检索结果-南通市图书馆

Investigation of the stress rupture behavior of GTD-111 superalloy melted by VIM/VAR

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2018年第9期25卷 1035-1041页

作者： Ainaz Agh alireza Amini Department of Materials Engineering Islamic Azad University Karaj Branch

The effects of vacuum induction melting(VIM) and vacuum arc remelting(VAR) processes on the microstructure and stress rupture properties of Ni-based GTD-111 superalloy were investigated. Samples of GTD-111 master alloy were melted in VIM and VAR furnaces and then poured into a preheated ceramic mold for VIM melt or into a water-cooled copper mold for VAR melt. The as-cast samples were examined radiographically to ensure that no casting defects were present in the final castings; the samples were then heat-treated using a standard heat-treatment cycle. The microstructure of the samples was investigated using optical microscopy and scanning electron microscopy in conjunction with energy-dispersive X-ray spectroscopy for microanalysis. On the basis of standard ASTM-E139, stress rupture tests were carried out at 1000°C under a stress of 300 MPa. The results showed that a γ matrix, fine γ′ precipitates, a γ–γ′ eutectic structure, carbide particles, and some harmful phases such as σ and η phases were present in the as-cast samples. The γ′ precipitates with cubic morphology appeared in the matrix after the standard heat-treatment process. The extent of segregation and the amount of γ–γ′ eutectic structure formed in the VAR-prepared sample were less than in the VIM-prepared sample. The results of stress rupture tests showed that the rupture time for the VAR sample was 43% longer than that for the VIM sample.

关键词： GTD-111 vacuum induction melting(VIM) vacuum arc remelting(VAR) stress rupture

Effect of simulating training of the fundamentals of laparoscopic surgery on the attitude of operating room nurses students:an intervention study

在线全文

学校读者我要写书评

暂无评论

Frontiers of Nursing 2024年第3期11卷 295-302页

作者： Reza Mohebbi Armin Fereidouni Sedigheh Hannani Esmaeil teymoori Nursing and Midwifery School Torbat Heydariyeh University of Medical SciencesTorbat HeydariyehIran Department of Operating Room Technology Community Based Psychiatric Care Research CenterSchool of Nursing and MidwiferyShiraz University of Medical SciencesShirazIran Department of Operating Room Technology School of ParamedicineIran University of Medical SciencesTehranIran Trauma and Surgery Research Center Aja University of Medical SciencesTehranIran Department of Operating Room Technology School of Paramedical SciencesAja University of Medical SciencesTehranIran

Objective:Clinical education plays a key role in preparing students for patient *** is one of the most important minimally invasive surgeries(MISs)wherein surgical technologists are responsible for camera navigation and assistant surgeons are responsible for peg ***,it is necessary to improve the attitude of the operating room students toward these skills during their study *** present study was conducted to determine the effect of simulating training in the fundamentals of laparoscopic surgery(FLS)on the attitude of the operating room ***:This interventional study was conducted on 28 operating room students of Iran University of Medical Sciences in *** census sampling method was *** data-collection tool included the“Intrinsic motivation inventory(IMI)questionnaire.”The educational intervention was carried out in theoretical(booklet design)and practical(simulation)*** analysis was carried out using descriptive and inferential analyses including the paired t-test,Mann–Whitney U test,and independent *** collected data were analyzed using R and SPSS software.P-value<0.05 was considered as the significant ***:The mean±SD of the participants'age was 22.93±2.14 years,and the majority of them were women(67.9%).There was a significant difference in the mean scores of students'attitudes toward the FLS before and after the educational intervention(P<0.001)in all dimensions(interest,perceived competence,perceived choice,and tension).There was also a significant correlation between gender and interest dimension(P=0.005).Conclusions:The results of the present study showed that simulating the training FLS curriculum positively affects students'***,the researchers suggest that for creating a positive attitude,increasing students'interest in laparoscopic surgery,and ensuring a more effective presence in the operating room,this training should be considered in the operating room curr

关键词： attitude education fundamentals of laparoscopic surgery nurse,operating room students stimulation

Indole cyanation via C-H bond activation under catalysis of Ru(Ⅲ)-exchanged NaY zeolite(RuY) as a recyclable catalyst

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2012年第8期23卷 903-906页

作者： alireza Khorshidi Department of Chemistry Faculty of SciencesUniversity of GuilanP.O.Box:41335-1914RashtIran

Selective 3-cyanation of indoles was achieved under heterogeneous catalysis of Ru（III）-exchanged NaY zeolite （RuY） as a recyclable catalyst, in combination with K4[Fe（CN）6] as a nontoxic, slow cyanide releasing ... 详细信息

关键词： Cyanation Indole Zeolite Heterogeneous Catalysis

Reliability Assessment of Integrated Electricity and Natural Gas Transmission Systems in Presence of Power-to-gas and Combined Heat and Power Technologies

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2023年第3期9卷 1193-1202页

作者： alireza Tabebordbar Mohammad Rastegar School of Electrical and Computer Engineering Shiraz UniversityShiraz 71946-84636Iran(the Islamic Republic of)

Assessing the reliability of integrated electricity and gas systems has become an important issue due to the strong dependence of these energy networks through the power-to-gas(P2G)and combined heat and power(CHP)*** current work,initially,presents a detailed energy flow model for the integrated power and natural gas system in light of the P2G and CHP *** the simultaneous load flow of networks,a contingency analysis procedure is proposed,and reliability is assessed through sequential Monte Carlo *** current study examines the effect of independent and dependent operation of energy networks on the reliability of the *** particular,the effect of employing both P2G and CHP technologies on reliability criteria is *** addition,a series of sensitivity analysis are performed on the size and site of these technologies to investigate their effects on system *** proposed method is implemented on an integrated IEEE 24-bus electrical power system and 20-node Belgian natural gas *** simulation procedure certifies the proposed method for reliability assessment is practical and *** addition,the results prove connection between energy networks through P2G and CHP technologies can improve reliability of networks if the site and size of technologies are properly determined.

关键词： CHP technology P2G technology integrated electrical power and natural gas network reliability assessment sequential Monte Carlo simulation method

Implementation of electrolyte CPA EoS to model solubility of CO2 and CO2+ H2S mixtures in aqueous MDEA solutions

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

Chinese Journal of Chemical Engineering 2019年第8期27卷 1912-1920页

作者： alireza Afsharpour Ali Haghtalab Department of Chemical Engineering Tarbiat Modares UniversityP.O.Box 14115-114TehranIran Faculty of Chemical and Materials Engineering Shahrood University of TechnologyShahroodIran

The electrolyte version of SRK plus association equation of state(e SRK-CPA Eo S) was employed to correlate CO2 solubility in MDEA aqueous solutions. The applied model comprises the classic form of CPA Eo S including SRK Eo S plus Wertheim association term in addition to MSA theory and Born terms so that the two last terms are responsible for the long-range interactions. A reaction-containing bubble pressure computation technique comprising two nested loops was utilized to model the systems. The internal loop, calculates the liquid phase concentrations via reaction, mass and charge balance equation solving, whereas, the vapor phase concentrations will be obtained in the external one. 470 experimental data were used to correlate binary subsystems and the H2O + MDEA + CO2 ternary system. Since, there not exist any binary VLE data for MDEA + CO2 subsystem, two fitting scenarios were applied. At the first scenario, the binary interaction parameter was assumed equal to zero, while, in second approach the parameter was obtained through ternary system correlation. Both scenarios show very good accuracy in that the Absolute Average Deviation percentages(AAD) obtained were 19.12% and 18.85%, respectively. Also, to show the efficiency of the used model, a comparison between our results and those of the best-known models was ***, having model parameters for H2S solubility from our previous work [A. Afsharpour, Petroleum Science and Technology 35(3)(2017) 292-298], simultaneous solubility of CO2+ H2S mixtures in MDEA solutions was predicted using the e SRK-CPA Eo S with no new optimizable parameters. As the results show,the applied model has a good performance for correlation and prediction of acid gas solubility in a wide range of pressures, temperatures, acid gas loadings, and MDEA concentrations.

关键词： Acid gas solubility MDEA Thermodynamic modeling Phase equilibria CPA EoS Prediction

Nonlinear vibration analysis of a circular micro-plate in two-sided NEMS/MEMS capacitive system by using harmonic balance method

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2019年第1期35卷 129-143,I0004页

作者： Milad Saadatmand alireza Shooshtari Department of Electrical Engineering Technical University of DenmarkKgs.LyngbyDenmark Department of Mechanical Engineering Bu-Ali Sina UniversityHamedanIran

In this study, forced nonlinear vibration of a circular micro-plate under two-sided electrostatic, two-sided Casimir and external harmonic forces is investigated analytically. For this purpose, at first, von Karman plate theory including geometrical nonlinearity is used to obtain the deflection of the micro-plate. Galerkin decomposition method is then employed, and nonlinear ordinary differential equations (ODEs) of motion are determined. A harmonic balance method (HBM) is applied to equations and analytical relation for nonlineaT frequency response (F-R) curves are derived for two categories (including and neglecting Casimir force) separately. The analytical results for three cases:(1) semi-linear vibration;(2) weakly nonlinear vibration;(3) highly non linear vibration, are validated by comparing with the numerical solutio ns. After validation, the effects of the voltage and Casimir force on the natural frequency of two-sided capacitor system are investigated. It is shown that by assuming Casimir force in small gap distances, reduction of the natural frequency is considerable. The influences of the applied voltage, damping, micro-plate thickness and Casimir force on the frequency response curves have been presented too. The results of this study can be useful for modeling circular parallel-plates in nano /microelectromechanical transducers such as microphones and pressure sensors.

关键词： Nonlinear vibration Two-sided MEMS capacitor Circular plate Harmonic balance method

Identification of a novel nonsense mutation in kyphoscoliosis peptidase gene in an Iranian patient with myofibrillar myopathy

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

Genes & Diseases 2018年第4期5卷 331-334页

作者： Reza Ebrahimzadeh-Vesal Atieh teymoori Ali Mohammad Dourandish Mohsen Azimi-Nezhad Department of Basic Medical Sciences Neyshabur University of Medical SciencesNeyshaburIran Department of Medical Genetics School of MedicineGolestan University of Medical SciencesGorganIran Medical Genetics Counseling Center NeyshaburIran Department of Medical Genetics School of MedicineMashhad University of Medical SciencesMashhadIran

Myofibrillar myopathies(MFMs)are rare genetic and slowly progressive neuromuscular *** pathogenic mutations have been reported in MFM-related genes including DES,CRYAB,MYOT,LDB3 or ZASP,FLNC,BAG3,FHL1 and *** MFMs is commonly inherited in an autosomal dominant manner,the inheritance pattern and novel mutated genes are not thoroughly elucidated in some ***,we report discovery of a novel nonsense mutation in a 29-year-old Iranian male patient with motor disorders and deformity in his lower *** parents are second *** Motor Sensory Neuropathy as initial genetic diagnosis was ruled *** exome sequencing using NGS on Illumina Hi-Seq4000 platform was performed to identify the disease and possible mutated gene(s).Our data analysis identified a homozygous nonsense unreported c.C415T(p.R139X)variant on kyphoscoliosis peptidase(KY)gene(NM_178554:exon4).Sanger sequencing of this mutation has been performed for his other related family *** and segregation analysis was confirmed the NGS results and autosomal recessive inheritance pattern of the disease.

关键词： Kyphoscoliosis peptidase gene Myofibrillar myopathy Next generation sequencing Novel mutation Rare genetic neuromuscular disorders

Intelligent modeling and identification of aircraft nonlinear flight

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

Chinese Journal of Aeronautics 2014年第4期27卷 759-771页

作者： alireza Roudbari Fariborz Saghafi Department of Aerospace Engineering Sharif University of Technology

In this paper, a new approach has been proposed to identify and model the dynamics of a highly maneuverable fighter aircraft through artificial neural networks（ANNs）. In general, aircraft flight dynamics is considered as a nonlinear and coupled system whose modeling through ANNs, unlike classical approaches, does not require any aerodynamic or propulsion information and a few flight test data seem sufficient. In this study, for identification and modeling of the aircraft dynamics, two known structures of internal and external recurrent neural networks（RNNs） and a proposed structure called hybrid combined recurrent neural network have been used and *** order to improve the training process, an appropriate evolutionary method has been applied to simultaneously train and optimize the parameters of ANNs. In this research, it has been shown that six ANNs each with three inputs and one output, trained by flight test data, can model the dynamic behavior of the highly maneuverable aircraft with acceptable accuracy and without any priori knowledge about the system.

关键词： Flight test Genetic algorithms Nonlinear flight dynamicsNonlinear systemidentification Recurrent neural network

A New Characterization of L_2(r) by Their Sylow Numbers

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2015年第10期31卷 1593-1598页

作者： alireza Khalili ASBOEI Department of Mathematics Farhangian University Department of Mathematics Buinzahra Branch Islamic Azad University

Let G be a finite centerless group, let π（G） be the set of prime divisors of the order of G, and let np（G） be the number of Sylow p-subgroups of G, that is, np（G） = ｜Sylp（G）｜. Set NS（G）：= ｜np（G）｜ p ∈ π（G）}. In this paper, we are investigating whether L2（r） is determined up to isomorphism by NS（L2（r）） when r is prime.

关键词： Finite group simple group Sylow subgroup