Performance monitoring of the EC - 1030 system by a microprocessor - based monitor

This paper presents a M6800 microprocessor based hardware monitor for measuring certain selected parameters of the EC-1030 computer system. The motivation for this work was to get an insight into the operation of the system under the present work load and use these results towards improvement and design studies. The three main classes of quantitative indices of computer system performance/productivity, responsiveness and use have been measured using hardware and software tools. This paper describes the hardware monitor design and discusses the measurements made.     

Competitive dynamics and economic learning: an extended resource-based view

In this paper a conceptual framework for the analysis of economiclearning is developed. Economic learning, by analogy with organizationallearning, results in the development of economic competences,or capabilities, shared between firms, which rest on a foundationof economic resources, from which value is generated, and economicroutines, through which resources are utilized. It is the mobilityof resources, and their exchange and production dynamics, alongevolutionary pathways, which underpins the plausibility of anotion of economic learning. The paper elaborates this frameworkas a ‘resource-based view’ (RBV) of the economyas a whole, as an extension of the RBV of the firm. Such a frameworkcaptures the dynamics of exchange and circulation of technologies,know-how and intangible assets, as well as of tangible assetsand capital goods; it is concerned with investment behaviorby entrepreneurs rather than with the behavior of producersand consumers in goods and services markets. Within this resourceeconomy framework, it is possible to generate an account ofthe resource dynamics that underpin production of goods andservices—including resource propagation, diffusion, imitation,replication and recombination. These processes encompass evolutionarypressures, experienced through resource variation, selectionand retention. Entrepreneurial initiatives take the form ofresource recombinations, while resource innovation capturesthe creation of new economic resources, such as technologicalstandards. Such a perspective brings into focus the resourcespecialization and configurations that drive real economies,within firms and between firms, that translates into enhancedor diminished performance of the economy as a whole.     

Passive cooling of the PBMR spent and used fuel tanks

The pebble bed modular reactor (PBMR) is a new generation high temperature gas-cooled reactor, making use of spherical fuel elements. The spent fuel and partially burnt fuel (called used fuel) is stored in large storage tanks. This paper presents the cooling design of the storage tanks, with special emphasis on its passive cooling ability.For corrosion protection, the tanks are cooled with a closed loop active system, however, passive cooling is seen as the ultimate cooling mode for the storage tanks. If the active cooling fails, the flow automatically bypasses the active system and passive cooling takes over. The active cooling is thus not safety-related; rather its purpose is for investment protection.The storage tank design with its longitudinal internal cooling pipes has a good passive cooling ability. The layout of the tank concrete cubicle ensures that cooling air can flow only in the desired direction. Computational fluid dynamics (CFD) analyses have been done for various heat load scenarios inside the tank. Passive cooling exists for tanks with a low spent fuel fill level with heat load below 25 kW up to a tank containing a full PBMR core (used fuel) with heat load of 640 kW. For all scenarios, the maximum fuel temperature is below 400 °C.A method was developed to calculate the passive cooling characteristics of the tank at a fraction of the time it takes CFD by using the pipe network simulation software Flownex. The method was also used to analyze transient passive cooling events and showed flow phenomenon similar to what CFD analyses have predicted.A small-scale two-dimensional representation of the storage tank and cubicle layout has been built. This experiment demonstrates the passive cooling ability of the tank. It also proved the flow characteristics that were predicted by the CFD and Flownex analyses.It has been shown through diverse techniques that the fuel inside the tanks can be cooled passively. There are still a few aspects which need to be explored in more detail, but overall it can be said that passive cooling of the PBMR spent and used fuel in bulk storage tanks is viable.     

Spectroscopic Measurements of Oxygen Saturation in the Retina

We introduce a new type of retinal oximeter able to capture multiple spectroscopic sensitive images of the retina in a single snapshot. The core of our apparatus is a multiaperture camera that can be easily interfaced with a fundus camera system. A lenslet array divides the image collected by a fundus camera into identical subimages. A bandpass filter array in front of the lens system is used to collect the subimages only at the wavelengths of interest. Two different instruments were designed based on this simple principle. The first system can collect six different images, while the second system can collect up to 18 different images in a single snapshot.     

Facilitating a benign attentional bias reduces negative thought intrusions.

The causal role of biased attention in worry was investigated in an experiment in which high worriers were assigned either to a condition requiring attention to nonthreatening words and text while ignoring worry-related material or to a mixed-attention control condition. The former procedure led to fewer negative thought intrusions in a worry test (as rated by both participants and an assessor) than did the control condition. These findings suggest that attentional bias plays a causal role in worry and that its modification can reduce excessive worry. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Amygdaloid lesion increases the toxicity of intrahippocampal kainic acid injection and reduces the late occurrence of spontaneous recurrent seizures in rats

Spontaneous recurrent seizures (SRS) following intrahippocampal kainic acid (KA) injection have been described in a previous paper from our laboratory. The SRSs are clinically similar to the seizures induced by kindling the amygdala and we suggested that the amygdala plays a role in initiating the SRSs. Accordingly, the present paper examines the effect of amygdaloid lesions on intrahippocampal KA-treated rats. There were short- and long-term effects. (1) Short-term: the toxicity of KA was increased in lesioned animals. Status epilepticus followed by death of the animals was evoked with half of the dose required to cause the same effect in intact rats. Moreover, a gross haematuria was encountered 6-12 h after KA injection. This was not observed in non-lesioned rats even following the highest KA doses. (2) Long-term: amygdaloid lesions delayed the occurrence of the SRSs, reduced their incidence and modified their expression. In lesioned animals seizures began with a period of tonic immobility with no sign of the masticatory movements seen in intact animals. Histological examination of the KA-induced lesions did not show any major differences between lesioned and intact animals. It is suggested that the short-term effects are due to an unspecific effect on homeostatic mechanisms, whereas the long-term ones reflect a specific involvement of the amygdala in the late appearing seizures.     

Using conscious reflection,group processes,and AI to facilitate development of expertise

Three experiments investigated procedures derived from research on knowledge acquisition, group processes, and artificial intelligence for facilitating the development of expertise. In each experimental session, subjects learned to control a simulated sugar production factory. Then they formulated written policies for controlling sugar production either alone as individuals or in small groups. An adaptive AI system provided feedback on policy quality. The research also investigated the use of forced reflective practice in which learners attempted to predict what their policy would do while performing the task. The AI system provided feedback about what their policy would have done in each situation and the outcome based on their policy's response or their suggested alternative response. Results indicated that group interaction and feedback from the AI system improved policy quality. However, only when all three procedures were employed, group interaction, AI feedback, and forced reflective practice, was the development of individual expertise on the task enhanced.     

Kinetics and mechanisms of chemical reactions in nonequilibrium-plasma etching of silicon and silicon compounds

Plasma-chemical etching of silicon and silicon compounds is reviewed. It is shown that present data indicates that fluorine atoms and molecules are the main particles responsible for etching of silicon and that atomic fluorine is the main active particle for etching of silicon dioxide. Insufficient data exists to establish the contribution of charged and excited states to the etching of silicon and its compounds but oxygen atoms and molecules are seen to have a strong influence and fluorocarbon radicals can passivate the surface by forming polymer films.     

Detailed active site configuration of a new crystal form of methanol dehydrogenase from Methylophilus W3A1 at 1.9 A resolution

The three-dimensional structure of a new crystal form of methanol dehydrogenase from Methylophilus W3A1 has been obtained in the presence of substrate using data recorded at a synchrotron. The structure of this approximately 140 kDa heterotetramer, refined at 1. 9 A resolution, reveals the detailed configuration of its redox cofactor, pyrroloquinoline quinone (PQQ). C4, one of the oxygen-bearing atoms of this orthoquinone is in a planar configuration while C5, which bears the other quinone oxygen, is tetrahedral, suggesting that the PQQ is in the semiquinone redox state. The substrate binding site has been identified close to PQQ and to the side chain of Asp297, the putative active site base. The proximity of the hydroxyl of methanol to C5 of PQQ compared to the greater separation of the substrate methyl group from C5 supports the addition-elimination reaction mechanism involving a hemiketal intermediate.