Disclosure: Chaotic implementation thwarts intention of directive

Jan Willem Langeraar of Ecofys and Rolf de Vos of Greenprices argue that, as well as the Guarantee of Origin (see Refocus, Jul/Aug 2003, p. 62), European harmonisation is also needed for the mandatory disclosure of the fuel mix (legislation to be implemented before July 1st 2004). This they claim is needed foremost in the monitoring of the environmental quality of power generation. A harmonised way of collecting information will guarantee transparency and - in the end - establish the consumer's trust. There are several initiatives currently on the table. The implementation of the disclosure in Austria shows what the harmonisation could look like.     

A critical review of Iran''s buyback contracts

Iran's oil and gas industry requires investments of US$ 15 billion in the short term and over US$70 billion in the medium term. Iran tries to interest international oil companies (IOC) in investing in Iran's oil and gas business by offering buyback contracts. Under a buyback contract an IOC invests and when production starts, the field is handed over to the National Iranian Oil Company (NIOC) or one of its representatives. The IOC gets its costs and an agreed upon profit paid out of the oil and/or gas gross profits, assuming the field produces as agreed upon and the international energy prices are high enough. According to the Iranian government, the buyback contract contains sufficient incentives for an IOC to invest in Iran. The IOCs, however, disagree. They claim that they solely bare the risks in a buyback contract, whereas the Iranian counterpart receives all windfall profits. Furthermore, the IOCs claim that the utilisation of Iran's oil and gas reserves will be sub-optimal if they are not involved in optimising long-term recovery. In this paper, we investigate these claims and show that they are partly correct. Given Iran's need for investment capital, Iran might have to change its policy.     

Corrosion of high temprature alloys in the primary circuit helium of high temperature gas cooled reactors. – Part I: Theoretical background

The interaction of Ni and Fe-Ni base alloys with the reactive impurities H₂O, CO, H₂ and CH₄ in simulated cooling gas of the primary circuit of the High Temperature Gas Cooled Reactor (HTGR) causes corrosion effects that can significantly influence the mechanical properties. Apart from the formation of surface scales (oxides, carbides or mixed oxides/carbides), structural changes of the alloys are observed; depending on gas composition, gas supply rate and test temperature, carburization or decarburization can occur. In this report it is shown that an interpretation of the basic corrosion effects is possible on the basis of a modified stability diagram for chromium provided that - the kinetics of elementary gas metal reactions are incorporated in the expressions for carbon activity and oxygen partial pressure of the atmosphere and - the gradients of the potentials across the surface scales are taken into account. The interpretation allows the derivation of the corrosion behaviour of NiCr-base alloys in different HTGR helium compositions and enables the limits for the formation of protective chromia surface scales to be given. The influence of alloying elements other than chromium can be explained qualitatively. The results can be transferred to other reactive gas mixtures, which are characterized by an oxygen partial pressure near to the dissociation pressure of the scale forming oxides.     

A comparison of two paradigms for distributed shared memory

Two paradigms for distributed shared memory on loosely-coupled computing systems are compared: the shared data-object model as used in Orca, a programming language specially designed for loosely-coupled computing systems, and the shared virtual memory model. For both paradigms two systems are described, one using only point-to-point messages, the other using broadcasting as well. The two paradigms and their implementations are described briefly. Their performances are compared on four applications: the travelling-salesman problem, alpha-beta search, matrix multiplication and the all-pairs shortest-paths problem. Measurements were obtained on a system consisting of 10 MC68020 processors connected by an Ethernet. For comparison purposes, the applications have also been run on a system with physical shared memory. In addition, the paper gives measurements for the first two applications above when remote procedure call is used as the communication mechanism. The measurements show that both paradigms can be used efficiently for programming large-grain parallel applications, with significant speed-ups. The structured shared data-object model achieves the highest speed-ups and is easiest to program and to debug.     

Improved chitin production by pretreatment of shrimp shells

Pretreatment of shrimp shells was investigated in order to lower the costs and to improve the sustainability of chitin production. Physical pretreatment comprising drying, grinding and sieving is attractive for the recovery of 50% of shrimp protein as a dry powder. Pretreatment of shells by shearing in acidified water results in the removal of up to 60% of the protein and a reduction of their mineral content without a decrease in the chitin yield. Both pretreatment procedures will lead to cleaner technology for chitin production, to a considerably lower need for chemicals, to useful protein by‐products, and to less‐contaminated industrial effluent. Copyright © 2004 Society of Chemical Industry     

Proper elimination of latent variables

We consider behaviors in which we distinguish two types of variables, manifest variables, the variables that are of interest to the user and latent variables, the variables that are introduced to obtain a first representation. The problem is to find a representation of the manifest behavior, that is, we want to eliminate the latent variables. If the original behavior can be represented by linear differential equations with constant coefficients, then under certain conditions the same is true for the manifest behavior. In this note we formulate and study these conditions. The results are illustrated by means of some examples. As an application we study behaviors in image representation.     

Screening for posttraumatic stress disorder: An evaluation of two self-report scales among crime victims.

The validity of the Impact of Events Scale (IES) and the Posttraumatic Stress Disorder (PTSD) Symptom Scale, Self-Report version (PSS-SR) was examined among crime victims. Both instruments performed well as screeners for PTSD. For the IES, sensitivity ranged between .93 and 1.00; for the PSS-SR, sensitivity ranged between .80 and .90. Specificity for the IES ranged between .78 and .84 and for the PSS-SR ranged between .84 and .88. Some individual items from the 2 scales performed just as well as the total scales. The authors conclude that either of these short self-report instruments or their individual items are suitable as screeners for PTSD, specifically in settings where mental health professionals are unavailable. Cross-validation of these results is necessary because of the small sample size in this study. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Technology, society, and culture: A framework for understanding

The many specific studies of science-technology-society relationships fail to provide a general framework for understanding the fundamental transformation that is taking place in human society. An analysis of the central role of culture in traditional societies—and how technology competes with and partially replaces culture as a mediating factor in human experience—can provide the basis for such a framework by thorough recognition of the phenomenon of Technique. This concept also provides some guidance for practical responses to the diverse problems characteristic of our society.