74 research outputs found
Tecniche di ragionamento spaziale e temporale nella ricostruzione assistita delle unità sedimentarie
No full textPreliminary research on trace elements, ectomycorrhizal symbiosis and wood decline.
No full textLNL (Laboratori Nazionali Legnaro), Annual Report
Cultura de tecidos de plantas no apoio ao melhoramento genético vegetal e à produção massal de plantas
No full textTCC (graduação) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Curso de Agronomia.O arroz (Oryza sativa) é uma gramínea pertencente à família Poacea. Juntamente com o milho e o trigo é o cereal de maior produção em nível mundial. Esse fator desperta interesse por parte de muitos países que investem em pesquisas para o desenvolvimento de cultivares com maior resistência a patógenos, pragas entre outros males que afetam negativamente a cultura. Presente em diversos países como constituinte básico da dieta populacional, o arroz deixa de ter apenas importância econômica, apresentando também uma forte importância cultural, como pode ser observado com maior intensidade em países asiáticos, China e Japão, por exemplo. Para que o Brasil permaneça competitivo no mercado mundial é preciso que pesquisas sejam desenvolvidas de forma contínua para que novos produtos sejam lançados frequentemente. Nesse âmbito entra o melhoramento genético e com ele a criação constante de novas ferramentas que auxiliam no desenvolvimento e aperfeiçoamento da cultura. O presente trabalho objetivou o estudo e a realização de um experimento relativo ao processo de obtenção de plantas duplo-haplóides de arroz através da cultura de anteras. O experimento foi realizado com o intuito de definir o melhor momento para a utilização das anteras, levando em conta o estágio de desenvolvimento das plantas de arroz e também dos micrósporos presentes nas anteras. A pesquisa consistiu do cultivo das anteras em meio de cultura N6 adicionado de diferentes concentrações de auxina 2,4-D (0,5; 2,0 e 4,0 mg/L). As anteras foram coletadas no estágio de emborrachamento da panícula, com 6 e 10 cm de distância entre o colar da folha bandeira e o colar da última folha, da linhagem SC 471. O estágio de desenvolvimento dos micrósporos presentes nas panículas do experimento foi determinado pela análise citológica em microscópio com diferentes períodos de maturação. Além, dos trabalhos com arroz, foram acompanhadas e desenvolvidas atividades visando à multiplicação de bananeiras, limpeza de vírus em citros e definição de novos protocolos para multiplicação, em ambiente asséptico, de diferentes espécies ornamentais. Os resultados alcançados serão importantes para futuras pesquisas pelo Laboratório de Biotecnologia, tanto para a obtenção de novas variedades pelo programa de melhoramento genético quanto para a obtenção de protocolos e multiplicação de mudas matrizes livres de vírus ou não de espécies de interesse do Estado de Santa Catarina
Schottky SiC Diodes in Power Applications
No full textThe first Silicon Carbide power diodes have only recently become commercially available [1]: the high electrical breakdown field and the very high thermal conductivity of this material make it particularly suited to the manufacturing of power devices. The characteristics of a 4A, 600V SiC Schottky diode –the Infineon SDP04S60- is experimentally evaluated and its performance in a typical power application is compared with two ultra-fast, soft-recovery, silicon power diodes with same ratings -the RURD460 and the recently presented STTH5R06D- in terms of efficiency improvement and EMI reduction
Schottky SiC Diodes in Power Switching Applications
No full textThe first Silicon Carbide power diodes have only recently become commercially available: the high electrical breakdown field and the very high thermal conductivity of this material make it particularly suited to the manufacturing of power devices. The characteristics of a 4A, 600V SiC Schottky diode –the Infineon SDP04S60- is experimentally evaluated and its performance in a typical power application is compared with two ultra-fast, soft-recovery, silicon power diodes with same ratings -the RURD460 and the recently presented STTH5R06D- in terms of efficiency improvement and EMI reduction
Characterization of Schottky SiC Diodes for Power Applications
No full textThe performance of a 600V, 4A Silicon Carbide (SiC) Schottky diode (Infineon
SDP04S60) is experimentally evaluated and compared with an ultra-fast, soft-recovery, silicon
power diode (Fairchild RURD460). A substantially negligible recovery current is observed for
the SiC Schottky diode with expected great advantage on EMI generation; on the other hand,
the forward voltage drop is larger than that of Si diodes with not easily predictable behavior in
power applications efficiency
Performance Evaluation of a Schottky SiC Power Diode in a Boost PFC Application
No full textThe performance of a 600 V, 4 A silicon carbide (SiC) Schottky diode (Infineon SDP04S60) is experimentally evaluated. A 300 W boost power factor corrector with average current mode control (PFC) is considered as a key application. Measurements of overall efficiency, switch and diode losses and conducted electromagnetic interference (EMI) are performed both with the SiC diode and with two ultra-fast, soft-recovery, silicon power diodes, namely the RURD460 and the recently presented STTH5R06D. The paper compares the results to quantify the impact of the recovery current reduction provided by SiC diode on these key aspects of the converter behavior
Sensorial potential of new fungi-resistant varieties in modern oenology
No full textContext and purpose of the study – The introduction into the Italian wine supply chain of the latest generation of fungi-resistant grapevine varieties, endowed with a greater or lesser strong resistance to downy and powdery mildews, represents a valid tool of making viticulture more sustainable, particularly in northern regions of the peninsula, where climatic conditions accentuate the pressure of fungal diseases However, the affirmation of resistant varieties is a function of their agronomic value, as well as of their oenological and sensorial value. The purpose of this study was to evaluate in detail the sensory potential of the new resistant varieties, in order to understand their real possibility of inclusion in the modern global enological context.
Material and methods – The research involved the sensory analysis of 29 resistant wines from two vintages (2019 and 2020), plus 2 control wines (Pinot bianco and Pinot noir), carried out by a trained panel. Samples were anonymized with numerical codes, to ensure anonymous evaluations, and randomized. Additionally, a replicate sample was introduced into each block. The work plan envisaged a first step in which a special file was created to identify the salient qualitative and quantitative characteristics of wines from resistant grape varieties. The descriptors usually used in the sensory cards have been integrated with the dominant descriptors identified by the panelists, in particular floral, fruity, vegetable, spicy and the foxy note characteristic of the non-noble breeding parent. The sensory analysis data were processed with descriptive and parametric techniques in order to identify specificities with significant and potentially usable differences for the creation of new brands or blends with traditional varieties.
Results – An analysis of the sensory characteristics of wines obtained from the latest generation of resistant varieties was carried out. The general characteristics typical of each resistant wine have been highlighted, yet interesting sensory potential for both white and red wines was found, at any rate variability between varieties arose. In general, results obtained are promising and can be used to define the criteria for a gradual diffusion of these new varieties. In particular, the identification of some dominant descriptors for the olfactory part will be used to manage the viticultural and oenological techniques, in order to optimize the most interesting sensory characteristics of the resistant varieties, limiting the perception of the Volpino flavour, that has been perceived. The sensory data can also be used to define the possibilities of vinification in purity, or in blends, of the new generation resistant varieties. In general, the results confirm the possibility of using the new resistant varieties as a tool for a real low-impact viticulture
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