909 research outputs found

    Using Markov Models of Fault Growth Physics and Environmental Stresses to Optimize Control Actions

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    A generalized Markov chain representation of fault dynamics is presented for the case that available modeling of fault growth physics and future environmental stresses can be represented by two independent stochastic process models. A contrived but representatively challenging example will be presented and analyzed, in which uncertainty in the modeling of fault growth physics is represented by a uniformly distributed dice throwing process, and a discrete random walk is used to represent uncertain modeling of future exogenous loading demands to be placed on the system. A finite horizon dynamic programming algorithm is used to solve for an optimal control policy over a finite time window for the case that stochastic models representing physics of failure and future environmental stresses are known, and the states of both stochastic processes are observable by implemented control routines. The fundamental limitations of optimization performed in the presence of uncertain modeling information are examined by comparing the outcomes obtained from simulations of an optimizing control policy with the outcomes that would be achievable if all modeling uncertainties were removed from the system

    PAN AIR: A computer program for predicting subsonic or supersonic linear potential flows about arbitrary configurations using a higher order panel method. Volume 4: Maintenance document (version 1.1)

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    The Maintenance Document is a guide to the PAN AIR software system, a system which computes the subsonic or supersonic linear potential flow about a body of nearly arbitrary shape, using a higher order panel method. The document describes the over-all system and each program module of the system. Sufficient detail is given for program maintenance, updating and modification. It is assumed that the reader is familiar with programming and CDC (Control Data Corporation) computer systems. The PAN AIR system was written in FORTRAN 4 language except for a few COMPASS language subroutines which exist in the PAN AIR library. Structured programming techniques were used to provide code documentation and maintainability. The operating systems accommodated are NOS 1.2, NOS/BE and SCOPE 2.1.3 on the CDC 6600, 7600 and Cyber 175 computing systems. The system is comprised of a data management system, a program library, an execution control module and nine separate FORTRAN technical modules. Each module calculates part of the posed PAN AIR problem. The data base manager is used to communicate between modules and within modules. The technical modules must be run in a prescribed fashion for each PAN AIR problem. In order to ease the problem of supplying the many JCL cards required to execute the modules, a separate module called MEC (Module Execution Control) was created to automatically supply most of the JCL cards. In addition to the MEC generated JCL, there is an additional set of user supplied JCL cards to initiate the JCL sequence stored on the system

    Sulfur in Assam Coal

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    Research carried out on sulphur in Assam coals are reviewed. It is intended to provide a general overview with some recent advances on the forms of sulphur in these coals and their desulphurization and recovery in the forms of elemental sulphur or useful compounds. Greater emphasis is given on a new form of sulphur, i.e., secondary sulphur, in Assam coals. Studies on sulphur in Assam coals would be potentially useful in coal utilization

    X-Ray scattering study of the average polycyclic aromatic unit in Ledo coal

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    This report is an attempt to understand the short-range structural features, to determine the relationship(s) between the aryl/alkyl carbon ratio, and to determine the size of the average polycyclic aromatic unit in Ledo coal from Makum coalfield, Assam, India. An X-ray scattering analysis of the average polycyclic aromatic unit in the coal indicates that the aromatic fraction in this coal is 74% with the aliphatic fraction correspondingly estimated to be 26%. The average carbon atom has 2.3 nearest carbon atom neighbours at an average bond distance of 1.50 (1) Å. The average stacking height of the parallel aromatic layers and the average diameter of the aromatic layers are estimated to be 7.58 Å and 4.86 Å, respectively. For this coal, the average number of stacking layers and the average number of atoms per layer are estimated to be 2 and 8, respectively. In addition, the Gamma band is observed at a d value of 4.42 Å

    A First Order Regional Model of IEC Derived From Ionosonde Measurements for Application in Radio Astronomy

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    Effect of Graded Levels of Condensed Tannin (CT) from \u3cem\u3eMimosa pudica\u3c/em\u3e on \u3cem\u3ein-Vitro\u3c/em\u3e Methane Production

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    Livestock in the country are primarily being fed on fibrous feed resulted in high enteric methane (CH4) emission along with low nutrients availability to host animal. Rumen methano genesis is necessary for the host system as this process ensure the removal of fermentative H2 through the reduction of CO2 into CH4. At the same time this process is wasteful because the emission also represents a loss of dietary energy (6-12% of gross energy intake) apart from contributing to global warming. Worldwide livestock contribute around 90-95 Tg methane to the pool with a contribution of 12-13% from the Indian livestock. Various nutritional and other approaches have been attempted with highly variable success rate in the country and elsewhere for the enteric methane amelioration. The cost of the item used for the mitigation purpose, adaptation of ruminal microbes and toxicity to either host animal or inhabiting microbes are few important criteria for an economic, sustainable and effective amelioration approach (Malik et al. 2015). Herbal materials are being used by the peoples since ages; however, their anti-methanogenic effect is recently established. The anti-methanogenic effect of different herbal materials mainly lies in their secondary metabolites which are highly effective even at very low concentration (Bhatta et al., 2014). Keeping these facts in view, a study was carried to ascertain the effect of varying levels of CT on in vitro total gas and methane production

    Numerical Coefficients for Generation of foF2 in the Indian Zone : Low Solar Activity

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    EXTENT OF LEAD IN HIGH-SULFUR ASSAM COALS

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    This study has been undertaken to understand the precise nature of association of lead in high sulphur Assam coal. Sequential extraction of lead with ammonium acetate, HCl and RuCl 3 solutions havebeen carriedout. RuCl3 hasbeenusedasasuitable reagent fortheextractionoflead.Itisfound thattreatment ofsamplewithCCl 4increasestheextractionofleadbyRuCl 3solution. Theamountof leadinthecoalstudiedvariesbetween43.2and50.4ppm.Ithasbeenfoundthatleadispredominantly occurring in coals in association with organic matter and needs concerted attention to understand its bio-availability. The chemical principles involved therein are also discussed. D 2004 Elsevier B.V. All rights reserved
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