توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱THE NECESSITY OF PARTICIPATORY MANAGEMENT IN WATER SECTOR IN IRAN
نویسنده(ها): ، ،
اطلاعات انتشار: چهارمین کنفرانس آسیایی و دهمین سمینار بین المللی مدیریت مشارکتی آبیاری، سال
تعداد صفحات: ۹
During the past decades, most of the investment, construction and management of the water projects in Iran have been the responsibility of the government, and the private sector had little influence in this regard. This policy of the government has caused the water projects to become less successful and have low efficiency, despite the large amount of the investment. In order to overcome some of these problems, the government passed several laws to attract the participation of farmers in development and construction of irrigation and drainage networks. This movement was the beginning of the official participation of farmers in the water sector in Iran and it proved that despite the difficulties of implementation of the program, it was successful in overall. Therefore, it is necessary to develop a mechanism to have more involvement from the farmers in different levels of projects including decision making, design, construction, operation, and maintenance. In order to achieve such objective, a proper structure and organization are needed in governmental agencies, investment institutes, and farmers associations. These components of the participatory management and responsibility should be well defined. Practical laws, methodologies, and instructions are necessary to achieve the objectives of the program. In this paper, the proposed structure of the farmers’ participation in water sector is explained.<\div>

۲Optimum Automated Performance Based Design of Concentric Steel Braced Frames
نویسنده(ها): ، ،
اطلاعات انتشار: پنجمین کنفرانس بین المللی زلزله شناسی و مهندسی زلزله، سال
تعداد صفحات: ۸
Earthquake and structural engineering challenge of creating optimized, reliable and cost effective structures leads to the combination of optimization and performance based seismic design theory. The prime goal is to automate the optimum design of the structure on the basis of performance based design and also considering the inherent uncertainties. In this study automating the design process of concentric steel braced frames is performed by use of genetic algorithms. The optimal design of structure minimizes the structural weight subjected to performance constraints on axial deformations of braces and plastic hinge rotation of beam – columns and also the force interactions relationships for them. Nonlinear static analysis (pushover) is implemented by considering the effect of post–buckling in compression brace elements and the performance based criteria is derived from the FEMA–356 (2000). The developed software in this study is capable of optimally automating the design of braced Frames with different spans and stories for a prescribed performance objective, with the limitation of usage for structures in which the first mode is dominant. It is found that a wide range of valid design alternatives exists, from which a decision maker selects the one that balances and optimizes different objectives in the most preferred way.<\div>

۳A NEW METHOD FOR DYNAMIC ANALYSIS OF STRUCTURES USING CELLULAR AUTOMATA
نویسنده(ها): ، ،
اطلاعات انتشار: پنجمین کنفرانس بین المللی زلزله شناسی و مهندسی زلزله، سال
تعداد صفحات: ۸
The emerging idea of Parallel Computing makes the use of new algorithms inevitable to deal with the problem of structural optimization. Simultaneous analysis and design has been a well known optimization method whose efficiency can be increased by the use of parallel computation methods. Cellular Automata are among those algorithms which their models are composed of regular lattice of cell or automata. Each cell may change its state at discrete, fixed times (iterations) according to a local rule. In this way overall global behavior of a system can be modeled by simple interaction of cells which only know local conditions. Local rules which are dependent on the present state of the cells and their neighbors are based on the behavior of system which should be modeled. This study contributes to the dynamic behavior of multi degrees of freedom (MDOF) structures. The proposed method establishes local update rules which act on the stories of the structures as system cells. Any of the stories interacts with its neighbors, while applying a ground motion record to the base of the structure which leads to its global dynamic response after some iterations. These analysis update rules tend to solve the global differential equation of motion by solving some local differential equations at the cell levels. In this method structural analysis is performed in time iterations with regards to the response of neighboring stories. What makes Cellular Automata an efficient computational tool for modeling large systems is its inherent massive parallel computation capability in which by the use of new parallel computer processors its efficiency can be increased rapidly.<\div>

۴Experimental Behavior of Multilayer Infilled Steel Frame
نویسنده(ها): ،
اطلاعات انتشار: پنجمین کنفرانس بین المللی زلزله شناسی و مهندسی زلزله، سال
تعداد صفحات: ۸
Results of an experimental program to investigate the behavior of multilayer infill panels are presented here. For the purpose five single or multilayer infilled frames are tested under cyclic loading. The most important advantage of multilayer infilled frames is the possibility of adjusting their stiffness and strength, and it is one step forward to produce engineered infill panels. The strength and stiffness of such panels can be adjusted by changing the material properties and thickness of the constitutive layers. Strengths of multilayer specimens are compared with single layer infill panels. It was observed in experimental tests of multilayer infilled frames, composed of concrete and masonry layers, that the decrease in the entire thickness of brick layers or increase in total thickness of concrete layers will reduce the displacement of the ultimate strength. Stiffness, strength and damping of the specimens are also presented and compared.<\div>

۵A Nano–porous Faujasite Membrane for Nanofiltration: Preparation and Characterization
نویسنده(ها): ، ، ،
اطلاعات انتشار: نخستین کنگره بین المللی نانوفنآوری و کاربردهای آن در صنایع نفت، گاز و پتروشمی، سال
تعداد صفحات: ۷
Zeolite membranes as nanofilters have potential in separating mixtures that are difficult to isolate with traditional techniques. They offer distinct advantages in the nano–separation of close–boiling mixtures and azeotropes in many industrially important separation processes. Nano–scale separations such as air pollution control, removal of H2S and SO2 in obtaining ultra–pure gas streams, H2 production from steam\methane reforming, and the separation of aromatic and n\i–isomers are some of their various applications in the petrochemical industry. In this work, nanoporous faujasite membranes (pore diameter = 0.74 nm) was prepared on cylindrical Porous Mullite Supports. Seeding treatments were performed using the NaX zeolite powders prepared before. The obtained zeolite was characterized with XRD and SEM. A thin and continuous X–type zeolitic top layer covered the outer surface of the support.<\div>

۶Implementation of fast motion estimation algorithms and comparison with full search method in H.264
نویسنده(ها): ، ،
اطلاعات انتشار: پانزدهیمن کنفرانس مهندسی برق ایران، سال
تعداد صفحات: ۶
In this paper, Three motion estimation algorithms for H.264 standard have been implemented and performance and some features of these three have been tested. These algorithms are full search and two fast search method. Finally some parameters such as bit rate, speed up and PSNR for different value of QP have been compared. Implementation has been performed in Matlab software.<\div>

۷FDTD Calculation of Light Sattering by 2D Nanoparticles
نویسنده(ها): ، ،
اطلاعات انتشار: اولین کنفرانس فناوری نانو در محیط زیست، سال
تعداد صفحات: ۱۱
Based on two dimensional Finite Difference Time Domain (FDTD) method, a code is developed to calculate the light scattering by nanoparticles of arbitrary shape. We employ Recursive Convolution (RC) technique to implement dispersive materials in FDTD method. Finally, we utilize the code to investigate the dependency of the total scattering cross section (SCS) on nanoparticle properties such as shape, size, background refractive index, etc.<\div>

۸MATERIAL REMOVAL SIMULATION OF AUTOFRETTAGED COMPOUND TUBES
نویسنده(ها): ، ، ،
اطلاعات انتشار: پانزدهمین کنفرانس سالانه مهندسی مکانیک، سال
تعداد صفحات: ۶
Real loading– unloading behavior of an A723–1130 MPa high–strength steel alloy incorporated in the variable material properties (VMP) numerical algorithm to predict residual stresses resulted from autofrettage and shrink fit in two autofrettage compound tubes design philosophies. Using an analytical method, the numerical solutions were developed to estimate residual stresses induced by bore material removal via machining. Using developed VMP code and isotropic hardening rule in both autofrettaged compound tube design philosophies, residual stresses resulted from shrink fit and autofrettage processes and via post machining, were calculated. Machining process simulation was performed for 10 mm bore material removal. ANSYS commercial FEM software was used for validating the results of VMP code. The results of VMP method and ANSYS were in good agreement with each other. Finally with the help of recorded real unloading behavior of A723–1130 MPa high–strength steel alloy, also aforementioned simulations were performed on various tubes. The material removal simulation was modeled for 20 mm material removal
from the bore.<\div>

۹FATIGUE CRACK GROWTH RATE OF ADHESIVELY REPAIRED THIN ALUMINIUM PANELS IN GENERAL MIXED MODE CONDITION
نویسنده(ها): ، ،
اطلاعات انتشار: پانزدهمین کنفرانس سالانه مهندسی مکانیک، سال
تعداد صفحات: ۶
In this paper, finite element fatigue crack growth rate of thin aluminium panels containing a central inclined crack of 45o with single–side glass\epoxy patch are performed considering the general mixed–mode conditions (modes I, II and III). These panels are repaired with the 4 layers
glass\epoxy composite materials with the lay–up configurations of [90]4, [105]4, [–45]4, [–45\+45]2, and [902\02]. Effects of patch lay–up configuration on the restarting crack growth (crack re–initiation) life and crack growth rate of the repaired panels are investigated. Also the effects of patch lay–up configurations on the crack trajectories at patched and un–patched surfaces of the repaired panels are investigated. Results shown that, using the patch lay–up configurations of [90]4 and [902\02] are more efficient than the patch lay–ups perpendicular to the initial inclined crack in term of crack growth life extension.<\div>

۱۰Separation of Water and Glycol by Vacuum Membrane Distillation (VMD)
نویسنده(ها): ،
اطلاعات انتشار: نهمین کنگره ملی مهندسی شیمی ایران، سال
تعداد صفحات: ۵
In the present paper feasibility of VMD for concentration of glycol from used coolant liquid is presented. VMD experiments were performed with water–ethylene glycol (EG) mixtures, using a flat sheet Polypropylene (PP) membrane at various temperatures and recirculation rates. Results show that the membrane rejects almost completely EG and desired concentration is achieved. This is due to the fact that vapor pressure of EG is negligible compared with that of water. Increasing temperature and recirculation rate increases flux with no effect on EG rejection.<\div>

۱۱Modeling of Moisture Distribution in Thin Layer Drying Process
نویسنده(ها): ، ، ،
اطلاعات انتشار: یازدهمین کنگره ملی مهندسی شیمی ایران، سال
تعداد صفحات: ۸
Apple slices were dried with hot air and combined microwave hot air drying methods in an microwave dryer, the apple slices were prepared as single layer with thickness of 5, external and internal diameter 60 and 20 mm respectively. The effect of drying air temperature and microwave
power on the drying characteristics were determined. It was found that apple slices would dry perfectly within 30–54 min under convective conditions and 27–48 min under microwave–convective conditions. The transport of water during dehydration was described by applying the Fick s diffusion model and the effective diffusivity changed between 2.39*10–9 and 4.14*10 –9 m2\s in convective method. A non–linear regression procedure was used to fit 5 thin layer drying models available in the literature to the experimental drying curves. The models were compared using the coefficient of determination, mean relative percent error, root mean square error and SSE. The 3rd Degree polynomial model has shown a better fit to the experimental drying data as compared to other models. Finally, this paper presents a developed mathematical model for predicting transport phenomena in drying process of apple slices.<\div>

۱۲Biped Running Robots Dynamics Modeling and Path Generation
نویسنده(ها): ،
اطلاعات انتشار: شانزدهمین کنفرانس سالانه مهندسی مکانیک، سال
تعداد صفحات: ۶
Design and simulation of two running biped robots is addressed in this paper, called Robot and Robot I . The robots consist of 9 links. All joints of Robot I are rotary joints and only the knee joints of Robot II are prismatic. All physical characteristics of robots bodies are as like as
human bodies are. It is assumed that: 1– all joints are friction–free 2– all joints are driven by an independent driver 3– motion of all links occurs in sagittal plane (2D motion). Firstly, kinematical equations of links are derived. Then equations of motion of each robot are derived, using Lagrange method, in two main phases of running, i.e., single support and flight. For making trajectory of the robots' path with the given break points of hip and two ankles, third–order spline method has been used. Then, using inverse kinematics equations of each robot, trajectories of link angles are calculated. Required torques and forces of the robots' joints and power and energy consumption for passing through these trajectories
were calculated by writing some programs in MATLAB. Also, a graphical simulation, in MATLAB, has been used for visual observation of the robots motion. Finally, effect of upper body motion i.e. hands on running, is discussed and addressed.<\div>

۱۳Study of hydrogen separation from carbon monoxide using polyimide membrane
نویسنده(ها): ، ،
اطلاعات انتشار: پنجمین کنگره بین المللی مهندسی شیمی، سال
تعداد صفحات: ۶
In this work separation of hydrogen from carbon monoxide (syngas ratio adjustment) using a hollow fiber polyimide membrane was investigated. Pure and mixed gas tests were carried out at different feed conditions. Feed pressure, temperature and flow rate was changed between 5–9 bar, 20–80 C ° and 150–300 ml\min, respectively. Membrane performance (for both gases) was obtained as a function of these parameters. Membrane permeance for hydrogen and carbon monoxide at different test conditions was between 70–130 GPU and 2.5–5 GPU, respectively.<\div>

۱۴Modeling of MMA Bulk Polymerization Reactor: Gel and Glass Effects
نویسنده(ها): ، ، ،
اطلاعات انتشار: پنجمین کنگره بین المللی مهندسی شیمی، سال
تعداد صفحات: ۷
The effects of gel and glass on the modeling of MMA bulk polymerization reactor equipped with a thermal jacket were studied. The modeling results showed that the gel and glass effects occurred during the polymerization influenced substantially the inlet and outlet temperature of the cooling fluid in order to provide an isothermal polymerization condition. On the other hand, the effect of these diffusional limitations on the variation of monomer conversion and viscosity of the polymerization was investigated. A rather good accordance between the experimental and modeling results was observed.<\div>

۱۵Preparation of Polymeric Membrane for pervaporation separation
نویسنده(ها): ، ،
اطلاعات انتشار: پنجمین کنگره بین المللی مهندسی شیمی، سال
تعداد صفحات: ۷
Poly (ether–block–amide) membranes were made via casting a solution on a non solvent surface. In this research, effects of different parameters such as ratio of solvent mixture (n–butanol \ iso propanol), temperature and polymer concentration, on quality of the thin film membranes were studied. The results showed that the film quality enhances with increasing iso propanol ratio in the solvent mixture. This behavior can be related to reduction of solution surface tension and interfacial tension between solution and non solvent. Uniform films were made at a temperature rang of 70–80 0C and a polymer concentration of 4–7 wt%. Morphology of the membrane was investigated with Scanning Electronic Micrograph (SEM). Pervaporation of ethyl butyrate \ water and iso propanol \ water mixtures was studied using these membranes and high separation performance was achieved. For ethyl butyrate \ water mixtures, It was observed that both permeation flux and separation factor increase with increasing ethyl butyrate content in the feed. However, for iso propanol \ water mixtures, it was found that by increasing iso propanol content in the feed, permeation flux enhances but separation factor diminishes. Increasing temperature in limited range studied resulted in decreasing separation factor and increasing permeation flux.<\div>

۱۶Development of ANN and SVM models for Prediction of Cell Voltage and Current Efficiency in a Lab Scale Chlor–Alkali Membrane Cell
نویسنده(ها): ، ،
اطلاعات انتشار: پنجمین کنگره بین المللی مهندسی شیمی، سال
تعداد صفحات: ۱۱
This paper presents the comparison of artificial neural network (ANN) and Support Vector Machine (SVM) models for the prediction of cell voltage and caustic current efficiency (CCE) versus various operating parameters in a lab scale chlor–alkali membrane cell. In order to validate the model predictions, the effects of various operating parameters on the cell voltage and CCE of the membrane cell were experimentally investigated. Each of six process parameters including anolyte pH (2–5), operating temperature (25–90 o C), electrolyte velocity (1.3–5.9 cm\s), brine concentration (200–300 g\L), current density (1–4 kA\m 2 ), and run time (up to 150 min) were thoroughly studied at four levels for low caustic concentrations (5 g\L). The predictions of ANN & SVM models as well as those from other statistical methods were evaluated against the measured values. It was found that the developed ANN & SVM models are not only capable to predict the voltage and CCE but also to reflect the impacts of process parameters on the same functions. The predicted cell voltages and current efficiencies using these models were found to be close to the measured values with an average deviation of only 1.27% for predicted cell voltages with ANN and 1.98% for CCE with SVM.<\div>

۱۷Fault Diagnosis of Analog Circuits with Tolerances By Using RBF and BP Neural Networks
نویسنده(ها): ، ،
اطلاعات انتشار: هشتمین کنفرانس سالانه انجمن کامپیوتر ایران، سال
تعداد صفحات: ۵
This paper presents a method for analog circuit fault diagnosis by using neural networks. This method exploits DC approach for constructing dictionary in fault diagnosis by neural networks classification capability. In addition, Radial basis function (RBF) and backward error propagation (BEP) networks are considered and compared for analog fault diagnosis. The primary focus of the paper is to provide robust diagnosis using a mechanism to deal with the problem of component tolerance and reduce testing time. Simulation results show that the radial basis function network with reasonable dimension has double precision in fault classification but its classification is local, and backward error propagation network with reasonable dimension has single precision in fault classification but its classification is global.<\div>

۱۸Nonlinear Model Control of DC\AC Voltage Converter of an Isolated Three Phase Power Network
نویسنده(ها): ، ، ،
اطلاعات انتشار: دومین کنفرانس بین المللی الکترونیک قدرت و سیستم های درایو، سال
تعداد صفحات: ۶
Most of the reported control algorithms for uninterruptible power supplies use either inductor currents or capacitor currents of their filter as feedback variables to regulate the output voltage. This paper proposes a simple non linear control using current and voltage of a DC\AC inverter of an isolated three phase power network. Theoretical analysis and simulation results demonstrate fast response, and develop a good performance. This nonlinear control algorithm is applicable to both single–phase and three–phase systems. Theory and simulation results are presented in the paper.<\div>

۱۹The Effect of Premedication by Remifentanil and Magnesium Sulfate in Hemodynamic Responses to Tracheal Intubation in Cesarean Section Delivery: 1 A Randomized Double–Blinded Controlled Study
اطلاعات انتشار: Academic Journal of Surgery، دوم،شماره۳-۴، ۲۰۱۵، سال
تعداد صفحات: ۵
Background: The preventing effects of remifentanil and magnesium sulfate on hemodynamic responses to tracheal intubation were evaluated in a double–blinded controlled trial on pregnant women undergoing cesarean section delivery.Methods: A total of 54 American Society of Anesthesiologists Class I–II women candidate for cesarean section delivery were randomly assigned to one of three groups (n = 18) to receive one of the following premedication: Intravenous (IV) remifentanil 0.75 µg\kg, IV magnesium sulfate 30 mg\kg, or IV normal saline 10 cc as placebo. All hemodynamic profiles were recorded immediately before and after intubation, and 2, 3, 5 minutes after tracheal intubation.Results: Heart rate and systolic and diastolic blood pressures were significantly lower in the remifentanil group than in other groups both before and immediately after intubation. The trend of the changes in homodynamic responses within 5 minutes following intubation in the magnesium sulfate and placebo group was similar, but this trend in the remifentanil group was significant difference. In the same time, 1st and 5th minute Apgar scores were slightly lower in the remifentanil group than others. The measured parameters of umbilical cord blood pH and PO had no significant differences between the groups.Conclusions: Remifentanil can attenuate hemodynamic response to tracheal intubation more effectively than magnesium sulfate, and thus it can be considered safe for a pregnant candidate for cesarean section.

۲۰Prevalence of Parental Postnatal Depression in Fathers and Its Relationship with Demographic Characteristics
اطلاعات انتشار: Journal of Client-Centered Nursing Care، اول،شماره۳، Aug ۲۰۱۵، سال
تعداد صفحات: ۶
Background: Childbirth brings many changes to family and fathers who are at risk of depression.During this period, fathers face a lot of challenges and several new roles. Negative effects of paternal postpartum depression (PPND) affect arital\partner relationships, infant bonding, and child development. This study aimed to investigate the prevalence of PPND and its relationship with some individual characteristics.Methods: This research is a descriptive cross–sectional study. The statistical population was all literate men whose wives had recently given birth to a child. The method of sampling was consecutive technique. A total of 328 men were recently become fathers. All samples completed the demographics questionnaire during their wives’ hospitalization after delivery. Then 8 weeks later, they completed Edinburgh questionnaire at home or hospital. Data were analyzed by Chisquare test (using SPSS software version 14).Results: The findings revealed that 59.8% of the fathers had postpartum depression, and depression rate was higher in the age range of 30–39 years (65.5%) (P=0.202). The depression was more in men who were low–educated (61.8%) and whose partners were housewives (59.4%). There is a significant correlation between men’s employment and depression (P=0.018). The depression was more in unemployed men; therefore, bad economic situation can be a reason for severe depression (65.5%).Conclusion: Considering high prevalence parental postpartum depression and its multifactorial nature, dealing with each effective factor can decrease the probability of parental postpartum depression. Also, its prompt diagnosis and treatment decreases the consequences of this problem in mother, infant, and family and improves family performance and quality of life.

۲۱Is the Contemporary Account of Weakness of Will Complete?
نویسنده(ها): ،
اطلاعات انتشار: Religious Inquiries، دوم،شماره۳، Winter and Spring ۲۰۱۳، سال
تعداد صفحات: ۱۱
Before an outstanding article in 1999 by Richard Holton, weakness of will was identified as an agent's action contrary to his or her better judgment, while other better choices are available. The contemporary account of weakness of will (i.e., Holton’s theory) explains it in terms of intention. Accordingly, weakness of will happens if an agent fails to stick to his or her previously formed intention unreasonably while he or she should. However, this account fails to explain all cases of weakness of will and never takes into account the different types of reasonable judgments as found in deontological theories. This paper suggests that although weakness of will can be explained in terms of intention, the object which the will refers to plays a key role in identifying a complete understanding of weakness of will.

۲۲The effectiveness of psychodrama on reducing depression among multiple sclerosis patients
نویسنده(ها): ، ، ، ،
اطلاعات انتشار: International Journal of Behavioral Sciences، دهم،شماره۱، Winter ۲۰۱۶، سال
تعداد صفحات: ۴
Introduction: Psychodrama, as a form of art therapy, helps people to enact and use role–plays for a specific problem, rather than just talking about it, in an effort to review the problem, gain feedback from group members, find appropriate solutions, and practice them for their life. The current paper aims to investigate the effectiveness of psychodrama therapy on the reduction of depression for multiple sclerosis (MS) patients. Method: This research was a quasi–experimental study, using pre–post and follow–up testing plan with a control group. By using a convenience sampling technique, a total of 20 individuals were selected among clients with MS referring to the Iranian Multiple Sclerosis Society. The subjects were randomly placed into two control and experimental groups. The experimental group participated in a twelve–session therapy plan for 6 weeks, while the control group received no intervention. In order to collect data, the Beck Depression Inventory (BDI) and the demographical information questionnaire were used. Data analysis was performed by analysis of covariance (ANCOVA).Results: The results revealed a decrease in the post test and follow–up test scores for depression, and such decrease is statistically significant.Conclusion: The findings indicate the effectiveness of the psychodrama intervention to decrease depression among patients with MS. Due to increased group and social interactions and enhanced interpersonal experiences, psychodrama can relieve depression symptoms. Hence, participating in the psychodrama therapy will enable patients to decrease the levels of depression.

۲۳Assessing Regional Habitat Changes for the Persian fallow deer (Dama dama mesopotamicus) usingMaximumEntropymodeling approach in Khouzestan province, Iran
نویسنده(ها): ، ، ، ، ، ، ،
اطلاعات انتشار: International Journal Of Environmental Research، نهم،شماره۲، Spring ۲۰۱۵، سال
تعداد صفحات: ۸
This study was conducted in Dez and Karkheh regions in southwestern Iran to model habitat suitability of the Persian fallow deer Dama dama mesopotamicus and assessing trend of habitat changes since 1989. A total of 22 confirmed presence records of the species were collected from 1988 to 2003. MaxEnt approach was used to develop habitat suitability model with regards to nine environmental variables, including density of farmlands, forests, and disturbed forests, density of livestock, vegetation, residential areas and distance to the forest edge, residential areas, protected areas and frequency of surface water bodies. After validation of the model for all parameters used for 1989, relative developed map was extrapolated to the habitat conditions in 2007. Comparing the habitat suitability maps developed for 1989 and 2007 reveals that area of suitable habitats for the Persian fallow deer has declined by 30% within 18 years. A total of 1000 ha of forests (within suitable habitats for the species) has been degraded. About 100 ha of these habitats were converted to farmlands and less than 0.5 ha was altered to the residential areas. In addition, area of about 1000 ha has lost the suitability without any land use changes. Currently, reintroduction of the Persian fallow deer to the area is under consideration by Department of Environment of Iran. Therefore, results of this study are recommended for choosing reintroduction sites based on the predicted suitable maps to enhance the probability of survival for reintroduced individuals.

۲۴Thermo–Elastic Damping in Nano–beam Resonators Based on Nonlocal Theory
اطلاعات انتشار: International Journal of Engineering، بيست و ششم،شماره۱۲، December۲۰۱۳ ، سال
تعداد صفحات: ۱۰
In this article thermoelastic damping in nano–beam resonators is investigated based on nonlocal theory of elasticity and the Euler–Bernoulli beam assumptions. The governing equation of deflection of the beam is obtained from shear and moment resultants and stress–strain relationship of the nonlocal elasticity model and also the governing equations of thermoelastic damping are established by using, two dimensional non–Fourier heat conduction with one relaxation time based on continuum theory frame. Free vibration of the nano–beam resonators is analyzed using Galerkin reduced order model formulation for the first mode of vibration. In the present investigation a clamped–clamped nano–beam with isothermal boundary conditions at both ends is studied. This nonlocal nano–beam model incorporates the length scale parameter (nonlocal parameter) which can capture the small scale effect. The obtained results are compared with the numerical results of the classical thermoelastic models. Thermoelastic damping effects on the damping ratio are studied for the various nano–beam thicknesses and ambient temperatures. In addition to, the study includes computations for different values of nonlocal theory parameter. The results show that with increasing the amount of nonlocal parameter and also with decreasing the length of the nano–beam, difference of the results of classical and nonlocal theory increases.

۲۵Mechanical Response of a Piezoelectrically Sandwiched Nano–Beam Based on the Non–Local Theory
اطلاعات انتشار: International Journal of Engineering، بيست و ششم،شماره۱۲، December۲۰۱۳ ، سال
تعداد صفحات: ۱۰
This article deals with the mechanical analysis of a fixed–fixed nano–beam based on nonlocal elasticity theory. The nano–beam is sandwiched with two piezoelectric layers through it’s upper and lower sides. The electromechanical coupled equations governing the problem are derived based nonlocal theory considering to Euler–Bernoulli beam assumptions and based on the nonlocal piezoelectricity according to the electrostatic Maxwell’s equations. Two piezoelectric voltages are employed to tune the stiffness of the nano–beam. The obtained equations are solved by step by step linearization method and Galerkin’s weighted residual method. The obtained results are compared with the results of the local model, and also the effect of piezoelectric voltages on the non–locality of the model is investigated.
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