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Synergistic effect of adsorption and photocatalytic degradation of oilfield-produced water by electrospun photocatalytic fibers of Polystyrene/Nanorod-Graphitic carbon nitride

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Journal of Environmental Sciences 2024年第7期141卷 287-303页

作者： Parisa Azmoon mehrdad Farhadian Alireza Pendashteh Amir h.Navarchian Department of Chemical Engineering Faculty of EngineeringUniversity of IsfahanIsfahanIran Department of Chemical Engineering Faculty of EngineeringUniversity of GuilanRashtIran Department of Water and Environmental Engineering Caspian Sea Basin Research CenterUniversity of GuilanRashtIran

Graphitic carbon nitride with nanorod structure(Nr-GCN)was synthesized using melamine as a precursor without any other reagents by hydrothermal pretreatment ***,FTIR,SEM,N_(2)adsorption-desorption from BET,UV-Vis DRS spectroscopy,and photoluminescence were used to characterize the prepared ***,the photoelectrochemical behavior of nanoparticles was studied by photocurrent transient response and cyclic voltammetry ***(PS)fibrous mat was fabricated by electrospinning technique and used as a support for the stabilization of the *** performance of the synthesized nanoparticles and photocatalytic fibers(PS/Nr-GCN)was evaluated in oilfield-produced water treatment under visible light *** this process,oil contaminants were adsorbed by hydrophobic polystyrene fibers and simultaneously degraded by *** removal efficiency of chemical oxygen demand(COD)has been obtained 96.6%and 98.4%by Nr-GCN and PS/Nr-GCN,respectively,at the optimum conditions of ph4,photocatalyst dosage 0.5 g/L,COD initial concentration 550 mg/L,and illumination time 150 *** gas chromatography-mass spectroscopy analysis results showed 99.3%removal of total petroleum hydrocarbons using photocatalytic fibers of PS/*** results demonstrated that the GCN has outstanding features like controllable morphology,visible-light-driven,and showing high potential in oily wastewater ***,the synergistic effect of adsorption and photocatalytic degradation is an effective technique in oilfield-produced water treatment.

关键词： Graphitic carbon nitride(GCN) Nanorod structure Polystyrene fibrous mat Photocatalytic fibers Oilfield-produced water(OPW)

Experimental study of flow field distribution over a generic cranked double delta wing

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Chinese Journal of Aeronautics 2016年第5期29卷 1196-1204页

作者： Mojtaba Dehghan Manshadi Mehdi Eilbeigi Mohammad Kazem Sobhani mehrdad Bazaz zadeh Mohammad Ali Vaziry Department of Mechanical and Aerospace Engineering Malek Ashtar University of Technology

The flow fields over a generic cranked double delta wing were investigated. Pressure and velocity distributions were obtained using a Pitot tube and a hot wire anemometer. Two different leading edge shapes, namely ＂sharp＂ and ＂round＂, were applied to the wing. The wing had two sweep angles of 55° and 30°. The experiments were conducted in a closed circuit wind tunnel at velocity 20 m/s and angles of attack of 5°- 20° with the step of 5°. The Reynolds number of the model was about 2 - 105 according to the root chord. A dual vortex structure was formed above the wing surface. A pressure drop occurred at the vortex core and the root mean square of the measured velocity increased at the core of the vortices, reflecting the instability of the flow in that region. The magnitude of power spectral density increased strongly in spanwise direction and had the maximum value at the vortex core. By increasing the angle of attack, the pressure drop increased and the vortices became wider; the vortices moved inboard along the wing, and away from the surface; the flow separation was initiated from the outer portion of the wing and developed to its inner part. The vortices of the wing of the sharp leading edge were stronger than those of the round one.

关键词： Cranked double delta wing Flow field hot wire Leading edge shape Vortical flow

Effect of Solid Solution Supersaturation on Precipitation of γ′ in Rapidly Quenched Ni-Al Binary Alloys

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Journal of Materials Science & Technology 2009年第1期25卷 130-134页

作者： A. Samadi A. Abdollah.zadeh S. Behrouzghaemi S.h. Razavi Department of Materials Engineering Tarbiat Modarres University P.O. Box 14115-143 Tehran Iran Department of Materials and Metallurgical Engineering Iran University of Science and Technology (IUST) Narmak#16846 Tehran Iran

The effect of solid solution supersaturation on the precipitation of γ＇ in rapidly quenched Ni-AI binary alloys containing 11.6, 14.2 and 16.5 at. pct AI was investigated. The samples were solutioned at 1250℃, quenched in iced brine, and then analyzed by electron microscopy and XRD （X-ray diffraction） techniques. In Ni-11.6 at. pct Al alloy, ordering and phase separation took place simultaneously, resulting in a uniform distribution of γ＇. A transition from uniform to bimodal γ＇ phase distribution occurred in the composition range between 14.2 and 16.5 at. pct Al. This transition was accompanied by changes in the morphology of γ＇ precipitates. The microstructural observations were discussed in view of both kinetics and crystallographic considerations.

关键词： Ni-Al system heat treatment γ' precipitation Lattice mismatch

Microstructure and Mechanical Properties of a Dissimilar Friction Stir Weld between Austenitic Stainless Steel and Low Carbon Steel

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Journal of Materials Science & Technology 2013年第4期29卷 367-372页

作者： M Jafarzadegan A.Abdollah.zadeh A.h.Feng T.Saeid J.Shen h.Assadi Department of Materials Eng. Tarbiat Modares UniversityP.O.Box 14115-143TehranIran School of Materials Science and Eng. Harbin Institute of TechnologyP.O.Box 150001HarbinChina Advanced Materials Research Center Sahand University of TechnologyP.O.Box 51335-1996TabrizIran

Dissimilar fusion welding of austenitic stainless steels to carbon steels has some metallurgical and technical problems. It was suggested that the solid-state nature of friction stir welding （FSW） can overcome these problems and produce a sound weld with reliable mechanical properties. In this study, plates of 304 stainless steel and st37 steel were welded together by FSW at tool rotational speed of 600 r/rain and welding speed of 50 ram/rain. In the stir zone （SZ） of 304 stainless steel, the results showed a refined grain structure with some features of metadynamic recrystallization. In the SZ of st37 steel, the hot deformation of material in the austenite region produced small austenite grains. These grains transformed to fine ferrite and pearlite by cooling the material after FSW. The production of fine grains increased the hardness and tensile strength in the SZ of both sides with respect to their base metals （BMs）.

关键词： Friction stir welding Microstructure Mechanical properties Stainless steel Low carbon steel

Laboratory large-scale pullout investigation of a new reinforcement ofcomposite geosynthetic strip

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第5期13卷 1147-1159页

作者： mehrdad Tajabadipour Seyed hamid Lajevardi Department of Civil Engineering Sirjan University of TechnologySirjanIran Department of Civil Engineering Arak BranchIslamic Azad UniversityArakIran

In this paper,more than 70 large-scale pullout tests were performed to evaluate the performance of an innovative composite geosynthetic strip(CGS)reinforcement in sandy *** CGS reinforcement is composed of a geosynthetic strip(GS)and parts of a scrap truck tire as transverse *** experimental pullout results for the CGS reinforcement were compared with the suggested theoretical equations and ordinary reinforcements,including the GS,the steel strip(SS),and the steel strip with rib(SSR).The pullout test results show that adding three transverse members to the GS reinforcement(CGS3)with S/h?6.6(where S and h are the space and height of the transverse members,respectively)increases pullout resistance by more than 120%,170%,and 50%compared to the GS,the SS,and the SSR,*** result shows that the CGS3(CGS with three transverse members)reinforcement needs at least 55.5%,63%,and 33.3%smaller length compared to the GS,the SS,and the SSR,*** general,implementation of mechanically stabilized earth wall(MSEW)with the proposed strip may help geotechnical engineers prevent costly designs and solve the problem of MSEW implementation in cases where there are limitations of space.

关键词： Pullout resistance Composite geosynthetic strip(CGS) Soilegeosynthetic interface Scrap tires Large-scale pullout tests

Kinetic study of methane hydrate formation in the presence of carbon nanostructures

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Petroleum Science 2019年第3期16卷 657-668页

作者： Saeid Abedi-Farizhendi Mina Iranshahi Abolfazl Mohammadi mehrdad Manteghian Amir h. Mohammadi Faculty of Chemical Engineering Tarbiat Modares University Tehran Iran Department of Petroleum Engineering South Tehran Branch Islamic Azad University Tehran Iran Department of Chemical Engineering University of Bojnord Bojnord Iran Institut de Recherche en Genie Chimique et Petrolier (IRGCP) Paris Cedex France Discipline of Chemical Engineering School of Engineering University of KwaZulu-Natal Howard College Campus King George V Avenue Durban 4041 South Africa

The effect of synthesized nanostructures,including graphene oxide,chemically reduced graphene oxide with sodium dodecyl sulfate(SDS),chemically reduced graphene oxide with polyvinylpyrrolidone,and multi-walled carbon nanotubes,on the kinetics of methane hydrate formation was investigated in this *** experiments were carried out at a pressure of 4.5 MPa and a temperature of 0 ℃ in a batch *** adding nanostructures,the induction time decreases,and the shortest induction time appeares at certain concentrations of reduced graphene oxide with SDS and graphene oxide,that is,at a concentration of 360 ppm for reduced graphene oxide with SDS and 180 ppm for graphene oxide,with a 98% decrease in induction time compared to that in pure ***,utilization of carbon nanostructures increases the amount and the rate of methane consumed during the hydrate formation *** of multi-walled carbon nanotubes with a concentration of 90 ppm showes the highest amount of methane *** amount of methane consumption increases by 173% in comparison with that in pure *** addition of carbon nanostructures does not change the storage capacity of methane hydrate in the hydrate formation process,while the percentage of water conversion to hydrate in the presence of carbon nanotubes increases considerably,the greatest value of which occurres at a 90 ppm concentration of carbon nanotubes,that is,a 253% increase in the presence of carbon nanotubes compared to that of pure water.

关键词： Clathrate hydrate Kinetics Carbon nanostructures Graphene oxide SDS PVP

Effects of Mn and Cu on the Mechanical Properties of a high Strength Low Alloy NiCrMoV Steel

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Journal of Materials Science & Technology 2005年第4期21卷 470-474页

作者： A.Abdollah.zadeh M.Belbasy Department of Materials Engineering Tarbiat Modarres University P.O. Box 14115-143 Tehran IranDepartment of Materials Engineering Tarbiat Modarres University P.O. Box 14115-143 Tehran Iran

The present study focuses on the effects of Mn and Cu on the mechanical properties, in particular, strength and toughness of a low alloy steel containing Ni, Cr, Mo and V. Specimens with different amounts of Mn （0.23%-0.85%）and Cu （0.15%-0.45%） were cast and forged, and then austenitized at 870℃ for 1h, followed by oil quenching. All specimens were tempered at 650℃ for 1h. The results show that as the amounts of Mn and Cu increase respectively from 0.35% to 0.85% and from 0.15% to 0.45%, the yield and tensile strength increase. The highest impact energies were observed in the specimen with 0.35% Mn and in the specimen with 0.25% Cu. The impact energy decreases with increasing the Mn and Cu from 0.35% to 0.85% and from 0.25% to 0.45%, respectively. Furthermore, the variation of Mn and Cu does not cause a considerable change in the tempered martensite microstructure. The optimum strength and toughness is observed in 0.35% Mn containing steel and in the 0.25% Cu containing steel.

关键词： NiCrMoV steel Cu Mn Tensile strength Impact energy

Estimating Water Retention with Pedotransfer Functions Using Multi-Objective Group Method of Data handling and ANNs

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Pedosphere 2011年第1期21卷 107-114页

作者： h.BAYAT M.R.NEYShABOURI K.MOhAMMADI N.NARIMAN-zadeh Department of Soil Science Faculty of AgricultureBu Ali Sina University Department of Soil Science Faculty of AgricultureTabriz University Department of Irrigation and Drainage Engineering Tarbiat Modares University Department of Mechanical Engineering Engineering FacultyGuilan University

Pedotransfer functions （PTFs） have been developed to estimate soil water retention curves （SWRC） by various techniques. In this study PTFs were developed to estimate the parameters （θs, θr, α and λ） of the Brooks and Corey model from a data set of 148 samples. Particle and aggregate size distribution fractal parameters （PSDFPs and ASDFPs, respectively） were computed from three fractal models for either particle or aggregate size distribution. The most effective model in each group was determined by sensitivity analysis. Along with the other variables, the selected fractal parameters were employed to estimate SWRC using multi-objective group method of data handling （mGMDh） and different topologies of artificial neural networks （ANNs）. The architecture of ANNs for parametric PTFs was different regarding the type of ANN, output layer transfer functions and the number of hidden neurons. Each parameter was estimated using four PTFs by the hierarchical entering of input variables in the PTFs. The inclusion of PSDFPs in the list of inputs improved the accuracy and reliability of parametric PTFs with the exception of ~s- The textural fraction variables in PTF1 for the estimation of a were replaced with PSDFPs in PTF3. The use of ASDFPs as inputs significantly improved a estimates in the model. This result highlights the importance of ASDFPs in developing parametric PTFs. The mCMDh technique performed significantly better than ANNs in most PTFs.

关键词： aggregate size distribution fraetal parameters particle size distribution

Investigation of sediment transport pattern and beach morphology in the vicinity of submerged groyne （case study： Dahane Sar Sefidrood）

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Frontiers of Structural and Civil Engineering 2015年第1期9卷 82-90页

作者： h. Afsoos BIRIA M. A. Lashteh NEShAEI A. GhABRAEI M. A. mehrdad Marine structure engineer University of Guilan Rasht Iran Department of Civil Engineering University of Guilan Rasht Iran

Marine structures, such as Groynes, Sea walls and Detached Breakwaters, are constructed in coast of area to improve coast stability against bed erosions due to changing wave and current pattern. Marine mechanisms and interaction with the hydraulic structures need to be intensively studied. Groynes are one of the most prominent structures that are used in shore protection and littoral sediment. The main hydraulic function of the groyne is to control the long shore current and littoral sediment transport. This structure can be submerged and provide the necessary beach protection without negative aesthetic impact. however, for submerged structures adopted for beach protection, the shoreline response to these structures is not well understood. The objective of this study is to predict sediment transport in the vicinity of submerged groyne and comparison with non-submerged groyne focusing on a part of the coast at Dahane Sar Sefidrood, Guilan Province, Iran, where serious coast erosion has been occurred. The simulations were designed using a one-line model which can be used as a first approximation of shoreline prediction in the vicinity of groyne. The results of the proposed model are compared with experimental data to determine the shape of the coast. The results of predicted beach deformation show that when submerged groyne construct in the beach, sediment accumulation will be slightly less than the non-submerged groyne; because transfer coefficient for the submerged groyne is more than non-submerged groyne. This result will cause more sediment passing on submerged groyne. Finally, the result of the present study show that using submerged groyne is an efficient way to control the sediment and beach erosion without causing severe environmental effect on the coast.

关键词： submerged groyne non-submerged groyne beach morphology Dahane Sar Sefidrood sediment transport