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Journal of Forestry Research 2020年第5期31卷 1933-1938页

作者： Amitava chatterjee Department of Soil Science North Dakota State UniversityFargoND 58108-6050USA

Mineralisable soil organic carbon(SOC)pools vary with ecosystem type in response to changes in climate,vegetation and soil *** the effect of climate and soil factors on SOC pools is critical for predicting change over *** soil samples from six ecoregions of the United States were analyzed for permanganate oxidizable C(KMnO4-C)and mineralizable C *** of SOC ranged from 7.9 mg g^-1(Florida site)to 325 mg g^-1(Hawaii site).Mineralisable C pools and KMnO4-C were highest in soils from the Hawaii *** annual precipitation explains SOC and resistant C pool *** content was related to mineralisable active C pools and bacterial *** annual precipitation and clay content are potential variables for predicting changes in SOC pools at large spatial scales.

关键词： Permanganate oxidizable carbon(KMnO4-C) Resistant carbon pool Mean residence time Soil carbon pools United States

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

Novel synthesis with an atomized microemulsion technique and characterization of nano-calcium carbonate(CaCO_3)/poly(methyl methacrylate) core-shell nanoparticles

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Particuology 2013年第6期11卷 760-767页

作者： Aniruddha chatterjee Satyendra Mishra University Institute of Chemical Technology North Maharashtra University

The synthesis of hard-core/soft-shell calcium carbonate （CaCO3）/poly（methyl methacrylate）（PMMA） hybrid structured nanoparticles （〈100nm） by an atomized microemulsion polymerization process is reported. The polymer chains were anchored onto the surface of nano-CaCO3 through use of a cou- pling agent, triethoxyvinyl silane （TEVS）. Ammonium persulfate （APS）, sodium dodecyl sulfate （SDS） and n-pentanol were used as the initiator, surfactant and cosurfactant, respectively. The polymeriza- tion mechanism of the core-shell latex particles is discussed. The encapsulation of nano-CaCO3 by PMMA was confirmed using a transmission electron microscope （TEM）. The grafting percentage of the core-shell particles was investigated by thermogravimetric analysis （TGA）. The nano-CaCO3/PMMA core-shell par- ticles were characterized by Fourier transform infrared （FTIR） spectroscopy and differential scanning calorimetry （DSC）. The FTIR results revealed the existence of a strong interaction at the interface of the nano-CaCO3 particle and the PMMA, which implies that the polymer chains were successfully grafted onto the surface of the nano-CaCO3 particles through the link of the coupling agent, In addition, the TGA and DSC results indicated an enhancement of the thermal stability of the core-shell materials compared with that of the pure nano-PMMA, The nano-CaCO3/PMMA particles were blended into a polypropylene （PP） matrix by melt processing. It can also be observed using scanning electron microscopy （SEM） that the PMMA chains grafted onto the CaCO3 nanoparticles interfere with the aggregation of CaCO3 in the polymer matrix （PP matrix） and thus improve the compatibility of the CaCO3 nanoparticles with the PP matrix.

关键词： Atomized microemulsion Core-shell nanoparticles Thermal properties Compatibility of core-shell nanoparticles with polymer matrix

Time-dependent diffusive interactions between dark matter and dark energy in the context of k-essence cosmology

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Research in Astronomy and Astrophysics 2021年第1期21卷 15-24页

作者： Abhijit Bandyopadhyay Anirban chatterjee Department of Physics Ramakrishna Mission Vivekananda Educational and Research InstituteBelur MathHowrah 711202India

We investigated the scenario of time-dependent diffusive interaction between dark matter and dark energy and showed that such a model can be accommodated within the observations of luminosity distanceredshift data in Supernova la(SN la)*** obtain constraints on different relevant parameters of this model from the observational *** consider a homogeneous scalar field(t)driven by a k-essence Lagrangian of the form L=V(φ)F(X)with constant potential V(φ)=V,to describe the dynamics of dark energy in this *** the temporal behaviour of the FRW scale factor,the equation of state and total energy density of the dark fluid,extracted from the analysis of SN la(JLA)data,we have obtained the time-dependence of the k-essence scalar field and also reconstructed the form of the function F(X)in the k-essence Lagrangian.

关键词： Dark Energy Dark Matter k-essence

Propagation, reflection, and transmission of SH-waves in slightly compressible, finitely deformed elastic media

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Applied Mathematics and Mechanics(English Edition) 2015年第8期36卷 1045-1056页

作者： M.chatterjee A.CHATTOPADHYAY Department of Applied Mathematics Indian School of Mines

The propagation, reflection, and transmission of SH waves in slightly com- pressible, finitely deformed elastic media are considered in this paper. The dispersion relation for SH-wave propagation in slightly compressible, finitely deformed layer over- lying a slightly compressible, finitely deformed half-space is derived. The present paper Mso deals with the reflection and refraction （transmission） phenomena due to the SH wave incident at the plane interface between two distinct slightly compressible, finitely deformed elastic media. The closed form expressions for the amplitude ratios of reflection and refraction coefficients of the reflected and refracted SH waves are obtained from suit- able boundary conditions. For the numerical discussions, we consider the Neo-Hookean form of a strain energy function. The phase speed curves, the variations of reflection, and transmission coefficients with the angle of incidence, and the plots of the slowness sections are presented by means of graphs.

关键词： slightly compressible SH wave propagation inhomogeneity reflection,transmission slowness section

A Novel Approach for Mitigating Power Quality Issues in a PV Integrated Microgrid System Using an Improved Jelly Fish Algorithm

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Journal of Bionic Engineering 2023年第1期20卷 30-46页

作者： Swati Suman Debashis chatterjee Rupali Mohanty Department of Electrical Engineering Jadavpur UniversityKolkataWest Bengal700032India

A two-step methodology was used to address and improve the power quality concerns for the PV-integrated microgrid system. First, partial shading was included to deal with the real-time issues. The Improved Jelly Fish Algorithm integrated Perturb and Obserb (IJFA-PO) has been proposed to track the Global Maximum Power Point (GMPP). Second, the main unit-powered via DC–AC converter is synchronised with the grid. To cope with the wide voltage variation and harmonic mitigation, an auxiliary unit undergoes a novel series compensation technique. Out of various switching approaches, IJFA-based Selective Harmonic Elimination (SHE) in 120° conduction gives the optimal solution. Three switching angles were obtained using IJFA, whose performance was equivalent to that of nine switching angles. Thus, the system is efficient with minimised higher-order harmonics and lower switching losses. The proposed system outperformed in terms of efficiency, metaheuristics, and convergence. The Total Harmonic Distortion (THD) obtained was 1.32%, which is within the IEEE 1547 and IEC tolerable limits. The model was developed in MATLAB/Simulink 2016b and verified with an experimental prototype of grid-synchronised PV capacity of 260 W tested under various loading conditions. The present model is reliable and features a simple controller that provides more convenient and adequate performance.

关键词： Harmonic mitigation Selective harmonic elimination pulse width modulation inverters Search-based optimization techniques Bionic algorithm Total harmonic distortion Modulation indices

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