检索结果-南通市图书馆

Earthquake Engineering and Engineering Vibration 2014年第4期13卷 707-716页

作者： Kazem Shakeri Karim Tarbali Mohtasham mohebbi Faculty of Engineering University of Mohaghegh Ardabili International Institute of Earthquake Engineering and Seismology

A pushover procedure with a load pattern based on the height-wise distribution of the combined modal story shear and torsional moment is proposed to estimate the seismic response of 3D asymmetric-plan building frames. Contribution of the higher modes and torsional response of asymmetric-plan buildings are incorporated into the proposed load pattern. The proposed pushover method is a single-run procedure, which enables tracing the nonlinear response of the structure during the analysis and averts the elusiveness of conducting multiple pushover analyses. The proposed method has been used to estimate the response of two moment-resisting building frames with 9 and 20 stories. The obtained results indicate the appropriate accuracy and efficiency of the proposed procedure in estimating the trend of the drift profiles of the structures resulted from nonlinear time history analyses.

关键词： pushover analysis asymmetric-plan building torsional response story shear torsional moment

Experimental and statistical assessments of the mechanical strength reliability of gamma alumina catalyst supports

在线全文

学校读者我要写书评

暂无评论

Particuology 2015年第4期13卷 74-81页

作者： Abdolreza Samimi Mozhgan Zakeri Basir Maleki Davod mohebbi-Kalhori Department of Chemical Engineering University of Sistan and Baluchestan

The mechanical strength of solid catalysts is considered an important factor in terms of ensuring the reliable performance of industrial reactors. In this work, a pelletizing method was used to form gamma alumina support for catalysts. Response surface methodology （RSM） was employed to analyze and model the effects of various manufacturing parameters on the crushing strength of the supports. These parameters were binder concentration, compaction pressure, calcination temperature, and drying mode. The suggested model was verified by applying an analysis of variance to assess its validity with regard to crushing strength. The mechanical reliability of various supports was also determined by calculating their Weibull modulus values through linear regression of the Weibull equation. The material with the highest mechanical strength reliability will have both a high mean crushing strength and a high Weibull modulus, and the best values obtained for a support in this work were 70.7 MPa and 6.63, respectively. The conditions used to form this sample were： 20mass% binder concentration, 861 MPa compaction pressure, 466 ℃ calcination temperature, and gentle drying.

关键词： Crushing strength Brittle material Weibull modulus Pelletizing Response surface methodology

Investigation of Poly(ether-b-amide)/Nanosilica Membranes for CO_2/CH_4 Separation

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2014年第4期32卷 402-410页

作者： Ehsan Seddigh Morteza Azizi Ehsan Shirzaei Sani Davod mohebbi-Kalhori Department of Chemical Engineering University of Sistan and Baluchestan

The results of molecular dynamics （MD） simulations on transport process of CO2 and CH4 gases in poly（ether-b- amide）（PEBAX）/nanosilica membranes are discussed. The diffusion coefficients for CH4 and CO2 gases at 6 cases with different amounts of nanosilica loading in the simulation boxes are presented. The results show that diffusion coefficients for CO2 gas in all cases are larger than those for the CH4 one. Moreover 10% nanosilica loading case shows maximum effects on diffusion coefficients and improves them by more than 68% and 157% for CO2 and CH4 gases, respectively. Additionally, the results of 3-D Cartesian trajectories and displacements curves are presented and the jumping attempt of CO2 is significantly more than that of CH4. Due to the rubbery state of PEBAX membranes in ambient temperature, the results confirm that channel lifetimes are very short and then back diffusion is not observed for this polymer.

关键词： Gas separation Polymeric membrane Molecular dynamics Diffusion coefficient.

A laboratory study of hot WAG injection into fractured and conventional sand packs

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2009年第4期6卷 400-404页

作者： M J Dorostkar A mohebbi A Sarrafi A Soltani Department of Chemical Engineering College of EngineeringShahid Bahonar University of Kerman

Gas injection is the second largest enhanced oil recovery process, next only to the thermal method used in heavy oil fields. To increase the extent of the reservoir contacted by the injected gas, the gas is generally injected intermittently with water. This mode of injection is called water-alternating-gas (WAG). This study deals with a new immiscible water alternating gas (IWAG) EOR technique, “hot IWAG” which includes combination of thermal, solvent and sweep techniques. In the proposed method CO2 will be superheated above the reservoir temperature and instead of normal temperature water, hot water will be used. Hot CO2 and hot water will be alternatively injected into the sand packs. A laboratory test was conducted on the fractured and conventional sand packs. Slugs of water and CO2 with a low and constant rate were injected into the sand packs alternatively; slug size was 0.05 PV. Recovery from each sand pack was monitored and after that hot water and hot CO2 were injected alternatively under the same conditions and increased oil recovery from each sand pack and breakthrough were measured. Experimental results showed that the injection of hot WAG could significantly recover residual oil after WAG injection in conventional and fractured sand packs.

关键词： Hot water-alternating-gas (WAG) enhanced oil recovery (EOR) fractured sand pack conventional sand pack gas injection

Spatial study of particulate matter distribution, based on climatic indicators during major dust storms in the State of Arizona

在线全文

学校读者我要写书评

暂无评论

Frontiers of Earth Science 2021年第1期15卷 133-150页

作者： Amin mohebbi Fan YU Shiqing CAI Simin AKBARIYEH Edward J.SMAGLIK Department of Civil Engineering Construction Managementand Environmental EngineeringNorthern Arizona UniversityFlagstaffAZ 86011USA Department of Civil and Environmental Engineering California Polytechnic State UniversitySan Luis ObispoCA 93407USA

Arizona residents have been dealing with the suspended particulate matter caused health issues for a long time due to Arizona’s arid *** state of Arizona is vulnerable to dust stomas,especially in die monsoon season because of the anomalies in wind direction and *** this study,a high-resolution Weather Research and Forecasting(WRF)model coupled with a chemistry module(WRF-Chem)was simulated to compute the particulate matter spatiotemporal distribution as well as the climatic parameters for the state of ***,Ordinary Least Square(OLS),spatial lag,spatial error,and Geographically Weighted Regression(GWR)techniques were utilized to develop predictive models based on the climatic indicators that impacted the formation and dispersion of the particulate matter during dust *** tracts were adopted to create local spatial averages for the chosen *** height,temperature,wind speed,and vegetation fraction were designated as the most significant variables,whereas base state and perturbation pressures,planetary boundary layer height and soil moisture were adopted as supplementary *** determination coefficient for OLS,spatial lag,spatial error,and GWR models peaked at 0.92,0.93,0.96,and 0.97,*** models provide a better understanding of the current distribution of the particulate matter and can be used to forecast future trends.

关键词： particulate matter dust storm Weather Research and Forecasting census tracts Ordinary Least Square Geographically Weighted Regression

Relationship between quality of professional life and organizational commitment in intensive care unit nurses

在线全文

学校读者我要写书评

暂无评论

Frontiers of Nursing 2021年第4期8卷 399-406页

作者： Mahboobeh Magharei Zinat mohebbi Soheila Jafari Department of Nursing School of Nursing and MidwiferyShiraz University of Medical SciencesShirazIran Student Research Committee Shiraz University of Medical SciencesShirazIran

Objective:The quality of professional life has attracted the attention of many managers owing to its importance,and organizational commitment differs according to work conditions in an *** the largest professional group in the healthcare system,nurses face many stressful factors that can endanger their quality of professional life and organizational *** their huge importance,these 2 variables have rarely been addressed or evaluated in the nursing *** present study was conducted to determine the relationship between quality of professional life and organizational commitment in nurses working in the intensive care units(ICUs)and critical care units(CCUs).Methods:The present descriptive-analytical study was conducted on 221 nurses working in the ICUs of hospitals affiliated to Shiraz University of Medical Sciences and selected through proportional stratified *** data collection tools comprised demographic questionnaires,the quality of work-life questionnaire by Walton with 8 dimensions,and the valid and reliable organizational commitment scale by Meyer and *** data were analyzed in SPSS,version 23(IBM Corporation,Armonk,New York,United States),using descriptive and inferential statistical techniques,including Spearman correlation,Pearson correlation,the Kruskal-Wallis test,the Mann-Whitney U test,the c2 test,and the independent t test.P<0.050 was set as the level of statistical ***:The mean scores of quality of professional life and organizational commitment were 58.996±14.427 and 93.840±13.900,respectively,in the ICU *** Pearson test showed positive and significant relationships between quality of professional life and organizational commitment(r=0.392,P<0.001).Conclusions:Given the positive relationship found in the present study between organizational commitment and quality of professional life,it is recommended that organizational commitment be modified to improve the quality of profession

关键词： quality of professional life organizational commitment nurses ICU CCU

Synthesis and antibacterial activity of Schiff bases of 5-substituted isatins

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2016年第2期27卷 221-225页

作者： Kamaleddin Haj Mohammad Ebrahim Tehrani Maryam Hashemi Maryam Hassan Farzad Kobarfard Shohreh mohebbi Department of Medicinal Chemistry School of PharmacyZanjan University of Medical SciencesZanjanlran Department of Pharmaceutical Biotechnology School of PharmacyZanjan University of Medical SciencesZanjanIran Department of Medicinal Chemistry School of PharmacyShahid Beheshti University of Medical SciencesTehranIran Phytochemistry Research Center Shahid Beheshti University of Medical SciencesTehranIran

Based on the existing reports on the bioactive isatin derivatives, a number of Schiff bases were synthesized by reacting 5-substituted isatins with bioactive amines/hydrazides and their structures were confirmed using spectroscopic methods such as NMR, IR and mass spectrometry. Furthermore, Nbenzylation of isatin followed by the Schiff base formation furnished a new series of compounds（11a-13c） which allowed the analysis of the effect of isatin N-substitution on the bioactivity of the resulting compounds. The antibacterial activity of the synthesized derivatives was evaluated using a microtiter plate method on a series of gram positive and gram negative bacterial strains. Compounds 2d, 3b, 5c and 6a were among the most potent derivatives against Pseudomonas aeruginosa（MIC = 6.25 μg/m L）.Analysis of the structure-activity relationship showed that the incorporation of（thio）urea-based Schiff bases lead to more potent derivatives with a broader spectrum of antibacterial activity. In addition,highly lipophilic compounds such as 11a-12c did not show any measurable antibacterial activity, which implies that an optimal lipophilicity might be an important requirement for the antibacterial activity of the studied isatins. Finally, the finding that hydantoin derivatives of N-benzylisatins（13a-13c） still exhibit some antibacterial activity prompted us to consider exploring the bioactivity of more diverse derivatives of isatin-aminohydantoin Schiff bases（compounds 1a-1d） in our future studies.

关键词： Synthesis Isatin Schiff base Hydantoin Antibacterial

Generation of 40-as few-cycle pulse through chirp manipulation

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2012年第8期10卷 50-52页

作者： Masoud mohebbi Saeed Batebi Department of Physics Faculty of ScienceUniversity of Guilan No.41335-19141RashtIran

We discuss theoretically how supercontinuum spectra produced from high-order harmonic generation processes in a synthesized same-color laser field is optimized by adjusting the chirp parameter of the controlling pulse. Furthermore, a 40-attosecond isolated pulse with an effective bandwidth of 121 orders is obtained from He＋ ion when the chirp rate ratio of pulses has a small value. The numerical results show that the efficiency of single as pulse generation is enhanced, and the quantum paths are controlled successfully. Our simulation shows that the produced pulses with high signal-to-noise ratio are obtained straightforwardly without any phase compensation. These results are explained using the classical approach.

关键词： 190.0190 Nonlinear optics 140.0140 Lasers and laser optics

Correlation of Shear Viscosity of Nanofluids Using the Local Composition Theory

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2010年第1期18卷 102-107页

作者： M.S. Hosseini A. mohebbi S Ghader Department of Chemical Engineering College of Engineering Shahid Bahonar University of Kerman Kerman Iran

In this study,a new method is presented to correlate the shear viscosity of nanofluids by local composition *** Eyring theory and nonrandom two-liquid(NRTL)equation are used for this *** effects of temperature and particle volume concentration on the viscosity are *** adjustable parameters of NRTL equation are obtained by fitting with experimental *** calculated shear viscosities for nanofluids of CuO/water with 29 nm particle size,Al2O3/water with two different particle diameters,36 nm and 47 nm,and CuO/(ethylene glycol,water)are compared with experimental data and the average absolute deviation(AAD)is 1.2%,while the results from some conventional models yield an AAD of 190%.The results of this study are in excellent agreement with experimental data.

关键词： nanofluid viscosity local composition theory nonrandom two-liquid equation Eyring theory

Hydroxycitric acid ameliorates inflammation and oxidative stress in mouse models of multiple sclerosis

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2016年第10期11卷 1610-1616页

作者： Mahdi Goudarzvand Sanaz Afraei Somaye Yaslianifard Saleh Ghiasy Ghazal Sadri Mustafa Kalvandi Tina Alinia Ali mohebbi Reza Yazdani Shahin Khadem Azarian Abbas Mirshafiey Gholamreza Azizi Department of Physiology and Pharmacology Faculty of Medicine Alborz University of Medical Sciences Department of Immunology School of Public Health Tehran University of Medical Sciences Department of Microbiology and Immunology School of MedicineAlborz University of Medical Sciences Research Centre for Immunodeficiencies Pediatrics Centre of Excellence Children's Medical Centre Tehran University of Medical Sciences Growth and Development Research Centre Paediatrics Centre of Excellence Children's Medical Centre Tehran University of Medical Sciences Department of Immunology School of Medicine Isfahan University of Medical Sciences Department of Laboratory Medicine Imam Hassan Mojtaba Hospital Alborz University of Medical Sciences

Hydroxycitric acid （HCA） is derived primarily from the Garcinia plant and is widely used for its anti-in- flammatory effects. Multiple sclerosis can cause an inflammatory demyelination and axonal damage. In this study, to validate the hypothesis that HCA exhibits therapeutic effects on multiple sclerosis, we established female C57BL/6 mouse models of multiple sclerosis, i.e., experimental autoimmune encephalomyelitis, using Complete Freund＇s Adjuvant （CFA） emulsion containing myelin oligodendrocyte glycoprotein （35-55）. Treatment with HCA at 2 g/kg/d for 3 weeks obviously improved the symptoms of nerve injury of experimental autoimmune encephalomyelitis mice, decreased serum interleulin-6, tumor necrosis factor alpha, nitric oxide, and malondialdehyde levels, and increased superoxide dismutase and glutathione reduc- tase activities. These findings suggest that HCA exhibits neuroprotective effects on multiple sclerosis-caused nerve injury through ameliorating inflammation and oxidative stress.

关键词： nerve regeneration hydroxycitric acid multiple sclerosis inflammation oxidative stress experimentalautoimmune encephalomyelitis neural regeneration