Showing papers by "University of Wollongong published in 1981"
TL;DR: In this paper, an approximate integral-equation approach is used to model the growth and collapse of a vapour cavity in close proximity to an initially plane free surface, and features observed and predicted include the formation of an accelerating liquid jet in the bubble and a pronounced spike in the free surface during the collapse phase of the bubble's life.
Abstract: An approximate integral-equation approach is used to model the growth and collapse of a vapour cavity in close proximity to an initially plane free surface. By comparison with experiment, it is shown to predict all the salient features of the bubble and freesurface interaction, provided that the complete nonlinear Bernoulli pressure condition is applied on both surfaces. Features observed and predicted include the formation of an accelerating liquid jet in the bubble and a pronounced spike in the free surface during the collapse phase of the bubble's life. If the bubble is initially sufficiently close to the free surface, it will become ‘entrained’ in the raised free surface with a veneer of liquid separating the two free surfaces.
292 citations
TL;DR: In this paper, it was shown that if a stream emerges into more open rural valleys at lower slopes and are accompanied by extensive floodplains formed of fine cohesive sediment, there is a dramatic reduction in channel size, accompanied by a downstream increase in flood frequency in their lower reaches.
110 citations
TL;DR: Younger, less educated patients with higher occupational status were found to show much uncertainty and depression but also much sociability and few feelings of helplessness and patients with more severe disabilities expressed more anxiety, depression and anger and fewer good feelings but considerable sociability.
66 citations
TL;DR: In this paper, the existence or non-existence of viscous eddies due to point, ring or line distribution of stokeslets near no-slip boundaries is investigated, and it is found that the following constraints on the fluid lead to the existence of eddies (i) a zero flux condition, (ii) confinement due to boundaries, (iii) streamline convergence near the singularity, and (iv) the interaction of flow fields due to adjacent stokeslet.
Abstract: Kinematic and dynamic conditions for the existence, or otherwise, of viscous eddies due to point, ring or a line distribution of stokeslets near no-slip boundaries are investigated. Boundaries considered are (i) a single plane boundary, (ii) two parallel plane boundaries, (iii) an infinite cylinder, and (iv) a finite cylinder. It is found that the following constraints on the fluid lead to the existence of eddies (i) a zero flux condition, (ii) confinement due to boundaries, (iii) streamline convergence near the singularity, and (iv) the interaction of flow fields due to adjacent stokeslets. The existence or non-existence of various viscous eddies is illustrated and discussed in detail for the case of infinite line distributions of stokeslets (i.e. a two-dimensional stokeslet). The paper suggests that flow fields produced by sessile micro-organisms are determined primarily by the container geometry in which they are located.
60 citations
TL;DR: In this article, two hypotheses were proposed to explain the formation of distinct scroll bars and subsequent floodplain ridges on the Beatton River, and these hypotheses were reassessed here in the light of recent field observations, which suggest that an initial scroll bar may form around a stranded dead tree that acts as a sedimentation nucleus.
Abstract: In recent work, two hypotheses were proposed to explain the formation of distinct scroll bars and subsequent floodplain ridges on the Beatton River. These hypotheses are reassessed here in the light of recent field observations, which suggest that an initial scroll bar may form around a stranded dead tree that acts as a sedimentation nucleus on a point-bar platform.
58 citations
TL;DR: In the Bega batholith of southeastern Australia, the authors of as mentioned in this paper showed that the distribution of these mantles can be determined largely by mineralogical variations in the parent rock.
Abstract: Summary Arenaceous weathering mantles on the Bega batholith, southeastern Australia, are similar to those described from Europe by MILLOT. As in Europe, they have been formed by hydrothermal alteration of the parent rock, and later by chemical weathering of biotites and feldspars. But comparisons with nearby torfields shows that their distribution is determined largely by mineralogical variations in the parent rock. Unlike the examples cited by MILLOT, in the Bega mantles kaolinite is the dominant clay mineral. Nonetheless these mantles seem to be contemporary, not relict features, and apparently formed under a temperate climate.
53 citations
TL;DR: The authors argued that cultural pluralism as public policy was a means of preventing the hegemonic control by any one ethnic group of the political and economic life of a society, thus triggering autonomous and break-away moves in these areas by subordinate ethnic groups.
Abstract: of language and ethnic-origin based behaviours which did not require autonomous or conflicting ’social structures’. That is, cultural pluralism as public policy was seen as a means of preventing the hegemonic control by any one ethnic group of the political and economic life of a society, thus triggering autonomous and break-away moves in these areas by subordinate ethnic groups. Such ’breaks’ would create, it was feared, a disintegration of overall social relations and a fragmentation of allegiances to ’society as a whole’. Such fears were a reflection of the activities of Black, Spanish-American and White Ethnic ’blacklash’ groups, which disruptcd mainstream American life in the mid and late 1960s.
47 citations
TL;DR: In this paper, the authors present preliminary details of a laboratory study aimed at identifying the mechanism or mechanisms whereby the incorporation of fly ash influences the strength of lean concrete mixes suitable for use in the construction of concrete gravity dams.
47 citations
TL;DR: The identification of mesaconic acid may indicate that the methylsuccinic acid formed in patients with isovaleric acidemia is subject to further metabolism, and supports the contention that urinary methylsuCCinic acid seen in these patients has arisen by omega-oxidation of isovalic acid.
37 citations
33 citations
TL;DR: An injury report from designed for use in a large strip and sheet steel processing plant incorporated check lists intended to yield detailed ergonomics data, which shows the injury rate was almost halved over the five years.
TL;DR: Rhodoplast envelope rupture appeared to be accompanied by phycobilisome loss from the thylakoids and the response of the rate of photosynthesis to the inorganic phosphate and pyrophosphate concentrations in the medium was qualitatively similar to that previously reported for spinach chloroplasts.
Abstract: A procedure is described for isolating photosynthetically active rhodoplasts (“red algal chloroplasts”) from the marine alga Griffithsia monilis. The rhodoplasts exhibited rates of CO2 fixation and CO2-dependent O2 evolution in the order of 200 micromoles per milligram chlorophyll a per hour when illuminated with red or green light and were approximately 80% intact. The response of the rate of photosynthesis to the inorganic phosphate and pyrophosphate concentrations in the medium was qualitatively similar to that previously reported for spinach chloroplasts. Osmotically shocked rhodoplasts evolved O2 from ferricyanide in red, but not in green, light and were completely uncoupled. Rhodoplast envelope rupture appeared to be accompanied by phycobilisome loss from the thylakoids.
TL;DR: In this article, K-Ar age determinations on Tertiary basalts provide the basis of a new chronology for part of the southcentral uplands of N.W.S.
Abstract: Summary K‐Ar age determinations on Tertiary basalts provide the basis of a new chronology for part of the south‐central uplands of N.S.W. A master planation surface which truncates a very diverse lithology was formed before Tertiary times, probably during the Triassic. There is evidence neither of the early Tertiary nor mid‐Tertiary planations which figured so prominently in many accounts of the N.S.W. uplands. By the beginning of Miocene times the Lachlan and Wollondilly Rivers had cut to within 80 metres of their present beds. Basalts in headwater valleys show that this part of the Great Divide was well‐established by Eocene times. The sequence of events in this region is strikingly similar to that proposed for the southern part of the Sydney Basin.
TL;DR: A stimulator adapter is described that automatically generates true biphasic constant current pulses from the single pulse output of a standard stimulator, permitting great ease of control of stimulating parameters.
TL;DR: Stimulation at 10 pulses/sec resulted in a doubling of the release of aspartic acid over the resting level and about a 60% increase in glutamate release, which is in essential agreement with studies utilizing K+ depolarization-evoked release from slices.
TL;DR: Two unusual sulphur-containing amino acids have been isolated from urine of a baby who died with major physical malformations and failure of growth and development, suggesting their origin from conjugation of methacrylic acid with Cysteine and subsequent decarboxylation of the cysteine conjugate.
Abstract: Two unusual sulphur-containing amino acids have been isolated from urine of a baby who died with major physical malformations and failure of growth and development. Sensitive mass spectrometric methods were used to identify the nanomole quantities of the compounds available as S-(2-carboxypropyl)-cysteine and S-(2-carboxypropyl)-cysteamine. Incubation of fibroblasts in either [14C]Valine or [35S]cysteine resulted in radioactive labelling of the compounds, suggesting their origin from conjugation of methacrylic acid with cysteine and subsequent decarboxylation of the cysteine conjugate. Specific assay of methacrylyl-CoA hydratase is needed for final proof that this is a new inborn error of that enzyme, but these findings and parental consanguinity make this very likely. It seems possible that methacrylic acid or one of its derivatives may have caused the malformations present in the baby.
TL;DR: In this paper, residual chlorine in aqueous solution is converted to 4-chloro-2,6-dimethylphenol, which is extracted into hexane and determined by gas chromatography.
TL;DR: It is shown that besides the known minimum variance control law design, a D - optimal experiment consisting of sinusoidai input test signals without feedback can be obtained by solving a set of nonlinear equations.
Abstract: The output power constraint problem of optimal experiment design for an autoregressive model is considered. It is shown that besides the known minimum variance control law design, a D - optimal experiment consisting of sinusoidai input test signals without feedback can be obtained by solving a set of nonlinear equations. Two examples are also given to illustrate this design methodology.
TL;DR: DEAE-Sephadex equilibrated in 0.5 M triethylammonium acetate is suitable for the quantitative isolation of lactonisable organic acids as discussed by the authors.
TL;DR: The authors evaluated the effects of a youth work programme with a focus on interpersonal relationships, contacts were made with young people on the streets of a large Australian city, and indicated that they were experiencing a poverty of interpersonal regard.
Abstract: To evaluate the effects of a youth work programme with a focus on interpersonal relationships, contacts were made with young people on the streets of a large Australian city. Verbalizations from them were recorded and content analysed and indicated that they were experiencing a poverty of interpersonal regard. They mentioned few satisfying interpersonal relationships and talked of being lonely. Comparison of young people who participated in the programme with others who did not indicated that the former had made at least short term gains in both of these areas, while other aspects of their experience outside the focus of the programme had not varied from the beginning to the end of the four month period of the evaluation.
TL;DR: It was concluded that under the defined conditions, reductive pentose phosphate cycle activity could be measured without interference from oxidative carbohydrate metabolism in this experimental system.
Abstract: Oxidative and reductive carbohydrate metabolism was studied in reaction mixtures based on chlorophyll-free stromal extracts from chloroplasts of Pisum sativum A new assay system for the reductive pentose phosphate cycle was characterized When provided with ATP, an enzymic ATP-regenerating system and reduced pyridine nucleotide, substantial rates of CO 2 fixation and pyridine nucleotide oxidation were observed following the addition of millimolar concentrations of reductive pentose phosphate cycle intermediates The reduced pyridine nucleotide requirement could be met either by NADPH, or by NADH plus the added enzymes NAD + -glyceraldehyde phosphate dehydrogenase and phosphoglycerate kinase When the assay system was primed with small amounts of reductive pentose phosphate cycle intermediates, lower rates of pyridine nucleotide oxidation were observed, but turnover of the complete cycle was demonstrated Autocatalytic effects were not evident The optimum pH and Mg concentrations for cycle turnover were similar to those believed to exist in the stroma of intact chloroplasts in the light Oxidative carbohydrate metabolism was studied by supplying oxidized pyridine nucleotide and measuring its rate of reduction in the presence of sugar phosphates Glycolytic activity, estimated as the rate of fructose-6-phosphate entry to the phosphofructokinase reaction was 27 micromoles per milligram chlorophyll per hour when fructose-6-phosphate was provided as substrate Evidence based on glucose-6-phosphate and ribose-5-phosphate-dependent NADP + reduction showed that the oxidative pentose phosphate cycle was also active Apparent oxidative pentose phosphate cycle turnover in the presence of ribose-5-phosphate, estimated as the rate of glucose-6-phosphate entry to the glucose-6-phosphate dehydrogenase reaction, was 17 micromoles per milligram chlorophyll per hour It was concluded that under the defined conditions, reductive pentose phosphate cycle activity could be measured without interference from oxidative carbohydrate metabolism in this experimental system
TL;DR: In this article, a data set of 102 analyses of these igneous rocks has been used to evaluate the effectiveness of various discriminants based on univariate and multivariate analysis.
Abstract: Permian and post-Permian igneous rocks of the southern Sydney Basin of New South Wales can be distinguished on the basis of major-element geochemistry. A data base of 102 analyses of these igneous rocks has been used to evaluate the effectiveness of various discriminants based on univariate and multivariate analysis. Inspection of histograms of compositional frequency for each major-element oxide is an efficient method of univariate analysis and assigns up to 92.2% of the rocks to the correct age group. Discriminant function analysis using up to 10 variables does not produce a more efficient discriminant than the simple binary plot of SiO
2
versus TiO
2,which assigns 95.1% of the rocks to the correct age group. No other binary or ternary diagram commonly used in petrology produces such an efficient discriminator.
TL;DR: In this article, the authors show that the widely quoted semiclasdcal inversion of the 4 He-4 He total scattering cross section data in the region of the low repulsive wall is inconsistent with both a recent ab initio and a semi-empirical potential representing the helium interatomic forces.
01 Jan 1981
TL;DR: The lIIawarra between Stanwell Park and Werri fit within a general dynamic classification characterizing most beaches of the world as mentioned in this paper, where reflective and dissipative beaches are two types of beaches.
Abstract: The beaches of the lIIawarra between Stanwell Park and Werri fit within a general dynamic classification characterizing most beaches of the world. At the one end of this classification lies the reflective beach which is devoid of inshore topography, mainly sheltered and temporally stable. At the other end lies the dissipative beach which is characterized by a barred surf zone, situated on exposed coastline and susceptible to rapid change. Because of structural control on the geology of the lIIawarra coastline some of the beaches are often directed. or even forced, into morphology which may at first appear abnormal for the setting of that beach. Additionally man is interfering in places with the coastal environment to the extent that some beaches may be irreversibly locked into an erosional cycle.
01 Jan 1981
TL;DR: This chapter discusses the evolution from ectothermia toward endothermia, and it seems almost certain that the pre-mammalian reptiles possessed this vasomotor ability to alter their body conductance.
Abstract: Publisher Summary This chapter discusses the evolution from ectothermia toward endothermia. Many reptiles have been shown to possess a rate of heating different to their rate of cooling. It has been shown in a variety of lizards that vasomotor control of blood flow is a significant contributor to this difference between rates of heating and cooling. This has also been demonstrated in the tuatara and in turtles. Measurement of local cutaneous blood flow in a lizard has shown it to increase during heating. In view of the variety of reptiles in which it has been reported, it seems almost certain that the pre-mammalian reptiles possessed this vasomotor ability to alter their body conductance. Endotherms have a high level of metabolism compared to ectotherms. The resting mammal that is undergoing no extra expenditure of energy for thermoregulation will have a level of energy metabolism that is four to five times that of a similar sized resting reptile that is at the same body temperature. Mammals may have larger internal organs than reptiles and thus a larger resting metabolism. The reptile–mammal difference in standard metabolism also exists when levels of maximal metabolism are considered.
TL;DR: In this article, an analytical expression for the electrical transparency of a corona triode with a biased parallel wire grid was derived and extended to a square grid by modelling it with an equivalent parallel grid having the same optical transparency.