621 research outputs found

    Investigations on Deposit Formation in the Holes of Diesel Injector Nozzles

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    Current developments in fuels and emissions regulations are resulting in an increasingly severe operating environment for diesel fuel injection systems. The formation of deposits within the holes or on the outside of the injector nozzle can affect the overall system performance. The rate of deposit formation is affected by a number of parameters, including operating conditions and fuel composition. For the work reported here an accelerated test procedure was developed to evaluate the relative importance of some of these parameters in a high pressure common rail fuel injection system. The resulting methodology produced measurable deposits in a custom made injector nozzle on a single cylinder engine. The results indicate that fuels containing 30%v/v and 100% Fatty Acid Methyl Ester (FAME), that does not meet EN 14214 produced more deposit than an EN590 petroleum diesel fuel. Overall, the addition of zinc to the fuel had the biggest effect on deposit formation and resulted in a 12.2% decrease in Indicated Mean Effective Pressure (IMEP). The effects of zinc were unexpectedly reduced when it was added to fuel containing 30%v/v biodiesel. Reducing the common-rail pressure with 30%v/v biodiesel (no added zinc) increased the loss in IMEP. Raising the air and fuel temperatures by 40°C and 30°C respectively showed no bigger loss in IMEP. The results indicate that deposit formation may continue after engine shut down. © 2011 Society of Automotive Engineers of Japan, Inc. and SAE International

    Dressing up for stormy weather : bank lending to SME’s in the face of natural disasters : evidence from the U.S. market

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    My work examines the lending behavior of U.S. banks to SMEs in the aftermath of natural disasters. The study is based on 2016-2019 panel data at bank-county-neighborhood-year level. To identify a causal effect of natural disasters on bank lending, I use an ordinary least squares regression model with group fixed effects. My results demonstrate that there are differences in post shock lending behavior of affected local versus non-local banks. In normal times a strong positive relationship can be observed between SME lending and local bank presence, my results show robust evidence for the existence of a negative disaster lending effect. After a natural disaster, local banks lend significantly less to firms in affected areas than non-local banks. This pattern manifests itself especially for major disasters and hurricanes. My results further show different disaster lending effects based on the income structure of affected regions. I observe positive disaster lending effects for high income regions, negative effects for lower income regions.O meu trabalho examina o comportamento dos bancos dos EUA em matéria de empréstimos às PME na sequência de catástrofes naturais. O estudo baseia-se nos dados compreendidos entre 2016-2019 a nível do ano de vizinhança dos bancos. Para identificar um efeito causal das catástrofes naturais nos empréstimos bancários, utilizo um modelo normal de regressão de mínimos quadrados com efeitos fixos de grupo. Os meus resultados demonstram que existem diferenças no comportamento de empréstimo pós-choque dos bancos locais afectados versus bancos não-locais. Em tempos normais pode ser observada uma forte relação positiva entre os empréstimos às PMEs e a presença de bancos locais, os meus resultados mostram provas robustas da existência de um efeito de empréstimo negativo em caso de catástrofe. Após uma catástrofe natural, os bancos locais emprestam significativamente menos às empresas nas áreas afectadas do que os bancos não locais. Este padrão manifesta-se especialmente no caso de grandes catástrofes e furacões. Os meus resultados mostram ainda diferentes efeitos de empréstimo em caso de catástrofe, com base na estrutura de rendimentos das regiões afectadas. É também possível observar efeitos positivos dos empréstimos em caso de catástrofes para regiões de elevado rendimento, efeitos negativos para regiões de menor rendimento

    Biochemical Profile and Productive Performance in Dairy Cows with Lameness During Postpartum Period

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    Background: Lameness in dairy cows is classified as a gait change caused by multifactorial process. The phase of the peripartum causes intense physiological changes for the adaptation of late gestation and onset of lactation. The aim of this study was to characterize the changes in the biochemical profile and productive performance in dairy cows with lameness during postpartum period.Materials, Methods & Results: This study was conducted at the University of São Paulo farm, in Pirassununga, São Paulo State, Brazil, from January to March 2017. A total, of 48 multiparous (2 to 3 lactations and 3-4 years old) dairy cows, that had the milk production of 9,200 kg/ dairy cow in a period of 305 days in the previous lactation, were included in the study. All cows were managed under the same conditions and nutritional regimen. Evaluation of body condition score was performed by a single person on -18, -12, -8, -5, and -2 days before parturition, at parturition, and on days 1, 7, 14, 21, 30, 45 and 60 after parturition. Milk production was recorded on days 7, 14, 21, 30, 45 and 60 after parturition and saved in the software program. Blood samples were performed on -18, -12, -8, -5, and -2 days before parturition, at parturition, and on days 1, 7, 14, 21, 30, 45 and 60 after parturition. Blood samples were assayed for albumin, calcium, cholesterol, triglycerides, non-esterified fatty acids, β-hydroxybutyrate, urea, creatinine, gamma-glutamil-transferase and total protein concentrations. Dairy cows were divided into a lame group (11) and normal group (37) based on locomotion score from parturition to seven days postpartum. Lame cows was classified if their score was > 2, and normal cows was classified if their score was ≤ 2 and free of any disease. Dairy cows that suffer by any health disorder other than lameness were excluded from this study. Cow diagnosed with lameness outside the diagnostic period were excluded from this study. The averages of the milk production, body condition score and biochemical profile were compared with the Tukey’s test. Lame cows showed lower (P < 0.05) concentrations of albumin (on days -18 -12, -8, -5, -2 relative to parturition, at parturition, and on days 7, 14, 21, 45 and 60 after parturition) calcium (on days -18, -12, -8, -5 and -2 before parturition, and on days 7, 14, 21, 45 and 60 after parturition), cholesterol (on days -12, -8, -5 before parturition and on days 7, 14, 21, 30, 45 and 60 after parturition) than normal cows. Cow with lameness showed higher (P < 0.05) concentration of triglyceride (on days 7, 14, 21, 30, 45 and 60 after parturition), non-esterified fatty acids (on days 1, 7, 14, 21, 30, 45 and 60 after parturition) and β-hydroxybutyrate (on days -12, -5 and -2 before parturition, at parturition, and on days 1, 14, 21 and 30 after parturition) than normal group. Cows with lameness presented higher (P < 0.05) values of body condition score on days -18, -12 and -8 before parturition, and lower (P < 0.05) values on days 7, 14, 21, 30, 45 and 60 after parturition than normal cows. Milk production was lower (P < 0.05) for cows with lameness (on days 7, 14, 21, 30, 45 and 60 after parturition) than normal cows.Discussion: The overall prevalence of lameness in the evaluated period was 22.92% (11/48). Among lame cows, 07 presented laminitis, 02 had interdigital hyperplasia and 02 had sole ulcer. Our findings prove that the biochemical profile and productivity of dairy cows during the peripartum and postpartum period were affected by lameness at the early lactation.

    The death of cows poisoned by the trichothecene is reported from a cattle herd of animals fed with citrus pulp containing 7 mg/kg of the micotoxin diacetoxyscirpenol

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    The death of cows poisoned by the trichothecene is reported from a cattle herd of animals fed with citrus pulp containing 7 mg/kg of the micotoxin diacetoxyscirpenolRelata-se a morte de bovinos causada pela ingestão de polpa cítrica contaminada pela micotoxina Diacetoxiscirpenol (7mg/kg), pertencente ao grupo dos tricotecenos

    Enzootic bovine leukosis: prevalence of seric antibodies on dairy cows breed at Bahia and comparison between results of ELISA tests and ágar gel immunodiffusion tests

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    The prevalence of infection by the Enzootic Bovine Leukosis virus was determined in dairy cows breed in five micro-regions of Bahia State, comparing the efficiency of three serodiagnostic tests for the detection of antibodies anti Enzootic Bovine Leukosis virus: ELISA test, AGID Immunodiffusion test / gp 51 from foreign origin and AGID Immunodiffusion test / gp 51 produced by the Institute of Technology of Paraná - TECPAR. Seven hundred and ninety-six dairy cattle , from 13 bovine flocks were used. The infection for VLB was detected in every flock, with an prevalence of 41,0%, showing an individual flock value variation between 6,3% (4/64) and 65,8% (25/38). The animals were stratified in six age groups: a) 2 - 6 months; b) 7 - 12 months; c) 13 - 24 months; d) 25 - 48 months; e) 49 - 72 months; f) more than 72 months of age, observing that the indexes of infection in the mentioned groups were 8,8%; 16,9%; 17,7%; 50,8%; 54,4% and 56,5% respectively, showing these indexes increased significantly with age. Were used 434 serum samples were used to evaluate the comparative efficiency of the three serodiagnostic tests, considering ELISA as the standard test. In the comparison between ELISA and IDGA test with antigen of foreign origin, were found a sensibility of 85% and specificity of 80%; a positive predictive value (PPV) of 63% and a negative predictive value (NPV) of 93%, with an agreement index of 81%. Comparatively to the ELISA results, IDGA test with antigen of national origin presented a sensibility of 82%, specificity of 93%, PPV of 79% and NPV of 93%, with an agreement index of 85%. The overall results of these studies suggest that IDGA test with antigen of national origin is sufficiently efficient to its use.Determinou-se a prevalência de infecção pelo vírus da Leucose Enzoótica dos Bovinos (LEB) em animais criados na bacia leiteira de cinco micro-regiões do Estado da Bahia, comparando a eficiência de três provas sorológicas para detecção de anticorpos anti-Vírus da LEB: Teste ELISA, prova de Imunodifusão IDGA / gp 51 importado e a IDGA / gp 51 produzido pelo Instituto de Tecnologia do Paraná - TECPAR. Foram utilizados bovinos de 13 propriedades, totalizando 796 animais. A infecção pelo VLB foi detectada em todos os rebanhos, com taxa de prevalência de 41,0%, com variação de 6,3% (4/64) a 65,8% (25/38). Os bovinos foram estratificados em seis grupos etários: a) de dois a seis meses; b) de 7 a 12 meses; c) de 13 a 24 meses; d) entre 25 e 48 meses; e) de 49 a 72 meses; f) com mais de 72 meses de idade, observando-se que os índices de infecção aumentaram significativamente com o desenvolvimento etário e os resultados foram, respectivamente: 8,8%; 16,9%; 17,7%; 50,8%; 54,4% e 56,5%. Em 434 amostras avaliou-se comparativamente a eficiência das três provas sorológicas, considerando-se o Teste ELISA como padrão. Na comparação entre a prova ELISA e o Teste de IDGA / gp 51 importado a sensibilidade foi de 85% e especificidade de 80%, com valor preditivo positivo (VPP) de 63% e o valor preditivo negativo (VPN) de 93%, sendo a concordância igual a 81%. O estudo comparativo do teste ELISA e IDGA / gp 51 - TECPAR apresentou sensibilidade igual a 82% e a especificidade 93%, com VPP de associação igual a 79% e o VPN de 93% , sendo a concordância igual a 85%. Os resultados dos estudos comparativos sugerem IDGA com antígeno de procedência nacional suficientemente eficiente para a sua utilização

    Chloride and lactose contents and chloride/lactose ratio in milk from Jersey cows in the first month of lactation

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    Avaliou-se a influência do período colostral nos teores lácteos de cloretos, lactose e do índice cloretos/lactose. Foram colhidas 418 amostras de leite provenientes de glândulas mamárias sadias, e que não apresentavam crescimento bacteriano ao exame microbiológico, de 127 vacas da raça Jersey. As amostras foram distribuídas em oito grupos: 0 ?1/2 dia; 1/2 ?1 dia; 1 ?2 dias; 2 ?3 dias; 3 ?5 dias; 5 ?7 dias; 7 ?15 dias; 15 ?30 dias em lactação. Nas amostras, colhidas antes da ordenha, foram determinados os valores de cloretos, por titulação colorimétrica, e de lactose, por radiação infravermelho, e calculou-se o índice cloretos/lactose. Nas primeiras 24 horas da lactação, observou-se abrupta diminuição no teor lácteo de cloretos e do índice cloretos/lactose, associada com o aumento no teor lácteo de lactose. A transição da secreção de colostro para leite em relação ao teor de cloretos e lactose e ao índice cloretos/lactose na secreção láctea ocorreu na primeira semana da lactação, a partir do terceiro dia da lactação para o valor de cloretos e para a relação cloretos/lactose e a partir do quarto dia da lactação para o teor de lactose. Recomenda-se, nas primeiras 24 horas da lactação, a adoção dos seguintes limites de normalidade: cloretos, <173,4mg/dL; lactose >3,94g/dL e índice cloretos/lactose, <6,11%. Entre o segundo e o sétimo dia da lactação (transição de colostro para leite), indicamse os seguintes limites: cloretos <125,9mg/dL; lactose, >4,03g/dL e índice cloretos/lactose <3,54In order to assess the influence of the colostral period on chloride and lactose levels and on the chloride/lactose ratio, 419 milk samples from 127 Jersey cows were analyzed. The samples were collected from healthy udders that did not present any bacterial growth in the microbiological examination. Cows were distributed into eight groups as follows: 0 ?1/2 day; 1/2 ?1 day; 1 ?2 days; 2 ?3 days; 3 ?5 days; 5 ?7 days; 7 ?15 days; 15 ?30 days of lactation. The samples were collected before milking to analyze the levels of chloride by colorimetric titration, lactose by infrared radiation, and to determine the chloride/lactose ratio. In the first 24 hours after partition, there was an abrupt reduction in chloride levels as well in chloride/ lactose ratio, associated with an increase in lactose levels. It was observed that the transition of the secretion from colostrum to milk, regarding chloride and lactose levels and chloride/lactose ratio occurred during the first week of lactation: from the 3rd day of lactation for chloride and chloride/lactose ratio and from 4th for the lactose levels. It is recommended the use the following thresholds as normal ranges for the first 24 hours of lactation: chloride <173.4mg/dL; lactose >3.94g/dL, and chloride/lactose ratio <6.11%; and between 2nd and 7th days of lactation (transition from colostrum to milk), it was suggested the use of the following values: chloride <125.9mg/dL; lactose >4.03g/dL and chloride/lactose ratio <3.5

    The influence of retained fetal membranes on the hemogram of Holstein cows

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    Analisou-se o hemograma de 177 amostras de sangue de fêmeas bovinas da raça Holandesa nos primeiros 90 dias pós-parto. As amostras foram colhidas de vacas não reagentes ao antígeno (GP 51) do vírus da leucose dos bovinos, distribuídas em dois grupos (I: puerpério fisiológico; II: puerpério com retenção dos anexos fetais) e subdivididas em quatro grupos de acordo com o momento de colheita. Nos primeiros 10 dias após o parto, o eritrograma não sofreu influência da retenção dos anexos fetais. Com a evolução do puerpério, observou-se, nas vacas com retenção dos anexos fetais, anemia de grau leve entre o 10º e 30º dia pós-parto. O leucograma dos animais com retenção dos anexos fetais foi predominantemente linfocitário, caracterizado por leucopenia, neutropenia com desvio à esquerda degenerativo e eosinopenia. A partir do 10º dia após o parto, o leucograma não foi influenciado pela retenção dos anexos fetaisHematological profiles of 177 blood samples from Holstein cows were determined during the first 90 days after parturition. Blood samples were collected from cows that were non-reactive to the bovine leukosis virus (GP 51) antigen. The animals were divided into two groups (group I: physiological puerperium and group II: puerperim with retained fetal membranes), and subdivided into four groups, based on the time that the samples were collected. During the first 10 days after parturition, retained fetal membranes did not influence the erythrogram. However, with the evolution of the puerperium period, a mild anemia was observed from the 10th to the 30th day postpartum in cows with retained fetal membranes. The leukocyte profile was predominantly lymphocytic, characterized by leucopenia induced by neutropenia with a left degenerative shift and eosinopenia. From the 10th day postpartum, the retained fetal membranes did not influence the leukogra

    Influência de fatôres raciais e alimentares sôbre o quadro protéico do sangue de caprinos

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    In the following research the authors endeavors to establish the normal blood protein picture in goats (Capra hircus), raised in the State of São Paulo (Brazil). The authors studied 150 healthy female goats, raised in several areas of the State of São Paulo (Brazil), their breedings were Anglo Nubian (60), Toggenbourg (60) and Angora (30). For verifying the eventual influence of feeding on the blood proteic picture, the Anglo Nubian and the Toggenbourg goats, were separated in 4 groups of 30 animals, each group; 2 groups of each breeding were submitted to different feedings, one group of each breeding, grazed in pangola grass (Digitaria decumbens) pasture and the other received besides the forrage a supplementary concentrated feed. In order to verify whether the breed factor have some influences upon the proteic contents in the results obtained in the serum of the Anglo Nubian, Toggenbourg and Angora animals submitted to a standard feed and raised under the same conditions. The author used the Gornall and cols. (1949) method to determine the total protein, albumin, globulin and ratio of albumin/globulin in the serum. The original method was modified by precipitating the globulins in a 27 g% sodiumsulfite solutions, as recommended by Birgel (1967). The determination of fibrinogen in the plasma was reached by means the Cullen an Van Slyke modified method as recommended Quick (1959).O artigo apresenta resumo em inglês
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