Remote sensing of water quality in reservoirs and lakes in semi-arid climates

Overlake measurements using aerial cameras (remote sensing) combined with water truth collected from boats most economically provided wide-band photographs rather than precise spectra. With use of false color infrared film (400-950 nm), the reflected spectral signatures seen from hundreds to thousands of meters above the lake merged to produce various color tones. Such colors were easily and inexpensively obtained and could be recognized by lake management personnel without any prior training. The characteristic spectral signatures of various algal types were also recognizable in part by the color tone produced by remote sensing

A PRELIMINARY REVIEW OF THE BIOSTRATIGRAPHY OF THE UPPERMOST PERMIAN, TRIASSIC AND LOWERMOST JURASSIC OF GONDWANALAND

This review pager was born out of a desire to visualize in some detail the picture of the evolving Gondwana Triassic landscape and the story of life and ecology upon it; a desire to provide a general setting in which to view the details of the work in which we are actively involved at the present-the macro flora (H.M.A.) and microflora (J.M.A.) of the Molteno 'Formation' of the Karroo Basin of South Africa

Ultracold atoms in optical lattices with random on-site interactions

We consider the physics of lattice bosons affected by disordered on-site interparticle interactions. Characteristic qualitative changes in the zero temperature phase diagram are observed when compared to the case of randomness in the chemical potential. The Mott-insulating regions shrink and eventually vanish for any finite disorder strength beyond a sufficiently large filling factor. Furthermore, at low values of the chemical potential both the superfluid and Mott insulator are stable towards formation of a Bose glass leading to a possibly non-trivial tricritical point. We discuss feasible experimental realizations of our scenario in the context of ultracold atoms on optical lattices.Comment: 4 pages, 3 eps figure

Shaping an ultracold atomic soliton in a travelling wave laser beam

An ultracold wave packet of bosonic atoms loaded into a travelling laser wave may form a many-atom soliton.This is disturbed by a homogeneous force field, for example by the inevitable gravitation. The wave packet is accelerated and therefore the laser frequency appears to be chirped in the rest frame of the atoms. We derive the effective nonlinear Schr\"odinger equation. It shows a time dependent nonlinearity coefficient which amounts to a damping or antidamping, respectively. The accelerated packet solution remains a soliton which changes its shape adiabatically. Similarly, an active shaping can be obtained in the force-free case by chirping the laser frequency thus representing a way of coherent control of the soliton form. The experimental consequences are discussed.Comment: 5 pages, Latex, to published in Europhys. Let

Development of Collembolans after coversion towards organic farming

In Northern Germany, a diverse and complex experimental farm of the Federal Agricultural Research Centre (FAL) was set-up in 2001 covering all main aspects of organic farming. Previously, the 600 ha farm had been managed conventionally. Adjacent conventional farms were used as reference. The aim of this project was to study collembolans, microbial biomass and soil organic carbon in six organically farmed fields managed as a crop rotation of six different crops compared with an adjacent conventionally managed field. We hypothesised that the specific management in organic farming promotes soil biota. Soil samples were taken during the growing season in 2004. Collembolan abundances and microbial biomass were lower under organic management, but, generally, collembolan diversity was higher in organically farmed fields combined with a shifting in the dominance structure of the species. This result reveals that, even after three years, the soil biota is still changing with management conversion

Dynamical Instability in a Trimeric Chain of Interacting Bose-Einstein Condensates

We analyze thoroughly the mean-field dynamics of a linear chain of three coupled Bose-Einstein condensates, where both the tunneling and the central-well relative depth are adjustable parameters. Owing to its nonintegrability, entailing a complex dynamics with chaos occurrence, this system is a paradigm for longer arrays whose simplicity still allows a thorough analytical study.We identify the set of dynamics fixed points, along with the associated proper modes, and establish their stability character depending on the significant parameters. As an example of the remarkable operational value of our analysis, we point out some macroscopic effects that seem viable to experiments.Comment: 5 pages, 3 figure

Detector arrays for low-background space infrared astronomy

The status of development and characterization tests of integrated infrared detector array technology for astronomy applications is described. The devices under development include intrinsic, extrinsic silicon, and extrinsic germanium detectors, with hybrid silicon multiplexers. Laboratory test results and successful astronomy imagery have established the usefulness of integrated arrays in low-background astronomy applications