887 resultados para SELF-SUSTAINING PROCESS
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This paper reviews the development of the agricultural sector in Myanmar after the transition to an open economy in 1988 and analyzes the nature as well as the performance of the agricultural sector. The avoidance of social unrest and the maintenance of control by the regime are identified as the two key factors that have determined the nature of agricultural policy after 1988. A major consequence of agricultural policy has been a clear difference in development paths among the major crops. Production of crops that had a potential for development showed sluggish growth due to policy constraints, whereas there has been a self-sustaining increase in the output of those crops that have fallen outside the remit of agricultural policy.
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El objetivo de este proyecto es desarrollar un equipo para la realización de un ensayo de emisión de gases. Con esto se pretende simplificar el ensayo de calentamiento de sólidos y emisión de gases y hacerlo más fiable. Para la realización de este proyecto se utilizo un método de ensayo más rudimentario pero también eficaz. Así mismo se analizara el fenómeno de la autocombustión y las propiedades de distintos tipos de biomasa, en concreto dos tipos: astillas de madera y pellets de madera. Las propiedades que son caso de estudio son: las emisiones de gases que se producen durante el proceso de autocombustión; y las temperaturas de inflamación en capa a diferentes tamaños de grano y grosores de capa. Para analizar las propiedades de las muestras de biomasa se realizaran dos tipos de ensayos: ensayos de extracción de gases, y ensayos de temperatura mínima de inflamación en capa. Abstract: The main object of this Project is to develop an equipment to simplify our gas emissions test. During this project a more elementary method was used, however this method is extremely efficient. Also the self-heating phenomenon will be analyzed and several kinds of biomass properties, specifically two: wood chops and wood pellets. The properties that will be analyzed are: gas emissions during the self-heating process; and layer inflammation temperatures at several grain size and layer thickness. The biomass properties will be analyzed with two different tests: gas extraction tests, and TIMc.
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Superoxide-mediated clastogenesis is characteristic for various chronic inflammatory diseases with autoimmune reactions and probably plays a role in radiation-induced clastogenesis and in the congenital breakage syndromes. It is consistently prevented by exogenous superoxide dismutase (SOD), but not by heat-inactivated SOD, indicating that the anticlastogenic effect is related to the catalytic function of the enzyme. Increased superoxide production by activated monocytes/macrophages is followed by release of more long-lived metabolites, so-called clastogenic factors, which contain lipid peroxidation products, unusual nucleotides of inosine, and cytokines such as tumor necrosis factor α. Since these components are not only clastogenic, but can stimulate further superoxide production by monocytes and neutrophils, the genotoxic effects are self-sustaining. It is shown here that anticlastogenic effects of exogenous SOD are preserved despite extensive washing of the cells and removal of all extracellular SOD. Using flow cytometry and confocal laser microscopy, rapid adherence of the fluorescently labeled enzyme to the cell surface could be observed with slow uptake into the cell during the following hours. The degree of labeling was concentration and time dependent. It was most important for monocytes, compared with lymphocytes, neutrophils, and fibroblasts. The cytochrome c assay showed significantly diminished O2− production by monocytes, pretreated with SOD and washed thereafter. The preferential and rapid binding of SOD to monocytes may be of importance not only for the superoxide-mediated genotoxic effects, described above, but also from a therapeutic standpoint. It can explain the observation that beneficial effects of injected SOD lasted for weeks and months despite rapid clearance of the enzyme from the blood stream according to pharmacodynamic studies.
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To what extent do local populations of tropical reef fishes persist through the recruitment of pelagic larvae to their natal reef? Endemics from small, isolated islands can help answer that question by indicating whether special biological attributes are needed for long-term survival under enforced localization in high-risk situations. Taxonomically and biologically, the endemics from seven such islands are broadly representative of their regional faunas. As natal-site recruitment occurs among reef fishes in much less isolated situations, these characteristics of island endemics indicate that a wide range of reef fishes could have persistent self-sustaining local populations. Because small islands regularly support substantial reef fish faunas, regional systems of small reserves could preserve much of the diversity of these fishes.
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Relying on a quantitative analysis of the patenting and assignment behavior of inventors, we highlight the evolution of institutions that encouraged trade in technology and a growing division of labor between those who invented new technologies and those who exploited them commercially over the nineteenth and early-twentieth centuries. At the heart of this change in the organization of inventive activity was a set of familiar developments which had significant consequences for the supply and demand of inventions. On the supply side, the growing complexity and capital intensity of technology raised the amount of human and physical capital required for effective invention, making it increasingly desirable for individuals involved in this activity to specialize. On the demand side, the growing competitiveness of product markets induced firms to purchase or otherwise obtain the rights to technologies developed by others. These increasing incentives to differentiate the task of invention from that of commercializing new technologies depended for their realization upon the development of markets and other types of organizational supports for trade in technology. The evidence suggests that the necessary institutions evolved first in those regions of the country where early patenting activity had already been concentrated. A self-reinforcing process whereby high rates of inventive activity encouraged the evolution of a market for technology, which in turn encouraged greater specialization and productivity at invention as individuals found it increasingly feasible to sell and license their discoveries, appears to have been operating. This market trade in technological information was an important contributor to the achievement of a high level of specialization at invention well before the rise of large-scale research laboratories in the twentieth century.
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Bacterial adhesion to other bacteria, to eukaryotic cells, and to extracellular matrix proteins is frequently mediated by cell surface-associated polymers (fimbriae) consisting of one or more subunit proteins. We have found that polymerization of curlin to fimbriae-like structures (curli) on the surface of Escherichia coli markedly differs from the prevailing model for fimbrial assembly in that it occurs extracellularly through a self-assembly process depending on a specific nucleator protein. The cell surface-bound nucleator primes the polymerization of curlin secreted by the nucleator-presenting cell or by adjacent cells. The addition of monomers to the growing filament seems to be driven by mass action and guided only by the diffusion gradient between the source of secreted monomer and the surface of monomer condensation.
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The rationale is disclosed for a substructure within the Earth's inner core, consisting of an actinide subcore at the center of the Earth, surrounded by a subshell composed of the products of nuclear fission and radioactive decay. Estimates are made as to possible densities, physical dimensions, and chemical compositions. The feasibility for self-sustaining nuclear fission within the subcore is demonstrated, and implications bearing on the structure and geodynamic activity of the inner core are discussed.
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Diferentes complexos de cobre(II), contendo ligantes do tipo base de Schiff e um grupamento imidazólico, com interesse bioinorgânico, catalítico e como novos materiais, foram preparados na forma de sais perclorato, nitrato ou cloreto e caracterizados através de diferentes técnicas espectroscópicas (UV/Vis, IR, EPR, Raman) e espectrometria de massa Tandem (ESI-MS/MS), além de análise elementar, condutividade molar e medidas de propriedades magnéticas. Alguns destes compostos, obtidos como cristais adequados, tiveram suas estruturas determinadas por cristalografia de raios-X. As espécies di- e polinucleares contendo pontes cloreto, mostraram desdobramentos das hiperfinas nos espectros de EPR, relacionados à presença do equilíbrio com a respectiva espécie mononuclear, devido à labilidade dos íons cloretos, dependendo do contra-íon e do tipo de solvente utilizado. Adicionalmente, em solução alcalina, estes compostos estão em equilíbrio com as correspondentes espécies polinucleares, onde os centros de cobre estão ligados através de um ligante imidazolato. Em meio alcalino, estes compostos polinucleares contendo ponte imidazolato foram também isolados e caracterizados por diferentes técnicas espectroscópicas e magnéticas. Através da variação estrutural e também do ligante-ponte foi possível modular o fenômeno da interação magnética entre os íons de cobre em estruturas correlatas di- e polinucleares. Os respectivos parâmetros magnéticos foram obtidos com ajuste das curvas experimentais de XM vs T, correlacionando-se muito bem com a geometria, ângulos e distâncias de ligação entre os íons, quando comparado com outros complexos similares descritos na literatura. Posteriormente, estudaram-se os fatores relacionados com a reatividade de todas essas espécies como catalisadores na oxidação de substratos de interesse (fenóis e aminas), através da variação do tamanho da cavidade nas estruturas cíclicas ou de variações no ligante coordenado ao redor do íon metálico. Vários deles se mostraram bons miméticos de tirosinases e catecol oxidases. Um novo complexo-modelo da citocromo c oxidase (CcO), utilizando a protoporfirina IX condensada ao quelato N,N,-bis[2-(1,2-metilbenzimidazolil)etil]amino e ao resíduo de glicil-L-histidina, foi sintetizado e caracterizado através de diferentes técnicas espectroscópicas, especialmente EPR. A adição de H2O2 ao sistema completamente oxidado, FeIII/CuII, a -55°C, ou o borbulhamento de oxigênio molecular a uma solução do complexo na sua forma reduzida, FeII/CuI, saturada de CO, resultou na formação de adutos com O2, de baixo spin, estáveis a baixas temperaturas.
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This paper examines Finster’s collection of Inventions of Mankind and his paintings of American industrial icons such as Henry Ford and Eli Whitney. Additionally, this study explores Finster’s compulsive artistic productivity and his experimentation with mechanisms designed to create self-sustaining energy. By providing a comprehensive overview of Howard Finster’s fascination with inventions and industry, this paper serves to provide new insight and dimension into the often over-generalized interpretations of his extensive body of work
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In Canada, increases in rural development has led to a growing need to effectively manage the resulting municipal and city sewage without the addition of significant cost- and energy- expending infrastructure. Storring Septic Service Limited is a family-owned, licensed wastewater treatment facility located in eastern Ontario. It makes use of a passive waste stabilization pond system to treat and dispose of waste and wastewater in an environmentally responsible manner. Storring Septic, like many other similar small-scale wastewater treatment facilities across Canada, has the potential to act as a sustainable eco-engineered facility that municipalities and service providers could utilize to manage and dispose of their wastewater. However, it is of concern that the substantial inclusion of third party material could be detrimental to the stability and robustness of the pond system. In order to augment the capacity of the current facility, and ensure it remains a self-sustaining system with the capacity to safely accept septage from other sewage haulers, it was hypothesized that pond effluent treatment could be further enhanced through the incorporation of one of three different technology solutions, which would allow the reduction of wastewater quality parameters below existing regulatory effluent discharge limits put in place by Ontario’s Ministry of the Environment and Climate Change (MOECC). Two of these solutions make use of biofilm technologies in order to enhance the removal of wastewater parameters of interest, and the third utilizes the natural water filtration capabilities of zebra mussels. Pilot-scale testing investigated the effects of each of these technologies on treatment performance under both cold and warm weather operation. This research aimed to understand the important mechanisms behind biological filtration methods in order to choose and optimize the best treatment strategy for full-scale testing and implementation. In doing so, a recommendation matrix was elaborated provided with the potential to be used as a universal operational strategy for wastewater treatment facilities located in environments of similar climate and ecology.
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Relatório de estágio de mestrado, Educação (Área de especialidade em Administração Educacional), Universidade de Lisboa, Instituto de Educação, 2016
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A porous, high surface area TiO2 with anatase or rutile crystalline domains is advantageous for high efficiency photonic devices. Here, we report a new route to the synthesis of mesoporous titania with full anatase crystalline domains. This route involves the preparation of anatase nanocrystalline seed suspensions as the titania precursor and a block copolymer surfactant, Pluronic P123 as the template for the hydrothermal self-assembly process. A large pore (7 - 8 nm) mesoporous titania with a high surface area of 106 - 150 m(2)/g after calcination at 400degreesC for 4 h in air is achieved. Increasing the hydrothermal temperature decreases the surface area and creates larger pores. Characteristics of the seed precursors as well as the resultant mesoporous titania powder were studied using XRD analysis, N-2-adsorption/desorption analysis, and TEM. We believe these materials will be especially useful for photoelectrochemical solar cell and photocatalysis applications.
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Mesostructured titania thin films were prepared by an evaporation-induced self-assembly process. The highly acidic sot precursors contained titanium(IV) tetraisopropoxide (TTIP) as a titanium source, a tri-block copolymer Pluronic P123 as a template, and acetylacetonate and HCl as hydrolysis inhibitors. Characteristics of the resultant titania thin films were studied using X-ray diffraction (XRD) analysis, N-2-adsorption/desorption analysis, and transmission electron microscopy (TEM). XRD and TEM investigations on the as-synthesised films revealed the appearance of cubic-like, pseudohexagonal, and lamellar mesophases; depending on the amount of water in the sols of film precursors. Template removal by a calcination process yields high surface area (320-360 m(2)/g) mesoporous materials with crystalline anatase frameworks. Water content also influences the degree of anatase crystallinity of the calcined films. Higher water content resulted in improved anatase crystallinity. These nanostructured materials are of interest for photocatalysts, pbotoelectrochemical solar cells and other photonic devices. (C) 2003 Elsevier B.V. All rights reserved.
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Translocation is an important tool for the conservation of species that have suffered severe range reductions. The success of a translocation should be measured not only by the survival of released animals, but by the reproductive output of individuals and hence the establishment of a self-sustaining population. The bridled nailtail wallaby is an endangered Australian macropod that suffered an extensive range contraction to a single remaining wild population. A translocated population was established and subsequently monitored over a four year period. The aim of this study was to measure the reproductive success of released males using genetic tools and to determine the factors that predicted reproductive success. Captive-bred and wild-caught animals were released and we found significant variation in male reproductive success among release groups. Variation in reproductive success was best explained by individual male weight, survival and release location rather than origin. Only 26% of candidate males were observed to sire an offspring during the study. The bridled nailtail wallaby is a sexually dimorphic, polygynous macropod and reproductive success is skewed toward large males. Males over 5800 g were six times more likely to sire an offspring than males below this weight. This study highlights the importance of considering mating system when choosing animals for translocation. Translocation programs for polygynous species should release a greater proportion of females, and only release males of high breeding potential. By maximizing the reproductive output of released animals, conservation managers will reduce the costs of translocation and increase the chance of successfully establishing a self-sustaining population. (C) 2004 Elsevier Ltd. All rights reserved.