The spatial distribution of Lyα forest absorption systems toward a group of 8, closely spaced QSOs has been analysed and evidence for large scale structure has been found at z = 2.8. Our technique is based on the first and second moments of the transmission probability density function which is capable of identifying and assessing the significance of regions of over-or underdense Lyα absorption...

N. A. Krivova, Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Str. 2, 37191 Katlenburg-Lindau, Germany ([email protected]) S. K. Solanki, Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Str. 2, 37191 Katlenburg-Lindau, Germany T. Wenzler, Hochschule für Technik Zürich, CH-8004 Zürich, Switzerland B. Podlipnik, Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Str. ...

The manuscript describes a method to obtain spectral aerosol optical thicknesses from measurements with a spectroradiometer in the UV-visible range. The direct solar light is inferred from the difference between total radiation and diffuse radiation. The latter is obtained by the use of a sun blocking disc. An error budget is presented. The results are validated against the measurements with a ...

In the naive form of most resummations we get into conflict with order-by-order renormalization. We present a method that is capable to ensure UV consistency of any resummations satisfying certain conditions. The method is based on the observation that resummation is equivalent with a calculation in an adequate perturbation scheme, followed by a renormalization scheme changing. This framework w...

UV-visible absorption and AFM studies suggest that carboxyphenylethynyl zinc porphyrins aggregate on nanocrystalline TiO2 surfaces in an H-type fashion.

A Matlab implemented computer code for spectral resolution is presented. The code enables the user to resolve the UV-visible absorption spectrum of a mixture of up to 3 previously known components, to the individual components, thus, evaluating their quantities. The resolving procedure is based on searching the combination of the components which yields the spectrum which is the most similar (m...

The frequency of marine sponges that harbour photosynthetic organisms was examined in a tropical area of the Western Indian Ocean. Out of 77 species from five different habitats in Zanzibar, 55 (71.5%) were found to have photosynthetic activity, as assayed by in situ pulse amplitude modulated (PAM) fluorometry (and validated by measurements of chlorophyll content). A significantly higher percen...