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Effect of rock bolt support mechanism on tunnel deformation in jointed rockmass: A numerical approach

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Underground Space 2021年第4期6卷 409-420页

作者： Ratan das Trilok nath Singh Department of Geology Rajiv Gandhi UniversityArunachal Pradesh 791112India Department of Earth Sciences Indian Institute of Technology BombayMumbaiIndia

A parametric study was conducted to determine the influence of different bolt parameters(bolt length and diameter)on the maximum induced boundary displacements in jointed rockmass,using a numerical method based on finite element *** different types of jointed systems(Type A,Type B,and Type C)were considered and *** A displays normal joint closure,Type B demonstrates a combination of normal and shear joint closure,and in Type C,the majority of the joint is loaded in shear *** ground surface settlement profiles for these three joint systems,under unsupported conditions,are presented in this *** the same rockmass properties,the cases in Type A and Type B exhibit the maximum and minimum settlement,*** each joint type,the effect of variable bolt parameters on the tunnel boundary is studied in terms of the total *** simulation results confirm that an increase in the bolt length does not significantly reduce the boundary displacement,whereas an increase in the bolt diameter substantially reduces the tunnel boundary displacement.

关键词： Jointed rockmass Tunnel deformation Rock bolt FEM

A Survey on Modelling and Compensation for Hysteresis in High Speed Nanopositioning of AFMs:Observation and Future Recommendation

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International Journal of Automation and computing 2020年第4期17卷 479-501页

作者： Maniza ArminPriyo nath RoySajal Kumar das Department of Mechatronics Engineering Rajshahi University of Engineering&TechnologyRajshahi 6204Bangladesh Department of Mechatronics Engineering Khulna University of Engineering&TechnologyKhulna 9203Bangladesh

This paper surveys the recent advances on the modeling and control of hysteresis of piezoelectric actuators(PTAs)in the context of high precision applications of atomic force microscopes(AFMs).The current states,findings,and outcomes on hysteresis modeling and control in terms of achievable bandwidth and accuracy are discussed in *** challenges and the scope of possible research are presented to pave the way to video rate atomic force microscopy.

关键词： Hysteresisno nlinearities piezoelectric actuator smart actuatoratomic force microscope

Culm characteristics and volume-weight relationship of a forest bamboo(Melocanna baccifera(Roxb.) Kurz) from northeast India

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Journal of Forestry Research 2015年第4期26卷 841-849页

作者： Pator Singnar Arun Jyoti nath Ashesh Kumar das Department of Ecology and Environmental Science Assam University

Culm characteristics of Melocanna baccifera, locally ＇muli＇, culms at five different culm ages of 11 girth classes （5-6 to 15-16 cm） were studied from Cachar Dis- trict of southern Assam, northeast India. We recorded internode length, internode diameter, number of internodes per culm, total culm height, total culm green weight and total culm volume of all five culm age classes. Data were gathered on 165 culms, each culm age class containing 33 culms with 3 culms per girth class. Culm height ranged from 3.2 to 15.3 m with highest mean of 9.15 m （in threeyear old culms） and maximum culm height was recorded in four-year old culms. Highest mean and maximum internode length （27.45 and 54.2 cm, respectively）, internode diameter （3.12 and 4.75 cm, respectively） and total culm green weight （5.42 and 12.87 kg/culm, respectively） were recorded in three-year old culms and lowest in current-year culms. Best fitted regression models for all parameters were developed. Significant linear relationships between culm green weight and culm solid volume were documented for all five culm age classes. Their corresponding best-fit regression models were also developed.

关键词： Regression model - Volume equation Ageclass Girth class Yield determination

Extraction of locked-up coal by strengthening of rib pillars with FRP--A comparative study through numerical modelling

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International Journal of Mining Science and Technology 2017年第2期27卷 261-267页

作者： das Arka Jyoti Mandal Prabhat Kumar Ghosh Chandra nath Sinha Amalendu CSIR-Central Institute of Mining and Fuel Research Dhanbad 826001India

In some of the coalfields in India, coal seams are only developed but no extraction of pillars is possible due to the presence of surface or sub-surface structures and also non-availability of stowing materials which leads to huge amounts of coal being locked-up underground. Spontaneous heating and fire, accumulation of poisonous gases, severe stability issues leading to unsafe workings and environmental hazards are the major problems associated with the developed coal pillars. So, there is a pressing need for a technology for the mining industry to extract the huge amount of coal locked-up under different constraints. In this study, the locked-up coal is proposed to be extracted by artificially strengthening the rib pillars. The detailed comparative study is carried out to know the increase of extraction percentage of locked-up coal by strengthening the rib pillars with FRP. Extraction methodology is designed and studied through numerical modelling for its stability analysis to evaluate its suitability of application in underground.

关键词： Locked-up coal Confined core Yield criterion Strengthened rib pillar Strain softening

Population status and regeneration of a tropical clumping bamboo Schizostachyum dullooa under two management regimes

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Journal of Forestry Research 2011年第1期22卷 43-46页

作者： Arun Jyoti nath Ashesh Kumar das Department of Ecology and Environmental Science Assam University Silchar 788011 Assam India

Schizostachyum dullooa （Gamble） Majumder ＇dolu bamboo＇ is a thin walled sympodial moderate sized to large tufted bamboo, dominant in the successional fallows of northeast India. The impact of resource management on productivity and sustainability of the species was evaluated by investigating the population status and regeneration in Cachar tropical semi evergreen forest under private property resource management （PPRM） and common property resource management （CPRM） regimes. Population status revealed current-year, one-year, two-year and three-year-old culms contribute 54%, 24%, 16% and 6% of the total culms per clump, respectively, under PPRM. Three-year-old culms were absent in CPRM and population status was thus represented by current year （83%）, one-year （16%） and two-year （1%） old culms. Net change, rate of change and % gain in population for different age classes showed the prevalence of management practices under CPRM was unscientific. Efficiency of new culm production per clump used as an index of regeneration was 69.7% in PPRM and 59.88% in CPRM. New culms produced under CPRM were small and thin. We conclude that CPRM is inappropriate for a long term economic and ecological sustainability of the species and alternative management protocols are needed for conservation of the species.

关键词： management regime population structure production efficiency Schizostachyum dullooa

Development and evaluation of robust tree biomass equations for rubber tree (Hevea brasiliensis) plantations in India

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Forest Ecosystems 2017年第3期4卷 241-250页

作者： Biplab Brahma Gudeta W.Sileshi Arun Jyoti nath Ashesh Kumar das Department of Ecology and Environmental Science Assam University

Background： In India, rubber（Hevea brasiliensis） plantations cover -0.8 million ha of land, emphasizing its significant role in the Earth＇s carbon dynamics. Therefore, it is important to estimate the biomass stocks of plantations precisely in the context of carbon management. Previous studies in India have focused on development of allometric equations for estimating aboveground biomass（AGB） through harvesting younger trees（up to 14 yr）only or on studies with small sample sizes without assessing model bias. The objective of this study was to develop biomass estimation models for different tree components in rubber plantations and assess model predictive performance at the stand ***： A total of 67 trees were harvested from plantations of different ages（6, 15, 27 and 34 yr） in North East India and their diameter at 200 cm（D）, height and dry weights of different tree components were recorded. The data were used for evaluation of H-D and biomass estimation models at the stand ***： The Michaelis-Menten function was found to be the most appropriate model for estimating tree height among 10 commonly used H-D models. For estimation of AGB and coarse root biomass, a model that involves tree volume（i.e. D2 H） was found to provide better prediction than either D or H alone or a model that combines H, D and stand density. The estimated AGB varied from 28 Mg·ha-（-1） in 6 yr. old plantation to 169 Mg·ha-（-1） in 34 yr. old *** coarse root biomass was estimated at 4 Mg·ha-（-1） for 6 yr. old plantation and 12 Mg·ha-（-1） for 34 yr. old ***： It is concluded that models involving tree volume are more appropriate for regional level biomass estimation than simple power-law models for individual stands. We recommend that the power-law model should not be used for estimation of AGB in plantations at different growth stages because power-law parameters can be biased due to data truncation.

关键词： Aboveground biomass Data truncation Michaelis-Menten function Power-law

xF_3(x,Q^2) Structure Function and Gross-Llewellyn Smith Sum Rule with Nuclear Effect and Higher Twist Correction

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Communications in Theoretical Physics 2016年第12期65卷 663-670页

作者： N.M.nath A.Mukharjee M.K.das J.K.Sarma Department of Physics Rajiv Gandhi University High Energy Physics Laboratory Department of Physics Tezpur University

We present an analysis of the xF_3(x,Q^2) structure function and Gross-Llewellyn Smith(GLS) sum rule taking into account the nuclear effects and higher twist correction. This analysis is based on the results presented in[N.M. nath, et al., Indian J. Phys. 90(2016) 117]. The corrections due to nuclear effects predicted in several earlier analysis are incorporated to our results of xF_3(x,Q^2) structure function and GLS sum rule for free nucleon, corrected upto next-next-to-leading order(NNLO) perturbative order and calculate the nuclear structure function as well as sum rule for nuclei. In addition, by means of a simple model we have extracted the higher twist contributions to the nonsinglet structure function xF_3(x,Q^2) and GLS sum rule in NNLO perturbative orders and then incorporated them to our results. Our NNLO results along with nuclear effect and higher twist corrections are observed to be compatible with corresponding experimental data and other phenomenological analysis.

关键词： perturbative QCD Regge theory nuclear effect higher twist effect

1,3-Bis(2-chloroethyl)-1-nitrosourea enhances the inhibitory effect of Resveratrol on 5-fluorouracil sensitive/resistant colon cancer cells

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World Journal of Gastroenterology 2013年第42期19卷 7374-7388页

作者： Dipon das Ranjan Preet Purusottam Mohapatra Shakti Ranjan Satapathy Chanakya nath Kundu Cancer Biology Division KIIT School of BiotechnologyKIIT UniversityBhubaneswarOdisha 751024India

AIM:To study the mechanism of 5-fluorouracil(5-FU)resistance in colon cancer cells and to develop strategies for overcoming such resistance by combination ***:We established and characterized a 5-FU resistance(5-FU-R)cell line derived from continuous exposure(25μmol/L)to 5-FU for 20 wk in 5-FU sensitive HCT-116 *** proliferation and expression of different representative apoptosis and anti-apoptosis markers in 5-FU sensitive and 5-FU resistance cells were measured by the MTT assay and by Western blotting,respectively,after treatment with Resveratrol(Res)and/or 1,3-Bis(2-chloroethyl)-1-nitrosourea(BCNU).Apoptosis and cell cycle arrest was measured by 4',6'-diamidino-2-phenylindole hydrochloride staining and fluorescence-activated cell sorting analysis,*** extent of DNA damage was measured by the Comet *** measured the visible changes in the DNA damage/repair cascade by Western ***:The widely used chemotherapeutic agents BCNU and Res decreased the growth of 5-FU sensitive HCT-116 cells in a dose dependent *** application of BCNU and Res caused more apoptosis in5-FU sensitive cells in comparison to individual *** addition,the combined application of BCNU and Res caused a significant decrease of major DNA base excision repair components in 5-FU sensitive *** established a 5-FU resistance cell line(5-FU-R)from 5-FU-sensitive HCT-116(mismatch repair deficient)cells that was not resistant to other chemotherapeutic agents(e.g.,BCNU,Res)except *** 5-FU resistance of 5-FU-R cells was assessed by exposure to increasing concentrations of 5-FU followed by the MTT *** was no significant cell death noted in5-FU-R cells in comparison to 5-FU sensitive cells after5-FU *** resistant cell line overexpressed anti-apoptotic[e.g.,AKT,nuclear factorκB,FLICE-like inhibitory protein),DNA repair(e.g.,DNA polymerase beta(POL-β),DNA polymerase eta(POLH),protein Flap endonuclease 1(FEN1),DNA dam

关键词： 5-fluorouracil 1,3-Bis(2-chloroethyl)-1-nitrosourea Resveratrol Colon cancer Combination therapy

Design of Energy Efficient WSN Using a Noble SMOWA Algorithm

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Computers, Materials & Continua 2022年第8期72卷 3585-3600页

作者： Avishek Banerjee Deepak Garg Victor das Laxminarayan Sahoo Ira nath Vijayakumar Varadarajan Ketan Kotecha Department of Computer Science and Engineering Bennett UniversityGreater Noida201310India Department of Information Technology Asansol Engineering CollegeAsansol713305India Department of Computer and Information Science Raiganj UniversityRaiganj733134India Department of Computer Science and Engineering JIS College of EngineeringKalyani741235India School of Computer Science and Engineering University of New South WalesSydneyAustralia Symbiosis Centre for Applied Artificial Intelligence Symbiosis International(Deemed University)PuneIndia

In this paper,the establishment of efficientWireless Sensor Network(WSN)networks has been projected to minimize the consumption of energy using a new Self-adaptive Multi-Objective Weighted Approach(SMOWA)algorithm for solving a multi-objective *** Different WSN nodes deployment policies have been proposed and applied in this paper to design an efficientWireless Sensor Network to minimize energy *** that,the cluster head for each cluster has been selected with the help of the duty *** configuring the WSN networks,the SMOWA algorithms have been developed to obtain the minimum energy consumption for the *** minimization,as well as the amount of day-saving,has been calculated for the differentWSNswhich has been configured through different deployment *** major finding of the research paper is to improve the durability of Wireless Sensor Network(i)applying different deployment strategies:(Random,S pattern and nautilus shell pattern),and(ii)using a new Meta-heuristic algorithm(SMOWA Algorithm).In this research,the lifetime of WSN has been increased to a significant *** choose the best result set from all the obtained results set some constraints such as“equivalent distribution”,“number of repetitions”,“maximum amount energy storage by a node”has been set to an allowable range.

关键词： Wireless Sensor Network(WSN) Self-adaptive Multi-Objective Weighted Approach(SMOWA) deployment strategies Meta-heuristicMethods energy minimization duty cycle