Numerical calculations of aerodynamic performance for ATM train at crosswind conditions

Mohammad Ali Rezvani,Masoud Mohebbi 한국풍공학회 2014 Wind and Structures, An International Journal (WAS Vol.18 No.5

This article presents the unsteady aerodynamic performance of crosswind stability obtained numerically for the ATM train. Results of numerical investigations of airflow past a train under different yawing conditions are summarized. Variations of occurrence flow angle from parallel to normal with respect to the direction of forward train motion resulted in the development of different flow patterns. The numerical simulation addresses the ability to resolve the flow field around the train subjected to relatively large yaw angles with three-dimensional Reynolds-averaged Navier-Stokes equations (RANS). k- ε turbulence model solved on a multi-block structured grid using a finite volume method. The massively separated flow for the higher yaw angles on the leeward side of the train justifies the use of RANS, where the results show good agreement with verification results. A method of solution is presented that can predict all aerodynamic coefficients and the wind characteristic curve at variety of angles at different speed.

An organic–inorganic hybrid compound constructed by polytungsto-vanadosilicate and hexadecyltrimethyl ammonium as an efficient catalyst for demercaptanization of crude oil

Mohammad Ali Rezvani,Farokhzad Mohammadi Zonoz 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.22 No.-

[C16H33N(CH3)3]4H3SiV3W9O40 has been synthesized by reaction of Na10[a-SiW9O34] with sodiumvanadate and encapsulated by cetyltrimethyl ammonium. Then this organic–inorganic hybrid compoundcondensation with titanium tetraisopropoxide at 100 C via sol–gel method under oil-bath condition. [C16H33N(CH3)3]4H3SiV3W9O40-TiO2 was prepared. The materials characterized by IR, XRD, TEM andUV–vis techniques. This alkyl ammonium keggin- type nanoparticle be able to scavenge mercaptans andhydrogen sulfide (with high yield) in the presence of H2O2. This system provides a practical, convenientand efficient method for scavenging of sulfur compound in light and heavy crude oil.

Dynamic response of railway bridges traversed simultaneously by opposing moving trains

Rezvani, Mohammad Ali,Vesali, Farzad,Eghbali, Atefeh Techno-Press 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.46 No.5

Bridges are vital components of the railroads. High speed of travel, the periodic and oscillatory nature of the loads and the comparable vehicle bridge weight ratio distinguish the railway bridges from the road bridges. The close proximity between estimations by some numerical methods and the measured data for the bridge-vehicle dynamic response under the moving load conditions has boosted the confidence in the numerical analyses. However, there is hardly any report regarding the responses of the railway bridges under the effect of the trains entering from the opposite directions while running at unequal speed and having dissimilar geometries. It is the purpose of this article to present an analytical method for the dynamic analysis of the railway bridges under the influence of two opposing series of moving loads. The bridge structural damping and many modes of vibrations are included. The concept of modal superposition is used to solve for the system motion equations. The method of solution is indeed a computer assisted analytical solution. It solves for the system motion equations and gives output in terms of the bridge deflection. Some case studies are also considered for the validation of the proposed method. Furthermore, the effects of varying some parameters such as the distance between the bogies, and the bogie wheelset distance are studied. Also, the conditions of resonance and cancellation in the dynamic response for a variety of vehicle-bridge specifications are investigated.

Numerical calculations of aerodynamic performance for ATM train at crosswind conditions

Rezvani, Mohammad Ali,Mohebbi, Masoud Techno-Press 2014 Wind and Structures, An International Journal (WAS Vol.18 No.5

This article presents the unsteady aerodynamic performance of crosswind stability obtained numerically for the ATM train. Results of numerical investigations of airflow past a train under different yawing conditions are summarized. Variations of occurrence flow angle from parallel to normal with respect to the direction of forward train motion resulted in the development of different flow patterns. The numerical simulation addresses the ability to resolve the flow field around the train subjected to relatively large yaw angles with three-dimensional Reynolds-averaged Navier-Stokes equations (RANS). ${\kappa}-{\varepsilon}$ turbulence model solved on a multi-block structured grid using a finite volume method. The massively separated flow for the higher yaw angles on the leeward side of the train justifies the use of RANS, where the results show good agreement with verification results. A method of solution is presented that can predict all aerodynamic coefficients and the wind characteristic curve at variety of angles at different speed.

Dynamic response of railway bridges traversed simultaneously by opposing moving trains

Mohammad Ali Rezvani,Farzad Vesali,Atefeh Eghbali 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.46 No.5

Bridges are vital components of the railroads. High speed of travel, the periodic and oscillatory nature of the loads and the comparable vehicle bridge weight ratio distinguish the railway bridges from the road bridges. The close proximity between estimations by some numerical methods and the measured data for the bridge-vehicle dynamic response under the moving load conditions has boosted the confidence in the numerical analyses. However, there is hardly any report regarding the responses of the railway bridges under the effect of the trains entering from the opposite directions while running at unequal speed and having dissimilar geometries. It is the purpose of this article to present an analytical method for the dynamic analysis of the railway bridges under the influence of two opposing series of moving loads. The bridge structural damping and many modes of vibrations are included. The concept of modal superposition is used to solve for the system motion equations. The method of solution is indeed a computer assisted analytical solution. It solves for the system motion equations and gives output in terms of the bridge deflection. Some case studies are also considered for the validation of the proposed method. Furthermore, the effects of varying some parameters such as the distance between the bogies, and the bogie wheelset distance are studied. Also, the conditions of resonance and cancellation in the dynamic response for a variety of vehiclebridge specifications are investigated.

Mono Mn(II)-substituted phosphotungstate@modified graphene oxide as a high-performance nanocatalyst for oxidative demercaptanization of gasoline

Mohammad Ali Rezvani,Zahra Shokri Aghbolagh,Hassan Hosseini Monfared,Sahar Khandan 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.52 No.-

In this study, the removal of hazardous sulfur compounds from gasoline was provided based on catalyticoxidation demercaptanization technique. The cesium salt of mono Mn(II)-substituted Keggin-typepolyoxometalate Cs5PMnW11O39 (PMnW11) was successfully synthesized and immobilized on modifiedgraphene oxide (mGO) as a new nanocatalyst (PMnW11@mGO) for demercaptanization process. Thesynthesized materials were characterized by powder X-ray diffraction (XRD), scanning electronmicroscopy (SEM), ultraviolet–visible (UV–vis), Fourier transform infrared spectroscopy (FT-IR), andcyclic voltammetry (CV) analysis. Characterization of the prepared nanocomposite was confirmed thatthe structures of the PMnW11 and mGO were retained after immobilization. The sulfur-containingmolecules in real gasoline and simulated fuel were oxidized and extracted efficiently under mild reactioncondition. After treatment, the mercaptans and total sulfur content of real gasoline were lowered with98.8% and 98% yield, respectively. The PMnW11@mGO hybrid nanocatalyst was separated and reusedconveniently at the end of the reaction forfive times. The excellent performance of this new catalyticoxidation system can be a promising rout to achieve ultra-clean gasoline.

RESEARCH : Open Access ; Effects of extrusion of rice bran on performance and phosphorous bioavailability in broiler chickens

( Ali Akbar Zare Sheibani ),( Masoud Arab ),( Mohammad Javad Zamiri ),( Mohammad Reza Rezvani ),( Mohammad Dadpasand ),( Farhad Ahmadi ) 한국동물자원과학회(구 한국축산학회) 2015 한국축산학회지 Vol.57 No.26

Background: Rice bran is a by-product of the rice-milling process, which remains largely underutilized; however, efficient processing treatments may improve its feeding value for chickens. This is of great economic and environmental importance, as this can lower the production costs, and offer an opportunity for valorization of a low-quality agricultural by-product, to a high-value feed source. Methods: This experiment was conducted to study the effect of extruded rice bran on performance and phosphorous (P) bioavailability in broiler chickens. In a completely randomized design, 200 seven-day-old broilers (Cobb 500) were allotted to five treatments with five replicates per treatment and 8 chicks per replicate, and fed with their respective diet during the starter (8 to 21 days) and grower (22 to 42 days) periods. Diets were a basal corn-soybean based diet (T1), or diets containing 20 % rice bran (T2), 30 % rice bran (T3), 20 % extruded rice bran (T4), or 30 % extruded rice bran (T5). Results: Birds feeding on T4 and T5 diets had a higher body weight gain and lower feed-to-gain ratio compared to those feeding on T2 and T3 diets (p < 0.05). Birds receiving diets containing extruded rice bran had higher total P availability and tibia ash content, as compared with those receiving diets containing un-extruded rice bran (p < 0.05). Relative weight of the pancreas was higher in birds receiving T2 and T3 diets. Conclusions: The results confirmed the beneficial effect of extrusion treatment of rice bran on performance and P availability in broilers. Up to 30 % extruded rice bran may be included in the broiler diet without apparent adverse effects on the performance.

Effects of extrusion of rice bran on performance and phosphorous bioavailability in broiler chickens

Zare-Sheibani, Ali Akbar,Arab, Masoud,Zamiri, Mohammad Javad,Rezvani, Mohammad Reza,Dadpasand, Mohammad,Ahmadi, Farhad Korean Society of Animal Science and Technology 2015 한국축산학회지 Vol.57 No.7

Background: Rice bran is a by-product of the rice-milling process, which remains largely underutilized; however, efficient processing treatments may improve its feeding value for chickens. This is of great economic and environmental importance, as this can lower the production costs, and offer an opportunity for valorization of a low-quality agricultural by-product, to a high-value feed source. Methods: This experiment was conducted to study the effect of extruded rice bran on performance and phosphorous (P) bioavailability in broiler chickens. In a completely randomized design, 200 seven-day-old broilers (Cobb 500) were allotted to five treatments with five replicates per treatment and 8 chicks per replicate, and fed with their respective diet during the starter (8 to 21 days) and grower (22 to 42 days) periods. Diets were a basal corn-soybean based diet (T1), or diets containing 20 % rice bran (T2), 30 % rice bran (T3), 20 % extruded rice bran (T4), or 30 % extruded rice bran (T5). Results: Birds feeding on T4 and T5 diets had a higher body weight gain and lower feed-to-gain ratio compared to those feeding on T2 and T3 diets (p < 0.05). Birds receiving diets containing extruded rice bran had higher total P availability and tibia ash content, as compared with those receiving diets containing un-extruded rice bran (p < 0.05). Relative weight of the pancreas was higher in birds receiving T2 and T3 diets. Conclusions: The results confirmed the beneficial effect of extrusion treatment of rice bran on performance and P availability in broilers. Up to 30 % extruded rice bran may be included in the broiler diet without apparent adverse effects on the performance.

Design of LQR controller for active suspension system of Partially Filled Tank Cars

Mohammad Mahdi Feizi,Mohammad Ali Rezvani 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.49 No.3

Increasing usage of tank cars and their intrinsic instability due to sloshing of contents have caused growing maintenance costs as well as more frequent hazards and defects like derailment and fatigue of bogies and axels. Therefore, varieties of passive solutions have been represented to improve dynamical parameters. In this task, assuming 22 degrees of freedom, dynamic analysis of partially filled tank car traveling on a curved track is investigated. In order to consider stochastic geometry of track; irregularities have been derived randomly by Mont Carlo method. More over the fluid tank model with 1 degree of freedom is also presented by equivalent mechanical approach in terms of pendulum. An active suspension system for described car is designed by using linear quadratic optimal control theory to decrease destructive effects of fluid sloshing. Eventually, the performance of the active suspension system has been compared with that of the passive one and a study is carried out on how active suspension may affect the dynamical parameters such as displacements and Nadal’s derailment index.

Design of LQR controller for active suspension system of Partially Filled Tank Cars

Feizi, Mohammad Mahdi,Rezvani, Mohammad Ali Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.49 No.3

Increasing usage of tank cars and their intrinsic instability due to sloshing of contents have caused growing maintenance costs as well as more frequent hazards and defects like derailment and fatigue of bogies and axels. Therefore, varieties of passive solutions have been represented to improve dynamical parameters. In this task, assuming 22 degrees of freedom, dynamic analysis of partially filled tank car traveling on a curved track is investigated. In order to consider stochastic geometry of track; irregularities have been derived randomly by Mont Carlo method. More over the fluid tank model with 1 degree of freedom is also presented by equivalent mechanical approach in terms of pendulum. An active suspension system for described car is designed by using linear quadratic optimal control theory to decrease destructive effects of fluid sloshing. Eventually, the performance of the active suspension system has been compared with that of the passive one and a study is carried out on how active suspension may affect the dynamical parameters such as displacements and Nadal's derailment index.