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Environmental impact of aquaculture-sedimentation and nutrient loadings from shrimp culture of the southeast coastal region of the Bay of Bengal

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Journal of Environmental Sciences 2004年第3期16卷 466-470页

作者： Biplob das Yusuf Sharif Ahmed Khan pranab das Department of Earth and Atmospheric Sciences Institute of Marine SciencesInstitute of Marine Sciences 1-26 Earth Sciences Building University of Alberta Edmonton Alberta T6G 2E3CanadaUniversity of ChittagongChittagong 4331BangladeshUniversity of ChittagongChittagong 4331Bangladesh

Nutrient loadings were measured for surface seawater and bottom sediments of semi intensive and improved extensive shrimp culture pond, adjacent estuary, and fallow land in the south east coastal region of Bangladesh during August, 2000—January, 2001 to evaluate the impact of shrimp culture. The mean levels of nutrients found in the pond surface water were 108 780 mg/L for CaCO 3, 0 526 mg/L for NH + 4 N, 3 075 wt% for organic carbon, 7 00 mg/L for pO 4 p, 5 57 mg/L for NO 3 N, and 7 33 mg/L for chlorophyll a. The maximum mean value of H 2S(0 232 mg/L) was found in estuarine water. Nutrients loading were found to be decreased with distance from the shrimp farm discharge unit in estuarine water. The mean level of organic matter, total nitrogen, and organic carbon were found in higher concentrations in sediments of cultured pond compared to bottom soil of adjacent fallow land at the same elevation. Extractable Ca values were found in higher concentration(550 33 ppt) in adjacent fallow land, as the shrimps for molting in shrimp ponds use extractable Ca. The relation between seawater H 2S value and sediment pH ( r= -0 94); sediment organic carbon and sediment pH values ( r= -0 76), sediment total nitrogen and sediment pH ( r= - 0 74) were found to be highly negatively correlated. Whereas the relation between seawater H 2S value and sediment total nitrogen ( r= 0 92), water NH + 4 N and sediment pH ( r= 0 66) were found to be positively correlated. The results revealed that load of nutrients at eutrophic level in estuarine water, and decrease of soil pH; leading to acid sulphate soil formation indicates a negative impact of shrimp culture.

关键词： environment eutrophication impact nutrients shrimp culture

Ethno-Medico-Biology of Bhadrak district, Odisha, India

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Journal of Forestry research 2013年第1期24卷 187-192页

作者： T. panda N. Mishra B. K. Tripathy p. K. das r.B.Mohanty Department of Botany S.N.CollegeRajkanikaKendrapara- 754220OdishaIndia. Department of Zoology Chandbali CollegeChandbaliBhadrak-756133OdishaIndia Department of Botany Dharmasala MohavidyalayaDharmasalaJajpurOdishaIndia Department of Botany Aul CollegeAulKendraparaOdishaIndia Department of Botany N.C.Autonomous CollegeJajpurOdishaIndia

We carried out an ethno-medico-biological investigation in the interior of Bhadrak district, Odisha, India to explore the therapeutic use of traditional plants/animals by local inhabitants. The villagers and rural people used plant and animal species as medicine. We recorded therapeutic use of 18 plant species of 13 families and 12 animal species of seven taxonomic categories. Different plant/animal parts like bark, leaf, flower, seed, stem, root, whole plant, oil, blood, milk, urine and flesh were reported as used in raw or cooked form against 17 specific diseases. prominent diseases treated by plant/animal remedies were asthma, cardiovascular ailments, diabetes, epilepsy, jaundice, malaria, skin disorder and rheumatism. This study provides a better database for future studies.

关键词： Ethnobiology folklore phytotherapy traditional knowledge zootherapy

Multiuser Detection for MIMO-OFDM system in Underwater Communication Using a Hybrid Bionic Binary Spotted Hyena Optimizer

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Journal of Bionic Engineering 2021年第2期18卷 462-472页

作者： Md rizwan Khan Bikramaditya das Department of Electronics&Telecommunication Engineering VSS University of TechnologyBurla-768018OdishaIndia

Multi Access Interference (MAI) is the main source limiting the capacity and quality of the Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) system which fulfills the demand of high-speed transmission rate and high quality of service for future underwater acoustic (UWA) communication. Multi User Detection (MUD) is needed to overcome the performance degradation caused by MAI. In this research, both local and global optimal solutions are obtained in Bionic Binary Spotted Hyena Optimizer (BBSHO) algorithm using the position Coordinate Vectors (pCVs) of the social behavior of spotted hyenas to achieve MUD. Further, Extremal Optimization (EO) is introduced in BBSHO algorithm to improve the local search ability within the search space. Hence, a hybrid BBSHO algorithm is proposed for achieving MUD at the receiver of the MIMO-OFDM system whose transceiver model in underwater is implemented using BELLHOp simulation system. By MATLAB simulation, it is shown that the Bit Error rate (BEr) performance of the proposed hybrid algorithm outperforms with best optimal solution within the search space towards MUD for Interference to Noise ratio (INr) at 10 dB, 20 dB, and 40 dB over conventional detectors and metaheuristic approaches such as Binary Spotted Hyena Optimizer (BSHO), Binary particle Swarm Optimization (BpSO) in the UWA network.

关键词： Underwater Acoustic(UWA) Orthogonal Frequency Division Multiplexing(OFDM) Multiuser Detection(MUD) Multi-Access Interference(MAI) Bionic Binary Spotted Hyena Optimizer(BBSHO) Extremal Optimization(EO)

Effect of extrusion on properties of Al-based composite

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Transactions of Nonferrous Metals Society of China 2010年第12期20卷 2229-2233页

作者： r.dasGUpTA S.das S.CHATUrVEDI A.K.JHA Advanced Materials and processes research Institute CSIR Bhopal 462064Madhya PradeshIndia

An aluminium alloy and its composite with dispersed SiC particles made by liquid metallurgy route were extruded under optimized *** properties were characterized in terms of microstructure,hardness and sliding wear behaviour and then compared between the extruded and cast alloys and composites,in order to understand the benefits of composite and extrusion on the *** was observed that composites drastically increased the hardness and the extruded composites further increased this *** advantage of composites was realized in sliding wear tests.

关键词： extrusion Al-alloy composites microstructure wear

Closed-Form Solutions of Stress Intensity Factors for Semi-elliptical Surface Cracks in a Cylindrical Bar Under pure Tension

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Acta Mechanica Solida Sinica 2022年第2期35卷 344-356页

作者： M.K.ramezani S.ramesh J.purbolaksono r.das Centre of Advanced Manufacturing and Materials processing Department of Mechanical EngineeringFaculty of EngineeringUniversity of MalayaKuala Lumpur 50603Malaysia Department of Mechanical Engineering University of PertaminaJakarta 12220Indonesia Sir Lawrence Wackett Aerospace research Centre School of EngineeringRMIT UniversityMelbourneVI 3000Australia

In this work,the stress intensity factors(SIFs)for a wide range of semi-elliptical surface cracks with different inclination angles in a cylindrical bar subjected to pure tension were investigated *** main parameters considered to evaluate the SIFs were the crack size ratio(a/d),the crack aspect ratio(a/c),and the crack inclination angle(0).The dual-boundary element met hod implemented in software BEASY was used to compute the SIF values for *** her more,the general closed-form solutions were proposed to evaluate the corresponding SIFs for Mode I,Mode II and Mode III types of fracture through curve fitting *** solutions can provide accurate and reliable values of stress intensity factors for a crack on a cylindrical bar under pure tension in a rapid way compared to those obtained using computational *** addition,these results can be used as inputs for failure studies and life evaluations of cracked cylinder under working conditions.

关键词： Stress intensity factor Surface crack Solid cylinder Closed-form solution Dual-boundary element method

An Intelligent Multi-robot path planning in a Dynamic Environment Using Improved Gravitational Search Algorithm

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International Journal of Automation and computing 2021年第6期18卷 1032-1044页

作者： p.K.das H.S.Behera p.K.Jena B.K.panigrahi Department of Computer Sceime and Engineering and Information TechnologyVeer Surendra Sai University of TechnologyBurlaOdishaIndia Departmet of Mechanical Engineering Veer Surendra Sai University of TechnologyBurlaOdishaIndia Departmet of Electrical Engineering Indian Institute of TechnologyDelhiIndia

This paper proposes a new methodology to optimize trajectory of the path for multi-robots using improved gravitational search algorithm(IGSA) in clutter environment. Classical GSA has been improved in this paper based on the communication and memory characteristics of particle swarm optimization(pSO). IGSA technique is incorporated into the multi-robot system in a dynamic framework, which will provide robust performance, self-deterministic cooperation, and coping with an inhospitable environment. The robots in the team make independent decisions, coordinate, and cooperate with each other to accomplish a common goal using the developed IGSA. A path planning scheme has been developed using IGSA to optimally obtain the succeeding positions of the robots from the existing position in the proposed environment. Finally, the analytical and experimental results of the multi-robot path planning were compared with those obtained by IGSA, GSA and differential evolution(DE) in a similar environment. The simulation and the Khepera environment result show outperforms of IGSA as compared to GSA and DE with respect to the average total trajectory path deviation, average uncovered trajectory target distance and energy optimization in terms of rotation.

关键词： Gravitational search algorithm multi-robot path planning average total trajectory path deviation average uncovered trajectory target distance average path length

On the design of an AI-driven secure communication scheme for internet of medical things environment

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Digital Communications and Networks 2023年第5期9卷 1080-1089页

作者： Neha Garg rajat petwal Mohammad Wazid D.p.Singh Ashok Kumar das Joel J.p.C.rodrigues Department of Computer Science and Engineering Graphic Era Deemed to be UniversityDehradun248002India Center for Security Theory and Algorithmic ResearchInternational Institute of Information TechnologyHyderabad500032India College of Computer Science and Technology China University of Petroleum(East China)Qingdao266555China Instituto de Telecomunicaçoes 6201-001CovilhaPortugal

The Internet of Medical Things(IoMT)is a collection of smart healthcare devices,hardware infrastructure,and related software applications,that facilitate the connection of healthcare information technology system via the *** is also called IoT in healthcare,facilitating secure communication of remote healthcare devices over the Internet for quick and flexible analysis of healthcare *** other words,IoMT is an amalgam of medical devices and applications,which improves overall healthcare ***,this system is prone to securityand privacy-related attacks on healthcare ***,providing a robust security mechanism to prevent the attacks and vulnerability of IoMT is *** mitigate this,we proposed a new Artificial-Intelligence envisioned secure communication scheme for *** discussed network and threat models provide details of the associated network arrangement of the IoMT devices and attacks relevant to ***,we provide the security analysis of the proposed scheme to show its security against different possible ***,a comparative study of the proposed scheme with other similar schemes is *** results show that the proposed scheme outperforms other similar schemes in terms of communication and computation costs,and security and functionality ***,we provide a pragmatic study of the proposed scheme to observe its impact on various network performance parameters.

关键词： Internet of Medical Things(IoMT) Security Authentication and key agreement Artificial Intelligence(AI) Big data analytics

Quantitative mineralogical characterization of chrome ore beneficiation plant tailing and its beneficiated products

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International Journal of Minerals,Metallurgy and Materials 2015年第4期22卷 335-345页

作者： S.K.das CSIr-Institute of Minerals and Materials Technology

Mineralogical characterization and liberation of valuable minerals are primary concerns in rnineml processing industries. The pre- sent investigation focuses on quantitative mineralogy, elemental deportment, and locking-liberation characteristics of the beneficiation of tailings from a chrome ore beneficiation plant in the Sukinda region, Odisha; methods used for the study of the beneficiated tailings are QEMSCAN~, X-ray diffraction （XrD）, and mineral chemistry by a scanning electron microscope equipped with an energy-dispersive spec- trometer （SEM-EDS）. The tailing sample was fine grained （69.48wt% below 45 μm size）, containing 20.25wt% Cr203 and 39.19wt% Fe203, with a Cr：Fe mass ratio of 0.51. Mineralogical investigations using QEMSCAN studies revealed that chromite, goethite, and gibbsite are the dominant mineral phases with minor amounts of hematite, kaolinite, and quartz. The sample contained 34.22wt% chromite, and chromite liberation is more than 80% for grains smaller than 250 ~tm in size. Based on these results, it was predicted that liberated chromite and high-grade middling chromite particles could be separated from the gangue by various concentration techniques. The tailing sample was beneficiated by hydrocyclone, tabling, wet high-intensity magnetic separation （WHIMS）, and flotation in order to recover the chromite. A chromite concentrate with 45.29wt% Cr203 and a Cr：Fe mass ratio of 1.85 can be produced from these low-grade chromite ore beneficiation plant rejects.

关键词： tailings mineralogy chromites beneficiation

Antioxidants in Food and Chronic Degenerative Diseases

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Biomedical and Environmental Sciences 1996年第2期9卷 117-123页

作者： J．K．CANDLISH N．p．das BiochemistryDepartment NationalUniversityofSingaporeKentRidgeCrescentSingapore0511 BiochemistryDepa

Both preventive and chain breaking antioxidants have a role in the limitation of free radical damage. Some of these may be regarded as 'classical', like vitamins E and C but others are more recently discovered, such as the flavonoids, widespread in plant tissues, and the muscle constituents anserine and carnosine. The major conditions in which the role of antioxidants is under intense investigation include coronary artery disease, cancer and diabetes. There are theoretical underpinnings for the efficacy of antioxidants in each of these, with the protection of low density lipoprotein (in respect of the first) being exceptionally *** attention is now being focussed on the flavonoids, which are surprisingly pleiotropic in their effects. For one of them, quercetin, over a dozen seemingly independent biologica1 effects can be listed, including the inhibition of low density lipoprotein *** also inhibit peroxidation in foodstuffs, as opposed to *** is much controversy over antioxidant supplementation policies, some authorities recommending a massive programme of supplementation for all ages and classes, others stressing the value of the traditional mixed diet. This matter is unlikely to be resolved soon,but in the meantime sensible supplementation policies should be continued for those most vulnerable, that is, babies and the aged

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