Browsing by Author "Barry, JM"

Now showing 1 - 14 of 14
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    AESYNTAX: a FORTRAN syntax analysis system for the PDP9L
    (Australian Atomic Energy Commission, 1972-12) Barry, JM
    A facility is presented to assist FORTRAN programmers in the development of new programs by the immediate listing and syntax analysis of FORTRAN coded source decks independently of the central computer.
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    AUS diffusion neutronics module - POW3D : a mathematical description
    (Australian Atomic Energy Commission, 1987-04) Barry, JM; Pollard, JP
    The mathematical and computational structure of POW3D, a general purpose zero, one, two and three-dimensional multigroup neutron diffusion code including feedback-free kinetics, is described. The code serves as a diffusion module for the AUS nuclear code system. During the production of this efficient nuclear code, a novel mathematical approach was developed to solve the large number of linear equations involved. A description is given of this technique, the method of implicit non-stationery iteration (MINI), and the way in which it is implemented in the code. The three-dimensional implementation of several other conventional approaches to the solution of the linear systems is also discussed.
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    Heat source determination in waste rock dumps
    (World Scientific, 1997-09-29) Barry, JM
    Oxidation of sulfidic materials in waste rock dumps leads to a degradation in water quality and consequent environmental impacts through acid mine drainage. Predicting the pollutant loads from a dump requires the sulfidic oxidation rates be determined. Oxidation generates heat at a rate proportional to the oxidation rate. The temperature profile of the dump depends upon the distribution and magnitude of heat sources, the thermal conductivity of the dump material, heat transport mechanisms and the dump boundary conditions (heat losses and insolation). A technique originally reported [1][2] to determine the heat source distribution from a dump by solving an inverse time dependent heat conduction equation showed considerable promise. That model is extended to allow for the transport of heat by water moving downwards in the dump and to accommodate additional boundary conditions. The inverse problem is solved with regularisation. Once the heat source terms are found, the rate of sulfidic oxidation is computable. The methods described here form the basis of a software package available for use in rock dump investigations. The methods are applied to determine heat sources in sections of a stable Australian rock dump well suited to treatment by this inverse process. Results of incorporating water transport and new boundary condition in the model are reported and their effect on the predictive power of the approach discussed.
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    An implicit iterative scheme for solving large systems of linear equations
    (Australian Atomic Energy Commission, 1986-12) Barry, JM; Pollard, JP
    An implicit iterative scheme for the solution of large systems of linear equations arising from neutron diffusion studies is presented. The method is applied to three-dimensional reactor studies and its performance is compared with alternative iterative approaches.
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    An introduction to Pascal programming for numerical computers.
    (Australian Atomic Energy Commission, 1986-05) Barry, JM
    These notes arose out of a series of Summer Schools conducted by the AAEC for Higher School Certificate students who were about to enter their final school year. The approach adopted avoids formalism and introduces quickly to the students sufficient programming concepts to enable them to undertake scientific problem solving with the help of tutorial sessions. The notes have been modified extensively so that the reader can work alone through this introduction, attempting exercises designed to build up programming and mathematical skills. The reader needs a knowledge of calculus to work through all the practice exercises; however, School Certificate mathematics is more than sufficient for understanding the expository sections. The examples and the orientation of the presentation are very much mathematical problems. There is no attempt to develop computer games writing skills since, in the author's opinion, more than enough material is available elsewhere. The Pascal programming language is extensive and contains many more facets than are considered here. These features involve more intricate and interesting aspects of data structures, most of which are not necessary for numerical scientific problem solving. Their omission is completely intentional to keep the volume of material presented suitable for a basic first course in computational computing. The students who work successfully through these notes should be able to come to terms with the other concepts by extending their reading (for this the student is referred to Welsh and Elder [1979]). The material presented here could also be programmed in other scientific computer languages such as FORTRAN or BASIC. The programming methodology with languages such as Pascal needed to achieve the same goal can be very different. Hopefully, the student who works through this presentation will be capable of thinking in a modern structured sense and not merely rewriting FORTRAN or BASIC concepts in Pascal.
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    An inverse problem in environmental protection
    (World Scientific, 1995-07-03) Barry, JM
    Where rock dumps are created in many open cut mining operations, Serious pollution problems may be created due to oxidation of sulphide components. The resulting acids and acidic compounds may be released into rivers and streams with Serious on sequences for the environment. Knowledge as to the rate at which these substances are formed and the location within the dump where oxidisation is occurring are important factors in devising optimal strategies for managing the waste site. The oxidisation process generates heat. From temperature recordings taken in boreholes through the rock dump over a period of time, it is expected that both the strength and position of the thermal source may be determined. For this preliminary study it is assumed that one spatial dimension will be sufficient to evaluate the effectiveness of the inverse solution procedure adopted. In determining the internal heat sources it is necessary to allow for heating of the rock dump from the seasonably varying conditions.
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    A mathematician's computer study of the reactor MOATA
    (Australian Atomic Energy Commission, 1974-01) Barry, JM; Clancy, BE; Gilbert, CP; McCulloch, DB; Pollard, JP; Sanger, PL
    These notes collect together lectures on analysis of time dependent (kinetics) experiments on the reactor MOATA. The student will be introduced to scientific problem solving through the kinetics study and he will use mathematics and computers in his analysis in much the same way as a research scientist (although on a somewhat reduced scale).
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    MED-records: an add database of AAEC medical records since 1966
    (Australian Atomic Engery Commission, 1986-08) Barry, JM; Pollard, JP; Tucker, AD
    Since its inception in 1958 most of the staff of the AAEC Research Establishment at Lucas Heights have had annual medical examinations. Medical information accrued since 1966 has been collected as an ADD database to allow ad hoc enquiries to be made against the data. Details are given of the database schema and numerous support routines ranging from the integrity checking of input data to analysis and plotting of the summary results.
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    POW3D - neutron diffusion module of the AUS system: a user's manual
    (Australian Nuclear Science and Technology Organisation, 1996-11) Harrington, BV; Pollard, JP; Barry, JM
    POW3D is a three-dimensional neutron diffusion module of the AUS modular neutronics code system. It performs eigenvalue source of feedback-free kinetics calculations. The module includes general criticality search options and extensive editing facilities including perturbation calculations. Output options include flux or reaction rate plot files. The code permits selection from one of a variety of different solution methods (MINI ICCG or SLOR) for inner iterations with region re balance to enhance convergence. A MINI accelerated Gauss-Siedel method is used for upscatter iterations with group rebalance to enhance a convergence. Chebyshev source extrapolation is applied for outer iterations.
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    Reactors, mathematics and computers summer school
    (Australian Atomic Energy Commision, 1975-01) Backstrom, RP; Barry, JM; Clancy, BE; Gilbert, CP; McCulloch, DB
    Chapter 1 - Physics of reactor kinetics, Chapter 2 - Mathematics of reactors, Chapter 3 - ACL - programming, Chapter 4 - Loading and saving ACL programs on IBM360 disk storage, Chapter 5 - Analogue and hybrid computers.
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    SPLINS and SMOOTH: two FORTRAN smoothing routines
    (Australian Atomic Energy Commission, 1973-01) Barry, JM
    Two FORTRAN subroutines are presented that determine interpolating functions for experimental data. The first produces a spline where the smoothness of the function and the degree to which it fits the data is determined by the user. The second allows subdivision of the data, with individual polynomials being used to approximate the data on each interval and the polynomials are constrained to be piecewise continuous along with their first derivatives. An option to make the second derivative continuous is also available.
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    Subroutine MLTGRD a multigrid algorithm based on multiplicative correction and implicit non-stationary iteration
    (Australian Atomic Energy Commission, 1986-11) Barry, JM; Pollard, JP
    A FORTRAN subroutine MLTGRD is provided to solve efficiently the large systems of linear equations arising from a five-point finite difference discretisation of some elliptic partial differential equations. MLTGRD is a multigrid algorithm which provides multiplicative correction to iterative solution estimates from successively reduced systems of linear equations. It uses the method of implicit non-stationary iteration for all grid levels.
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    Synergic factors in murine nephrosis, demonstrated by computer techniques
    (Australian Atomic Energy Commission, 1975-07) Tucker, AD; Ehmen, G; Smith, HE; Barry, JM; Bills, JW
    Simple environmental changes, including a whole, fresh diet, delayed the onset of the usual diseases of lungs and kidneys in laboratory rats. 'Spontaneous' nephrosis appears to develop from interactions involving inherent immune status, nurture, and environmental 'triggers', particularly inhalants. These methods could be adapted to toxicological investigations and the results suggest the need for new approaches in statistical and interpretative analyses.
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    Vascular injury in lung disease
    (Australian Atomic Energy Commission, 1975) Tucker, AD; Wyatt, JH; Barry, JM; Undery, D
    Inhaled particulates which stimulate a 'delayed', cellular mode of alveolar clearance are excreted to the airways through lymphoid foci in the bronchial bifurcations. The anatomic relations and developing pathology of the tissues adjacent to these foci, including the divisions of accompanying arteries, were studied by serial sectioning and photo-micrographic modelling of rat lungs. The changes are typical of classic 'delayed' inflammatory reactions and, in the rat, the fully developed stage is characterised by fibrinoid necrosis involving all three layers of the arterial wall in a linear lesion across the leading edge of the flow divider. An hypothesis was developed to relate the injury to pulsatile forces. Recent published findings indicate that similarly placed lesions, with species-specific changes in development, are universal in both cerebral and extra-cranial arterial forks of man and animals. Possible associations of the microvascular changes with human atherosclerosis and their further significance in pulmonary and systemic effects arising from industrial and environmental contaminants are explored.