19,472 research outputs found

    High density circuit technology

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    Polyimide dielectric materials were acquired for comparative and evaluative studies in double layer metal processes. Preliminary experiments were performed. Also, the literature indicates that sputtered aluminum films may be successfully patterned using the left-off technique provided the substrate temperature remains low and the argon pressure in the chamber is relatively high at the time of sputtering. Vendors associated with dry processing equipment are identified. A literature search relative to future trends in VLSI fabrication techniques is described

    High density circuit technology

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    Acquisition of polyimide materials for inter-metal dielectrics was obtained from three vendors, with considerable evaluation conducted on the Dupont PI2550 material. Experimental results indicate this material can be patterned using contact printing to line width far below 0.1 mils. Optimum line width is acquired using plasma etch equipment. Metal lift-off experiments on thermal evaporated films were optimized for application to sputtered deposited films. Alternate metal-lift-off experiments are proposed for future investigation. Dry processing equipment studies and future trends in VLSI fabrication techniques are on-going

    Post heat treatment effects on double layer metal structures for VLSI applications

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    The realization of high yield double layer metal systems using wet chemistry processes and the ability to extend yields beyond that attainable with wet chemistry by means of post sintering processes at temperatures below 500 C for potential applications in very large scale integration structures were studied. Yields in excess of 98% and average total contact resistance of less than 150 ohms and 200 ohms were realized for a series of 560 vias of 0.5 X 0.5 mils and 0.2 X 0.2 mils in size, respectively

    Digital Scotland, the relevance of library research and the Glasgow Digital Library Project

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    The Glasgow Digital Library (GDL) Project has a significance over and above its primary aim of creating a joint digital library for the citizens of Glasgow. It is also both an important building block in the development of a planned and co-ordinated 'virtual Scotland' and a rich environment for research into issues relevant to that enterprise. Its creation comes at a time of political, social, economic and cultural change in Scotland, and may be seen, at least in part, as a response to a developing Scottish focus in these areas, a key element of which is a new socially inclusive and digitally driven educational vision and strategy based on the Scottish traditions of meritocratic education, sharing and common enterprise, and a fiercely independent approach. The initiative is based at the Centre for Digital Library Research at Strathclyde University alongside a range of other projects of relevance both to the development of a coherent virtual landscape in Scotland and to the GDL itself, a supportive environment which allows it to draw upon the research results and staff expertise of other relevant projects for use in its own development and enables its relationship to virtual Scotland to be both explored and developed more readily. Although its primary aim is the creation of content (based initially on electronic resources created by the institutions, on public domain information, and on joint purchases and digitisation initiatives) the project will also investigate relationships between regional and national collaborative collection management programmes with SCONE (Scottish Collections Network Extension project) and relationships between regional and national distributed union catalogues with CAIRNS (Co-operative Academic Information Retrieval Network for Scotland) and COSMIC (Confederation of Scottish Mini-Clumps). It will also have to tackle issues associated with the management of co-operation

    Welfare Implications of Selected Supply and Demand Shocks on Producers and Marketers of U.S. Meats

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    An equilibrium displacement model is developed and used to estimate the welfare impacts of government and industry-funded promotion programs, country of origin labeling (COOL), and the disease-driven, international bans on U.S. beef. The model goes beyond past studies by including the U.S. domestic market and both U.S. meat imports and exports, with meats differentiated by source of origin. The results indicate that while the benefits from beef and pork promotions are higher, the negative impacts of COOL are lower in a model with international trade than in a model without trade. International bans on U.S. beef decrease the welfare of producers and marketers of U.S. beef.beef ban, country of origin, equilibrium displacement model, pork, poultry, promotion, Demand and Price Analysis,

    A model for the fast ionic diffusion in alumina-doped LiI

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    Lithium Iodide shows enhanced ionic conductivity when doped with a powder of the insulator, alumina. We extend Landauer's effective medium model to see if the observations are consistent with a high conductivity layer forming on each non-conducting particle. The predictions are consistent with experiment provided one assumes the layer a few hundred Angstroms thick. At the outside, away from the particle, the enhancement of conductivity should fall off slowly, as in Debye-Huckel screening, whereas it is possible a new phase forms close to the insulator surface

    HD66051: the first eclipsing binary hosting an early-type magnetic star

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    Early-type magnetic stars are rarely found in close binary systems. No such objects were known in eclipsing binaries prior to this study. Here we investigated the eclipsing, spectroscopic double-lined binary HD66051, which exhibits out-of-eclipse photometric variations suggestive of surface brightness inhomogeneities typical of early-type magnetic stars. Using a new set of high-resolution spectropolarimetric observations, we discovered a weak magnetic field on the primary and found intrinsic, element-dependent variability in its spectral lines. The magnetic field structure of the primary is dominated by a nearly axisymmetric dipolar component with a polar field strength Bd600B_{\rm d}\approx600 G and an inclination with respect to the rotation axis of βd=13o\beta_{\rm d}=13^{\rm o}. A weaker quadrupolar component is also likely to be present. We combined the radial velocity measurements derived from our spectra with archival optical photometry to determine fundamental masses (3.16 and 1.75 MM_\odot) and radii (2.78 and 1.39 RR_\odot) with a 1-3% precision. We also obtained a refined estimate of the effective temperatures (13000 and 9000 K) and studied chemical abundances for both components with the help of disentangled spectra. We demonstrate that the primary component of HD66051 is a typical late-B magnetic chemically peculiar star with a non-uniform surface chemical abundance distribution. It is not an HgMn-type star as suggested by recent studies. The secondary is a metallic-line star showing neither a strong, global magnetic field nor intrinsic spectral variability. Fundamental parameters provided by our work for this interesting system open unique possibilities for probing interior structure, studying atomic diffusion, and constraining binary star evolution.Comment: 14 pages, 15 figures; accepted for publication in MNRA
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