The hydrogen storage properties of pure magnesium and magnesium ZK60 alloy containing 2.5 wt% of mischmetal (Mm) processed by Cold Rolling (CR) and Low Temperature Rolling (LTR) were investigated. Before CR and LTR processing, Equal Channel Angular Pressing (ECAP) was employed in the alloys as an initial processing step to refine their microstructures. Microstructure findings showed that the ECAP+LTR route is more effective than the others to generate grain refinement - a desirable aspect in hydrogen storage materials. SEM and TEM results in combination with XPS analysis revealed that the ZK60 + 2.5 wt. % Mm alloy after being processed by ECAP + LTR had more refined grains (with sizes < 1μm) and exhibited superior resistance to the formation of oxides and/or hydroxides when compared with the pure magnesium alloy. The refined microstructures of the ECAP+LTR samples combined with the presence of highly oriented grains along to the (002) plane and large amount of defects – which are features associated to the LTR route - such as cracks and voids, resulted in a fast activation kinetics than for the samples processed by ECAP + CR route.

RESUMO O tamanduá-bandeira (Myrmecophaga tridactyla) e o tamanduá-mirim (Tamandua tetradactyla) são mamíferos xenartros amplamente distribuídos no território nacional. Apesar disso, suas populações estão em constante ameaça, principalmente o primeiro, categorizado como vulnerável de acordo com classificação da União Internacional para Conservação da Natureza. Diante disso e da escassez de estudos com endoparasitas nesses animais, objetivou-se descrever a helmintofauna dessas duas espécies de tamanduá, utilizando espécimes atropelados nas rodovias BR-050 e BR-455, região do Triângulo Mineiro, Minas Gerais, Brasil. Os animais foram submetidos à necropsia, tendo seus órgãos e conteúdo intestinal e estomacal examinados para recuperação de helmintos. Os parasitos coletados foram identificados com base em suas características morfológicas e morfométricas. As espécies/os gêneros caracterizados para M. tridactyla e T. tetradactyla, suas respectivas prevalências, bem como órgãos de origem, foram: Gaphidiops dissimilis (33,33% e 0%) no estômago; Gigantorhynchus echinodiscus (25% e 66,66%) no intestino delgado; Physaloptera magnipapilla (50% e 66,6%) no estômago; e Mathevotaenia spp. (25% e 66,66%) no intestino delgado. Physaloptera magnipapilla foi a espécie com os maiores índices de infecção, e novo registro de localização foi registrado para o nematódeo Graphidiops dissimilis. Detectou-se uma provável sobreposição da área de vida dos tamanduás estudados, bem como uma helmintofauna característica da região.

ABSTRACT Myrmecophaga tridactyla, giant anteater and Tamandua tetradactyla, collared anteater are nationally widespread mammals. Despite that, their populations are in danger, especially the first one, categorized as vulnerable according to the International Union for Conservation of Nature. This study reports the occurrence of helminths in these two anteater species using road killed specimens from BR-050 and BR-455 highways, Triângulo Mineiro region, Minas Gerais state, Brazil. The species were necropsied, and their gastrointestinal organs and contents were opened and examined for parasite recovery. The identification was based on morphological and morphometric features. The species/ genera found for M. tridactyla and T. tetradactyla, their prevalence, as well the organs, were: Gaphidiops dissimilis (33.33% and 0%) in stomach; Gigantorhynchus echinodiscus (25% and 66.66%) in small intestine; Physaloptera magnipapilla (50% and 66.6%) in stomach and Mathevotaenia spp. (25% and 66.66%) in small intestine. Physaloptera magnipapilla was the most common species and a new location was reported for Graphidiops dissimilis. There is a probable overlap in the home range of these animals and a local helminth diversity was described on the study site.

Este trabalho teve por objetivo avaliar o efeito dos sistemas de ordenha e de resfriamento na contagem bacteriana total (CBT) e na quantidade de leite com CBT < 10(5), que representa leite de alta qualidade. Um total de 12.221 registros de CBT do leite foi obtido de uma indústria láctea da região Oeste do Paraná, no período de janeiro a outubro de 2006. Após as coletas, a qualidade do leite foi analisada em laboratório pelo método de citometria de fluxo. Os dados de CBT foram classificados por sistema de ordenha, tipo de resfriador e intervalos da CBT, segundo critério da Instrução Normativa 62, e submetidos à análise de independência de Qui-Quadrado. As proporções de CBT do leite entre tipos de resfriadores, em cada sistema de ordenha, foram comparadas utilizando-se a estatística calculada Z. Observou-se menor (p < 0,01) valor de CBT do leite de vacas submetidas à ordenha canalizada e do leite resfriado a granel. A proporção das amostras de leite avaliadas nos três níveis de CBT resfriadas por sistema de imersão não diferiu (p = 0,1549) do leite resfriado a granel, quando o leite foi obtido de rebanhos ordenhados por ordenha canalizada. A alta qualidade microbiológica do leite da região Oeste do Paraná é obtida quando os produtores utilizam em suas propriedades rurais a ordenha canalizada e o sistema de resfriamento a granel.

This study aimed to evaluate the effect of milking systems and cooling on total bacterial count (TBC), and the amount of milk samples with TBC < 10(5), which represents high-quality milk. A total of 12,221 records of milk TBC were obtained from a dairy industry in the western region of Paraná State, Brazil, from January to October 2006. After the sampling was conducted, the milk quality was analyzed in the laboratory by the method of flow cytometry. The TBC data were classified by milking system, type of coolers and intervals of the TBC, in accordance with Normative Instruction 62, and submitted to the chi-square test for independence. The proportions of milk TBC among types of coolers at each milking system were compared using the calculated statistic Z. A lower TBC value (p < 0.01) was observed in milk obtained from cows milked using a piped system and from bulk cooled milk. The proportion of milk samples evaluated at three levels of TBC cooled by the immersion system did not differ (p = 0.1549) from bulk cooled milk when the milk was obtained from herds milked with a piped system. The best microbiological quality of milk in the western region of Paraná was achieved with a piped milking system and bulk cooling.

Calculations of the total dielectric functions and the optical bandgap energy (OBGE) of 4HSiC were performed by the full-potential linear muffin-tin-orbital method. The results are compared to spectroscopic ellipsometry dielectric measurements agreeing closely over in a wide range of energies. The obtained theoretical value of the (OBGE) agrees very closely with the measured ones obtained by transmission and photoacoustic spectroscopies at room temperature performed on 470 µm thick wafer and a 25 µm thick homoepitaxial layer of 4H-SiC samples grown (n-type, Siface) by hot wall CVD.

The optical bandgap energies (OBGE) of 3C, 15R, 6H and 4H-SiC have been investigate experimentally by transmission and photoacoustic spectroscopies. The measurements were performed on 470 mum thick wafers. The OBGE obtained from both spectroscopies for different polytypes show very good agreement. In order to have a better understanding of these materials calculations of eletronic band structure were performed by the full-potential linearized augmented plane wave (FPLAPW) method. For the OBGE the results are compared to the measurements agreeing closely over the energies of those polytypes.