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Search Results: 1 - 10 of 145159 matches for " Vale F. "
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Solubilidade de micronutrientes contidos em formula??es de fertilizantes, em extratores químicos
Alcarde, J. C.;Vale, F.;
Revista Brasileira de Ciência do Solo , 2003, DOI: 10.1590/S0100-06832003000200016
Abstract: in brazilian legislation, the control for micronutrient concentrations in mineral fertilizers considers the total content. as a consequence, low-cost by-products and even industrial residues are generally used as a source for micronutrients, despite their low availability to plants. to evaluate fertilizer solubilities, water, citric acid 20 g l-1, and neutral ammonium citrate (1 + 9) extracting solutions were applied to mixtures containing micronutrients. the same study was realized for micronutrient sources. results were similar for both sources and mixtures. citric acid solution 20 g l-1 was the most promising option to evaluate micronutrient contents in fertilizer mixtures. from the agronomic point of view, the total content is an inadequate criterion for the determination of micronutrient contents in chemical fertilizers.
Solubilidade de micronutrientes contidos em formula es de fertilizantes, em extratores químicos
Alcarde J. C.,Vale F.
Revista Brasileira de Ciência do Solo , 2003,
Abstract: A legisla o brasileira adota o teor total para a garantia dos micronutrientes em fertilizantes. Isso permite a utiliza o de subprodutos de várias origens, baratos, mas que nem sempre apresentam os micronutrientes em formas disponíveis às plantas. Estudou-se a solubilidade dos micronutrientes em formula es de fertilizantes, utilizando os extratores água e solu es de ácido cítrico 20 g L-1 e citrato neutro de am nio (1 + 9), já usados na avalia o de matérias-primas. Os resultados foram semelhantes, tanto na avalia o das formula es como de matérias-primas, isto é, a solu o de ácido cítrico a 20 g L-1 possibilita avaliar, com mais seguran a, o conteúdo de micronutrientes em formula es de fertilizantes, representando uma alternativa para o teor total, que n o é um critério adequado, do ponto de vista agron mico, para avaliar os micronutrientes contidos em fertilizantes.
Study of water-repellent treatments applied on limestone from Andalusian Cathedrals
Villegas, R.,Vale, J. F.,Alcalde, M.
Materiales de Construccion , 1991,
Abstract: Five types of stone used in Andalusian Cathedrals have been treated with different water-repellent treatments, to evaluate the effects of this products. The stones studied are limestone, calcarenite and dolomite; the products applied are organosilicones and acrylics. In this work properties related with water access and movement through the stone have been measured and compared their values before and after the application of the treatments. Se han tratado varios tipos de piedra utilizados en Catedrales Andaluzas con diversos productos hidrófugos, con el fin de evaluar las características conferidas por los mismos. Los tipos de piedra son de naturaleza caliza, calcarenitas y dolomías; los productos son organosilícicos y acrílicos. En este trabajo se han medido las propiedades relacionadas con el acceso y movimiento de agua en la piedra, comparándose sus valores antes y después de la aplicación del tratamiento.
Successfully resisting a pathogen is rarely costly in Daphnia magna
Pierrick Labbé, Pedro F Vale, Tom J Little
BMC Evolutionary Biology , 2010, DOI: 10.1186/1471-2148-10-355
Abstract: We designed specific experiments to study the costs induced by exposure to this parasite, and we re-analysed previously published data in an effort to determine the generality of such costs. However, despite the variety of genetic backgrounds of both hosts and parasites, and the different exposure protocols and environmental conditions used in these experiment, this work showed that costs of exposure can only rarely be detected in the D. magna-P. ramosa system.We discuss possible reasons for this lack of detectable costs, including scenarios where costs of resistance to parasites might not play a major role in the co-evolution of hosts and parasites.Parasites are thought to be a major cause of evolutionary change due to the deleterious fitness effects they impose on their hosts [1-3]. Coevolution between hosts and parasites has resulted in the evolution of several mechanisms to avoid or limit these deleterious effects, including behavioural modifications, boundary defences (e.g. the cuticle) and finally the immune system [reviewed in [4]]. Following theory on the evolution of life-history traits [5], the evolution of the immune system is thought to be shaped by costs of resistance, as investment in fighting infection by mounting and then maintaining an immune response should divert resources from other fitness-related traits [4,6-10].These costs fall into two broad categories. Constitutive costs of resistance arise from a negative genetic covariance between immunity and other fitness-related traits (a genetic-based trade-off) [4,7,9,10]. Inducible costs of resistance are the physiological costs incurred by hosts when mounting an immune response [4,9,10]. Such inducible costs of mounting an immune response can be measured by comparing the fitness of individuals that are challenged with infection but successfully fight it off, to the fitness of hosts that are unchallenged [7]. The mechanistic cause of these costs (induced or constitutive) is thought to be the energy r
Geographic distribution of methyltransferases of Helicobacter pylori: evidence of human host population isolation and migration
Filipa F Vale, Francis Mégraud, Jorge MB Vítor
BMC Microbiology , 2009, DOI: 10.1186/1471-2180-9-193
Abstract: Independence tests and logistic regression models revealed that ten R-M systems correlate with geographical localization. The distribution pattern of these methyltransferases may have been originated by co-divergence of regional H. pylori after its human host migrated out of Africa. The expression of specific methyltransferases in the H. pylori population may also reflect the genetic and cultural background of its human host. Methyltransferases common to all strains, M. HhaI and M. NaeI, are likely conserved in H. pylori, and may have been present in the bacteria genome since the human diaspora out of Africa.This study indicates that some methyltransferases are useful geomarkers, which allow discrimination of bacterial populations, and that can be added to our tools to investigate human migrations.Helicobacter pylori colonizes about half of the human population and is associated with several gastrointestinal diseases, such as gastritis, peptic ulcer, and gastric cancer [1,2]. The similar pattern of human and H. pylori geographic diversity and distribution suggests a co-evolution between bacteria and man, which can be used to understand human migrations [2]. The H. pylori distribution pattern follows the human migration roots, which suggests that the colonization of the human stomach occurred before modern man left East Africa [2-5].Several H. pylori gene alleles present different prevalence rates among the world H. pylori population. This is the case for vacA that presents allelic diversity of the s-, m- and i-region [6,7]. The cagA gene DNA motifs also presents a clear geographic association, and five types of deletion, insertion, and substitution motifs were found at the 3' end of the H. pylori cag pathogenicity island associated with different human populations [8]. Another study confirms that the candidate virulence factors, vacA, cagA and iceA, cluster according to geographic region [9]. Interestingly, iceA has two known alleles, iceA1 and iceA2 [10,11], with t
Evaluation of hydrophobic treatments applied to stones used in andalusian cathedrals. III.-Accelerated weathering test with polluted atmosphere
Villegas Sánchez, R.,Vale Parapar, J. F.
Materiales de Construccion , 1993,
Abstract: SUMMARY In this work we study the weathering resistance of samples of five types of stone used in Andalusian Cathedrals, treated with six water repellent products, by subjecting the samples to a SO2 polluted atmosphere. To evaluate the alteration of the samples, besides visual observation of macroscopic aspect, changes in weight and the quantity of sulfate that remains on the surface have been measured. Also properties related with water have been measured after the test to determine if there have been any changes in the hydrophobic characteristics. En el presente artículo se estudia el comportamiento de muestras de cinco tipos de piedra utilizados en catedrales andaluzas, tratadas con seis productos hidrófugos, sometiéndolas a un ensayo acelerado de alteración en atmósfera contaminada con SO2 . Para evaluar la alteración, además de la observación visual de las manifestaciones macroscópicas, se ha medido la variación de peso de las muestras expuestas y la cantidad de sulfato que permanece en la superficie tras el ensayo. Así mismo, se han detectado los cambios experimentados en las propiedades hidrófugas conferidas por los tratamientos, mediante la medida de propiedades relacionadas con el movimiento del agua.
Evaluation of water repellent treatments applied to stones used in andalusian cathedrals. II. Salt crystallization test
Villegas Sánchez, R.,Vale Parapar, J. F.
Materiales de Construccion , 1993,
Abstract: In a previous paper we have studied the changes that have ocurred in the properties related to water access and movement in the stone after the application of water repellent treatments. In this work we compare the weathering resistance of treated and untreated samples by means of sodium sulphate crystallization test. After finishing the test (75 cycles) properties related to water have been measured again to know if the treatments have undergone any kind of deterioration and lose their water repellent characteristics. En un artículo anterior se han evaluado los cambios producidos en las propiedades relacionadas con el acceso y movimiento de agua en la piedra como consecuencia de la aplicación de tratamientos de hidrofugación. En este trabajo se compara la resistencia a la alteración producida por sales de las probetas tratadas y sin tratar, sometiéndolas al ensayo de cristalización de sulfato sódico. Tras finalizar el ensayo (75 ciclos) se han medido nuevamente las propiedades relacionadas con el agua, con objeto de comprobar si los tratamientos han sufrido alguna alteración y si mantienen sus características hidrófugas.
Coal fly ash-containing sprayed mortar for passive fire protection of steel sections
Vilches, L. F.,Leiva, C.,Olivares, J.,Vale, J.
Materiales de Construccion , 2005,
Abstract: The present article addresses the possible use of coal fly ash as the chief component of sprayed mortars to fireproof steel structures. A pilot wet-mix gunning rig was specifically designed and built to spray different pastes on to sheet steel and sections with different surface/volume ratios. After gunning, the specimens were placed in a furnace and subjected to standard fire resistance testing. Product fire resistance was calculated from the test results. The mortar used in this study, with a high fly ash content, was found to have acceptable mechanical properties as well as afire resistance potential comparable to those of commercial passive fire protection products. En este artículo se estudia el posible uso de las cenizas volantes procedentes de la combustión del carbón como constituyente principal de morteros que pueden ser proyectados sobre estructuras metálicas, para protegerlas contra el fuego. Con objeto de estudiar el proceso de proyección, se ha construido una planta piloto de gunitado por vía húmeda. La pasta se ha proyectado sobre placas metálicas y perfiles metálicos con diferentes relaciones superficie/volumen. Tras el gunitado, las probetas proyectadas se colocan en un horno y se someten a un programa de calentamiento según la norma de resistencia al fuego. A partir de los datos obtenidos se ha podido realizar una estimación de la resistencia al fuego del producto. Los resultados muestran que el material proyectado usado en este estudio, que contiene una alta proporción de cenizas volantes, tiene unas propiedades mecánicas aceptables y unas características potenciales de resistencia al fuego comparables a las de otros productos comerciales utilizados en la protección pasiva contra el fuego.
Adi § £o de sal na gua de hidrata § £o reduz o tempo de cozimento em feij £o comum ao longo do tempo de armazenamento
Addition of salt to in the soaking water reduces the cooking time of common beans over storage time

Alimentos e Nutri??o , 2011,
Abstract: O objetivo deste trabalho foi avaliar o efeito da adi § £o dos sais cloreto de s 3dio (NaCl) e cloreto de pot ssio (KCl) na gua de hidrata § £o de gr £os de feij £o sobre o tempo de coc § £o como uma alternativa de minimizar o tempo de cozimento ao longo do armazenamento. O experimento foi conduzido na Universidade do Estado de Santa Catarina - UDESC no Centro de Ci ancias Agroveterin rias-CAV, sob delineamento experimental inteiramente casualizado, com tr as repeti § μes. As cultivares utilizadas foram P rola e IPR Uirapuru. Os tratamentos consistiram de 25g de gr £os de feij £o previamente armazenados por 45 e 90 dias, os quais foram hidratados em diferentes concentra § μes de NaCl e KCl (0, 10 e 25g em 100mL de gua destilada), durante 8 e 16 horas, a 25 °C. Ap 3s a embebi § £o, os gr £os foram submetidos coc § £o, utilizando cozedor de Mattson. Os sais NaCl e KCl adicionados gua de hidrata § £o proporcionaram redu § £o signi cativa no tempo de coc § £o de gr £os de feij £o, quando comparados com gr £os hidratados sem adi § £o de sal. A hidrata § £o de gr £os de feij £o por 16 horas com solu § £o salina contendo 14% de KCl reduziu signi cativamente o tempo de cozimento, apresentando o menor tempo para a coc § £o.
DAG defect in Murrah buffalo bulls in Brazil
H.F.L. Ribeiro,W.G. Vale
Italian Journal of Animal Science , 2010, DOI: 10.4081/ijas.2007.s2.667
Abstract: Dag defect sperms have an abnormal tail coiled morphology are totally or almost totally immotile and have severe abnormalities on the fibers in the axial filament. This defect in bovine was shown to be due an autosomal recessive gene. In the present study 23 buffalo bulls age 18-34 months examined for BSE (Breeding Soundness Examination) showed sperm motility varied between 0 to 70% accomplished with 10 a 65% of sperm pathology with or not a predominance of strong coiled tails with or without persistence of droplet. In Brazil Murrah breed have had only eight female PO (pure of origin - India) gave origin of the herd and not more than four males where also imported from India, although in the last two decades some quantity of frozen semen were introduced in the country imported from India. As in the other domestic species inbreed seems to be the main cause of this abnormalities in different breeds. The knowledge and further study of such abnormalities is the only way to overcome a problem that if not controlled will tend to spread out without control causing in the future more problem for development of some herds.
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