Fluidised bed gasification of a metallurgical coke with CO2/N2 Mixtures

The gasification of a metallurgical coke with CO₂/N₂ mixtures in a 0.1 m diameter fluidised bed has been studied over the temperature range 810–1050°C. The rate of gasification was found to be essentially kinetically controlled, with negligible influence of fluidisation parameters below 1000°C. A number of flow models were assessed. The plug flow model was found to be the simplest model which could predict the experimental results, giving similar results to the more complex two-phase flow model of Davidson and Harrison (1963). For the range of conditions studied, the simple nth order reaction model was used to determine a best value of the reaction order of 0.8. For this combination of flow and reaction models, an activation energy of 197 kJ/mol was deduced from the experiments, in agreement with packed bed results and literature data. Very simple models can be used to predict the experimental results within the range studied.     

Immunocytochemical and biochemical studies of the mobilisation of storage oil-bodies and proteins in germinating cotyledons of oilseed rape,Brassica napus

Seeds of Brassica napus L cv Mikado contain about 25% w/w protein in addition to 40–50% w/w storage oil. About 50% of the seed protein is the legumin-like neutral protein, cruciferin, and a further 20% is the small basic protein, napin. The only other major seed protein (20% of total) is a polypeptide of apparent molecular mass (M_r) 19 000±200, which is associated with the membranes of the storage oil-bodies. The purification of this protein and preparation of monospecific antibodies have recently been reported. The kinetics of protein and oil mobilisation and the subcellular distribution of the M_r 19 000 oil-body protein have been studied by techniques including sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), gas-liquid chromatography (GLC), sucrose density gradient fractionation, and electron microscop-immunocytochemistry. The results show that the mobilisation of the storage products of rapeseed occurs in at least three distinct phases: (1) a lag phase of 10–15 h, (2) breakdown of cruciferin and napin from 12 h until day 3, (3) breakdown of storage oil and oil-body membranes from day 2 until day 7. The M_r 19000 protein was localised on oil-body membranes in early stages of germination but was later associated with a light membrane fraction, which probably contained oil-body ghosts. Relatively little difference in the kinetics of the mobilisation of storage oils and proteins was found whether seedlings were grown in the light or in the dark. The implications of these results for the mechanism of storage oil mobilisation in oilseeds are discussed.     

Conversational processes and causal explanation.

Causal explanation takes place in and takes the form of conversation. Explanations are selected by questions and are thus governed by general rules of discourse. A conversational model of causal explanation is introduced that explicates social aspects of the explanation process by postulating that good explanations must be relevant to the focus of a why question, as well as being true. The notion of explanatory relevance enables an integration of the major models of the attribution process by showing that they use the same counterfactual logic but address different causal questions. The conversational perspective suggests a reinterpretation of many attributional biases, and also highlights the role of interpersonal goals in generating implicit questions, which in turn constrain explanations. Finally, the relevance of the conversational perspective for research on causal networks, the social context of explanation, and intrapsychic explanation is noted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Characterization of key-aroma compounds of botrytized wines,influence of grape botrytization

Botrytized wines (BW) are famous for their distinctive, complex aromas. To date, only a few studies have analysed the volatile compounds involved in their typical flavours. In this paper, GC–O was applied to BW and dry white wines (DW) made from the same grape varieties to characterize the main odorants responsible for their sensory differences. Surprisingly, only two odorous zones, with grapefruit or curry nuances, were apparently specific to BW. However, GC–AEDA revealed important differences in the FD values between BW and DW, making it possible to screen potent odorants of BW, such as 3-mercaptohexan-1-ol, homofuraneol^®, furaneol^®, sotolon, methional, and phenylacetaldehyde. GC–MS quantification of homofuraneol^®, furaneol^®, norfuraneol^®, phenylacetaldehyde, and methional in 14 BW, mostly at levels above their perception thresholds, confirmed their contribution to the aroma of BW. Increased concentrations of some of these odorants in BW were shown to be associated with grape botrytization, partially through the desiccation process.     

The computer-based patient record challenges towards timeless and spaceless medical practice

Although computerization is increasingly advocated as a means for hospitals to enhance quality of care and control costs, few studies have evaluated its impact on the day-to-day organization of medical work. This study investigated a large Computerized Patient Record (CPR) project ($50 million U.S.) aimed at allowing physicians to work in a completely electronic record environment. The present multiple-case study analyzed the implementation of this project conducted in four hospitals. Our results show the intricate complexity of introducing the CPR in medical work. Profound obstructions to the achievement of a tighter synchronization between the care and information processes were the main problems. The presence of multiple information systems in one (Communication, Decision Support, and Archival record keeping) was overlooked. It introduced several misconceptions in the meaning and codification of clinical information that were then torn apart between information richness to sustain clinical decisions and concision to sustain care coordination.     

On Implementation of Logical Time in Distributed Systems Operating over Wireless Data Networks

We address the problem of maintaining logical time in a distributed system operating over a wireless data network. In such a network a group of mobile nodes currently located in a specific area use services of a mobility service agent to communicate with each other and with the rest of the world. The graph model of the network is represented by fully-connected mesh of star-topology subgraphs. We discuss the complementary logical clocks for the wireline and wireless segment of the network and their integration into an isomorphic logical time system.     

Optimized partitioning of unstructured finite element meshes

We address the problem of automatic partitioning of unstructured finite element meshes in the context of parallel numerical algorithms based on domain decomposition. A two-step approach is proposed, which combines a direct partitioning scheme with a non-deterministic procedure of combinatorial optimization. In contrast with previously published experiments with non-deterministic heuristics, the optimization step is shown to produce high-quality decompositions at a reasonable compute cost. We also show that the optimization approach can accommodate complex topological constraints and minimization objectives. This is illustrated by considering the particular case of topologically one-dimensional partitions, as well as load balancing of frontal subdomain solvers. Finally, the optimization procedure produces, in most cases, decompositions endowed with geometrically smooth interfaces. This contrasts with available partitioning schemes, and is crucial to some modern numerical techniques based on domain decomposition and a Lagrange multiplier treatment of the interface conditions.