توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱Simulation of Tubular Solid Oxide Fuel cell with Natural Gas Fuel
نویسنده(ها): ، ،
اطلاعات انتشار: پنجمین کنگره بین المللی مهندسی شیمی، سال
تعداد صفحات: ۷
In this study, a 2–D model of a tubular solid oxide fuel cell fed with natural gas is presented. The conservation equations for energy, mass, momentum and voltage were solved simultaneously using appropriate numerical techniques. Gibbs free energy minimization method was used to obtain the equilibrium species concentrations in the fuel cell. Numerical results are in good agreement with the experimental and numerical data available in the literature.<\div>

۲Electroosmotic Flow in PEM Fuel Cells with Variable Zeta Potential
نویسنده(ها): ، ، ،
اطلاعات انتشار: پنجمین کنگره بین المللی مهندسی شیمی، سال
تعداد صفحات: ۶
Water management is critically important for polymer electrolyte membrane (PEM) fuel cells, and is complicated by electroosmotic flow of water from anode to cathode through the polymer electrolyte membrane. In this work, the characteristics of electroosmotic flow in a Nafion® membrane with non–uniform zeta potential were investigated. The Poisson–Boltzmann and Navier–Stokes equations were used to model electrical double layer and the flow fields, respectively. The numerical results show the distorted electroosmotic velocity profiles resulting from the axial variation of the zeta potential.<\div>

۳Visco–resolvent algorithms for monotone operators and nonexpansive mappings
نویسنده(ها): ، ، ،
اطلاعات انتشار: Journal of Nonlinear Sciences and Applications، هفتم،شماره۵، ۲۰۱۴، سال
تعداد صفحات: ۲۰
Two new type of visco–resolvent algorithms for nding a zero of the sum of two monotone operators and a xed point of a nonexpansive mapping in a Hilbert space are investigated. The algorithms consist of the zeros and the xed points of the considered problems in which one operator is replaced with its resolvent and a viscosity term is added. Strong convergence of the algorithms are shown. As special cases, we can approach to the minimum norm common element of the zero of the sum of two monotone operators and the xed point of a nonexpansive mapping without using the metric projection. Some applications are included.

۴Copper and Nickel Recovery from Electroplating Sludge by the Process of Acid–leaching and Electro–depositing
نویسنده(ها): ، ، ، ، ، ،
اطلاعات انتشار: International Journal Of Environmental Research، پنجم،شماره۳، Summer ۲۰۱۱، سال
تعداد صفحات: ۸
In this work, we developed a method which combined the processes of acid–leaching, ammonium jarosite precipitating and electro–depositing to recover copper and nickel from electroplating sludge. Residual sludge from an electroplating plant located in Qingdao was used for acid–leaching, and more than 95% of copper, nickel, zinc, chromium and iron were extracted from the sludge. After acid–leaching, the extracted solution was put into an electrolytic cell for copper recovery by electro–depositing process, and about 95% of copper was recovered under the optimized operation parameters such as cell voltage, pH and electrode material. After copper recovery, the extracted solution was treated with ammonium jarosite precipitating process. About 99% of chromium and iron could be deposited as chromium ferrite in this process. Finally, the left solution was treated with electro–depositing process again for nickel recovery, and about 57% of nickel could be recovered in this process under the condition of pH 5.5 and voltage 5.5V.

۵Copper and Nickel Recovery from Electroplating Sludge by the Process of Acid–leaching and Electro–depositing
نویسنده(ها): ، ، ، ، ، ،
اطلاعات انتشار: International Journal Of Environmental Research، پنجم،شماره۳، Summer ۲۰۱۱، سال
تعداد صفحات: ۸
In this work, we developed a method which combined the processes of acid–leaching, ammonium jarosite precipitating and electro–depositing to recover copper and nickel from electroplating sludge. Residual sludge from an electroplating plant located in Qingdao was used for acid–leaching, and more than 95% of copper, nickel, zinc, chromium and iron were extracted from the sludge. After acid–leaching, the extracted solution was put into an electrolytic cell for copper recovery by electro–depositing process, and about 95% of copper was recovered under the optimized operation parameters such as cell voltage, pH and electrode material. After copper recovery, the extracted solution was treated with ammonium jarosite precipitating process. About 99% of chromium and iron could be deposited as chromium ferrite in this process. Finally, the left solution was treated with electro–depositing process again for nickel recovery, and about 57% of nickel could be recovered in this process under the condition of pH 5.5 and voltage 5.5V.

۶Distribution and Fractions of Phosphorus and Nitrogen in Surface Sediments from Dianchi Lake China
نویسنده(ها): ، ، ، ، ، ، ، ، ، ، ،
اطلاعات انتشار: International Journal Of Environmental Research، ششم،شماره۱، Winter ۲۰۱۲، سال
تعداد صفحات: ۱۴
Dianchi Lake is one of the most three seriously eutrophic lakes in China. In the present study, the phosphorus (P) and nitrogen (N) fractions in 37 surface sediments samples collected in the Dianchi Lake were investigated. The total phophorus (TP) in sediments was divided into two parts: inorganic P (IP) and residual P (Res–P). The results showed that the total phosphorus content in surface sediments ranged from 1465.27 to 3650.12 mg\kg, IP was the major component of TP and the Ca bound P was the main fraction of IP. The bio–available phosphorus (BAP) in Dianchi Lake was first estimated in this study. BAP ranged from 215.66 to 678.02 mg\kgand the mean concentration was 382.78±89.77 mg\kgfor all 37 samples. The nitrogen fractions for the whole Dianchi Lake were firstly studied. It was shown that the sediment had been an important N nutrient source of the water, owing to the high content of transferable nitrogen forms in the sediment.

۷Dynamics of Ecosystem Service Value Caused by Land use Changes in Manas River of Xinjiang, China
نویسنده(ها): ، ، ، ، ، ، ، ،
اطلاعات انتشار: International Journal Of Environmental Research، ششم،شماره۲، Spring ۲۰۱۲، سال
تعداد صفحات: ۱۰
This study aims to quantify the impacts of land use changes on ecosystem service value during large scale land development, and to provide key information for both economic development and policy makers for eco–environmental protection. The study area locates in Manas river watershed which is a typical land development region in northwest China. Landsat MSS\TM\ETM+ images in 1976, 1989, 1999 and 2008 were applied to estimate ecosystem service value based on land use, and subsequently ecosystem service value dynamics were analyzed in response to land use changes. It is found that the built–up area and cultivated land increased significantly from 1976 to 2008. The decreasing ecosystem service value (from 17362.2 million Yuan in 1976 to 16975.0 million Yuan in 2008) is mainly caused by the reduced grassland. The combined ecosystem service value of water body and grassland is over 60% of the total value. Functions of water supply, waste treatment, soil formation and retention and biodiversity protection contributed to over 70% of the total service value. The results suggest that a reasonable land use plan should emphasize protection of water body, woodland and grassland as they have the highest ecosystem service value.

۸Effect of Alternative Electrolytes on Enhanced Electrokinetic Remediation of Hexavalent Chromium in Clayey Soil
نویسنده(ها): ، ، ، ، ،
اطلاعات انتشار: International Journal Of Environmental Research، هفتم،شماره۱، Winter ۲۰۱۳، سال
تعداد صفحات: ۱۲
Hexavalent chromium is mobile and hazardous in the environment. Electrokinetic remediation of chromium (IV)–contaminated soils is intended either to remove or to reduce Cr (VI) to Cr (III). This study examines the effectiveness of utilizing EDTA and acetic acid solutions as alternative electrolytes in the electrokinetic (EK) process, with coupled nano–scale zero–valent iron (nZVI) as a barrier for the remediation of Cr (VI)–contaminated clay. An nZVI barrier was installed adjacent to the anode, and different electrolyte solutions (0.1 M EDTA and 1 M acetic acid) were used to investigate the effect of both on the electrokinetic remediation efficiency. Soil was contaminated to 300 ppm of Cr (IV), and a constant DC voltage gradient of 1 V\cm was applied to the soil sample for 72 h. It was found that an nZVI permeable reactive barrier (PRB)could improve the Cr (VI) remediation efficiency and reduce electrical energy consumption. Results also showed that acetic acid as electrolyte promoted the reduction of Cr (VI) to Cr (III), while EDTA application as electrolyte led to more chromium removal and reduction than an EK–nZVI barrier.

۹Effect of Fiber Surface Treatment on Wear Characteristics of Carbon Fiber Reinforced Polyamide 6
نویسنده(ها): ،
اطلاعات انتشار: Iranian Journal of Chemistry and Chemical Engineering (IJCCE)، بيست و نهم،شماره۱(پياپي ۵۳)، ۲۰۱۰، سال
تعداد صفحات: ۱۵
Ozone modification method and air–oxidation were used for the surface treatment of polyacrylonitrile(PAN)–based carbon fiber. The surface characteristics of carbon fibers were characterized by X–ray photoelectron spectroscopy (XPS). The interfacial properties of carbon fiber reinforced polyamide 6 (CF\PA6) composites were investigated by means of the single fiber pull–out tests. As a result, it was found that IFSS values of the composites with ozone treated carbon fiber are increased by 60% compared to that without treatment. XPS results show that ozone treatment increases the amount of carboxyl groups on carbon fiber surface, thus the interfacial adhesion between carbon fiber and PA6 matrix is effectively promoted. The effect of surface treatment of carbon fibers on the tribological properties of CF\PA6 composites was comparatively investigated. Experimental results revealed that surface treatment can effectively improve the wear resistance of CF\PA6 .

۱۰Conversion of Sawdust into 5–Hydroxymethylfurfura by Using 1,3–Dimethyl–2–Imidazolidinone as the Solvent
نویسنده(ها): ، ، ، ، ، ، ، ، ، ، ، ، ، ، ،
اطلاعات انتشار: Iranian Journal of Chemistry and Chemical Engineering (IJCCE)، سي و دوم،شماره۳(پياپي ۶۷)، ۲۰۱۳، سال
تعداد صفحات: ۶
The conversion of the cellulose into 5–HMF would experience three steps, cellulose to glycose, glycose to fructose and fructose to 5–HMF. Chloride ion can break down the hydrogen bond in cellucose, chromium can catalyze the isomerization of glycose to fructose, and the high temperature is helpful to cyclohydration of fructose to 5–HMF. In this paper, the sawdust has been directly degraded into 5–HMF in 1,3–dimethyl–2–imidazolidinone (DMI) solvent containing alkali halides or ionic liquid with chromium(III) as the catalyst. The factors including the reaction temperature, reaction time, amount of catalyst and liquid–solid ratio, are investigated. The results indicate that the additive —— alkali halides plays an important role in the degradation of sawdust, for example that NaCl and KCl give rise to 28% (140°C) and 25.5% (120°C) of the final yield calculated on m(5–HMF)\m(sawdust), respectively.

۱۱Some Results on Necessary Conditions for Tow Quasidifferentiable Optimization Problems (انگلیسی)
نویسنده(ها): ، ، ، ، ،
اطلاعات انتشار: دو فصلنامه تحقيق در عمليات، اول،شماره۲، ۲۰۰۹، سال
تعداد صفحات: ۱۱

۱۲An Efficient Procedure for the Production of trans–4–Hydroxy–L–proline Using Recombinantly Expressed Proline Hydroxylase
اطلاعات انتشار: Scientia Iranica، بيست و دوم،شماره۶، ۲۰۱۵، سال
تعداد صفحات: ۸
Due to the codon usage and high G+C contentof thetrans–4–proline–L–hydroxylase gene from the Dactylosporangium sp.strain RH1, the whole gene was optimized and cloned into several vectors for expression. In biotransformations with resting cells, the activity of the enzyme was investigated. The in–house modified plasmid pet–M–3C was found to yield the highest enzymatic activity. Additionally, after the primary fragment screening, the conversion efficiency of fragment 1–257 aa was enhanced from 76.60% to 88.97% compared with the full–length proline 4–hydroxylase within 60 h; we also found that truncation of the gene improved the solubility of the encoded protein.After optimizing the various induction conditions with respect to the enzymatic activity of the engineered strain, including the concentration of the inducer IPTG, the cell density before the inducer was added, the induction temperature and the induction time, the conversion efficiency was more than 97%within 48 h.
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