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Search Results: 1 - 10 of 350176 matches for " Brivaldo G. de; "
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Variabilidade espacial de atributos físicos em solos de vale aluvial no semiárido de Pernambuco Spatial variability of physical attributes of soil in alluvial valley of semiarid region of Pernambuco state
Karla S. Santos,Abelardo A. A. Montenegro,Brivaldo G. de Almeida,Suzana M. G. L. Montenegro
Revista Brasileira de Engenharia Agrícola e Ambiental , 2012, DOI: 10.1590/s1415-43662012000800003
Abstract: As características físicas e hidráulicas do solo se constituem em condicionantes a planos de manejo agrícola. Objetivou-se avaliar atributos físicos em solos de um vale aluvial e sua variabilidade, no semiárido do Estado de Pernambuco, na bacia hidrográfica do Rio Ipanema. Técnicas estatísticas e geoestatísticas foram utilizadas a fim de se investigar o grau de dependência e a variabilidade espacial dos atributos, em lotes de agricultura familiar. O coeficiente de varia o apresentou-se alto para a condutividade hidráulica do solo e médio para a resistência à penetra o de raízes e para as fra es granulométricas areia, argila e silte. Tal coeficiente foi baixo para a densidade do solo e de partículas e porosidade total. Foram investigadas as estruturas de dependência espacial para as variáveis estudadas, encontrando-se alcances variando de 135 m para a condutividade hidráulica a 465 m para o conteúdo de silte. Mapa de isolinhas foi elaborado por krigagem representando a variabilidade espacial da condutividade hidráulica, com moderado grau de dependência espacial. As fra es granulométricas areia total e silte (%) também apresentaram grau de dependência espacial moderado. A resistência à penetra o, densidade do solo e de partículas, n o apresentaram dependência espacial na escala de investiga o adotada. Foi possível identificar regi es de maior aptid o agrícola verificando-se, através do mapeamento, que os solos francos tendem a apresentar elevada resistência à penetra o e baixa condutividade hidráulica. Soil physical and hydraulic characteristics are relevant for agricultural management, particularly at irrigation districts. The objective of this study was to evaluate the spatial variability of physical attributes of soil in an alluvial valley in the semiarid region of Pernambuco State, at the Ipanema River Watershed. Statistical techniques and geostatistics were applied to observe the degree of dependence and the spatial variability of soil physical properties, in plots adopted for communal agriculture. The coefficient of variation for the hydraulic conductivity was high, medium for soil resistance to root penetration and for sand, clay and silt. For bulk density, particle density and porosity, however, such coefficient was low. Spatial dependence structures were investigated, with ranges spanning from 135 m, for soil hydraulic conductivity, to 465 m, for silt content. Contour map was produced by kriging interpolation, representing the spatial variability of hydraulic conductivity, which showed moderate spatial dependence. Resistance to root penetr
Compara o de métodos de extra o da solu o do solo Comparison of methods for extracting soil solution
Edivan R. de Souza,Hidelblandi F. de Melo,Brivaldo G. de Almeida,Diego V. M. de Melo
Revista Brasileira de Engenharia Agrícola e Ambiental , 2013,
Abstract: A composi o i nica da solu o do solo é de grande relevancia para o monitoramento da disponibilidade de nutrientes e manejo da aduba o tal como, também, processos de contamina o ambiental. Assim, métodos mais viáveis que estimem a composi o i nica desta solu o, s o bem aceitos na literatura. Esta pesquisa objetiva avaliar o desempenho de métodos de extra o da solu o do solo como: via pasta de satura o, extratores munidos de cápsulas porosas e rela es solo:água de 1:2; 1:5 e 1:10, com e sem processo de filtragem. Utilizaram-se amostras de Neossolo Flúvico em colunas de PVC e solu es saturantes correspondentes a 0; 20; 30; 40; 50; 60; 70; 80; 90; 100; 110 e 120 mmol c L-1 de NaCl, em delineamento em blocos ao acaso com quatro repeti es. Os extratores munidos de cápsulas porosas apresentam-se como alternativa viável para extra o da solu o do solo e monitoramento da condutividade elétrica, do potencial osmótico e composi o i nica. Os extratos aquosos em diferentes rela es solo:água apresentam potencial de uso para extra o e posterior caracteriza o da fase aquosa do solo. O processo de filtragem pode ser descartado quando o intuito é a determina o somente da condutividade elétrica. The ionic composition of the soil solution is of great importance for monitoring the availability of nutrients and fertilizer management, as well as processes of environmental contamination. Thus, the most viable methods to estimate the composition of the soil solution are well accepted in the literature. This study aims to evaluate the performance of the extraction methods by saturation paste, porous extractor cups and soil:water relations of 1:2, 1:5 and 1:10, with and without filtering process. Samples of Fluvic Neossol were used in PVC columns and saturated with solutions corresponding to 0, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110 and 120 mmol c L-1 NaCl, in randomized block design with four replications. The extractors with porous cup are indicated to extract the soil solution for monitoring the electrical conductivity, osmotic potential and ionic composition. The aqueous extract in different soil:water ratio has a potential use for the extraction and subsequent characterization of the aqueous phase of soil. The filtering process can be discarded when the intention is only to determine the electrical conductivity.
Dinamica de íons em solo salino-sódico sob fitorremedia o com Atriplex nummularia e aplica o de gesso Dynamics of ions in saline-sodic soil under phytoremediation with Atriplex nummularia and gypsum applications
Monaliza A. dos Santos,Maria B. G. dos S. Freire,Brivaldo G. de Almeida,Cíntia M. T. Lins
Revista Brasileira de Engenharia Agrícola e Ambiental , 2013,
Abstract: Desenvolveu-se este trabalho em um Cambissolo salino sódico do Perímetro Irrigado Cachoeira II, Serra Talhada, PE, com o objetivo de avaliar a dinamica de cátions e anions básicos em um solo salino sódico submetido a fitorremedia o com Atriplex nummularia e corre o com aplica o de gesso. Realizaram-se amostragens semestrais com quatro coletas de solo (0, 6, 12 e 18 meses). O delineamento experimental utilizado foi de blocos ao acaso avaliando-se quatro tratamentos: controle (sem nenhum manejo do solo), corre o química com gesso (sem cultivo) e dois com cultivo de Atriplex nummularia Lindl (espa amentos 1 x 1 m e 2 x 2 m), com quatro repeti es. Os resultados das análises do solo revelaram a contribui o da aplica o de gesso, especialmente do cultivo de plantas de atriplex na redu o dos teores de sais no solo. The study was conducted in a saline-sodic Inceptisol from the Cachoeira II Irrigation Perimeter, Serra Talhada (PE), with the objective of evaluating the dynamics of basic cations and anions in a saline-sodic soil subjected to phytoremediation with Atriplex nummularia and correction with application of gypsum. Samples were taken every six months, at four times (0, 6, 12 and 18 months). The experimental design was in randomized blocks, the four Treatments evaluated were: control (without any management practice), chemical correction with gypsum (no crop) and two Atriplex nummularia cultivation (1 x 1 m and 2 x 2 m plant spacing), with four replications. The results of soil analysis revealed the contribution of gypsum application and especially the cultivation of Atriplex plants in reducing the levels of salts in the soil.
Condicionadores químicos e organicos na recupera??o de solo salino-sódico em casa de vegeta??o
Miranda, Marcelo A.;Oliveira, Emanoel E. M. de;Santos, Karen C. F. dos;Freire, Maria B. G. dos S.;Almeida, Brivaldo G. de;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2011, DOI: 10.1590/S1415-43662011000500008
Abstract: the salinization is degrading brazilian semi-arid soils, which need to be reclaimed for agricultural utilization. this work aimed to evaluate use of organic and chemical amendments in a fluvic entisol having saline-sodic properties in pernambuco's semi-arid region. soil experiment was conducted in soil columns, with 10 treatments: sheep manure, cow manure, gypsum, synthetic polymer in six concentrations and the control, in randomized block design. the columns were submitted to leaching during 70 days, being analyzed the leachates collected at 7 and 70 days and the soil after leaching. in leachates, the ph, ec and concentration of na+, k+ and cl- were determined; in the saturation extract, ph and ec were measured, and na+ concentration in saturation extract, and exchangeable na+ and cation exchange capacity (cec) were determined to calculate exchangeable sodium percentage (esp). soil physico-hydric variables were also determined. the data obtained were submitted to variance analysis and to scott knott test at 0,05 level of probability. the treatments, especially manures, gypsum and polymer at smaller concentration decreased ec, esp and soluble na+, increasing hydraulic conductivity of the soil.
Valor prognóstico da ecocardiografia sob estresse com dipiridamol em mulheres
Almeida, Maria Celita de;Markman Filho, Brivaldo;
Arquivos Brasileiros de Cardiologia , 2011, DOI: 10.1590/S0066-782X2010005000156
Abstract: background: stress echocardiography is an important diagnostic and prognostic tool in ischemic heart disease. objective: to evaluate the role of dipyridamole stress echocardiography (dse) in the investigation of myocardial ischemia in women and its ability to predict combined events (cardiovascular death, acute myocardial infarction [ami], unstable angina, coronary artery bypass grafting [surgery or percutaneous intervention] at an average follow-up of 16 months. methods: a prospective study using the protocol of dipyridamole at 0.84 mg in 10 minutes, associated with atropine (0.25 mg/min up to 1.0 mg). results: this study evaluated 147 women. dse was positive in 14 patients (9.5%), negative in 128 (87.1%) and inconclusive in 5 (3.4%). events occurred in 8 patients, 7 had positive dse. the other 138 did not present any events. our of these, 128 had negative dse. the sensitivity, specificity, accuracy, the positive and negative predictive values of the test before the events were respectively: 83%, 95%, 94%, 42% and 99%. the event-free survival for patients with negative dse was 99.2% compared with 58% for positive dse (p < 0.001). univariate analysis identified the dse result, basal electrocardiogram (ecg), lv ejection fraction, dyslipidemia, wall motion score index at rest and peak, history of ami, coronary artery bypass grafting, as prognostic predictors related to outcomes. the results of dse and ecg remained significantly associated with outcomes in the multivariate analysis (p < 0.001). conclusion: the baseline ecg and positive dse were independent variables for the occurrence of outcomes. the dse showed excellent negative predictive value, confirming its usefulness in evaluating prognosis in such patients.
Angina pré-infarto na evolu??o intra-hospitalar de pacientes idosos com infarto agudo do miocárdio
Shian, Chiu Wen;Lima, Sandro Gon?alves de;Markman Filho, Brivaldo;
Arquivos Brasileiros de Cardiologia , 2007, DOI: 10.1590/S0066-782X2007001800004
Abstract: background: preinfarction angina (pia) may be a marker of ischemic preconditioning. a decrease in infarct size, ventricular remodeling, congestive heart failure, cardiogenic shock or death was demonstrated in the presence of preinfarction angina. these findings were more evident in adults, but not in the elderly. objective: to assess the relationship between pia and the clinical course of elderly patients with acute myocardial infarction (ami). methods: this was a case-series study with a comparison group. a total of 36 patients with st-segment elevation ami were included in the study and divided into two groups: group a (21 patients with pia) and group b (15 patients without pia). results: mean age of the study population was 70.5 years, and there was a predominance of males (73%). mean body mass index was 25.3 kg/m2. hypertension was present in 77.8%, diabetes in 27.8% and dyslipidemia in 32.4%. type-a chest pain was reported by 71.4% of patients, and the majority of them (72.2%) were in killip class i. clinical endpoints for groups a and b were as follows: postinfarction angina 9.5% versus 20%, p = 0.630; heart failure 23.8% versus 13.3%, p = 0.674; urgent revascularization 4.8% versus 6.7%, p = 1; and cardiac arrhythmia 0% versus 6.7%, p = 0.417. there was no case of reinfarction, cardiogenic shock or death within 30 days of follow up in either group. conclusion: in this case series, preinfarction angina was not associated with better clinical course in elderly patients with ami.
Influência dos Direcionadores do Uso da TI na Governan a de TI The Influence of Use Drivers in it Governance Influencia de los Gestores del Uso de la TI en la Gobernanza de TI
SILVA, Brivaldo André Marinho da,MORAES, Gustavo Hermínio Salati Marcondes de
Revista Brasileira de Gest?o de Negócios , 2011,
Abstract: RESUMO O presente trabalho prop e-se a analisar como as dimens es que tipificam o ambiente organizacional, aqui entendidas como direcionadores do uso de Tecnologia de Informa o (TI), influenciam na estrutura o de sua governan a. Para tanto, o quadro teórico apoiou-se nas rela es das dimens es do uso da TI por meio de direcionadores de mercado, organizacional, do indivíduo e de TI, bem como na vis o de sua governan a, baseada em estágios dos processos de decis o de TI, mapeando-os nas principais decis es críticas, que envolvem seus princípios, arquitetura, infraestrutura, investimentos e prioriza o, bem como aplica es de negócio. O estudo prop e um modelo teórico resultante da revis o da literatura específica que, por meio da estratégia de estudo de caso, foi aplicado em entrevistas com os principais tomadores de decis o da estrutura de governan a de uma institui o de educa o profissional, atuante em nível nacional, somado às informa es baseadas em registros internos e observa o n o participativa. Obteve-se que as características de investimentos em TI influenciam positivamente as principais decis es sobre sua governan a, por meio dos direcionadores de uso que envolvem a institui o e que est o presentes nos fatores externos que impactam as principais decis es críticas da área, influenciando-as, exceto às relacionadas aos princípios de TI. Verificou-se também que o contexto interno n o influencia diretamente todos os aspectos das decis es sobre a governan a. Por fim, percebeu-se que a TI n o é vista como elemento capaz de estruturar os arquétipos de governan a pelo seu uso, ficando definidos pela hierarquia organizacional da institui o. ABSTRACT This study aims to examine how the dimensions that typify the organizational environment, here understood as drivers of the use of Information Technology (IT), influence in structuring their governance. So, the theoretical framework has relied on the relations of the IT dimensions use by market drivers, organizational, individual and IT, and in view of its governance, based on stages of decision-making IT, mapping them in the main critical decisions involving its principles, architecture, infrastructure, investment and prioritization, as well as business applications. The study has proposed a theoretical model resulting from the review of specific literature that by means of case study strategy it was applied through interviews with key decision makers of the governance structure of an institution of professional education active in the national level, coupled information based on internal records and no
Avalia??o cardiológica de pacientes portadores de doen?a renal cr?nica: quais as li??es?
Lordsleem, Andrea;Gueiros, Ana Paula Santana;Gueiros, José Edevanilson de Barros;Markman Filho, Brivaldo;Victor, Edgar Guimar?es;
Jornal Brasileiro de Nefrologia , 2012, DOI: 10.1590/S0101-28002012000100002
Abstract: introduction: patients with chronic kidney disease (ckd) experiment a synergistic effect of the traditional and the emerging uremia-related risk factors for atherosclerosis. objective: draw the epidemiologic profile of a group of ckd patients who underwent cardiac evaluation. methods: symptomatic patients, patients with ischemia on myocardial scintigraphy and/or systolic dysfunction on echocardiography, patients older than 50 years and diabetes mellitus (dm) as a cause of ckd, and those with two or more risk factors underwent coronary angiography. asymptomatic, non-diabetic patients and patients with no risk factors were investigated with echocardiography. those with a single risk factor were investigated with echocardiography and scintigraphy. results: 46 patients (58.7% men) were enrolled. their mean age was 50.7 ± 11.7 years. 91.3% were on dialysis, for 61.96 ± 55.1 months. hypertension was the cause of ckd in 56.5%. of the 28 patients (60.9%) who underwent angiography, 53.6% had coronary artery disease (cad). the patients were divided into three groups: those with cad (a), those without cad (b) and those who didn't undergo coronary angiography (c). a significant difference occurred only between groups b and c, as regards an abnormal abi (p = 0.026), with no abi abnormality in group c, and as regards the mean age, which was higher in group b (p = 0.045). in group a, 53.3% of the patients were in the preoperative stage of parathyroidectomy. conclusion: this study confirmed the high rate of cardiovascular disorders, including cad, in patients with ckd, especially those on dialysis.
Desenvolvimento de um consolid?metro pneumático: modelagem da compacta??o, penetrometria e resistência tênsil de agregados de solo
Figueiredo, Getulio Coutinho;Silva, Alvaro Pires da;Tormena, Cássio Antonio;Giarola, Neyde Fabíola Balarezo;Moraes, Sergio Oliveira;Almeida, Brivaldo Gomes de;
Revista Brasileira de Ciência do Solo , 2011, DOI: 10.1590/S0100-06832011000200009
Abstract: soil compaction is one of the processes responsible for soil physical degradation that may result in the loss of sustainability of agricultural production. therefore, it is important to have instrumental strategies to quantify soil physical properties that are influenced by soil compression and used to assess soil quality. the objectives of this study were to: (i) develop an inexpensive pneumatic consolidometer, (ii) evaluate its functionality by the study of the compressive behaviour of a sandy clay rhodic hapludox under no-tillage, (iii) evaluate the potential use of pneumatic propulsion to determine penetration resistance (pr) and tensile strength of aggregates (ts) using the proposed consolidometer. compression curves based on undisturbed soil sampled in and between rows under black oat were used to evaluate the soil compressive behaviour. uniaxial compression tests were performed in these samples at a soil water content corresponding to a matric potential of -10 kpa and used to determine the compression index (ci) and preconsolidation pressure (σp) and their correlations with other soil physical properties. pr of undisturbed samples of a sandy loam soil under citrus was determined. aggregates from two ultisols were used to determine ts in a hardsetting and a non-hardsetting horizons. results showed that soil bulk density before the uniaxial compression test was higher (p < 0.05) in-between the black oat rows. the compression curve was sensitive to differences in soil structure between sampling positions, and σp and ci indicated, respectively, higher load support and less susceptibility to compaction (p < 0.05) in-between the black oat rows. the use of pneumatic propulsion did not influence the results of pr and ts. therefore, the soil compression curve, pr and ts can be determined with the equipment developed in this study.
Improvement of a testing apparatus for dynamometry: procedures for penetrometry and influence of strain rate to quantify the tensile strength of soil aggregates
Figueiredo, Getulio Coutinho;Silva, Alvaro Pires da;Tormena, Cássio Antonio;Giarola, Neyde Fabíola Balarezo;Moraes, Sergio Oliveira;Almeida, Brivaldo Gomes de;
Revista Brasileira de Ciência do Solo , 2011, DOI: 10.1590/S0100-06832011000200008
Abstract: soil penetration resistance (pr) and the tensile strength of aggregates (ts) are commonly used to characterize the physical and structural conditions of agricultural soils. this study aimed to assess the functionality of a dynamometry apparatus by linear speed and position control automation of its mobile base to measure pr and ts. the proposed equipment was used for pr measurement in undisturbed samples of a clayey "nitossolo vermelho eutroférrico" (kandiudalfic eutrudox) under rubber trees sampled in two positions (within and between rows). these samples were also used to measure the volumetric soil water content and bulk density, and determine the soil resistance to penetration curve (srpc). the ts was measured in a sandy loam "latossolo vermelho distrófico" (lvd) - typic haplustox - and in a very clayey "nitossolo vermelho distroférrico" (nvdf) - typic paleudalf - under different uses: lvd under "annual crops" and "native forest", nvdf under "annual crops" and "eucalyptus plantation" (> 30 years old). to measure ts, different strain rates were applied using two dynamometry testing devices: a reference machine (0.03 mm s-1), which has been widely used in other studies, and the proposed equipment (1.55 mm s-1). the determination coefficient values of the srpc were high (r2 > 0.9), regardless of the sampling position. mean ts values in lvd and nvdf obtained with the proposed equipment did not differ (p > 0.05) from those of the reference testing apparatus, regardless of land use and soil type. results indicate that pr and ts can be measured faster and accurately by the proposed procedure.
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