Steel Desulphurisation and Sulphur Bonding in Solidified Ladle Slags

It was investigated in which form sulphur is bonded in ladle slags. For this purpose, the mineralogical phases of the ladle slags were qualitatively and quantitatively evaluated by means of a microprobe. This slag characterisation allowed reconstructing the bonding of sulphur into the phases of the ladle slag. Moreover, the reaction process with regard to the ionic theory as well as the structural formula for the mechanism of sulphur bonding were discussed. The bonding of sulphur into calcium aluminate slags is determined by the sulphide ion content in the slag as well as by the ratio of (CaO)/(Al₂O₃). Calcium sulphide separates only if the slag contains a large number of sulphide ions. When Ca₁₂Al₁₄O₃₃ is separated the sulphide ion is successively integrated into the lattice. The crystal lattice of Ca₁₂Al₁₄O₃₃ is characterised by an open, three‐dimensional anionic network composed of aluminium‐oxygen tetrahedrons linking the edges. In this network, large interstitial spaces are formed, which may be filled with calcium ions on the one hand and statistically with a free oxygen or sulphide ion on the other hand.     

A tele‐experiment on rover motor control via internet

Modern Internet and multimedia techniques enable experiments with remote hardware. This way engineering students can gather practical experience even in areas where their own university does not have the related equipment in place. The focus of this paper is on an experiment to develop a motor controller for a remote mobile robot. Implementation details of such an experiment are addressed with emphasis placed on the subject of tuning a PID controller for steering and speed adaptation of a rover. The complete experiment is conceived as a self‐explaining learning unit on the web. The learning unit comprises material on theory, exercises to provide feedback to the student about his learning progress, simulations to study motor control effects, and finally the experiment with remote robot hardware. This paper presents software techniques to realize a robust system implementation, the educational considerations necessary to present the experiment material properly for the tele‐education context, and experiences obtained during the use of this remote experiment in previously taught classes. © 2005 Wiley Periodicals, Inc.     

Pop-out into memory: A retrieval mechanism that is enhanced with the recall of subject-performed tasks.

Subject-performed tasks (SPTs; i.e., carrying out the actions during study) improve free recall of action phrases without enhancing relational information. By this mechanism, items pop into a person's mind without active search, and this process especially extends the recency effect. The authors demonstrated the existence of the extended recency effect and its importance for the SPT recall advantage (Experiments 1 and 2). Carrying out the action and not semantic processing caused the effect (Experiment 3). The extended recency effect was also not a consequence of a deliberate last-in, first-out strategy (Experiment 4), and performing a difficult secondary task (an arithmetic task) during recall reduced memory performances but did not influence the extended recency effect (Experiment 5). These data support the theory that performing actions during study enhances the efficiency of an automatic pop-out mechanism in free recall. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Moving cultures: The perilous problems of cultural dichotomies in a globalizing society.

The accelerating process of globalization and the increasing interconnections between cultures involve an unprecedented challenge to contemporary psychology. In apparent contrast to these trends, academic mainstream conceptions continue to work in a tradition of cultural dichotomies (e.g., individualistic vs. collectivistic, independent vs. interdependent), reflecting a classificatory approach to culture and self. Three developments are presented that challenge this approach: (a) cultural connections leading to hybridization, (b) the emergence of a heterogeneous global system, and (c) the increasing cultural complexity. By elaborating on these challenges, a basic assumption of cross-cultural psychology is questioned: culture as geographically localized. Finally, 3 themes are described as examples of an alternative approach: a focus on the contact zones of cultures rather than on their center, the complexities of self and identity, and the experience of uncertainty. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Small‐angle X‐ray scattering investigation of the deformation processes in the amorphous phase of high density polyethylene

In situ small‐angle X‐ray scattering of high density polyethylene under uni‐axial tensile test was used for investigating the deformation at the scale of the periodic crystalline–amorphous nano‐structure. The more or less uniform elastic straining of the rubbery amorphous layers is discussed in terms of mechanically active intercrystalline tie chains. Correlation is made with the long‐term use properties. It is concluded that this approach is a powerful means to assess the mechanical efficiency of tie molecules. Copyright © 2004 Society of Chemical Industry     

Measurement of thermal conductivity of polymer melts by the line-source method

An apparatus has been developed for the measurement of thermal conductivity of polymer melts. Based on the transient “line source method,” it is ideally suited to these materials because measurements can be made quickly, before the onset of thermal degradation. Also, little or no sample preparation is required. A number of commercial polymers have been tested, including some glass-fiber filled composites.     

Microfluidic push-pull probe for scanning electrochemical microscopy

This paper presents a microfluidic push-pull probe for scanning electrochemical microscopy (SECM) consisting of a working microelectrode, an integrated counter/reference electrode and two microchannels for pushing and pulling an electrolyte solution to and away from a substrate. With such a configuration, a droplet of a permanently renewed redox mediator solution is maintained just at the probe tip to carry out SECM measurements on initially dry substrates or in microenvironments. For SECM imaging purposes, the probe fabricated in a soft polymer material is used in a contact regime. SECM images of various gold-on-glass samples demonstrate the proof-of-concept of a push-pull probe for local surface activity characterization with high spatial resolution even on vertically oriented substrates. Finite element computations were performed to guide the improvement of the probe sensitivity.