75 resultados para Underground distribution system


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The mud crab, Scylla olivacea, is one of the most economically valuable marine species in Southeast Asian countries. However, commercial cultivation is disadvantaged by reduced reproductive capacity in captivity. Therefore, an understanding of the general and detailed anatomy of central nervous system (CNS) is required before investigating the distribution and functions of neurotransmitters, neurohormones, and other biomolecules, involved with reproduction. We found that the anatomical structure of the brain is similar to other crabs. However, the ventral nerve cord (VNC) is unlike other caridian and dendrobrachiate decapods, as the subesophageal (SEG), thoracic and abdominal ganglia are fused, due to the reduction of abdominal segments and the tail. Neurons in clusters within the CNS varied in sizes, and we found that there were five distinct size classes (i.e., very small globuli, small, medium, large, and giant). Clusters in the brain and SEG contained mainly very small globuli and small-sized neurons, whereas, the VNC contained small-, medium-, large-, and giant-sized neurons. We postulate that the different sized neurons are involved in different functions. Microsc. Res. Tech. 77:189–200, 2014. © 2013 Wiley Periodicals, Inc.

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Over the past decade, the growing demand of Grid-connected photo voltaic (GCPV) system has been increasing due to an extensive use of renewable energy technologies for sustainable power generation and distribution. High-penetrated GCPV systems enhance the operation of the network by improving the voltage levels and reducing the active power losses along the length of the feeder. This paper aims to investigate the voltage variations and Total Harmonic Distortion (THD) of a typical GCPV system modelled in Power system simulator, PSS SINCAL with the change of level of PV integrations in a Low Voltage (LV) distribution network. Five different case studies are considered to investigate the impact of PV integrations on LV nodes and the corresponding voltage variations and harmonics. In addition, this paper also explores and benchmarks the voltage improvement techniques by implementing On Load Tap Changer (OLTC) with respective to the main transformer and addition of Shunt Capacitor (SC) at appropriate node points in LV network,

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The distribution and attributes of properties involved in three major programs for biodiversity protection on private land in Victoria, Australia, was investigated to determine their role in relation to the reserve system. Overlaying of dowsets in a geographic information system, with particular emphasis on property distribution in relation to bioregional and population centres, was undertaken. Land for Wildlife agreements had greater numbers of properties and total area protected in all bioregions throughout the State, yet average protected area sizes were lower than those of conservation covenants and Trust for Nature reserves. A combination of large bioregional area and human population size tended to attract more private conservation properties and, to a lesser extent, the total area they protected. The potential contribution that such properties made to biodiversity conservation varied between bioregions. Inclusion of properties within a national reserve framework is proposed to improve the coordination and effectiveness of conservation measures.

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The extent of disease caused by Phytophthora cinnamomi was determined within vegetation communities of Wilsons Promontory National Park. Aerial survey of visible symptoms by helicopter and systematic survey along all roads and tracks followed by isolation of the pathogen from soil found that in total 551 ha of moist foothill forest, heath and heathy woodland broad vegetation types were affected by the disease. P. cinnamomi was isolated from 93% of sites that, based on the presence of visible symptoms, were expected to yield the pathogen. The species-rich heathy woodland was most affected with 6.5% of the total area of this type showing symptoms of disease. The size of infestation ranged from 229 ha on the slopes of the Vereker Range in the north to less than 1 ha along the Sealers Cove Walking Track in the south. The potential for disease to spread into uninfested vegetation was estimated for all sites from which P. cinnamomi was isolated. Eight of 18 sites where evidence of disease was found were estimated to have a high potential for further disease spread. This study indicates that even though the disease may be waning in some areas of the Park, the pathogen is active and easily isolated from others and provides a continuing threat to susceptible vegetation communities.

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A model of a yam package is established for a ring spinning system. The yarn layer, surface area, and mass of the yam package are formulated with respect to the diameters of the empty bobbin and full yarn package, yarn count, and yarn winding-on time. Based on the principles of dynamics and aerodynamics, models of the power requirements for overcoming the skin friction drag, increasing the kinetic energy of the yarn package (bobbin and wound yarn), and overcoming the yarn wind-on tension are developed. The skin friction coefficient on the surface of a rotating yam package is obtained from experiment. The power distribution during yam packaging is discussed based on a case study. The results indicate that overcoming the skin friction drag during yarn winding consumes the largest amount of energy. The energy required to overcome the yarn wind-on tension is also significant.

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Knowledge of the spatial arrangement of the seagrass distribution and biomass within the Hopkins Estuary is an essential step towards gaining an understanding of the functioning of the estuarine ecosystem. This study marks the first attempt to map seagrass distribution and model seagrass biomass and epiphyte biomass along depth gradients by the use of global positioning system (GPS) and geographical information system (GIS) technologies in the estuary. For mapping seagrass in small estuaries, ground-surveying the entire system is feasible. Three species of seagrasses, Heterozostera tasmanica (Martens ex Aschers), Zostera muelleri (Irmisch ex Aschers) and Ruppia megacarpa (Mason), were identified in the Hopkins Estuary. All beds investigated contained a mixed species relationship. Three harvest techniques were trialed in a pilot study, with the 25 × 25-cm quadrat statistically most appropriate. Biomass of seagrasses and epiphytes was found to vary significantly with depth, but not between sites. The average estimate of biomass for total seagrasses and their epiphytes in the estuary in January 2000 was 222.7 g m–2 (dry weight). Of the total biomass, 50.6% or 112.7 g m–2 (dry weight) was contributed by seagrasses and 49.4% of the biomass (110.0 g m–2) were epiphytes. Of the 50.6% of the total biomass represented by seagrasses, 39.3% (87.5 g m–2) were leaves and 11.3% (25.2 g m–2) were rhizomes. The total area of seagrasses present in the Hopkins Estuary was estimated to be 0.4 ± 0.005 km2, with the total area of the estuary estimated to be 1.6 ± 0.02 km2 (25% cover). The total standing crop of seagrasses and epiphytes in the Hopkins Estuary in January 2000 was estimated to be 102.3 ± 57 t in dry weight, 56% (56.9 ± 17 t, dry weight) seagrasses and 44% (45.4 ± 19 t, dry weight) epiphytes. Of the seagrass biomass, 39% (39.7 ± 13 t, dry weight) was contributed by leaves and 17% (17.3 ± 7 t, dry weight) by rhizomes.

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Although the development of geographic information system (GIS) technology and digital data manipulation techniques has enabled practitioners in the geographical and geophysical sciences to make more efficient use of resource information, many of the methods used in forming spatial prediction models are still inherently based on traditional techniques of map stacking in which layers of data are combined under the guidance of a theoretical domain model. This paper describes a data-driven approach by which Artificial Neural Networks (ANNs) can be trained to represent a function characterising the probability that an instance of a discrete event, such as the presence of a mineral deposit or the sighting of an endangered animal species, will occur over some grid element of the spatial area under consideration. A case study describes the application of the technique to the task of mineral prospectivity mapping in the Castlemaine region of Victoria using a range of geological, geophysical and geochemical input variables. Comparison of the maps produced using neural networks with maps produced using a density estimation-based technique demonstrates that the maps can reliably be interpreted as representing probabilities. However, while the neural network model and the density estimation-based model yield similar results under an appropriate choice of values for the respective parameters, the neural network approach has several advantages, especially in high dimensional input spaces.

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More intelligent scheduling methods are required for manufacturing scheduling due to the move to more agile systems. Multi-agent methods are one such approach. This paper describes the application of a reconfigurable multi-agent scheduler to the problem of allocating orders to warehouses in a distribution supply chain. This multi-agent system was originally developed for allocation of orders to machines in a highly reconfigurable manufacturing system and this work was aimed at investigating the ease of applying this same scheduler to other problems. It was found that this new application was readily achieved because of the modular structure of the scheduler. This paper shows how the application to the new problem was achieved.

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The peer-to-peer content distribution network (PCDN) is a hot topic recently, and it has a huge potential for massive data intensive applications on the Internet. One of the challenges in PCDN is routing for data sources and data deliveries. In this paper, we studied a type of network model which is formed by dynamic autonomy area, structured source servers and proxy servers. Based on this network model, we proposed a number of algorithms to address the routing and data delivery issues. According to the highly dynamics of the autonomy area, we established dynamic tree structure proliferation system routing, proxy routing and resource searching algorithms. The simulations results showed that the performance of the proposed network model and the algorithms are stable.

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This paper concerns the ways in which public policy regarding the distribution of resources might be used to increase the happiness of the Thai population. The term happiness refers to the subjective side of life quality, which in contemporary science is more commonly referred to as subjective wellbeing (SWB). The SWB construct is described within the theoretical context of SWB homeostasis. This is a proposed management system which has the role of maintaining a positive view of the self It will be described how the homeostatic system can be challenged by hardship. The resources that the system requires to manage such challenges will also be described.  Recommended forms of SWB measurement will be considered. It is concluded that public policy which directs resources to disadvantaged population sectors may be one of the most effective initiatives to enhance population wellbeing and national productivity.

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Wildlife managers are often faced with the difficult task of determining the distribution of species, and their preferred habitats, at large spatial scales. This task is even more challenging when the species of concern is in low abundance and/or the terrain is largely inaccessible. Spatially explicit distribution models, derived from multivariate statistical analyses and implemented in a geographic information system (GIS), can be used to predict the distributions of species and their habitats, thus making them a useful conservation tool. We present two such models: one for a dasyurid, the Swamp Antechinus (Antechinus minimus), and the other for a ground-dwelling bird, the Rufous Bristlebird (Dasyornis broadbenti), both of which are rare species occurring in the coastal heathlands of south-western Victoria. Models were generated using generalized linear modelling (GLM) techniques with species presence or absence as the independent variable and a series of landscape variables derived from GIS layers and high-resolution imagery as the predictors. The most parsimonious model, based on the Akaike Information Criterion, for each species then was extrapolated spatially in a GIS. Probability of species presence was used as an index of habitat suitability. Because habitat fragmentation is thought to be one of the major threats to these species, an assessment of the spatial distribution of suitable habitat across the landscape is vital in prescribing management actions to prevent further habitat fragmentation.

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The Rufous Bristlebird Dasyornis broadbenti is a ground-dwelling bird that is listed as nearthreatened (Lower Risk) in Victoria. The species has been observed in a variety of habitats ranging from thickets of shrubs in coastal gullies, shrubland and heathlands on limestone cliffs to sheltered gullies. This study aimed to assess the distribution and habitat preferences of a population of the species in Portland, southwest Victoria. Monthly surveys were conducted on foot in the study area for one hour following sunrise and one hour prior to sunset, and bird presence was recorded on the basis of calls and sightings. Observations outside of the survey times were also recorded to determine habitat utilisation. Vegetation floristics and structure and food availability were measured in areas where birds were present as well as surrounding areas where they were absent to determine habitat preferences. A population size of between 45 and 60 individuals was estimated in the 200ha study area. Bird presence was significantly positively correlated with increasing vegetation density. No significant associations were found between Rufous Bristlebird presence and the floristic associations. Although Rufous Bristlebirds occupy a variety of vegetation communities, results indicate that the key common factor appears to be structure of the vegetation. The findings of this study will be incorporated into a Geographic Information System to develop a spatial model of suitable habitat.

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As obesity prevention becomes an increasing health priority in many countries, including Australia
and New Zealand, the challenge that governments are now facing is how to adopt a systematic
policy approach to increase healthy eating and regular physical activity. This article sets out a
structure for systematically identifying areas for obesity prevention policy action across the food
system and full range of physical activity environments. Areas amenable to policy intervention can
be systematically identified by considering policy opportunities for each level of governance (local,
state, national, international and organisational) in each sector of the food system (primary
production, food processing, distribution, marketing, retail, catering and food service) and each
sector that influences physical activity environments (infrastructure and planning, education,
employment, transport, sport and recreation). Analysis grids are used to illustrate, in a structured
fashion, the broad array of areas amenable to legal and regulatory intervention across all levels of
governance and all relevant sectors. In the Australian context, potential regulatory policy
intervention areas are widespread throughout the food system, e.g., land-use zoning (primary
production within local government), food safety (food processing within state government), food
labelling (retail within national government). Policy areas for influencing physical activity are
predominantly local and state government responsibilities including, for example, walking and
cycling environments (infrastructure and planning sector) and physical activity education in schools
(education sector). The analysis structure presented in this article provides a tool to systematically
identify policy gaps, barriers and opportunities for obesity prevention, as part of the process of
developing and implementing a comprehensive obesity prevention strategy. It also serves to
highlight the need for a coordinated approach to policy development and implementation across
all levels of government in order to ensure complementary policy action.

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To combine the merits of both metals and ceramics into one material, many researchers have been studying the deposition of alumina coating using plasma spray on metal substrates. However, as the coatings are deposited at a high temperature, residual thermal stresses develop due to the mismatch of thermal expansion coefficients of the coating and substrate and these are responsible for the initiation and expansion of cracks, which induce the possible failure of the entire material. In this paper, the residual thermal-structural analysis of a Fe3Al/Al2O3 gradient coating on carbon steel substrate is performed using finite element modelling to simulate the plasma spray. The residual thermal stress fields are obtained and analyzed on the basis of temperature fields in gradient coatings during fabrication. The distribution of residual thermal stresses including radial, axial and shear stresses shows stress concentration at the interface between the coatings and substrate. The mismatch between steel substrate and composite coating is still the dominant factor for the residual stresses

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The requirement for the automotive industry at present and even more so in the future is to simultaneously develop materials, economic forming processes and techniques for weight reduction of the component. To fulfil this need steel manufacturers have developed Advanced High Strength Steels which have high strength and good formability. Due to high strength, material thickness can be reduced without compromising the function of the component. High pressure hydro forming is one process that can be used to produce complex components from these materials. However, reduction in material thickness of these steels does not result in a large decrease of internal fluid pressure and die closing force during tube hydro forming and hence the higher strengths of these steels will require higher pressures. Tube crushing is a process in which the component can be formed with low pressures. In this paper numerical comparison of ramp and constant pressurization system during tube crushing for a TRIP steel is studied. It is proposed that ramp pressure is the best option to obtain a part with accurate geometrical shape from tube crushing with less die closing force. The stress and thickness distribution of the part during tube crushing were critically analysed.