http://nova.newcastle.edu.au/vital/access/services/Feed ${session.getAttribute("locale")} 5 http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:12757 We have decided to raise questions rather than provide answers, realizing that the thoracic circulations have very complex interconnecting control system relationships. For example, parts of the 6th vascular arch embryologically form the pulmonary circulation, which in turn interface with the developing airways, themselves a derivative of the foregut. This alone begs the question of expectations with respect to control systems common to gut, and the pulmonary, bronchial and lung lymph systems. Since the 6th arch system joins with evaginations from the folding vascular tube destined to be the heart, would the enveloping innervation also affect the control of cardiac function? And finally, both the coronary and the bronchial vessels do constitute some sort of vasa vasorum to the myocardium and indeed, the major pulmonary vessels, as well as in the case of the bronchial vessels, to the airways, with secretory mechanisms driven in part by non-adrenergic, non-cholinergic mechanisms. 2013-05-16T03:39:23.293Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:12763 The Kubicek thoracic cylinder model of impedance cardiography (IC) for measuring beat-by-beat stroke volume (SV) was evaluated in controlled studies using the electromagnetic flowmeter (FM) as the reference technique. Assuming the validity of the Kubicek equation for stroke volume calculation, IC stroke volume was found to be a linear function of EM values at any one haematocrit over a wide range of SV, but the slope of the relationship fell as haematocrit fell. Experiments using the same equation in dogs, in which blood resistivity in vivo (pt) was made the dependent variable, and the EM-derived value was usedfor stroke volume, showed that pt was almost constant over a wide range of haematocrits. These findings were supported by studies in man and rabbit where Fick and thermodilution-derived values were used for stroke volume. When these data were applied to normotensive and hypertensive human subjects with normal hearts and lungs in controlled studies at rest, during tilting, with drug therapy and on exercise, IC measured stroke volume and cardiac output with a variability at least as good as the 9–11% acceptable for clinical use. This conclusion applied to thoracic configurations of d sizes and shapes from adult man to the neonate. In chronic disease states, while assessments of relative changes are valuable, absolute data are questionable. Further research is required under these conditions, as it is also for other models of IC, which are based on different asswnptions. 2013-05-16T03:35:32.482Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:12835 Multi-commodity flow problems arise naturally in telecommunications and scheduling. Such applications typically involve large network optimization problems with constraints of a form which make standard optimization techniques inapplicable. Linear programming methods can solve only small instances of such problems. New theoretical work by Soviet researchers on network-based techniques is shown in this paper to yield practical algorithms which enable certain types of multi-commodity flow problems to be solved quickly. As these methods generalize efficient single-commodity methods, there is promise that further research will allow more general problems to be solved in an analogous manner. 2013-05-01T04:06:27.305Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:12782 The functional characteristics and control factors of the bronchoesophageal circulation under natural conditions are unknown. In 8 awake dogs 2-3 weeks after mounting a 3mm i.d. Doppler flow probe on the right bronchoesophageal artery under halothane-oxygen anaesthesia, the bronchial circulation is a low-flow, high resistance bed under resting thermoneutral conditions (mean bronchovascular flow (Qbr) = 0.27ml·s⁻¹, range 0.03-0.75, n=8; mean bronchovascular conductance (Cbr) = 8.5x10⁻⁴ml·s⁻¹·mmHg⁻¹, range 2x10⁻⁴21x10⁻⁴, n=5). Sequential autonomic blockade (i.v. methscopolamine 270 μg·kg⁻¹; propranolol 1 mg·kg⁻¹; phentolamine 4mg followed by 0.15−0·4 mg·min⁻¹ infusion) reveals significant resting α-adrenoceptor vasoconstrictor tone and suggest the presence of resting cholinoceptor vasoconstrictor tone. Notwithstanding acetylcholine (0.063-2·0 μg·kg⁻¹, i.v. bolus) evokes transient increased in Qbr (2-7 times; ED₅₀ 0.68 μg·kg⁻¹) and in Cbr (2-8 times; ED₅₀ 0.46 μg·kg⁻¹). Rapid ( 2013-04-17T00:19:49.531Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:722 The hydrodynamic phenomena occurring inside the enclosed downcomer section of a plunging jet bubble column are described in the study. The gas entrainment rate for a plunging liquid jet was found to consist of two components, namely the gas trapped within the effective jet diameter at the point of impact, and the gas contained within the film between the jet and induction trumpet surface at the point of rupture. Entrainment within the effective jet diameter has been examined by McCarthy (1972). In this study, a model was supported by the experimental results, provided the film attained a region of constant thickness. When the induction trumpet was ruptured prior to a constant film thickness being reached, the measured rate of filmwise entrainment was higher than the prediction. Filmwise entrainment was found to be initiated once a critical velocity along the surface of the induction trumpet was reached. The critical velocity was a function only of the liquid physical properties and was independent of the jet conditions and downcomer diameter. The velocity of the free surface of the induction trumpet was obtained from the velocity profile for the recirculating eddy generated by the confined plunging liquid jet. The jet angle used to describe the expansion of the submerged jet inside the downcomer was predicted from the radial diffusion of jet momentum into the recirculation eddy. The model was able to predict the jet angle when it was assumed that the radial diffusion of jet momentum was a function of the Euler number based on the jet velocity and absolute pressure in the headspace at the top of the downcomer. The model was also developed to predict the maximum stable bubble diameter generated within the submerged jet volume, where the energy dissipation attributed to bubble breakup was given by the energy mixing loss derived for the throat section of a liquid-jet-gas-pump. Good agreement was found between the measured and predicted maximum bubble diameter values. The average experimental Sauter mean/maximum diameter ratio was found to be 0.61, which was similar to that for other bubble generation devices. It was found that for turbulent liquid conditions in the uniform two-phase flow region, a transition from bubble to churn-turbulent flow occurred at a gas void fraction of approximately 0.2 when the gas drift-flux was zero. Under laminar liquid flow, this transition took place at a gas void fraction above 0.3. For the bubbly flow regime the Distribution parameter Co used by Zuber and Findlay (1965) to describe the velocity and gas void fraction profile, was found to be a function of the liquid Reynolds number. For laminar liquid flow, values of Co greater than unity were obtained. As the liquid Reynolds number was increased it was found that Co decreased, until a constant value of unity was obtained for fully turbulent flow. For the churn-turbulent regime it was found that the gas void fraction measurements for all of the experimental runs could be collapsed onto a single curve when a modified gas void fraction was plotted against the gas-to-liquid volumetric flow ratio. The modified gas void fraction included a correction factor to account for the difference in the bubble slip velocity between the experimental runs. The experimental results also indicated that the value of the constant in the gas void fraction correction factor was different for laminar and turbulent flow. Prior to bubble coalescence, it was found that the experimental drift-flux curves could be predicted from the measured bubble diameter, using the separated flow model development by Ishii and Zuber (1979). After the onset of coalescence the drift flux measurements departed from the original drift-flux curves at a rate which increased linearly with increasing gas void fraction. It was found that the slope of the line fitted to the coalesced region of the drift-flux curves increased with increasing liquid Reynolds number and reached a constant value under fully turbulent flow conditions. The model developed, together with the implications of the experimental results, are discussed with regard to optimising the design of an industrial plunging jet bubble column. 2011-12-20T23:20:14.670Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2329 Research Doctorate - Doctor of Philosophy (PhD) 2011-12-19T23:00:11.213Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:786 2010-04-27T06:49:11.186Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:817 Focusing on gender relations in a working class co-educational school, this paper reports on the differences in power, status and control when male and female students interact with school-based curricular processes. The research site provided an interesting arena for the empowerment of pupils, particularly female, through a negotiated school-based curriculum fragment of the total school organisation. This paper aims to portray teacher/student negotiations in the context of classwork and classroom behaviour and the making of appropriate subject selections, a process which portrays an experimental interaction between students and the organisation and authority of the school. The research identified areas linked closely to emerging shifts in female student career options, as well as reflecting perspectives relevant to policy and theory development for the 1990s. 2010-04-27T06:48:42.386Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:818 2010-04-27T06:48:39.606Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2117 2010-04-27T06:43:39.739Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2115 This paper is a report of research-in-progress. Comparisons will be made with parallel research in England. The study began in 1989 as a pilot investigation into decision-making by the first group of Leading Teachers appointed to secondary government schools in the Hunter Region preliminary to the 'Schools Renewal' programme. The field of study is relevant to the conference sub-theme "Teachers in Today's Climate" with particular reference to the Scott report (1990) view of 'school-centred education'. The research findings present qualitative and quantitative data collected on what a group of executive decision-makers actually attempted in the management of change. This experience was mediated by the LTs own sense of self, by the culture of their setting, and by wider social and political contexts. This paper thus aims to present an instance of the process of policy implementation and the micro-political interactions derived from managing reform. 2010-04-27T06:43:37.804Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2114 This paper will present details of a project on becoming a teacher and preview the direction of future research issues. The 1990 emphasis of this research-in-progress was to conduct a literature review and build up a theoretical overview on teacher education and the relationship between teacher training and induction. 2010-04-27T06:43:37.753Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:948 The issue of the gender-bound aspects of secondary education is one with an extensive history and literature (see, Brehony, 1984; Deem, 1978), and the subject changing research perspectives over recent history. While a complete analysis is beyond the scope of outlining the initial stages of this research project, an overview serves to establish the context of the investigation. 2010-04-27T06:40:39.700Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2048 2010-04-27T06:21:19.645Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2034 2010-04-27T06:21:03.113Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2624 The MONADS-PC computer system implements an architecture supporting a very large persistent store based on a uniform virtual memory. We have previously shown how this virtual memory scheme can be extended to encompass a local area network of MONADS-PC computers. In this paper we examine the question of the integrity of the store in such a network. A modification to the MONADS architecture to implement stability is reviewed and extended to guarantee stability of a network-wide persistent store. The stability scheme allows for temporary interruption to the physical network without affecting the validity of exported pages owned by a node. 2010-04-27T06:18:56.570Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:757 A decade ago Lawton (1979) addressed the issue of the politics of the curriculum in a lecture entitled "The End of the Secret Garden". This phrase was taken from a British Minister for Education, David Eccles, who called (in 1960) for greater government influence over the curriculum which he saw as an important public arena closed to scrutiny and discussion. Certainly the issue of who controls curriculum remains pertinent today with every state in Australia undergoing major reviews of curriculum. In most cases, as in New South Wales, the conclusion has been to re-assert centralised bureaucratic and party political control over what has come to be perceived by sections of the community as a failed educational system. While acknowledging that greater centralised control might be warranted, one would also wish to protect the achievements gained over the last decade through school-based curriculum development. It is thus time to be pragmatic in the development of what those at the school level understand to be appropriate curricula for secondary schools, in the hope that those at other levels will listen. This article will present the findings of three years of action research on the formation of curricular problems and solutions. 2010-04-27T06:05:26.674Z ]]>