Computer-aided display control Final report

Human composition and modification of computer driven cathode ray tube displa

Separation of intrinsic dielectric and resistive electrode losses in ferroelectric capacitors at radio frequencies

To analyze the intrinsic dielectric performance of planar high-density capacitors at radio frequencies (RF), the dielectric losses need to be distinguished from the resistive electrode losses. The resistive losses of the electrodes at RF are de-embedded employing a linear regression procedure with partial compensation for distributed effects. We use tunable ferroelectric capacitors with a barium strontium titanate (BST) dielectric with an inner diameter d ≥ 8 μm on a silicon substrate. The de-embedding of the electrode losses has been successfully performed utilizing 1-Port RF measurement data from of an Advantest R3767CG vector network analyzer (VNA) in the frequency range of 10 MHz – 8 GHz

Ten Simple Rules for Organizing a Virtual Conference—Anywhere

Etienne P. de Villiers and Sheila C. Ommeh are ILRI author

Cirrus, contrails, and ice supersaturated regions in high pressure systems at northern mid latitudes

During the European heat wave summer 2003 with predominant high pressure conditions we performed a detailed study of upper tropospheric humidity and ice particles which yielded striking results concerning the occurrence of ice supersaturated regions (ISSR), cirrus, and contrails. Our study is based on lidar observations and meteorological data obtained at Lindenberg/Germany (52.2° N, 14.1° E) as well as the analysis of the European centre for medium range weather forecast (ECMWF). Cirrus clouds were detected in 55% of the lidar profiles and a large fraction of them were subvisible (optical depth <0.03). Thin ice clouds were particularly ubiquitous in high pressure systems. The radiosonde data showed that the upper troposphere was very often supersaturated with respect to ice. Relating the radiosonde profiles to concurrent lidar observations reveals that the ISSRs almost always contained ice particles. Persistent contrails observed with a camera were frequently embedded in these thin or subvisible cirrus clouds. The ECMWF cloud parametrisation reproduces the observed cirrus clouds consistently and a close correlation between the ice water path in the model and the measured optical depth of cirrus is demonstrated

Cirrus clouds and ice supersaturated regions observed by Raman lidar and radiosondes.

With our mobile Aerosol Raman Lidar (MARL) we have performed field campaigns in the mid latitudes in 2003 (Lindenberg/Germany, 53°N, 15°E) and in the tropics in 2004/05(Paramaribo/Suriname, 6°N, 55°W). The lidar system detects aerosols and clouds in the UTLS region. It is capable of detecting thin cirrus including extremely thin clouds with optical depth below 10-3. The system measures cloud altitudes with high vertical and temporal resolution and determines the depolarisation and optical depth. It operates day and night. During daytime cloud types including contrails are classified with the help of a video camera. During the campaigns, water vapour was measured by means of balloon borne sondes (Vaisala RS80/RS90, 'Snow white' frost point hygrometer) and by the LIDAR using the Raman technique. We investigated the occurrence of ice supersaturated regions and their relation to the occurrence of clouds. The accuracy of the water vapour measurements needs to be critically evaluated for this purpose. The cloudiness in the upper troposphere was found to be very high in the tropics where in about 90% of all measured profiles cirrus was present. In the mid latitudes cirrus were found in 55% of the measurements