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Fuzzy model prediction of Co(Ⅲ)/Al_2O_3 catalytic behavior in Fischer-Tropsch synthesis

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Journal of Natural Gas Chemistry 2011年第6期20卷 603-610页

作者： Mohammad Ali Takassi mahdi Koolivand Salooki Morteza Esfandyari Department of Science Petroleum CollegePetroleum University of Technology Oil&Gas Processing Center of Excellence Chemical Engineering DepartmentUniversity of Tehran Department of Chemical Engineering Faculty of EngineeringFerdowsi University of Mashad

The application of Co（Ⅲ）/Al2O3 catalyst in Fischer-Tropsch synthesis（FTS）was studied in a wide range of synthesis gas conversions and compared with Fuzzy Simulation *** study applies fuzzy model to predicting the product composition of CH4,CO2 and CO in Fischer-Tropsch process for natural gas synthesis,in which the input vector was 4-dimension including four variables（operating pressure, operating temperature,time and CO/H2 ratio）of 70 different experiments and the output product is a composition of CO2,CO and CH4. The Mamdani algorithm has been applied to the training of the fuzzy system and the test set was used to evaluate the performance of the system including R2,ARE,AARE and *** results demonstrated that the predicted values from the model were in good consistency with the experimental *** work indicates how fuzzy inference system（FIS）,as a promising predicting technique,would be effectively used in FTS.

关键词： fuzzy inference system Fischer-Tropsch natural gas catalyst Co (III) Al2O3

Tracer advection in a pair of adjacent side-wall cavities, and in a rectangular channel containing two groynes in series

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Journal of Hydrodynamics 2018年第4期30卷 564-572页

作者： Mohammad mahdi Jalali Alistair G.L.Borthwick Institute for Energy Systems School of Engineering The University of Edinburgh

A model is presented of particle advection near groynes in an open channel. Open channel hydrodynamics is modelled using the shallow water equations, obtained as the depth-averaged form of Reynolds-averaged continuity and Navier-Stokes momentum equations. A Lagrangian particle-tracking model is used to predict trajectories of tracer particles advected by the flow field, with bilinear interpolation representing the continuous flow field. The particle-tracking model is verified for chaotic advection in an alternating flow field of a pair of blinking vortices. The combined shallow flow and Lagrangian particle-tracking model is applied to the simulation of tracer advection in flow past a pair of side-wall cavities separated by a groyne, and in an open rectangular channel containing a pair of parallel groynes oriented normal to the channel wall. The study is potentially useful in understanding mixing processes in shallow flow fields near hydraulic structures in wide rivers.

关键词： Shallow water equations Lagrangian particle tracking chaotic advection blinking vortices side-wall cavities groynes

Investigating the relationship between crash severity,traffic barrier type,and vehicle type in crashes involving traffic barrier

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Journal of Traffic and Transportation Engineering(English Edition) 2020年第1期7卷 125-136页

作者： Amirarsalan Mehrara Molan mahdi Rezapour Khaled Ksaibati Department of Civil and Environmental Engineering California Polytechnic State UniversitySan Luis ObispoCA 93407USA Wyoming Technology Transfer Center Department of Civil and Architectural EngineeringUniversity of WyomingLaramieWY 82071USA

Roadside safety is one of the important components of highway systems due to its considerable rate of high-severity *** barriers play a key role in reducing the crash severity and saving more lives on roadsides but choosing an inappropriate traffic barrier could decrease traffic barriers’*** paper investigated the variables affecting crash severity in different traffic barrier types(cable,guardrail,and rigid)and vehicle types(truck,and non-truck).For this purpose,an ordinal logistic regression approach was conducted on the crash data collected between 2007 and 2016 in *** to the results,different traffic barrier types show different relationships to crash severity based on posted speed limit at the *** guardrail segments,a high-severity crash is more likely when the posted speed limit is more than 55 mph;however,cable barrier crashes were less severe in high-speed limit(>55 mph)*** light vehicles were more vulnerable to crashes hitting rigid barriers,no significant difference was found between performances of cable and rigid barriers in terms of truck crash *** analytical models proposed in this study would make a clear view for designers and decision-makers in selecting the most appropriate traffic ***,the effective factors introduced in each model could be used to rank the risk posed by existing traffic barrier segments based on traffic barrier type,truck volume percentage,and other highway characteristics.

关键词： Traffic barrier Roadside safety Truck Crash severity Ordinal logistic regression Wyoming

Comparison of efficacy of folic acid and silymarin in the management of antiepileptic drug induced liver injury:a randomized clinical trial

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Hepatobiliary & Pancreatic Diseases International 2017年第3期16卷 296-302页

作者： Masoumeh Asgarshirazi Mamak Shariat mahdi Sheikh Department of Pediatrics Vali-asr HospitalTehran University of Medical SciencesTehranIran Maternal Fetal and Neonatal Research CenterTehran University of Medical SciencesTehranIran

BACKGROUND： Liver injury associated with antiepileptic drugs accounts for a large proportion of drug-induced liver injuries （DILI） in children. Although withdrawal of the causative agent is the only proved treatment for DILI, in some dinical situations it is not possible. Recent studies have reported promising results of using hepatoprotective drugs with antioxidant actions for the management of DILl. This study aimed to evaluate the efficacy of folic acid versus silymarin treatment in relation to decreasing liver enzymes in patients with DILI due to antiepileptic therapy. METHODS： This randomized, open-label, clinical trial evalu- ated 55 children with epilepsy who were on antiepileptic treat- ment and experienced DILL The children were randomized to receive either silymarin （5 mg/kg per day） or folic acid （1 mg per day） for one month and were followed up for three months. RESULTS： Liver enzymes significantly decreased in both groups. The decrease trend in alanine aminotransferase （ALT） and aspartate aminotransferase （AST） were stronger in the folic acid group compared to silymarin group （P=0.04 and P=0.007, respectively）. At the end of the study patients in the folic acid group had significantly lower ALT （P=0.04）, AST （P=0.02）, and gamma-glntamyl transferase （GGT）（P〈0.001） levels and also higher percentage of normal ALT （30.7% vs 3.4%, P=0.009） and AST （42.3% vs 0%, P〈0.001）, and GGT （23.1% vs 0%, P=0.008） values compared to the patients in the silymarin group. No rebound elevations in ALT, AST and GGT levels or adverse reactions were noted in neither of the study ***： Although both treatments were safe and effective in decreasing liver enzymes, folic acid seems to be superior to silymarin in the management of DILl.

关键词： anticonvulsant antiepileptic enzymes hepatitis hepatotoxicity

Structural Control on the Salmas Geothermal Region, Northwest Iran, from Fractal Analysis and Paleostress Data

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Acta Geologica Sinica(English Edition) 2018年第5期92卷 1728-1738页

作者： mahdi BEHYARI Javad NOURALIEE Davar EBRAHIMI Department of Geology Faculty of Sciences Urmia University Renewable Energy Department Niroo Research Institute (NRI)

The Salmas geothermal field is located in NW Iran. Subduction of Neo-Tethys oceanic crust beneath the Iranian microcontinent caused to propagation of the magmatic-Arc. Fractures and faults in the convergent zone have created path-ways for the circulation of geothermal fluid. Fracture concentration in the Salmas geothermal field has been characterized using of the fractal method and creation of a fracture density map that shows the highest concentration in the central part of the study area. The permeability of fractures has been evaluated by analyzing their orientation in respect to the paleostress axes. Also, the fractal analyzing result indicates the maximum fractal dimension（1.96） is around the thermal spring outlet. Paleostress analyzing revealed that in the central part of the study area, σ1 axes orientation is S90°W/10° and the σ2 dip is near to the vertical in this stress field, where strike slip faults can be propagated. In the SE part near the recharge of the thermal springs, the σ3 plunge increases to 70？ and σ1 orientation is N15°E/20°, in this local tectonic regime thrust fault developed. Fractures have an important role in the circulation of fluid and the fractal dimension increases near the thermal springs in the Salmas geothermal field. Regarding the paleostress data fracture with N-S direction such as the F1 fault zone（parallel to the σ1 axes）, a suitable pathway for deep circulation of geothermal fluid flow has been created.

关键词： lineament extraction fractal method geothermal field paleostress Salmas NW Iran

Tracer advection in an idealised river bend with groynes

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Journal of Hydrodynamics 2018年第5期30卷 780-790页

作者： Mohammad mahdi Jalali Alistair G.L.Borthwick Institute for Energy Systems School of Engineering The University of Edinburgh

This paper presents numerical simulations of particle advection in the bend of an open channel containing groynes, which is an idealised form of a shallow river bend in a wide river. The flow field is computed using a boundary-fitted solver of the non-orthogonal, curvilinear shallow water equations. The computational grid is generated by solving Poisson-type elliptic partial differential equations using an iterative multi-grid scheme for prescribed boundary coordinates. The shallow water equations are discretised with finite differences in space, and 4 t h order Runge-Kutta integration in time. Tracers introduced at specific initial locations have their trajectories computed using Lagrangian particle tracking. The numerical shallow flow model is verified by comparison to the analytical solution of fully developed flow in an open channel. The combined shallow flow and Lagrangian particle-tracking model is then used to simulate the advection of tracer particles in a rectangular channel containing a pair of parallel groynes, and tracer particles in a curved open channel containing groynes, of dimensions roughly equivalent to a Danube River bend.

关键词： Shallow water equations tracer advection Lagrangian particle curvilinear coordinates system river bend groynes

Analgesic and anti-inflammatory properties of hydroalcoholic extracts of Malva sylvestris, Carum carvi or Medicago sativa, and their combination in a rat model

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Journal of Integrative Medicine 2020年第2期18卷 181-188页

作者： Masoud Seddighfar Sayid mahdi Mirghazanfari Masoumeh Dadpay Department of Physiology and Iranian Medicine School of MedicineAJA University of Medical SciencesTehran ***Iran Department of Animal Biology School of BiologyCollege of ScienceUniversity of TehranTehran ***Iran Department of Pathology School of MedicineAJA University of Medical SciencesTehran ***Iran

Objective: The aim of this study was to evaluate the analgesic and anti-inflammatory effects of the hydroalcoholic extracts of Malva sylvestris flowers or Carum carvi and Medicago sativa seeds, alone and in combination, which have been used in traditional Iranian ***: Male Wistar rats were divided into 6 treatment groups: distilled water, sodium salicylate(SS),M. sylvestris extract(600 mg/kg), C. carvi extract(600 mg/kg), M. sativa extract(300 mg/kg) and combined extract(including 300 mg/kg M. sylvestris and C. carvi extracts, and 150 mg/kg M. sativa extract). The formalin pain model was used to evaluate the antinociceptive effects of the treatments. For anti-inflammatory effect, acute(one hour after injection) and chronic(during a week after injection)paw inflammation was measured after subcutaneous injection of 2.5% formalin in the ***, tissue samples from all groups were prepared for histopathological ***: The combined extract significantly inhibited the nociception in the acute phase of the formalin test(P < 0.001). In the chronic phase, all the extracts and SS had significant analgesic effect(P < 0.001).Analgesic activity of the combined extract was significantly stronger than SS(P < 0.01). In the acute inflammation model, M. sylvestris, C. carvi and the combined drug had significant inhibitory effects against paw edema(P < 0.05). All extracts, individually and in combination, significantly alleviated chronic paw inflammation(P < 0.01). The combined extract had much more anti-inflammatory activity than SS(P < 0.05). Histopathological results indicated improvement and reduction of inflammatory factors in the treatment ***: M. sylvestris, C. carvi and M. sativa have analgesic and anti-inflammatory ***, each of these extracts or a mixture of them might be a valuable alternative drug to control pain and inflammation.

关键词： Analgesic Anti-inflammatory Formalin test Malva sylvestris Carum carvi Medicago sativa

Plasma Sprayed NiAl Intermetallic Coating Produced with Mechanically Alloyed Powder

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Journal of Materials Science & Technology 2011年第9期27卷 816-820页

作者： Mehrshad Moshref Javadi Hossein Edris mahdi Salehi Marine Engineering Department Maleke-Ashtar University of Technology Department of Materials Engineering Isfahan University of Technology

In the present research, mechanically alloyed Ni-AI powder was utilized to develop plasma sprayed coatings, and the effect of the spray distance and heat treatment on the phases, microstructure, and hardness of the coat- ings were examined. Coatings were analyzed by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, energy-dispersive spectroscopy （EDS） and through microhardness measurements. Although mechanically alloyed Ni-AI powder showed no intermetallic phases, the coatings did. Different spray distances from 5 to 19 cm were employed for plasma spray and the specimens were heat treated at different temperatures, then the amount of oxides, porosity and hardness of the coatings were changed according to the spray condition. The thermal energy of the plasma spray caused the formation of NiAI phases while particles flew to the substrate or after that. Extreme increase in heat treatment temperature and spray distance resulted in oxidation and reduction in the quality of the coating. Furthermore, the best spray distance and heat treatment temperature to gain the NiAI intermetallic coating were established.

关键词： Coating materials Intermetallics Phase transformation Plasma spray

On the higher-order thermal vibrations of FG saturated porous cylindrical micro-shells integrated with nanocomposite skins in viscoelastic medium

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Defence Technology（防务技术） 2022年第8期18卷 1416-1434页

作者： Zeinab Soleimani-Javid Ehsan Arshid Saeed Amir mahdi Bodaghi Department of Solid Mechanics Faculty of Mechanical EngineeringUniversity of KashanKashanIran Department of Engineering School of Science and TechnologyNottingham Trent UniversityNottinghamNG118NSUK

Since the multi-layered structures are widely used nowadays, and due to interesting applications of cylindrical shells, this study is dedicated to analyzing free vibrational behaviors of functionally graded saturated porous micro cylindrical shells with two nanocomposite skins. Based on Biot's assumptions, constitutive relations for the core are presented and effective properties of the skins are determined via the rule of mixture. A sinusoidal theory is used to capture the shear deformation effects, and to account for the scale effects, the modified couple stress theory is employed which suggests a material length-scale parameter for predicting the results in small-dimension. With the aid of extended form of Hamilton's principle for dynamic systems, differential equations of motion are extracted. Fourier series functions are used to obtain natural frequencies and after validating them, a set of parametric studies are carried out. The results show the significant effects of porosity and Skempton coefficient, pores placement patterns, CNTs addition and distribution patterns, temperature variations, material length-scale parameter and viscoelastic medium on the natural frequencies of the microstructure. The outcomes of this work could be used to design and manufacture more reliable micro cylindrical structures in thermo-dynamical environments.

关键词： Vibration analysis Cylindrical shells Saturate porous materials Nanocomposite materials Carbon nanotubes Sinusoidal shear deformation theory Viscoelastic medium