Maxwell

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1 - بررسی خصوصیات ویسکوالاستیک کیک اسفنجی غنی‌شده با پودر سیب
فخرالدین صالحی مهدی کاشانی نژاد

مقدمه: سیب یک منبع غنی از فیبر و پلی فنول‌ها می‌باشد. به منظور بررسی اثر جایگزینی پودر سیب با آرد گندم بر خواص ویسکوالاستیک کیک اسفنجی آزمون رهایی تنشانجام گرفت. مواد و روش‌ها: ابتدا سیب زرد در شرایط بهینه خشک و آسیاب شد و سپس پودر سیب جهت غنی‌سازی کیک اسفنجی در پنج سطح چکیده کامل

مقدمه: سیب یک منبع غنی از فیبر و پلی فنول‌ها می‌باشد. به منظور بررسی اثر جایگزینی پودر سیب با آرد گندم بر خواص ویسکوالاستیک کیک اسفنجی آزمون رهایی تنشانجام گرفت. مواد و روش‌ها: ابتدا سیب زرد در شرایط بهینه خشک و آسیاب شد و سپس پودر سیب جهت غنی‌سازی کیک اسفنجی در پنج سطح 0، 5، 10، 15 و 20 درصد (وزنی/وزنی) به ‌عنوان جایگزین آرد گندم در فرمولاسیون کیک استفاده شد. پس از آماده‌سازی نمونه، آزمایش رهایی تنش با استفاده از دستگاه بافت سنج در طی دوره نگهداری انجام و ضرایب مدل پلگ-نورمند و ماکسول تعمیم‌یافته محاسبه شد. یافته‌ها: نتایج نشان‌داد با افزایش درصد جایگزینی پودر سیب و زمان نگهداری، مقادیر نیروی اولیه و نیروی تعادلی افزایش می‌یابند. پارامترهای مدل پلگ-نورمند شامل k1 و k2 با گذشت زمان کاهش یافت که نشان از کاهش الاستیسیته کیک با گذشت زمان می‌باشد. کیک‌ها رفتار جامد ویسکوالاستیک از خود نشان ‌داده و با افزایش درصد جایگزینی، مجموع نیروهای کاهشی (F1+F2 +F3) مدل ماکسول تعمیم‌یافته افزایش یافت که نشان‌دهنده کاهش الاستیسیته است. نتیجه‌گیری: نتایج مدل‌سازی داده‌های آزمایشگاهی رهایی تنش با مدل‌های پلگ نورمند و ماکسول تعمیم‌یافته نشان‌داد که مدل ماکسول تعمیم‌یافته کارایی بیشتری جهت بررسی خصوصیات ویسکوالاستیک کیک اسفنجی غنی‌شده با پودر سیب دارد. پرونده مقاله

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2 - بررسی اثر صمغ‌های گوار و زانتان بر خصوصیات ویسکوالاستیکی کیک اسفنجی بدون گلوتن با استفاده از آزمون رهایی تنش
هادی باقری عبدالستار عوض صوفیان مهران اعلمی

مقدمه: با توجه به نیاز تغذیه ای بیماران سلیاکی به یک رژیم غذایی فاقد گلوتن، مطالعه در مورد تولید و بهبود محصولات بدون گلوتن افزایش یافته است. با توجه به برخی از مشکلات کیفی مانند حجم پایین و بافت ضعیف در محصولات بدون گلوتن نظیر کیک برنجی، استفاده از ترکیبات بهبود دهنده چکیده کامل

مقدمه: با توجه به نیاز تغذیه ای بیماران سلیاکی به یک رژیم غذایی فاقد گلوتن، مطالعه در مورد تولید و بهبود محصولات بدون گلوتن افزایش یافته است. با توجه به برخی از مشکلات کیفی مانند حجم پایین و بافت ضعیف در محصولات بدون گلوتن نظیر کیک برنجی، استفاده از ترکیبات بهبود دهنده مانند هیدروکلوئیدها که خواص ویسکوالاستیک گلوتن را شبیه سازی می‌کنند، ضروری به نظر می رسد. از آنجا که گلوتن به عنوان یک ترکیب ویسکوالاستیک شناخته می شود و با توجه به عدم حضور گلوتن در کیک برنجی و استفاده از هیدروکلوئید ها که منجر به تغییر خصوصیات ویسکوالاستیک خواهد گردید، بنابراین مطالعه رفتار ویسکوالاستیک کیک برنجی بدون گلوتن حاوی هیدروکلوئید ها ضرروری به نظر می رسد. مواد و روش‌ها: دراین مطالعه اثر صمغ های گوار و زانتان بر خصوصیات ویسکوالاستیکی کیک برنجی بدون گلوتن با استفاده از آزمون رهایی تنش مورد مطالعه قرار گرفت و سپس توسط دو مدل پلک- نورمند و ماکسول تعمیم یافته مورد مدل سازی قرار گرفت. آنالیز آماری داده ها با استفاده از آنالیز واریانس یک طرفه و به منظور مقایسه میانگین ها از آزمون دانکن در سطح 5 درصد استفاده شد. یافته‌ ها: نتایج نشان داد که با افزایش غلظت صمغ های گوار و زانتان، مقدار F0،K1،K2و پارامتر های مدل ماکسول کاهش یافت. این بدین معنی است که با افزودن صمغ گوار و زانتان نرخ کاهش نیروی اولیه افزایش یافت، بنابراین رفتار کیک حاوی صمغ، بیشتر متمایل به رفتار شبه مایع می باشد. با توجه به SSEو R2 مدل می توان بیان کرد که مدل پلگ- نورمند نیز می تواند به شکلی مناسب رفتار تنش ویسکوالاستیک کیک بدون گلوتن را در طول زمان توجیه نماید اما نسبت به مدل ماکسول از اعتبار پائین تری برخوردار است. نتیجه گیری: خصوصیات ویسکوالاستیکی کیک بدون گلوتن حاوی صمغ گوار و زانتان بهبود یافته و رفتار کیک حاوی صمغ متمایل به رفتار شبه مایع گردید. پرونده مقاله

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3 - Influence of Guar Gum on Texture Profile Analysis and Stress Relaxation Characteristics of Carrot Sponge Cake
F. Salehi M. Kashaninejad

Stress relaxation has traditionally been employed as one of the principal means for measuring the viscoelastic behavior of foods. The objective of this study was to determine the texture profile analysis and stress relaxation characteristics of carrot sponge cake formul چکیده کامل

Stress relaxation has traditionally been employed as one of the principal means for measuring the viscoelastic behavior of foods. The objective of this study was to determine the texture profile analysis and stress relaxation characteristics of carrot sponge cake formulated with four different levels of guar gum (0, 0.25, 0.5 and 0.75 %). Texture profile analysis results showed a decrease in the carrot cake consistency, gumminess and chewiness with increasing the level of gum. The consistency and hardness values decreased from 4773.11 to 2260.60 g.s and 915.45 to 458.54 g with increasing guar gum levels from 0 to 0.75 %, respectively. The results showed that mechanical stress relaxation data of carrot sponge cakes were fitted well by both the Peleg-Normand and four-element Maxwell models. The F0 (initial force) and %SR (percentage stress relaxation) parameter of carrot sponge cakes decreased with increasing gum concentration (P<0.05). Although all decay forces (F1, F2 , F3 and F4) of the carrot sponge cakes obviously decreased with increasing guar gum concentration. The elasticity of the carrot sponge cakes was the highest at 0.75% guar gum concentration. پرونده مقاله

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4 - Simulation and analysis of electromagnetic fields resulting from lightning in the proximity of watercraft using Maxwell v.15 software
Shahrouz Nasiri Mehdi Tabasi Alireza Bakhshinejhad

Strike of lightnings with sea, due to the high conductivity of salty water creates more extreme electromagnetic fields in comparison with lightnings in land. This paper deals with analysis and simulation of electromagnetic fields resulting from lightning in the proximit چکیده کامل

Strike of lightnings with sea, due to the high conductivity of salty water creates more extreme electromagnetic fields in comparison with lightnings in land. This paper deals with analysis and simulation of electromagnetic fields resulting from lightning in the proximity of a watercraft in sea and its effect on the equipment on the watercraft. The magnitude of electric and magnetic fields is first calculated using Uman integral equations to calculate the electric field resulting from a limited current channel on a perfect conductor. To solve the field integrals, dual precision exponential model was used for the lightning’s current. Due to limitations of the solution of field integrals, parametric analysis is difficult. For this reason, the lightning channel and watercraft model was simulated in Maxwell software and the obtained fields were compared with the results of integral solution. Considering the closeness of integral and simulation results, with alteration of the peak lightning current and its distance off the watercraft, the field sensitivity to these variables was measured and the results of parametric analysis have been presented for different parts of the watercraft. پرونده مقاله

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5 - Deformation Field Produced by a Doublet Source in a Half-Space Model
N Verma K Singh

10.22034/jsm.2021.1904644.1621

Using Galerkin vector approach closed-form analytic expressions for the displacements and stresses caused by a doublet source buried in a homogenous, isotropic, perfectly elastic half-space have been obtained. Further, the viscoelastic deformation field has been obtaine چکیده کامل

Using Galerkin vector approach closed-form analytic expressions for the displacements and stresses caused by a doublet source buried in a homogenous, isotropic, perfectly elastic half-space have been obtained. Further, the viscoelastic deformation field has been obtained by applying the correspondence principle of linear viscoelasticity, assuming the medium to be elastic in dilatation and Kelvin, Maxwell, or SLS (Standard linear solid) type viscoelastic in distortion. The effect of Poisson’s ratio on the deformation field due to a doublet source is examined in elastic half-space. The effect of relaxation time on displacement and stress fields is studied due to a doublet source in viscoelastic half-space. The variation of the displacements and stresses with the epicentral distance is studied graphically using MATLAB software. Stresses for a doublet with axis parallel to x-axis attain minimum value for Poissonian half- space. Viscoelastic displacements and stresses attain maxima for the Maxwell model and minima for the Kelvin model. پرونده مقاله

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6 - Modeling of Compression Curves of Flexible Polyurethane Foam with Variable Density, Chemical Formulations and Strain Rates
M.F Alzoubi S Al-Hallaj M Abu-Ayyad

Flexible Polyurethane (PU) foam samples with different densities and chemical formulations were tested in quasi-static stress-strain compression tests. The compression tests were performed using the Lloyd LR5K Plus instrument at fixed compression strain rate of 0.033 s- چکیده کامل

Flexible Polyurethane (PU) foam samples with different densities and chemical formulations were tested in quasi-static stress-strain compression tests. The compression tests were performed using the Lloyd LR5K Plus instrument at fixed compression strain rate of 0.033 s-1 and samples were compressed up to 70% compression strains. All foam samples were tested in the foam rise direction and their compression test stress results were modeled using a constitutive Polymeric or Phenomenological Foam Model (PFM). In this research, a new constitutive PFM model that consists of mechanical systems such as dashpots and springs was formulated to be used for different strain rate experiments. The experimental compression test results for different strain rates were compared to the PFM model results for all foam samples. Both modeling and experimental results showed pretty good agreement. From curve fitting of the experimental tests with the PFM model; different mechanical materials’ coefficients such as elastic and viscous parameters were computed. These mechanical parameters are indeed important characteristics for viscoelastic materials. This model can be used for constant and variable strain rates and for characterizing biomechanical material applications such as bone tissues, muscle tissues and other cellular materials. پرونده مقاله

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7 - Damping Ratio in Micro-Beam Resonators Based on Magneto-Thermo-Elasticity
A Khanchehgardan G Rezazadeh A Amiri

This paper investigates damping ratio in micro-beam resonators based on magneto-thermo-elasticity. A unique aspect of the present study is the effect of permanent magnetic field on the stiffness and thermo-elastic damping of the micro resonators. In our modeling the the چکیده کامل

This paper investigates damping ratio in micro-beam resonators based on magneto-thermo-elasticity. A unique aspect of the present study is the effect of permanent magnetic field on the stiffness and thermo-elastic damping of the micro resonators. In our modeling the theory of thermo-elasticity with interacting of an externally applied permanent magnetic field is taken into account. Combined theoretical and numerical studies investigate the permanent magnetic field effect on the damping ratio in clamped-clamped and cantilever micro-beams. Furthermore, the influence of the magnetic field intensity on the frequency of the micro-beams with thermo-elastic damping effect is evaluated. Such evaluations are used to determine the influence of magnetic field on the vibration amplitude of the resonators. The meaningful conclusion is that the magnetic field increases the equivalent stiffness and thermo-elastic damping and consequently the energy consumption of the resonators. پرونده مقاله

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8 - Theory of Generalized Piezoporo Thermoelasticity
M Jabbari A Yooshi

In this paper, the basic constitutive equations and equations of motion are derived to describe the behavior of thermoelastic porous piezoelectric medium by using Biot’s theory and the theory of generalized thermoelasticity with on relaxation time (Lord-Shulman). چکیده کامل

In this paper, the basic constitutive equations and equations of motion are derived to describe the behavior of thermoelastic porous piezoelectric medium by using Biot’s theory and the theory of generalized thermoelasticity with on relaxation time (Lord-Shulman). The electrical enthalpy density function is derived in the general coordinates. Also, clear definitions for the poroelastic modulus, electrical, thermal and additional mixed coefficients are embedded. The uniqueness of the solution for the complete system of equations is presented. پرونده مقاله

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9 - On the Stability of an Electrostatically-Actuated Functionally Graded Magneto-Electro-Elastic Micro-Beams Under Magneto-Electric Conditions
A Amiri G Rezazadeh R Shabani A Khanchehgardan

In this paper, the stability of a functionally graded magneto-electro-elastic (FG-MEE) micro-beam under actuation of electrostatic pressure is studied. For this purpose Euler-Bernoulli beam theory and constitutive relations for magneto-electro-elastic (MEE) materials ha چکیده کامل

In this paper, the stability of a functionally graded magneto-electro-elastic (FG-MEE) micro-beam under actuation of electrostatic pressure is studied. For this purpose Euler-Bernoulli beam theory and constitutive relations for magneto-electro-elastic (MEE) materials have been used. We have supposed that material properties vary exponentially along the thickness direction of the micro-beam. Governing motion equations of the micro-beam are derived by using of Hamilton’s principle. Maxwell’s equation and magneto-electric boundary conditions are used in order to determine and formulate magnetic and electric potentials distribution along the thickness direction of the micro-beam. By using of magneto-electric potential distribution, effective axial forces induced by external magneto-electric potential are formulated and then the governing motion equation of the micro-beam under electrostatic actuation is obtained. A Galerkin-based step by step linearization method (SSLM) has been used for static analysis. For dynamic analysis, the Galerkin reduced order model has been used. Static pull-in instability for 5 types of MEE micro-beam with different gradient indexes has been investigated. Furthermore, the effects of external magneto-electric potential on the static and dynamic stability of the micro-beam are discussed in detail. پرونده مقاله

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10 - Evaluation of CO2/CH4 Gas Separation in PVA and PVC Mixed Matrix Membrane Permeation Models
Elaheh Gandomkar Ghalhari Samaneh Koudzari Farahani Abdolreza Moghadassi Ezzatollah Joudaki Seyyed Mohsen Hosseini

The purpose of this paper is to examine, predict and compare gas transport behavior of mixed matrix membranes (MMMs) combined with porous particles with different polymeric matrix. In this regard, composite flat sheet membranes are prepared from different amounts of pol چکیده کامل

The purpose of this paper is to examine, predict and compare gas transport behavior of mixed matrix membranes (MMMs) combined with porous particles with different polymeric matrix. In this regard, composite flat sheet membranes are prepared from different amounts of poly(Polyvinyl alcohol) (PVA) and poly vinyl chloride (PVC) Gas permeability were studied for the prepared membranes. Then these membranes modelled were performed by Maxwell, and the results of Maxwell model with the experimental data were compared and the percentage of error was shown. Studied results showed that despite higher permeability emissions of carbon dioxide with PVC membrane grid with carbon nanotubes in the membrane of PVA but Maxwell model for PVA membranes without any additive as a polymeric membrane has provided more acceptable results. پرونده مقاله

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11 - Mathematic modeling of purification of biodiesel with PES polymeric membrane
Samaneh Koudzari Farahani Elaheh Gandomkar Ghalhari Abdolreza Moghadassi Seyyed Mohsen Hosseini Ezzatollah Joudaki

One of the new separation methods for purifying biodiesel used in recent years is the membrane separation process. In the current research, purification of produced biodiesel was carried out using Polymeric Poly Ether Sulfone(PES) based membrane. The prepared PVP membra چکیده کامل

One of the new separation methods for purifying biodiesel used in recent years is the membrane separation process. In the current research, purification of produced biodiesel was carried out using Polymeric Poly Ether Sulfone(PES) based membrane. The prepared PVP membranes was containing 1, 1.5, 2 and 3 wt.% of PVP concentration with 16 wt.% PES. as additive. Reported experimental determining the membrane flux and separation efficiency (glycerol rejection) membrane was modeled by Maxwell Model. The result, including penetration rate, theory graph and experimental data comparison for biodiesel and glycerin, and error graphs have been explained. Results showed that the experimental data’s have Compatibility with the model and, membrane with 2 percent PVP has provided more acceptable results. پرونده مقاله

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12 - Design of Optimum Active Layer Thickness in Double Heterostructure Broad Area Ga As/Al_x Ga_(1-x) As Laser Diodes
nasser moslehi milani mohammad salmani yengejeh Majid shabzendeh

In this work, we calculate optimum thickness of bulk active layer for Ga As/〖Al〗_x 〖Ga〗_(1-x) As laser diodes. We have done these calculations for fundamental oscillation mode of laser with different aluminium contents (fractional percents) in confinement layers. Our ca چکیده کامل

In this work, we calculate optimum thickness of bulk active layer for Ga As/〖Al〗_x 〖Ga〗_(1-x) As laser diodes. We have done these calculations for fundamental oscillation mode of laser with different aluminium contents (fractional percents) in confinement layers. Our calculations were based on the analytical solution of Maxwell equations. The results indicate that the optimum thickness for fundamental mode is dependent on difference of refractive indices of active and confinement layers. The results reveal that the best active layer thicknesses for fundamental mode of laser are d_0=0.63,0.44,0.36 and 0.32 μm for x=0.1,0.2,0.3 and 0.4 aluminium percents in separate confinement heterostructure (SCH) layers respectively. پرونده مقاله

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13 - Design Optimization for Total Volume Reduction of Permanent Magnet Synchronous Generators
Reza Ilka Yousef Alinejad-Beromi Hossein Asgharpour-Alamdari Hamid Yaghobi

Permanent magnet synchronous generators (PMSGs) are novel generators which can be used in high-performance wind farms. High efficiency and flexibility in producing electricity from variable rotation make them good candidate for wind power applications. Furthermore, beca چکیده کامل

Permanent magnet synchronous generators (PMSGs) are novel generators which can be used in high-performance wind farms. High efficiency and flexibility in producing electricity from variable rotation make them good candidate for wind power applications. Furthermore, because these kinds of generators have no excitation winding, there is no copper loss on rotor; hence, they can operate at high power factor. Besides, performance characteristics of such generators could be further improved by design optimization. This paper presents design optimization of PMSGs used in small wind turbines using novel and efficient optimization algorithm i.e. Artificial Bee Colony (ABC) Algorithm. Then, a well-known optimization algorithm i.e. Genetic Algorithm (GA) is used to show the validity and efficiency of the before-mentioned algorithm. For this purpose, the necessary equations are provided. Objective function of this study is to reduce the total volume of motor. Case study of this study is a 5 kW, 220 V, 50 Hz, 100 rpm generator. Finally, results obtained by optimization are verified with Maxwell software which is based on finite element method (FEM). Comparison shows that the results of optimization approach are in good agreement with that of FEM ones. پرونده مقاله

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14 - Anisotropic Charged Stellar Models
Kalikkuddy Komathiraj

10.30495/ijm2c.2022.684825

A new class of exact solutions of the Einstein-Maxwell system is found in closed form for a static spherically symmetric anisotropic star in the presence of an electric field by generalizing earlier approaches. The field equations are integrated by specifying one of the چکیده کامل

A new class of exact solutions of the Einstein-Maxwell system is found in closed form for a static spherically symmetric anisotropic star in the presence of an electric field by generalizing earlier approaches. The field equations are integrated by specifying one of the gravitational potentials, the anisotropic factor and electric field which are physically reasonable. We demonstrate that it is possible to obtain a more general class of solutions to the Einstein-Maxwell system in the form of series with anisotropic matter. For specific parameter values it is possible to find new exact models for the Einstein-Maxwell system in terms of elementary functions from the general series solution. Our results contain particular solutions found previously including models of Thirukkanesh and Maharaj (2009) and Komathiraj and Maharaj (2007) charged relativistic models. پرونده مقاله

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15 - A NOTE ON THE UNSTEADY FLOW OF A VISCO-ELASTIC MAXWELL FLUID THROUGH A RECTILINEAR PIPE
R. Dube

The unsteady flow of a visco-elastic Maxwell fluid through a rectilinear pipe having its cross-section as a parallelogram under the influence of a axial pressure gradient (I) varying linearly with time , and (II) decreasing exponentially with time has been discussed in چکیده کامل

The unsteady flow of a visco-elastic Maxwell fluid through a rectilinear pipe having its cross-section as a parallelogram under the influence of a axial pressure gradient (I) varying linearly with time , and (II) decreasing exponentially with time has been discussed in the present paper. Variables separable and Laplace transform methods have been used to solve the problem. پرونده مقاله

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16 - Use of Ansoft to Model a Slice Magnetic Bearing
محمد اسماعیلی ادبی شهربانو فرخنده

Maxwell 3D of Ansoft software were used for this study. Ansoft’s solutions are based on a more general program using Maxwell’s equations. A simple analysis has been done for calculating the magnetic force interacted between two magnets of similar poles facin چکیده کامل

Maxwell 3D of Ansoft software were used for this study. Ansoft’s solutions are based on a more general program using Maxwell’s equations. A simple analysis has been done for calculating the magnetic force interacted between two magnets of similar poles facing each other. The modeling in Anosoft has been described. پرونده مقاله

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