مقالههای Afzal Karimi
توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقالههای نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده میشوند.
۱Production of biodegradable polyster (PHA) from wastewater of olive oil mills by recombinant microorganisms
اطلاعات انتشار: اولین سمینار تخصصی محیط زیست و رنگ، سال ۱۳۸۲
تعداد صفحات: ۷
This study demonstrated that microorganisms could recycle waste organic molecules to commercially useful and environmentally innocuous products, such as poly – hydrozyalkanoatcs (PHA), and simultaneously treat wastewater effectively to meet discharge standard . the nutritionallu vcrsatile pseudomonas putida had showed to grow in olive waste water celled “alpechina” which is toxic many other microorganisms. The transformation with the plasmid Psk 2665 , Harboring alcaligenes eutrophus genes needed for synthesis of poly (3– hidroxybutiric acid ) allow pscudomonas strain to grow in high concentration of the wastewater “alpachino”accumulating biofegradable thermoplastic.<\div>
اطلاعات انتشار: هفتمین کنفرانس دانشجویی مهندسی مکانیک، سال ۱۳۹۲
تعداد صفحات: ۴
Two–inlet one–outlet stirred tanks are widely used in both small and large scale industries especially for dilution purposes. In this study, a computational fluiddynamics (CFD) model for simulation of a stirred tank was developed and evaluated experimentally. Two fluid flows with different physical properties were enteredinto a tank stirred by a six–blade turbine impeller. Multiple Reference Frame (MRF) technique and standard k–ε turbulence model in steady state form wereutilized to model fluids agitation in the tank. A user defined function (UDF) was also implemented fordefining flow viscosity. Moreover, unsteady state formwas used to analyze residence time distribution (RTD) in the tank. The simulation showed a successful andcomplete mixing of two flows corresponding to different inlets. Results demonstrated operational effects of turbine impeller on the fluid flow. Impeller forcedflows vigorously toward the tank walls and after stroke with walls, flows changed suddenly their rout and moved upward or downward; these violent motionsdeveloped a well–mixed pattern and consequently caused two fluids to be dispersed in the tank. In addition, RTD analysis proved that increase in impellerspeed makes the mixing process closer to the perfect agitation and reduces residence time discrepancies ofdifferent paths of fluids. This study makes it easier to understand flow behavior in two–inlet one–outlet stirred tanks and provides engineers with supplementary scale up information.<\div>
اطلاعات انتشار: اولین کنفرانس بین المللی مهندسی محیط زیست، سال ۱۳۹۳
تعداد صفحات: ۹
Biodiesel is a fuel of renewable origin, that can be used efficiently in common petrodiesel engines with no need for further changes in engine structure. This fuel can be produced in many ways, from which the enzymatic transesterification has been proved to be more efficient. The only barrier of this method is the industrializing this method through novel reactor designs. In this study, Impinging Jet Reactor (IJR) has been used as an efficient way to produce biodiesel from sunflower oil. The reaction was carried out at various oil\methanol molar ratios and water contents to get the best operational condition of IJR. The results of IJR were also compared with the corresponding results of reaction taking place in shaker, which showed higher efficiency of IJR.<\div>
۴Decolorization of Maxilon–Red by Kissiris Immobilized Phanerochaete Chrysosporium in a Trickle–Bed Bioreactor–Involvement of Ligninolytic Enzymes
نویسنده(ها): Afzal Karimi
اطلاعات انتشار: Iranian Journal of Chemistry and Chemical Engineering (IJCCE)، بيست و هشتم،شماره۲(پياپي ۵۰)، ۲۰۰۹، سال ۰
تعداد صفحات: ۱۴
The decolorization of Maxilon–red dye by Kissiris immobilized Phanerochaete chrysosporium in the trickle–bed reactor (TBR) using the basal nitrogen–limited growth medium was studied. The influence of the superficial liquid velocity (SLV) on the decolorizing ability of the fungus was examined at four SLVs (cm sec–1): 0.05, 0.075, 0.1, and 0.15. Maximum level of the decolorizing activity was about 94 % by day 4–5 of the process when the TBR operated at SLV=0.075 to 0.1 cm sec–1. At these SLVs, the maximum activities of the lignin peroxidase (LiP) and the manganese peroxidase (MnP) were (UL–1): 87 and 207, respectively. In a successive decolorization of the tested dye in a continuous dye addition in the TBR when glucose level decreased to 2 gL–1, significant reduction in the characteristics of the interest were observed. While by controlling the glucose concentration, these properties were improved considerably: The decolorizing ability of the Kissiris immobilized mycelia was more than 85 % after nearly 20 days of the process while the maximum activities of the LiP and the MnP were (UL–1): 320 and 151, respectively. Considerable levels of the enzyme activities were detected by day 19 and after 11 times of the dye additions.
نویسنده(ها): Mojtaba Ahmadi، Mohammad Rezvani، Shabnam Shoa Bargh، Mohammad Sadegh Shakeri، Afzal Karimi
اطلاعات انتشار: journal of advanced materials and processing، اول،شماره۴، ۲۰۱۳، سال ۰
تعداد صفحات: ۹
Microporous glass ceramic with skeleton of CaTi4(PO 4)6 with average pore size of 12.7 nm has been synthesized and used as a carrier of glucose oxidase. The glass ceramic was prepared by controlled heat treatment of glass samples, which causes the phase separation in their structure and creates CaTi4(PO 4)6 and β–Ca3(PO4)2 phases. The β–Ca3(PO4)2 phase was dissolved by soaking the glass ceramics in HCl and CaTi4(PO 4)6 built the skeleton of microporous glass ceramic. Analysis of the ability of the carrier for immobilization of glucose oxidase (GOx) was undertaken. Average amount of immobilized enzyme and percentage of enzyme activity on the carrier were 27 gr GOx\gr carrier and 60.15%, respectively. Effect of pH and temperature variations on the enzyme activity has been studied and results demonstrated that maximum activity for both free and immobilized enzyme was at T=40˚C and pH=7.0. Due to the same value of maximum activity, no serious conformational change of enzyme had taken place through immobilization. However, immobilization of GOx on CTP caused to considerable increase of enzyme stability under different environmental conditions.
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