The importance of incorporating reliability of supply criteria in a regulatory system of electricity distribution: An empirical analysis for Austria

Grid tariffs are the main source of income for distribution system operators (DSOs). Reductions of tariffs increase the cost pressure on DSOs; assuming they work efficiently, tariff reductions potentially lead to a decrease of the electricity system's quality if no reliability of supply criteria are incorporated in the regulatory system. Our statistical analysis shows that the correlation between grid tariffs and electricity supply interruptions in a regulatory regime neglecting this incorporation is significant and that furthermore decreasing tariffs harm the reliability of supply even in the short run. Our econometric analysis of the influence of tariffs on reliability of supply shows a significant correlation between the grid tariffs and the duration of power outages in the Austrian electricity grid; an annual average interruption duration per installed capacity of a specific grid increases ceteris paribus by 1.36 min if the grid tariff of this specific grid is decreased in the previous year by 1€/MWh.     

Volume and surface-area measurements using tomography,with an example from the Brenham pallasite meteorite

Increased computer speed has helped to proliferate tomography throughout the geosciences. Although best known from the medical CATscan, tomography is also a powerful tool for geological problems. Whereas qualitative tomography is widely used, quantitative data from tomograms are not so commonly available. Presented here are two programs, Electron Tomography Segmentation, surface Area, and Volume (ETSAV) and Electron Tomography CUTter (ETCut), that were written to obtain quantitative volume and surface-area data from tomograms. Based on a specified threshold value, ETSAV distinguishes objects within a tomogram and then returns volume and surface-area data for each object. If object separation is unsatisfactory using a single threshold, ETCut is called to digitally separate objects that appear connected in the tomogram, allowing ETSAV to perform its functions. By knowing the nature of the object of interest, error can be corrected to, on average, less than 5% for a single object; combined volumes of many particles of different sizes may result in lesser errors. A section of the Brenham pallasite meteorite was examined using the programs. Olivine comprises 67.2% of the volume (50.4% wt%), followed by FeNi metal at 23.1% (39.3% wt%), troilite at 4.4% (4.8% wt%), and schreibersite at 3.4% (5.5% wt%). In all, 56.1% and 44.7% of the troilite and schreibersite surface areas, respectively, border olivine, suggesting that they wet olivine. Since the programs can be applied to any tomogram, from any field, there are many potential applications.     

Willibald Riedler emeritiert — Ein Rückblick auf das Leben und Wirken eines großen Österreichers

Ohne Zusammenfassung     

Naßmahlung in Rührwerksmühlen

Wet grinding in agitated ball mills. To ensure certain product qualities it is necessary to have very fine particles or a narrow particle size distribution. For this process agitated ball mill grinding can be used as well as crystallisation and precipitation. Cost effective grinding of very fine products to a narrow particle size distribution requires that the effects of variation of strain intensity, frequency of impacts, residence time distribution, size of grinding media, viscosity of liquid and concentration of feed material should be known. The most important parameters and their effects on the grinding result are demonstrated, as well as explained by a model, and the consequences for the operating conditions of agitated ball mills are presented. By using small grinding media in agitated ball mills the production rate can be increased, or at the same energy level smaller particles can be obtained by grinding or deagglomeration. At high flow rates and a narrow residence time distribution the feed material becomes more homogeneous. These facts require the development of new or modified types of agitated ball mills.     

Geräte für die betriebsmäßige Prüfung von Lacken und Lackschichten bei der Holzverarbeitung

European Journal of Wood and Wood Products - Es wurde eine Reihe von Prüfverfahren und Prüfgeräten beschrieben, wie sie bei der Prüfung von Lacken und Farbanstrichen in der...     

Improvements of metabolic imbalances after enteral sodium bicarbonate supplementation in infants of very low birth weight (VLBW) (Short communication)

One of the main points of clinical care is the catch-up growth of VLBW infants especially those of small gestational age (SGA). The required high amounts of protein are often not tolerated [1]. Metabolic imbalances due to immaturities of protein metabolism are described [2, 3] also in infants SGA feeding amounts of proteins comparable to mature newborns [4]. Remarkable signs of overloading by proteins are the elevation of amino acid and the bile acid concentrations in the serum [3, 5, 6]. In some of those cases [7] late metabolic acidosis (LMA) is to be seen. There is evidence in the literature that sodium bicarbonate influences nitrogen [8] and ionic balances [9] in newborn animals without any signs of acidosis, besides its simple buffer function. The aim of this study was to control changes of metabolic imbalances after bicarbonate supplementation before development of acidosis in predisposed infants. Therefore we determined parameters, which were significantly changed with LMA [6] during two feeding schedules: firstly, during bolus supplementation in infants feeding (2.0 ± 0.4) g/kg BW · d protein and secondly during chronic supplementation of bicarbonate to (3.0 ± 0.4) g/kg BW · d protein. In relation to the improvement of the nitrogen balance in growing lambs [7] we supposed comparable effect of bicarbonate on metabolic imbalances caused by protein overloading.