检索结果-南通市图书馆

COMPARISON OF TWO METHODS TO INCREASE TIP CLEARANCE AND ITS EFFECT ON PERFORMANCE OF TURBOCHARGER CENTRIFUGAL COMPRESSOR STAGE

引用

Chinese Journal of Mechanical Engineering 2007年第4期20卷 60-65页

作者： syed noman danish School of Mechanical and Vehicular Engineering Beijing Institute of TechnologyBeijing 100081China

Tip clearance between the blade tip and casing of a centrifugal compressor can be varied through two methods： by changing the blade height （MI） or by changing the casing diameter （M2）. Numerical simulations are carried out to compare these two methods and their effect on the stage and impeller performance. The impeller and diffuser are connected through rotor stator boundary using frozen rotor approach. Overall stage performance and the flow configuration have been investigated for nine tip clearance levels from no gap to 1 mm. Impeller and diffuser performances are also presented separately. It has been found that the overall and impeller performance are comparatively better for MI below tip clearance of 0.5 mm whereas M2 is found advantageous above 0.5 mm of tip clearance. Both MI and M2 show performance degradation with the increase in tip clearance. Two models have been proposed for the stage total pressure ratio and efficiency, which are found to be in agreement with experimental results. The impeller efficiency and the pressure ratio are found to be maximum at tip clearance of 0.1 mm for both the cases however minimum diffuser effectiveness is also observed at the same clearance level. Diffuser effectiveness is found to be maximum at zero gap for both cases. As it is practically impossible to have zero gap for unshrouded impellers so it is concluded that the optimum thickness is 0.5 mm onwards for MI and 0.5 mm for M2 in terms of diffuser effectiveness. Mass averaged flow parameters, entropy, blade loading diagram and relative pressure fields are presented, showing the loss production within the impeller passage with tip clearance.

关键词： Centrifugal impeller Diffuser Stage Tip clearance Numerical simulation Entropy

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Numerical Investigation & Comparison of a Tandem-Bladed Turbocharger Centrifugal Compressor Stage with Conventional Design

引用

Journal of Thermal Science 2014年第6期23卷 523-534页

作者： syed noman danish Shafiq Rehman Qureshi Abdelrahman EL-Leathy Salah Ud-Din Khan Usama Umer Ma Chaochen Sustainable Energy Technologies Center King Saud University National University of Sciences and Technology PNS JauharKarachiPakistan Mechanical Engineering Department King Saud University FARCAMT Advanced Manufacturing InstituteKing Saud University Beijing Institute of Technology

Extensive numerical investigations of the performance and flow structure in an unshrouded tandem-bladed centrifugal compressor are presented in comparison to a conventional *** characteristics are explored for various tip clearance levels,axial spacings and circumferential *** impeller was modified to tandem-bladed design with no modifications in backsweep angle,meridional gas passage and camber distributions in order to have a true comparison with conventional *** degradation is observed for both the conventional and tandem designs with increase in tip ***-equation models for correlating stage characteristics with tip clearance are *** two designs,it is clearly evident that the conventional design shows better performance at moderate flow ***;near choke flow,tandem design gives better results primarily because of the increase in throat *** point flow rate also seems to drop for tandem compressor resulting in increased range of operation.

关键词： tandem blade conventional compressor inducer exducer numerical simulation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Waste heat recovery from heavy-duty diesel engine exhaust gases by medium temperature ORC system

引用

Science China(Technological Sciences) 2011年第10期54卷 2746-2753页

作者： WEI MingShan FANG JinLi MA ChaoChen danish syed noman School of Mechanical Engineering Beijing Institute of Technology Beijing 100081 China National University of Sciences and Technology (NUST) Islamabad H-12 Pakistan

A medium-temperature waste-heat recovery system based on the organic Rankine cycle (ORC) is designed to recover the exhaust energy from a heavy-duty diesel engine. Analysis of the 1st law of thermodynamics for an ORC system is performed. This analysis contains two parts. The first part is an analysis with undefined heat exchangers to gain an understanding of the ORC and find out suitable organic fluid parameters for a better ORC efficiency. The second part of the analysis uses combined engine test results and two designs of heat exchangers. By comparing the two designs, an improved system of heat exchangers is described. This analysis also quantifies the effect of engine parameters on ORC system. The study concludes that the supercritical Rankine cycle is a better approach towards waste heat recovery. The ORC system is found to perform better under part-load conditions if the medium-high power condition rather than rated working point of the engine is used as the design parameter. The ORC system achieves the highest waste-heat recovery efficiency of up to 10-15% for the optimised heat ex-changer design.

关键词： waste heat recovery organic-fluid Rankine cycle heavy-duty diesel engine medium temperature waste heat

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Modeling and Performance Simulation of an Innovative Concept of Linear Fresnel Reflector based CSP System

引用

Journal of Thermal Science 2021年第5期30卷 1614-1624页

作者： danish syed noman ALMUTAIRI Zeyad EL-LEATHY Abdelrahman AL-ANSARY Hany JARDAN Yazeed ALAQEL Shaker Sustainable Energy Technologies Center King Saud UniversityP.O.Box 800Riyadh11421Saudi Arabia K.A.CARE Energy Research and Innovation Center at Riyadh RiyadhSaudi Arabia Mechanical Engineering Department King Saud UniversityP.O.Box 800Riyadh11421Saudi Arabia Mechanical Power Engineering Department Faculty of EngineeringEl-MatariaHelwan UniversityCairo11718Egypt

Concentrating solar power technology is one of the most promising alternative energy *** recent past,Linear Fresnel Reflector systems have received great attention and novel designs have been proposed keeping in view the objective to enhance its functionality and *** achieving the same objective,this study presents a novel concept where a conventional LFR is enclosed in a greenhouse called *** was expected that such an enclosure can:(1)increase the incoming solar radiation,(2)further improve the overall efficiency due to simplified cleaning process and(3)reduce the capital cost for the construction of LFR support system.A complete thermal and optical analysis was presented for modeling and performance evaluation of the solar field of both conventional-LFR and novel *** of non-linear equations for each system were solved using Newton-Raphson *** detailed optical analysis was further performed for conventional-LFR considering the seasonal *** results concluded that the greenhouse-LFR is better than the conventional-LFR as it had higher efficiency and useful heat with lesser heat *** greenhouse-LFR,the maximum thermal efficiency was 73.2%whereas for conventional-LFR it was 37.2%.Also,there was an average increase of useful heat by 3 times in the month of February and 4.7 times in the month of ***^(TM) analysis indicated significant spillage loss when a conventional-LFR was used without a secondary reflector or slight curvature of the mirrors.

关键词： solar energy concentrated solar power linear Fresnel reflector greenhouse thermal and optical analysis experimentation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Debating the magnesium-selenium battery technology

引用

Journal of Magnesium and Alloys 2020年第4期8卷 980-988页

作者： Muhammad Rashada syed danish Ali Zaidi Muhammad Asif School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212003JiangsuChina Advanced Rechargeable Batteries Laboratory Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China Department of Chemical Sciences School of Natural SciencesUniversity of LimerickLimerick V94 T9PXIreland

Magnesium ion batteries(MIBs)have received tremendous research attention owing to their low cost,dendrite free electroplating,and high theoretical capacities compared with lithium ion batteries(LIBs).Despite these advantages,the launching of MIBs is hindered by sluggish kinetics of the magnesium ions inside the host ***,several magnesium-selenium batteries have been developed to achieve the fast kinetics of magnesium ions inside the selenium-based ***,we have critically reviewed the five-year advancements made in the field of selenium cathode design,selenium loadings,compatible organic and inorganic electrolytes,their resultant reversible capacities,working voltages,cycle life,and specific *** selenium-based cathodes were critically debated in terms of their electrochemical performance and *** the end of this review article,several irmovative directions are proposed to shed light on future research.c 2020 Published by Elsevier *** behalf of Chongqing University.

关键词： Magnesium-selenium batteries Energy storage Selenium cathodes Electrolytes Electrochemical properties

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

AI-Driven Energy Optimization in UAV-Assisted Routing for Enhanced Wireless Sensor Networks Performance

引用

Computers, Materials & Continua 2024年第9期80卷 4085-4110页

作者： syed Kamran Haider Abbas Ahmed noman Mujeeb Khan Ali Nauman Sung Won Kim College of Internet of Things(IoT)Engineering Hohai UniversityChangzhou213001China Department of Electrical and Electronics Engineering Beaconhouse International CollegeIslamabad44000Pakistan School of Computer Science and Engineering Yeungnam UniversityGyeongsan38428Republic of Korea

In recent advancements within wireless sensor networks(WSN),the deployment of unmanned aerial vehicles(UAVs)has emerged as a groundbreaking strategy for enhancing routing efficiency and overall network *** research introduces a sophisticated framework,driven by computational intelligence,that merges clustering techniques with UAV mobility to refine routing strategies in *** proposed approach divides the sensor field into distinct sectors and implements a novel weighting system for the selection of cluster heads(CHs).This system is primarily aimed at reducing energy consumption through meticulously planned routing and path *** a greedy algorithm for inter-cluster dialogue,our framework orchestrates CHs into an efficient communication *** comparative analysis,the proposed model demonstrates a marked improvement over traditional methods such as the cluster chain mobile agent routing(CCMAR)and the energy-efficient cluster-based dynamic algorithms(ECCRA).Specifically,it showcases an impressive 15%increase in energy conservation and a 20%reduction in data transmission time,highlighting its advanced ***,this paper investigates the impact of various network parameters on the efficiency and robustness of the WSN,emphasizing the vital role of sophisticated computational strategies in optimizing network operations.

关键词： UAV trajectory clustering next-generation wireless sensor network(NGWSN) energy efficiency mobile sink

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Polymer-free electrospun separator film comprising silica nanofibers and alumina nanoparticles for Li-ion full cell

引用

Journal of Energy Chemistry 2020年第3期29卷 217-226页

作者： syed danish Ali Zaidi Chong Wanga Qinjun Shao Jing Gao Shengdong Zhu Haifeng Yuan Jian Chen Advanced Rechargeable Batteries Laboratory Dalian Institute of Chemical PhysicsChinese Academy of Sciences457 Zhongshan RoadDalian 116023LiaoningChina University of Chinese Academy of Science Beijing 100039China

A separator film for high-performance Li-ion batteries was prepared by electrospinning. The film had a hybrid morphology of silica nanofibers(SNFs) and alumina nanoparticles(ANPs), with a smooth surface, polymer-free composition, high porosity(79%), high electrolyte uptake(876%), and excellent thermal stability. Contact angle measurements demonstrated the better immersion capability of the SNF-ANP separator film for commercial liquid electrolytes than a commercial CELGARD 2500 separator film. Moreover,compared to the commercial CELGARD 2500 separator, the ionic conductivity of the SNF-ANP separator film was nearly three times higher, the bulk resistance was lower at elevated temperature(120 ℃), the interfacial resistance with lithium metal was lower, and the electrochemical window was wider. Full cells were fabricated to determine the cell performance at room temperature. The specific capacity of the full cell with the SNF-ANP separator film was 165 mAh g-1;the cell was stable for 100 charge/discharge cycles and exhibited a capacity retention of 99.9%. Notably, the electrospun SNF-ANP separator film can be safely used in Li-ion or Li-S rechargeable batteries.

关键词： Electrospun nanofiber Hybrid materials Separator film Silica nanofiber Li-ion batteries

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Incorporation of layered tin(Ⅳ) phosphate in graphene framework for high performance lithium-sulfur batteries

引用

Journal of Energy Chemistry 2021年第2期30卷 99-108,I0004页

作者： Haifeng Yuan Na Zhang Leiwu Tian Lei Xu Qinjun Shao syed danish Ali Zaidi Jianping Xiao Jian Chen Advanced Rechargeable Battery Laboratory Dalian National Laboratory for Clean EnergyDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina University of Chinese Academy of Sciences.Beijing 100049 China

To anchor the polysulfide and enhance the conversion kinetics of polysulfide to disulfide/sulfide is critical for improving the performance of lithium-sulfur *** this purpose,the graphene-supported tin(Ⅳ) phosphate(Sn(HPO_4)_2·H_2 O,SnP) composites(SnP-G) are employed as the novel sulfur hosts in this *** compared to the graphene-sulfur and carbon-sulfur composites,the SnP-G-sulfur composites exhibit much better cycling performance at 1.0 C over 800 ***,the pouch cell fabricated with the SnP-G-sulfur cathodes also exhibits excellent performance with an initial capacity of1266.6 mAh g^(-1)(S) and capacity retention of 76.9% after 100 cycles at 0.1 *** adsorption tests,density functional theory(DFT) calculations in combination with physical cha racterizations and electrochemical measurements provide insights into the mechanism of capture-accelerated conversion mechanism of polysulfide at the surface of *** calculations indicate that the Li-O bond formed between Li atom(from Li_2 S_n,n=1,2,4,6,8) and O atom(from PO_3-OH in SnP) is the main reason for the strong interactions between Li_2 S_n and *** a result,SnP can effectively restrain the shuttle effect and improving the cycling performance of Li-S *** addition,by employing the climbing-image nudged elastic band(ciNEB) methods,the energy barrier for lithium sulfide decomposition(charging reaction) on SnP is proved to decrease significantly compared to that on *** can be concluded that SnP is an effective sulfur hosts acting as dual-functional accelerators for the conversion reactions of polysulfude to sulfide(discharging reaction) as well as polysulfide to sulfur(charging reaction).

关键词： Lithium-sulfur battery Tin(Ⅳ)phosphate Dual-functional accelerator Sulfur host Density functional theory calculations

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A Quantum Spatial Graph Convolutional Network for Text Classification

引用

Computer Systems Science & Engineering 2021年第2期36卷 369-382页

作者： syed Mustajar Ahmad Shah Hongwei Ge Sami Ahmed Haider Muhammad Irshad Sohail M.noman Jehangir Arshad Asfandeyar Ahmad Talha Younas College of Computer Science and Technology Dalian University of TechnologyDalian116024China Department of Computing University of WorcesterUK Department of Information Engineering Chang’an UniversityXi’an710054China Department of Cell Biology and Genetics Shantou University Medical CollegeShantou515041China Electrical and Computer Engineering Department COMSATS University IslamabadLahore CampusPakistan School of Information&Communication Engineering Dalian University of Technology Dalian116024China Electrical and Computer Engineering Department COMSATS University IslamabadSahiwal CampusPakistan

The data generated from non-Euclidean domains and its graphical representation(with complex-relationship object interdependence)applications has observed an exponential *** sophistication of graph data has posed consequential obstacles to the existing machine learning *** this study,we have considered a revamped version of a semi-supervised learning algorithm for graph-structured data to address the issue of expanding deep learning approaches to represent the graph ***,the quantum information theory has been applied through Graph Neural Networks(GNNs)to generate Riemannian metrics in closed-form of several graph *** further,to pre-process the adjacency matrix of graphs,a new formulation is established to incorporate high order *** proposed scheme has shown outstanding improvements to overcome the deficiencies in Graph Convolutional Network(GCN),particularly,the information loss and imprecise information representation with acceptable computational ***,the proposed Quantum Graph Convolutional Network(QGCN)has significantly strengthened the GCN on semi-supervised node classification *** parallel,it expands the generalization process with a significant difference by making small random perturbationsG of the graph during the training *** evaluation results are provided on three benchmark datasets,including Citeseer,Cora,and PubMed,that distinctly delineate the superiority of the proposed model in terms of computational accuracy against state-of-the-art GCN and three other methods based on the same algorithms in the existing literature.

关键词： Text classiﬁcation deep learning graph convolutional networks semi-supervised learning GPUs performance improvements

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Burnout amongst radiologists:A bibliometric study from 1993 to 2020

引用

World Journal of Psychiatry 2022年第2期12卷 368-378页

作者： Muhammad Fazal Hussain Qureshi danish Mohammad syed Mustafa Ali Shah Mahira Lakhani Muzna Shah Muhammad Hassan Ayub Sara Sadiq Medical College Ziauddin UniversityKarachi 75000SindhPakistan Department of Physiology CMH Institute of Medical SciencesBahawalpur 75000Pakistan

BACKGROUND Burnout amongst radiologists is common in many different institutions and is increasing day by *** battle burnout,we have to address the root causes already recognized in published ***,it is crucial to examine and discern important *** To provide evidence-based data and trends related to burnout in radiologists so that researchers can work on it further and develop preventive strategies to overcome this *** Bibliometric analysis conducted by two independent reviewers separately used Scopus Library for data extraction by using medical subject heading and International Classification of Diseases ***-nine articles were selected for analysis after an extensive *** Package for the Social Sciences version 20 was used for *** correlation coefficient,Kruskal Wallis test,and Mann-Whitney U test were *** The most productive period with regards to the number of publications was between 2017 and 2019.A total of 160 authors contributed to the topic burnout among radiologists,with an average of 3.26 authors per *** 41.68%of the authors were female,whilst 35%of them were first *** co-citation analysis by author involved 188 cited authors,13 of whom were cited at least 70 *** six out of forty-nine studies were funded by various government institutions and non-governmental *** Current analysis casts a spotlight on important trends being witnessed in regard to the mental health of radiologists,including lack of funding for mental health research,narrowing of female vs male citation gap,as well as authorship and citation trends.

关键词： Bibliometric Analysis Burnout Radiologist Stress Scientometrics

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：