Ball, JE 1990, 'Unsteady flow model for urban drainage systems', Transactions of the Institution of Engineers, Australia. Civil engineering, vol. CE32, no. 2, pp. 66-74.
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A numerical model which uses the algorithm presented by Ball (1) and the results of an investigation into the relative importance of the terms in the full dynamic wave equation of motion presented by Ball (2) for the prediction of unsteady flow propagation within an urban drainage system is presented. Results obtained from the use of the proposed model and also from use of the EXTRAN block of SWMM (3) on sample hypothetical networks are presented. These results indicate a more stable and physically reasonable hydrograph is predicted by the proposed model than that obtained from EXTRAN. Finally, an application of the proposed model to the analysis of an existing drainage network is presented.
CAO, HT, BAWEJA, D & ROPER, H 1990, 'CORROSION CHARACTERISTICS OF STEEL IN SOLUTIONS DERIVED FROM CEMENTS AND BLENDED CEMENTS', CEMENT AND CONCRETE RESEARCH, vol. 20, no. 3, pp. 325-334.
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Potentiodynamic Anodic Polarization techniques were used to investigate the corrosion characteristics of steel in solutions. The solutions were prepared by mixing different cements at a water-binder ratio of 2.0 and extraction after 3 and 7 days. Cements used in this investigation included an OPC with low C3A content, an OPC with high C3A content, a Slag Cement and a Fly Ash Cement. Results indicate that in the absence of chloride ions, the corrosion characteristics of steel in these solutions are very similar to those of steel in lime-saturated water. Despite differences in the rest potentials found in solutions made with the range of binder materials, steel passivation could be observed in all solutions. Passivation imparted to the steel by binder solutions was found to vary in the presence of increasing levels of chloride. A threshold chloride ion concentration for depassivation was established for each binder solution tested. Solutions made from the High C3A Cement and the Slag Cement displayed the best steel passivation characteristics, white the Low C3A Cement solution rated worst. © 1990.
Emanuel, PD, Peiper, SC, Chen, Z, Sheng, DC & Zuckerman, KS 1990, 'Specific inhibition of interleukin 3 bioactivity by a monoclonal antibody reactive with hematopoietic progenitor cells.', Proceedings of the National Academy of Sciences, vol. 87, no. 12, pp. 4449-4452.
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HIM1, originally designated HI98, a murine monoclonal IgM antibody raised against human mononuclear cells, has been reported at the Fourth International Leukocyte Typing Workshop (called antibody M0141) to be the only one of 157 antibodies tested that inhibited binding of interleukin 3 (IL-3) to KG-1 human acute myelogenous leukemia cells and normal human monocytes. We have carried out detailed studies of the selective effect of HIM1 on IL-3-mediated stimulation of hematopoietic progenitors. Preincubation of normal human bone marrow mononuclear cells, depleted of adherent cells and T cells, with HIM1 antibody resulted in a dose-dependent inhibition of IL-3-mediated stimulation of both erythroid burst-forming units (maximum inhibition 55%) and granulocyte/macrophage colony-forming units (maximum inhibition 49%). HIM1 antibody had no effect on growth of erythroid colony-forming units in culture. In addition, preincubation of the cells with HIM1 antibody had no deleterious effect on granulocyte/macrophage colony-stimulating factor-induced growth of either erythroid bursts or granulocyte/macrophage colonies. To be certain that the HIM1 antibody did not react directly with IL-3 itself, we attempted to use immunodepletion to remove IL-3 that had been added to our culture medium. Although we were able to remove IL-3 bioactivity by immunodepletion with anti-IL-3 antibody bound to Sepharose beads, beads with attached HIM1 did not remove IL-3 activity from the medium. Polymorphonuclear neutrophils bind high levels of HIM1, although they have very few or no detectable IL-3 receptors. Therefore, this antibody appears to recognize a cell surface antigen that is critical for optimal IL-3 binding and bioactivity but is not the actual IL-3 receptor.
EZE, OC & LOGANATHAN, P 1990, 'EFFECTS OF PH ON PHOSPHATE SORPTION OF SOME PALE-ADULTS OF SOUTHERN NIGERIA', SOIL SCIENCE, vol. 150, no. 3, pp. 613-621.
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The effect of pH on phosphate sorption by soil samples from two coarse-textured pedons of typic Paleudults in the perhumid tropical zone of Nigeria was studied by equilibrating air-dried soil samples adjusted to pH 3.5–6.5 for 48 h with 10 ppm P and 60 ppm P solutions at two concentrations of CaCl2 and NaCl. Phosphate sorption was generally unaffected by pH at low P additions at the two concentrations of the salts, whereas at high P additions sorption generally decreased with increase in soil pH, except in the presence of the high concentration of CaCl2 (10−2 M) where sorption decreased up to pH 5.0–5.5; beyond this pH range it increased. In both 10−2 M CaCl2 and 3 × 10−2 M NaCl systems, phosphate sorption decreased by 19–89% as a result of dithionite-citrate-bicarbonate (DCB) treatment. The effects of pH on phosphate sorption by treated samples were similar to those by untreated samples. Phosphate sorption increased with increase in depth, probably due to the increase in oxalate and dithionite-citrate-bi-carbonate extractable Fe and Al and the decrease in organic matter content down the pedons. Phosphate sorption by samples from the B horizon increased with increase in period of incubation with lime, whereas in the samples of Ap horizons no consistent trend was obtained. © 1990 Williams and Wilkins.
Indraratna, B 1990, 'Development and applications of a synthetic material to simulate soft sedimentary rocks', Géotechnique, vol. 40, no. 2, pp. 189-200.
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Due to the fact that a model material can be made homogeneous, the influence of different variables on behavioural mechanisms can be investigated independently. Consequently, large experimental scatter attributed to inherent variables (generally unknown) of a natural material can be avoided. This Paper presents the development of an artificial material which can effectively simulate the behaviour of an array of weak, sedimentary rocks. This synthetic soft rock was constituted with gypsum cement, fine sand and water, and characterized with homogeneous and isotropic properties with insignificant variability from one batch to another. It can be easily manufactured in the laboratory and can be cast either in large or small volumes to occupy any predetermined shape of given physical dimensions. An experimental application to study the behaviour of reinforced composites (simulated bolted rock) is also described in this Paper. Puis qu'une matière-modèle peut être rendue homogène, il est possible d'étudier de façon indépendante l'influence exercée par de diverses variables sur les mécanismes de comportement. On peut par conséquent éviter la dispersion considérable expérimentale attribuée aux variabilités inhérentes, généralement inconnues, à une matière naturelle. L'article décrit le développement d'une matière artificielle qui peut simuler effectivement le comportement d'un groupe de roches tendres Sédimentaires. Cette rocbe tendre synthétique comprenait du ciment de gypse, du sable fin et de l'eau et possédait des propriétés homogènes et isotropes qui ne variaient que très peu d'un lot à l'autre. Cette matière peut se produire très facilement dans le laboratoire et être coulée dans de petits ou grands volumes pour prendre n'importe quelle forme prédeterminée de dimensions données. L'article présente aussi une application expérimentale pour étudier le comportement des matières composites renforcées (simulation de rocbes boulonnées).
Indraratna, B & Kaiser, PK 1990, 'Analytical model for the design of grouted rock bolts', International Journal for Numerical and Analytical Methods in Geomechanics, vol. 14, no. 4, pp. 227-251.
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AbstractAn analytical model which represents the behaviour of a reinforced rock mass near a circular underground opening in a homogeneous, uniform stress field has been developed. The theory adopts the concepts of elastoplasticity and considers a proper interaction mechanism between the ground and the grouted (or friction) bolts. It highlights the influence of the bolt pattern on the extent of the yield zone and tunnel deformation. A dimensionless parameter is introduced as a design tool which relates the tunnel convergence to the bolt spacing for a given bolt length. This publication contains the derivation of the analytical model and an illustration of the effect of bolts on the stress and displacement field near an opening. Its application to tunnel design is discussed briefly. The verification of the theory by laboratory simulation and field measurements will be presented, in detail, in a future publication.
Indraratna, B & Kaiser, PK 1990, 'Design for grouted rock bolts based on the convergence control method', International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, vol. 27, no. 4, pp. 269-281.
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A design approach for the application of fully grouted bolts as a passive support system in underground openings is introduced in this paper. The analytical solution was developed based on elasto-plastic concepts and was verified by laboratory simulations with physical models. The application of the theory to one case history and a comparison with an empirical design method (RMR) are presented. Computational examples and general design guides are provided to facilitate the use of the proposed method in practice. © 1990.
Stewart, MG 1990, 'Human error in steel beam design', Civil Engineering Systems, vol. 7, no. 2, pp. 94-101.
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Zhou, JL & Banks, CJ 1990, 'Fractionation of humic acid components by ion exchange chromatography', Environmental Technology, vol. 11, no. 12, pp. 1147-1152.
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