Inventário estadual de emissão de gases de efeito estufa no setor agropecuário.

2009

Spectral self-action of THz emission from ionizing two-color laser pulses in gases

The spectrum of terahertz (THz) emission in gases via ionizing two-color femtosecond pulses is analyzed by means of a semi-analytic model and numerical simulations in 1D, 2D and 3D geometries taking into account propagation effects of both pump and THz fields. We show that produced THz signals interact with free electron trajectories and thus significantly influence further THz generation upon propagation, i.e., make the process inherently nonlocal. This self-action contributes to the observed strong spectral broadening of the generated THz field. We show that diffraction of the generated THz radiation is the limiting factor for the co-propagating low frequency amplitudes and thus for the self-action mechanism in 2D and 3D geometries.

Avaliação do impacto de poluentes estrogénicos em peixes

Dissertação de Mestrado, Biologia Marinha, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015

Short Term Outcome of Neonates Born With Abnormal Umbilical Cord Arterial Blood Gases

Background: Umbilical arterial blood gas (UABG) analysis is more objective than other methods for predicting neonatal outcome. Acidemic neonates may be at risk for unfavorable outcome after birth, but all neonates with abnormal arterial blood gas (ABG) analysis do not always have poor outcome. Objectives: This study was carried out to determine the short term outcome of the neonates born with an abnormal ABG. Patients and Methods: In a cohort prospective study 120 high risk mother-neonate pairs were enrolled and UABG was taken immediately after birth. All neonates with an umbilical cord pH less than 7.2 were considered as case group and more than 7.2 as controls. Outcomes like need to resuscitation, admission to newborn services and/or NICU), seizure occurrence, hypoxic ischemic encephalopathy (HIE), delayed initiation of oral feeding and length of hospital stay were recorded and compared between the two groups. P value less than 0.05 was considered as being significant. Results: Comparison of short term outcomes between normal and abnormal ABG groups were as the fallowing: need for advanced resuscitation 4 vs. 0 (P = 0.001), NICU admission 16 vs. 4 (P = 0.001), convulsion 2 vs. 0 (P = 0.496), HIE 17 vs. 4 (P = 0.002), delay to start oral feeding 16 vs. 4 (P = 0.001), mean hospital stay 4 vs. 3 days (P = 0.001). None of the neonates died in study groups. Conclusions: An umbilical cord PH less than 7.2 immediately after birth can be used as a prognostic factor for unfavorable short term outcome in newborns.

Emissões de gases de efeito estufa em área de produção de arroz em função do manejo do solo e da cobertura vegetal.

2015

PARAMETRIC STUDY OF REAXFF SIMULATION PARAMETERS FOR MOLECULAR DYNAMICS MODELING OF REACTIVE CARBON GASES

Abstract The development of innovative carbon-based materials can be greatly facilitated by molecular modeling techniques. Although the Reax Force Field (ReaxFF) can be used to simulate the chemical behavior of carbon-based systems, the simulation settings required for accurate predictions have not been fully explored. Using the ReaxFF, molecular dynamics (MD) simulations are used to simulate the chemical behavior of pure carbon and hydrocarbon reactive gases that are involved in the formation of carbon structures such as graphite, buckyballs, amorphous carbon, and carbon nanotubes. It is determined that the maximum simulation time step that can be used in MD simulations with the ReaxFF is dependent on the simulated temperature and selected parameter set, as are the predicted reaction rates. It is also determined that different carbon-based reactive gases react at different rates, and that the predicted equilibrium structures are generally the same for the different ReaxFF parameter sets, except in the case of the predicted formation of large graphitic structures with the Chenoweth parameter set under specific conditions.

Composting of different agro-food wastes: Effects of the phenolic and lignocellulosic fractions on greenhouse gases emissions

Currently, society faces a number of challenges related to the large amounts of organic wastes generated and accumulated by the increasing expansion of agroindustrial activities1. Most of these wastes are rich in lignocellulosic compounds, which represents a major fraction of all plant biomass (of above 90%), so, its degradation is crucial for global carbon cycle2. These organic wastes may be introduced directly on agriculture sector as soil organic amendment, however, these might contain phytochemicals, such as phenolic compounds which may introduce toxic effects to soil and to beneficial organisms. Transformation and degradation of these renewable organic wastes into composts (COMPOSTING) is a possible solution for these problems and an environmentally friendly processes that allows make use of natural resources efficiently3. The main potential handicap is generation and emission of greenhouse gases such as carbon dioxide (CO2 ), methane (CH4 ) and nitrous oxide (N2O) and another ones which may led serious problems like nitric oxide (NO) and ammonia (NH3) 4. For this reason, quantification of GHG emissions from composting and finding possible relations with the chemical and structural composition of the wastes used is crucial to the development of technologies for mitigating emissions and should help to make decisions concerning waste management.

Contribuição para o ensino da meteorologia e do clima

Numa época em que tanto se fala e escreve sobre Alterações Climáticas torna­ se pertinente elaborar um documento de apoio ao ensino que ajude os professores e alunos a explicar/perceber as complexas interacções do sistema climático. O presente trabalho tem o objectivo de contribuir para uma melhor compreensão dos aspectos físicos elementares que afectam a variabilidade climática e a forma como as diversas actividades desenvolvidas pelo Homem podem desequilibrar o sistema climático. O texto encontra-se amplamente ilustrado, facilitando a sua compreensão, e foram desenvolvidas ferramentas de cálculo em Excel que permitem utilizar as observações recolhidas nas Estações Meteorológicas Automáticas, instaladas nas escolas secundárias aderentes ao projecto PROCURA, para avaliar a difusão e dispersão de uma pluma de poluentes ou para simular o efeito de alterações na concentração de Gases com Efeito de Estufa na temperatura média à superfície. ABSTRACT: At a time when so much is said and written about Climate Changes it becomes relevant to draw up a document to support teaching, helping teachers and students to explain/understand the complex interactions of the climate system. This document aims to contribute to a better understanding of the physical elements that affect climate variability and how the various activities undertaken by humans can disrupt the climate system. The text is amply illustrated, facilitating its understanding, and calculating tools have been developed in Excel to allow the use of observations collected from Automatic Weather Stations, installed in the high schools which joined the project PROCURA, to evaluate the diffusion and dispersion of a plume of pollutants or to simulate the effect of changes in the concentration of Greenhouse Gases on the average temperature at the surface.

Victor Regnault e os gases: medidas de alta precisão e agnosticismo teórico

O objetivo deste artigo é apresentar uma síntese histórica dos estudos de propriedades estáticas de gases reais feitas pelo experimentalista francês Regnault e estabelecer a sua relação com a recepção francesa da teoria cinética dos gases durante a segunda metade do século XIX, notando a sua relevância epistemológica. Com este caso histórico ilustra-se a complexa relação entre a teoria e a experimentação.

Emissões de gases de efeito estufa, resultantes da queima pré-colheita de cana-de-açúcar var.SP83-2847.

2008

Simulação do risco de lixiviação de poluentes orgânicos de lodos.

O objetivo desse trabalho foi simular o risco de lixiviação de trinta e oito poluentes orgânicos presentes em lodos de esgotos provenientes de estações de tratamentos. Para tanto, foi assumido um cultivo hipotético de milho em um solo Latossolo vermelho distrófico, característico de solos de regiões produtoras de milho, no qual foi aplicada uma dose de lodo de esgoto como fertilizante. Lodos de esgotos são ricos em matéria orgânica e micronutrientes úteis na fertilização de solos para a produção de plantas, mas também podem conter poluentes de importância ambiental. A lixiviação dos poluentes foi simulada utilizando-se o modelo CMLS94 e os dados climáticos de mil anos independentes e igualmente prováveis gerados pelo simulador de clima WGEN, a partir de uma seqüência de quatorze anos consecutivos observados e registrados pela Estação Experimental do Instituto Agronômico de Campinas. A análise de risco de lixiviação indicou que os poluentes benzidina > n-nitrosodi-n-propilamina > fenol > 2,4-dinitrofenol > isoforano > nitrobenzeno > p-cresol > o-cresol > m-cresol > 2-clorofenol, nessa ordem, devem ser monitorados em águas subterrâneas de regiões de solos nos quais foram aplicados doses de lodo.

Emissões de gases de efeito estufa, resultantes da queima pré-colheita de cana-de-açúcar var. SP83-2847.

2008

Greenhouse gases of animal agriculture in Brazil: urrent status and perspectives.

2007

Simulação do risco de lixiviação de poluentes orgânicos de lodos.

2008