Matrix Transformation in Boron Containing High-Temperature Co–Re–Cr Alloys

An addition of boron largely increases the ductility in polycrystalline high-temperature Co–Re alloys. Therefore, the effect of boron on the alloy structural characteristics is of high importance for the stability of the matrix at operational temperatures. Volume fractions of ε (hexagonal close-packed—hcp), γ (face-centered cubic—fcc) and σ (Cr₂Re₃ type) phases were measured at ambient and high temperatures (up to 1500 °C) for a boron-containing Co–17Re–23Cr alloy using neutron diffraction. The matrix phase undergoes an allotropic transformation from ε to γ structure at high temperatures, similar to pure cobalt and to the previously investigated, more complex Co–17Re–23Cr–1.2Ta–2.6C alloy. It was determined in this study that the transformation temperature depends on the boron content (0–1000 wt. ppm). Nevertheless, the transformation temperature did not change monotonically with the increase in the boron content but reached a minimum at approximately 200 ppm of boron. A probable reason is the interplay between the amount of boron in the matrix and the amount of σ phase, which binds hcp-stabilizing elements (Cr and Re). Moreover, borides were identified in alloys with high boron content.     

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).     

Dynamique motivationnelle de l'epuisement et du bien-etre chez des enseignants africains.

This study examines the links between antecedents and consequences of Gabonese teachers' (N= 152) work motivation. The theoretical underpinnings are based on the Motivational Model of Job Burnout (MMJB) which is grounded in Self-Determination Theory (SDT) and states that the more supervisors satisfy an employee's need for self-determination, competence, and relatedness, the more self-determined is the latter's work motivation. The level of self-determined motivation has an impact on job satisfaction, which in turn determines life satisfaction. Higher levels of self-determined motivation also buffer emotional exhaustion and psychological distress. The model was confirmed via structural equation modeling and provides support for the validity and generalizability of the MMJB and SDT. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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.     

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)     

基于SIP的新一代电信业务

第二代(2G)移动网络和传统的固定网络都提供了一套相对完整的话音业务。尽管智能网络(IN)技术使电信业务有所增强,但电信业务的发展仍然缓慢,而且样式基本保持不变。下一代网络(NGN)和第三代(3G)移动网络就是为了克服这些局限性而设计的,它们通过重组网络架构将业务同网络分离开来、将信息和电话技术融合起来并引进了会话初始协议(SIP)等开放协议。同时,它们还有望提供满足用户和运营商需求的新的增值业务。这些网络包括满足用户对业务期望所需的所有组成部分。NGN和3G就其服务能力而言有3个主要优点:首先,它们将信息世界和电话世界结…     

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.