1,109 research outputs found
Experimental clean combustor program, phase 2
The alternate fuels investigation objective was to experimentally determine the impacts, if any, on exhaust emissions, performance, and durability characteristics of the hybrid and vorbix low pollution combustor concepts when operated on test fuels which simulate composition and property changes which might result from future broadened aviation turbine fuel specifications or use of synthetically derived crude feedstocks. Results of the program indicate a significant increase in CO and small NOX increase in emissions at idle for both combustor concepts, and an increase in THC for the vorbix concept. Minimal impact was observed on gaseous emissions at high power. The vorbix concept exhibited significant increase in exhaust smoke with increasing fuel aromatic content. Altitude stability was not affected for the vorbix combustor, but was substantially reduced for the hybrid concept. Severe carbon deposition was observed in both combustors following limited endurance testing with No. 2 home heat fuel. Liner temperature levels were insensitive to variations in aromatic content over the range of conditions investigated
Experimental clean combustor program, phase 1
A program of screening three low emission combustors for conventional takeoff and landing, by testing and analyzing thirty-two configurations is presented. Configurations were tested that met the emission goals at idle operating conditions for carbon monoxide and for unburned hydrocarbons (emission index values of 20 and 4, respectively). Configurations were also tested that met a smoke number goal of 15 at sea-level take-off conditions. None of the configurations met the goal for oxides of nitrogen emissions at sea-level take-off conditions. The best configurations demonstrated oxide of nitrogen emission levels that were approximately 61 percent lower than those produced by the JT9D-7 engine, but these levels were still approximately 24 percent above the goal of an emission index level of 10. Additional combustor performance characteristics, including lean blowout, exit temperature pattern factor and radial profile, pressure loss, altitude stability, and altitude relight characteristics were documented. The results indicate the need for significant improvement in the altitude stability and relight characteristics. In addition to the basic program for current aircraft engine combustors, seventeen combustor configurations were evaluated for advanced supersonic technology applications. The configurations were tested at cruise conditions, and a conceptual design was evolved
Thyroid ultrasonography reporting: consensus of Italian Thyroid Association (AIT), Italian Society of Endocrinology (SIE), Italian Society of Ultrasonography in Medicine and Biology (SIUMB) and Ultrasound Chapter of Italian Society of Medical Radiology (SIRM)
Thyroid ultrasonography (US) is the gold standard for thyroid imaging and its widespread use is due to an optimal spatial resolution for superficial anatomic structures, a low cost and the lack of health risks. Thyroid US is a pivotal tool for the diagnosis and follow-up of autoimmune thyroid diseases, for assessing nodule size and echostructure and defining the risk of malignancy in thyroid nodules. The main limitation of US is the poor reproducibility, due to the variable experience of the operators and the different performance and settings of the equipments. Aim of this consensus statement is to standardize the report of thyroid US through the definition of common minimum requirements and a correct terminology. US patterns of autoimmune thyroid diseases are defined. US signs of malignancy in thyroid nodules are classified and scored in each nodule. We also propose a simplified nodule risk stratification, based on the predictive value of each US sign, classified and scored according to the strength of association with malignancy, but also to the estimated reproducibility among different operators
Produção e estado nutricional do milho em cultivo intercalar com adubos verdes.
O presente trabalho teve por objetivo avaliar o estado nutricional e a produção do milho quando submetido ao cultivo intercalar com adubos verdes
Root Morphology, Allometric Relations and Rhizosheath of Ancient and Modern Tetraploid Wheats (Triticum durum Desf.) in Response to Inoculation with Trichoderma harzianum T-22
Early root traits and allometrics of wheat are important for competition and use of resources. They are under-utilized in research and un-explored in many ancient wheats. This is especially true for the rhizosheath emerging from root-soil interactions. We investigated root morphology, root/shoot relations and the amount of rhizosheath of four tetrapoid wheat seedlings (30 days after emergence): the italian landrace Saragolle Lucana and modern varieties Creso, Simeto and Ciclope, and tested the hypothesis that inoculation with Trichoderma harzianum T-22 (T-22) enhances rhizosheath formation and affects wheat varieties differently. Overall growth of non-inoculated plants showed different patterns in wheat varieties, with Saragolle and Ciclope at the two extremes: Saragolle invests in shoot rather than root mass, and in the occupation of space with highest (p < 0.05) shoot height to the uppermost internode (5.02 cm) and length-to-mass shoot (97.8 cm g−1) and root (more than 140 m g−1) ratios. This may be interpreted as maximizing competition for light but also as a compensation for low shoot efficiency due to the lowest (p < 0.05) recorded values of optically-measured chlorophyll content index (22.8). Ciclope invests in biomass with highest shoot (0.06 g) and root (0.04 g) mass and a thicker root system (average diameter 0.34 mm vs. 0.29 in Saragolle) as well as a highest root/shoot ratio (0.95 g g−1 vs. 0.54 in Saragolle). Rhizosheath mass ranged between 22.14 times that of shoot mass in Ciclope and 43.40 in Saragolle (different for p < 0.05). Inoculation with Trichoderma increased the amount of rhizosheath from 9.4% in Ciclope to 36.1% in Simeto and modified root architecture in this variety more than in others. Ours are the first data on roots and seedling shoot traits of Saragolle Lucana and of Trichoderma inoculation effects on rhizosheath. This opens to new unreported interpretations of effects of Trichoderma inoculation on improving plant growth
Parametrização do modelo DSSAT/CANEGRO para as cultivares brasileiras de cana-de-açúcar.
A parametrização do modelo DSSAT/CANEGRO para a realidade brasileira tem grande importância para a obtenção de uma ferramenta capaz de otimizar o planejamento da produção sucroalcooleira nacional e analisar os impactos do aquecimento global na cultura da cana-de-açúcar no Brasil. O trabalho foi realizado com as cultivares IAC 91-1099 e SP 89-1115. Os dados biométricos foram coletados na APTA em Piracicaba-SP e analisados na Embrapa Informática Agropecuária em Campinas-SP, comparando-se com os dados gerados pelo modelo. Verificou-se que é possÃvel parametrizar os dados de perfilhamento e altura de colmo, com bons resultados, porém a parametrização do IAF necessita de mais estudos. Essas análises indicam possibilidades promissoras para o uso do modelo CANEGRO para as cultivares brasileiras.CBA 2009
Arquitetura foliar e coeficiente de extinção de radiacao solar para duas variedades de cana-de-açúcar.
O objetivo do trabalho foi avaliar um método computacional para a determinação do ângulo de inserção foliar (AIF) em cana-de-açúcar com base em imagens digitais, em comparação com medidas de campo segundo uma metodologia tradicional, para duas cultivares de cana-de-açúcar (IAC91-1099 e SP89-1115). Além dessa comparação, estimou-se o coeficiente de extinção (K) para radiação solar, observando-se a propagação do erro de estimativa do AIF nesta estimativa. Os ângulos medidos e os estimados não tiveram diferença estatisticamente significativa a 5% de probabilidade com o teste Tukey, com exceção da folha +2 na cultivar SP89-1115. Isso, contudo, não resultou em diferença na determinação do K medido e estimado. A cultivar SP89-1115 obteve K maior do que o estimado para a cultivar IAC91-1099, variando entre 0,44 e 0,74 considerando valores calculados para as 12:00. Considerando a variação horária de K, os valores oscilaram entre 0,5 e 6,5. Podemos concluir que o método computacional é valido para estimar o ângulo de inserção foliar e existe diferença entre as duas cultivares no ângulo de inserção ocasionando diferença no cálculo do K.CBA 2009
Efeito do enxofre, aplicado na forma de gesso, sobre a produção e qualidade do capim colonião (Panicum maximum Jacq.)
Foram conduzidos em vasos com terra em casa de vegetação, ensaios com doses crescentes de enxofre na forma de gesso e nitrogênio em esquema fatorial com repetições em capim Colonião visando verificar o comportamento da gramÃnea em relação a produção e qualidade.Resumo
Resposta de Panicum maximum cv. Tanzânia a fontes e doses de fósforo no estabelecimento.
O objetivo deste estudo foi verificar a resposta do Capim Tanzânia a fontes e doses de fósforo (P) no estabelecimento
Controle integrado de Botrytis cinerea na cultura do morango.
A viabilidade do controle de Botrytis cinerea foi estudada através do uso de antagonistas ao patógeno, associados ou nao a tratamentos fungicidas. Isolados de Trichoderma, obtidos pelo método de iscas, foram selecionados quanto ao antagonismo a B. cinerea, in vitro. A partir dos isolados selecionados foram obtidas linhagens resistentes a iprodione e caracterizadas quanto a adaptabilidade. Testes de sobrevivência das linhagens resistentes em folhas de morangueiro mostraram que, 37 dias apos a aplicacao de 10 7 conÃdios/ml, aproximadamente, 400 conÃdios permaneceram viáveis em discos de folha com 0,4 cm de diâmetro. A resistência a iprodione mostrou-se estável após 15 gerações na ausência do fungicida. Em ensaio realizado em condições de campo, o tratamento feito com a linhagem resistente a iprodione aplicada em mistura com a metade da dose do fungicida não apresentou controle satisfatório da doença
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