فهرست مطالب
Iranica Journal of Energy & Environment
Volume:3 Issue: 1, Winter 2012
- تاریخ انتشار: 1391/01/12
- تعداد عناوین: 12
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Page 1The fully coupled WRF/Chem (Weather Research and Forecasting/Chemistry) model is used to simulate air quality over the Sea of Japan coastal area. Anthropogenic surface emissions database used as input for this model are mainly based on Global hourly emissions data (dust, sea salt, biomass burning), RETRO (REanalysis of the TROpospheric chemical composition), GEIA (Global Emissions Inventory Activity) and POET (Precursors of ozone and their Effects in the Troposphere). Climatologic concentrations of particulate matters derived from Regional acid Deposition Model (RADM2) chemical mechanism and Secondary Organic Aerosol Model (MADE/SORGAM) with aqueous reaction were used to deduce the corresponding aerosols fluxes for input to the WRF/Chem. The model was firstly integrated for 48 hours continuously starting from 00:00 UTC of 14 March 2008 to evaluate ozone concentrations and other precursor pollutants were analyzed. WPS meteorological data were used for the simulation of WRF/Chem model in this study. Despite the low resolution of the area global emissions and the weak density of the local point emissions, it has been found that WRF/Chem simulates quite well with the diurnal variation of the chemical species concentrations over the Sea of Japan coastal area. The simulations conducted in this study showed that due to the geographical and climatologically characteristics, it is still environmentally friendly by the transported pollutants in this region.Keywords: Air quality, Modeling, WRF, Chem, Ozone concentrations
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Page 17Aiming to evaluate the phosphorus adsorption in Oxisols with phosphorus remaining classified using the Langmuir isotherm, a study was developed in the laboratory at Federal University of Campina Grande, PB, with samples of the surface layer (0-20 cm) of three Oxisols of the State of Paraíba, differentiating among these the classification of the remaining P-values. The phosphorus levels for adjusting the isotherm were defined based on the remaining P-values. To assess the maximum P adsorption capacity data from P adsorbed and equilibrium concentrations of the solutions were adjusted Langmuir isotherm. This isotherm model could satisfactorily describe the adsorption of phosphorus in soils. The Oxisol sample with high P-rem was the highest value of maximum P adsorption capacity. The maximum P adsorption capacity was correlated with CEC and Ki for the samples classified as P-rem medium and high, respectively.Keywords: Langmuir, Isotherm, Tropical soils
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Page 23An effective biosorbent was developed from Citrullus Lanatus Rind and its various biosorption characteristics were studied for removing a basic dye (Crystal Violet) from its aqueous solution. A series of experiments were conducted in a batch system to assess the effects of the system variables such as contact time, biosorbent dosage, pH, initial dye concentration, temperature, particle size and agitation speed. The biosorbent studied exhibits high efficiency for crystal violet adsorption and the equilibrium states could be achieved in 180 min for the different initial concentrations. The equilibrium adsorption data were analyzed by the Langmuir, Freundlich, Tempkin and Harkins-Jura isotherm models. The equilibrium data indicates the following order to fit the isotherms: Freundlich > Tempkin > Harkins-Jura isotherm > Langmuir. The maximum dye adsorption capacity was found to be 11.99 mg/g at 50°C. The biosorption kinetics was found to follow pseudo-second-order rate kinetic model, with good correlation (R = 0.99) and the intra particle 2 diffusion as one of the rate determining steps. Different thermodynamic parameters, like Gibb’s free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) of the adsorption process have also been evaluated. The thermodynamic parameters of crystal violet biosorption indicated, the process was spontaneous and endothermic. The results indicated that the biosorbent studied was found to be a promising alternative for the adsorption of crystal violet from aqueous solution.Keywords: Citrullus Lanatus Rind, Crystal Violet, Biosorption, Kinetics, Equilibrium, Thermodynamic
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Page 35This paper investigates the ability of Bottom ash to adsorb three cationic dyes from aqueous solution in single and tertiary systems. Crystal Violet (CV), Methylene Blue (MB) and Malachite Green (MG) were used as cationic dye models. The surface characteristics of Bottom ash were investigated using Fourier Transform Infrared (FTIR). Pseudo second order model was fitted better than Pseudo First order model for all system of MG, MB and CV. From the isotherm study, the adsorption capacity increased in the order of MB< MG
Keywords: Fly ash, Adsorption, Tertiary system, Isotherm, Kinetics
Page 46
In this article, the electrochemical synthesis and the characterization of Cu nanoparticles dispersed poly (o-aminophenol) (POAP) nanotube electrode is reported. The morphology of the electrode was characterized by scanning electron microscopy (SEM). Catalytic activity and stability for the oxidation of methanol were studied by using cyclic voltammetry and electrochemical impedance spectroscopy (EIS) were performed. The results show that poly (o-aminophenol) nanotubes electrodes significantly enhance the catalytic activity of copper nanoparticles for oxidation of methanol. The results obtained affirm that the dispersion of the copper particles is connected with catalytic response to a higher activity. The nanotubular morphology of poly (o-aminophenol) helps in the effective dispersion of Cu particles facilitating the easier access of methanol to the catalytic sites. The poly (o-aminophenol) nanotubes modified with copper nanoparticles cause a great increase in electroactivity and the electro-catalytic oxidation of methanol.
Keywords:
Methanol oxidation, Conducting polymers, Nanostructured materials, Electro, catalyst
Page 52
In this study the equilibrium uptakes of hydrogen and carbon dioxid as the main constituents of syngas by the multi-walled carbon nanotube (MWCNT) were investigated at the temperature range of 288-318 K and pressure up to 40 bars. The results have shown that temperature had much less effect on the adsorption of H on MWCNT than adsorption of CO. Several model isotherms such as Langmuir and Freundlich were 2 2 examined to fit the equilibrium uptake data. The kinetics of H and CO adsorption on MWCNT were also 2 2 investigated and the results revealed a fast sorption kinetic for both gas adsorption on MWCNT. Isosteric heat of adsorption was evaluated based on the Clausius-Clapeyron equation at different temperatures. Small values of isosteric heat of adsorption confirmed that although the adsorption of H and CO on MWCNT were 2 2 exothermic, but the heat of adsorption was too low, therefore the process of adsorption of both gases on the MWCNT used in this study is physisorption.
Keywords:
Syngas, Adsorption, MWCNT, Kinetic, Isosteric heat
Page 59
Lipase was produced under desired growth conditions in a novel tray bioreactor using the fungus strain of Rhizopus oryzae. Several agricultural residues/products including sugarcane bagasse, wheat bran, corn meal, barely bran and equal mixtures of sugarcane bagasse with agricultural residues were applied as solid substrate. Lipase produced from the pure sugarcane bagasse showed higher activities than other substrates; which resulted enzyme activities of 155.76 and 138.37 U/gds for the top and middle trays respectively. Furthermore, the influence of carbon and nitrogen supplements was investigated. Addition of carbon sources as substrate was found to be ineffective, while lipase activity remarkably increased by supplementation of bagasse with adequate amount of nitrogen source. Among the nitrogen supplements, urea as a suitable nitrogen source was considered; as a result the average lipolytic activity of 229.355 U/gds was achieved. In addition, various concentrations of vegetable oils including canola oil, soybean oil, olive oil and castor oil were applied. The inducing effect of vegetable oil on lipase activity was investigated. Among them, olive oil and canola oil increased lipolytic activity of lipase with an average value of 192.26 and 183.57 U/gds, respectively.
Keywords:
Lipase, Enzyme activities, Solid state fermentation, Nitrogen sources, Rhizopus oryzae, Ttray bioreactor
Page 66
In this research, the preparation of polyaniline (PAn)/ rice husk nanocomposite as adsorbent was discussed and the capability of adsorbing zinc is studied. The polyaniline nanocomposite was prepared in presence of KIO as an oxidant, coated on rice husk ash via casting method. The morphology and chemical 3 structure of absorbent evaluated by with scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR), respectively. Batch studies were performed to evaluate the influence of various experimental parameters such as pH, adsorbent dosage and contact time. Optimum conditions for zinc removal were found to be pH 3, adsorbent dosage of 10 g/L and equilibrium time of 20 minutes. The equilibrium adsorption isotherm was better described by Langmuir adsorption isotherm model. The adsorption capacity (q) of PAn/RH for zinc ions in terms of monolayer adsorption was 24.3 mg/g. max.
Keywords:
Polyaniline, Nanocomposite, Rice husk, Zinc Removal
Page 72
The necessity of making buildings taller and height of new buildings is now one of the major problems in building design and codes of interest is located. With height, the need for further ductility and the capability of energy dissipation can be a significant role in the proper and safe design of structures to play. It seems that changes the height of buildings can be treated directly on the response modification factor of structures and thus the seismic performance of structures under severe earthquake to be effective. This research is an attempt to evaluate the ductility, over-strength and response modification factors of the Open Chevron Eccentrically Braced Frames (EBFs) with 5, 10, 15 and 20 stories under Tabas, Naghan, Bam and El- Centro strong ground motions. These frames were analyzed by using static pushover analysis, linear dynamic and incremental nonlinear dynamic analysis and the values of these factors for different models have been determined separately and it is resulted that with increasing the height of buildings, the ductility reduction factor and the response modification factor of EBFs, decrease, but this variation hasn’t any influence on the over strength reduction factor.
Keywords:
Response modification factor, Ductility reduction factor, Over strength reduction factor, Open
Page 78
One type of outlet works in dams are Three-side spillways that despite of their hydraulic limitations and construction problems, they were being selected, in storage dams, as best option under specific topographical conditions. Considerable energy losses and great turbulence are hydraulic characteristic of these spillways. Hydraulic performance with targeting to reduce pressure fluctuations in side channel is an important issue in this type of spillways design. In this study, effect of stepping of three-side spillway’s Ogee profile on the dynamic pressure fluctuation have been investigated using finite volume method and RNG turbulence model. The turbulence intensity as a dimensionless number was used for quantitative study of dynamic pressure fluctuations. The results showed that the proposed form of ogee profile caused a significant reduction in turbulence intensity within the side channel. On the other hand, the stepped Ogee profiles of three-side spillways caused to simple construction and ease of operation.
Keywords:
Three, side spillway, Stepped Spillway, Dynamic pressure fluctuation, RNG turbulent model
Page 88
In this paper a numerical investigation is given for a Rankine type vortex flow inside the cylindrical vortex chamber using FLOW-3D. The FLOW-3D is a general purpose computational fluid dynamics (CFD) package. The fluid motion is described with non-linear, transient, second-order differential equations. Additionally the free surface also exists in many simulations carried out with FLOW-3D because flow parameters and materials properties, such as density, velocity and pressure experience a discontinuity at it. After analysis of the vortex by mentioned details, the finding of time-averaged velocity components, turbulent components, turbulence dissipation, in the 2D briefed sections of chamber were depicted. It was found that there are different flow patterns like clockwise/anticlockwise vortices and some sink points combined with each other in different time intervals, decaying and generating along the time. Also the turbulence intensity and dissipations around the boundary conditions of chamber like central flushing discharge are higher than the flow body. It was also found that this CFD package was not able to simulate thoroughly the central air core of chamber after filling of chamber. This analysis is validated by comparison with previous experimental data that was measured in vortex settling basin.
Keywords:
Vortex flow, Flow 3D, Numerical Investigation, Turbulence
Page 97
Solvatochromic properties of a series of bis(3–substituted derivatives of acetylacetone copper(II) (X-acacH, X = Cl, H. CH) complexes were studied. All the complexes demonstrated negative 3 solvatochromism. Among the complexes the Cu(Cl-acac), demonstrated the most solvatochromism. A multi-parametric equation 2 has been utilized to explain the solvent effect on the d-d transition of the complexes using SPSS/PC software. The stepwise multiple linear regression (SMLR) method demonstrated that the donor power of the solvent plays the most important role in the solvatochromism of the compounds.
Keywords:
Solvatochromism, Multiple linear regression, Visible spectroscopy, Copper (II) complex, Acetylacetonate
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