oalib

OALib Journal期刊

ISSN: 2333-9721

费用：99美元

投稿

时间不限

( 2673 )

( 2672 )

( 2208 )

( 2024 )

自定义范围…

匹配条件： “José Miguel Barros” ，找到相关结果约94035条。
列表显示的所有文章，均可免费获取
第1页/共94035条
每页显示 条
CHARCAS Y EL MAR: ？SECUELA TERMINAL?
Barros,José Miguel;
Cuadernos de historia (Santiago) , 2011, DOI: 10.4067/S0719-12432011000200006
Abstract: this is a reply to the article "around the sea of bolivia" by mr. sergio villalobos ("cuadernos de historia" 32, 2009). basically, its purpose is to specify the scope ofthe debate arisen about thejurisdiction ofcharcas during spanish colonial times. furthermore, its author rejects some personal disqualifications emitted by professor villalobos.
CHARCAS Y EL MAR: SECUELA TERMINAL? CHARCAS AND THE SEA: A FINAL SEQUEL?
José Miguel Barros
Cuadernos de historia , 2011,
Abstract: Este trabajo es una réplica al artículo "En torno al mar de Bolivia" de don Sergio Villalobos (Cuadernos de Historia N° 32, 2009). Básicamente, su objetivo es precisar el alcance de la polémica producida respecto de la jurisdicción de Charcas en la época colonial. Al mismo tiempo, se impugnan descalificaciones personales emitidas por el profesor Villalobos. This is a reply to the article "Around the sea of Bolivia" by Mr. Sergio Villalobos ("Cuadernos de Historia" 32, 2009). Basically, its purpose is to specify the scope ofthe debate arisen about thejurisdiction ofCharcas during Spanish colonial times. Furthermore, its author rejects some personal disqualifications emitted by professor Villalobos.
Escoamento superficial e desagrega？？o do solo em entressulcos em solo franco-argilo-arenoso com resíduos vegetais
Cassol, Elemar Antonino;Cantalice, José Ramon Barros;Reichert, José Miguel;Mondardo, Arcangelo;
Pesquisa Agropecuária Brasileira , 2004, DOI: 10.1590/S0100-204X2004000700010
Abstract: soil surface cover with crop residue modifies surface flow characteristics, generated by excess rainfall, and soil detachment and sediment transport resulting from the erosion process. the objective of this study was to evaluate the hydraulic conditions, detachment and flow resistance on interrill erosion on soil covered with residue. the experiment was conducted in the laboratory, on a hapludult soil at a slope of 0.10 m m-1, under simulated rainfall and soil surface covered with soybean residue at the rates of 0, 0.05, 0.1, 0.2, 0.4, and 0.8 kg m-2. the increase in soil surface cover (sc) with residue, caused an increase in water flow depth and hydraulic roughness, and a decrease in the mean flow velocity, due to an increase in the viscous forces from the physical interference of residue on runoff, thus contributing to a reduction in interrill soil detachment rate (di). the di was 5.35x10-4 kg m-2 s-1 for bare soil and was reduced to 1.50x10-5 kg m-2 s-1 for soil with 100% of surface cover. the laflen's and the potential models were adequate to estimate the coefficient of soil coverage by residue in direct contact with soil as a function of the soil surface cover.
Hidráulica do escoamento e transporte de sedimentos em sulcos em solo franco-argilo-arenoso
Cantalice, José Ramon Barros;Cassol, Elemar Antonino;Reichert, José Miguel;Borges, Ana Luiza de Oliveira;
Revista Brasileira de Ciência do Solo , 2005, DOI: 10.1590/S0100-06832005000400012
Abstract: rill erosion is characterized by concentrated surface water flow, with enough shear stress and detachment capacity to deform the rill and alter flow hydraulics, responsible for rill formation dynamics. the objective of this study was to evaluate flow hydraulic conditions that can provide important information on erosion relationships, soil erodibility and sediment transport in furrows of a recently-tilled palleudult. rills were pre-formed in a sandy clay loam soil with an average slope of 0.067 m m-1. simulated rainfall with an intensity of 74 mm h-1 was applied during 80 min, while rainfall and extra inflows of 0, 10, 20, 30, 40, and 50 l min-1 were jointly applied for the last 20 min of each run in the rill. results indicated that the rill flow regime varied from transitional subcritical to turbulent subcritical. the rill erosion detachment rates were linear to shear stress. rill erodibility (kr) was 0.0024 kg-1 s-1 n and critical shear stress (tc) was 2.75 pa. two functions to predict sediment transport based on stream power explained 53% of data variability, which indicates the inherent difficulty of predicting solid transport through shallow flows on eroding agricultural lands, and the physical and mineralogical diversity of particles and aggregates of the studied soil.
Compressibilidade de um Argissolo Vermelho-Amarelo trafegado e escarificado
Vogelmann, Eduardo Saldanha;Mentges, Marcelo Ivan;Reichert, José Miguel;Rosa, David Peres da;Barros, Cláudia Alessandra Peixoto de;Reinert, Dalvan José;
Ciência Rural , 2012, DOI: 10.1590/S0103-84782012005000004
Abstract: farm machinery wheeling is considered a major source of soil compaction. the use of chisel plow can minimize such effects, but the chisel can cause subsurface compaction. the aim of this study was to evaluate the effect of traffic and is present below the compaction layer thought compressive parameters of soil. the treatments investigated were: no-tillage, no-tillage with additional traffic (traffic intensity of 24.67mg km ha-1), no-tillage chiseling recent implanted, no-tillage with additional traffic and chiseling recent implanted. for the density, void ratio, preconsolidation pressure and coefficient of compressibility determination in the layers 0.0-0.10m, 0.10-0.20m, 0.20-0.30m and 0.30 to 0.40m samples were collected. the treatment no-tillage showed the lowest load support capacity and greater susceptibility to compaction. the traffic intensity of 24.67mg km ha-1 increased bulk density and decreased void ratio until 0.30m depth. the chisel plow did not affect the preconsolidation pressure and coefficient of compressibility of soil layer below the line of action of the chisel tip.
Unveiling modal parameters with forced response using SVD and QR during flutter flight testing
José Barros-Rodríguez,José Miguel Fernández Fructuoso,Oscar Rodríguez Polo,Roberto Flores Le Roux,Sebastián Sánchez Prieto
- , 2018, DOI: 10.1177/0954410016673393
Abstract: This article presents an algorithm for the identification of modal parameters during flutter flight testing when forced excitation is employed and the aircraft possesses several sensors for structural response acquisition. The main novelty of the method, when compared with other classical modal analysis methods, is that the analysis is carried out in intervals of time instead of in the whole duration of the excitation. It means that, even when the response signal is only partially available, some modal parameters may be still identified. Application to analytic signals as well as structural response of modern fighter aircraft using frequency-swept excitation is provided in order to demonstrate the effectiveness, robustness and noise immunity of the proposed method
Radon: risk to health? El radón: riesgo para la salud?
Juan Miguel Barros Dios
Revista de Salud Ambiental , 2011,
Abstract: Radon (Rn222) is a radioactive noble gas whose origin is Radium (Ra226) when it emits an alpha particle (two protons and two neutrons) or a helium nucleus. Rn222 transforms in another radioactive element (Po218) when an alpha particle is emitted. Its carcinogenic effect on the lung was discovered various decades ago, first on uranium miners and later on general population exposed at home to residential radon. The main factor influencing radon concentration in dwellings is the uranium content of the subsoil, since uranium is the first element of the radioactive disintegration chain where radon appears. Geological risk areas of Spain due to their granite and therefore uranium content are Galicia, the Northwest and the West of Spain. Numerous countries of Europe and America have enforced legislation focused to protect population and reduce radon concentration in order to prevent lung cancer appearance. These laws comprise public buildings and private homes. Since the late 80s, alpha radiation generated by radon and its short-life descendents has been classified as carcinogenic agents by the International Agency for Research on Cancer (Lyon, 1988) and the National Research Council (BEIR IV, 1988). El radón (Rn222) es un gas noble radiactivo que procede directamente del radio (Ra226) cuando este emite una partícula alfa (dos protones y dos neutrones) o núcleo de helio, y que a su vez se transforma en otro elemento radiactivo (Po218) al desprenderse de otra partícula alfa. Desde hace varias décadas se conoce su efecto como factor de riesgo del cáncer primario pulmonar, primero en mineros del uranio y posteriormente en la población general expuesta al radón residencial en hogares construidos sobre suelos de rocas ricas en uranio (U238), elemento inicial de la cadena de degradación radiactiva de la que procede el radón. áreas geológicamente constituidas por granitos o pizarras, como son las de gran parte de Galicia y todo el noroeste y oeste de la península ibérica, han sido catalogadas como de alto riesgo de exhalación de radón al interior de edificios y domicilios. En numerosos países de América y Europa existen desde hace varios lustros, políticas de prevención del cáncer pulmonar en aquellas zonas de riesgo basadas en programas de reducción de radón en los domicilios y edificios públicos. Desde finales de los a os 80, la radiación alfa procedente del radón y sus descen- dientes de vida media corta han sido clasificados como agentes cancerígenos por la Internacional Agency of Research on Cancer (Lyon, 1988) y el Nacional Research Council (BEIR IV, 1988), con
Risks related to exposure to radon Riesgos vinculados a la exposición al radón
Juan Miguel Barros Dios
Revista de Salud Ambiental , 2010,
Abstract: They discuss the different scientific evidence that radon and its short half-life descendants are responsible for the appearance of a considerable number of lung cancers among the exposed population in homes and public buildings (occupational exposure). It also draws a small glimpse at the road traveled by this knowledge and acceptance difficult administrations in many countries and, in particular, of Spain, as well as the various investigations that the team do Galego Radon and Radon Laboratory from Galicia, the area of Public Health, University of Santiago de Compostela (USC), are contributing to scientific knowledge. Finally, they appreciate the few legislative initiatives on the problem in Spain. Se comentan las diferentes evidencias científicas de que el radón y sus descendientes de vida media corta son responsables de la aparición de un número no desde able de cánceres de pulmón entre la población expuesta en domicilios y edificios públicos (exposición laboral). Asimismo, se traza una peque a aproximación al camino recorrido por este conocimiento y su difícil aceptación por parte de las diferentes Administraciones de numerosos países y, en concreto, de Espa a, así como las diversas investigaciones que el Grupo Galego do Radon y el Laboratorio de Radón de Galicia, del área de Salud Pública, de la Universidad de Santiago de Compostela, llevan aportando a ese conocimiento científico. Por último, se valoran las escasas iniciativas legislativas sobre el problema en Espa a.
Uso oral do óleo de linha？a (Linum usitatissimum) no tratamento do olhoseco de pacientesportadores da síndrome de Sj？gren
Pinheiro Jr., Manuel Neuzimar;Santos, Procópio Miguel dos;Santos, Regina Candido Ribeiro dos;Barros, Jeison de Nadai;Passos, Luiz Fernando;Cardoso Neto, José;
Arquivos Brasileiros de Oftalmologia , 2007, DOI: 10.1590/S0004-27492007000400016
Abstract: purpose: to evaluate if oral flaxseed oil (linum usitatissimum), which reduces the inflammation in rheumatoid arthritis, may help keratoconjunctivitis sicca's treatment in sj？gren's syndrome patients. methods: in a randomized clinical trial, 38 female patients with rheumatoid arthritis or systemic lupus erithematosus associated with keratoconjunctivitis sicca and sj？gren's syndrome were consecutively selected from patients of the departament of reumatology of the amazonas university hospital. keratoconjunctivitis sicca diagnosis was based on a dry-eye symptom survey score (ocular surface disease index - osdi？), schirmer-i test, fluorescein break-up time, 1% rose bengal staining of ocular surface measured by the van bijsterveld scale. all patients had ocular surface inflammation evaluated and quantified by conjunctival impression cytology, before and after the study. the subjects were divided into three groups with 13 (group i), 12 (group ii) and 13 (group iii) patients. group i received flaxseed oil capsules with a final 1 g/day dosis, group ii flaxseed oil capsules with a final 2 g/day dosis and group iii - controls - placebo, for 180 days. results: comparing the results at the beginning and at the end of the treatment, statistically significant changes (p<0.05) in symptoms (osdi？), ocular surface inflammation quantified by conjunctival impression cytology, schirmer-i test and fluorescein break-up time occurred in groups i e ii when compared to controls. conclusions: therapy with oral flaxseed oil capsules 1 or 2 g/day reduces ocular surface inflammation and ameliorates the symptoms of keratoconjunctivitis sicca in sj？gren's syndrome patients. long-term studies are needed to confirm the role of this therapy for keratoconjunctivitis sicca in sj？gren's syndrome.
Estrutura e padr？o espacial de Tacinga palmadora (Britton & Rose) N.P.Taylor & Stuppy (Cactaceae) em vegeta？？o de caatinga conservada
Alberício Pereira de Andrade,Alex da Silva Barbosa,José Nailson Barros Santos,Miguel Avelino Barbosa Neto,ROBSON LUIS SILVA DE MEDEIROS
- , 2017, DOI: http://dx.doi.org/10.17058/cp.v29i2.9404
Abstract: A família Cactaceae compreende a segunda maior família botanica endêmica das Américas. O objetivo do trabalho foi descrever a distribui？？o espacial de T. palmadora e obter subsídios sobre o comportamento ecológico e estrutural da espécie numa área de caatinga conservada. Para a avalia？？o quantitativa da popula？？o foi utilizado o método de parcelas contíguas, que foram divididas em 100 parcelas de 10m x 10m. Para verificar o padr？o de distribui？？o da espécie na área foram utilizados mapas de distribui？？o espacial, construídos através de sistema de coordenadas SURFER？. A popula？？o foi estimada em 1.883 indivíduos ha -1, obtendo-se uma alta densidade absoluta e frequência relativa de 100% nas parcelas experimentais. Os espécimes encontram-se uniformemente distribuídos na área amostral, sem a presen？a de grandes aglomerados. Em aproximadamente 43,5% da área foram amostrados até 10 indivíduos por unidade amostral. A utiliza？？o dos mapas foi capaz de caracterizar a estrutura vertical e o modo de distribui？？o da popula？？o na área, demonstrando aleatoriedade no padr？o de distribui？？o espacial. A popula？？o estudada demonstra estabilidade o que permite predizer que a espécie terá boa representatividade e ausência de problemas futuros. A T. palmadora tende a apresentar distribui？？o uniforme e elevada abundancia em áreas de caatinga conservada
第1页/共94035条
每页显示 条


Home
Copyright © 2008-2020 Open Access Library. All rights reserved.