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Comparative study of polyhydroxyalkanoates production from acidified and anaerobically treated brewery wastewater using enriched mixed microbial culture

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Journal of Environmental Sciences 2019年第4期31卷 137-146页

作者： Pravesh Tamang Rintu banerjee Stephan K?ster Regina Nogueira Institute for Sanitary Engineering and Waste Management Leibniz Universitat Hannover Welfengarten 1D-30167 HannoverGermany Indian Institute of Technology Kharagpur Department of Agricultural and Food Engineering721302 KharagpurIndia

The production of polyhydroxyalkanoates(PHA) from wastewaters using microbial mixed cultures(MMC) has been attracting increased interest because of PHA's biodegradability characteristics. Production of PHA by an MMC enriched with PHA-accumulating bacteria was compared using anaerobically treated and acidified brewery wastewaters under various feeding strategies, namely pulse and batch feed addition. To obtain an enriched MMC, a sequencing batch reactor was inoculated with activated sludge fed with acetate and subjected to aerobic dynamic feeding. The enriched MMC was able to accumulate PHA up to 72.6% of cell dry weight(CDW) with pulse addition of acetate controlled by the dissolved oxygen(DO) concentration in the reactor. In a batch accumulation experiment with acetate,the PHA content achieved(28.5% CDW) was less than that of the pulse feeding strategy with the same amount of acetate(～2000 mg C/L). Using anaerobically treated and acidified brewery wastewater fed in pulses, the maximum PHA accumulated by the enriched MMC was similar for both wastewaters(45% CDW), in spite of the higher volatile fatty acid concentration in acidified brewery wastewater. The pulse feed addition controlled by the DO concentration was difficult to implement for wastewater as compared to acetate because the difference in DO concentration between substrate availability and depletion was low. For the batch addition of acidified wastewater, a slightly lower PHA content(39%CDW) was obtained. These results show that both brewery wastewaters can be utilized for PHA production with a similar maximum PHA storage capacity.

关键词： Polyhydroxyalkanoates PHA-accumulating bacteria Microbial mixed culture Brewery wastewater Aerobic dynamic feeding Pulse feeding and batch feeding

Cellular arsenic transport pathways in mammals

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Journal of Environmental Sciences 2016年第11期28卷 38-58页

作者： Barbara A.Roggenbeck Mayukh banerjee Elaine M.Leslie Department of Physiology and Membrane Protein Disease Research Group University of Alberta Division of Analytical and Environmental Toxicology Department of Laboratory Medicine and Pathology University of Alberta

Natural contamination of drinking water with arsenic results in the exposure of millions of people world-wide to unacceptable levels of this metalloid. This is a serious global health problem because arsenic is a Group 1（proven） human carcinogen and chronic exposure is known to cause skin, lung, and bladder tumors. Furthermore, arsenic exposure can result in a myriad of other adverse health effects including diseases of the cardiovascular,respiratory, neurological, reproductive, and endocrine systems. In addition to chronic environmental exposure to arsenic, arsenic trioxide is approved for the clinical treatment of acute promyelocytic leukemia, and is in clinical trials for other hematological malignancies as well as solid tumors. Considerable inter-individual variability in susceptibility to arsenic-induced disease and toxicity exists, and the reasons for such differences are incompletely understood. Transport pathways that influence the cellular uptake and export of arsenic contribute to regulating its cellular, tissue, and ultimately body levels. In the current review, membrane proteins（including phosphate transporters, aquaglyceroporin channels, solute carrier proteins, and ATP-binding cassette transporters） shown experimentally to contribute to the passage of inorganic, methylated, and/or glutathionylated arsenic species across cellular membranes are discussed. Furthermore, what is known about arsenic transporters in organs involved in absorption, distribution, and metabolism and how transport pathways contribute to arsenic elimination are described.

关键词： Arsenic Glutathione Cellular uptake Cellular efflux Transport

Corrosion behavior of AZ31-WC nano-composites

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Journal of Magnesium and Alloys 2019年第4期7卷 681-695页

作者： Sudip banerjee Suswagata Poria Goutam Sutradhar Prasanta Sahoo Department of Mechanical Engineering Jadavpur UniversityKolkata 700032India Department of Mechanical Engineering Heritage Institute of TechnologyKolkata 700107India National Institute of Technology Manipur LangolImphal 795004ManipurIndia

In this study,the effects of WC nano-particles amount and surface roughness on corrosion behavior of magnesium metal matrix nanocomposites in 3.5%NaCl solution are examined with the help of electrochemical *** wt%of WC nano-particles(0.5,1,1.5 and 2)are used to fabricate metal matrix nano-composites through ultrasonic vibration assisted stir casting *** characterizations of fabricated composites are performed by using scanning electron microscopy(SEM)and energy dispersive x-ray analysis(EDAX).SEM images show that nano-particles are well distributed throughout the magnesium matrix while EDAX results confirm the presence of WC particles in ***-hardness result shows increasing trend with increasing weight percentage of *** nano-composite containing 0.5 wt%WC nano-particles is found to be the most corrosion resistive one followed by base alloy,Mg-2 wt%WC,Mg-1.5 wt%WC and Mg-1 wt%***,corrosion behavior of Mg-2WC with different surface quality is examined and it is observed that sample with lowest surface roughness shows better corrosion *** the end,corrosion mechanisms are assessed with the help of SEM and EDAX study of corroded surfaces.

关键词： Mg-WC Nano-composite Corrosion Roughness Electrochemical test

Effect of desliming on the magnetic separation of low-grade ferruginous manganese ore

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International Journal of Minerals,Metallurgy and Materials 2015年第7期22卷 661-673页

作者： Sunil Kumar Tripathy P.K.banerjee Nikkam Suresh Tata Steel Limited Hindalco Industries Limited Aditya Birla Group Indian School of Mines

In the present investigation, magnetic separation studies using an induced roll magnetic separator were conducted to beneficiate low-grade ferruginous manganese ore. The feed ore was assayed to contain 22.4% Mn and 35.9% SiO2, with a manganese-to-iron mass ratio （Mn：Fe ratio） of 1.6. This ore was characterized in detail using different techniques, including quantitative evaluation of minerals by scan- ning electron microscopy, which revealed that the ore is extremely siliceous in nature and that the associated gangue minerals are more or less evenly distributed in almost all of the size fractions in major proportion. Magnetic separation studies were conducted on both the as-received ore fines and the classified fines to enrich their manganese content and Mn：Fe ratio. The results indicated that the efficiency of separation for deslimed fines was better than that for the treated unclassified bulk sample. On the basis of these results, we proposed a proc- ess flow sheet for the beneficiation of low-grade manganese ore fines using a Floatex density separator as a pre-concentrator followed by two-stage magnetic separation. The overall recovery of manganese in the final product from the proposed flow sheet is 44.7% with an assay value of 45.8% and the Mn：Fe ratio of 3.1.

关键词： manganese ore treatment mineralogy beneficiation magnetic separation flow sheet analysis

Magnetic separation studies on ferruginous chromite fine to enhance Cr:Fe ratio

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International Journal of Minerals,Metallurgy and Materials 2015年第3期22卷 217-224页

作者： Sunil Kumar Tripathy P.K.banerjee Nikkam Suresh Research and Development Division Tata Steel Ltd. Fuel and Mineral Engineering Dept. Indian School of Mines

The Cr：Fe ratio （chromium-to-iron mass ratio） of chromite affects the production of chrome-based ferroalloys. Although the lit- erature contains numerous reports related to the magnetic separation of different minerals, limited work concerning the application of mag- netic separation to fine chromite from the Sukinda region of India to enhance its Cr：Fe ratio has been reported. In the present investigation, magnetic separation and mineralogical characterization studies of chromite fines were conducted to enhance the Cr：Fe ratio. Characterization studies included particle size and chemical analyses, X-ray diffraction analysis, automated mineral analysis, sink-and-float studies, and mag- netic susceptibility measurements, whereas magnetic separation was investigated using a rare earth drum magnetic separator, a rare earth roll magnetic separator, an induced roll magnetic separator, and a wet high-intensity magnetic separator. The fine chromite was observed to be upgraded to a Cr：Fe ratio of 2.2 with a yield of 55.7% through the use of an induced roll magnetic separator and a feed material with a Cr：Fe ratio of 1.6.

关键词： chromite ore treatment magnetic separation characterizafion mineral processing industry

Large signal and noise properties of heterojunction Al_xGa_(1-x)As/GaAs DDR IMPATTs

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Journal of Semiconductors 2016年第6期37卷 52-59页

作者： suranjana banerjee monojit mitra Indian Institute of Engineering Science and Technology Shibpur WB 711113 India

Simulation studies are carried out on the large signal and noise properties of heterojunction（HT）Al_xGa_（1-x）As/GaAs double drift region（DDR） IMPATT devices at V-band（60 GHz）.The dependence of Al mole fraction on the aforementioned properties of the device has been investigated.A full simulation software package has been indigenously developed for this *** large signal simulation is based on a non-sinusoidal voltage excitation *** mole fractions of Al and two complementary HT DDR structures for each mole fraction i.e.,six DDR structures are considered in this *** purpose is to discover the most suitable structure and corresponding mole fraction at which high power,high efficiency and low noise are obtained from the *** noise spectral density and noise measure of all six HT DDR structures are obtained from a noise model and simulation *** studies are carried out on homojunction（HM） DDR GaAs IMPATTs at 60 GHz to compare their RF properties with those of HT DDR *** results show that the HT DDR device based on N-Al_xGa_（1-x）As/p-GaAs with 30%mole fraction of Al is the best one so far as large signal power output,DC to RF conversion efficiency and noise level are concerned.

关键词： heterojunction AlxGa1-xAs/GaAs mole fraction DDR IMPATTS

Pressure Drop of Non-Newtonian Liquid Flow Through Elbows

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Chinese Journal of Chemical Engineering 2000年第4期8卷 388-390页

作者： T.K.banerjee S.K.DAS Chemical Engineering Department University of Calcutta92A.P.C.RoadCalcutta-700 009IndiaChemical Engineering DepartmentUniversity of Calcutta92A.P.C.RoadCalcutta-700 009India

Experimental data on the pressure drop across different types of elbow for non-Newtonian pseudoplastic liquid flow in laminar condition have been presented. A generalized correlation has been developed for predicting ... 详细信息

关键词： non-Newtonian liquid pseudoplastic elbow

Transmission dynamics of depression in socially connected population: A nonlinear modeling study

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International Journal of Modeling, Simulation, and Scientific Computing 2021年第5期12卷 162-177页

作者： Abhinav Tandon Arti Mishra Sankha banerjee Department of Mathematics Birla Institute of Technology Mesra Ranchi-835215 JharkhandIndia

Human emotions are considered to be contagious that can be transmitted from one person to another during social ***,interaction with people having excessive negative emotions may make other people *** this aspect into consideration,a SIR nonlinear model is formulated to investigate the transmission dynamics of depression in social *** qualitative analysis of the model,critical value of depression is *** equilibria,*** free and depression state,are obtained and their stability behaviors are *** stability analysis reveals the fact that both the equilibria are locally and globally stable,depending on critical value of *** sensitivity analysis of crucial parameters of critical value of depression is performed to point out the key parameters that can drastically influence the propagation of *** results demonstrate the importance of counselling for depressed persons in order to suppress the growth of depression in social *** model calibration has been done for the annual depression cases of *** results of our study show that individuals will catch major depression disorders more quickly once they get initially(primary)*** this,counselling rate for primary depressed population should be increased.

关键词： SIR model depression stability sensitivity analysis model calibration

Global dynamics of hepatitis C viral infection with logistic proliferation

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International Journal of Biomathematics 2016年第4期9卷 121-145页

作者： Sandip banerjee Ram Keval Sunita Gakkhar Department of MathematicsIndian Institute of Technology Roorkee Roorkee 247667 Uttarakhand India Department of Mathematics Keshav MahavidyalayaUniversity of Delhi Pitampura Delhi 110034 India

A modified mathematical model of hepatitis C viral dynamics has been presented in this paper, which is described by four coupled ordinary differential equations. The aim of this paper is to perform global stability analysis using geometric approach to stability, based on the higher-order generalization of Bendixson＇s criterion. The result is also supported numerically. An important epidemiological issue of eradicating hepatitis C virus has been addressed through the global stability analysis.

关键词： Hepatitis C virus (HCV) global stability geometric approach Lozinskiimeasure.