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Search Results: 1 - 10 of 8440 matches for " Leonardo Peres; "
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Efeito da variabilidade da precipita??o pluvial e do uso e manejo do solo sobre o escoamento superficial e o aporte de sedimento de uma bacia hidrográfica do Distrito Federal
Chaves, Henrique Marinho Leite;Piau, Leonardo Peres;
Revista Brasileira de Ciência do Solo , 2008, DOI: 10.1590/S0100-06832008000100031
Abstract: the objective of this study was to evaluate the effect of the rainfall variability on the runoff and sediment amount in the pipiripau river basin (a = 235 km2), in the distrito federal, brazil. to represent the climatic variability of the historic precipitation series, 5 years were selected: the moistest, the driest, an average, and 2 years representing the standard deviations from the series (half-wet and half-dry). after the calibration of the model with basin rainfall and runoff data, each rainfall event was simulated in each one of the selected years, and sediment yields were computed using software musle for three different land-use and management situations: (a) the present conditions, with predominantly conventional agriculture in the agricultural areas (pc); (b) the former scenario, where native (cerrado) vegetation existed in the basin (cer); and (c) no-till in the agricultural areas (pd). although the relationship of the mean annual flow rates with the annual rainfall volume was linear, there was an exponential increase in runoff volume and sediment yield with precipitation in all scenarios; the most significant increases were observed for pc, followed by pd and cer. the exponential increase can be explained by the non-linearity of the musle model regarding both precipitation and runoff volume.
Caracterización de un material compuesto por suelo arenoso, ceniza de cáscara de arroz y cal potencialmente útil para su uso en pavimentación
Behak,Leonardo; Peres Nú?ez,Washington;
Revista ingeniería de construcción , 2008, DOI: 10.4067/S0718-50732008000100004
Abstract: an investigation of characterization of a sandy soil mixture with rice husk ash (rha) and lime is presented. their objective was to study the physic and mechanic properties of the mixtures, trying to find an economical solution for low-volume transit pavements and to solve an environmental problem like is the deposition of the residual ash from de husk rice burning. the soil was extract in the nearness of montevideo. a residual rha of the husk incineration, carried out in an oven of the rice parboilization plant localized in treinta y tres city, was used. an analysis of the influence of different mixtures of soil with rha and lime in the mineralogical composition by x-ray difractograms, optimum compaction parameters, cbr, unconfined compression and split tensile strength and durability is made
Caracterización de un material compuesto por suelo arenoso, ceniza de cáscara de arroz y cal potencialmente útil para su uso en pavimentación Characterization of a material comprised of sandy soil, rice husk ash and potentially useful lime in pavements
Leonardo Behak,Washington Peres Nú?ez
Revista ingeniería de construcción , 2008,
Abstract: Se presenta una investigación de caracterización de una mezcla de suelo arenoso con ceniza de cáscara de arroz (CCA) y cal. El objetivo fue estudiar las propiedades físicas y mecánicas de las mezclas, procurando encontrar una solución económica para pavimentos de bajo volumen de tránsito y resolver el problema ambiental de la disposición de la ceniza residual de la quema de la cáscara de arroz. El suelo arenoso fue extraído de las proximidades de Montevideo. Fue utilizada una CCA residual de la incineración de cascara, realizada en un horno de una planta de parboilización de arroz localizada en la Ciudad de Treinta y Tres. Se realiza un análisis de la influencia de diferentes mezclas de suelo con CCA y cal en la composición mineralógica mediante difractogramas de rayos-x, parámetros óptimos de compactación, CBR, resistencia a la compresión inconfinada y a la tracción diametral y durabilidad An investigation of characterization of a sandy soil mixture with rice husk ash (RHA) and lime is presented. Their objective was to study the physic and mechanic properties of the mixtures, trying to find an economical solution for low-volume transit pavements and to solve an environmental problem like is the deposition of the residual ash from de husk rice burning. The soil was extract in the nearness of Montevideo. A residual RHA of the husk incineration, carried out in an oven of the rice parboilization plant localized in Treinta y Tres City, was used. An analysis of the influence of different mixtures of soil with RHA and lime in the mineralogical composition by x-ray difractograms, optimum compaction parameters, CBR, unconfined compression and split tensile strength and durability is made
Porosity study of synthetic sandstones by non-destructive nuclear techniques
Marques, Leonardo Carmezini;Appoloni, Carlos Roberto;Fernandes, Celso Peres;
Materials Research , 2011, DOI: 10.1590/S1516-14392011005000048
Abstract: in this paper nuclear techniques were used to describe the structural characteristics of ceramic samples. these samples were produced mainly with silica to simulate sandstones. three sets of samples with different characteristics were analyzed using gamma ray transmission to obtain point by point porosity and x-ray microtomography to obtain the porosity, for 2d sections and the scanned bulk, as well as the pore size distribution. the transmission results indicated total porosity values of 28.6 (4.5)% for the group of samples called ceramic i and 59.6 (2.1)% for ceramic ii. the samples analyzed by microtomography achieved resolutions of 1.7, 0.6 and 1.3 μm for the ceramic i, ii, and iii samples, respectively. this analysis indicated average porosity values of 27.9 (1.4)% for ceramic i samples and 29.4 (1.2)% for ceramic iii samples.
Comparative Study between Endometrial Resection and Electrocoagulation in Patients with Abnormal Uterine Bleeding  [PDF]
Leonardo Vieira Elias, Daniel Spadoto-Dias, Nilton José Leite, Flávia Neves Bueloni-Dias, Gustavo Filipov Peres, Carlos Roberto Padovani, Rogério Dias
Open Journal of Obstetrics and Gynecology (OJOG) , 2017, DOI: 10.4236/ojog.2017.73033
Abstract: Objective: To compare clinical outcomes between two first-generation endometrial ablation techniques. Design: Prospective comparative coorte. Setting: Tertiary public hospital, university teaching center. Seventy-three patients with abnormal uterine bleeding unresponsive to clinical treatment submitted to endometrial ablation from October 2011 to September 2013. Methods and Main Outcome Measures: Patients were assigned to either monopolar U-shaped electrode resection with rollerball electrocoagulation (group A, n = 36) or rollerball electrocoagulation alone (group B, n = 37). Mean follow-up length was 359 (280 - 751) and 370 days (305 - 766) in groups A and B, respectively. Bleeding pattern, associated symptoms, failure/success rates were assessed 30, 90, 180 and 360 days post-procedure. Findings: Patient characteristics were similar in both groups (P ≥ 0.05). Surgery duration (mean of 48.5 [±12.0] vs. 31.9 [±5.6] min, P < 0.001) and medium distention use (5.700 mL vs. 3.500 mL, P < 0.01) were decreased in group B. Post-ablation clinical improvement was considerable in both groups. Vaginal discharge incidence after the procedure was lower in group B (30.5% vs. 8.1%, P < 0.05). Hysterectomy rate was 9.6%. Overall success rate was 86.1% and 88.1% in groups A and B, respectively. Conclusions: Endometrial ablation using rollerball electrocoagulation alone may be considered safer than resection with rollerball electrocoagulation, which requires shorter surgical time and less distention medium, and is associated with lower postoperative vaginal discharge incidence. Success rate did not statistically differ between groups, but study parameters in absolute values and percents were superior in group B.
Neuroimaging during Trance State: A Contribution to the Study of Dissociation
Julio Fernando Peres, Alexander Moreira-Almeida, Leonardo Caixeta, Frederico Leao, Andrew Newberg
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0049360
Abstract: Despite increasing interest in pathological and non-pathological dissociation, few researchers have focused on the spiritual experiences involving dissociative states such as mediumship, in which an individual (the medium) claims to be in communication with, or under the control of, the mind of a deceased person. Our preliminary study investigated psychography – in which allegedly “the spirit writes through the medium's hand” – for potential associations with specific alterations in cerebral activity. We examined ten healthy psychographers – five less expert mediums and five with substantial experience, ranging from 15 to 47 years of automatic writing and 2 to 18 psychographies per month – using single photon emission computed tomography to scan activity as subjects were writing, in both dissociative trance and non-trance states. The complexity of the original written content they produced was analyzed for each individual and for the sample as a whole. The experienced psychographers showed lower levels of activity in the left culmen, left hippocampus, left inferior occipital gyrus, left anterior cingulate, right superior temporal gyrus and right precentral gyrus during psychography compared to their normal (non-trance) writing. The average complexity scores for psychographed content were higher than those for control writing, for both the whole sample and for experienced mediums. The fact that subjects produced complex content in a trance dissociative state suggests they were not merely relaxed, and relaxation seems an unlikely explanation for the underactivation of brain areas specifically related to the cognitive processing being carried out. This finding deserves further investigation both in terms of replication and explanatory hypotheses.
Identifica??o de ilhas de calor na área urbana de Ilha Solteira - SP através da utiliza??o de geotecnologias
Costa, Douglas F. da;Silva, Hélio R.;Peres, Leonardo de F.;
Engenharia Agrícola , 2010, DOI: 10.1590/S0100-69162010000500019
Abstract: with climate change expected in the coming decades, scientists suggest that one of the consequences is the increase in average temperatures and also the increasing number of hot days, which will enhance the thermal discomfort in the population. therefore, this study aimed to identify the main thermal variations in the urban area of ilha solteira - sp, brazil. the methodology involved the transformation of landsat tm data into values of surface temperature and their comparison to distinct urban land use. the results showed the presence of variations in surface temperatures in the different regions of the municipality. the areas that have higher amount of vegetation, such as the forest area of the zoo and the recreation area, showed surface temperatures between 21 oc and 23 oc. the areas that showed higher temperatures (41 oc to 44 oc) were located in the regions in which occur the largest percentages of classes "buildings" and "paved-building", thus characterizing the phenomenon of heat islands. these results could be used to support urban planning strategies to minimize the effects of thermal discomfort of the areas identified as heat islands.
Avalia??o da exposi??o dos médicos à radia??o em procedimentos hemodinamicos intervencionistas
Silva, Leonardo Peres da;Maurício, Claudia Lúcia de Pinho;Canevaro, Lucía Viviana;Oliveira, Paulo Sérgio;
Radiologia Brasileira , 2008, DOI: 10.1590/S0100-39842008000500010
Abstract: objective: the present study evaluates the dose distribution received by physicians involved in hemodynamic procedures of coronary angiography and coronariography. the influence of some factors such as pulsed or continuous fluoroscopy mode and vein and/or artery access site was investigated. materials and methods: measurements have been performed with lif:mg,ti thermoluminescent dosimeters placed on seven different sites of the practitioners' bodies: hands, left knee, neck, forehead and chest, under and over the lead apron. radiation doses for each procedure were evaluated in physicians who had performed 60 coronariography and 30 angioplasty procedures. the thermoluminescent dosimeters were calibrated in the operational quantity personal dose equivalent, hp(d), at depths of 0.07, 3 and 10 mm. results: the results of the present study demonstrate the significant role played by thyroid protectors and lead aprons for reducing radiation doses received by practitioners. occupational doses in continuous mode fluoroscopy through brachial access were higher than with pulsed mode fluoroscopy through femoral access. conclusion: the present study has demonstrated the necessity of implementing additional protective measures as well as a mechanism of training in radiation protection for physicians involved in interventional cardiological procedures.
Thermal Soliton Correlation Functions in Theories with a Z(N) Symmetry  [PDF]
Leonardo Mondaini
Journal of Modern Physics (JMP) , 2012, DOI: 10.4236/jmp.2012.311221
Abstract: We show that the quantum solitons occurring in theories describing a complex scalar field in (1 + 1)-dimensions with a Z(N) symmetry may be identified with sine-Gordon quantum solitons in the phase of this field. Then using both the Euclidean thermal Green function of the two-dimensional free massless scalar field in coordinate space and its dual, we obtain an explicit series expression for the corresponding solitonic correlation function at finite temperature.
The Rise of Solitons in Sine-Gordon Field Theory: From Jacobi Amplitude to Gudermannian Function  [PDF]
Leonardo Mondaini
Journal of Applied Mathematics and Physics (JAMP) , 2014, DOI: 10.4236/jamp.2014.213141
Abstract: We show how the famous soliton solution of the classical sine-Gordon field theory in (1 + 1)-dimensions may be obtained as a particular case of a solution expressed in terms of the Jacobi amplitude, which is the inverse function of the incomplete elliptic integral of the first kind.
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