Investigation on fat-quality of embryo, endosperm and crush fractions of maize kernel (author's transl)]

Investigations were conducted on the composition of fatty acids in the fat of the embryo, the endosperm and several crush fractions of the maize kernel. The following results were obtained: 1. The embryo fat contained relatively lower contents of palmitin-, stearin- and linolenic acid, on the other hand higher contents of oleic- and linoleic acid in comparism to endosperm fat. 2. This result was identical to each one of the seven varieties examined. 3. The examined varieties presented clear differences both in the absolute contents of single fatty acids in the embryo and in the endosperm, as well as in the relationship between the components in the germ and in the endosperm. 4. The differences observed between the germ- and the endosperm fat in the crush fractions in some cases were clearly visible, while in other cases were not traceable.     

Simulations and developments of the Low Energy Neutron detector Array LENA

Prototypes of the Low Energy Neutron detector Array (LENA) have been tested and compared with detailed GEANT simulations. LENA will consist of plastic scintillation bars with the dimensions 1000×45×10 mm³. The tests have been performed with γ-ray sources and neutrons originating from the neutron-induced fission of ²³⁵U. The simulations agreed very well with the measured response and were therefore used to simulate the response to mono-energetic neutrons with different detection thresholds. LENA will be used to detect low-energy neutrons from (p,n)-type reactions with low momentum transfer foreseen at the R³B and EXL setups at FAIR, Darmstadt.     

Shine Bright Like a Diamond: New Light on an Old Polymeric Semiconductor

Brilliance usually refers to the light reflected by the facets of a gemstone such as diamond due to its high refractive index. Nowadays, high-refractive-index materials find application in many optical and photonic devices and are mostly of inorganic nature. However, these materials are usually obtained by toxic or expensive production processes. Herein, the synthesis of a thin-film organic semiconductor, namely, polymeric carbon nitride, by thermal chemical vapor deposition is presented. Among polymers, this organic material combines the highest intrinsic refractive index reported so far with high transparency in the visible spectrum, even reaching the range of diamond. Eventually, the herein presented deposition of high quality thin films and their optical characteristics open the way for numerous new applications and devices in optics, photonics, and beyond based on organic materials.     

Investigations of fat-quality of maize with special consideration of linoleic acid contents (author's transl)]

In the past years the cultivation of maize in the Federal Republic of Germany has been intensified, and with the processing of localy bred maize a production of maize germ oil from German varieties could be expected. In order to maintain certain essential points about the amplitude of variations in the specimen of fatty acids in the localy bred maize, a greater number of maize samples from cultural practice trials (varieties, locations and fertilizer) were taken for the year 1971 and 1972 and their fatty acid composition was analysed. The following results were obtained: 1. Comparared to maize of foreign origin, processed in the Federal Republic of Germany, in most cases the localy bred, has higher contents of linoleic acid and lower contents of oleic acid. Thus the linoleic acid contents of the Germany maize varies between 54.3 and 68.8% while the foreign maize varies between 39.5 and 58.7%. 2. Great differences in quality exist between the local genotypes (varieties). Also clear, but not so great differences are induced by ecological factors, as locations, weather and nutrient supply. The differences of local environment in the linoleic acid content in case of variety "Inrakorn" varies between 60.8 and 64.5%.     

Mass transfer from a finite strip near an oscillating stagnation point – implications for atherogenesis

The mass transfer from a finite-length strip near a two-dimensional, oscillating stagnation-point flow in an incompressible, Newtonian fluid is considered. The problem is investigated using a combination of asymptotic and numerical methods. The aim of the study is to determine the effect of the location of the strip, relative to the time-averaged position of the stagnation point, on the mass transfer into the fluid. The study is motivated by the problem of mass transfer from an injured region of the arterial wall into the blood, a process that may be of considerable importance in atherogenesis. For physiologically realistic parameter values, it is found that the fluid flow is quasi-steady, but the mass transfer exhibits genuine time-dependence and a high-frequency asymptotic solution provides an accurate prediction of the time-average mass transfer. In this regime, there is a significant reduction in mass transfer when the centre of the strip is located at the point of zero time-averaged wall shear rate, or equivalently wall shear stress, which may serve to explain, at least partially, the correlation between arterial disease and regions of low wall shear stress.     

Microbiological oxidation of 2-methylbutanol of differing enantiomeric ratios by Gluconobacter species

 2-Methylbutanoic acid, an aroma compound of high economic interest, was synthesised using Gluconobacter species for bioconversion. The main focus was on enantioselective effects during metabolism. A preference for the (S)-enantiomer was observed when the microorganisms were fed with 2-methylbutanol of known enantiomeric ratios. Received: 15 December 1997