NUMERICAL STUDY OF TURBULENCE DYNAMICS IN PLUNGING & SURGING BREAKING WAVES

KHAYYER ABBAS,YEGANEH-BAKHTIARY ABBAS,GHAHERI ABBAS,GOTOH HITOSHI,SAKAI TETSUO 한국수자원학회 2005 한국수자원학회 학술대회 Vol.2005 No.1

A comparative study of adsorption and removal of organophosphorus insecticides from aqueous solution by Zr-based MOFs

Abbas Jamali,Farzaneh Shemirani,Ali Morsali 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.80 No.-

The adsorptive removal of hazardous materials of organophosphorus insecticides by adsorbents withhigh adsorption capacities is highly desirable. In this work, we present the removal of two representativeorganophosphorus insecticides, Dichlorvos and Metrifonate by two exceptionally stable Zr-based MOFsof UIO-66 and UIO-67. The MOFs were characterized by TGA, FTIR, SEM, XRD, BET and XPS analyses. Effectof some parameters such as adsorbent dose, contact time, pH and ionic strength on the removal efficiencyof Dichlorvos and Metrifonate were investigated. The mechanism of interaction was carefullyinvestigated by XPS and FTIR. The isotherm and kinetic data were accurately described by the Langmuirand pseudo-second-order models. The adsorption capacities in UIO-67 approached as high as571.43 mg g 1 for Dichlorvos and 378.78 mg g 1 for Metrifonate, which were much higher than UIO-66. Compared to other works this work has shown better adsorption capacity and cost efficient. Thecalculated removals for the samples are in the range from 97.8 to 99%, indicating that the UIO-67 can beapplied for removal of Dichlorvos and Metrifonate in real samples.

The Content and Necessity of the New International Order in the New International Environment

Abbas Maleki 한국중동학회 1991 韓國 中東 學會 論叢 Vol.12 No.1

Solar-Assisted Heat Pump Drying of Coriander: An Experimental Investigation

Abbas Alishah,Mohammad Valizadeh Kiamahalleh,Fereshteh Yousefi,Anita Emami,Meisam Valizadeh Kiamahalleh 대한설비공학회 2018 International Journal Of Air-Conditioning and Refr Vol.26 No.4

In this study, the solar-assisted heat pump dryer was designed, manufactured, tested and optimized for drying operations of coriander for its preservation. The heat of drying was mainly provided by a solar collector and a heat pump with two experimental modes of turned on and off. The air temperatures and velocity were identified as the critical drying variables. The responses of the experiments were evaluated in terms of coefficient of performance (COP), energy consumption and the specific moisture extraction rate (SMER). Dehumidification of coriander from the moisture contents of 0.9 to 0.1 kg/kg was considerable. The results demonstrated that utilizing heat pump noticeably decreases the drying time (down to ~25%), energy consumption (down to ~12%) and increases SMER (up to ~ 20%). The increasing of air flow rate and air temperature significantly led to decreasing the drying time and energy consumption, however, increasing the COP and SMER.

Theoretical analysis of oxidative coupling of methane and Fischer Tropsch synthesis in two consecutive reactors: Comparison of fixed bed and membrane reactor

Abbas Ghareghashi,Sattar Ghader,Hassan Hashemipour Rafsanjani 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.6

In this paper, theoretical performance of Fischer Tropsch (FT) synthesis is analyzed where its feed comes from an oxidative coupling of methane (OCM) reactor. In this model based analysis, two consecutive reactors are intended that first reactor is OCM and second reactor is FT and FT reactor performance is compared in two conditions of fixed bed and membrane reactor (MR). The parameters concerned, were CH4/O2 ratio, contact time, temperature, and amount of N2 in OCM feed. High CH4/O2 ratio gave low yield of C2+ in OCM due to insufficient oxygen, but favored FT reaction due to more yield of C5+ and other products. Therefore, it was concluded that production and yield of C5+ could be more by use of these configurations.

Surface functionalization of phosphazenenanosphere derivatives by Schiff-base-assisted metal complexes through a Si-spacer

Abbas Tarassoli,Tahereh Sedaghat,Zeinab Ansari-Asl 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4

Surface functionalization of organometallic derivatives of phosphazenenanosphere (PNS) by the metal-coordinated Schiff base through (3-chloropropyl)trimethoxysilane as a silicon linker and spacer was investigated. The PNS’s derivative of 4,40-sulfonyldiphenol (BPS) was added to Si–H2 saldien under ultrasonic irradiation. Metal ion (Mn2+, Ni2+or Zn2+) was loaded on the PNS–Si–H2 saldien as desired metal salt. The structure and morphology was characterized by means of FT-IR, TGA, SEM, EDX and X-ray diffraction. The average diameters of nanosphere compounds are in the range of 250–300 nm.

Performance analysis and modeling of catalytic trickle-bed reactors: a comprehensive review

Abbas Azarpour,Nima Rezaei,Sohrab Zendehboudi 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.103 No.-

Trickle-bed reactors (TBRs) are extensively used in industry. There have been great progresses in designand control of the TBRs. However, more improvements are required in the performance/operation ofTBRs. These improvements can lead to more efficient process control and further reduction of the operationcosts. In terms of process efficiency, the product quality can be improved since a large number ofthe TBRs are used in purification processes. In terms of operation costs, the process improvement canresult in longer utilization of the catalysts because the catalytic TBRs’ operations usually suffer fromthe deactivation phenomenon for expensive catalysts. Hydrodynamic parameters play significant rolesin the control and operation of TBRs. We provide comprehensive information and discussion on TBRsapplication and hydrodynamic characteristics. Moreover, a systematic methodology is proposed todevelop a TBR mathematical model. A detailed review on the previous TBRs studies is presented, andtechnical issues in their design and operation are discussed. In addition, current challenges in the TBRmodeling are summarized, and further research plans/topics are suggested. This review provides anexhaustive knowledge and practical and theoretical tips that can be employed to more efficaciouslymodel targeted TBR processes, leading to better understanding of the process behaviours, and more efficientoperation of the relevant plants.

Influence and Application of an External Variable Magnetic Field on the Aqueous HCl Solution Behavior: Experimental Study and Modelling Using the Taguchi Method

Abbas Hashemizadeh,Mohammad Javad Ameri,Babak Aminshahidy,Mostafa Gholizadeh 한국공업화학회 2018 공업화학 Vol.29 No.2

Influences of the magnetic field on 5, 10 and 15 wt% (1.5, 3 and 4.5 M) HCl solution behaviour, which has widespread applications in petroleum well acidizing, were investigated in various conditions. Differences in the pH of magnetized hydrochloric acid compared to that of normal hydrochloric acid were measured. Taguchi design of experimental (DoE) method were used to model effects of the magnetic field intensity, concentration, velocity and temperature of acid in addition to the elapsed time. The experimental results showed that the magnetic field decreases [H+] concentration of hydrochloric acid up to 42% after magnetization. Increasing the magnetic field intensity (with 28% contribution), concentration (with 42% contribution), and velocity of acid increases the effect of magnetic treatment. The results also demonstrated that the acid magnetization wasnot influenced by the fluid velocity and heating. It was also displayed that the acid preserves its magnetic memory during time. The optimum combination of factors with respect to the highest change of [H+] concentration was obtained as an acid concentration of 10% and an applied magnetic field of 4,300 Gauss. Due to the reduction of HCl reaction rate under the magnetization process, it can be proposed that the magnetized HCl is a cost effective and reliable alternative retarder in the matrix acidizing of hydrocarbon (crude oil and natural gas) wells.

Exact vibration and buckling analyses of arbitrary gradation of nano-higher order rectangular beam

Abbas Heydari 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.28 No.5

The previous studies reflected the significant effect of neutral-axis position and coupling of in-plane and out-of-plane displacements on behavior of functionally graded (FG) nanobeams. In thin FG beam, this coupling can be eliminated by a proper choice of the reference axis. In shear deformable FG nanobeam, not only this coupling can't be eliminated but also the position of neutral-axis is dependent on through-thickness distribution of shear strain. For the first time, in this paper it is avoided to guess a shear strain shape function and the exact shape function and consequently the exact position of neutral axis for arbitrary gradation of higher order nanobeam are obtained. This paper presents new methodology based on differential transform and collocation methods to solve coupled partial differential equations of motion without any simplifications. Using exact position of neutral axis and higher order beam kinematics as well as satisfying equilibrium equations and traction-free conditions without shear correction factor requirement yields to better results in comparison to the previously published results in literature. The classical rule of mixture and Mori-Tanaka homogenization scheme are considered. The Eringen.s nonlocal continuum theory is applied to capture the small scale effects. For the first time, the dependency of exact position of neutral axis on length to thickness ratio is investigated. The effects of small scale, length to thickness ratio, Poisson's ratio, inhomogeneity of materials and various end conditions on vibration and buckling of local and nonlocal FG beams are investigated. Moreover, the effect of axial load on natural frequencies of the first modes is examined. After degeneration of the governing equations, the exact new formulas for homogeneous nanobeams are computed.

A Comprehensive Analysis of the End-to-End Delay for Wireless Multimedia Sensor Networks

Abbas, Nasim,Yu, Fengqi The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.6

Wireless multimedia sensor networks (WMSNs) require real-time quality-of-service (QoS) guarantees to be provided by the network. The end-to-end delay is very critical metric for QoS guarantees in WMSNs. In WMSNs, due to the transmission errors incurred over wireless channels, it is difficult to obtain reliable delivery of data in conjunction with low end-to-end delay. In order to improve the end-to-end delay performance, the system has to drop few packets during network congestion. In this article, our proposal is based on optimization of end-to end delay for WMSNs. We optimize end-to-end delay constraint by assuming that each packet is allowed fixed number of retransmissions. To optimize the end-to-end delay, first, we compute the performance measures of the system, such as end-to-end delay and reliability for different network topologies (e.g., linear topology, tree topology) and against different choices of system parameters (e.g., data rate, number of nodes, number of retransmissions). Second, we study the impact of the end-to-end delay and packet delivery ratio on indoor and outdoor environments in WMSNs. All scenarios are simulated with multiple run-times by using network simulator-2 (NS-2) and results are evaluated and discussed.