Caracterização tecnológica do minério aurífero de Riacho dos Machados - MG para fins de cianetação e estudo da utilização de agentes oxidantes na lixiviação

Este trabalho consistiu na caracterização tecnológica do minério primário de Riacho dos Machados (MG) para fins de seu tratamento por métodos de lixiviação por solução cianetada. O minério foi sujeito às seguintes etapas de estudo: (1) extração do ouro/prata por cianetação, em diferentes frações granulométricas para avaliar o grau de exposição do ouro cianetável, (2) ensaios de bottle roll test da cinética de extração do ouro em minério britado e moído e (3) comparação do desempenho de lixiviação em função do agente oxidante adicionado (ar, oxigênio e peróxido de hidrogênio) em condições ambiente. Os ensaios foram realizados em escala de laboratório. A amostra de minério estudada apresentou teores na faixa de 7 ppm de ouro e 2 ppm de prata. Os metais preciosos encontram-se na forma de partículas microscópicas e submicroscópicas. A extração máxima de ouro obtida foi de 90%. O uso de oxigênio e peróxido de hidrogênio adicionados à polpa representou um incremento apreciável na velocidade de dissolução do ouro.This work evaluates the behavior in the cyanide leaching of primary gold ore from Riacho dos Machados (MG), central Brazil. This deposit belongs to Cia. Vale do Rio Doce. It was studied: (1) the extraction of gold/silver in different ore size to determine the liberation of precious metais, (2) the rate of extraction in bottle roll test with crushed and ground ores and (3) the effect of oxidants addition (air, oxigen and hydrogen peroxid) on gold/silver leaching at atmosphere pressure. The experiments were carried out in laboratory scale. The ROM ore had about 7 ppm of gold and 2 ppm of silver. The gold/silver particles had microscopic and submicroscopic sizes and in the leaching of ore of gold extraction was obtained 90%. The use of oxygen and hydrogen peroxide mixed with air increase the rate of gold dissolution

COMMITMENT AND LOYALTY IN BANKING SERVICES: TWO CONSTRUCTS OR TWO DIMENSIONS OF THE SAME CONSTRUCT?

There are a lot of papers in business-to-consumer relationship literature that applies Loyalty and Commitment as independent constructs, and in others they are used as the same construct. Comparing their conceptual definitions, there is no convergence about the discrimination between them. Therefore, this paper discusses and verifies with empirical data the relation between Loyalty and Commitment in a contractual service relationship context. As a result, Commitment could be considered as a dimension of Loyalty (as an attitudinal loyalty).Em diversos artigos que procuram mensurar os resultados de um relacionamento com o consumidor, os construtos da Lealdade e do Comprometimento são utilizados de forma independente e, em outros casos, indiscriminadamente. Mesmo nas suas definições conceituais, não existe concordância sobre a discriminação entre eles. Assim, este artigo visa discutir e verificar com dados empíricos a relação entre os conceitos do Comprometimento e da Lealdade em um processo de relacionamento com prestação de um serviço contínuo. Em seus resultados, mostra-se que o Comprometimento pode ser considerado uma dimensão da Lealdade (Lealdade Atitudinal)

Classificação das imagens de satélite utilizadas no Cadastro Ambiental Rural (CAR): estudo de caso no município de Parobé - RS

Introduction: Based on the historical suppression of native vegetation to another type of land use (agriculture, livestock, mining) and with the advancement of geotechnology, it became increasingly important to rationally plan the occupation and the territorial use. In this context comes the CAR (Rural Environmental Registration) as a promotion of environmental sustainability mechanisms, sanctioned by the New Brazilian Forest Code (Law 12,651 / 2012). Objetive: In this way, this research has the objective of evaluating how the images used for the generation of the CAR homologation base, referring to the years 2008 and 2011, are effective for environmental mapping, analyzing the municipality of Parobé, in Rio Grande do Sul. Methodology: The images of temporal analysis, using the district of Parobé as a case of study, were divided into two groups. The first compared images of the years 2008 and 2011 (as sanctioned in the Forest Code) and the second group analyzed images from 1985 and 2015 (for which there was a greater coverage for comparison purposes). Results: The results showed that between the years of 2008 and 2011 the disturbed areas of Parobé decreased by 1%, as the areas with native vegetation grew by 11% in this period. Between 1985 and 2015 there was a decrease of 6% in disturbed areas and areas of native vegetation remained in both years occupying 21% of the city. The CAR is of extreme importance for the society because it facilitates the mapping of rural properties, helps to control deforestation and the location of legal reserves, in addition to encouraging economic growth through legal activities within the property. The district of Parobé is ahead of the national average over the quality of environmental planning. Conclusions: This result was expressed by rates of deforestation of native vegetation near zero over 30 years.Introducción: A partir de la supresión histórica de la vegetación nativa para otro tipo de uso del suelo (agricultura, ganadería, minería) y con el avance de la geotecnología, se hizo cada vez más importante planificar racionalmente la ocupación y el uso territorial. En este contexto surge el CAR (Registro Ambiental Rural) como mecanismo de promoción de la sustentabilidad ambiental, sancionado por el Nuevo Código Forestal Brasileño (Ley 12.651 / 2012). Objetivo­: De esta manera, esta investigación tiene como objetivo evaluar cómo las imágenes utilizadas para la generación de la base de homologación CAR, en referencia a los años 2008 y 2011, son eficaces para la cartografía ambiental, analizando el municipio de Parobé, en Rio Grande do Sul. Metodología: Las imágenes de análisis temporal, utilizando el distrito de Parobé como caso de estudio, se dividieron en dos grupos. El primero comparó imágenes de los años 2008 y 2011 (como sancionado en el Código Forestal) y el segundo grupo analizó imágenes de 1985 y 2015 (para las cuales había una mayor cobertura para fines de comparación). Resultados: Los resultados mostraron que entre los años de 2008 y 2011 las áreas perturbadas de Parobé disminuyeron un 1%, ya que las áreas con vegetación nativa crecieron un 11% en este período. Entre 1985 y 2015 hubo una disminución del 6% en las áreas perturbadas y las áreas de vegetación nativa se mantuvieron en ambos años ocupando el 21% de la ciudad. Conclusiones: La CAR es de extrema importancia para la sociedad, pues facilita el mapeo de las propiedades rurales, ayuda a controlar la deforestación y de vegetación autóctona cercana a cero en 30 años.Introdução: A histórica supressão da vegetação nativa visando a implantação de usos econômicos da terra (agricultura, pecuária, mineração) e o avanço das geotecnologias, tornou cada vez mais importante planejar racionalmente a ocupação e o uso territorial. É nesse contexto que surge o CAR (Cadastro Ambiental Rural) como um mecanismo de promoção da sustentabilidade ambiental, sancionado pelo Novo Código Florestal Brasileiro (Lei 12.651/2012). Objeto: Dessa forma, esta pesquisa tem por objetivo avaliar de que forma as imagens utilizadas para a geração da base de homologação do CAR, referentes aos anos 2008 e 2011, são eficazes para o mapeamento ambiental, analisando o município de Parobé, no Rio Grande do Sul. Metodologia: As análises temporais das imagens, usando o município de Parobé como estudo de caso, foram divididas em dois grupos: o primeiro comparou imagens dos anos de 2008 e 2011 (conforme sancionado no código florestal) e o segundo grupo analisou imagens dos anos de 1985 e 2015 (para que houvesse uma maior abrangência temporal para comparação dos resultados). Resultado: Os resultados obtidos demonstram que entre os anos de 2008 e 2011 as áreas antropizadas de Parobé diminuíram 1%, à medida que as áreas com vegetação nativa tiveram um crescimento de 11% nesse período. No período entre 1985 e 2015, houve uma diminuição de 6% nas áreas antropizadas e as áreas de vegetação nativa se mantiveram em ambos os anos ocupando 21% do município. O CAR é de extrema importância para a sociedade, pois facilita o mapeamento das propriedades rurais, auxilia no controle do desmatamento e da localização das reservas legais, além de incentivar o crescimento econômico através das atividades legais dentro da propriedade. O município de Parobé está à frente da média brasileira em relação à qualidade do planejamento ambiental. Conclusões: Esse resultado é expresso pelos índices de desmatamento da vegetação nativa quase nulos ao longo de 30 anos

Evaluation of Soil Re-mineralizer from By-Product of Volcanic Rock Mining: Experimental Proof Using Black Oats and Maize Crops

This study was focused on physical, petrographical, mineralogical, and chemical characterization of a volcanic-rock mining by-product (dacite rock), as well as on greenhouse experiment with black oats and maize crops to evaluate the potential use of the by-product as soil re-mineralizer. The by-product sample was obtained from a quarry in the Nova Prata mining district in southern Brazil. The particle size distribution of the by-product and soil was determined by sieving. Dacite rock petrographic description was performed on a polished thin section by optical microscopy. The soil and dacite rock mineralogical phases were identified by X-ray diffraction. The by-product and soil chemical composition was determined by X-ray fluorescence. Inductively coupled plasma mass spectrometry was performed to determine potentially toxic elements, As, Cd, Hg and Pb in by-product. Additional chemical compositions of the by-product and soil were analyzed using a scanning electron microscope equipped with an energy dispersive X-ray detector. Black oats and, sequentially maize, crops were cultivated in a typical Hapludox soil treated with the by-product in a greenhouse. Five by-product doses (0, 906, 1813, 3625, and 7251 kg ha−1) were added into pots containing soil, each with seven replications. Responses to treatments were evaluated from dry matter production, nutritional status of the crops, and in the changes in soil properties after 70 days of each cultivation. The results showed that the by-product is composed of plagioclase, K-feldspar, quartz, clinopyroxene, smectites, and opaque minerals with apatite as accessory mineral. The addition of 3625 and 7251 kg ha−1 doses of the by-product substantially increased the dry matter yield in maize leaves. The Ca uptake by maize leaves cultivated in soil with 7251 kg ha−1 dose of the by-product was significantly higher in soil with other doses, and all by-product doses promoted high concentrations of Mg and Ca. The accumulated amounts of Ca, K, Mg and P indicated that they were enough to supply maize nutritional needs. Improvements in soil properties, such as high levels of Ca, K and P and low levels of exchangeable Al and Al saturation were observed. The results of the study suggest that the by-product can be used as soil re-mineralizer. The dacite rock by-product studied here has potential to be an environmental solution to soil fertilization problem because it does not require chemical processing and can be used as it is mined

Plantas medicinais utilizadas pela comunidade rural de Guamirim, Município de Irati, PR

O objetivo do presente trabalho foi realizar um levantamento das plantas medicinais utilizadas pela comunidade rural de Guamirim, distrito do município de Irati – PR, a fim de conhecer o emprego medicinal das plantas, parte da planta usada e a forma de preparo. Foram realizadas 18 entrevistas utilizando questionário. No total foram encontradas 49 espécies de plantas, pertencentes a 27 famílias e 46 gêneros (61,2 % exóticas e 38,8 % nativas). A comunidade menciona o uso das plantas medicinais principalmente para o tratamento de estômago (27,9 %), como calmante (18,0 %), ferimentos na pele (9,8 %) e garganta (9,0 %). As folhas e a parte aérea das plantas são as porções mais utilizadas para a produção dos medicamentos. O chá é a principal forma de preparo das plantas (80,0 %). Percebe-se que as plantas medicinais são amplamente utilizadas por essa comunidade rural e o cultivo no quintal é considerada uma tradição

Epidemiology of and prenatal molecular distinction between invasive and colonizing group B streptococci in The Netherlands and Taiwan

The identification of markers for virulent group B streptococci (GBS) could guide prenatal prevention and intervention strategies. We compared the distribution of serotypes and potential pathogenicity islands (PPIs) between invasive and colonizing GBS. Colonizing and invasive strains from The Netherlands and Taiwan were serotyped. We used polymerase chain reaction (PCR) for the amplification of several new PPI markers. Several combinations of PPI-specific markers and serotypes were associated with invasiveness. For Dutch neonatal strains, a receiver operating characteristic (ROC) curve with serotype and five PPI markers showed an area under the curve (AUC) of 0.963 (95% confidence interval [CI] 0.935–0.99). For Taiwanese neonatal strains, serotype and four different PPI markers resulted in an ROC curve with an AUC of 0.894 (95% CI 0.826–0.963). PPI-specific and serological markers can distinguish local neonatal invasive GBS strains from colonizing ones. Apparently, there are clear regional differences in the GBS epidemiology and infection potential of clones

Areas activated during naturalistic reading comprehension overlap topological visual, auditory, and somatotomotor maps

Cortical mapping techniques using fMRI have been instrumental in identifying the boundaries of topological (neighbor-preserving) maps in early sensory areas. The presence of topological maps beyond early sensory areas raises the possibility that they might play a significant role in other cognitive systems, and that topological mapping might help to delineate areas involved in higher cognitive processes. In this study, we combine surface-based visual, auditory, and somatomotor mapping methods with a naturalistic reading comprehension task in the same group of subjects to provide a qualitative and quantitative assessment of the cortical overlap between sensory-motor maps in all major sensory modalities, and reading processing regions. Our results suggest that cortical activation during naturalistic reading comprehension overlaps more extensively with topological sensory-motor maps than has been heretofore appreciated. Reading activation in regions adjacent to occipital lobe and inferior parietal lobe almost completely overlaps visual maps, whereas a significant portion of frontal activation for reading in dorsolateral and ventral prefrontal cortex overlaps both visual and auditory maps. Even classical language regions in superior temporal cortex are partially overlapped by topological visual and auditory maps. By contrast, the main overlap with somatomotor maps is restricted to a small region on the anterior bank of the central sulcus near the border between the face and hand representations of M-I