توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱Welded Plate Heat Exchangers, a Good Solution to Minimize Costs in a Bitumen Plant
نویسنده(ها): ،
اطلاعات انتشار: اولین همایش بین المللی قیر، سال
تعداد صفحات: ۵
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۲DEVELOPING AN ENGINEERING STANDARDIZED TRAINING PACKAGE
اطلاعات انتشار: اولین کنفرانس بین المللی فناوری اطلاعات و دانش، سال
تعداد صفحات: ۷
The main purpose of this paper is to present the major steps for upgrading the existing courses to Standardized Training Packages (STP) or developing new STPs. The all steps of the proposed method has been successfully applied to an electrical engineering course (i.e. 32–Bit Microprocessor). This STP has been certified and registered by TRAINAIR Central Unit of International Civil Aviation Organization (ICAO). Also, this method is now being applied to a new electrical engineering course (i.e. Microwave Measurements). Running this type of course in companies and institutes leads to a high standard of training with minimum overall cost. The proposed methodology is an important approach in Information Technology and education.<\div>

۳FDLTD method for the Physical Simulation of Microwave FET Transistor
اطلاعات انتشار: نوزدهمین کنفرانس مهندسی برق ایران، سال
تعداد صفحات: ۴
This paper describes an new application of weighted Laguerre polynomial functions to produce a unconditionally stable Finite–Difference Laguerre–Time–domain (FDLTD) scheme for simulation of the Drift–Diffusion Model (DDM) of microwave active devices. The unconditionally stability of FDLTD method leads to a significant reduction in the simulation time. For example, when 100 weighted Laguerre polynomial functions is used, FDLTD is 5 times faster than conventional FDTD method while they have the same degree of accuracy.<\div>

۴Harmonic Suppression Slot Antenna Using Rectangular Defected Ground Structure
اطلاعات انتشار: نوزدهمین کنفرانس مهندسی برق ایران، سال
تعداد صفحات: ۴
In this letter, a wide rectangle–shaped microstrip–fed 2.62 GHz slot antenna using defected ground structure (DGS) with a low design complexity is proposed to achieve wideband harmonic suppression. To accomplish this, two rectangular DGS (RDGS) with various positions and dimensions are etched into the ground plane, which could have a wide band–stop characteristic. Simulated and measured return losses indicate that proposed structure effectively suppress the third harmonic up to 23 dB between 3 and 10.5 GHz with a maximum ripple of 2 dB. In addition, the measured radiation pattern and peak gain of the antenna show at least 17 dB and 7.1 dBi, respectively suppression at the third harmonic frequency of 7.86 GHz<\div>

۵Comparison of Distribution Functions for Characterization of C7+ Fraction in One of Iranian Oil Field
اطلاعات انتشار: سومین کنفرانس علمی مهندسی مخازن هیدروکربوری و صنایع بالادستی، سال
تعداد صفحات: ۷
In characterization of wide boiling range heptane plus (C7+) fractions in addition to bulk properties such as molecular weight (MW), specific gravity (SG), etc., properties distribution is also required. Bulk properties can be measured easily but determination of properties distribution is more costly and time consuming. So the characterization methods is used for determining the properties distribution. Methods selected for the characterization of reservoir fluids have significant impact on the estimation of physical properties and phase behavior needed in reservoir simulation for petroleum production. Characterization of reservoir fluids involves representing the fluid as a continuous, semi–continuous mixture or through a number of components\pseudocomponents with known basic characterization data. Understanding of various characterization schemes and their limitations is the key to selecting the right one in a reservoir simulator. The main objective of these paper is to compare the results of characterization methods for one of Iranian south oil field to determine the best method that is compactible with that reservoir fluid. The results show that all models can estimate the mole fraction distribution very close to the experimental data from C7 to C30+ but the average absolute error for single carbon number (SCN) model is lower than other models for this reservoir fluid.<\div>

۶A New preparation method for LaNiO3 perovskite for dry reforming of methane
اطلاعات انتشار: هفتمین کنگره ملی مهندسی شیمی، سال
تعداد صفحات: ۷
LaNiO3 perovskite–type was prepared successfully by impregnation method with ethanol and acetic acid as solvent. After reduction, catalytic activity in CO2 reforming of CH4 was tested in a fixed bed reactor at 700, 750 and 800˚C. It was found that LaNiO3 prepared by this new method, shows good activity, selectivity and long term stability for dry reforming of methane at 800˚C. In all tests at different temperatures CO2 conversion is lower than CH4 conversion. This catalyst produces higher H2\CO ratio at low flow rate in comparison with the other preparation methods which published in the literature for this catalyst.<\div>

۷Biodiesel production by transesterification of soybean oil using BaO\γ–Al2O3 as a solid base catalyst :An optimization study
نویسنده(ها): ،
اطلاعات انتشار: هفتمین کنگره ملی مهندسی شیمی، سال
تعداد صفحات: ۷
Heterogeneous catalysts are now being tried extensively for biodiesel synthesis. In this work, a new solid catalyst has been developed and optimized to produce biodiesel from soybean oil. The main advantage of solid catalysts is that it requires lower investment costs, since no separation steps for methanol\catalyst and glycerin\catalyst are needed. The calcinations temperature and experimental conditions were investigated and optimized by response surface methodology in experimental design. The optimized conditions found to be 60 wt% of BaO loading as catalyst on the γ–Al2O3 as support , calcination temprature 545°C and 12:1 molar ratio methanol\oil.<\div>

۸Thermodynamical VLE modeling of water and methanol mixture using PRSV2 equation of state
نویسنده(ها): ،
اطلاعات انتشار: چهارمین همایش علمی مهندسی فرآیند، سال
تعداد صفحات: ۹
Nowadays, researchers are trying to synthesis a hundreds of new material that acquiring their thermodynamical properties using experimental procedure is impossible. So by using modeling softwares and accessibility of thermodynamical equations, thermodynamic and equilibrium properties can be predicted accurately.PRSV2 equation of state is a modified form of Peng–Robinson EOS that is recently considered by researchers for prediction of multicomponent mixtures thermodynamic equilibrium behavior. In this study is tried to emphasize on advantages of VLE thermodynamic modeling using EOS for liquid and vapor phases rather than using EOS for vapor phase and activity coefficient method for liquid phase. Equilibrium calculations were performed using experimental data in two condition of isothermal and isobar. In two condition advantages of using EOS for vapor and EOS for liquid rather than using EOS for vapor and activity model for liquid has been demonstrated. A first order equation was obtained to show the dependence of kij to temperature that has shown good relation in the temperature range TR<0.7.<\div>

۹Characterization of C7+ Fraction by Use of Distribution Functions in One of Iranian Oil Fields
نویسنده(ها): ،
اطلاعات انتشار: اولین همایش ملی توسعه میادین نفت و گاز، سال
تعداد صفحات: ۵
In characterization of heptane plus (C7+) fractions in addition to bulk properties such as molecular weight, specific gravity, etc., properties distribution is also required. Bulk properties can be measured easily but determination of properties distribution is more costly and time consuming. So the characterization methods are used for determining the properties distribution. Methods selected for the characterization of reservoir fluids have significant impact on the estimation of physical properties and phase behavior needed in reservoir simulation for petroleum production. Characterization of reservoir fluids involves representing the fluid as a continuous, semi–continuous mixture or through a number of components\pseudocomponents with known basic characterization data. Understanding of various characterization schemes and their limitations is the key to selecting the right one in a reservoir simulator. The main objective of these paper is to compare the results of characterization methods for one of Iranian south oil field to determine the best method that is compactible with that reservoir fluid. The results show that all models can estimate the mole fraction distribution very close to the experimental data from C7 to C30+ but the average absolute error for single carbon number (SCN) model is lower than other models for this reservoir fluid<\div>

۱۰Investigation the effect of different solvents on the oil extraction of castor beans (Ricinus communis L.)
نویسنده(ها): ،
اطلاعات انتشار: چهارمین همایش ملی فن آوری های نوین شیمی و مهندسی شیمی، سال
تعداد صفحات: ۷
Castor oil identified as a potential resource for different pharmaceutical, chemical and industrial utilization due to its physiochemical properties, which attracted the attention of many researchers. In this study, the influence of various solvents such as methanol, acetone and n–hexane on the yield of castor oil extraction was investigated. For this purpose, Soxhlet extraction method was used to generate oil from castor been (Ricinus communis L.). After determining the solvent with high yield of oil extraction, further evaluation was conducted on the best solvent. The result demonstrated that castor seeds contain a high oil percentage and the mixture of methanol–acetone solvents (ratio equal to 2) with the yield of 50.96%, has a high strength to extract the oil. Furthermore, the physiochemical properties and fatty acid structure of castor oil were analyzed<\div>

۱۱Aging time investigation in dry reforming of methane over 5%wt Ni\SiO2 catalyst
اطلاعات انتشار: دومین کنفرانس بین المللی یافته های نوین پژوهشی در شیمی و مهندسی شیمی، سال
تعداد صفحات: ۷
The CO2 reforming of methane over 5wt% Ni\SiO2 catalyst for perusing the effect of aging time in this process was discussed by two methods using Citric acid with different concentrations and mixture of NH3 and water by sol–gel process. All the catalysts prepared with the above methods were calcined at 500 ˚C. After reduction, catalytic activity toward CO2 reforming of CH4 with CO2\CH4 ratio equal to 1 was tested at 700, 750 and 800˚C. It was found that CO2 and CH4 conversions were similar for both mentioned methods in this work, indeed, aging time and surface area do not have key roles in DRM. The results demonstrated that the conversions of CO2 and CH4 and the H2\CO ratio for both approaches were 0.9772, 0.9700 and 0.9500 respectively.<\div>

۱۲Wideband Multisection Hybrid Coupler in Slot–coupled Structure for L\S\C band Applications
اطلاعات انتشار: اولین کنفرانس بین المللی دستاوردهای نوین پژوهشی در مهندسی برق و کامپیوتر، سال
تعداد صفحات: ۵
This paper presents a wideband compact hybrid coupler working on 1–6 GHz frequency band. This 3–dB hybrid coupler is in slot–coupled structure designed on multilayer Rogers RO4003C substrate. The proposed coupler consists of elliptically shaped transmission line and the combination of rectangular and elliptical shaped slots on the ground plane. To improve characteristics of the designed coupler especially in lower frequency band, multisection transmission line and altering shape of the slot on ground is proposed. By etching extra rectangular slots on the ground plane the overall size reduction is achieved. Simulation results show that the proposed coupler provides coupling of 3±0.8 dB with 90°±0.85 phase shift and demonstrate the return loss and isolation better than 16 dB over 1–6 GHz (143%) frequency band which increased by 34% compared to other slot–coupled configuration in literature review. The coupler size is 20 mm × 30 mm. The results indicate that the proposed coupler covers GPS\DCS\PCS\UMTS\WiBro\ S–DMB\WiMax\WLAN frequency bands.<\div>

۱۳Modified Transition For Substrate Integrated Waveguide(SIW) Structures
نویسنده(ها): ،
اطلاعات انتشار: کنفرانس بین المللی مهندسی برق، سال
تعداد صفحات: ۱۰
In this paper a new X–band SIW to Microstrip transition based on SIW structure is proposed. The recent transition has better performance in terms of return loss than the traditional Microstrip tapers transition. Chebyshev multi–section matching transformer is used in order to inter–stage network between Microstrip and SIW, whereof it is the most optimum and efficient in matching networks theory. The 5th–order Chebyshev polynomial is employed to get about 30 dB return loss. For this purpose, curve–fitting technique is utilized to obtain a mathematical function based on Chebyshev polynomial that presents the optimum position of vias in SIW transition. In order to validation of theoretical method and results, a full–wave simulation is carried out by CST STUDIO SUITE software<\div>

۱۴Optimization and Fully Distributed Analysis of Single Pole Single Throw Traveling Wave Switchesat Millimeter Wave Frequency Band
اطلاعات انتشار: International Journal Information and Communication Technology Research، سوم،شماره۲، Mar ۲۰۱۱، سال
تعداد صفحات: ۸
In this paper, a fully distributed model for a single pole single throw traveling wave switch is introduced and important parameters of the switch such as insertion loss, isolation, and reflection coefficient are presented based on the lossy transmission line model of switch. The results of fully distributed model are compared with the semi–distributed model’s results and have good agreement with them. By applying the fully distributed model and calculating various switch’s parameters as a function of the switch length and operating frequency, the optimum switch length and operating frequency are obtained versus the parameters of switch, especially the reflection coefficient and isolation in OFF and ON conditions.

۱۵A New Correlation for Prediction of Wax Disappearance Temperature of Hydrocarbon Mixtures at Various Pressures
اطلاعات انتشار: Journal of Chemical and Petroleum Engineering، چهل و هفتم،شماره۱، ، سال
تعداد صفحات: ۱۲
Wax precipitate is one of the most serious issues the oil industry is currently facing, since it can cause some troubles such as increasing of the pressure losses in pipe which subsequently increases the required power for pumpage. To remove this problem, prediction of wax disappearance temperature (WDT) seems necessary. In this study, the pressure influence on the wax disappearance temperature in multi–component mixtures has been surveyed and some correlations have been proposed to predict the wax disappearance temperature instead of using thermodynamic models. The accuracies of the correlations as AARD are 0.30 %, 0.27 % and 0.68 % for binary, ternary and multi–component mixtures, respectively.

۱۶Estimation of Binary Infinite Dilute Diffusion Coefficient Using Artificial Neural Network
اطلاعات انتشار: Journal of Chemical and Petroleum Engineering، چهل و هشتم،شماره۱، ، سال
تعداد صفحات: ۱۹
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