检索结果-南通市图书馆

Frontiers of Structural and Civil Engineering 2012年第4期6卷 385-392页

作者： Amin MANOUCHEHRIAN Mohammad Fatehi MARJI mohsen mohebbi Mining and Metallurgical Engineering Department Yazd UniversityYazd 89195Iran

Because of the high importance of transportation tunnels,most precise analyses of stress concentration and displacement around them are essential to provide safety of them as much as ***,various numerical methods such as finite element method(FEM),discrete element method(DEM),finite difference method(FDM)and boundary element method(BEM)have been used extremely in geosciences problems,but among these numerical methods,BEM has been used less than others because the computational algorithm is not so *** paper suggests the implementation of the indirect boundary element method(IBEM)as a formulation of BEM to analyze displacement around Shiraz-Esfahan railway tunnel in Zagros Mountains southwest of *** this purpose,this tunnel has been modeled numerically using two-dimensional fictitious stress method(TWOFS)*** validate the results,they were compared with FEM results as a commonly used numerical *** of current theoretical study have shown that the presented approach using IBEM is reasonably accurate and can be used for analysis of displacement in geosciences *** rock mechanics,for problems with a low ratio of boundary surface to volume,FEM is not very well suited and may be cumbersome,but use of such a proposed IBEM approach can be particularly attractive.

关键词： indirect boundary element method finite element method displacement tunnel case study

CFD simulation and optimization of an industrial cement gas-solid air classifier

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第6期89卷 172-184页

作者： Mohamadreza Esmaeilpour Ali mohebbi Vahab Ghalandari Department of Chemical Engineering Faculty of EngineeringShahid Bahonar University of KermanKermanIran Kerman Momtazan Cement Company KermanIran

An air classifier is one of the main and effective devices in cement *** this study,a three-dimensional,steady and two-phase(solid-gas)computational fluid dynamics(CFD)simulation was performed to optimize the performance of this device in the Kerman Momtazan cement plant,*** the validation of CFD results,the air flow field and air path lines between fixed blades were checked carefully and the non-uniformity in velocity distribution and the formation of vortex flows between the blades close to particle inlets were *** study tried to improve the device efficiency by changing the method of entering particles into the device,resulting in a reduction in air classifier electrical energy consumption(from 41 to 35(kW h)/t)and an increase in production rate(from 203 to 214 t/h).Additionally,the study investigated the effects of other modifiable operating conditions like rotary cage rotation speed,pressure difference,and inlet air temperature on the particle size distribution and classifier *** results showed that increasing the cage rotation speed decreased the product rate and the product particles mean diameter while increasing pressure difference or increasing temperature increased the product rate and the product particles mean *** was concluded that these modifiable operating conditions can significantly affect the performance of the air classifier in the cement industry.

关键词： Cement air classifier Computational fluid dynamics Gas-solid two-phase flow Optimization Eulerian-Lagrangian method Efficiency

Effects of coating formulation on structural changes of turkey nugget during frying:MRI evaluation

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 Future Foods 2024年第2期4卷 142-148页

作者： Arash Ghaitaranpour Mohebbat mohebbi Seyed Amir Oleyaei Department of Food Science and Technology Faculty of AgricultureUrmia UniversityUrmia ***Iran Advanced Frying Research Core Department of Food Science and TechnologyFerdowsi University of MashhadMashhad ***Iran Department of Food Science and Technology Ferdowsi University of MashhadMashhad ***Iran

Application of nondestructive techniques combined with image processing techniques has been increasing in investigating the internal structure of food *** resonance imaging(MRI)is one of these *** aim of this research is to investigate the effect of coating formulation on structural properties of turkey nugget samples(turkey nugget with typical batter,tragacanth-containing batter and tragacanth)by *** revealed that the changes caused by the batter formulation could also be examined using the tomographic *** results also indicated that the brightness of the MRI images of the nugget core and crust decreased during *** core of the nugget with the tragacanth-containing batter was brighter revealing its higher moisture ***,the nugget core was less reduced in this sample compared with the other *** research aimed to present a valuable knowledge about nugget frying pertaining to quality evaluation.

关键词： NuggetDeep fat frying Structural characterization Magnetic resonance imaging(MRI) Image processing

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

维普期刊数据库

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

Assessment of pH-responsive nanoparticles performance on laboratory column flotation cell applying a real ore feed

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2020年第2期30卷 197-205页

作者： Samiramis Nasirimoghaddam Ali mohebbi mohsen Karimi M.Reza Yarahmadi Department of Chemical Engineering Faculty of EngineeringShahid Bahonar University of KermanKermanIran Department of Chemistry and Chemical Engineering Chalmers University of TechnologySE-41296 GothenburgSweden Sarcheshmeh Copper Complex KermanIran

Nanoparticles(NPs)can promote the column flotation process in mining ***'effects on column flotation process(copper recovery,grade and flotation rate constant)are assessed in Sarcheshmeh Copper Complex,Iran,through response surface methodology(RSM)optimization *** c-Al2O3,a-Fe2O3,SiO2,and TiO2 nanoparticles are selected for these experiments.A flotation rate constant is chosen as a response to assess the effect of nanoparticles on flotation in its kinetic *** process p H and nanoparticle dosage are selected as the influential *** obtained from RSM indicated that the maximum percentage of Cu recovery and grade is obtained at p H of 12 and nanoparticle dosage of 6 kg/t,through a-Fe2O3 and c-Al2O3 nanoparticles,*** nanoparticles in particular c-Al2O3 and a-Fe2O3 increases the Cu recovery by 8–10%together with the grade by 3–6%in a significant *** is revealed that nanoparticles could effectively be applied in enhancing the flotation performance.

关键词： Column flotation Nanoparticles Cu recovery Response surface methodology

Natural Convection Heat Transfer in a Porous Cavity with Sinusoidal Temperature Distribution Using Cu/Water Nanofluid: Double MRT Lattice Boltzmann Method

在线全文

学校读者我要写书评

暂无评论

Communications in Computational Physics 2021年第1期29卷 292-318页

作者： Hasan Sajjadi Amin Amiri Delouei Rasul mohebbi mohsen Izadi Sauro Succi Department of Mechanical Engineering Faculty of EngineeringUniversity of BojnordBojnordIran School of Engineering Damghan UniversityDamghanIran Mechanical Engineering Department Faculty of EngineeringLorestan UniversityKhorramabadIran Center for Life Nanoscience Italian Institute of TechnologyViale Regina Margherita 29500161RomaItaly Physics Department Harvard University29 Oxford StreetCambridgeMA 02138USA

In this study,natural convection flow in a porous cavity with sinusoidal temperature distribution has been analyzed by a new double multi relaxation time(MRT)Lattice Boltzmann method(LBM).We consider a copper/water nanofluid filling a porous *** simulating the temperature and flow fields,D2Q5 and D2Q9 lattices are utilized respectively,and the effects of different Darcy numbers(Da)(0.001-0.1)and various Rayleigh numbers(Ra)(10^(3)-10^(5))for porosity(ε)between 0.4 and 0.9 have been *** deviation(θ)changed from 0 toπand the volume fraction of nanoparticles(∅)varied from 0 to 6%.The present results show a good agreement with the previous works,thus confirming the reliability the new numerical method proposed in this *** is indicated that the heat transfer rate increases at increasing Darcy number,porosity,Rayleigh number,the volume fraction of nanoparticles and phase ***,the most sensitive parameter is the Rayleigh *** maximum Nusselt deviation is 10%,32%and 33%for Ra=10^(3),10^(4) and 10^(5),respectively,withε=0.4 toε=*** can be concluded that the effect of Darcy number on the heat transfer rate increases at increasing Rayleigh number,yielding a maximum enhancement of the average Nusselt number around 12%and 61%for Ra=10^(3) and Ra=10^(5),respectively.

关键词： Porous media double multi relaxation time-lattice Boltzmann method nanofluid natural convection sinusoidal temperature distribution

Multiple failure function based fragility curves for structures equipped with TMD

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2021年第2期20卷 471-482页

作者： Sina Bakhshinezhad Mohtasham mohebbi Faculty of Engineering University of Mohaghegh ArdabiliArdabilIran

This paper presents a procedure to develop fragility curves of structures equipped with TMD considering multiple failure *** failure criteria considered are maximum inter-story drift ratio as a safety criterion,maximum absolute acceleration as a convenience criterion and TMD stroke *** relationship between intensity measure and responses of the structure was assumed to follow the power-law model,and a regression analysis was used to estimate its properties.A nonlinear eight-story shear building subjected to near-fault earthquakes was used for the numerical *** curves using multiple and single failure functions for an uncontrolled structure and a structure equipped with optimal TMDs were *** analysis showed that using multiple failure functions led to increasing the fragility when compared with using the single failure function for both the uncontrolled and controlled ***,TMDs slightly reduced the seismic fragility and have the capability to improve the reliability of the ***,it was found that the fragility was significantly influenced by the values of the capacity thresholds of both the acceleration of the structure and TMD stroke length,which should be selected by considering the target performance and application of the structure and control device.

关键词： fragility curves multiple failure function passive control tuned mass dampers

Experimental and modeling study of the kinetics of methane hydrate formation and dissociation

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2021年第1期34卷 365-374页

作者： Vafa Feyzi Vahid mohebbi Ahvaz Petroleum Faculty Petroleum University of Technology(PUT)AhvazIran

In this work,several experiments were conducted at isobaric and isothermal condition in a CSTR reactor to study the kinetics of methane hydrate formation and *** were performed at five temperatures and three pressure levels(corresponding to equilibrium pressure).Methane hydrate formation and dissociation rates were modeled using mass transfer limited kinetic models and mass transfer coefficients for both formation and dissociation were *** of results,shows that mass transfer coefficients for methane hydrate dissociation are one order greater than formation *** transfer coefficients were correlated by polynomials as relations of pressure and *** results and the method can be applied for prediction of methane production from naturally occurring methane hydrate deposits.

关键词： Methane hydrate Kinetics Formation Dissociation Mass transfer

A Numerical Algorithm for Determination of a Control Parameter in Two-dimensional Parabolic Inverse Problems

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2015年第1期31卷 213-224页

作者： Akbar mohebbi Department of Applied Mathematics Faculty of Mathematical Science University of Kashan

Numerical solution of the parabolic partial differential equations with an unknown parameter play a very important role in engineering applications. In this study we present a high order scheme for determining unknown control parameter and unknown solution of two-dimensional parabolic inverse problem with overspe- cialization at a point in the spatial domain. In this approach, a compact fourth-order scheme is used to discretize spatial derivatives of equation and reduces the problem to a system of ordinary differential equations （ODEs）. Then we apply a fourth order boundary value method to the solution of resulting system of ODEs. So the proposed method has fourth order of accuracy in both space and time components and is unconditionally stable due to the favorable stability property of boundary value methods. The results of numerical experiments are presented and some comparisons are made with several well-known finite difference schemes in the literature. Also we will investigate the effect of noise in data on the approximate solutions.

关键词： compact finite difference scheme boundary value method control parameter parabolic inverseproblem temperature over=specification high accuracy noise

Optimization of the reflux ratio of benzene-toluene stage distillation columns by the Cuckoo algorithm

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2014年第3期11卷 446-453页

作者： Bahador Abolpour Ali mohebbi Department of Chemical Engineering Faculty of Engineering Shahid Bahonar University of Kerman

In this study, an enthalpy-concentration method was applied in order to model a steady state continuous benzene-toluene mixture distillation column. For a distillation tower such as the benzene- toluene splitter, there are relatively few degrees of freedom that can be manipulated in order to minimize the total annualized cost. The reflux ratio can influence the steady-state operating point and therefore influence the total annualized cost. The trade-offs between reflux ratios and total annualized cost were discussed. The Cuckoo optimization algorithm was applied to obtain a correlation for the optimum value of the reflux ratio as a power function of the economic parameters of energy price and capital cost. The results show that, at low energy price or high capital cost, the optimum reflux factor is high.

关键词： Benzene-toluene mixture distillation column Cuckoo optimization algorithm optimized reflux ratio total annualized cost