Investigations into effective methods for assessing the condition of insulation in aged power transformers

This paper investigates the effective diagnostic technique(s) for assessing the condition of insulation in aged power transformers. A number of electrical, mechanical and chemical techniques were investigated. Many of these techniques are already used by the utility engineers and two comparatively new techniques are proposed in this paper. Results showing the effectiveness of these diagnostics are presented and correlation between the techniques are also presented. Finally, merits and suitability of different techniques are discussed in this paper.

The efficiency and condition of oysters and macroalgae used as biological filters of shrimp pond effluent

Current shrimp pond management practices generally result in elevated concentrations of nutrients, suspended solids, bacteria and phytoplankton compared with the influent water. Concerns about adverse environmental impacts caused by discharging pond effluent directly into adjacent waterways have prompted the search for cost-effective methods of effluent treatment. One potential method of effluent treatment is the use of ponds or raceways stocked with plants or animals that act as natural biofilters by removing waste nutrients. In addition to improving effluent water quality prior to discharge, the use of natural biofilters provides a method for capturing otherwise wasted nutrients. This study examined the potential of the native oyster, Saccostrea commercialis (Iredale and Roughley) and macroalgae, Gracilaria edulis (Gmelin) Silva to improve effluent water quality from a commercial Penaeus japonicus (Bate) shrimp farm, A system of raceways was constructed to permit recirculation of the effluent through the oysters to maximize the filtration of bacteria, phytoplankton and total suspended solids. A series of experiments was conducted to test the ability of oysters and macroalgae to improve effluent water quality in a flow-through system compared with a recirculating system. In the flow-through system, oysters reduced the concentration of bacteria to 35% of the initial concentration, chlorophyll a to 39%, total particulates (2.28-35.2 mum) to 29%, total nitrogen to 66% and total phosphorus to 56%. Under the recirculating flow regime, the ability of the oysters to improve water quality was significantly enhanced. After four circuits, total bacterial numbers were reduced to 12%, chlorophyll a to 4%, and total suspended solids to 16%. Efforts to increase biofiltration by adding additional layers of oyster trays and macroalgae-filled mesh bags resulted in fouling of the lower layers causing the death of oysters and senescence of macroalgae. Supplementary laboratory experiments were designed to examine the effects of high effluent concentrations of suspended particulates on the growth and condition of oysters and macroalgae. The results demonstrated that high concentrations of particulates inhibited growth and reduced the condition of oysters and macroalgae. Allowing the effluent to settle before biofiltration improved growth and reduced signs of stress in the oysters and macroalgae. A settling time of 6 h reduced particulates to a level that prevented fouling of the oysters and macroalgae.

Illusions in advanced cancer: The effect of belief systems and attitudes on quality of life

Patients with advanced cancer frequently express positive attitudes and can be unduly optimistic about the potential benefits of treatment. In order to evaluate an illusory domain in the context of advanced cancer, we developed a scale of will to live and characterized the beliefs that patients held about the curability of their cancer, and how committed they were to using alternative treatments. A measure of quality of life was used as the dependent variable in order to assess the association between these attributes. After a preliminary exploration confirmed the presence of an illusory domain, these concepts were prospectively tested in 149 ambulant patients with advanced cancer who attended for palliative systemic treatment, radiation treatment or supportive care. The scale of global quality of life was reliable (Cronbach's alpha coefficient 0.72). The distribution of the scores of will to live was skewed, with no respondent scoring poorly, and the scale was reliable (Cronbach's alpha coefficient 0.82). The scale of belief in curability showed diverse beliefs. In some cases, there was a discrepancy between respondents' beliefs in curability and what they believed to be the report by their doctors. There was also an association between a committed use of alternative treatments and a belief in the curability of the cancer (p

Bounding the stability and rupture condition of emulsion and foam films

A scaling law is presented that provides a complete solution to the equations bounding the stability and rupture of thin films. The scaling law depends on the fundamental physicochemical properties of the film and interface to calculate bounds for the critical thickness and other key film thicknesses, the relevant waveforms associated with instability and rupture, and film lifetimes. Critical thicknesses calculated from the scaling law are shown to bound the values reported in the literature for numerous emulsion and foam films. The majority of critical thickness values are between 15 to 40% lower than the upper bound critical thickness provided by the scaling law.

Monitoring the condition of savanna riparian zones in Northern Australia using high spatial resolution imagery and a field based rapid assessment method

Government agencies responsible for riparian environments are assessing the combined utility of field survey and remote sensing for mapping and monitoring indicators of riparian zone condition. The objective of this work was to compare the Tropical Rapid Appraisal of Riparian Condition (TRARC) method to a satellite image based approach. TRARC was developed for rapid assessment of the environmental condition of savanna riparian zones. The comparison assessed mapping accuracy, representativeness of TRARC assessment, cost-effectiveness, and suitability for multi-temporal analysis. Two multi-spectral QuickBird images captured in 2004 and 2005 and coincident field data covering sections of the Daly River in the Northern Territory, Australia were used in this work. Both field and image data were processed to map riparian health indicators (RHIs) including percentage canopy cover, organic litter, canopy continuity, stream bank stability, and extent of tree clearing. Spectral vegetation indices, image segmentation and supervised classification were used to produce RHI maps. QuickBird image data were used to examine if the spatial distribution of TRARC transects provided a representative sample of ground based RHI measurements. Results showed that TRARC transects were required to cover at least 3% of the study area to obtain a representative sample. The mapping accuracy and costs of the image based approach were compared to those of the ground based TRARC approach. Results proved that TRARC was more cost-effective at smaller scales (1-100km), while image based assessment becomes more feasible at regional scales (100-1000km). Finally, the ability to use both the image and field based approaches for multi-temporal analysis of RHIs was assessed. Change detection analysis demonstrated that image data can provide detailed information on gradual change, while the TRARC method was only able to identify more gross scale changes. In conclusion, results from both methods were considered to complement each other if used at appropriate spatial scales.

No(i)stalgia: On the impossibility of recognising noise in the present

Starting from a comparison between the process of writing by hand and writing to screen, this paper contends that there is a continuity between the former, apparently archaic form of writing, and the latter, supposedly more modern form of writing. It will be suggested that, rather than being truly archaic, writing by hand perhaps constitutes a nostalgic act which attempts to bypass the perceived virtuality of the postmodern condition. As such, it will be claimed, via Baudrillard, that nostalgia of this kind is a type of hyper-simulacrum that relies on a misinterpretation of the noise created by the very act of expression. It will be claimed, however, that if interpreted without the sort of wilful misinterpretation to which noise often falls prey, many kinds of noise grafted onto contemporary cultural objects bear testimony to a certain continuity across historical eras as well as to the fact that we are ultimately incapable of recognising many cultural products' noise (and thus the products themselves in their entirety) in their own era. This paper therefore calls for a noisy theory which, analysing the world from an immanent position, would acknowledge the impossibility of full knowledge of the sign

Characterisation of sea-water intrusion in the Pioneer Valley, Australia using hydrochemistry and three-dimensional numerical modelling

Sea-water intrusion is actively contaminating fresh groundwater reserves in the coastal aquifers of the Pioneer Valley,north-eastern Australia. A three-dimensional sea-water intrusion model has been developed using the MODHMS code to explore regional-scale processes and to aid assessment of management strategies for the system. A sea-water intrusion potential map, produced through analyses of the hydrochemistry, hydrology and hydrogeology, offsets model limitations by providing an alternative appraisal of susceptibility. Sea-water intrusion in the Pioneer Valley is not in equilibrium, and a potential exists for further landward shifts in the extent of saline groundwater. The model required consideration of tidal over-height (the additional hydraulic head at the coast produced by the action of tides), with over-height values in the range 0.5-0.9 m giving improved water-table predictions. The effect of the initial water-table condition dominated the sensitivity of the model to changes in the coastal hydraulic boundary condition. Several salination processes are probably occurring in the Pioneer Valley, rather than just simple landward sea-water advancement from modern sources of marine salts. The method of vertical discretisation (i.e. model-layer subdivision) was shown to introduce some errors in the prediction of watertable behaviour.

Analysis and application of an equilibrium model for in vitro bioassay systems with three components: Receptor, hormone and hormone-binding-protein

A simple theoretical framework is presented for bioassay studies using three component in vitro systems. An equilibrium model is used to derive equations useful for predicting changes in biological response after addition of hormone-binding-protein or as a consequence of increased hormone affinity. Sets of possible solutions for receptor occupancy and binding protein occupancy are found for typical values of receptor and binding protein affinity constants. Unique equilibrium solutions are dictated by the initial condition of total hormone concentration. According to the occupancy theory of drug action, increasing the affinity of a hormone for its receptor will result in a proportional increase in biological potency. However, the three component model predicts that the magnitude of increase in biological potency will be a small fraction of the proportional increase in affinity. With typical initial conditions a two-fold increase in hormone affinity for its receptor is predicted to result in only a 33% increase in biological response. Under the same conditions an Ii-fold increase in hormone affinity for receptor would be needed to produce a two-fold increase in biological potency. Some currently used bioassay systems may be unrecognized three component systems and gross errors in biopotency estimates will result if the effect of binding protein is not calculated. An algorithm derived from the three component model is used to predict changes in biological response after addition of binding protein to in vitro systems. The algorithm is tested by application to a published data set from an experimental study in an in vitro system (Lim et al., 1990, Endocrinology 127, 1287-1291). Predicted changes show good agreement (within 8%) with experimental observations. (C) 1998 Academic Press Limited.

A numerical study of flexural buckling of foliated rock slopes

The occurrence of foliated rock masses is common in mining environment. Methods employing continuum approximation in describing the deformation of such rock masses possess a clear advantage over methods where each rock layer and each inter-layer interface (joint) is explicitly modelled. In devising such a continuum model it is imperative that moment (couple) stresses and internal rotations associated with the bending of the rock layers be properly incorporated in the model formulation. Such an approach will lead to a Cosserat-type theory. In the present model, the behaviour of the intact rock layer is assumed to be linearly elastic and the joints are assumed to be elastic-perfectly plastic. Condition of slip at the interfaces are determined by a Mohr-Coulomb criterion with tension cut off at zero normal stress. The theory is valid for large deformations. The model is incorporated into the finite element program AFENA and validated against an analytical solution of elementary buckling problems of a layered medium under gravity loading. A design chart suitable for assessing the stability of slopes in foliated rock masses against flexural buckling failure has been developed. The design chart is easy to use and provides a quick estimate of critical loading factors for slopes in foliated rock masses. It is shown that the model based on Euler's buckling theory as proposed by Cavers (Rock Mechanics and Rock Engineering 1981; 14:87-104) substantially overestimates the critical heights for a vertical slope and underestimates the same for sub-vertical slopes. Copyright (C) 2001 John Wiley & Sons, Ltd.

An overview of diversion strategies for Australian drug-related offenders

This paper provides a descriptive overview of options for diversion of drug-related offenders from the criminal justice system. Drug-related offences include drug offences (for example, possession of a prohibited substance); offences that are directly linked to intoxication (for example, drink-driving or assault); and offences committed to support drug use (for example, theft). After an offence has been detected by police, multiple opportunities for diversion occur throughout the criminal justice process. (a) Pre-arrest: when an offence is first detected, prior to a charge being laid. This is known as police diversion and includes fines, warnings and cautions, sometimes with educational information or referral to assessment and treatment. (b) Pre-trial: when a charge is made but before the matter is heard at court. Examples are treatment as a condition of bail, conferencing and prosecutor discretion. (c) Pre-sentence: a delay of sentence while assessment and treatment are sought. (d) Post-sentence: as part of sentencing, for example suspended sentences, drug courts, noncustodial sentences and circle sentencing. (e) Pre-release: prior to release from a sentence, on parole. Issues for diversion programmes include net widening, the ethics of coercion to treatment, the needs of families and intersectoral collaboration. A framework for diversion is presented in which increasingly treatment-focused and coercive diversion strategies are used as offenders' criminal careers and drug problems increase.

Biodiversity: bridging the gap between condition and conservation

The aim of this study is to create a two-tiered assessment combining restoration and conservation, both needed for biodiversity management. The first tier of this approach assesses the condition of a site using a standard bioassessment method, AUSRIVAS, to determine whether significant loss of biodiversity has occurred because of human activity. The second tier assesses the conservation value of sites that were determined to be unimpacted in the first step against a reference database. This ensures maximum complementarity without having to set a priori target areas. Using the reference database, we assign site-specific and comparable coefficients for both restoration (Observed/Expected taxa with > 50% probability of occurrence) and conservation values (O/E taxa with < 50%, rare taxa). In a trial on 75 sites on rivers around Sydney, NSW, Australia we were able to identify three regions: (1) an area that may need restoration; (2) an area that had a high conservation value and; (3) a region that was identified as having significant biodiversity loss but with high potential to respond to rehabilitation and become a biodiversity hotspot. These examples highlight the use of the new framework as a comprehensive system for biodiversity assessment.

Dating the dreaming? Creation of myths and rituals for mounds along the northern Australian coastline

Shell mounds ceased to be built in many parts of coastal northern Australia about 800-600 years ago. They are the subject of stories told by Aboriginal people and some have been incorporated in ritual and political activities during the last 150 ears. These understandings emerged only after termination of the economic and environmental system that created them, 800-600 years ago, in a number of widely separated coastal regions, Modern stories and treatments of these mounds by Aboriginal people concern modern or near-modern practices. Modern views of the mounds, their mythological and ritual associations, may be explained by reference to the socioeconomic transitions seen in the archaeological record; but the recent cultural, social and symbolic statements about these places cannot inform us of the process or ideology concerned with the formation of the mounds. Many Aboriginal communities over the last half a millennium actively,formed understandings of new landscapes and systems of land use. Attempts to impose historic ideologies and cosmologies on earlier times fail to acknowledge the magnitude and rate of economic and ideological change on the tropical coastline of Australia.