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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.

Inertial Frame Independent Forcing for Discrete Velocity Boltzmann Equation:Implications for Filtered Turbulence Simulation

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Communications in Computational Physics 2012年第8期12卷 732-766页

作者： Kannan N.Premnath Sanjoy banerjee Department of Mechanical Engineering University of WyomingLaramieWY 82071USA Department of Chemical Engineering City College of New YorkCity University of New YorkNew YorkNY 10031USA.

We present a systematic derivation of a model based on the central moment lattice Boltzmann equation that rigorously maintains Galilean invariance of forces to simulate inertial frame independent flow *** this regard,the central moments,*** shifted by the local fluid velocity,of the discrete source terms of the lattice Boltzmann equation are obtained by matching those of the continuous full Boltzmann equation of various *** results in an exact hierarchical identity between the centralmoments of the source terms of a given order and the components of the central moments of the distribution functions and sources of lower *** corresponding source terms in velocity space are then obtained from an exact inverse transformation due to a suitable choice of orthogonal basis for ***,such a central moment based kinetic model is further extended by incorporating reduced compressibility effects to represent incompressible ***,the description and simulation of fluid turbulence for full or any subset of scales or their averaged behavior should remain independent of any inertial frame of ***,based on the above formulation,a new approach in lattice Boltzmann framework to incorporate turbulence models for simulation of Galilean invariant statistical averaged or filtered turbulent fluid motion is discussed.

关键词： Lattice Boltzmann method central moments Galilean invariance turbulence filtering

Relativistic compact stars with charged anisotropic matter

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Chinese Physics C 2018年第5期42卷 104-116页

作者： S.K.Maurya Ayan banerjee Phongpichit Channuie Department of Mathematical & Physical Sciences College of Arts & Science University of Nizwa Department of Mathematics Faculty of Applied Sciences Durban University of Technology School of Science Walailak University

In this article, we perform a detailed theoretical analysis of new exact solutions with anisotropic fluid distribution of matter for compact objects subject to hydrostatic equilibrium. We present a family solution to the Einstein-Maxwell equations describing a spherically symmetric, static distribution of a fluid with pressure *** implement an embedding class one condition to obtain a relation between the metric functions. We generalize the properties of a spherical star with hydrostatic equilibrium using the generalised Tolman-Oppenheimer-Volkoff(TOV)equation. We match the interior solution to an exterior Reissner-Nordstr?m one, and study the energy conditions,speed of sound, and mass-radius relation of the star. We also show that the obtained solutions are compatible with observational data for the compact object Her X-1. Regarding our results, the physical behaviour of the present model may serve for the modeling of ultra compact objects.

关键词： Class I spacetime exact solutions compact objects electromagnetic mass models

A new protocol for concurrently allocating licensed spectrum to underlay cognitive users

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Digital Communications and Networks 2018年第3期4卷 200-208页

作者： Sabyasachi Chatterjee Prabir banerjee Mita Nasipuri Department of Electronics and Communication Engineering Heritage Institute of Technology Kolkata India Department of Computer Science Engineering Jadavpur university Kolkata India

Cognitive radio technology makes efficient use of the valuable radio frequency spectrum in a non-interfering manner to solve the problem of spectrum scarcity. This paper aims to design a scheme for the concurrent use of licensed frequencies by Underlay Cognitive Users （UCUs）. We develop a new receiver-initiated Medium Access Control （MAC） protocol to facilitate the selections of alternative reliable carrier frequencies. A circuit is designed to establish reliable carrier selections based on the Received Signal Strength Indicator （RSSI） at the receiving end. Based on both packet-level simulations and various performance parameters, a comparison is carried out among conventional techniques, including the Multiple Access with Collision Avoidance （MACA） and MACA by invitation（MACA-BI） techniques, and our scheme. The simulated results demonstrate that when conventional techniques are used, the system overhead time increases from 0.5 s on the first attempt to 16.5 s on the sixth attempt. In the proposed scheme under the same failure condition, overhead time varies from 0.5 s to 2 s. This improvement is due to the complete elimination of the exponential waiting time that occurs during failed transmissions. An average efficiency of 60% is achieved with our scheme while only 43% and 34% average efficiencies are achieved with the MACA and MACA-BI techniques, respectively. The throughput performance of our scheme on the fourth attempt is 7 Mbps, whereas for the MACA and MACA-BI protocols, it is 1.9 Mbps and 2.2 Mbps respectively.

关键词： Exponential back-off time Interference temperature limit Medium-access control protocol Received signal strength indicator Underlay cognitive user