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Journal of Arid Land 2015年第6期7卷 814-819页

作者： Amitava chatterjee George d JENERETTE department of Soil Science North Dakota State University department of Botany and Plant Sciences University of California

Variations in soil organic matter accumulation across an elevation can be used to explain the control of substrate supply and variability on soil metabolic activity. We investigated geographic changes in soil organic matter and metabolic rates along an elevation gradient（289–2,489 m） in the Santa Rosa Mountains, California, USA from subalpine and montane pine forests through chaparral to desert. From base（289 m） to summit（2,489 m）, 24 sites were established for collecting soil samples under canopies and inter-canopy spaces, at 0–5 and 5–15 cm soil depths increments. Soil organic matter（SOM） content was determined using weight loss on ignition at 550°C and soil CO2 efflux（R） was measured at day 5（R5） and day 20（R20） of incubation. Changes in SOM content along the elevation gradient showed a significant relationship（P〈0.05） but R5 and R20 were not related to either elevation or SOM content. However, the ratio of R and SOM（R5/SOM） showed a strong relationship across the mountains at both soil depths. R5/SOM, as an indicator of carbon use efficiency, may be applicable to other semi-arid transects at larger scale modeling of soil metabolic processes.

关键词： elevation gradient soil organic matter CO2 efflux metabolic activity

Spatio-temporal variation and propagation direction of coal fire in Jharia Coalfield,India by satellite-based multi-temporal night-time land surface temperature imaging

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International Journal of Mining Science and Technology 2021年第5期31卷 765-778页

作者： Narendra Singh R.S.chatterjee dheeraj Kumar d.C.Panigrahi department of Mining Engineering Indian Institute of Technology(Indian School of Mines)Dhanbad 826004India Geosciences department Indian Institute of Remote SensingDehradun 248001India

In this paper,the spatio-temporal variation and propagation direction of coal fire were studied in the Jharia Coalfield(JCF),India during 2006–2015 through satellite-based night-time land surface temperature(LST)*** LST was retrieved from Advanced Spaceborne Thermal Emission and Reflection Radiometer(ASTER)night-time thermal-infrared data by a robust split-window algorithm based on scene-specific regression coefficients,band-specific hybrid emissivity,and night-time atmospheric *** LST-profile-based coal fire detection algorithm was formulated through statistical analysis of the LST values along multiple transects across diverse coal fire locations in the JCF in order to compute date-specific threshold temperatures for separating thermally-anomalous and background *** algorithm efficiently separates surface fire,subsurface fire,and thermally-anomalous transitional *** the observation period,it was noticed that the coal fire area increased significantly,which resulted from new coal fire at many places owing to extensive opencast-mining *** was observed that the fire propagation occurred primarily along the dip direction of the coal *** places,lateral-propagation of limited spatial extent was also observed along the strike direction possibly due to spatial continuity of the coal seams along ***,the opencast-mining activities carried out during 2009–2015 and the structurally weak planes facilitated the fire propagation.

关键词： Satellite-based night-time imaging Land surface temperature Coal fire Spatio-temporal variation Propagation direction Jharia Coalfield

development of a Tribofidelic Human Heel Surrogate for Barefoot Slip Testing

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Journal of Bionic Engineering 2022年第2期19卷 429-439页

作者： Subhodip chatterjee Arnab Chanda Centre for Biomedical Engineering Indian Institute of Technology DelhiNew Delhi 110016India department of Biomedical Engineering All India Institute of Medical ScienceNew Delhi 110029India

Barefoot slips contribute to over 37% of recurrent fall-related injuries across all age *** study slip risk across a wide range of flooring conditions,slip meters with barefoot surrogates(i.e.,sensors,as per ASTM standard nomenclature)such as animal skins and rubbers have been used to date,which exhibit biomechanical and frictional properties widely different from the barefoot human *** of a surrogate which can accurately simulate the human heel skin properties would be immensely beneficial for realistic assessment of barefoot slipping risk.A novel surrogate was developed using 3d scanning and printing,and biomimetics,which precisely simulates the biomechanical and frictional properties of the barefoot human heel *** slip testing was conducted with this surrogate on three common bathroom floorings and with six different *** of Friction(COF)results similar to human slipping experiments,high repeatability and reproducibility across wet and oily flooring conditions,were confirmed through experiments with the developed heel skin *** heel skin surrogate would be an indispensable model for accurate estimation of barefoot risk against slips and falls in bathrooms,bathtubs,and swimming pools.

关键词： Barefoot Surrogate Slip Fall Bathroom Bathtub

Isolation and characterization of a profenofos degrading bacterium

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Journal of Environmental Sciences 2009年第11期21卷 1591-1597页

作者： Saadatullah Malghani Nivedita chatterjee Key Laboratory of Biogeology and Environmental Geology Ministry of Education of China School of Environmental StudiesChina University of Geosciences

Profenofos, a well known organophosphate pesticide, has been in agricultural use over the last two decades for controlling Lepidopteron pests of cotton and tobacco crops. In this study, a bacterial strain, OW, was isolated from a long term profenofos exposed soil by an enrichment technique, and its ability to degrade profenofos was determined using gas chromatography. The isolated strain OW was identified as Pseudomonas aeruginosa according to its physiological and biochemical properties, and the analysis of its 16S rRNA gene sequence. The strain grew well at pH 5.5-7.2 with a broad temperature profile. Bioremediation of profenofos-contaminated soil was examined using soil treated with 200 μg/g profenofos, which resulted in a higher degradation rate than control soils without inoculation. In a mineral salt medium （FTW）, removal in the level of profenofos of 86.81% was obtained within 48 h of incubation. The intermediates of profenofos metabolism indicated that the degradation occurred through a hydrolysis mechanism, and one of the metabolites was found to be 4 bromo-2-cholorophenol （BCP） which in turn was also mineralized by the strain. The results of this study highlighted the potentiality of P. aeruginosa as a biodegrader which could be used for the bioremediation of profenofos contaminated soil.

关键词： profenofos organophosphate pesticide Pseudomonas aeruginosa

Effect of heavy load carriage on cardiorespiratory responses with varying gradients and modes of carriage

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Military Medical Research 2019年第1期6卷 53-59页

作者： Subhojit chatterjee Tirthankar chatterjee debojyoti Bhattacharyya Suranjana Sen Madhusudan Pal defence Institute of Physiology and Allied Sciences Defence Research & Development Organisation Ministry of Defence

Background: The present study was undertaken to determine the effect of different uphill and downhill gradients on cardiorespiratory and metabolic responses of soldiers while carrying heavy military loads in two different ***: Eight physically fit male soldiers with a mean age 32.0±2.0 years, a mean height of 169.5±4.9 cm, and a mean weight of 63.8±8.4 kg volunteered for this study. Each volunteer completed treadmill walking trials at a speed of 3.5 km/h while carrying no external load, 31.4 kg load in a distributed mode(existing load carriage ensembles) and compact mode(new back pack) over 5 different downhill and uphill gradients(–5%, –10%, 0%, 5%, 10%) for 6 min at each gradient. during the walking trials, heart rate(HR), oxygen uptake(VO_2), respiratory frequency(RF) and energy expenditure(EE) were determined by the process of breath-by-breath gas analysis using a K4 b2 system. The average of the last 2 min data from each 6 min walking trial for each individual was subjected to statistical ***: All parameters(HR, VO_2, RF, and EE) gradually increased with the change in gradient from downhill to level to uphill. The distributed mode showed higher values compared to compact mode for all gradients, e.g., for VO_2, there was a 10.7, 7.4, 5.1, 28.2 and 18.7% increase in the distributed mode across the 5 different ***: It can be concluded from the present study that the compact mode of load carriage is more beneficial than the distributed mode in terms of cardiorespiratory responses while walking on downhill and uphill surfaces with a 31.4 kg load.

关键词： Heavy load carriage Cardio respiratory responses Gradients Soldiers

Estimation of petrophysical parameters using seismic inversion and neural network modeling in Upper Assam basin, India

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Geoscience Frontiers 2019年第3期10卷 1113-1124页

作者： Triveni Gogoi Rima chatterjee department of Applied Geophysics Indian Institute of Technology (Indian School of Mines)

Estimation of petrophysical parameters is an important issue of any reservoirs. Porosity, volume of shale and water saturation has been evaluated for reservoirs of Upper Assam basin, located in northeastern India from well log and seismic data. Absolute acoustic impedance(AAI) and relative acoustic impedance(RAI) are generated from model based inversion of 2-d post-stack seismic data. The top of geological formation, sand reservoirs, shale layers and discontinuities at faults are detected in RAI section under the study area. Tipam Sandstone(TS) and Barail Arenaceous Sandstone(BAS) are the main reservoirs,delineated from the logs of available wells and RAI section. Porosity section is obtained using porosity wavelet and porosity reflectivity from post-stack seismic data. Two multilayered feed forward neural network(MLFN) models are created with inputs: AAI, porosity, density and shear impedance and outputs: volume of shale and water saturation with single hidden layer. The estimated average porosity in TS and BAS reservoir varies from 30% to 36% and 18% to 30% respectively. The volume of shale and water saturation ranges from 10% to 30% and 20% to 60% in TS reservoir and 28% to 30% and 23% to 55% in BAS reservoir respectively.

关键词： Upper Assam basin Relative acoustic impedance Porosity Volume of shale Water saturation Neural network model

Accretion flow properties of XTE J1118+480 during its 2005 outburst

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Research in Astronomy and Astrophysics 2020年第11期20卷 222-230页

作者： dipak debnath d.bjit chatterjee Arghajit Jana Sandip K.Chakrabarti Kaushik chatterjee Indian Centre for Space Physics 43 ChalantikaGaria St.Rd.Kolkata700084India Physical Research Laboratory NavrangpuraAhmedabad 380009India

We study spectral and temporal properties of Galactic short orbital period transient black hole XTE J1118+480 during its 2005 outburst using archival data of RXTE PCA and HEXTE instruments in the combined energy range of 3−100 *** analysis with the physical two component advective flow(TCAF)model allows us to understand the accretion flow properties of the *** found that this outburst of XTE J1118+480 is an unconventional outburst as the source was only in the hard state(HS).Our spectral analysis suggests that during the entire outburst,the source was highly dominated by the low angular momentum sub-Keplerian halo *** the source was active in radio throughout the outburst,we make an effort to estimate X-ray contribution of jets to total observed X-ray emissions from the spectral analysis with the TCAF *** total X-ray intensity shows a similar nature of evolution as that of radio and jet X-ray *** allowed us to define this‘outburst’also as a jet dominated‘outburst’.Total X-ray flux is also found to subside when jet activity *** detailed spectral analysis also indicated that although the source was only in the HS during the outburst,in the late declining phase the spectrum became slightly softer due to the slow rise in the Keplerian disk rate.

关键词： X-Rays binaries-stars black holes-stars individual (XTE J1118+480)-accretion,accretion disks-ISM jets and outflows-radiation dynamics

Modeling the drain current and its equation parameters for lightly doped symmetrical double-gate MOSFETs

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Journal of Semiconductors 2015年第4期36卷 44-50页

作者： Mini Bhartia Arun Kumar chatterjee Electronics and Communication department Thapar Institute of Engineering and Technology

A 2d model for the potential distribution in silicon film is derived for a symmetrical double gate MOS- FET in weak inversion. This 2d potential distribution model is used to analytically derive an expression for the subthreshold slope and threshold voltage. A drain current model for lightly doped symmetrical dG MOSFETs is then presented by considering weak and strong inversion regions including short channel effects, series source to drain resistance and channel length modulation parameters. These derived models are compared with the simulation results of the SILVACO （Atlas） tool for different channel lengths and silicon film thicknesses. Lastly, the effect of the fixed oxide charge on the drain current model has been studied through simulation. It is observed that the obtained analytical models of syrnmetrical double gate MOSFETs are in good agreement with the simulated results for a channel length to silicon film thickness ratio greater than or equal to 2.

关键词： double gate MOSFET 2d potential distribution model drain current model

d-optimal designs for Multiresponse Linear Models with a Qualitative Factor Under General Covariance Structure

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Acta Mathematicae Applicatae Sinica 2023年第4期39卷 878-885页

作者： Rong-Xian YUE Xin LIU Kashinath chatterjee College of Mathematics and Science Shanghai Normal UniversityShanghai 200234China College of Science Donghua UniversityShanghai 201620China department of Statistics Visva-Bharati UniversitySantiniketanIndia

This paper considers a linear regression model involving both quantitative and qualitative factors and an m-dimensional response variable y. The main purpose of this paper is to investigate d-optimal designs when the levels of the qualitative factors interact with the levels of the quantitative factors. Under a general covariance structure of the response vector y, here we establish that the determinant of the information matrix of a product design can be separated into two parts corresponding to the two marginal designs. Moreover, it is also proved that d-optimal designs do not depend on the covariance structure if we assume hierarchically ordered system of regression models.

关键词： d-optimal designs Multiresponse linear models Qualitative factors

Investigating the fission dynamics of the following neutron shell closed nuclei within a stochastic dynamical approach:^(210)Po,^(212)Rn,and ^(213)Fr

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Chinese Physics C 2023年第3期47卷 127-137页

作者： divya Arora P.Sugathan A.chatterjee Inter-University Accelerator Centre Aruna AsafAli MargNew Delhi 110067India

The dissipative dynamics of nuclear fission is a well confirmed phenomenon that can be either described by a Kramers-modified statistical model or by a dynamical model employing the Langevin *** dynamical models as well as statistical models incorporating fission delays have been found to explain the measured fission observables in several studies,they present conflicting results for shell closed nuclei in the mass region of ***,an analysis of the recent data on neutron shell closed nuclei in the excitation energy range of 40-80 MeV failed to provide a satisfactory description of the data,which was attributed to a mismatch with shell effects and/or entrance channel effects,without reaching a definite *** the present study,we demonstrate that a well established stochastic dynamical code can simultaneously reproduce the available data for pre-scission neutron multiplicities and fission and evaporation residue excitation functions for the following neutron shell closed nuclei^(210)Po and^(212)Rn and their isotopes^(206)Po and^(214,216)Rn without the need for including any extra shell or entrance channel *** relevant calculations are performed by using a phenomenological universal friction form factor with no ad-hoc adjustment of the model ***,we note a significant deviation,beyond experimental errors,for some Frisotopes.

关键词： fusion-fission nuclear dissipation dynamical model neutron shell closure saddle shell corrections