899 resultados para United Nations Conference on Environment and Development (1992 : Rio de Janeiro, Brazil)
Resumo:
This paper presents a study on the implementation of Real-Time Pricing (RTP) based Demand Side Management (DSM) of water pumping at a clean water pumping station in Northern Ireland, with the intention of minimising electricity costs and maximising the usage of electricity from wind generation. A Genetic Algorithm (GA) was used to create pumping schedules based on system constraints and electricity tariff scenarios. Implementation of this method would allow the water network operator to make significant savings on electricity costs while also helping to mitigate the variability of wind generation.
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This paper presents a study on the implementation of Real-Time Pricing (RTP) based Demand Side Management (DSM) of water pumping at a clean water pumping station in Northern Ireland, with the intention of minimising electricity costs and maximising the usage of electricity from wind generation. A Genetic Algorithm (GA) was used to create pumping schedules based on system constraints and electricity tariff scenarios. Implementation of this method would allow the water network operator to make significant savings on electricity costs while also helping to mitigate the variability of wind generation.
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Desde a publicação do livro Silent Spring, 1962, de Rachel Carson, do livro The Limits to Growth, 1972, do Clube de Roma e do impacto provocado pelo Relatório Brundtland, Our Common Future, 1987, pela World Commission on Environment and Development, que os organismos internacionais se envolvem em parcerias e assinam declarações de compromisso com a Educação Ambiental para o Desenvolvimento Sustentável – EADS. O objetivo do presente artigo é realizar uma narrativa sobre os eventos dedicados à EADS, com início na Conferência de Estocolmo até à Conferência do Rio+20. O estudo teve como base metodológica uma revisão crítica da literatura. Concluiu-se que a sociedade tomou maior consciência sobre os problemas ambientais a partir de 1970. Despontaram as primeiras respostas político-administrativas na Conferência de Estocolmo e, mais tarde, publicou-se a Informação Brundtland pela equipa interdisciplinar de experts em meio ambiente. Daqui resultaram o Tratado de Bem-estar (garantia dos direitos mínimos aos cidadãos pelo Estado) e o conceito de Desenvolvimento Sustentável. Surgiu assim a solidariedade social para com o futuro da humanidade, que implicou o princípio de “não hipotecar os recursos das gerações futuras”. Na Conferência do Rio a EADS foi plenamente aceite e divulgada pelo mundo. Todavia, com a entrada do novo milénio, a atenção dada à EADS regrediu significativamente.
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Résumé : Au Canada, près de 80% des émissions totales, soit 692 Mt eq. CO[indice inférieur 2], des gaz à effet de serre (GES) sont produits par les émissions de dioxyde de carbone (CO[indice inférieur 2]) provenant de l’utilisation de matières fossiles non renouvelables. Après la Conférence des Nations Unies sur les changements climatiques, COP21 (Paris, France), plusieurs pays ont pour objectif de réduire leurs émissions de GES. Dans cette optique, les microalgues pourraient être utilisées pour capter le CO[indice inférieur 2] industriel et le transformer en biomasse composée principalement de lipides, de glucides et de protéines. De plus, la culture des microalgues n’utilise pas de terre arable contrairement à plusieurs plantes oléagineuses destinées à la production de biocarburants. Bien que les microalgues puissent être transformées en plusieurs biocarburants tels le bioéthanol (notamment par fermentation des glucides) ou le biométhane (par digestion anaérobie), la transformation des lipides en biodiesel pourrait permettre de réduire la consommation de diesel produit à partir de pétrole. Cependant, les coûts reliés à la production de biodiesel à partir de microalgues demeurent élevés pour une commercialisation à court terme en partie parce que les microalgues sont cultivées en phase aqueuse contrairement à plusieurs plantes oléagineuses, ce qui augmente le coût de récolte de la biomasse et de l’extraction des lipides. Malgré le fait que plusieurs techniques de récupération des lipides des microalgues n’utilisant pas de solvant organique sont mentionnées dans la littérature scientifique, la plupart des méthodes testées en laboratoire utilisent généralement des solvants organiques. Les lipides extraits peuvent être transestérifiés en biodiesel en présence d’un alcool tel que le méthanol et d’un catalyseur (catalyses homogène ou hétérogène). Pour la commercialisation du biodiesel à partir de microalgues, le respect des normes ASTM en vigueur est un point essentiel. Lors des essais en laboratoire, il a été démontré que l’extraction des lipides en phase aqueuse était possible afin d’obtenir un rendement maximal en lipides de 36% (m/m, base sèche) en utilisant un prétraitement consistant en une ébullition de la phase aqueuse contenant les microalgues et une extraction par des solvants organiques. Pour l’estérification, en utilisant une résine échangeuse de cations (Amberlyst-15), une conversion des acides gras libres de 84% a été obtenue à partir des lipides de la microalgue Chlorella protothecoïdes dans les conditions suivantes : température : 120°C, pression autogène, temps de réaction : 60 min, ratio méthanol/lipides: 0.57 mL/g et 2.5% (m/m) Amberlyst-15 par rapport aux lipides. En utilisant ces conditions avec une catalyse homogène (acide sulfurique) et une seconde étape alcaline avec de l’hydroxyde de potassium (température : 60°C ; temps de réaction : 22.2 min; ratio catalyseur microalgue : 2.48% (m/m); ratio méthanol par rapport aux lipides des microalgues : 31.4%), un rendement en esters méthyliques d’acides gras (EMAG) de 33% (g EMAG/g lipides) a été obtenu à partir des lipides de la microalgue Scenedesmus Obliquus. Les résultats démontrent que du biodiesel peut être produit à partir de microalgues. Cependant, basé sur les présents résultats, il sera necessaire de mener d’autre recherche pour prouver que les microalgues sont une matière première d’avenir pour la production de biodiesel.
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El presente estudio de caso tiene como principal objetivo el de analizar la manera como las características sociopolíticas de los Estados del Mekong, específicamente en el caso de Camboya y Myanmar, dificultan la implementación de las normas enunciadas en el Protocolo de las Naciones Unidas para Prevenir, Reprimir y Sancionar la Trata de Personas, Especialmente Mujeres y Niños, también conocido como el Protocolo de Palermo. En este sentido, se parte de las características principales del Protocolo y de la manera como el tráfico de personas se presenta en el Mekong para posteriormente analizar la forma como la corrupción, la impunidad y la desigualdad de género representan retos sociopolíticos que obstruyen la implementación de los mandatos internacionales enmarcados en este instrumento
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We introduce K-tree in an information retrieval context. It is an efficient approximation of the k-means clustering algorithm. Unlike k-means it forms a hierarchy of clusters. It has been extended to address issues with sparse representations. We compare performance and quality to CLUTO using document collections. The K-tree has a low time complexity that is suitable for large document collections. This tree structure allows for efficient disk based implementations where space requirements exceed that of main memory.
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This paper presents a framework for evaluating information retrieval of medical records. We use the BLULab corpus, a large collection of real-world de-identified medical records. The collection has been hand coded by clinical terminol- ogists using the ICD-9 medical classification system. The ICD codes are used to devise queries and relevance judge- ments for this collection. Results of initial test runs using a baseline IR system are provided. Queries and relevance judgements are online to aid further research in medical IR. Please visit: http://koopman.id.au/med_eval.
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In 2002, the United Nations Office on Drugs and Crime (UNODC) issued a report entitled Results of a pilot survey of forty selected organized criminal groups in sixteen countries which established five models of organised crime. This paper reviews these and other common organised crime models and drug trafficking models, and applies them to cases of South East Asian drug trafficking in the Australian state of Queensland. The study tests the following hypotheses: (1) South-East Asian drug trafficking groups in Queensland will operate within a criminal network or core group; (2) Wholesale drug distributors in Queensland will not fit consistently under any particular UN organised crime model; and (3) Street dealers will have no organisational structure. The study concluded that drug trafficking or importation closely resembles a criminal network or core group structure. Wholesale dealers did not fit consistently into any UN organised crime model. Street dealers had no organisational structure as an organisational structure is typically found in mid- to high-level drug trafficking.
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Biodiesel, produced from renewable feedstock represents a more sustainable source of energy and will therefore play a significant role in providing the energy requirements for transportation in the near future. Chemically, all biodiesels are fatty acid methyl esters (FAME), produced from raw vegetable oil and animal fat. However, clear differences in chemical structure are apparent from one feedstock to the next in terms of chain length, degree of unsaturation, number of double bonds and double bond configuration-which all determine the fuel properties of biodiesel. In this study, prediction models were developed to estimate kinematic viscosity of biodiesel using an Artificial Neural Network (ANN) modelling technique. While developing the model, 27 parameters based on chemical composition commonly found in biodiesel were used as the input variables and kinematic viscosity of biodiesel was used as output variable. Necessary data to develop and simulate the network were collected from more than 120 published peer reviewed papers. The Neural Networks Toolbox of MatLab R2012a software was used to train, validate and simulate the ANN model on a personal computer. The network architecture and learning algorithm were optimised following a trial and error method to obtain the best prediction of the kinematic viscosity. The predictive performance of the model was determined by calculating the coefficient of determination (R2), root mean squared (RMS) and maximum average error percentage (MAEP) between predicted and experimental results. This study found high predictive accuracy of the ANN in predicting fuel properties of biodiesel and has demonstrated the ability of the ANN model to find a meaningful relationship between biodiesel chemical composition and fuel properties. Therefore the model developed in this study can be a useful tool to accurately predict biodiesel fuel properties instead of undertaking costly and time consuming experimental tests.
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The Quantum Probability Ranking Principle (QPRP) has been recently proposed, and accounts for interdependent document relevance when ranking. However, to be instantiated, the QPRP requires a method to approximate the interference" between two documents. In this poster, we empirically evaluate a number of different methods of approximation on two TREC test collections for subtopic retrieval. It is shown that these approximations can lead to significantly better retrieval performance over the state of the art.
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Retrieval with Logical Imaging is derived from belief revision and provides a novel mechanism for estimating the relevance of a document through logical implication (i.e. P(q -> d)). In this poster, we perform the first comprehensive evaluation of Logical Imaging (LI) in Information Retrieval (IR) across several TREC test Collections. When compared against standard baseline models, we show that LI fails to improve performance. This failure can be attributed to a nuance within the model that means non-relevant documents are promoted in the ranking, while relevant documents are demoted. This is an important contribution because it not only contextualizes the effectiveness of LI, but crucially ex- plains why it fails. By addressing this nuance, future LI models could be significantly improved.
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The assumptions underlying the Probability Ranking Principle (PRP) have led to a number of alternative approaches that cater or compensate for the PRP's limitations. In this poster we focus on the Interactive PRP (iPRP), which rejects the assumption of independence between documents made by the PRP. Although the theoretical framework of the iPRP is appealing, no instantiation has been proposed and investigated. In this poster, we propose a possible instantiation of the principle, performing the first empirical comparison of the iPRP against the PRP. For document diversification, our results show that the iPRP is significantly better than the PRP, and comparable to or better than other methods such as Modern Portfolio Theory.
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Recently, Portfolio Theory (PT) has been proposed for Information Retrieval. However, under non-trivial conditions PT violates the original Probability Ranking Principle (PRP). In this poster, we shall explore whether PT upholds a different ranking principle based on Quantum Theory, i.e. the Quantum Probability Ranking Principle (QPRP), and examine the relationship between this new model and the new ranking principle. We make a significant contribution to the theoretical development of PT and show that under certain circumstances PT upholds the QPRP, and thus guarantees an optimal ranking according to the QPRP. A practical implication of this finding is that the parameters of PT can be automatically estimated via the QPRP, instead of resorting to extensive parameter tuning.
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Biodiesel derived from microalgae is one of a suite of potential solutions to meet the increasing demand for a renewable, carbon-neutral energy source. However, there are numerous challenges that must be addressed before algae biodiesel can become commercially viable. These challenges include the economic feasibility of harvesting and dewatering the biomass and the extraction of lipids and their conversion into biodiesel. Therefore, it is essential to find a suitable extraction process given these processes presently contribute significantly to the total production costs which, at this stage, inhibit the ability of biodiesel to compete financially with petroleum diesel. This study focuses on pilot-scale (100 kg dried microalgae) solvent extraction of lipids from microalgae and subsequent transesterification to biodiesel. Three different solvents (hexane, isopropanol (IPA) and hexane + IPA (1:1)) were used with two different extraction methods (static and Soxhlet) at bench-scale to find the most suitable solvent extraction process for the pilot-scale. The Soxhlet method extracted only 4.2% more lipid compared to the static method. However, the fatty acid profiles of different extraction methods with different solvents are similar, suggesting that none of the solvents or extraction processes were biased for extraction of particular fatty acids. Considering the cost and availability of the solvents, hexane was chosen for pilot-scale extraction using static extraction. At pilot-scale the lipid yield was found to be 20.3% of total biomass which is 2.5% less than from bench scale. Extracted fatty acids were dominated by polyunsaturated fatty acids (PUFAs) (68.94±0.17%) including 47.7±0.43 and 17.86±0.42% being docosahexaenoic acid (DHA) (C22:6) and docosapentaenoic acid (DPA) (C22:5, ω-3), respectively. These high amounts of long chain poly unsaturated fatty acids are unique to some marine microalgae and protists and vary with environmental conditions, culture age and nutrient status, as well as with cultivation process. Calculated physical and chemical properties of density, viscosity of transesterified fatty acid methyl esters (FAMEs) were within the limits of the biodiesel standard specifications as per ASTM D6751-2012 and EN 14214. The calculated cetane number was, however, significantly lower (17.8~18.6) compared to ASTM D6751-2012 or EN 14214-specified minimal requirements. We conclude that the obtained microalgal biodiesel would likely only be suitable for blending with petroleum diesel to a maximum of 5 to 20%.