1,713 research outputs found

    The cleanability of stainless steel used as a food contact surface: an updated short review

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    The effect of surface roughness on the cleanability of stainless steel as used in the foodindustry

    Fault-tolerant logical gates in quantum error-correcting codes

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    Recently, Bravyi and K\"onig have shown that there is a tradeoff between fault-tolerantly implementable logical gates and geometric locality of stabilizer codes. They consider locality-preserving operations which are implemented by a constant depth geometrically local circuit and are thus fault-tolerant by construction. In particular, they shown that, for local stabilizer codes in D spatial dimensions, locality preserving gates are restricted to a set of unitary gates known as the D-th level of the Clifford hierarchy. In this paper, we elaborate this idea and provide several extensions and applications of their characterization in various directions. First, we present a new no-go theorem for self-correcting quantum memory. Namely, we prove that a three-dimensional stabilizer Hamiltonian with a locality-preserving implementation of a non-Clifford gate cannot have a macroscopic energy barrier. Second, we prove that the code distance of a D-dimensional local stabilizer code with non-trivial locality-preserving m-th level Clifford logical gate is upper bounded by O(LD+1−m)O(L^{D+1-m}). For codes with non-Clifford gates (m>2), this improves the previous best bound by Bravyi and Terhal. Third we prove that a qubit loss threshold of codes with non-trivial transversal m-th level Clifford logical gate is upper bounded by 1/m. As such, no family of fault-tolerant codes with transversal gates in increasing level of the Clifford hierarchy may exist. This result applies to arbitrary stabilizer and subsystem codes, and is not restricted to geometrically-local codes. Fourth we extend the result of Bravyi and K\"onig to subsystem codes. A technical difficulty is that, unlike stabilizer codes, the so-called union lemma does not apply to subsystem codes. This problem is avoided by assuming the presence of error threshold in a subsystem code, and the same conclusion as Bravyi-K\"onig is recovered.Comment: 13 pages, 4 figure

    Thermoplastics for aircraft interiors

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    The goal for this contract is the development of processes and techniques for molding thermally stable, fire retardant, low smoke emitting polymeric materials. Outlined in this presentation are: (1) the typical molding types; (2) a program schedule; (3) physical properties of molding types with the test methods to be used; (4) general properties of injection molding materials; and (5) preliminary materials selection

    Graffiti Resistance of Wax-based and Epoxy-based Coatings on Steel and Concrete Substrates

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    The graffiti resistance of two coatings developed by MicroCor Technologies, Inc. – MicroCor-300 and MicroCor-500 – was analyzed on steel and concrete substrates. The coatings were tested in accordance with ASTM D6578 Standard Practice for Determination of Graffiti Resistance and ASTM D7089 Standard Practice for Determination of the Effectiveness of Anti-Graffiti Coating for Use on Concrete. Masonry and Natural Stone Surfaces by Pressure Washing. In addition, the coatings were evaluated for time of set (ASTM D1640) and chemical resistance (ASTM D1308). Of the two coatings, MicroCor-300 demonstrated better overall graffiti resistant qualities on both steel and concrete surfaces but was not as durable as MicroCor-500. Therefore, MicroCor-300 should be reapplied after each cleaning cycle for its graffiti resistant qualities to remain effective.Research was sponsored by MicroCor Technologies, Inc

    Furniture Fabrics

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    Exact date of bulletin unknown.PDF pages: 1

    Cleanability Improvement of Cotton Fabrics Through Their Topographical Changes Due to the Conditioning with Cellulase Enzyme

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    In this study, topographical changes of woven cotton fabrics conditioned with a cellulase enzyme during several wash–dry cycles are systematically studied. A recent study of cellulase enzyme effect on cellulose films has proven that this substance selectively attacks amorphous regions of cellulose, consisting of small hills in a matrix of flat crystalline regions. In another study, topographical changes caused by cotton treatment with cellulase by conditioning while washing were analysed on three different length scales in order to interpret their cooperation on water and oil absorption mechanisms and, hence, on the cleanability of cotton fabrics stained with liquid–solid, liquid and solid soils. In the present study, we emphasise the micro-topographical changes resulting from several wash–dry cycles by the application of mathematical methods to quantify the changes of yarn micro-surfaces. As a result, we present a conceptual model that describes how the topographical effect of washing and conditioning by cellulase enzyme improves the cleanability of woven plain cotton fabrics

    A two-stage ceramic tile grout sealing process using a high power diode laser Part II: Mechanical, chemical and physical properties

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    Ceramic tiles sealed using a portable 60 W-cw high power diode laser (HPDL) and a specially developed grout material having an impermeable enamel surface glaze have been tested in order to determine the mechanical, chemical and physical characteristics of the seals. The work showed that the generation of the enamel surface glaze resulted in a seal with improved mechanical and chemical properties over conventional epoxy tile grouts. Both epoxy tile grout and laser generated enamel seals were tested for compressive strength, surface roughness, wear, water permeability and acid/alkali resistance. The enamel seal showed clear improvements in strength, roughness and wear, whilst being impermeable to water, and resistance (up to 80% concentration) to nitric acid, sodium hydroxide and detergent acids. The bond strength and the rupture strength of the enamel seal were also investigated, revealing that the enamel adhered to the new grout and the ceramic tiles with an average bond strength of 45-60 MPa, whilst the rupture strength was comparable to the ceramic tiles themselves. The average surface roughness of the seals and the tiles was 0.36m and 0.06m respectively, whilst for the conventional epoxy grout the average surface roughness when polished was 3.83m, and in excess of 30m without polishing. Life assessment testing revealed that enamel seals had an increase in actual wear life of 2.9 to 30.4 times over conventional epoxy tile grout, depending upon the corrosive environment
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