Umwelttechnikindustrie - Zukunftsmarkt China

China, das Reich der Mitte, ist mit schwerwiegenden Umweltproblemen konfrontiert die hohe Kosten verursachen. Mit der zunehmenden Anwendung der Umwelttechnik kann der Herausforderung diese Problemfelder zu beheben sinnvoll begegnet werden. Die Indikatoren Wirtschaftswachstum, notwendiger Schutz der natürlichen Ressourcen, externe Kosten, politische und institutionelle Faktoren prognostizieren einen stark wachsenden Absatzmarkt für Umwelttechnik in China. Um dieses Marktpotential tatsächlich auszuschöpfen ist es notwendig in China und in Österreich verschiedene Anforderungen zu erfüllen die in diesem Artikel erörtert werden

Umwelttechnikindustrie - Zukunftsmarkt China

China, das Reich der Mitte, ist mit schwerwiegenden Umweltproblemen konfrontiert die hohe Kosten verursachen. Mit der zunehmenden Anwendung der Umwelttechnik kann der Herausforderung diese Problemfelder zu beheben sinnvoll begegnet werden. Die Indikatoren Wirtschaftswachstum, notwendiger Schutz der natürlichen Ressourcen, externe Kosten, politische und institutionelle Faktoren prognostizieren einen stark wachsenden Absatzmarkt für Umwelttechnik in China. Um dieses Marktpotential tatsächlich auszuschöpfen ist es notwendig in China und in Österreich verschiedene Anforderungen zu erfüllen die in diesem Artikel erörtert werden.

CaCu_3Ti_4O_12/CaTiO_3 Composite Dielectrics: A Ba/Pb-free Ceramics with High Dielectric Constants

We have measured dielectric properties of Ca$_{1+x}$Cu$_{3-x}$Ti$_4$O$_{12}$ ($x$ = 0, 0.1, 0.5, 1, 1.5, 2, 2.9 and 3), and have found that Ca$_2$Cu$_2$Ti$_4$O$_{12}$ (a composite of CaCu$_3$Ti$_4$O$_{12}$ and CaTiO$_3$) exhibits a high dielectric constant of 1800 with a low dissipation factor of 0.02 below 100 kHz from 220 to 300 K. These are comparable to (or even better than) those of the Pb/Ba-based ceramics, which could be attributed to a barrier layer of CaTiO$_3$ on the surface of the CaCu$_3$Ti$_4$O$_{12}$ grains. The composite dielectric ceramics reported here are environmentally benign as they do not contain Ba/Pb.Comment: 4 pages, 4 figures, Appl. Phys. Lett. (scheduled on July 25, 2005

Application of UV-C irradiation prevented a severe outbreak of proliferative kidney disease in rainbow trout aquaculture

There is an urgent need to establish protocols on how to protect salmonids in aquaculture from outbreaks of proliferative kidney disease (PKD). For this purpose, systems for a continuous application of peracetic acid (PAA, 0.1 mg l−1) and of ultraviolet C light (UV-C, 323.5− 158.6 mW s cm−2) were installed in the inlet of raceway-channels within a sub-unit of a commercial rainbow trout Oncorhynchus mykiss farm. After 127 d of rearing, a fish health examination was conducted. Fish in the control and PAA treatment groups showed signs of PKD. In contrast, fish in the UV-C treatment group showed almost no signs of disease based on clinical examinations and necropsy. This observation indicates that UV-C irradiation could be a promising tool to protect fish from PKD in the future

On the mixing rules for interstellar inhomogeneous grains

We present the computation of effective refractive coefficients for inhomogeneous two-component grains with 3 kinds of inclusions with ${\rm m_{incl}=3.0+4.0i, 2.0+1.0i, 2.5+0.0001i}$ and a matrix with ${\rm m_m=1.33+0.01i}$ for 11 volume fractions of inclusions from 0% to 50% and wavelengths ${\rm\lambda}$=0.5, 1.0, 2.0 and 5.0 ${\rm \mu m}$. The coefficients of extinction for these grains have been computed using a discrete dipole approximation (DDA). Computation of the extinction by the same method for grains composed of a matrix material with randomly embedded inclusions has been carried out for different volume fractions of inclusions. A comparison of extinction coefficients obtained for both models of grain materials allows to choose the best mixing rule for a mixture. In cases of inclusions with ${\rm m_{incl}}$=2.0+1.0i and 2.5+0.0001i the best fit for the whole wavelengths range and volume fractions of inclusions from 0 to 50% has been obtained for Lichtenecker mixing rule. In case of ${\rm m_{incl}=3.0+4.0i}$ the fit for the whole wavelength range and volume fractions of inclusions from 0 to 50% is not very significant but the best has been obtained for Hanai rule. For volume fractions of inclusion from 0 to 15% a very good fit has been obtained for the whole wavelength range for Rayleigh and Maxwell-Garnett mixing rules.Comment: 11 pages, 13 figures, accepted for publication in MNRA

Influência do método de proporcionamento pó/líquido nas propriedades de uma resina acrílica de uso odontológico

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Projeto e implementação de ensaio de fadiga por tração-compressão direta (uniaxial) para avaliação de dano em misturas asfálticas

No país, são dois os mais recorrentes defeitos encontrados nas rodovias: deformação permanente e trincamentopor fadiga. Dentre as mais variadas causas, a formação e propagação de trincas no revestimento asfálticoocorrem em consequência das repetidas solicitações do tráfego que, com o tempo, reduzirão drasticamentea vida de serviço do pavimento, por exemplo, facilitando a penetração de água nas camadas granularesda estrutura e acelerando sua deterioração. Além disso, os ensaios mais comumente utilizados no Brasil paraavaliação e previsão de desempenho quanto à fadiga do concreto asfáltico ainda suscitam muitos questionamentosno meio técnico-científico. Assim, no contexto da caracterização avançada de misturas asfálticas,realizou-se o desenvolvimento de projetos referentes a um sistema mecânico para ensaio bem como de tratamentode dados após os testes. Trata-se do ensaio de Fadiga por Tração-Compressão Direta (Uniaxial) quepossibilita avaliar e caracterizar o comportamento de misturas asfálticas quanto ao dano por fadiga. Foramrealizadas adaptações de peças já existentes em outros dois centros de pesquisa para que se ajustassem àprensa hidráulica utilizada na Universidade Federal de Santa Maria (UFSM): a Universal Testing Machine(UTM-25). Testes foram efetuados e monitorados para certificar a compatibilidade entre as peças produzidase a prensa hidráulica utilizada e os resultados encontrados demonstraram sucesso no caminho proposto.Palavras-chave: Pavimentação asfáltica. Fadiga por Tração-Compressão Direta (Uniaxial). Aparato deensaio