1,442 research outputs found

    Utilização racional de energia em equipamentos de força motriz

    Get PDF
    A utilização racional de energia (URE) visa proporcionar o mesmo nível de produção de bens, serviços e de conforto através de tecnologias que reduzem os consumos face a soluções convencionais. A URE pode conduzir a reduções substanciais do consumo de energia e das emissões de poluentes associadas à sua conversão. Em muitas situações a URE pode também conduzir a uma elevada economia nos custos do ciclo de vida dos equipamentos utilizadores de energia (custo inicial mais custo de funcionamento ao longo da vida útil). Embora geralmente sejam mais dispendiosos, em termos de custo inicial, os equipamentos mais eficientes consomem menos energia, conduzindo a custos de funcionamento mais reduzidos e apresentando outras vantagens adicionais. Os motores elétricos são de longe as cargas mais importantes na indústria e no sector terciário. A figura 1 mostra a importância relativa da força motriz nesses sectores. A iluminação aparece como a carga mais importante no sector terciário, sendo na indústria a segunda carga mais relevante. Os motores elétricos são utilizados numa vasta gama de aplicações, principalmente na movimentação de fluidos em bombas, compressores e ventiladores

    Biological control as part of the soybean Integrated Pest Management (IPM) : potential and challenges

    Get PDF
    Soybean production is usually performed on large scales, requiring simple but efficient pest management to be successful. Soybean fields are inhabited by several species of arthropods, demanding constant development of management practices to prevent pest outbreaks. More recently, stink bugs have become the most important pest group of soybeans in the Neotropics, responsible for up to 60% of the applied insecticides in Brazil. Natural enemies represent an important mortality factor that can keep the damage caused by stink bugs below the economic threshold levels without additional control actions. Thus, Conservation Biological Control (CBC) strategies can be adopted to preserve or even promote the increase in such natural enemies in the fields, or alternatively, massive releases of biocontrol agents in Augmentative Biological Control (ABC) programs could be adopted. Simple practices such as reducing insecticide use (with the adoption of economic thresholds), prioritizing harmless insecticides or biopesticides, and planting resistant soybean cultivars have been adopted in Brazil with positive results. The challenges to increasing the adoption of more complex stink bug management in commodity crops such as soybean may be overcome using the more recent economic incentives in the global agenda of decarbonized agriculture. The potential and challenges of conservation and augmentative biological control are further discussed in this review

    «O que é, bebé?», ou o que a Mãe diz ao Recém-nascido no Contacto Precoce

    Get PDF
    Com o presente estudo, que se insere numa investigação mais lata sobre padrões de comunicação precoce mãe-criança, pretende-se descrever algumas das características da linguagem verbal que as mães dirigem aos seus filhos, durante o contacto-precoce e da forma como o bebé real é, nesse momento, percepcionado e investido pela mãe. Para tal realizou-se o registo auditivo do contacto precoce de 30 pares de mães-bebés. Posteriormente analisou-se o discurso materno que foi classificado em diversas categorias relacionadas com aspectos da estrutura sintáctica e com análise de conteúdo. Constatou-se que as mães recorrem pouco a expressao verbal, no primeiro contacto com os seus filhos. Quando o fazem utilizam uma linguagem que tem características da «fala de bebé)) e é constituída, sobretudo, por interjeições, exclamações, frases com duas a três palavras e palavras isoladas. O discurso emitido centra-se em torno da realidade vivida no momento. O bebé que a mãe descreve é um ser pequenino e frágil, que chora e tem fome, pouco individualizado e pouco «humano», a quem atribui essencialmente, necessidades fisiológicas.In the present study, part of a broader research on mother-child early communication patterns, we describe some of the verbal language characteristics of mothers speaking to their children in early interactions, and we discuss the way in wich the real baby is, at that stage, perceived and elaborated by the mother. The early contacts of 30 pairs mother-child were recorded. The speech of these mothers was classified in severa1 categories according to syntax structure and also through content analysis. ment. In these initial contacts, mothers don’t use much verbal language. When they do, they use «baby talk» expressions and emit mostly exclamations and interjections, two or three-word sentences and isolated words. The speech is centered in the reality of the mo- The baby described by the mother is a small and fragile being, who cries and feels hunger, not very individualized and not very «human», and in whom she recognizes, essentially, psysiological needs.info:eu-repo/semantics/publishedVersio

    Chemical Structure and Localization of Levan, the Predominant Fructan Type in Underground Systems of Gomphrena marginata (Amaranthaceae)

    Get PDF
    Gomphrena marginata Seub. (Amaranthaceae) is an endemic species from Brazilian campos rupestres with a fructan accumulating underground reserve system. Analyses of high performance anion exchange chromatography (HPAEC–PAD) revealed the presence of the soluble carbohydrates glucose, fructose, sucrose, 1-kestose, 6-kestose, nystose and fructans with degree of polymerization (DP) up to approximately 40 fructose units. Data of 1H and 13C Nuclear Magnetic Resonance (NMR) spectroscopy, including Heteronuclear Single-Quantum Correlation (HSQC) and Heteronuclear Multiple-Bonds Correlation (HMBC) showed the presence of β (2,6) linkages, characteristic of the linear molecule of levan-type fructan(2,6). These results confirmed previous studies suggesting that the reserve carbohydrate in the underground system of this species was levan-type fructans, similar to that of G. macrocephala. Structural analyses of the thickened underground system using light microscopy revealed a mixed origin system consisting mainly of a gemmiferous tuberous root with the upper region formed by short branched stems, both presenting vascular cylinders with unusual growth patterns. Fructan spherocrystals were visualized under polarized light and scanning electron microscopy (SEM) mostly in the cortex and vascular cylinder in both thickened stem and root. In addition to data reported in the literature concerning the occurrence of fructans in the Amaranthaceae, the results presented here suggest that fructans are a trait in this family while the levan-type fructan prevail in Gomphrena species

    Framing REDD+ in the Brazilian national media: how discourses evolved amid global negotiation uncertainties

    Get PDF
    Reducing emissions from deforestation and degradation (REDD+) in tropical countries is an important and contested element of the post-Kyoto climate regime. For policy options which generate controversy between diverse actor groups, such as REDD+, mass media plays an important role in defining and supporting policy possibilities. Analysis of the way in which national media frames issues of climate change and deforestation can offer insights into the nature of the contested domains of the REDD+ policy process. Here, we examine the Brazilian national media discourses surrounding REDD+ because it contributes to setting the tone of policy debates at the federal level. Specifically, we ask the following: (i) How was REDD+ portrayed in the Brazilian national print media and whose opinions and perceptions were represented? and (ii) How have media frames on REDD+ in the national print media changed over time? Our results contribute with new knowledge for understanding the observed progress of REDD+ in Brazil. We identify two main themes that dominate the focus in the national media coverage of REDD+, specifically “politics and policymaking” (representing half the coverage) and “economics and market” (with over a third). Results show that discussions around carbon markets were amongst the most contested and that optimism in relation to REDD+ effectiveness declined over time. The analysis suggests that positions adopted on the national REDD+ strategy were shaped by state and federal collision of interests. We demonstrate an evolution of national concerns from an initial focus on efficiency (e.g. finance and carbon markets) to a recentred focus on equity issues (e.g. implementation of safeguards). We conclude with some thoughts on the implications of these features for REDD+ interventions and implementation in Brazil
    corecore