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A Compact Quad-Band Sickle-Shaped Monopole Antenna for GSM 900/WiMax/WLAN Applications

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Computers, Materials & Continua 2022年第10期73卷 397-410页

作者： Sujit Goswami Sujit Kumar Mandal Soumen banerjee Department of Electronics and Communication Engineering National Institute of TechnologyDurgapur713213West BengalIndia Department of Electronics and Communication Engineering University of Engineering and ManagementNew TownKolkata700156West BengalIndia

In this paper a novel,compact,microstrip-fed,quad-band monopole antenna is presented for the application of Global System for Mobile communication(GSM 900),Worldwide Interoperability for Microwave Access(WiMAX)and Wireless Local Area Network(WLAN).The proposed antenna comprises of a sickle-shaped structure with four circular arc strips,and a modified rectangular ground *** four strips of the antenna are independently responsible for the four different resonant frequencies of the operating bands and can be tuned separately to control the radiation *** proposed quad-band antenna is designed to resonate at 940 MHz for GSM 900,2.5 and 3.5 GHz for WiMAX and 5.85 GHz for WLAN *** the four intended operating bands,the antenna exhibits impedance bandwidth of 60 MHz(905–965MHz),80 MHz(2.45–2.53 GHz),110 MHz(3.48–3.59 GHz)and 2.39 GHz(4.82–7.21 GHz),*** the resonance frequency of the four bands,the gain of the proposed antenna is obtained as 4.2,2.5,1.7 and 1.9 dBi,respectively.A prototype of the designed antenna is fabricated and a good agreement between simulated and measured results is ***,the proposed antenna shows good radiation characteristics and gains at all the four operating bands.

关键词： Antenna gain GSM 900 IEEE 802.11a monopole strips quad-band sickle-shaped WiMAX WLAN

Petrography of Middle Jurassic to Early Cretaceous sandstones in the Kutch Basin,western India:Implications on provenance and basin evolution

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Journal of Palaeogeography 2018年第3期7卷 239-252页

作者： Angana Chaudhuri Santanu banerjee Emilia Le Pera Department of Earth Sciences Indian Institute of Technology Bombay Dipartimento di Biologia Ecologia e Scienze della Terra University della

This paper investigates the provenance of Middle Jurassic to Early Cretaceous sediments in the Kutch Basin, western India, on the basis of mineralogical investigations of sandstones composition （Quartz-Feldspar-Lithic （QFL） fragment）, Zircon-Tourmaline-Rutile （ZTR） index, and mineral chemistry of heavy detrital minerals of the framework. The study also examines the compositional variation of the sandstone in relation to the evolution of the Kutch Basin, which originated as a rift basin during the Late Triassic and evolved into a passive margin basin by the end Cretaceous. This study analyzes sandstone samples of Jhumara, Jhuran and Bhuj Formations of Middle Jurassic, Upper Jurassic and Lower Cretaceous, respectively, in the Kutch Mainland. Sandstones record a compositional evolution from arkosic to subarkosic as the feldspar content decreases from 68% in the Jhumara Formation to 27% in the Bhuj Formation with intermediate values in the Jhuran Formation. The QFL modal composition indicates basement uplifted and transitional continental settings at source. Heavy mineral content of these sandstones reveals the occurrence of zircon, tourmaline, rutile, garnet, apatite, monazite and opaque minerals. Sub-rounded to well-rounded zircon grains indicate a polycyclic origin. ZTR indices for samples in Jhumara, Jhuran and Bhuj Formations are 25%, 30% and 50% respectively. Chemistry of opaque minerals reveals the occurrence of detrital varieties such as ilmenite, rutile, hematite/magnetite and pyrite, in a decreasing order of abundances. Chemistry of ilmenites in the Jhumara Formation reveals its derivation from dual felsic igneous and metabasic source, while those in Jhuran and Bhuj Formations indicate a metabasic derivation. Chemistry of garnet reveals predominantly Fe-rich （almandine） variety of metabasic origin. X-ray microscopic study provides the percentage of heavy minerals ranging from 3% to 5.260. QFL detrital modes reflect the evolution of the basin from an active rif

关键词： Siliciclastic provenance Tectonic setting Heavy minerals Mineral chemistry X-ray microscopy Mesozoic,Kutch Basin

Large-signal characterization of DDR silicon IMPATTs operating in millimeter-wave and terahertz regime

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Journal of Semiconductors 2013年第10期34卷 46-53页

作者： Aritra Acharyya Jit Chakraborty Kausik Das Subir Datta Pritam De Suranjana banerjee J.P.banerjee Institute of Radio Physics and Electronics University of Calcutta92APC RoadKolkata 700009India Supreme Knowledge Foundation Group of Institutions Sir J.C.Bose School of Engineering1Khan RoadMankunduHooghlyWest Bengal 712139India Academy of Technology West Bengal University of TechnologyAdisaptagramHooghly 712121West BengalIndia

The authors have carried out the large-signal characterization ofsilicon-based double-drift region （DDR） impact avalanche transit time （IMPATT） devices designed to operate up to 0.5 THz using a large-signal simulation method developed by the authors based on non-sinusoidal voltage excitation. The effect of band-to-band tunneling as well as parasitic series resistance on the large-signal properties of DDR Si IMPATTs have also been studied at different mm-wave and THz frequencies. Large-signal simulation results show that DDR Si IMPATT is capable of delivering peak RF power of 633.69 mW with 7.95% conversion efficiency at 94 GHz for 50% voltage modulation, whereas peak RF power output and efficiency fall to 81.08 mW and 2.01% respectively at 0.5 THz for same voltage modulation. The simulation results are compared with the experimental results and are found to be in close agreement.

关键词： band to band tunneling DDR silicon IMPATTs large-signal simulation millimeter-wave series resistance terahertz regime

A review on palaeogeographic implications and temporal variation in glaucony composition

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Journal of Palaeogeography 2016年第1期5卷 43-71页

作者： Santanu banerjee Udita Bansal Anup Vilas Thorat Department of Earth Sciences Indian Institute of Technology Bombay

This study presents a review on palaeogeographic implications and temporal variations of giaucony coveringboth modern and ancient records. Phanerozoic giaucony preferably forms in a shelf depositional setting. Deep marine conditions and low seawater temperature discourage formation of glaucony. Around 75% of glaucony is recorded from the Cretaceous to the Holo- eene sediments, which are related to the abundance of the most common substrates, faecal pellets and bioclasts. TFe203 （total）, A1203, K20 and MgO contents of glaucony vary appreciably through geological time. IMhile TFe203 content of most Mesozoic and Cenozoic giaucony ex- ceeds 20%, it is always less than 20% in Precambrian varieties. High K20, A1203, MgO and low TFe203 distinguish the Precambrian glaucony from its Phanerozoic counterpart. Precambrian glaucony, preferably formed within a K-feldspar substrate, is always rich in potassium irre- spective of its degree of evolution, while high K-content in Phanerozoic evolved glaucony in- dicates significant stratigraphic condensation. K20 iJs. TFe203 relationship of glaucony exhibits three different evolutionary trends corresponding to three common modes of origin. Depositional conditions may influence the composition of glaucony as slightly reducing conditions favour Fe enrichment, whereas oxidising conditions cause Fe depletion in giaucony.

关键词： Glaucony Glauconite Evolutionary trend Substrate Palaeogeography Faecal pellet

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

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

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

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