25,330 research outputs found

    Island formation without attractive interactions

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    We show that adsorbates on surfaces can form islands even if there are no attractive interactions. Instead strong repulsion between adsorbates at short distances can lead to islands, because such islands increase the entropy of the adsorbates that are not part of the islands. We suggest that this mechanism cause the observed island formation in O/Pt(111), but it may be important for many other systems as well.Comment: 11 pages, 4 figure

    Materials analysis of fluorocarbon films for MEMS applications

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    In this paper the results of the materials analysis of fluorocarbon (FC) films are presented. The properties of the fluorocarbon films are comparable to those of polytetrafluoroethylene (PTFE), better known under the trademarks such as teflon and fluon. The properties of PTFE are desirable for MEMS applications and enable new designs, new applications and new technological processing routes for microsystems. Therefore, FC films have a tremendous potential for MEMS applications. Furthermore, FC films can easily be deposited via spin coating, e-beam evaporation, in conventional reactive ion etchers and in plasma-enhanced deposition chambers using a carbonhydrotrifluoride plasma facilitating the use of the films for micro electro-mechanical structures. The films deposited in a reactive ion etcher are extremely chemical resistant. The X-ray photoelectron spectroscopy (XPS) analyses results are presente

    Contemplating workplace change: evolving individual thought processes and emergent story lines

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    Drawing on topical life histories of physicians in a particularly volatile public health sector environment, we build theory around the contemplation of workplace change. Overall, our study provides evidence as to why single or multiple independent factors, such as pay or job structure, may fail to predict or explain individual decisions to stay in or change workplaces. Instead, the contemplation process we argue is a complex, evolutionary, and context-dependent one that requires individualized interventions. Our findings reveal the prevalence of episodic context-self fit assessments prompted by triggering stimuli, two mechanisms by which thought processes evolved (reinforcement and recalibration), and four characteristic story lines that explain why the thought processes manifested as they did (exploring opportunities, solving problems, reconciling incongruence, and escaping situations). Based on our findings, we encourage practitioners to regularly engage in story-listening and dialogic conversations to better understand, and potentially affect the evolving socially constructed realities of staff members

    Deemo: a new technology for the fabrication of microstructures

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    The recent innovations in dry etching make it a promising technology for the fabrications of micromoulds. The high aspect ratios, directional freedom, low roughness, high etch rates and high selectivity with respect to the mask material allow a versatile fabrication process of micromoulds for subsequent electroplating and embossing, as is demonstrated with the DEEMO process. DEEMO is an English acronym and stands for Dry Etching, Electroplating and Moulding

    Molecular Lines as Diagnostics of High Redshift Objects

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    Models are presented for CO rotational line emission by high redshift starburst galaxies. The influence of the cosmic microwave background on the thermal balance and the level populations of atomic and molecular species is explicitly included. Predictions are made for the observability of starburst galaxies through line and continuum emission between z=5 and z=30. It is found that the Millimeter Array could detect a starburst galaxy with ~10^5 Orion regions, corresponding to a star formation rate of about 30 Mo yr^{-1}, equally well at z=5 or z=30 due to the increasing cosmic microwave background temperature with redshift. Line emission is a potentially more powerful probe than dust continuum emission of very high redshift objects.Comment: 15 pages LaTex, uses aasms4.sty, Accepted by ApJ
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