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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
261

Efluente de estação de tratamento de esgoto aplicado em solo com Brachiaria colhida com duas alturas /

Dantas, Geffson de Figueiredo. January 2019 (has links)
Orientador: Rogério Teixeira de Faria / Banca: Fernando Campos Mendonça / Banca: Antonio Sérgio Ferraudo / Banca: Gilmar Oliveira Santos / Banca: Abmael da Silva Cardoso / Resumo: Em manejo de pastejo intensivo de forragens tropicas dispendem-se níveis de trabalho e recursos elevados para se aumentar a produtividade por área e ou por animal. Dentre as estratégias de manejo, destaca-se a frequência de corte por altura do dossel, que estimula maior produção de folhas do que colmo e material morto para obtenção de maior produtividade e valor nutritivo da forragem. Outra estratégia é a adubação nitrogenada, que possibilita o crescimento vegetal mais rápido, além de forragem de melhor qualidade. As águas residuárias são promissoras para uso em pastagens, na forma de fertirrigação, pois pode suprir as necessidades hídrica e nutricional do cultivo em parte ou na sua totalidade. Devido às limitações climáticas ao longo do ano, a efetividade dessas estratégias pode ser comprometida, o que resulta a sazonalidade de produção. Há carência de estudos sobre a interação das estratégias de manejo de fertirrigação com água residuária e de colheita da forragem com diferentes alturas de corte para as forrageiras tropicais. Os objetivos deste trabalho foi determinar a produtividade e o valor nutritivo da forragem, e as características morfogênicas e estruturais de Urochloa brizantha, em função da fertirrigação com efluente de estação de tratamento de esgoto (EETE), complementada com ureia (U), associada à colheita com duas alturas de plantas, durante os períodos seco (PS) e chuvoso (PC). O experimento foi conduzido em Jaboticabal, SP (Latitude 21º15'S, Longitude 48º18'W),... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In tropical forages under intensive grazing management, high labor and resources are used to increase productivity per area and / or animal units. Among the management strategies, the frequency of harvesting by canopy height is advantageous because it stimulates more leaf production than stalk and dead material to obtain high productivity and forage nutritive value. Another strategy is nitrogen fertilization, which enables faster plant growth, in addition to better forage quality. Wastewater is promising for use in pasture in the form of fertigation, since it can meet the water and nutritional needs of the crop in part or in its entirety. Due to climatic limitations throughout the year, the effectiveness of these strategies can be compromised, resulting in seasonality of production. There is a lack of studies on the interaction of fertigation management strategies with wastewater and forage harvesting with different cutting heights for tropical forages. The objectives of this work were to determine the productivity and nutritive value of forage, and the morphogenic and structural characteristics of Urochloa brizantha, as a function of fertigation with treated sewage (TSW), complemented with urea (U), associated with harvest at two plant heights during the dry (DP) and rainy (RP) periods. The experiment was conducted in Jaboticabal, SP, Brazil (Latitude 21º15'S, Longitude 48º18'W), from february, 2015 to february, 2017. The management strategies for forage harvesting heights w... (Complete abstract click electronic access below) / Doutor
262

Improving Reuse and Maintainability of Communication Software With Conversation-Aware Aspects

Raza, Ali 01 May 2014 (has links)
Inter-process communications (IPC) are ubiquitous in today’s software systems, yet they are rarely treated as first-class programming concepts. Implementing crosscutting concerns for message-based IPC are difficult, even using aspect-oriented programming languages (AOPL) such as AspectJ. Many of these challenges are because the context of a communication-related crosscutting concern is often a conversation consisting of message sends and receives. Hence, developers typically have to implement communication protocols manually using primitive operations, such as connect, send, receive, and close. This dissertation describes an extension to AspectJ, called CommJ, with which developers can implement communication-related concerns in cohesive and loosely coupled aspects. It then presents preliminary, but encouraging results from a subsequent study that begin by defining a reuse and maintenance quality model. Subsequently the results show seven different ways in which CommJ can improve the reusability and maintainability of applications requiring network communications.
263

An Economic Appraisal of Reuse Concepts in Regional Water Supply Planning

Narayanan, Rangesan 01 May 1976 (has links)
Using a conceptual model of a water supply firm, the necessary conditions for production and market efficiency are derived when renovated wastewater is considered as a potential water resource. The nature and extent of the supply augmentation due to recycled reuse is demonstrated using classical optimization techniques. Three stages of short-run supply corresponding to no recycling, partial recycled reuse and complete recycling of all reclaimable water are identified through appropriate Lagrangian Multipliers as well as graphical techniques. A mathematical programming model is structured to determine the optimal water resource allocation and pricing policy for Salt Lake County. By maximizing the sum of consumer and producer surplus (the difference between total willingness-to-pay and total cost) economically efficient equilibria are derived. The feasibility of recycled reuse for municipal purposes is examined in a planning context. The impact of higher water quality discharge standards on the attractiveness of water recycling option is studied. To ensure social acceptability of renovated wastewater for culinary purposes, blending restrictions are imposed, which stipulate that the amount of water for reuse be less than a fixed percentage of the water from other sources. The effect of such a constraint on the prices and water allocation are delineated. The hydrologic uncertainty in water supply is treated using stochastic programming techniques. Application of the concepts of single and joint chance-constrained programming are illustrated. The resulting changes in pricing and allocation policies are discussed.
264

Sustainability and participation in the governing of water use: the case of water recycling

Stenekes, Nyree, Civil & Environmental Engineering, Faculty of Engineering, UNSW January 2006 (has links)
Urban water recycling has been promoted as one of several ways that water use efficiency could be improved in Australia???s cities, but few such schemes have been introduced. Many urban water-recycling schemes have been proposed, but often, these projects have been rejected because of community opposition. These difficulties suggest that recycling water is not just about having the right answer to any problem, but about the way in which the question is addressed. It is concerned with how practice is institutionalised; not just the rule making, but also the understandings and values that make the rule-making possible. In this thesis, the question of how the system of water governance could be strengthened to encourage sustainable water use through water recycling is examined. An analysis of experiences in three Australian case studies is conducted, in which recycled water was proposed for sustainability, to illuminate the way in which water use is institutionalised. Particular attention is given to the construction of meaning in relation to water use, by considering how water problems are framed and negotiated by different stakeholders and groups and the significance of the multiplicity of interpretive frameworks in use for the institutionalisation of practice. The analysis draws on institutional organisational theory and interpretive methods, which regard interpretation as one element (cognitive) in the stabilisation of social practice and closely linked to organisation (regulative) and values (normative). The study findings suggest meaning was a very important part of institutional change. Participants tended to construct policy issues as they became involved by drawing on different interpretive frameworks embodying different values and expectations. These interpretations reflected the organisational structuring of practice, such that the position/role in the organisational field reflected an actor???s interpretation of problems and/or solutions. Outcomes of the study suggest that institutionalising change in water management is problematic and depends on changes in the regulative, normative and cognitive dimensions of practice, as part of a continuous feedback loop between interpretation and practice. This view of change contrasts with existing research, which tends to see the problem in terms of influencing attitudes of specific groups and assumes preferences precede the action.
265

Planning for sustainable urban water: systems-approaches and distributed strategies.

Fane, Simon Anthony January 2005 (has links)
This thesis develops and applies a number of methods for systems analysis and assessment within the field of sustainable urban water. These focus on the evaluation of distributed strategies. In line with arguments made within the thesis, the methods developed assess urban water on a whole-system basis, with the system defined in terms of the services provided. Further, the thesis argues for sustainable urban water planning to take a pluralist stance; both in the conception of sustainable urban water and the strategies considered. The challenges of sustainability and sustainable development are fundamentally problems of complex systems. Planning and assessment of sustainable urban water therefore require a systems-approach. Systems-thinking is not, however, a unified body of knowledge and this thesis develops a unique perspective on systems-thinking which is used to critically review the fields of sustainable urban water and its assessment. Within these reviews, the thesis develops a framework for understanding sustainable urban water in terms of a number of varied approaches, and describes a feasible theoretical basis for assessing sustainable urban water. Many, so called, sustainable strategies are small-scale and distributed in nature. Distributed strategies include decentralised systems, embedded technologies, and local measures for conservation. Traditional systems analysis methods have failed to account for distributed strategies. To adequately include distributed strategies, this thesis argues that assessment methods will need to be based on whole-system modelling, utilise end-use models of service provision, and include - in the form of a demand forecast - a time dimension in relation to service provision. This thesis proposes new methods for microbial risk assessment on a whole-system basis and Least cost planning for (urban water) Sustainable Scenarios (LeSS). A novel evaluation framework for least cost planning for water supply, which provides an equivalent comparison of demand- and supply-side options, is also developed. These methods are illustrated through case studies. These case studies illustrate the potential of distributed strategies. When assessed on an equivalent basis, in various examples, distributed strategies are shown to be particularly cost effective. Decentralised wastewater reuse systems are also shown to impose a theoretically lower level of pathogen risk on the community than equivalent centralised reuse schemes. Despite the advances in assessment methodologies made within the thesis, further development of practical tools for assessing and planning sustainable urban water remains an urgent goal.
266

Development and trial of a low-cost aerobic greywater treatment system

Okalebo, Susan, University of Western Sydney, College of Science, Technology and Environment, School of Engineering and Industrial Design January 2004 (has links)
This study was undertaken to examine the feasibilty of a low-cost aerobic system to treat greywater for reuse.Its purpose was to provide a system that would be easy to maintain, flexible and be affordable for households and small communities in developing countries. This thesis outlines and evaluates the key biological and chemical hazards associated with greywater reuse. It discusses the performance of a variety of wastewater treatment options in use. It presents details of the components of the greywater system,namely, an aerobic grease trap and slow sand filter. Reference is made to the evaporation and treatment bed and ultraviolet disinfection components, but these are not examined. The incorporation of vermitechnology in the preliminary stages of the system for reduction of organics in greywater is reviewed. This study takes the traditional approach to water quality assessment with the measurement of physical, chemical and biological indicators. Assessment of the system involved examining the input characteristics of the greywater, monitoring the vermiculture system and sampling the liquid discharge from the aerobic grease trap and slow sand filter for analysis of the quality indicators. The results obtained under the framework of this study have provided recommendations for further use of the aerobic grease trap and slow sand filter, while propsing an approach for an appropriate long-term monitoring program. / Master of Engineering (Hons)
267

Spatial reuse in TDMA wireless networks

Oh, Inhee, Electrical Engineering & Telecommunications, Faculty of Engineering, UNSW January 2008 (has links)
In this thesis we investigate the performance of spatial reuse in wireless networks. More specifically, we investigate the performance of location-based spatial reuse built upon the identification of links in the network that form Collision-Free Sets (CFSs). We develop algorithms that efficiently find such CFSs. The main focus of this thesis is the application of our CFS-based algorithms to emerging WiMAX (Worldwide Interoperability for Microwave Access) networks. However, we will also apply our CFS-based algorithms to smaller scale networks, as well as to the issue of QoS routing. This thesis makes several contributions. We first show how CFSs can be found within polynomial time in small scale wireless networks. We then probe how CFSs can be used to enhance network efficiency when location is available. We also explore how CFS determination is affected by location error, determining what level of location error renders the use of CFSs ineffective. In this context, we discuss the density of access points required to ensure CFS-based spatial reuse remains effective. We then focus on the use of CFSs in emerging multihop WiMAX networks, showing in detail how enhanced spatial reuse is delivered. The spatial reuse gains are probed both in the presence of realistic channel conditions and realistic location errors. Within the context of the IEEE 802.16 standard we show how CFSs can enhance, by factors of two, the VoIP capacity of multihop WiMAX networks. We also discuss how our CFS algorithms can be applied to other ongoing efforts aimed at improving VoIP capacity in WiMAX networks. Finally, an application of our CFS algorithms in the context of QoS routing is studied. Specifically, we develop a two-hop QoS routing protocol that guarantees QoS specifications by securing higher bandwidth for the chosen routes.
268

The experience of urban water recycling and the development of trust

Marks, June Sylvia, june.marks@flinders.edu.au January 2003 (has links)
Water scarcity and water pollution are ongoing problems that require a rethinking of water use in the community. This calls for cooperation between the expert systems of water supply and sewerage as well as some level of public involvement. It is the interaction between the experts or providers, and the public as users or customers, that is the focus of this study on the experience of recycling water sourced from sewage effluent. This cross-national research explores the drivers behind water reuse; the way water reuse is presented to the public for consideration; the public response to water reuse; the influence of environmental and public health risk concerns; and the function of trust in the acceptance of potable water reuse and the sustainability of non potable reuse. The absence of social science published literature relating to the experience of recycled water guided a grounded theory approach to this research, using a triangulation of methods for data collection and case study analysis. The social-psychological studies of Bruvold (1972-1988), located in water industry literature, were consulted to organise an audit of secondary, survey data obtained through industry contacts and fieldwork. In this way, acceptance of potable and non potable water reuse in the USA, UK and Australia is mapped to provide background data for a set of minor case studies that explore the experience of potable reuse. Residential water reuse experience is investigated through embedded case study research. Primary data were collected at two residential sites in Adelaide and two in Florida. Recycled water is used for garden watering and toilet flushing at New Haven, and is planned for Mawson Lakes in Adelaide. Altamonte Springs and Brevard County in Florida recycle water for garden watering and outdoor uses only. Twenty residents were interviewed at each site involving semi-structured interviews: in-depth, face-to-face interviews in Adelaide and telephone interviews on site in Florida. Individual managers of the recycled water systems were also interviewed and, at New Haven, additional key stakeholders were consulted. Qualitative data analysis, employing a grounded theory approach, discovered the value of Sztompka�s (1999) framework for the �social becoming of trust�. This research illustrates that the positive historical culture of trust at the Florida sites, coupled with robust structural support for residential water reuse that encourages positive provider-customer interactions, develops trust in non potable reuse and uses involving a higher level of contact. In the Adelaide sites, weak structural support induces reliance on informal structure that increases the public health risk, jeopardising the sustainability of residential reuse. In relation to potable reuse experience that centres on the Californian experience, a social dilemma is created through a strategic, marketing approach to public consultation and the lack of public communication on current water sources. Sztompka�s (1999) framework for trust as an ongoing process is expanded to include principles of public participation that will further consolidate trust in water reuse to achieve sustainable outcomes.
269

Greywater Systems: Barriers for Builders

Dinama, Desmond, s3084691@student.rmit.edu.au January 2008 (has links)
Australia is one of the driest continents in the world with changing climatic conditions continuing to put a strain on potable water sources. The use of water saving technologies such as greywater systems in residential properties is an important water conservation tool in order to reduce the consumption of the finite potable water resources in Australia. To this end, Master Builders Association Victoria with the assistance of RMIT University investigated the current barriers that builders face with regard to the installation of greywater systems in residential properties. Builders like other property and construction professionals have a part to play in promoting the use of sustainable technologies. The main aims of the project were to firstly find out or identify barriers that are inhibiting builders from installing greywater systems and secondly to identify and formulate strategies to reduce or eliminate the barriers identified. The main barriers for builders are; high cost, government regulations, lack of builder awareness or knowledge, and low client demand. The potential solutions for the reduction or elimination of the barriers identified as part of the research include; economic and reliable greywater systems, creation of a website with link on greywater systems and educating the general public.
270

Ground water monitoring system for effluent irrigated areas : a case study of Hawkesbury water recycling scheme

Beveridge, Gavin John, University of Western Sydney, College of Health and Science, School of Natural Sciences January 2006 (has links)
Water recycling schemes are increasingly being implemented across Australia as an effective means of converting wastewater into a valuable resource. There is currently a lack of specific guidelines for the monitoring of groundwater resources associated with these schemes. This is despite it being widely acknowledged that a monitoring system is a fundamental component of a scheme, due to the risk of altering the hydrogeological processes and resource devaluation. The aim of this research was to address this information gap, by developing guidelines that provide a platform for the continuous improvement in groundwater monitoring systems for recycling schemes. To achieve the stated aim, an action research strategy formed the methodological approach for the implementation of the objectives. Existing guidelines for monitoring systems were reviewed, consolidated and refined, in consultation with industry expertise. The developed guidelines were then verified through the implementation of a case study at the Hawkesbury Water Recycling Scheme (HWRS), with the resulting information providing for a preliminary characterisation of the resources. Designed on current best practice, and to meet statutory requirements, the guidelines addressed the identified information gap. The research recommends the integration of groundwater monitoring systems into the environmental management system for recycling schemes, to provide for continuous refinement through the interpretation of the knowledge base developed in previous cycles. Adoption of this practice will initiate improved decision making and management processes, and provide for future resource protection and enhancement. / Master of Science (Hons)

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