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International Journal of Minerals,Metallurgy and Materials 2015年第3期22卷 225-232页

作者： Ritayan Chatterjee Shamik chaudhuri Saikat Kumar Kuila Dinabandhu Ghosh Department of Metallurgical and Materials Engineering Jadavpur University Division of Materials Engineering Lund University

The structural and morphological characterizations of a chalcopyrite concentrate, collected from the Indian Copper Complex, Ghatshila, India, were carried out by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The con- centmte powder was composed mainly of free chalcopyrite and low quartz in about 3：1 weight ratio. The particle size was about 100 μm. Spectroscopic studies （FTIR, Raman, UV-visible） of the concentrate supported the XRD findings, and also revealed a marginal oxidation of the sulfide phase. The energy band gap of the sulfide was found to be 3.4 eV. Differential thermal analysis and thermogravimetry of the con- centrate showed a decomposition of chalcopyrite at 658 K with an activation energy of 208 kJ-mol 1, and two successive structural changes of silica at 848 K and 1145 K.

关键词： chalcopyrite structural properties microstructure thermal characteristics

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

Creeping Tiger,Soaring Dragon:India,China and Competition in Information Technologies

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China & World Economy 2012年第6期20卷 1-28页

作者： Anindya chaudhuri National Institute of Science Technology & Development Studies

Although conventional international economic wisdom holds China ＇s hardware and India ＇s software industries to be equipotential, little attempt has been made to compare their information industries in an overarehing dynamic framework. Using a schema that links intellectual to financial value creation, it is found that China has systematically moved ahead in creating a self-supporting industrial and innovation ecosystem. Hardware enjoys higher barriers to entry, which the Chinese companies are increasingly reinforcing with intellectual property investments. In addition to being better integrated with the global economy, they are also buttressed by the huge domestic market. The overdependence of Indian firms on selling low-value services to a few countries and insulation from domestic demand make them vulnerable to emerging competition and international economic ill-winds. The two countries provide a study in contrast on the effects of divergent industrial strategies.

关键词： China India information technology innovation

Effects of threshold based relay selection algorithms on the performance of an IEEE 802.16j mobile multi-hop relay （MMR） WiMAX network

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Digital Communications and Networks 2018年第1期4卷 58-68页

作者： chaudhuri Manoj Kumar Swam Susmita Das Signal Processing and Communication Laboratory Department of Electrical Engineering National Institute of Technology Rourkela 769008 India

IEEE 802.16j MMR WiMAX network introduces multi-hop relay architecture, which involves cooperative relay stations focusing on increasing the network throughput and coverage. Relay selection algorithms can be used to choose the optimal relay, which help in reducing the computational complexity during the signal processing operation of the wireless network. In this research work, a conventional Amplify-Forward （AF）/Decode-Forward （DF） assisted multi-relay IEEE 802.16j WiMAX network is considered. The effects of relay selection algorithms on the performance metrics such as Symbol Error Rate （SER） and channel capacity are investigated in detail through simulation-based study. Further, the performance of this network utilizing the proposed relay selection algo- rithms, namely threshold based max_rain and threshold based harmonic mean of SNR, are compared with the existing max_rain and harmonic mean of SNR based algorithms. Standard diversity combining techniques such as Maximal Ratio Combining （MRC） and Selection Combining （SC） are used for combining the transmitted signal at the receiver. In addition, the impact of relay locations on the performance metrics are explored. It is observed that both the proposed threshold based max_min and threshold based harmonic mean of SNR based relay selection algorithms outperform the max_rain and harmonic mean of SNR based algorithms, as both the SER and channel capacity for the considered multi-relay WiMAX network is improved significantly. Further, this extensive study and analysis will be beneficial for the design of MMR WiMAX networks.

关键词： WiMAX Amplify-forward Decode-forward Selection combining MRC

A supply chain model with two competitive buyers under a hybrid greening cost and revenue-sharing contract

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Journal of Management Analytics 2023年第2期10卷 270-307页

作者： Biswarup Samanta Bibhas CGiri Kripasindhu chaudhuri Department of Mathematics Jadavpur UniversityKolkataIndia

This article considers a vendor-buyer supply chain model where a single vendor produces a single product and markets it through two competitive buyers to a group of *** customer demand for the product depends on the selling price,green level and warranty period of the *** deliveries from the vendor are scheduled at a fixed time interval wherein the subsequent shipments appear when each of the buyer’s inventories from the former delivery has just been cleared out.A hybrid greening cost and revenue sharing(HGRS)contract is introduced,which provides more profit to individual members than their decentralised *** numerical study reveals that,under the HGRS contract,customers are influenced to buy a more reliable product at a reasonable price with a higher green level.A sensitivity analysis is also carried out to examine the impact of key model parameters on the optimal results.

关键词： supply chain pricing warranty greening revenue-sharing contract

Tracking sources and paleotectonic settings of Mesozoic sandstones in interlinked rift basins of western India:An integrated approach using petrography and heavy mineral chemistry

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Journal of Palaeogeography 2022年第2期11卷 173-193页

作者： Pawan Kumar Rajak Angana chaudhuri Naraga Prabhakar Santanu Banerjee Department of Earth Sciences Indian Institute of Technology BombayMumbai 400076India

Based on integration of field,petrographic and heavy mineral chemical data,this study highlights the source and tectonic setting of the Mesozoic sandstones of Kutch,Saurashtra,Narmada and Cambay basins at the western margin of India,formed by the progressive splitting of the eastern *** Kutch Basin is dominated by arkosic sandstone,whereas Saurashtra,Narmada and Cambay basins show the predominance of sub-arkose and *** modal analyses of framework grains in Kutch sandstones indicate basement uplift and transitional continent *** contrast,the sandstones of Saurashtra,Narmada and Cambay basins bear imprints of recycled orogenic and craton interior *** presence of abraded and detrital quartz overgrowth and rounded zircons in most sandstones reveal the recycling of sediments in these *** and rutile mineral compositions constrain the possible lithology of source *** tourmaline mineral chemistry(Ca-Fe_(tot)-Mg plot)suggests the derivation of sediments from various sources,including Li-poor granitoids associated with pegmatites,aplites,Ca-poor metapelites,metapsammites and quartz-tourmaline-rich granitic *** compositions of rutile grains(Cr *** plot)in sandstones indicate metapelitic *** gamut of all mineral chemical data supports the predominance of sediment sources from quartzo-feldspathic rocks with minor inputs from mafic *** on available paleocurrent data and correlation of source compositions,we infer that the Mesozoic sediments of Kutch,Saurashtra,Narmada and Cambay basins were primarily sourced by various lithologies of the Aravalli *** Narmada Basin possibly received additional sediment input from the Bundelkhand Craton.

关键词： Mesozoic sandstones Rift basins Tourmaline chemistry Rutile chemistry Kutch Basin Saurashtra Basin Cambay Basin Narmada Basin

Deep Neural Network Based Detection and Segmentation of Ships for Maritime Surveillance

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Computer Systems Science & Engineering 2023年第1期44卷 647-662页

作者： Kyamelia Roy Sheli Sinha chaudhuri Sayan Pramanik Soumen Banerjee Department of Electronics and Tele-Communication Engineering Jadavpur UniversityKolkata700032India Department of Electronics and Communication Engineering University of Engineering and ManagementKolkata700160India

In recent years,computer visionfinds wide applications in maritime surveillance with its sophisticated algorithms and advanced ***-matic ship detection with computer vision techniques provide an efficient means to monitor as well as track ships in water *** being an important medium of transport require continuous monitoring for protection of national *** remote sensing satellite images of ships in harbours and water bodies are the image data that aid the neural network models to localize ships and to facilitate early identification of possible threats at *** paper proposes a deep learning based model capable enough to classify between ships and no-ships as well as to localize ships in the original images using bounding box ***,classified ships are again segmented with deep learning based auto-encoder *** proposed model,in terms of classification,provides suc-cessful results generating 99.5%and 99.2%validation and training accuracy *** auto-encoder model also produces 85.1%and 84.2%validation and training *** the IoU metric of the segmented images is found to be of 0.77 *** experimental results reveal that the model is accu-rate and can be implemented for automatic ship detection in water bodies consid-ering remote sensing satellite images as input to the computer vision system.

关键词： Auto-encoder computer vision deep convolution neural network satellite imagery semantic segmentation ship detection

Effect of anisotropy on thermoelastic contact problem

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Applied Mathematics and Mechanics(English Edition) 2008年第4期29卷 501-510页

作者： Sakti Pada Barik M.Kanoria P.K.chaudhuri Departmemt of Mathematics Gobardanga Hindu CollegeKhantura24-Parganas(N)West BengalIndia Department of Applied Mathematics University of Calcutta92A.P.C.RoadKolkata-700009India

This paper is concerned with the stationary plane contact of an insulated rigid punch and a half-space which is elastically anisotropic but thermally conducting. The frictional heat generation inside the contact region due to the sliding of the punch over the half-space surface and the heat radiation outside the contact region are taken into account. With the help of Fourier integral transform, the problem is reduced to a system of two singular integral equations. The equations are solved numerically by using Gauss-Jacobi and trapezoidal-rule quadratures. The effects of anisotropy and thermal effects are shown graphically.

关键词： transversely isotropic medium Fourier transform frictional heating punch heat radiation singular integral equation Fredholm integral equation

A review of stress concentration factors in tubular and non-tubular joints for design of offshore installations

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Journal of Ocean Engineering and Science 2016年第3期1卷 186-202页

作者： Dikshant Singh Saini Debasis Karmakar Samit Ray-chaudhuri Department of Civil Engineering Indian Institute of Technology KanpurKanpurUP 208016India

Tubular structures are widely used in offshore installations,trusses,high rise buildings,towers for wind turbines,ski-lift installations,lightning,road pole signals etc.,owing to their excellent structural performance and attractive *** concentration,especially in the welded joints of these structures,is an important design consideration particularly for fatigue *** the context of tubular and non-tubular joints,this paper provides a review of the experimental and numerical studies that have been carried out so far to determine the stress concentration factor(SCF).Emphasis is also placed on the complexity of capturing different types of stresses in tubular/non-tubular joints for estimation of *** code provisions for evaluation of SCF are also ***,a few issues,which require significant research effort to advance our understanding and to improve the current design guidelines,have been identified.©2016 Shanghai Jiaotong *** by Elsevier B.V.

关键词： Hot-spot stress Stress concentration factor(SCF) Fatigue Tubular joints Non-tubular joints

Kinetic studies on the reduction of iron ore nuggets by devolatilization of lean-grade coal

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International Journal of Minerals,Metallurgy and Materials 2016年第12期23卷 1360-1368页

作者： Chanchal Biswas Prithviraj Gupta Arnab De Mahua Ghosh chaudhuri Rajib Dey Department Metallurgical and Material Engineering Jadavpur University Department of Metallurgy and Materials Engineering Indian Institute of EngineeringScience & Technology School of Materials Science and Nano Technology Jadavpur University

An isothermal kinetic study of a novel technique for reducing agglomerated iron ore by volatiles released by pyrolysis of lean-grade non-coking coal was carried out at temperature from 1050 to 1200℃ for 10-120 min. The reduced samples were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and chemical analysis. A good degree of metallization and reduction was achieved. Gas diffusion through the solid was identified as the reaction-rate-controlling resistance; however, during the initial period, particularly at lower temperatures, resistance to interfacial chemical reaction was also significant, though not dominant. The apparent rate constant was observed to increase marginally with decreasing size of the particles constituting the nuggets. The apparent activation energy of reduction was estimated to be in the range from 49.640 to 51.220 kJ/mol and was not observed to be affected by the particle size. The sulfur and carbon contents in the reduced samples were also determined.

关键词： iron ore reduction coal devolatilization kinetic studies