In-situ real-time monitoring of spurious modes in HE11_{11} transmission lines using multi-hole couplers in miter bends

Transmission of high-power millimeter waves for ECRH is often realised with oversized corrugated circular waveguides. Coupling from the gyrotron source to the waveguide is typically done via matching mirrors in free space. Small alignment errors of the system lead to the excitation of higher-order modes inside the waveguide beside the main transmission mode HE$_{11}$. Tose modes have comparably higher losses and can in worst case result in local fields exceeding the breakdown limit of the medium inside the waveguide. For alignment control over the whole pulse duration of the gyrotron, a set of hole-array couplers placed into a miter bend mirror probes the field inside the waveguide. The arrays are designed to detect the marker modes for beam offset and tilt (LP$^{(e=0)}$$_{11}$) as well as for beam waist mismatch (LP$_{02}$). In addition, a main mode coupler sensitive mostly for the HE$_{11}$ content is used as a power monitor. By maximizing the signal of the power monitor and minimizing the content of marker modes, a first-order optimization of the coupling from free space to the waveguide can be achieved. Signal processing of the 140 GHz information is done at kHz range after downmixing, using a frequency shifted part of the power monitor signal. As the measurement system is placed in a miter bend mirror, it can also be easily installed at various locations along the transmission line to check for possible misalignments of the waveguide connections between miter bends. Simulation and low power experimental results will be shown

Combination of Lidar and Model Data for Studying Deep Gravity Wave Propagation

The paper presents a feasible method to complement ground-based middle atmospheric Rayleigh lidar temperature observations with numerical simulations in the lower stratosphere and troposphere to study gravity waves. Validated mesoscale numerical simulations are utilized to complement the temperature below 30-km altitude. For this purpose, high-temporal-resolution output of the numerical results was interpolated on the position of the lidar in the lee of the Scandinavian mountain range. Two wintertime cases of orographically induced gravity waves are analyzed. Wave parameters are derived using a wavelet analysis of the combined dataset throughout the entire altitude range from the troposphere to the mesosphere. Although similar in the tropospheric forcings, both cases differ in vertical propagation. The combined dataset reveals stratospheric wave breaking for one case, whereas the mountain waves in the other case could propagate up to about 40-km altitude. The lidar observations reveal an interaction of the vertically propagating gravity waves with the stratopause, leading to a stratopause descent in both cases

Discutindo a educação ambiental no cotidiano escolar: desenvolvimento de projetos na escola formação inicial e continuada de professores

A presente pesquisa buscou discutir como a Educação Ambiental (EA) vem sendo trabalhada, no Ensino Fundamental e como os docentes desta escola compreendem e vem inserindo a EA no cotidiano escolar., em uma escola estadual do município de Tangará da Serra/MT, Brasil. Para tanto, realizou-se entrevistas com os professores que fazem parte de um projeto interdisciplinar de EA na escola pesquisada. Verificou-se que o projeto da escola não vem conseguindo alcançar os objetivos propostos por: desconhecimento do mesmo, pelos professores; formação deficiente dos professores, não entendimento da EA como processo de ensino-aprendizagem, falta de recursos didáticos, planejamento inadequado das atividades. A partir dessa constatação, procurou-se debater a impossibilidade de tratar do tema fora do trabalho interdisciplinar, bem como, e principalmente, a importância de um estudo mais aprofundado de EA, vinculando teoria e prática, tanto na formação docente, como em projetos escolares, a fim de fugir do tradicional vínculo “EA e ecologia, lixo e horta”.Facultad de Humanidades y Ciencias de la Educació

Bedingungen und Chancen der Transformation des deutschen Kammerwesens

Sack D. Bedingungen und Chancen der Transformation des deutschen Kammerwesens. In: Schmidt-Trenz H-J, Stober R, eds. Brauchen wir eine Wirtschaftskammer?. Jahrbuch Recht und Ökonomik des Dritten Sektors 2007/2008. Baden-Baden: Nomos; 2008: 151-170