872 research outputs found

    International market assessment of stand-alone photovoltaic power systems for cottage industry applications

    Get PDF
    The final result of an international assessment of the market for stand-alone photovoltaic systems in cottage industry applications is reported. Nonindustrialized countries without centrally planned economies were considered. Cottage industries were defined as small rural manufacturers, employing less than 50 people, producing consumer and simple products. The data to support this analysis were obtained from secondary and expert sources in the U.S. and in-country field investigations of the Philippines and Mexico. The near-term market for photovoltaics for rural cottage industry applications appears to be limited to demonstration projects and pilot programs, based on an in-depth study of the nature of cottage industry, its role in the rural economy, the electric energy requirements of cottage industry, and a financial analysis of stand-alone photovoltaic systems as compared to their most viable competitor, diesel driven generators. Photovoltaics are shown to be a better long-term option only for very low power requirements. Some of these uses would include clay mixers, grinders, centrifuges, lathes, power saws and lighting of a workshop

    Aterros sobre solos moles: Análises de recalque e tempos de estabilização para duas seções características da BR-280

    Get PDF
    TCC (graduação) - Universidade Federal de Santa Catarina. Centro Tecnológico. Engenharia Civil.O presente trabalho descreve a avaliação das magnitudes de recalques e tempos de estabilização para duas seções características da duplicação da BR-280. Os aterros estudados foram executados sobre um depósito de argila mole com espessuras variando de 8 a 12 metros, intercaladas com camadas e lentes de areia. Inicialmente foram identificados perfis característicos para a região com base em dois pontos de investigação, localizados no Km 44+780 (PI 01) e no K m 42+551 (PI 02). Tais investigações foram utilizadas para a elaboração de perfis geotécnicos característicos de cada ponto. Na interpretação dos resultados dos ensaios foram utilizadas correlações com os ensaios CPTu confrontando-as com os resultados obtidos com resultados característicos para a região e para as argilas brasileiras. Posteriormente a elaboração do perfis geotécnicos característicos para cada ponto estudado, foram realizadas previsões de recalque pela teoria clássica e por elementos finitos, através do software PLAXIS. Ainda, foram realizadas análises da sensibilidade dos parâmetros geotécnicos de compressibilidade e permeabilidade das camadas moles, através de método numérico, de forma a identificar faixas de variação das deformações e dos tempos de estabilização, possíveis para o depósito. De maneira geral, foram observados recalques e tempos de estabilização semelhantes quando comparadas as análises em elementos finitos e cálculos analíticos. Recalques de 0,7 e 0,66 metros e tempos de estabilização de 298 e 287 meses foram calculados analiticamente para os pontos PI01 e PI02. Numericamente os recalques atingiram 0,91 e 0,67 metros com tempos de 244 e 283 meses. Verificando os tempos de estabilização elevados foi proposta uma solução com geodrenos para as seções que possibilitaram reduzir os tempos de recalque em 88,2 e y 80,8%, para as seções PI 01 e PI 02, respectivamente.The present work describes the evaluation of settlement amplitude and stabilization times for two characteristic sections of the BR-280 duplication. The studied embankments were carried out on a soft clay deposit with thicknesses varying from 8 to 12 meters, interspersed with layers and lenses of sand. Initially, characteristic profiles fot the region were aditified based on two reserch points, located at Km 44+780 (PI 01) and K m 42+551 (PI 02). Such investigations were used for the elaboration of characteristic geotechnical profiles of each point. In the interpretation of the results of the tests, correlations with ther CPTu test were used, comparing them with results of the region and of the Brazilian clays. Subsequently the elaboration of the characteristic geotechnical profiles, predictions of settlement by classical theory and finite elements were made, using the PLAXIS sofware. Furthermore, analyzes of the sensitivity of the geotechnical parameters of compressibility and permeability of the soft layers were carried out, using a numerical method, in order to identify possible ranges of variation of the deformation and stabilization times for the deposit. In general, similar settlements and stabilization times were observed when comparing finite elemet analyzes and analytical calculations. Settlements of 0,7 and 0,6 metters and stabilization time of 298 and 287 months were calculated analytucally for points PI 01 and PI 02. Numerically, the settlements reached 0,91 and 0,67 meters, with times of 244 and 283 months. Checking the hight stabilization times, a solution with geodrain was propoased for the sections that mad possible to reduce the settlement times by 88,2 and 80,8 %, for the PI 01 and PI 02 sections, respectively

    The Influence of Anhedonic Symptom Severity on dmPFC Connectivity in PTSD

    Get PDF
    This study examined resting state functional connectivity (rsFC) of the dorsal medial prefrontal cortex ( dmPFC ) as a function of anhedonia in individuals with posttraumatic stress disorder (PTSD). Results showed that anhedonia positively correlated with hyperconnectivity between the dmPFC and the left retrosplenial cortex. These findings support that anhedonia is associated with increased rsFC within the default mode network (DMN) for PTSD

    Civic engagement, pedagogy, and information technology on Web sites for youth

    Get PDF
    Scholars of political socialization are paying increasing attention to how the Internet might help cure the civic disengagement of youth. This content analysis of a sample of 73 U.S.-based civic Web sites for youth introduces a framework for evaluating Web sites’ strategies for fostering active communication for citizenship. We offer the first systematic assessment of the extent to which a broad range of Web sites aim to develop young people’s abilities to use information and communication technology (ICT) as a vehicle for civic participation and to engage with ICT as a policy domain that encompasses issues (such as freedom of speech and intellectual property rights) that shape the conditions for popular sovereignty online. The study finds low levels of interactive features (such as message boards) that allow young people to share editorial control by offering their own content. In addition, few sites employ active pedagogical techniques (such as simulations) that research suggests are most effective at developing civic knowledge, skills, and participation. We also find little attention to ICT policy issues, which could engage budding citizens in debates over the formative conditions for political communication in the information age. We conclude with suggestions for civic Web site designers and hypotheses for user studies to test

    Food lists from the diet of a group of elderly individuals: analysis and perspectives

    Get PDF
    INTRODUÇÃO: A despeito do aumento expressivo da população idosa nos últimos anos, são escassos os estudos brasileiros relacionados ao consumo alimentar desses indivíduos. OBJETIVOS: Propor uma lista de alimentos mais consumidos por idosos residentes na Zona Leste de São Paulo e analisar os alimentos que contribuem para o consumo de nutrientes relevantes ao estado nutricional e, consequentemente, à saúde dos idosos. MÉTODOS: Foram avaliados 100 indivíduos acima de 60 anos, frequentadores de um centro de referência. Para caracterização do estado nutricional foi calculado o Índice de Massa Corporal (IMC). Para elaboração das listas de alimentos foram aplicados dois recordatórios alimentares de 24 horas (RA24h) em duas estações diferentes do ano, que foram analisados quanto à frequência de consumo de cada alimento e quanto à contribuição percentual de energia, macronutrientes, fibras, cálcio e vitamina D. RESULTADOS: Com relação ao estado nutricional, 52% apresentaram o IMC < 28 kg/m²; 15% entre 28 e 30 kg/m²; 26% entre 30 e 35 kg/m² e 7% com IMC &gt; 35 kg/m². O aspecto positivo da dieta foi a preservação de hábitos saudáveis como o consumo de arroz e feijão, e também de vegetais verde-escuros. Como aspecto negativo observou-se que a dieta dos idosos é monótona, pois poucos alimentos contribuem para o consumo de vários nutrientes. Além disso, houve um elevado consumo de carboidratos refinados em detrimento do consumo de alimentos integrais. CONCLUSÕES: As listas de alimentos obtidas, além de permitirem a reflexão sobre intervenções educativas, permitem o desenvolvimento subsequente de um Questionário de Frequência Alimentar específico para esse grupo.BACKGROUND: Despite the phenomena of population aging, Brazilian studies related to the feeding practices of elderly individuals are scarce. AIMS: To develop a list of the most ingested foods from community-dwelling elderly persons in the east-zone of São Paulo- Brazil and to analyse the foods that contribute most to relevant health-related nutrients of these individuals. METHODS: The study was performed with 100 individuals aged 60 years and above, registered at a local reference center. To describe the nutritional status, the weight and stature were measured and the BMI- body mass index was calculated. To develop the food lists, two 24h food recalls were applied, during two different seasons of the year. The food recalls were analysed for food intake frequency and for percentage contribution of each food and each nutrient: energy, macronutrients, calcium and vitamin D. RESULTS: The participants were classified as following: 52% with BMI < 28 kg/m²; 15% with BMI between 28 and 30 kg/m²; 26% between 30 and 35 kg/m² and 7% presented BMI&gt; 35 kg/m². The positive aspects related to food intake were rice, bean and green vegetable consumption. As negative aspects, we observed that the diet pattern was repetitive, since few foods contributed to a high number of nutrients. Furthermore, a high ingestion of refined carbohydrates was observed instead of whole foods. CONCLUSION: The food lists allowed reflecting on educative interventions, and also allow future development of different food frequency questionnaires that are specific for this group

    Games for civic learning: A conceptual framework and agenda for research and design

    Get PDF
    Scholars, educators, and media designers are increasingly interested in whether and how digital games might contribute to civic learning. However, there are three main barriers to advancing understanding of games’ potential for civic education: the current practices of formal schooling, a dearth of evidence about what kinds of games best inspire learning about public life, and divergent paradigms of civic engagement. In response, this article develops a conceptual framework for how games might foster civic learning of many kinds. The authors hypothesize that the most effective games for civic learning will be those that best integrate game play and content, that help players make connections between their individual actions and larger social structures, and that link ethical and expedient reasoning. This framework suggests an agenda for game design and research that could illuminate whether and how games can be most fruitfully incorporated into training and education for democratic citizenship and civic leadership

    Portrayals of information and communication technology on World Wide Web sites for girls

    Get PDF
    This study reports a content analysis of 35 World Wide Web sites that included in their mission the goal of engaging girls with information and communication technology (ICT). It finds that sites emphasize cultural and economic uses of ICT, doing little to foster civic applications that could empower girls as citizens of the information age. The study also finds that sites foster a narrow range of ICT proficiencies, focusing mostly on areas such as communication, in which girls have already achieved parity with boys. An examination of the role models portrayed in ICT occupations indicates that the sites show females mainly in elite technology jobs, reversing stereotypical mass media depictions of females in low-status roles in relation to ICT. Employing an original index of ICT knowledge and skills, the study finds that the sites that scored highest both on fostering comprehensive knowledge and skills as well as featuring civic content were general interest Web communities. Ownership (for-profit or not-for-profit) of sites was less important than editorial control: Sites that offered girls a place to contribute their own content were more likely to offer civic material and a broader range of ICT knowledge and skills. We conclude with recommendations for Web site designers to rethink their design strategies and their rationales for closing the gender gap in computing

    Structure-Property Relation of Trimethyl Ammonium Ionic Liquids for Battery Applications

    Get PDF
    Ionic liquids are attractive and safe electrolytes for diverse electrochemical applications such as advanced rechargeable batteries with high energy densities. Their properties that are beneficial for energy storage and conversion include negligible vapor-pressure, intrinsic conductivity as well as high stability. To explore the suitability of a series of ionic liquids with small ammonium cations for potential battery applications, we investigated their thermal and transport properties. We studied the influence of the symmetrical imide-type anions bis(trifluoromethanesulfonyl)imide ([TFSI]−) and bis(fluorosulfonyl)imide ([FSI]−), side chain length and functionalization, as well as lithium salt content on the properties of the electrolytes. Many of the samples are liquid at ambient temperature, but their solidification temperatures show disparate behavior. The transport properties showed clear trends: the dynamics are accelerated for samples with the [FSI]− anion, shorter side chains, ether functionalization and lower amounts of lithium salts. Detailed insight was obtained from the diffusion coefficients of the different ions in the electrolytes, which revealed the formation of aggregates of lithium cations coordinated by anions. The ionic liquid electrolytes exhibit sufficient stability in NMC/Li half-cells at elevated temperatures with small current rates without the need of additional liquid electrolytes, although Li-plating was observed. Electrolytes containing [TFSI]− anions showed superior stability compared to those with [FSI]− anions in battery tests

    Graph-based analysis and visualization of experimental results with ONDEX

    Get PDF
    Motivation: Assembling the relevant information needed to interpret the output from high-throughput, genome scale, experiments such as gene expression microarrays is challenging. Analysis reveals genes that show statistically significant changes in expression levels, but more information is needed to determine their biological relevance. The challenge is to bring these genes together with biological information distributed across hundreds of databases or buried in the scientific literature (millions of articles). Software tools are needed to automate this task which at present is labor-intensive and requires considerable informatics and biological expertise. Results: This article describes ONDEX and how it can be applied to the task of interpreting gene expression results. ONDEX is a database system that combines the features of semantic database integration and text mining with methods for graph-based analysis. An overview of the ONDEX system is presented, concentrating on recently developed features for graph-based analysis and visualization. A case study is used to show how ONDEX can help to identify causal relationships between stress response genes and metabolic pathways from gene expression data. ONDEX also discovered functional annotations for most of the genes that emerged as significant in the microarray experiment, but were previously of unknown function
    corecore