Shallow gas features and distribution in the Patos Lagoon: a coastal trap for gas-generator sediments

Sedimentos gasosos são muito comuns nos ambientes costeiros em todo o mundo e suas ocorrências são claramente reveladas como anomalias acústicas por diversas ferramentas sísmicas, em diferentes escalas e resoluções. Este artigo apresenta exemplos de anomalias acústicas relacionadas ao gás, em perfis sísmicos (SBP) de alta resolução da Lagoa dos Patos, Sul do Brasil. Os ecogramas mostram anomalias acústicas devidas ao gás, as quais podem apresentar uma morfologia distinta para gás aprisionado no sedimento, percolação ou gás livre na coluna de água. As depressões topográficas pretéritas preenchidas com sedimentos gasosos são relacionadas aos antigos sistemas de drenagem, desenvolvidos na região costeira devido às oscilações do nível do mar durante o Quaternário. Assim, essas ocorrências de gás raso parecem ser controladas pela configuração paleoambiental, arranjo de preenchimento da bacia de sedimentação e condições hidrodinâmicas. Desde o estabelecimento da configuração atual, após o período de nível do mar alto do Holoceno, o interior da lagoa de Patos comporta-se como uma armadilha costeira para sedimentos finos, ricos em matéria orgânica e propícios a formação de gás, margeado por sedimentos mais grossos e sem gás.Gas-charged sediments are very common in coastal environments worldwide, and their occurrence is usually clearly revealed as acoustic anomalies by a number of different seismic tools at differing scales and resolutions. This paper presents examples of gas-related acoustic anomalies in high resolution sub-bottom profiles (SBP) from the Patos Lagoon, Southern Brazil. The echograms show acoustic gas-related anomalies, which can present distinctive morphology for sediment-trapped gas, leaking or free gas in the water column. The paleo-topographic depressions filled with gas-charged sediments are related to former drainage systems developed in the coast in response to Quaternary sea level up and down events. Hence, such shallow gas occurrences seem to be controlled by the previous environmental configuration, the transgressive infilling arrangement of the basin, and the hydrodynamic conditions. Since the establishment of the present configuration, following sea level highstand of the Holocene, the Patos Lagoon interior seems to behave as a coastal trap for fine-grained, organic-rich gas-generator sediments, bordered by coarser gas-free sediments

Elementos Arquiteturais do Substrato da Lagoa dos Patos Revelados por Sísmica de Alta Resolução

A high-resolution seismic survey was performed on the Lagoa dos Patos, southern Brazil. The survey was conducted aboard the research vessel LARUS of the Fundação Universidade Federal do Rio Grande. The seismic profiles were obtained using a 3.5 kilohertz frequency, which provided a rather good penetration depth and resolution of the records. Results of the seismic records allowed the determination and mapping of seismic facies and seismic sequences, as well as related architectural elements, which were identified basically through the configuration patterns of the seismic reflectors. The analysis of the seismic records allowed the identification of the architectural elements that build up the sedimentary pile accumulated in the coastal prism of the State of Rio Grande do Sul, contributing to a better understanding of the geological evolution of the southern Brazilian coastal plain during the Quaternary period.Fil: Weschenfelder, Jair. Universidade Federal do Rio Grande do Sul; BrasilFil: Corrêa, Iran C. S.. Universidade Federal do Rio Grande do Sul; BrasilFil: Aliotta, Salvador. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentin

Thermal comfort for pregnant sows housed in individual and group stalls

Este experimento foi realizado no período compreendido entre 04/01 e 11/03/2005, em uma propriedade de produção industrial de suínos, localizada no município de Elias Fausto, estado de São Paulo. O objetivo da pesquisa consistiu na avaliação de diferentes sistemas de alojamento para matrizes gestantes, verificando-se as influências dos elementos meteorológicos e os aspectos relacionados à qualidade química do ar e seus reflexos no conforto animal na fase de gestação, determinando-se as condições favoráveis ao melhor desempenho animal, com base nas respostas ao ambiente de criação. O estudo foi desenvolvido no setor de gestação, com 24 matrizes primíparas, 12 fêmeas alojadas em baias individuais (T1) e 12 animais em baias coletivas (T2). O trabalho foi dividido em duas etapas: análise bioclimática e análise da qualidade química do ar. O delineamento experimental foi em blocos casualizados, com dois tratamentos e 67 blocos, e as médias comparadas pelo teste de Tukey. As variáveis meteorológicas (T, °C e h, kJ kg-1) apontam o sistema de alojamento em baias coletivas como aquele que permitiu melhor condicionamento térmico natural às matrizes em gestação apresentando valores da ordem de 25,03 °C e 62,02 kJ kg-1. As concentrações dos teores de gases não superaram as concentrações consideradas críticas para as matrizes.The experiment was carried out from January 4 to March 11, 2005 in a farm specialized in industrial production of pork, located in Elias Fausto, São Paulo State. This study evaluated different housing systems for pregnant sows looking at meteorological element influences and aspects of air chemical quality on the animal thermal comfort. The optimal conditions for animal performance improvement were determined by analyzing behavioral data taken in the breeding environment. In the gestation facility 24 gilts were allocated: 12 in individual stalls (T1) and 12 in group housings (T2). This study was divided into two steps: bioclimatic analysis and analysis of the chemical quality of air. An experimental design using randomized blocks with two treatments and 67 blocks was used. Means were compared by the Tukey test. The variables (T, °C e h, kJ kg-1) indicated which confinement system in group-houses was the one that permitted the better natural thermal environment for pregnant gilts with values of 25.03 °C and 62.02 kJ kg-1. In relation to concentration of gases, mean levels did not exceed the concentrations considered limiting for sows

Cis-Dioxido-molybdenum(VI) complexes of tridentate ONO hydrazone Schiff base: Synthesis, characterization, X-ray crystal structure, DFT calculation and catalytic activity

Two new cis-MoO₂ [MoO₂(L)(EtOH)] (1), [MoO₂(L) (Py)] (2) [L: (3-methoxy-2oxidobenzylidene)benzohydrazidato], complexes have been synthesized and fully characterized on the basis of elemental analysis, FT-IR, molar conductivity, ¹H NMR, ¹³C NMR and electronic spectra. The structure of complexes has been accomplished by single crystal X-ray diffraction. All experimental results confirmed that both complexes have an octahedral geometry around the Mo(VI) central atom, which is coordinated by the donor atoms of the dianionic hydrazone ligand, two oxido groups and oxygen/nitrogen atoms of solvent molecules. Computational studies were also performed using DFT calculations at B3LYP/DGDZVP level of theory. Furthermore, their catalytic activities were investigated on the electrophilic reaction of indole with aldehydes in molten tetrabutyl ammonium bromide (TBAB) to obtain bis(indolyl)methane derivatives