Bird, TS 1980, 'Asymptotic behaviour of TE11 mode coupling in circular apertures', Electronics Letters, vol. 16, no. 14, pp. 529-529.
View/Download from: Publisher's site
Bird, TS & Boomars, JL 1980, 'Evaluation of focal fields and radiation characteristics of a dual-offset reflector antenna', IEE Proceedings H Microwaves, Optics and Antennas, vol. 127, no. 4, pp. 209-209.
View/Download from: Publisher's site
Chuang, JC, Strong, RT & Waldron, KJ 1980, 'IMPLEMENTATION OF SOLUTION RECTIFICATION TECHNIQUES IN AN INTERACTIVE LINKAGE SYNTHESIS PROGRAM.', American Society of Mechanical Engineers (Paper), no. 80 -DET-91.
View description>>
The numerical and analytical problems encountered in the implementation of the theory developed by Strong and Waldron in an interactive graphic linkage synthesis program are discussed. The resulting program, called RECSYN, is more effective than earlier programs Since the interactive experimentation capability no longer is needed to eliminate defective solutions but can be turned to other uses.
Clark, BE & Shannon, AG 1980, 'A module in mathematics: description and evaluation', International Journal of Mathematical Education in Science and Technology, vol. 11, no. 1, pp. 133-141.
View/Download from: Publisher's site
View description>>
This paper describes an approach to the problem of teaching first year tertiary level mathematics students who have widely varying levels of achievement and ability in mathematics. The evaluation of some aspects of the proposed solution to the problem is based on a semantic differential and a Likert-type questionnaire. © Taylor & Francis Group, LLC.
Dovey, KA 1980, 'Politics and guidance: An overview of the South African school guidance service', British Journal of Guidance & Counselling, vol. 8, no. 1, pp. 1-10.
View/Download from: Publisher's site
View description>>
The South African guidance service is an example of the way in which the population can be manipulated when a guidance service is used to serve the political and economic ends of a ruling group. The South African government views the guidance service as an ‘auxiliary education service’, the function of which is to ensure conformity to the official Christian National Education policy for White schools. ‘Pedagogy’ provides a theoretical explanation for deviance from Christian National norms, and thus is emphasised in the training of guidance personnel. The focus of the guidance service is upon the identification and reorientation of children who are ‘different’. The overview presented here provides an example of the consequences of unquestioning compliance of a guidance service with the values and norms of the dominant culture. It is argued that all guidance services constantly need to make explicit, and to question, the cultural assumptions upon which they operate. © 1980, American Industrial Hygiene Association. All rights reserved.
Goodwin, GC, Doan, HB & Cantoni, A 1980, 'Application of ARMA models to automatic channel equalization', Information Sciences, vol. 22, no. 2, pp. 107-129.
View/Download from: Publisher's site
View description>>
This paper describes a novel approach to automatic channel equalization in digital transmission systems. The approach is based on the use of a finite-dimensional rational approximation to the channel characteristics. This class of channel approximation has the following advantages: it allows a finite parametrization of the channel impulse response which may be of infinite duration, it allows for the possibility of the noise being colored, it applies to either single- or multiple-channel systems, and it has the pedigogical advantage that many other algorithms in current use are based on models which are special cases of this model. The rational approximation to the channel characteristics is used in the paper to develop a new receiver structure using fixed-lag smoothing ideas. Simulation studies are presented showing that the receiver offers advantages over other algorithms for mitigating the effects of intersymbol and interchannel interference including those arising from carrier phase errors. © 1980 Elsevier North Holland, Inc. All rights reserved.
Heiman, JL, Bakoss, SL, Burfitt, AJ & Cridland, L 1980, 'MEASURED AND PREDICTED AXIAL STRAINS AND DEFORMATIONS IN A COLUMN OF A TALL REINFORCED CONCRETE BUILDING.', Institution of Engineers, Australia, Civil Engineering Transactions, vol. CE22, no. 3, pp. 193-201.
View description>>
A site investigation was carried out to determine the axial deformations of a column in a tall reinforced concrete building. Strains were measured in the column concrete using vibrating wire gages and the column deformations were measured by precise leveling. In addition to strain measurements on standard laboratory shrinkage and creep specimens, strain data were obtained from tests that related more closely to the site conditions. Appreciable differences occurred between shrinkage and creep strains measured in the laboratory and some of those obtained by methods given in codes. Shortcomings were found in some of the equations used to predict long-term creep strains from laboratory data and a hyperbolic equation was developed that enabled more accurate predictions to be made. Measured strains in the column were compared with predicted values obtained by two calculation methods and good agreement was obtained.
Hung, NT & Anderson, BDO 1980, 'Analysis and Synthesis of Nonlinear Reciprocal Networks Containing Two Element Types and Transformers', IEEE Transactions on Circuits and Systems, vol. 27, no. 4, pp. 263-276.
View/Download from: Publisher's site
View description>>
This paper presents results for some analysis and synthesis problems of nonlinear reciprocal networks. In particular, for special systems such as lossless reciprocal networks and nonlinear RC reciprocal networks, synthesis techniques are introduced. The central feature of these techniques is the method of finding an appropriate stored energy function for the synthesizing network from prescribed network equations. Under certain assumptions, the stored energy function can be determined directly from the controllability and observability matrices of a system obtained by linearization around any state of the original system. © 1980 IEEE
Kumar, A & Waldron, KJ 1980, 'WORKSPACES OF A MECHANICAL MANIPULATOR.', American Society of Mechanical Engineers (Paper), no. 80 -DET-107.
View description>>
A new theory and a resulting algorithm for tracing the bounding surfaces of mechanical manipulator workspaces is presented. The natures of the numerous singular configurations and means of accommodating them within the algorithm are also studied. In order to sort surfaces of interest from the large number of possible solutions, a numerically implementable labelling technique is also presented. The algorithm is applicable to all practicable manipulator configurations with three, or more, degrees of freedom.
LOGANATHAN, P & BALAKRISHNAMURTI, TS 1980, 'EFFECTS OF NPK FERTILIZERS ON YOUNG COCONUT (COCOS-NUCIFERA) ON A SANDY SOIL IN SRI-LANKA', EXPERIMENTAL AGRICULTURE, vol. 16, no. 1, pp. 41-48.
View/Download from: Publisher's site
View description>>
In a 4 × 4 × 4 NPK field experiment with coconut on a sandy soil, N increased girth, height and leaf production during the pre-bearing period, but phosphorus (up to 6½ years) and K (up to 3½ years) had no effect on any vegetative growth parameters. The rates of fertilizers for optimum copra and nut yield (13 to 16 years) were 0.35, 0.73 and 0.64 kg N, PO and KO/palm/ year respectively. The high P requirement was due to the low solubility of the saphos phosphate in these sandy soils. A positive N × P interaction was also observed. © 1980, Cambridge University Press. All rights reserved.
LOGANATHAN, P & FERNANDO, WT 1980, 'PHOSPHORUS SORPTION BY SOME COCONUT-GROWING ACID SOILS OF SRI-LANKA AND ITS RELATIONSHIP TO SELECTED SOIL PROPERTIES', JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, vol. 31, no. 7, pp. 709-717.
View/Download from: Publisher's site
View description>>
Phosphorus (P) sorption in the presence of 10−2M calcium chloride by ten coconut‐growing acid soil samples of Sri Lanka belonging to the Ultisol, Alfisol and Entisol orders was evaluated using the Langmuir sorption isotherm. The data for all samples fitted the single‐site Langmuir sorption isotherm when equilibrium P was less than 1 μg ml−1, but showed some deviations at larger concentrations of P. A two‐site Langmuir sorption isotherm was successfully used to describe the sorption data of three samples at these high concentrations. The single‐site Langmuir sorption maxima were greater for Ultisols (349–825 μg g−1) than for the other soils (136–345 μg g−1). These sorption maxima were significantly correlated with %‐clay, %‐silt, dithionite‐extractable iron, and 1M ammonium acetate (pH 4.8)‐extractable aluminium. Regression analysis of P sorption on different forms of iron (Fe) and aluminium (Al) indicated that crystalline ‘free Fe oxides’ (dithionite‐extractable Fe minus 0.3M oxalate‐extractable Fe) and ‘active Al’ which consists of hydroxy Al monomers and polymers [1M ammonium acetates, (pH 4.8)‐extractable Al minus 1M potassium chloride extractable Al] were the important factors contributing towards P sorption. Copyright © 1980 John Wiley & Sons, Ltd
Phuoc, HB & Tanner, RI 1980, 'Thermally-induced extrudate swell', Journal of Fluid Mechanics, vol. 98, no. 2, pp. 253-271.
View/Download from: Publisher's site
View description>>
In many polymer processing applications, the generation of heat by viscous losses in the flowing molten polymer is highly significant. The heating reduces the viscosity of the melt sharply and the flow patterns are different from the isothermal case. In this paper, a finite element scheme based on the Galerkin method is developed and is used to explore the effects of thermally induced property changes in extrusion.In the program we solve simultaneously for the flow and temperature fields at each iteration. To check the program for accuracy and correctness, some simple problems were first attempted. A solution for viscous heating in Poiseuille flow was used to check the variable-viscosity part of the program. The crucial convection (‘radiation’) boundary condition was checked using the solution for cooling of a moving rod. Finally, the swelling of extruded jets with self-heating was investigated. A new phenomenon, thermal extrudate swell, was thereby discovered. We have found extrudate expansions up to 70% of the die diameter in a Newtonian fluid with thermal properties similar to those of low density polyethylene. It is clear that this phenomenon will affect many experimental interpretations of extrudate swelling.
