *** includes both visual modalities,manual gestures consisting of movements of hands,and non-manual gestures incorporating body movements including head,facial expressions,eyes,shoulder shrugging,*** both gestures have been detected;identifying separately may have better accuracy,butmuch communicational information is *** sign language mechanism is needed to detect manual and non-manual gestures to convey the appropriate detailed message to *** novel proposed system contributes as Sign LanguageAction Transformer Network(SLATN),localizing hand,body,and facial gestures in video *** we are expending a Transformer-style structural design as a“base network”to extract features from a spatiotemporal *** impulsively learns to track individual persons and their action context inmultiple ***,a“head network”emphasizes hand movement and facial expression simultaneously,which is often crucial to understanding sign language,using its attention mechanism for creating tight bounding boxes around classified *** model’s work is later compared with the traditional identification methods of activity *** not only works faster but achieves better accuracy as *** achieves overall 82.66%testing accuracy with a very considerable performance of computation with 94.13 Giga-Floating Point Operations per Second(G-FLOPS).Another contribution is a newly created dataset of Pakistan Sign Language forManual and Non-Manual(PkSLMNM)gestures.

关键词： Sign language gesture recognition manual signs non-manual signs action transformer network

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Effect of hot rolling on microstructure and properties of the ZEK100 alloy

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Journal of Magnesium and Alloys 2019年第1期7卷 27-37页

作者： Amjad javaid Frank Czerwinski CanmetMATERIALS 183 Longwood Road SouthHamiltonOntario L8P 0A5Canada

Attempts to expand manufacturing capabilities of magnesium-based sheet materials are *** as-cast ZEK100(Mg-1.2Zn-0.35Zr-0.17Nd,in wt%)magnesium alloy was subjected to hot rolling at temperatures from 350℃to 450℃using the laboratory 50 ton reversible mill with preheated rolls to manufacture the 1.5-1.7 mm thick *** rolling temperature affected the sheet properties and an increase in the rolling temperature from 250 to 450℃caused reduction of tensile strength from 257 to 228 MPa ac-companied by a reduction in tensile yield stress from 237 to 185 *** the same time,the alloy elongation increased from 17 to 21%.For the same rolling temperature range,the compressive strength reduced from 418 to 351 *** post-rolling annealing at 450℃led to reduction of both tensile and compressive properties with the largest changes corresponding to the rolling temperature of 350°*** correlation between the alloy grain size after rolling and the sheet properties was established where a reduction in grain size was accompanied by an increase of both the tensile/compressive strength and yield *** on Hall-Petch relationship and an average grain size the correlation developed in this study may be used as the prediction model for properties of the hot rolled magnesium *** results are discussed in terms of recent developments in magnesium sheet alloys and the vital role played in this process by rare earth elements.

关键词： Magnesium alloys Hot deformation Microstructure Rare earths Sheet rolling

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Phytodiversity and medicinal plant distribution in pasturelands of North Western Himalaya in relation to environmental gradients

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Journal of Mountain Science 2019年第4期16卷 884-897,955-963页

作者： javaid M.DAD Central Institute of Temperate Horticulture

This study aimed at elucidating phytodiversity of pasturelands of North-western Kashmir Himalayan biotic province in relation to various environmental gradients, with added focus on assessing distribution of important threatened medicinal plant taxa across surveyed pasturelands. A total of 16 sites that spanned across a broad altitudinal gradient(2502-4120 m) were selected. Phytosociological data like density, cover, frequency and abundance of vascular flora were collected and processed using gradient analysis. Soil moisture, nitrogen, organic carbon, acidity and electrical conductivity, altitude, degree of slope and human disturbance were recorded from each site. Analysis of species composition showed a total of 293 species of vascular plants, belonging to 192 genera and 64 families recorded from surveyed sites. Rank abundance exhibited that majority of species are locally rare and patchily distributed, with over 60% of species recording frequencies between 0%-20% and none showing frequencies more than 80%. Species richness showed significant variations and ranged from 20(Parihasmaidan) to 114(Nagbarren) for macro and 3.53±2.11(Thajwas) to 8.76± 1.01(Marsar) for micro-scale of measurement. The ShannonWiener(H') and Simpson's diversity(Ds) indices also varied greatly and were recorded highest(H'= 2.76 & Ds= 0.36) for Marsar and lowest(0.87 & 0.62) for Parihasmaidan. The diversity attributes suggested that pasturelands with lower species richness and diversity on macro-scale were not always species poor and less diverse on micro-measurement scale. The life form groupings highlighted the hemicryptophytic character of vegetation and species with highest importance value index were Sibbaldia cuneata(5.71), Rumex nepalensis(2.89), Juniperus wallichiana(2.88), Cynodon dactylon(2.83), Poa annua(2.49) and Sambucus wightiana(2.41). The results of canonical correspondence analysis showed that effect of altitude and anthropogenic disturbance was overriding and among various en

关键词： Anthropogenic disturbance Kashmir Himalaya Medicinal plants Mountain grasslands

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Changes in soil organic carbon,nitrogen and sulphur along a slope gradient in apple orchard soils of Kashmir Himalaya

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Journal of Mountain Science 2021年第9期18卷 2377-2387页

作者： javaid M DAD Lotfollah ABDOLLAHI Department of Botany University of KashmirHazratbalSrinagar(J&K)India Faculty of Agriculture Payame Noor UniversityTehranP.O.Box 19395-3697Iran

Accumulation and losses of soil organic carbon(SOC),total nitrogen(TN)and sulphur(S)influence food security and global ***,their spatial distribution and variability at regional scale,and their relation to topographical variables are of great *** this study,the variability of SOC,TN and S content was evaluated in apple orchard soils of Kashmir region,at three depths(D1:0-10,D2:10-20,and D3:20-30 cm)on slope gradient i.e.:flat,medium,and *** an increase in slope,a significant decrease of SOC and TN was observed,with concentration of SOC and TN recorded highest(14.3±2.06 g kg-1&0.97±0.35 g kg-1)in flat slope orchards and lowest(9.6±2.07 g kg-1&0.84±0.41 g kg-1)in high slope *** stock basis,the values recorded for flat,medium,and high slope orchards,for SOC and TN were 54.62±4.24 Mg ha-1&0.38±0.06 Mg ha-1,44.13±5.11 Mg ha-1&0.32±0.09 Mg ha-1,and 38.73±5.94 Mg ha-1&0.28±0.10,*** differences for S concentration and stocks were modest,with flat(0.21±0.15 mg kg-1&0.09±0.0.003 Mg ha-1)>high(0.16±0.07 mg kg-1&0.06±0.007 Mg ha-1)>medium(0.12±0.04 mg kg-1&0.075±0.009 Mg ha-1).Across slopes,SOC,TN and S decreased with increasing soil depth,suggesting clear downward ***,SOC and TN increased with the increase of altitude,precipitation and clay content while its relationship with soil acidity and soil bulk density was *** findings may provide scientific basis to structure agricultural development plans or prioritize regions for soil conservation efforts.

关键词： Apple orchards Slope Soil organic carbon Sulphur Total nitrogen Soil bulk density

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Resolvability in Circulant Graphs

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Acta Mathematica Sinica,English Series 2012年第9期28卷 1851-1864页

作者： Muhammad SALMAN Imran javaid Muhammad Anwar CHAUDHRY Center for Advanced Studies in Pure and Applied Mathematics Bahauddin Zakariya University

A set W of the vertices of a connected graph G is called a resolving set for G if for every two distinct vertices u, v E V（G） there is a vertex w E W such that d（u, w） ≠ d（v, w）. A resolving set of minimum cardinality is called a metric basis for G and the number of vertices in a metric basis is called the metric dimension of G, denoted by dim（G）. For a vertex u of G and a subset S of V（G）, the distance between u and S is the number minses d（u,s）. A k-partition II = {$1,$2,..., Sk} of V（G） is called a resolving partition if for every two distinct vertices u, v E V（G） there is a set Si in H such that d（u, Si） ≠ d（v, Si）. The minimum k for which there is a resolving k-partition of V（G） is called the partition dimension of G, denoted by pd（G）. The circulant graph is a graph with vertex set Zn, an additive group of integers modulo n, and two vertices labeled i and j adjacent if and only if i - j （rood n） E C, where C C Zn has the property that C = -C and 0 ￠ C. The circulant graph is denoted by Xn,△ where A = ｜C｜. In this paper, we study the metric dimension of a family of circulant graphs Xn,3 with connection set C = {1, 3, n - 1} and prove that dim（Xn,3） is independent of choice of n by showing that dim（Xn,a） = {3 for all n ≡0 （mod 4）,4 for all n≡2 （mod4）.We also study the partition dimension of a family of circulant graphs Xm,4 with connection set C = {±1, ±2} and prove that pd（Xn,4） is independent of choice of n and show that pd（X5,4） = 5 and pd（Xn,a） ={ 3 for all odd n≥9,4 for all even n≥6 and n=7.

关键词： Circulant graphs metric dimension partition dimension

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Blend of Polyhydroxyalkanoates Synthesized By Lipase Positive Bacteria From Plant Oils

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Journal of Renewable Materials 2019年第5期7卷 463-476页

作者： Nasir javaid Rida Batool Nazia Jamil Department of Microbiology and Molecular Genetics University of the PunjabQuaid-e-Azam CampusLahore-54590Pakistan

A total of 5 biochemically characterized lipase positive bacterial strains were screened for Polyhydroxyalkanoates(PHA)production by Nile blue staining and confirmation was done by Sudan Black *** production ability for all strains was optimized followed by time profiling calculation and comparison via using glucose and two plant oils i.e.,canola and mustard *** analysis showed that glucose can serve as a carbon source for maximum biomass(2.5 g/L CDW for strain 5)and PHA production(70.3%for strain 2).PHA produced by strain 2 was further analyzed for its chemical composition and type via Fourier Transform Infrared(FT-IR)*** revealed homopolymer(PHB)and copolymer(PHB-co-PHV)production of PHA(peaks at 1743 cm-1 and 2861 cm-1,respectively)with both canola and mustard oil unlike glucose which produced only homopolymer one i.e.,PHB(peaks at 1110 cm-1,1411 cm-1 and 1650 cm-1).Crystallinity of FT-IR analyzed PHA was calculated using mathematical formulas which showed decrease from glucose to canola to mustard *** study revealed that plant oils can serve as better carbon source to produce better quality(ductile and copolymer)***,16S rRNA gene sequencing analysis showed that strain 1,strain 2,strain 3,strain 4 and strain 5 are Stenotrophomonas sp.N3,Exiguobacterium sp.N4,Exiguobacterium ***3,Cellulosimicrobium sp.A8 and Klebsiella ***2,respectively.

关键词： Bioplastics polyhydroxyalkanoates lipase positive bacteria plant oils,FT-IR

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