The influence of wine polymers on the spontaneous precipitation of calcium tartrate in a model wine solution

The influence of wine polymers on the spontaneous precipitation of calcium tartrate in a model wine system has been examined. Rhamnogalacturonan‐I was identified as the most effective inhibitor (precipitation induction time of 180 min compared with 7 min for the standard model). It is argued that this is a consequence of rhamnogalacturonan‐I's ability to participate in the ‘egg‐box’ type sequestration of calcium ions. The more structurally complex rhamnogalacturonan‐II had only a minor influence on the induction time (22 min). Arabinogalactan proteins and mannoproteins also have little influence with induction times ranging from 12 to 15 min. An ultra‐filtration study of four Chardonnay wines, prepared with and without the use of pectolytic enzymes, was performed in a search for conditions that might maximise the concentration of rhamnogalacturonan‐I. However, rhamnogalacturonan‐I could not be identified in any of the four wines. Implications of these observations, specifically the need to understand the inhibition exerted by specific uronic acids, for winemaking and calcium tartrate precipitation are discussed.     

Influence of various process conditions on surface finishes induced by the direct metal deposition laser technique on a Ti–6Al–4V alloy

The direct metal deposition (DMD) with laser is a free-form metal deposition process for manufacturing dense pieces, which allows generating a prototype or small series of near net-shape structures. One of the most critical issues is that produced pieces have a deleterious surface finish which systematically requires post machining steps. This problem has never been fully addressed before.The present work describes investigations on the DMD process, using an Yb-YAG disk laser, and a widely used titanium alloy (Ti–6Al–4V) to understand the influence of the main process parameters on the surface finish quality. The focus of our work was: (1) to understand the physical mechanisms responsible for deleterious surface finishes, (2) to propose different experimental solutions for improving surface finish.In order to understand the physical mechanisms responsible for deleterious surface finishes, we have carried out: (1) a precise characterization of the laser beam and the powder stream; (2) a large number of multi-layered walls using different process parameters (P(W), V(m/min), D_m (g/min), Gaussian or uniform beam distribution); (3) a real time fast camera analysis of melt pool dynamics and melt-pool – powder stream coupling; (4) a characterization of wall morphologies versus process parameters using 2D and 3D profilometry.The results confirm that surface degradation depends on two distinct aspects: the sticking of non-melted or partially melted particles on the free surfaces, and the formation of menisci with more or less pronounced curvature radii. Among other aspects, a reduction of layer thickness and an increase of melt-pool volumes to favor re-melting processes are shown to have a beneficial effect on roughness parameters. Last, a simple analytical model was proposed to correlate melt-pool geometries to resulting surface finishes.     

Hypothesized simple factor structure for the Alcohol Expectancy Questionnaire: Confirmatory factor analysis.

This study proposed and tested a theoretical factor structure for the Alcohol Expectancy Questionnaire (AEQ; S. A. Brown, M. S. Goldman, A. Inn, & L. R. Anderson [see record 1981-01217-001]). Factors were hypothesized to (a) reflect either positive or negative reinforcement, and (b) target either personal feelings or social contexts, resulting in 4 hypothesized factors (Social Enhancement, Social Coping, Personal Enhancement, Personal Coping). Participants were 180 male and 226 female undergraduates who completed the AEQ and additional self-report measures. Confirmatory factor analysis revealed that the hypothesized model fit the data. Post hoc adjustments further improved the model. Finally, a higher order factor model fit the data best. Factors correlated in hypothesized ways with other measures: (a) Only Personal Coping expectancies correlated with negative affect; (b) self-efficacy to resist drinking for emotional relief correlated highest with Personal Coping; and (c) self-efficacy to resist social pressure to drink correlated highest with Social Enhancement. Correlations with B. C. Leigh and A. W. Stacy's (see record 1993-35856-001) Drinking Expectancy Questionnaire indicated congruent and divergent validity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Training system issues in the year 2000.

This article discusses the influence of future changes in the demographics of working populations and the characteristics of the workplace on research, development, and policy for training systems. Analyses of these changes indicate that there will be more expectations that training programs will serve as a positive hope to maximize the potential of each person. This will result in increased emphasis on research to identify abilities required to perform more cognitively complex jobs. Also, research on basic skill and support programs to permit unskilled youth to enter the world of work will be required. In addition, there will be a need for research on training necessary to help future managers and leaders work with members of a more diverse work force. Finally, the implications of these changes suggest that we need policies that consider research and development on retraining as a national need to help all individuals maximize their individual talents. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

New Design of Quaternary Sequences

 We construct new families of quaternary periodic sequences having good autocorrelation properties that are useful for the synchronisation of messages in multiple access communications systems. The design of these quaternary periodic sequences makes use of a general construction based on the Gray map starting from couples of binary words with particular weight or correlation properties. Received: June 26, 2000; revised version: January 21, 2002     

As-cast microstructures and behavior at high temperature of chromium-rich cobalt-based alloys containing hafnium carbides

Hafnium is often used to improve the high temperature oxidation resistance of superalloys but not to form carbides for strengthen them against creep. In this work hafnium was added in cobalt-based alloys for verifying that HfC can be obtained in cobalt-based alloys and for characterizing their behavior at a very temperature. Three Co–25Cr–0.25 and 0.50C alloys containing 3.7 and 7.4 Hf to promote HfC carbides, and four Co–25Cr– 0 to 1C alloys for comparison (all contents in wt.%), were cast and exposed at 1200 °C for 50 h in synthetic air. The HfC carbides formed instead chromium carbides during solidification, in eutectic with matrix and as dispersed compact particles. During the stage at 1200 °C the HfC carbides did not significantly evolve, even near the oxidation front despite oxidation early become very fast and generalized. At the same time the chromium carbides present in the Co–Cr–C alloys totally disappeared in the same conditions. Such HfC-alloys potentially bring efficient and sustainable mechanical strengthening at high temperature, but their hot oxidation resistance must be significantly improved.     

Enhancement of optical processes in coupled plasmonic nanocavities [Invited

We present detailed experimental and numerical investigations of resonances in deep nanogroove gratings in metallic substrates. These plasmonic nanocavity gratings feature enhanced fields within the grooves that enable a large enhancement of linear and nonlinear optical processes. This enhancement relies on both localized and propagating surface plasmons on the nanopatterned surface. We show that the efficiency of optical processes such as Raman scattering and four-wave mixing is dramatically enhanced by plasmonic nanocavity gratings.     

On-line resources allocation for ATM networks with rerouting

This paper presents an application we developed for France Telecom R&D to solve a difficult real-life network problem. The problem takes place in an Asynchronous Transfer Mode (ATM) network administration context and consists in planning demands of connection over a period of 1 year. A new demand is accepted if both bandwidth and Quality of Service (QoS) requirements are satisfied. Demands are not known prior to the assignment and must be performed on-line according to their arrival. Moreover, the acceptance or the reject of a demand must be decided within a given time of 1 min.     

Gallium (III) Triflate Catalyzed Beckmann Rearrangement

Gallium triflate catalyzed Beckmann rearrangement is described. Various aliphatic or aromatic amides are obtained from the corresponding ketoximes in good yields. Gallium triflate exhibits high catalytic activity for a wide variety of substrates.