ALBERT

Notes: Abstract We report on the development and current capabilities of the ALOMAR Rayleigh/Mie/Raman lidar. This instrument is one of the core instruments of the international ALOMAR facility, located near Andenes in Norway at 69°N and 16°E. The major task of the instrument is to perform advanced studies of the Arctic middle atmosphere over altitudes between about 15 to 90 km on a climatological basis. These studies address questions about the thermal structure of the Arctic middle atmosphere, the dynamical processes acting therein, and of aerosols in the form of stratospheric background aerosol, polar stratospheric clouds, noctilucent clouds, and injected aerosols of volcanic or anthropogenic origin. Furthermore, the lidar is meant to work together with other remote sensing instruments, both ground- and satellite-based, and with balloon- and rocket-borne instruments performing in situ observations. The instrument is basically a twin lidar, using two independent power lasers and two tiltable receiving telescopes. The power lasers are Nd:YAG lasers emitting at wavelengths 1064, 532, and 355 nm and producing 30 pulses per second each. The power lasers are highly stabilized in both their wavelengths and the directions of their laser beams. The laser beams are emitted into the atmosphere fully coaxial with the line-of-sight of the receiving telescopes. The latter use primary mirrors of 1.8 m diameter and are tiltable within 30° off zenith. Their fields-of-view have 180 μrad angular diameter. Spectral separation, filtering, and detection of the received photons are made on an optical bench which carries, among a multitude of other optical components, three double Fabry-Perot interferometers (two for 532 and one for 355 nm) and one single Fabry-Perot interferometer (for 1064 nm). A number of separate detector channels also allow registration of photons which are produced by rotational-vibrational and rotational Raman scatter on N2 and N2+O2 molecules, respectively. Currently, up to 36 detector channels simultaneously record the photons collected by the telescopes. The internal and external instrument operations are automated so that this very complex instrument can be operated by a single engineer. Currently the lidar is heavily used for measurements of temperature profiles, of cloud particle properties such as their altitude, particle densities and size distributions, and of stratospheric winds. Due to its very effective spectral and spatial filtering, the lidar has unique capabilities to work in full sunlight. Under these conditions it can measure temperatures up to 65 km altitude and determine particle size distributions of overhead noctilucent clouds. Due to its very high mechanical and optical stability, it can also employed efficiently under marginal weather conditions when data on the middle atmosphere can be collected only through small breaks in the tropospheric cloud layers.

Notes: In this article we describe an electrochemical experimental setup for cyclic voltammetry operating from low (1 V/s) to very high (200 kV/s) scan rates. The system is designed to achieve an acceptable cost and to be user friendly for nonexperts. The instrumentation is based on a commercial arbitrary wave form generator, a digital oscilloscope, a general purpose interface bus interface to a PC, and a laboratory-built potentiostat. There are no complicated manual operations, instead the software creates dialog with an operator to control commands for the instruments. Requirements for the wave form synthesis and the data acquisition are given. Various data-smoothing methods for treating 8-bit fast scan data are evaluated. The performance was tested on the oxidation of ferrocene in acetonitrile. The estimated value of the standard heterogeneous rate constant, k0=0.8±0.1 cm s−1, is in reasonable agreement with the most recent reports from other laboratories. © 2000 American Institute of Physics.

Notes: Abstract TLC characteristics are described of some psychopharmacological agents (Chlorprothixen, Prothixen, Clopenthixol, Flupentixol, Meprotixol, Amitriptylin und Nortriptylin) and of their metabolites and derivatives in six different developing solvent systems as well as the fluorescence maxima of these compounds in 60% sulphuric acid. By way of the examples of Chlorprothixen and Chlorprothixen sulphoxide the isolation of reactive agents from biological material and their determination are shown. The determination of Clopenthixol and Flupentixol in mixtures with their corresponding metabolites is possible due to differences in their fluometric spectra.

Notes: Abstract Psychotherapeutics of the Thioxanthene type are degraded to the analogous Thioxanthone derivates in very diluted Ce(SO4)2 solutions. These are determined by fluorescence spectrophotometry. In this way Flupenthixol, Chlorprothixen, Prothixen, Clopenthixol and their secondary amino-derivates are determined quantitatively. The corresponding sulphoxides and Meprothixol are not degraded by Ce(SO4)2 solution. Furthermore, the determination of Flupenthixol and 2-Chlorthioxanthone from biological material is described. The method is especially suitable because the different psychotherapeutics of the Thioxanthene type are degraded to the same kind of degradation product.