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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: SCIENTIA IRANICA
- نوع مقاله: Journal Article
- کلمات کلیدی: Nash Equilibrium,Transportation network,Equilibrium flow,Wardrop Principle,Link capacity
- چکیده:
- چکیده انگلیسی: In transportation literature, User Equilibrium (UE) has been widely studied since early 1950’s, many studies of which define equilibrium flow of traffic for uncapacitated networks based on Wardrop’s first principle, implying also a Nash Equilibrium (NE). Although, in general, the two equilibria (UE and NE) are not explicitly the same, they are shown to be equivalent under special conditions, for uncapacitated UE, when volume-delay functions are separable, continuous, non-decreasing and non-negative.
A good deal of research is devoted to explain UE in capacitated networks based on Wardrop’s first principle and the concept of generalized costs. However, UE for capacitated networks, even under the defined special conditions, is not equivalent to NE. This paper extends Wardrop’s first principle to explain UE in capacitated networks, which, under the same special conditions of uncapacitated networks, would represent an NE as well. Moreover, a complementarity equilibrium model is proposed for UE, based on an extension of Wardrop’s principle.- انتشار مقاله: 13-12-1397
- نویسندگان: H. Zokaei Aashtiani,H. Poorzahedy,M. Nourinejad
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Computational and Applied Research in Mechanical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: softening,cylindrical shell,Hysteresis curve,Cyclic axial loading,Ratcheting
- چکیده:
- چکیده انگلیسی: In this research, softening and ratcheting behaviors of Ck20 alloy steel cylindrical shells were studied under displacement-control and force-control cyclic axial loading and the behavior of hysteresis curves of specimens was also investigated. Experimental tests were performed by a servo-hydraulic INSTRON 8802 machine. The mechanical properties of specimens were determined according to ASTM E8 standard. Under force-control loading with non-zero mean force, ratcheting behavior occurred on cylindrical shell and plastic strain accumulation continued up to the collapse point of cylindrical shell. The rate of ratcheting strain became higher using the higher force amplitude. Softening behavior was observed under displacement control loading and, due to the occurred buckling in compression zone, this behavior became more extreme. The behavior of hysteresis curves of this alloy was not symmetrical under tensile and compressive loads. Moreover, the influence of loading history was studied on the behavior of hysteresis curves of the specimens under various types of loadings.
- انتشار مقاله: 04-03-1391
- نویسندگان: M. Shariati,H. Hatami,M. Damghani Nouri
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Veterinary Research
- نوع مقاله: Journal Article
- کلمات کلیدی: Pseudomonas aeruginosa,Sheep,Osteomyelitis,Mandibular,Maxillary
- چکیده: این گزارش به تشریح شیوع استئومیلیت چرکی فک بالا و پایین حاصل از سودوموناس آئروژینوزا در یک گله گوسفند در استان خوزستان میپردازد. در این گله استخوانهای فک بالا و پایین 100 رأس از کل 500 رأس گوسفند بالغ دچار تغییر شکل شدید ناشی از تورم سخت استخوانی در اندازههای مختلف شدند ولی هیچگونه علائمی از وجود التهاب در بافتهای نرم اطراف آن مشاهده نشد. حیوانات مبتلا علائم بیاشتهایی، خمودگی، وجود تورم در ناحیه فک بالا و پایین، افتادن دندانهای آسیاب و وضعیت ضعیف بدنی را نشان میدادند و به تدریج در یک دوره سه ماهه از گله حذف میشدند. در کالبد گشایی تورم سخت استخوانهای فک بالا و پایین، وجود چرک سبز رنگ که حفرات آلوئولی دندانهای آسیاب را پر کرده بود همراه با لیز شدن بافت استخوانی مورد توجه قرار گرفت. بررسی بافت شناسی وجود نواحی نکروز احاطه شده توسط جمعیت مختلطی از سلولهای التهابی همراه با فیبروز فراوان در اطراف بعضی از نواحی آسیب دیده و وجود ترابکولهای نامنظم استخوانی را آشکار ساخت. در میکروب شناسی کشت خالص سودوموناس آئروژینوزا از تمام 7 گوسفند مورد آزمایش جدا شد. بر اساس یافتههای بالینی، رادیوگرافی، بافت شناسی و میکروب شناسی، استئومیلیت چرکی مزمن حاصل از سودوموناس آئروژینوزا تشخیص داده شد. با توجه به نتایج میکروب شناسی، منبع احتمالی آلودگی باکتریایی در این مطالعه آب آشامیدنی بود.
- چکیده انگلیسی: This report describes an outbreak of purulent mandibular and/or maxillary osteomyelitis caused by Pseudomonas aeruginosa in a sheep flock located in the Khuzestan province, Iran. Jaw bones of almost 100 out of 500 mature sheep in a flock became severely deformed with a variably sized firm swelling, without any signs of inflammation in the surrounding soft tissues. The affected animals showed anorexia, depression, swelling of the mandibular and/or maxillary area, loss of cheek teeth and poor body condition. These animals were gradually culled in a period of 3 months. Postmortem examination showed a hard swelling of jaw bones with dirty greenish pus that filled alveolar molar teeth cavities. Histopathologic findings revealed necrotic areas surrounded by mixed population of inflammatory cells with exuberant fibrosis around some area of the lesions and irregular trabeculae of woven bone. In bacteriology, pure culture of P. aeruginosa was isolated from all of 7 sampled sheep. Based on clinical examination, radiography, histopathological features and bacteriology, the lesions were diagnosed as chronic suppurative osteomyelitis caused by P. aeruginosa. According to bacteriological results, the likely source of bacterial infection in this study was drinking water.
- انتشار مقاله: 29-09-1396
- نویسندگان: A. Rasooli,M. Nouri,S. Esmaeilzadeh,A. Ghadiri,D. Gharibi,M. Javaheri Koupaei,M. Moazeni
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Veterinary Research
- نوع مقاله: Journal Article
- کلمات کلیدی: Cortisol,Anxiolytic,Anti-nociceptive,Depressive behavior,Farnesol
- چکیده: اضطراب شایعترین اختلال رفتاری است. تحقیقات بر روی مواد جدید دارای ارزش درمانی برای چنین اختلالاتی اخیرا پیشرفت داشته است. مطالعات متعدد فعالیتهای نوروفارماکولوژیک از ترپنهای مشتق شده از گیاهان را گزارش کردند. فارنسول یک ترپن شش تایی است که میوهها رایجترین منبع آن محسوب میشوند ولی فعالیت ضد اضطرابی از فارنسول هنوز ناشناخته است. مطالعه حاضر بر روی 32 راس موش سوری آلبینو سوئیسی (8 عدد در هر گروه) انجام شده و خواص نوروفارماکولوژیک فارنسول و اثرات آن بر سطح کورتیزول سرم را مورد ارزیابی قرار داده است. فارنسول به صورت داخل صفاقی در دوزهای واحد 50 و 100 میلیگرم بر کیلوگرم تجویز شد در حالی که از دیازپام با دوز استاندارد 2 میلیگرم بر کیلوگرم به عنوان داروی ضد اضطراب استاندارد استفاده شد. سی دقیقه پس از تزریقات، تست جعبه باز (OFT)، ماز به علاوه مرتفع (EPM)، تست شنای اجباری (FST) و تست صفحه داغ (HPT) برای ارزیابی رفتار شبه اضطرابی، افسردگی و ضد دردی انجام شدند. در تست OPT فارنسول در دوز mg/kg 100 منجر به کاهش معنیدار در فعالیت لوکوموتور در مقایسه با سایر گروهها گردید (P<0.01). در EPM، فارنسول در دوز 100 و نه mg/kg 50، مشابه با دیازپام منجر به افزایش معنیدار در تعداد ورود به بازوهای باز و زمان حضور در بازوهای باز شد (P<0.01). افزایش در زمان بیحرکت ماندن در FST در موشهای تحت تیمار با فارنسول مشاهده شد .(P<0.001) فارنسول در دوز mg/kg 100 موجب طولانی شدن معنیدار زمان پاسخ به محرک دردناک در HPT گردید. مشابه با دیازپام، فارنسول منجر به کاهش سطوح پلاسمایی کورتیزول گردید. یافتههای حاصل از این مطالعه اثرات ضد اضطرابی، ضد دردی، و همچنین افسرده کننده از فارنسول را در مدل موش سوری نشان داد. مطالعه حاضر شاهدی فارماکولوژیک برای استفاده از فارنسول به عنوان آرامبخش در درمان اختلالات اضطرابی را فراهم مینماید.
- چکیده انگلیسی: Research on new compounds of therapeutic value for behavioral disorders has progressed recently. Several studies have reported neuropharmacological activities of plant derived terpenes. Farnesol is a sesquiterpene whose most popular source is fruits but the anxiolytic activity for farnesol is still unknown. The present study was conducted on 32 male Swiss Albino mice (8 in each group) to evaluate the neuropharmacological properties of farnesol and its effects on plasma cortisol levels. Farnesol was administered intraperitoneally at single doses of 50 and 100 mg/kg, while diazepam 2 mg/kg was used as standard anxiolytic. Thirty minutes after injections, open field test (OFT), elevated plus maze (EPM), a forced swimming test (FST), and a hot plate test (HPT) were performed for evaluation of anxiety-like behavior, depression and nociception. In OFT, farnesol at the dose of 100 mg/kg led to significant decrease in locomotor activity (P<0.01). In EPM, only farnesol 100 mg/kg led to significant increase in the number of entries to the open arms and the time spent in open arms (P<0.01). Increase in immobility time in FST was seen in farnesol 50 and 100 mg/kg (P<0.001). Farnesol 100 mg/kg exerts significant prolongation in the latency of responses to noxious heat stimuli in HPT. Like diazepam, farnesol decreased plasma levels of cortisol. Results revealed that farnesol had anxiolytic, anti-nociceptive and depressant effects in murine models. The present study provides pharmacological evidence supporting the use of farnesol as a sedative for anxiety disorders.
- انتشار مقاله: 04-12-1394
- نویسندگان: M. Shahnouri,M. Abouhosseini Tabari,A. Araghi
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Medical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی:
- چکیده:
- چکیده انگلیسی:
- انتشار مقاله: 09-09-1394
- نویسندگان: M. Nouri,Mohammad Hassan Pipelzadeh,A Badiei
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Mechanical Engineering Transactions of the ISME
- نوع مقاله: Journal Article
- کلمات کلیدی: ARMAX identification,model predictive control (MPC),Intelligent Transportation Systems,car following behavior,modeling and control
- چکیده:
- چکیده انگلیسی: The control of car following is essential due to its safety and its operational efficiency. For this purpose, this paper builds a model of car following behavior based on ARMAX structure from a real traffic dataset and design a Model Predictive Control (MPC) system. Based on the relative distance and relative acceleration of each instant, the MPC predicts the future behavior of the leader vehicle and according to this behavior, the acceleration of the follower vehicle is controlled. Validation of the presented controller is done by comparing the behavior of the controller with the human drivers. Results show that the MPC controller has a behavior much safer than that of real drivers and it can provide a pleasant trip for passengers.
- انتشار مقاله: 10-08-1392
- نویسندگان: A. Ghaffari,A.R. Khodayari,S. Salehinia,M. Nouri-Khajavi,M.R. Arbab Tafti
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Engineering, Transactions A: Basics
- نوع مقاله: Journal Article
- کلمات کلیدی: Structural Characterization,Chitosan bead,Alpha Amylase,Covalent immobilization
- چکیده:
- چکیده انگلیسی: In the present study, textural and structural characterizations of chitosan bead for immobilization of alpha amylase were studied in detail by N2 adsorption–desorption, Microspore Analysis (MP), Barrett–Joyner–Halenda (BJH) plots and Field Emission Scanning Electron Microscope (FESEM) observations. Pore structure observation revealed chemical activation of chitosan bead by glutaraldehyde can change both the isotherm type of adsorption and pores shape. In consistence with textural analysis, the high value of pore volume distribution with range of mesopores region indicated the porosity of activated chitosan bead was uniformly increased. Intra-particle diffusion model indicated that 97.6% of amylase was adsorbed inside the mesopores of activated chitosan bead owing to increase in kid (rate constant) and reduce of boundary layer effect on diffusion process. In addition, the stability experiments (pH, storage and thermal stability), enzyme leakage, Ca2+ and salt concentration effects were evaluated for immobilized amylase and compared with its free form. Ca2+ concentration of 1 mM shows an excellent impact on relative activity of amylase in its free and immobilized form. NaCl experiments indicated that 84% of amylase was covalently immobilized on activated chitosan beads. Further, the Michaelis–Menten kinetic coefficients, Km (~0.4mg/ml) and, Vmax(~227 U/mg Enzyme), point out strong affinity and high activity of immobilized enzyme
- انتشار مقاله: 14-07-1397
- نویسندگان: H. Heydarzadeh Darzi,S. Gilani,M. Farrokhi,S. M. M. Nouri,G. Karimi
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Engineering, Transactions A: Basics
- نوع مقاله: Journal Article
- کلمات کلیدی: Mathematical Modeling,Scheduling,Flexible manufacturing system,Earliness and tardiness penalties
- چکیده:
- چکیده انگلیسی: Nowadays, flexible manufacturing system (FMS) is introduced as a response to the competitive environment. Scheduling of FMS is more complex and more difficult than the other scheduling production systems. One of the main factors in scheduling of FMS is variable time of taking orders from customers, which leads to a sudden change in the manufacturing process. Also, some problems are created in production system such as waste, earliness and tardiness costs, and increase inventory. In this paper, a part of flexible manufacturing system where products are produced in two stages and in multiple repositories, is known as a bottleneck. In this study, a mathematical model for scheduling of this problem considering the limitations of the production system such as flow rate and output reservoirs, variable time order entry, waste resulting from the cessation of production, and the storage capacity of reservoirs is developed. Then, the proposed model has been solved by GAMS software. Results confirm the validity of the proposed model.
- انتشار مقاله: 11-10-1348
- نویسندگان: M. Nouri Koupaei,M. Mohammadi,B. Naderi
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Engineering, Transactions A: Basics
- نوع مقاله: Journal Article
- کلمات کلیدی: Simulation,Explosive Welding,Impactor,Impulse Loading
- چکیده:
- چکیده انگلیسی: Effects of some important parameters like impactor effects, plug geometry and initiation points on bonding aluminum tubes to aluminum plugs were studied. The impact velocity and dynamic angle between tube and plug should be precisely managed to achieve an optimum bonding condition. A new explosive bonding technique with the use of two material impactors was proposed. Results are especially suitable for using high-speed explosive materials to bond welded parts having dissimilar properties. A welding window was first presented for bonding aluminum tube to aluminum plug with the help of the experimental data. Numerical simulation was then performed to understand the effect of impactor on flat and curved plugs:. However, due to limited data analysis systems used to register explosive welding parameters, it became evident that numerical analysis was necessary. The important findings were, therefore, explosion modeling and fast tube deformation. For low process duration time and fast deformation, the modeling is very difficult. At the same time, numerical analysis with Abaqus software was performed to investigate the bonding conditions. The calculated impact velocity of the tube and the dynamic angle between the tube and the plug were compared with the numerical results under the same conditions. It was shown that the numerical analysis was consistent with the predicted data. Eventually we concluded that in explosive welding, curved plugs were more advantageous than flat plugs. It can be recommended that due to having a connection surface in high-speed explosives, the use of plastic impactors is more favorable than using hypoelastic impactors.
- انتشار مقاله: 11-10-1348
- نویسندگان: G. Liaghat,M. D. Nouri,A. Darvizeh
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Advanced Design and Manufacturing Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: CFD,Propeller,Axisymmetric submerged body,Ducted propulsion system
- چکیده:
- چکیده انگلیسی: The present paper numerically discusses the design procedure of marine ducts used for multi-component ducted propulsion systems at the stern of an axisymmetric submerged body. The results are presented in the form of tables showing the effects of dihedral angel as well as camber ratio of the duct as the two most important geometrical parameters on hydrodynamic performance of the propulsion system. Furthermore, a correlation has been extracted between the results of two and three dimensional analysis of ducted propellers. The results show that the design procedure of the duct used for a ducted propulsion system could be performed using some two dimensional analyses. The simulations are performed using a Reynolds averaged Navier Stokes Equations (RANS) based Computational Fluid Dynamics (CFD) tool.
- انتشار مقاله: 18-02-1396
- نویسندگان: N. M. Nouri,Mehrdad Kalantar Neyestanaki,Saber Mohammadi
- مشاهده