Material Strength in Polymer Shape Deposition Manufacturing

Shape Deposition Manufacturing (SDM) is a layered manufacturing process involving an iterative combination of material addition and material removal. Polymer SDM processes have used castable thermoset resins to build a variety of parts. The strength of such parts is determined by the bulk material properties of the part materials and by their interlayer adhesion. This paper describes tensile testing of three thermoset resins used for SDM - two polyurethane resins and one epoxy resin. Both monolithic specimens and specimens with two interlayer !nterfaces were tested. Interlayer tensile strengths were found to vary greatly among the three matenals, from 5-40 MPa.Mechanical Engineerin

What re-enactment earns us

Evidence from both behavioural and brain studies suggests that perception of actions and their outcomes may induce (overt or covert) production of related actions in perceivers. Three views of the proper function of such re-enactment have been suggested: imitation, identification, and anticipation. Here I propose that the proper function of re-enactment is to subserve anticipation of upcoming action. Re-enactment exploits the motor system's inbuilt capacity to anticipate the consequences of action and extends it from the planning of own action to the perception of foreign action

The Social Web Cockpit

The Social Web Cockpit integrates different services that have been developed in the Social Web research programme at GMD-FIT to support a knowledge sharing community. This includes a web-search based on recommendations, a concept index to develop a community vocabulary, shared workspaces for knowledge sharing, and an awareness service

What Difference Do Alternative Immigration and Integration Levels Make to Western Europe?

The population of Western Europe (EC plus EFTA) is seen as consisting of three subpopulations: the natives, the East-European immigrants, and the non-European immigrants. Different immigration levels assumed from Eastern Europe and from the rest of the world add to the non-native populations while different levels of "integration" describe the transition intensities from the non-native sub-populations to the native category. The paper gives alternative population projections to 2050 based on six scenarios with different assumptions on net migration, "integration", as well as fertility and mortality in the three categories. The results indicate that (i) in the case of no further immigration the total population of Western Europe will start to decline after 2010; (ii) the rate of integration into the native population influences the future size of the non-European population much more than alternative levels of immigration; (iii) in the long run the Eastern Europeans will be quantitatively insignificant; (iv) the Western European population is bound to significant population aging no matter what happens with immigration; and (v) in the short to medium run immigrants contribute to the alleviation of the pension burden

Scenarios for the World Population in the Next Century: Excessive Growth or Extreme Aging

For six major regions of the world, ten alternative scenarios on future fertility and mortality trends are defined and projections performed from the base year 1985 up to the year 2100. Because of the great inertia of population changes, for the next 20-30 years the scenarios based on widely diverging assumptions do not produce very different patterns. In the longer run, however, the assumption of constant fertility and mortality rates resulting in continued exponential growth yields a total population size of 15 billion in 2050 and even 39 billion in 2100. The immediate replacement fertility scenario, on the other hand, would result in 7.5 billion by 2050. This still means an addition of more than two billion people to today's population of 5.3, which is entirely due to the momentum of population growth. Another major finding is that further aging of the population structure is inevitable even under constant rates. In the case of successful curbing of population growth, aging would be extremely rapid. For example, in Africa under the immediate replacement scenario the mean age of the population would increase from presently 22.2 years to more than 40 years by 2050. More moderate scenarios also result in very significant aging

The Supernova Remnant G296.7-0.9 in X-rays

Aims: We present a detailed study of the supernova remnant (SNR) G296.7-0.9 in the 0.2-12 keV X-ray band. Methods: Using data from XMM-Newton we performed a spectro-imaging analysis of G296.7-0.9 in order to deduce the basic parameters of the remnant and to search for evidence of a young neutron star associated with it. Results: In X-rays the remnant is characterized by a bright arc located in the south-west direction. Its X-ray spectrum can best be described by an absorbed non-equilibrium collisional plasma model with a hydrogen density of N_H=1.24_{-0.05}^{+0.07} x 10^{22} cm^{-2} and a plasma temperature of 6.2^{+0.9}_{-0.8} million Kelvin. The analysis revealed a remnant age of 5800 to 7600 years and a distance of 9.8_{-0.7}^{+1.1} kpc. The latter suggests a spatial connection with a close-by HII region. We did not find evidence for a young neutron star associated with the remnant.Comment: accepted by A&A, 5 pages, 2 figure

How two share two tasks: Evidence of a social psychological refractory period effect

A strong assumption shared by major theoretical approaches to cognition posits that the human cognitive system has a limited capacity for information processing. Evidence supporting this claim comes from the dual-task paradigm in which one cognitive system has to process two tasks simultaneously. In this study, we examined whether bottleneck-like processing can also be elicited when a dual task is shared between two individuals. Under dual-task instructions giving priority to Task 1, we found evidence of a psychological refractory period effect in dual-task and joint-task conditions. Under equal priority instructions, we replicated the finding of a psychological refractory period effect in the dual-task, but not in the joint-task condition. These findings are in line with the assumption that a social psychological refractory period effect can be induced across two individuals. We suggest that this effect is due to task-specific monitoring requirements. We discuss our findings with respect to both dual-task and joint action theories

DocuDrama

This paper presents an approach combining concepts of virtual storytelling with cooperative processes. We will describe why storytelling is relevant in cooperation support applications. We will outline how storytelling concepts provide a new quality for groupware applications. Different prototypes illustrate a combination of a groupware application with various storytelling components in a Theatre of Work