Showing papers by "University of South Australia published in 1993"
TL;DR: Three dimensions of interpersonal relations among Australian school children were hypothesized as reflecting tendencies to bully others, to be victimized by others, and to relate to others in a prosocial and cooperative manner, supporting the factorial independence of the three hypothesized dimensions.
Abstract: Three dimensions of interpersonal relations among Australian school children were hypothesized as reflecting tendencies (a) to bully others, (b) to be victimized by others, and (c) to relate to others in a prosocial and cooperative manner. School children from two secondary schools (School A, n = 285; School B, n = 877) answered 20 questions assessing styles of interpersonal relations. Factor analyses of the item scores obtained from each of the two schools provided highly similar results, supporting the factorial independence of the three hypothesized dimensions. Students attending School B answered additional questions to assess self-esteem, level of happiness, and liking for school. Generally low levels of self-esteem were found among children who reported being more victimized than others, and high self-esteem among children practicing more prosocial behavior. The tendency to bully others was correlated negatively with happiness and liking school, but no relationship was found between this variable and self-esteem.
528 citations
TL;DR: The headache group was found to be significantly different from the non-headache group in respect to forward head posture, and the need to screen for cervical etiology in patients who are suspected of suffering from common migraine is highlighted.
Abstract: In this study, 60 female subjects, aged between 25 and 40 years, were divided into two equal groups on the basis of absence or presence of headache. A passive accessory intervertebral mobility (PAIVM) examination was performed to confirm an upper cervical articular cause of the subjects' headache and a questionnaire was used to establish a profile of the headache population. Measurements of cranio-cervical posture and isometric strength and endurance of the upper cervical flexor muscles were compared between the two groups of subjects. The headache group was found to be significantly different from the non-headache group in respect to forward head posture (FHP) (t = -5.98, p < 0.00005), less isometric strength (t = 3.43, p < 0.001) and less endurance (t = 8.71, p < 0.0005) of the upper cervical flexors. A statistically significant relationship was also established between natural head posture and isometric endurance of the upper cervical flexor musculature which demonstrated that FHP corresponded with a low endurance capacity (chi 2 = 13.2; p < 0.01). The outcome of this study highlights the need to screen for cervical etiology in patients who are suspected of suffering from common migraine.
413 citations
TL;DR: The authors argue that occupation fulfils basic human needs essential for survival, provides the mechanism for people to exercise and develop innate capacities of a biological, social and cultural nature, to adapt to environmental changes, and to flourish as individuals.
Abstract: This paper discusses occupation as a central aspect of the human experience. It argues that occupation fulfils basic human needs essential for survival, provides the mechanism for people to exercise and develop innate capacities of a biological, social and cultural nature, to adapt to environmental changes, and to flourish as individuals. However the basic occupational needs of people have been obscured by the current complexity of occupational technology and economy, and the social strictures, divisions, and values which have been established progressively throughout time.
349 citations
TL;DR: The presence of dissolved organic matter (humic material in particular) in source water decreases the effectiveness of granular activated carbon filters in the treatment of drinking water as discussed by the authors, which may be due to an increase in the negative charge on the carbon surface and a decrease in available surface area after adsorption.
249 citations
TL;DR: In this article, the authors examined the relevance of selected personality variables, namely Eysenck's factors of extraversion, psychoticism and neuroticism, and the psychological well being factor of self-esteem to the tendency to bully and to be victimized.
240 citations
TL;DR: In this paper, the development of multicomponent and multilayer coatings for tribological applications is reviewed and the rationale behind the improved performance of such coatings is discussed, as well as the advantages of these coatings.
185 citations
TL;DR: In this paper, a single chemisorbed monolayer was used to study contact electrification and adhesion between two silica surfaces, one coated with an amino-silane.
Abstract: ELECTRICAL charge separation following contact between two materials (contact electrification or the triboelectric effect) is well known to occur between different materials as a consequence of their different electronic structures1,2. Here we show that the phenomenon occurs between two surfaces of the same material if one is coated with a single chemisorbed monolayer. We use the surface force apparatus3 to study contact electrification4 and adhesion between two silica surfaces, one coated with an amino-silane. The presence of this monolayer results in significantly enhanced adhesion between the surfaces, owing to electrostatic attraction following contact electrification, in accord with Derjaguin's electrostatic theory of adhesion5. At the same time, the observed increase in adhesion is consistent with Fowkes' acid–base model6 (in which acid–base interactions between surface groups are considered to be the predominant factor determining adhesion), as the monolayer converts the originally acidic silica surface to a basic (amine-terminated) one. These observations demonstrate a link between acid–base interactions and contact electrification.
184 citations
TL;DR: The extent and nature of bullying among South Australian primary school children and their self appraisals of peer relations were investigated and the tendency to be victimised correlated negatively with self appraisal of the number of friends, popularity, happiness at school and feelings of safety at school.
Abstract: The extent and nature of bullying among South Australian primary school children and their self appraisals of peer relations were investigated in a survey of 412 primary school children between the ages of 7 to 13 years. It was found that 10% of boys and 6% of girls were subject to peer group bullying and for 8% of such children the bullying episodes lasted 6 months or more. Factor analysis of styles of interpersonal relating amongst children identified three independent factors including a tendency to bully, to be victimised and to act in a pro-social manner. The tendency to be victimised correlated negatively with self appraisals of the number of friends, popularity, happiness at school and feelings of safety at school. The findings are discussed in relation to research linking negative self appraisals of interpersonal competence with isolation and proneness to depression in later years.
182 citations
TL;DR: In this article, the plausibility of electrical double layers acting to stabilize an equilibrium thickness of intergranular glass films in polycrystalline ceramics is explored and estimates of the screening length, surface potential, and surface charge required to provide a repulsive force sufficiently large to balance the attractive van der Waals and capillary forces for observable thicknesses.
Abstract: The plausibility of the entropic repulsion of electrical double layers acting to stabilize an equilibrium thickness of intergranular glass films in polycrystalline ceramics is explored. Estimates of the screening length, surface potential, and surface charge required to provide a repulsive force sufficiently large to balance the attractive van der Waals and capillary forces for observable thicknesses of intergranular film are calculated and do not appear to be beyond possibility. However, it has yet to be established whether crystalline particles in a liquid-phase sintering medium possess an electrical double layer at high temperatures. If they do, such a surface charge layer may well have important consequences not only for liquid-phase sintering but also for high-frequency electrical properties and microwave sintering of ceramics containing a liquid phase.
166 citations
TL;DR: The tendency to be victimized by peers at school among girls was found to be associated with poorer family functioning and more negative attitudes toward mothers; negative relations with absent fathers in single-parent families characterized boys who reported being victimized at school.
Abstract: Links were examined between three dimensions of peer relating at school among Australian children and selected family and parental background factors. Questionnaires containing measures of children's tendencies to bully others, to be victimized, and to act in a prosocial manner were administered to boys and girls (N = 1,012) aged 11 to 16 years. In addition, subjects completed a standardized 42-item measure of family functioning and reliable scales assessing attitudes toward, and relationships with, their mother and father. When differences in age were controlled for, multiple regression results for both boys and girls indicated that the tendency to bully peers and the tendency to act prosocially were independently predictive of family functioning and attitudes toward, and relationships with, each parent, negatively for bullying and positively for prosocial behavior. The tendency to be victimized by peers at school among girls was found to be associated with poorer family functioning and more negative attitudes toward mothers; negative relations with absent fathers in single-parent families characterized boys who reported being victimized at school.
152 citations
TL;DR: The absence of a consistent reciprocal effect indicates that the fatigue-related changes in the ability to match arm position are not solely due to changes in proprioceptive signals and that central fatigue processes are probably involved.
Abstract: Fatigue is often associated with increased clumsiness. One possible explanation for this is that the proprioceptive signals from receptors in and around muscles change during muscle fatigue. Thirteen human subjects were tested for their ability to match the elbow angle of one arm with the contralateral arm, before and after a fatiguing contraction of one arm. Contractile fatigue was induced by a series of maximal voluntary contractions of the elbow flexors of the dominant arm. While fatigue of either the target arm or the matching arm usually changed the ability of individual subjects to match arm position, this effect varied markedly from one subject to another and no consistent pattern was discerned. In particular, there was no reciprocal change when the fatigued arm was the matching arm compared with when the nonfatigued arm was the matching arm. The absence of a consistent reciprocal effect indicates that the fatigue-related changes in the ability to match arm position are not solely due to changes in proprioceptive signals and that central fatigue processes are probably involved.
TL;DR: In this paper, the dynamic wetting and dewetting of polyethylene terephthalate (PET) by polar liquids (water and glycerol) has been studied.
TL;DR: In the Glanville Formation of South Australia, foraminifera have been found to be abundant in the last interglacial equivalent of the Leeuwin Current as discussed by the authors.
01 Dec 1993
TL;DR: In this article, an approach based on the abstract concept of logistical events and treating intermodalism as a sequence of linked events is proposed to solve the problem of global sourcing, just-in-time inventory control and the growth of the global marketplace.
Abstract: Global sourcing, just‐in‐time inventory control and the growth of the global marketplace have made intermodal transport an increasingly important aspect of distribution and logistics. Discusses intermodal system modelling from the perspective of intermodalism as an integrated transport service rather than as a technology. Reviews current modelling paradigms and implementations and proposes an innovative approach based on the abstract concept of logistical events and treating intermodalism as a sequence of linked events. Addresses some of the technical issues involved in embedding the proposed framework in a traditional network model.
01 Jan 1993
TL;DR: Alternative access strategies for multi-media wireless systems are discussed and the major performance issues are discussed.
Abstract: Alternative access strategies for multi-media wireless systems are discussed. FDMA, TDMA, CDMA and random packet access schemes are considered. A number of possible strategies are presented and the major performance issues are discussed.
TL;DR: In this group of patients, average steady-state plasma concentrations of morphine, M3G and M6G were related to the morphine dose per kilogram of bodyweight, and it was not possible to detect a relationship between the renal clearance, and that of creatinine.
Abstract: The plasma concentrations and renal clearance values of morphine, morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) were determined in 11 adult cancer patients maintained on a long term oral morphine dosage (10 to 100mg every 4h). Concentrations in plasma and urine were determined by a specific high performance liquid chromatography assay. In this group of patients, whose creatinine clearance values ranged from 52 to 180 ml/min (3.12 to 10.8 L/h), average steady-state plasma concentrations of morphine, M3G and M6G were related (p < 0.01) to the morphine dose per kilogram of bodyweight. The mean total urinary recovery as morphine, M3G and M6G was 74.6 +/- 26.5% of the dose. Renal clearance values for M3G and M6G were closely related (r2 = 0.80; p < 0.0005). It was not possible to detect a relationship between the renal clearance of morphine, M3G and M6G, and that of creatinine. The renal tubular handling of all 3 compounds showed wide interindividual variation, and there was evidence of either net renal tubular secretion or reabsorption. There was no apparent relationship between plasma morphine and M6G concentrations and pain relief.
TL;DR: In this article, the authors used ultraviolet-visible (UV-vis) and Fourier Transform Infrared (FTIR) spectroscopy to determine the kinetics of ethyl xanthate adsorption onto pyrite and pyrrhotite.
TL;DR: It is shown that genetic algorithms provide an efficient and computationally powerful optimisation technique that can be applied to geotechnical problems.
15 Dec 1993
TL;DR: A taxonomy of changes applicable to the Entity-Relationship Model together with their effects on the underlying relational model expressed in terms of a second taxonomy relevant to the relational model is presented.
Abstract: Recently there has been increasing interest in both the problems and the potential of accommodating evolving schema in databases, especially in systems which necessitate a high volume of structural changes or where structural change is difficult. This paper presents a taxonomy of changes applicable to the Entity-Relationship Model together with their effects on the underlying relational model expressed in terms of a second taxonomy relevant to the relational model.
TL;DR: The impulse-response technique was used to investigate the influence of changes in the perfusate concentration of human serum albumin on the distribution and elimination kinetics of [14C]diclofenac in the isolated perfused rat liver.
TL;DR: This paper found that students do not perceive literary studies to be useful in helping them to achieve their primary goal of oral proficiency, and this hypothesis was supported from the evidence of a survey of a group of intermediate-level university students of French, but it does not account for all the findings.
Abstract: It is well-known that language students consistently rate the study of literature below the linguistic aspects of their foreign language course. The reasons for this low priority accorded to literary studies are less well understood. One plausible hypothesis was tested: Students do not perceive literary studies to be useful in helping them to achieve their primary goal of oral proficiency. This hypothesis can be supported from the evidence of a survey of a group of intermediate-level university students of French, but it does not account for all the findings. The phenomenon of “culture panic” may be at least as important.
TL;DR: It is shown how the solutions of these problems can be used to construct suboptimal controls for singularly perturbed problems when approximation by reduced problems is not possible.
Abstract: A traditional approach to singularly perturbed optimal control problems is based on an approximation of these problems by reduced problems which are obtained via the formal replacement of the fast variables by the states of equilibrium of the fast subsystems considered with frozen slow variables and controls. It is shown that such an approximation is valid if and only if certain families of periodic optimization problems admit steady state solutions. It is also shown how the solutions of these problems can be used to construct suboptimal controls for singularly perturbed problems when approximation by reduced problems is not possible. >
TL;DR: This structured intervention strategy is a useful approach for reducing levels of chronic benzodiazepine use among residents of aged-care accommodation.
Abstract: Background: Many residents of aged-care accommodation are chronic users of benzodiazepines. This pattern of use contradicts current guidelines and may adversely affect residents. It was hypothesised that a lasting reduction in benzodiazepine use could be achieved through a programme which involved prescribers, residents and caregivers in the change process.
Aim: To demonstrate that an intervention which involved education and relaxation training for patients, and education of prescribers and caregivers, could reduce levels of chronic benzodiazepine use among residents of an aged-care facility.
Methods: Two aged-care facilities from metropolitan Adelaide were chosen; one received the intervention, the other was a no-intervention comparison. Pre-test, post-test and follow-up interviews were conducted with 60 residents: 27 from the intervention setting and 33 from the comparison setting. Residents at the intervention setting were provided with relaxation skills training, and their medical practitioners and caregivers were provided with information about alternative strategies for managing sleep disturbance. Outcome measures were: the proportion of residents using benzodiazepines, total medication use, cognitive performance, emotional responsiveness, subjective health and sleep ratings and an index of well-being.
Results: The proportion of participants in the intervention condition who used benzodiazepines declined significantly (from 70% to 35%); the reduction was maintained over the subsequent three months. No adverse consequences were associated with cessation of benzodiazepine use; there was improvement in emotional responsiveness among those who ceased benzodiazepine use. This structured intervention strategy is a useful approach for reducing levels of chronic benzodiazepine use among residents of aged-care accommodation.
TL;DR: In this article, the effect of cyanide on the adsorption kinetics of ethyl xanthate on galena depends on the pulp electrochemical potential (Eh) as well as the order of reagent addition.
TL;DR: This paper investigated teachers' views on discipline in primary schools in metropolitan Adelaide, South Australia, using a survey instrument developed for the Elton Enquiry into school discipline in England and Wales, and found that primary and junior primary teachers experience frequent but minor discipline problems in their classes and in the school yard, but that they cope with these problems reasonably well.
Abstract: Summary Teachers’ views on discipline in primary schools in metropolitan Adelaide, South Australia, were investigated using a survey instrument developed for the Elton Enquiry into school discipline in England and Wales. Results of the survey suggest that primary and junior primary teachers experience frequent but minor discipline problems in their classes and in the school yard, but that they cope with these problems reasonably well. Data are presented summarising and comparing primary and junior primary teachers’ most common discipline problems, which are the most difficult to handle, teachers’ perceptions of the seriousness of these problems, and their suggestions to improve their capacity to deal with these problems. Differences between public and teacher perceptions of discipline problems in government primary schools are exposed. The implications of several findings for teacher training and development are briefly discussed.
TL;DR: A numeric age of 46,500 ± 9100 yr B.P. was obtained on marine molluscs from these sediments, using a model based on "apparent" parabolic racemization kinetics as mentioned in this paper.
TL;DR: In this paper, the effects of hot forging and post-deformation annealing on carbide distribution and morphology in M2 grade high speed steel were studied, and it was shown that hot forging accelerates the spheroidization rate of M6C carbide with little effect on coarsening.
Abstract: High speed steels have a complex carbide pattern in the as-cast state which has to be modified to achieve the desired properties of adequate toughness, hot hardness, and wear resistance. The effects of hot forging and postdeformation annealing on carbide distribution and morphology in M2 grade high speed steel were studied, and it was shown that hot forging accelerates the spheroidization rate of M6C carbide with little effect on coarsening. The mechanism responsible for such acceleration is dominated by mechanical disintegration of M6C carbide plates, while diffusion-controlled spheroidization was not significant. For MC carbide particles, coarsening was the dominant mechanism, but it was not possible to ascertain whether diffusion had been unaffected by deformation or even increased by a factor that could be as high as 10,000 times. Annealing after deformation accelerated spheroidization which was attributed to the damaging of carbide plates during forging rather than an increase in diffusion rate, since the matrix was almost substructure-free in the annealed condition,i.e., lack of short-circuiting paths for diffusion.
TL;DR: In this paper, a pin-on-ring wear testing machine was used to evaluate the wear properties of aluminum-12.3wt.%silicon alloy against copper rings under ambient conditions.
TL;DR: In this paper, the authors compared the wear rate of 5mm-thick pressed steel shares with those of 10mmthick cast steel shares and found that the cast shares lost mass at 0.48 of the rate of the pressed shares, irrespective of the soil type or condition.
Abstract: The draft force, vertical up force and wear rate of 5-mm-thick pressed steel shares were compared with those of 10-mm-thick cast steel shares. The tests were conducted using a range of soil types and moisture contents over several years. Because they were made of a harder material, the cast shares lost mass at 0.48 of the rate of the pressed shares, irrespective of the soil type or condition. However, the cast shares, because they were made from thicker material, had a blunter cutting edge which in moist soil conditions increased the draft and vertical up forces. The results showed the wear rate (based on distance) to be independent of the speed of tillage but the soil type and condition had a large effect on the wear rates and tillage forces.
01 Jan 1993
TL;DR: In this article, a statistical model is proposed to represent the discontinuity orientation characteristics of a given rock mass, based on the fact that geological processes usually generate one or more clusters (or sets) of nearly parallel discontinuities.
Abstract: Publisher Summary Rock masses usually contain such features as fractures, faults, joints, bedding planes, cleavage and other mechanical defects which are here collectively referred to as discontinuities. These discontinuities can have a major influence on the deformability, strength, stability and permeability of the rock mass and thereby play a major part in dictating the design of foundations, slopes, tunnels and other structures associated with discontinuous rock masses. Discontinuity orientation data can be presented and utilized in design by two different methods. If the rock face at the design site is readily accessible, the locations and orientations of actual discontinuities can be measured and used explicitly in the design calculations. If, however, the rock face is not accessible it is necessary to measure discontinuity orientation at other rock faces, or from boreholes, and build up a statistical model that represents the discontinuity orientation characteristics of the rock mass. In most cases the statistical model is based on the fact that geological processes usually generate one or more clusters (or sets) of nearly parallel discontinuities in a given rock mass.