Application of neural networks as an auxiliary technique in the modelling of power station

Artificial neural network (NN) is an alternative way (to conventional physical or chemical based modeling technique) to solve complex ill-defined problems. Neural networks trained from historical data are able to handle nonlinear problems and to find the relationship between input data and output data when there is no obvious one between them. Neural Networks has been successfully used in control, robotic, pattern recognition, forecasting areas. This paper presents an application of neural networks in finding some key factors eg. heat loss factor in power station modeling process. In the conventional modeling of power station, these factors such as heat loss are normally determined by experience or “rule of thumb”. To get an accurate estimation of these factors special experiment needs to be carried out and is a very time consuming process. In this paper the neural networks (technique) is used to assist this difficult conventional modeling process. The historical data from a real running brown coal power station in Victoria has been used to train the neural network model and the outcomes of the trained NN model will be used to determine the factors in the conventional energy modeling of the power stations that is under the development as a part of an on-going ARC Linkage project aiming to detail modeling the internal energy flows in the power station.

Microscopic nature and elemental composition of brown coal fly ash particles from a large coal fired power station

In this study, Australian brown coal fly ash particles have been collected from power station and analysed by scanning electron microscopy to obtain morphological information and elemental composition of individual particles. The most common particles found to be the irregular shape particle aggregates. Other shapes include ball shape with smooth surface and with some attachments; and crystal shape fine particles. The X-ray spectra of each fly ash particle revealed five groups of elemental composition, they are Si-rich particles; Ca-rich particles; Fe-rich particles; particles with Mg-Ca Matrix and particles with Si-Ca matrix. A particle sire distribution analysis has been conducted using particle size analyser and found to have a mean particle size of 21fim. The sample then was separated into fine and coarse fractions using aerodynamic classifier, and the elemental composition of both fractions were determined by ICP-AES. Borate fusion and acid dissolution method was used for sample preparation. It is found that some environmental sensitive elements such as Zn, Pb, Ni, K and Cu are enriched in fine fly ash particles. Ca has much higher contents in fine particles as well. Si and Mg have higher concentrations in coarse particles.

Solar adsorption refrigeration : an alternative/auxiliary way for thermal storage for air conditioning

This paper presents an idea of using solar powered adsorption ice making system as an alternative or an auxiliary way for the traditional ice storage air conditioning systems. A simple solar adsorption refrigeration system runs in intermittent cycle. It makes cooling effect at night, and the cooling effect can be stored for the day use. It fits in well with the cycle of the existing off-peak ice storage air conditioning system. On the top of green effect of the solar powered ice making system, the idea is specifically beneficial for places where the price of the off-peak electricity is not significantly lower than peak price. Based on our many years experience on the solar ice making systems, the paper discusses the technical feature of the solar ice making technology and the solutions we are working on to attack the problems which may have potential damage to application of the solar ice making system for air conditioning purposes.

Improving contaminated land remediation practices for service station sites in Queensland

The research aims to provide improvements to remediation practices for land contaminated by service station activities in the period 1988-2004 by assessing previous methods of remediation. Thirty-four such Queensland sites were examined. The resultes will be useful to government, developers, land holders, consultants and the community.

Power saving in sensor networks via mobile base station repositioning

This research investigated the effect of dynamically repositioning the geographic location of a mobile base station within a sensor network in order to reduce energy consumption and increase network lifetime. Through simulation and experimental methodology, the proposed approach outperformed existing methods by extending network lifetime whilst reducing energy consumption.

Too close for comfort : a fishway exit and a hydro-power station inlet

A major environmental issue for hydro-electric power generation is passage of fish through turbines, or entrainment onto trash racks. At Yarrawonga Weir, on the upper Murray River in south-eastern Australia, the positioning of a fish lock resulted in the potential for upstream migrating fish to be swept back into the adjacent power station by cross flows. In 2004, a 4.5-m long steel extension flume was attached to the exit to alleviate this problem. To determine the fate of native fish after exiting the extension flume, 72 individuals (305–1015 mm long) were implanted with radio-transmitters and released into the fish lock exit channel. In 2004 (power station inflows 10 300 ML day^–1), the majority of fish exited successfully (44 of 45) and only a single fish (2%) was entrained into the power station. In 2005 (power station inflows 12 000 ML day^–1), fish again exited successfully (26 of 27) but with a higher proportion entrained (5 of 27; 18%). This reduced success appeared to be related to strong transverse flows with high water velocities adjacent to the fish lock exit. The efficiency of fish passage at this site might be improved by altering water management strategies, integrating engineering and fish biology, and through field-testing of proposed solutions

Environmental impact assessment of the sewage outfall at Davis Station, East Antarctica

During the summer 2009/10, an environmental impact assessment of the sewage outfall was conducted at Davis Station, East Antarctica. An investigation of the nature and extent of impacts to the marine environment associated with current sewage treatment and effluent discharge practices included ecological surveys of macrobiological communities, physico-chemical analysis of sediments and receiving waters, microbiological analysis, and histopathological analysis of fish. Ecotoxicological testing using local invertebrates to determine effluent toxicity was interpreted alongside dispersal modelling data of the discharge plume to determine the potential extent of impacts and inform recommendations on the level of treatment and dilution of sewage required to minimise impacts. No evidence of impacts was detected on soft sediment infaunal or epifaunal communities, and only low levels of contamination and accumulation were found in sediments and waters in the immediate vicinity of the outfall and in the direction of primary current flow. In contrast, sterol biomarkers and faecal coliforms (E. coli) were detected in sediments collected adjacent to the outfall and in most water column samples. Marine invertebrates (Abatus and Laternula) also tested positive for E. coli and antibiotic resistance mechanisms were present in Laternula indicating the introduction and dispersal through the water column of foreign microbes and bacteria associated with human effluent. Fish (Trematomus bernacchii) close to the outfall showed significant histological alterations in all major tissues (liver, gill, gonad, muscle) resulting from exposure to sewage. Effluent was toxic to amphipods (Paramoera walkeri) and microgastropods (Skenella paludionoides), with reduced survival in concentrations as low as 3.125% over a 21d exposure period. Acute effects were also observed in both species following 24h exposure, with 100% mortality at the highest effluent concentrations tested (68%). The application of these results to support and guide decisions regarding the planned installation of new sewage treatment facilities at Davis will be discussed.

Histological alterations in the Antarctic cod, Trematomus bernacchii from Davis Station, East Antarctica

During the summer season 2009/10, a comprehensive environmental impact assessment of the sewage discharge was conducted at Davis Station in the Vestfold Hills region of East Antarctica. As part of this project, a survey of the histology of liver, gill, gonad and muscle tissues in the Antarctic rock cod Trematomus bernacchii from nearshore sites in the receiving environment close to Davis Station in was completed. Fish from 4 sites were examined; 1 site adjacent to the Davis Station sewage outfall (within 500 m of the point of discharge), 2 sites approximately 2 km from the outfall (Anchorage Island and Antennae farm), and 1 site approximately 10 km away from the outfall and adjacent to an Adelie penguin population (Kazak Island). All fish sampled from the sewage outfall site exhibited significant histological alterations in all major tissues. Fish from the other 3 sites showed some alterations in either gill and/or liver tissues. Pathological abnormalities present in all fish collected near the sewage outfall included: extensive multifocal cysts of unknown etiology with necrotic liquification; multifocal granuloma with associated inflammation; coagulative necrosis in the liver; and lamellar hyperplasia with associated proliferation and lamella fusion of the gills. Results of this work form part of a weight of evidence approach alongside ecological monitoring, chemical analysis, ecotoxicological testing and dispersal modelling of the discharge plume which is being used to inform and direct upgrades to the Australian Antarctic Divisions operations and current sewage discharge practises at Davis Station.

Whither Australian Hill-Station creation : re-writing Adelaide Hills narratives about the architectural imperatives that crafted their establishment

This paper explores the historiography of the Adelaide Hills and offers a new perspective as to the reasons behind hill-station residence constructions that crafted this distinct cultural and designed landscape. Australian hill-station communities, and their major architectural edifices, were extensively established in two periods: the 1870s-1890s and the 1920s-1930s. Sites in the Darling Ranges, Adelaide Hills, Macedon and Dandenong Ranges, Blue Mountains and the Tamborine Mountains were favoured summer retreats for both the new and established wealthy families, who erected grand residences that have come to be celebrated in recent heritage assessments, and architectural and social histories of these environments. The majority of these studies and discourses have echoed an agenda that celebrates the architectural significance and personal associations of these structures, and thereupon have made a range of assumptions about the societal rationale for their establishment, construction and associated landscape plantings.

Taking examples from the Adelaide Hills, this paper argues that both architectural and social historians have ‘mistakenly’ concluded that the rationale behind these hill-station residences was based primarily on the provision of a ‘pleasant’ summer that echo the British Raj hill-stations. Further, it is argued that this conclusion constitutes a myth, or fabulation, about South Australian (SA) design, heritage and social histories, as many of these owners consciously sought out and selected hill-station allotments on the basis of their horticultural properties and possibilities, and that house-siting and construction were actually subservient to these imperatives.

Identification of nonlinear fMRI models using Auxiliary Particle Filter and kernel smoothing method

Hemodynamic models have a high potential in application to understanding the functional differences of the brain. However, full system identification with respect to model fitting to actual functional magnetic resonance imaging (fMRI) data is practically difficult and is still an active area of research. We present a simulation based Bayesian approach for nonlinear model based analysis of the fMRI data. The idea is to do a joint state and parameter estimation within a general filtering framework. One advantage of using Bayesian methods is that they provide a complete description of the posterior distribution, not just a single point estimate. We use an Auxiliary Particle Filter adjoined with a kernel smoothing approach to address this joint estimation problem.