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People usually associate power with military force, multinational corporations, as well as ele-vated political positions. However, marriage and family are not exempted from power strug-gles too; couples often encounter power issues. Present article discusses power in families with focussing on power between married partners or conjugal power.The paper also high-lights some of the questions like, what are the sources of conjugal power? what are the deci-sion-making areas? what are the analytical models of power relation among Iranian fami-lies?and tries to find out answer of these questions. At the beginning, it discusses some classic theories and studies about decision making in marriage and family life and then look at what new generations of social scientists say about conjugal power. Finally, taking advantage of document and comparative analysis as the main methods used in this paper, it tries to exam-ine the structure of power relations in Iranian contemporary family.

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The estimation of velocity distribution plays a major role in the hydrodynamics of vegetated streams or rivers of extensive natural floodplains. The velocity profile in vegetated channels can be divided into three zones: uniform zone which is close to bed with uniform velocity distribution, logarithmic zone which involves the main channel with no vegetive cover and the transition zone that is affected by the upper zone flow. In order to arrive at an analytical solution to the force balance that governs the flow specific turbulence, characteristics of the flow through the vegetation are required. A new analytical model for the velocity distribution in the transition zone of vegetated (inflexible submerged vegetation) channels is hereby developed. The model is based on a force equilibrium equation and on Prandtl Mixing Length concept. Vegetation is treated as a homogeneous field of identical cylindrical stems and the flow field considered as uniform and steady. The proposed procedure is straightforward; it follows principles of fluid mechanics and shows good agreement with laboratory flume experiments. The new model can be employed for an exact estimation of discharge through naturally vegetated rivers. The model has been calibrated and verified. The results imply a desirable correlation between calculated and observed data.

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چکیده-مطالعه آزمایشگاهی انجام شده، تأثیر مقاوم سازی برشی تیرهای بتن مسلح به کمک روش نصب نزدیک سطح  با استفاده از میله های ساخته شده از صفحات الیاف کربن را ارزیابی می کند. برای ایجاد تأخیر در شروع جداشدگی میله از تیر، مهار انتهایی جدیدی برای آن ها پیشنهاد شده که آزمایش می شود. در این مقاله، نتایج آزمایش های انجام شده روی شش عدد تیر بتن مسلح دوسر ساده با مقطع مستطیل شکل که در برش، مقاوم سازی شده است، ارائه می شود. پاسخ نیرو- تغییرمکان همه ی نمونه ها و تغییرات کرنش در قسمت های مختلف ارائه خواهد شد. همچنین کارکرد و مدهای گسیختگی تیرها بررسی خواهد شد. نتایج آزمایش ها بیانگر از کارامدی میله ها و مهارهای پیشنهادی بوده است؛ به گونه ای که افزایش ظرفیت باربری نمونه های مقاوم سازی شده روش پیشنهادی، 25 تا 48 درصد نمونه مرجع به دست آمده است و در نتیجه استفاده از مهارهای انتهایی پیشنهادی، انرژی جذب شده به وسیله ی نمونه ها، افزایش چشم گیری پیدا کرده است. در انتها، مدل تحلیلی Rizzo and De Lorenzis برای برآورد مشارکت سامانه مقاوم سازی این پژوهش ارائه شده است که در مقایسه با نتایج آزمایشگاهی، تخمین قابل قبولی به دست می دهد.

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Ultrasonic technology has been applied in many industrial processes such as ultrasonic machining, welding, cutting, sewing, homogenizing, etc. In an ultrasonic system, acoustic horn transmits the vibration energy of ultrasonic transducer to the application area and amplifies the oscillation amplitude. Depending on the application and industrial operating conditions, different horns with different geometries and magnifications are required to be designed. In the present study exponential horns with rectangular cross-section for application in ultrasonic assisted grinding process are designed and analyzed. An analytical approach is applied to model this type of horns. For evaluating the analytical model, some acoustic horns are designed using analytical method and then analyzed by the finite-element method (FEM) in ANSYS. Then, their design parameters such as resonance frequency and amplification factor are compared and verified. A very good agreement is obtained between the results of analytical modeling and those of FEM simulation. Furthermore, geometrical modification was introduced as a solution to coincide the vibration related parameters of the horn to the desired design values. Moreover, a horn-workpiece assembly for applying in ultrasonic assisted grinding was simulated.

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In this paper, the behavior of concrete subjected to eroding penetration of projectiles is studied. Based on qualitative similarities of eroding penetration at metallic and concrete targets, plastic flow of the particles around the projectile tip in a concrete target is illustrated. Based on visco-plastic behavior of concrete, changes on the plastic field of the target at Walker-Anderson model is made in order to analyze eroding penetration into concrete. Since there is not any analytical model and standard tests for eroding long rod (9≤L/d≤11 and 11gr<m<9gr) penetration into the concrete, 52 high velocity penetration tests were designed and carried out. Furthermore, with solving the final equations of the Forrestal model, penetration depth of eroding projectiles is calculated. Comparison between the results of the improved Walker-Anderson model and the Forrestal model showed that although the Forrestal model is a comprehensive model in rigid penetration, using it for assessment of eroding penetration into concrete is completely wrong. Besides, the improved Walker-Anderson model can analyze this phenomenon satisfactorily.

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In this paper, ballistic impact on sandwich panel with composite face sheet made of Glass/Epoxy and aluminum honeycomb core has been studied. The solution is derived from a wave propagation model. At first both analytical and numerical solutions were clarified and their results were compared with experimental results. Some deformation patterns, failure modes and energy absorption mechanisms were identified by observation, such as: dynamic movement of the target, stretching, bending deformation, delamination, debonding, shear fracture honeycomb, tensile fracture of Glass/Epoxy and plug and petal formation in composite facings. The solution involves a four-stage and effective masses of the face sheets and core as the shock waves travel through sandwich panel are derived using Lagrangian mechanics. The resulting non-linear differential equation of motion was solved considering the local damage effects and corresponding energy absorptions. Also numerical model, analysis of the penetration process was performed by a nonlinear explicit finite element code, LSDYNA. The results of analytical solution and numerical simulation are compared with experimental tests. Ballistic impact tests is carried out on the samples by flat-ended projectile with 8/5 gr mass and 10 mm diameter in difference velocities.

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Incremental sheet metal forming process is considered as one of methods which able manufacturer to produce parts without dedicated die in low and rapid prototype production, and many researches have been done to improve it. Using of ultrasonic vibration is one of the modern approaches in forming processes which reduce friction and forming force. The purpose of this study is to investigate the effect of ultrasonic vibration applied to the tool in single point incremental sheet metal forming process. For this, first theory of single point incremental forming has been studied; its principle has been investigated and analytical relations have been modified then analytical relations in the case of applying ultrasonic are derived from those. To practical evaluation of applying ultrasonic to this process a set can be installed to the head of CNC milling machine is designed and manufactured. According to results of analytic compared to experimental results a reasonable approximation of forming force variation in normal single point incremental forming process and applying ultrasonic can be offered. Based on tests results forming force in applying ultrasonic compare to normal mode reduces between 33 to 63.5 percent depend on test circumstances.

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In this paper, the efficiency of Proton membrane exchange (PEM) fuel cell system by using ejector for returning the additional fuel in the fuel supply circuit and comparison with conventional systems, with compressor in fuel supply circuit, are studied. For this purpose a semi - analytical developed model for calculating the amount of efficiency increment, as well as the amount of power saving as a result of employing ejector in the fuel cell return line is provided by extending the previous models. In this developed model the important stack design parameters and ejector design parameters are correlated by presenting a new dimensionless parameter. The results for a typical fuel cell show that the amount of efficiency increment at different values of current density is different and there is a maximum point for it. The amount of power saving as a result of employing ejector compared with fuel cell power is considerable and will increase with increasing the current density. These results indicate that the ejector for those applications that require high power (for instance the transport applications) is more efficient.

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The aim of this study is to investigate analytical and experimental energy absorbing capacity for a hat shape structure with three different boundary conditions. Four layered unidirectional (UD) E-glass fiber /polyester resin was used to construct hat shape beam energy absorber. The length of the composite hat shape was 1m and the thickness was 3mm. Result shows good coloration between experimental energy absorption and the values obtained from the model. The best coloration between experimental and the model is related to [75,0,0,-75] fiber stacking configuration with 0.23% accuracy in clamp-free boundary condition, and the worst coloration between experimental and the model is related to [30,60,-30,-60] fiber stacking configuration with 19.88% accuracy in clamp-free boundary condition.

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Plasma assisted machining (PAM) is a method to improve machinability of hard turning. The process of plasma assisted machining for turning applications utilizes a high-temperature plasma arc to provide a controlled source of localized heat, which softens only that small portion of the work material removed by the cutting tool. The goal of this study is to present a methodology for determination cutting force during plasma enhanced turning of hardened steel AISI 4140. In this regard, a finite differential model was made to estimate the uncut chip temperature under different plasma currents, cutting speeds and feeds during PAM. A mechanistic model developed to estimate cutting force under different PAM conditions by considering shear stresses in the primary, secondary shear zones and force on the tool edge. The proposed model was calibrated with experimental hard turning data, and further validated over practical PAM conditions. Mean errors of predicted values and experimental data is lower than 10 percent. It is shown that PAM can decrease main cutting force in comparison to convectional to 40 percent in turning of hardened steel at high levels of uncut chip temperature due to softening the material.

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Sandwich panels due to high strength to weight ratio and energy absorption properties, are widely used in various industries including aerospace industries, marine and automotive industries. Analysis of ballistic resistance of sandwich panels is mainly numerical and experimental, and there are a few analytical models in this field due to mathematical complexities. Hoo Fatt et al. have studied analytically high velocity impact on sandwich panels with composite skins and foam core. Because of the widespread use of sandwich panels with metal face-sheets and foam core in aerospace industry, by modifying the analytical method provided by Hoo Fatt et al. the ballistic resistance of the foam core sandwich panels with metal surfaces impacted by high velocity cylindrical projectile is analytically investigated in this paper. Two types of panels with polymeric and metallic foam cores and aluminum surfaces have been used to assess the accuracy of the analytical method. Results show that the proposed analytical method can predict the residual velocity of the projectiles impacted at high velocities on the foam and metallic core panels with different relative densities of the core.

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In the present study, a new analytical model for Earth to Air Heat Exchanger is presented. To this end, transient energy equation is solved employing duhamel's theorem and the soil temperature distribution is achieved with the concept of G function. Then, the outlet temperature will be achieved by solving the energy equation along the length of heat exchanger. In comparison to previous models, the present results are in better agreement with those obtained experimentally. Parametric investigation and feasibility study of this system in Tehran has been made using this analytical model for summer season with two different input temperatures. Parametric investigation showed for each mass flow rate, the corresponding optimum diameter is gained. It is observed that optimum diameter is a function of mass flow rate and operation time and independent of soil and input temperature of heat exchanger. For major mass flow rate supply, utilization of heat exchangers with minor mass flow rate is suggested; accordingly the temperature of heat exchanger is decreased. The depth and distance between heat exchangers can be calculated by the present model. It is also revealed this system can solely supply thermal comfort in continuous summer operation for cities with cold climate and low annual average temperature.

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Reactant gases should be humidified before entering a polymer electrolyte membrane (PEM) fuel cell stack. Humidification of the gases can be performed by a membrane humidifier. In the present study, an analytical model has been proposed to investigate the performance of a water-gas membrane humidifier which is used in the fuel cell systems. At first, a set of nonlinear equations was obtained by applying the mass and energy conservation laws on the gas side of the humidifier. The temperature and the humidity ratio of the outlet gases from the humidifier are the unknowns of these nonlinear equations. The proposed model can evaluate the performance of the humidifier based on the temperature and relative humidity of the outlet gases from the humidifier. The effects of different parameters like: gas flow rate, channel's length and depth, temperature and pressure of the inlet gases on the performance of the humidifier were studied by the developed model. The results show that the channel depth does not have an effect on the temperature and humidity of the humidified outlet gases. In addition, increasing the channel length causes an increase on the dew point of the outlet gases but the relative humidity of the dry inlet gas does not have a noticeable effect on the dew point of the outlet gases. Increasing the temperature of the inlet gases cannot improve the humidifier performance, considerably. The results of the model show that increasing the inlet pressure and using less air flow improve the humidifier performance.

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The application of woven fabrics in composites manufacturing has been increased because of their special mechanical behavior. Due to the complexity of modeling and simulation of these composites, in this research a micromechanics based analytical model has been developed to predict the elastic properties of woven fabric composites. The present model is simple to use and has a high accuracy in predicting the elastic properties of woven fabric composites. One of the most important effective factors on the modeling accuracy is utilizing a proper homogenization method. Therefore, a new homogenization method has been developed by using a laminate analogy based method for the woven fabric composites. The proposed homogenization method is a multi-scale homogenization procedure. This model divides the representative volume element to several sub-elements, in a way that the combination of the sub-elements can be considered as a laminated composite. To determine the mechanical properties of laminates, instead of using an iso-strain assumption, the assumptions of constant in-plane strains and constant out of plane stress have been considered. Then, the proposed homogenization model has been combined with a micromechanical model to propose the new micromechanical model. The applied assumptions improve the prediction of mechanical properties of woven fabrics composites, especially the out of plane elastic properties. The proposed model has been evaluated by comparing the predicted results with four available experimental results available in the literature, and the accuracy of the present model has been shown.

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One of the most important machining processes in the field of orthopedic surgeries and biomedical engineering is the drilling process. Applying excessive forces on the bone tissue, it can be caused cracking and damage bone tissue during the drilling process. In this paper, it is produced an improved analytical model based on early work done by Bono and Ni, Chandrasekharan, and Lee to predict the thrust force in the bone drilling process. In this model, the cutting action at the drill point is divided into three regions: the primary cutting lips, outer portion of the chisel edge (the secondary cutting edges), and inner portion of the chisel edge (the indentation zone). All three regions have been investigated for the cutting process by the analytical model. In order validating the model, some experiments performed on the fresh bovine bone. Feed rate and rotational speed are adapted as the effective parameter in the drilling process, The statistical model to obtain the mathematical model and provide interaction diagrams of input variables experiments, to response surface methodology and experimental investigation of bone drilling have been offered. Comparing the analytical model and experimental results show good agreement. From both analytical model and experiments, it is can conclude that with decreasing feed rate and increasing rotational speed, thrust force on the bone tissue decreases.

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Manufacturing structures with light weight and high strength in the industry is growing. Therefore, use of bent profiles and tubes in structures is increasing. In this paper, method of the incremental tube forming for bending tube is investigated. In this method using combination of spining and bending tube simultaneously improves the bending process for high-strength metals. The analytical model for incremental tube forming process is provided. The model is used for understanding the physics of the process and determine the amount of the required bending moment. In addition, numerical modeling of the incremental tube forming process for to forecast failures caused by bending is performed. The numerical modeling has been used to evaluate the effective parameters on the incremental tube forming process, such as feeding the second step, the rotational speed of spinning tool, feeding tube axis in the whole process and the effect of attack angle the spinning rolls and the results show The numerical model can be used to examine defects related to the speed of the process and Before producing the appropriate parameters to produce higher quality final product selected.

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The two thermal effects, thermophoresis and photophoresis phenomena that cause particle movements due to thermal gradient through the liquid and thermal gradient through the particle, respectively, have been widely studied over the past years because of their wide range of applications. This thermal gradient can be made by laser beam. There are a few studies concerning these two effects, especially photophoresis, in liquid media. In this paper, these two effects and their induced velocity to particles are studied in liquid media. The affecting parameters on these effects are studied and their effect on particles are determined. Effect of laser parameters like laser power and wavelength in the channel are discussed and the maximum velocity and temperature inside the channel are calculated. Also in the photophoresis part, the effect of parameters like laser power, particle and laser beam diameter is calculated. By considering the existing models for calculation of thermophoretic velocity, Brenner model is chosen as the most accurate model and will be used in calculations. It is also found that the effect of laser wavelength on thermophoretic velocity is more than changing laser power. In the photophoresis part, photophoretic velocity is calculated by using existing analytical models. The calculated velocities of thermophoresis and photophoresis are compared with the experimental values and there is an acceptable matching between them. The results of this paper will be used for designing and making a particle separator tool.

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In this research the influence of the striker shape on orthotropic composite plates for states, no damage (delamination) and damaged (delamination) are studied. In the analytical method, the spring mass system is used and new analytical model for flat and conical strikers are investigated. In the numerical method, the impact of different strikers on the composite laminate is simulated by using of finite element package (AnsysLs Dyna). These studies have been done on plates made of carbon and epoxy and the sheet thickness has been investigated in the size of 2, 4 and 6 mm. The striker mass is 3 g and its velocity for each thickness is different. To investigate the effects of the striker shape, three nose shapes spherical, conical and cylindrical with flat nose are modeled. The impacting time, the displacement time history and the maximum central deflection, and the contact force for all strikers are obtained and compared with each other. The results of analytical model are good agreement with numerical simulation. According to the results, when the delamination occurs, the maximum central deflection is more than once that damage dose not occurs. According to the results, the maximum central deflection of the flat striker on for both cases, with and without delamination, is less than the other strikers, conversely, the maximum contact force is more than the other strikers.

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The purpose of this study is to develop the previous proposed analytical model by the first and second authors for short links, so it can be used for all kinds of links including short, intermediate, and long links. Eccentrically braced frames (EBF) offer high lateral stiffness because of their braced configuration while also providing high ductility and energy dissipation. They are widely used as a lateral-force resisting system for multi-story buildings located in seismic areas. The key components of the EBF system include columns, collector beams, braces and active links. The active links are designed to provide ductility and energy dissipation through yielding under design basis earthquakes, while all other structural members are designed to be stronger than the links and stay in elastic range. The link is defined by a horizontal eccentricity between the intersection points of the two brace centerlines with the beam centerline. Sufficient analytical model which can accurately predict the inelastic performance of the links is needed to perform reliable nonlinear analyses of EBFs. Analytical models that are used to study the inelastic seismic response of the EBFs usually reflect the anticipated behavior of the different frame elements. Links are modeled as inelastic elements with concentrated end flexural and shear hinges. Beams outside of the link, braces, and columns are typically modeled as elastic beam-column elements, because no inelastic behavior is anticipated in design. Ricles and Popov proposed an analytical model for short links. Ramadan and Ghobarah replaced the sub-hinges with translational and rotational springs and proposed a new model. Both models had incorrect shear stiffness so that the shear stiffness of model was half the link shear stiffness. Richards and Uang corrected the shear stiffness of the model proposed by Ramadan and Ghobarah, and proposed a new analytical model for short links. Koboevic et al. proposed an analytical model based on the results of experimental test performed by Okazaki and Engelhardt, regardless of the fact that the actual measured dimensions of sections were different from the standard dimensions of sections. To account for this issue, despite of what is said in their paper, the strain-hardening ratio was set to 0.0045. For this reason, the shear stiffness of their proposed model was incorrect and the predicted shear forces are 15 to 24 percent more than the experimental shear forces. Ashtari and Erfani showed that available analytical models do not predict very well the maximum shear forces and deformations too, and proposed an analytical model which can accurately predict both maximum and intermediary values of shear force and deformation of short links. To the authors’ knowledge, currently there are only suitable analytical models for short links. In this study an analytical model which can accurately predict both maximum and intermediary values of forces and deformations for short, intermediate, and long links, is proposed. The parameters of model are established based on test results from several experiments on links and EBFs. Comparison of available test results with the hysteresis curves obtained using the proposed analytical model established the accuracy of the model. The proposed model is recommended to be used to perform inelastic analyses of EBFs.

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In this study, the influences of drying conditions on the mass transfer characteristics of kiwi slices are investigated using the analytical model proposed by Dincer and Dost. The experiments were conducted at temperature range of 50–80°C with 0.5 m s^-1 air velocity for convective drying and in the microwave power range of 200–500W for microwave drying as single layers with sliced thickness of 3, 6, and 9 mm. The results show that the mass transfer characteristics strongly depend on the drying conditions. Through the convective drying method, parameters including moisture diffusivity, mass transfer coefficient, Biot number, and drying time were varying from 0.16-1.45×10^-8 m² s^-1, 1.93-4.95×10⁻⁷ m s^-1, 0.103-0.225, and 90-604 minutes, respectively. In comparison, for microwave drying, they were within the ranges of 0.66-25.60×10^-8 m² s^-1, 0.62-5.64×10⁻⁵ m s^-1, 0.960-1.742, and 4-23.5 minutes, respectively. Results reveal that the activation energy for moisture diffusion is higher than that needed for the convective mass transfer process.