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Journal of Forestry Research 2014年第3期25卷 591-596页

作者： Gopal Shukla rajib biswas A. P. Das Sumit Chakravarty Department of Forestry Uttar Banga Krishi Viswavidyalaya Pundibari-736165 (Cooch Behar) West Bengal India Department of Botany University of North Bengal

From March 2007 to March 2009 we quantified plant diversity at Chilapatta Reserve Forest in Terai Duars in the Indian eastern Himala-yas. We sampled stratified random nested quadrats. Species richness was 311, representing 167 genera and 81 families. The species diversity index and concentration of dominance of the forest were 2.20 and 0.0072, respectively. Shannon-Wiener index and evenness indices were 4.77 and 1.44, respectively. The Importance Value Index （IVI） of species ranged from 0.13 to 37.94. The estimated diversity indices indicated heterogene-ity of the forest in its composition, structure, function and dynamics. Rich forest plant diversity supports the need for continued conservation of tropical forests.

关键词： Terai Duars phyto-sociology plant diversity diversity indices

Seed germination of Albizia procera(Roxb.)*** Bangladesh:a basis for seed source variation and pre-sowing treatment effect

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Forestry Studies in China 2012年第2期14卷 124-130页

作者： Md.Salim AZAD rajib Kumar biswas Abdul MATIN Forestry and Wood Technology Discipline Khulna University

An experiment in seed morphology and seed germination techniques of Albizia procera was carried out in the nursery of the Forestry and Wood Technology Discipline, Khulna University, Bangladesh in order to discover the source variation in seeds and pre-sowing treatment effects on seed germination. Mature seeds ofA. procera were collected from healthy trees in home garden plan- tations from five different districts in Bangladesh and treated with four pre-sowing treatments, i.e., control, immersion in cold water （4~C for 24 h） and immersion in hot water （80~C for 10 min and 100~C for 1 min）. The average length, width and thickness of seeds were calculated as 0.502 ＋ 0.485, 0.420 ~ 0.060 and 0.191 ~ 0.118 cm, respectively. Germination was conducted in poly-bags with a mixture of topsoil and cow dung in a ratio of 3：1. The results revealed that pre-sowing treatments affected the rate of germination of seeds, which significantly increased the germination percentages of seeds in hot water treatments compared with those in control （60.60%） and the cold water treatment （4℃ for 24 h, 63.53%）. The highest germination success was 82.07% in the treatment of im- mersion in hot water （80℃） for 10 min, followed by 79.00% in immersion in hot water （100℃） for l rain. Germination started 4 to 6 days after seed sowing and completed in a period of 22 to 25 days in all treatments. ANOVAs showed statistically significant dif- ferences （p 〈 0.05） in seed germination starting dates, closing dates, germination percentages and rates of germination among treat- ments, but no significant differences in seed germination starting dates, closing dates, germination period, germination percentages and rates of germination among the seed sources. The study also revealed that the interaction between seed source variation and treat- ment effect significantly differed in seed germination starting dates, closing dates, germination percentages and rates of germination. The hot water （100℃ for 1min） treatm

关键词： seed dormancy provenance variation germination techniques water treatment small-scale nursery owners

Probabilistic seismic design of pile-supported building structure incorporating inherent variability of subsoil and ground motion uncertainty

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Earthquake Engineering and Engineering Vibration 2023年第1期22卷 135-156页

作者： Swagata DebRoy rajib Saha Civil Engineering Department National Institute of Technology AgartalaJirania-799046Tripura(West)India

Seismic failure of structures supported on pile foundation has revealed the importance of seismic soil-foundation-structure interaction(SSFSI)for ensuring safe *** uncertainties in subsoil properties and seismic loading may lead the problem to be more *** this context,the present study attempts to assess the seismic reliability of pile foundation-supported building structure embedded in inhomogeneous clay layer considering inertial *** strength of clay and earthquake loading is considered as spatially variable uncertain parameters.A non-linear soil-pile-structure system was assumed,and Monte Carlo simulation(MCS)was adopted to obtain probabilistic response of the ***-order reliability method(FORM)is used for reliability *** study indicates significant influence of uncertain parameters on the seismic response of building ***,the influence of material and load uncertainty parameters on the probabilistic seismic response of structure designed following older version of code is higher than counterpart structure designed following recent *** based reliability analysis infers thatserviceability criterion may be the governing parameter for pile foundation ***,the study also indicates that the curvature ductility demand of pile may be considered another crucial design parameter to assess the reliability of pile foundation.

关键词： seismic soil-foundation-structure interaction pile foundation soft clay Monte Carlo simulation FORM OPENSees

Seismic bearing capacity of strip footing on partially saturated soil using modal response analysis

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Earthquake Engineering and Engineering Vibration 2022年第3期21卷 641-662页

作者： Abhijit Anand rajib Sarkar Department of Civil Engineering IIT(ISM)DhanbadDhanbad 826004India

The present study proposes a novel and simplified methodology to assess the seismic bearing capacity(SBC) of a shallow strip footing by incorporating strength non-linearity arising due to partial saturation of a soil matrix. Furthermore, developed methodology incorporates the modal response analysis of soil layers to assess SBC. A constant matric suction distribution profile has been considered throughout the depth of the soil. The Van Genuchten equation and corresponding fitting parameters have been considered to quantify matric suction in the analysis. SBC has been obtained for three different geomaterials;viz. sand, fly ash and clay, based on their predominant grain size and diverse soil water characteristics curve(SWCC) attributes. Variation of SBC with different modes of vibration and damping ratio are reported for ranges of matric suction pertinent to the geomaterials considered in the study. The relative significance of matric suction on SBC has been reported for suction values within the transition zone of each geomaterial. It is observed that the SBC of sand is drastically reduced, with matric suction reaching beyond the residual suction value. The SBC of fly ash remains constant beyond the residual suction value, whereas the SBC of clay shows an increasing trend toward the practical range of matric suction values.

关键词： seismic bearing capacity modal analysis matric suction

Bound for the Regularity of Binomial Edge Ideals of Cactus Graphs

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Algebra Colloquium 2022年第3期29卷 443-452页

作者： A.V.Jayanthan rajib Sarkar Department of Mathematics Indian Institute of Technology Madras Chennai 600036India

In this article,we obtain an upper bound for the regularity of the binomial edge ideal of a graph whose every block is either a cycle or a *** a consequence,we obtain an upper bound for the regularity of binomial edge... 详细信息

关键词： binomial edge ideal cactus graph Cohen-Macaulayness regularity

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

Microbial leaching of chromite overburden from Sukinda mines,Orissa,India using Aspergillus niger

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International Journal of Minerals,Metallurgy and Materials 2013年第8期20卷 705-712页

作者： Supratim biswas Saikat Samanta rajib Dey Siddhartha Mukherjee Pataki C.Banerjee Department of Metallurgical and Material Engineering Jadavpur UniversityKolkata-700032India School of Materials Science and Nanotechnology Jadavpur UniversityKolkata-700032India

Leaching of nickel and cobalt from two physical grades （S1, 125-190 μm, coarser and S3, 53-75 μm, finer） of chromite overburden was achieved by treating the overburden （2% pulp density） with 21-d culture filtrate of an Aspergillus niger strain grown in sucrose medium. Metal dissolution increases with ore roasting at 600℃ and decreasing particle size due to the alteration of microstructural properties involving the conversion of goethite to hematite and the increase in surface area and porosity as evident from X-ray diffraction （XRD）, thermogravimetry-differential thermal analysis （DT- TGA）, and field emission scanning electron microscopy （FESEM）. About 65% Ni and 59% Co were recovered from the roasted S3 ore employing bioleaching against 26.87% Ni and 31.3% Co using an equivalent amount of synthetic oxalic acid under identical conditions. The results suggest that other fungal metabolites in the culture filtrate played a positive role in the bioleaching process, making it an efficient green approach in Ni and Co recovery from lateritic chromite overburden.

关键词： nickeliferous laterite bioleaching Aspergillus niger chromite nickel metallurgy cobalt metallurgy

Charge transfer of carbon nanomaterials for efficient metal‐free electrocatalysis

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Interdisciplinary Materials 2022年第1期1卷 28-50页

作者： rajib Paul Qingfeng Zhai Ajit K.Roy Liming Dai Department of Macromolecular Science and Engineering Case School of EngineeringCase Western Reserve UniversityClevelandOhioUSA Australian Carbon Materials Centre(A-CMC) School of Chemical EngineeringUniversity of New South WalesSydneyNew South WalesAustralia Materials and Manufacturing Directorate Air Force Research LaboratoryDaytonOhioUSA

Recently,carbon-based metal-free electrocatalysts(C‐MFECs)have drawn considerable research attention because of their attractive physicochemical characteristics,cost-effectiveness,and ability to convert and store energy *** intramolecular charge transfer among different parts of the carbon electrocatalyst and/or intermolecular charge transfer between elec-trocatalyst and electrolyte dictate the ultimate energy conversion *** results and theoretical analyses have demonstrated that rational design of metal-free carbon nanomaterials,coupled with proper in-tramolecular charge transfer through heteroatom doping,incorporation of Stone-Wales defects,and/or intermolecular charge transfer through adsorp-tion of appropriate molecules/moieties,can promote efficient *** this article,we will first provide the related theoretical principles and then present an overview on the rational design and development of C-MFECs for efficient charge transfer,followed by elucidating charge-transfer processes for different electrocatalytic reactions related to renewable energy conversion and environmental remediation ***,the current challenges and future perspectives in this exciting field will be discussed.

关键词： carbon catalyst charge transfer defect doping

Thirty Years of Science,Technology,and Academia in Disaster Risk Reduction and Emerging Responsibilities

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International Journal of Disaster Risk Science 2020年第4期11卷 414-425页

作者： rajib Shaw Graduate School of Media and Governance Keio UniversityFujisawa 252-0882Japan

The 1990 initiation of the International Decade for Natural Disaster Reduction marked its 30th year in *** three decades since then have seen significant developments in science and technology and their incorporation into the decision making in the field of disaster risk *** disasters that have occurred during that time have enhanced the importance of the field,and new research and innovations have *** article summarizes this evolution through the review of specific *** the Sendai Framework for Disaster Risk Reduction 2015–2030 provides opportunities for synergies with the sustainable development agenda,the science and technology communities have also changed their roles from advisory to co-designing and co-delivering *** education plays an important role in developing new generations of professionals,and the role of thematic incubation in higher education institutions is highlighted along with the development of the professional society in disaster risk *** evolution from Society 4.0(information age)to Society 5.0 will see an enhanced role of the technology-driven approach in disaster risk reduction,while traditional knowledge and indigenous technologies still remain valid for *** and science communities need to be more sensitive to changing the“last mile”concept to“first mile”thinking with respect to the users’needs and perspectives.

关键词： Co-design solutions in disaster risk reduction Professional society Science and technology in disaster risk reduction Society 5.0

Time delay of the appearance of a new strain can affect vaccination behavior and disease dynamics:An evolutionary explanation

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Infectious Disease Modelling 2023年第3期8卷 656-671页

作者： Md.Mamun-Ur-Rashid Khan Md.rajib Arefin Jun Tanimoto Interdisciplinary Graduate School of Engineering Sciences Kyushu UniversityKasuga-koenKasuga-shiFukuoka816-8580Japan Faculty of Engineering Sciences Kyushu UniversityKasuga-koenKasuga-shiFukuoka816-8580Japan Department of Mathematics University of DhakaDhaka1000Bangladesh

The emergence of a novel strain during a pandemic,like the current COVID-19,is a major concern to the healthcare *** most effective strategy to control this type of pandemic is *** previous studies suggest that the existing vaccine may not be fully effective against the new ***,the new strain's late arrival has a significant impact on the disease dynamics and vaccine *** on these issues,this study presents a two-strain epidemic model in which the new strain appears with a time *** considered two vaccination provisions,namely preinfection and post-infection vaccinations,which are governed by human behavioral *** such a framework,individuals have the option to commit vaccination before being infected with the first ***,people who forgo vaccination and become infected with the first train have the chance to be vaccinated(after recovery)in an attempt to avoid infection from the second ***,a second strain can infect vaccinated and unvaccinated *** may have additional opportunities to be vaccinated and to protect themselves from the second strain due to the time *** the cost of the vaccine,the severity of the new strain,and the vaccine's effectiveness,our results indicated that delaying the second strain decreases the peak size of the infected ***,by estimating the social efficiency deficit,we discovered that the social dilemma for receiving immunization decreases with the delay in the arrival of the second strain.

关键词： Vaccination Behavior dynamics Two-strain epidemic Time delay Social efficiency deficit