Determination du coefficient d'extinction molaire de OH− dans les verres fluores a base de metaux lourds

The extinction coefficient ? at 2.9 μm for OH in fluoride glasses is measured by determining the amount of HF evolved during heating of the glass under steam and the corresponding intensity of the OH absorption band. This coefficient is respectively equal to 31 litre mole^?1 cm^?1 for BTYbZ glass (15 BaF₂ - 29 ThF₄ - 28 YbF₃ - 28 ZnF₂) and 19.5 litre mole^?1 cm^?1 for BALLA glass (34 BaF₂ - 57 ZrF₄ - 4 AlF₃ - 5 LaF₃).     

On coordinating warehouse sizing, leasing and inventory policy

Organizations often fulfil their storage needs by supplementing their own warehouse with leased space, a scenario modeled here under the assumption of constant product demand. Closed-form formulae are obtained for the decision variables of interest, namely, the replenishment lot size and the warehouse size, as well as the amount of space to lease. Cost savings due to leasing are shown to have an upper bound of approximately 29% when the optimal warehouse capacity can be installed without restrictions (such as a budgetary constraint). A numerical example further indicates that leasing is significantly more beneficial when the warehouse size is tightly constrained, and that total costs are robust with respect to demand fluctuations.     

Comparative influence of a single allergen exposure on the different components of airway response to methacholine

We compared the effects of an allergen challenge on airway responsiveness to methacholine, the slope of the dose-response curve (DRC) and post-methacholine fall in forced vital capacity (FVC) or forced expiratory volume in 1 s (FEV1)/FVC, and determined whether any changes in these parameters were related to the presence and magnitude of the late asthmatic response (LAR) in mild stable asthma. Twenty-three allergic asthmatic subjects had an allergen challenge, preceded and followed 24 (n = 12) and/or 48 (n = 22) h later by a methacholine challenge. Sixteen subjects had a dual asthmatic response to the allergen. On the post-allergen methacholine challenge, as compared with the pre-allergen test, differences in mean fall in FVC or FEV1/FVC at 20% fall in FEV1 and the slope of the DRC did not achieve statistical significance, even in the group with LAR, which showed a significant increase in airway responsiveness at 24 h. There was, however, a correlation between allergen-induced changes in PC20 and (1) the change in post-methacholine FVC fall in the LAR group at 48 h, and (2) the change in the slope of the DRC in the early-asthmatic-response group at 24 h. In conclusion, allergen-challenge-induced changes in airway response to methacholine are heterogeneous among asthmatic subjects and although it may increase airway responsiveness (PC20), particularly in late responders, it minimally affects the other aspects of airway response to methacholine, suggesting that a more powerful or sustained allergic stimulus is required to modify the latter.     

Bizarre imagery, interference, and distinctiveness.

Previous studies have shown that bizarre and common images produce equivalent levels of recall in unmixed-list designs. Using unmixed lists, we tested the view that bizarre images would be less susceptible than common images to common sources of interference. In all experiments, subjects imaged a list of either bizarre or common sentences and then performed some kind of interfering task before recalling the initial list of sentences. Experiment 1 showed that bizarre images were better accessed than common images after imaging an intervening list of common sentences. Also, components of common images tended to be better recalled than those of bizarre images after imaging an intervening list of bizarre sentences. Experiments 2a and 2b showed that interfering tasks consisting of studying lists of common concrete nouns did not differentially affect memory for bizarre and common images. In Experiment 3, labeling and imaging an interfering list of common pictures produced higher recall of bizarre images. Generally, bizarre images appeared to be less susceptible than common images to interference from certain types of common encodings. Importantly, the superior recall of bizarre images was always due to greater image (sentence) access, whereas higher recall of common images was associated with greater recovery of the image (sentence) constituents. Explanation of the precise pattern of results requires consideration of the distinctive properties of bizarre images. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

SMC composites waste management as reinforcing fillers in polypropylene by combination of mechanical and chemical recycling processes

A new process of management of waste of composite materials from Sheet Moulding Compounds (SMC), as reinforcing fillers for thermoplastic materials, including both mechanical and chemical processes is proposed in this paper. Communited SMC being composed of coated glass fibres intimately mixed with calcium carbonate powder, their reinforcing power is low. First, the fibrous part was increased by partial dissolution of calcium carbonate present in the crushed products SMC. Second, a process of partial solvolysis was developed aiming at strong increasing the interfacial mechanical properties by functionalising of SMC load incorporated into polypropylene/grafted maleic anhydride polypropylene (PP/PP_gma). At this effect, we investigated a treatment with a hot triamine (diethylenetriamine, DETA) in order to create a functionalisation, after scission of the bond ester of unsaturated polyester, as bridging amino-succinimide.The effect of this recycling way by partial solvolysis was checked from the mechanical properties of the resulting reinforced PP/PP_gma material: Although a lower of Young modulus, better yield stress and especially resilience were observed.     

Agent-oriented techniques for network supervision

This paper presents the results of the Réseau futé (smart net) project, the goal of which is to use distributed AI and multi-agent techniques for network management and supervision. More precisely, these techniques have been applied to the partial automation of the dynamic processing (what is known about a network is always incomplete and can change at any time) of alarms and of various event notifications received by network management platforms. The system that we propose is able for example to automatically handle some alarms or to filter events of no-interest for a given operator. To achieve this goal, an assistant, or interface agent according to the model proposed by Patti Maes [MK93], has been realized. The goal of the assistant is first to learn, by observation, the behavior of the network supervision operator and second to reproduce such a behavior when the conditions in which the behavior has been learned are detected again. The learned information are stored using chronicles [Gha94]. A chronicle is a data-structure allowing programmers to represent sequences of events while taking temporal knowledge into account. Our assistant has been implemented and tested within Magenta which is a program, written in Smalltalk, that simulates (in a simplified way) a network management platform. This program respects roughly the gdmo and cmis standards.     

Aging and prospective memory: Examining the influences of self-initiated retrieval processes.

Past research has frequently failed to find age differences in prospective memory. This article tested the possibility that age differences would be more likely to emerge on a prospective memory task that was high in self-initiated retrieval. In the 1st experiment, participants were asked to perform an action every 10 min (a time-based task presumed to be high in self-initiated retrieval); in the 2nd experiment, participants were asked to perform an action whenever a particular word was presented (an event-based task presumed to be relatively low in self-initiated retrieval). Age differences were found with the time-based task but not with the event-based task. This pattern of age differences was again found in a 3rd experiment in which a new experimental procedure was used and the nature of the prospective memory task was directly varied. Generally, the results suggest that self-initiated retrieval processes are an important component of age-related differences across both retrospective and prospective memory tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)