An investigation on Kangan gas refinery wastewater     

S. M. T. Sadatipour  L. Mirzaie  A. A. Rezaei 《International Journal of Environmental Science and Technology》2004,1(3):205-213

Kangan Gas Refinery is one of the greatest gas refineries in Iran. Environmental affects of this refinery should be assessed because of its high economic importance, as well as its considerable revenue. Since the gas refinery is classified in highly polluted industry, therefore the impact of wastewater the refinery should be determined. This research is carried out on March 2002 at Kangan refinery, which is located in Kangan city, southern part of Iran. The gas refinery wastewater generally includes oil, hydrocarbon materials and chemical additives, which are in the form of emulsion in water. The following parameters, such as oil and grease, PAHs, BOD, TH, turbidity, COD, EC, pH, TSS, SiO₂, PO₄ are determined in wastewater of the refinery in order to determine the amount of pollutants, which are affecting the area where the refinery is located. The oil and grease are analyzed by FTIR and PAHs are determined by UV-Luminance and physico-chemical parameters are determined according to the Standard Methods. The results show that although pollution of the refinery wastewater is within world permissible limits (EPA), but since the area is affected by the wastewater and surrounding area is confined with river basin it could be concluded that pollutants, which are discharged to the echo environment, are not in the permissible limits of the similar Industries.  相似文献   

The Tabas (Iran) earthquake of 16 September 1978     

Bahram Akasheh  Iraj Eshghi 《Pure and Applied Geophysics》1980,119(1):207-211

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Hubble Space Telescope imaging survey of sub-mJy star-forming galaxies – I. Morphologies at z ∼ 0.2     

Stephen Serjeant  Bahram Mobasher  †  Carlotta Gruppioni  Seb Oliver 《Monthly notices of the Royal Astronomical Society》2000,317(2):L29-L33

We present the first results of our Hubble Space Telescope HST WFPC2 F814W snapshot imaging survey, targeting virtually all sub-mJy decimetric radio-selected star-forming galaxies. The radio selection at ∼1 GHz is free from extinction effects and the radio luminosities are largely unaffected by AGN contamination, making these galaxies ideal tracers of the cosmic star formation history. A subsample of four targets is presented here, selected at 1.4 GHz from the spectroscopically homogenous and complete samples of Benn et al. and Hopkins et al. The redshifts are confined to a narrow range around z ∼0.2, to avoid differential evolution, with a radio luminosity close to L ∗ where the galaxies dominate the comoving volume-averaged star formation rate. We find clearly disturbed morphologies resembling those of ultraluminous infrared galaxies, indicating that galaxy interactions may be the dominant mechanism for triggering star formation at these epochs. The morphologies are also clearly different from those of coeval quasars and radio galaxies, as found in star-forming galaxies selected at other wavelengths. This may prove challenging for models that propose direct causal links between AGN evolution and the cosmic star formation history at these epochs. The asymmetries are typically much larger than seen in the Canada–France Redshift Survey at similar redshifts, optical luminosities and H α -derived star formation rates, indicating the possible existence of an obscuration-related morphological bias in such samples.  相似文献   

Solving land-use suitability analysis and planning problem by a hybrid meta-heuristic algorithm     

Kaveh Khalili-Damghani  Bahram Aminzadeh-Goharrizi  Saeed Rastegar  Babak Aminzadeh-Goharrizi 《International journal of geographical information science》2014,28(12):2390-2416

The aim of Land-use Suitability Analysis and Planning Problem (LSAPP) is to identify the most suitable parcels of land for future land-uses considering several conflicting criteria. LSAPP can be modeled using a variant of a well-known combinatorial optimization problem called Quadratic Assignment Problem (QAP). In this paper, a multi-objective mathematical model is developed for LSAPP based on QAP modeling. The large-size instances of the proposed multi-objective mathematical model are difficult to solve in a reasonable CPU time using exact algorithms. So, an efficient three-phase hybrid solution procedure is proposed. In the first phase, the compensatory objectives are integrated using Analytic Hierarchy Process (AHP) and Decision-Making Trial and Evaluation Laboratory. Then, based on the aforementioned suitability objective function and other spatial objectives and constraints, a multi-objective LSAPP is constructed. Finally, a hybrid multiple objective meta-heuristic algorithm is proposed to solve the LSAPP. The core of the proposed algorithm is based on Scatter Search while Tabu Search and Variable Neighborhood Search are also utilized. The proposed algorithm is equipped with the concepts of Pareto optimality and Veto Threshold, which improve its efficacy. The proposed algorithm is applied on a real LSAPP case study, in ‘Persian Gulf Knowledge Village’, wherein its performance is compared with a well-known evolutionary computation algorithm called Vector Evaluated Genetic Algorithm (VEGA) using comprehensive statistical analysis. A survey on time complexity of the proposed algorithm is also accomplished. The results show that MOSVNS is significantly superior to VEGA both in single and in multi-objective modes. Furthermore, analysis of time complexity of the proposed algorithm shows that it is of polynomial time and can be applied to significantly larger problems with multiple compensatory and non-compensatory objectives.  相似文献   

Biofiltration of Hexane Vapor: Experimental and Neural Model Analysis     

Morteza Zamir  Rouein Halladj  Mohammad Saber  Milad Ferdowsi  Bahram Nasernejad 《洁净——土壤、空气、水》2011,39(9):813-819

Biofiltration is a commonly practiced biological technique to remove volatile compounds from waste gas streams. From an industrial view‐point, biofilter (BF) operation should be flexible to handle temperatures and inlet load (IL) variations. A compost BF was operated at different temperatures (30–45°C) and at various inlet loading rates (ILR; 8–598 g m^?3 h^?1) under intermittent loading conditions. Complete removal of n‐hexane was observed at 30 and 35°C at ILRs up to 330 g m^?3 h^?1. Besides, 20–75% of the pollutant was removed at 40°C, corresponding to the different ILs applied to the BF. Increasing the temperature to 45°C decreased the removal efficiency (RE) significantly. A feed forward neural network was used to predict the RE of BF with temperature and ILR as the input variables. The experimental data was divided into training (2/3) and test datasets (1/3). The best structure of neural network was obtained by trial and error on the basis of the least differences between predicted and experimental values, as ascertained from their coefficient of regression (R²) values. The modeling results showed that a multilayer network with the topology 2?10?1 was able to predict BF performance effectively with R²‐value of 0.995 for the test data. The results from this study showed the predicting capability of ANNs which can be considered as an alternative for conventional knowledge‐based models.  相似文献   

Modification of MCM‐41 with Anionic Surfactant: A Convenient Design for Efficient Removal of Cationic Dyes from Wastewater     

Mohammad Ali Zanjanchi  Hassan Sajjadi  Majid Arvand  Ali Mohammad‐Khah  Bahram Ghalami‐Choobar 《洁净——土壤、空气、水》2011,39(11):1007-1013

The potential of MCM‐41 for the removal of cationic dyes from water solution was evaluated using sodium dodecyl sulfate (SDS) for the surface modification of this mesoporous material. Admicelle structures formed on the surface of the calcined MCM‐41 are capable of removing organic pollutants and cationic species from water environment. The structural, textural, and surface chemical characteristics of the prepared SDS‐modified MCM‐41 (SDS‐MCM‐41) were studied. The adsorption capacity of SDS‐MCM‐41 was evaluated for methylene blue (MB) as a target cationic dye. Equilibrium adsorption isotherm data were manipulated employing nonlinear regression analysis. The Langmuir, Freundlich, and Sips isotherm models were examined. The adsorption data were well fitted to both Langmuir and Sips isotherm models. The maximum adsorption capacity of SDS‐MCM‐41 for MB, based on Langmuir and Sips models, were 290.8 and 297.3 mg g^?1, respectively. Ethanol was found to be an effective solvent for partial regeneration of the adsorbent.  相似文献   

Shock structures in dusty plasma in the presence of strong electrostatic interaction     

M. Shahmansouri  M. Rezaei 《Astrophysics and Space Science》2014,351(1):197-205

The fluid approach is employed to investigate theoretically the effect of strong electrostatic interaction on the dust acoustic (DA) shock waves near to the liquid-crystal phase transition in strongly coupled dusty plasma. The strong electrostatic interaction is modeled by effective electrostatic temperature which is considered as a dynamical variable. It is shown that the nonlinear evolution of dust acoustic shock waves in the present model is governed by a Burger equation, the coefficients in which are modified by strong coupling effect. Then, it is shown that how the perturbation of the effective electrostatic temperature modifies the basic properties of the DA shock waves.  相似文献   

A Complete Microjansky Radio Survey     

José Afonso  Bahram Mobasher  Andrew Hopkins  Lawrence Cram 《Astrophysics and Space Science》2001,276(2-4):941-948

The Phoenix Deep Survey is an ongoing multi-wavelength survey of a 2^° diameter field aimed at studying the properties of the sub-mJy and μJy radio population. Here, we present the latest 1.4 GHz observations of this field. The new data, reaching a 5 σ flux level of 45 μJy at the centre of a 50′ diameter field, comprise more than 700 sources with flux densities less than 1 mJy (187 of which have S_1.4 < 100 μJy). This provides one of the deepest radio (1.4 GHz) surveys currently available. The 1.4 GHz source counts are presented and show a flattening down to the 50 μJy level. At flux densities around 300 μJy there are indications that the sources detected may exhibit higher clustering than those observed at higher flux levels. This suggests that deep radio surveys could be useful for studies of large-scale structure but it also presents a warning for the representativity of sources in deep pencil-beam radio surveys. The study of the optical counterparts of the μJy population seems to indicate that the median R magnitude starts to decrease below 100 μJy. Spectroscopic classification of a sample of sources in this survey confirms the trend for an increasing fraction of star-forming galaxies over other systems down to ～ 100 μJy.  相似文献   

Spectroscopy at the Solar Limb: II. Are Spicules Heated to Coronal Temperatures?     

C. Beck  R. Rezaei  K. G. Puschmann  D. Fabbian 《Solar physics》2016,291(8):2281-2328

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Ultrafast removal of heavy metals by tin oxide nanowires as new adsorbents in solid-phase extraction technique     

R. Alizadeh  R. K. Kazemi  M. R. Rezaei 《International Journal of Environmental Science and Technology》2018,15(8):1641-1648

In the present research, the removal of lead(II) and copper(II) from aqueous solutions is studied, using SnO₂ nanowires as new adsorbent on solid-phase extraction disk and compared with pine core and buttonwood as biosorbents. Batch adsorption experiments were performed as a function of pH, adsorption time, solute concentration and adsorbent dose for biosorbents. Also, the pH, transfer rate of solution and metal concentration were selected as experimental parameters for the removal of heavy metals by SnO₂ nanowires. All of the parameters were optimized by experimental design method for sorbents. The experimental equilibrium adsorption data are tested for the Langmuir and Freundlich equations. Results indicate the following order to fit the isotherms: Langmuir > Freundlich, in case of lead and copper ions. The removal of Cu(II) and Pb(II) was performed by selected sorbents in the presence of interferences ions. This led to no remarkable decrease in the removal efficiency of SnO₂ nanowires. Using the SnO₂ nanowires in the wastewater treatment indicated 96.8 and 85.28% removal efficiency in only 7 min for Pb(II) and Cu(II), respectively. SnO₂ nanowires were found as reusable sorbent. Therefore, SnO₂ nanowires have a good potential for application in environmental protection.  相似文献