检索结果-南通市图书馆

Evaluation of mine scale longwall top coal caving parameters using continuum analysis

在线全文

学校读者我要写书评

暂无评论

Mining Science and Technology 2011年第6期21卷 787-796页

作者： Manoj Khanal deepak adhikary Rao Balusu Earth Science and Resource Engineering Commonwealth Scientific and Industrial Research OrganizationQueensl and Center for Advanced Technology1Technology CourtPullenvaleQLD4069Australia

A mine-scale analysis of Longwall Top Coal Caving (LTCC) is performed using a continuum mechanics finite element solver called COSFLOW. The uniqueness of COSFLOW is that it incorporates Cosserat continuum theory in its formulation for describing the load deformation of bedded rocks. It is shown that such a continuum based code is valuable for assessing the feasibility of introducing LTCC in any mine. Various LTCC parameters, for example chock convergences, top coal failure behavior, strata cavingmechanism, abutment stresses and vertical stresses, were evaluated for a mine using COSFLOW.

关键词： LTCC COSFLOW Cosserat FEM Modeling Simulation

Numerical Modeling of Porous Flow in Fractured Rock and Its Applications in Geothermal Energy Extraction

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2015年第1期26卷 20-27页

作者： Yucang Wang Shimin Wang Sheng Xue deepak adhikary Earth Science and Resource Engineering CSIROKenmore Qld 4069BrisbaneAustralia Key Laboratory of Computational Geodynamics University of Chinese Academy of Sciences

Understanding the characteristics of hydraulic fracture, porous flow and heat transfer in fractured rock is critical for geothermal power generation applications, and numerical simulation can provide a powerful approach for systematically and thoroughly investigating these problems. In this paper, we present a fully coupled solid-fluid code using discrete element method （DEM） and lattice Boltzmann method （LBM）. The DEM with bonded particles is used to model the deformation and fracture in solid, while the LBM is used to model the fluid flow. The two methods are two-way coupled, i.e., the solid part provides a moving boundary condition and transfers momentum to fluid, while the fluid exerts a dragging force to the solid. Two widely used open source codes, the ESyS Particle and the OpenLB, are integrated into one code and paralleled with Message Passing Interface （MPI） library. Some preliminary 2D simulations, including particles moving in a fluid and hydraulic fracturing induced by injection of fluid into a borehole, are carried out to validate the integrated code. The preliminary results indicate that the new code is capable of reproducing the basic features of hydraulic fracture and thus offers a promising tool for multiscale simulation of porous flow and heat transfer in fractured rock.

关键词： discrete element method lattice Boltzmann method hydraulic fracturing geothermalenergy extraction multiscale modelling.

Effect of strata properties and panel widths on chock performance

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2011年第S1期3卷 407-414页

作者： Manoj Khanal deepak adhikary Rao Balusu Earth Science and Resource Engineering Commonwealth Scientific and Industrial Research Organization (CSIRO) ClaytonVIC 3169Australia Queensland Center for Advanced Technology Commonwealth Scientific and Industrial Research Organization(CSIRO)Pullenvale QLD 4069Australia

The selection of optimum chock (support) capacity is very crucial for a successful longwall mining. The selection of chock capacity depends on the site-specific geotechnical parameters, constraints and longwall panel geometry, which are generally not known in detail in priority. Hence, based on the field and laboratory data, various possible combinations should be analyzed to cater for the unforeseeable mining conditions. This paper discusses the use of numerical model for selecting an appropriate chock capacity based on the site-specific geological and geotechnical information and longwall panel geometry. The fracture mechanisms of immediate and main roofs are also discussed for various panel widths and support capacities. For the models considered, the chock convergence is predicted to increase by about 33% due to the increase in face width from 100 to 260 m. Similarly, the massive roof strata are found to yield higher chock convergence compared to bedded strata.

关键词： chock capacity longwall simulation underground mining

Effect of site amplification on inelastic seismic response

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2019年第3期18卷 535-554页

作者： adhikary S Singh Y Department of Civil Engineering Visvesvaraya National Institute of Technology Nagpur-440010 Maharashtra India Department of Earthquake Engineering Indian Institute of Technology Roorkee-247667 Uttarakhand India

The available models for eff ective periods of site and structure are reviewed in context of frequency tuning in the inelastic seismic response of soil-structure system. The eff ect of seismic intensity and ductility demand, on the eff ective periods, is investigated, and inelastic site amplifi cation is shown to be strongly correlated to the normalized eff ective period. Two non-dimensional parameters, analogous to the conventional site amplifi cation factors in codes, are defi ned to quantify the inelastic site amplifi cation. It is shown that the inelastic site amplifi cation factor (i.e. ratio of constant ductility spectral ordinates at soil site to those at rock outcrop) is able to represent the site eff ects more clearly, as compared to the inelastic site amplifi cation ratio (i.e. ratio of inelastic spectral ordinates at soil site to the corresponding elastic spectral ordinates at rock outcrop). Further, the peak in the amplifi cation factor corresponding to the eff ective site period diminishes rapidly with increasing ductility demand.

关键词： site amplifi cation normalized response spectra eff ective period inelastic seismic response inelastic site amplifi cation factor

L-theanine: A potential multifaceted natural bioactive amide as health supplement

在线全文

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Biomedicine 2017年第9期7卷 842-848页

作者： Rajsekhar adhikary Vivekananda Mandal Plant and Microbial Physiology and Biochemistry Laboratory Department of BotanyUniversity of Gour BangaMalda 732 103W.B.India

Natural bioactive compounds from plants are of great importance in modern therapeutics,which are used to prepare antibiotics, growth supplements or some other therapeutics. Ltheanine is such a bioactive amide amino acid presented in different plants and fungi,especially in tea. Theanine has influential effects on lifestyle associated diseases, such as diabetes, cardiovascular disorders, hypertension, stress relief, tumor suppression,menstruation and liver injury. This amino acid can maintain normal sleep and improve memory function and nullify effect of the neurotoxins. The rate of bioavailability and its medium of ingestion in the body is one of the great concerns for its additional antioxidant properties. Pharmacokinetics of the bioactive compound and its mode of action are described herewith. The biosynthesis and industrial synthesis are also reviewed to promote accelerated production of this bioactive compound in the pharmaceutical industries.

关键词： Bioactive amide Bioavailability L-theanine Lifestyle associated diseases Pharmacokinetics

Nonlinear ion-acoustic solitary waves in an electron-positron-ion plasma with relativistic positron beam

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2018年第10期27卷 471-476页

作者： Ridip Sarma Amar P Misra Nirab C adhikary Department of Mathematics University of Science and TechnologyTechno CityKhanaparaBaridua9th MileRi-BhoiMeghalayaIndia Department of Mathematics Siksha BhavanaVisva-Bharati University Physical Sciences Division Institute of Advanced Study in Science and TechnologyVigyan PathPaschim BoragaonGarchukGuwahati-781035AssamIndia

The propagation characteristics of nonlinear ion–acoustic（IA） solitary waves（SWs） are studied in thermal electron–positron–ion plasma considering the effect of relativistic positron beam. Starting from a set of fluid equations and using the reductive perturbation technique, we derive a Korteweg–de Vries（KdV） equation which governs the evolution of weakly nonlinear IA SWs in relativistic beam driven plasmas. The properties of the IA soliton are studied, and it is shown that the presence of relativistic positron beam significantly modifies the characteristics of IA solitons.

关键词： electron-positron-ion plasma relativistic effect ion-acoustic wave homogeneous balance method

Analysis of electron energy distribution function in a magnetically filtered complex plasma

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2013年第4期22卷 324-329页

作者： M K Deka H Bailung N C adhikary Physical Sciences Division Institute of Advanced Study in Science and Technology Vigyan Path Paschim Boragaon Garchuk Guwahati-781035 Assam India

The electron energy distribution function （EEDF） for a magnetically filtered dusty plasma is studied in a dusty double plasma device where the electron energy can be varied from 0.15 eV to ～ 2.8 eV and plasma density from 10 6 cm-3 to 10 9cm-3 . The characteristics of EEDF for these ranges of plasma parameters are investigated in a pristine plasma as well as in a dusty plasma. The results show that in the presence of dust, there is a drastic modification in EEDF patterns in a plasma with higher electron temperature and density than those in a low temperature and low density plasma produced by the magnetic filter.

关键词： dusty plasma magnetic filter electron energy distribution function

Comprehensive G?bner Basis Theory for a Parametric Polynomial Ideal and the Associated Completion Algorithm

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2017年第1期30卷 196-233页

作者： KAPUR deepak Department of Computer Science University of New Mexico Albuquerque NM USA.

Groebner basis theory for parametric polynomial ideals is explored with the main objec- tive of nfinicking the Groebner basis theory for ideals. Given a parametric polynomial ideal, its basis is a comprehensive GrSbner basis if and only if for every specialization of its parameters in a given field, the specialization of the basis is a GrSbnerbasis of the associated specialized polynomial ideal. For various specializations of parameters, structure of specialized ideals becomes qualitatively different even though there are significant relationships as well because of finiteness properties. Key concepts foundational to GrSbner basis theory are reexamined and/or further developed for the parametric case：（i） Definition of a comprehensive Groebner basis, （ii） test for a comprehensive GrSbner basis, （iii） parameterized rewriting, （iv） S-polynomials among parametric polynomials, （v） completion algorithm for directly computing a comprehensive Groebner basis from a given basis of a parametric ideal. Elegant properties of Groebner bases in the classical ideal theory, such as for a fixed admissible term ordering, a unique GrSbner basis can be associated with every polynomial ideal as well as that such a basis can be computed from any Groebner basis of an ideal, turn out to be a major challenge to generalize for parametric ideals; issues related to these investigations are explored. A prototype implementation of the algorithm has been successfully tried on many examples from the literature.

关键词： Comprehensive GrSbner basis minimal comprehensive GrSbner basis parametric polyno-mial system parametric S-polynomial redundancy.

Conditional Congruence Closure over Uninterpreted and Interpreted Symbols

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2019年第1期32卷 317-355页

作者： KAPUR deepak Department of Computer Science University of New Mexico

A framework for generating congruence closure and conditional congruence closure of ground terms over uninterpreted as well as interpreted symbols satisfying various properties is proposed. It is based on some of the key concepts from Kapur's congruence closure algorithm(RTA97)for ground equations based on introducing new symbols for all nonconstant subterms appearing in the equation set and using ground completion on uninterpreted constants and puri?ed equalities over interpreted symbols belonging to different theories. In the original signature, the resulting rewrite systems may be nonterminating but they still generate canonical forms. A byproduct of this framework is a constant Horn completion algorithm using which ground canonical Horn rewrite systems can be generated for conditional ground *** effcient algorithms for generating congruence closure of conditional and unconditional equations on ground terms over uninterpreted symbols are presented. The complexity of the conditional congruence closure is shown to be O(n*log(n)), which is the same as for unconditional ground *** proposed algorithm is motivated by our attempts to generate effcient and succinct interpolants for the quanti?er-free theory of equality over uninterpreted function symbols which are often a conjunction of conditional equations and need additional simpli?cation. A completion algorithm to generate a canonical conditional rewrite system from ground conditional equations is also presented. The framework is general and ?exible and is used later to develop congruence closure algorithms for cases when function symbols satisfy simple properties such as commutativity, nilpotency, idempotency and identity as well as their combinations. Interesting outcomes include algorithms for canonical rewrite systems for ground equational and conditional theories on uninterpreted and interpreted symbols leading to generation of canonical forms for ground terms, constrained terms and Horn equat

关键词： Completion congruence closure conditional congruence closure intepreted symbols rewrit-ing uninterpreted symbols