۱تفسیری بر برداشت های لرزه نگاری کم عمق در استان لرستان
اطلاعات انتشار: دوازدهمین کنفرانس ژئوفیزیک، سال
تعداد صفحات: ۶
Two seismic lines (Shallow Reflection – High Resolution) were shot in Lorestan Province in order to define the weathered layers, crashed zones and faults trend, and to recognize the bed rock with high resolution. At first, the survey for the stages of shallow reflection seismic was designed. After acquiring the data, they were processed by Winseis Turbo Software. The results then were interpreted by taking into consideration the region geology and characteristics of wells. The outcome of this study is recognition of trend of weathered layers and crashed zones, the main fault, minor faults and also the bed rock. In addition, travel time – distance curve and finally tomography sections were prepared by using the first breaks of each line.

۲چگونگی تشکیل اقیانوس های بازالتی ماه: همرفتی ناشی از برخورد شهاب سنگی و تولید مذاب در جبه ماه
اطلاعات انتشار: دوازدهمین کنفرانس ژئوفیزیک، سال
تعداد صفحات: ۴
We present impact–induced convection models in the Moon that explain the formation of lunar mare basalt, and the long duration of the basaltic flow. A large projectile that produces an Imbrium–size impact basin can induce three stage of melting at different depths. The first occurs near the surface, by strong heating of the projectile and target that results in melting and vaporization of the major part of the projectile and near–surface part of the target. This rapid melting does not create mare basalt. The second melting arises from the sudden reduction of the pressure in the upper mantle due to excavation of the basin. The ascending upper mantle material in the process of isostatic adjustment in response to the excavation partially melts by decompression within less than a few Myr after the impact. The possible related volcanism cannot explain basaltic flow on the Moon that lasted about ٨٠٠ Myr. The local impact–induced perturbations, however, trigger global–scale convection, and a large plume from lower mantle ascends directly beneath the impact basin. This convection causes the third stage of melting in the mantle and produces well over ١٠٧ km٣ of mare basalt that give rise to substantial mare flooding. We investigate the effects of an impact on the thermal evolution of the Moon and melt production in the mantle, using convection calculations in an axi–symmetric cylindrical coordinate system. The models have temperature–dependent viscosity, and time dependent heat sources arising from decay of radioactive materials. The mantle is allowed to melt as it crosses the solidus temperature and partial melting is calculated. We consider two different models, permeable and impermeable. Five different viscosity models are examined, where the ratio between the viscosity at the surface and at the bottom of the computation domain is ١٠٠, ٥٠٠, ١٠٠٠, ١٥٠٠ and ٢٠٠٠, respectively. The permeable model with viscosity contrast of ١٠٠٠ can explain the observed amount of basaltic flow as well as the duration of the volcanic eruption.

۳فعالیت لرزه خیزی ترکیه و مقایسه آن با لرزه خیزی فلات ایران
اطلاعات انتشار: دوازدهمین کنفرانس ژئوفیزیک، سال
تعداد صفحات: ۱۰
In this study we evaluated seismic region of Iran and Turkey during this century and from the comparison of this two, the result was obtained that the number of earthquakes in Iran exceeded Turkey. Anatolian plate seismotectonic conditions, is very similar to central Iran zone, special Tehran region. Meanwhile the activities of earthquakes in north of Turkey follow special arrangement that it have been seen in south of khorasan. low–depth earthquakes and strike slip mechanism in two region are caused high intensity, vast damage and many mortality during occurrence earthquakes. with pay attention seismic activity paterns and earthquakes migration, in south of Khorasan, Birjand and west of Turkey, Stambul city, We will have earthquakes in future.

۴کاربرد تابع انتقال گیرنده در مطالعه ناهمسانگردی (مطالعه موردی تعیین ناهمسانگردی پوسته البرز مرکزی)
اطلاعات انتشار: دوازدهمین کنفرانس ژئوفیزیک، سال
تعداد صفحات: ۷
Although there can be up to ٢١ independent elastic constants, any material in which more than two are needed is called anisotropy. More than two elastic constants means that the material’s properties differ depending on the direction. Seismic wave through anisotropic materials travel faster or slower depend on their direction. The shear wave can be spitted into two pulses, each with a different polarity and travel at a different speed. This phenomenon is called shear wave splitting. Shear wave splitting of different shear phases can be applied to determine the anisotropy parameters. Also, different shear velocities (fast and slow) of Ps phase on horizontal components of Receiver function can interpret the physical description of anisotropy phenomenon. In this paper, we attempt to automate the choice of analysis window by performing a grid search over different windows to find stable splitting measurements with minimum error. Finally, for determining anisotropy in the crust under centeral Alborz, we use ٤ events where recorded by DAMV seismic broad band station. In this study we find out the fast direction of hear wave velocity is about ٧٠ degree and its delay time is about ٠٫٣٣ second.

۵نقش زمین ساخت جدید و داده های زمین لرزه های دیرینه در آنالیز خطر لرزه ای زمین لرزه ویرانگر 26 دسامبر 2003 سهرستان بم
نویسنده(ها):
اطلاعات انتشار: سومین کنگره ملی مهندسی عمران، سال
تعداد صفحات: ۱۰
The town of Bam with geographical coordinates of about 59o in eastern length and 28–29o latitude lies east south of Iran. Its distance to the border of Pakistan is about 370 km and to Tehran is about 6o, 51_ and 11__ and its height from high seas is 1050 m. Bam devastating earthquake with the magnitude of 6.5 degree on the scale of Richter which occurred on December 26 2003 caused killing of about 28000 people, wounding of 25000 persons. It made the rest 90 percent of residents in the town and its suburbs homeless, collapsing and devastating 85–90 percent of urban buildings and structures. The region of Bam is located between two large tectonic Lut depression at the north and Jazmourian depression at the south. Two main tectonic elements of Lut block and the zone of flysch extends to out of central Lut and includes the main part of eastern state of Iran. The block of Lut which Bam town resides in its western edge is an extended part with northern extension surrounded with different unstable faults which faults are often at the raw of seismic faults. Lut block extends to the more than 800 km from Jazmourian depression at the south to the region of Gonabad in Khorasan at the north. The average width of it in the central part and south is about 200–250 Km. Its western border is performed by an extended and main fault called Nayband. If we study the movement and action of Nyband fault, it is observed that it has experienced the segmentation of strike – slip fault, and faulting series of 1978–2004 is one of the most obvious type of segmentation which is observable on the ground and any segment of it has been activated at one time and this activity has been accomplished from north to the south, i.e. from Tabas city towards the country of Nayband (Nayband seismic fault is nominated through the same country) and from Nayband towards Shahdad and from there towards Bam.

۶تاثیر توزیع نسبت کشش در کشش دو مرحله ای بر خواص و ساختار نخ فیلامنتی پلی آمید
اطلاعات انتشار: چهارمین همایش مراکز تحقیق و توسعه صنایع و معادن، سال
تعداد صفحات: ۱۹
نخهای صنعتی یکی از محصولات صنایع نساجی می باشد که امروزه کاربردهای زیادی پیدا کرده است. از جمله کاربردهای اینگونه نخها، بافت تورهای ماهیگیری می باشد. نخ فیلامنتی پلی آمید 6 با استحکام نسبتا زیاد یکی از محصولات شرکت الیاف ایران میباشد که در بافت این قبیل تورها مصرف می شود.
در فرایند تولید نخهای فیلامنتی، عملیات کشش یک مرحله ای و با نسبت کشش زیادتر از نخهای مورد مصرف در صنایع نساجی اعمال می گردد. این روش سبب ایجاد پارگی، کاهش راندمان نخ درجه یک و افت کیفی برخی از خصوصیات فیزیکی می شود. به این منظور در این تحقیق، نسبت کشش به صورتهای مختلف در کشش دو مرحله ای توزیع شده و ساختار نخ های حاصله در هر مرحله (مانند دانسیته، آرایش یافتگی، آنالیز حرارتی و...) و خواص فیزیکی آنها (مانند استحکام، مدول اولیه ، ازدیاد طول تا حد پارگی، جمع شدگی و ...) مورد اندازه گیری و ارزیابی قرار گرفت و در پایان شرایط بهینه جهت نیل به بهترین خصوصیات ساختاری و فیزیکی نسبت به شرایط عادی عملیات کشش، مورد بررسی قرار گرفت.
در پایان با توجه به نتایج حاصله از دو بخش این تحقیق شرای بهینه جهت نیل به بهترین خصوصیات ساختاری و فیزیکی نسبت به شرایط عادی عملیات کشش، تعیین گردید.

۷طرح های جامع ، هادی ، تفصیلی ، GIS شهری
نویسنده(ها):
اطلاعات انتشار: اولین همایش GIS شهری، سال
تعداد صفحات: ۱۳
Become proficient with two major modeling software packages that will enhance your stormwater drainage and sanitary system modeling and design. In two days of hands–on workshops, you can learn the US EPA’s Stormwater Management Model (SWMM), and the newly–released PCSWMM 2006 graphical decision support system. Attend this comprehensive workshop to gain expertise in this next generation of modeling software tools, and evaluate how this scaleable, integrated and open tool set can improve your current modeling work.

۸CFD Simulation of Gas–Liquid Dynamic and Axial Liquid Velocity in Two Phase Cylindrical Bubble Column Reactors
نویسنده(ها): ، ، ،
اطلاعات انتشار: دهمین کنگره ملی مهندسی شیمی ایران، سال
تعداد صفحات: ۱۱
In this research, we have attempted to validate a transient, three–dimensional dynamic Eulerian–Eulerian two–phase model for the modeling of bubble column hydrodynamics in the homogeneous flow regime. The turbulence in liquid phase is considered by k–ε model. Further numerical studies investigate the influence of additional turbulence production through the dispersed gas phase. The experimental data, which is taken from P.Spicka et al (2002) works literature that was obtained via particle image velocimetry, allow for the validation of the model simulation. The comparison between experimental data and CFD modeling focus on the local axial liquid velocity. The simulations are done using Fluent CFD software. Reasonably, good quantitative agreement is obtained between the experimental data and simulations profiles that will expect for the turbulent kinetic energy and the other variables profiles. Employing finer grids impr oves the description of the flow structure in the bubble
column and the agreement with the experimental data. However, the computation power increases significantly and a compromise between efficiency and quality of results has to be found.<\div>

۹Wider Bandwidth and Higher Transmission for 60o Photonic Crystal Waveguide Bends
نویسنده(ها): ، ،
اطلاعات انتشار: پانزدهیمن کنفرانس مهندسی برق ایران، سال
تعداد صفحات: ۵
In this paper, a 6f waveguide bend in a twodinensional photonic crystal (PC) is designed. The structure used is a 2D PC with air holes in a triangular lattice Also, TE modes are considered in the single mode frequency region. The frequency characteristics of the bend can be improved by changing the geometrical parameters. Using this method, the bandwidth of the bend can surpass the values previously reported in the literature. The results show that wider bandwidth and higher transmission can be obtained.<\div>

۱۰EXPERIMENTAL INVESTIGATION OF CONDENSATION IN COUNTERCURRENT STEAM–WATER FLOW
نویسنده(ها): ، ،
اطلاعات انتشار: سیزدهمین کنفرانس سالانه مهندسی مکانیک، سال
تعداد صفحات: ۸
Steam condensation in countercurrent stratified flow of steam and subcooled water was experimentally investigated in a near horizontal rectangular channel. The effect of inlet water and steam flow rates, and the inlet water temperature on condensation was studied. Correlations are proposed for Nusselt number for the smooth and wavy interface regimes.<\div>

۱۱Transient characteristics of combined conduction, convection and radiation heat transfer in porous radiant burners
نویسنده(ها): ،
اطلاعات انتشار: چهاردهمین کنفرانس سالانه مهندسی مکانیک، سال
تعداد صفحات: ۸
This work has been carried out towards a low emission, high energy density combustion burner that does not operate with free flames. The entire combustion takes place in a porous matrix. A one dimensional model is used to solve the governing equations for porous medium and gas flow. Combustion in the porous medium is modeled as a spatially dependent heat generation zone. In order to analyze the transient thermal characteristics of porous burners, the coupled energy equations for the gas and porous medium based on two–flux radiation model are solved numerically and the effect of various factors on the performance of porous radiant burners are determined. Comparison between the present results with those obtained by other investigators shows a good agreement.<\div>

۱۲POSTURE CONTROL OF TWO–WHEELED ROBOTS USING THE RESULTS OF LABORATORY TESTS
نویسنده(ها): ،
اطلاعات انتشار: چهاردهمین کنفرانس سالانه مهندسی مکانیک، سال
تعداد صفحات: ۵
This paper discusses the overall design process and tracking control of two–wheeled mobile robots that have some inaccuracy in their structure. Therefore, a modified method is proposed, to solve the problem using the generalized tests. The experimental results show that the tracking of posture can be improved and the efficiency of robot is increased because logical responses can be obtained by considering suggested formulation. Finally, In order to validate the derived functions, the consequences of simulation are carried out in Visual Basic software.<\div>

۱۳IMPROVEMENT OF LIF TECHNIQUE IN TEMPERATURE MEASUREMENT OF AQUEOUS AMMONIUM CHLORIDE SOLUTION DURING SOLIDIFICATION PROCESS
اطلاعات انتشار: پانزدهمین کنفرانس سالانه مهندسی مکانیک، سال
تعداد صفحات: ۸
In this study Two–color laser induced fluorescence (LIF) technique was used to measure the instantaneous temperature maps during uni–directional solidification of aqueous ammonium chloride. The improved temperature resolution was achieved by using two temperature sensitive dyes (fluorescein and kiton red) having opposite signs in their sensitivity. The fact that the intensity of one dye increases and the other decreases with decreasing temperature, resulted in a higher temperature sensitivity (4% K–1) in the two–color LIF two–dye approach compared to all previous implementations of the two dye approach (maximum of 1.7% K–1). Temperature fields of some of the complex flow features, such as plumes and fingers, that had not been available before were obtained and will be presented in this study.<\div>

۱۴NUMERICAL COMPUTATION OF MULTI COMPONENT TWO PHASE FLOW IN THE CATHODE OF PEM FUEL CELLS
نویسنده(ها): ،
اطلاعات انتشار: پانزدهمین کنفرانس سالانه مهندسی مکانیک، سال
تعداد صفحات: ۸
A two dimensional, unsteady, isothermal and two–phase flow of reactant–product mixture in the air–side electrode of proton exchange membrane fuel cells (PEMFC) is studied numerically in the present study. The mixture is composed of oxygen, nitrogen, liquid water and water vapor. The overning equations are two species conservation, a single momentum equation for mobile mixture, liquid mass conservation, and the whole mixture mass conservation. In this study, liquid mass conservation is used to calculate the saturation, so, the effect of liquid phase velocity and also saturation at previous time step are accounted in calculating the next time step saturation. The capillary pressure was used to express the slip velocity between the phases. The strongly coupled equations are solved using the finite volume SIMPLER scheme of Patankar (1984). The computational domain consists of an open area (gas delivery channel), and a porous Gas Diffusion Layer (GDL). A single set of governing equations are solved for both sub domains with respect to each sub domain property. The Comparison between the numerical current density and that of experimental (Ticianelli et al.(1988)) shows a good agreement.<\div>

۱۵USING A STAND ALONE MODEL TO INVESTIGATE KNOCK CRITERION IN AN SI GAS ENGINE FUELED WITH METHANE
نویسنده(ها): ، ،
اطلاعات انتشار: پانزدهمین کنفرانس سالانه مهندسی مکانیک، سال
تعداد صفحات: ۸
Natural Gas has been widely considered as an alternative fuel for internal combustion, since it is a major source of fuel after crude oil products and is capable to meet low emission standards specially CO2. In this paper combustion phenomenon of natural gas in from of methane is studied in detail.
Knock limits compression ratio and spark timing in SI engines; that would directly affects the thermal efficiency and output power and may be the cause of mechanical damage in engine.
In this paper, a two zone thermodynamic model is developed using a chemical kinetics mechanism with 20 reactions and 15 chemical species for methane combustion. It is assumed that the flame, with adiabatic temperature is in equilibrium stage. The unburned zone is considered extensively to analyze the conditions that lead to knock. The “Knock Criterion” has been used to forecast the knock intensity. The influence of engine parameters such as spark advance, compression ratio and relative humidity of air intake is studied on knock phenomenon. The experimental engine results from reference works are used to validate the accuracy of our model.<\div>

۱۶A NUMERICAL STUDY OF THE MOTION OF DROPS IN COUETTE FLOW:(HIGH REYNOLDS NUMBERS) THE EFFECTS OF VISCOSITY RATIO
نویسنده(ها): ،
اطلاعات انتشار: پانزدهمین کنفرانس سالانه مهندسی مکانیک، سال
تعداد صفحات: ۷
In this paper, the motion of two–dimensional deformable drops suspended in a linear shear flow at finite Reynolds numbers is studied numerically by a fronttracking method. The simulations are carried out for suspensions of 36 drops within each periodic domain, for an extended period of time up to Gt=341, where G is the shear rate. The effects of flow parameters such as the Reynolds number, the Weber number and the viscosity ratio on the rheological properties of suspensions are reported. Simulations show that at constant viscosity ratio and Weber number, the effective viscosity increases with the Reynolds number. It is also shown that suspensions of deformable drops exhibit a shear thinning behavior, but the shear thinning is reduced as the Reynolds number increases.<\div>

۱۷The Effects of Polymer Solutions on Drag Reduction in Horizontal Pipe Two–Phase Flow
نویسنده(ها): ،
اطلاعات انتشار: نهمین کنگره ملی مهندسی شیمی ایران، سال
تعداد صفحات: ۸
The effect of the presence of a drag reducing agent (DRA) on the pressure drop in a horizontal pipe cocurrent two–phase flow of gas and liquid is investigated in this study. The employing DRA is an anionic polyacrylamide. An experimental set–up is erected in which pressure drop is measured in a test section of 10m long horizontal pipe with an I.D. of 2.54 cm. Based on the experimental data which are obtained for different
operating conditions, a mathematical model is proposed for prediction of drag reduction for a given polymer. The proposed model contains a few parameters which should be obtained for the used polymer. These parameters are obtained for Superfloc A–95, in a given range of Reynold`s number. The proposed model could also be used for calculation of friction and maximum drag reduction as a function of DRA concentration<\div>

۱۸Neural Network Two–terminal Approach for Fault Location in Transmission Line Distance Protection
نویسنده(ها): ، ،
اطلاعات انتشار: بیست و دومین کنفرانس بین المللی برق، سال
تعداد صفحات: ۹
This paper presents a new approa ch to locate shunt faults in power transmission lines using a two–layer Adaptive Linear Neural Network
(ADALINE) in a two–end protection scheme. First, a transmission line with actual parameters is simulated in the PSCAD\EMTDC software and signals are fed to the MATLAB software to implement a real time adaptive filtering. In this approach, twoend unsynchronized measurements are used to estimate the unknown synchronization angle, fundamental frequency components using ADALINE. Finally, the distance to fault is
calculated in a special process. The proposed method’s aim is to increase convergence accuracy and speed in the first period after fault inception. In this respect, the simulation results show that fault location, reactance effect and fault impedance cannot affect the proposed protection scheme.<\div>

۱۹Ecological consequences of earthquake
نویسنده(ها): ،
اطلاعات انتشار: سومین کنفرانس بین المللی مدیریت جامع بحران در حوادث غیرمترقبه، سال
تعداد صفحات: ۱۳
Each day, at least two large natural disasters take place on the planet, affecting the lives of people. There are now about 450 cities worldwide with a population of more than 1 million inhabitants. Of these, 50 cities have a population greater than 3.5 million and 25 cities have populations greater than 8 million. Some sobering statistics underscore the physical and financial risk of disaster to mega cities in the developing world: about 50 percent of the world's largest cities are situated along major earthquake belts or tropical cyclone tracks; and the average number of victims is 150 times larger during disasters than in the developed world. Cities like Istanbul, Dhaka, Manila, Cairo, Mexico City, Katmandu, Bogotá, Algiers, Tehran and many others are threatened by earthquakes .An earthquake in these cities would cause a catastrophe of unheard proportions.
The concern over the risk to mega cities, particularly in the developing world, is their growing vulnerability caused by their hyper–concentrations of population, dependence on complex and aging infrastructure, and unprepared local institutions. The risk of natural disasters occurring in mega cities is growing. To develop a coherent set of international standards to assess urban vulnerability and devise approaches for mitigation. Vulnerability will be assessed along four dimensions:
– Physical
– Organizational
– Cultural\Social
– Economic
Proper planning by local governments can reduce the human and financial loss to cities. In 2002 the Government of the Russian Federation has approved the Federal Program “Seismic safety of the Russian territory” (2002–2010). This paper provides an overview of global environmental problems related to earthquakes and researches of seismic hazard in Russia.

۲۰The Preparedness Assessment Indicators Of Hospitals to Response Earthquake
اطلاعات انتشار: سومین کنفرانس بین المللی مدیریت جامع بحران در حوادث غیرمترقبه، سال
تعداد صفحات: ۱۱
“During the last two decades Iran has experienced its lion share of natural disasters: four major earthquakes, a number of devastating floods and the worst draught in the last thirty years.”(WHO Report; 2007; citation on web searched)
“Adverse natural phenomena affect health systems’ operations both directly and indirectly.
Direct effects include: 1– Damaged health care facilities; 2– and damaged infrastructure across the locality (including the destruction of access roads), leading to the breakdown of public services that are indispensable to health facility operations.
Indirect effects include: 1– An unexpected number of deaths, injuries, or disease outbreaks in the affected community, exceeding the capacity of the local health care network to provide treatment;2– Spontaneous or organized migrations away from the affected area towards other areas where health system capacity may be overwhelmed by the new arrivals; 3– Increases in the potential risk of a critical outbreak of communicable diseases, and an increase in the risk for psychological diseases among the affected population ; 4– and food shortages leading to malnutrition and weakened resistance to various diseases.”(WHO Workshop report; 2004; page13– 14)
To those of us who live and work in Iran, earthquakes and other natural emergencies are a reality. In order to deal with this situation, emergency preparedness must become a way of life.
“Preparedness is an ongoing process and this may be achieved by planning and testing this plan regularly through drills and exercises. Policies and guidelines also make a country more prepared in its capacity to face disasters.”(WHO report, Report Series No.: (VTU); page19; 2003) “Emergency preparedness programs should use standard management techniques.”(Koob; page9; 1998)
“Health care facilities play a significant role in the mitigation of disasters because their particular function is to treat the injured and handle outbreaks of disease. They are fundamental referral points for any community and should be prepared to deal with crises. Unfortunately, health care facilities are also susceptible to the effects of natural hazards and are victims of the effects of disasters. The consequences of a disaster can severely impede a health care facility’s ability to function just when its services are most needed by the. Hospitals may find themselves short of staff, without functioning equipment or communications and lacking water and electricity. But, in the aftermath of a crisis, they will never lack patients who rely on their services.”(Strengthening health systems' response to crises; 2004; p28)

۲۱سنتزو ساختار بلوری کمپلکس جدید دو هسته ای m– اکسوبیس [اکتا اتیل اکسوپورفیرین) آهن (III)] تترا فلوئوروبورات
اطلاعات انتشار: چهاردهمین همایش بلور شناسی و کانی شناسی ایران، سال
تعداد صفحات: ۴
برای اولین بار کمپلکس دو هسته ای [{OEOPFe)2O] (BF4)2 سنتر و توسط روشهای مختلف طیف سنجی و تجزیه عنصر مورد شناسایی قرار گرفت.
ORTEP کملپکس ساختار این بلور توسط STOE IPDII two circle diffractometer مجهز به منو کروماتوگرافیتی و باستفاده از تابش l=0.71073Å (Mo ka) مشخص شد. داهده های X–Ray در دمای 173(2)K بر اساس تعداد کل 19126 انعکاسی که 5222 انعکاس از آنها مناسب بودند، مورد پردازش قرار گرفت. ساختار این کمپلکس به کمک رووش مستقیم و با استفاده از Full–matrix least – squares on f\\2 تحلیل گردید. سیستم بلوری این کمپلکس مونو کلینی با Z=2 و گروه فضای آن P2 1\c می باشد. Final R indices برای این کمپلکس برابر 0.0760 می باشد.

۲۲Efficient Control of Superheater Steam Temperature
نویسنده(ها):
اطلاعات انتشار: شانزدهمین کنفرانس سالانه مهندسی مکانیک، سال
تعداد صفحات: ۶
In this paper, in order to compensate the nonlinearity and load dependent dynamics of once–through steam generators, a hybrid fuzzy logic based control system is designed to control the steam temperature at superheater sections. The proposed control system is a combination of a fuzzy logic feed–forward controller and two local fuzzy regulators, which is responsible for regulating the temperature of intermediate and final superheaters. This coupled two–stage attemperation strategy distributes the total spray demand between attemperation stages. The performance of the proposed control system is compared with the results of others recent researches as well as with response of the actual conventional cascade control system. The results show significant enhancement of the system with proposed control strategy.<\div>

۲۳Investigation and Analysis on Formability of Al1100\St12 Sheet – Considering properties of layers separately
نویسنده(ها): ، ،
اطلاعات انتشار: شانزدهمین کنفرانس سالانه مهندسی مکانیک، سال
تعداد صفحات: ۶
Today's application of two–layer metallic sheet in production of industrial and domestic parts is increased. Their advantages are increasing wear and corrosion resistance, sound and vibration damping, uniform temperature distribution due to different heat expansion coefficients of layers, decreasing spring back and wrinkling and finally reducing weight and cost. Formability of Al1100–St12 sheet is investigated in this paper. Theoretical and experimental studies have been carried out to analyze forming limit diagram (FLD) of Al1100–St12 two–layer sheet. Theoretical
results are compared with experimental ones and FLD of two–layer sheet is compared with formability of its metallic components. There is good accordance between theoretical and experimental results and FLD of Al1100–St12 is much better than Al1100.<\div>

۲۴Numerical Analysis of Supercavitating flows over 2D and 3D bodies by Large Eddy Simulation
نویسنده(ها): ، ،
اطلاعات انتشار: شانزدهمین کنفرانس سالانه مهندسی مکانیک، سال
تعداد صفحات: ۶
In this paper, The Kunz’s cavitation model is utilized to simulate supercavitating flow over a disk. The multiphase Navier–Stokes equations are solved for the mixture of liquid and vapor. The vaporization and condensation processes are controlled by Kunz cavitation model. The Large Eddy Simulation, LES, model is selected which is found to be suitable in comparison with the standard k–ε model. Close agreement between the obtained results and the available experimental data shows LES can improve the accuracy of this cavitation model. It can be concluded that the utilized model describes the cavitation behavior in 2 and 3D geometries well.<\div>

۲۵Self–Tuning Iterative Learning Control for Time Variant Systems
نویسنده(ها): ،
اطلاعات انتشار: سیزدهیمن کنفرانس مهندسی برق ایران، سال
تعداد صفحات: ۶
We consider the iterative learning control problem from an adaptive control viewpoint. The STILCS (self–tuning iterative learning control systems) problem is formulated in a general case, when the underlying repetitive linear process is time–variant and its parameters are all unknown, its initial conditions are not fixed and are not determinable in various iterations. A solution procedure is presented for this problem. The Lyapunov technique is employed to ensure the convergence of the presented STILCS. The computer simulation results are included to illustrate the effectiveness of the proposed STILCS.<\div>
نمایش نتایج ۱ تا ۲۵ از میان ۱۲۳۶ نتیجه