检索结果-南通市图书馆

A novel approach for the design of axial flow fan by increasing by-pass ratio in a constantdiameter turbofan

在线全文

学校读者我要写书评

暂无评论

propulsion and power Research 2020年第2期9卷 142-158页

作者： Ali shahsavari Mahdi Nili-Ahmadabadi Department of Mechanical Engineering.Isfahan University of Technology Isfahan***Iran

The present study introduces an innovative aerodynamic redesign of an axial flow fan based on constant diffusion factor and radial *** input design parameters such as mass flow rate,hub to tip ratio,aspect ratio,tip diameter and angular velocity are taken from NASA Rotor 67 as a conventional axial flow fan.A computer program is developed to extract the three-dimensional geometry of a fan and to estimate the span-wise distribution of *** new designed fan flow field is investigated in detail by CFD tool at both design and off design ***,a turbofan cycle analysis is conducted based on thermodynamic and gas dynamic principles to evaluate the fan performance in a turbofan engine in comparison to NASA Rotor *** a higher total pressure ratio,meeting the target pressure ratio in lower rotational speed with higher efficiency,delivering more bypass air in a constant diameter and less fuel consumption for the same specific thrust force are the main advantages for the new design strategy in comparison to the conventional designed fans such as Rotor ***,efficiency reduction in fan over speed is the main disadvantage.

关键词： Axial flow fan Bypass ratio Computer simulation Design methodology Thermodynamic turbofan cycle analysis

A robust predictive tool for estimating CO2 solubility in potassium based amino acid salt solutions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2018年第4期26卷 740-746页

作者： Ebrahim Soroush Shohreh shahsavari Mohammad Mesbah Mashallah Rezakazemi Zhi'en Zhang Young Researchers and Elites Club Ahvaz Branch Islamic Azad University Ahvaz Iran Department of Cheraical Engineering Sahand University of Technology Tabriz Iran Young Researchers and Elites Club Science and Research Branch Islaraic Azad University Tehran Iran Department of Cheraical Engineering Shahraod University of Technology Shahrood Iran School of Cheraistry and Chemical Engineering Chongqing University of Technology Chongqing 400054 China Key Laboratory of Low-grade Energy Utilization Technologies and Systems Ministry of Education of China Chongqing University Chongqing 400044 China

The acid gas absorption in four potassium based amino acid salt solutions was predicted using artificial neural network(ANN). Two hundred fifty-five experimental data points for CO_2 absorption in the four potassium based amino acid salt solutions containing potassium lysinate, potassium prolinate, potassium glycinate, and potassium taurate were used in this modeling. Amine salt solution's type, temperature, equilibrium partial pressure of acid gas, the molar concentration of the solution, molecular weight, and the boiling point were considered as inputs to ANN to prognosticate the capacity of amino acid salt solution to absorb acid gas. Regression analysis was employed to assess the performance of the network. Levenberg–Marquardt back-propagation algorithm was used to train the optimal ANN with 5:12:1 architecture. The model findings indicated that the proposed ANN has the capability to predict precisely the absorption of acid gases in various amino acid salt solutions with Mean Square Error(MSE) value of 0.0011, the Average Absolute Relative Deviation(AARD) percent of 5.54%,and the correlation coefficient(R^2) of 0.9828.

关键词： Amino acid salt solutions Acid gas absorption Neural network CO2 capture

RANS simulations on combustion and emission characteristics of a premixed NH_(3)/H_(2) swirling flame with reduced chemical kinetic model

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2021年第12期34卷 17-27页

作者： Yuze SUN Tao CAI Mohammad shahsavari Dakun SUN Xiaofeng SUN Dan ZHAO Bing WANG Department of Mechanical Engineering University of CanterburyChristchurch 8041New Zealand School of Aerospace Engineering Tsinghua UniversityBeijing 100084China Collaborative Innovation Center for Advanced Aero-Engine Beihang UniversityBeijing 100083China

Ammonia(NH_(3))is considered as a potential alternative carbon free fuel to reduce greenhouse gas emission to meet the increasingly stringent emission ***-burning NH_(3) and H_(2) is an effective way to overcome ammonia’s relative low burning *** this work,3D Reynolds Averaged Navier-Stokes(RANS)numerical simulations are conducted on a premixed NH_(3)/H_(2) swirling flame with reduced chemical kinetic *** effects of(A)overall equivalence ratio Φ and(B)hydrogen blended molar fraction XH2 on combustion and emission characteristics are *** present results show that when 100%NH_(3)-0%H_(2)-air are burnt,the NO emission and unburned NH3 of at the swirling combustor outlet has the opposite varying *** the increase of Φ,NO emission is found to be decreased,while the unburnt ammonia emission is ***_(2)→HNO,NH→HNO and HNO→NO sub-paths are found to play a critical role in NO *** reaction rate of all these three sub-paths is shown to be decreased with increased Φ.Hydrogen addition is shown to significantly increase the laminar burning velocity of the mixed ***,adding H_(2) does not affect the critical equivalence ratio corresponding to the maximum burning *** emission trend of NO and unburnt NH_(3) with increased Φ is unchanged by blending H_(2).NO emission with increased X_(H2) is increased slightly less at a larger Φ than that at a smaller Φ.In addition,reaction rates of NH_(2)→HNO and HNO→NO sub-paths are decreased with increased X_(H2),when Φ is *** all tested cases,blending H_(2) with NH_(3) reduces the unburned NH_(3) emission,especially for rich combustion *** summary,the present work provides research finding on supporting applying ammonia with hydrogen blended in low-emission gas turbine engines.

关键词： Ammonia Emission Hydrogen premixed combustion Reduced mechanism Swirling flame

Expanding beyond endoscopy: A review of non-invasive modalities in Barrett’s esophagus screening and surveillance

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2022年第32期28卷 4516-4526页

作者： Dariush shahsavari praneeth Kudaravalli John Erikson L Yap Kenneth J Vega Division of Gastroenterology and Hepatology Augusta University-Medical College of GeorgiaAugustaGA 30912United States

Barrett’s esophagus(BE)is a condition that results from replacement of the damaged normal squamous esophageal mucosa to intestinal columnar mucosa and is the most significant predisposing factor for development of esophageal *** guidelines recommend endoscopic evaluation for screening and surveillance based on various risk factors which has limitations such as invasiveness,availability of a trained specialist,patient logistics and ***-nasal endoscopy is a less invasive modality but still has similar limitations such as limited availability of trained specialist and ***-endoscopic modalities,in comparison,require minimal intervention,can be done in an office visit and has the potential to be a more ideal choice for mass public screening and surveillance,particularly in patents at low risk for *** include newer generations of esophageal capsule endoscopy which provides direct visualization of BE,and tethered capsule endomicroscopy which can obtain high-resolution images of the *** cell collection devices coupled with biomarkers have been used for BE ***,in combination with TFF3,as well as EsophaCap and EsoCheck have shown promising results in various studies when used with various *** modalities including circulatory microRNAs and volatile organic compounds that have demonstrated favorable *** of these cell collection methods for BE surveillance is a potential area of future research.

关键词： Barrett’s esophagus Screening Surveillance Non-endoscopic Cytosponge Esophacap Esocheck

Oligocene subduction-related plutonism in the Nodoushan area,Urumieh-Dokhtar magmatic belt: petrogenetic constraints from U-pb zircon geochronology and isotope geochemistry

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2019年第2期10卷 725-751页

作者： Badieh shahsavari Alavijeh Nematollah Rashidnejad-Omran Fatma Toksoy-K?ksal Wenliang Xu Jalil Ghalamghash Department of Geology Faculty of Basic SciencesTarbiat Modares University Department of Geological Engineering Middle East Technical University College of Earth Sciences Jilin University State Key Laboratory of Geological processes and Mineral Resources China University of Geosciences Research Institute for Earth Sciences Geological Survey of Iran

Geochemical data and Sr-Nd isotopes of the host rocks and magmatic microgranular enclaves(MMEs)collected from the Oligocene Nodoushan plutonic Complex(NpC) in the central part of the Urumieh-Dokhtar Magmatic Belt(UDMB) were studied in order to better understand the magmatic and geodynamic evolution of the UDMB. New U-pb zircon ages reveal that the NpC was assembled incrementally over ca. 5 m.y., during two main episodes at 30.52 ± 0.11 Ma and 30.06 ± 0.10 Ma in the early Oligocene(middle Rupelian) for dioritic and granite intrusives, and at 24.994 ± 0.037 Ma and 24.13 ± 0.19 Ma in the late Oligocene(latest Chattian) for granodioritic and diorite porphyry units,respectively. The spherical to ellipsoidal enclaves are composed of diorite to monzodiorite and minor gabbroic diorite(SiO_2 = 47.73-57.36 wt.%; Mg# = 42.15-53.04); the host intrusions are mainly granite,granodiorite and diorite porphyry(SiO_2 = 56.51-72.35 wt.%; Mg# = 26.29-50.86). All the samples used in this study have similar geochemical features, including enrichment in large ion lithophile elements(LILEs, e.g. Rb, Ba, Sr) and light rare earth elements(LREEs) relative to high field strength elements(HFSEs) and heavy rare earth elements(HREEs). These features, combined with a relative depletion in Nb,Ta, Ti and p, are characteristic of subduction-related magmas. Isotopic data for the host rocks display ISr = 0.705045-0.707959, εNd(t) =-3.23 to +3.80, and the Nd model ages(TDM) vary from 0.58 Ga to 1.37 Ga. Compared with the host rocks, the MMEs are relatively homogeneous in isotopic composition,with Isr ranging from 0.705513 to 0.707275 and εNd(t) from -1.46 to 4.62. The MMEs have TDM ranging from 0.49 Ga to 1.39 Ga. Geochemical and isotopic similarities between the MMEs and their host rocks demonstrate that the enclaves have mixed origins and were most probably formed by interactions between the lower crust-and mantle-derived magmas. Geochemical data, in combination with geodynamic evidence, suggest that

关键词： Urumiehe-Dokhtar magmatic belt Granitoid rocks Subduction Zircon U-pb ages Radiogenic isotopes Central Iran

Concept analysis of coping with multiple sclerosis

在线全文

学校读者我要写书评

暂无评论

International Journal of Nursing Sciences 2018年第2期5卷 168-173页

作者： Ali Dehghani Abdolkhalegh Keshavarzi Mohsen Faseleh Jahromi Sara shahsavari isfahani Soheila Keshavarzi School of Nursing and paramedical Jahrom University of Medical ScienceJahromIran Research Center for Noncommunicable Diseases Jahrom University of Medical SciencesJahromIran Department of General Surgery School of MedicineMember of Shiraz Burn Research CenterShiraz University of Medical SciencesShirazIran Department of Counseling Faculty of Psychology and Educational SciencesIslamic Azad UniversityMarvdasht BranchMarvdashtIran

Objective:The concept of coping with disease appears frequently in the literature;however,there is no precise definition of *** aim of this study is to clarify coping concept,and to identify its attributes,antecedents,and consequences in patients with multiple ***:Rodgers'evolutionary method of concept analysis was used to clarify the concept of coping.A literature review was conducted with key terms‘multiple sclerosis’,‘coping’,‘adjustment’,and‘deal with’.After searching databases,1370 papers were found for the period ***,55 articles and texts were selected for *** analysis was carried out using thematic *** independent researcher checked the process to ensure credibility and reduce personal ***:Coping with multiple sclerosis is a multidimensional concept with three main attributes:maintenance of emotional balance,acceptance of the disease,and *** support,awareness toward the disease,attitude toward the disease,and religious-spiritual beliefs were found as *** promotion,adherence to treatment regimen,independence in personal life and social relationships,and improvement of family relationships were found as consequences of these ***:These findings not only add to the body of knowledge in health science,but also serve as an important motivation for further theory development and research in this *** and health professions can also benefit from a deeper understanding of coping concept in providing and planning healthcare for these patients.

关键词： Concept analysis Coping Evolutionary method Multiple sclerosis

Etiology and resistance of asymptomatic bacteriuria isolates among school going children in Sanadaj-Iran

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian pacific Journal of Tropical Medicine 2008年第4期1卷 28-31页

作者： Sofei-Majidpur H Kalantar E Verdi F Khaksar N shahsavari S Beiranvand S Department of Urology Beassat HospitalKurdistan University of Medical SciencesSanandajIran Department of Microbiology School of MedicineKurdistan University of Medical SciencesSanandajIran Microbiology Laboratory Qodss HospitalKurdistan University of Medical SciencesSanandajIran Department of Hygiene School of HealthKurdistan University of Medical SciencesSanandajIran Food and Drug Department Kurdistan University of Medical SciencesSanandajIran

Objective:The objective of this study was to determine the etiology and antimicrobial susceptibility patterns of asymptomatic bacteriuria pathogens isolated among school going children in Sanandaj,***:A total of 1 457 urine samples of 5 to 10 years children from forty different schools of Sanandaj city were screened to see asymptomatic bacteriuria during November 2007 to June ***:Bacterial colony count of over (105) colony forming units CFU/ mL were found in 28(1.90%) of total cases,with 767(52.64%) girls and 690(47.35%) *** highest class-specific prevalence was found in the fourth standard(2.8%) and the lowest in the first standard(1.0%).The dominant bacterial isolates were *** 20(74.1%),followed by Klebsiella pneumoniae 04(14.8%) and Staphylococcus aureus 04(14.8%).Cefotaxime,Cefixime,Kanamycin, Co-trimoxazole,nalidicxic acid,nitrofurantoin and Amoxicillin,resistance rates were above 90.0%. Ceftriaxone expressed the highest susceptibility among *** ***,*** showed 100. 0%resistance to ***:In the present study in which Escherichia coli is the most frequently incriminated as the causative *** results show a very serious antibiotic resistance of *** isolated. Surveillance and monitoring studies will be essential in preventing of renal scarring or other abnormalities.

关键词： School going children Asymptomatic Urinary tract infections

Time History Dynamic Analysis of a New Constructed Offshore Jacket platform in persian Gulf Due to Random Waves

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Marine Science and Application 2019年第3期18卷 372-379页

作者： Abdolrahim Taheri Ehsan shahsavari Department of Mechanical Engineering Petroleum University of Technology

ApI Rp2AWSD is a design code in practice for design of jacket platforms in the persian Gulf but is based on the Gulf of Mexico environmental condition. So for the sake of using this code for the persian Gulf, it is better to perform a calibration based on this specific region. Analysis and design of jacket platforms based on ApI code are performed in a static manner and dynamic analysis is not recommended for such structures. Regarding the fact that the real behavior of the offshore jacket platforms is a dynamic behavior, so in this research, dynamic analysis for an offshore jacket platform in the persian Gulf under extreme environmental condition is performed using random time domain method. Therefore, a new constructed offshore jacket platform in the persian Gulf is selected and analyzed. Fifteen, 1-h storm, simulations for the water surface elevation is produced to capture the statistical properties of extreme sea condition. Time series of base shear and overturning moment are derived from both dynamic and static responses. By calculating the maximum dynamic amplification factor (DAF) from each simulation and fitting the collected data to Weibull distribution, the most probable maximum extreme (MpME) value for the DAF is achieved. Results show that a realistic value for DAF for this specific platform is 1.06, which is a notable value and is recommended to take into practice in design of fixed jacket platform in the persian Gulf.

关键词： Offshore platforms Weibull distribution Water surface simulation Time history analysis Dynamic amplification factor persian Gulf

Identification of medicinal plants effective in infectious diseases in Urmia, northwest of Iran

在线全文

学校读者我要写书评

暂无评论

Asian pacific Journal of Tropical Biomedicine 2015年第10期5卷 858-864页

作者： Mahmoud Bahmani Kourosh Saki Somayeh shahsavari Mahmoud Rafieian-Kopaei Reza Sepahvand Ahmad Adineh Food and Beverages Safety Research Center Urmia University of Medical Sciences Shahid Beheshti University of Medical Sciences Young Researchers and Elite Club Khorramabad BranchIslamic Azad University Medical plants Research Center Shahrekord University of Medical Sciences Razi Herbal Medicines Research Center Lorestan University of Medical Sciences Department of pharmacology and Toxicology Faculty of PharmacyPharmaceutical Sciences BranchIslamic Azad University

Objective: To identify the medicinal plants effective in infectious ***: Initially, we obtained a list of herbalists and traditional healers from Food and Drug Deputy. Direct observations and interviews as well as collection of herbarium specimens of indigenous medicinal plants effective in infectious diseases of urinary tract,reproductive, digestive, respiratory and skin systems were performed. This study was conducted through questionnaires and interviews; the questionnaires were distributed among traditional healers and simultaneous interviews were also run. The plants were herbariumized, herbarium specimens were authenticated, and their species were determined by using reliable flora and other sources. Finally, the data were input into Excel2010 and analyses were ***: Out of the studied plants, 35 native medicinal plants belonging to 17 families were effective in the treatment of various diseases and infections. In this study, the Lamiaceae family had the highest frequency of plants for the treatment of *** healers of Urmia in 24% of cases used the leaves of medicinal herb to treat patients. In 68% of cases, they prescribed medicinal herbs in the boiled forms. Most medicinal herbs showed therapeutic effect on the digestive ***: Traditional medicinal sources, valuable knowledge of traditional healers in Urmia, the scientific investigation of the effects of the herbs offered in this study and their effects in traditional medicine may provide a good source for new drugs in modern medicine.

关键词： medicinal infectious digestive northwest simultane