285 research outputs found

    ANÁLISE DE DESEMPENHO DO SISTEMA FOTOVOLTAICO CONECTADO À REDE DA UNIVERSIDADE FEDERAL DE ITAJUBÁ – CAMPUS ITABIRA

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    Com o aumento das demandas energéticas e a busca de novas alternativas de geração, visando o desenvolvimento sustentável, a energia solar fotovoltaica vem ganhando destaque no cenário mundial. O desempenho energético de operação de um sistema fotovoltaico não depende somente das características de sua tecnologia, mas também, das características climáticas do local de onde está instalado e da instalação adequada dos equipamentos. Existem vários coeficientes de desempenho energético de sistemas fotovoltaicos utilizados para avaliação, os mais usuais na literatura internacional são YIELD, Performance Ratio e Fator de Capacidade. Nesse sentido, utilizando os coeficientes de desempenho, o presente estudo avalia o sistema fotovoltaico on grid de 10,2 kW de potência instalada na Universidade Federal de Itajubá, na cidade de Itabira-MG. As avaliações demonstraram que o sistema tem operado com baixa eficiência, devido aos efeitos da instalação inadequada, tanto referente à inclinação dos painéis, quanto à orientação dos mesmos, e a possíveis intervenções que podem ocorrer para a realização de outros estudos. Palavras-chaveGeração Solar, Desempenho Energético, Energia Fotovoltaica

    Efficient fully blade-coated perovskite solar cells in air with nanometer-thick bathocuproine buffer layer

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    Fully printed perovskite solar cells (PSCs) were fabricated in air with all constituent layers, except for electrodes, deposited by the blade coating technique. The PSCs incorporated, for the first time, a nanometer-thick printed bathocuproine (BCP) hole blocking buffer using blade coating and deposited at relative humidity up to 50%. The PSCs with a p-i-n structure (glass/indium tin oxide (ITO)/poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)/CH3NH3PbI3/[6,6]-phenyl-C61-butyric acid methyl ester (PCBM)/BCP/Ag) delivered a maximum power conversion efficiency (PCE) of 14.9% on an active area of 0.5 cm2 when measured under standard test conditions. The PSCs with a blade coated BCP delivered performance of 10% and 63% higher (in relative terms) than those incorporating a spin coated BCP or without any BCP film, respectively. The atomic force microscopy (AFM) showed that blade coated films were more homogeneous and acted also as a surface planarizer leading to a reduction of roughness which improved BCP/Ag interface lowering charge recombination. The demonstration of 15% efficient devices with all constituent layers, including nanometer-thick BCP (∼ 10 nm), deposited by blade coating in air, demonstrates a route for industrialization of this technology

    16S rRNA amplicon sequencing reveals a polymicrobial nature of complicated claw horn disruption lesions and interdigital phlegmon in dairy cattle

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    Lameness represents an intractable problem for the dairy industry. Complicated claw horn disruption lesions, interdigital hyperplasia, and interdigital phlegmon are important lameness causing foot lesions. Their aetiology is multifactorial, but infectious processes are likely implicated in disease pathogenesis. Our aim was to investigate the bacterial profiles of these lesions using 16S rRNA gene sequencing of samples obtained from 51 cattle across ten farms in the UK. In this study, interdigital hyperplasia, interdigital hyperplasia with signs of interdigital dermatitis, interdigital phlegmon, complicated sole ulcers, complicated toe ulcers lesions, and complicated white line lesions were investigated; corresponding healthy skin control samples were also analysed. All diseased tissues displayed reduced microbial richness and diversity (as described by Chao1, Shannon, and Simpson alpha-diversity indices) compared to their healthy skin control samples. Our results confirm the association of Treponema spp with some of these disorders. Other anaerobic bacteria including Fusobacterium spp., Fastidiosipila spp. and Porphyromonas spp. were implicated in the aetiology of all these lesions with the exception of interdigital hyperplasia. Complicated claw horn disruption lesions, and interdigital phlegmon were found to have similar bacterial profiles. Such sharing of bacterial genera suggests many of the infectious agents detected in these foot lesions are acting opportunistically; this finding could contribute towards future treatment and control strategies

    Effect of Chitosan Microparticles on the Uterine Microbiome of Dairy Cows with Metritis

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    The objective of this study was to evaluate the effect of chitosan microparticles on the uterine microbiome of cows with metritis. Dairy cows with metritis (n = 89) were assigned to 1 of 3 treatments: chitosan microparticles (n = 21), in which the cows received an intrauterine infusion of chitosan microparticles at metritis diagnosis (day 0), day 2, and day 4; ceftiofur (n = 25), in which the cows received a subcutaneous injection of ceftiofur on day 0 and day 3; and no intrauterine or subcutaneous treatment (n = 23). Nonmetritic cows (n=20) were healthy cows matched with cows with metritis by the number of days postpartum at metritis diagnosis. Uterine swab samples collected on days 0, 3, 6, 9, and 12 were used for 16S rRNA gene sequencing and 16S RNA gene copy number quantification by quantitative PCR. Principal-coordinate analysis showed that the microbiome of the ceftiofur-treated and metritic untreated groups progressed toward that of the nonmetritic group by day 3, whereas that of the chitosan microparticletreated group remained unchanged. The differences on day 3 were mainly due to a greater relative abundance of Fusobacteria, particularly Fusobacterium, in the chitosan microparticle-treated group than in the ceftiofur-treated and metritic untreated groups. Furthermore, the microbiome of the ceftiofur-treated group became similar to that of the nonmetritic group by day 9, whereas the microbiome of the chitosan microparticle-treated and metritic untreated groups became similar to that of the nonmetritic group only by day 12. The total bacterial 16S rRNA gene counts in the chitosan microparticle-treated group were greater than those in the metritic untreated controls on days 6 and 9, whereas the ceftiofur treatment group was the only group in which the total bacterial 16S rRNA gene count became similar to that in the nonmetritic group by day 12. In summary, chitosan microparticles slowed the progression of the uterine microbiome toward a healthy state, whereas ceftiofur hastened the progression toward a healthy state.Fil: Galvão, Klibs N.. University of Florida; Estados UnidosFil: de Oliveira, Eduardo B.. University of Florida; Estados UnidosFil: Cunha, Federico. University of Florida; Estados UnidosFil: Daetz, Rodolfo. University of Florida; Estados UnidosFil: Jones, Kristi. University of Florida; Estados UnidosFil: Ma, Zhengxin. University of Florida; Estados UnidosFil: Jeong, Kwangcheol C.. University of Florida; Estados UnidosFil: Bicalho, Rodrigo C.. Cornell University; Estados UnidosFil: Higgins, Catherine H.. Cornell University; Estados UnidosFil: Rodrigues, Marjory X.. Cornell University; Estados UnidosFil: Gonzalez Moreno, Candelaria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Jeon, Soojin. Long Island University; Estados Unido

    The bovine foot skin microbiota is associated with host genotype and the development of infectious digital dermatitis lesions

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    Abstract Background Bovine Digital Dermatitis (BDD) is a prevalent infectious disease, causing painful foot skin lesions and lameness in cattle. We describe herein the bovine foot skin microbiota and its associations with BDD using 16S rRNA gene amplicon and shotgun metagenomic sequencing on samples from 259 dairy cows from three UK dairy farms. Results We show evidence of dysbiosis, and differences in taxonomy and functional profiles in the bovine foot skin microbiome of clinically healthy animals that subsequently develop BDD lesions, compared to those that do not. Our results suggest that taxonomical and functional differences together with alterations in ecological interactions between bacteria in the normal foot skin microbiome may predispose an animal to develop BDD lesions. Using genome-wide association and regional heritability mapping approaches, we provide first evidence for interactions between host genotype and certain members of the foot skin microbiota. We show the existence of significant genetic variation in the relative abundance of Treponema spp. and Peptoclostridium spp. and identify regions in the bovine genome that explain a significant proportion of this variation. Conclusions Collectively this work shows early changes in taxonomic and functional profiles of the bovine foot-skin microbiota in clinically healthy animals which are associated with subsequent development of BDD and could be relevant to prevention of disease. The description of host genetic control of members of the foot skin microbiota, combined with the association of the latter with BDD development offer new insights into a complex relationship that can be exploited in selective breeding programmes. </jats:sec
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