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Measurement of ^(59)Co(ai,x)reaction cross sections with the fast neutrons based on the ^(9)Be(p,n)reaction

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Chinese Physics C 2021年第4期45卷 248-255页

作者： muhammad zaman muhammad Nadeem muhammad Sahid Kwangsoo Kim Guinyun Kim Nguyen Thi Hien Department of Physics and Center for High Energy Physics Kyungpook National UniversityDaegu 41566Republic of Korea Institute of Physics Vietnam Academy of Science and Technology10 Dao TanHanoiVietnam

The cross sections of the ^(59)Co(n,x)reaction in the average energy range of 15.2-37.2 MeV were meas-ured using activation and an off-line γ-ray spectrometric *** neutrons were generated from the ^(9)Be(p,n)reaction with proton beam energies of 25-45 MeV at the MC-50 Cyclotron facility of the Korean Institute of Radi-ological and Medical Sciences(KIRAMS).Theoretical cal lculations of neutron-induced reactions on ^(59)Co were per-formed using the nuclear model code *** results for the ^(59)Co(n,x)reactions were compared with the theoretical values obtained using TALYS-1.9 and the literature data provided in EXFOR and the TENDL 2019 nuc-lear data *** theoretical values obtained using TALYS-1.9 with adjusted parameters are comparable to the experimental *** measured reaction cross sections of a few radionuclides are new,and the others are compar-able to the literature data,and thus,they can strengthen the *** present study on cross sections leads to useful insight into the mechanisms of ^(59)Co(n,x)reactions.

关键词： ^(59)Co(n,x)reaction cross sections average neutron energy of 15.2-37.2 MeV off-lineγ-ray spectrometry MCNPX 2.6.0 simulation TALYS-1.9

Trends in species distribution modelling in context of rare and endemic plants:a systematic review

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Ecological Processes 2022年第1期11卷 525-535页

作者： Ammad Waheed Qazi Zafeer Saqib muhammad zaman‑ul‑Haq Department of Environmental Science International Islamic University IslamabadIslamabad 46000Pakista

Background:Many research papers have utilized Species Distribution Models to estimate a species’current and future geographic distribution and environmental *** study aims to(a)understand critical features of SDMs used to model endemic and rare species and(b)to identify possible constraints with the collected *** present systematic review examined how SDMs are used on endemic and rare plant species to identify optimal practices for future ***:The evaluated literature(79 articles)was published between January 2010 and December *** number of papers grew considerably over *** studies were primarily conducted in Asia(41%),Europe(24%),and Africa(2%).The bulk of the research evaluated(38%)focused on theoretical ecology,climate change impacts(19%),and conservation policy and planning(22%).Most of the papers were published in publications devoted to biodiversity conservation,ecological or multidisciplinary *** degree of uncertainty was not disclosed in most studies(81%).Conclusion:This systematic review provides a broad overview of the emerging trends and gaps in the SDMs *** majority of studies failed to present uncertainties and error ***,when model performance estimates are given,the model results will be highly effective,allowing for more assurance in the predictions they ***,based on our systematic review,we recommend that in the future rare and endemic SDMs should represent uncertainty levels and estimates of errors in the modelling process.

关键词： Species distribution modelling Endemic Rare Uncertainty measures Model validation

Revascularization strategies for patients with myocardial infarction and multi-vessel disease: A critical appraisal of the current evidence

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Journal of Geriatric Cardiology 2019年第9期16卷 717-723页

作者： muhammad O zaman Mohammad K Mojadidi Islam Y Elgendy Division of Cardiovascular Medicine Department of Medicine University of Florida College of Medicine Gainesville Florida USA Division of Cardiovascular Medicine Department of Medicine Virginia Commonwealth University Richmond Virginia USA Division of Cardiovascular Medicine Massachusetts General Hospital and Harvard Medical School Boston MA USA

Approximately half of patients presenting with myocardial infarction are found to have non-infarct related multi-vessel severe coronary artery disease. Various observational studies and randomized controlled trials have been conducted to assess if revascularization of non-infarct related artery is associated with better clinical outcomes. In this review, the authors discuss the various revascularization strategies in patients with multi-vessel disease who present with myocardial infarction.

关键词： Coronary artery disease Mortality Myocardial Infarction Percutaneous coronary intervention

Evaluation of SWAT Model performance on glaciated and non-glaciated subbasins of Nam Co Lake, Southern Tibetan Plateau, China

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Journal of Mountain Science 2019年第5期16卷 1075-1097页

作者： muhammad ADNAN KANG Shi-chang ZHANG Guo-shuai muhammad Naveed ANJUM muhammad zaman ZHANG Yu-qing State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences China University of Chinese Academy of Sciences CAS Centre for Excellence in Tibetan Plateau Earth Sciences Key Laboratory of Tibetan Environment Changes and Land Surface Processes Institute of Tibetan Plateau Research Chinese Academy of Sciences Division of Hydrology Water-Land Resources in Cold and Arid Regions Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Department of Irrigation & Drainage University of AgricultureFaisalabad Research Center of Fluid Machinery Engineering & Technology Jiangsu University School of Urban and Environmental Sciences Huaiyin Normal University

This paper presents an assessment of the Soil and Water Assessment Tool(SWAT) on a glaciated(Qugaqie) and a non-glaciated(Niyaqu) subbasin of the Nam Co Lake. The Nam Co Lake is located in the southern Tibetan Plateau, two subbasins having catchment areas of 59 km^2 and 388 km^2, respectively. The scores of examined evaluation indices(i.e., R^2, NSE, and PBIAS) established that the performance of the SWAT model was better on the monthly scale compared to the daily scale. The respective monthly values of R^2, NSE, and PBIAS were 0.94, 0.97, and 0.50 for the calibration period while 0.92, 0.88, and -8.80 for the validation period. Glacier melt contribution in the study domain was simulated by using the SWAT model in conjunction with the Degree Day Melt(DDM) approach. The conjunction of DDM with the SWAT Model ensued improved results during both calibration(R^2=0.96, NSE=0.95, and PBIAS=-13.49) and validation (R^2=0.97, NSE=0.96, and PBIAS=-2.87) periods on the monthly time scale. Average contribution(in percentage) of water balance components to the total streamflow of Niyaqu and Qugaqie subbasins was evaluated. We found that the major portion(99.45%) of the streamflow in the Niyaqu subbasin was generated by snowmelt or rainfall surface runoff(SURF_Q), followed by groundwater(GW_Q, 0.47%), and lateral(LAT_Q, 0.06%) flows. Conversely, in the Qugaqie subbasin, major contributor to the streamflow(79.63%) was glacier melt(GLC_Q), followed by SURF_Q(20.14%), GW_Q(0.13%), and LAT_Q(0.089%). The contribution of GLC_Q was the highest(86.79%) in July and lowest(69.95%) in September. This study concludes that the performance of the SWAT model in glaciated catchment is weak without considering glacier component in modeling; however, it performs reasonably well in non-glaciated catchment. Furthermore, the temperature index approach with elevation bands is viable in those catchments where streamflows are driven by snowmelt. Therefore, it is recommended to use the SWAT Model in con

关键词： SWAT Model Nam Co Lake Degree-day melt model Streamflow Hydrological Response Unit

Counter-current three-phase fluidization in a turbulent contact absorber： A CFD simulation

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Particuology 2017年第6期15卷 51-67页

作者： Syed Shah Jehan Gillani Atta Ullah muhammad zaman Imran Rafique Chugtai Mansoor Hameed Inayat Department of Chemical Engineering Pakistan Institute of Engineering and Applied Sciences (PIEAS) 45650 Islamabad. Pakistan

A computational fluid dynamics study of three-phase counter-current fluidization occurring in a turbu- lent contact absorber was performed. A two-dimensional, transient Eulerian multi-fluid model was used, in which the dispersed solid phase was modeled employing a kinetic theory of granular flow. The grid independence of the model, the effect of wall boundary conditions, the choice of granular temperature model, the effects of order of discretization scheme and drag models were studied for a base case setting, The results of simulations were validated against experimental results obtained from the literature. Once the model settings were finalized, simulations were performed for different gas and liquid velocities to predict the hydrodynamics of the absorber. Computed bed expansion and pressure drop were compared with experimental data. Good agreement between the two was found for low velocities of gas and liquid.

关键词： Multiphase Counter-current Computational fluid dynamics (CFD) Fluidization Turbulent contact absorber

Modeling the density gradient of 3D nanofiber scaffolds fabricated by divergence electrospinning

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Advances in Manufacturing 2021年第3期9卷 414-429页

作者： muhammad Adib Uz zaman Dilshan Sooriyaarachchi Ying-Ge Zhou George Z.Tan Dong-Ping Du Department of Industrial Manufacturing and Systems EngineeringTexas Tech UniversityLubbockTXUSA

Following recent insights on structure-cell-function interactions and the critical role of the extracellular matrix(ECM),the latest biofabrication approaches have increasingly focused on designing materials with biomimetic *** electrospinning is a novel fabrication method for three-dimensional(3D)nanofiber *** is introduced to produce 3D nanofiber mats that have numerous applications in regenerative medicine and tissue *** of the most important characteristics of 3D nanofiber mats is the density *** study provides a statistical analysis and response surface modeling framework based on experimental data to evaluate the manner by which the geometric designs of double-bevel collectors influence the fiber density ***,variance of analysis and sensitivity analysis were performed to identify parameters that had significant effects,and a response surface model embedded with seven location indicators was developed to predict the spatial distribution of fiber density for different collector *** was concluded that the collector height,bevel angle,and their interactions were significant factors influencing the density *** study revealed the sensitivity of system configuration and provided an optimization tool for process controllability of microstructure gradients.

关键词： Electrospinning 3D nanofiber scaffold Statistical model Design of experiments Response surface method

Recommender System for Configuration Management Process of Entrepreneurial Software Designing Firms

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Computers, Materials & Continua 2021年第5期67卷 2373-2391页

作者： muhammad Wajeeh Uz zaman Yaser Hafeez Shariq Hussain Haris Anwaar Shunkun Yang Sadia Ali Aaqif Afzaal Abbasi Oh-Young Song University Institute of Information Technology Pir Mehr Ali Shah Arid Agriculture UniversityRawalpindi46000Pakistan Department of Software Engineering Foundation University IslamabadIslamabad44000Pakistan Department of Electrical Electronics and Telecommunication EngineeringUniversity of Engineering and TechnologyLahore54000Pakistan School of Reliability and Systems Engineering Beihang UniversityBeijing100191China Department of Software Sejong UniversitySeoul05006South Korea

The rapid growth in software demand incentivizes software development organizations to develop exclusive software for their customers *** problem is addressed by the software development industry by software product line(SPL)practices that employ feature ***,optimal feature selection based on user requirements is a challenging ***,there is a requirement to resolve the challenges of software development,to increase satisfaction and maintain high product quality,for massive customer needs within limited *** this work,we propose a recommender system for the development team and clients to increase productivity and quality by utilizing historical information and prior experiences of similar developers and *** proposed system recommends features with their estimated cost concerning new software requirements,from all over the globe according to similar developers’and clients’needs and *** system guides and facilitates the development team by suggesting a list of features,code snippets,libraries,cheat sheets of programming languages,and coding references from a cloud-based knowledge management ***,a list of features is suggested to the client according to their needs and *** experimental results revealed that the proposed recommender system is feasible and effective,providing better recommendations to developers and *** provides proper and reasonably well-estimated costs to perform development tasks effectively as well as increase the client’s satisfaction *** results indicate that there is an increase in productivity,performance,and quality of products and a reduction in effort,complexity,and system ***,our proposed system facilitates developers and clients during development by providing better recommendations in terms of solutions and anticipated ***,the increase in productivity and satisfaction level maximizes the benefits and usability of SPL in the

关键词： Feature selection recommender system software reuse configuration management

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太阳能喷灌系统供给能源与水力性能关系

排灌机械工程学报 2021年第6期39卷 637-642页

作者：刘俊萍许继恩李滔 muhammad zaman 江苏大学国家水泵及系统工程技术研究中心江苏镇江212013

为了解决太阳能喷灌系统应用中无法对喷头水力性能进行有效预测的问题,以光照强度为影响因素,太阳能喷灌系统泵出口流量、泵出口压力、喷洒射程、水量分布及系统灌溉均匀性系数为评价指标,通过在夏季典型天气25~36℃下的系统水力性能试... 详细信息

为了解决太阳能喷灌系统应用中无法对喷头水力性能进行有效预测的问题,以光照强度为影响因素,太阳能喷灌系统泵出口流量、泵出口压力、喷洒射程、水量分布及系统灌溉均匀性系数为评价指标,通过在夏季典型天气25~36℃下的系统水力性能试验,寻找不同光照强度下系统喷洒水力性能的变化规律,获得系统最佳工作状态下所需光照强度.试验结果表明:随着光照强度的增大,系统流量及泵出口压力均增大,泵的流量和压力随光照强度的变化规律基本符合指数分布规律.当光照强度大于900.0 W/m^(2)时,系统流量、泵出口压力、射程及水量分布基本保持不变.获得了平均光照强度与均匀性系数函数关系,当光照强度大于900.0 W/m^(2)时,系统喷灌均匀系数大于88%.当光照强度为200.0~600.0 W/m^(2)时,系统喷灌均匀系数为76%~82%.太阳能喷灌系统在光照强度大于200.0 W/m2时可正常工作.该研究为改善太阳能喷灌系统水力性能,促进太阳能喷灌系统在实际工程中的推广应用提供了参考.

关键词：喷灌系统太阳能水力性能光照强度喷灌均匀系数

基于CO2混合工质的跨临界朗肯循环内燃机余热回收系统稳态性能分析

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基于CO2混合工质的跨临界朗肯循环内燃机余热回收系统稳态性能分析

作者： muhammad zaman Shakir 天津大学

学位级别：硕士

内燃机是获得机械动力的主要来源之一,它被广泛应用于现代工业中的各个行业,尤其是交通运输领域,并且内燃机仍会在将来很长的一段时间作为主要动力源发挥其重要的作用,特别是在重型卡车和远洋货轮等重型运载工具中。目前中国是全球最大... 详细信息

内燃机是获得机械动力的主要来源之一,它被广泛应用于现代工业中的各个行业,尤其是交通运输领域,并且内燃机仍会在将来很长的一段时间作为主要动力源发挥其重要的作用,特别是在重型卡车和远洋货轮等重型运载工具中。目前中国是全球最大的内燃机制造商。2014年中国内燃机总产量超过8000万台,总功率超过20亿千瓦,占中国石油消耗总量的三分之二。但中国的石油储量较低,人均占有的石油量仅仅为世界平均值的大约11%,面临着严峻的资源紧缺问题。据国家中长期科技发展规划纲要专家组的估计,到2020年左右中国的总石油消费量至少高达4.5亿吨,同时石油对外依存度也会超过60%,这会对国家的能源供给和能源安全造成极大的压力。所以提高内燃机效率,减少石油消耗和污染物排放,对环境保护和国家能源安全具有十分重要的意义。然而,内燃机通常仅仅将30%-40%的输入燃料转变为有用功,大量的能量被烟气,缸套冷却水,机油等带走,造成了大量能量浪费。其中烟气和缸套冷却水是最重要的余热源,分别占输入能量的30%和20%左右。由于烟气和缸套冷却水所蕴含的巨大废热,余热回收成为一项有效提高内燃机效率的关键技术,受到了世界各国政府和各大主要相关企业的广泛重视。例如2014年8月,美国能源部投入5500万美元开展车辆节能减排技术的相关研究以降低车辆的整体油耗,其中就有两个专项是针对内燃机的余热回收技术。中国在2017年1月启动了与美国合作的为期五年的国际合作项目“超级卡车”,旨在将重载货车的燃油经济性在实际道路工况中提高至50%以上,而余热能回收技术是其中一项非常重要的专项课题。在各种不同的余热回收技术中,采用不同工质的朗肯循环因为对内燃机效率提升作用明显,而尤为受到关注。美国康明斯,德国宝马,奥地利AVL等汽车行业的公司都对各种结构和工质的朗肯循环开展了充分的研究,并认为它是进一步提升内燃机效率所必须采用的技术手段。大型船舶主机制造商MAN和瓦锡兰公司也都对内燃机余热回收技术投入了大量的研发力量。但是目前主流的采用有机工质的朗肯循环,存在着与内燃机多品位大温差的热源不相匹配的问题(缸套冷却水80-95℃,烟气500-700℃),既不能对烟气和缸套冷却水的热量同时进行完全的回收利用。另一方面,对于移动装置内燃机余热回收系统的小型化和轻量化至关重要。国际铝协的汽车轻量化研究结果表明,整车的重量每降低10%,大概可降低5%-9%的燃油消耗,尤其是重载卡车的油耗可平均降低高达9%。为了一步提升余热的回收利用率和内燃机的效率,近年来有学者提出CO跨临界朗肯朗循环。这种结构和工质的循环,仅仅通过单级循环就能实现烟气和缸套冷却水余热的完全回收,同时CO在系统小型化和轻量化方面有着非常明显的优势。因为超临界CO具有高气相密度和低液相粘度的物性特征,在微通道换热中可以显著减小流通阻力和减小压降,所以能够实现微通道换热器的在余热回收系统中的应用,从而显著减小系统尺寸;而另一方面超临界CO流体的膨胀比小,但同时单位体积的做功能力大,其膨胀机能够设计成简单的单级小型透平。但是CO跨临界朗肯循环也存在着自身的一些缺点,并在一定程度上限制了它的广泛应用。主要技术问题表现在以下几个方面:1.循环操作压力非常高,通常高达15MPa,给循环的正常运行带来了极大的安全隐患,同时也大大增加了系统的制造和运行成本。***的临界温度低,临界压力高(31℃,7.38MPa),因此在跨临界循环中用普通冷源冷凝CO非常困难,循环对冷源要求很高。***跨临界朗肯循环的热效率普遍低于其他制冷剂循环。为了解决纯CO跨临界朗肯循环的上述问题,提高系统的热力学和经济性能,通过在纯CO中添加其他工质而主动构建流体物性的方法是一种潜在的解决方案。因此,本研究选择了一些不同的有机工质R123,R161,R32,R1234yf,R22,R1234ze,R132a和R152a作为添加剂,以不同组分与CO混合作为系统工质。并广泛探索了以上述CO混合物为工质的跨临界循环系统性能。本文以改善循环性能,冷凝条件和操作压力为目标进行了模拟计算,从而为CO跨临界朗肯循环选择最合适的混合工质提供重要的参考依据,并通过实验研究验证了理论模拟工作。具体研究工作如下所述。在第三章中,本文首先基于本课题组的CO跨临界朗肯循环实验台架的结构形式,选取了带预热器和回热器的预回热循环系统为理论研究对象。详细的带预热过程和回热过程的预回热循环系统主要包括预热器、回热器、蒸发器、膨胀机、冷凝器、工质泵等部件。在这种结构的循环中,二氧化碳工质首先通过预热器回收缸套冷却水的大部分热量,然后流经回热器回收膨胀机出口的乏汽中所含的能量,从而进一步提高工质的温度,同时也减小了冷凝负荷,提升了系统能量利用率;在这之后工质进入蒸发器利用内燃机烟气余热对其进行最后的加热,从蒸发器出来的高温高

关键词：内燃机发动机余热回收跨临界朗肯循环 CO2混合物物理性质计算性能评估