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Revisiting Conserved Currents in the F(R)Theory of Gravity via Noether Symmetry

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Chinese Physics Letters 2013年第2期30卷 41-45页

作者： Nayem sk. Abhik Kumar Sanyal Deptment of Physics University of KalyaniNadia 741235India Deptment of Physics Jangipur CollegeMurshidabad 742213India

Noether symmetry of the F(R)theory of gravity in a vacuum and in the presence of pressureless dust yields F(R)∝R^(3/2) along with the conserved current d/dt(a√R)in the Robertson-Walker metric and nothing ***,some authors recently claimed to have obtained four conserved currents setting F(R)∝R^(3/2) a-priori,taking time translation along with a gauge *** show that the first one of these does not satisfy the field equations and the second one is the Hamiltonian which is constrained to vanish in gravity and thus a part and parcel of the field *** also show that the other two conserved currents,which do not contain time translation,are the same in disguise and identical to the one mentioned *** the claim is wrong.

关键词： conserved satisfy mentioned

Geochemical characteristics and mode of occurrence of trace elements in coal at West Bokaro coalfield

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International Journal of Coal Science & Technology 2016年第4期3卷 399-406页

作者： sk. Md. Equeenuddin Subhasish Tripathy Prafuila Kumar Sahoo Amit Ranjan Department of Earth & Atmospheric Sciences NationalInstitute of Technology Rourkela Odisha 769008 India Department of Geology and Geophysics Indian Institute of Technology Kharagpur West Bengal 721302 India Vale Institute of Technology Boaventura da Silva BelemPardi 66055-090 Brazil

The mineralogy and trace element contents in coals from the West Bokaro coalfield, which is the one of the biggest Gondwana coalfields of India, were studied to delineate enrichment of trace elements and their modes of occur- rence. Elemental concentrations with reference to their crustal abundances indicated that coals are relatively enriched in As （4.4-15.5 mg/kg）, Cd （0.3-3.0 mg/kg）, Cu （28.0-68.1 mg/kg） and V （46.6-178.0 mg/kg）; depleted in Co （10.8-28.4 mg/ kg）, Mn （7.6-483.4 mg/kg）, Ni （13.0-31.6 mg/kg）, Cr （14.2-85.5 mg/kg） and Zn （5.25-70.4 mg/kg）. The concentration of As, Cd, Co, Cu and V were higher than the average values of world and Indian coals. Mineralogical study carried out by X-ray diffraction shows that quartz and kaolinite occur as dominant mineral phases in this coal. Fourier transform infrared spectroscopy pattern suggests organic structures primarily containing aromatic nuclei, aliphatic side chain and some oxygen containing groups. The modes of occurrence of trace elements present in these coals have been determined through statistical approach. Both Cu and Cr are more closely associated with mineral matter, whereas Co is dominantly present with its organic form. The concentrations of Cd, Mn, Ni, Zn, As and V have apparently occur in both organic and inorganic constituents. This study would be helpful to assess the potential environmental impacts during mining and combustion of this coal.

关键词： Mineralogy Organic group Trace elements Coal West Bokaro

Growth performance of Avicennia officinalis L. and the effect of spacing on growth and yield of trees planted in the Western coastal belt of Bangladesh

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Journal of Forestry Research 2014年第4期25卷 835-838页

作者： Md. Abdul Quddus Miah sk. Ahiul Islam Md. Ahsan Habib Md. Golam Moula Plantation Trial Unit Division Bangladesh Forest Research Institute Rupatoli Barisal-8206 Bangladesh

A trial ofAvicennia officinalis L. with five different spacings was conducted in the newly accreted lands along the western coastline （Patuakhali district） of Bangladesh since 1993 to assess growth perform- ance and the effect of spacing on tree growth. Data on tree density, height, diameter, bole height, crown diameter were recorded and ana- lyzed when the stand was 19 years old. Mean height ranged from 12.89-13.52 m and diameter at breast height （dbh） from 26.57-32.16 cm in plots of different spacings. The mean annual height increment ranged from 0,67-0.71 m, mean annual diameter increment from 1.40-1.69 cm and wood volume from 6.02-10.04 ***＇*** in different treatments. Significantly greater diameter （32.16 cm） and wood volume （10.04 ***.a-1） were obtained with wider （2.13 m × 2.13 m） spacing than with closer spacings. But tree growth was unaffected by other spacings. Growth data were also recorded from other .4. officinalis plantations raised by Forest Department （FD） on different islands in Patuakhali and Bhola districts of Bangladesh. At these sites, mean annual height incre- ment ranged from 0.33-0.62 m, mean annual diameter increment from 0.72-1,37 cm and wood volume from 1.55-5.73 m3·ha-1·a·-1. The growth performance of A. offindicated that the newly aecreted lands along the western shoreline may be suitable for raising Avicennia planta- tions for the enrichment of coastal vegetation.

关键词： growth Avicennia officinalis plantation spacing coastal belt

Bilayer expurgated LDPC codes with uncoded relaying

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Digital Communications and Networks 2017年第3期3卷 176-179页

作者： Md. Noor-A-Rahim Nan Zhang sk. Md. Rabiul Islam Y.L. Guan Centre for Infocomm Technology (INFINITUS) Nanyang Technological University Singapore Institute for TelecommunicationsResearch University of South Australia Adelaide Australia Dept.of Eleetronics and Communication Engineering Khulna University of Engineering & Technology Bangladesh

Bilayer low-density parity-check （LDPC） codes are an effective coding technique for decode-and-forward relaying, where the relay forwards extra parity bits to help the destination to decode the source bits correctly. In the existing bilayer coding scheme, these parity bits are protected by an error correcting code and assumed reliably available at the receiver. We propose an uneoded relaying scheme, where the extra parity bits are forwarded to the destination without any protection. Through density evolution analysis and simulation results, we show that our proposed scheme achieves better performance in terms of bit erasure probability than the existing relaying scheme. In addition, our proposed scheme results in lower complexity at the relay.

关键词： Bilayer codes LDPC codes Density evolution Decode-and-forward relaying

Implementation of Pre-Heating System in Stenters for Improving Machine Performance and Increasing Efficiency

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Journal of Textile Science and Technology 2021年第4期7卷 143-151页

作者： sk. Mohammad Raafi Ummul Khair Fatema Department of Wet Process Engineering Bangladesh University of Textiles Dhaka Bangladesh Department of Environmental Science and Engineering Bangladesh University of Textiles Dhaka Bangladesh

In textile finishing, stenters always draw considerable attention to newer inventions to boost up production via maximum utilization of energy. Prior to main drying or heat-setting chambers, intermediate heating of cylindrical system especially by steam has a direct blessing to moisture evaporation, processing speed, fabric quality and so on. Based on actual operational data, this study reveals the outcomes of a pre-heating module installed within a stenter. After employing the pre-heating system to knit fabrics of different structures and compositions, 23% - 61% moisture reduction was found and the speed of processing fabrics was increased simultaneously by 17% - 30% without any compromise on fabric quality. Moreover, no less than 8.21% savings in annual electricity consumption were observed.

关键词： Stenter Pre-Heating Machine Performance Fabric Processing Speed Energy Savings

Historical Development in Soil Micromorphological Imaging

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Journal of Mountain Science 2009年第2期6卷 107-112页

作者： A.R.Mermut University of Sask.tchewan Department of Soil ScienceSaskatoon SK. Canada Harran University Department of Soil ScienceSanliurfa Turkey

The book ＂micropedolog＂ by Kubieana and a large number of publications has induced many people to practice soil micromorphology. Quantification of the soil fabric and its components was a major challenge. The use of the image analyses in soil science was a breakthrough. Attempts to make soil thin sections go back to the beginning of the 2oth century. Microscopic techniques and recently high resolution electron microscope and use of computer assisted imaging techniques enabled the in vitro study of soils in three dimensional levels. It is now possible to store and process massive amounts of data. Micro- morphological concepts and techniques are applied in paleopedological, ecological, and archaeological studies. The aim of this work was to examine soil micromorphological imaging in historical perspective.

关键词： Soil micromorphology quantification imaging techniques history

A Pilot School Meal Program Using Local Foods with Soybean in Rural Bangladesh: Effects on the Nutritional Status of Children

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Food and Nutrition Sciences 2018年第4期9卷 290-313页

作者： Nobuko Murayama Mieko Magami Salima Akter Israt Ara Hossain Liaquat Ali Mahmud Hossain Faruquee sk.akhtar ahmad Department of Health and Nutrition University of Niigata Prefecture Niigata Japan General Incorporated Association Fair Trade Roshun Tokyo Japan Department of Medical Biotechnology Bangladesh University of Health Sciences Dhaka Bangladesh Department of Biochemistry and Cell Biology Bangladesh University of Health Sciences Dhaka Bangladesh Department of Occupational & Environmental Health University of Health Sciences Dhaka Bangladesh

Background: Growth retardation is a challenge in Bangladesh. School feeding programs with fortified biscuits have been evaluated in Bangladesh. However, the impacts of a school meal program using local foods on the growth and nutritional status of children have not been investigated. Objective: To determine whether a school meal program (SMP) using local foods with soybean could improve children’s growth and micronutrient status in rural Bangladesh. Methods: Two primary schools were randomly assigned as intervention (SMP;n = 200) and control (non-SMP;n = 200) schools. Children in the intervention school were supplied a school meal with local foods including soybean, containing more than one-third of the recommended daily allowance of energy and nutrients, 5 days/week for 8 months. The attendance rate and school lunch consumption of the children were monitored. Baseline and final anthropometry, hemoglobin and micronutrient status were assessed. Results: There were no significant differences in anthropometric measurements at baseline between the intervention and control groups, but there were differences in the prevalence of anemia, vitamin A deficiency and zinc deficiency. After the intervention, children in the SMP school showed a larger degree of improvement in the height-for-age Z-score (P Conclusion: A school meal program using local foods with soybean improved the height velocity and hemoglobin concentration of children in rural Bangladesh.

关键词： School Meal Program Local Food Child Growth Anemia Bangladesh

Internal States of Temperature Hysteresis in Shape Memory Alloys

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Journal of Materials Science & Technology 1997年第3期13卷 206-210页

作者： Xu, HB Gong, sk Dept. of Materials Science and Engineering Beijing University of Aeronautics and Astronautics Beijing 100083 China

We propose a thermodynamic theory that permits us to connect the size of the temperature hysteresis loop to the interfacial energy between martensite and austenite. The free energy is a function of four variables, viz. deformation of austenite, deformation of martensite, phase fraction and temperature. A diagonal line inside the hysteresis loop in the deformation-temperature diagram is identified as the line of unstable phase equilibrium. Upon reaching this line the phase mixture loses its (meta-)stability, and the transformation from one phase to the other should occur. The theoretical results are supported by experiments on NiTi and CuAlNi specimens.

关键词： Shape memory effect

Radial basis function‐based exosk.leton robot controller development

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IET Cyber-Systems and Robotics 2022年第3期4卷 228-250页

作者： sk.Hasan Department of Mechanical and Manufacturing Engineering Miami UniversityOxfordOhioUSA

The realisation of a model‐based controller for a robot with a higher degree of freedom requires a substantial amount of computational power.A high‐speed CPU is required to maintain a higher sampling *** processors cannot boost the performance or reduce the execution time as the programs are sequentially *** neural network is a great tool to convert a sequentially structured program to an equivalent parallel architecture *** this study,a radial basis function(RBF)neural network is developed for controlling 7 degrees of freedom of the human lower extremity exosk.l-eton robot.A realistic friction model is used for modelling joint *** trajectory tracking accuracies have been *** of computational efficiency has been *** stability analysis of the developed controller is *** of variance is used to assess the controller's resilience to parameter *** show the effectiveness of the developed controller,a comparative study was performe between the developed RBF network‐based controller and Sliding Mode Controller,Computed Tor-que Controller,Adaptive controller,Linear Quadratic Regulator and Model Reference Computed Torque Controller.

关键词： exosk.leton robot dynamic modelling lower extremity exosk.leton robot control radial basis function(RBF)controller