Similarity solutions describing the melting of a mushy layer

A model of the melting of a mushy region in the absence of fluid flow is presented. Similarity solutions are obtained which are used to describe melting from a hot plate with and without the generation of a completely molten region. These solutions are extended to describe the melting of a mushy region in contact with a hot liquid. A significant feature of melting mushy regions is that the phase change occurs internally by dissolution. Our solutions for melting of a mushy region are used to investigate this internal phase change and are compared with the classical Neumann solutions for melting of a pure substance.

Detecting abnormal and collusive bids in capped tendering

Recent developments in the area of Bid Tender Forecasting have enabled bidders to implement new types of easy-to-use tools for increasing their chances of winning contracts. Although these new tools (such as iso-Score Curve Graphs, Scoring Probability Graphs, and Position Probability Graphs) are designed for bidders in capped tendering (tenders with an upper price limit), some of their principles can also be applied by a Contracting Authority to detect which bidders do not follow a standard pattern, that is, their bids are extremely high or low. Since a collusive bid generally needs to be sufficiently high or low to make an impact on the bid distribution, any person in charge of supervising capped tenders can be alerted to any bidder that might be involved in a cartel after identifying the same abnormal behavior in a series of tenders through simple calculations and a new type of graph.

Skull Modularity in Neotropical Marsupials and Monkeys: Size Variation and Evolutionary Constraint and Flexibility

An organism is built through a series of contingent factors, yet it is determined by historical, physical, and developmental constraints. A constraint should not be understood as an absolute obstacle to evolution, as it may also generate new possibilities for evolutionary change. Modularity is, in this context, an important way of organizing biological information and has been recognized as a central concept in evolutionary biology bridging on developmental, genetics, morphological, biochemical, and physiological studies. In this article, we explore how modularity affects the evolution of a complex system in two mammalian lineages by analyzing correlation, variance/covariance, and residual matrices (without size variation). We use the multivariate response to selection equation to simulate the behavior of Eutheria and Metharia skulls in terms of their evolutionary flexibility and constraints. We relate these results to classical approaches based on morphological integration tests based on functional/developmental hypotheses. Eutherians (Neotropical primates) showed smaller magnitudes of integration compared with Metatheria (didelphids) and also skull modules more clearly delimited. Didelphids showed higher magnitudes of integration and their modularity is strongly influenced by within-groups size variation to a degree that evolutionary responses are basically aligned with size variation. Primates still have a good portion of the total variation based on size; however, their enhanced modularization allows a broader spectrum of responses, more similar to the selection gradients applied (enhanced flexibility). Without size variation, both groups become much more similar in terms of modularity patterns and magnitudes and, consequently, in their evolutionary flexibility. J. Exp. Zool. (Mol. Dev. Evol.) 314B:663-683, 2010. (C) 2010 Wiley-Liss, Inc.

Facade integration of polymeric solar collectors

The present paper examines building integrated solar collectors with absorbers of polymeric materials. Efficiency measurements of façade-integrated collectors with non-selective black and spectrally selective coloured absorbers are carried out. The performance of the polymeric absorber was compared with solar glass and polycarbonate twin-wall sheets as collector cover. Simulations demonstrate a high solar fraction for a solar combisystem with façade collectors for a well-insulated house in a Nordic climate. Two examples of house concepts with façade collectors are presented which address a new type of customer than the solar enthusiasts with special interest in renewable energy

Development of a Compact Solar Combisystem

Within the frame of the project REBUS, "Competitive solar heating systems for residential buildings", which is financed by Nordic Energy Research, a new type of compact solar combisystem with high degree of prefabrication was developed. A hydraulic and control concept was designed with the goal to get highest system efficiency for use with either a condensing natural gas boiler or a pellet boiler. Especially when using the potential of high peak power of modern condensing natural gas boilers, a new operation strategy of a natural gas boiler/solar combisystem can increase the energy savings of a small solar combisystem by about 80% compared to conventional operation strategies.

Energy Efficiency through Thermal Energy Storage : Possibilities for the Swedish Building Stock

The need for heating and cooling in buildings constitutes a considerable part of the total energy use in a country and reducing this need is of outmost importance in order to reach national and international goals for reducing energy use and emissions. One important way of reaching these goals is to increase the proportion of renewable energy used for heating and cooling of buildings. Perhaps the largest obstacle with this is the often occurring mismatch between the availability of renewable energy and the need for heating or cooling, hindering this energy to be used directly. This is one of the problems that can be solved by using thermal energy storage (TES) in order to save the heat or cold from when it is available to when it is needed. This thesis is focusing on the combination of TES techniques and buildings to achieve increased energy efficiency for heating and cooling. Various techniques used for TES as well as the combination of TES in buildings have been investigated and summarized through an extensive literature review. A survey of the Swedish building stock was also performed in order to define building types common in Sweden. Within the scope of this thesis, the survey resulted in the selection of three building types, two single family houses and one office building, out of which the two residential buildings were used in a simulation case study of passive TES with increased thermal mass (both sensible and latent). The second case study presented in the thesis is an evaluation of an existing seasonal borehole storage of solar heat for a residential community. In this case, real measurement data was used in the evaluation and in comparisons with earlier evaluations. The literature reviews showed that using TES opens up potential for reduced energy demand and reduced peak heating and cooling loads as well as possibilities for an increased share of renewable energy to cover the energy demand. By using passive storage through increased thermal mass of a building it is also possible to reduce variations in the indoor temperature and especially reduce excess temperatures during warm periods, which could result in avoiding active cooling in a building that would otherwise need it. The analysis of the combination of TES and building types confirmed that TES has a significant potential for increased energy efficiency in buildings but also highlighted the fact that there is still much research required before some of the technologies can become commercially available. In the simulation case study it was concluded that only a small reduction in heating demand is possible with increased thermal mass, but that the time with indoor temperatures above 24 °C can be reduced by up to 20%. The case study of the borehole storage system showed that although the storage system worked as planned, heat losses in the rest of the system as well as some problems with the system operation resulted in a lower solar fraction than projected. The work presented within this thesis has shown that TES is already used successfully for many building applications (e.g. domestic hot water stores and water tanks for storing solar heat) but that there still is much potential in further use of TES. There are, however, barriers such as a need for more research for some storage technologies as well as storage materials, especially phase change material storage and thermochemical storage.

Thermal energy storage in Swedish single family houses : a case study

In a Nordic climate, space heating (SH) and domestic hot water (DHW) used in buildings constitute a considerable part of the total energy use in the country. For 2010, energy used for SH and DHW amounted to almost 90 TWh in Sweden which corresponds to 60 % of the energy used in the residential and service sector, or almost 24 % of the total final energy use for the country. Storing heat and cold with the use of thermal energy storage (TES) can be one way of increasing the energy efficiency of a building by opening up possibilities for alternative sources of heat or cold through a reduced mismatch between supply and demand. Thermal energy storage without the use of specific control systems are said to be passive and different applications using passive TES have been shown to increase energy efficiency and/or reduce power peaks of systems supplying the heating and cooling needs of buildings, as well as having an effect on the indoor climate. Results are however not consistent between studies and focus tend to be on the reduction of cooling energy or cooling power peaks. In this paper, passive TES introduced through an increased thermal mass in the building envelope to two single family houses with different insulation standard is investigated with building energy simulations. A Nordic climate is used and the focus of this study is both on the reduction of space heating demand and space heating power, as well as on reduction of excess temperatures in residential single family houses without active cooling systems. Care is taken to keep the building envelope characteristics other than the thermal mass equal for all cases so that any observations made can be derived to the change in thermal mass. Results show that increasing the sensible thermal mass in a single family house can reduce the heating demand only slightly (1-4 %) and reduce excess temperatures (temperatures above 24 degrees C) by up to 20 %. Adding a layer of PCM (phase change materials) to the light building construction can give similar reduction in heating demand and excess temperatures, however the phase change temperature is important for the results.

Fyrtiotalisterna och äldreomsorgen : massmediala konstruktioner av en ny sorts omsorgstagare

Baby boomers and elderly care: expectations in print media about a new kind of care users The Swedish baby boomer generation – known as the forties generation – has been characterized as youthful and powerful. At present, members of this generation are entering the category of old age and in about ten years they will start reaching ages where the likelihood of encountering elderly care increases significantly. The present study reports on how this expected meeting has been discussed in Swedish newspapers. Data consisted of 481 articles during the period 1995–2012 and was analyzed through qualitative content analysis. Results show that the generation was predicted to become a new type of demanding and self-conscious care users. Claims were backed by descriptions of formative events and typical characteristics that were projected onto a future as care user. Such projections tended to portray care users of present time as passive and submissive, and partly responsible for problems associated with elderly care 

O país tem importância?

A técnica de componentes de variância pode oferecer perspectivas interessantes na avaliação dos vários tipos de efeitos que afetam desempenho em uma abordagem descritiva. Após o trabalho original de Rumelt (1991) vários autores estudaram a composição de variância do desempenho das firmas, decompondo este elemento em fatores de firma, de corporação, de indústria e efeitos de ano. A maioria vasta destes estudos indica efeitos da firma como o componente dominante de variância explicada. Isto alimentou o debate entre a organização industrial e a RBV, ainda que a importância de efeitos corporativos apresentou resultados contraditórios e pareceu ser sensível à amostra e período analisados. Foram identificados efeitos de ano muito pequenos ou inexistentes. Todos os estudos previamente elaborados foram baseados em dados dos EUA e descrevem o ambiente empresarial de economia americana. Este estudo visa verificar se a estrutura de variância de rentabilidade em outros países é diferente da americana.

Securitização de recebíveis da agroenergia: um estudo de caso baseado em títulos do agronegócio

Desde o final da década de 90, a securitização de ativos vem se firmando no mercado brasileiro como uma importante alternativa de captação de recursos. Essa inovação financeira permite às empresa o acesso direto ao mercado de capitais, para a venda de títulos lastreados em suas carteiras de recebíveis, eliminando a intermediação bancária e permitindo reduções no custo de capital, inclusive em comparação com títulos convencionais de dívida corporativa. Os títulos de securitização são em regra emitidos por um veículo de propósito específico (FIDC ou companhia securitizadora), com o objetivo de segregar os riscos do originador/tomador em relação aos créditos securitizados (lastro da emissão). Em 2004, a Lei 11.076 criou os novos títulos do agronegócio (CDA-WA, CDCA, LCA e CRA), inspirada na legislação da securitização imobiliária (SFI - Lei 9.514/97), buscando disponibilizar ao agronegócio uma nova fonte de recursos, via emissão de títulos no mercado de capitais. Desde então, um número crescente de operações estruturadas com esses papéis pôde ser observada, demonstrando sua funcionalidade e potencial. No entanto, o volume de captações públicas mais sofisticadas fundadas na emissão de cotas de FIDCs e de CRAs ainda se apresenta muito reduzida em relação à demanda do agronegócio por financiamento, sobretudo levando-se em conta a representatividade desse setor no Brasil. O setor sucro-energético é provavelmente o segmento do agronegócio que está em melhor posição para o desenvolvimento de operações de securitização, por apresentar características como: escala, padronização dos produtos, grau de consolidação dos grupos empresariais e perspectivas de crescimento, além do forte apelo ambiental. Os papéis associados a esse segmento possuem, dessa forma, um potencial singular para superar a resistência natural de investidores às aplicações financeiras na área agrícola. Este trabalho dedica-se a investigar como o conceito de securitização pode ser aplicado em operações ligadas ao agronegócio, particularmente ao setor sucro-alcooleiro. A partir de um estudo de caso, serão analisados aspectos operacionais de uma emissão pública de CRAs, ressaltando os mecanismos e procedimentos adotados para lidar com as particularidades dos títulos oriundos do agronegócio. O estudo mostra que a estruturação desse tipo de operação apresenta algumas características e desafios diferentes das operações fundadas em outros papéis, porém a priori administráveis a partir das técnicas tradicionais de securitização e da incorporação de mecanismos suplementares de gestão de riscos.

As dimensões estratégia e sócio-comunicacional da rede de terceirização: impactos e perspectivas na visão gerencial, sindical e dos trabalhadores terceirizados na Petrobrás

O objetivo do trabalho foi estudar as implicações/impactos (sociais, gerenciais e políticos) do processo de terceirização - viabilizado por um novo tipo de competição capitalista por intermédio de redes inter-empresas - em um segmento da indústria do petróleo. Dessa forma, desenvolveu-se uma pesquisa empírica tendo como material de investigação o setor de manutenção industrial de uma refinaria de petróleo do Rio de Janeiro, durante o período de 1999 a 2001. As diferentes ópticas dos sujeitos sociais envolvidos foram consideradas nesta investigação, quais sejam: gerencial, sindical e dos próprios trabalhadores terceirizados. Os resultados do estudo demonstraram que a terceirização em curso no setor pesquisado tem implicado em movimentos simultâneos de destruição/reconstrução de relações produtivas tradicionais, combinando modernização e organização da produção em rede com práticas tayloristas/fordistas. Novas e antigas formas de (des)sociabilização e precarização podem ser evidenciadas através de discrepantes condições salariais e de trabalho e na criação de duas categorias de trabalhadores: os petroleiros e os terceirizados. A partir desse estudo a ambigüidade e fragilidade dessa "rede" de terceirização ficaram bem nítidas, pois a concentração de poder e recursos em pontos específicos e o prevalecente aspecto instrumental e economicista em detrimento do dialógico remetem a um distanciamento do próprio princípio de interdependência, inerente a noção de rede. A forma como a terceirização está sendo implementada nessa indústria aproxima-se mais à um padrão predatório que à um padrão flexível e interdependente como características inerentes a concepção gerencial de rede. Além disso, os mecanismos de inclusão/exclusão social e econômica entre efetivos e terceirizados, indicando cidadanias diferenciadas no âmbito da empresa, evidenciam a coexistência de velhas e novas formas de exploração sob o paradigma da rede.

Ouvindo as vozes na escola: análise de discurso de professores e alunos na escola de primeiro grau

Este trabalho foi desenvolvido a partir de pesquisa realizada em escolas públicas do Município do Rio de Janeiro. Procedeu-se à Análise de Discurso de professores e alunos das séries iniciais do Primeiro Grau, bem como técnicos das escolas, dos Distritos Educacionais e da secretaria de Educação. As enunciações registradas tiveram como tema principal a alfabatização, e foram analizadas com base no modelo proposto por Pêcheux, que articula três regiões do conhecimento científico: a ideológico-cultural, a linguística e a discursiva, relacionando-se o discurso e suas condicões de produção, e situando os protagonistas e o objeto do discurso. A fundamentação teórica da análise partiu das teorias linguísticas de Saussure e Beneviste, utilizando-se também os trabalhos de Baktin, Blikstein, Vital Brazil e Orlani. Segue-se a discussão em torno de aspectos da teoria da subjetividade, de natureza psicanalítica, onde foram utilizadas as teorias de Freud e Lacan. À alienação do sujeito na ordem da linguagem associa-se a alienação do trabalho, considerada por Marx e discutida no trabalho de Meszaros. As relações do sujeito com o trabalho e com a produção são também pensadas a partir dos pontos de vista de Baudrillard e Giannotti. A partir da análise das falas, propõe-se a desconstrução do simbólico e o estabelecimento dee uma nova prática, de novas relações institucionais que possam transformar o cotidiano escolar, livrando alunos e professores do assujeitamento a que ficam submetidos.

A cooperação trilateral brasileira em Moçambique: um estudo de caso comparado: o ProALIMENTOS e o ProSAVANA

A arquitetura do sistema de ajuda internacional passa por um processo de transformação, no qual as barreiras Norte e Sul tornam-se cada vez mais indefinidas, e a cooperação trilateral, que une as práticas opostas da cooperação Norte-Sul com a cooperação Sul-Sul, emerge como uma nova modalidade da cooperação técnica brasileira. Com o objetivo de compreender esse cenário, esta tese almeja identificar e contrastar as motivações e as práticas dos agentes da cooperação trilateral brasileira por meio de um estudo de caso comparado de dois projetos, desenvolvidos pela Agência Brasileira de Cooperação (ABC), no setor agrícola em Moçambique: o ProALIMENTOS, parceria entre a United States Agency for International Development (USAID- -Brasil) e ABC, e o ProSAVANA, parceria entre Japan International Cooperation Agency (JICA) e ABC. Para isso, a pesquisa parte dos pressupostos da actor-oriented approach para estabelecer uma análise multinível, que cria desta forma um elo entre o agente e a estrutura, a prática e a política, com um olhar sobre o contexto macro, meso e micro. A utilização da metodologia qualitativa aplicada a essa investigação combinou a técnica de participação observante com a técnica de análise documental, acrescentando à análise 59 entrevistas semiestruturadas, realizadas principalmente entre os meses de março e junho de 2013, em Moçambique. Os resultados da pesquisa indicam que, no caso do ProALIMENTOS, há ganhos em complementaridade e troca de conhecimento para as três contrapartes, porém há a sobreposição das práticas Norte-Sul de cooperação para o desenvolvimento internacional sobre as práticas da cooperação Sul-Sul. Enquanto que, no caso do ProSAVANA, não há qualquer ganho de complementariedade, uma vez que o Programa enfrenta desafios internos e externos. A falta de harmonização e coordenação técnica no âmbito interno intensificam o embate externo com os representantes da sociedade civil ao gerar constantes falhas de comunicação, o que coloca em xeque a própria continuidade do ProSAVANA. Por último, a pesquisa mostra que é necessário um maior comprometimento do governo brasileiro nos projetos de Cooperação Trilateral, uma vez que os resultados desses projetos podem impactar e afetar a credibilidade do Brasil como um novo prestador de ajuda internacional.

As distintas percepções sobre o empreendedorismo social

This dissertation is a literature review with exploratory and descriptive purposes, which aims to compile the different perceptions of the term Social Entrepreneurship, but not propon-being of an epistemological analysis on the topic. The main objectives of this research were: 1) to identify the convergences and divergences in the various perceptions of the Social Entrepre-neurship, from the perspectives: American, European and Brazilian; 2) identify whether Social Entrepreneurship can be considered as a new theoretical trend, or can be understood as a sub-category of an existing theory; 3) identify whether Social Entrepreneurship can be considered as practice of Social Management; 4) identify whether the "Social Business", proposed by Yunus (2010), can be considered as a completely new type of organization, as the author says. For this research were studied literary works available in the physical environment and elec-tronic database. The main concepts studied in this research were: Entrepreneurship; Social Management; Third Sector; Business Management and Social Entrepreneurship. The conclu-sions reached by this study were: 1-a) the main theoretical convergence is the Social Entrepre-neur ability to apply methods and process typically used in for-profit companies, in business that aimed social value creation; 1-b) the main difference is the different perceptions that the United States, Europe and Brazil have about what is Social Entrepreneurship. In the American perspective, these are private sector organizations operating according to market logic and that somehow generates social value. In the European perspective, closer to the social economy, emphasizes the activities of civil society organizations with public functions. In Brazil empha-sizes market initiatives aimed at reducing poverty and transform the social conditions of mar-ginalized or excluded individuals; 2) Social Entrepreneurship is an activity that incorporates much all the practices, methods and processes of commercial entrepreneurship and, as such, should not be considered as a new theoretical trend, but a subcategory of Entrepreneurship theory. 3) Social Entrepreneurship cannot be considered as a practice of Social Management, being much closer to the commercial entrepreneurship practices; 4) the "Social Business" pro-posed by Yunus (2010), closely resembled in its modus operandi with the Social Enterprises in Western Europe, thus, not supporting the author's claim.

Estudo da Potencialidade da produção de tijolos de adobe misturado com outros materiais: uma alternativa de baixo custo para a construção civil

The production of the red pottery brick, made traditionally with clay, is a technique that is already stabled. However, in spite of the little complexity that involves the conventional process of these bricks production, it are exposed to many problems that begin in the fase of exploration of the mines, the problems get worse because of the lack of the clay's characterization, and they continue through the steps of the dough preparation, conformation of the products, the drying and the burning process. The wastefulness is shown and so is the low quality of the material produced. Among other factors, the high use of energy in the burning makes the cost of this material inaccessible to the low income consumer. Besides this, the destruction of the environment around the mines and the use of native vegetation to produce wood - the most used fuel in the pottery industry - make serious environmental damage. The production technique of a new type of simple brick (adobe), that has low cost and no environmental damage, can be the viable altemative to lower the cost of this part of the civil construction, and, consequently, in the building of cheaper houses. In this paper, the results of the mechanical resistance of the adobe brick are shown, using in its composition, clay, natural vegetable fibers, cement and plaster in a process that is completely handcrafted and manual. It is intented to make clear that are possible alternatives to be put in practice, with the simple process, using "raw earth" that has been used in the construction of houses in thousands of years, trying to solve these severe problems. Analysis and tests were performed to find results that could prove the possibility of the utilization of this kind of material. Other studies are in progress, and the new researches are necessary to enrich this work, but it stays the certainty that there is potential to produce bricks from adobe, as an alternative that has low cost to civil construction