Hydro reservoir handling in Norway before and after deregulation

The Norwegian Energy Act that came into force in 1991 deregulated the electricity market and removed the former obligation power companies had to supply electricity to the geographical area they were responsible for. Hence producers can supply electricity on the basis of profitability. In 2007 the Energy Act was evaluated by the Government. As a part of this, a study concerning hydro reservoir handling before and after deregulation was carried out by SINTEF. Public statistics show that average hydro reservoir levels measured in per cent of reservoir capacity have been reduced after 1990. We have used the power-market model EMPS¹ (EFI's Multi-area Power-market Simulator) to analyze if this reduction can be explained by natural variation in climatic variables or by structural changes that have occurred after 1990. Simulation results show that the reduced reservoir levels cannot be explained by natural variation in climatic variables. Structural changes such as increased transmission capacities can, however, explain some of the reduction. Our study does not indicate that the present reservoir handling gives reservoir levels that are too low. In this paper we also describe the stochastic dynamic optimization problem for long-term hydropower scheduling, and we explain how this problem actually is solved by the EMPS model.     

Snowmobile fatalities aspects on preventive measures from a 25-year review

During October 1973 through May 1998, 157 snowmobile fatalities were autopsied in Northern Sweden, including 131 riders, 15 passengers, six occupants with unknown position and five victims pulled by a snowmobile. Most fatalities occurred during March and April (41%), on weekends/holidays (75%), between 18:00 and 02:00 h (59%), during darkness (63%), in clear weather (84%) and at leisure time (94%). The median age was 39 years and 92% were men. The most common causes of death were blunt trauma (53%) and drowning (38%). A total of 64% were inebriated by alcohol, with a mean blood alcohol concentration of 1.7 g/l. More inebriated victims were found during weekends/holidays than on weekdays (75 vs. 51%) and during nighttime than during daytime (92 vs. 52). Driving into water was the most common event (38%) followed by collisions with immobile objects (20%). Alcohol and speeding were the most common contributors to the crashes, while flotation snowmobile suit and helmet use were considered to be the most important injury prevention factors.     

Procurement Bidding in First-Price and Second-Price,Sealed-Bid Auctions within the Common-Value Paradigm

Within the common-value paradigm, I examine the magnitude of the differencein expected outcome between first-price and second-price, sealed-bid auctions.I limit myself to two empirical specifications of bidders' signals: Weibulland normal distribution. The optimal bid functions and the expected procurer'scost under both auction formats are derived. Simultions are undertaken toanalyze the impact that random draws of signals have on the differences inoutcome from the two auction formats. Using estimates from structuralestimation in previous empirical work on first-price auction data, whereWeibull and normal distributions of signals have been applied, thehypothetical expected gain from switching from a first-price, sealed-bidauction to a second-price, sealed-bid auction mechanism is computed.     

An approach to genetic transformation in the Xiphophorine fish

The paper describes the clinical and morphological features of a congenital neurological disease affecting two in-bred litter-mate kittens. The principal neurological features were ataxia and dysmetria. In one of the kittens light microscopy revealed widespread vacuolation of white and grey matter of the brain and spinal cord. Electron microscopy revealved intra-myelinic vacuolation and some expansion of the extracellular space. Neuronal, axonal and glial changes were not seen, nor was there evidence of myelin breakdown. The entity is compared with congenital brain oedema of calves and spongy degeneration of the CNS in man.     

Coke formation during cracking of hydrocarbons. I. The effect of pre-sulphiding on coke formation on a nickel-chromium-iron alloy under steam cracking conditions

Studies have been carried out on the effect of pre-sulphiding a nickel-chromium-iron alloy on coke formation under steam cracking conditions. Pre-sulphiding has no great effect on the gaseous product spectrum as long as some sulphur is present, but the coking rate is dependent on the amount of sulphur pre-deposited. Small amounts of sulphur reduce the coke formation, but the coking rate increases with increasing amounts of pre-deposited sulphur. As the sulphur content increases still further, coke formation passes through a maximum. A tentative explanation of these observations is advanced in terms of the effect of metal sulphides on the established mechanism of coke formation. Initial sulphiding is suggested to increase grain boundary penetration by coke and to result in the accumulation of iron sulphide on the surface. Eventually this may act to seal off grain boundaries, thereby inhibiting further coke formation.     

Dynamic demonstration of diffractive optic analog-to-digital converter scheme

Dynamic behavior of an analog-to-digital converter (ADC) based on diffractive optical element(s) (DOE)(s) was studied and found to be in agreement with predictions. The analog signal was translated to an angular deflection of a laser beam by means of an acousto-optic (AO) cell. The number of bits in this experimental demonstration was three, using an eight-element DOE array. The maximum sample rate was found to be 2.5 MS/s, the limiting factor being the transit time for the acoustic wave across the width of the laser beam in the AO cell. The study is intended as a first dynamic demonstration of a proposed ADC scheme previously demonstrated in a quasi-static version. The full potential of the ADC scheme will require the use of a fast tunable diode laser to replace the AO deflection scheme used here.     

1H-spectroscopic imaging with read gradient during acquisition in inhomogeneous fields: analysis, measurement strategy, and data processing

The proton magnetic resonance spectroscopic imaging techniques that use read gradient during acquisition produce proton spectra with high spatial and moderately high spectroscopic resolution in a reasonable time forin vivo applications. These techniques suffer mainly from the spatial and pectral distortions caused by the convolution of spectral/spatial information (chemical-shift artifacts) and from the spectral shifts caused by static magnetic field inhomogeneities. The investigators analyze the chemical-shift artifacts in the presence of nonnegligible static magnetic field inhomogeneities and propose a postdetection processing scheme to correct for such effects. Spectral artifacts caused by chemical shifts, spectral line overlapping, streak broadening, and magnetic field inhomogeneities are discussed. The postdetection data processing scheme is demonstrated on measurements of a phantom as well as a human leg. Supported by the Swedish Medical Research Council, project B-96-17x-006676-14A, and by Uppsala University are gratefully acknowledged. One of us (J.W.) is indebted to the Institute of Measurement Science, Slovak Academy of Sciences, for continuous support, VEGA Grant No. 95/5305/585,468 & 2/1207/96     

Realism in eyewitness confidence as a function of type of event witnessed and repeated recall.

This study investigated how the type of event witnessed and a repeated test schedule for confidence influenced the realism in confidence judgments. The experimental design contrasted 2 film versions (a violent and a nonviolent scenario) and 3 tests of confidence (immediate, repeated, and delayed). On average, for all single items, participants were highly overconfident in their judgments. However, the same participants severely underestimated their own performance when they, at the end of the test session, were asked to provide an estimate of how many questions they thought they had answered correctly. Whereas the effects on realism in confidence for the 2 different film versions were small, the realism in witnesses' confidence judgments increased when participants repeated their confidence ratings. The theoretical and forensical implications of these findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)