Quality change and mass loss of paddy during airtight storage in a ferro-cement bin in Sri Lanka

In Sri Lanka, prices for paddy fluctuate severely showing a minimum price at harvest. To benefit from higher prices, farmers strive to store paddy, but lack of facilities and poor storage management cause quantitative and qualitative losses by rodents, insects and microbial deterioration. To overcome these problems an airtight storage system, based on a ferro-cement bin, has been developed. The objective of this study was to evaluate the storage system in terms of paddy quality and mass loss. Before and after storage, samples were drawn from this bin and a control to analyse moisture content, thousand-grain mass, insect infestation, mould, germination rate and head rice yield. Additional samples were taken from different regions in the bin.Oxygen concentration dropped to 2.7% within 30 days and carbon dioxide rose to 9.1%. The change in gas composition was caused mainly by insect respiration. Ephestia cautella were found on the top layer in the bin and Sitophilus spp. and Rhyzopertha dominica in the bottom layer. The average infestation rate was 4.8 insects/kg. Most of the insects were dead at unloading. After 6 months storage, mass loss was 0.4% in the bin and 2.1% in the control. Head rice yield was 35.8% in the bin and 27.3% in the control. A significant amount of mould was found only in the control (0.85%). Germination rate, however, decreased from 85% to 0% in the airtight bin, whereas it was still 38% in the control. The study has shown that airtight ferro-cement bins provide a safe and convenient method for farmers in the tropics to preserve their harvest for later sale at a higher price. Further work is necessary to develop strategies for avoiding the decrease in germination capacity.     

Solar hydrogen

The intermittance and the geographical distribution of solar energy require means of storing and transporting it to the user's place. An ideal means of doing this is to split water in order to obtain hydrogen.Hydrogen is a carbon-free fuel which oxidizes to water as combustion product. The generated water becomes, together with renewable primary energy for splitting it, a source of clean and abundant energy in a carbon-free, natural cycle.Hydrogen is a fuel which can be transported over long distances and stored so that solar energy can be transported from energy rich countries over long distances in ships to Europe, stored underground or in containers and used in gaseous or liquid form in industry, households, power stations, motor cars and aviation.Solar energy as primary energy is discussed. A special form of it, the cheapest and by now largely available hydropower, is stressed.Techniques of hydrogen production, vectorisation and end use are discussed as well as safety aspects, costs and strategy for its implementation.     

Untersuchungen im Dreistoffsystem Eisen (II)-oxid–Chrom(III)-oxid–Tonerde

Schrifttumsübersicht über die beteiligten Randsysteme. Klärung der Frage, welche Fassung des Zustandsschaubildes Eisen(II)-oxid–Tonerde zutreffend ist, mit Hilfe von Schmelzen im Tonerdetiegel. Ermittlung des Schmelzpunktes des Hercynits. Sättigungsisothermen eisen(II)-oxidreicher Schlacken an Hercynit. Untersuchung des quasibinären Schnittes Hercynit–Chromit mit Röntgenfeinstruktur- und Mikrosondenmessungen. Entwurf des Zustandsschaubildes FeO–Cr₂O₃–Al₂O₃.     

Derivation of variational principles for rigid-plastic solids obeying non-associated flow laws—II: Unprescribed jumps

In the second part of the paper variational principles have been derived for discontinuous stress and velocity fields. An essential new feature consists in taking into account of a jump of the velocity field as related to the traction. Some discontinuity relations have also been discussed.     

Investigations on the damage caused by ion etching of SiO2 layers at low energy and high dose

The radiation damage caused by argon ion bombardment during ion etching of thermally grown SiO₂ films at an energy below 1 keV and a dose of about 10¹⁸ cm^?2 has been studied by evaluating MOS C-V curves, FET characteristics, as well as Rutherford ion backscattering spectra. The bombarded samples revealed that ion beam etching in this energy range causes a damaged layer of 5–10 nm thickness at the single crystal silicon surface. Moreover, traces of metal atoms are found in the damaged layer together with argon atoms (≈ 10²¹cm^?3).     

Superconductors with crystalline-field split impurities: Upper critical field and specific heat

We continue the investigation of crystalline-field effects on the properties of superconductors containing rare-earth impurities. Attention is focused on impurities with a nonmagnetic ground state. We calculate the upper critical fieldH _{c 2} and the jump of the specific heat at the phase transition.     

Ermittlung der Sequenzverteilung und Taktizität bei Acrylnitrill/Vinylidenchlorid-Copolymeren

An acrylonitrile/vinylidene chloride copolymer prepared by continuous suspension polymerization in aqueous medium was examined by carbon magnetic resonance at 90.52 MHz. The sequence distribution was evaluated from the diad and tetrad distribution of the methylene carbon regions and from the triad distributions of the other carbon atoms. The stereochemical configuration of the acrylonitrile units was determined from the peaks of the methine and the nitrile carbons which showed a low preference of the isotactic triad against the syndiotactic triad in agreement with freeradical polymerized polyacrylonitrile.