Showing papers by "University of Newcastle published in 1984"
TL;DR: In this paper, moments of the velocity structure function up to the eighteenth order were calculated, primarily with a view to establish accurately the dependence on the order of the inertial range power-law exponent and to draw conclusions about the distribution of energy transfer in the Inertial range.
Abstract: Measurements are presented of the velocity structure function on the axis of a turbulent jet at Reynolds numbers Rλ ≤ 852 and in a turbulent duct flow at Rλ = 515. Moments of the structure function up to the eighteenth order were calculated, primarily with a view to establish accurately the dependence on the order of the inertial range power-law exponent and to draw conclusions about the distribution of energy transfer in the inertial range. Adequate definition of the probability density of the structure function was achieved only for moments of order n ≤ 10. It is shown, however, that, although the values of moments of n > 10 diverges from their true values, the dependence of the moment of the structure function on the separation r is still given to a fair accuracy for moments up to n ≈ 18. The results demonstrate that the inertial-range power-law exponent is closely approximated by a quadratic dependence on the power which for lower-order moments (n [lsim ] 12) would be consistent with a lognormal distribution. Higher-order moments diverge, however, from a lognormal distribution, which gives weight to Mandelbrot's (1971) conjecture that ‘Kolmogorov's third hypothesis’ is untenable in the strict sense. The intermittency parameter μ, appearing in the power-law exponent, has been determined from sixth-order moments 〈(δμ)6〉 ∼ r2−μ to be μ = 0.2 ± 0.05. This value coincides with that determined from non-centred dissipation correlations measured in identical conditions.
934 citations
TL;DR: In this article, a limited number of empirical investigations, into possible causes of tax evasion, have been carried out and most of these have been conducted since 1970 and they have been performed in countries other than Australia.
183 citations
TL;DR: In this article, the convergence and properties of the Riccati difference equation are studied for systems which are not necessarily stabilizable (in the filtering sense), particularly those having uncontrollable roots on the unit circle.
Abstract: This paper studies the convergence and properties of the solutions of the Riccati difference equation Special emphasis is given to systems which are not necessarily stabilizable (in the filtering sense), particularly those having uncontrollable roots on the unit circle Besides generalizing and unifying previous work, the results have application to a number of important problems including filtering and control of systems with purely deterministic disturbances such as sinusoids and drift components
180 citations
TL;DR: In this paper, the Raman spectrum of Graphon carbon black has been recorded using rotating cell techniques and the angular dependence of scattering at 1360, 1580 and 2700 cm−1 are reported and these data suggest that the 1360 cm −1 line is associated with nonplanar microstructure distortions.
157 citations
TL;DR: In this paper, the inertial-range behavior of measured temperature structure functions, up to order 12, is compared with predictions by the log-normal and the $\ensuremath{\beta}$ model.
Abstract: The inertial-range behavior of measured temperature structure functions, up to order 12, is compared with predictions by the log-normal and the $\ensuremath{\beta}$ model. Both models are unsatisfactory from a quantitative viewpoint. The comparison between measurements and models indicates that the intermittency of the temperature field is different from that of the velocity field.
155 citations
TL;DR: It is thus possible for hippocampectomized rats to show apparently normal overshadowing and blocking, at least under some testing conditions, and to have a previously reinforced stimulus blocked conditioning to another stimulus when both were presented as a reinforced compound stimulus.
114 citations
TL;DR: In this article, the authors report the results of a questionnaire survey conducted one month after the Granville rail disaster on ninety-five of the personnel involved in the rescue work and a follow-up on thirteen of them one year later.
Abstract: There is virtually no literature detailing the effects of a disaster on the rescue workers. This paper reports the results of a questionnaire survey conducted one month after the Granville rail disaster on ninety-five of the personnel involved in the rescue work and a follow-up on thirteen of them one year later. Seventy-seven of the ninety-five found the experience stressful; in particular, the feelings of helplessness engendered by the disaster, the magnitude of the destruction, the sight and smell of mutilated bodies, the anguish of relatives, and the need to work under pressure were items highlighted by the respondents. While only about 20 percent experienced specific psychological sequelae as a result of the disaster (depression, anxiety, insomnia), approximately 70 percent of the helpers showed evidence of being temporarily strained (half of them being over this by the end of one week). Thirty-five percent felt more positive about their own lives as a result of their involvement. The utility of debr...
114 citations
TL;DR: Subjects were able to respond to a lens-induced stereoscopic slant more quickly and more accurately when it was imposed on only part of a surface rather than on the whole surface, showing that the presence of a stereoscopic boundary, where disparity is discontinuous, increases the efficiency of stereoscopic processing.
Abstract: Subjects were able to respond to a lens-induced stereoscopic slant more quickly and more accurately when it was imposed on only part of a surface rather than on the whole surface. This shows that the presence of a stereoscopic boundary, where disparity is discontinuous, increases the efficiency of stereoscopic processing. This finding is not consistent with many current models of stereopsis.
106 citations
TL;DR: The magnetic field in the Earth's mantle is computed using a depth-dependent electrical conductivity, of form σ = σa(r/a)−α, and an approximation scheme in which the electromagnetic time constant of the mantle is assumed small compared with the time scales of the secular variation.
95 citations
TL;DR: In this paper, the authors considered a slightly heated turbulent plane jet and examined the effect of the generation, in the interaction region, of new structures, asymmetric with respect to the centreline, which evolve into the self-preserving flow region downstream.
Abstract: All three velocity fluctuations and the temperature fluctuation have been measured in a slightly heated turbulent plane jet. Attention is focused on the interaction region of the flow, which is situated between the location where the two mixing layers nominally merge and that which corresponds to approximate self-preservation.For the jet considered here the mixing-layer structures are symmetrical with respect to the centreline, and when they meet in the interaction region the redistribution of turbulence quantities is dramatic. This redistribution is examined in detail. Also examined is the effect of the generation, in the interaction region, of new structures, asymmetric with respect to the centreline, which evolve into the self-preserving flow region downstream.Turbulence parameters, such as the turbulent Prandtl number, probability density functions, skewness and flatness factors, are also presented, primarily to guide computer simulations of this flow. The superposition procedure of Weir, Wood & Bradshaw (1981), which assumes that the turbulence structure of each mixing layer is not significantly altered by the interaction, is not appropriate to the present flow.
95 citations
TL;DR: It is shown that this extension of the well-known minimum variance control strategy to the multi-input-multi-output case is straightforward when the system interactor matrix is diagonal but presents some unexpected difficulties in the general case.
TL;DR: On montre que les solutions solitons de 3 equations d'evolution non lineaires sont representables par des determinants wronskiens as discussed by the authors, a.k.a.
Abstract: On montre que les solutions solitons de 3 equations d'evolution non lineaires sont representables par des determinants wronskiens
TL;DR: A FORTRAN 77 implementation of Watson's algorithm for computing two-dimensional Delaunay triangulations is described and is shown to have an asymptotic time complexity bound which is better than O(N 1.5) by applying it to collections of N points generated randomly within the unit square.
TL;DR: In this article, surface sites on a series of dealuminated zeolitic catalysts of the H-ZSM-5 and mordenite types have been investigated using Fourier-transform-infrared spectroscopy (FT-IR) using three methods: silanol stretching mode absorbance changes, relative changes in absorbance of adsorbed pyridine modes and analytical data from X-ray fluorescence (XRF) characterizing the extracted surface layer.
TL;DR: A new algorithm which is able to successfully control unknown systems with quite rapidly varying parameters is presented and a convergence proof in the linearly time-varying parameter case is given.
TL;DR: A new type of receiving array which adaptively minimizes ouput noise power while simultaneously satisfying certain robustness and/or bandwidth criteria is considered, and the resulting array gains are shown to be robust against direction uncertainty in the assumed look direction, against wavefront distortions and against array geometry errors.
Abstract: A new type of receiving array which adaptively minimizes ouput noise power while simultaneously satisfying certain robustness and/or bandwidth criteria is considered. The resulting array gains are shown to be robust against direction uncertainty in the assumed look direction, against wavefront distortions and against array geometry errors. The robustness property is incorporated directly into the adaption algorithm via constraints. Extensive simulation has established very satisfactory performance of this new algorithm, both as a limited broad-band processor and as a robust narrow-band processor.
TL;DR: It was tentatively proposed that the turgor-sensitive unloading process provided the appropriate mechanism for sink control of assimilate unloading in the developing bean ovules.
Proceedings Article•
16 Oct 1984TL;DR: In this article, a new fault model, which encompasses the existing fault models, is proposed and a scheme of testing faults from the new model using built-in testing techniques is proposed.
Abstract: In this paper we study the problem of testing RAM. A new fault model, which encompasses the existing fault models, is proposed. We then propose a scheme of testing faults from the new fault model using built-in testing techniques. We also determine the complexity of the extra hardware required to implement built-in testing. A novel approach using microcoded ROM for implementation of built-in testing is also proposed and its complexity is determined.
TL;DR: An algorithm is described which generates a random labeled cubic graph on n vertices which yields a random (0,1)-matrix with prescribed row and column sums which yields procedures which, if successful, generate random labeled graphs with specified degree sequence and random labeled bipartite graphs withspecified degree sequences.
TL;DR: This paper presents an overview of the current status of convergence theory for adaptive control algorithms and focuses on the conceptual common ground between different approaches.
TL;DR: Five women whose infertility was believed to be related primarily to their serum antisperm antibodies underwent in-vitro fertilisation and embryo transfer, and two became pregnant.
TL;DR: The economics of general practice To the Editor: I have just completed studying Dickinson et al.'s article in the May 26 issue of the Journal, and the figures generalized by this model are almost exactly those relating to my practice over the past four years, during which I have kept detailed comparative statistics.
Abstract: The economics of general practice To the Editor: I have just completed studying Dickinson et al.'s article in the May 26 issueof the Journal.' Although they are dealing with a model only, it is extremely close to medical practice as I have experienced it over the past 10 years, both as member of a group practice and, more recently, as a solo practitioner. The figures generalized by this model are almost exactly those relating to my practice over the past four years, during which I have kept detailed comparative statistics. I would encourage much wider exposure of this article to news media and our political masters, with emphasis on the conclusions about the quality of medical attention which may become available in the future. Naoom Haimson, MB BS AMP Building St Georges Terrace, Perth, WA 6000
TL;DR: It is concluded that MPTP has reliable effects on locomotor activity in rats without producing measurable histological or neurochemical changes in the nigrostriatal dopaminergic system.
TL;DR: Dietary compliance was related to initial patterns of dietary intake but could not be predicted from any other factors such as demographic characteristics, duration of disease, knowledge or health beliefs, although this could have been due to small sample sizes.
TL;DR: Mortality rates from ischaemic heart disease in Australia for the period 1969-78 have been analysed by place of residence, occupation and country of birth, finding that Australian born residents showed a greater decline, while men born in Greece and Italy may have had an increase in IHD mortality.
Abstract: Mortality rates from ischaemic heart disease (IHD) in Australia for the period 1969-78 have been analysed by place of residence, occupation and country of birth. Large variations were found among subpopulations. Throughout the period IHD mortality was lowest among professional and farming occupations and highest among workers in mining, transport and communications. Geographically, mortality from IHD was highest on the east coast and lowest in Western Australia. Mortality among immigrants was lower than among people born in Australia, with death rates for those born in Greece, Italy and Yugoslavia about half the average rates. Mortality from IHD in Australia has declined by about 25% over the last decade. However, the decline has not occurred uniformly. By occupation, the professional, technical and related workers showed the largest decline, while administrative, executive and managerial workers experienced the smallest decline. By place of residence in Australia, the largest declines occurred in the Hunter and Geelong regions, although the Hunter region still has the highest rate. Western Australia, excluding Perth, and rural Victoria did not show any marked decline. The remaining regions particularly the capital cities all experienced similar declines. When analysed by country of birth, Australian born residents showed a greater decline, while men born in Greece and Italy may have had an increase in IHD mortality. There is every indication that the decline will continue. Even those subpopulations with low initial IHD mortality experienced the decline, thus Perth and Adelaide (with low rates) had similar declines to Brisbane and Sydney (with high rates) and the professional occupation group which had the lowest rate also experienced the greatest decline.(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: In this article, the atmospheric surface layer of sixth-order velocity structure functions and of mixed velocity-temperature structure functions were measured in the laboratory at moderate turbulence Reynolds numbers, and the results support values of Μ and Μθ previously obtained in the lab.
Abstract: Measurements in the atmospheric surface layer of sixth-order velocity structure functions and of sixth-order mixed velocity-temperature structure functions support values of Μ and Μθ previously obtained in the laboratory at moderate turbulence Reynolds numbers.
01 Sep 1984-Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science
TL;DR: In this article, it was shown that the rate limiting step in the interfacial oxidation of these melts by CO2 is the dissociation of CO2- Rates of oxidation, in mol cm−2 s−1, in CO 2-CO atmospheres are deduced to be given by the equations:v = (consuming p CO 2 CO 3 ) exp(−15,900/T − 2.03) andv = pCO 2
Abstract: Measurements of the rates of dissociation of CO2 on liquid iron oxides and CaO-saturated liquid calcium ferrites have been made by the14CO2-CO isotope exchange technique. For temperatures up to about 1550 °C, the apparent first order rate constants for both melts are essentially inversely proportional to the equilibrium CO2/CO ratio over the range studied (≈0.4 to 12). Evidence is presented that the rate limiting step in the interfacial oxidation of these melts by CO2 is the dissociation of CO2- Rates of oxidation, in mol cm−2 s−1, in CO2-CO atmospheres are deduced to be given by the equations:v =(
p
CO
2
a
−
p
CO) exp(−15,900/T − 2.03) andv = (pCO2
α
o
-1
−pCO) exp(−3800/T − 6.93) for the iron oxides and CaO-saturated calcium ferrites, respectively, wherea
0
is the oxygen activity of the melt expressed as the equilibrium CO2/CO ratio and the pressures are in atmospheres. The strong dependence on the CO2/CO ratio is shown to be consistent with the need to transfer two charges to the adsorbing or dissociating CO2 molecule. Correlation with the existing surface tension data is inconclusive.
TL;DR: In this paper, the authors considered the problem of spiral self-avoiding walks and proved that the number of n-step spiral self avoidance walks is given by sn =exp(exp(2 pi (n/3)12/)/(n74/c)(1+O(1/square root n)) where c= pi /(4354/) where c = pi / (4354)/
Abstract: The authors consider the problem of spiral self-avoiding walks as recently introduced by Privman (1983) They prove that the number of n-step spiral self-avoiding walks is given by sn=exp(2 pi (n/3)12/)/(n74/c)(1+O(1/ square root n)) where c= pi /(4354/) Similar results for various subsets of these walks are also obtained
01 Dec 1984
TL;DR: In this paper, a new algorithm for discrete time adaptive pole assignment is proposed, which incorporates the internal model principle and allows for rejection of deterministically modelled disturbances and tracking of simple reference signals.
Abstract: This paper considers a new algorithm for discrete time adaptive pole assignment which incorporates the internal model principle and hence allows for rejection of deterministically modelled disturbances and tracking of simple reference signals. A complete global stability analysis is given.
TL;DR: In this paper, the axial momentum integral equation is used to show that the wall shear stress distribution is determined primarily by the pressure gradient and the transverse shear stresses, a result that confirms the negligible size of the mean secondary flow.