Comparative study of the influence of minerals in gas sorption isotherms of three coals of similar rank

This investigation compares the gas adsorption behaviour and capacity of three bituminous coals from South Africa, of similar rank, by assessing the characteristics of the raw coal, as well as the resulting float and sink fractions (at 1.80 cm3/g) obtained by density separation of crushed coal samples. Calculations were also made to obtain the raw coal gas storage capacity from the weighted contribution of both float and sink fractions results, thereby permitting comparison with the analysed results of the raw coal. The study demonstrated that the clean fraction of a coal has the highest capacity to retain gas in the sorbed state, followed by raw coal, and lastly the sink fraction, and re–confirmed previous investigations that showed minerals to be inhibitors of gas adsorption and retention

Interlaboratory comparisons of petrography of liquefaction residues from three Argonne Premium coals

Three Argonne Premium coal samples, the Beulah-Zap lignite (North Dakota), the high volatile A bituminous Stockton (West Virginia), and the low volatile Pocahontas No. 3 (Virginia), were ground to three initial sizes: -20 mesh, -100 mesh, and "micronized". The samples were each subjected to liquefaction at 673 K for 30 min at a 2:1 tetralin :coal ratio and in an H 2 atmosphere at 13.79 MPa (~ 2000 psi). Polished pellets of the unconverted residues were circulated to three laboratories for a study designed to determine, albeit on a limited scale, the interlaboratory consistency in constituent identification and the problem areas in maceral/neo-maceral/mineral recognition. Within broad categories, the agreement for the Beulah-Zap and Pocahontas No. 3 residues is good. The high volatile A bituminous Stockton coal was the most plastic and most altered, resulting in a residue lending itself to more subjective interpretations. The biggest discrepancy between the laboratories is in the distinction of granular residue and mineral matter and in the transitions between "partially reacted macerals" and "vitroplast" and between "vitroplast" and "granular residue". The initial size of the feed coal appears to influence the recognition of material in the residue

Interlaboratory comparisons of petrography of liquefaction residues from three Argonne Premium coals

Three Argonne Premium coal samples, the Beulah-Zap lignite (North Dakota), the high volatile A bituminous Stockton (West Virginia), and the low volatile Pocahontas No. 3 (Virginia), were ground to three initial sizes: -20 mesh, -100 mesh, and "micronized". The samples were each subjected to liquefaction at 673 K for 30 min at a 2:1 tetralin :coal ratio and in an H 2 atmosphere at 13.79 MPa (~ 2000 psi). Polished pellets of the unconverted residues were circulated to three laboratories for a study designed to determine, albeit on a limited scale, the interlaboratory consistency in constituent identification and the problem areas in maceral/neo-maceral/mineral recognition. Within broad categories, the agreement for the Beulah-Zap and Pocahontas No. 3 residues is good. The high volatile A bituminous Stockton coal was the most plastic and most altered, resulting in a residue lending itself to more subjective interpretations. The biggest discrepancy between the laboratories is in the distinction of granular residue and mineral matter and in the transitions between "partially reacted macerals" and "vitroplast" and between "vitroplast" and "granular residue". The initial size of the feed coal appears to influence the recognition of material in the residue

Soroprevalência da Toxoplasmose em ovinos no Estado da Paraíba.

Resumo: Objetivou-se com este estudo avaliar a soroprevalência da Toxoplasmose em ovinos de duas mesorregiões do estado da Paraíba: Borborema e Sertão Paraibano. Cada uma delas foi representada por quatro municípios, nos quais foram coletadas amostras de sangue de 459 ovinos em 24 propriedades. A análise sorológica foi realizada através da técnica de ELISA, sendo avaliadas, em média, 10 amostras de soro por propriedade. Observou-se soropositividade em 15,2% (36/237) dos animais e 70,8% (17/24) das propriedades avaliadas em todo o Estado. Na mesorregião da Borborema, 18% (25/137) dos animais apresentaram soropositividade para Toxoplasmose ovina, com 78% (11/14) das propriedades infectadas. Já no Sertão Paraibano, 11% (11/100) dos animais foram soropositivos e 60% das propriedades estavam infectadas. Tais resultados são indícios de que a enfermidade pode estar presente nos rebanhos, atuando como um fator determinante para a diminuição da produtividade animal. A implementação de medidas de controle torna-se necessária para evitar a disseminação da enfermidade no Estado, considerando que a Toxoplasmose também atua como um problema de saúde pública. Abstract: The aim of this study was to determine the seroprevalence of Toxoplasmosis in sheep belonged to two mesoregions of Paraíba State: Borborema and Sertão Paraibano, each one represented by four different municipalities. Blood samples were collected from 459 sheep of 24 farms. The serological analysis was performed by ELISA, considering 10 samples per farm, approximately. It was detected seropositivity in 15,2% (36/237) of animals and 70,8% (17/24) of properties on the whole State. In Borborema, 18% (25/137) of animals were seropositive and 78% (11/14) of properties were infected. In Sertão Paraibano, 11% of animals were seropositive and 60% of properties were infected for Toxoplasmosis. Those results indicate the disease is probably present in the flocks and it can be a determinant fact to decrease animal productivity. The sanitary measures implementation become necessary in order to avoid Toxoplasmosis dissemination on the flocks, considering it is also considered a public health problem