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Sample records for porcelain tile part

  1. High-performance and anti-stain coating for porcelain stoneware tiles based on nanostructured zirconium compounds.

    PubMed

    Ambrosi, Moira; Santoni, Sergio; Giorgi, Rodorico; Fratini, Emiliano; Toccafondi, Nicola; Baglioni, Piero

    2014-10-15

    The technological characteristics of porcelain stoneware tiles make them suitable for a wide range of applications spanning far beyond traditional uses. Due to the high density, porcelain stoneware tiles show high bending strength, wear resistance, surface hardness, and high fracture toughness. Nevertheless, despite being usually claimed as stain resistant, the surface porosity renders porcelain stoneware tiles vulnerable to dirt penetration with the formation of stains that can be very difficult to remove. In the present work, we report an innovative and versatile method to realize stain resistant porcelain stoneware tiles. The tile surface is treated by mixtures of nanosized zirconium hydroxide and nano- and micron-sized glass frits that thanks to the low particle dimension are able to penetrate inside the surface pores. The firing step leads to the formation of a glass matrix that can partially or totally close the surface porosity. As a result, the fired tiles become permanently stain resistant still preserving the original esthetical qualities of the original material. Treated tiles also show a remarkably enhanced hardness due to the inclusion of zirconium compounds in the glass coating. PMID:25086385

  2. Synthesis of low-temperature, fast, single-firing body for porcelain stoneware tiles with coal gangue.

    PubMed

    Qiangwei Wei; Wenyuan Gao; Xinguo Sui

    2010-10-01

    Coal gangue is a major industrial solid waste in China, causing great environment pollution. According to phase diagram theory, a low-temperature, fast, single-firing body mix for porcelain stoneware tiles was designed in the quaternary system CaO--MgO--Al₂O₃--SiO₂, using coal gangue as the main raw material. The coal gangue was from Baishan city, Jilin province and mainly composed of kaolinite and quartz. Mineralogical compositions and microstructures of some selected samples sintered at different temperatures were identified with X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The results indicated that the optimal body mix was the one containing 34 wt% coal gangue sintered at 1170°C for about 1 h, with rupture strength of 43 MPa and water absorption of 0.22%. The main crystalline phases of the sintered body were quartz, anorthite and mullite. PMID:19942651

  3. South front, west part, showing wrought iron gates and tiling ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    South front, west part, showing wrought iron gates and tiling at the former main entrance. - San Bernardino Valley College, Life Science Building, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  4. Beautiful math, part 2: aesthetic patterns based on fractal tilings.

    PubMed

    Peichang Ouyang; Fathauer, Robert W

    2014-01-01

    A fractal tiling (f-tiling) is a tiling whose boundary is fractal. This article presents two families of rare, infinitely many f-tilings. Each f-tiling is constructed by reducing tiles by a fixed scaling factor, using a single prototile, which is a segment of a regular polygon. The authors designed invariant mappings to automatically produce appealing seamless, colored patterns from such tilings. PMID:24808170

  5. Beautiful Math, Part 5: Colorful Archimedean Tilings from Dynamical Systems.

    PubMed

    Ouyang, Peichang; Zhao, Weiguo; Huang, Xuan

    2015-01-01

    The art of tiling originated very early in the history of civilization. Almost every known human society has made use of tilings in some form or another. In particular, tilings using only regular polygons have great visual appeal. Decorated regular tilings with continuous and symmetrical patterns were widely used in decoration field, such as mosaics, pavements, and brick walls. In science, these tilings provide inspiration for synthetic organic chemistry. Building on previous CG&A “Beautiful Math” articles, the authors propose an invariant mapping method to create colorful patterns on Archimedean tilings (1-uniform tilings). The resulting patterns simultaneously have global crystallographic symmetry and local cyclic or dihedral symmetry. PMID:26594960

  6. Analysis of Tile-Reinforced Composite Armor. Part 1; Advanced Modeling and Strength Analyses

    NASA Technical Reports Server (NTRS)

    Davila, C. G.; Chen, Tzi-Kang; Baker, D. J.

    1998-01-01

    The results of an analytical and experimental study of the structural response and strength of tile-reinforced components of the Composite Armored Vehicle are presented. The analyses are based on specialized finite element techniques that properly account for the effects of the interaction between the armor tiles, the surrounding elastomers, and the glass-epoxy sublaminates. To validate the analytical predictions, tests were conducted with panels subjected to three-point bending loads. The sequence of progressive failure events for the laminates is described. This paper describes the results of Part 1 of a study of the response and strength of tile-reinforced composite armor.

  7. Deposition patterns of porcelain coatings obtained by electrophoretic deposition in acetone. Part 1. Voltage and time effect.

    PubMed

    García, Georgina; Vargas, Gregorio; Varela, F J Rodríguez

    2013-02-14

    Homogeneous surface morphologies are of interest to form different functional coatings. In order to verify if these morphologies could be observed and controlled in an electrophoretic cell, voltage and time effect have been studied on the deposition patterns of porcelain particle on a stainless steel substrate. The suspensions were prepared at 1 wt % of porcelain submicronic particles using acetone as dispersing media. The EPD experiments were carried out at 400, 600, and 800 V at deposition times of 1, 15, 30, 45, and 60 s. The morphology of the particle deposit patterns were characterized by scanning electron microscopy. At 1 s, submicronic particles without any pattern formation were observed on the stainless steel substrate. At subsequent deposition times, the patterns evolved from worm like forms to ring like forms and finally to labyrinth-type agglomerates of particles depending on voltage and deposition times. At deposition times longer than 60 s, the particle deposit patterns were difficult to observe. The coatings obtained at deposition times below this value were subjected to thermal treatments at 900 °C for 2 h. The patterns were maintained after the sintering process, exhibiting dense, homogeneous, and crack-free surface coatings. PMID:23039864

  8. Task 4 supporting technology. Part 1: Detailed test plan for leading edge tile development. Leading edge material development and testing

    NASA Technical Reports Server (NTRS)

    Hogenson, P. A.; Staszak, Paul; Hinkle, Karrie

    1995-01-01

    This task develops two alternative candidate tile materials for leading edge applications: coated alumina enhanced thermal barrier (AETB) tile and silicone impregnated reusable ceramic ablator (SIRCA) tile. Upon reentry of the X-33/RLV space vehicle, the leading edges experience the highest heating rates and temperatures. The wing leading edge and nose cap experience peak temperatures in the range 2000 to 2700 F. Replacing reinforced carbon-carbon (RCC) with tile-based thermal protection system (TPS) materials is the primary objective. Weight, complexity, coating impact damage, and repairability are among the problems that this tile technology development addresses. The following subtasks will be performed in this development effort: tile coating development; SIRCA tile development; robustness testing of tiles; tile repair development; tile operations/processing; tile leading edge configuration; and life cycle testing.

  9. Task 4 supporting technology. Part 1: Detailed test plan for leading edge tile development. Leading edge material development and testing

    NASA Astrophysics Data System (ADS)

    Hogenson, P. A.; Staszak, Paul; Hinkle, Karrie

    1995-05-01

    This task develops two alternative candidate tile materials for leading edge applications: coated alumina enhanced thermal barrier (AETB) tile and silicone impregnated reusable ceramic ablator (SIRCA) tile. Upon reentry of the X-33/RLV space vehicle, the leading edges experience the highest heating rates and temperatures. The wing leading edge and nose cap experience peak temperatures in the range 2000 to 2700 F. Replacing reinforced carbon-carbon (RCC) with tile-based thermal protection system (TPS) materials is the primary objective. Weight, complexity, coating impact damage, and repairability are among the problems that this tile technology development addresses. The following subtasks will be performed in this development effort: tile coating development; SIRCA tile development; robustness testing of tiles; tile repair development; tile operations/processing; tile leading edge configuration; and life cycle testing.

  10. ASBESTOS EXPOSURES DURING ROUTINE FLOOR TILE MAINTENANCE. PART 1: SPRAY-BUFFING AND WET-STRIPPING

    EPA Science Inventory

    This study was conducted to ealuate airborne asbestos concentrations during spray-uffing and wet-stripping of asbestos-containing residient floor tile under three levels of floor conditions (poor, medium, and good). Airborne asbestos concentrations were measured by transmission e...

  11. Porcelain-composite interface microleakage with various porcelain surface treatments.

    PubMed

    Sorensen, J A; Kang, S K; Avera, S P

    1991-04-01

    This study evaluated the effects of various porcelain surface treatments on the microleakage of the porcelain-composite interface. The experimental model isolated and evaluated only the porcelain-composite interface without the presence of a bond to tooth structure. Four types of porcelain were fired into circular porcelain tabs 1.0 mm thick by 8.5 mm in diameter. The groups of porcelain were divided into subgroups for treatment with hydrofluoric acid-etching and silane. A jig standardizing composite thickness to 0.2 mm was used to photopolymerize composite to porcelain. The margins were finished and polished with burs and disks. Samples were stored in 37 degrees C water thermocycled 1000X, placed in AgNO3 solution, embedded in epoxy, and cross-sectioned every 90 degrees for measurement of stain penetration at the composite-porcelain interface. Occasional crazing of porcelain from composite polymerization shrinkage was observed. Porcelain surface treatment significantly increased the specimens' ability to withstand water storage and thermal-cycling procedures. Porcelain surface treatment with silane alone did not reduce microleakage, but, in combination with etching, reduced microleakage significantly. PMID:1718804

  12. 21 CFR 872.3920 - Porcelain tooth.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Porcelain tooth. 872.3920 Section 872.3920 Food... DEVICES DENTAL DEVICES Prosthetic Devices § 872.3920 Porcelain tooth. (a) Identification. A porcelain tooth is a prefabricated device made of porcelain powder for clinical use (§ 872.6660) intended for...

  13. 21 CFR 872.3920 - Porcelain tooth.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Porcelain tooth. 872.3920 Section 872.3920 Food... DEVICES DENTAL DEVICES Prosthetic Devices § 872.3920 Porcelain tooth. (a) Identification. A porcelain tooth is a prefabricated device made of porcelain powder for clinical use (§ 872.6660) intended for...

  14. 21 CFR 872.3920 - Porcelain tooth.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Porcelain tooth. 872.3920 Section 872.3920 Food... DEVICES DENTAL DEVICES Prosthetic Devices § 872.3920 Porcelain tooth. (a) Identification. A porcelain tooth is a prefabricated device made of porcelain powder for clinical use (§ 872.6660) intended for...

  15. 21 CFR 872.3920 - Porcelain tooth.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Porcelain tooth. 872.3920 Section 872.3920 Food... DEVICES DENTAL DEVICES Prosthetic Devices § 872.3920 Porcelain tooth. (a) Identification. A porcelain tooth is a prefabricated device made of porcelain powder for clinical use (§ 872.6660) intended for...

  16. 21 CFR 872.3920 - Porcelain tooth.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Porcelain tooth. 872.3920 Section 872.3920 Food... DEVICES DENTAL DEVICES Prosthetic Devices § 872.3920 Porcelain tooth. (a) Identification. A porcelain tooth is a prefabricated device made of porcelain powder for clinical use (§ 872.6660) intended for...

  17. ASBESTOS EXPOSURES DURING ROUTINE FLOOR TILE MAINTENANCE. PART 2: ULTRA HIGH SPEED BURNISHING AND WET-STRIPPING

    EPA Science Inventory

    This study was conducted to evaluate airborne asbestos concentrations during ultra high speed (UHS) burnishing and wet-stripping of asbestos-containing resilient floor tile under two levels of floor care condition (poor and good). Airborne asbestos concentrations were measured by...

  18. Porcelain enamel neutron absorbing material

    DOEpatents

    Iverson, Daniel C.

    1990-02-06

    A porcelain enamel composition as a neutron absorbing material can be prepared of a major proportion by weight of a cadmium compound and a minor proportion of compounds of boron, lithium and silicon. These compounds in the form of a porcelain enamel coating or layer on several alloys has been found to be particularly effective in enhancing the nuclear safety of equipment for use in the processing and storage of fissile material. The composition of the porcelain enamel coating can be tailored to match the coefficient of thermal expansion of the equipment to be coated and excellent coating adhesion can be achieved.

  19. Porcelain enamel neutron absorbing material

    DOEpatents

    Iverson, D.C.

    1987-11-20

    A porcelain enamel composition as a neutron absorbing material can be prepared of a major proportion by weight of a cadmium compound and a minor proportion of compound of boron, lithium and silicon. These compounds in the form of a porcelain enamel coating or layer on several alloys has been found to be particularly effective in enhancing the nuclear safety of equipment for use in the processing and storage of fissile material. The composition of the porcelain enamel coating can be tailored to match the coefficient of thermal expansion of the equipment to be coated and excellent coating adhesion can be achieved. 2 figs.

  20. Porcelain enamel neutron absorbing material

    DOEpatents

    Iverson, Daniel C.

    1990-01-01

    A porcelain enamel composition as a neutron absorbing material can be prepared of a major proportion by weight of a cadmium compound and a minor proportion of compounds of boron, lithium and silicon. These compounds in the form of a porcelain enamel coating or layer on several alloys has been found to be particularly effective in enhancing the nuclear safety of equipment for use in the processing and storage of fissile material. The composition of the porcelain enamel coating can be tailored to match the coefficient of thermal expansion of the equipment to be coated and excellent coating adhesion can be achieved.

  1. Chemical Expertise: Chemistry in the Royal Prussian Porcelain Manufactory.

    PubMed

    Klein, Ursula

    2014-01-01

    Eighteenth-century chemists defined chemistry as both a "science and an art." By "chemical art" they meant not merely experimentation but also parts of certain arts and crafts. This raises the question of how to identify the "chemical parts" of the arts and crafts in eighteenth-century Europe. In this essay I tackle this question with respect to porcelain manufacture. My essay begins with a brief discussion of historiographical problems related to this question. It then analyzes practices involved in porcelain manufacture that can be reasonably identified as chemical practices or a chemical art. My analysis yields evidence for the argument that chemical experts and expertise fulfilled distinct technical functions in porcelain manufacture and, by extension, in eighteenth-century "big industry," along with its system of division of labor. PMID:26103759

  2. Programmable DNA tile self-assembly using a hierarchical sub-tile strategy

    NASA Astrophysics Data System (ADS)

    Shi, Xiaolong; Lu, Wei; Wang, Zhiyu; Pan, Linqiang; Cui, Guangzhao; Xu, Jin; LaBean, Thomas H.

    2014-02-01

    DNA tile based self-assembly provides a bottom-up approach to construct desired nanostructures. DNA tiles have been directly constructed from ssDNA and readily self-assembled into 2D lattices and 3D superstructures. However, for more complex lattice designs including algorithmic assemblies requiring larger tile sets, a more modular approach could prove useful. This paper reports a new DNA ‘sub-tile’ strategy to easily create whole families of programmable tiles. Here, we demonstrate the stability and flexibility of our sub-tile structures by constructing 3-, 4- and 6-arm DNA tiles that are subsequently assembled into 2D lattices and 3D nanotubes according to a hierarchical design. Assembly of sub-tiles, tiles, and superstructures was analyzed using polyacrylamide gel electrophoresis and atomic force microscopy. DNA tile self-assembly methods provide a bottom-up approach to create desired nanostructures; the sub-tile strategy adds a useful new layer to this technique. Complex units can be made from simple parts. The sub-tile approach enables the rapid redesign and prototyping of complex DNA tile sets and tiles with asymmetric designs.

  3. Efficient Tiled Loop Generation: D-Tiling

    NASA Astrophysics Data System (ADS)

    Kim, Daegon; Rajopadhye, Sanjay

    Tiling is an important loop optimization for exposing coarse-grained parallelism and enhancing data locality. Tiled loop generation from an arbitrarily shaped polyhedron is a well studied problem. Except for the special case of a rectangular iteration space, the tiled loop generation problem has been long believed to require heavy machinery such as Fourier-Motzkin elimination and projection, and hence to have an exponential complexity. In this paper we propose a simple and efficient tiled loop generation technique similar to that for a rectangular iteration space. In our technique, each loop bound is adjusted only once, syntactically and independently. Therefore, our algorithm runs linearly with the number of loop bounds. Despite its simplicity, we retain several advantages of recent tiled code generation schemes - unified generation for fixed, parameterized and hybrid tiled loops, scalability for multi-level tiled loop generation with the ability to separate full tiles at any levels, and compact code. We also explore various schemes for multi-level tiled loop generation. We formally prove the correctness of our scheme and experimentally validate that the efficiency of our technique is comparable to existing parameterized tiled loop generation approaches. Our experimental results also show that multi-level tiled loop generation schemes have an impact on performance of generated code. The fact that our scheme can be implemented without sophisticated machinery makes it well suited for autotuners and production compilers.

  4. Preassembly Of Insulating Tiles

    NASA Technical Reports Server (NTRS)

    Izu, Y. D.; Yoshioka, E. N.; Rosario, T.

    1988-01-01

    Concept for preassembling high-temperature insulating tiles speeds and simplifies installation and repair and reduces damage from handling. Preassembly concept facilitates placement of tiles on gently contoured surfaces as well as on flat ones. Tiles bonded to nylon mesh with room-temperature-vulcanizing silicon rubber. Spacing between tiles is 0.03 in. Applications include boilers, kilns, and furnaces.

  5. Interlocking wettable ceramic tiles

    SciTech Connect

    Tabereaux, Jr., Alton T.; Fredrickson, Guy L.; Groat, Eric; Mroz, Thomas; Ulicny, Alan; Walker, Mark F.

    2005-03-08

    An electrolytic cell for the reduction of aluminum having a layer of interlocking cathode tiles positioned on a cathode block. Each tile includes a main body and a vertical restraining member to prevent movement of the tiles away from the cathode block during operation of the cell. The anode of the electrolytic cell may be positioned about 1 inch from the interlocking cathode tiles.

  6. Dynamic fatigue of feldspathic porcelain.

    PubMed

    Fairhurst, C W; Lockwood, P E; Ringle, R D; Twiggs, S W

    1993-07-01

    Several studies (Sherrill and O'Brien, 1974; Southan and Jørgensen, 1974; Jones, 1983) have shown that stress corrosion fatigue occurs in dental porcelains. Morena et al. (1986) reported on an assessment of slow crack growth parameters for dental ceramics. The purpose of the study reported here was to evaluate the fatigue parameters of a model experimental porcelain using dynamic fatigue testing. This test procedure makes use of several constant stressing rates to perform strength tests. Dynamic stress testing was first described by Evans (1974) and later defined as a distinct test modality by Ritter (1978). From such data, the fatigue parameters can be calculated. These fatigue parameters, n and sigma f0, are, respectively, the crack growth exponent from the crack velocity expression and a materials constant which is dependent on the test environment and the inert (moisture-free) strength. The model porcelain was made from 60% component 1 and 40% component 3 according to the Weinstein patent (Weinstein, et al., 1962). The biaxial flexure strength of 300 specimens 1 mm thick was tested in 37 degrees C water by testing 50 samples at each of 6 constant stressing rates: 100, 10, 1, 0.1, 0.01, and 0.001 MPa/s. One hundred specimens were tested in a moisture-free environment at 100 MPa/s using a servo-mechanical testing machine. A commercial porcelain (Jelenko Gingival-Lot # 2012, Jelenko Dental Health Products, Armonk, NY, USA) was chosen as a reference material. One hundred twenty specimens were tested using the same procedures as those used for the model porcelain; however, only 20 samples were tested for 5 stressing rate groups and an inert group.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7988760

  7. Application of porcelain enamel as an ultra-high-vacuum-compatible electrical insulator

    SciTech Connect

    Biscardi, C.; Hseuh, H.; Mapes, M.

    2000-07-01

    Many accelerator vacuum system components require electrical insulation internal to the vacuum system. Some accelerator components at Brookhaven National Laboratory are installed in ultra-high-vacuum systems which require the insulation to have excellent vacuum characteristics, be radiation resistant, and be able to withstand high temperatures when used on baked systems. Porcelain enamel satisfies all these requirements. This article describes the process and application of coating metal parts with porcelain enamel to provide electrical insulation. The mechanical and vacuum testing of Marman flanges coated with porcelain and using metal Helicoflex seals to form a zero-length electrical break are detailed. The use of porcelain enameled parts is attractive since it can be done quickly, is inexpensive and environmentally safe, and most of all satisfies stringent vacuum system requirements. (c) 2000 American Vacuum Society.

  8. Porcelain enameling furnaces retrofitted with ceramic fiber to increase fuel savings and production

    SciTech Connect

    Not Available

    1984-07-01

    Appliance manufacturers and companies supplying porcelainized parts have done considerable revamping and modernizing of their furnaces. As a result, economy of production has been improved through either substantial fuel savings or increased productivity or both. Coinciding with this industry furnace upgrading, a refractory engineering and contracting firm, Ronalco Inc., Louisville, KY has emerged, within a few years, as experts in porcelain enameling furnace renovations devising their own innovative methodology for lining and heating these units.

  9. Two Views of Islam: Ceramic Tile Design and Miniatures.

    ERIC Educational Resources Information Center

    Macaulay, Sara Grove

    2001-01-01

    Describes an art project focusing on Islamic art that consists of two parts: (1) ceramic tile design; and (2) Islamic miniatures. Provides background information on Islamic art and step-by-step instructions for designing the Islamic tile and miniature. Includes learning objectives and resources on Islamic tile miniatures. (CMK)

  10. Handmade Tile Mosaics

    ERIC Educational Resources Information Center

    Keeler, Rusty

    2007-01-01

    Just like the classroom, children's outdoor environments should be filled with artistic creations that add sparkle and imagination to the space. One of the author's favorite ways to add art to the outdoors is by installing a mosaic mural of child-made tiles. The process of making the tiles is fun for all; each tile is a charming work of art in…

  11. Regulating the working properties of porcelain slip

    SciTech Connect

    Karpilovskii, L.P.; Kralinina, L.N.; Makarov, V.A.; Sidorenko, Z.I.

    1986-05-01

    It was decided to introduce changes in the recipe of the clay part of the raw material to provide a reduction in the density and a restoration of the Prosyyanovsk kaolin (PK) slip's fluidity, the volume of the PK batch would be maintained, and the working properties of the body could be insured within the same limits as prevailed before recipe of the stone materials and the chemical composition of the porcelain would be left unchanged. The results indicate the effectiveness of using the analytical method for clay suspensions for operational assessment of the technical properties of raw materials and regulating the working properties of the body. The method of filtration analysis and determination of the elastic properties of the suspension can also be recommended for use in benefication combines. The advantage of the methods consists in the rapidity of carrying out the analysis which means where necessary can operationally intervene in the technological process.

  12. 46 CFR 111.01-13 - Limitations on porcelain use.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Limitations on porcelain use. 111.01-13 Section 111.01... SYSTEMS-GENERAL REQUIREMENTS General § 111.01-13 Limitations on porcelain use. Porcelain must not be used... solidly mounted by machine screws or their equivalent, unless the porcelain piece is resiliently mounted....

  13. 46 CFR 111.01-13 - Limitations on porcelain use.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Limitations on porcelain use. 111.01-13 Section 111.01... SYSTEMS-GENERAL REQUIREMENTS General § 111.01-13 Limitations on porcelain use. Porcelain must not be used... solidly mounted by machine screws or their equivalent, unless the porcelain piece is resiliently mounted....

  14. 46 CFR 111.01-13 - Limitations on porcelain use.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Limitations on porcelain use. 111.01-13 Section 111.01... SYSTEMS-GENERAL REQUIREMENTS General § 111.01-13 Limitations on porcelain use. Porcelain must not be used... solidly mounted by machine screws or their equivalent, unless the porcelain piece is resiliently mounted....

  15. 46 CFR 111.01-13 - Limitations on porcelain use.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Limitations on porcelain use. 111.01-13 Section 111.01... SYSTEMS-GENERAL REQUIREMENTS General § 111.01-13 Limitations on porcelain use. Porcelain must not be used... solidly mounted by machine screws or their equivalent, unless the porcelain piece is resiliently mounted....

  16. Modelling the viscoelasticity of ceramic tiles by finite element

    NASA Astrophysics Data System (ADS)

    Pavlovic, Ana; Fragassa, Cristiano

    2016-05-01

    This research details a numerical method aiming at investigating the viscoelastic behaviour of a specific family of ceramic material, the Grès Porcelain, during an uncommon transformation, known as pyroplasticity, which occurs when a ceramic tile bends under a combination of thermal stress and own weight. In general, the theory of viscoelasticity can be considered extremely large and precise, but its application on real cases is particularly delicate. A time-depending problem, as viscoelasticity naturally is, has to be merged with a temperature-depending situation. This paper investigates how the viscoelastic response of bending ceramic materials can be modelled by commercial Finite Elements codes.

  17. Study of insulator mortars. Part 1: Comparative analysis of the freeze-thaw durability of cement grouts and mortars in line and sub-station porcelain insulators

    SciTech Connect

    Durand, B.

    1995-11-01

    As part of a major study being conducted on the durability of insulators in transmission lines and sub-station equipment comprising insulating components, seven Hydro-Quebec suppliers have contributed a number of samples made from the cement grouts and mortars used in manufacturing their equipment. The manufacturers` samples and those made in house were tested in the laboratory for compressive, tensile and flexural strength, as well as freezing and thawing, shrinkage/expansion to wetting and drying, autoclave expansion and carbonation. This paper presents the results of the freeze-thaw tests that consisted in determining changes in mass and length, uniaxial compressive strength, and tensile and flexural strength. The freeze-thaw test was conducted according to ASTM Test Method C666(B), which was used to determine the resistance of concrete specimens to rapidly repeated cycles of freezing and thawing (freezing in air at {minus}18 C and thawing in water at 4 C, 3-h cycles, 530 cycles in total). Two specific trends were noted: (1) eleven series of prisms showed less than 0.055% linear expansion after 530 freeze-thaw cycles, and (2) eight series of prisms showed more than 0.200% linear expansion. Two definite trends also emerged regarding changes in mass: (1) twelve series of prisms showed little change in mass after 530 freeze-thaw cycles and (2) seven series of prisms registered substantial changes in mass, in some cases over 10%. An analysis of the test results for compressive, tensile and flexural strengths showed that the specimens exhibiting little increase in expansion and loss of mass had an increase in mechanical resistance during the freeze-thaw test, while the opposite was true for specimens that showed considerable linear expansion and loss of mass, i.e. their compressive, tensile and flexural strengths decreased during the freeze-thaw test.

  18. Contact pressure distribution during the polishing process of ceramic tiles: A laboratory investigation

    NASA Astrophysics Data System (ADS)

    Sani, A. S. A.; Sousa, F. J. P.; Hamedon, Z.; Azhari, A.

    2016-02-01

    During the polishing process of porcelain tiles the difference in scratching speed between innermost and peripheral abrasives leads to pressure gradients linearly distributed along the radial direction of the abrasive tool. The aim of this paper is to investigate such pressure gradient in laboratory scale. For this purpose polishing tests were performed on ceramic tiles according to the industrial practices using a custom-made CNC tribometer. Gradual wear on both abrasives and machined surface of the floor tile were measured. The experimental results suggested that the pressure gradient tends to cause an inclination of the abraded surfaces, which becomes stable after a given polishing period. In addition to the wear depth of the machined surface, the highest value of gloss and finest surface finish were observed at the lowest point of the worn out surface of the ceramic floor tile corresponding to the point of highest pressure and lowest scratching speed.

  19. Rewaterproofing Silica Tiles

    NASA Technical Reports Server (NTRS)

    Lleger, L. J.; Wade, D. C.

    1983-01-01

    Waterproofing agent, vaporized in bubbler transported by gas flowing in system and deposits in pores of tiles. Vapor carried through hole of approximately 1/16 inch (1.6.mm) diameter made in tile coating. Technique used to waterproof buildups (concrete and brick) and possibly fabrics.

  20. New raw material for electrical porcelain

    SciTech Connect

    Khristoforov, K.K.; Portnova, I.G.; Omel'chenko, Yu.A.

    1986-09-01

    Research is described in finding new raw materials for the fabrication of porcelain electrical insulators for power transmission lines. The materials tested come from several deposits in the Soviet Union and include alumina minerals, quartz, feldspars, pegmatites, clays, and two kaolins, as well as waste materials recovered from porcelain production. Comparative electrical and mechanical properties, grain sizes, sinterabilities, and mineral compositions are tabulated for the candidate materials.

  1. Surface preparation for orthodontic bonding to porcelain.

    PubMed

    Zachrisson, Y O; Zachrisson, B U; Büyükyilmaz, T

    1996-04-01

    This study evaluated the effect of various porcelain surface treatments on the tensile strength of orthodontic brackets bonded to a feldspathic metal ceramic porcelain. The porcelain was fused to flat gold alloy tabs and divided into six groups that were subjected to sandblasting, silane application, intermediate resin, or etchants (9.6% hydrofluoric acid or 4% APF gels). Two brackets were bonded onto each porcelain/metal tab (n=60) with Bis-GMA resin (Concise, 3M Corp., St. Paul, Minn.) or 4-META resin (MCP-bond, Sun Medical Co. Ltd., Tokyo, Japan). The samples were stored in 37 degrees C water, thermocycled 1000 times from 5 degrees C to 55 degrees C and tested in tension. Alignment and uniform loading during testing were secured by engaging a hook in a circular ring soldered onto the bracket slot before bonding. Similar control brackets (n=12) were bonded with Concise to extracted caries-free mandibular incisors. Bond failure sites were classified according to a modified Adhesive Remnant Index (ARI) system. Silane application to the sandblasted porcelain surface significantly increased the bond strengths according to analysis of variance and Duncan's multiple range test. The quality of the bonds was further enhanced by the addition of the intermediate resin. Etching the porcelain with 9.6% hydrofluoric acid provided similar bond strengths, but the 4% APF gel was less effective. The MCP-bond was not significantly better than Concise in bond strength to sandblasted porcelain. Several difficulties associated with the clinical interpretation of laboratory data on bonding to dental porcelains are discussed, and clinical trials are necessary for final evidence of efficacy. PMID:8638584

  2. A thermal shock test for porcelain-metal systems.

    PubMed

    Anusavice, K J; Ringle, R D; Morse, P K; Fairhurst, C W; King, G E

    1981-09-01

    Certain conclusions may be made on the basis of this study. 1) The effects of alloy, porcelain, and alloy-porcelain interaction on the temperature differential required to induce porcelain crazing are significant. 2) The effect of porcelain is the most significant determinant of delta T values. 3) Under thermal shock conditions, the crazing resistance of porcelains decreases in the order: V less than [C, N, W] greater than B, where C greater than W. 4) For the conditions used, the thermal shock test is a sensitive discriminator of the crazing resistance of porcelain-metal systems. PMID:6943163

  3. Penrose tilings as model sets

    NASA Astrophysics Data System (ADS)

    Shutov, A. V.; Maleev, A. V.

    2015-11-01

    The Baake construction, based on generating a set of vertices of Penrose tilings as a model set, is refined. An algorithm and a corresponding computer program for constructing an uncountable set of locally indistinguishable Penrose tilings are developed proceeding from this refined construction. Based on an analysis of the parameters of tiling vertices, 62 versions of rhomb combinations at the tiling center are determined. The combinatorial structure of Penrose tiling worms is established. A concept of flip transformations of tilings is introduced that makes it possible to construct Penrose tilings that cannot be implemented in the Baake construction.

  4. Voronoi spiral tilings

    NASA Astrophysics Data System (ADS)

    Yamagishi, Yoshikazu; Sushida, Takamichi; Hizume, Akio

    2015-04-01

    The parameter set of Voronoi spiral tilings gives a dual of van Iterson's bifurcation diagram for phyllotactic spirals. We study the Voronoi tilings for the Bernoulli spiral site sets, as the simplest spirals in the centric representation with similarity symmetry. Their parameter set is composed of a family of real algebraic curves in the complex plane, with the Farey sequence structure. This naturally extends to the parameter set for multiple tilings, i.e., the tilings of the covering spaces of the punctured plane. We show the denseness of the parameters z = reiθ for quadrilateral Voronoi spiral multiple tilings. The techniques of dynamical systems are applied to the group of similarity symmetry. The parastichy numbers and the distortion of the Voronoi regions depend on the rational approximations of θ/2π. We consider the limit set of the shapes of the quadrilateral tiles by taking the limit as r → 1, with θ fixed. If θ/2π is a quadratic irrational number, then the limit set is a finite set of rectangles. In particular, if θ/2π is linearly equivalent to the golden section, then the limit is the square.

  5. 21 CFR 872.6660 - Porcelain powder for clinical use.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Porcelain powder for clinical use. 872.6660... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6660 Porcelain powder for clinical use. (a) Identification. Porcelain powder for clinical use is a device consisting of a mixture of...

  6. 21 CFR 872.6660 - Porcelain powder for clinical use.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Porcelain powder for clinical use. 872.6660... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6660 Porcelain powder for clinical use. (a) Identification. Porcelain powder for clinical use is a device consisting of a mixture of...

  7. 21 CFR 872.6660 - Porcelain powder for clinical use.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Porcelain powder for clinical use. 872.6660... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6660 Porcelain powder for clinical use. (a) Identification. Porcelain powder for clinical use is a device consisting of a mixture of...

  8. 21 CFR 872.6660 - Porcelain powder for clinical use.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Porcelain powder for clinical use. 872.6660... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6660 Porcelain powder for clinical use. (a) Identification. Porcelain powder for clinical use is a device consisting of a mixture of...

  9. 21 CFR 872.6660 - Porcelain powder for clinical use.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Porcelain powder for clinical use. 872.6660... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6660 Porcelain powder for clinical use. (a) Identification. Porcelain powder for clinical use is a device consisting of a mixture of...

  10. 46 CFR 111.01-13 - Limitations on porcelain use.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Limitations on porcelain use. 111.01-13 Section 111.01-13 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS General § 111.01-13 Limitations on porcelain use. Porcelain must not be...

  11. Stress intensity factor threshold in dental porcelains.

    PubMed

    Yoshimura, Humberto Naoyuki; Cesar, Paulo Francisco; Soki, Fabiana Naomi; Gonzaga, Carla Castiglia

    2008-05-01

    The stress intensity factor threshold (KI0) is related to the stress level at which cracks start to grow stably, causing the weakening of porcelain prostheses during their use. The values of KI0 of seven dental porcelains (with and without reinforcing leucite crystal, KAlSi2O6) stored in air (22 degrees C, 60% relative humidity) and artificial saliva (37 degrees C) were determined by measuring the crack growth velocity of radial cracks generated at the corner of Vickers indentations. The results of KI0 were correlated with the leucite content, fracture toughness (KIc), and chemical composition of the porcelains. It was observed that KI0 increased with the increase of leucite content (only for the leucite-based porcelains) and with the increase of KIc. The increase in Al2O3 content or the decrease in the alkali oxide (K2O and Na2O) content of the material's glassy matrix tended to increase the KI0 values. Storage media (air and saliva) did not significantly affect the KI0 of porcelains tested, indicating that the control parameter of KI0 value was not the water content of the storage media. PMID:17943412

  12. Universal adhesive (glue composition) for electrical porcelain products

    SciTech Connect

    Khristoforov, K.K.; Belen'kaya, E.S.; Omel'chenko, Y.A.; Vinogradova, T.K.

    1986-05-01

    The aim of this work is to develop an adhesive for porcelain insulators that exhibits high physicomechanical properties and increased resistance to the simultaneous action of heat and moisture. One method of solving this problem is to introduce special additives possessing hydrophobic (waterrepelling) properties into the adhesive composition during the process of its preparation. The adhesive based on the ED-20 epoxy resin and TEA hardened with 5 parts of AF-2 additive possesses higher resistance to the action of heat and moisture as compared to the adhesive used at the present time for assembling insulators. The improved and stable physiomechanical properties of the developed adhesive permit its use in any climactic conditions.

  13. Tiling Motion Patches.

    PubMed

    Hyun, Kyunglyul; Kim, Manmyung; Hwang, Youngseok; Lee, Jehee

    2013-05-01

    Simulating multiple character interaction is challenging because character actions must be carefully coordinated to align their spatial locations and synchronized with each other. We present an algorithm to create a dense crowd of virtual characters interacting with each other. The interaction may involve physical contacts, such as hand shaking, hugging, and carrying a heavy object collaboratively. We address the problem by collecting deformable motion patches, each of which describes an episode of multiple interacting characters, and tiling them spatially and temporally. The tiling of motion patches generates a seamless simulation of virtual characters interacting with each other in a non-trivial manner. Our tiling algorithm uses a combination of stochastic sampling and deterministic search to address the discrete and continuous aspects of the tiling problem. Our tiling algorithm made it possible to automatically generate highly-complex animation of multiple interacting characters. We achieved the level of complexity far beyond the current state-of-the-art animation techniques could generate, in terms of the diversity of human behaviors and the spatial/temporal density of interpersonal interactions. PMID:23669532

  14. Tiling motion patches.

    PubMed

    Hyun, Kyunglyul; Kim, Manmyung; Hwang, Youngseok; Lee, Jehee

    2013-11-01

    Simulating multiple character interaction is challenging because character actions must be carefully coordinated to align their spatial locations and synchronized with each other. We present an algorithm to create a dense crowd of virtual characters interacting with each other. The interaction may involve physical contacts, such as hand shaking, hugging, and carrying a heavy object collaboratively. We address the problem by collecting deformable motion patches, each of which describes an episode of multiple interacting characters, and tiling them spatially and temporally. The tiling of motion patches generates a seamless simulation of virtual characters interacting with each other in a nontrivial manner. Our tiling algorithm uses a combination of stochastic sampling and deterministic search to address the discrete and continuous aspects of the tiling problem. Our tiling algorithm made it possible to automatically generate highly complex animation of multiple interacting characters. We achieve the level of interaction complexity far beyond the current state of the art that animation techniques could generate, in terms of the diversity of human behaviors and the spatial/temporal density of interpersonal interactions. PMID:24029911

  15. Effects of dental porcelain containing silver nanoparticles on static fatigue.

    PubMed

    Fujieda, Tokushi; Uno, Mitsunori; Ishigami, Hajime; Kurachi, Masakazu; Kamemizu, Hideo; Wakamatsu, Nobukazu; Doi, Yutaka

    2013-01-01

    The purpose of this study was to clarify the effect of silver nanoparticles on the behavior of subcritical crack growth (SCG) in dental porcelains. Prior to occurrence of fast fracture in dental porcelains, SCG occurs and leads to strength degradation over time. SCG in dental porcelains can be characterized by the stress corrosion susceptibility coefficient, n. A higher n value means a higher resistance to SCG. In this study, porcelain disks were prepared by mixing a commercial dental porcelain powder with different concentrations of silver nanoparticles, and then air-dried and fired according to manufacturer's instructions. Stress corrosion susceptibility coefficients of powder compacts were determined using a post-indentation method. A Vickers indenter was applied to the porcelain surface, and lengths of median cracks were measured at fixed time intervals over a 24-h period to calculate n. Addition of silver nanoparticles significantly increased the stress corrosion susceptibility coefficient of dental porcelain. PMID:23719000

  16. Effect of porcelain shape for strain behavior of strengthened porcelain in impact test

    NASA Astrophysics Data System (ADS)

    Hayashi, Akemi; Kurachi, Kazumasa; Mizuno, Masatoshi; Ota, Toshitaka

    2011-10-01

    Four types of strengthened porcelains were evaluated by an impact examination machine based on ASTM C368-88. The waveform of strain developed on impact was measured by a strain gauge pasted on the inside surface and the outside surface, vertical and horizontal direction of porcelain. In minute scales, procelain deformed into an oval shape as a whole by an impact onto the rim, where the higher tensile strain occurred in the horizontal direction on the inside surface of porcelain. The maximum tensile strain occurred at the impact point. The waveform of strain, that showed two remarkable peaks, was greatly affected by porcelain shape. In addition it was more or less affected by measurement conditions such as impact energy, weight or speed of hammer, weight for holding, and position of backstops.

  17. Strength and Fracture Origins of a Feldspathic Porcelain

    PubMed Central

    Quinn, George D.; Hoffman, Kathleen; Quinn, Janet B.

    2012-01-01

    Objectives To identify the strength limiting flaws in in-vitro test specimens of a fine-grained feldspathic dental porcelain. Methods Four-point flexural strengths were measured for 26 test specimens. The fracture origin site of every test specimen was studied using stereoptical and scanning electron microscopy. A fractographically-labeled Weibull strength distribution graph was prepared. Results The complex microstructure of the feldspathic dental porcelain included a variety of feldspars, tridymite, and a feldspathoid as well as pores/bubbles and residual glass. The relatively high flexural strength is due in part to the fine grain size. Fractography revealed five flaw types that controlled strength: baseline microstructural flaws, pores/bubbles, side wall grinding damage, corner machining damage, and inclusions. The baseline microstructural flaws probably were clusters of particular crystalline phases. Significance Each flaw type probably has a different severity and size distribution, and hence has a different strength distribution. The Weibull strength distribution graph blended the strength distributions of the five flaw types and the apparent good fit of the combined data to a unimodal strength distribution was misleading. Polishing failed to eliminate deeper transverse grinding cracks and corner damage from earlier preparation steps in many of the test pieces. Bend bars should be prepared carefully with longitudinal surface grinding whenever possible and edge chamfers should be carefully applied. If the grinding and preparation flaws were eliminated, the Weibull modulus for this feldspathic porcelain would be greater than 30. Pores/bubbles sometimes controlled strength, but only if they touched each other or an exposed surface. Isolated interior bubble/pores were harmless. PMID:22217606

  18. Seamless tiled display system

    NASA Technical Reports Server (NTRS)

    Dubin, Matthew B. (Inventor); Larson, Brent D. (Inventor); Kolosowsky, Aleksandra (Inventor)

    2006-01-01

    A modular and scalable seamless tiled display apparatus includes multiple display devices, a screen, and multiple lens assemblies. Each display device is subdivided into multiple sections, and each section is configured to display a sectional image. One of the lens assemblies is optically coupled to each of the sections of each of the display devices to project the sectional image displayed on that section onto the screen. The multiple lens assemblies are configured to merge the projected sectional images to form a single tiled image. The projected sectional images may be merged on the screen by magnifying and shifting the images in an appropriate manner. The magnification and shifting of these images eliminates any visual effect on the tiled display that may result from dead-band regions defined between each pair of adjacent sections on each display device, and due to gaps between multiple display devices.

  19. Tiling Microarray Analysis Tools

    SciTech Connect

    Nix, Davis Austin

    2005-05-04

    TiMAT is a package of 23 command line Java applications for use in the analysis of Affymetrix tiled genomic microarray data. TiMAT enables: 1) Rebuilding the genome annotation for entire tiled arrays (repeat filtering, chromosomal coordinate assignment). 2) Post processing of oligo intensity values (quantile normalization, median scaling, PMMM transformation), 3) Significance testing (Wilcoxon rank sum and signed rank tests, intensity difference and ratio tests) and Interval refinement (filtering based on multiple statistics, overlap comparisons), 4) Data visualization (detailed thumbnail/zoomed view with Interval Plots and data export to Affymetrix's Integrated Genome Browser) and Data reports (spreadsheet summaries and detailed profiles)

  20. Low absorptance porcelain-on-aluminum coating

    NASA Technical Reports Server (NTRS)

    Leggett, H.

    1979-01-01

    Porcelain thermal-control coating for aluminum sheet and foil has solar absorptance of 0.22. Specially formulated coating absorptance is highly stable, changing only 0.03 after 1,000 hours of exposure to simulated sunlight and can be applied by standard commercial methods.

  1. Molecular random tilings as glasses

    PubMed Central

    Garrahan, Juan P.; Stannard, Andrew; Blunt, Matthew O.; Beton, Peter H.

    2009-01-01

    We have recently shown that p-terphenyl-3,5,3′,5′-tetracarboxylic acid adsorbed on graphite self-assembles into a two-dimensional rhombus random tiling. This tiling is close to ideal, displaying long-range correlations punctuated by sparse localized tiling defects. In this article we explore the analogy between dynamic arrest in this type of random tilings and that of structural glasses. We show that the structural relaxation of these systems is via the propagation–reaction of tiling defects, giving rise to dynamic heterogeneity. We study the scaling properties of the dynamics and discuss connections with kinetically constrained models of glasses. PMID:19720990

  2. Quasiperiodic tilings generated by matrices

    NASA Astrophysics Data System (ADS)

    Rao, Nagaraja S.; Suryanarayan, E. R.

    1994-02-01

    Using the inflation method, Watanabe, Ito and Soma [3], Clark and Suryanarayan [4] and Balagurusamy, Ramesh and Gopal [5] have obtained nonperiodic tilings of the plane with n-fold rotational symmetry, n = 2, 3, 4, 5, 8, using two unit prototiles. Fortunately, there is an easier way to generate a more general class of nonperiodic tilings which contains the above-mentioned tilings as special cases. We do this by specifying two matrices of order two which define the two classes of tilings; thus, our approach uses the basic techniques from linear algebra in the study of quasiperiodic tilings and the method can be generalized to obtain tilings that have more than two prototiles. The tilings generated are fractals and their dimensions and the rate of growth are determined.

  3. Preparation and characterization of a titanium bonding porcelain.

    PubMed

    Guo, Litong; Shi, Yao; Guo, Lizhi; Zhang, Qian; Tian, Junlong; Zhu, Yabo; Guo, Tianwen

    2012-08-01

    The titanium bonding porcelain was synthesized through normal melting-derived route using borate-silicate system. The porcelain was characterized by thermal expansion, X-ray diffraction, scanning electron microscope and cytotoxicity tests. The results of X-ray diffraction showed that the main phase of the bonding porcelain was SnO2. The SnO2 microcrystals precipitated from the glass matrix when the SnO2 content was increased. The thermal expansion coefficient of bonding porcelains decreased with the increasing concentration of SiO2. The thermal expansion coefficient of bonding porcelains first decreased slightly with the increasing of B2O3 concentration (from 0 wt% to 10 wt%) and then increased to about 9.4×10(-6)/°C(from 10 wt% to 12 wt%). As an intermediate, B2O3 can act as both network formers and modifiers, depending on the relationship between the concentration of basic oxides and intermediates. The Vickers hardness of bonding porcelains increased with the increase of SnO2 concentration. When SnO2 concentration was 6 wt%, only Si and Sn elements attended the reaction between titanium and porcelain and mainly adhesive fracture was found at Ti-porcelain interface. When SnO2 concentration was 12 wt%, failure of the titanium-porcelain predominantly occurred in the bonding porcelain and mainly cohesive fracture was found at Ti-porcelain interface. The methyl thiazolyl tetrazolium assay results demonstrated that the cytotoxicity of the titanium porcelain was ranked as 0. PMID:24364956

  4. Tiling Microarray Analysis Tools

    Energy Science and Technology Software Center (ESTSC)

    2005-05-04

    TiMAT is a package of 23 command line Java applications for use in the analysis of Affymetrix tiled genomic microarray data. TiMAT enables: 1) Rebuilding the genome annotation for entire tiled arrays (repeat filtering, chromosomal coordinate assignment). 2) Post processing of oligo intensity values (quantile normalization, median scaling, PMMM transformation), 3) Significance testing (Wilcoxon rank sum and signed rank tests, intensity difference and ratio tests) and Interval refinement (filtering based on multiple statistics, overlap comparisons),more » 4) Data visualization (detailed thumbnail/zoomed view with Interval Plots and data export to Affymetrix's Integrated Genome Browser) and Data reports (spreadsheet summaries and detailed profiles)« less

  5. Producing superhydrophobic roof tiles

    NASA Astrophysics Data System (ADS)

    Carrascosa, Luis A. M.; Facio, Dario S.; Mosquera, Maria J.

    2016-03-01

    Superhydrophobic materials can find promising applications in the field of building. However, their application has been very limited because the synthesis routes involve tedious processes, preventing large-scale application. A second drawback is related to their short-term life under outdoor conditions. A simple and low-cost synthesis route for producing superhydrophobic surfaces on building materials is developed and their effectiveness and their durability on clay roof tiles are evaluated. Specifically, an organic-inorganic hybrid gel containing silica nanoparticles is produced. The nanoparticles create a densely packed coating on the roof tile surface in which air is trapped. This roughness produces a Cassie-Baxter regime, promoting superhydrophobicity. A surfactant, n-octylamine, was also added to the starting sol to catalyze the sol-gel process and to coarsen the pore structure of the gel network, preventing cracking. The application of ultrasound obviates the need to use volatile organic compounds in the synthesis, thereby making a ‘green’ product. It was also demonstrated that a co-condensation process effective between the organic and inorganic species is crucial to obtain durable and effective coatings. After an aging test, high hydrophobicity was maintained and water absorption was completely prevented for the roof tile samples under study. However, a transition from a Cassie-Baxter to a Wenzel state regime was observed as a consequence of the increase in the distance between the roughness pitches produced by the aging of the coating.

  6. Producing superhydrophobic roof tiles.

    PubMed

    Carrascosa, Luis A M; Facio, Dario S; Mosquera, Maria J

    2016-03-01

    Superhydrophobic materials can find promising applications in the field of building. However, their application has been very limited because the synthesis routes involve tedious processes, preventing large-scale application. A second drawback is related to their short-term life under outdoor conditions. A simple and low-cost synthesis route for producing superhydrophobic surfaces on building materials is developed and their effectiveness and their durability on clay roof tiles are evaluated. Specifically, an organic-inorganic hybrid gel containing silica nanoparticles is produced. The nanoparticles create a densely packed coating on the roof tile surface in which air is trapped. This roughness produces a Cassie-Baxter regime, promoting superhydrophobicity. A surfactant, n-octylamine, was also added to the starting sol to catalyze the sol-gel process and to coarsen the pore structure of the gel network, preventing cracking. The application of ultrasound obviates the need to use volatile organic compounds in the synthesis, thereby making a 'green' product. It was also demonstrated that a co-condensation process effective between the organic and inorganic species is crucial to obtain durable and effective coatings. After an aging test, high hydrophobicity was maintained and water absorption was completely prevented for the roof tile samples under study. However, a transition from a Cassie-Baxter to a Wenzel state regime was observed as a consequence of the increase in the distance between the roughness pitches produced by the aging of the coating. PMID:26854839

  7. Photocatalytic, highly hydrophilic porcelain stoneware slabs

    NASA Astrophysics Data System (ADS)

    Raimondo, M.; Guarini, G.; Zanelli, C.; Marani, F.; Fossa, L.; Dondi, M.

    2011-10-01

    Photocatalytic, highly hydrophilic industrial porcelain stoneware large slabs were realized by deposition of nanostructured TiO2 coatings. Different surface finishing and experimental conditions were considered in order to assess the industrial feasibility. Photocatalytic and wetting behaviour of functionalized slabs mainly depends on surface phase composition in terms of anatase/rutile ratio, this involving - as a key issue - the deposition of TiO2 on industrially sintered products with an additional annealing step to strengthen coatings' performances and durability.

  8. The effect of glaze on porcelain strength.

    PubMed

    Fairhurst, C W; Lockwood, P E; Ringle, R D; Thompson, W O

    1992-05-01

    The self-glazing technique provides an esthetic and hygienic surface for crowns and fixed partial dentures that use porcelain veneers. A study of the biaxial flexure strengths of polished vs. glazed specimens is needed to verify that current laboratory methods are appropriate for planned fatigue studies. Four groups of 50 porcelain disk specimens each were subjected to the following polishing and firing procedures: group one was fired, glazed-no hold, and polished; group two was fired, polished, and glazed-no hold; group three was fired, polished and glazed-1 min. hold; group four was fired, polished, and not glazed. The piston-on-three-ball method was used for testing biaxial flexure strengths. Significantly lower differences in biaxial flexure strengths were noted when group two values were compared with values from groups one, three and four. The results show that the Weibull distribution is an appropriate model for our studies. Differences in glaze thickness among the groups were noted in SEM examination; however, bulk (interior) microcrack density differences were absent. The specimens that were fired, polished to a 1 micron surface finish, and not glazed (group four) were significantly higher in flexure strength than groups one and three at the p less than 0.001 level. The hypothesis that glazing of porcelain surfaces improves the biaxial flexure strength of test specimens was rejected. PMID:1521711

  9. 57. ORIGINAL TILE PRESS AND EXPERIMENTAL DENTAL KILN, SECOND FLOOR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    57. ORIGINAL TILE PRESS AND EXPERIMENTAL DENTAL KILN, SECOND FLOOR, NORTH WING, HENRY MERCER USED THE KILN FOR HIS EARLIEST GLAZE TESTS. THE PRESS WAS DESIGNED TO BE USED WITH METAL CASED MOLDS. SINCE ONLY THE EARLIEST TILE DESIGNS ARE IN METAL CASES. THIS TECHNIQUE WAS PROBABLY DISCONTINUED. THIS PRESS WAS, THEREFORE, PROBABLY NOT USED EXTENSIVELY AT THIS SITE. THE UPPER PART OF GLAZE KILN No. 2 IS AT THE LEFT REAR. - Moravian Pottery & Tile Works, Southwest side of State Route 313 (Swamp Road), Northwest of East Court Street, Doylestown, Bucks County, PA

  10. Ceramic tile expansion engine housing

    DOEpatents

    Myers, B.

    1995-04-11

    An expandable ceramic tile housing for a high temperature engine is disclosed wherein each tile is independently supported in place in an interlocking matrix by retention mechanisms which mechanically couple the individual ceramic tiles to an outer metal support housing while maintaining thermal isolation of the metal housing from the ceramic tiles. The ceramic tiles are formed with either an octagonal front face portion and a square shank portion or a square front face portion with an octagonal shank portion. The length of the sides of the octagonal front face portion on one tile is equal to the length of the sides of the square front face portion of adjoining tiles to permit formation of an interlocking matrix. Fibrous ceramic sealing material may be placed between radial and tangential facing surfaces of adjacent tiles to limit radial gas flow there between. Labyrinth-sealed pressure-controlled compartments may be established between the tile housing and the outer metal support housing to control radial gas flow. 8 figures.

  11. Ceramic tile expansion engine housing

    DOEpatents

    Myers, Blake

    1995-01-01

    An expandable ceramic tile housing for a high temperature engine is disclosed wherein each tile is independently supported in place in an interlocking matrix by retention mechanisms which mechanically couple the individual ceramic tiles to an outer metal support housing while maintaining thermal isolation of the metal housing from the ceramic tiles. The ceramic tiles are formed with either an octagonal front face portion and a square shank portion or a square front face portion with an octagonal shank portion. The length of the sides of the octagonal front face portion on one tile is equal to the length of the sides of the square front face portion of adjoining tiles to permit formation of an interlocking matrix. Fibrous ceramic sealing material may be placed between radial and tangential facing surfaces of adjacent tiles to limit radial gas flow therebetween. Labyrinth-sealed pressure-controlled compartments may be established between the tile housing and the outer metal support housing to control radial gas flow.

  12. Porcelain three-dimensional shape reconstruction and its color reconstruction

    NASA Astrophysics Data System (ADS)

    Yu, Xiaoyang; Wu, Haibin; Yang, Xue; Yu, Shuang; Wang, Beiyi; Chen, Deyun

    2013-01-01

    In this paper, structured light three-dimensional measurement technology was used to reconstruct the porcelain shape, and further more the porcelain color was reconstructed. So the accurate reconstruction of the shape and color of porcelain was realized. Our shape measurement installation drawing is given. Because the porcelain surface is color complex and highly reflective, the binary Gray code encoding is used to reduce the influence of the porcelain surface. The color camera was employed to obtain the color of the porcelain surface. Then, the comprehensive reconstruction of the shape and color was realized in Java3D runtime environment. In the reconstruction process, the space point by point coloration method is proposed and achieved. Our coloration method ensures the pixel corresponding accuracy in both of shape and color aspects. The porcelain surface shape and color reconstruction experimental results completed by proposed method and our installation, show that: the depth range is 860 ˜ 980mm, the relative error of the shape measurement is less than 0.1%, the reconstructed color of the porcelain surface is real, refined and subtle, and has the same visual effect as the measured surface.

  13. Covering the Plane with Rep-Tiles.

    ERIC Educational Resources Information Center

    Fosnaugh, Linda S.; Harrell, Marvin E.

    1996-01-01

    Presents an activity in which students use geometric figures, rep-tiles, to design a tile floor. Rep-tiles are geometric figures of which copies can fit together to form a larger similar figure. Includes reproducible student worksheet. (MKR)

  14. Tiles for Reo

    NASA Astrophysics Data System (ADS)

    Arbab, Farhad; Bruni, Roberto; Clarke, Dave; Lanese, Ivan; Montanari, Ugo

    Reo is an exogenous coordination model for software components. The informal semantics of Reo has been matched by several proposals of formalization, exploiting co-algebraic techniques, constraint-automata, and coloring tables. We aim to show that the Tile Model offers a flexible and adequate semantic setting for Reo, such that: (i) it is able to capture context-aware behavior; (ii) it is equipped with a natural notion of behavioral equivalence which is compositional; (iii) it offers a uniform setting for representing not only the ordinary execution of Reo systems but also dynamic reconfiguration strategies.

  15. The Porcelain Crab Transcriptome and PCAD, the Porcelain Crab Microarray and Sequence Database

    SciTech Connect

    Tagmount, Abderrahmane; Wang, Mei; Lindquist, Erika; Tanaka, Yoshihiro; Teranishi, Kristen S.; Sunagawa, Shinichi; Wong, Mike; Stillman, Jonathon H.

    2010-01-27

    Background: With the emergence of a completed genome sequence of the freshwater crustacean Daphnia pulex, construction of genomic-scale sequence databases for additional crustacean sequences are important for comparative genomics and annotation. Porcelain crabs, genus Petrolisthes, have been powerful crustacean models for environmental and evolutionary physiology with respect to thermal adaptation and understanding responses of marine organisms to climate change. Here, we present a large-scale EST sequencing and cDNA microarray database project for the porcelain crab Petrolisthes cinctipes. Methodology/Principal Findings: A set of ~;;30K unique sequences (UniSeqs) representing ~;;19K clusters were generated from ~;;98K high quality ESTs from a set of tissue specific non-normalized and mixed-tissue normalized cDNA libraries from the porcelain crab Petrolisthes cinctipes. Homology for each UniSeq was assessed using BLAST, InterProScan, GO and KEGG database searches. Approximately 66percent of the UniSeqs had homology in at least one of the databases. All EST and UniSeq sequences along with annotation results and coordinated cDNA microarray datasets have been made publicly accessible at the Porcelain Crab Array Database (PCAD), a feature-enriched version of the Stanford and Longhorn Array Databases.Conclusions/Significance: The EST project presented here represents the third largest sequencing effort for any crustacean, and the largest effort for any crab species. Our assembly and clustering results suggest that our porcelain crab EST data set is equally diverse to the much larger EST set generated in the Daphnia pulex genome sequencing project, and thus will be an important resource to the Daphnia research community. Our homology results support the pancrustacea hypothesis and suggest that Malacostraca may be ancestral to Branchiopoda and Hexapoda. Our results also suggest that our cDNA microarrays cover as much of the transcriptome as can reasonably be captured in

  16. Kinetics of DNA tile dimerization.

    PubMed

    Jiang, Shuoxing; Yan, Hao; Liu, Yan

    2014-06-24

    Investigating how individual molecular components interact with one another within DNA nanoarchitectures, both in terms of their spatial and temporal interactions, is fundamentally important for a better understanding of their physical behaviors. This will provide researchers with valuable insight for designing more complex higher-order structures that can be assembled more efficiently. In this report, we examined several spatial factors that affect the kinetics of bivalent, double-helical (DH) tile dimerization, including the orientation and number of sticky ends (SEs), the flexibility of the double helical domains, and the size of the tiles. The rate constants we obtained confirm our hypothesis that increased nucleation opportunities and well-aligned SEs accelerate tile-tile dimerization. Increased flexibility in the tiles causes slower dimerization rates, an effect that can be reversed by introducing restrictions to the tile flexibility. The higher dimerization rates of more rigid tiles results from the opposing effects of higher activation energies and higher pre-exponential factors from the Arrhenius equation, where the pre-exponential factor dominates. We believe that the results presented here will assist in improved implementation of DNA tile based algorithmic self-assembly, DNA based molecular robotics, and other specific nucleic acid systems, and will provide guidance to design and assembly processes to improve overall yield and efficiency. PMID:24794259

  17. The DELPHI small angle tile calorimeter

    SciTech Connect

    Alvsvaag, S.J.; Maeland, O.A.; Klovning, A.

    1995-08-01

    The Small angle TIle Calorimeter (STIC) provides calorimetric coverage in the very forward region for the DELPHI experiment at the CERN LEP collider. A veto system composed of two scintillator layers allows to trigger on single photon events and provides e{minus}{gamma} separation. The authors present here some results of extensive measurements performed on part of the calorimeter and the veto system in the CERN test beams prior to installation and report on the performance achieved during the 1994 LEP run.

  18. [Study on Provenance of Kraak Porcelains from "Nan'ao I" Shipwreck].

    PubMed

    Du, Jing-nan; Chen, Yue; Li, Nai-sheng; Ming, Chao-fang; Zhu, Jian; Luo, Wu-gan

    2015-06-01

    The "Kraak Porcelain" was a kind of Blue and White Porcelain which exported from China to Europe in Ming and Qing period. The study of Kraak Porcelain is a focus issue in international field of porcelain research. In 2007, the discovery of "Nan'ao I" Shipwreck of Ming Dynasty and the porcelains loaded in it, provided precious materials for the research on Kraak Porcelain. In this paper, we explored the provenance of 10 Kraak Porcelain samples from Nan'ao I, using both traditional visual method and WDXRF. PMID:26601402

  19. Porcelain gallbladder: ultrasound and CT appearance

    SciTech Connect

    Kane, R.A.; Jacobs, R.; Katz, J.; Costello, P.

    1984-07-01

    Nine patients with calcification of the gallbladder wall (porcelain gallbladder) were analyzed by ultrasound and the appearance correlated with the CT, radiographic, clinical, and surgical findings. Three distinct patterns were identified: (a) a hyperechoic similunar structure with acoustic shadowing posteriorly, simulating a stone-filled gallbladder devoid of bile, which was seen in 5 patients; (b) a biconvex, curvilinear echogenic structure with variable acoustic shadowing, seen in all 3 patients with carcinoma of the gallbladder; and (c) an irregular clump of echoes with posterior acoustic shadowing, seen in 1 patient. Potential pitfalls in the diagnosis of gallbladder calcification are presented, and the association between calcification and cancer is emphasized.

  20. Porcelain enamel passive thermal control coatings

    NASA Technical Reports Server (NTRS)

    Leggett, H.; King, H. M.

    1978-01-01

    This paper discusses the development and evaluation of a highly adherent, low solar absorptance, porcelain enamel thermal control coating applied to 6061 and 1100 aluminum for space vehicle use. The coating consists of a low index of refraction, transparent host frit and a high volume fraction of titania as rutile, crystallized in-situ, as the scattering medium. Solar absorptance is 0.21 at a coating thickness of 0.013 cm. Hemispherical emittance is 0.88. The change in solar absorptance is 0.03, as measured in-situ, after an exposure of 1000 equivalent sun hours in vacuum.

  1. Temperature changes across porcelain during multiple exposure CO2 lasing

    NASA Astrophysics Data System (ADS)

    Barron, Joseph R.; Zakariasen, Kenneth L.; Peacocke, Larry

    1990-06-01

    Research indicates that laser energy may provide a useful method for glazing and fusing porcelain for intraoral prosthetic purposes. However, it is not known whether such lasing will result in the production of heat levels that may be damaging to adjacent vital tissues such as the dental pulp and periodontal tissues. This research is designed to measure the magnitude of temperature rise across porcelain observed during multiple exposure C02 lasing. Fifteen porcelain examples of 1000 jim (5), 1500 pm (5) and 2000 tm (5) x each received five C02 laser exposures on the same exposure site at 1.0 sec. intervals at 8.0 watts (0.2 sec. per exposure with a 1 mm focal spot). A YSI 144201 thermilinear precision thermistor was placed on the porcelain surface opposite each laser exposure site. Temperature rise above ambient was recorded by an HP3421A data acquisition unit and HP9816 technical microcomputer. Recording continued for sufficient time to allow temperatures to return to ambient. The mean temperature elevations ranged from a low of 2.97 0C (2000 pm) to a high of 7.77 °C (1000 μm). ANOVA and Duncan's Multiple Range Test indicated significant differences in temperature rise by porcelain thickness. It would appear from the results of this research that temperature elevations adjacent to lased porcelain may be sufficiently controllable that safe intraoral porcelain lasing will be possible.

  2. Residual Stresses in Porcelain-veneered Zirconia Prostheses

    PubMed Central

    Baldassarri, Marta; Stappert, Christian F. J.; Wolff, Mark S.; Thompson, Van P.; Zhang, Yu

    2012-01-01

    Objectives Compressive stress has been intentionally introduced into the overlay porcelain of zirconia-ceramic prostheses to prevent veneer fracture. However, recent theoretical analysis has predicted that the residual stresses in the porcelain may be also tensile in nature. This study aims to determine the type and magnitude of the residual stresses in the porcelain veneers of full-contour fixed-dental prostheses (FDPs) with an anatomic zirconia coping design and in control porcelain with the zirconia removed using a well-established Vickers indentation method. Methods Six 3-unit zirconia FDPs were manufactured (NobelBiocare, Gothenburg, Sweden). Porcelain was hand-veneered using a slow cooling rate. Each FDP was sectioned parallel to the occlusal plane for Vickers indentations (n = 143; load = 9.8 N; dwell time = 5 s). Tests were performed in the veneer of porcelain-zirconia specimens (bilayers, n = 4) and porcelain specimens without zirconia cores (monolayers, n = 2). Results The average crack lengths and standard deviation, in the transverse and radial directions (i.e. parallel and perpendicular to the veneer/core interface, respectively), were 67 ± 12 μm and 52 ± 8 μm for the bilayers and 64 ± 8 μm and 64 ± 7 μm for the monolayers. These results indicated a major hoop compressive stress (~40 to 50 MPa) and a moderate radial tensile stress (~10 MPa) in the bulk of the porcelain veneer. Significance Vickers indentation is a powerful method to determine the residual stresses in veneered zirconia systems. Our findings revealed the presence of a radial tensile stress in the overlay porcelain, which may contributed to the large clinical chip fractures observed in these prostheses. PMID:22578663

  3. Hydrothermally prepared inorganic siliceous wastes: Hydrothermal reaction of calcareous and steatite ceramic tile wastes

    SciTech Connect

    Maenami, Hiroki; Yamamoto, Takeyuki; Ishida, Hideki

    1996-12-31

    Possibility of solidification of various ceramic wastes by hydrothermal processing was investigated. The starting materials were feldspathic porcelain tile waste, steatite ceramic tile waste, and calcareous ceramic tile waste. These were mixed with CaO so as to obtain a Ca/Si molar ratio of 0.5. After forming, they were cured for 2 to 20 h under the saturated steam pressure at 200{degrees}C. Although the SiO{sub 2} content of these ceramic wastes was about 70 mass% and they contain various alkaline ions and alkaline earth ions, solidified specimens with flexural strength up to 35MPa were obtained. This is within the range of strengths when quartz or fused silica is used as pure SiO{sub 2} sources. Formation of tobermorite, which was detected in all systems after 2 h of curing, was considered to affect the increase of the strength. It was found that there is a possibility of aluminum and alkali ions being included in the structure of the formed tobermorite. In the case of using steatite ceramic tile waste containing Mg, magnesium silicate hydrates were also formed. The modal pore diameter shifted to 0.01 {mu} m with the formation of these hydrates and there was correlation between the flexural strength and the pore size distribution.

  4. PIXE analysis of Chinese ancient greenish white porcelain

    NASA Astrophysics Data System (ADS)

    Cheng, Lin; Ding, Xun-liang; Feng, Song-lin; Cheng, Huang-sheng; Zhang, Wen-Jiang; Fan, Chang-Sheng

    2006-03-01

    This paper reports the results about the PIXE analysis of major, minor and trace elements of Chinese ancient greenish white porcelain and blue-and-white porcelain produced in Hutian Kiln (Jingdezhen district, Jiangxi province) during 10th-14th centuries. The porcelain body and greenish white glaze from northern Song (AD 960), southern Song (AD 1037-1276), early Yuan (AD 1279-1320), later Yuan (AD 1320-1368) were investigated together with white-and-blue glaze from Ming dynasty (AD 1368-1644). The obtained data were further analyzed by factor analysis.

  5. PIXE analysis of ancient Chinese Qing dynasty porcelain

    NASA Astrophysics Data System (ADS)

    Cheng, Huansheng; He, Wenquan; Tang, Jiayong; Yang, Fujia; Wang, Jianhua

    1996-09-01

    The major and minor chemical compositions and trace element content of white glaze made in Qing dynasty at kuan kiln have been determined by PIXE. Experimental results show that trace element contents RbSrZr are useful to distinguish the place of production of ancient porcelain. In the porcelain from different kilns situated in a same province, the trace element contents can be different from each other. Determining and comparing the major and minor compositions and trace elemental concentrations in white glaze by PIXE technique, we can distinguish a precious Qing dynasty porcelain made at kuan kiln from a fake.

  6. Repairing high-temperature glazed tiles

    NASA Technical Reports Server (NTRS)

    Ecord, G. M.; Schomburg, C.

    1981-01-01

    Tetraethyl orthosilicate (TEOS) mixture fills chips and cracks in glazed tile surface. Filler is made by mixing hydrolyzed TEOS, silicon tetraboride powder, and pulverized tile material. Repaired tiles survived testing by intense acoustic emissions, arc jets, and intense heat radiation. Repair is reliable and rapid, performed in 1-1 1/2 hours with tile in any or orientation.

  7. The effects of extraoral porcelain polishing sequences on surface roughness and color of feldspathic porcelain.

    PubMed

    Yuzugullu, Bulem; Celik, Cigdem; Erkut, Selim; Ozcelik, Tuncer Burak

    2009-01-01

    The aim of this study was to evaluate the surface properties and color of porcelain modified by extraoral polishing sequences. Six different surface treatment regimens (diamond burs, self-glaze, overglaze, reglaze, Pearl Surface polishing system, and Diamond Twist SCL) were applied to 60 porcelain disks (n = 10 per group). Profilometry and atomic force microscopy (AFM) were used for the determination of surface roughness (Ra); color changes (deltaE*) were investigated by spectrophotometry. Statistical comparisons were made using analysis of variance, the Kruskal-Wallis test, and the Pearson correlation coefficient test. Surface treatments significantly affected Ra values (P < .001) but had no effect on color (P > .05). AFM findings were consistent with Ra values. Color did not appear to be correlated with surface roughness (P > .05). The findings concluded that the Pearl Surface system helps to decrease chairside time and may be used as an alternative to overglazing. PMID:20095196

  8. Lozenge Tilings and Hurwitz Numbers

    NASA Astrophysics Data System (ADS)

    Novak, Jonathan

    2015-10-01

    We give a new proof of the fact that, near a turning point of the frozen boundary, the vertical tiles in a uniformly random lozenge tiling of a large sawtooth domain are distributed like the eigenvalues of a GUE random matrix. Our argument uses none of the standard tools of integrable probability. In their place, it uses a combinatorial interpretation of the Harish-Chandra/Itzykson-Zuber integral as a generating function for desymmetrized Hurwitz numbers.

  9. A LINE POLE 2, DETAIL OF MODERN BROWN PORCELAIN SUSPENSIONTYPE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    A LINE POLE 2, DETAIL OF MODERN BROWN PORCELAIN SUSPENSION-TYPE INSULATORS. VIEW TO WEST. - Mystic Lake Hydroelectric Facility, Electric Transmission A Line, Along West Rosebud Creek, Fishtail, Stillwater County, MT

  10. Effect of interfacial variables on metal-porcelain bonding.

    PubMed

    Wagner, W C; Asgar, K; Bigelow, W C; Flinn, R A

    1993-04-01

    While ceramic-to-metal bonding has been used in many applications, the actual chemical and physical factors leading to optimum bond strength are not well understood. In this work, several variables affecting the bonding between dental porcelain and a palladium alloy (85% Pd, 10% Cu, and 5% Ga) were investigated: 1) precoating the metal by sputtering various oxides before porcelaining; 2) peroxidation of the metal base before porcelaining; 3) porcelaining under reducing atmosphere; and 4) surface roughening at controlled levels before porcelaining. Using a modification of the push doughnut shear bond strength test to measure bond strength the following results were obtained. 1) Compared with standard "control" samples, the aluminum oxide precoated specimens showed a bond strength improvement of 46%, while the copper, manganese, and tin oxide precoatings exhibited smaller effects. 2) Preoxidation of the metal base led to pronounced bond strengthening (152%) by surface roughening as well as oxide formation. 3) Porcelaining under a reducing atmosphere severely reduced bond strength (88% lower than the controls) indicating the role of oxidation during the standard firing cycle. 4) Mechanical roughening of the surface by controlled amounts gave pronounced improvements with greater notch depth. Coarse roughening produced the highest bond strength improvements (486%). PMID:8463354

  11. On Some New Properties of Binary Tilings

    NASA Astrophysics Data System (ADS)

    Aviram, Ira; Kleman, Maurice

    1996-05-01

    We show that one of the binary tilings introduced by Lançon & Billard (LB1) tends asymptotically towards an “universal” random tiling of decagonal symmetry, whatever the starting tiling may be, after an infinite sequence of random decorations preserving the LB1 structural properties; the successive steps of the sequence are described in terms of random substitution matrices. The universal character of the asymptotic tiling reveals in particular in: the existence of a well-defined intensive variable α_infty which measures the proportion of pairs of nearest neighbors of atoms of different species which belong to pairs o contiguous “fat” tiles F, its very characteristic Fourier transform, and finite size fluctuations. Our results rely on a series of extensive Monte-Carlo simulations and on analytic calculations of the statistics of the tilings (e.g. α_n) at different stages n of the substitution process. All these calculations concerns the sole entropy properties, which simplification is justified by the well known fact that binary tilings are degenerate for Lennard-Jones interactions between nearest-neighbors. A direct calculation of the entropy yields a value of α_infty slightly different from the value obtained by the analytic method above, by an amount of ≈ 1%. We suggest that the difference is due to long-range correlations which are not taken into account in the direct calculation as well as some specific ergodicity properties of our “microcanonical” ensemble of tilings realizations, which reveal for example in the non-abelian properties of the finite size fluctuations, and which remain to be studied in any case. Nous montrons que l'un des pavages binaires de Lançon & Billard (LB1) a une limite asymptotique “universelle”, c'est-à-dire ne dépendant pas du pavage de départ, sous l'effet d'une séquence infinie de substitutions aléatoires (décrites par une matrice de transfert aléatoire) qui préservent son caractère LB1. Le caract

  12. Supporting Students' Understanding of Linear Equations with One Variable Using Algebra Tiles

    ERIC Educational Resources Information Center

    Saraswati, Sari; Putri, Ratu Ilma Indra; Somakim

    2016-01-01

    This research aimed to describe how algebra tiles can support students' understanding of linear equations with one variable. This article is a part of a larger research on learning design of linear equations with one variable using algebra tiles combined with balancing method. Therefore, it will merely discuss one activity focused on how students…

  13. Calibration of the Tile Hadronic Calorimeter of ATLAS at LHC

    NASA Astrophysics Data System (ADS)

    Boumediene, Djamel; ATLAS Collaboration

    2015-02-01

    The Tile Calorimeter (TileCal) is the central section of the hadronic calorimeter of the ATLAS experiment. The TileCal provides important information for reconstruction of hadrons, jets, hadronic decays of tau leptons and missing transverse energy. This sampling calorimeter uses iron plates as absorber and scintillating tiles as active medium. The light produced by the passage of charged particles is transmitted by means of wavelength shifting fibers to photomultiplier tubes (PMTs). The TileCal readout is segmented into about 5000 cells (longitudinally and transversally), each of them being read by two PMTs. A brief description of the individual calibration systems (Cs radioactive source, laser, charge injection, minimum bias) is provided. Their combination allows to calibrate each part of the data acquisition chain (optical part, photomultiplier, readout electronics) and to monitor its stability to better than 1%. The procedure for setting and preserving the electromagnetic energy scale during Run 1 data taking is discussed. The issues of linearity and stability of the response, as well as the timing adjustment are also shown.

  14. Image Composition Engine for Tiles

    Energy Science and Technology Software Center (ESTSC)

    2011-08-22

    The Image Composition Engine for Tiles (lceT) is a high-performance sort-last parallel rendering library. It is designed to be used in parallel applications requiring rendering. The primary purpose of IceT is to be integrated into parallel visualization applications such as ParaView to provide parallel rendering capabilities. The Image Composition Engine for Tiles (lceT) is a high-performance sort-last parallel rendering library. IceT uses a "sort-Iasf' approach to rendering. Each process in a parallel application independently rendersmore » a local piece of geometry. The resulting images are given to IceT, and IceT combines the images together to form a single cohesive image. Ice T is also capable of driving tiled displays, largeformat displays comprising an array of smaller displays. To this end IceT can collect the smaller tile images and organize them such that the entire tiled display can be driven. Ice T takes advantage of spatial coherence in geometry by identifying empty regions of the display and reducing the overall required work.« less

  15. Image Composition Engine for Tiles

    SciTech Connect

    Moreland, Kenneth

    2011-08-22

    The Image Composition Engine for Tiles (lceT) is a high-performance sort-last parallel rendering library. It is designed to be used in parallel applications requiring rendering. The primary purpose of IceT is to be integrated into parallel visualization applications such as ParaView to provide parallel rendering capabilities. The Image Composition Engine for Tiles (lceT) is a high-performance sort-last parallel rendering library. IceT uses a "sort-Iasf' approach to rendering. Each process in a parallel application independently renders a local piece of geometry. The resulting images are given to IceT, and IceT combines the images together to form a single cohesive image. Ice T is also capable of driving tiled displays, largeformat displays comprising an array of smaller displays. To this end IceT can collect the smaller tile images and organize them such that the entire tiled display can be driven. Ice T takes advantage of spatial coherence in geometry by identifying empty regions of the display and reducing the overall required work.

  16. Evolutionary morphology of the organ systems in squat lobsters and porcelain crabs (crustacea: Decapoda: Anomala): an insight into carcinization.

    PubMed

    Keiler, Jonas; Richter, Stefan; Wirkner, Christian S

    2015-01-01

    Porcelain crabs (Porcellanidae) are one of three taxa within anomuran crustaceans (Anomala) which possess a crab-like body form. Curiously, these three lineages evolved this shape independently from true crabs (Brachyura) in the course of the evolutionary process termed carcinization. The entire pleon in porcelain crabs is flexed under the cephalothorax and the carapace is approximately as broad as long. Despite their crab-like habitus, porcelain crabs are phylogenetically nested within squat lobsters (Munidopsidae, Munididae, Galatheidae). With a pleon which is only partly flexed under the cephalothorax and a cephalothorax which is longer than it is broad, squat lobsters represent morphologically intermediate forms between lobster-like and crab-like body shapes. Carcinization has so far mostly been studied with respect to outer morphology; however, it is evident that internal anatomical features are influenced through this change of body shape too. In this paper, the situation in Galatheoidea is elucidated by adding more taxa to existing descriptions of the hemolymph vascular systems and associated structures and organs. Micro-computer tomography and 3D reconstruction provide new insights. Autapomorphic states of various internal anatomical characters are present in nearly all the studied species, also reflecting some degree of anatomical disparity found within Galatheoidea. The ventral vessel system of porcelain crabs differs distinctly from that of squat lobsters. The differences in question are coherent (i.e. structural dependent) with morphological transformations in the integument, such as the shortening of the sternal plastron, which evolved in the course of carcinization. Shifts in the gonads and the pleonal neuromeres are coherent with the loss of the caridoid escape reaction, which in turn is a consequence of carcinization. The arterial transformations, however, are minor compared to other instances of carcinization in anomuran crustaceans since the last

  17. [Research on the composition characteristics of Chinese ancient southern white porcelain].

    PubMed

    Wu, Juan; Ye, Zheng-Long; Wu, Jun-Ming; Zhang, Mao-Lin; Li, Qi-Jiang; Wang, Li-Li; Jiang, Peng-Fei

    2012-07-01

    The southern white porcelain is the rise in our country's pottery, it is later than the development of northern white porcelain, but it is rising stars, blockbuster, well-grounded, keeping continuous. Jingdezhen kiln and Dehua kiln are the most representative kilns among the southern white porcelain kilns. the present paper used EDXRF to test 30 pieces of Song, Yuan and Ming period' Dehua white porcelains and Jingdezhen Yuan dynasty Shufu white porcelains samples to analyze the different characteristics of the bodies and the glaze of these samples in terms of time and space. The results show that in the bodies and the glaze of Jingdezhen Shufu white porcelains the iron content is obviously on the high side, and the Dehua white porcelains' potassium content is obviously on the high side, and along with time development they have been in a rising trend, which should be the main reason for the sudden rise of Dehua white porcelain sculptures. PMID:23016370

  18. Composite treatment of ceramic tile armor

    DOEpatents

    Hansen, James G. R.; Frame, Barbara J.

    2012-01-02

    An improved ceramic tile armor has a core of boron nitride and a polymer matrix composite (PMC) facing of carbon fibers fused directly to the impact face of the tile. A polyethylene fiber composite backing and spall cover are preferred. The carbon fiber layers are cured directly onto the tile, not adhered using a separate adhesive so that they are integral with the tile, not a separate layer.

  19. Composite treatment of ceramic tile armor

    DOEpatents

    Hansen, James G. R. [Oak Ridge, TN; Frame, Barbara J [Oak Ridge, TN

    2010-12-14

    An improved ceramic tile armor has a core of boron nitride and a polymer matrix composite (PMC) facing of carbon fibers fused directly to the impact face of the tile. A polyethylene fiber composite backing and spall cover are preferred. The carbon fiber layers are cured directly onto the tile, not adhered using a separate adhesive so that they are integral with the tile, not a separate layer.

  20. Effects of flux concentrations and sintering temperature on dental porcelain

    NASA Astrophysics Data System (ADS)

    Ghose, Polash; Gafur, Md. Abdul; Das, Sujan Kumar; Ranjan Chakraborty, Shyamal; Mohsin, Md.; Deb, Arun Kumar; Rakibul Qadir, Md.

    2014-02-01

    In this study, samples of dental porcelain bodies have been made by using the materials collected from selected deposits employing different mixing proportions of clay, quartz and feldspar. Dental porcelain ceramics have been successfully fabricated by using the sintering technique together with some Na2CO3 additive. The dental porcelain powder has been pressed into pellets at first and subsequently sintered at 700, 800, 900, 1000 and 1100 °C for 2 h. The physical and mechanical properties of the prepared samples have been investigated. The sintering behavior of the fired samples has been evaluated by bulk density, linear shrinkage, water absorption and apparent porosity measurements. This study includes the evaluation of the Vickers's microhardness by microhardness tester. Phase analysis and microstructural study have been performed by XRD and optical microscope respectively. Optical properties have been investigated using UV-visible spectroscopy. Influence of firing conditions on leucite formation, densification and microstructural development of the sintered samples has been investigated. It has been found that the choice of sintering temperature is one of the key factors in controlling leucite crystallization in dental porcelain ceramics. It has also been found that the flux concentration of material and the effect of temperature on preparation of dental porcelain contribute to the firing shrinkage and hardness, which has been found to increase with the increase of treatment temperature.

  1. Cementing porcelain-fused-to-metal crowns.

    PubMed

    Vadachkoria, D

    2009-12-01

    The clinical success of fixed prosthodontic restorations can be complex and involve multifaceted procedures. Preparation design, oral hygiene/micro flora, mechanical forces, and restorative materials are only a few of the factors which contribute to overall success. One key factor to success is choosing the proper cement. Popular use of cements for PFM crowns has shifted from zinc phosphate and glass ionomer cements to resin-reinforced glass ionomer, or RRGI, cements. This change has been rapid and profound. Dental cements have always been less than ideal materials, but this is shift to the relatively new RRGI category justified. Resin-reinforced glass ionomer (RRGI) cements appear to be better than zinc phosphate and glass ionomer cements when placing porcelain-to-metal crowns. RRGI cements, such as RelyX Luting, Fuji Plus and Vitremer Luting Cement, satisfy more of the ideal characteristics of PFM cementation than any other previous cement. Expansion of all three cements has not caused any apparent problems with the cements when used with PFM or metal crowns, but these cements, however, should be avoided when cementing all-ceramic crowns. PMID:20090144

  2. Mechanical properties of alumina porcelain during heating

    NASA Astrophysics Data System (ADS)

    Šín, Peter; Podoba, Rudolf; ŠtubÅa, Igor; Trník, Anton

    2014-11-01

    The mechanical strength and Young's modulus of green alumina porcelain (50 wt. % of kaolin, 25 wt. % of Al2O3, and 25 wt. % of feldspar) were measured during heating up to 900 °C and 1100 °C, respectively. To this end, we used the three point-bending method and modulated force thermomechanical analysis (mf-TMA). The loss liberation - of the physically bound water (20 - 250 °C) strengthens the sample and Young's modulus increases its values significantly. The dehydroxylation that takes place in the range of 400 - 650 °C causes a slight decrease in Young's modulus. On the other hand, the mechanical strength slightly increases in this temperature range, although it has a sudden drop at 420 °C. Beyond the dehydroxylation range, above 650 °C, both Young's modulus and mechanical strength increase. Above 950 °C, a sharp increase of Young's modulus is caused by the solid-state sintering and the new structure created by the high-temperature reactions in metakaolinite.

  3. REACTOR CANAL AFTER IT HAS BEEN TILED. WATER FILLS CANAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    REACTOR CANAL AFTER IT HAS BEEN TILED. WATER FILLS CANAL PART WAY TO TOP. CAMERA FACES WEST. INL NEGATIVE NO. 3993-A. Unknown Photographer, 12/28/1951 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  4. Algebraic properties of basic isohedral marked tilings

    NASA Astrophysics Data System (ADS)

    Greco, Gabriele H.

    2006-05-01

    In 1977 Grünbaum and Shephard described all possible 93 types of isohedral marked tilings of the plane; 46 of them are called basic, since their induced tile group is trivial. The aim of this paper is to give an algebraic description of all basic tilings. A purely algebraic characterization of the adjacency symmetries of tiles of the 46 basic tilings is presented. Moreover, 46 related abstract definitions of two-dimensional crystallographic groups supplement and extend those of the well-known book Generators and Relations for Discrete Groups by Coxeter and Moser.

  5. X-ray spectrometric technique for measuring porcelain-metal adherence

    SciTech Connect

    Ringle, R.D.; Mackert, J.R. Jr.; Fairhurst, C.W.

    1983-08-01

    This study demonstrated a correlation between silicon x-ray counts and area fractions of adherent porcelain as determined by point-counting. This correlation has allowed a method to be devised for measuring area fractions of porcelain adherent to porcelain-fused-to-metal (PFM) fracture surfaces. The described method, after controlled destruction of the porcelain mass, uses silicon x-rays excited by the electron beam in a scanning electron microscope. Under the conditions employed in these studies, the x-ray technique has shown that this gold alloy retains more porcelain than does either of two particular nickel-chromium alloys.

  6. Toughening of dental porcelain by tetragonal ZrO/sub 2/ additions

    SciTech Connect

    Morena, R.; Lockwood, P.E.; Evans, A.L.; Fairhurst, C.W.

    1986-04-01

    The effect of mechanical behavior of ZrO/sub 2/ additions to a dental porcelain was investigated. The ZrO/sub 2/ was introduced into the glassy matrix phase of the porcelain by refritting the all-glass porcelain constituent. X-ray diffraction indicated that a sizeable fraction of the ZrO/sub 2/ was retained in the tetragonal from after the porcelain was fired. Zirconia additions to the porcelain produced substantial improvements in fracture toughness, strength, and thermal shock resistance.

  7. Porcelain enamelled absorbers, coated by spectral selective tin oxide

    SciTech Connect

    Simonis, F.; Faber, A.J.; Hoogendoorn, C.J.

    1987-02-01

    The use of porcelain enamelled absorbers in flat plate collectors features longevity thanks to the durability and thermal stability of the enamel finish. The porcelain enamel can be made spectral selective by coating with doped tin oxide or indium oxide. The application procedure involves an enamelling step followed by a pyrosol process with tin or indium compounds. The optical properties of tin oxide coated enamel yield values of 0.90-0.92 absorptance and 0.13-0.18 hemispherical emittance. The temperature dependence of the emittance is very small. The thermal stability has been proved up to 400/sup 0/C in air.

  8. [Fluorescence of dental porcelain: material and methods].

    PubMed

    Monsénégo, G; Burdairon, G; Porte, C; Naud, C

    1990-06-01

    Dental porcelain emits some fluorescence under the action of ultra-violet rays. This emission may be at the origin of errors in the choice of the colour of a crown. In order to study this fluorescence phenomenon, the following experimental protocol has been developed: 363.8 nm exciting radiation isolated from the emission by an Argon laser; Fluorescence emitted by the sample and dispersed via a spectrometer, protected by a stop-U.V. filter; Influx collected by a photomultiplier, then directed, after passage in a picoamperemeter, toward a mini-computer programmed to print the spectra; Correction of the spectra by a tungsten lamp used at the 2,600 K colour temperature; Use of reference spectra. On the same graph, the sample spectra are represented in solid lines, while the spectrum of the enamel used as a reference is shown as a dotted line. The results show that: Enamel has a fluorescence spectrum which has the shape of a wide band, with a maximum of 450 nm (characteristic of a blue-green shade) and a slow decrease up to 680 nm. The enamel fluorescence does not depend on the colour of the tooth; Dentine has a distribution spectrum which is similar to that of enamel but is three times fuller; The spectra of the ceramic samples reveal: a wide band due to transition metals, fine lines due to rare earth (terbium and europium). When the saturation degree of the ceramic increases, its fluorescence colour varies due to the relative increase in the amplitude of the lines in relation to the bands. Thus, when the sample colour progresses from B1 to B4, its fluorescence colour becomes greener.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2207845

  9. Fractal tiles associated with shift radix systems.

    PubMed

    Berthé, Valérie; Siegel, Anne; Steiner, Wolfgang; Surer, Paul; Thuswaldner, Jörg M

    2011-01-15

    Shift radix systems form a collection of dynamical systems depending on a parameter r which varies in the d-dimensional real vector space. They generalize well-known numeration systems such as beta-expansions, expansions with respect to rational bases, and canonical number systems. Beta-numeration and canonical number systems are known to be intimately related to fractal shapes, such as the classical Rauzy fractal and the twin dragon. These fractals turned out to be important for studying properties of expansions in several settings. In the present paper we associate a collection of fractal tiles with shift radix systems. We show that for certain classes of parameters r these tiles coincide with affine copies of the well-known tiles associated with beta-expansions and canonical number systems. On the other hand, these tiles provide natural families of tiles for beta-expansions with (non-unit) Pisot numbers as well as canonical number systems with (non-monic) expanding polynomials. We also prove basic properties for tiles associated with shift radix systems. Indeed, we prove that under some algebraic conditions on the parameter r of the shift radix system, these tiles provide multiple tilings and even tilings of the d-dimensional real vector space. These tilings turn out to have a more complicated structure than the tilings arising from the known number systems mentioned above. Such a tiling may consist of tiles having infinitely many different shapes. Moreover, the tiles need not be self-affine (or graph directed self-affine). PMID:24068835

  10. Developing tiled projection display systems

    SciTech Connect

    Hereld, M.; Judson, I. R.; Paris, J.; Stevens, R. L.

    2000-06-08

    Tiled displays are an emerging technology for constructing high-resolution semi-immersive visualization environments capable of presenting high-resolution images from scientific simulation [EVL, PowerWall]. In this way, they complement other technologies such as the CAVE [Cruz-Niera92] or ImmersaDesk, [Czernuszenko97], which by design give up pure resolution in favor of width of view and stereo. However, the largest impact may well be in using large-format tiled displays as one of possibly multiple displays in building ''information'' or ''active'' spaces that surround the user with diverse ways of interacting with data and multimedia information flows [IPSI, Childers00, Raskar98, ROME, Stanford, UNC]. These environments may prove to be the ultimate successor of the desktop metaphor for information technology work.

  11. Geometrical Tile Design for Complex Neighborhoods

    PubMed Central

    Czeizler, Eugen; Kari, Lila

    2009-01-01

    Recent research has showed that tile systems are one of the most suitable theoretical frameworks for the spatial study and modeling of self-assembly processes, such as the formation of DNA and protein oligomeric structures. A Wang tile is a unit square, with glues on its edges, attaching to other tiles and forming larger and larger structures. Although quite intuitive, the idea of glues placed on the edges of a tile is not always natural for simulating the interactions occurring in some real systems. For example, when considering protein self-assembly, the shape of a protein is the main determinant of its functions and its interactions with other proteins. Our goal is to use geometric tiles, i.e., square tiles with geometrical protrusions on their edges, for simulating tiled paths (zippers) with complex neighborhoods, by ribbons of geometric tiles with simple, local neighborhoods. This paper is a step toward solving the general case of an arbitrary neighborhood, by proposing geometric tile designs that solve the case of a “tall” von Neumann neighborhood, the case of the f-shaped neighborhood, and the case of a 3 × 5 “filled” rectangular neighborhood. The techniques can be combined and generalized to solve the problem in the case of any neighborhood, centered at the tile of reference, and included in a 3 × (2k + 1) rectangle. PMID:19956398

  12. Geometrical tile design for complex neighborhoods.

    PubMed

    Czeizler, Eugen; Kari, Lila

    2009-01-01

    Recent research has showed that tile systems are one of the most suitable theoretical frameworks for the spatial study and modeling of self-assembly processes, such as the formation of DNA and protein oligomeric structures. A Wang tile is a unit square, with glues on its edges, attaching to other tiles and forming larger and larger structures. Although quite intuitive, the idea of glues placed on the edges of a tile is not always natural for simulating the interactions occurring in some real systems. For example, when considering protein self-assembly, the shape of a protein is the main determinant of its functions and its interactions with other proteins. Our goal is to use geometric tiles, i.e., square tiles with geometrical protrusions on their edges, for simulating tiled paths (zippers) with complex neighborhoods, by ribbons of geometric tiles with simple, local neighborhoods. This paper is a step toward solving the general case of an arbitrary neighborhood, by proposing geometric tile designs that solve the case of a "tall" von Neumann neighborhood, the case of the f-shaped neighborhood, and the case of a 3 x 5 "filled" rectangular neighborhood. The techniques can be combined and generalized to solve the problem in the case of any neighborhood, centered at the tile of reference, and included in a 3 x (2k + 1) rectangle. PMID:19956398

  13. Porcelain veneering of titanium--clinical and technical aspects.

    PubMed

    Haag, Per

    2011-01-01

    Gold and other alloys have long been used for the production of crowns and bridges as replacements for damaged or lost teeth. However, doubts have arisen on the suitability of using these materials for dental restorations, as gold has also shown a capacity to cause side-effects such as allergic reactions. This is especially valid for alloys, which during the last decades have been used as porcelain-fused-to metal restorations. This fact has led to an interest in using titanium instead of these alloys. Trials to use titanium for this purpose were initiated in Japan in the early 1980s. Titanium as an unalloyed metal differs in two aspects from the above named alloys: it has a phase transformation at 882 degrees C, which changes its outer and inner properties, and it has an expansion that lies between that of the porcelain types available on the market at the time. In Japan a technique for casting titanium was developed, where the after-treatment of the casting was elaborate, to re-establish the original properties of titanium. The porcelain developed for veneering had shortcomings as the rendering produced a rough surface and non satisfactory esthetics. In Sweden a new concept was introduced in 1989. Here the processing of titanium was performed by industrial methods such as milling, spark erosion and laser welding. The idea behind this was to avoid phase transformation. During the 1990s a number of porcelain products were launched and a vast number of both laboratory and clinical studies were performed and published, with varying results. In the first study of this thesis a prospective clinical trial was performed at a public dental health clinic in Sweden. Twenty-five patients were provided with 40 copings of pure titanium, which were veneered with porcelain. After 2 years 36 of these crowns were evaluated and the patients were also interviewed regarding problems such as shooting pains or difficulties in cleaning around the teeth that were crowned. This evaluation

  14. Porcelain crabs from Brazil (Crustacea: Decapoda: Anomura: Porcellanidae).

    PubMed

    Ferreira, Luciane Augusto De Azevedo; De Melo, Gustavo Augusto Schmidt

    2016-01-01

    Twenty species of porcelain crabs are reported on the basis of material collected from Brazilian coasts. Considering the lack of systematic studies comprehending the Brazilian porcellanids, the present work presents a review of the regional species based on the current taxonomic information. New records, information about variation between specimens and a taxonomic discussion are given for porcellanid crabs from Brazil. PMID:27394448

  15. Development of dental casting and porcelainizing techniques for titanium alloys

    SciTech Connect

    Taira, M.

    1986-01-01

    Casting of titanium metals has been difficult due to their high chemical reactivity at elevated temperatures. Thus, special melting and mold materials are needed. This study investigated molds, Ti alloys, and porcelain applications, utilizing a new dental casting machine, Castmatic. It involved argon-arc melting and subsequent argon/vacuum pressurized casting. Special refractory oxides such as yttria or Zirconia A were utilized for a face coat under phosphate bonded silica investment. Studies of Ti alloys (Ti, Ti-6Al-4V, Ti-15V, Ti-20Cu and Ti-30Pd) involved metallography, phase identification (XRD), hardness, tensile tests, and electrochemical-corrosion tests. Preliminary porcelain studies included an experimental low fusing porcelain along with commercial low fusing porcelains. The bond was evaluated by three-point bending tests and SEM/EDX observations. The yttria face coat was inert, but lacked the necessary mechanical and thermal stability. The face coat, consisting of Zirconia A and zirconium acetate binder, was stable and resulted in less mold reactivity, good internal soundness, but slightly rough surfaces. Metallographs revealed quite larger grains in the cast structure, than in the wrought forms. XRD analysis showed that quasi-equilibrium phases present.

  16. Evaluation of the CO2 laser for porcelain laminate etching

    NASA Astrophysics Data System (ADS)

    Rypel, T. S.; Zakariasen, Kenneth L.

    1994-09-01

    Research has shown that CO2 laser energy can both fuse and etch enamel, the effect being dependent on the exposure parameters utilized. Such energy can also fuse dental porcelains, but it is not known whether porcelain can be etched by CO2 laser. The objective of this study was to evaluate whether CO2 laser energy can be utilized to etch porcelain laminates, an effect necessary for resin bonding. Porcelain laminate disks 10 mm in diameter were prepared. The disks were each numbered and divided into quadrants with a small carbide high speed bur. Six disks were utilized, each quadrant receiving a single laser exposure for a total of 24 exposures. Each exposure was at either 10 or 15 W for .01, .05, or .10 seconds, with a focal spot of either 0.8 or 0.35 mm. This range of exposures includes those exposures which cause enamel etching. Two exposures were made at each combination of exposure parameters. Each disk was prepared for scanning electron microscopy and viewed at 75X to examine the exposure sites. All 24 exposure sites were examined and no definite etching was observed.

  17. Shuttle Upgrade Program: Tile TPS

    NASA Technical Reports Server (NTRS)

    Leiser, Daniel B.; Stewart, David A.; DiFiore, Robert; Irby, Ed; Arnold, James (Technical Monitor)

    2001-01-01

    One of the areas where the thermal protection system on the Space Shuttle Orbiter could be improved is the RSI (Reusable Surface Insulation) tile. The improvement would be in damage resistance that would reduce the resultant maintenance and inspection required. It has performed very well in every other aspect. Improving the system's damage resistance has been the subject of much research over the past several years. One of the results of that research was a new system developed for damage prone areas on the orbiter (i.e., base heat shield). That system, designated as TUFI, Toughened Uni-Piece Fibrous Insulation, was successfully demonstrated as an experiment on the Orbiter and is now baselined for the base heat shield. This paper describes the results of a current research program to further improve the TUFI tile system, thus making it applicable to more areas on the orbiter. The way to remove the current limitations of the TUFI system (i.e., weight or thermal conductivity differences between it and the baseline tile (LI-900)) is to improve the characteristics of LI-900 or AETB-8. Specifically this paper describes the results of two efforts. The first shows performance data of an improved LI-900 system involving the application of TUFI and the second describes data that shows a reduced difference in thermal conductivity between the advanced TUFI substrate (AETB-8) now used on the orbiter and LI-900.

  18. Positive feedback fishery: Population consequences of `crab-tiling' on the green crab Carcinus maenas

    NASA Astrophysics Data System (ADS)

    Sheehan, E. V.; Thompson, R. C.; Coleman, R. A.; Attrill, M. J.

    2008-11-01

    Collection of marine invertebrates for use as fishing bait is a substantial activity in many parts of the world, often with unknown ecological consequences. As new fisheries develop, it is critical for environmental managers to have high quality ecological information regarding the potential impacts, in order to develop sound management strategies. Crab-tiling is a largely unregulated and un-researched fishery, which operates commercially in the south-west UK. The target species is the green crab Carcinus maenas. Those crabs which are pre-ecdysis and have a carapace width greater than 40 mm are collected to be sold to recreational anglers as bait. Collection involves laying artificial structures on intertidal sandflats and mudflats in estuaries. Crabs use these structures as refugia and are collected during low tide. However, the effect that this fishery has on populations of C. maenas is not known. The impact of crab-tiling on C. maenas population structure was determined by sampling crabs from tiled estuaries and non-tiled estuaries using baited drop-nets. A spatially and temporarily replicated, balanced design was used to compare crab abundance, sizes and sex ratios between estuaries. Typically, fisheries are associated with a reduction in the abundance of the target species. Crab-tiling, however, significantly increased C. maenas abundance. This was thought to be a result of the extra habitat in tiled estuaries, which probably provides protection from natural predators, such as birds and fish. Although crabs were more abundant in tiled estuaries than non-tiled estuaries, the overall percentage of reproductively active crabs in non-tiled estuaries was greater than in tiled estuaries. As with most exploited fisheries stocks, crabs in exploited (tiled) estuaries tended to be smaller, with a modal carapace width of 20-29 mm rather than 30-39 mm in non-tiled estuaries. The sex ratio of crabs however; was not significantly different between tiled and non-tiled

  19. Optimizing Tile Concentrations to Minimize Errors and Time for DNA Tile Self-assembly Systems

    NASA Astrophysics Data System (ADS)

    Chen, Ho-Lin; Kao, Ming-Yang

    DNA tile self-assembly has emerged as a rich and promising primitive for nano-technology. This paper studies the problems of minimizing assembly time and error rate by changing the tile concentrations because changing the tile concentrations is easy to implement in actual lab experiments. We prove that setting the concentration of tile T i proportional to the square root of N i where N i is the number of times T i appears outside the seed structure in the final assembled shape minimizes the rate of growth errors for rectilinear tile systems. We also show that the same concentrations minimize the expected assembly time for a feasible class of tile systems. Moreover, for general tile systems, given tile concentrations, we can approximate the expected assembly time with high accuracy and probability by running only a polynomial number of simulations in the size of the target shape.

  20. Fast Glazing of Alumina/Silica Tiles

    NASA Technical Reports Server (NTRS)

    Creedon, J. F.; Gzowski, E. R.; Wheeler, W. H.

    1986-01-01

    Technique for applying ceramic coating to fibrous silica/alumina insulation tiles prevents cracks and substantially reduces firing time. To reduce thermal stresses in tile being coated, high-temperature, shorttime firing schedule implemented. Such schedule allows coating to mature while substrate remains at relatively low temperature, reducing stress differential between coating and substrate. Technique used to repair tiles with damaged coatings and possibly used in heat-treating objects made of materials having different thermal-expansion coefficients.

  1. Heterogeneous solute transport in a tile-drained field

    NASA Astrophysics Data System (ADS)

    Basile, A.; Comegna, A.; Coppola, A.; Hassan, S.; Haikal, M. A.; Kassab, M.; Lamaddalena, N.

    2009-04-01

    Preferential flow and its diverse attributes: i) macropore flow; ii) fingered flow; iii) funnel flow, cannot be described by a single process hypothesis and are unpredictable from a priori analysis of field characteristics due to the inability of sampling methods to capture minute features triggering such flows. Most solute transport techniques are expensive and require extensive soil disturbance. Moreover, solute transport in heterogeneous porous media cannot always be conceptualized as being either a convective-dispersive or a stochastic-convective process. One approach to predict subsurface leaching could be the coupling of near surface measurements with a generalized transport model. A steady state field tracer experiment was conducted on a tile-drained "Terra Rossa" plot located in Valenzano (Bari - Italy), to test whether TDR BTCs measured 1 m a part along a transect of 40 m can be used in such a way for accurate prediction of tile's BTC. A Generalized Transfer Function (GTF) (Zhang, 2000) was fitted to the observed concentration a three depths for each site along the transect to identify the transfer function parameters. To account for vertical transport in the unsaturated zone and lateral divergence near the tile, these parameters were used in a 2D model (Utermann, 1990) to predict earlier breakthrough of tile flux concentration. The 2D model predictions of the flux concentrations were similar to the observed values, nearly reproducing the channel-like nature of solute flow.

  2. Kinetics of the clay roofing tile convection drying

    SciTech Connect

    Thomas, S. . Faculty of Food Technology); Skansi, D. . Faculty of Chemical Engineering and Technology); Sokele, M. . Telecommunications Center)

    1993-01-01

    Kinetics of the convection drying process of flat tile has been investigated experimentally in an industrial tunnel dryer. Several velocities of wet tile movement through the dryer were tested to obtain maximum allowable drying rate curve. As there are various models to describe the kinetics of convection drying, finding a model that would fairly well approximate the kinetics of the whole drying process was part of the research. Especially the polynomial and exponential models were tested. It was found that exponential model of the type: B(t) = (a[minus]B[sub e])[center dot]EXP([minus]bt[sup 2])+B[sub e], ([minus]dB(t)/dt) = 2bt(B(t)[minus]B[sub e]) significantly correlates the kinetics of the whole tile drying process. Applying the maximum allowable drying rate curve obtained for flat tile in the first period of drying, a grapho-analytic model for the optimal conducting of the process has been developed.

  3. Effects of core characters and veneering technique on biaxial flexural strength in porcelain fused to metal and porcelain veneered zirconia

    PubMed Central

    Oh, Ju-Won; Song, Kwang-Yeob; Ahn, Seung-Geun; Park, Ju-Mi; Lee, Min-Ho

    2015-01-01

    PURPOSE The purpose of this study was to assess the impact of the core materials, thickness and fabrication methods of veneering porcelain on prosthesis fracture in the porcelain fused to metal and the porcelain veneered zirconia. MATERIALS AND METHODS Forty nickel-chrome alloy cores and 40 zirconia cores were made. Half of each core group was 0.5 mm-in thickness and the other half was 1.0 mm-in thickness. Thus, there were four groups with 20 cores/group. Each group was divided into two subgroups with two different veneering methods (conventional powder/liquid layering technique and the heat-pressing technique). Tensile strength was measured using the biaxial flexural strength test based on the ISO standard 6872:2008 and Weibull analysis was conducted. Factors influencing fracture strength were analyzed through three-way ANOVA (α≤.05) and the influence of core thickness and veneering method in each core materials was assessed using two-way ANOVA (α≤.05). RESULTS The biaxial flexural strength test showed that the fabrication method of veneering porcelain has the largest impact on the fracture strength followed by the core thickness and the core material. In the metal groups, both the core thickness and the fabrication method of the veneering porcelain significantly influenced on the fracture strength, while only the fabrication method affected the fracture strength in the zirconia groups. CONCLUSION The fabrication method is more influential to the strength of a prosthesis compared to the core character determined by material and thickness of the core. PMID:26576250

  4. C∗-algebras of Penrose hyperbolic tilings

    NASA Astrophysics Data System (ADS)

    Oyono-Oyono, Hervé; Petite, Samuel

    2011-02-01

    Penrose hyperbolic tilings are tilings of the hyperbolic plane which admit, up to affine transformations a finite number of prototiles. In this paper, we give a complete description of the C∗-algebras and of the K-theory for such tilings. Since the continuous hull of these tilings have no transversally invariant measure, these C∗-algebras are traceless. Nevertheless, harmonic currents give rise to 3-cyclic cocycles and we discuss in this setting a higher-order version of the gap-labeling.

  5. Global Swath and Gridded Data Tiling

    NASA Technical Reports Server (NTRS)

    Thompson, Charles K.

    2012-01-01

    This software generates cylindrically projected tiles of swath-based or gridded satellite data for the purpose of dynamically generating high-resolution global images covering various time periods, scaling ranges, and colors called "tiles." It reconstructs a global image given a set of tiles covering a particular time range, scaling values, and a color table. The program is configurable in terms of tile size, spatial resolution, format of input data, location of input data (local or distributed), number of processes run in parallel, and data conditioning.

  6. Multilayer Impregnated Fibrous Thermal Insulation Tiles

    NASA Technical Reports Server (NTRS)

    Tran, Huy K.; Rasky, Daniel J.; Szalai, Christine e.; Hsu, Ming-ta; Carroll, Joseph A.

    2007-01-01

    The term "secondary polymer layered impregnated tile" ("SPLIT") denotes a type of ablative composite-material thermal- insulation tiles having engineered, spatially non-uniform compositions. The term "secondary" refers to the fact that each tile contains at least two polymer layers wherein endothermic reactions absorb considerable amounts of heat, thereby helping to prevent overheating of an underlying structure. These tiles were invented to afford lighter-weight alternatives to the reusable thermal-insulation materials heretofore variously used or considered for use in protecting the space shuttles and other spacecraft from intense atmospheric-entry heating.

  7. Foam on Tile Impact Modeling for the Space Shuttle Program

    NASA Technical Reports Server (NTRS)

    Stellingwerf, R. F.; Robinson, J. H.; Richardson, S.; Evans, S. W.; Stallworth, R.; Hovater, M.

    2003-01-01

    on the wings of the orbiter. Tiles used on the Wing Acreage, the Main Landing Gear Door, and the Carrier Panels near the front edge of the wing were modeled. Foam impacts shot for the CAB investigation were modeled, as well as impacts at larger angles, including rapid rotation of the projectile, and with varying foam properties. General results suggest that foam impacts on tiles at about 500 mph could cause appreciable damage if the impact angle is greater than about 20 degrees. Some variations of the foam properties, such as increased brittleness or increased density could increase damage in some cases. Rapid (17 rps) rotation failed to increase the damage for the two cases considered. This does not rule out other cases in which the rotational energy might lead to an increase in tile damage, but suggests that in most cases rotation will not be an important factor. Similar models will be applied for other impacting materials, other velocities, and other geometries as part of the Return to Flight process.

  8. Strengthening of Porcelain Provided by Resin Cements and Flowable Composites.

    PubMed

    Spazzin, A O; Guarda, G B; Oliveira-Ogliari, A; Leal, F B; Correr-Sobrinho, L; Moraes, R R

    2016-01-01

    This study evaluated the effect of mechanical properties of resin-based luting agents on the strength of resin-coated porcelain. The luting agents tested were two flowable resin composites (Filtek Z350 Flow and Tetric-N Flow), a light-cured resin cement (Variolink Veneer [VV]), and a dual-cured resin cement (Variolink II) in either light-cured (base paste) or dual-cured (base + catalyst pastes [VD]) mode. Flexural strength (σf) and modulus of elasticity (Ef) of the luting agents were measured in three-point bending mode (n=5). Porcelain discs (Vita VM7) were tested either untreated (control) or acid etched, silanized, and coated with the luting agents. Biaxial flexural strength (σbf) of the porcelain discs was tested using a ball-on-ring setup (n=30). The σbf of the resin-coated specimens was calculated at z-axial positions for multilayer specimens in the ball-on-ring test: position z = 0 (ceramic surface at the bonded interface) and position z = -t2 (luting agent surface above ring). The σf and Ef data were subjected to analysis of variance and the Student-Newman-Keuls test (α=0.05). A Weibull analysis was performed for σbf data. Weibull modulus (m) and characteristic strength (σ0) were calculated. Linear regression analyses investigated the relationship between mechanical properties of the luting agents and the strengthening of porcelain. VD had higher and VV had lower mechanical strength than the other materials. At z = 0, all resin-coated groups had higher σbf than the control group. No significant differences between the luting agents were observed for σbf and σ0. At z = -t2, VD had the highest σbf and σ0, whereas VV had the poorest results. No significant differences in m were observed across groups. A linear increase in flexural strength of the porcelain was associated with increased σf and Ef of the luting agents at position z = -t2. In conclusion, resin coating and use of luting agents with better physical properties generally improved the

  9. Parametric Multi-Level Tiling of Imperfectly Nested Loops

    SciTech Connect

    Hartono, Albert; Baskaran, Muthu M.; Bastoul, Cedric; Cohen, Albert; Krishnamoorthy, Sriram; Norris, Boyana; Ramanujam, J.; Sadayappan, Ponnuswamy

    2009-05-18

    Tiling is a critical loop transformation for generating high-performance code on modern architectures. Efficient generation of multilevel tiled code is essential to exploit several levels of parallelism and/or to maximize data reuse in deep memory hierarchies. Tiled loops with parameterized tile sizes (not compile time constants) facilitate runtime feedback and dynamic optimizations used in iterative compilation and automatic tuning. The existing parametric multilevel tiling approach has focused on transformation for perfectly nested loops, where all assignment statements are contained inside the innermost loop of a loop nest. Previous solutions to tiling for imperfect loop nests are limited to the case where tile sizes are fixed. In this paper, we present an approach to parameterized multilevel tiling for imperfectly nested loops. Our tiling algorithm generates loops that iterate over full rectangular tiles that are amenable for potential compiler optimizations such as register tiling. Experimental results using a number of computational benchmarks demonstrate the effectiveness of our tiling approach.

  10. Thermal Characterization of TPS Tiles

    SciTech Connect

    Kacmar, C. J.; LaCivita, K. J.; Jata, K. V.; Sathish, S.

    2006-03-06

    The Thermal Protection System (TPS) used on space shuttles protects the metallic structure from the large amounts of heat created during travel through the atmosphere, both on takeoff and reentry. The shuttle experiences high thermo-acoustic loading and impact damage from micro-meteorites, which can cause disbonds, delaminations, chips, cracks, and other defects to the TPS system. To enhance durability and damage tolerance, new TPS tiles with an added protective ceramic-matrix-composite layer are being developed. This paper explores the use of pulsed thermography as a quick, diverse, non-destructive technique, to characterize the TPS system. The pulsed thermography images obtained are presented and analyzed.

  11. Effectiveness of Combination of Dentin and Enamel Layers on the Masking Ability of Porcelain.

    PubMed

    Boscato, Noéli; Hauschild, Fernando Gabriel; Kaizer, Marina da Rosa; De Moraes, Rafael Ratto

    2015-01-01

    This study evaluated the masking ability of different porcelain thicknesses and combination of enamel and/or dentin porcelain layers over simulated background dental substrates with higher (A2) and lower (C4) color values. Combination of the enamel (E) and dentin (D) monolayer porcelain disks with different thicknesses (0.5 mm, 0.8 mm, and 1 mm) resulted in the following bilayer groups (n=10): D1E1, D1E0.8; D1E0.5; D0.8E0.8; D0.8E0.5, and D0.5E0.5. CIELAB color coordinates were measured with a spectrophotometer. The translucency parameter of mono and bilayer specimens and the masking ability estimated by color variation (ΔE*ab) of bilayer specimens over simulated dental substrates were evaluated. Linear regression analysis was used to investigate the relationships translucency parameter × ΔE*, translucency parameter × porcelain thickness, and ΔE* × porcelain thickness. Data were analyzed statistically (α= 0.05). Thinner porcelain disks were associated with higher translucency. Porcelain monolayers were considerably more translucent than bilayers (enamel + dentin). Dentin porcelain was less translucent than enamel porcelain with same thickness. ΔE* was always lower when measured over A2 background. Higher ΔE* was observed for the C4 background, indicating poorer masking ability. Increased ΔE* was significantly associated with increased translucency for both backgrounds. Decreased translucency and ΔE* were associated with increased total porcelain thickness or increased dentin thickness for both backgrounds. In conclusion, increased porcelain thickness (particularly increased dentin layer) and increased porcelain opacity resulted in better masking ability of the dental backgrounds. PMID:26963212

  12. High-temperature behavior of a Pd-Ag alloy for porcelain.

    PubMed

    Mackert, J R; Ringle, R D; Fairhurst, C W

    1983-12-01

    The mechanism of formation of nodular material on the surface of a Pd-Ag-based alloy for porcelain during pre-porcelainization heat treatment was investigated using scanning electron microscopy, x-ray diffraction, quantitative metallography, and Auger electron spectroscopy. The nodules were found to form by a Nabarro-Herring creep mechanism driven by the internal oxidation of tin and indium. Implications of this process with regard to porcelain bonding and discoloration are discussed. PMID:6581200

  13. Investigation on the Tribological Behavior and Wear Mechanism of Five Different Veneering Porcelains

    PubMed Central

    Min, Jie; Zhang, Qianqian; Qiu, Xiaoli; Zhu, Minhao; Yu, Haiyang; Gao, Shanshan

    2015-01-01

    Objectives The primary aim of this research was to investigate the wear behavior and wear mechanism of five different veneering porcelains. Methods Five kinds of veneering porcelains were selected in this research. The surface microhardness of all the samples was measured with a microhardness tester. Wear tests were performed on a ball-on-flat PLINT fretting wear machine, with lubrication of artificial saliva at 37°C. The friction coefficients were recorded by the testing system. The microstructure features, wear volume, and damage morphologies were recorded and analyzed with a confocal laser scanning microscope and a scanning electron microscope. The wear mechanism was then elucidated. Results The friction coefficients of the five veneering porcelains differ significantly. No significant correlation between hardness and wear volume was found for these veneering porcelains. Under lubrication of artificial saliva, the porcelain with higher leucite crystal content exhibited greater wear resistance. Additionally, leucite crystal size and distribution in glass matrix influenced wear behavior. The wear mechanisms for these porcelains were similar: abrasive wear dominates the early stage, whereas delamination was the main damage mode at the later stage. Furthermore, delamination was more prominent for porcelains with larger crystal sizes. Significance Wear compatibility between porcelain and natural teeth is important for dental restorative materials. Investigation on crystal content, size, and distribution in glass matrix can provide insight for the selection of dental porcelains in clinical settings. PMID:26368532

  14. Mössbauer study of the Ru porcelain of Chinese Song Dynasty and Yuan Dynasty

    NASA Astrophysics Data System (ADS)

    Zhengyao, Gao; Songhua, Chen; Xiande, Chen

    1994-12-01

    The Mössbauer spectra from the glazes of the Song Dynasty and the Yuan Dynasty Ru porcelains and the imitative ancient Ru porcelain are compared and analyzed. It is determined that the original firing atmosphere of the Yuan Dynasty Ru porcelain was reductive. The firing temperature was 1250±20 ‡C. The original firing atmosphere of the Song Dynasty Ru porcelain was also reductive; the firing temperature was above 1200 ‡C. The coloring mechanism of these glazes is discussed.

  15. Mechanically strengthened new Hagi porcelain developed by controlling the chemical environment of iron

    NASA Astrophysics Data System (ADS)

    Kubuki, Shiro; Iwanuma, Jun; Akiyama, Kazuhiko; Mikuni, Akira; Nishida, Tetsuaki

    2012-05-01

    In order to enhance the mechanical strength of Hagi Porcelain (Hagiyaki), one of the oldest and famous potteries in Japan, new preparation condition was examined. Tempered Hagi porcelain, denominated as ` Hagi Porcelain B', was prepared with the Porcelain clay originating from Daido district, Yamaguchi Prefecture, Japan. Structural change of ` Hagi Porcelain B' was investigated by means of 57Fe-Mössbauer spectroscopy, X-ray diffractometry (XRD) and three-point bending test. Mechanical strength of the ` original Hagi Porcelain B' was estimated to be 43.1 MPa by means of the three-point bending test, while much larger value of 104.5 MPa could be achieved when tempered by a chemical modification. Mössbauer spectrum of the ` original Hagi porcelain B' was composed of a paramagnetic doublet and a magnetic sextet due to Fe(III) of γ-Fe2O3(maghemite), while only one paramagnetic doublet due to to octahedral Fe(II)O6 was observed for the ` tempered Hagi Porcelain B' with isomer shift and quadrupole splitting values of 1.13 and 2.15 mm s-1, respectively. It is considered that the absence of magnetic phase causes an increase of the mechanical strength because the maghemite phase has a defect spinel structure. These results indicate that mechanical strength of the ` Hagi porcelain B' could be enhanced by controlling the sintering condition.

  16. Shaving Ceramic Tiles To Final Dimensions

    NASA Technical Reports Server (NTRS)

    Shaw, Ernest

    1992-01-01

    Combination of template and routing tool cuts ceramic tiles to final dimensions. Template guides router along precisely defined planes to accurately and uniformly shave chamfers on edge of tiles. Legs of template temporarily bonded to workpiece by double-backed adhesive tape. Adaptable to in-situ final machining of other nominally flat, narrow surfaces.

  17. Bonding Heat-Resistant Fabric to Tile

    NASA Technical Reports Server (NTRS)

    Holt, J. W.; Smiser, L. W.

    1985-01-01

    Acid etching, densification, and silica cement ensure strong bond. Key step in preparation for bonding to glazed tile is etching quartz fabric and tile with acid. This increases adhesion of silica cement used to form bond. Procedures use high-temperature materials exclusively and therefore suitable for securing flexible seals and heat barriers around doors and viewing ports in furnaces and kilns.

  18. Wind-Resistant Filler for Tile Gaps

    NASA Technical Reports Server (NTRS)

    Bellavia, J.; Quigley, I. A.; Callahan, T. S.

    1982-01-01

    Filler developed for gaps between insulating tiles on Space Shuttle finds application in industries that use tiles for thermal or environmental protection. Filler consists of tight-fitting ceramic tubes and fibrous alumina. Combination resists high wind loads while providing requisite heat protection. Quartz-thread stitching holds envelope together.

  19. Fibonacci words, hyperbolic tilings and grossone

    NASA Astrophysics Data System (ADS)

    Margenstern, Maurice

    2015-04-01

    In this paper, we study the contribution of the theory of grossone to the study of infinite Fibonacci words, combining this tool with the help of a particular tiling of the hyperbolic plane: the tiling { 7, 3 } , called the heptagrid. With the help of the numeral system based on grossone, we obtain a richer family of infinite Fibonacci words compared with the traditional approach.

  20. The Sad Case of the Columbine Tiles.

    ERIC Educational Resources Information Center

    Dowling-Sendor, Benjamin

    2003-01-01

    Analyzes free-speech challenge to school district's guidelines for acceptable expressions on ceramic tiles painted by Columbine High School students to express their feelings about the massacre. Tenth Circuit found that tile painting constituted school-sponsored speech and thus district had the constitutional authority under "Hazelwood School…

  1. Performance of the Tile PreProcessor Demonstrator for the ATLAS Tile Calorimeter Phase II Upgrade

    NASA Astrophysics Data System (ADS)

    Carrió, F.; Moreno, P.; Valero, A.

    2016-03-01

    The Tile Calorimeter PreProcessor demonstrator is a high performance double AMC board based on FPGA resources and QSFP modules. This board has been designed in the framework of the ATLAS Tile Calorimeter Demonstrator project for the Phase II Upgrade as the first stage of the back-end electronics. The TilePPr demonstrator has been conceived to receive and process the data coming from the front-end electronics of the TileCal Demonstrator module, as well as to configure it. Moreover, the TilePPr demonstrator handles the communication with the Detector Control System to monitor and control the front-end electronics. The TilePPr demonstrator represents 1/8 of the final TilePPr that will be designed and installed into the detector for the ATLAS Phase II Upgrade.

  2. Evaluation of a new protective coating for porcelain insulators

    SciTech Connect

    Hall, J.; Orbeck, T.

    1982-12-01

    This paper describes the evaluation of a new elastomeric coating made from a silicone rubber compound for use on porcelain insulators. Field experience has shown that coated insulators have a lower flashover probability under wet contaminated operation than uncoated insulators. Laboratory fog tests also show significant improvements in the wet electrical behavior of clean and contaminated insulators. The Room Temperature Vulcanized (RTV) silicone rubber coating offers both technical and economical advantages for high voltage system operation and maintenance.

  3. Microstructure Study For Optimization Of Dielectric Property Of Electrical Porcelain

    SciTech Connect

    Tak, S. K.; Shekhawat, M. S.; Mangal, R.

    2010-06-29

    Five sample mixtures of kaolin, ball clay, feldspar and Quartz were formulated and porcelain samples fabricated. Crystalline phases and mullite morphology were studied using XRD and SEM respectively. A composition of 30% kaolin, 15% ball clay, 30% feldspar and 25% quartz yielded a body with high dielectric strength of 19 kV/mm compare to an ISO graded product having dielectric strength 14.6 KV/mm after firing at 1225 deg. C.

  4. Microstructure Study For Optimization Of Dielectric Property Of Electrical Porcelain

    NASA Astrophysics Data System (ADS)

    Tak, S. K.; Shekhawat, M. S.; Mangal, R.

    2010-06-01

    Five sample mixtures of kaolin, ball clay, feldspar and Quartz were formulated and porcelain samples fabricated. Crystalline phases and mullite morphology were studied using XRD and SEM respectively. A composition of 30% kaolin, 15% ball clay, 30% feldspar and 25% quartz yielded a body with high dielectric strength of 19kV/mm compare to an ISO graded product having dielectric strength 14.6 KV/mm after firing at 1225°C.

  5. Emittance measurements of RCG coated Shuttle tiles

    NASA Technical Reports Server (NTRS)

    Bouslog, Stanley A.; Cunnington, George R., Jr.

    1992-01-01

    The spectral and total normal emittance of the Reaction Cured Glass (RCG) coating used on Shuttle tiles has been measured for surface temperatures of 300 to 1905 K. These measurements were made on two virgin and two flown Shuttle tile samples. Room temperature directional emittance data were also obtained and used to determine the total hemispherical emittance of RCG as a function of temperature. The data obtained from this calculation indicate that the total hemispherical emittance decreases from a room temperature value of 0.83 to a value of 0.76 at 1905 K. The flown Shuttle tiles exhibited a change in the spectral distribution of emittance compared to that of the virgin tile, but no significant trends in the total emittance from a virgin to a flown tile could be established.

  6. Consistency and derangements in brane tilings

    NASA Astrophysics Data System (ADS)

    Hanany, Amihay; Jejjala, Vishnu; Ramgoolam, Sanjaye; Seong, Rak-Kyeong

    2016-09-01

    Brane tilings describe Lagrangians (vector multiplets, chiral multiplets, and the superpotential) of four-dimensional { N }=1 supersymmetric gauge theories. These theories, written in terms of a bipartite graph on a torus, correspond to worldvolume theories on N D3-branes probing a toric Calabi–Yau threefold singularity. A pair of permutations compactly encapsulates the data necessary to specify a brane tiling. We show that geometric consistency for brane tilings, which ensures that the corresponding quantum field theories are well behaved, imposes constraints on the pair of permutations, restricting certain products constructed from the pair to have no one-cycles. Permutations without one-cycles are known as derangements. We illustrate this formulation of consistency with known brane tilings. Counting formulas for consistent brane tilings with an arbitrary number of chiral bifundamental fields are written down in terms of delta functions over symmetric groups.

  7. Porcelain laminate veneers: Clinical survey for evaluation of failure

    PubMed Central

    Alhekeir, Diemah F.; Al-Sarhan, Rana A.; Al Mashaan, Abdulmohsen F.

    2014-01-01

    Objective To investigate the association of the failure of porcelain laminate veneers with factors related to the patient, material, and operator. Methods This clinical survey involved 29 patients (19 women and 10 men) and their dentists, including undergraduate and postgraduate dental students and dental interns. Two questionnaires were distributed to collect information from participants. All patients were clinically examined. Criteria for failure of the porcelain laminate veneers included color change, cracking, fracture, and/or debonding. Results A total of 205 porcelain laminate veneers were evaluated. All of the restorations were fabricated from IPS e.max Press and cemented with Variolink Veneer (Ivoclar Vivadent, Schaan, Principality of Liechtenstein) or RelyX veneer cement (3M ESPE, St. Paul, MN, USA). The preparations were generally located in enamel (58.6%), and most veneers had an overlapped design (89.7%). Ten patients (34.48%) showed veneer failure, most often in terms of color change (60%). Overall, 82.8% of patients were satisfied with their restorations. Conclusion Insufficient clinical skills or operator experience resulted in restoration failure in one-third of patients. PMID:25408598

  8. Penrose Tilings as Jammed Solids

    NASA Astrophysics Data System (ADS)

    Stenull, Olaf; Lubensky, T. C.

    2014-10-01

    Penrose tilings form lattices, exhibiting fivefold symmetry and isotropic elasticity, with inhomogeneous coordination much like that of the force networks in jammed systems. Under periodic boundary conditions, their average coordination is exactly four. We study the elastic and vibrational properties of rational approximants to these lattices as a function of unit-cell size NS and find that they have of order √NS zero modes and states of self-stress and yet all their elastic moduli vanish. In their generic form, obtained by randomizing site positions, their elastic and vibrational properties are similar to those of particulate systems at jamming with a nonzero bulk modulus, vanishing shear modulus, and a flat density of states.

  9. Inspection of magnetic tile internal cracks based on impact acoustics

    NASA Astrophysics Data System (ADS)

    Xie, Luofeng; Huang, Qinyuan; Zhao, Yue; Yin, Guofu

    2015-04-01

    An automatic system is developed for internal cracks detection in magnetic tiles based on the impact acoustics, using wavelet packet transform (WPT), principal component analysis (PCA) and hidden Markov model (HMM). In this system, the detecting device is considered as core part to collect and analyse the impact sounds. The original impact sounds are first decomposed up to six levels based on WPT to extract the features. PCA is then performed for dimension reduction and clustering analysis. By adopting the features extracted based on WPT and optimised by PCA as inputs, an HHM classifier is developed for automatic inspection. The results of classification show that the accuracy rate is 100%, demonstrating that the system has significant potential in detecting magnetic tile internal cracks.

  10. Process Development of Porcelain Ceramic Material with Binder Jetting Process for Dental Applications

    NASA Astrophysics Data System (ADS)

    Miyanaji, Hadi; Zhang, Shanshan; Lassell, Austin; Zandinejad, Amirali; Yang, Li

    2016-03-01

    Custom ceramic structures possess significant potentials in many applications such as dentistry and aerospace where extreme environments are present. Specifically, highly customized geometries with adequate performance are needed for various dental prostheses applications. This paper demonstrates the development of process and post-process parameters for a dental porcelain ceramic material using binder jetting additive manufacturing (AM). Various process parameters such as binder amount, drying power level, drying time and powder spread speed were studied experimentally for their effect on geometrical and mechanical characteristics of green parts. In addition, the effects of sintering and printing parameters on the qualities of the densified ceramic structures were also investigated experimentally. The results provide insights into the process-property relationships for the binder jetting AM process, and some of the challenges of the process that need to be further characterized for the successful adoption of the binder jetting technology in high quality ceramic fabrications are discussed.

  11. On the structure of quadrilateral brane tilings

    NASA Astrophysics Data System (ADS)

    de Medeiros, Paul

    2012-01-01

    Brane tilings provide the most general framework in string and M-theory for matching toric Calabi-Yau singularities probed by branes with superconformal fixed points of quiver gauge theories. The brane tiling data consists of a bipartite tiling of the torus which encodes both the classical superpotential and gauge-matter couplings for the quiver gauge theory. We consider the class of tilings which contain only tiles bounded by exactly four edges and present a method for generating any tiling within this class by iterating combinations of certain graph-theoretic moves. In the context of D3-branes in IIB string theory, we consider the effect of these generating moves within the corresponding class of supersymmetric quiver gauge theories in four dimensions. Of particular interest are their effect on the superpotential, the vacuum moduli space and the conditions necessary for the theory to reach a superconformal fixed point in the infrared. We discuss the general structure of physically admissible quadrilateral brane tilings and Seiberg duality in terms of certain composite moves within this class.

  12. Fibrous-Ceramic/Aerogel Composite Insulating Tiles

    NASA Technical Reports Server (NTRS)

    White, Susan M.; Rasky, Daniel J.

    2004-01-01

    Fibrous-ceramic/aerogel composite tiles have been invented to afford combinations of thermal-insulation and mechanical properties superior to those attainable by making tiles of fibrous ceramics alone or aerogels alone. These lightweight tiles can be tailored to a variety of applications that range from insulating cryogenic tanks to protecting spacecraft against re-entry heating. The advantages and disadvantages of fibrous ceramics and aerogels can be summarized as follows: Tiles made of ceramic fibers are known for mechanical strength, toughness, and machinability. Fibrous ceramic tiles are highly effective as thermal insulators in a vacuum. However, undesirably, the porosity of these materials makes them permeable by gases, so that in the presence of air or other gases, convection and gas-phase conduction contribute to the effective thermal conductivity of the tiles. Other disadvantages of the porosity and permeability of fibrous ceramic tiles arise because gases (e.g., water vapor or cryogenic gases) can condense in pores. This condensation contributes to weight, and in the case of cryogenic systems, the heat of condensation undesirably adds to the heat flowing to the objects that one seeks to keep cold. Moreover, there is a risk of explosion associated with vaporization of previously condensed gas upon reheating. Aerogels offer low permeability, low density, and low thermal conductivity, but are mechanically fragile. The basic idea of the present invention is to exploit the best features of fibrous ceramic tiles and aerogels. In a composite tile according to the invention, the fibrous ceramic serves as a matrix that mechanically supports the aerogel, while the aerogel serves as a low-conductivity, low-permeability filling that closes what would otherwise be the open pores of the fibrous ceramic. Because the aerogel eliminates or at least suppresses permeation by gas, gas-phase conduction, and convection, the thermal conductivity of such a composite even at

  13. Seamless stitching of tile scan microscope images.

    PubMed

    Legesse, F B; Chernavskaia, O; Heuke, S; Bocklitz, T; Meyer, T; Popp, J; Heintzmann, R

    2015-06-01

    For diagnostic purposes, optical imaging techniques need to obtain high-resolution images of extended biological specimens in reasonable time. The field of view of an objective lens, however, is often smaller than the sample size. To image the whole sample, laser scanning microscopes acquire tile scans that are stitched into larger mosaics. The appearance of such image mosaics is affected by visible edge artefacts that arise from various optical aberrations which manifest in grey level jumps across tile boundaries. In this contribution, a technique for stitching tiles into a seamless mosaic is presented. The stitching algorithm operates by equilibrating neighbouring edges and forcing the brightness at corners to a common value. The corrected image mosaics appear to be free from stitching artefacts and are, therefore, suited for further image analysis procedures. The contribution presents a novel method to seamlessly stitch tiles captured by a laser scanning microscope into a large mosaic. The motivation for the work is the failure of currently existing methods for stitching nonlinear, multimodal images captured by our microscopic setups. Our method eliminates the visible edge artefacts that appear between neighbouring tiles by taking into account the overall illumination differences among tiles in such mosaics. The algorithm first corrects the nonuniform brightness that exists within each of the tiles. It then compensates for grey level differences across tile boundaries by equilibrating neighbouring edges and forcing the brightness at the corners to a common value. After these artefacts have been removed further image analysis procedures can be applied on the microscopic images. Even though the solution presented here is tailored for the aforementioned specific case, it could be easily adapted to other contexts where image tiles are assembled into mosaics such as in astronomical or satellite photos. PMID:25787148

  14. Aerogel: Tile Composites Toughen a Brittle Superinsulation

    NASA Technical Reports Server (NTRS)

    White, Susan; Rasky, Daniel; Arnold, James O. (Technical Monitor)

    1998-01-01

    Pure aerogels, though familiar in the laboratory for decades as exotic lightweight insulators with unusual physical properties, have had limited industrial applications due to their low strength and high brittleness. Composites formed of aerogels and the ceramic fiber matrices like those used as space shuttle tiles bypass the fragility of pure aerogels and can enhance the performance of space shuttle tiles in their harsh operating environment. Using a layer of aerogel embedded in a tile may open up a wide range of applications where thermal insulation, gas convection control and mechanical strength matter.

  15. The TileCal Laser Calibration System

    NASA Astrophysics Data System (ADS)

    Giangiobbe, Vincent; On Behalf Of The Atlas Tile Calorimeter Group

    TileCal is the central hadronic calorimeter of the ATLAS detector operating at LHC. It is a sampling calorimeter whose active material is made of scintillating plastic tiles. Scintillation light is read by photomultipliers. A Laser system is used to monitor their gain stability. During dedicated calibration runs the Laser system sends via long optical fibers, a monitored amount of light simultaneously to all the ≈10000 photomultipliers of TileCal. This note describes two complementary methods to measure the stability of the photomultipliers gain using the Laser calibration runs. The results of validation tests are presented for both methods and theirrespective performances and limitations are discussed.

  16. Remotely replaceable tokamak plasma limiter tiles

    DOEpatents

    Gallix, R.

    1987-12-09

    U-shaped tiles placed end-to-end over a pair of parallel runners have two rods which engage L-shaped slots. A sliding bar between the runners has grooves with clips to retain the rods pressed into receiving legs of the L-shaped slots in the runners. Sliding the bar in the direction of retaining legs of the L-shaped slots latches the tiles in place over the wall. Resilient contact strips under the parallel sides of the U-shaped tile assure thermal and electrical contact with the wall. 6 figs.

  17. 49 CFR 178.523 - Standards for composite packagings with inner glass, porcelain, or stoneware receptacles.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... glass, porcelain, or stoneware receptacles. 178.523 Section 178.523 Transportation Other Regulations... Standards § 178.523 Standards for composite packagings with inner glass, porcelain, or stoneware receptacles. (a) The following are identification codes for composite packagings with inner receptacles of...

  18. Intensity of energy input during radiation drying of porcelain products in metallic molds

    SciTech Connect

    Bondarev, V.A.; Mikhalev, V.P.; Gubskii, G.Z.

    1987-03-01

    The authors seek to optimize the energy input and efficiency of the process and equipment for drying porcelain in a parametric analysis which maximizes the drying rate against the limiting condition of the onset of temperature-dependent crack propagation in the porcelain.

  19. The challenging scales of the bird: Shuttle tile structural integrity

    NASA Technical Reports Server (NTRS)

    Schneider, W. C.; Miller, G. J.

    1985-01-01

    The principal design issues, tests, and analyses required to solve the tile integrity problem on the space shuttle orbiters are addressed. Proof testing of installed tiles is discussed along with an airflow test of special tiles. Orbiter windshield tiles are considered in terms of changes necessary to ensure acceptable margins of safety for flight.

  20. High-Strength, Low-Shrinkage Ceramic Tiles

    NASA Technical Reports Server (NTRS)

    Wheeler, W. H.; Creedon, J. F.

    1986-01-01

    Addition of refractory fibers and whiskers to insulating tiles composed primarily of fibrous silica, such as those used on the skin of Space Shuttle orbiter, greatly improves properties. New composition suitable for lightweight, thermally-stable mirror blanks and as furnace and kiln insulation. Improved tiles made with current tile-fabrication processes. For given density, tiles containing silicon carbide and boron additives stronger in flexure than tiles made from silica alone. In addition, tiles with additives nearly immune to heat distortion, whereas pure-silica tiles shrink and become severely distorted.

  1. Porcelain-coated antenna for radio-frequency driven plasma source

    DOEpatents

    Leung, Ka-Ngo; Wells, Russell P.; Craven, Glen E.

    1996-01-01

    A new porcelain-enamel coated antenna creates a clean plasma for volume or surface-conversion ion sources. The porcelain-enamel coating is hard, electrically insulating, long lasting, non fragile, and resistant to puncture by high energy ions in the plasma. Plasma and ion production using the porcelain enamel coated antenna is uncontaminated with filament or extraneous metal ion because the porcelain does not evaporate and is not sputtered into the plasma during operation. Ion beams produced using the new porcelain-enamel coated antenna are useful in ion implantation, high energy accelerators, negative, positive, or neutral beam applications, fusion, and treatment of chemical or radioactive waste for disposal. For ion implantation, the appropriate species ion beam generated with the inventive antenna will penetrate large or small, irregularly shaped conducting objects with a narrow implantation profile.

  2. [Mass Spectrometric Methods for Colorative Mechanism Analysis of Yaozhou Porcelain Glaze].

    PubMed

    Xiao, Yuan-fang; He, Miao-hong; Zhang, Shu-di; Hang, Wei

    2015-09-01

    An in-house-built femtosecond laser ionization time-of-flight mass spectrometry (fs-LI-TOFMS) has been applied to the multi-elemental analysis of porcelain glaze from Yaozhou kiln. The samples are selected representing products of different dynasties, including Tang, Five, Song, Jin, and Ming Dynasty. For exploring the colorative mechanism of Yaozhou porcelain through the elemental analysis of the glaze, the effects of all potential coloring elements, especially transition elements, were considered. There was a speculation that the typical Co-Cr-Fe-Mn recipe was used in the fabrication of Yaozhou black glaze; the low content of Fe and high content of Ni resulted in the porcelain of white glaze; an increase content of P could lead the porcelain to be yellow-glazed. Undoubtedly, this research is an important supplement to the study of the colorative mechanism of the Yaozhou porcelain system. PMID:26669145

  3. Porcelain-coated antenna for radio-frequency driven plasma source

    DOEpatents

    Leung, K.N.; Wells, R.P.; Craven, G.E.

    1996-12-24

    A new porcelain-enamel coated antenna creates a clean plasma for volume or surface-conversion ion sources. The porcelain-enamel coating is hard, electrically insulating, long lasting, non fragile, and resistant to puncture by high energy ions in the plasma. Plasma and ion production using the porcelain enamel coated antenna is uncontaminated with filament or extraneous metal ions because the porcelain does not evaporate and is not sputtered into the plasma during operation. Ion beams produced using the new porcelain-enamel coated antenna are useful in ion implantation, high energy accelerators, negative, positive, or neutral beam applications, fusion, and treatment of chemical or radioactive waste for disposal. For ion implantation, the appropriate species ion beam generated with the inventive antenna will penetrate large or small, irregularly shaped conducting objects with a narrow implantation profile. 8 figs.

  4. TGA-DTA and chemical composition study of raw material of Bikaner region for electrical porcelain

    NASA Astrophysics Data System (ADS)

    Tak, S. K.; Shekhawat, M. S.; Mangal, R.

    2013-06-01

    Porcelains are vitrified and a fine grained ceramic product, used either glazed or unglazed and is often manufactured from a tri-axial body mix of clays, quartz and alkaline feldspar. Physical properties associated with porcelain include those of permeability, high strength, hardness, glassiness, durability, whiteness, translucence, resonance, brittleness, high resistance to the passage of electricity, high resistance to thermal shock and high elasticity[1,2]. Porcelain insulators are made from three raw materials; clay; feldspar and quartz. For porcelain manufacture the clay is categorized in two groups; ball clay and kaolin, each of which plays an important role, either in the preparation of the product or in the properties of the finished products. The following research highlights the importance that suits these materials for their contributions to the final properties of the product. Keeping this view a TGA-DTA and chemical composition of these raw materials were observed and these materials are found suitable for production of Electrical Porcelain.

  5. Tensile bond strength of gold and porcelain inlays to extracted teeth using three cements.

    PubMed

    Michelini, F S; Belser, U C; Scherrer, S S; De Rijk, W G

    1995-01-01

    This in vitro study compared the tensile bond strength of gold and porcelain inlays to extracted molars in standardized cavities. Three cements were used: zinc phosphate, glass-ionomer, and a resin composite cement. The gold inlays were cemented using zinc phosphate or glass-ionomer cement, and the porcelain inlays were luted using resin composite or glass-ionomer cement. Surface treatments included, for gold inlays, either no treatment (zinc phosphate cement) or airborne particle abraded and tinplated (glass-ionomer cement); and for porcelain inlays, either no treatment (glass-ionomer cement) or etched and silane-treated (resin composite cement). Statistical analysis was performed using the Weibull distribution. Results showed no significant differences between gold inlays cemented using zinc phosphate or glass-ionomer cements and porcelain inlays luted using glass-ionomer cements. The bonded porcelain inlays (resin composite cement) showed tensile bond strengths two to three times higher than those obtained for cemented gold inlays. PMID:7575974

  6. Directed enzymatic activation of 1-D DNA tiles.

    PubMed

    Garg, Sudhanshu; Chandran, Harish; Gopalkrishnan, Nikhil; LaBean, Thomas H; Reif, John

    2015-02-24

    The tile assembly model is a Turing universal model of self-assembly where a set of square shaped tiles with programmable sticky sides undergo coordinated self-assembly to form arbitrary shapes, thereby computing arbitrary functions. Activatable tiles are a theoretical extension to the Tile assembly model that enhances its robustness by protecting the sticky sides of tiles until a tile is partially incorporated into a growing assembly. In this article, we experimentally demonstrate a simplified version of the Activatable tile assembly model. In particular, we demonstrate the simultaneous assembly of protected DNA tiles where a set of inert tiles are activated via a DNA polymerase to undergo linear assembly. We then demonstrate stepwise activated assembly where a set of inert tiles are activated sequentially one after another as a result of attachment to a growing 1-D assembly. We hope that these results will pave the way for more sophisticated demonstrations of activated assemblies. PMID:25625898

  7. A family of ternary decagonal tilings

    NASA Astrophysics Data System (ADS)

    Fujita, Nobuhisa

    2010-04-01

    A new family of decagonal quasiperiodic tilings are constructed by the use of generalized point substitution processes, which is a new substitution formalism developed by the author [N. Fujita, Acta Cryst. A 65, 342 (2009)]. These tilings are composed of three prototiles: an acute rhombus, a regular pentagon and a barrel shaped hexagon. In the perpendicular space, these tilings have windows with fractal boundaries, and the windows are analytically derived as the fixed sets of the conjugate maps associated with the relevant substitution rules. It is shown that the family contains an infinite number of local isomorphism classes which can be grouped into several symmetry classes (e.g., C10, D5, etc.). The member tilings are transformed into one another through collective simpleton flips, which are associated with the reorganization in the window boundaries.

  8. Characterizing DNA Star-Tile-Based Nanostructures Using a Coarse-Grained Model.

    PubMed

    Schreck, John S; Romano, Flavio; Zimmer, Matthew H; Louis, Ard A; Doye, Jonathan P K

    2016-04-26

    We use oxDNA, a coarse-grained model of DNA at the nucleotide level, to simulate large nanoprisms that are composed of multi-arm star tiles, in which the size of bulge loops that have been incorporated into the tile design is used to control the flexibility of the tiles. The oxDNA model predicts equilibrium structures for several different nanoprism designs that are in excellent agreement with the experimental structures as measured by cryoTEM. In particular we reproduce the chiral twisting of the top and bottom faces of the nanoprisms, as the bulge sizes in these structures are varied due to the greater flexibility of larger bulges. We are also able to follow how the properties of the star tiles evolve as the prisms are assembled. Individual star tiles are very flexible, but their structures become increasingly well-defined and rigid as they are incorporated into larger assemblies. oxDNA also finds that the experimentally observed prisms are more stable than their inverted counterparts, but interestingly this preference for the arms of the tiles to bend in a given direction only emerges after they are part of larger assemblies. These results show the potential for oxDNA to provide detailed structural insight as well as to predict the properties of DNA nanostructures and hence to aid rational design in DNA nanotechnology. PMID:27010928

  9. Radioactivity in zircon and building tiles

    SciTech Connect

    Wen Deng; Kaizhen Tian; Daifu Chen; Yiyun Zhang

    1997-08-01

    Zircon (ZrSiO{sub 4}) is commonly used in The manufacture of glazed tiles. In this study we found high concentrations of the radionuclides {sup 226}Ra, {sup 232}tH, {sup 40}k in zircon sand. The average radium equivalent (A{sub Ra} + 1.26 A{sub Th} + 0.086 A{sub k}) in zircon sand is 17,500 Bq kg{sup -1}, which is 106 times as much as that in ordinary building materials. The external radiation ({gamma} + {beta}) dose rates from 1.1 to 4.9 x 10{sup -2} mGy h{sup -1} with an average of 2.1 x 10{sup -2} mGy h{sup -1}. Although no elevated {gamma}-ray radiation or radon exhalation rate was detected in rooms decorated with glazed tiles, which is characteristic of combined {alpha}, {beta} and {gamma} emitting thin materials, the average {gamma} radiation dose rate at the surface of the tile stacks in shops is 1.5 times as much as the indoor background level. The average area density of total {beta} emitting radionuclides in glazed floor tiles and glazed wall tiles is 0.30 Bq cm{sup -2} and 0.28 Bq cm{sup -2}, respectively. It was estimated that the average {beta} dose rates in tissue at a depth 7 mg cm{sup -2} with a distance 20-100 cm from the floor tiles were 3.2 to 0.9 x 10{sup -7} Gy h{sup -1}. The study indicates that the {beta}-rays from glazed tiles might be one of the main factors leading to an increase in ionizing radiation received by the general public. Workers in glazed tile manufacturing factories and in tile shops or stores may be exposed to elevated levels of both {beta}-rays and {gamma}-rays from zircon sand or glazed tile stacks. No elevated radiation from unglazed tiles was detected. 10 refs., 1 fig., 3 tabs.

  10. Manufacture of ceramic tiles from fly ash

    DOEpatents

    Hnat, J.G.; Mathur, A.; Simpson, J.C.

    1999-08-10

    The present invention relates to a process for forming glass-ceramic tiles. Fly ash containing organic material, metal contaminants, and glass forming materials is oxidized under conditions effective to combust the organic material and partially oxidize the metallic contaminants and the glass forming materials. The oxidized glass forming materials are vitrified to form a glass melt. This glass melt is then formed into tiles containing metallic contaminants. 6 figs.

  11. Cutting Symmetrical Recesses In Soft Ceramic Tiles

    NASA Technical Reports Server (NTRS)

    Nesotas, Tony C.; Tyler, Brent

    1989-01-01

    Simple tool cuts hemispherical recesses in soft ceramic tiles. Designed to expose wires of thermocouples embedded in tiles without damaging leads. Creates neat, precise holes around wires. End mill includes axial hole to accommodate thermocouple wires embedded in material to be cut. Wires pass into hole without being bent or broken. Dimensions in inches. Used in place of such tools as dental picks, tweezers, spatulas, and putty knives.

  12. Manufacture of ceramic tiles from fly ash

    DOEpatents

    Hnat, James G.; Mathur, Akshay; Simpson, James C.

    1999-01-01

    The present invention relates to a process for forming glass-ceramic tiles. Fly ash containing organic material, metal contaminants, and glass forming materials is oxidized under conditions effective to combust the organic material and partially oxidize the metallic contaminants and the glass forming materials. The oxidized glass forming materials are vitrified to form a glass melt. This glass melt is then formed into tiles containing metallic contaminants.

  13. Non-Destructive Diagnostic Technique for Detection of Deteriorated Porcelain Shell Due to Alkali-Silica Reaction

    NASA Astrophysics Data System (ADS)

    Kobayashi, Takayuki; Yuasa, Sadayuki; Nakura, Toru; Hayashi, Tomohiro

    Recently we experienced gas leak trouble of a hollow porcelain shell, which had been working in service for more than a few decades. From our investigation, it was found that an alkali-silica reaction might occur in the porcelain body over time depending on the sealing structure, the number of times the porcelain was fired, and the amount of alkali in the cement. This paper describes the mechanism of porosity change in porcelain body, the factors of such deterioration speed, FEM stress analysis results, and an Ultrasonic Test (UT) for the integrity of porcelain. In addition, the UT inspection results are shown.

  14. An investigation into the bonding of orthodontic attachments to porcelain.

    PubMed

    Larmour, C J; Bateman, G; Stirrups, D R

    2006-02-01

    This study assessed bonding of orthodontic brackets to porcelain teeth using two different surface preparation techniques and comparing two bonding systems, Fuji Ortho L.C. and Transbond. Four groups of 20 porcelain premolar teeth were bonded with metal orthodontic brackets (0.022 inch Minitwin, 3M Unitek) according to the following protocol: Transbond with a phosphoric acid etch (group 1), Transbond with a hydrofluoric acid etch (group 2), Fuji Ortho L.C. with a hydrofluoric acid etch (group 3), and Fuji Ortho L.C. with a phosphoric acid etch (group 4). All groups were bonded with a silane coupling agent. The teeth were debonded with an Instron universal testing machine. Bond strength, site of bond failure and adhesive remnant index (ARI) were recorded for each group. Differences between groups were analysed statistically. The composite resin groups (groups 1 and 2) had the highest mean bond strength values at 7.9 and 9.7 MPa, respectively. The resin-modified glass ionomer cement groups (RMGIC; groups 3 and 4) had the lowest mean bond strength values at 6.3 and 1.8 MPa, respectively. The mean bond strength of group 3 was significantly lower than all other groups (P < 0.0001). The Fuji groups had also significantly (P < 0.001) lower ARI scores than the composite groups (groups 1 and 2). Most samples experienced porcelain surface damage, except group 4. In conclusion, the highest bond strength levels were achieved with a conventional composite resin cement (groups 1 and 2). No significant differences in bond strength were found between the hydrofluoric and phosphoric acid etch technique. PMID:16199411

  15. Cyclic testing of porcelain laminiate veneers on superficial enamel and dentin: Pressed vs. conventional layered porcelain

    NASA Astrophysics Data System (ADS)

    Tawde, Shweta

    Statement of Problem: Clinicians are inclined towards more aggressive teeth preparations to accommodate the thickness of the veneering material. The principle of conservative tooth preparation is compromised. Purpose: By using a conservative approach to treatment with porcelain veneers, long-lasting, esthetic and functional results may be achieved. Sacrificing as little tooth structure as possible and conserving the supporting tissues will facilitate prospective patients. Materials and Methods: Forty extracted human maxillary and mandibular canines were selected. The teeth were divided into one of two groups (pressable and stackable) and further subdivided according to tooth substrate (all-enamel or mixed enamel-dentin exposure). Twenty canine teeth were allotted to the pressable veneer group and 20 were allotted to the stackable veneer group. Of the 20 teeth in the pressable group, all were pressed with a lithium disilicate ceramic system (IPS e.max Press), 10 with labial tooth reduction of 0.3-0.5 mm maintaining superficial enamel (PEN) and the remaining 10 teeth with labial veneer reduction of 0.8-1.0 mm exposing superficial dentin (PDN). Of the 20 teeth in the stackable group, all were stacked/ layered with conventional feldspathic porcelain (Fortune; Williams/ Ivoclar); with labial veneer reduction of 0.3-0.5 mm maintaining superficial enamel (SEN) and the remaining 10 teeth with labial veneer reduction of 0.8-1.0 mm exposing superficial dentin (SDN). Silicon putty matrix was fabricated prior to teeth preparation to estimate the teeth reduction. The prepared facial reduction was limited to the incisal edge. No incisal or palatal/lingual reduction was performed. Impressions of the prepared teeth were taken in medium/light-bodied PVS. Master casts were made in Resin Rock. The stackable group specimens were made with fabricating refractory dies and after following the recommended steps of laboratory procedure, stackable veneers were processed. The pressable group

  16. Predictable Outcomes with Porcelain Laminate Veneers: A Clinical Report.

    PubMed

    Pimentel, Welson; Teixeira, Marcelo Lucchesi; Costa, Priscila Paganini; Jorge, Mônica Zacharias; Tiossi, Rodrigo

    2016-06-01

    This clinical report describes how to achieve predictable outcomes for anterior teeth esthetic restorations with porcelain laminate veneers by associating the digital planning and design of the restoration with interim restorations. The previous digital smile design of the restoration eliminates the communication barrier with the patient and assists the clinician throughout patient treatment. Interim restorations (diagnostic mock-ups) further enhance communication with the patient and prevent unnecessary tooth reduction for conservative tooth preparation. Adequate communication between patient and clinician contributes to successful definitive restorations and patient satisfaction with the final esthetic outcome. PMID:26633080

  17. Er:YAG laser debonding of porcelain veneers

    NASA Astrophysics Data System (ADS)

    Buu, Natalie; Morford, Cynthia; Finzen, Frederick; Sharma, Arun; Rechmann, Peter

    2010-02-01

    The removal of porcelain veneers using Er:YAG lasers has not been previously described in the scientific literature. This study was designed to systematically investigate the efficacy of an Er:YAG laser on veneer debonding without damaging the underlying tooth structure, as well as preserving a new or misplaced veneer. Initially, Fourier Transform Infrared Spectroscopy (FTIR) was used on flat porcelain veneer samples (IPS Empress Esthetic; Ivoclar Vivadent, Amherst, NY) to assess which infrared laser wavelengths are transmitted through the veneer. Additionally, FTIR spectra from a veneer bonding cement (RelyX Veneer Cement A1; 3M ESPE, St. Paul, MN) were obtained. While the veneer material showed no characteristic water absorption bands in the FTIR, the bonding cement has a broad H2O/OH absorption band coinciding with the ER:YAG laser emission wavelength. Consequently Er:YAG laser energy transmission through different veneer thicknesses was measured. The porcelain veneers transmitted 11 - 18 % of the incident Er:YAG laser energy depending on their thicknesses (Er:YAG laser: LiteTouch by Syneron; wavelength 2,940 nm, 10 Hz repetition rate, pulse duration 100 μs at 133 mJ/pulse; straight sapphire tip 1,100 μm diameter; Syneron, Yokneam, Israel). Initial signs of cement ablation occurred at approximately 1.8 - 4.0 J/cm2. This can be achieved by irradiating through the veneer with the fiber tip positioned at a distance of 3-6 mm from the veneer surface, and operating the Er:YAG laser with 133 mJ output energy. All eleven veneers bonded on extracted anterior incisor teeth were easily removed using the Er:YAG laser. The removal occurred without damaging underlying tooth structure as verified by light microscopic investigation (Incident Light Microscope Olympus B 50, Micropublisher RTV 3.3 MP, Image Pro software, Olympus). The debonding mainly occurred at the cement/veneer interface. When the samples were stored in saline solution for 5 days and/or an air-waterspray was

  18. [EDXRF study on the chemical composition and raw material recipe of Jindezhen porcelains in the five dynasties].

    PubMed

    zhang, Mao-lin; Zhou, Jian; Li, Qi-jiang; Wu, Jun-ming; Gan, Ke

    2012-05-01

    Early crafts of porcelain making in Jindezhen were an important issue in ceramic history of China. The chemical composition of white porcelain and celadon samples excavated from Xianghu Kiln in the five dynasties was analyzed using energy dispersive X-ray fluorescence (EDXRF). Raw material recipes of the samples were discussed. The results showed that white porcelain bodies of Xianghu Kiln in the Five Dynasties were made from porcelain stone, while celadon bodies were made from porcelain stone and Zijin clay. Glaze ash and glaze stone were both used in the formula of white porcelain and celadon glaze, and the amount of glaze ash in the celadon was higher than that in the white porcelain samples. PMID:22827103

  19. Strength, reliability and mode of fracture of bilayered porcelain/zirconia (Y-TZP) dental ceramics.

    PubMed

    Guazzato, Massimiliano; Proos, Kaarel; Quach, Linda; Swain, Michael Vincent

    2004-09-01

    The aim of this study was to investigate the biaxial flexural strength, reliability and the mode of fracture of bilayered porcelain/zirconia (Y-TZP) disks. For this purpose, 80 specimens were made from conventional dental porcelain and Y-TZP core ceramic, and equally divided into four groups as follows: monolithic specimens of porcelain; monolithic specimens of core material; bilayered specimens with the porcelain on top (facing the loading piston during testing); bilayered specimens with core material on top. The maximum load at fracture was calculated with a biaxial flexural test and finite element analysis was used to estimate the maximum tensile stress at fracture. Results were analyzed with one-way ANOVA, Tukey HSD. The reliability of strength was analyzed with the Weibull distribution. SEM was used to identify the initial crack and characterize the fracture mode. Monolithic core specimens and bilayered sample with the core material on the bottom were statistically significantly stronger than monolithic porcelain disks and bilayered samples with the porcelain on the bottom. The study, which was conducted with sample configurations that reproduce the clinical situation of crowns and fixed partial dentures, indicates that the material which lies on the bottom surface dictates the strength, reliability and fracture mode of the specimens. The contribution of strong and tough core materials to the performance of all-ceramics restorations may be offset by the weaker veneering porcelain if the actual distribution of the tensile stresses within the restoration is not taken into consideration. PMID:15109867

  20. Effect of sphered particles on the firing contraction of porcelain inlay processed by cold isostatic pressing.

    PubMed

    Konishi, Junko; Watari, Fumio; Kawamoto, Chiharu; Sano, Hidehiko

    2003-08-15

    The effect of the sphered particles on the contraction ratio of porcelain inlay processed by the cold isostatic pressure (CIP) method was investigated. The conventional lathe-cut porcelain powder was crushed to finer particles and the secondary particles with spherical shape by adding binders of acrylic resin, wax, and polyvinyl alcohol, respectively. Porcelain powder was molded as a disc-shaped green body in a refractory model and compressed at 200 MPa by CIP. From this green compact, the sintered porcelain was obtained by only one step of firing. The porcelain discs were then used for the measurements of contraction ratio, scanning microscopic observation, biaxial flexure strength, Vickers hardness, and density. Firing contraction was decreased to about 1% in the sphered particle groups, compared with 7% of the lathe-cut porcelain powder. Although biaxial flexure strength was about 85 MPa, which is lower than the 120 MPa of the control group, and the density was significantly decreased by about 10% from the 2.4 g/cm3 of the control substance, Vickers hardness, which ranged from 531 to 537, showed no significant differences among all of the groups. The CIP method could save labor in the process of making porcelain inlays, and sphered powders could contribute significantly to a decrease in the contraction ratio in the sintering process. PMID:12861607

  1. Bond strength of binary titanium alloys to porcelain.

    PubMed

    Yoda, M; Konno, T; Takada, Y; Iijima, K; Griggs, J; Okuno, O; Kimura, K; Okabe, T

    2001-06-01

    The purpose of this study was to investigate the bond strength between porcelain and experimental cast titanium alloys. Eleven binary titanium alloys were examined: Ti-Cr (15, 20, 25 wt%), Ti-Pd (15, 20, 25 wt%), Ti-Ag (10, 15, 20 wt%), and Ti-Cu (5, 10 wt%). As controls, the bond strengths for commercially pure titanium (KS-50, Kobelco, Japan) and a high noble gold alloy (KIK, Ishifuku, Japan) were also examined. Castings were made using a centrifugal casting unit (Ticast Super R, Selec Co., Japan). Commercial porcelain for titanium (TITAN, Noritake, Japan) was applied to cast specimens. The bond strengths were evaluated using a three-point bend test according to ISO 9693. Since the elastic modulus value is needed to evaluate the bond strength, the modulus was measured for each alloy using a three-point bend test. Results were analyzed using one-way ANOVA/S-N-K test (alpha = 0.05). Although the elastic moduli of the Ti-Pd alloys were significantly lower than those of other alloys (p = 0.0001), there was a significant difference in bond strength only between the Ti-25Pd and Ti-15Ag alloys (p = 0.009). The strengths determined for all the experimental alloys ranged from 29.4 to 37.2MPa, which are above the minimum value required by the ISO specification (25 MPa). PMID:11379602

  2. Surface treatment of feldspathic porcelain: scanning electron microscopy analysis

    PubMed Central

    Valian, Azam

    2014-01-01

    PURPOSE Topographic analysis of treated ceramics provides qualitative information regarding the surface texture affecting the micromechanical retention and locking of resin-ceramics. This study aims to compare the surface microstructure following different surface treatments of feldspathic porcelain. MATERIALS AND METHODS This in-vitro study was conducted on 72 porcelain discs randomly divided into 12 groups (n=6). In 9 groups, feldspathic surfaces were subjected to sandblasting at 2, 3 or 4 bar pressure for 5, 10 or 15 seconds with 50 µm alumina particles at a 5 mm distance. In group 10, 9.5% hydrofluoric acid (HF) gel was applied for 120 seconds. In group 11, specimens were sandblasted at 3 bar pressure for 10 seconds and then conditioned with HF. In group 12, specimens were first treated with HF and then sandblasted at 3 bar pressure for 10 seconds. All specimens were then evaluated under scanning electron microscopy (SEM) at different magnifications. RESULTS SEM images of HF treated specimens revealed deep porosities of variable sizes; whereas, the sandblasted surfaces were more homogenous and had sharper peaks. Increasing the pressure and duration of sandblasting increased the surface roughness. SEM images of the two combined techniques showed that in group 11 (sandblasted first), HF caused deeper porosities; whereas in group 12 (treated with HF first) sandblasting caused irregularities with less homogeneity. CONCLUSION All surface treatments increased the surface area and caused porous surfaces. In groups subjected to HF, the porosities were deeper than those in sandblasted only groups. PMID:25352961

  3. Influence of bruxism on survival of porcelain laminate veneers

    PubMed Central

    Agustín-Panadero, Rubén; Fons-Font, Antonio; Román-Rodríguez, Juan L.; Solá-Ruíz, María F.

    2014-01-01

    Objectives: This study aims to determine whether bruxism and the use of occlusal splints affect the survival of porcelain laminate veneers in patients treated with this technique. Material and Methods: Restorations were made in 70 patients, including 30 patients with some type of parafunctional habit. A total of 323 veneers were placed, 170 in patients with bruxism activity, and the remaining 153 in patients without it. A clinical examination determined the presence or absence of ceramic failure (cracks, fractures and debonding) of the restorations; these incidents were analyzed for association with bruxism and the use of splints. Results: Analysis of the ceramic failures showed that of the 13 fractures and 29 debonding that were present in our study, 8 fractures and 22 debonding were related to the presence of bruxism. Conclusions: Porcelain laminate veneers are a predictable treatment option that provides excellent results, recognizing a higher risk of failure in patients with bruxism activity. The use of occlusal splints reduces the risk of fractures. Key words:Veneer, fracture, debonding, bruxism, occlusal splint. PMID:23986018

  4. Analysis of elemental composition of porcelains unearthed from Waguantan kiln site by PIXE-RBS

    NASA Astrophysics Data System (ADS)

    Zhou, Z.; Zhang, K.; Xia, C. D.; Liu, M. T.; Zhu, J. J.; An, Z.; Bai, B.

    2015-03-01

    A method combining proton-induced X-ray emission spectrometry (PIXE) and Rutherford backscattering spectrometry (RBS) was used to determine the composition of 61 porcelain shards from the Yuan Dynasty (1271-1368 A.D.) unearthed from the Waguantan kiln site at Tianzhu County in Guizhou Province, China. Based on our previous experimental setup, an electron gun device with a LaB6 crystal cathode was installed to solve the problem created when the incident proton beams generated electric charge accumulations on the surfaces of the insulating porcelain samples, which induced a large bremsstrahlung background. The use of the electron gun has largely eliminated the large bremsstrahlung background and has therefore improved the detection limits for elements, especially for trace elements, and made it possible to determine the origin of the porcelains based on the trace elements. Major and trace elemental compositions of the porcelain bodies and glazes measured by PIXE and RBS were analyzed by the factor analysis method. The factor analysis showed that a few pieces of porcelain with a style similar to the porcelain of the Longquan kiln among the unearthed porcelains from the Waguantan kiln site did not have obvious differences in elemental compositions from other remaining porcelains unearthed from the Waguantan kiln site, indicating that the pieces of unearthed porcelain with the Longquan kiln style did in fact belong to the product fired locally by imitating the model of the Longquan celadon with local raw materials. This result therefore indicated that the Longquan kiln technology that originated from the Five Dynasties (907-960 A.D.) had been propagated to the Waguantan kiln site of Guizhou Province in the Yuan Dynasty.

  5. Tile drainage as karst: Conduit flow and diffuse flow in a tile-drained watershed

    NASA Astrophysics Data System (ADS)

    Schilling, Keith E.; Helmers, Matthew

    2008-02-01

    SummaryThe similarity of tiled-drained watersheds to karst drainage basins can be used to improve understanding of watershed-scale nutrient losses from subsurface tile drainage networks. In this study, short-term variations in discharge and chemistry were examined from a tile outlet collecting subsurface tile flow from a 963 ha agricultural watershed. Study objectives were to apply analytical techniques from karst springs to tile discharge to evaluate water sources and estimate the loads of agricultural pollutants discharged from the tile with conduit, intermediate and diffuse flow regimes. A two-member mixing model using nitrate, chloride and specific conductance was used to distinguish rainwater versus groundwater inputs. Results indicated that groundwater comprised 75% of the discharge for a three-day storm period and rainwater was primarily concentrated during the hydrograph peak. A contrasting pattern of solute concentrations and export loads was observed in tile flow. During base flow periods, tile flow consisted of diffuse flow from groundwater sources and contained elevated levels of nitrate, chloride and specific conductance. During storm events, suspended solids and pollutants adhered to soil surfaces (phosphorus, ammonium and organic nitrogen) were concentrated and discharged during the rapid, conduit flow portion of the hydrograph. During a three-day period, conduit flow occurred for 5.6% of the time but accounted for 16.5% of the total flow. Nitrate and chloride were delivered primarily with diffuse flow (more than 70%), whereas 80-94% of total suspended sediment, phosphorus and ammonium were exported with conduit and intermediate flow regimes. Understanding the water sources contributing to tile drainage and the manner by which pollutant discharge occurs from these systems (conduit, intermediate or diffuse flow) may be useful for designing, implementing and evaluating non-point source reduction strategies in tile-drained landscapes.

  6. Tiled WMS/KML Server V2

    NASA Technical Reports Server (NTRS)

    Plesea, Lucian

    2012-01-01

    This software is a higher-performance implementation of tiled WMS, with integral support for KML and time-varying data. This software is compliant with the Open Geospatial WMS standard, and supports KML natively as a WMS return type, including support for the time attribute. Regionated KML wrappers are generated that match the existing tiled WMS dataset. Ping and JPG formats are supported, and the software is implemented as an Apache 2.0 module that supports a threading execution model that is capable of supporting very high request rates. The module intercepts and responds to WMS requests that match certain patterns and returns the existing tiles. If a KML format that matches an existing pyramid and tile dataset is requested, regionated KML is generated and returned to the requesting application. In addition, KML requests that do not match the existing tile datasets generate a KML response that includes the corresponding JPG WMS request, effectively adding KML support to a backing WMS server.

  7. Approximation of virus structure by icosahedral tilings.

    PubMed

    Salthouse, D G; Indelicato, G; Cermelli, P; Keef, T; Twarock, R

    2015-07-01

    Viruses are remarkable examples of order at the nanoscale, exhibiting protein containers that in the vast majority of cases are organized with icosahedral symmetry. Janner used lattice theory to provide blueprints for the organization of material in viruses. An alternative approach is provided here in terms of icosahedral tilings, motivated by the fact that icosahedral symmetry is non-crystallographic in three dimensions. In particular, a numerical procedure is developed to approximate the capsid of icosahedral viruses by icosahedral tiles via projection of high-dimensional tiles based on the cut-and-project scheme for the construction of three-dimensional quasicrystals. The goodness of fit of our approximation is assessed using techniques related to the theory of polygonal approximation of curves. The approach is applied to a number of viral capsids and it is shown that detailed features of the capsid surface can indeed be satisfactorily described by icosahedral tilings. This work complements previous studies in which the geometry of the capsid is described by point sets generated as orbits of extensions of the icosahedral group, as such point sets are by construction related to the vertex sets of icosahedral tilings. The approximations of virus geometry derived here can serve as coarse-grained models of viral capsids as a basis for the study of virus assembly and structural transitions of viral capsids, and also provide a new perspective on the design of protein containers for nanotechnology applications. PMID:26131897

  8. Nematic colloidal tilings as photonic materials

    NASA Astrophysics Data System (ADS)

    Ravnik, M.; Dontabhaktuni, J.; Cancula, M.; Zumer, S.

    2014-02-01

    Colloidal platelets are explored as elementary building blocks for the shape-controlled assembly of crystalline and quasicrystalline tilings. Using three-dimensional (3D) numerical modelling based on the minimization of Landau-de Gennes free energy for modelling of colloids combined with Finite Difference Time Domain calculations for optics, we demonstrate the self-assembly and optical (transmission) properties of triangular, square and pentagonal sub-micrometer sized platelets in a thin layer of nematic liquid crystal. Interactions between platelets are explored, providing an insight into the assembly process. Two-dimensional tilings of various-shaped colloidal platelets are demonstrated, and their use as diffraction layers is explored by using FDTD simulations. Designing symmetry-breaking surface anchoring profiles on pentagonal platelets opens also a possibility to achieve interactions that could lead to tilings with non-crystalline symmetry.

  9. Fiber-tile optical studies at Argonne

    SciTech Connect

    Underwood, D.G.; Morgan, D.J.; Proudfoot, J.

    1991-07-23

    In support of a fiber-tile calorimeter for SDC, we have done studies on a number of topics. The most basic problems were light output and uniformity of response. Using a small electron beam, we have studied fiber placement, tile preparation, wrapping and masking, fiber splicing, fiber routing, phototube response, and some degradation factors. We found two configurations which produced more light output than the others and reasonably uniform response. We have chosen one of these to go into production for the EM test module on the basis of fiber routing for ease of assembly of the calorimeter. We have also applied some of the tools we developed to CDF end plug tile uniformity, shower max testing and development for a couple of detectors, and development of better techniques for radiation damage studies. 18 figs.

  10. Remotely replaceable tokamak plasma limiter tiles

    DOEpatents

    Tsuo, Simon , Langford, Alison A.

    1989-01-01

    U-shaped limiter tiles placed end-to-end over a pair of parallel runners secured to a wall have two rods which engage L-shaped slots in the runners. The short receiving legs of the L-shaped slots are perpendicular to the wall and open away from the wall, while long retaining legs are parallel to and adjacent the wall. A sliding bar between the runners has grooves with clips to retain the rods pressed into receiving legs of the L-shaped slots in the runners. Sliding the bar in the direction of retaining legs of the L-shaped slots latches the tiles in place over the runners. Resilient contact strips between the parallel arms of the U-shaped tiles and the wall assure thermal and electrical contact with the wall.

  11. INTERIOR VIEW OF BATHROOM 1. SHOWING ORIGINAL MOSAIC PATTERN TILE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW OF BATHROOM 1. SHOWING ORIGINAL MOSAIC PATTERN TILE FLOOR, TILE WAINSCOT AND SHOWER SURROUND, AND CERAMIC ACCESSORIES. VIEW FACING EAST. - Hickam Field, Officers' Housing Type J, 701 Beard Street, Honolulu, Honolulu County, HI

  12. INTERIOR VIEW OF BATHROOM 1 SHOWING THE MOSAICPATTERN TILE FLOOR. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW OF BATHROOM 1 SHOWING THE MOSAIC-PATTERN TILE FLOOR. CERAMIC TILE WAINSCOT, AND CERAMIC ACCESSORIES. VIEW FACING NORTH. - Hickam Field, Officers' Housing Type H, 208 Sixth Street, Honolulu, Honolulu County, HI

  13. Random and ordered phases of off-lattice rhombus tiles.

    PubMed

    Whitelam, Stephen; Tamblyn, Isaac; Beton, Peter H; Garrahan, Juan P

    2012-01-20

    We study the covering of the plane by nonoverlapping rhombus tiles, a problem well studied only in the limiting case of dimer coverings of regular lattices. We go beyond this limit by allowing tiles to take any position and orientation on the plane, to be of irregular shape, and to possess different types of attractive interactions. Using extensive numerical simulations, we show that at large tile densities there is a phase transition from a fluid of rhombus tiles to a solid packing with broken rotational symmetry. We observe self-assembly of broken-symmetry phases, even at low densities, in the presence of attractive tile-tile interactions. Depending on the tile shape and interactions, the solid phase can be random, possessing critical orientational fluctuations, or crystalline. Our results suggest strategies for controlling tiling order in experiments involving "molecular rhombi." PMID:22400760

  14. Random and ordered phases of off-lattice rhombus tiles

    NASA Astrophysics Data System (ADS)

    Whitelam, Stephen; Tamblyn, Isaac; Beton, Peter; Garrahan, Juan

    2012-02-01

    We study the covering of the plane by non-overlapping rhombus tiles, a problem well-studied only in the limiting case of dimer coverings of regular lattices. We go beyond this limit by allowing tiles to take any position and orientation on the plane, to be of irregular shape, and to possess different types of attractive interactions. Using extensive numerical simulations we show that at large tile densities there is a phase transition from a fluid of rhombus tiles to a solid packing with broken rotational symmetry. We observe self-assembly of broken-symmetry phases, even at low densities, in the presence of attractive tile-tile interactions. Depending on tile shape and interactions the solid phase can be random, possessing critical orientational fluctuations, or crystalline. Our results suggest strategies for controlling tiling order in experiments involving ``molecular rhombi.''

  15. Random and Ordered Phases of Off-Lattice Rhombus Tiles

    NASA Astrophysics Data System (ADS)

    Whitelam, Stephen; Tamblyn, Isaac; Beton, Peter H.; Garrahan, Juan P.

    2012-01-01

    We study the covering of the plane by nonoverlapping rhombus tiles, a problem well studied only in the limiting case of dimer coverings of regular lattices. We go beyond this limit by allowing tiles to take any position and orientation on the plane, to be of irregular shape, and to possess different types of attractive interactions. Using extensive numerical simulations, we show that at large tile densities there is a phase transition from a fluid of rhombus tiles to a solid packing with broken rotational symmetry. We observe self-assembly of broken-symmetry phases, even at low densities, in the presence of attractive tile-tile interactions. Depending on the tile shape and interactions, the solid phase can be random, possessing critical orientational fluctuations, or crystalline. Our results suggest strategies for controlling tiling order in experiments involving “molecular rhombi.”

  16. AIRBORNE ASBESTOS CONCENTRATIONS DURING BUFFING OF RESILIENT FLOOR TILE

    EPA Science Inventory

    Although asbestos-containing resilient floor tiles are considered nonfriable, the frictional forces exerted on the tile during routine maintenance operations can generate asbestos-containing structures. tudy was conducted to determine the level of airborne asbestos concentrations...

  17. Small form factor full parallax tiled light field display

    NASA Astrophysics Data System (ADS)

    Alpaslan, Zahir Y.; El-Ghoroury, Hussein S.

    2015-03-01

    With the recent introduction of Ostendo's Quantum Photonic Imager (QPI) display technology, a very small pixel pitch, emissive display with high brightness and low power consumption became available. We used QPI's to create a high performance light field display tiles with a very small form factor. Using 8 of these QPI light field displays tiled in a 4x2 array we created a tiled full parallax light field display. Each individual light field display tile combines custom designed micro lens array layers with monochrome green QPIs. Each of the light field display tiles can address 1000 x 800 pixels placed under an array of 20 x 16 lenslets with 500 μm diameters. The light field display tiles are placed with small gaps to create a tiled display of approximately 46 mm (W) x 17 mm (H) x 2 mm (D) in mechanical dimensions. The prototype tiled full parallax light field display demonstrates small form factor, high resolution and focus cues.

  18. Dynamical implications of Viral Tiling Theory.

    PubMed

    ElSawy, K M; Taormina, A; Twarock, R; Vaughan, L

    2008-05-21

    The Caspar-Klug classification of viruses whose protein shell, called viral capsid, exhibits icosahedral symmetry, has recently been extended to incorporate viruses whose capsid proteins are exclusively organised in pentamers. The approach, named 'Viral Tiling Theory', is inspired by the theory of quasicrystals, where aperiodic Penrose tilings enjoy 5-fold and 10-fold local symmetries. This paper analyses the extent to which this classification approach informs dynamical properties of the viral capsids, in particular the pattern of Raman active modes of vibrations, which can be observed experimentally. PMID:18353372

  19. Degenerate polygonal tilings in simple animal tissues

    NASA Astrophysics Data System (ADS)

    Ziherl, Primoz; Hocevar, Ana

    2009-03-01

    We study 2D polygonal tilings as models of the en-face structure of single-layer biological tissues. Using numerical simulations, we explore the phase diagram of equilibrium tilings of equal-area, equal-perimeter convex polygons whose energy is independent of their shape. We identify 3 distinct phases, which are all observed in simple epithelial tissues: The disordered phase of polygons with 4-9 sides, the hexatic phase, and the hexagonal phase with perfect 6-fold coordination. We quantify their structure using Edwards' statistical mechanics of cellular systems.

  20. Flexural strength of fluorapatite-leucite and fluorapatite porcelains exposed to erosive agents in cyclic immersion

    PubMed Central

    JUNPOOM, Peerapong; KUKIATTRAKOON, Boonlert; HENGTRAKOOL, Chanothai

    2011-01-01

    Objective The aim of this study was to evaluate the flexural strength of two porcelain materials (IPS d.SIGN and IPS e.max Ceram) exposed to erosive agents Material and Methods One hundred and twenty bar-shaped specimens were made from each of fluorapatite-leucite porcelain (IPS d.SIGN) and fluorapatite porcelain (IPS e.max Ceram) and divided into 8 groups of 15 specimens each. Six groups were alternately immersed in the following storage agents for 30 min: deionized water (control), citrate buffer solution, pineapple juice, green mango juice, cola soft drink and 4% acetic acid. Then, they were immersed for 5 min in deionized water at 37°C. Seven cycles were completed, totalizing 245 min. A 7th group was continuously immersed in 4% acetic acid at 80°C for 16 h. The final, 8th, group was stored dry at 37°C for 245 min. Three-point bending tests were performed in a universal testing machine. The data were analyzed statistically by 2-way ANOVA, Tukey’s HSD test and t-test at significance level of 0.05. Results The flexural strengths of all groups of each porcelain after exposure to erosive agents in cyclic immersion did not differ significantly (p>0.05). For both types of porcelain, dry storage at 37°C yielded the highest flexural strength, though without significant difference from the other groups (p>0.05). The flexural strengths of all groups of fluorapatite porcelains were significantly higher (p<0.05) than those of the fluorapatite-leucite porcelains. Conclusions This study demonstrated that the erosive agents evaluated did not affect the flexural strength of the tested dental porcelains. PMID:21552708

  1. A neutron-absorbing porcelain enamel for coating nuclear equipment

    SciTech Connect

    Iverson, D.C.

    1988-01-01

    In 1985, nuclear safety analyses showed that under upset conditions, strict administrative controls were necessary to limit access to a new processing vessel for enriched uranium service at the Savannah River Plant (SRP). In order to increase the level of nuclear safety associated with that vessel, the traditional methods of incorporating neutron absorbers (borated stainless steel, boral, cadmium foil, etc.) were reviewed, however, process conditions did not permit their use. A neutron-absorbing porcelain enamel containing large amounts of cadmium and boron was developed as a safe, cost-effective alternative to traditional neutron-absorbing methods. Several pieces of coated process equipment have been installed or are planned for installation at SRP.

  2. Production and characterization of glazed tiles containing incinerated sewage sludge.

    PubMed

    Lin, D F; Chang, W C; Yuan, C; Luo, H L

    2008-01-01

    In this article, glaze with different colorants was applied to tile specimens manufactured by incinerated sewage sludge ash (ISSA) and clay. Improvements using different amounts of colorants, and glaze components and concentrations on tile bodies were investigated. Four different proportions of clay (by weight ratio) were replaced by ISSA. Tiles of size 12 cm x 6 cm x 1 cm were made and left in an electric furnace to make biscuit tiles at 800 degrees C. Afterwards, four colorants, Fe2O3 (red), V2O5 (yellow), CoCO3 (blue), and MnO2 (purple), and four different glaze concentrations were applied on biscuit tile specimens. These specimens were later sintered into glazed tiles at 1050 degrees C. The study shows that replacement of clay by sludge ash had adverse effects on properties of tiles. Water absorption increased and bending strength reduced with increased amounts of ash. However, both water absorption and bending strength improved for glazed ash tiles. Abrasion of grazed tiles reduced noticeably from 0.001 to 0.002 g. This implies glaze can enhance abrasion resistance of tiles. Effects like lightfastness and acid-alkali resistance improved as different glazes were applied on tiles. In general, red glazed tiles showed the most stable performance, followed by blue, yellow, and purple. PMID:17433656

  3. Installation of Ceramic Tile: Residential Thin-Set Methods.

    ERIC Educational Resources Information Center

    Short, Sam

    This curriculum guide contains materials for use in teaching a course on residential thin-set methods of tile installation. Covered in the individual units are the following topics: the tile industry; basic math; tools; measurement; safety in tile setting; installation materials and guidelines for their use; floors; counter tops and backsplashes;…

  4. WATER TABLE LEVEL AS INFLUENCED BY TILING METHOD

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sections of the research farm were tiled in the fall of 1979. The primary reason for the tiling was to provide a good soil environment for large tillage trial plots that had been previously established. This was also used as an opportunity to install a comparison of tile installation with a conven...

  5. 21. TILES OF THE NEW WORLD PANEL, NORTH WALL OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. TILES OF THE NEW WORLD PANEL, NORTH WALL OF THE INDIAN HOUSE. THE RELIEF BROCADE TILES ILLUSTRATE SCENES OF NATIVE AMERICAN HISTORY AND CULTURE, AND THE EARLY EUROPEAN EXPLORATION OF THE NEW WORLD. - Moravian Pottery & Tile Works, Southwest side of State Route 313 (Swamp Road), Northwest of East Court Street, Doylestown, Bucks County, PA

  6. 90. TILES OF THE NEW WORLD PANEL, NORTH WALL OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    90. TILES OF THE NEW WORLD PANEL, NORTH WALL OF THE INDIAN HOUSE. THE RELIEF BROCADE TILES ILLUSTRATE SCENES OF NATIVE AMERICAN HISTORY AND CULTURE, AND THE EARLY EUROPEAN EXPLORATION OF THE NEW WORLD. SAME VIEW AS PA-107-21. - Moravian Pottery & Tile Works, Southwest side of State Route 313 (Swamp Road), Northwest of East Court Street, Doylestown, Bucks County, PA

  7. Solar-energy treatment of ceramic tile. Final report

    SciTech Connect

    Harris, J.N.; Clayton, M.E.

    1981-12-01

    The 400 kW Advanced Components Test Facility was used to provide a concentrated source of solar energy for firing ceramic wall tile. A domed top cylindrical cavity with a white refractory fiber lining provided diffuse reflection of the concentrated solar beam directly onto the upper surface of the unfired wall tile. The tile were placed directly on the cavity floor in a circular pattern, centered at 45/sup 0/ intervals so that eight tile could be fired at one time. The tile and cavity walls were instrumented with thermocouples, and pyrometric cones were used to determine temperature distribution within the cavity. The glazed and unglazed solar fired tiles were subjected to standard ceramic testing procedures to determine: flatness, modulus of rupture, water absorption, porosity, bulk density, apparent specific gravity, percent linear thermal expansion and crystalline phases present in the fired bodies. These data were compared with the same data for commercial fired tiles from the same batch of raw materials. The glazed tile surfaces were compared with commercially fired tile for reflectance and color match. The major problems encountered were: cracking by thermal shock, and uneven shrinkage and glaze maturity across individual tile. The cavity also failed to provide even heating at all eight tile positions. An alternate air heat exchanger system is recommended to fire the tile by convection rather than direct radiation.

  8. Adhesion of denture tooth porcelain to heat-polymerized denture resin.

    PubMed

    Marchack, B W; Yu, Z; Zhao, X Y; White, S N

    1995-09-01

    Use of porcelain denture teeth may be desirable in many clinical situations, including implant-supported prostheses. However, lack of space because of frameworks often precludes the use of conventional retention by diatorics and pins. Adhesion of porcelain denture teeth to denture resin could also stiffen and possibly strengthen dentures and decrease stain ingress between porcelain teeth and resin denture bases. Unlike previous studies that investigated the bond between conventional feldspathic metal-ceramic porcelain and bis-GMA based composite resin, this study investigated adhesion of denture tooth porcelain to polymethyl methacrylate (PMMA). High-energy air abrasion, hydrofluoric acid etching, and the use of a general purpose bonding agent resulted in an improved bond strength of heat-cured denture PMMA bonded to denture tooth porcelain. Silane coating did not improve bond strengths, and conventional air abrasion was no more effective than polishing with 600-grit silicon carbide. Storage in water and artificial aging substantially decreased bond strengths. The strongest bond strengths were achieved by a high-energy-abrasion + etching + multi-purpose bonding-agent treatment, but a simpler etching + multiple-purpose bonding-agent treatment also produced reliable results. A laboratory technique was suggested. The role of surface treatment in the mechanism of adhesion was examined with scanning electron microscopy. High-energy abrasion produced a slightly more detailed initial topography than conventional air abrasion, but after etching, the high-energy topography became much more detailed. Surface topography alone did not account for all differences found. PMID:7473277

  9. Provenance study of ancient Chinese Yaozhou porcelain by neutron activation analysis

    NASA Astrophysics Data System (ADS)

    Li, G. X.; Y Gao, Z.; Li, R. W.; Zhao, W. J.; Xie, J. Z.; Feng, S. L.; Zhuo, Z. X.; Y Fan, D.; Zhang, Y.; Cai, Z. F.; Liu, H.

    2003-09-01

    This paper reports our study of the provenance of ancient Chinese Yaozhou porcelain. The content of 29 elements in the Yaozhou porcelain samples was measured by neutron activation analysis (NAA). The NAA data were further analysed using fuzzy cluster analysis to obtain the trend fuzzy cluster diagrams. These samples with different glaze colour, ranging over more than 700 years, were fired in different kilns. Our analysis indicates the relatively concentrated distribution of the sources of the raw material for the Yaozhou porcelain body samples. They can be classified into two independent periods, i.e. the Tang (AD 618-907) and the Five Dynasties (AD 907-960) period, and the Song (AD 960-1279) and Jin (AD 1115-1234) period. Our analysis also indicates that the sources of the raw material for the ancient Yaozhou porcelain glaze samples are quite scattered and those for the black glaze in the Tang Dynasty are very concentrated. The sources of the raw material for the celadon glaze and the white glaze in the Tang Dynasty are widely distributed and those for the celadon glaze in the Song Dynasty are close to those of the bluish white glaze in the Jin Dynasty, and they are very concentrated. The sources of the raw material for the porcelain glazes cover those of the porcelain bodies.

  10. Compatibility of Ce-TZP/Al2O3 nanocomposite frameworks and veneering porcelains.

    PubMed

    Terui, Yuichi; Sato, Kotaro; Goto, Daisuke; Hotta, Yasuhiro; Tamaki, Yukimichi; Miyazaki, Takashi

    2013-01-01

    The aim of this study was to examine the compatibility of Ce-TZP/Al2O3 nanocomposite (CTA) frameworks and veneering porcelains using the Schwickerath crack initiation test and clarify the effects on debonding/crack initiation strength (DIS) of both surface pretreatment (include heat treatment) of the frameworks, type of veneering porcelain varying the coefficient of thermal expansion (CTE), and surface roughness of the frameworks. The surfaces of Ce-TZP/Al2O3 plates were mechanically treated and followed by post-heat treatment. The liner and body porcelains were built up and fired according to the manufacturer's instructions. Surface analyses of the fractured plates showed compatibility with liner porcelains. Since no statistically difference in the DIS was found amongst the different surface treatments, post-heat treatments don't be mandatory. Whereas, since differences in DIS were found when different porcelains with different CTE were used, we concluded the matching of CTE of the porcelain with that of Ce-TZP/Al2O3 was important for successful all-ceramic restorations using Ce-TZP/Al2O3 frameworks. PMID:24088843

  11. Effect of preoxidation on the bond strength of titanium and porcelain.

    PubMed

    Mahale, K M; Nagda, S J

    2014-06-01

    The purpose of this study was to investigate the effect of preoxidation on porcelain titanium- bond strength and the effect of paste bonder (adhesive) on the titanium porcelain bond strength. 11 specimens of commercially pure titanium (26 x 7 x 3 mm) were prepared by different heat treatments in programmable dental furnace. Identification of the oxides formed on the metal surface was conducted with an X-Ray diffractometer with CuKalpha radiation. Vickers hardness numbers were determine. Additional 50 specimens of commercially pure titanium were used to bond with low fusing porcelain. The bond strength was measured in a universal testing machine. X-ray diffraction analysis of the surface of pure titanium revealed that the relative peak intensity of alpha -Ti decreased and that of TiO2 increased with increasing firing temperature. The Vickers hardness number decreased initially as the temperature increased but it increased remarkably above 900 degrees C & was harder in air than vacuum. The tensile shear bond strength was highest in the green stage i.e. without preoxidation of metal, and decreased above 900 degrees C, and was the lowest in the group without paste bonder application. The difference in bond strengths was statistically highly significant for all groups. Preoxidation under vacuum before porcelain firing can effectively improve bonding. The adhesive provided with the low fusing porcelain helps in the bond between titanium & porcelain. PMID:25134366

  12. Tensile bond strength of ceramic orthodontic brackets bonded to porcelain surfaces.

    PubMed

    Kocadereli, I; Canay, S; Akça, K

    2001-06-01

    The aim of this study was to compare various surface treatment methods to define the procedure that produces adequate bond strength between ceramic brackets and porcelain. The specimens used in this study, 60 porcelain tabs, were produced by duplication of the labial surface of a maxillary first premolar. The 6 different preparation procedures tested were: (1) sandblasting with 50 microm aluminum oxide in a sandblasting device, (2) application of silane to the porcelain and the bracket base, (3) sandblasting followed by application of silane, (4) acid etching with 9.6% hydrofluoric acid, (5) acid etching with 9.6% hydrofluoric acid followed by application of silane, and (6) sandblasting followed by application of 4-Meta adhesive. The ceramic brackets were bonded with no-mix orthodontic bonding material. A bonding force testing machine was used to determine tensile bond strengths at a crosshead speed of 0.5 mm per second. The results of the study showed that porcelain surface preparation with acid etching followed by silane application resulted in a statistically significant higher tensile bond strength (P < .05). Sandblasting the porcelain surface before silane treatment provided similar bond strengths, but sandblasting or acid etching alone were less effective. Silane application was recommended to bond a ceramic bracket to the porcelain surface to achieve bond strengths that are clinically acceptable. PMID:11395705

  13. Effectiveness of conservation practices within watersheds: Case study in tile-drained systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effectiveness of conservation practices are governed in part by the spatial and temporal patterns of water flow as runoff and subsurface (tile) drainage. The variability in patterns of nitrate loss were examined using data from different sized catchments with four CEAP watersheds located in cent...

  14. Jagged Tiling for Intra-tile Parallelism and Fine-Grain Multithreading

    SciTech Connect

    Shrestha, Sunil; Manzano Franco, Joseph B.; Marquez, Andres; Feo, John T.; Gao, Guang R.

    2015-05-01

    In this paper, we have developed a novel methodology that takes into consideration multithreaded many-core designs to better utilize memory/processing resources and improve memory residence on tileable applications. It takes advantage of polyhedral analysis and transformation in the form of PLUTO, combined with a highly optimized finegrain tile runtime to exploit parallelism at all levels. The main contributions of this paper include the introduction of multi-hierarchical tiling techniques that increases intra tile parallelism; and a data-flow inspired runtime library that allows the expression of parallel tiles with an efficient synchronization registry. Our current implementation shows performance improvements on an Intel Xeon Phi board up to 32.25% against instances produced by state-of-the-art compiler frameworks for selected stencil applications.

  15. CFD-Predicted Tile Heating Bump Factors Due to Tile Overlay Repairs

    NASA Technical Reports Server (NTRS)

    Lessard, Victor R.

    2006-01-01

    A Computational Fluid Dynamics investigation of the Orbiter's Tile Overlay Repair (TOR) is performed to assess the aeroheating Damage Assessment Team's (DAT) existing heating correlation method for protuberance interference heating on the surrounding thermal protection system. Aerothermodynamic heating analyses are performed for TORs at the design reference damage locations body points 1800 and 1075 for a Mach 17.9 and a=39deg STS-107 flight trajectory point with laminar flow. Six different cases are considered. The computed peak heating bump factor on the surrounding tiles are below the DAT's heating bump factor values for smooth tile cases. However, for the uneven tiles cases the peak interference heating is shown to be considerably higher than the existing correlation prediction.

  16. Computer-controlled optical scanning tile microscope.

    PubMed

    Wang, C; Shumyatsky, P; Zeng, F; Zevallos, M; Alfano, R R

    2006-02-20

    A new type of computer-controlled optical scanning, high-magnification imaging system with a large field of view is described that overcomes the commonly believed incompatibility of achieving both high magnification and a large field of view. The new system incorporates galvanometer scanners, a CCD camera, and a high-brightness LED source for the fast acquisition of a large number of a high-resolution segmented tile images with a magnification of 800x for each tile. The captured segmented tile images are combined to create an effective enlarged view of a target totaling 1.6 mm x 1.2 mm in area. The speed and sensitivity of the system make it suitable for high-resolution imaging and monitoring of a small segmented area of 320 microm x 240 microm with 4 microm resolution. Each tile segment of the target can be zoomed up without loss of the high resolution. This new microscope imaging system gives both high magnification and a large field of view. This microscope can be utilized in medicine, biology, semiconductor inspection, device analysis, and quality control. PMID:16523776

  17. High Temperature Filler for Tile Gaps

    NASA Technical Reports Server (NTRS)

    Holt, J. W.; Wang, D. S.

    1983-01-01

    Gaps between ceramic tiles filled with ceramic-coated fabric that withstands temperatures as high as 2,000 degrees F (1,300 degrees C). Reusable high-temperature gap filler is made of fabric coated with ceramic slurry and bonded in place with room-temperature-vulcanized adhesive. Procedure used in kilns and furnaces.

  18. L-Tromino Tiling of Multilated Chessboards

    ERIC Educational Resources Information Center

    Gardner, Martin

    2009-01-01

    An "n" x "n" chessboard is called deficient if one square is missing from any spot on the board. Can all deficient boards with a number of cells divisible by 3 be tiled by bent (or L-shaped) trominoes? The answer is yes, with exception of the order-5 board. This paper deals with the general problem plus numerous related puzzles and proofs…

  19. TILE at Iowa: Adoption and Adaptation

    ERIC Educational Resources Information Center

    Florman, Jean C.

    2014-01-01

    This chapter introduces a University of Iowa effort to enhance and support active learning pedagogies in technology-enhanced (TILE) classrooms and three elements that proved essential to the campus-wide adoption of those pedagogies. It then describes the impact of those professional development efforts on the curricula and cultures of three…

  20. Performance of the ATLAS Tile Calorimeter

    NASA Astrophysics Data System (ADS)

    Heelan, Louise; ATLAS Collaboration

    2015-06-01

    The ATLAS Tile hadronic calorimeter (TileCal) provides highly-segmented energy measurements of incoming particles. It is a key detector for the measurement of hadrons, jets, tau leptons and missing transverse energy. It is also useful for identification and reconstruction of muons due to good signal to noise ratio. The calorimeter consists of thin steel plates and 460,000 scintillating tiles configured into 5000 cells, each viewed by two photomultipliers. The calorimeter response and its readout electronics is monitored to better than 1% using radioactive source, laser and charge injection systems. The calibration and performance of the calorimeter have been established through test beam measurements, cosmic ray muons and the large sample of proton-proton collisions acquired in 2011 and 2012. Results on the calorimeter performance are presented, including the absolute energy scale, timing, noise and associated stabilities. The results demonstrate that the Tile Calorimeter has performed well within the design requirements and it has given essential contribution to reconstructed objects and physics results. In addition, the data quality procedures used during the LHC data-taking are described and the outcome of the detector consolidation in the maintenance period is also presented.

  1. Tile-based Level of Detail for the Parallel Age

    SciTech Connect

    Niski, K; Cohen, J D

    2007-08-15

    Today's PCs incorporate multiple CPUs and GPUs and are easily arranged in clusters for high-performance, interactive graphics. We present an approach based on hierarchical, screen-space tiles to parallelizing rendering with level of detail. Adapt tiles, render tiles, and machine tiles are associated with CPUs, GPUs, and PCs, respectively, to efficiently parallelize the workload with good resource utilization. Adaptive tile sizes provide load balancing while our level of detail system allows total and independent management of the load on CPUs and GPUs. We demonstrate our approach on parallel configurations consisting of both single PCs and a cluster of PCs.

  2. Effect of cooling rate on leucite volume fraction in dental porcelains.

    PubMed

    Mackert, J R; Evans, A L

    1991-02-01

    Prasad et al. (1988) have shown that slow cooling of dental porcelain produces increases in thermal expansion sufficient to make a compatible metal-porcelain system incompatible. The present study was undertaken to determine whether the increase in porcelain thermal expansion might be attributable to crystallization of additional leucite during slow cooling of the porcelain. Eight x-ray diffraction specimens for each of six commercial dental porcelains and for the Component No. 1 frit of the Weinstein and Weinstein (1962) and Weinstein et al. (1962) patents were fabricated and divided into two groups. Specimens in the first group (termed fast-cooled) were cooled in the conventional manner by removing them from the furnace at the maximum firing temperature immediately into room air. Specimens in the second group (termed slow-cooled) were cooled slowly by interrupting power to the furnace muffle and allowing them to cool inside the closed furnace. Quantitative x-ray diffraction was performed on the fast- and slow-cooled porcelain specimens with standards containing leucite volume fractions of 0.111, 0.223, 0.334, and 0.445. Unpaired, one-tailed t tests were performed on the fast- and slow-cool data, and a significant increase (p less than 0.05) in the amount of leucite (as a function of the slow cooling) was found for each of the porcelains. The increases in the leucite volume fractions resulting from the slow cooling ranged from a low of 8.5% to a high of 55.8%, with an average increase of 26.9%.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1991871

  3. Self-Replication of Nanoscale tiles and patterns

    NASA Astrophysics Data System (ADS)

    Chaikin, Paul

    2012-02-01

    We want to make a ``non-biological'' system which can self-replicate. The idea is to design particles with specific and reversible and irreversible interactions, introduce seed motifs, and cycle the system in such a way that a copy is made. Repeating the cycle would double the number of offspring in each generation leading to exponential growth. Using the chemistry of DNA either on colloids or on DNA tiles makes the specific recognition part easy. In the case of DNA tiles we have in fact replicated the seed at least to the third generation. The DNA linkers can also be self-protected so that particles don't interact unless they are held together for sufficient time -- a nano-contact glue. Chemical modification of the DNA allows us to permanently crosslink hybridized strands for irreversible bonds and a new type of photolithography. We have also designed and produced colloidal particles that use novel ``lock and key'' geometries to get specific and reversible physical interactions.[4pt] With Tong Wang, Ruojie Sha, Remi Dreyfus, Mirjam E. Leunissen, Corinna Maass, David J. Pine, and Nadrian C. Seeman.

  4. Deuterium trapping and release in JET ITER-like wall divertor tiles

    NASA Astrophysics Data System (ADS)

    Likonen, J.; Heinola, K.; De Backer, A.; Koivuranta, S.; Hakola, A.; Ayres, C. F.; Baron-Wiechec, A.; Coad, P.; Matthews, G. F.; Mayer, M.; Widdowson, A.; Contributors, JET

    2016-02-01

    A selected set of samples from JET-ILW divertor tiles exposed in 2011-2012 has been analysed using thermal desorption spectrometry (TDS). The highest amount of deuterium was found on the regions with the thickest deposited layers, i.e. on the horizontal (apron) part and on the top part of Tile 1, which resides deep in the scrape-off layer. Outer divertor Tiles 6, 7 and 8 had nearly an order of magnitude less deuterium. The co-deposited layers on the JET tiles and the W coatings contain C, O and Ni impurities which may change the desorption properties. The D2 signals in the TDS spectra were convoluted and the positions of the peaks were compared with the Be and C amounts but no correlations between them were found. The remaining fractions of D in the analysed samples at ITER baking temperature 350 °C are rather high implying that co-deposited films may be difficult to be de-tritiated.

  5. Anosov Diffeomorphisms and {γ}-Tilings

    NASA Astrophysics Data System (ADS)

    Almeida, João P.; Pinto, Alberto A.

    2016-07-01

    We consider a toral Anosov automorphism {G_γ:{mathbb{T}}_γto{mathbb{T}}_γ} given by {G_γ(x,y)=(ax+y,x)} in the { < v,w > } base, where {ainmathbb{N} backslash\\{1\\}}, {γ=1/(a+1/(a+1/ldots))}, {v=(γ,1)} and {w=(-1,γ)} in the canonical base of {{mathbb{R}}^2} and {{mathbb{T}}_γ={mathbb{R}}^2/(v{mathbb{Z}} × w{mathbb{Z}})}. We introduce the notion of {γ}-tilings to prove the existence of a one-to-one correspondence between (i) marked smooth conjugacy classes of Anosov diffeomorphisms, with invariant measures absolutely continuous with respect to the Lebesgue measure, that are in the isotopy class of {G_γ}; (ii) affine classes of {γ}-tilings; and (iii) {γ}-solenoid functions. Solenoid functions provide a parametrization of the infinite dimensional space of the mathematical objects described in these equivalences.

  6. Boeing's High Voltage Solar Tile Test Results

    NASA Technical Reports Server (NTRS)

    Reed, Brian J.; Harden, David E.; Ferguson, Dale C.; Snyder, David B.

    2002-01-01

    Real concerns of spacecraft charging and experience with solar array augmented electrostatic discharge arcs on spacecraft have minimized the use of high voltages on large solar arrays despite numerous vehicle system mass and efficiency advantages. Boeing's solar tile (patent pending) allows high voltage to be generated at the array without the mass and efficiency losses of electronic conversion. Direct drive electric propulsion and higher power payloads (lower spacecraft weight) will benefit from this design. As future power demand grows, spacecraft designers must use higher voltage to minimize transmission loss and power cable mass for very large area arrays. This paper will describe the design and discuss the successful test of Boeing's 500-Volt Solar Tile in NASA Glenn's Tenney chamber in the Space Plasma Interaction Facility. The work was sponsored by NASA's Space Solar Power Exploratory Research and Technology (SERT) Program and will result in updated high voltage solar array design guidelines being published.

  7. Firing ceramic tiles in solar energy equipment

    SciTech Connect

    Pasichnyi, V.V.; Berezhetskaya, V.Ya.; Chop, Yu.I.; Kashket, G.I.

    1987-03-01

    In the interest of satisfying the growing demand for glazed ceramic tiles and conserving the natural gas ordinarily used to fire them, the authors assess the feasibility of using a solar kiln for the process. Their design incorporates a parabolic reflector and a tracking system to continuously focus radiant solar energy on the tile. Their energy analysis includes such factors as solar thermal input, radiant heat transfer, and heat flow, the relationship between the firing time and the heat flow density, and the surface quality of the glaze and colorizer. Their results indicate that when the heat flow density rises above a level at which the specific expenditure of heat is no longer dependent on the color of the pigment, this expenditure or input comes to a quarter of what is currently needed using existing technologies and fuels.

  8. Evidence of a critical leucite particle size for microcracking in dental porcelains.

    PubMed

    Mackert, J R; Twiggs, S W; Russell, C M; Williams, A L

    2001-06-01

    The leucite particles in dental porcelains are often partially encircled by microcracks that are the result of the thermal expansion mismatch between leucite and the surrounding glass matrix. Although the magnitude of the stress at the particle-matrix interface is independent of the particle size (Selsing, 1961), Davidge and Green (1968) showed experimentally that there is a critical particle size below which microcracking is absent. The critical particle size is explained by a Griffith-type energy balance criterion: Below the critical size, the stress magnitude may be sufficient to cause cracking, but there is insufficient strain energy for the creation of the new surfaces of the microcrack. The purpose of the present study was to determine whether the mean leucite particle size of a dental porcelain influences the degree of microcracking in the porcelain. Microcrack density, leucite particle surface area per unit volume, and leucite mean volume-surface diameter, D3,2, were determined by quantitative stereology on 10 specimens each of 6 dental porcelains and Component No. 1 of the Weinstein et al. patent (US Patent 3,052,982, 1962). The fraction of leucite particles with microcracks around them, f(mc), was estimated for each porcelain from the microcrack density and the leucite surface area. Using the equations of Selsing (1961) and Davidge and Green (1968), we calculated the critical particle diameter, Dc, for leucite to be 4 microm. The porcelains were partitioned according to whether their mean leucite particle diameters, D3,2, fell above or below Dc, and their values of f(mc) were analyzed by a permutation test with random re-sampling. The porcelains with mean leucite particle diameters below Dc had a significantly lower fraction of cracked particles compared with the porcelains with mean leucite particle diameters above Dc (p < 0.05). This study provides evidence that microcracking in dental porcelain can be minimized by a reduction of the mean leucite

  9. FITS Tile Compression in the NOAO DMS

    NASA Astrophysics Data System (ADS)

    Stobie, E.; Seaman, R.; Barg, I.

    2009-09-01

    The NOAO Data Management system (DMS) captures data from eleven NOAO and partner telescopes and transports these data from three mountaintops to replicate them between three data centers both North and South of the equator. Image files are annotated, remediated, ingested, and persisted through interfaces of the NOAO Science Archive. Wide-field optical and infrared images flow out of the archive, through the NOAO High Performance Pipeline creating several new data products that flow back into the archive. Raw, pipeline-reduced, and survey data products, both proprietary and post-proprietary, are made available through the NOAO Portal using VO standards and services. Each of these several steps requires access to both image data and metadata in the form of image header keywords. Measures of storage efficiency and throughput characterize performance, cost, schedule, and risk in a matrix across all telescopes and all subsystems. Anything that impedes access to data or metadata diminishes throughput, thus slowing schedules, increasing costs, revealing risks, and adversely affecting performance. The familiar gzip compression algorithm is often used to increase data storage efficiency. However, gzip actually reduces throughput due to initial and recurring overhead of compression and later uncompression. For example, if metadata for an image require remediation, the whole image must be compressed, uncompressed, and compressed again. By contrast, the FITS tile convention using the Rice algorithm achieves about 40% better compression than gzip in just one-third the time. Image headers remain readable such that images often need never be uncompressed at all; metadata can be simply edited in place. Further, a library such as CFITSIO can support tile compression as a native image format. The pixel tiling feature means that for applications such as a cutout service, only the tiles overlapping the desired image section need be uncompressed.

  10. Effect of surface treatments of porcelain on adhesion of Candida albicans.

    PubMed

    Lawaf, Shirin; Azizi, Arash; Farzad, Azin; Adimi, Parvaneh

    2016-01-01

    Surface treatment of porcelain is required to minimize the adhesion of microorganisms to surfaces of the restoration. This study sought to assess the effects of 3 different porcelain surface treatments on adhesion of Candida albicans. This in vitro experimental study was conducted on 60 porcelain disks (10 × 3 mm) randomly divided into 4 groups of 15. The nonglazed group received no surface treatment; specimens in the other 3 groups were glazed in the furnace, overglazed with liquid glaze, or polished using a polishing kit. The specimens were washed, sterilized, and separately incubated with 350 µL of Candida albicans suspension for 24 hours. Specimens were then rinsed for 20 seconds and shaken in 1 mL of saline solution for 1 minute, and 20 µL of this suspension was cultured in a plate and incubated at 37°C for 48 hours. Candida albicans colonies were counted to assess the number of microorganisms adhering to each disk. Data were analyzed with the Kruskal-Wallis test. Statistically significant differences were found among the 4 groups in terms of C albicans adherence (P = 0.001). The nonglazed porcelain had the highest and the overglazed porcelain had the lowest mean adherence value. No statistically significant difference was noted between glazed and polished specimens. Based on the obtained results, overglazing resulted in the least adhesion of C albicans, and polishing provided a surface as smooth as a glazed surface. PMID:27367639

  11. Effect of bracket base design on shear bond strength to feldspathic porcelain

    PubMed Central

    Dalaie, Kazem; Mirfasihi, Armin; Eskandarion, Solmaz; Kabiri, Sattar

    2016-01-01

    Objectives: This study sought to assess the effect of bracket base design on the shear bond strength (SBS) of the bracket to feldspathic porcelain. Materials and Methods: This in vitro, experimental study was conducted on 40 porcelain-fused-to-metal restorations and four different bracket base designs were bonded to these specimens. The porcelain surfaces were etched, silanized, and bonded to brackets. Specimens were thermocycler, incubated for 24 h and were subjected to SBS. Data were analyzed using Shapiro–Wilk test, Levene's test, one-way ANOVA, and Tukey's honest significant difference test. Adhesive remnant index was calculated and compared using Fisher's exact test. Results: One-way ANOVA showed that the SBS values were significantly different among the four groups (P < 0.001). Groups 1, 2, and 4 were not significantly different, but group 3 had significantly lower SBS (P < 0.001). Fractures mostly occurred at the porcelain-adhesive interface in Groups 1 and 2 while in Groups 3 and 4, bracket-adhesive and mixed failures were more common. Conclusion: The bracket base design significantly affects the SBS to feldspathic porcelain. PMID:27403052

  12. Influence of surface treatments on the shear bond strength of orthodontic brackets to porcelain

    NASA Astrophysics Data System (ADS)

    Wang, Cong; Zeng, Jishan; Wang, Shaoan; Yang, Zheng; Huang, Qian; Chen, Pixiu; Zhou, Shujuan; Liu, Xiaoqing

    2008-11-01

    The purpose of this study was to investigate the effect of various surface treatments after different storage time and thermocycling on the shear bond strength of orthodontic brackets to the feldspathic porcelain surfaces. 128 disc-shaped porcelain specimens were randomly assigned to the following surface treatments: 9.6% HFA, 9.6% HFA combined with silane, 50 μ aluminum trioxide sandblasting followed by silane and application of silane after 37% phosphoric acid. Metal or ceramic brackets were bonded onto each treated porcelain facet with light cured resin. The samples were stored in 37 °C water 1 day or 7 days, thermocycled 500 times from 5 to 55 °C. The shear bond strengths were measured (1 mm/min), and statistically analyzed. The bond failure sites were classified according to ARI system. The surface of the glazed, sandblasted, hydrofluoric and phosphoric acid etched porcelain were examined with SEM. All groups achieved reasonable bond strengths to withstand the application of orthodontic forces. Water storage for 7 days caused lower shear bond strength than that of 1 day. But there is no statistically significant difference between the two groups. The mean shear bond strength provided by ceramic bracket with mechanical retention had no statistical difference with that of metal bracket. Therefore, the optimal treatment for orthodontic brackets bonding to feldspathic porcelain was to apply phosphoric acid combined with silane.

  13. Evaluation of zirconia–porcelain interface using X-ray diffraction

    PubMed Central

    Alghazzawi, Tariq F; Janowski, Gregg M

    2015-01-01

    The aim of this study was to determine if accelerated aging of porcelain veneering had an effect on the surface properties specific to a tetragonal-to-monoclinic transformation (TMT) of zirconia restorations. Thirty-six zirconia samples were milled and sintered to simulate core fabrication followed by exposure to various combinations of surface treatments including as-received (control), hydrofluoric acid (HF), application of liner plus firings, application of porcelain by manual layering and pressing with firing, plus accelerated aging. The quantity of transformed tetragonal to monoclinic phases was analyzed utilized an X-ray diffractometer and one-way analysis of variance was used to analyze data. The control samples as provided from the dental laboratory after milling and sintering process had no TMT (Xm = 0). There was an effect on zirconia samples of HF application with TMT (Xm = 0.8%) and liner plus HF application with TMT (Xm = 8.7%). There was an effect of aging on zirconia samples (no veneering) with significant TMT (Xm = 70.25%). Both manual and pressing techniques of porcelain applications reduced the TMT (manual, Xm = 4.41%, pressing, Xm = 11.57%), although there was no statistical difference between them. It can be concluded that simulated applications of porcelain demonstrated the ability to protect zirconia from TMT after aging with no effect of a liner between different porcelain applications. The HF treatment also caused TMT. PMID:26208038

  14. Performance of the ATLAS Tile Calorimeter

    NASA Astrophysics Data System (ADS)

    Cole, Stephe

    2013-04-01

    The Tile Calorimeter is the central section (0 < |η| < 1.7) of the ATLAS hadronic calorimeter. It is a key detector for the measurement of hadrons, jets, tau leptons decaying hadronically, and missing transverse energy. Because of its very good signal to noise ratio it is also useful for the identification and reconstruction of muons. The calorimeter consists of thin steel plates and 460,000 scintillating tiles configured into 4900 cells, each viewed by two photomultipliers. The calorimeter response is monitored to better than 1% using radioactive source, laser, and electronic charge injection systems. The calibration and performance of the calorimeter have been established through test beam measurements, cosmic ray muons and the large sample of pp collisions acquired during 2011 and 2012. Results on the calorimeter performance will be presented, including the absolute energy scale, time resolution, and associated stabilities. These results demonstrate that the Tile Calorimeter is performing well within the design requirements and is giving essential input to the physics results.

  15. Foam-on-Tile Damage Model

    NASA Technical Reports Server (NTRS)

    Koharchik, Michael; Murphy, Lindsay; Parker, Paul

    2012-01-01

    An impact model was developed to predict how three specific foam types would damage the Space Shuttle Orbiter insulating tiles. The inputs needed for the model are the foam type, the foam mass, the foam impact velocity, the foam impact incident angle, the type being impacted, and whether the tile is new or aged (has flown at least one mission). The model will determine if the foam impact will cause damage to the tile. If it can cause damage, the model will output the damage cavity dimensions (length, depth, entry angle, exit angle, and sidewall angles). It makes the calculations as soon as the inputs are entered (less than 1 second). The model allows for the rapid calculation of numerous scenarios in a short time. The model was developed from engineering principles coupled with significant impact testing (over 800 foam impact tests). This model is applicable to masses ranging from 0.0002 up to 0.4 pound (0.09 up to 181 g). A prior tool performed a similar function, but was limited to the assessment of a small range of masses and did not have the large test database for verification. In addition, the prior model did not provide outputs of the cavity damage length, entry angle, exit angle, or sidewall angles.

  16. Survival rates of porcelain molar crowns-an update.

    PubMed

    Kassem, Amr Shebl; Atta, Osama; El-Mowafy, Omar

    2010-01-01

    The aim of this study was to identify recent studies that dealt with the clinical performance of porcelain molar crowns and to explore the possibility of grouping the findings from similar studies together to draw overall conclusions. A MEDLINE literature search was conducted in early 2009 covering the preceding 12 years. Seventeen studies were indentified. However, only seven met the specific inclusion criteria and were analyzed. Among seven studies, five European countries were covered. Five studies reported on Procera AllCeram molar crowns while one reported on In-Ceram Alumina and Spinell crowns and another on CEREC crowns. For comparison, one additional study that reported on premolar crowns was included. In the five Procera AllCeram studies, 235 molar crowns were evaluated for 5 or more years, of which 24 failed. When the results of the five studies on the performance of Procera AllCeram molar crowns were considered collectively, an overall failure rate of 10.2% was found at 5 or more years. Int J Prosthodont 2010;23:60-62. PMID:20234895

  17. Development of porcelain enamel passive thermal control coatings

    NASA Technical Reports Server (NTRS)

    Levin, H.; Lent, W. E.; Buettner, D. H.

    1973-01-01

    A white porcelain enamel coating was developed for application to high temperature metallic alloy substrates on spacecraft. The coating consists of an optically opacifying zirconia pigment, a lithia-zirconia-silica frit, and an inorganic pigment dispersant. The coating is fired at 1000 to 1150 C to form the enamel. The coating has a solar absorptance of 0.22 and a total normal emittance of 0.82 for a 0.017 cm thick coating. The coating exhibits excellent adhesion, cleanability, and integrity and is thermal shock resistant to 900 C. Capability to coat large panels has been demonstrated by successful coating of 30 cm x 30 cm Hastelloy X alloy panels. Preliminary development of low temperature enamels for application to aluminum and titanium alloy substrates was initiated. It was determined that both leaded and leadless frits were feasible when applied with appropriate mill fluxes. Indications were that opacification could be achieved at firing temperatures below 540 C for extended periods of time.

  18. 75 FR 81967 - Porcelain-on-Steel Cooking Ware From Taiwan: Final Results of Sunset Review and Revocation of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-29

    ... 19 CFR 351.218(c). See Initiation of Five-Year (``Sunset'') Review, 75 FR 60731 (October 1, 2010...; Porcelain-on-Steel Cooking Ware from Taiwan, 51 FR 43416 (December 2, 1986). In two subsequent sunset... Orders: Porcelain-on-Steel Cooking Ware From China, Mexico, and Taiwan, 65 FR 20136 (April 14,...

  19. Interference Lattice-based Loop Nest Tilings for Stencil Computations

    NASA Technical Reports Server (NTRS)

    VanderWijngaart, Rob F.; Frumkin, Michael

    2000-01-01

    A common method for improving performance of stencil operations on structured multi-dimensional discretization grids is loop tiling. Tile shapes and sizes are usually determined heuristically, based on the size of the primary data cache. We provide a lower bound on the numbers of cache misses that must be incurred by any tiling, and a close achievable bound using a particular tiling based on the grid interference lattice. The latter tiling is used to derive highly efficient loop orderings. The total number of cache misses of a code is the sum of (necessary) cold misses and misses caused by elements being dropped from the cache between successive loads (replacement misses). Maximizing temporal locality is equivalent to minimizing replacement misses. Temporal locality of loop nests implementing stencil operations is optimized by tilings that avoid data conflicts. We divide the loop nest iteration space into conflict-free tiles, derived from the cache miss equation. The tiling involves the definition of the grid interference lattice an equivalence class of grid points whose images in main memory map to the same location in the cache-and the construction of a special basis for the lattice. Conflicts only occur on the boundaries of the tiles, unless the tiles are too thin. We show that the surface area of the tiles is bounded for grids of any dimensionality, and for caches of any associativity, provided the eccentricity of the fundamental parallelepiped (the tile spanned by the basis) of the lattice is bounded. Eccentricity is determined by two factors, aspect ratio and skewness. The aspect ratio of the parallelepiped can be bounded by appropriate array padding. The skewness can be bounded by the choice of a proper basis. Combining these two strategies ensures that pathologically thin tiles are avoided. They do not, however, minimize replacement misses per se. The reason is that tile visitation order influences the number of data conflicts on the tile boundaries. If two

  20. Military Curriculum Materials for Vocational and Technical Education. Builders School, Ceramic Tile Setting 3-9.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    This course, for individualized or group instruction on ceramic tile setting, was developed from military sources for use in vocational education. The course provides students with skills in mortar preparation, surface preparation, tile layout planning, tile setting, tile cutting, and the grouting of tile joints. Both theory and shop assignments…

  1. Design, fabrication, and tests of a metallic shell tile thermal protection system for space transportation

    NASA Technical Reports Server (NTRS)

    Macconochie, Ian O.; Kelly, H. Neale

    1989-01-01

    A thermal protection tile for earth-to-orbit transports is described. The tiles consist of a rigid external shell filled with a flexible insulation. The tiles tend to be thicker than the current Shuttle rigidized silica tiles for the same entry heat load but are projected to be more durable and lighter. The tiles were thermally tested for several simulated entry trajectories.

  2. Transient and residual stresses in dental porcelains as affected by cooling rates.

    PubMed

    Asaoka, K; Tesk, J A

    1989-06-01

    The development of either transient or residual stress in a slab of dental porcelain during cooling was simulated by use of a super-computer. The temperature dependences of the elastic modulus, the thermal expansion coefficient, and the shear viscosity, and the cooling rate dependence of the glass transition temperature, Tg, were considered in this calculation. Internal stress and viscoelastic creep were computed for several cooling rates. Calculated results display stress profiles which agree reasonably well with reported measured profiles in quenched, tempered glasses. The calculated residual surface stress, sigma, could be fit by the following empirical formula, sigma = kl2(q/q0)n, q is the cooling rate, q0 is a reference cooling rate and l is the half-thickness of the porcelain. The method by which residual stress develops is also discussed. This discussion suggests a method for strengthening of the porcelain by the development of high-compressive residual stress on the surface. PMID:2638963

  3. Wear of combinations of acrylic resin and porcelain, on an abrasion testing machine.

    PubMed

    Harrison, A

    1978-04-01

    Wear tests of various combinations of acrylic resin and porcelain were made using a machine which was designed to test materials under conditions similar to those of masticatory function by simulating the loads, sliding distances, and contact times encountered in the human masticatory cycle. The results showed that the amount of wear of the two materials worn in combination depended on the nature of the surrounding medium and on the surface roughness of the opposing material. Acrylic resin showed good wear resistance provided no third party abrasive or opposing hard, rough surface was present. When a mild abrasive was incorporated in the system, the acrylic resin vs acrylic resin combination wore almost seven times more than porcelain vs porcelain. Clinical experience would suggest that this is a reasonably sound order of wear. PMID:213546

  4. Evaluation of Candida albicans formation on feldspathic porcelain subjected to four surface treatment methods.

    PubMed

    Karayazgan, Banu; Atay, Arzu; Saracli, Mehmet Ali; Gunay, Yumushan

    2010-03-01

    Candida albicans, known for its adhesion on prosthetic materials and oral tissues, is the most frequently encountered fungal infection in dentistry. The aim of this study was to evaluate the effects of four different surface treatment methods and immersion in artificial saliva on the surface roughness of and candida adhesion on dental porcelains. The four surface treatment methods were namely: natural glaze, overglaze, dual ion exchange, and polishing. Surface roughness of porcelain was evaluated using a surface profilometer and by SEM. Candida adhesion was examined by culturing two Candida strains on porcelain specimens followed by a colorimetric method using XTT/Coenzyme Q0. It became evident that Candida adhesion was found more in the specimens treated with natural glaze and polishing. Further, by the visual inspection of SEM images and comparison of surface roughness, polished and natural-glazed specimens showed rougher surface characteristics than overglazed and dual-ion-exchanged specimens. PMID:20379024

  5. 55. QUARRY TILE CUTTERS, SECOND FLOOR, NORTH WING. WORKERS PRESSED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    55. QUARRY TILE CUTTERS, SECOND FLOOR, NORTH WING. WORKERS PRESSED THE CUTTERS INTO SLABS OF CLAY, LIFTED THEM ONTO DRYING BOARDS AND PRESSED THE PLUNGERS TO RELEASE THE CUT TILES. REPRODUCTIONS CUTTERS ARE NOT USED IN PRODUCTION. WOODEN FORMS FOR PRODUCING CLAY SLABS WITH ROLLING PINS REST AGAINST THE WALL. - Moravian Pottery & Tile Works, Southwest side of State Route 313 (Swamp Road), Northwest of East Court Street, Doylestown, Bucks County, PA

  6. Design optimization methods for genomic DNA tiling arrays

    PubMed Central

    Bertone, Paul; Trifonov, Valery; Rozowsky, Joel S.; Schubert, Falk; Emanuelsson, Olof; Karro, John; Kao, Ming-Yang; Snyder, Michael; Gerstein, Mark

    2006-01-01

    A recent development in microarray research entails the unbiased coverage, or tiling, of genomic DNA for the large-scale identification of transcribed sequences and regulatory elements. A central issue in designing tiling arrays is that of arriving at a single-copy tile path, as significant sequence cross-hybridization can result from the presence of non-unique probes on the array. Due to the fragmentation of genomic DNA caused by the widespread distribution of repetitive elements, the problem of obtaining adequate sequence coverage increases with the sizes of subsequence tiles that are to be included in the design. This becomes increasingly problematic when considering complex eukaryotic genomes that contain many thousands of interspersed repeats. The general problem of sequence tiling can be framed as finding an optimal partitioning of non-repetitive subsequences over a prescribed range of tile sizes, on a DNA sequence comprising repetitive and non-repetitive regions. Exact solutions to the tiling problem become computationally infeasible when applied to large genomes, but successive optimizations are developed that allow their practical implementation. These include an efficient method for determining the degree of similarity of many oligonucleotide sequences over large genomes, and two algorithms for finding an optimal tile path composed of longer sequence tiles. The first algorithm, a dynamic programming approach, finds an optimal tiling in linear time and space; the second applies a heuristic search to reduce the space complexity to a constant requirement. A Web resource has also been developed, accessible at http://tiling.gersteinlab.org, to generate optimal tile paths from user-provided DNA sequences. PMID:16365382

  7. Robotic end-effector for rewaterproofing shuttle tiles

    NASA Technical Reports Server (NTRS)

    Manouchehri, Davoud; Hansen, Joseph M.; Wu, Cheng M.; Yamamoto, Brian S.; Graham, Todd

    1992-01-01

    This paper summarizes work by Rockwell International's Space Systems Division's Robotics Group at Downey, California. The work is part of a NASA-led team effort to automate Space Shuttle rewaterproofing in the Orbiter Processing Facility at the Kennedy Space Center and the ferry facility at the Ames-Dryden Flight Research Facility. Rockwell's effort focuses on the rewaterproofing end-effector, whose function is to inject hazardous dimethylethyloxysilane into thousands of ceramic tiles on the underside of the orbiter after each flight. The paper has five sections. First, it presents background on the present manual process. Second, end-effector requirements are presented, including safety and interface control. Third, a design is presented for the five end-effector systems: positioning, delivery, containment, data management, and command and control. Fourth, end-effector testing and integrating to the total system are described. Lastly, future applications for this technology are discussed.

  8. Effects of initial temperature and tempering medium on thermal tempering of dental porcelains.

    PubMed

    Hojjatie, B; Anusavice, K J

    1993-03-01

    The objective of this study was to test the hypothesis that quenching of porcelain in silicone oil rather than in compressed air will significantly increase the flexure strength by reducing the potential for crack formation during transient cooling. A secondary hypothesis to be tested is that the initial tempering temperature can be reduced significantly below the porcelain maturing temperature of 982 degrees C but well above Tg without a decrease in strength. Opaque-body porcelain disks, 16 mm in diameter and 2 mm in thickness, with a thermal contraction mismatch (delta alpha) of -1.5, 0, and +3.2 ppm/degrees C were tempered from initial temperatures of 650, 750, 850, and 982 degrees C in silicone oil with kinematic viscosities of 50, 1000, and 5000 centistokes. Porcelain disks were also subjected to three cooling procedures in air: slow cooling in a furnace (SC), free convective cooling in a laboratory bench (FC), and tempering (T) by blasting the surface of body porcelain with air. The crack size induced by a Vickers microhardness indenter was measured within one minute after crack development. For determination of the influence of initial cooling temperature on biaxial flexure strength, six body porcelain disks (delta alpha = 0) were tempered in air from initial temperatures of 650, 750, 850, and 982 degrees C. The mean crack size of specimens tempered in oil was significantly smaller (p < or = 0.001) than that of specimens that were slowly-cooled or fast-cooled in air for all thermal contraction mismatch cases.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8450115

  9. Porcelain laminate veneer conditioning for orthodontic bonding: SEM-EDX analysis.

    PubMed

    Aksakalli, Sertac; Ileri, Zehra; Yavuz, Tevfik; Malkoc, Meral Arslan; Ozturk, Nilgun

    2015-09-01

    The purpose of this in vitro study was to evaluate and compare the effects of different surface treatments and laser irradiation on the bond strength of brackets bonded to porcelain laminate veneer. Porcelain laminate veneer specimens were embedded in the centers of acrylic resin blocks. Thirty-nine teeth were used for shear bond strength testing and the remaining three (one tooth for each group) were used for evaluation of the debonded bracket interface. Specimens were randomly divided into three groups, each containing 13 specimens. The details of the groups are as follows: Group SB, sandblasting with alumina particles (50 μm); Group HFA, 9.6 % hydrofluoric acid etching; Group ER, erbium-doped yttrium-aluminum-garnet (Er: YAG) irradiation (from 1 mm distance, 2 W, 10 Hz for 10 s). After conditioning, the upper central brackets were bonded to the porcelain surfaces. Porcelain laminate veneers were examined under stereomicroscope for adhesive remnant index and surface damage after debonding. The highest shear bond strength values were obtained with Group HFA (10.8 ± 3.8 MPa) and Group ER (9.3 ± 1.5 MPa), whereas Group SB revealed the lowest values. Scanning electron microscopy energy-dispersive X-ray (SEM-EDX) analysis revealed that the silicon level in the porcelain decreased after debonding in all groups. The sandblasting method did not demonstrate any ideal bond strength values; however, the 9.6 % hydrofluoric acid etching and Er: YAG laser did. There were no significant differences among all groups in terms of laminate surface damages. The Er: YAG laser therefore can be selected for ideal bond strength and minimal damage to porcelain laminates. PMID:25344891

  10. On the interfacial fracture of porcelain/zirconia and graded zirconia dental structures.

    PubMed

    Chai, Herzl; Lee, James J-W; Mieleszko, Adam J; Chu, Stephen J; Zhang, Yu

    2014-08-01

    Porcelain fused to zirconia (PFZ) restorations are widely used in prosthetic dentistry. However, their susceptibility to fracture remains a practical problem. The failure of PFZ prostheses often involves crack initiation and growth in the porcelain, which may be followed by fracture along the porcelain/zirconia (P/Z) interface. In this work, we characterized the process of fracture in two PFZ systems, as well as a newly developed graded glass-zirconia structure with emphases placed on resistance to interfacial cracking. Thin porcelain layers were fused onto Y-TZP plates with or without the presence of a glass binder. The specimens were loaded in a four-point-bending fixture with the thin porcelain veneer in tension, simulating the lower portion of the connectors and marginal areas of a fixed dental prosthesis (FDP) during occlusal loading. The evolution of damage was observed by a video camera. The fracture was characterized by unstable growth of cracks perpendicular to the P/Z interface (channel cracks) in the porcelain layer, which was followed by stable cracking along the P/Z interface. The interfacial fracture energy GC was determined by a finite-element analysis taking into account stress-shielding effects due to the presence of adjacent channel cracks. The resulting GC was considerably less than commonly reported values for similar systems. Fracture in the graded Y-TZP samples occurred via a single channel crack at a much greater stress than for PFZ. No delamination between the residual glass layer and graded zirconia occurred in any of the tests. Combined with its enhanced resistance to edge chipping and good esthetic quality, graded Y-TZP emerges as a viable material concept for dental restorations. PMID:24769152

  11. A comparative study on the bond strength of porcelain to the millingable Pd-Ag alloy

    PubMed Central

    Hong, Jun-Tae

    2014-01-01

    PURPOSE The porcelain fused to gold has been widely used as a restoration both with the natural esthetics of the porcelain and durability and marginal fit of metal casting. However, recently, due to the continuous rise in the price of gold, an interest towards materials to replace gold alloy is getting higher. This study compared the bond strength of porcelain to millingable palladium-silver (Pd-Ag) alloy, with that of 3 conventionally used metal-ceramic alloys. MATERIALS AND METHODS Four types of metal-ceramic alloys, castable nonprecious nickel-chrome alloy, castable precious metal alloys containing 83% and 32% of gold, and millingable Pd-Ag alloy were used to make metal specimens (n=40). And porcelain was applied on the center area of metal specimen. Three-point bending test was performed with universal testing machine. The bond strength data were analyzed with a one-way ANOVA and post hoc Scheffe's tests (α=.05). RESULTS The 3-point bending test showed the strongest (40.42 ± 5.72 MPa) metal-ceramic bond in the nonprecious Ni-Cr alloy, followed by millingable Pd-Ag alloy (37.71 ± 2.46 MPa), precious metal alloy containing 83% of gold (35.89 ± 1.93 MPa), and precious metal alloy containing 32% of gold (34.59 ± 2.63 MPa). Nonprecious Ni-Cr alloy and precious metal alloy containing 32% of gold showed significant difference (P<.05). CONCLUSION The type of metal-ceramic alloys affects the bond strength of porcelain. Every metal-ceramic alloy used in this study showed clinically applicable bond strength with porcelain (25 MPa). PMID:25352959

  12. On the interfacial fracture of porcelain/zirconia and graded zirconia dental structures

    PubMed Central

    Chai, Herzl; Lee, James J.-W; Mieleszko, Adam J.; Chu, Stephen J.; Zhang, Yu

    2014-01-01

    Porcelain fused to zirconia (PFZ) restorations are widely used in prosthetic dentistry. However, their susceptibility to fracture remains a practical problem. The failure of PFZ prostheses often involves crack initiation and growth in the porcelain, which may be followed by fracture along the porcelain/zirconia (P/Z) interface. In this work, we characterized the process of fracture in two PFZ systems, as well as a newly developed graded glass-zirconia structure with emphases placed on resistance to interfacial cracking. Thin porcelain layers were fused onto Y-TZP plates with or without the presence of a glass binder. The specimens were loaded in a four-point-bend fixture with the thin porcelain veneer in tension, simulating the lower portion of the connectors and marginal areas of a fixed dental prosthesis (FDP) during occlusal loading. The evolution of damage was observed by a video camera. The fracture was characterized by unstable growth of cracks perpendicular to the P/Z interface (channel cracks) in the porcelain layer, which was followed by stable cracking along the P/Z interface. The interfacial fracture energy GC was determined by a FEA taking into account stress shielding effects due to the presence of adjacent channel cracks. The resulting GC was well less than commonly reported values for similar systems. Fracture in the graded Y-TZP samples occurred by a single channel crack at a much greater stress than for PFZ. No delamination between the residual glass layer and graded zirconia occurred in any of the tests. Combined with its enhanced resistance to edge chipping and good esthetic quality, graded Y-TZP emerges as a viable material concept for dental restorations. PMID:24769152

  13. NASA TileWorld manual (system version 2.2)

    NASA Technical Reports Server (NTRS)

    Philips, Andrew B.; Bresina, John L.

    1991-01-01

    The commands are documented of the NASA TileWorld simulator, as well as providing information about how to run it and extend it. The simulator, implemented in Common Lisp with Common Windows, encodes a particular range in a spectrum of domains, for controllable research experiments. TileWorld consists of a two dimensional grid of cells, a set of polygonal tiles, and a single agent which can grasp and move tiles. In addition to agent executable actions, there is an external event over which the agent has not control; this event correspond to a 'gust of wind'.

  14. Geopolymers as potential repair material in tiles conservation

    NASA Astrophysics Data System (ADS)

    Geraldes, Catarina F. M.; Lima, Augusta M.; Delgado-Rodrigues, José; Mimoso, João Manuel; Pereira, Sílvia R. M.

    2016-03-01

    The restoration materials currently used to fill gaps in historical architectural tiles (e.g. lime or organic resin pastes) usually show serious drawbacks in terms of compatibility, effectiveness or durability. The existing solutions do not fully protect Portuguese faïence tiles ( azulejos) in outdoor conditions and frequently result in further deterioration. Geopolymers can be a potential solution for tile lacunae infill, given the chemical-mineralogical similitude to the ceramic body, and also the durability and versatile range of physical properties that can be obtained through the manipulation of their formulation and curing conditions. This work presents and discusses the viability of the use of geopolymeric pastes to fill lacunae in tiles or to act as "cold" cast ceramic tile surrogates reproducing missing tile fragments. The formulation of geopolymers, namely the type of activators, the alumino-silicate source, the quantity of water required for adequate workability and curing conditions, was studied. The need for post-curing desalination was also considered envisaging their application in the restoration of outdoor historical architectural tiles frequently exposed to adverse environmental conditions. The possible advantages and disadvantages of the use of geopolymers in the conservation of tiles are also discussed. The results obtained reveal that geopolymers pastes are a promising material for the restoration of tiles, when compared to other solutions currently in use.

  15. The effect of fluxing agent MnO2 on alumina silicate porcelain insulator properties

    NASA Astrophysics Data System (ADS)

    Dudi, Dharmender; Shekhawat, M. S.; Singh, G. P.

    2016-05-01

    Higher strength electrical porcelain is a requirement for industry. This will be achieved by a specific composition of raw materials, which is consisted of clays and feldspars. High mechanical resistance, low porosity and water absorption are among their important properties. By decreasing the silica and increasing the alumina provides a higher mechanical strength in porcelain but on the other hand increases the body's baking temperature. Therefore adding MnO2 in different percentage is a suitable and practical solution to improve strength without increasing sinter temperature. Results have shown that addition of 1% MnO2 in body enhances mechanical strength of the body.

  16. Rehabilitation of the dominance of maxillary central incisors with refractory porcelain veneers requiring minimal tooth preparation.

    PubMed

    da Cunha, Leonardo Fernandes; Gonzaga, Carla Castiglia; Saab, Rafaella; Mushashe, Amanda Mahammad; Correr, Gisele Maria

    2015-01-01

    Central dominance is an important element of an esthetic smile. Color, form, and size have been suggested as tools for assessing the dominance of maxillary teeth. A spectrophotometer can be used to determine the value, hue, and chroma. Correct sizing of restorations according to the central incisor dominance principle improves not only esthetics but also aspects of occlusion, such as anterior guidance. Refractory porcelain systems can effectively restore the color, shape, emergence profile, and incisal translucency. This report illustrates the esthetic and occlusal rehabilitation of the dominance of maxillary central incisors using fabricated minimal thickness refractory porcelain veneers. PMID:26345102

  17. Effect of mineralizers on the sintering of porcelain bodies (a review)

    SciTech Connect

    Maslennikova, G.N.; Koneshova, T.I.

    1987-11-01

    The authors assess the effects of a wide range of mineralizing agents on the structure formation of porcelain in order to arrive at optimal crystallization and structure parameters for the resulting porcelain crystals and to determine those agents which best contribute to the energy efficiency of the sintering process. The assessment is carried out specifically for the kinetics of mullite formation. Reagents tested include salts of sodium, potassium, lithium, calcium, magnesium, zinc, and aluminum, and the oxides of chromium, titanium, iron, zirconium, molybdenum, boron, and tin.

  18. Clampless and Sutureless Hybrid Technique for Aortic Arch Debranching on a Porcelain Aorta.

    PubMed

    Poletto, Giorgio L; Musto, Liam; Civilini, Efrem; Giorgetti, PierLuigi

    2016-06-01

    An innovative hybrid approach to the supraaortic vessels in a porcelain aorta and severe fibrotic tissue reaction at the neck is described. The technique is demonstrated in an 80-year-old woman with previous several carotid operations but still experiencing recurrent transient ischemic attacks. Clinical success was achieved at midterm follow-up, demonstrating the efficacy of hybrid treatment for this high-risk patient. Novel prosthetic vascular grafts that can be applied without cross-clamping may also provide a solution to approaching a porcelain aorta and difficult anatomies. PMID:27211961

  19. Probing the mechanical properties of dental porcelain through nanoindentation

    NASA Astrophysics Data System (ADS)

    Manda, Marianthi; Moschakis, Nikolaos; Konstantinidis, Avraam; Christophilos, Demetrios; Papadopoulou, Lambrini; Koidis, Petros; Aifantis, Elias

    2012-11-01

    The purpose of this short communication is to report on some micro/nanoscale aspects of the mechanical behavior of dental porcelain. Specimens were characterized by micro-Raman spectroscopy and scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS). Massive nanoindentation experiments on the surface of the specimens were performed, and typical load-displacement or load-depth (P-h) curves were obtained, which in turn were used to determine the Young modulus (E) and nanoindentation hardness (n-H), based on the Oliver-Pharr method [1]. Statistical analyses were carried out to determine the Spearman’s rank correlation coefficient (Spearman’s ρ), along with non-parametric linear regression analysis by employing Kolmogorov-Smirnov and Two-Step Cluster tests. Densification due to grain boundary diffusion and open-pore elimination was revealed by SEM. EDS analysis indicated a leucite-dispersed silicate glass matrix, as well as its contamination by traces of other minerals. Raman spectroscopy supported the EDS assignments. The P-h curves suggested that inelastic deformation and material flow increases at larger depths. Spearman’s ρ value showed strong dependence of E and n-H on h, indicating the occurrence of a size effect. The logarithmic data of E and n-H as functions of h were fitted by using linear regression analysis. The data did not obey a normal distribution (as the Kolmogorov-Smirnov test showed) due to the chemical heterogeneity involved. The Two-Step Cluster analysis indicated clustering in four groups associated with the chemical heterogeneity of the surface. Similar works using nanoindentation to determine the mechanical properties of dental materials can be found, for example, in [2, 3]. Corresponding methods for extracting the values of E and n-H from P-h experimental curves can be found, for example, in [4-6].

  20. Complex tiling patterns in liquid crystals

    PubMed Central

    Tschierske, C.; Nürnberger, C.; Ebert, H.; Glettner, B.; Prehm, M.; Liu, F.; Zeng, X.-B.; Ungar, G.

    2012-01-01

    In this account recent progress in enhancing the complexity of liquid crystal self-assembly is highlighted. The discussed superstructures are formed mainly by polyphilic T-shaped and X-shaped molecules composed of a rod-like core, tethered with glycerol units at both ends and flexible non-polar chain(s) in lateral position, but also related inverted molecular structures are considered. A series of honeycomb phases composed of polygonal cylinders ranging from triangular to hexagonal, followed by giant cylinder honeycombs is observed for ternary T-shaped polyphiles on increasing the size of the lateral chain(s). Increasing the chain size further leads to new modes of lamellar organization followed by three-dimensional and two-dimensional structures incorporating branched and non-branched axial rod-bundles. Grafting incompatible chains to opposite sides of the rod-like core leads to quaternary X-shaped polyphiles. These form liquid crystalline honeycombs where different cells are filled with different material. Projected on an Euclidian plane, all honeycomb phases can be described either by uniformly coloured Archimedean and Laves tiling patterns (T-shaped polyphiles) or as multi-colour tiling patterns (X-shaped polyphiles). It is shown that geometric frustration, combined with the tendency to segregate incompatible chains into different compartments and the need to find a periodic tiling pattern, leads to a significant increase in the complexity of soft self-assembly. Mixing of different chains greatly enhances the number of possible ‘colours’ and in this way, periodic structures comprising up to seven distinct compartments can be generated. Relations to biological self-assembly are discussed shortly. PMID:24098852

  1. Symmetries and color symmetries of a family of tilings with a singular point.

    PubMed

    Evidente, Imogene F; Felix, Rene P; Loquias, Manuel Joseph C

    2015-11-01

    Tilings with a singular point are obtained by applying conformal maps on regular tilings of the Euclidean plane and their symmetries are determined. The resulting tilings are then symmetrically colored by applying the same conformal maps on colorings of regular tilings arising from sublattice colorings of the centers of the tiles. In addition, conditions are determined in order that the coloring of a tiling with singularity that is obtained in this manner is perfect. PMID:26522407

  2. Effect of fast neutrons on the electric resistivity of porcelain for application in fast-neutron dosimetry

    SciTech Connect

    Fadel, M.A.; Abdel-Fattah, W.I.; Abdulla, A.A.; Kadum, A.A.

    1982-11-01

    The electric resistivity (rho) of quartz and alumina porcelain was measured before and after irradiation with different fluences (phi) of fission neutrons in the range of 10/sup 7/-10/sup 12/ n/cm/sup 2/ and at different temperatures in the range of 20-90/sup 0/C. The results showed that the activation energy (..delta..E) for quartz porcelain decreased progressively with the increase of phi, while it remained approximately constant for alumina porcelain. Moreover, the electric resistivity of alumina porcelain decreased with the increase of phi. However, there were no measureable effects of /sup 60/Co ..gamma.. doses up to 0.6 Mrad on the electric resistivities of the samples. An empirical formula for calculating phi from the measured value of ..delta..E for quartz porcelain was achieved. A semiempirical formula for calculating phi for the resistivity data for the alumina porcelain is given. The effect of neutron energies on the induced changes in (rho) for the alumina porcelain was investigated. Additionally, the effect of storage at 50/sup 0/C for periods up to 3 weeks on these changes were also measured.

  3. Dynamic out-of-plane and in-plane testing of full-scale hollow clay tile infilled frames. [Final report

    SciTech Connect

    Gambill, J.B.

    1994-12-31

    Many of the Y-12 Plant buildings are made of steel and concrete frames infilled with unreinforced clay tile walls; in many instances these infill walls comprise the major lateral load resisting capacity of the structures. A research program was begun to evaluate clay tile infill behavior. This test report describes testing done by USACERL as part of shake table testing; the tests were on a biaxial shock test machine.

  4. 49. TILE PACKING AREA AND APPRENTICE WORKSPACE, SECOND FLOOR, SOUTH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    49. TILE PACKING AREA AND APPRENTICE WORKSPACE, SECOND FLOOR, SOUTH END OF EAST WING. THE SKYLIGHT, ADDED IN 1976. COVERS A ROOF OPENING LEFT FOR THE CHIMNEY OF A POSSIBLE THIRD BISCUIT KILN. - Moravian Pottery & Tile Works, Southwest side of State Route 313 (Swamp Road), Northwest of East Court Street, Doylestown, Bucks County, PA

  5. Highly Symmetric and Congruently Tiled Meshes for Shells and Domes

    PubMed Central

    Rasheed, Muhibur; Bajaj, Chandrajit

    2016-01-01

    We describe the generation of all possible shell and dome shapes that can be uniquely meshed (tiled) using a single type of mesh face (tile), and following a single meshing (tiling) rule that governs the mesh (tile) arrangement with maximal vertex, edge and face symmetries. Such tiling arrangements or congruently tiled meshed shapes, are frequently found in chemical forms (fullerenes or Bucky balls, crystals, quasi-crystals, virus nano shells or capsids), and synthetic shapes (cages, sports domes, modern architectural facades). Congruently tiled meshes are both aesthetic and complete, as they support maximal mesh symmetries with minimal complexity and possess simple generation rules. Here, we generate congruent tilings and meshed shape layouts that satisfy these optimality conditions. Further, the congruent meshes are uniquely mappable to an almost regular 3D polyhedron (or its dual polyhedron) and which exhibits face-transitive (and edge-transitive) congruency with at most two types of vertices (each type transitive to the other). The family of all such congruently meshed polyhedra create a new class of meshed shapes, beyond the well-studied regular, semi-regular and quasi-regular classes, and their duals (platonic, Catalan and Johnson). While our new mesh class is infinite, we prove that there exists a unique mesh parametrization, where each member of the class can be represented by two integer lattice variables, and moreover efficiently constructable. PMID:27563368

  6. Computerized Machine for Cutting Space Shuttle Thermal Tiles

    NASA Technical Reports Server (NTRS)

    Ramirez, Luis E.; Reuter, Lisa A.

    2009-01-01

    A report presents the concept of a machine aboard the space shuttle that would cut oversized thermal-tile blanks to precise sizes and shapes needed to replace tiles that were damaged or lost during ascent to orbit. The machine would include a computer-controlled jigsaw enclosed in a clear acrylic shell that would prevent escape of cutting debris. A vacuum motor would collect the debris into a reservoir and would hold a tile blank securely in place. A database stored in the computer would contain the unique shape and dimensions of every tile. Once a broken or missing tile was identified, its identification number would be entered into the computer, wherein the cutting pattern associated with that number would be retrieved from the database. A tile blank would be locked into a crib in the machine, the shell would be closed (proximity sensors would prevent activation of the machine while the shell was open), and a "cut" command would be sent from the computer. A blade would be moved around the crib like a plotter, cutting the tile to the required size and shape. Once the tile was cut, an astronaut would take a space walk for installation.

  7. Low-Density, Aerogel-Filled Thermal-Insulation Tiles

    NASA Technical Reports Server (NTRS)

    Santos, Maryann; Heng, Vann; Barney, Andrea; Oka, Kris; Droege, Michael

    2005-01-01

    Aerogel fillings have been investigated in a continuing effort to develop low-density thermal-insulation tiles that, relative to prior such tiles, have greater dimensional stability (especially less shrinkage), equal or lower thermal conductivity, and greater strength and durability. In preparation for laboratory tests of dimensional and thermal stability, prototypes of aerogel-filled versions of recently developed low-density tiles have been fabricated by impregnating such tiles to various depths with aerogel formations ranging in density from 1.5 to 5.6 lb/ft3 (about 53 to 200 kg/cu m). Results available at the time of reporting the information for this article showed that the thermal-insulation properties of the partially or fully aerogel- impregnated tiles were equivalent or superior to those of the corresponding non-impregnated tiles and that the partially impregnated tiles exhibited minimal (<1.5 percent) shrinkage after multiple exposures at a temperature of 2,300 F (1,260 C). Latest developments have shown that tiles containing aerogels at the higher end of the density range are stable after multiple exposures at the said temperature.

  8. Improving Efficiency of 3-SAT-Solving Tile Systems

    NASA Astrophysics Data System (ADS)

    Brun, Yuriy

    The tile assembly model has allowed the study of the nature's process of self-assembly and the development of self-assembling systems for solving complex computational problems. Research into this model has led to progress in two distinct classes of computational systems: Internet-sized distributed computation, such as software architectures for computational grids, and molecular computation, such as DNA computing. The design of large complex tile systems that emulate Turing machines has shown that the tile assembly model is Turing universal, while the design of small tile systems that implement simple algorithms has shown that tile assembly can be used to build private, fault-tolerant, and scalable distributed software systems and robust molecular machines. However, in order for these types of systems to compete with traditional computing devices, we must demonstrate that fairly simple tile systems can implement complex and intricate algorithms for important problems. The state of the art, however, requires vastly complex tile systems with large tile sets to implement such algorithms.

  9. Drainage water management effects on tile discharge and water quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nitrogen (N) fluxes from tile drained watersheds have been implicated in water quality studies of the Mississippi River Basin, but the contribution of tile drains to N export in headwater watersheds is not well understood. The objective of this study was to ascertain seasonal and annual contribution...

  10. New SWAT tile drain equations: Modifications, Calibration, Validation, and Application

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Subsurface tile drainage is a commonly used agricultural practice to enhance crop yield in poorly drained but highly productive soils in many other regions of the world. However, the presence of subsurface tile drainage systems also expedites the transport of nitrate-nitrogen (NO3-N) and other chemi...

  11. Creative Tiling: A Story of 1000-and-1 Curves

    ERIC Educational Resources Information Center

    Al-Darwish, Nasir

    2012-01-01

    We describe a procedure that utilizes symmetric curves for building artistic tiles. One particular curve was found to mesh nicely with hundreds other curves, resulting in eye-catching tiling designs. The results of our work serve as a good example of using ideas from 2-D graphics and algorithms in a practical web-based application.

  12. METHOD FOR EVALUATING MOLD GROWTH ON CEILING TILE

    EPA Science Inventory

    A method to extract mold spores from porous ceiling tiles was developed using a masticator blender. Ceiling tiles were inoculated and analyzed using four species of mold. Statistical analysis comparing results obtained by masticator extraction and the swab method was performed. T...

  13. Nutrient and Pesticide Removal From Laboratory Simulated Tile Drainage Discharge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Excess nutrient and pesticide transport through subsurface tile drainage is well documented. One approach receiving consideration for reducing the amount of nutrients and pesticides in subsurface drainage waters is end-of-tile filters. The filters are often comprised of industrial wastes or by-produ...

  14. Clinical performance of porcelain laminate veneers: outcomes of the aesthetic pre-evaluative temporary (APT) technique.

    PubMed

    Gurel, Galip; Morimoto, Susana; Calamita, Marcelo A; Coachman, Christian; Sesma, Newton

    2012-12-01

    This article evaluates the long-term clinical performance of porcelain laminate veneers bonded to teeth prepared with the use of an additive mock-up and aesthetic pre-evaluative temporary (APT) technique over a 12-year period. Sixty-six patients were restored with 580 porcelain laminate veneers. The technique, used for diagnosis, esthetic design, tooth preparation, and provisional restoration fabrication, was based on the APT protocol. The influence of several factors on the durability of veneers was analyzed according to pre- and postoperative parameters. With utilization of the APT restoration, over 80% of tooth preparations were confined to the dental enamel. Over 12 years, 42 laminate veneers failed, but when the preparations were limited to the enamel, the failure rate resulting from debonding and microleakage decreased to 0%. Porcelain laminate veneers presented a successful clinical performance in terms of marginal adaptation, discoloration, gingival recession, secondary caries, postoperative sensitivity, and satisfaction with restoration shade at the end of 12 years. The APT technique facilitated diagnosis, communication, and preparation, providing predictability for the restorative treatment. Limiting the preparation depth to the enamel surface significantly increases the performance of porcelain laminate veneers. PMID:23057051

  15. ISOLATION AND PHYLOGENETIC ANALYSIS OF XYLELLA FASTIDIOSA FROM ITS INVASIVE ALTERNATIVE HOST, PORCELAIN BERRY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A strain of X. fastidiosa was isolated from an invasive alternative host species, porcelain berry. Its genetic relationship with strains isolated from a native alternative host, wild grape, and other economically important hosts including grape, peach, plum, oak, mulberry, maple and oleander was det...

  16. The non-destructive identification of early Chinese porcelain by PIXE

    NASA Astrophysics Data System (ADS)

    Cheng, H. S.; Zhang, Z. Q.; Zhang, B.; Yang, F. J.

    2004-06-01

    PIXE is used for the non-destructive differentiation of early precious Chinese blue and white porcelain made in Yuan (AD 1206-1368), Ming (AD 1368-1644) Dynasty in Jingdezhen from imitations. Also, ancient celadon made in Song Dynasty (AD 960-1279) is identified by measuring the trace elements contained in the glazes.

  17. 49 CFR 178.523 - Standards for composite packagings with inner glass, porcelain, or stoneware receptacles.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... high-density polyethylene from some other comparable plastic material. The removable lid required for... expanded plastic packaging; and (11) 6PH2 for glass, porcelain, or stoneware receptacles within a protective solid plastic packaging. (b) Construction requirements for composite packagings with...

  18. 49 CFR 178.523 - Standards for composite packagings with inner glass, porcelain, or stoneware receptacles.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... high-density polyethylene from some other comparable plastic material. The removable lid required for... expanded plastic packaging; and (11) 6PH2 for glass, porcelain, or stoneware receptacles within a protective solid plastic packaging. (b) Construction requirements for composite packagings with...

  19. 49 CFR 178.523 - Standards for composite packagings with inner glass, porcelain, or stoneware receptacles.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... high-density polyethylene from some other comparable plastic material. The removable lid required for... expanded plastic packaging; and (11) 6PH2 for glass, porcelain, or stoneware receptacles within a protective solid plastic packaging. (b) Construction requirements for composite packagings with...

  20. 49 CFR 178.523 - Standards for composite packagings with inner glass, porcelain, or stoneware receptacles.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Standards for composite packagings with inner glass, porcelain, or stoneware receptacles. 178.523 Section 178.523 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS...

  1. Principal Component Analysis of Chinese Porcelains from the Five Dynasties to the Qing Dynasty

    NASA Astrophysics Data System (ADS)

    Yap, C. T.; Hua, Younan

    1992-10-01

    This is a study of the possibility of identifying antique Chinese porcelains according to the period or dynasty, using major and minor chemical components (SiO2 , Al2O3 , Fe2O3 , K2O, Na2O, CaO and MgO) from the body of the porcelain. Principal component analysis is applied to published data on 66 pieces of Chinese procelains made in Jingdezhen during the Five Dynasties and the Song, Yuan, Ming and Qing Dynasties. It is shown that porcelains made during the Five Dynasties and the Yuan (or Ming) and Qing Dynasties can be segregated completely without any overlap. However, there is appreciable overlap between the Five Dynasties and the Song Dynasty, some overlap between the Song and Ming Dynasties and also between the Yuan and Ming Dynasties. Interestingly, Qing procelains are well separated from all the others. The percentage of silica in the porcelain body decreases and that of alumina increases with recentness with the exception of the Yuan and Ming Dynasties, where this trend is reversed.

  2. Study on the elemental features of ancient Chinese white porcelain at Jingdezhen by INAA

    NASA Astrophysics Data System (ADS)

    Xie, Guoxi; Feng, Songlin; Feng, Xiangqian; Li, Yongqiang; Han, Hongye; Wang, Yanqing; Zhu, Jihao; Yan, Lingtong; Li, Li

    2009-03-01

    Shards of ancient Chinese white porcelain, which were excavated at Maojiawan in the city of Beijing, were analyzed by instrumental neutron activation analysis (INAA). These shards were fired in the period between the Yuan (AD 1271-1368) and Ming (AD 1368-1644) dynasties at Jingdezhen in southern China. According to the analytical results, different raw materials were used for making porcelain body in this period. Fe and Na are the characteristic elements which can be used for identifying the specific date of these porcelains. Furthermore, shards of Hongwu era (AD 1368-1398), Yongle-Xuande era (AD 1403-1435) and Chenghua-Zhengde era (AD 1465-1561) of the Ming dynasty can be clearly distinguished by their elemental body composition. The temporal chemical variation in the porcelain body of these eras is observed. The elemental body composition of Zhengde-Tianshun era (AD 1436-1464) is mainly similar to that of the Hongwu and Yongle-Xuande eras. The temporal chemical feature of Zhengtong-Tianshun era was not found.

  3. The Earliest Chinese Proto-Porcelain Excavated from Kiln Sites: An Elemental Analysis

    PubMed Central

    Li, Yu; Zhang, Bin; Cheng, Huansheng; Zheng, Jianming

    2015-01-01

    In June 2012, the Piaoshan kiln site was excavated in Huzhou, Zhejiang Province, which hitherto proved to be the earliest known Chinese proto-porcelain kiln. Judging from the decorative patterns of unearthed impressed stoneware and proto-porcelain sherds, the site was determined to date to the late Xia (c. 2070–c. 1600 BC), the first dynasty of China. Here, we report on proton-induced X-ray emission analyses of 118 proto-porcelain and 35 impressed stoneware sherds from Piaoshan and five subsequent kiln sites in the vicinity. Using principal components analysis on the major chemical compositions, we reveal the relationships between impressed stoneware and proto-porcelain samples from the six kiln sites. The sherds from different sites have distinctive chemical profiles. The results indicate that the raw materials were procured locally. We find a developmental tendency for early glazes towards mature calcium-based glaze. It is most likely that woody plant ashes with increased calcia-potash ratios were applied to the formula. PMID:26535583

  4. Study of Glazes and Their Effects on Properties of Triaxial Electrical Porcelains from Ugandan Minerals

    NASA Astrophysics Data System (ADS)

    Olupot, Peter W.; Jonsson, Stefan; Byaruhanga, Joseph K.

    2010-11-01

    Kaolin, ball clay, feldspar, and sand were collected from deposits in Uganda, milled and sieved to particle sizes of 45, 45, 53, and 25 μm, respectively. Three porcelain bodies and five glazes were formulated from them. The glazes were applied on porcelain specimens and subsequently evaluated for their effects on properties of porcelain samples. The formulated specimens were investigated using dilatometry, Steger test, FEG-SEM, XRD, 4-point bending, dielectric strength, and fracture toughness tests. A porcelain specimen consisting of 68% SiO2, 19% Al2O3, 4.7% K2O, and a glaze RO:0.57Al2O3:4.86SiO2 exhibited MOR of 105 MPa with Weibull modulus of 5.6 and a dielectric strength of 18 kV/mm upon firing at a heating rate of 6 °C/min to 1250 °C and holding for 2 h. The microstructure of the high-strength specimen exhibited round mullite needles, quartz, and glass. Holding samples for 2 h at peak temperature resulted in a 22% increase in MOR compared to 1 h holding. Glazing further improved strength by 67% for the best sample. Compressive stresses in glaze contributed to the strengthening effect. The dielectric and mechanical strength values obtained qualify the formulated sample for application in electrical insulation.

  5. The Earliest Chinese Proto-Porcelain Excavated from Kiln Sites: An Elemental Analysis.

    PubMed

    Li, Yu; Zhang, Bin; Cheng, Huansheng; Zheng, Jianming

    2015-01-01

    In June 2012, the Piaoshan kiln site was excavated in Huzhou, Zhejiang Province, which hitherto proved to be the earliest known Chinese proto-porcelain kiln. Judging from the decorative patterns of unearthed impressed stoneware and proto-porcelain sherds, the site was determined to date to the late Xia (c. 2070-c. 1600 BC), the first dynasty of China. Here, we report on proton-induced X-ray emission analyses of 118 proto-porcelain and 35 impressed stoneware sherds from Piaoshan and five subsequent kiln sites in the vicinity. Using principal components analysis on the major chemical compositions, we reveal the relationships between impressed stoneware and proto-porcelain samples from the six kiln sites. The sherds from different sites have distinctive chemical profiles. The results indicate that the raw materials were procured locally. We find a developmental tendency for early glazes towards mature calcium-based glaze. It is most likely that woody plant ashes with increased calcia-potash ratios were applied to the formula. PMID:26535583

  6. The effect of repeated porcelain firings on corrosion resistance of different dental alloys

    PubMed Central

    Karahan, Ismail; Polat, Serdar; Malkoc, Meral Arslan; Dalkiz, Mehmet

    2013-01-01

    PURPOSE The aim of this study was to evaluate the effects of repeated porcelain firing process on the corrosion rates of the dental alloys. MATERIALS AND METHODS Cr-Co, Cr-Ni and Pd-Ag alloys were used for this study. Each metal supported porcelain consisted of 30 specimens of 10 for 7, 9 and 11 firing each. Disc-shaped specimens 10 mm diameter and 3 mm thickness were formed by melting alloys with a propane-oxygen flame and casted with a centrifuge casting machine and then with the porcelain veneer fired onto the metal alloys. Corrosion tests were performed in quintuplicate for each alloy (after repeated porcelain firing) in Fusayama artificial saliva solution (pH = 5) in a low thermal-expansion borosilicate glass cell. Tamhane and Sheffe test was used to compare corrosion differences in the results after repeated firings and among 7, 9 and 11 firing for each alloy. The probability level for statistical significance was set at α=0.05. RESULTS The corrosion resistance was higher (30 mV), in case of 7 times firing (Commercial). On the other hand, it was lower in case of 11 times firing (5 mV) (P<.05). CONCLUSION Repeated firings decreased corrosion resistance of Pd-Ag, Cr-Co and Cr-Ni alloys. The Pd-Ag alloy exhibited little corrosion in in vitro tests. The Cr-Ni alloy exhibited higher corrosion resistance than Cr-Co alloys in in vitro tests. PMID:23507983

  7. Development of conical silicone rubber bushings to replace porcelain on SF{sub 6} circuit breakers

    SciTech Connect

    Freeman, W.B.; Orbeck, T.; Moal, E.

    1994-12-31

    A unique design of a composite polymer bushing is introduced and evaluated. A comprehensive test program defined the mechanical and electrical performance of a conical silicone polymer composite bushing. This evaluation also included aging and pollution tests to assess the long-term stability of the new design. Results show that the composite bushing offers technical and safety benefits over conventional porcelain bushings.

  8. AC Clean Fog tests on non-ceramic insulating materials and a comparison with porcelain

    SciTech Connect

    De La O, A.; Gorur, R.S.; Chang, J. . Dept. of Electrical Engineering)

    1994-10-01

    AC Clean Fog tests were performed on non-ceramic materials used for outdoor high voltage insulators, namely, Room and High Temperature Vulcanizing (RTV and HTV) silicone rubber, and ethylene propylene rubber (EPR), with porcelain used as the reference. The steam input rate was varied upwards from the value standardized for porcelain insulators. Results indicate that higher steam input rates produce a significant reduction in the flashover voltage of silicone rubber family materials, although it is always higher than that obtained for EPR and porcelain. For EPR, the reduction is less and is similar to that established for porcelain. The mechanisms involved have been examined. The trend in the results is found to be consistent for different formulations and insulator geometries of the generic polymer (e.g. silicone rubber, EPR) evaluated. A new, simple method for consistently applying uniform contamination on silicone rubber (both RTV and HTV) is described, without the use of extensive physical or chemical treatments, or prior conditioning by dry band arcing.

  9. Influence of tile-drainage on groundwater flow and nitrate transport in heterogeneous geological materials

    NASA Astrophysics Data System (ADS)

    De Schepper, G.; Therrien, R.; Refsgaard, J.

    2012-12-01

    Subsurface drainage is a common agricultural practice in poorly drained production fields to guarantee the productivity of crops and to reduce flooding risks. The impact of shallow tile-drainage networks on groundwater flow patterns and associated nitrate transport from the surface needs to be quantified for adequate agricultural management. A challenge is to represent tile-drain networks in numerical models, at the field scale, while accounting for the influence of subsurface heterogeneities on flow and transport. A numerical model of a tile-drainage system has been developed with the fully integrated HydroGeoSphere model for the Lillebaek agricultural catchment, Denmark. The Lillebaek catchment is an experimental study area where hydraulic heads, stream and drain discharges, as well as groundwater and surface water nitrate concentrations are regularly measured. This catchment includes various tile-drainage networks that are monitored on a daily basis; the one we have been focusing on is about 5 ha within a 34 ha model domain. The Lillebaek catchment subsurface is made of about 30 m thick Quaternary deposits which consist of a local sandy aquifer with upper and lower clayey till units, confining the aquifer in the upper part. The main modelling objective is to assess the influence of tile drains on the water flow pattern within the confining clayey till unit with and on the nitrate reduction zone depth, also known as the redox-interface, while accounting for local geological heterogeneities. Using the national-scale geological model for Denmark combined with available local data, a hydrogeological model at field scale has been generated. A proper representation of the tile-drains geometry is essential to calibrate and validate the water flow model associated with nitrate transport. HydroGeoSphere can represent drains directly into a model as one-dimensional features, which however requires a very fine mesh discretization that limits the size of the simulation

  10. Introduction to building projection-based tiled display systems.

    SciTech Connect

    Hereld, M.; Judson, I. R.; Stevens, R.; Mathematics and Computer Science; Univ. of Chicago

    2000-07-01

    This tutorial introduces the concepts and technologies needed to build projector-based display systems. Tiled displays offer scalability, high resolution, and large formats for various applications. Tiled displays are an emerging technology for constructing semi-immersive visualization environments capable of presenting high-resolution images from scientific simulation. The largest impact may well arise from using large-format tiled displays as one of possibly multiple displays in building information or active spaces that surround the user with diverse ways of interacting with data and multimedia information flows. These environments may prove the ultimate successor to the desktop metaphor for information technology work. Several fundamental technological problems must be addressed to make tiled displays practical. These include: the choice of screen materials and support structures; choice of projectors, projector supports, and optional fine positioners; techniques for integrating image tiles into a seamless whole; interface devices for interaction with applications; display generators and interfaces; and the display software environment.

  11. Surface treatment of dental porcelain: CO2 laser as an alternative to oven glaze.

    PubMed

    Sgura, Ricardo; Reis, Mariana Cavalcante; Hernandes, Antonio Carlos; de Abreu Fantini, Márcia Carvalho; Andreeta, Marcello Rubens Barsi; Medeiros, Igor Studart

    2015-02-01

    This work tested continuous CO2 laser as a surface treatment to dental porcelain and compared it to oven glaze (auto-glaze) by means of roughness and color parameters. Three commercial veneering porcelains with different crystalline content were tested: VM7, VM9, and VM13. Porcelain discs (3.5 × 2.0 mm, diameter × height) were sintered and had one side ground by a diamond bur (45 μm) simulating a chairside adjustment in a clinical office. Specimens (n = 7) were divided into the following groups: C--control (no treatment), G--auto-glaze (oven), and L--surface continuous irradiation with CO2 laser (Gem Laser, Coherent; λ = 10.6 μm). Laser was tested in three exposure times (3, 4, or 5 min) and two irradiances (45 and 50 W/cm(2)). Roughness parameters (Ra, Rz, and Rpm/Rz) were measured using a rugosimeter (Surftest 301, Mitutoyo). Color differences (ΔE) between the G and L groups were calculated (VITA Easyshade); ΔE values up to 3.3 were considered as not perceivable. A surface analysis was conducted by stereomicroscopy (Olympus SZ61) and SEM (Stereoscan 440, LEO). Crystalline content of specimens from groups C and L (50 W/cm(2), 5 min) was assessed by X-ray diffraction and then compared. Surface roughness (Ra and Rz) observed for laser-irradiated groups was similar to G for all studied porcelains. Rpm/Rz ratios were near 1.0 for all groups that indicated a sharp ridge profile for all specimens. Only one laser condition studied (50 W/cm(2), 3 min) from VM7 porcelain resulted in color difference (ΔE = 3.5) to G. Specimens irradiated with 50 W/cm(2) for 5 min presented the smoother surface observed by SEM, comparable to G. X-ray diffraction data revealed an increase in leucite crystallite size for VM9 and VM13 porcelains after laser treatment. Regarding roughness, continuous CO2 laser applied on porcelain surface was as effective as conventional oven auto-glaze. PMID:23881534

  12. Removal of nutrient and pesticides from tile drainage discharge using an end-of-tile cartridge approach

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nutrient transport from subsurface tile drainage is pretty well documented. One approach receiving consideration for reducing the amount of nutrients and pesticides in subsurface drainage waters is end-of-tile filters. The filters are often comprised of industrial wastes or by-products that have a s...

  13. Effect of metal conditioner on bonding of porcelain to cobalt-chromium alloy

    PubMed Central

    Kajihara, Yutaro; Takenouchi, Yoshihisa; Tanaka, Takuo; Suzuki, Shiro; Minami, Hiroyuki

    2016-01-01

    PURPOSE The purpose of this study was to evaluate the efficacy of two different metal conditioners for non-precious metal alloys for the bonding of porcelain to a cobalt-chromium (Co-Cr) alloy. MATERIALS AND METHODS Disk-shaped specimens (2.5×10.0 mm) were cast with Co-Cr alloy and used as adherend materials. The bonding surfaces were polished with a 600-grid silicon carbide paper and airborne-particle abraded using 110 µm alumina particles. Bonding specimens were fabricated by applying and firing either of the metal conditioners on the airborne-particle abraded surface, followed by firing porcelain into 5 mm in diameter and 3 mm in height. Specimens without metal conditioner were also fabricated. Shear bond strength for each group (n=8) were measured and compared (α=.05). Sectional view of bonding interface was observed by SEM. EDS analysis was performed to determine the chemical elements of metal conditioners and to determine the failure modes after shear test. RESULTS There were significant differences among three groups, and two metal conditioner-applied groups showed significantly higher values compared to the non-metal conditioner group. The SEM observation of the sectional view at bonding interface revealed loose contact at porcelain-alloy surface for non-metal conditioner group, however, close contact at both alloy-metal conditioner and metal conditioner-porcelain interfaces for both metal conditioner-applied groups. All the specimens showed mixed failures. EDS analysis showed that one metal conditioner was Si-based material, and another was Ti-based material. Si-based metal conditioner showed higher bond strengths compared to the Ti-based metal conditioner, but exhibited more porous failure surface failure. CONCLUSION Based on the results of this study, it can be stated that the application of metal conditioner is recommended for the bonding of porcelain to cobalt-chromium alloys. PMID:26949481

  14. Clinical performance of novel-design porcelain veneers for the recovery of coronal volume and length.

    PubMed

    Magne, P; Perroud, R; Hodges, J S; Belser, U C

    2000-10-01

    The present study evaluated the clinical performance of bonded porcelain veneers (PV) restoring substantial coronal volume and length in the anterior dentition. Forty-eight PVs were placed in 16 patients, with systematic coverage and reconstitution of the incisal edge, including well-defined anterior guidance. A standardized protocol comprising diagnostic steps that integrate additive waxups and acrylic mockups was used. PVs were fabricated using feldspathic and low-fusing porcelains in a refractory die technique. Incisal overlaps featured freestanding porcelain spans ranging from 1.5 to 5.5 mm. After a mean clinical service of 4.5 years, 13 clinical parameters for each tooth and 4 parameters that applied to persons were recorded. Permutation tests evaluated the effects of margin location, incisal edge span of porcelain, overbite, opposing contact location, and restoration age on ceramic failure and clinical marginal adaptation and seal. At recall, 100% of the veneers were satisfactory with minor interventions. The effect of slight marginal defects and porcelain cracking was negligible. Biologic, periodontal, and esthetic parameters showed excellent results, which were supported by 100% patient-reported satisfaction. All patients felt comfortable with the newly defined anterior guidance. Aging was negligible, and there were no significant effects of margin location (P > 0.08), incisal edge span of the ceramic, or overbite (P > 0.22) on ceramic failure and marginal performance. Minor alterations of the palatal margin, however, tended to be more frequent compared to facial locations, and were found especially when the opposing tooth contact in centric occlusion was located on the palatal margin (P = 0.028). Bonded ceramic restorations represent a reliable, effective procedure to restore extensive coronal volume and length in the anterior dentition. PMID:11203582

  15. Tile-in-ONE: A web platform which integrates Tile Calorimeter data quality and calibration assessment

    NASA Astrophysics Data System (ADS)

    Sivolella, A.; Ferreira, F.; Maidantchik, C.; Solans, C.; Solodkov, A.; Burghgrave, B.; Smirnov, Y.

    2015-12-01

    The ATLAS Tile Calorimeter collaboration assesses the quality of calibration data in order to ensure its proper operation. A number of tasks is then performed by executing several tools and accessing web systems, which were independently developed to meet distinct collaboration's requirements and do not necessarily are connected with each other. Thus, to attend the collaboration needs, several programs are usually implemented without a global perspective of the detector, requiring basic software features. In addition, functionalities may overlap in their objectives and frequently replicate resources retrieval mechanisms. Tile-in-ONE is a designed and implemented platform that assembles various web systems used by the calorimeter community through a single framework and a standard technology. It provides an infrastructure to support the code implementation, avoiding duplication of work while integrating with an overall view of the detector status. Database connectors smooth the process of information access since developers do not need to be aware of where records are placed and how to extract them. Within the environment, a dashboard stands for a particular Tile operation aspect and gets together plug-ins, i.e. software components that add specific features to an existing application. A server contains the platform core, which represents the basic environment to deal with the configuration, manage user settings and load plug-ins at runtime. A web middleware assists users to develop their own plug-ins, perform tests and integrate them into the platform as a whole. Backends are employed to allow that any type of application is interpreted and displayed in a uniform way. This paper describes Tile-in-ONE web platform.

  16. Floor tile and mastic removal project report

    SciTech Connect

    Not Available

    1992-11-01

    A test program was developed and coordinated with State and Federal Regulators and carried out at Fort Sill, Oklahoma. This program was carefully designed to create the worst conditions in order to evaluate whether asbestos fibers are released when asbestos containing floor tile and mastic are removed. There were over 1,000 samples taken and analyzed during the execution of the program. The conclusions reached were based upon analysis of the critical samples using the Transmission Electron Microscope (TEM) technology. Additionally, the TEM procedures were used to evaluate personnel samples to determine whether those fibers found were asbestos or other materials. Most of the (TEM) samples were analyzed by the US Environmental Protection Agency (EPA) Risk Reduction Engineering Laboratory in Cincinnati, Ohio.

  17. Tile-Compressed FITS Kernel for IRAF

    NASA Astrophysics Data System (ADS)

    Seaman, R.

    2011-07-01

    The Flexible Image Transport System (FITS) is a ubiquitously supported standard of the astronomical community. Similarly, the Image Reduction and Analysis Facility (IRAF), developed by the National Optical Astronomy Observatory, is a widely used astronomical data reduction package. IRAF supplies compatibility with FITS format data through numerous tools and interfaces. The most integrated of these is IRAF's FITS image kernel that provides access to FITS from any IRAF task that uses the basic IMIO interface. The original FITS kernel is a complex interface of purpose-built procedures that presents growing maintenance issues and lacks recent FITS innovations. A new FITS kernel is being developed at NOAO that is layered on the CFITSIO library from the NASA Goddard Space Flight Center. The simplified interface will minimize maintenance headaches as well as add important new features such as support for the FITS tile-compressed (fpack) format.

  18. Local growth of icosahedral quasicrystalline tilings

    NASA Astrophysics Data System (ADS)

    Hann, Connor T.; Socolar, Joshua E. S.; Steinhardt, Paul J.

    2016-07-01

    Icosahedral quasicrystals (IQCs) with extremely high degrees of translational order have been produced in the laboratory and found in naturally occurring minerals, yet questions remain about how IQCs form. In particular, the fundamental question of how locally determined additions to a growing cluster can lead to the intricate long-range correlations in IQCs remains open. In answer to this question, we have developed an algorithm that is capable of producing a perfectly ordered IQC yet relies exclusively on local rules for sequential, face-to-face addition of tiles to a cluster. When the algorithm is seeded with a special type of cluster containing a defect, we find that growth is forced to infinity with high probability and that the resultant IQC has a vanishing density of defects. The geometric features underlying this algorithm can inform analyses of experimental systems and numerical models that generate highly ordered quasicrystals.

  19. Nucleosome positioning from tiling microarray data

    PubMed Central

    Yassour, Moran; Kaplan, Tommy; Jaimovich, Ariel; Friedman, Nir

    2008-01-01

    Motivation: The packaging of DNA around nucleosomes in eukaryotic cells plays a crucial role in regulation of gene expression, and other DNA-related processes. To better understand the regulatory role of nucleosomes, it is important to pinpoint their position in a high (5–10 bp) resolution. Toward this end, several recent works used dense tiling arrays to map nucleosomes in a high-throughput manner. These data were then parsed and hand-curated, and the positions of nucleosomes were assessed. Results: In this manuscript, we present a fully automated algorithm to analyze such data and predict the exact location of nucleosomes. We introduce a method, based on a probabilistic graphical model, to increase the resolution of our predictions even beyond that of the microarray used. We show how to build such a model and how to compile it into a simple Hidden Markov Model, allowing for a fast and accurate inference of nucleosome positions. We applied our model to nucleosomal data from mid-log yeast cells reported by Yuan et al. and compared our predictions to those of the original paper; to a more recent method that uses five times denser tiling arrays as explained by Lee et al.; and to a curated set of literature-based nucleosome positions. Our results suggest that by applying our algorithm to the same data used by Yuan et al. our fully automated model traced 13% more nucleosomes, and increased the overall accuracy by about 20%. We believe that such an improvement opens the way for a better understanding of the regulatory mechanisms controlling gene expression, and how they are encoded in the DNA. Contact: nir@cs.huji.ac.il PMID:18586706

  20. Spectral response data for development of cool coloured tile coverings

    NASA Astrophysics Data System (ADS)

    Libbra, Antonio; Tarozzi, Luca; Muscio, Alberto; Corticelli, Mauro A.

    2011-03-01

    Most ancient or traditional buildings in Italy show steep-slope roofs covered by red clay tiles. As the rooms immediately below the roof are often inhabited in historical or densely urbanized centres, the combination of low solar reflectance of tile coverings and low thermal inertia of either wooden roof structures or sub-tile insulation panels makes summer overheating a major problem. The problem can be mitigated by using tiles coated with cool colours, that is colours with the same spectral response of clay tiles in the visible, but highly reflecting in the near infrared range, which includes more than half of solar radiation. Cool colours can yield the same visible aspect of common building surfaces, but higher solar reflectance. Studies aimed at developing cool colour tile coverings for traditional Italian buildings have been started. A few coating solutions with the typical red terracotta colour have been produced and tested in the laboratory, using easily available materials. The spectral response and the solar reflectance have been measured and compared with that of standard tiles.

  1. [Bond strength of etched enamel to direct composite resins, to indirect composite resins and to etched and silanized porcelain].

    PubMed

    Prévost, A P; Desautels, P

    1990-07-01

    The adhesion to enamel of composite resin inlays are not documented as much as porcelain inlays and direct composite resins. This study evaluates the adhesion of a light cured composite resin (P-50) used in an indirect technique and secondarily polymerized by heat. No significant differences were found between adhesion of P-50 used with an indirect technique and adhesion of porcelain (Mirage). P-50 used with the direct technique yield adhesion values significantly lower than the indirect techniques. PMID:2204471

  2. Tiling and demand-driven evaluation for picture processing

    NASA Astrophysics Data System (ADS)

    Horain, Patrick J.; Dogaru, Victor

    1995-08-01

    We propose a software architecture for picture processing that allows efficient memory management when algorithms with many operators are applied to large images, and that allows automated parallelization. This architecture relies on image tiling and operators with a call back function that evaluates image tiles on demand. Several tiling strategies with and without overlapping are discussed. The compexity of this evaluation strategy is hidden to application programs. This is shown with a sample program. This architecture is well suited for neighborhood operators such as convolutions and mathematical morphology operators.

  3. ATLAS Tile Calorimeter: simulation and validation of the response

    NASA Astrophysics Data System (ADS)

    Faltova, Jana; ATLAS Collaboration

    2015-02-01

    The Tile Calorimeter (TileCal) is the central section of the ATLAS hadronic calorimeter at the Large Hadron Collider. Scintillation light produced in the tiles is readout by wavelength shifting fibers and transmitted to photomultiplier tubes (PMTs). The resulting electronic signals from approximately 10000 PMTs are measured and digitized before being further transferred to off-detector data-acquisition systems. Detailed simulations are described in this contribution, ranging from the implementation of the geometrical elements to the realistic description of the electronics readout pulses, including specific noise treatment and the signal reconstruction. Special attention is given to the improved optical signal propagation and the validation with the real particle data.

  4. Effect of Oxidation and SiO2 Coating on the Bonding Strength of Ti-Porcelain

    NASA Astrophysics Data System (ADS)

    Guo, Litong; Liu, Xiaochen; Zhu, Yabo; Xu, Cheng; Gao, Jiqiang; Guo, Tianwen

    2010-11-01

    Investigations on the effect of oxidation on titanium-ceramic adhesion were performed. Cast pure titanium was subjected to surface modification by preoxidation and introduction of an intermediate layer of SiO2 by sol-gel process. Specimens were characterized by TG-DSC, XRD, and SEM/EDS. The adhesion between the titanium and porcelain was evaluated by three-point flexure bond test. Failure of the titanium-porcelain with preoxidation treatment predominantly occurred at the titanium-oxide interface. Preoxidation treatment did not affect the fracture mode of the titanium-ceramic system and did not increase the bonding strength of Ti-porcelain. The SEM results revealed the existence of microcracks on the SiO2 coating surface oxidized at 800 °C in an air furnace. During the porcelain fusion, minute amounts of oxygen were able to penetrate the cracks and caused localized oxidation of the Ti-substrate. Failure of the titanium-porcelain with SiO2 coating predominantly occurred at the SiO2 layer. The SiO2 coating served as an effective oxygen diffusion barrier and improved the mechanical and chemical bonding between porcelain and titanium.

  5. Hardening by cooling rate control and post-firing heat treatment in Pd-Ag-Sn alloy for bonding porcelain.

    PubMed

    Yu, Young-Jun; Seol, Hyo-Joung; Cho, Mi-Hyang; Kim, Hyung-Il; Kwon, Yong Hoon

    2016-01-01

    The aim of this study was to determine the hardening effect by controlling the cooling rate during the porcelain firing process and performing an additional post-firing heat treatment in a Pd-Ag-Sn alloy. The most effective cooling rate for alloy hardening was determined by cooling the specimens at various cooling rates after oxidation treatment. A subsequent porcelain firing simulation followed by cooling at the selected cooling rate was performed. A post-firing heat treatment was then done at 600°C in a porcelain furnace. The hardening mechanism was characterized by a hardness test, X-ray diffraction, field emission scanning electron microscopy and energy dispersive X-ray spectroscopy. Alloy softening occurred during the porcelain firing process followed by cooling at a controlled cooling rate. A post-firing heat treatment allowed apparent precipitation hardening. It is advisable to perform a postfiring heat treatment at 600°C in a porcelain furnace by annealing metal substructure after porcelain fusing. PMID:27041022

  6. Microshear bond strength of composite resins to enamel and porcelain substrates utilizing unfilled versus filled resins

    PubMed Central

    Najafi-Abrandabadi, Ahmad; Najafi-Abrandabadi, Siamak; Ghasemi, Amir; Kotick, Philip G.

    2014-01-01

    Background: Failures such as marginal discoloration and composite chipping are still the problems of tooth-colored restorations on the substrate of enamel and porcelain, which some of these problems are consequently as a result of failures in the bonding layer. Using filled resin has been recently introduced to increase the bond strength of this layer. The aim of this study was to compare the microshear bond strength (μ-SBS) of composite resins to enamel incubated in periods of 24 h and 9 months and porcelain with unfilled resin and flowable composites (filled resin). Materials and Methods: In this in vitro study, two groups of 75 enamel samples with different storage times (24 h and 9 months) and a group of 75 porcelain samples were used. They were divided into 5 experimental groups of 15 samples in each. Composite cylinders in tygon tubes were bonded on the surface of acid-etched enamel and pretreated porcelain. Wave, Wave MV, Wave HV, Grandioflow and Margin Bond were used as bonding agents. The μ-SBS was measured at the speed of 1.0 mm/min. The bond strengths were analyzed with one-way analysis of variance (ANOVA) test followed by Tukey test. P < 0.05 was selected as the level of statistical significance in this study. Results: The results showed that for enamel (24 h), the μ-SBS of the Wave MV and Wave HV groups were significantly lower than the Margin Bond group. Tukey test indicated the absence of a significant difference between the μ-SBS of the Wave group and the Margin Bond group. However, the μ-SBS of the Grandioflow group was significantly higher than the one for the Margin Bond as a bonding agent. In enamel (9 months), there was a significant difference between the Grandioflow and Margin Bond groups. Regarding bonding to the porcelain the one-way ANOVA test did not show a significant difference among the groups. Conclusion: This study revealed that flowable composites (filled resins) can be used instead of unfilled resins in bonding composite

  7. Diatoms as an indicator for tile drainage flow in a German lowland catchment

    NASA Astrophysics Data System (ADS)

    Wu, Naicheng; Faber, Claas; Ulrich, Uta; Schmalz, Britta; Fohrer, Nicola

    2014-05-01

    The separation of flow components within a model simulation is of great importance for a successful implementation of management measures. Tracers are commonly used to identify and assess runoff-generating processes and to detect sources of stream flow components within a target catchment. Diatoms could be an ideal tracer due to their diverse preferences to different aquatic habitats (van Dam et al. 1994, Pfister et al. 2009). As a part of a DFG (Deutsche Forschungsgemeinschaft) project, we collected diatom samples of 9 sites (4 tile drainage, and 5 river sites) weekly or biweekly from March to July 2013 in a German lowland catchment (the Kielstau catchment). First results showed that diatom species Achnanthes lanceolata, Fragilaria biceps and Navicula ingapirca dominated in tile drainage flow with relative abundances of 22.2%, 21.5% and 10.9%, respectively. For river sites, the most abundant species was Navicula cryptocephala (20.5%), followed by Fragilaria biceps (12.9%), Cyclotella meneghiniana (9.5%) and Achnanthes lanceolata (9.3%). Compared with river sites, tile drainage flow had lower diatom density, biomass, species richness and percentage of Aquatic/Riparian diatoms (AqRi%). However, the proportion of Riparian diatoms (RiZo%) increased at tile drainage flow. Indicator value method (IndVal) revealed that the two water types were characterized by different indicator species. Fifteen taxa (e.g. Cocconeis placentula, Cyclotella meneghiniana, Navicula cryptocephala and Fragilaria biceps) were significant indicators for river sites. Achnanthes lanceolata, Achnanthes minutissima and Navicula ingapirca were significant indicators for tile drainage flow. These results highlight the suitability of diatoms as an indicator for tile drainage flow. Spatial and temporal variations of diatom community should be considered in future surveys. Keywords: Diatoms, Flow components, Indicator value method, Tracer References: Pfister, L., J. J. McDonnell, S. Wrede, D. Hl

  8. Tools Developed to Prepare and Stabilize Reactor Spent Fuel for Retrieval from Tile Holes - 12251

    SciTech Connect

    Horne, Michael; Clough, Malcolm

    2012-07-01

    Spent fuel from the Chalk River Laboratories (CRL) nuclear reactors is stored in the waste management areas on site. This fuel is contained within carbon steel spent fuel cans that are stored inside vertical carbon steel lined concrete pipes in the ground known as tile holes. The fuel cans have been stored in the tile holes for greater than 30 years. Some of the fuel cans have experienced corrosion which may have affected their structural integrity as well as the potential to form hydrogen gas. In addition to these potential hazards, there was a need to clean contaminated surfaces inside of and around the exposed upper surface of the tile holes. As part of the site waste management remediation plan spent fuel will be retrieved from degraded tile holes, dried, and relocated to a new purpose built above ground storage facility. There have been a number of tools that are required to be developed to ensure spent fuel cans are in a safe condition prior to retrieval and re-location. A series of special purpose tools have been designed and constructed to stabilize the contents of the tile holes, to determine the integrity of the fuel containers and to decontaminate inside and around the tile holes. Described herein are the methods and types of tools used. Tools that have been presented here have been used, or will be used in the near future, in the waste management areas of the CRL Site in preparation for storage of spent fuel in a new above ground facility. The stabilization tools have been demonstrated on mock-up facilities prior to successful use in the field to remove hydrogen gas and uranium hydrides from the fuel cans. A lifting tool has been developed and used successfully in the field to confirm the integrity of the fuel cans for future relocation. A tool using a commercial dry ice blaster has been developed and is ready to start mock-up trials and is scheduled to be used in the field during the summer of 2012. (authors)

  9. 25. CAFETERIA Note remains of tile floor in foreground. Food ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    25. CAFETERIA Note remains of tile floor in foreground. Food cooked on the stove was served to workers in the eating area to the left of the counter (off picture). - Hovden Cannery, 886 Cannery Row, Monterey, Monterey County, CA

  10. Using Homemade Algebra Tiles To Develop Algebra and Prealgebra Concepts.

    ERIC Educational Resources Information Center

    Leitze, Annette Ricks; Kitt, Nancy A.

    2000-01-01

    Describes how to use homemade tiles, sketches, and the box method to reach a broader group of students for successful algebra learning. Provides a list of concepts appropriate for such an approach. (KHR)

  11. 44. Everett Weinreb, photographer DETAIL, CEMENT TILE PATTERN, FROM LOGGIA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    44. Everett Weinreb, photographer DETAIL, CEMENT TILE PATTERN, FROM LOGGIA LOOKING EAST ACROSS RECEPTION HALL - Los Angeles Union Passenger Terminal, Tracks & Shed, 800 North Alameda Street, Los Angeles, Los Angeles County, CA

  12. 45. Everett, Weinreb, photographer DETAIL, CEMENT TILE PATTERN FROM RECEPTION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    45. Everett, Weinreb, photographer DETAIL, CEMENT TILE PATTERN FROM RECEPTION HALL LOOKING EAST ACROSS ARRIVAL LOBBY FLOOR - Los Angeles Union Passenger Terminal, Tracks & Shed, 800 North Alameda Street, Los Angeles, Los Angeles County, CA

  13. VIEW OF COMPASS ROSE TILE INLAY IN FLOOR OF LOBBY, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF COMPASS ROSE TILE INLAY IN FLOOR OF LOBBY, BUILDING 1, LOOKING SOUTHEAST - Roosevelt Base, Administration & Brig Building, Bounded by Nevada & Colorado Streets, Reeves & Richardson Avenues, Long Beach, Los Angeles County, CA

  14. 12. FIREPLACE: TILES AND CARVED WOOD PANEL. IN THE LATTER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. FIREPLACE: TILES AND CARVED WOOD PANEL. IN THE LATTER READS THE WORDS OF THE MORRIS FAMILY'S HOMES: CEDAR GROVE, A.D. 1774 AND COMPTON, A.D. 1887. - Compton, Meadowbrook Avenue, Philadelphia, Philadelphia County, PA

  15. Self-glazing ceramic tiles based on acidic igneous glasses

    SciTech Connect

    Merkin, A.P.; Nanazashvili, V.I.

    1988-07-01

    A technology was derived to produce self-glazing ceramic tiles based on single-component systems of acidic igneous (volcanic) glasses. A weakly alkaline solution of NaOH or KOH was used as the sealing water to activate the sintering process. Tests conducted on the self-glazing ceramic tiles showed that their water absorption amounts to 2.5-8%, linear shrinkage is 3.2-7%, and frost resistance amounts to 35-70 cycles. The application of acidic igneous glasses as the main raw material for the production of ceramic facing tiles made it possible to widen the raw material base and simplify the technology for fabricating ceramic facing tiles at lower cost. The use of waste products when processing perlite-bearing rocks, when carrying out mining and cutting of tuffs, slags, and tuff breccia for recovering cut materials was recommended.

  16. Detail of first floor of loading dock showing composition tile ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of first floor of loading dock showing composition tile over wood floor/basement ceiling - Southern Pacific Railroad Depot, Railroad Terminal Post Office & Express Building, Fifth & I Streets, Sacramento, Sacramento County, CA

  17. Interference Heating to Cavities Between Simulated RSI Tiles

    NASA Technical Reports Server (NTRS)

    Johnson, C. B.

    1973-01-01

    Test results for full scale simulated surface insulation tiles on both the tunnel wall and in the free stream, for in-line and staggered tile orientations, are summarized as follows: (1) The staggered tile orientation has heating on the forward face which is a factor of 4.5 times higher than the heating to the forward face of the in-line tile orientation; (2) the longitudinal gap heating was the highest for the 0.3175 cm gap and the lowest for the 0.1587 cm gap; and (3) there was an order of magnitude decrease in the heating on the forward face of a spanwise gap when the gap size was decreased from 0.3175 cm to 0.1587 cm.

  18. Indirect porcelain veneers in periodontally compromised teeth. The hybrid technique: a case report.

    PubMed

    Garcia-Baeza, David; Saavedra, Carlos; Garcia-Adámez, Ramón

    2015-01-01

    The loss of periodontal structure causes an esthetic problem for many patients, especially when the esthetic zone is compromised. Among the various types of solutions is the use of composite resins. While this procedure is not aggressive towards tooth structure, it does require the clinician to have a precise technique, and demands strict longterm maintenance. 1 Another way of treating the compromised teeth is with porcelain veneers. This procedure is especially difficult, however, if carried out on periodontal teeth, as it requires preparation along the roots. 2 The intention of the hybrid technique described in this article is to combine both of these procedures in order to obtain a less aggressive treatment with precise management of the soft tissue and an adequate esthetic outcome. The hybrid technique consists of enlarging the root portion of the teeth with composite resin to obtain a less aggressive tooth preparation, and thereafter placing porcelain veneers. PMID:26171444

  19. Effect of recasting on the oxidation layer of a palladium-silver porcelain alloy

    SciTech Connect

    Hong, J.M.; Razzoog, M.E.; Lang, B.R.

    1988-04-01

    The oxidation zone of a commercial palladium-silver porcelain alloy was compared after repeated casting with and without the addition of new alloy. The intensity of palladium, silver, tin, indium, and O K-alpha near the oxidation zone was analyzed with XMA. The intensity curves of tin, silver, and oxygen increased progressively through each generation despite the addition of new alloy. The thickness of the oxidation zone and the microporosities at the internal oxidation zone increased through each generation without the addition of new alloy. Although the findings indicated that the oxidation zone was favorably formed by adding new alloy, 50% by weight, for four generations, the silver and metallic oxides of the oxidation zone increased through each generation. The reuse of the palladium-silver porcelain alloy remains questionable.

  20. Peculiarities of milling porcelain bodies with an increased content of technological waste products

    SciTech Connect

    Sergeevich, L.P.; Gulai, O.S.

    1986-07-01

    A study of the dependence of the duration of milling on the quantity and the type of the technological waste products introduced into the porcelain body was conducted. Tables show the dependence of the milling fineness of the stony materials on the duration of milling. With an increasing content of waste products of the first firing in the porcelain body compositions, the duration of milling decreases. When using increased amounts of the waste products of the second firing, it was shown that it is necessary to subject the scrap to prior milling in edge-roller mills. Using the milled product scrap of the second firing does not lead to an increase in the duration of milling.

  1. [Technology and provenance of proto-porcelain of Yingguo graveyard in Henna province].

    PubMed

    Zhu, Jian; Wang, Long-zheng; Wang, Li-hua; Ma, Hong-jiao; Wang, Chang-sui

    2010-07-01

    Protoporcelain is a kind of multi-epoch and multi-culture-area ceramic hangover with iterative appearance, and it is the important interim of the development from pottery to porcelain. Therefore, its origin, development and prevalence problems, which relate directly to China development mode and Shang Zhou culture visage, are the important discussion of archaeology, ceramic technic history and chemistry history, and have important learning value. XRF and XRD technique were used to determine several shreds excavated from Yingguo graveyard site in Henan province. The result shows that some samples have abnormity phosphor, hinting that some plant or wood ash was ever used as raw material. From the rate of Ca/Al and P/Al and comparative analysis, we discovered that proto-porcelain of Yingguo site has different chemical character compared to south production. PMID:20828016

  2. ATLAS Tile Calorimeter performance with Run 1 data

    NASA Astrophysics Data System (ADS)

    Cerdá Alberich, L.

    2016-07-01

    The performance of the central hadronic calorimeter, TileCal, in the ATLAS Experiment at the Large Hadron Collider is studied using cosmic-ray muons and the large sample of proton-proton collisions acquired during the Run 1 of LHC (2010-2012). Results are presented for the precision of the absolute energy scale and timing, noise characterization, and time-stability of the detector. The results show that the Tile Calorimeter performance is within the design requirements of the detector.

  3. 56. ORIGINAL MOLDS. THE MORAVIAN POTTERY AND TILE WORKS HAS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    56. ORIGINAL MOLDS. THE MORAVIAN POTTERY AND TILE WORKS HAS APPROXIMATELY 6,000 PLASTER MOLDS OF VARIOUS TYPES, INCLUDING THE DEEP CAVITY MOLDS IN THE CENTER OF THE PHOTOGRAPH. THESE MOLDS PRODUCED ALLEGORICAL FIGURES TO BE INSTALLED AROUND THE CORNICES OF PUBLIC SCHOOLS. - Moravian Pottery & Tile Works, Southwest side of State Route 313 (Swamp Road), Northwest of East Court Street, Doylestown, Bucks County, PA

  4. No inherent glassiness in a Penrose tiling quasicrystal

    SciTech Connect

    Strandburg, K.J.; Dressel, P.R.

    1988-11-01

    Consideration of the structure of the Penrose pattern has led to speculation that a system with a Penrose tiling ground state might be subject to inherent glassy behavior. Monte Carol simulations show, using a simple model of the energetics, that there is no inherent glassiness in the Penrose tiling. Thermodynamic quantities measured are completely reversible, displaying no observable hysterisis, and the system may be easily cooled from a highly disordered configuration into its lowest energy state. 11 refs., 7 figs.

  5. Ceramic tile grout removal & sealing using high power lasers

    SciTech Connect

    Lawrence, J.; Li, L.; Spencer, J.T.

    1996-12-31

    Work has been conducted using a Nd:YAG laser, a CO{sub 2} laser and a high power diode laser (HPDL) in order to determine the feasibility of removing contaminated tile grout from the void between adjoining vitrified ceramic tiles, and to seal the void permanently with a material having an impermeable surface glaze. Reported on in the paper are; the basic process phenomena, the process effectiveness, suitable vitrifiable material development, a heat affect study and a morphological and compositional analysis.

  6. Influence of porcelain veneering on the marginal fit of Digident and Lava CAD/CAM zirconia ceramic crowns

    PubMed Central

    Pak, Hyun-Soon; Han, Jung-Suk; Lee, Jai-Bong; Kim, Sung-Hun

    2010-01-01

    PURPOSE Marginal fit is a very important factor considering the restoration's long-term success. However, adding porcelain to copings can cause distortion and lead to an inadequate fit which exposes more luting material to the oral environment and causes secondary caries. The purpose of this study was to compare the marginal fit of 2 different all-ceramic crown systems before and after porcelain veneering. This study was also intended to verify the marginal fit of crowns originated from green machining of partially sintered blocks of zirconia (Lava CAD/CAM system) and that of crowns obtained through machining of fully sintered blocks of zirconia (Digident CAD/CAM system). MATERIALS AND METHODS 20 crowns were made per each system and the marginal fit was evaluated through a light microscope with image processing (Accura 2000) at 50 points that were randomly selected. Each crown was measured twice: the first measurement was done after obtaining a 0.5 mm coping and the second measurement was done after porcelain veneering. The means and standard deviations were calculated and statistical inferences among the 2 groups were made using independent t-test and within the same group through paired t-test. RESULTS The means and standard deviations of the marginal fit were 61.52 ± 2.88 µm for the Digident CAD/CAM zirconia ceramic crowns before porcelain veneering and 83.15 ± 3.51 µm after porcelain veneering. Lava CAD/CAM zirconia ceramic crowns showed means and standard deviations of 62.22 ± 1.78 µm before porcelain veneering and 82.03 ± 1.85 µm after porcelain veneering. Both groups showed significant differences when analyzing the marginal gaps before and after porcelain veneering within each group. However, no significant differences were found when comparing the marginal gaps of each group before porcelain veneering and after porcelain veneering as well. CONCLUSION The 2 all-ceramic crown systems showed marginal gaps that were within a reported clinically

  7. Effects of metal surface grinding at the porcelain try-in stage of fixed dental prostheses

    PubMed Central

    Kesim, Bülent; Gümüş, Hasan Önder; Dinçel, Mehmet; Erkaya, Selçuk

    2014-01-01

    PURPOSE This study was to evaluate the effect of grinding of the inner metal surface during the porcelain try-in stage on metal-porcelain bonding considering the maximum temperature and the vibration of samples. MATERIALS AND METHODS Ninety-one square prism-shaped (1 × 1 × 1.5 mm) nickel-chrome cast frameworks 0.3 mm thick were prepared. Porcelain was applied on two opposite outer axial surfaces of the frameworks. The grinding was performed from the opposite axial sides of the inner metal surfaces with a low-speed handpiece with two types of burs (diamond, tungsten-carbide) under three grinding forces (3.5 N, 7 N, 14 N) and at two durations (5 seconds, 10 seconds). The shear bond strength (SBS) test was performed with universal testing machine. Statistical analyzes were performed at 5% significance level. RESULTS The samples subjected to grinding under 3.5 N showed higher SBS values than those exposed to grinding under 7 N and 14 N (P<.05). SBS values of none of the groups differed from those of the control group (P>.05). The types of bur (P=.965) and the duration (P=.679) did not affect the SBS values. On the other hand, type of bur, force applied, and duration of the grinding affected the maximum temperatures of the samples, whereas the maximum vibration was affected only by the type of bur (P<.05). CONCLUSION Grinding the inner metal surface did not affect the metal-porcelain bond strength. Although the grinding affected the maximum temperature and the vibration values of the samples, these did not influence the bonding strength. PMID:25177476

  8. Bond strength of three dental porcelains to Ni-Cr and Co-Cr-Ti alloys.

    PubMed

    Fernandes Neto, Alfredo Julio; Panzeri, Heitor; Neves, Flavio Domingues; Prado, Ricardo Alves do; Mendonça, Gustavo

    2006-01-01

    Ceramometal bond strength has played an important role for the replacement of gold alloys by nickel-chromium alloys in dentistry. This study evaluated the metal/porcelain bond strength of three ceramic systems (Vita VMK 88, Williams and Duceram) associated with three nickel-chromium alloys (Durabond, Lite Cast B and Resistal P) and one experimental cobalt-chromium-titanium alloy. Thirty cast cylinder specimens (15 mm in height; 6 mm in diameter) were obtained for each alloy, in away that 10 specimens of each alloy were tested with each porcelain. Bond strength was measured with an Emic screw-driven mechanical testing machine by applying parallel shear forces to the specimens until fracture. Kruskal-Wallis and Mann-Whitney U tests were used for statistical analysis of the alloy/ceramic combinations (p<0.05). Resistal P/Duceram had significantly higher bond strength (44.38+/-9.12 MPa) (p<0.05) than the other combinations, except for Co-Cr-Ti alloy/Vita VMK 88 (38.41+/-12.64 MPa). The association of the experimental Co-Cr-Ti alloy with Williams porcelain had significantly higher bond strength (28.20+/-3.86 MPa) than the combination of other alloys with the same porcelain (p<0.05). Based of these results and within the limitations of an in vitro study, it may be concluded that the bond strength of the three ceramic systems to the Ni-Cr and Co-Cr-Ti alloys varied significantly, indicating that metal/ceramic compatibility was very important to the bond strength. PMID:16721460

  9. Microscale resolution fracture toughness profiling at the zirconia-porcelain interface in dental prostheses

    NASA Astrophysics Data System (ADS)

    Lunt, Alexander J. G.; Mohanty, Gaurav; Neo, Tee K.; Michler, Johann; Korsunsky, Alexander M.

    2015-12-01

    The high failure rate of the Yttria Partially Stabilized Zirconia (YPSZ)-porcelain interface in dental prostheses is influenced by the micro-scale mechanical property variation in this region. To improve the understanding of this behavior, micro-scale fracture toughness profiling by nanoindentation micropillar splitting is reported for the first time. Sixty 5 μm diameter micropillars were machined within the first 100 μm of the interface. Berkovich nanoindentation provided estimates of the bulk fracture toughness of YPSZ and porcelain that matched the literature values closely. However, the large included tip angle prevented precise alignment of indenter with the pillar center. Cube corner indentation was performed on the remainder of the pillars and calibration between nanoindentation using different tip shapes was used to determine the associated conversion factors. YPSZ micropillars failed by gradual crack propagation and bulk values persisted to within 15 μm from the interface, beyond which scatter increased and a 10% increase in fracture toughness was observed that may be associated with grain size variation at this location. Micropillars straddling the interface displayed preferential fracture within porcelain parallel to the interface at a location where nano-voiding has previously been observed and reported. Pure porcelain micropillars exhibited highly brittle failure and a large reduction of fracture toughness (by up to ~90%) within the first 50 μm of the interface. These new insights constitute a major advance in understanding the structure-property relationship of this important bi-material interface at the micro-scale, and will improve micromechanical modelling needed to optimize current manufacturing routes and reduce failure.

  10. Design and testing of 15kv to 35kv porcelain terminations using new connection techniques

    SciTech Connect

    Fox, J.W.; Hill, R.J.

    1982-07-01

    New techniques for conductor connection in underground cable terminations were investigated in a design of a new distribution class porcelain cable termination. Connections to the conductor were accomplished using set screws, building upon previous designs with additions to assure a conservative design approach. The connector design was tested according to applicable standards for load cycling of connections, and the result appears capable of conservative performance in the operating environment.

  11. Spatial chaos of Wang tiles with two symbols

    NASA Astrophysics Data System (ADS)

    Chen, Jin-Yu; Chen, Yu-Jie; Hu, Wen-Guei; Lin, Song-Sun

    2016-02-01

    This investigation completely classifies the spatial chaos problem in plane edge coloring (Wang tiles) with two symbols. For a set of Wang tiles B , spatial chaos occurs when the spatial entropy h ( B ) is positive. B is called a minimal cycle generator if P ( B ) ≠ 0̸ and P ( B ' ) = 0̸ whenever B ' ⫋ B , where P ( B ) is the set of all periodic patterns on ℤ2 generated by B . Given a set of Wang tiles B , write B = C 1 ∪ C 2 ∪ ⋯ ∪ C k ∪ N , where Cj, 1 ≤ j ≤ k, are minimal cycle generators and B contains no minimal cycle generator except those contained in C1∪C2∪⋯∪Ck. Then, the positivity of spatial entropy h ( B ) is completely determined by C1∪C2∪⋯∪Ck. Furthermore, there are 39 equivalence classes of marginal positive-entropy sets of Wang tiles and 18 equivalence classes of saturated zero-entropy sets of Wang tiles. For a set of Wang tiles B , h ( B ) is positive if and only if B contains a MPE set, and h ( B ) is zero if and only if B is a subset of a SZE set.

  12. Critical appraisal: clinical considerations for restoring mandibular incisors with porcelain laminate veneers.

    PubMed

    Walter, Robert D; Raigrodski, Ariel J

    2008-01-01

    Porcelain laminate veneers have been proven to be a successful treatment modality for maxillary incisors in clinical practice and in controlled clinical studies. However, the data in clinical studies on the success of veneers for restoring mandibular incisors are limited. Clinically, the successful restoration of mandibular incisors with porcelain laminate veneers is one of the more challenging procedures in all of esthetic restorative dentistry. Limited coronal dimensions, the small amount of enamel available for bonding (particularly in the cervical areas), materials and techniques for the bonding procedures, and the response of the tooth-veneer complex to forces generated during the incisal loading in both functional as well as parafunctional contacts must be considered as potential sources of success or failure. This Critical Appraisal reviews three recent scientific articles to shed some light on these issues and, as in all research endeavors, leads the reader to identify additional areas of concern that might stimulate further scientific inquiry. The first publication studied predictors for enamel thickness for mandibular incisors. The second examined bonding protocols for exposed dentin and suggested immediate dentin sealing. The third paper addressed fracture behavior of mandibular incisors restored with porcelain laminate veneers in vitro. PMID:18768002

  13. Bonding of low-fusing dental porcelain to commercially pure titanium.

    PubMed

    Könönen, M; Kivilahti, J

    1994-09-01

    The objective of the investigation was to study the basic problems related to the firing of dental porcelain to commercially pure titanium. The firing of a low-fusing porcelain to sandblasted or electrolytically polished titanium was carried out in an ordinary dental furnace. The interfacial regions between the ceramic coatings and titanium were analyzed using scanning acoustic microscopy (C-SAM) and scanning electron microscopy (SEM) techniques. Thermal stresses in the joints were evaluated by means of a finite element model based on multilayer elastic strain analysis. The chemical reactions and their formation sequence at 750 degrees C was predicted thermodynamically and observed experimentally both at 750 and 800 degrees C. The C-SAM results gave evidence that the integrity of the porcelain-titanium joints are better in the sandblasted samples than in the electropolished ones, where defects were larger. SEM analyses of the same samples confirmed the C-SAM findings. Because the reaction layers are more continuous in the electropolished samples, cracks propagated more readily in these samples during the cooling procedure. Both thermodynamic calculations and experimental chemical analyses strongly indicate that the cause for the cracking of the reaction zone is thin layer of Ti (oxo)silicide and/or a relatively thick solid solution layer of Ti and oxygen. PMID:7814430

  14. Porcelain repair - Influence of different systems and surface treatments on resin bond strength

    PubMed Central

    Yoo, Ji-Young; Yoon, Hyung-In; Park, Ji-Man

    2015-01-01

    PURPOSE The purpose of this study was to evaluate the bond strength of composite resin on the fracture surface of metal-ceramic depending on the repair systems and surface roughening methods. MATERIALS AND METHODS A total of 30 disk specimens were fabricated, 15 of each were made from feldspathic porcelain and nickel-chromium base metal alloy. Each substrate was divided into three groups according to the repair method: a) application of repair system I (Intraoral Repair Kit) with diamond bur roughening (Group DP and DM), b) application of repair system I with airborne-particle abrasion (Group SP and SM), and c) application of repair system II (CoJet Intraoral Repair System, Group CP and CM). All specimens were thermocycled, and the shear bond strength was measured. The data were analyzed using the Kruskal-Wallis analysis and the Mann-Whitney test with a significance level of 0.05. RESULTS For the porcelain specimens, group SP showed the highest shear bond strength (25.85 ± 3.51 MPa) and group DP and CP were not significantly different. In metal specimens, group CM showed superior values of bond strength (13.81 ± 3.45 MPa) compared to groups DM or SM. CONCLUSION Airborne-particle abrasion and application of repair system I can be recommended in the case of a fracture localized to the porcelain. If the fracture extends to metal surface, the repair system II is worthy of consideration. PMID:26576249

  15. Effects of Oxide Layer on the Bonding Strength of Ni-Cr Alloys with Porcelain Ceramics.

    PubMed

    Park, W U; Jung, S H; Zhao, Jingming; Hwang, Kyu H; Lee, J K; Mitchell, John C

    2015-08-01

    The metal-ceramic crown restoration was the most actively used at esthetic restoration for its convenience of forming. Due to constant rise of gold price, non-precious metal such as Ni-Cr alloy have been widely used as metal-ceramic restorations. For easy casting and lower melting point Be was added as minor component to Ni-Cr for a long time, but the use of Be was regulated to deteriorate to human lung. In this study, Ni-Cr specimens containing Be (T-3, Ticonium, USA) and non-Be (Bellabond Plus, BEGO, Germany) were fabricated and by heat treatments at 800-1050 0C oxide layer was formed for subsequent bonding to porcelain ceramics. By heat treatment of the non-Be specimens at high temperature more thick oxide layer was formed and showed lower bonding strength due to the debonding at oxide layers. But in the Be-containing specimens debonding was occurred at porcelain layer so that they showed higher bonding strength. So by heat treatment of non-Be specimens at vacuum condition rather thinner oxide film could be formed so that showed higher coupling strength due to the debonding at porcelain layers than oxide layers. PMID:26369169

  16. Clinical gap changes after porcelain firing cycles of zirconia fixed dentures

    PubMed Central

    Bugurman, Bugurman Burcu

    2014-01-01

    PURPOSE The aim of this study was to measure the changes on the marginal and internal adaptation of zirconia based anterior fixed partial dentures after the porcelain firing process. MATERIALS AND METHODS A total of 34 anterior fixed partial dentures using LAVA CAD/CAM system (3M ESPE, Germany) were applied. Two silicone replicas were obtained: one is obtained before porcelain firing process (initial) and the other is obtained after porcelain firing process (final), followed by the examination under a binocular stereomicroscope. Kruskal Wallis and Wilcoxon Signed Ranks tests were used for the statistical analysis (P<.05). RESULTS No statistically significant difference was found between initial and final marginal gap values (P>.05). At the internal gap measurements, final marginal area values (59.54 µm) were significantly lower than the initial marginal area values (68.68 µm)(P<.05). The highest and the lowest internal gap values were observed at the incisal/occlusal area and at the marginal area, respectively. In addition, lower internal gap values were obtained for canines than for central incisors, lateral incisors and premolars at the incisal area (P<.05). CONCLUSION The firing cycles did not affect the marginal gap of Lava CAD/CAM system, but it is controversial for the internal gap. PMID:25006381

  17. Inspection and detection techniques: Defects in porcelain insulator strings. Final report

    SciTech Connect

    Loynes, K.

    1997-12-01

    The scope of this project was to investigate inspection techniques or means to detect damaged or defective porcelain insulators within an insulator string using commercially available devices. Many suppliers claimed to offer devices that would identify specific physical characteristics of the object being observed. The difficulty in applying these devices to porcelain insulators is recognizing which of these characteristics could be present and which characteristics would be indicative of a defective or damaged insulator. The terms defective insulator or damaged insulator can have many implications. For this project, damaged was assumed to imply some physical anomaly that can be readily observed without sophisticated means. Defective implies that the insulator may no longer be suited for the intended application. The objective of this project was to evaluate technologies to determine if there were reasonable techniques for identifying damaged or defective insulator units on porcelain insulator strings. Using the above definitions of the terms damaged and defective, the project proceeded to use various technologies for identifying characteristics of test insulators that varied from a known, good insulator string. Ultimately it is hoped that this work will aid in defining standardized terms for defective and damaged insulators.

  18. Tiled fuzzy Hough transform for crack detection

    NASA Astrophysics Data System (ADS)

    Vaheesan, Kanapathippillai; Chandrakumar, Chanjief; Mathavan, Senthan; Kamal, Khurram; Rahman, Mujib; Al-Habaibeh, Amin

    2015-04-01

    Surface cracks can be the bellwether of the failure of any component under loading as it indicates the component's fracture due to stresses and usage. For this reason, crack detection is indispensable for the condition monitoring and quality control of road surfaces. Pavement images have high levels of intensity variation and texture content, hence the crack detection is difficult. Moreover, shallow cracks result in very low contrast image pixels making their detection difficult. For these reasons, studies on pavement crack detection is active even after years of research. In this paper, the fuzzy Hough transform is employed, for the first time to detect cracks on any surface. The contribution of texture pixels to the accumulator array is reduced by using the tiled version of the Hough transform. Precision values of 78% and a recall of 72% are obtaining for an image set obtained from an industrial imaging system containing very low contrast cracking. When only high contrast crack segments are considered the values move to mid to high 90%.

  19. Are Tiled Display Walls Needed for Astronomy?

    NASA Astrophysics Data System (ADS)

    Meade, Bernard F.; Fluke, Christopher J.; Manos, Steven; Sinnott, Richard O.

    2014-08-01

    Clustering commodity displays into a Tiled Display Wall (TDW) provides a cost-effective way to create an extremely high resolution display, capable of approaching the image sizes now generated by modern astronomical instruments. Many research institutions have constructed TDWs on the basis that they will improve the scientific outcomes of astronomical imagery. We test this concept by presenting sample images to astronomers and non-astronomers using a standard desktop display (SDD) and a TDW. These samples include standard English words, wide field galaxy surveys and nebulae mosaics from the Hubble telescope. Our experiments show that TDWs provide a better environment than SDDs for searching for small targets in large images. They also show that astronomers tend to be better at searching images for targets than non-astronomers, both groups are generally better when employing physical navigation as opposed to virtual navigation, and that the combination of two non-astronomers using a TDW rivals the experience of a single astronomer. However, there is also a large distribution in aptitude amongst the participants and the nature of the content also plays a significant role in success.

  20. Tiling solutions for optimal biological sensing

    NASA Astrophysics Data System (ADS)

    Walczak, Aleksandra M.

    2015-10-01

    Biological systems, from cells to organisms, must respond to the ever-changing environment in order to survive and function. This is not a simple task given the often random nature of the signals they receive, as well as the intrinsically stochastic, many-body and often self-organized nature of the processes that control their sensing and response and limited resources. Despite a wide range of scales and functions that can be observed in the living world, some common principles that govern the behavior of biological systems emerge. Here I review two examples of very different biological problems: information transmission in gene regulatory networks and diversity of adaptive immune receptor repertoires that protect us from pathogens. I discuss the trade-offs that physical laws impose on these systems and show that the optimal designs of both immune repertoires and gene regulatory networks display similar discrete tiling structures. These solutions rely on locally non-overlapping placements of the responding elements (genes and receptors) that, overall, cover space nearly uniformly. xml:lang="fr"

  1. Phase change material in floor tiles for thermal energy storage

    NASA Astrophysics Data System (ADS)

    Lee, Amy Sarah

    Traditional passive solar systems have relied on sensible heat storage for energy savings. Recent research has investigated taking advantage of latent heat storage for additional energy savings. This is accomplished by the incorporation of phase change material into building materials used in traditional passive applications. Trombe walls, ceilings and floors can all be enhanced with phase change materials. This research introduces a new flooring material that incorporates a phase change material ready for commercial manufacture. An agglomerate floor tile containing 20% by mass of encapsulated octadecane has been manufactured. Flexural and compressive strength of 7.4 MPa and 24.5 MPa respectively, were measured for the tile. Peak melting transition temperature was determined to be 27.2°C with a latent heat of 33.9 J/g of tile. Structural and thermal performance of the tile surpassed that of a typical ceramic tile. Each tile was composed of quartz, resin and phase change material. Statistical modeling was performed to analyze the response of flexural and compressive strength on varying amounts of quartz, resin and phase change material. Resulting polynomials described the effect of adding phase change material into the tile. With as little as 10% by mass of phase change material, the strength was reduced to less than 50% of tile without phase change material. It was determined that the maximum phase change material content to attain structural integrity greater than ceramic tile was 20% by mass. The statistical analysis used for this research was based on mixture experiments. A procedure was developed to simplify the selection of data points used in the fit of the polynomials to describe the response of flexural and compressive strengths. Analysis of energy savings using this floor tile containing 20% by mass of phase change material was performed as an addendum to this research. A known static simulation method, SLR (solar load ratio), was adapted to include

  2. Foam on Tile Impact Modeling for the STS-107 Investigation

    NASA Technical Reports Server (NTRS)

    Stellingwerf, R. F.; Robinson, J. H.; Richardson, S.; Evans, S. W.; Stallworth, R.; Hovater, M.

    2004-01-01

    Following the breakup of the Space Shuttle Columbia during reentry a NASA/Contractor investigation team was formed to examine the probable damage inflicted on Orbiter Thermal Protection System elements by impact of External Tank insulating foam projectiles. The authors formed a working subgroup within the larger team to apply the Smooth Particle Hydrodynamics code SPHC to the damage estimation problem. Numerical models of the Orbiter's tiles and of the Tank's foam were constructed and used as inputs into the code. Material properties needed to properly model the tiles and foam were obtained from other working subgroups who performed tests on these items for this purpose. Two- and three-dimensional models of the tiles were constructed, including the glass outer layer, the main body of LI-900 insulation, the densified lower layer of LI-900, the Nomex felt mounting layer, and the Aluminum 2024 vehicle skin. A model for the BX-250 foam including porous compression, elastic rebound, and surface erosion was developed. Code results for the tile damage and foam behavior were extensively validated through comparison with Southwest Research Institute foam-on-tile impact experiments carried out in 1999. These tests involved small projectiles striking individual tiles and small tile arrays. Following code and model validation we simulated impacts of larger foam projectiles on the examples of tile systems used on the Orbiter. Results for impacts on the main landing gear door are presented in this paper, including effects of impacts at several angles, and of rapidly rotating projectiles. General results suggest that foam impacts on tiles at about 500 mph could cause appreciable damage if the impact angle is greater than about 20 degrees. Some variations of the foam properties, such as increased brittleness or increased density could increase damage in some cases. Rotation up to 17 rps failed to increase the damage for the two cases considered. This does not rule out other cases

  3. Comparative evaluation of shear bond strengths of veneering porcelain to base metal alloy and zirconia substructures before and after aging – An in vitro study

    PubMed Central

    Sreekala, Laju; Narayanan, Mahesh; Eerali, Sunil M.; Eerali, Susil M.; Varghese, Joju; Zainaba Fathima, A. l.

    2015-01-01

    Objective: The aim of this study was to evaluate and compare the shear bond strength of veneering porcelain to base metal alloy and zirconia substructures before and after aging. Scanning electron microscopy (SEM) was used to determine the failure pattern. Materials and Methods: Twenty rectangular blocks (9 mm length × 4 mm height × 4 mm width) of base metal alloy (Bellabond plus, Bego, Germany) and zirconia (Will ceramZ zirconia K block) were fabricated for shear bond strength test. Surface of the base metal alloy block (4 mm × 4 mm area) was veneered with corresponding veneering porcelain (Ivoclar, IPS classic, vivadent). Similarly, surface of the zirconia rectangular block (4 mm × 4 mm) was veneered with corresponding veneering ceramic (Cercon ceram kiss, Degudent). Out of forty rectangular porcelain veneered core specimen, ten porcelain veneered base metal alloy specimen and ten porcelain veneered zirconia specimen were immersed in water at 37°C for one month to simulate the oral environment. Results: On comparison, the highest shear bond strength value was obtained in porcelain veneered base metal alloy before aging group followed by porcelain veneered base metal alloy after aging group, Porcelain veneered zirconia before aging group, porcelain veneered zirconia after aging group. SEM analysis revealed predominantly cohesive failure of veneering ceramic in all groups. Conclusion: Porcelain veneered base metal alloy samples showed highest shear bond strength than porcelain veneered zirconia samples. Study concluded that aging had an influence on shear bond strength. Shear bond strength was found to be decreasing after aging. SEM analysis revealed cohesive failure of veneering ceramic in all groups suggestive of higher bond strength of the interface than cohesive strength of ceramic. Hence, it was concluded that veneering ceramic was the weakest link. PMID:26942121

  4. The effect of leucite crystallization and thermal history on thermal expansion measurement of dental porcelains

    NASA Astrophysics Data System (ADS)

    Khajotia, Sharukh Soli

    1997-12-01

    Objectives. Measurement of thermal expansion in glassy materials is complicated by thermal history effects. The purpose of this research was to determine whether the occurrence of structural relaxation in glassy materials, such as dental porcelains, and changes in porcelain leucite content could interfere with the accurate measurement of the coefficient of thermal expansion during the thermal expansion measurement itself. Methods. In a randomized design, thermal expansion specimens were fabricated using six commercial body porcelains and the leucite-containing Component No. 1 frit (Weinstein et al. patent, 1962), and subjected to one of the following heat treatments: a single heating run at 3sp°C/min in a conventional dilatometer followed by air quenching; three successive low-rate heating and cooling thermal expansion runs at 3sp°C/min in a conventional dilatometer; or three successive high-rate heating and cooling thermal expansion runs at 600sp°C/min in a laser dilatometer. The remaining specimens were left untreated and served as controls. Potential changes in porcelain leucite content were monitored via quantitative X-ray diffraction. Thermal expansion data for each run over a temperature range of 25-500sp°C and the leucite content of all specimens were subjected to repeated measures analysis of variance. Results. The thermal expansion coefficient measured on first slow heating was significantly lower than the values for succeeding low-rate heating and cooling runs in all materials (p $ 0.05). No significant effect of dilatometer thermal treatments on leucite content (p >$ 0.05) was shown for all materials studied using both dilatometers. Significance. The crystallization of additional amounts of leucite during thermal expansion runs can be ruled out as a possible interference in the determination of the thermal expansion coefficient of dental porcelain. Conventional dilatometer measurements exhibited structural relaxation during the first heating run, as

  5. Use of the frozen elephant trunk technique in complicated chronic dissection with porcelain aorta and visceral arteries originating from different lumens.

    PubMed

    Zembala, Michal O; Irimie, Vadim; Urbanski, Paul P

    2016-04-01

    A rare case of aortic arch aneurysm combined with chronic aortic dissection is reported. Because the visceral arteries originated from different, equivalently perfused lumens and the descending aorta was circumferentially calcified (porcelain aorta) limiting the possibilities of anastomosing, careful planning of the surgical strategy was of utmost importance. The complex surgery consisted of ascending and total arch replacement using the 'frozen elephant trunk' technique with Thoraflex™ Hybrid Prosthesis (Vascutek, Terumo, Inchinnan, Scotland); however, before insertion of the stent graft, an angioscopic resection of the dissection membrane in the proximal part of the descending aorta was carried out to ensure a complete expansion of the distal edge of the stent within the entire common lumen of the aorta and unimpaired distal flow in both lumens below the stent graft. The surgery and the postoperative course were uneventful. PMID:27002017

  6. Hollow clay tile wall program summary report

    SciTech Connect

    Henderson, R.C.; Jones, W.D.

    1995-07-30

    Many of the Y-12 Plant buildings, constructed during the 1940s and 1950s, consist of steel ed concrete framing infilled with hollow clay tile (HCT). The infill was intended to provide for building enclosure and was not designed to have vertical or lateral load-carrying capacity. During the late 1970s and early 1980s, seismic and wind evaluations were performed on many of these buildings in conjunction with the preparation of a site-wide safety analysis report. This analytical work, based on the best available methodology, considered lateral load-carrying capacity of the HCT infill on the basis of building code allowable shear values. In parallel with the analysis effort, DOE initiated a program to develop natural phenomena capacity and performance criteria for existing buildings, but these criteria did not specify guidelines for determining the lateral force capacity of frames infilled with HCT. The evaluation of infills was, therefore, based on the provisions for the design of unreinforced masonry as outlined in standard masonry codes. When the results of the seismic and wind evaluations were compared with the new criteria, the projected building capacities fell short of the requirements. Apparently, if the buildings were to meet the new criteria, many millions of dollars would be required for building upgrades. Because the upgrade costs were significant, the assumptions and approaches used in the analyses were reevaluated. Four issues were identified: (1) Once the infilled walls cracked, what capacity (nonlinear response), if any, would the walls have to resist earthquake or wind loads applied in the plane of the infill (in-plane)? (2) Would the infilled walls remain within the steel or reinforced concrete framing when subjected to earthquake or high wind loads applied perpendicular to the infill (out-of-plane)? (3) What was the actual shear capacity of the HCT infill? (4) Was modeling the HCT infill as a shear wall the best approach?

  7. Construction of 2D quasi-periodic Rauzy tiling by similarity transformation

    SciTech Connect

    Zhuravlev, V. G.; Maleev, A. V.

    2009-05-15

    A new approach to constructing self-similar fractal tilings is proposed based on the construction of semigroups generated by a finite set of similarity transformations. The Rauzy tiling-a 2D analog of 1D Fibonacci tiling generated by the golden mean-is used as an example to illustrate this approach. It is shown that the Rauzy torus development and the elementary fractal boundary of Rauzy tiling can be constructed in the form of a set of centers of similarity semigroups generated by two and three similarity transformations, respectively. A centrosymmetric tiling, locally dual to the Rauzy tiling, is constructed for the first time and its parameterization is developed.

  8. Reappraisal of flow to tile drains III. Drains with limited flow capacity

    NASA Astrophysics Data System (ADS)

    Khan, S.; Rushton, K. R.

    1996-09-01

    This third paper of the series on the reappraisal of flow to tile drains considers the time-variant situations in tile drain drainage systems when the quantity of water carried by tile drains is limited due to the capacity of the drains or the pumping equipment. Two categories of problem are analysed in this paper: (i) a series of parallel tile drains with a maximum specified flow and (ii) interceptor drains in the vicinity of canals. Complete details for satisfying the maximum specified flow conditions in tile drains are given. The effect of different capacities of tile drains on the performance of drainage system is explored.

  9. Investigation of registration algorithms for the automatic tile processing system

    NASA Technical Reports Server (NTRS)

    Tamir, Dan E.

    1995-01-01

    The Robotic Tile Inspection System (RTPS), under development in NASA-KSC, is expected to automate the processes of post-flight re-water-proofing and the process of inspection of the Shuttle heat absorbing tiles. An important task of the robot vision sub-system is to register the 'real-world' coordinates with the coordinates of the robot model of the Shuttle tiles. The model coordinates relate to a tile data-base and pre-flight tile-images. In the registration process, current (post-flight) images are aligned with pre-flight images to detect the rotation and translation displacement required for the coordinate systems rectification. The research activities performed this summer included study and evaluation of the registration algorithm that is currently implemented by the RTPS, as well as, investigation of the utility of other registration algorithms. It has been found that the current algorithm is not robust enough. This algorithm has a success rate of less than 80% and is, therefore, not suitable for complying with the requirements of the RTPS. Modifications to the current algorithm has been developed and tested. These modifications can improve the performance of the registration algorithm in a significant way. However, this improvement is not sufficient to satisfy system requirements. A new algorithm for registration has been developed and tested. This algorithm presented very high degree of robustness with success rate of 96%.

  10. Leaching of dissolved phosphorus from tile-drained agricultural areas.

    PubMed

    Andersen, H E; Windolf, J; Kronvang, B

    2016-01-01

    We investigated leaching of dissolved phosphorus (P) from 45 tile-drains representing animal husbandry farms in all regions of Denmark. Leaching of P via tile-drains exhibits a high degree of spatial heterogeneity with a low concentration in the majority of tile-drains and few tile-drains (15% in our investigation) having high to very high concentration of dissolved P. The share of dissolved organic P (DOP) was high (up to 96%). Leaching of DOP has hitherto been a somewhat overlooked P loss pathway in Danish soils and the mechanisms of mobilization and transport of DOP needs more investigation. We found a high correlation between Olsen-P and water extractable P. Water extractable P is regarded as an indicator of risk of loss of dissolved P. Our findings indicate that Olsen-P, which is measured routinely in Danish agricultural soils, may be a useful proxy for the P leaching potential of soils. However, we found no straight-forward correlation between leaching potential of the top soil layer (expressed as either degree of P saturation, Olsen-P or water extractable P) and the measured concentration of dissolved P in the tile-drain. This underlines that not only the source of P but also the P loss pathway must be taken into account when evaluating the risk of P loss. PMID:27332841

  11. Microwave versus conventional sintering of silicon carbide tiles

    SciTech Connect

    Kass, M.D.; Caughman, J.B.O.; Forrester, S.C.; Akerman, A.

    1997-05-07

    Silicon carbide is being evaluated as an armor material because of its lightweight, high-hardness, and excellent armor efficiency. However, one of the problems associated with silicon carbide is the high cost associated with achieving fully dense tiles. Full density requires either hot pressing and sintering or reaction bonding. Past efforts have shown that hot pressed tiles have a higher armor efficiency than those produced by reaction bonded sintering. An earlier stuy showed that the acoustic properties of fully-dense silicon carbide tiles were enhanced through the use of post-sintered microwave heat treatments. One of the least expensive forming techniques is to isostatically press-and-sinter. In this study, the authors have used microwave energy to densify silicon carbide green bodies. Microwave sintering has been demonstrated to be a very quick way to sinter ceramics such as alumina to exceptionally high densities. Previous work has shown that microwave post treatment of fully-dense reaction bonded silicon carbide tiles significantly improves the acoustic properties of the tiles. These properties include Poisson`s ratio, Young`s modulus, shear modulus, and bulk modulus.

  12. Interlaced Particle Systems and Tilings of the Aztec Diamond

    NASA Astrophysics Data System (ADS)

    Fleming, Benjamin J.; Forrester, Peter J.

    2011-02-01

    Motivated by the problem of domino tilings of the Aztec diamond, a weighted particle system is defined on N lines, with line j containing j particles. The particles are restricted to lattice points from 0 to N, and particles on successive lines are subject to an interlacing constraint. It is shown that this particle system is exactly solvable, to the extent that not only can the partition function be computed exactly, but so too can the marginal distributions. These results in turn are used to give new derivations within the particle picture of a number of known fundamental properties of the tiling problem, for example that the number of distinct configurations is 2 N( N+1)/2, and that there is a limit to the GUE minor process, which we show at the level of the joint PDFs. It is shown too that the study of tilings of the half Aztec diamond—not known from earlier literature—also leads to an interlaced particle system, now with successive lines 2 n-1 and 2 n ( n=1,…, N/2-1) having n particles. Its exact solution allows for an analysis of the half Aztec diamond tilings analogous to that given for the Aztec diamond tilings.

  13. Analysis of Thick Sandwich Shells with Embedded Ceramic Tiles

    NASA Technical Reports Server (NTRS)

    Davila, Carlos G.; Smith, C.; Lumban-Tobing, F.

    1996-01-01

    The Composite Armored Vehicle (CAV) is an advanced technology demonstrator of an all-composite ground combat vehicle. The CAV upper hull is made of a tough light-weight S2-glass/epoxy laminate with embedded ceramic tiles that serve as armor. The tiles are bonded to a rubber mat with a carefully selected, highly viscoelastic adhesive. The integration of armor and structure offers an efficient combination of ballistic protection and structural performance. The analysis of this anisotropic construction, with its inherent discontinuous and periodic nature, however, poses several challenges. The present paper describes a shell-based 'element-layering' technique that properly accounts for these effects and for the concentrated transverse shear flexibility in the rubber mat. One of the most important advantages of the element-layering technique over advanced higher-order elements is that it is based on conventional elements. This advantage allows the models to be portable to other structural analysis codes, a prerequisite in a program that involves the computational facilities of several manufacturers and government laboratories. The element-layering technique was implemented into an auto-layering program that automatically transforms a conventional shell model into a multi-layered model. The effects of tile layer homogenization, tile placement patterns, and tile gap size on the analysis results are described.

  14. The ATLAS tile calorimeter ROD injector and multiplexer board

    NASA Astrophysics Data System (ADS)

    Valero, A.; Castillo, V.; Ferrer, A.; González, V.; Hernández, Y.; Higón, E.; Sanchís, E.; Solans, C.; Torres, J.; Valls, J. A.

    2011-02-01

    The ATLAS Tile Calorimeter is a sampling detector composed by cells made of iron-scintillator tiles. The calorimeter cell signals are digitized in the front-end electronics and transmitted to the Read-Out Drivers (RODs) at the first level trigger rate. The ROD receives triggered data from up to 9856 channels and provides the energy, phase and quality factor of the signals to the second level trigger. The back-end electronics is divided into four partitions containing eight RODs each. Therefore, a total of 32 RODs are used to process and transmit the data of the TileCal detector. In order to emulate the detector signals in the production and commissioning of ROD modules a board called ROD Injector and Multiplexer Board (RIMBO) was designed. In this paper, the RIMBO main functional blocks, PCB design and the different operation modes are described. It is described the crucial role of the board within the TileCal ROD test-bench in order to emulate the front-end electronics during the validation of ROD boards as well as during the evaluation of the ROD signal reconstruction algorithms. Finally, qualification and performance results for the injection operation mode obtained during the Tile Calorimeter ROD production tests are presented.

  15. The ATLAS tile calorimeter performance at the LHC

    SciTech Connect

    Calkins, R.

    2011-07-01

    The Tile Calorimeter (TileCal), the central section of the hadronic calorimeter of the ATLAS experiment, is a key detector component to detect hadrons, jets and taus and to measure the missing transverse energy. Due to the very good muon signal to noise ratio it assists the spectrometer in the identification and reconstruction of muons. TileCal is built of steel and scintillating tiles coupled to optical fibers and read out by photomultipliers. The calorimeter is equipped with systems that allow to monitor and to calibrate each stage of the read out system exploiting different signal sources: laser light, charge injection and a radioactive source. The performance of the calorimeter has been measured and monitored using calibration data, random triggered data, cosmic muons and more importantly LHC collision events. The results presented here assess the absolute energy scale calibration precision, the energy and timing uniformity and the synchronization precision. The ensemble of the results demonstrates a very good understanding of the performance of the Tile Calorimeter that is proved to be well within the design expectations. (authors)

  16. Development document for effluent limitations guidelines and standards for the porcelain enameling. Point source category. Final report

    SciTech Connect

    Not Available

    1982-11-01

    EPA has subcategorized the porcelain enameling industry based on the basis material coated. The subcategories are defined as porcelain enameling on: steel, cast iron, aluminum and copper. No limitations are established for porcelain enameling on precious metals (gold, silver and platinum group metals) because they are believed to be very small sources and virtually all would be excluded from regulation by the small indirect discharger exemption. The study included the identification of raw waste and treated effluent characteristics, including: (1) the sources and volume of water used, the processes employed, and the sources of pollutants and wastewaters in the plant, and (2) the constituents of wastewaters. Such analysis enabled EPA to determine the presence and concentration of toxic pollutants in wastewater discharges.

  17. Fly ash of mineral coal as ceramic tiles raw material.

    PubMed

    Zimmer, A; Bergmann, C P

    2007-01-01

    The aim of this work was to evaluate the use of mineral coal fly ash as a raw material in the production of ceramic tiles. The samples of fly ash came from Capivari de Baixo, a city situated in the Brazilian Federal State of Santa Catarina. The fly ash and the raw materials were characterized regarding their physical chemical properties, and, based on these results; batches containing fly ash and typical raw materials for ceramic tiles were prepared. The fly ash content in the batches varied between 20 and 80 wt%. Specimens were molded using a uniaxial hydraulic press and were fired. All batches containing ash up to 60 wt% present adequate properties to be classified as several kinds of products in the ISO 13006 standard () regarding its different absorption groups (pressed). The results obtained indicate that fly ash, when mixed with traditional raw materials, has the necessary requirements to be used as a raw material for production of ceramic tiles. PMID:16540298

  18. Identification of Low PT Muon with the Atlas Tile Calorimeter

    NASA Astrophysics Data System (ADS)

    Usai, G.

    2005-02-01

    A method for the identification of muons with the ATLAS Tile Calorimeter is presented and its efficiency and mis-tagging fraction are discussed. It is demonstrated that the Tile Calorimeter can identify muons with good efficiency down to 2 GeV/c transverse momentum, where the stand-alone Muon Spectrometer has zero efficiency. This kinematic region is important for study of B meson physics and in the particular for the CP violating decay channels. The effectiveness of this method is tested, in particular, in the case of bbar {b} events at low LHC luminosity (1033cm-1s-2) with full simulation of experimental conditions. The muon identification with the Tile Calorimeter is fast and can be used for muon selection at the trigger level. A method of exploiting the information available in other ATLAS sub-detectors in order to reduce spurious muon-tag and measure the candidate muon momentum is discussed.

  19. Solare Cell Roof Tile And Method Of Forming Same

    DOEpatents

    Hanoka, Jack I.; Real, Markus

    1999-11-16

    A solar cell roof tile includes a front support layer, a transparent encapsulant layer, a plurality of interconnected solar cells and a backskin layer. The front support layer is formed of light transmitting material and has first and second surfaces. The transparent encapsulant layer is disposed adjacent the second surface of the front support layer. The interconnected solar cells has a first surface disposed adjacent the transparent encapsulant layer. The backskin layer has a first surface disposed adjacent a second surface of the interconnected solar cells, wherein a portion of the backskin layer wraps around and contacts the first surface of the front support layer to form the border region. A portion of the border region has an extended width. The solar cell roof tile may have stand-offs disposed on the extended width border region for providing vertical spacing with respect to an adjacent solar cell roof tile.

  20. Flutter Analysis of the Shuttle Tile Overlay Repair Concept

    NASA Technical Reports Server (NTRS)

    Bey, Kim S.; Scott, Robert C.; Bartels, Robert E.; Waters, William A.; Chen, Roger

    2007-01-01

    The Space Shuttle tile overlay repair concept, developed at the NASA Johnson Space Center, is designed for on-orbit installation over an area of damaged tile to permit safe re-entry. The thin flexible plate is placed over the damaged area and secured to tile at discreet points around its perimeter. A series of flutter analyses were performed to determine if the onset of flutter met the required safety margins. Normal vibration modes of the panel, obtained from a simplified structural analysis of the installed concept, were combined with a series of aerodynamic analyses of increasing levels of fidelity in terms of modeling the flow physics to determine the onset of flutter. Results from these analyses indicate that it is unlikely that the overlay installed at body point 1800 will flutter during re-entry.

  1. Multitracer Study of Flow to Tile Drains in Irrigated Macroporous Soil

    NASA Astrophysics Data System (ADS)

    Bishop, J. M.; Callaghan, M. V.; Cey, E.; Bentley, L. R.

    2010-12-01

    Multiple tracer experiments have been conducted to test the effectiveness of using irrigation along with a tile drain system for salt remediation in west central Alberta, Canada. The experiments were designed to characterize the shallow flow system as part of a salt flushing pilot study and to determine the role of macroporosity in groundwater flow and transport. Soils at the site are primarily silty glaciolacustrine material underlain by a relatively impermeable till layer at approximately 2.5 m below ground surface. A 20 m by 20 m infiltration test plot is underlain by two tile drains at 2 m depth that are separated by 10 m. The test plot contains a drip irrigation system and has been irrigated regularly in the summer months over the past three seasons (2008-2010). Two reportedly conservative tracers, 2,6-difluorobenzoic acid [2,6-DFBA] and pentafluorobenzoic acid [PFBA], have been used on the plot and the pre-existing soil salinity was also used as a tracer. In August of 2009 a 2,6-DFBA solution (865g/L) was applied to the surface of the plot. Irrigation of the study plot continued after tracer application on a schedule that averaged roughly 12mm/day, applied 3 days a week. During the 2010 field season, a PFBA solution (at 4.2 g/L) was injected into two separate monitoring wells. One monitoring well is situated 0.5 m directly above the north tile drain (in which samples were collected regularly). The other well is situated at 2 m depth in the center of the study plot and samples were collected from a down gradient well. Tracer concentrations in the subsurface were monitored through sampling of tile drain effluent and monitoring wells in and around the plot, in addition to soil core extractions taken at several locations within the test plot at the end of the 2009 field season. Initial breakthrough of the DFBA in the tile drains occurred 24 hours after application and remained in all subsequent water samples at concentrations of 2 to 6 mg/L. Results from the DFBA

  2. Mechanical properties of glass-only porcelains prepared by the use of two feldspathic frits with different thermal properties.

    PubMed

    Kon, M; O'Brien, W J; Rasmussen, S T; Asaoka, K

    2001-08-01

    Low- and non-leucite-containing commercial porcelains with low firing temperatures have become popular. However, improving the strength of glass porcelains is difficult. The purpose of this study was to determine if dispersed glass particles could be used as a reinforcing agent for an all-glass porcelain. We produced 3 feldspathic glasses (high-fusing, medium-fusing, low-fusing) by melting powders consisting of potassium-feldspar and 0, 5, or 20 mass% Na2O, respectively. For high-fusing, medium-fusing, and low-fusing feldspathic glasses, the deformation temperatures were 945 degrees C, 647 degrees C, and 518 degrees C, and the thermal expansion coefficient values were 8.6 x 10(-6)/degrees C, 10.3 x 10(-6)/degrees C, and 13.4 x 10(-6)/degrees C between 25 degrees C and the glass-transition temperature, respectively. The high-fusing-glass (or medium-fusing-glass) powders were mixed with low-fusing-glass powders before being fired into test specimens. The mean flexural strength and fracture toughness (K1C) of 3 single-glass porcelains ranged from 57 to 63 MPa and from 0.68 to 0.73 MPa m(1/2), respectively, presenting no significant differences in one-way ANOVA. However, the flexural strength of 50% high-fusing-glass + 50% low-fusing-glass porcelain was 114 MPa (p < 0.05) and K1C was 1.2 MPa m(1/2) (p < 0.05). Microcracks were observed with a back-scattered scanning electron microscope and were associated with the high- (or medium-) fusing glass particles, suggesting residual stress in the low-fusing-glass matrix due to a coefficient of thermal expansion mismatch between the dispersed glass particles and the matrix glass. The dispersing glass particles appeared to act as a reinforcing agent for strengthening a glassy porcelain. PMID:11669489

  3. Thermal contact conductance measurements on Doublet III armor tile graphite

    SciTech Connect

    Doll, D.W.; Reis, E.

    1983-12-01

    Several tests were performed on the Doublet III wall armor tiles to determine the cool-down rate and to evaluate improvements made by changing the conditions at the interface between the graphite tile and the stainless steel backing plate. Thermal diffusivity tests were performed in vacuum on both TiC coated and bare graphite tiles with and without 0.13 mm (.005'') thick silver foil at the interface. The results of the armor tile cool-down tests showed improvement when a 0.13 mm (0.005'') silver foil is used at the interface. At 2.1 x 10/sup 5/ Pa (30 psi) contact pressure, the e-folding cool-down times for a TiC coated tile, bare graphite and bare graphite with a 0.06 mm (0.0035'') silver shim were 10 min., 5.0 min., and 4.1 min., respectively. Tests using high contact pressures showed that the cool-down rates converged to approx. 4.0 min. At this limit, the conduction path along the backing plate to the two cooling tubes controls the heat flow, and no further improvement could be expected. Thermal diffusivity measurements confirmed the results of the cool-down test showing that by introducing a silver foil at the interface, the contact conductance between Poco AXF-5Q graphite and 316 stainless steel could be improved by a factor of three to eight. The tests showed an increasing improvement over a range of temperatures from 25/sup 0/C to 400/sup 0/C. The data provides a technical basis for further applications of graphite tiles to cooled backing plates.

  4. PHASE CHANGE MATERIALS IN FLOOR TILES FOR THERMAL ENERGY STORAGE

    SciTech Connect

    Douglas C. Hittle

    2002-10-01

    Passive solar systems integrated into residential structures significantly reduce heating energy consumption. Taking advantage of latent heat storage has further increased energy savings. This is accomplished by the incorporation of phase change materials into building materials used in passive applications. Trombe walls, ceilings and floors can all be enhanced with phase change materials. Increasing the thermal storage of floor tile by the addition of encapsulated paraffin wax is the proposed topic of research. Latent heat storage of a phase change material (PCM) is obtained during a change in phase. Typical materials use the latent heat released when the material changes from a liquid to a solid. Paraffin wax and salt hydrates are examples of such materials. Other PCMs that have been recently investigated undergo a phase transition from one solid form to another. During this process they will release heat. These are known as solid-state phase change materials. All have large latent heats, which makes them ideal for passive solar applications. Easy incorporation into various building materials is must for these materials. This proposal will address the advantages and disadvantages of using these materials in floor tile. Prototype tile will be made from a mixture of quartz, binder and phase change material. The thermal and structural properties of the prototype tiles will be tested fully. It is expected that with the addition of the phase change material the structural properties will be compromised to some extent. The ratio of phase change material in the tile will have to be varied to determine the best mixture to provide significant thermal storage, while maintaining structural properties that meet the industry standards for floor tile.

  5. An automated data management/analysis system for space shuttle orbiter tiles. [stress analysis

    NASA Technical Reports Server (NTRS)

    Giles, G. L.; Ballas, M.

    1982-01-01

    An engineering data management system was combined with a nonlinear stress analysis program to provide a capability for analyzing a large number of tiles on the space shuttle orbiter. Tile geometry data and all data necessary of define the tile loads environment accessed automatically as needed for the analysis of a particular tile or a set of tiles. User documentation provided includes: (1) description of computer programs and data files contained in the system; (2) definitions of all engineering data stored in the data base; (3) characteristics of the tile anaytical model; (4) instructions for preparation of user input; and (5) a sample problem to illustrate use of the system. Description of data, computer programs, and analytical models of the tile are sufficiently detailed to guide extension of the system to include additional zones of tiles and/or additional types of analyses

  6. Comparative study of WLS fibres for the ATLAS Tile Calorimeter

    NASA Astrophysics Data System (ADS)

    Gomes, A.; David, M.; Henriques, A.; Maio, A.

    1998-02-01

    The Wave Length Shifting (WLS) fibres are one of the most important components of the ATLAS barrel hadronic tile calorimeter (Tilecal). The fibres collect the hght produced in the injection molded scintillating tiles and transport it to the photomultipliers. Parameters like attenuation length and light yield are important, as well as flexibility and radiation hardness. Comparative results of WLS fibres produced by Bicron, Kuraray and Pol.Hi.Tech are presented. The performance of the fibres BCF91A from Bicron and S048 from Pol.Hi.Tech was significatively improved, but the most performant are still the double clad Y11 fibres from Kuraray.

  7. Comparative study of WLS fibres for the ATLAS tile calorimeter

    NASA Astrophysics Data System (ADS)

    Gomes, A.; David, M.; Henriques, A.; Maio, A.

    1997-02-01

    The Wave Length Shifting (WLS) fibres are one of the most important components of the ATLAS barrel hadronic tile calorimeter (Tilecal). The fibres collect the light produced in the injection molded scintillating tiles and transport it to the photomultipliers. Parameters like attenuation length and light yield are important, as well as flexibility and radiation hardness. Comparative results of WLS fibres produced by Bicron, Kuraray and Pol.Hi.Tech are presented. The performance of the fibres BCF91A from Bicron and S048 from Pol.Hi.Tech was significatively improved, but the most performant are still the double clad Y11 fibres from Kuraray.

  8. Cesium monitoring system for ATLAS Tile Hadron Calorimeter

    NASA Astrophysics Data System (ADS)

    Starchenko, E.; Blanchot, G.; Bosman, M.; Cavalli-Sforza, M.; Karyukhin, A.; Kopikov, S.; Miagkov, A.; Nessi, M.; Shalimov, A.; Shalanda, N.; Soldatov, M.; Solodkov, A.; Soloviev, A.; Tsoupko-Sitnikov, V.; Zaitsev, A.

    2002-11-01

    A system to calibrate and monitor ATLAS Barrel Hadronic Calorimeter (TileCal) is under construction at CERN Laboratory. A movable radioactive source driven by a liquid flow travels through the calorimeter body deposing a known energy to the calorimeter cells. Extensive R&D studies have been carried out and the main system parameters are evaluated. The prototypes are currently used for quality check and inter-calibration of the TileCal modules. A distributed control system, hardware as well as corresponding on-line and off-line software is developed.

  9. High-Performance Tiled WMS and KML Web Server

    NASA Technical Reports Server (NTRS)

    Plesea, Lucian

    2007-01-01

    This software is an Apache 2.0 module implementing a high-performance map server to support interactive map viewers and virtual planet client software. It can be used in applications that require access to very-high-resolution geolocated images, such as GIS, virtual planet applications, and flight simulators. It serves Web Map Service (WMS) requests that comply with a given request grid from an existing tile dataset. It also generates the KML super-overlay configuration files required to access the WMS image tiles.

  10. Resin bonding of metal brackets to glazed zirconia with a porcelain primer

    PubMed Central

    Lee, Jung-Hwan; Lee, Milim; Kim, Kyoung-Nam

    2015-01-01

    Objective The aims of this study were to compare the shear bond strength between orthodontic metal brackets and glazed zirconia using different types of primer before applying resin cement and to determine which primer was more effective. Methods Zirconia blocks were milled and embedded in acrylic resin and randomly assigned to one of four groups: nonglazed zirconia with sandblasting and zirconia primer (NZ); glazed zirconia with sandblasting, etching, and zirconia primer (GZ); glazed zirconia with sandblasting, etching, and porcelain primer (GP); and glazed zirconia with sandblasting, etching, zirconia primer, and porcelain primer (GZP). A stainless steel metal bracket was bonded to each target surface with resin cement, and all specimens underwent thermal cycling. The shear bond strength of the specimens was measured by a universal testing machine. A scanning electron microscope, three-dimensional optical surface-profiler, and stereoscopic microscope were used to image the zirconia surfaces. The data were analyzed with one-way analyses of variance and the Fisher exact test. Results Group GZ showed significantly lower shear bond strength than did the other groups. No statistically significant differences were found among groups NZ, GP, and GZP. All specimens in group GZ showed adhesive failure between the zirconia and resin cement. In groups NZ and GP, bonding failed at the interface between the resin cement and bracket base or showed complex adhesive and cohesive failure. Conclusions Porcelain primer is the more appropriate choice for bonding a metal bracket to the surface of a full-contour glazed zirconia crown with resin cement. PMID:26629476

  11. Influence of a prophylaxis paste on surface roughness of different composites, porcelain, enamel and dentin surfaces

    PubMed Central

    Yurdaguven, Haktan; Aykor, Arzu; Ozel, Emre; Sabuncu, Hilmi; Soyman, Mubin

    2012-01-01

    Objective: To investigate the effect of a prophylaxis paste on surface roughness of different composites, enamel, dentin and porcelain surfaces. Methods: Three different composites (FiltekZ250/Group1, Filtek Supreme XT/Group2, Premise/Group3), enamel/Group4, dentin/Group5 and porcelain/Group6 samples were used in this study. All specimens were prepared flat by SiC discs and polished with a diamond polishing paste. The surface roughness measurements were determined with a profilometer after polishing (initial surface roughness). Prophylaxis paste was applied to the samples for 12 seconds, renewing every 6 seconds. After cleaning the samples, roughness values were measured again. Data were analyzed by Kruskal Wallis and Dunn’s multiple comparison test. Wilcoxon test was performed for the comparison of the initial and final surface roughness values (P<.05). The results were evaluated within the P<.05 confidence level. Results: The initial and final surface roughness values (μm) were determined as follows: Group1: 0.039±0.009 and 0.157±0.018, Group2: 0.023±0.005 and 0.145±0.027, Group3: 0.028±0.008 and 0.109±0.012, Group4: 0.024±0.006 and 0.071±0.015, Group5: 0.030±0.007 and 0.143±0.029, Group6: 0.024±0.006 and 0.064±0.014. Significant difference was determined between the initial and final values for all groups. Conclusions: Composite and dentin surfaces were more affected by the application of prophylaxis paste than enamel and porcelain surfaces. The prophylaxis paste increased the surface roughness of all groups, but did not reach the bacterial retention roughness rate of 0.2μm. PMID:22229001

  12. Shear bond strength of dental porcelains to nickel-chromium alloys.

    PubMed

    do Prado, Ricardo Alves; Panzeri, Heitor; Fernandes Neto, Alfredo Julio; das Neves, Flávio Domingues; da Silva, Marlete Ribeiro; Mendonça, Gustavo

    2005-01-01

    The continuous technological advance and increasing availability of new base metal alloys and ceramic systems in the market, coupled to the demands of daily clinical practice, have made the constant evaluation of the bond strength of metal/porcelain combinations necessary. This study evaluated the metal/porcelain shear bond strength of three ceramic systems (Duceram, Williams and Noritake) in combination with three nickel-chromium (Ni-Cr) alloys (Durabond, Verabond and Viron). Thirty cast cylinder specimens (15 mm high; 6 mm in diameter) were obtained for each alloy, in a way that 10 specimens of each alloy were tested with each porcelain. Bond strength was measured with an Emic screw-driven mechanical testing machine by applying parallel shear forces to the specimens until fracture. Shear strength was calculated using the ratio of the force applied to a demarcated area of the opaque layer. Mann-Whitney U test was used for statistical analysis of the alloy/ceramic combinations (p<0.05). Viron/Noritake had the highest shear bond sregnth means (32.93 MPa), while Verabond/Duceram (16.31 MPa) presented the lowest means. Viron/Noritake differed statistically from other combinations (p<0.05). Viron/Duceram had statistically significant higher bond strengths than Verabond/Duceram, Verabond/Williams and Durabond/Noritake (p<0.05). It was also found significant difference (p<0.05) between Verabond/Noritake, Verabond/Duceram and Durabond/Noritake. No statistically significant difference (p>0.05) were observed among the other combinations. In conclusion, the Noritake ceramic system used together with Viron alloy presented the highest resistance to shear forces, while Duceram bonded to Verabond presented the lowest bond strength. Viron/Duceram and Verabond/Noritake provided intermediate results. The combinations between the Williams ceramic system and Ni-Cr alloys had similar shear strengths among each other. PMID:16429185

  13. [Pharmacists as pioneers in porcelain production: what the service, Flora Danica owe to the Bordeaux's apothecary Marc-Hilaire Vilaris].

    PubMed

    Devaux, Guy

    2004-01-01

    In 1766, The Bordeaux's apothecary Marc-Hilaire Vilaris (1719-1792) identified with certainty a kaolin's deposit at Saint-Yrieix, in the country of Limousin, allowing so the porcelain manufacture in France and the development of a china clay's and porcelain's dough trade. Archives documents give evidence of regularly supplies of limousin's raw materials by the pharmacist Frantz Heinrich Müller (1732-1820), Director of the Royal china's Manufactury of Denmark, some time before production of the famous table service Flora Danica. PMID:15264339

  14. Proper restorative material selection, digital processes allow highly esthetic shade match combined with layered porcelain.

    PubMed

    Kahng, Luke S

    2014-03-01

    Today's digital technologies are affording dentists and laboratory technicians more control over material choices for creating restorations and fabricating dental prostheses. Digital processes can potentially enable technicians to create ideal marginal areas and account for the thickness and support of layering porcelain over substructures in the design process. In this case report of a restoration of a single central incisor, a number of issues are addressed that are central to using the newest digital technology. As demonstrated, shade selection is a crucial early step in any restorative case preparation. PMID:24773196

  15. EDXRF analysis of Straits Chinese porcelains for zirconium and niobium using a cadmium-109 source

    SciTech Connect

    Yap, C.T.

    1986-08-01

    An annular Cd-109 source was used to induce fluorescent X-rays from 37 pieces of Straits Chinese porcelain of which four were modern pieces and the rest were produced from the nineteenth century up to the Republic period (1912-1939). Experimental data show that for zirconium and niobium infinite thickness is reached for a thickness of about 1.5 mm. A plot of the intensity of the K/sub ..cap alpha..//sub 1/ line of Zr against that of Nb shows that all Ch'ing and Republic pieces cluster together and are quite distinct from the modern pieces, allowing easy nondestructive identification of modern fakes.

  16. Automatically controlled high temperature furnace for the first firing of porcelain products

    SciTech Connect

    Kryzhanovskii, K.S.; Davidenko, V.K.; Oliyarnik, P.N.

    1987-11-01

    A computer-controlled gas furnace, intended for the first firing of porcelain products, is described. The design specifications include measures taken for protecting the firing products from contamination by combustion products and structural imhomogeneities caused by nonuniform temperature distributions, as well as temperature and combustion control regimes to ensure maximum energy utilization during firing. Burner and fuel system configurations are described, performance data on fuel economy, quality control, and productivity are determined, and results of a cost benefit analysis on the implementation of the furnace in industry are given.

  17. The minimum thickness of a multilayer porcelain restoration required for masking severe tooth discoloration

    PubMed Central

    Shadman, Niloofar; Kandi, Saeideh Gorji; Ebrahimi, Shahram Farzin; Shoul, Maryam Azizi

    2015-01-01

    Background: Although studies have shown that porcelain veneers are very efficient for treating discolored teeth, they did not address in particular the minimum thickness of a multilayer IPS e.max Press (IvoclarVivadent, Schaan, Liechtenstein) restoration required to mask discolored tooth. The aim of this study was to determine the minimum thickness of a multilayer porcelain restoration required for masking severe tooth discoloration. Materials and Methods: A total of 24 disk-shaped multilayer specimens were prepared from IPS e.max Press with the diameter of 13 mm and four different thicknesses (core/veneer: 0.4/0.4 mm, 0.5/0.5 mm, 0.6/0.6 mm and 0.8/0.7 mm). Two backgrounds, C4-shade body porcelain and an opaque background from the selected IPS e.max ceramic itself were fabricated to mimic a discolored or stained natural tooth structure and to determine the masking ability. After applying the resin cement layer (Panavia F2.0) with 0.01 mm thickness on each background, all specimens were measured on both background using a spectrophotometer and values of L*, a* and b* were calculated to determine the color differences (ΔE*ab). One-way ANOVA and post-hoc tests of specimen average one-to-one comparison (Tukey HSD) were conducted and P ≤ 0.05 was set as the level of significance. Results: ΔE*ab of all groups were within the range of the clinically acceptable color difference (ΔE≤3.3), thus all the groups could mask the C4 background even group 1 with only 0.8 mm thickness. A trend was shown in the results as by increasing the thickness, ΔE*ab is was decreased. The mean ΔE*1*a*b between different thicknesses were statistically significant (P < 0.05) only between group 4 with groups 1 and 2, respectively. Conclusion: Within the limitations of this study, all studied thicknesses could mask the C4 background. However, the minimum thickness of a multilayer porcelain restoration (IPS e.max Press) required for masking severe tooth discoloration was 0.8 mm. PMID

  18. Topological Invariants and CW Complexes of Cartesian Product and Hexagonal Tiling Paces

    NASA Astrophysics Data System (ADS)

    Escudero, Juan García

    2011-09-01

    The cohomology of a class of cartesian product tiling spaces in N dimensions when the inflation factor is a Pisot-Vijayaraghavan unit is analyzed. A CW complex for an hexagonal tiling space is defined in terms of collared tiles for the study of its topological invariants.

  19. Effect of tile effluent on nutrient concentration and retention efficiency in agricultural drainage ditches

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tile drainage is a common water management practice in many agricultural landscapes in the Midwestern United States. Drainage ditches regularly receive water from agricultural fields through these tile drains. This field-scale study was conducted to determine the impact of tile discharge on ambient ...

  20. A scintillating tile/fiber system for the CDF plug upgrade EM calorimeter

    NASA Astrophysics Data System (ADS)

    Aota, S.; Asakawa, T.; Hara, K.; Hayashi, E.; Kim, S.; Kondo, K.; Kuwabara, T.; Miyashita, S.; Nakada, H.; Nakano, I.; Seiya, Y.; Takikawa, K.; Toyoda, H.; Uchida, T.; Yasuoka, K.; Mishina, M.; Iwai, J.; Albrow, M.; Freeman, J.; Limon, P. J.

    1995-01-01

    The plug calorimeter of the Collider Detector at Fermilab (CDF) [1] will be upgraded, replacing the existing gas calorimeter by a scintillating tile/fiber calorimeter. We have completed R&D for the CDF plug upgrade EM calorimeter. We describe the results of the R&D leading to the final design of the tile/fiber system for the calorimeter. Kuraray SCSN38, Kuraray Y11 and PET film (E65) were chosen as materials for scintillating tiles, wavelength shifting (WLS) fibers and a surface reflector on tiles, respectively, in view of obtaining large light yield and uniform response from a tile/fiber system. We decided fiber groove path in a tile, groove cross-sectional shape and groove depth for each tile to get uniform response from a tile/fiber. For the tile/fiber system of the final design, the average light yield was larger than 3.0 photoelectrons per minimum ionizing particle (MIP), the response uniformity in a tile was less than 2.5% and a total cross talk from a tile to the adjacent tiles was less than 2.0%. These results satisfied our requirements.

  1. Steep-Slope Assembly Testing of Clay and Concrete Tile With and Without Cool Pigmented Colors

    SciTech Connect

    Miller, William A

    2005-11-01

    Cool color pigments and sub-tile venting of clay and concrete tile roofs significantly impact the heat flow crossing the roof deck of a steep-slope roof. Field measures for the tile roofs revealed a 70% drop in the peak heat flow crossing the deck as compared to a direct-nailed asphalt shingle roof. The Tile Roofing Institute (TRI) and its affiliate members are keenly interested in documenting the magnitude of the drop for obtaining solar reflectance credits with state and federal "cool roof" building efficiency standards. Tile roofs are direct-nailed or are attached to a deck with batten or batten and counter-batten construction. S-Misson clay and concrete tile roofs, a medium-profile concrete tile roof, and a flat slate tile roof were installed on fully nstrumented attic test assemblies. Temperature measures of the roof, deck, attic, and ceiling, heat flows, solar reflectance, thermal emittance, and the ambient weather were recorded for each of the tile roofs and also on an adjacent attic cavity covered with a conventional pigmented and directnailed asphalt shingle roof. ORNL measured the tile's underside temperature and the bulk air temperature and heat flows just underneath the tile for batten and counter-batten tile systems and compared the results to the conventional asphalt shingle.

  2. GROWTH EVALUATION OF FUNGI (PENICILLIUM AND ASPERGILLUS SPP.) ON CEILING TILES

    EPA Science Inventory

    The paper gives results of an evaluation of the potential for fungal growth on four different ceiling tiles in static chambers. It was found that even new ceiling tiles supported fungal growth under favorable conditions. Used ceiling tiles appeared to be more susceptible to funga...

  3. 40 CFR 427.70 - Applicability; description of the asbestos floor tile subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... asbestos floor tile subcategory. 427.70 Section 427.70 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Asbestos Floor Tile Subcategory § 427.70 Applicability; description of the asbestos floor tile...

  4. 40 CFR 427.70 - Applicability; description of the asbestos floor tile subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... asbestos floor tile subcategory. 427.70 Section 427.70 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Asbestos Floor Tile Subcategory § 427.70 Applicability; description of the asbestos floor tile...

  5. Nutrient export in tile drainage: Comparing manure injection to fertigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Subsurface tile drainage of agricultural land is implicated as a major source of nutrients to the Mississippi River. To protect water quality, land application of manure should maximize crop nutrient use and minimize nutrient loss. Weather constraints and regulations restrict the period during which...

  6. EVALUATION OF FUNGAL GROWTH (PENICILLIUM GLABRUM) ON A CEILING TILE

    EPA Science Inventory

    The paper gives results of a study employing static chambers to study the impact of different equilibrium relative humidities (RHs) and moisture conditions on the ability of a new ceiling tile to support fungal growth. Amplification of the mold, Penicillium glabrum, occurred at R...

  7. Nutrient Transport in Tile-Fed Drainage Ditches

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drainage ditches receive water and associated contaminants from agricultural fields via surface runoff or sub-surface tile drains. Little consideration has been given to the processes affecting nutrient transport once in surface water. The objective of this research was to evaluate the nutrient fa...

  8. EVALUATION OF FUNGAL GROWTH (PENICILLIUM GLABRUM) ON A CEILING TILE

    EPA Science Inventory

    The paper gives results of a study employing static chambers to study the impact of different equilibrium relative humidities (RHs) and moisture conditions on the ability of a new ceiling tile to support fungal growth. mplification of the mold, Penicillium glabrum, occurred at RH...

  9. In-Field Bioreactor for Removing Nitrate from Tile Drainage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nitrate in water leaving subsurface drain ('tile') systems often exceeds the 10 mg-N L-1 maximum contaminant level (MCL) set by the U.S. EPA for drinking water and has been implicated in contributing to the hypoxia problem within the Gulf of Mexico. Much of the NO3 from agricultural lands impacting ...

  10. A design rationale for NASA TileWorld

    NASA Technical Reports Server (NTRS)

    Philips, Andrew B.; Swanson, Keith J.; Drummond, Mark E.; Bresina, John L.

    1991-01-01

    Automated systems that can operate in unrestricted real-world domains are still well beyond current computational capabilities. This paper argues that isolating essential problem characteristics found in real-world domains allows for a careful study of how particular control systems operate. By isolating essential problem characteristics and studying their impact on autonomous system performance, we should be able to more quickly deliver systems for practical real-world problems. For our research on planning, scheduling, and control, we have selected three particular domain attributes to study: exogenous events, uncertain action outcome, and metric time. We are not suggesting that studies of these attributes in isolation are sufficient to guarantee the obvious goals of good methodology, brilliant architectures, or first-class results; however, we are suggesting that such isolation facilitates the achievement of these goals. To study these attributes, we have developed the NASA TileWorld. We describe the NASA TileWorld simulator in general terms, present an example NASA TileWorld problem, and discuss some of our motivations and concerns for NASA TileWorld.

  11. A novel surface defect inspection algorithm for magnetic tile

    NASA Astrophysics Data System (ADS)

    Xie, Luofeng; Lin, Lijun; Yin, Ming; Meng, Lintao; Yin, Guofu

    2016-07-01

    In this paper, we propose a defect extraction method for magnetic tile images based on the shearlet transform. The shearlet transform is a method of multi-scale geometric analysis. Compared with similar methods, the shearlet transform offers higher directional sensitivity and this is useful to accurately extract geometric characteristics from data. In general, a magnetic tile image captured by CCD camera mainly consists of target area, background. Our strategy for extracting the surface defects of magnetic tile comprises two steps: image preprocessing and defect extraction. Both steps are critical. After preprocessing the image, we extract the target area. Due to the low contrast in the magnetic tile image, we apply the discrete shearlet transform to enhance the contrast between the defect area and the normal area. Next, we apply a threshold method to generate a binary image. To validate our algorithm, we compare our experimental results with Otsu method, the curvelet transform and the nonsubsampled contourlet transform. Results show that our algorithm outperforms the other methods considered and can very effectively extract defects.

  12. Phosphorus modeling in tile drained agricultural systems using APEX

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phosphorus losses through tile drained systems in agricultural landscapes may be causing the persistent eutrophication problems observed in surface water. The purpose of this paper is to evaluate the state of the science in the Agricultural Policy/Environmental eXtender (APEX) model related to surf...

  13. Increasing the frost resistance of facade glazed tiles

    SciTech Connect

    Egerev, V.M.; Zotov, S.N.; Romanova, G.P.

    1986-09-01

    The authors investigate the protective properties of a coating of boron oxides and zirconium oxides applied as a glaze to ceramic tiles by conducting a series of tests to determine the frost resistance, the propensity to absorb water, the moisture expansion coefficient, the fracture behavior, and the effect of thermal cycling on the oxides. Results are graphed and tabulated.

  14. Contributions of systematic tile drainage to watershed scale phosphorus transport

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phosphorus (P) transport from agricultural fields continues be a focal point for addressing harmful algal blooms (HABs) and nuisance algae in freshwater systems throughout the world. In humid, poorly drained regions, attention has turned to P delivery through subsurface tile drainage. Research on th...

  15. Water Quality from Grass-Based Dairy Farm Tile Lines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Subsurface water quality from agricultural systems varies with the type of system and management. Systems with high inputs from fertilizer and/or manure may have high nutrient levels, e.g. NO3-N, in subsurface water. This study investigates the water quality from tile lines on grass-based dairy fa...

  16. Tiled architecture of a CNN-mostly IP system

    NASA Astrophysics Data System (ADS)

    Spaanenburg, Lambert; Malki, Suleyman

    2009-05-01

    Multi-core architectures have been popularized with the advent of the IBM CELL. On a finer grain the problems in scheduling multi-cores have already existed in the tiled architectures, such as the EPIC and Da Vinci. It is not easy to evaluate the performance of a schedule on such architecture as historical data are not available. One solution is to compile algorithms for which an optimal schedule is known by analysis. A typical example is an algorithm that is already defined in terms of many collaborating simple nodes, such as a Cellular Neural Network (CNN). A simple node with a local register stack together with a 'rotating wheel' internal communication mechanism has been proposed. Though the basic CNN allows for a tiled implementation of a tiled algorithm on a tiled structure, a practical CNN system will have to disturb this regularity by the additional need for arithmetical and logical operations. Arithmetic operations are needed for instance to accommodate for low-level image processing, while logical operations are needed to fork and merge different data streams without use of the external memory. It is found that the 'rotating wheel' internal communication mechanism still handles such mechanisms without the need for global control. Overall the CNN system provides for a practical network size as implemented on a FPGA, can be easily used as embedded IP and provides a clear benchmark for a multi-core compiler.

  17. Direct readout of gaseous detectors with tiled CMOS circuits

    NASA Astrophysics Data System (ADS)

    Visschers, J. L.; Blanco Carballo, V.; Chefdeville, M.; Colas, P.; van der Graaf, H.; Schmitz, J.; Smits, S.; Timmermans, J.

    2007-03-01

    A coordinated design effort is underway, exploring the three-dimensional direct readout of gaseous detectors by an anode plate equipped with a tiled array of many CMOS pixel readout ASICs, having amplification grids integrated on their topsides and being contacted on their backside.

  18. Breakthrough of two pesticides into tile drain and shallow groundwater: comparison of tile drain reaction and soil profiles within a field scale irrigation experiment

    NASA Astrophysics Data System (ADS)

    Klaus, Julian; Zehe, Erwin; Elsner, Martin; Palm, Juliane; Schneider, Dorothee; Schröder, Boris; Steinbeiss, Sibylle; West, Stephanie

    2010-05-01

    and bromide. The tile drain water showed traces of bromide and both pesticides within a few minutes. IPU showed highest concentration before the hydrograph started to increase, while bromide and FLU are strongly correlated to the hydrograph. Although IPU is less sorptive than FLU the concentrations and total transported mass of FLU were significantly higher then for IPU. The hydrograph reacted with two peaks on the three block irrigation; the two peaks can be attributed to the second and third irrigation block. Analysis of the water isotopes showed that during the experiment the event water mainly consisted of soil water. While the tile drain showed significant reaction in pesticides transport the picture deriving from soil profiles were different. Especially FLU was found mainly in the upper soil parts, so the bypassing might occurred so fast that it was only marginally absorbed in deeper soil party, but transported to the drain or shallow groundwater. As preferential flow paths earthworm burrows of different species could be identified, although the area density and species number of anecic earthworms was quite low compared to other field sites.

  19. Influence of framework design, contraction mismatch, and thermal history on porcelain checking in fixed partial dentures.

    PubMed

    Anusavice, K J; Gray, A E

    1989-01-01

    The objective of this study was to characterize the relative influence of contraction mismatch, framework design, furnace type, cooling rate, and multiple firings on immediate or delayed checking in fixed partial dentures. Frameworks for 60 anterior bridges (three-unit fixed partial dentures) were cast from a low-expansion Au-Pd alloy (O) and a high-expansion Pd-Ag alloy (J). A high-expansion porcelain (B) was applied to each of three framework designs. Firing was performed at heating rates of 56 degrees C/min and 180 degrees C/min. Specimens were cooled at two rates after each of five glazing cycles. For O-B specimens which exhibited a negative thermal contraction mismatch between 600 degrees C and 25 degrees C, 60% of the bridge specimens failed when they were subjected to slow cooling preceded by either fast or slow heating. When J-B specimens (which exhibited a smaller negative contraction mismatch) were heated and cooled rapidly, no failures occurred through all of the firing cycles. However, cracks were observed in 13.3% of the J-B bridges which were slowly heated and rapidly cooled. Delayed cracks (after the fifth glaze cycle) developed over periods of up to two years only in bridges which were slowly cooled in the furnace chamber. The results of this study suggest that checking in conventional feldspathic porcelains can be promoted by slow cooling rates and an excessive number of firing cycles. PMID:2691298

  20. Use of glazes on porcelain from near ground zero to measure Hiroshima neutron fluence.

    PubMed

    MacDonald, J; Fleischer, R L; Fujita, S; Hoshi, M

    2003-10-01

    Several porcelain samples from almost directly beneath the atomic explosion at Hiroshima on 6 August 1945, have been scanned for induced fission tracks, produced mostly by the thermal neutrons from the bomb due to interactions with trace uranium in their glass coatings. The ability to use porcelain opens a new and abundant material for retrospective dosimetry. Four different samples had thermal neutron fluences in 1945 of 1.0, 3.8, 4.1, and 8.9 x 10(12) cm(-2). The different values are not caused by track fading, but are likely to result from differing shielding at different nearby positions. Assuming that the three highest fluences, which have overlapping uncertainties, are at locations of minimum shielding, the statistically weighted thermal fluence in the air at ground level and ground zero was 4.8 x 10(12) cm(-2) with a statistical uncertainty of 15%. This value lies between the calculated value of 6.5 x 10(12) given in DS86 and the 3.7 x 10(12) inferred from induced radionuclides by Hoshi et al. (1998). PMID:13678283

  1. Comparison of shear bond strength of two porcelain repair systems after different surface treatment

    PubMed Central

    Kalra, Ashish; Mohan, Murali S.; Gowda, E. Mahesh

    2015-01-01

    Introduction: Intraoral chair side porcelain repair system is a quick, painless and highly patient acceptable procedure, without removal of restoration or fabrication of new restoration. There are very limited studies conducted to evaluate the shear bond strength of repair systems after different surface treatment. Objectives of Research: The objective of research was to evaluate the shear bond strength of two intraoral porcelain repair systems Clearfil repair system (Kuraray) and Ceramic repair system (Ivoclar) to repair metal-ceramic restoration after three different surface treatment. Materials and Methods: Totally, 120 discs of base metal alloy were fabricated. The opaque, dentine and enamel of ceramic were applied to achieve the uniform thickness. Defect was created, and repair was done using two repair systems after different surface treatment. Shear bond strength was measured. Results: Analysis of variance was utilized. Ceramic repair system after 40% phosphoric acid surface treatment showed the highest mean value and Clearfil repair system after surface treatment with 37% phosphoric acid showed the lowest. The statistical difference was found to be significant between the groups. Conclusion: The shear bond strength of Ceramic repair system with 40% phosphoric acid etching showed highest shear bond strength as compared to other system and surface treatment used in the study. PMID:26097354

  2. Identification of proteins interacting with lactate dehydrogenase in claw muscle of the porcelain crab Petrolisthes cinctipes

    PubMed Central

    Cayenne, Andrea P.; Gabert, Beverly; Stillman, Jonathon H.

    2011-01-01

    Biochemical adaptation of enzymes involves conservation of activity, stability and affinity across a wide range of intracellular and environmental conditions. Enzyme adaptation by alteration of primary structure is well known, but the roles of protein-protein interactions in enzyme adaptation are less well understood. Interspecific differences in thermal stability of lactate dehydrogenase (LDH) in porcelain crabs (genus Petrolisthes) are related to intrinsic differences among LDH molecules and by interactions with other stabilizing proteins. Here, we identified proteins that interact with LDH in porcelain crab claw muscle tissue using co-immunoprecipitation, and showed LDH exists in high molecular weight complexes using size exclusion chromatography and Western blot analyses. Co-immunoprecipitated proteins were separated using 2D SDS PAGE and analyzed by LC/ESI using peptide MS/MS. Peptide MS/MS ions were compared to an EST database for Petrolisthes cinctipes to identify proteins. Identified proteins included cytoskeletal elements, glycolytic enzymes, a phosphagen kinase, and the respiratory protein hemocyanin. Our results support the hypothesis that LDH interacts with glycolytic enzymes in a metabolon structured by cytoskeletal elements that may also include the enzyme for transfer of the adenylate charge in glycolytically produced ATP. Those interactions may play specific roles in biochemical adaptation of glycolytic enzymes. PMID:21968246

  3. Effect of the Chemical Composition on The Pyroplastic Deformation of Sanitaryware Porcelain Body

    NASA Astrophysics Data System (ADS)

    Yeşim Tunçel, Derya; Kerim Kara, Mustafa; Özel, Emel

    2011-10-01

    Pyroplastic deformation is the bending of a ceramic specimen caused by gravity during heat treatment. It can be defined as the loss of shape of product during its firing. Pyroplastic deformation is related to properties of liquid phases formed during firing. Therefore, the effect of the chemical composition on the pyroplastic deformation of sanitaryware porcelain was investigated in this study. Systematical compositional arrangements were made according to different combinations of (SiO2/Al2O3) and (Na2O/K2O) ratios by using Seger formula approach. Pyroplastic deformation behaviour of compositions within a controlled firing regime was investigated by using fleximeter. The bodies were also prepared in a special form by slip casting method at laboratory scale in order to determine the pyroplastic deformation of the samples. The experimental results showed that a definite combination at SiO2/Al2O3 ratio of 5 and Na2O/K2O ratio of 4 give the lowest pyroplastic deformation in the porcelain body formulations. The pyroplastic deformation value of this composition was determined as 25 mm which is 44% lower than that of the standard composition (45 mm).

  4. Relation Between Roughness of Interface and Adherence of Porcelain Enamel to Steel

    NASA Technical Reports Server (NTRS)

    Richmond, J C; Moore, D G; Kirkpatrick, H B; Harrison, W N

    1954-01-01

    Porcelain-enamel ground coats were prepared and applied under conditions that gave various degrees of adherence between enamel and a low-carbon steel (enameling iron). The variations in adherence were produced by (a) varying the amount of cobalt-oxide addition in the frit, (b) varying the type of metallic-oxide addition in the frit, keeping the amount constant at 0.8 weight percent, (c) varying the surface treatment of the metal before application of the enamel, by pickling, sandblasting, and polishing, and (d) varying the time of firing of the enamel containing 0.8 percent of cobalt oxide. Specimens of each enamel were given the standard adherence test of the Porcelain Enamel Institute. Metallographic sections were made on which the roughness of interface was evaluated by counting the number of anchor points (undercuts) per centimeter of specimen length and also by measuring the length of the interface and expressing results as the ratio of this length to the length of a straight line parallel to the over-all direction of the interface.

  5. 52. UPPER PART OF BISCUIT KILN No 4, FROM THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    52. UPPER PART OF BISCUIT KILN No 4, FROM THE SECOND FLOOR. REPRODUCTION MOSAIC MOLDS ARE IN THE FOREGROUND. - Moravian Pottery & Tile Works, Southwest side of State Route 313 (Swamp Road), Northwest of East Court Street, Doylestown, Bucks County, PA

  6. Fixed tile rate codec for bandwidth saving in video processors

    NASA Astrophysics Data System (ADS)

    Lachine, Vladimir; Dinh, Chon-Tam Le; Le, Dinh Kha; Wong, Jeffrey

    2014-02-01

    The paper presents an image compression circuit for bandwidth saving in video display processors. This is intra frame tile based compression algorithm offering visually lossless quality for compression rates between 1.5 and 2.5. RGB and YCbCr (4:4:4, 4:2:2 and 4:2:0) video formats are supported for 8/10 bits video signals. The Band Width Compressor (BWC) consists of Lossless Compressor (LC) and Quantization Compressor (QC) that generate output bit streams for tiles of pixels. Size of output bit stream generated for a tile by the LC may be less or greater than a required size of output memory block. The QC generates bit stream that always fits output memory block of the required size. The output bit stream generated by the LC is transmitted if its size is less than the required size of the output memory block. Otherwise, the output bit stream generated by the QC is transmitted. The LC works on pixel basis. A difference between original and predicted pixel's values for each pixel of a tile is encoded as prefix and suffix. The prefix is encoded by means of variable length code, and suffix is encoded as is. The QC divides a tile of pixels on a set of blocks and quantizes pixels of each block independently of the other blocks. The number of quantization bits for all pixels of a block depends on standard deviation calculated over the block. A difference between pixel's value and average value over the block is quantized and transmitted.

  7. Substructure procedure for including tile flexibility in stress analysis of shuttle thermal protection system

    NASA Technical Reports Server (NTRS)

    Giles, G. L.

    1980-01-01

    A substructure procedure to include the flexibility of the tile in the stress analysis of the shuttle thermal protection system (TPS) is described. In this procedure, the TPS is divided into substructures of (1) the tile which is modeled by linear finite elements and (2) the SIP which is modeled as a nonlinear continuum. This procedure was applied for loading cases of uniform pressure, uniform moment, and an aerodynamic shock on various tile thicknesses. The ratios of through-the-thickness stresses in the SIP which were calculated using a flexible tile compared to using a rigid tile were found to be less than 1.05 for the cases considered.

  8. Improvement in Ti-porcelain bonding by SiO(2) modification of titanium surface through cast method.

    PubMed

    Wei, Yanhua; Zhang, Zutai; Ding, Ning; Zheng, Dongxiang; Li, Hui; Liu, Xu

    2013-01-01

    This study aimed to improve Ti-porcelain bonding strength through SiO2 modifications. Wax patterns were coated with SiO2 mixed with tetraethoxy silane (group C), patterns without coating were used as controls and subdivided into sandblasting group (group S) and polishing group (group P). Castingsurfaces were analyzed with XRD, while Ti-ceramic interfaces were characterized using SEM/EDS. Metal-ceramic specimens were tested in three point bending, and characterizations were also analyzed with SEM/EDS of porcelain debonding surfaces. In group C, SiO2 and Ti5Si3 phases were observed; SEM micrograph showed that Ti-porcelain had a compacted interface, and EDS maps of the interface illustrated the diffusion of Si, Al, and Sn to Ti, and cohesive fracture within the bonding agent. The bond strength of group C was 39.04±5.0 MPa, which was 15% higher than that of group S and 32% higher than that of group P. SiO2 coating could improve Ti-porcelain bond strength. PMID:23903637

  9. 76 FR 7534 - Porcelain-on-Steel Cooking Ware from the People's Republic of China: Final Results of the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-10

    ... FR 60731 (October 1, 2010) (``Sunset Initiation''); see also Antidumping Duty Order; Porcelain-on-Steel Cooking Ware from the People's Republic of China, 51 FR 43414 (December 2, 1986) (``Order''). On... Initiation, 75 FR 60731. On October 18, 2010, the Department received a timely notice of intent...

  10. The effect of abrasive blasting on the strength of a joint between dental porcelain and metal base.

    PubMed

    Pietnicki, Krzysztof; Wołowiec, Emilia; Klimek, Leszek

    2014-01-01

    This paper presents the effect of selected parameters of abrasive blasting on the strength of a joint between dental porcelain and metal base. Experiments were conducted for different grain sizes of abrasive material and different blasting angles, with a constant blasting pressure. InLine dental porcelain was fused on samples of cobalt-chromium alloy following abrasive blasting; they were subsequently subjected to shearing forces on a testing machine. The fractures were observed under an electron scanning microscope in order to determine the character and course of fracturing. Strength tests showed that the grain size of abrasive material was a parameter with the greatest effect on the strength. The best effects were achieved for samples subjected to abrasive blasting with material with grain size of 110 μm. No statistically significant differences were found for the strength of samples worked at different angles. The results of the fractographic examinations have shown that in all the samples, fracturing occurred mainly along the porcelain-metal boundary, with few cases of fracturing through porcelain. PMID:24708248

  11. Evaluation of the Hooghoudt and Kirkham tile drain equations in SWAT to simulate tile flow and nitrate-nitrogen

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Subsurface tile drains in agricultural systems of Midwest U.S. are a major contributor of nitrate-N (NO3-N) loadings to hypoxic conditions in the Gulf of Mexico. Existing soil moisture retention parameter computation algorithm in the widely used Soil and Water Assessment Tool (SWAT) model is known t...

  12. Tile-in-ONE An integrated framework for the data quality assessment and database management for the ATLAS Tile Calorimeter

    NASA Astrophysics Data System (ADS)

    Cunha, R.; Solans, C.; Sivolella, A.; Ferreira, F.; Maidantchik, C.

    2014-06-01

    In order to ensure the proper operation of the ATLAS Tile Calorimeter and assess the quality of data, many tasks are performed by means of several tools which have been developed independently. The features are displayed into standard dashboards, dedicated to each working group, covering different areas, such as Data Quality and Calibration.

  13. Analysis of elemental maps from glaze to body of ancient Chinese Jun and Ru porcelain by micro-X-ray fluorescence

    NASA Astrophysics Data System (ADS)

    Cheng, Lin; Li, Rongwu; Pan, Qiuli; Li, Guoxia; Zhao, Weijuan; Liu, Zhiguo

    2009-01-01

    The reasons how the middle layer of Ru and Jun porcelain between the glaze and body came into being are still not completely understood. Here, elemental maps from the glaze to the body of pieces of ancient Chinese Ru and Jun porcelain were analyzed by micro-X-ray fluorescence. The results show the middle layer was probably formed by the chemical composition of the glaze turning into glassy states and undergoing complex physical-chemical reactions with the body. However, the middle layer of Jun porcelain was formed by the chemical composition of the glaze turning into glassy states and then infiltrating the body at high temperatures during the firing process.

  14. The TileCal Online Energy Estimation for the Next LHC Operation Period

    NASA Astrophysics Data System (ADS)

    Sotto-Maior Peralva, B.; ATLAS Collaboration

    2015-05-01

    The ATLAS Tile Calorimeter (TileCal) is the detector used in the reconstruction of hadrons, jets and missing transverse energy from the proton-proton collisions at the Large Hadron Collider (LHC). It covers the central part of the ATLAS detector (|η| < 1.6). The energy deposited by the particles is read out by approximately 5,000 cells, with double readout channels. The signal provided by the readout electronics for each channel is digitized at 40 MHz and its amplitude is estimated by an optimal filtering algorithm, which expects a single signal with a well-defined shape. However, the LHC luminosity is expected to increase leading to pile-up that deforms the signal of interest. Due to limited resources, the current hardware setup, which is based on Digital Signal Processors (DSP), does not allow the implementation of sophisticated energy estimation methods that deal with the pile-up. Therefore, the technique to be employed for online energy estimation in TileCal for next LHC operation period must be based on fast filters such as the Optimal Filter (OF) and the Matched Filter (MF). Both the OF and MF methods envisage the use of the background second order statistics in its design, more precisely the covariance matrix. However, the identity matrix has been used to describe this quantity. Although this approximation can be valid for low luminosity LHC, it leads to biased estimators under pile- up conditions. Since most of the TileCal cell present low occupancy, the pile-up, which is often modeled by a non-Gaussian distribution, can be seen as outlier events. Consequently, the classical covariance matrix estimation does not describe correctly the second order statistics of the background for the majority of the events, as this approach is very sensitive to outliers. As a result, the OF (or MF) coefficients are miscalculated leading to a larger variance and biased energy estimator. This work evaluates the usage of a robust covariance estimator, namely the Minimum

  15. Analytical solutions for two-dimensional groundwater flow with subsurface drainage tiles

    NASA Astrophysics Data System (ADS)

    Liang, Xiuyu; Zhang, You-Kuan; Schilling, Keith E.

    2015-02-01

    The tile drainage problem in an unconfined aquifer was investigated. A mathematical model was established that describes two-dimensional groundwater flow in an unconfined aquifer near a river with a linearized Boussinesq equation, time-dependent sources and a sloped tile. Analytical solutions for groundwater level and discharge were derived and used to compare hydrologic conditions in a system with and without tile (natural drainage). We found that the spatial and temporal variations of groundwater level and discharge were significantly altered by the presence of drainage tile. In an aquifer with tile drainage, the groundwater level was lower and total groundwater discharge to the river increased compared to an aquifer with no tile. Application of the solutions to a synthetic case demonstrates that the analytical solutions derived can be used to quantify effect of tiles on nitrate loads in the baseflow of a river and assess the effectiveness of various conservation practices.

  16. Life considerations of the shuttle orbiter densified-tile thermal protection system

    NASA Technical Reports Server (NTRS)

    Cooper, P. A.; Sawyer, J. W.

    1983-01-01

    The Shuttle orbiter themal protection system (TPS) incorporates ceramic reusable surface insulation tiles bonded to the orbiter substructure through a strain isolation pad. Densification of the bonding surface of the tiles increases the static strength of the tiles. The densification proces does not, however, necessarily lead to an equivalent increase in fatigue strength. Investigation of the expected lifetime of densified tile TPS under both sinusoidal loading and random loading simulating flight conditions indicates that the strain isolation pads are the weakest components of the TPS under fatigue loading. The felt pads loosen under repetitive loading and, in highly loaded regions, could possibly cause excessive step heights between tiles causing burning of the protective insulation between tiles. A method of improving the operational lifetime of the TPS by using a strain isolation pad with increased stiffness is presented as is the consequence of the effect of increased stiffness on the tile inplane strains and transverse stresses.

  17. Shear Bond Strengths of Methacrylate- and Silorane-based Composite Resins to Feldspathic Porcelain using Different Adhesive Systems.

    PubMed

    Mohammadi, Narmin; Shakur Shahabi, Maryam; Kimyai, Soodabeh; Pournagi Azar, Fatemeh; Ebrahimi Chaharom, Mohammad Esmaeel

    2015-01-01

    Background and aims. Use of porcelain as inlays, laminates and metal-ceramic and all-ceramic crowns is common in modern dentistry. The high cost of ceramic restorations, time limitations and difficulty of removing these restorations result in delays in replacing fractured restorations; therefore, their repair is indicated. The aim of the present study was to compare the shear bond strengths of two types of composite resins (methacrylate-based and silorane-based) to porcelain, using three adhesive types. Materials and methods. A total of 156 samples of feldspathic porcelain surfaces were prepared with air-abrasion and randomly divided into 6 groups (n=26). In groups 1-3, Z250 composite resin was used to repair porcelain samples with Ad-per Single Bond 2 (ASB), Clearfil SE Bond (CSB) and Silorane Adhesive (SA) as the bonding systems, afterapplication of silane, respectively. In groups 4-6, the same adhesives were used in the same manner with Filtek Silorane composite resin. Finally, the shear bond strengths of the samples were measured. Two-way ANOVA and post hoc Tukey tests were used to compare bond strengths between the groups with different adhesives at P<0.05. Results. There were significant differences in the mean bond strength values in terms of the adhesive type (P<0.001). In addition, the interactive effect of the adhesive type and composite resin type had no significant effect on bond strength (P=0.602). Conclusion. The results of the present study showed the highest repair bond strength values to porcelain with both composite resin types with the application of SA and ASB. PMID:26697151

  18. Shear Bond Strengths of Methacrylate- and Silorane-based Composite Resins to Feldspathic Porcelain using Different Adhesive Systems

    PubMed Central

    Mohammadi, Narmin; Shakur Shahabi, Maryam; Kimyai, Soodabeh; Pournagi Azar, Fatemeh; Ebrahimi Chaharom, Mohammad Esmaeel

    2015-01-01

    Background and aims. Use of porcelain as inlays, laminates and metal-ceramic and all-ceramic crowns is common in modern dentistry. The high cost of ceramic restorations, time limitations and difficulty of removing these restorations result in delays in replacing fractured restorations; therefore, their repair is indicated. The aim of the present study was to compare the shear bond strengths of two types of composite resins (methacrylate-based and silorane-based) to porcelain, using three adhesive types. Materials and methods. A total of 156 samples of feldspathic porcelain surfaces were prepared with air-abrasion and randomly divided into 6 groups (n=26). In groups 1-3, Z250 composite resin was used to repair porcelain samples with Ad-per Single Bond 2 (ASB), Clearfil SE Bond (CSB) and Silorane Adhesive (SA) as the bonding systems, afterapplication of silane, respectively. In groups 4-6, the same adhesives were used in the same manner with Filtek Silorane composite resin. Finally, the shear bond strengths of the samples were measured. Two-way ANOVA and post hoc Tukey tests were used to compare bond strengths between the groups with different adhesives at P<0.05. Results. There were significant differences in the mean bond strength values in terms of the adhesive type (P<0.001). In addition, the interactive effect of the adhesive type and composite resin type had no significant effect on bond strength (P=0.602). Conclusion. The results of the present study showed the highest repair bond strength values to porcelain with both composite resin types with the application of SA and ASB. PMID:26697151

  19. The Effect of Porcelain Firing and Type of Finish Line on the Marginal Fit of Zirconia Copings

    PubMed Central

    Vojdani, Mahroo; Safari, Anahita; Mohaghegh, Mina; Pardis, Soheil; Mahdavi, Farideh

    2015-01-01

    Statement of the Problem Although all-ceramic restorations are broadly used, there is a lack of information concerning how their fit is affected by fabrication procedure and marginal configuration. Purpose The purpose of this study was to evaluate the marginal fit of zirconia CAD/CAM ceramic crowns before and after porcelain firing. The influence of finish line configuration on the marginal fit was also evaluated. Materials and Method Twenty standardized zirconia CAD/CAM copings were fabricated for chamfer and shoulder finish line designs (n=10). The marginal fit of specimens was measured on 18 points, marked on the master metal die by using a digital microscope. After the crowns were finalized by porcelain veneering, the measurements of marginal fit were performed again. The means and standard deviations were calculated and data were analyzed using student’s t-test and paired t-test (α=0.05). Results There were significant differences between marginal fit of chamfer and shoulder finish line groups before and after porcelain firing (p= 0.014 and p= 0.000, respectively). The marginal gap of copings with shoulder finish line was significantly smaller than those with chamfer configuration (p= 0.000), but there were no significant differences between the two marginal designs, after porcelain firing (p= 0.341). Conclusion Porcelain veneering was found to have a statistically significant influence on the marginal fit of zirconia CAD/CAM crowns. Both margin configurations showed marginal gaps that were within a reported clinically acceptable range of marginal discrepancy. PMID:26046107

  20. Evolution of silica coating layer on titanium surface and the effect on the bond strength between titanium and porcelain

    NASA Astrophysics Data System (ADS)

    Wang, Aili; Ge, Chaoqun; Yin, Hengbo; Gao, Yu; Jiang, Tao; Xia, Chunlin; Wu, Gang; Wu, Zhanao

    2013-07-01

    SiO2 coating layers were uniformly anchored at the surfaces of sandblasted/pre-oxidized commercially pure titanium (CP-Ti) substrates by the chemical deposition method using Na2SiO3 as the SiO2 precursor at the pH values of 8-10 with the Na2SiO3 concentrations of 0.05-0.5 mol/L. The SiO2 coating layers were composed of small-sized SiO2 nanoparticles with the average particle sizes ranging from 18.0 to 20.5 nm. After firing porcelain (Ti-22) on SiO2-coated sandblasted/pre-oxidized CP-Ti substrates, the bond strengths of CP-Ti and porcelain ranged from 33.56 to 40.43 MPa, which were detected by the three-point flexure bend test method. In the absence of SiO2 interlayer, the bond strength of sandblasted/pre-oxidized CP-Ti and porcelain was 25.6 MPa. The bond strengths in the presence of SiO2 interlayer were higher than that in the absence of SiO2 interlayer. On the other hand, when the CP-Ti substrates were only treated by hydrochloric acid pickling, the bond strengths of SiO2-coated acid-pickled CP-Ti and porcelain ranged from 12.99 to 16.59 MPa. The chemical interaction between the SiO2 interlayers and the oxidized CP-Ti surfaces probably played an important role in increasing the bond strength of CP-Ti and porcelain.

  1. Upgrade of the Laser calibration system for the ATLAS hadronic calorimeter TileCal

    NASA Astrophysics Data System (ADS)

    van Woerden, Marius Cornelis

    2016-07-01

    We present in this contribution the new system for Laser calibration of the ATLAS hadronic calorimeter TileCal. The Laser system is a part of the three stage calibration apparatus designed to compute the calibration factors of the individual cells of TileCal. The Laser system is mainly used to correct for short term drifts of the readout of the individual cells. A sub-percent accuracy in the control of the calibration factors is required. To achieve this goal in the LHC Run2 conditions, a new Laser system was designed. The architecture of the system is described with details on the new optical line used to distribute Laser pulses in each individual detector module and on the new electronics used to drive the Laser, to read out optical monitors and to interface the system with the ATLAS readout, trigger and slow control. The LaserII system has been fully integrated into the framework used for measuring calibration factors and for monitoring data quality. First results on the Laser system performances studied are presented.

  2. Thermal conductivity measurements of aerogel-impregnated shuttle tile at cryogenic temperatures

    NASA Astrophysics Data System (ADS)

    Helvensteijn, B. P. M.; Maddocks, J. R.; Salerno, L. J.; Roach, P. R.; Kittel, P.; White, S. M.

    2002-05-01

    New materials are being designed to allow the implementation of innovative concepts in future space transportation vehicles. In present day spacecraft, launch vehicles consist of an overall structure in which the cryogenic propellant tanks are mounted in a framework covered by an aeroshell. In NASA s next generation space transportation vehicles the innovative concept of conformal propellant tanks will be utilized. In addition to containing the propellants the cryogen tanks will serve as part of the main vehicle structure. This concept enables significant reduction in launch mass. Crucial to this approach will be the development of a material that will serve not only as cryogenic insulation on the launchpad and early in flight, but also as a thermal protection system (TPS), protecting the vehicle on re-entry. Prior to selection for this challenging application various material properties are to be assessed. The present paper discusses experimental results on the thermal conductivity of a preliminary candidate material (an aerogel-impregnated shuttle tile) in the presence of helium gas. Data have been taken at room temperature and near 80 K at pressures ranging from 1 atm down to 20 m Torr. The capability to extend the tests down to lower temperatures (4 K) was not utilized considering the noted adsorptive qualities of the open cell structure of the tile.

  3. Large-scale testing of structural clay tile infilled frames

    SciTech Connect

    Flanagan, R.D.; Bennett, R.M.

    1993-03-18

    A summary of large-scale cyclic static tests of structural clay tile infilled frames is given. In-plane racking tests examined the effects of varying frame stiffness, varying infill size, infill offset from frame centerline, and single and double wythe infill construction. Out-of-plane tests examined infilled frame response to inertial loadings and inter-story drift loadings. Sequential in-plane and out-of-plane loadings were performed to determine the effects of orthogonal damage and degradation on both strength and stiffness. A combined out-of-plane inertial and in-plane racking test was conducted to investigate the interaction of multi-directional loading. To determine constitutive properties of the infills, prism compression, mortar compression and various unit tile tests were performed.

  4. Simulation and validation of the ATLAS Tile Calorimeter response

    NASA Astrophysics Data System (ADS)

    Karpov, S. N.

    2014-09-01

    The Tile Calorimeter is the central section of the ATLAS hadronic calorimeter at the Large Hadron Collider. Scintillation light produced in the tiles is transmitted by wavelength shifting fibers to photomultiplier tubes (PMTs). The resulting electronic signals from approximately 10000 PMTs are amplified, shaped and digitized before being transferred to off-detector data acquisition systems. This paper describes the detailed simulation of this large scale calorimeter from the implementation of the geometrical elements down to the realistic description of the electronics readout pulses, the special noise treatment and the signal reconstruction. Recently improved description of the optical and electronic signal propagation is highlighted and the validation with the real particle data is presented.

  5. An integrated approach for assessing the bioreceptivity of glazed tiles to phototrophic microorganisms.

    PubMed

    Coutinho, M L; Miller, A Z; Rogerio-Candelera, M A; Mirão, J; Cerqueira Alves, L; Veiga, J P; Águas, H; Pereira, S; Lyubchyk, A; Macedo, M F

    2016-01-01

    A laboratory-based methodology was designed to assess the bioreceptivity of glazed tiles. The experimental set-up consisted of multiple steps: manufacturing of pristine and artificially aged glazed tiles, enrichment of phototrophic microorganisms, inoculation of phototrophs on glazed tiles, incubation under optimal conditions and quantification of biomass. In addition, tile intrinsic properties were assessed to determine which material properties contributed to tile bioreceptivity. Biofilm growth and biomass were appraised by digital image analysis, colorimetry and chlorophyll a analysis. SEM, micro-Raman and micro-particle induced X-ray emission analyses were carried out to investigate the biodeteriorating potential of phototrophic microorganisms on the glazed tiles. This practical and multidisciplinary approach showed that the accelerated colonization conditions allowed different types of tile bioreceptivity to be distinguished and to be related to precise characteristics of the material. Aged tiles showed higher bioreceptivity than pristine tiles due to their higher capillarity and permeability. Moreover, biophysical deterioration caused by chasmoendolithic growth was observed on colonized tile surfaces. PMID:26900634

  6. Dual Poisson-Disk Tiling: an efficient method for distributing features on arbitrary surfaces.

    PubMed

    Li, Hongwei; Lo, Kui-Yip; Leung, Man-Kang; Fu, Chi-Wing

    2008-01-01

    This paper introduces a novel surface-modeling method to stochastically distribute features on arbitrary topological surfaces. The generated distribution of features follows the Poisson disk distribution, so we can have a minimum separation guarantee between features and avoid feature overlap. With the proposed method, we not only can interactively adjust and edit features with the help of the proposed Poisson disk map, but can also efficiently re-distribute features on object surfaces. The underlying mechanism is our dual tiling scheme, known as the Dual Poisson-Disk Tiling. First, we compute the dual of a given surface parameterization, and tile the dual surface by our specially-designed dual tiles; during the pre-processing, the Poisson disk distribution has been pre-generated on these tiles. By dual tiling, we can nicely avoid the problem of corner heterogeneity when tiling arbitrary parameterized surfaces, and can also reduce the tile set complexity. Furthermore, the dual tiling scheme is non-periodic, and we can also maintain a manageable tile set. To demonstrate the applicability of this technique, we explore a number of surface-modeling applications: pattern and shape distribution, bump-mapping, illustrative rendering, mold simulation, the modeling of separable features in texture and BTF, and the distribution of geometric textures in shell space. PMID:18599912

  7. DNA triangles and self-assembled hexagonal tilings.

    PubMed

    Chelyapov, Nickolas; Brun, Yuriy; Gopalkrishnan, Manoj; Reishus, Dustin; Shaw, Bilal; Adleman, Leonard

    2004-11-01

    We have designed and constructed DNA complexes in the form of triangles. We have created hexagonal planar tilings from these triangles via self-assembly. Unlike previously reported structures self-assembled from DNA, our structures appear to involve bending of double helices. Bending helices may be a useful design option in the creation of self-assembled DNA structures. It has been suggested that DNA self-assembly may lead to novel materials and efficient computational devices. PMID:15506744

  8. A hollow clay tile wall seismic performance program overview

    SciTech Connect

    Beavers, J.E.; Jones, W.D.; Stoddart, W.C.T.

    1992-02-25

    An overview of a multiyear hollow clay tile wall (HCTW) program being conducted by Martin Marietta Energy Systems, Inc., at the Oak Ridge Y-12 Plant, for the US Department of Energy is presented. The purpose of the HCTW program is to determine the load capacity of unreinforced infilled HCTW buildings when subjected to earthquakes. Progress to date tends to indicate that extensive retrofit of such structures may not be warranted in low-to-moderate seismic zones.

  9. Towards a DNA Nanoprocessor: Reusable Tile-Integrated DNA Circuits.

    PubMed

    Gerasimova, Yulia V; Kolpashchikov, Dmitry M

    2016-08-22

    Modern electronic microprocessors use semiconductor logic gates organized on a silicon chip to enable efficient inter-gate communication. Here, arrays of communicating DNA logic gates integrated on a single DNA tile were designed and used to process nucleic acid inputs in a reusable format. Our results lay the foundation for the development of a DNA nanoprocessor, a small and biocompatible device capable of performing complex analyses of DNA and RNA inputs. PMID:27430161

  10. The geometry of the 37-tile microwave antenna support structure

    NASA Technical Reports Server (NTRS)

    Finley, L. A.

    1980-01-01

    The geometry of the support structure for a proposed parabolic shaped microwave antenna is examined. The surface of the antenna is comprised of 37 hexagonal shaped tiles, each connected to a truss module. The units are joined together to form a rigidized, faceted, concave parabolic surface. The geometry specifications are described through an explanation of the structural components which make up the antenna, a description of the coordinate system devised to identify the structure, and a presentation of the nondimensional results.

  11. Response and Uniformity Studies of Directly Coupled Tiles

    SciTech Connect

    Zutshi, Vishnu

    2010-04-02

    A finely-segmented scintillator-based calorimeter which capitalizes on the marriage of proven detection techniques with novel solid-state photo-detector devices such as Multi-pixel Photon Counters (MPPCs) is an interesting calorimetric system from the point of view of future detector design. A calorimeter system consisting of millions of channels will require a high degree of integration. The first steps towards this integration have already been facilitated by the small size and magnetic field immunity of the MPPCs. The photo-conversion occurs right at the tile, thus obviating the need for routing of long clear fibers. Similar considerations apply to the presence of wave-length shifting (WLS) fibers inside the tiles which couple it to the photo-detectors. Significant simplification in construction and assembly ensue if the MPPCs can be coupled directly to the scintillator tiles. Equally importantly, the total absence of fibers would offer greater flexibility in the choice of the transverse segmentation while enhancing the electro-mechanical integrability of the design. The NIU high-energy physics group has been studying the fiberless or direct-coupling option for some time now. Encouraging results on response and response uniformity have been obtained using radioactive sources. This MOU seeks to set up a framework to extend these tests using beams at the MTBF. The results will be relevant to high granularity scintillator/crystal electromagnetic and hadronic calorimetry. The tests involve a set of small directly-coupled tile counters fabricated at NIU which will be placed in the beam to study their response and response uniformity as a function of the incident position of the particles passing through them.

  12. Esthetic Rehabilitation of the Smile with No-Prep Porcelain Laminates and Partial Veneers

    PubMed Central

    Farias-Neto, Arcelino; Gomes, Edna Maria da Cunha Ferreira; Sánchez-Ayala, Alfonso; Sánchez-Ayala, Alejandro; Vilanova, Larissa Soares Reis

    2015-01-01

    Rehabilitation of patients with anterior conoid teeth may present a challenge for the clinician, especially when trying to mimic the nature with composite resins. This clinical report exemplifies how a patient with conoid upper lateral incisors was rehabilitated with minimally invasive adhesive restorations. Following diagnostic wax-up and cosmetic mock-up, no-prep veneers and ceramic fragments (partial veneers) were constructed with feldspathic porcelain. This restorative material presents excellent reproduction of the optical properties of the dental structure, especially at minimal thicknesses. In this paper, the details about the treatment are described. A very pleasing outcome was achieved, confirming that minimally invasive adhesive restorations are an excellent option for situations in which the dental elements are healthy, and can be modified exclusively by adding material and the patient does not want to suffer any wear on the teeth. PMID:26568893

  13. Bond strength of composites to etched and silica-coated porcelain fusing alloys.

    PubMed

    Schneider, W; Powers, J M; Pierpont, H P

    1992-05-01

    In vitro bond strengths of two composite veneering materials to two porcelain fusing alloys were measured utilizing two storage conditions. The alloys were etched or treated with silica applied by blasted, thermal or pyrogenic techniques and then silanated. Bond strengths were higher for the Ni-Cr-Be than the Au-Pd alloy with most values greater than 18 MPa. Bond strengths to etched and silanated Au-Pd alloy were low (less than 6.5 MPa), whereas samples treated with silica and silanated had significantly higher values. Bond strengths to the Ni-Cr-Be alloy were highest with the thermal and pyrogenic silica treatments. After thermocycling, most bond strengths to the Au-Pd alloy decreased, but were the same or higher to the Ni-Cr-Be alloy. Cohesive failures of the opaquers were observed. PMID:1325930

  14. Spectrophotometric evaluation of the color changes of different feldspathic porcelains after exposure to commonly consumed beverages

    PubMed Central

    Jain, Chandni; Bhargava, Akshay; Gupta, Sharad; Rath, Rishi; Nagpal, Abhishek; Kumar, Prince

    2013-01-01

    Objective: The aim of this study was to compare color stability and surface topography of three different feldspathic porcelains both qualitatively and quantitatively after exposure to routinely consumed beverages over different time periods using a Spectrophotometer, Stereomicroscope and Surface roughness tester, respectively. Materials and Methods: A total of 90 plastic discs were casted to obtain metal dies for three different newer ceramic applications each on thirty samples. The color and surface roughness of these samples were measured using stereomicroscope and surface roughness tester following which they were kept in different test solutions for different durations and revaluated for color changes and surface roughness in the similar manner. Results and Conclusion: Among all the five test solutions, Coffee showed the maximum staining of the ceramic whereas maximum surface roughness was shown by the Duceram Kiss (1.48 μm) by Orange Juice which could be due to its high titratable acidity. PMID:24883022

  15. Effect of various surface treatments on the bond strength of porcelain repair.

    PubMed

    Saraç, Duygu; Saraç, Yakup Sinasi; Külünk, Safak; Erkoçak, Ayca

    2013-01-01

    This study evaluated the effect of surface treatments on the repair strength of composite resin on a feldspathic ceramic. Ninety ceramic specimens were divided into six groups. In the experimental groups, 4% hydrofluoric acid etching, Er:YAG laser irradiation, CO2 laser irradiation, airborne-particle abrasion, and silica coating were used as surface treatments. After the application of a porcelain repair kit, composite resin was placed on the treated surfaces. After a shear bond strength test, data were statistically analyzed (α = .05). Surface treatments increased the repair bond strength values (P < .05). Airborne particle abrasion and silica coating were found to be the most effective. CO2 laser showed higher repair strength values than Er:YAG laser. PMID:23820715

  16. Effects of thermal blooming on systems comprised of tiled subapertures

    NASA Astrophysics Data System (ADS)

    Leakeas, Charles L.; Bartell, Richard J.; Krizo, Matthew J.; Fiorino, Steven T.; Cusumano, Salvatore J.; Whiteley, Matthew R.

    2010-04-01

    Laser weapon systems comprise of tiled subapertures are rapidly emerging in the directed energy community. The Air Force Institute of Technology Center for Directed Energy (AFIT/CDE), under sponsorship of the HEL Joint Technology Office has developed performance models of such laser weapon system configurations consisting of tiled arrays of both slab and fiber subapertures. These performance models are based on results of detailed waveoptics analyses conducted using WaveTrain. Previous performance model versions developed in this effort represent system characteristics such as subaperture shape, aperture fill factor, subaperture intensity profile, subaperture placement in the primary aperture, subaperture mutual coherence (piston), subaperture differential jitter (tilt), and beam quality wave-front error associated with each subaperture. The current work is a prerequisite for the development of robust performance models for turbulence and thermal blooming effects for tiled systems. Emphasis is placed on low altitude tactical scenarios. The enhanced performance model developed will be added to AFIT/CDE's HELEEOS parametric one-on-one engagement level model via the Scaling for High Energy Laser and Relay Engagement (SHaRE) toolbox.

  17. Orion EFT-1 Catalytic Tile Experiment Overview and Flight Measurements

    NASA Technical Reports Server (NTRS)

    Salazar, Giovanni; Amar, Adam; Hyatt, Andrew; Rezin, Marc D.

    2016-01-01

    This paper describes the design and results of a surface catalysis flight experiment flown on the Orion Multipurpose Crew Vehicle during Exploration Flight Test 1 (EFT1). Similar to previous Space Shuttle catalytic tile experiments, the present test consisted of a highly catalytic coating applied to an instrumented TPS tile. However, the present catalytic tile experiment contained significantly more instrumentation in order to better resolve the heating overshoot caused by the change in surface catalytic efficiency at the interface between two distinct materials. In addition to collecting data with unprecedented spatial resolution of the "overshoot" phenomenon, the experiment was also designed to prove if such a catalytic overshoot would be seen in turbulent flow in high enthalpy regimes. A detailed discussion of the results obtained during EFT1 is presented, as well as the challenges associated with data interpretation of this experiment. Results of material testing carried out in support of this flight experiment are also shown. Finally, an inverse heat conduction technique is employed to reconstruct the flight environments at locations upstream and along the catalytic coating. The data and analysis presented in this work will greatly contribute to our understanding of the catalytic "overshoot" phenomenon, and have a significant impact on the design of future spacecraft.

  18. Biofilm formation on the surface of ceramic tiles.

    PubMed

    Sessa, R; Di Pietro, M; Zamparelli, M; Schiavoni, G; Del Piano, M

    2000-10-01

    The aim of the study was to investigate the formation of biofilm on the surface of ceramic tiles, widely present in public and private buildings, using six parallel flow chambers. Our flow system was conceived and made to compare biofilm results by parallel distributed rectangular tiles. The tiles, divided into two identical A and B sections, were placed within the flow chambers. Biofilm formation was performed after 72 h and was quantified by viable counts of bacteria. Average viable counts ranged from 1.1x10(7) to 7.3x10(7) cfu cm(-2) and from 1.1x10(7) to 5.8x10(7) cfu cm(-2) respectively for biofilm A and B sections. As statistical analysis does not show significant differences, we can conclude that biofilms obtained were so similar to each other that they confirmed the system reproducibility. Our next step will be to use our system to study Legionella pneumophila and to evaluate the efficacy of antibacterial agents. PMID:11061629

  19. Buffing, burnishing, and stripping of vinyl asbestos floor tile

    SciTech Connect

    Hollett, B.A.; Edwards, A.; Clark, P.J.

    1995-10-01

    Studies were conducted to evaluate airborne asbestos concentrations during the three principal types of preventative maintenance (low-speed spray-buffing, ultra high-speed burnishing, and wet-stripping) used on asbestos-containing floor tiles. These were done under pre-existing and prepared levels of floor care maintenance. Airborne asbestos concentrations were measured before and during each floor care procedure to determine the magnitude of the increase in airborne asbestos levels during each procedure. Airborne total fiber concentrations were also measured for comparison with the Occupational Safety and Health Administration`s (OSHA) Permissible Exposure Limit (PEL) of 0.1 f/cm{sup 3}. Low-speed spray-buffing and wet-stripping were evaluated on pre-existing floor conditions and three levels of prepared floor care conditions (poor, medium, and good). Ultra high-speed burnishing and wet-stripping were evaluated on two levels of prepared floor care conditions (poor and good). Floor care conditions were defined in consultation with the Chemical Specialty Manufacturers Association and other representatives of floor-care chemical manufacturers. Controlled studies were conducted in an unoccupied building at the decommissioned Chanute Air Force Base in Rantoul, Illinois, with the cooperation of the U.S. Air Force. The building offered approximately 8600 ft{sup 2} of open floor space tiled with 9-inch by 9-inch resilient floor tile containing approximately 5% chrysotile asbestos.

  20. Effects of 2 polishing techniques and reglazing on the surface roughness of dental porcelain.

    PubMed

    Schneider, Jacqueline; Dias Frota, Bruna Marjorie; Passos, Vanara Florencio; Santiago, Sergio Lima; Freitas Pontes, Karina Matthes de

    2013-01-01

    The aim of this study was to compare the effect of 2 polishing systems and reglazing of dental porcelain through a quantitative and qualitative analysis of surface roughness using a stylus profilometer and scanning electron microscope. Fifteen porcelain specimens (10 x 3 x 3 mm) were used. On 1 surface of each block, a layer of glaze was applied, and surface roughness (Ra) was analyzed. All specimens were ground with aluminum oxide sandpaper until the shine was removed and the resulting Ra values were obtained. Afterwards, they were randomly divided into 3 treatment groups (n = 5): Group I (GI), polished with diamond-impregnated rubber wheels; Group II (GII), polished with silicon carbide-impregnated rubber wheels; and Group III (GIII), reglazed firing procedure alone. After the treatments, new Ra measurements were done. Data were submitted to analysis of variance (ANOVA), and Tukey tests at 5%. Comparisons between ground surface and treated surface were made by paired t-test. The ground and treated Ra values (µm) were determined as follows: GI: 0.66 ± 0.14, 0.35 ± 0.06; GII: 0.60 ± 0.04, 0.09 ± 0.03; and GIII: 0.67 ± 0.05, 0.75 ± 0.24. Significant differences were found between the ground and treated values for all groups. After the treatments, all groups differed statistically (P < 0.05). The silicon carbide system re-established the initial surface smoothness, while polishing with diamond-impregnated rubber or reglazing alone were not able to achieve a satisfactory smoothness. PMID:24192749

  1. Four chemical methods of porcelain conditioning and their influence over bond strength and surface integrity

    PubMed Central

    Stella, João Paulo Fragomeni; Oliveira, Andrea Becker; Nojima, Lincoln Issamu; Marquezan, Mariana

    2015-01-01

    OBJECTIVE: To assess four different chemical surface conditioning methods for ceramic material before bracket bonding, and their impact on shear bond strength and surface integrity at debonding. METHODS: Four experimental groups (n = 13) were set up according to the ceramic conditioning method: G1 = 37% phosphoric acid etching followed by silane application; G2 = 37% liquid phosphoric acid etching, no rinsing, followed by silane application; G3 = 10% hydrofluoric acid etching alone; and G4 = 10% hydrofluoric acid etching followed by silane application. After surface conditioning, metal brackets were bonded to porcelain by means of the Transbond XP system (3M Unitek). Samples were submitted to shear bond strength tests in a universal testing machine and the surfaces were later assessed with a microscope under 8 X magnification. ANOVA/Tukey tests were performed to establish the difference between groups (α= 5%). RESULTS: The highest shear bond strength values were found in groups G3 and G4 (22.01 ± 2.15 MPa and 22.83 ± 3.32 Mpa, respectively), followed by G1 (16.42 ± 3.61 MPa) and G2 (9.29 ± 1.95 MPa). As regards surface evaluation after bracket debonding, the use of liquid phosphoric acid followed by silane application (G2) produced the least damage to porcelain. When hydrofluoric acid and silane were applied, the risk of ceramic fracture increased. CONCLUSIONS: Acceptable levels of bond strength for clinical use were reached by all methods tested; however, liquid phosphoric acid etching followed by silane application (G2) resulted in the least damage to the ceramic surface. PMID:26352845

  2. Coverage percentage and raman measurement of cross-tile and scaffold cross-tile based DNA nanostructures.

    PubMed

    Gnapareddy, Bramaramba; Ahn, Sang Jung; Dugasani, Sreekantha Reddy; Kim, Jang Ah; Amin, Rashid; Mitta, Sekhar Babu; Vellampatti, Srivithya; Kim, Byeonghoon; Kulkarni, Atul; Kim, Taesung; Yun, Kyusik; LaBean, Thomas H; Park, Sung Ha

    2015-11-01

    We present two free-solution annealed DNA nanostructures consisting of either cross-tile CT1 or CT2. The proposed nanostructures exhibit two distinct structural morphologies, with one-dimensional (1D) nanotubes for CT1 and 2D nanolattices for CT2. When we perform mica-assisted growth annealing with CT1, a dramatic dimensional change occurs where the 1D nanotubes transform into 2D nanolattices due to the presence of the substrate. We assessed the coverage percentage of the 2D nanolattices grown on the mica substrate with CT1 and CT2 as a function of the concentration of the DNA monomer. Furthermore, we fabricated a scaffold cross-tile (SCT), which is a new design of a modified cross-tile that consists of four four-arm junctions with a square aspect ratio. For SCT, eight oligonucleotides are designed in such a way that adjacent strands with sticky ends can produce continuous arms in both the horizontal and vertical directions. The SCT was fabricated via free-solution annealing, and self-assembled SCT produces 2D nanolattices with periodic square cavities. All structures were observed via atomic force microscopy. Finally, we fabricated divalent nickel ion (Ni(2+))- and trivalent dysprosium ion (Dy(3+))-modified 2D nanolattices constructed with CT2 on a quartz substrate, and the ion coordinations were examined via Raman spectroscopy. PMID:26340356

  3. Filler bar heating due to stepped tiles in the shuttle orbiter thermal protection system

    NASA Technical Reports Server (NTRS)

    Petley, D. H.; Smith, D. M.; Edwards, C. L. W.; Patten, A. B.; Hamilton, H. H., II

    1983-01-01

    An analytical study was performed to investigate the excessive heating in the tile to tile gaps of the Shuttle Orbiter Thermal Protection System due to stepped tiles. The excessive heating was evidence by visible discoloration and charring of the filler bar and strain isolation pad that is used in the attachment of tiles to the aluminum substrate. Two tile locations on the Shuttle orbiter were considered, one on the lower surface of the fuselage and one on the lower surface of the wing. The gap heating analysis involved the calculation of external and internal gas pressures and temperatures, internal mass flow rates, and the transient thermal response of the thermal protection system. The results of the analysis are presented for the fuselage and wing location for several step heights. The results of a study to determine the effectiveness of a half height ceramic fiber gap filler in preventing hot gas flow in the tile gaps are also presented.

  4. Generalized Penrose tiling as a quasilattice for decagonal quasicrystal structure analysis.

    PubMed

    Chodyn, Maciej; Kuczera, Pawel; Wolny, Janusz

    2015-03-01

    The generalized Penrose tiling is, in fact, an infinite set of decagonal tilings. It is constructed with the same rhombs (thick and thin) as the conventional Penrose tiling, but its long-range order depends on the so-called shift parameter (s ∈ 〈0; 1)). The structure factor is derived for the arbitrarily decorated generalized Penrose tiling within the average unit cell approach. The final formula works in physical space only and is directly dependent on the s parameter. It allows one to straightforwardly change the long-range order of the refined structure just by changing the s parameter and keeping the tile decoration unchanged. This gives a great advantage over the higher-dimensional method, where every change of the tiling (change in the s parameter) requires the structure model to be built from scratch, i.e. the fine division of the atomic surfaces has to be redone. PMID:25727864

  5. Modal analysis and dynamic stresses for acoustically excited Shuttle insulation tiles

    NASA Technical Reports Server (NTRS)

    Ojalvo, I. U.; Ogilvie, P. I.

    1976-01-01

    The thermal protection system of the Space Shuttle consists of thousands of separate insulation tiles, of varying thicknesses, bonded to the orbiter's surface through a soft strain-isolation pad which is bonded, in turn, to the vehicle's stiffened metallic skin. A modal procedure for obtaining the acoustically induced RMS stress in these comparatively thick tiles is described. The modes employed are generated by a previously developed iterative procedure which converges rapidly for the combined system of tiles and primary structure considered. Each tile is idealized by several hundred three-dimensional finite elements and all tiles on a given panel interact dynamically. Acoustic response results from the present analyses are presented. Comparisons with other analytical results and measured modal data for a typical Shuttle panel, both with and without tiles, are made, and the agreement is good.

  6. CAD Tools for Creating Space-filing 3D Escher Tiles

    SciTech Connect

    Howison, Mark; Sequin, Carlo H.

    2009-04-10

    We discuss the design and implementation of CAD tools for creating decorative solids that tile 3-space in a regular, isohedral manner. Starting with the simplest case of extruded 2D tilings, we describe geometric algorithms used for maintaining boundary representations of 3D tiles, including a Java implementation of an interactive constrained Delaunay triangulation library and a mesh-cutting algorithm used in layering extruded tiles to create more intricate designs. Finally, we demonstrate a CAD tool for creating 3D tilings that are derived from cubic lattices. The design process for these 3D tiles is more constrained, and hence more difficult, than in the 2D case, and it raises additional user interface issues.

  7. Radiation hardness of 3HF-tile/O2-WLS-fiber calorimeter

    SciTech Connect

    Han, S.W.; Hu, L.D.; Liu, N.Z.

    1993-11-01

    The radiation hardness of a 3HF-tile/O2-WLS-fiber calorimeter with two different tile/fiber patterns has been studied. Two calorimeter modules were irradiated up to 10 Mrad with the BEPC 1.3 GeV electron beam. The radiation damage of these modules is compared with our previous measurements from SCSN81-tile/BCF91A-WLS-fiber modules. The longitudinal damage profiles are fitted as a function of depth.

  8. Study of tile/fiber systems manufactured from Kharkov injection molded and Kuraray SCSN-81 scintillators

    NASA Astrophysics Data System (ADS)

    Nemashkalo, A.; Popov, V.; Rubashkin, A.; Sorokin, P.; Zatserklianiy, A.; Borisenko, A.; Senchishin, V.; Skrebtsov, O.; Bolotov, V.

    1998-12-01

    We present the measurements of light output, light yield uniformity, and recovery after radiation damage of the tile/fiber systems made from the Kharkov injection molded and Kuraray SCSN-81 scintillators. The tiles were trapezoidal in shape, 131×90×122 mm3, with a Kuraray Y11 multiclad WLS read-out. The results are compared with those obtained using the tile/fiber systems manufactured from the Kuraray SCSN-81 scintillator and tested under the same conditions.

  9. Optimization of the light yield properties from scintillator tiles read out directly by silicon photomultipliers

    NASA Astrophysics Data System (ADS)

    Bobchenko, B.; Chadeeva, M.; Danilov, M.; Mironov, D.; Rusinov, V.; Tarkovskiy, E.

    2016-02-01

    The research of the light yield from the scintillator tiles with direct readout by silicon photomultipliers (SiPM) has been performed. The tile size is 30 x 30 x 3 mm3 as planned for the AHCAL of the ILD at the ILC. The different tile geometries were studied. The uniformity of light yield has been optimized and one geometry has been selected. The results are compared to the studies on the same topic, performed by another groups.

  10. Numerical investigation of the spatial scale and time dependency of tile drainage contribution to stream flow

    NASA Astrophysics Data System (ADS)

    Thomas, Nicholas W.; Arenas, Antonio A.; Schilling, Keith E.; Weber, Larry J.

    2016-07-01

    Tile drainage systems are pervasive in the Central U.S., significantly altering the hydrologic system. The purpose of this study was to assess the effects of tile drainage systems on streamflow. A physically based coupled hydrologic model was applied to a 45 km2 agricultural Iowa watershed. Tile drainage was incorporated though an equivalent porous medium approach, calibrated though numerical experimentation. Experimental results indicated that a significant increase in hydraulic conductivity of the equivalent medium layer was needed to achieve agreement in total outflow with an explicit numerical representation of a tiled system. Watershed scale analysis derived the tile drainage contribution to stream flow (QT/Q) from a numerical tracer driven analysis of instream surface water. During precipitation events tile drainage represented 30% of stream flow, whereas during intervals between precipitations events, 61% of stream flow originated from the tile system. A division of event and non-event periods produced strong correlations between QT/Q and drainage area, positive for events, and negative for non-events. The addition of precipitation into the system acted to saturate near surface soils, increase lateral soil water movement, and dilute the relatively stable instream tile flow. Increased intensity precipitation translated the QT/Q relationship downward in a consistent manner. In non-event durations, flat upland areas contributed large contributions of tile flow, diluted by larger groundwater (non-tile) contribution to stream flow in the downstream steeper portion of the watershed. Study results provide new insights on the spatiotemporal response of tile drainage to precipitation and contributions of tile drainage to streamflow at a watershed scale, with results having important implications for nitrate transport.

  11. Changes in physical and chemical properties of a dental palladium-silver alloy during metal-porcelain bonding.

    PubMed

    Payan, J; Moya, G E; Meyer, J M; Moya, F

    1986-07-01

    The hardening ability of a dental palladium-silver (Pd-Ag-Sn-In) bonding alloy has been investigated, and the distribution of the elements along the metal-ceramic interface have been studied by microprobe analysis. The alloy was found to be highly heterogeneous in its 'as-cast' condition, but homogenized alloy was obtained after heating the alloy at 1000 degrees C for 2 h. Hardening occurred after annealing at 650 degrees C for 1 h. A longer thermal treatment caused the hardness to decrease (over-ageing). The change in hardness could be attributed to an internal oxidation phenomenon. The additional elements tin and indium segregated towards the ceramic-metal interface, with a diffusion of indium only into the porcelain. Diffusion of silver in the ceramics, supposed to be the cause of the 'greening' of dental porcelains baked on silver-rich alloys, has not been detected by the microprobe across the interface. PMID:3531444

  12. Performance of a 64-channel, 3.2×3.2 cm2 SiPM tile for TOF-PET application

    NASA Astrophysics Data System (ADS)

    Ferri, Alessandro; Acerbi, Fabio; Gola, Alberto; Piemonte, Claudio; Paternoster, Giovanni; Zorzi, Nicola

    2016-07-01

    In this work, we present a new 3.2×3.2 cm2 detector tile, composed of 8×8 single SiPMs, having a regular 4 mm pitch in both the X and Y directions. The tile fill factor is 85%. We produced two versions of the tile with different SiPM technologies: RGB-HD and NUV. The first one features square micro-cells with 25 μm pitch, a PDE peaked at 550 nm and a DCR of 300 kHz/mm2, at 20 °C and at maximum detection efficiency. The second one features micro-cells with 40 μm pitch and a PDE peaked in the blue part of the spectrum. The dark count rate at 20 °C and at maximum PDE is 100 kHz/mm2. In this work, we show the energy and timing resolution measurements at 511 keV obtained coupling the two tiles to an 8×8 LYSO array with a pixel size of 4×4×22 mm3, perfectly matching the photo-detector array.

  13. Thermal Structure Analysis of SIRCA Tile for X-34 Wing Leading Edge TPS

    NASA Technical Reports Server (NTRS)

    Milos, Frank S.; Squire, Thomas H.; Rasky, Daniel J. (Technical Monitor)

    1997-01-01

    This paper will describe in detail thermal/structural analyses of SIRCA tiles which were performed at NASA Ames under the The Tile Analysis Task of the X-34 Program. The analyses used the COSMOS/M finite element software to simulate the material response in arc-jet tests, mechanical deflection tests, and the performance of candidate designs for the TPS system. Purposes of the analysis were to verify thermal and structural models for the SIRCA tiles, to establish failure criteria for stressed tiles, to simulate the TPS response under flight aerothermal and mechanical load, and to confirm that adequate safety margins exist for the actual TPS design.

  14. Tethers as Debris: Simulating Impacts of Tether Fragments on Shuttle Tiles

    NASA Technical Reports Server (NTRS)

    Evans, Steven W.

    2004-01-01

    The SPHC hydrodynamic code was used to simulate impacts of Kevlar and aluminum projectiles on a model of the LI-900 type insulating tiles used on Space Shuffle Orbiters The intent was to examine likely damage that such tiles might experience if impacted by orbital debris consisting of tether fragments. Projectile speeds ranged from 300 meters per second to 10 kilometers per second. Damage is characterized by penetration depth, tile surface-hole diameter, tile body-cavity diameter, coating fracture diameter, tether and cavity wall material phases, and deformation of the aluminum backwall.

  15. High Resolution Modeling of Tile-Drained Controls on Ecohydrologic Dynamics in Intensively Managed Landscapes.

    NASA Astrophysics Data System (ADS)

    Wagner, D.; Le, P. V.; Kumar, P.; Woo, D.

    2015-12-01

    Tile drains are widely used in the Midwestern United States to improve the productivity of poorly drained agricultural fields. Since tile drain reduces vadose zone soil moisture by lowering the water table, and its outlets feed directly into streams and ditches, tile flow can affect various hydrologic, biotic and biogeochemical processes in the watershed. However, the effects of tile flow on ecohydrologic and nutrient dynamics at scales dominated by microtopographic variability, such as depression and roadside ditches, remain poorly understood. Here we present an explicit model of tile flow and incorporate into the integrated ecohydrologic-flow model, MLCan-GCSFlow, to investigate the impacts of tile drain on ecohydrologic and nutrient dynamics in intensively managed agricultural fields at lidar-resolution scales. Explicit coupling between subsurface and tile flow is obtained by modifications of variably saturated Richards equation to capture the impacts of tile drain on soil moisture. The coupling between subsurface and overland flow is obtained by prescribing a boundary condition switching approach at the top surface of the computational domain. Model results for study sites in Critical Zone Observatory for Intensively Managed Landscapes (IMLCZO) show the significance of tile drain flow on the vertical and spatial soil moisture distribution and coupled surface - sub-surface flow dynamics.

  16. Hypothetical Reentry Thermostructural Performance of Space Shuttle Orbiter With Missing or Eroded Thermal Protection Tiles

    NASA Technical Reports Server (NTRS)

    Ko, William L.; Gong, Leslie; Quinn, Robert D.

    2004-01-01

    This report deals with hypothetical reentry thermostructural performance of the Space Shuttle orbiter with missing or eroded thermal protection system (TPS) tiles. The original STS-5 heating (normal transition at 1100 sec) and the modified STS-5 heating (premature transition at 800 sec) were used as reentry heat inputs. The TPS missing or eroded site is assumed to be located at the center or corner (spar-rib juncture) of the lower surface of wing midspan bay 3. For cases of missing TPS tiles, under the original STS-5 heating, the orbiter can afford to lose only one TPS tile at the center or two TPS tiles at the corner (spar-rib juncture) of the lower surface of wing midspan bay 3. Under modified STS-5 heating, the orbiter cannot afford to lose even one TPS tile at the center or at the corner of the lower surface of wing midspan bay 3. For cases of eroded TPS tiles, the aluminum skin temperature rises relatively slowly with the decreasing thickness of the eroded central or corner TPS tile until most of the TPS tile is eroded away, and then increases exponentially toward the missing tile case.

  17. Ceramic-ceramic shell tile thermal protection system and method thereof

    NASA Technical Reports Server (NTRS)

    Riccitiello, Salvatore R. (Inventor); Smith, Marnell (Inventor); Goldstein, Howard E. (Inventor); Zimmerman, Norman B. (Inventor)

    1986-01-01

    A ceramic reusable, externally applied composite thermal protection system (TPS) is proposed. The system functions by utilizing a ceramic/ceramic upper shell structure which effectively separates its primary functions as a thermal insulator and as a load carrier to transmit loads to the cold structure. The composite tile system also prevents impact damage to the atmospheric entry vehicle thermal protection system. The composite tile comprises a structurally strong upper ceramic/ceramic shell manufactured from ceramic fibers and ceramic matrix meeting the thermal and structural requirements of a tile used on a re-entry aerospace vehicle. In addition, a lightweight high temperature ceramic lower temperature base tile is used. The upper shell and lower tile are attached by means effective to withstand the extreme temperatures (3000 to 3200F) and stress conditions. The composite tile may include one or more layers of variable density rigid or flexible thermal insulation. The assembly of the overall tile is facilitated by two or more locking mechanisms on opposing sides of the overall tile assembly. The assembly may occur subsequent to the installation of the lower shell tile on the spacecraft structural skin.

  18. Preliminary assessment of metal-porcelain bonding strength of CoCrW alloy after 3wt.% Cu addition.

    PubMed

    Lu, Yanjin; Zhao, Chaoqian; Ren, Ling; Guo, Sai; Gan, Yiliang; Yang, Chunguang; Wu, Songquan; Lin, Junjie; Huang, Tingting; Yang, Ke; Lin, Jinxin

    2016-06-01

    In this work, a novel Cu-bearing CoCrW alloy fabricated by selective laser melting for dental application has been studied. For its successful application, the bonding strength of metal-porcelain is essential to be systematically investigated. Therefore, the aim of this study was to evaluate the metal-porcelain bonding strength of CoCrWCu alloy by three-point bending test, meanwhile the Ni-free CoCrW alloy was used as control. The oxygen content was investigated by an elemental analyzer; X-ray photoelectron spectroscopy (XPS) was used to analyze the surface chemical composition of CoCrW based alloy after preoxidation treatment; the fracture mode was investigated by X-ray energy spectrum analysis (EDS) and scanning electron microscope (SEM). Result from the oxygen content analysis showed that the content of oxygen dramatically increased after the Cu addition. And the XPS suggested that Co-oxidation, Cr2O3, CrO2, WO3, Cu2O and CuO existed on the preoxidated surface of the CoCrWCu alloy; the three-point bending test showed that the bonding strength of the CoCrWCu alloy was 43.32 MPa, which was lower than that of the CoCrW group of 47.65 MPa. However, the average metal-porcelain bonding strength is significantly higher than the minimum value in the ISO 9693 standard. Results from the SEM images and EDS indicated that the fracture mode of CoCrWCu-porcelain was mixed between cohesive and adhesive. Based on the results obtained in this study, it can be indicated that the Cu-bearing CoCrW alloy fabricated by the selective laser melting is a promising candidate for use in dental application. PMID:27040193

  19. Evaluation of the Effect of Four Surface Conditioning Methods on the Shear Bond Strength of Metal Bracket to Porcelain Surface

    PubMed Central

    Zarif Najafi, Hooman; Torkan, Sepideh; Yousefipour, Bahareh; Salehi, Raha

    2014-01-01

    Abstract Objective: This study evaluated the effect of superpulse CO2 laser irradiation and deglazing of porcelain surfaces on the shear bond strength (SBS) of metal orthodontic brackets, and compared it with two conventional etching techniques. Methods: Forty-eight Feldspathic porcelain fused to metal specimens embedded in cylindrical acrylic resin tubes were fabricated, and all the specimens were divided into four groups. In Group 1, the specimens were roughened with a diamond bur and etched with hydrofluoric acid (HFA) gel for 4 min. In Group 2, the specimens were roughened with a bur and irradiated by a CO2 laser with a 2 W power setting for 20 sec. In Group 3, the specimens were only irradiated by a CO2 laser. In Group 4, the porcelain surface was sandblasted with 50 μm aluminum oxide. Before bonding, the bracket silane was applied on the porcelain surfaces. SBS was evaluated by a Universal testing machine (Zwickroll, Germany). The remaining adhesive after the bond failure was evaluated using an adhesive remnant index (ARI). Statistical analysis was conducted by analysis of variance (ANOVA), Tukey, and Kruskal–Wallis tests. Results: ANOVA revealed significant differences in SBS among the four groups (p<0.001). Group 1 demonstrated significantly higher bond strength (13.13±2.47) when compared with the other groups. Group 2 showed higher bond strength (9.60±1.91) when compared with group 4 (6.40±1.67) (p=0.016). Group 1 displayed the highest ARI scores among the groups. Conclusions: Deglazing combined with HFA etching produced the highest bond strength, but CO2 laser irradiation provided adequate bond strength and allowed for elimination of the HFA step. Deglazing is not recommended as a preliminary step before CO2 laser conditioning. PMID:25455957

  20. Long-term mechanical life testing of polymeric post insulators for distribution and a comparison to porcelain

    SciTech Connect

    Cherney, E.A. )

    1988-07-01

    The paper presents the results and analyses of long-term cantilever strength tests on polymeric line post insulators. The time-to-failure data for static cantilever loads are represented by the Weibull distribution. The life distribution, obtained from the maximum likelihood estimates of the accelerated failure times, fits an exponential model. An extrapolation of the life distribution to normal loads provides an estimate of the strength rating and mechanical equivalence to porcelain line post insulators.

  1. Evaluation of shear bond strengths of gingiva-colored composite resin to porcelain, metal and zirconia substrates

    PubMed Central

    An, Hong-Seok; Park, Ji-Man

    2011-01-01

    PURPOSE The purpose of this study is to evaluate and compare the shear bond strength of the gingiva-colored composite resin and the tooth-colored composite resin to porcelain, metal and zirconia. MATERIALS AND METHODS Sixty cylindrical specimens were fabricated and divided into the following 6 groups (Group 1-W: tooth-colored composite bonded to porcelain, Group 1-P: gingiva-colored composite bonded to porcelain, Group 2-W: tooth-colored composite bonded to base metal, Group 2-P: gingiva-colored composite bonded to base metal, Group 3-W: toothcolored composite bonded to zirconia, Group 3-P: gingiva-colored composite bonded to zirconia). The shear bond strength was measured with a universal testing machine after thermocycling and the failure mode was noted. All data were analyzed using the two-way analysis of variance test and the Bonferroni post-hoc test at a significance level of 0.05. RESULTS The mean shear bond strength values in MPa were 12.39, 13.42, 8.78, 7.98, 4.64 and 3.74 for Group 1-W, 1-P, 2-W, 2-P, 3-W and 3-P, respectively. The difference between the two kinds of composite resin was not significant. The shear bond strength of Group 1 was the highest and that of Group 3 was the lowest. The differences among Group 1, 2 and 3 were all significant (P<.05). CONCLUSION The shear bond strength of the gingiva-colored composite was not less than that of the tooth-colored composite. Thus, repairing or fabricating ceramic restorations using the gingiva-colored composite resin can be regarded as a practical method. Especially, the prognosis would be fine when applied on porcelain surfaces. PMID:22053249

  2. Evaluation of shear bond strength of porcelain bonded to laser welded titanium surface and determination of mode of bond failure.

    PubMed

    Patil, Narendra P; Dandekar, Minal; Nadiger, Ramesh K; Guttal, Satyabodh S

    2010-09-01

    The aim of this study was to evaluate the shear bond strength of porcelain to laser welded titanium surface and to determine the mode of bond failure through scanning electron microscopy (SEM) and energy dispersive spectrophotometry (EDS). Forty five cast rectangular titanium specimens with the dimension of 10 mm x 8 mm x 1 mm were tested. Thirty specimens had a perforation of 2 mm diameter in the centre. These were randomly divided into Group A and B. The perforations in the Group B specimens were repaired by laser welding using Cp Grade II titanium wire. The remaining 15 specimens were taken as control group. All the test specimens were layered with low fusing porcelain and tested for shear bond strength. The debonded specimens were subjected to SEM and EDS. Data were analysed with 1-way analysis of variance and Student's t-test for comparison among the different groups. One-way analysis of variance (ANOVA) showed no statistically significant difference in shear bond strength values at a 5% level of confidence. The mean shear bond strength values for control group, Group A and B was 8.4 +/- 0.5 Mpa, 8.1 +/- 0.4 Mpa and 8.3 +/- 0.3 Mpa respectively. SEM/EDS analysis of the specimens showed mixed and cohesive type of bond failure. Within the limitations of the study laser welding did not have any effect on the shear bond strength of porcelain bonded to titanium. PMID:21077419

  3. Mechanical strength and local structure of 'new' Hagi porcelain investigated by 57Fe-Mössbauer spectroscopy

    NASA Astrophysics Data System (ADS)

    Kubuki, S.; Uehara, H.; Akagi, K.; Mikuni, A.; Isobe, N.; Homonnay, Z.; Sinkó, K.; Kuzmann, E.; Nishida, T.

    2010-03-01

    A relationship between the local structure and mechanical strength of 'new' Hagi porcelain 'A' and 'B' prepared by sintering two types of iron containing aluminosilicate soils under oxidizing and reducing atmospheres were investigated by means of 57Fe-Mössbauer spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), as well as three point bending test. The largest mechanical strength (σ) value of 64.3±3.1 MPa was estimated from the three-point bending test of reductively sintered Hagi porcelain 'A'. The Mössbauer spectrum was composed of two paramagnetic doublets due to tetrahedral FeII FeIII with the isomer shift (δ) values of 1.13±0.02 and 0.31±0.01 mm s-1. On the other hand, a paramagnetic doublet and a magnetic sextet with the δ values of 0.30±0.01 and 0.35±0.02 mm s-1 were observed from the Mössbauer spectra of other samples. It can be concluded that the mechanically strengthened Hagi porcelain was successfully fabricated by choosing soil 'A' and by sintering under a reducing atmosphere.

  4. Comparison of the surface roughness of feldspathic porcelain polished with a novel alumina-zirconia paste or diamond paste.

    PubMed

    Yamockul, Suparaksa; Thamrongananskul, Niyom; Poolthong, Suchit

    2016-01-01

    This study compared the surface roughness of feldspathic porcelain polished with newly developed alumina-zirconia pastes or diamond paste. Porcelain discs were prepared and polished with sandpaper using a polishing-machine. The surface roughness (Ra) of each sample was measured using a profilometer. The samples were randomly divided into 6 groups (n=10). The control group was polished with diamond paste (DP), and the five remaining groups were polished with the newly developed alumina-zirconia paste with the following ratios of glycerin:alumina:zirconia by weight: 1:0.5:0.5 (Z0.5), 1:0.5:0.75 (Z0.75), 1:0.5:1 (Z1), 1:0.5:1.5 (Z1.5), and 1:0.5:2 (Z2). The specimens were polished for 120 s. The Ra values were determined again and the surface morphology of the porcelain samples was analyzed using SEM. The Ra values decreased as the amount of zirconia in the polishing paste increased, except for the Z2 group. The surface roughness as observed by SEM showed a correlation with the Ra values. PMID:27251992

  5. Assembly of a tile-based multilayered DNA nanostructure

    NASA Astrophysics Data System (ADS)

    Son, Junyoung; Lee, Junywe; Tandon, Anshula; Kim, Byeonghoon; Yoo, Sanghyun; Lee, Chang-Won; Park, Sung Ha

    2015-04-01

    The Watson-Crick complementarity of DNA is exploited to construct periodically patterned nanostructures, and we herein demonstrate tile-based three dimensional (3D) multilayered DNA nanostructures that incorporate two design strategies: vertical growth and horizontal layer stacking with substrate-assisted growth. To this end, we have designed a periodically holed double-double crossover (DDX) template that can be used to examine the growth of the multilayer structures in both the vertical and horizontal directions. For vertical growth, the traditional 2D double crossover (DX) DNA lattice is seeded and grown vertically from periodic holes in the DDX template. For horizontal stacking, the DDX layers are stacked by binding the connector tiles between each layer. Although both types of multilayers exhibited successful formation, the observations with an atomic force microscope indicated that the DDX layer growth achieved with the horizontal stacking approach could be considered to be slightly better relative to the vertical growth of the DX layers in terms of uniformity, layer size, and discreteness. In particular, the newly designed DDX template layer provided a parallel arrangement between each domain with substrate-assisted growth. This kind of layer arrangement suggests a possibility of using our design scheme in the construction of other periodic structures.The Watson-Crick complementarity of DNA is exploited to construct periodically patterned nanostructures, and we herein demonstrate tile-based three dimensional (3D) multilayered DNA nanostructures that incorporate two design strategies: vertical growth and horizontal layer stacking with substrate-assisted growth. To this end, we have designed a periodically holed double-double crossover (DDX) template that can be used to examine the growth of the multilayer structures in both the vertical and horizontal directions. For vertical growth, the traditional 2D double crossover (DX) DNA lattice is seeded and grown

  6. In Vitro Effect of Porcelain Firing Cycle and Different Thicknesses of IPS E.max CAD Core on Marginal Accuracy of All-Ceramic Restorations

    PubMed Central

    Jalalian, Ezatollah; Zarbakhsh, Arash; Mohtashamrad, Zahra; Nourbakhsh, Nazanin; Jafarpour, Esmat

    2015-01-01

    Objectives: Marginal adaptation is important for long-term success of full-coverage restorations. The aim of this study was to determine the effect of porcelain firing cycle and different thicknesses of IPS e.max core on marginal accuracy of all-ceramic restorations. Materials and Methods: A standard stainless steel die with 0.8 mm classic chamfer finish line and 10° taper was used in this in vitro study. An impression was taken from the stainless steel die to fabricate 20 epoxy resin dies, which were then scanned and IPS e.max CAD cores were fabricated using computer-aided design/computer-aided manufacturing (CAD/CAM) technique in two groups of 10 with 0.7 mm (group A) and 0.4mm (group B) core thickness. Copings were then placed on their respective dies and randomly numbered. The amount of marginal gap was measured in 10 points under a stereomicroscope (×90 magnification) before and after porcelain veneering. Results: The mean gap in 0.7mm and 0.4mm core thicknesses was 15.62±2.55μm and 19.68±3.09μm before porcelain firing and 32.01±3.19μm and 35.24±3.8μm after porcelain firing. The difference in marginal gap between the two thicknesses was significant before porcelain firing but not significant after veneering. Significant differences were also found in the marginal gap before and after porcelain veneering in each group. Conclusion: The porcelain firing cycle increases marginal gap in IPS e.max CAD restorations; 0.3 mm decrease in core thickness slightly increased marginal discrepancy, however it was not significant. PMID:27507992

  7. Dissolved organic carbon losses from tile drained agroecosystems.

    PubMed

    Ruark, Matthew D; Brouder, Sylvie M; Turco, Ronald F

    2009-01-01

    Artificial subsurface drainage is commonly used in midwestern agriculture and drainage losses of dissolved organic carbon (DOC) from such systems are an under-quantified portion of the terrestrial carbon (C) cycle. The objectives of this study were to determine the effect of common agricultural management practices on DOC losses from subsurface tile drains and to assess patterns of loss as a function of year, time of year, and drainflow. Daily drainflow was collected across six water years (1999-2004) from a restored prairie grass system and cropping systems which include continuous corn (Zea mays L.) and corn-soybean [Glycine max (L.) Merr.] rotations fertilized with urea-ammonium-nitrate (UAN) or swine (Sus scrofa) manure lagoon effluent. The DOC concentrations in tile drainflow were low, typically <2 mg L(-1). Yearly DOC losses, which ranged from 1.78 to 8.61 kg ha(-1), were not affected by management practices and were small compared to organic C inputs. Spring application of lagoon effluent increased yearly flow-weighted (FW)-DOC concentrations relative to other cropping systems in three of the years and increased monthly FW-DOC concentrations when drainflow occurred within 1 mo of application. Drainflow was significantly and positively correlated with DOC loss. Drainflow also affected DOC concentrations as greater 6-yr cumulative drainflow was associated with lower 6-yr FW-DOC concentrations and greater daily drainflow was associated with higher daily DOC concentrations. Our results indicate that lagoon effluent application and fertilizer N rates do not affect long-term losses of DOC from tile drains and that drainflow is the main driver of DOC losses. PMID:19398518

  8. Ballistic performance of polyurea-coated armor grade ceramic tiles

    NASA Astrophysics Data System (ADS)

    Samiee, Ahsan; Isaacs, Jon; Nemat-Nasser, Sia

    2010-04-01

    The use of ceramics as energy absorbents has been studied by many researchers and some improvements in the ballistic performance of ceramic tiles have been made by coating them with different classes of materials (e.g. E-glass/epoxy, carbon-fiber/epoxy, etc.). Using ceramics for energy absorbing applications leads to a significant weight reduction of the system. Therefore, any modification to the ceramic configuration in the system which leads to more energy absorption with the same or less areal density is significant. On the other hand, polyurea has been proved to be an excellent energy dissipating agent in many applications. Inspired by this, we are studying the effect of coating ceramics with polyurea and other materials, on the energy absorption and ballistic performance of the resulting ceramic-based composites. In this study, we investigate the effect of polyurea on ballistic efficiency of ceramic tiles. To this end, we have performed a set of penetration tests on polyurea-ceramic composites. In our experiments, a high velocity projectile is propelled to impact and perforate the ceramic-polyurea composite. The velocity and mass of the projectile are measured before and after the penetration. The change in the kinetic energy of the projectile is evaluated and compared for different polyurea-ceramic configurations (e.g., polyurea on front face, polyurea on back face, polyurea between two ceramic tiles, etc.). The experimental results suggest that polyurea is not as effective as other restraining materials such as E-glass/epoxy and carbon-fiber/epoxy.

  9. New family of tilings of three-dimensional Euclidean space by tetrahedra and octahedra.

    PubMed

    Conway, John H; Jiao, Yang; Torquato, Salvatore

    2011-07-01

    It is well known that two regular tetrahedra can be combined with a single regular octahedron to tile (complete fill) three-dimensional Euclidean space . This structure was called the "octet truss" by Buckminster Fuller. It was believed that such a tiling, which is the Delaunay tessellation of the face-centered cubic (fcc) lattice, and its closely related stacking variants, are the only tessellations of that involve two different regular polyhedra. Here we identify and analyze a unique family comprised of a noncountably infinite number of periodic tilings of whose smallest repeat tiling unit consists of one regular octahedron and six smaller regular tetrahedra. We first derive an extreme member of this unique tiling family by showing that the "holes" in the optimal lattice packing of octahedra, obtained by Minkowski over a century ago, are congruent tetrahedra. This tiling has 694 distinct concave (i.e., nonconvex) repeat units, 24 of which possess central symmetry, and hence is distinctly different and combinatorically richer than the fcc tetrahedra-octahedra tiling, which only has two distinct tiling units. Then we construct a one-parameter family of octahedron packings that continuously spans from the fcc to the optimal lattice packing of octahedra. We show that the "holes" in these packings, except for the two extreme cases, are tetrahedra of two sizes, leading to a family of periodic tilings with units composed four small tetrahedra and two large tetrahedra that contact an octahedron. These tilings generally possess 2,068 distinct concave tiling units, 62 of which are centrally symmetric. PMID:21690370

  10. New family of tilings of three-dimensional Euclidean space by tetrahedra and octahedra

    PubMed Central

    Conway, John H.; Jiao, Yang; Torquato, Salvatore

    2011-01-01

    It is well known that two regular tetrahedra can be combined with a single regular octahedron to tile (complete fill) three-dimensional Euclidean space . This structure was called the “octet truss” by Buckminster Fuller. It was believed that such a tiling, which is the Delaunay tessellation of the face-centered cubic (fcc) lattice, and its closely related stacking variants, are the only tessellations of that involve two different regular polyhedra. Here we identify and analyze a unique family comprised of a noncountably infinite number of periodic tilings of whose smallest repeat tiling unit consists of one regular octahedron and six smaller regular tetrahedra. We first derive an extreme member of this unique tiling family by showing that the “holes” in the optimal lattice packing of octahedra, obtained by Minkowski over a century ago, are congruent tetrahedra. This tiling has 694 distinct concave (i.e., nonconvex) repeat units, 24 of which possess central symmetry, and hence is distinctly different and combinatorically richer than the fcc tetrahedra-octahedra tiling, which only has two distinct tiling units. Then we construct a one-parameter family of octahedron packings that continuously spans from the fcc to the optimal lattice packing of octahedra. We show that the “holes” in these packings, except for the two extreme cases, are tetrahedra of two sizes, leading to a family of periodic tilings with units composed four small tetrahedra and two large tetrahedra that contact an octahedron. These tilings generally possess 2,068 distinct concave tiling units, 62 of which are centrally symmetric. PMID:21690370

  11. Quantitative crystalline silica exposure assessment for a historical cohort epidemiologic study in the German porcelain industry.

    PubMed

    Birk, Thomas; Guldner, Karlheinz; Mundt, Kenneth A; Dahmann, Dirk; Adams, Robert C; Parsons, William

    2010-09-01

    A time-dependent quantitative exposure assessment of silica exposure among nearly 18,000 German porcelain workers was conducted. Results will be used to evaluate exposure-response disease risks. Over 8000 historical industrial hygiene (IH) measurements with original sampling and analysis protocols from 1954-2006 were obtained from the German Berufs- genossenschaft der keramischen-und Glas-Industrie (BGGK) and used to construct a job exposure matrix (JEM). Early measurements from different devices were converted to modern gravimetric equivalent values. Conversion factors were derived from parallel historical measurements and new side-by-side measurements using historical and modern devices in laboratory dust tunnels and active workplace locations. Exposure values were summarized and smoothed using LOESS regression; estimates for early years were derived using backward extrapolation techniques. Employee work histories were merged with JEM values to determine cumulative crystalline silica exposures for cohort members. Average silica concentrations were derived for six primary similar exposure groups (SEGs) for 1938-2006. Over 40% of the cohort accumulated <0.5 mg; just over one-third accumulated >1 mg/m(3)-years. Nearly 5000 workers had cumulative crystalline silica estimates >1.5 mg/m(3)-years. Similar numbers of men and women fell into each cumulative exposure category, except for 1113 women and 1567 men in the highest category. Over half of those hired before 1960 accumulated >3 mg/m(3)-years crystalline silica compared with 4.9% of those hired after 1960. Among those ever working in the materials preparation area, half accumulated >3 mg/m(3)-year compared with 12% of those never working in this area. Quantitative respirable silica exposures were estimated for each member of this cohort, including employment periods for which sampling used now obsolete technologies. Although individual cumulative exposure estimates ranged from background to about 40 mg/m(3)-years

  12. The sROD module for the ATLAS Tile Calorimeter Phase-II Upgrade Demonstrator

    NASA Astrophysics Data System (ADS)

    Carrió, F.; Castillo, V.; Ferrer, A.; Fiorini, L.; Hernández, Y.; Higón, E.; Mellado, B.; March, L.; Moreno, P.; Reed, R.; Solans, C.; Valero, A.; Valls, J. A.

    2014-02-01

    TileCal is the central hadronic calorimeter of the ATLAS experiment at the Large Hadron Collider (LHC) at CERN. The main upgrade of the LHC to increase the instantaneous luminosity is scheduled for 2022. The High Luminosity LHC, also called upgrade Phase-II, will imply a complete redesign of the read-out electronics in TileCal. In the new read-out architecture, the front-end electronics aims to transmit full digitized information to the back-end system in the counting rooms. Thus, the back-end system will also provide digital calibrated information with enhanced precision and granularity to the first level trigger to improve the trigger efficiencies. The demonstrator project is envisaged to qualify this new proposed architecture. A reduced part of the detector, 1/256 of the total, will be equipped with the new electronics during 2014 to evaluate the proposed architecture in real conditions. The upgraded Read-Out Driver (sROD) will be the core element of the back-end electronics in Phase-II. The sROD module is designed on a double mid-size AMC format and will operate under an AdvancedTCA framework. The module includes two Xilinx Series 7 Field Programmable Gate Arrays (FPGAs) for data receiving and processing, as well as the implementation of embedded systems. Related to optical connectors, the sROD uses 4 QSFPs to receive and transmit data from the front-end electronics and 1 Avago MiniPOD to send preprocessed data to the first level trigger system. An SFP module maintains the compatibility with the existing hardware. A complete description of the sROD module for the demonstrator including the main functionalities, circuit design and the control software and firmware will be presented.

  13. Effect of two different finishing systems on surface roughness of feldspathic and fluorapatite porcelains in ceramo-metal restorations: Comparative in vitro study

    PubMed Central

    Anmol, Cherry; Soni, Sumeet

    2014-01-01

    Objective: The objective of present study was to qualitatively and quantitatively evaluate and compare the effect of two ceramic finishing systems and diamond polishing paste on surface texture of two ceramic materials. Methodology: The 40 test specimens were randomly divided into two main groups (Group I and Group II). Which were subsequently veneered with feldspathic porcelain and fluorapatite leucite porcelain systems respectively. The samples in Test group I and Test group II were subjected to different abrasion and finishing systems (Soft Lex and White silicon and grey rubber respectively). The surface roughness of all the four groups was assessed qualitatively using the scanning Electron Microscope and profilometer. Results: The surface roughness of Feldspathic and fluorapetite porcelain increased after abrasion and finishing as compared to auto-glazed porcelin. The surface roughness was more in grey rubber disc group (Gp Ib) as compared to the soft lex disc groups. After polishing with the diamond paste, there was reduction in the surface roughness of both the disc groups. The Mean Ra values of the Feldspathic porcelain at three intervals were 0.52 ± 0.06, 0.54 ± 0.06, 0.32 ± 0.06 and 0.50 ± 0.04, 1.25 ± 0.10, 0.45 ± 0.6 respectively for grey rubber disc and soft lex groups. The Mean Ra values of Fluorapetite porcelain at three intervals were 0.40 ± 0.06, 0.52 ± 0.06, 0.30 ± 0.03 and 0.41 ± 0.04, 1.17 ± 0.09, 0.39 ± 0.07 respectively for grey rubber disc and soft lex groups. Discussion and Conclusion: The surface roughness was less in the polished samples as compared to the auto-glazed porcelain. The findings were more reinforcing in the soft lex group as compared to the white/grey rubber disc group. Between the two porcelain systems, the Fluorapatite leucite porcelain specimens exhibited better surface smoothness than feldspathic porcelain. PMID:24818090

  14. A Scintillator tile-fiber preshower detector for the CDF Central Calorimeter

    SciTech Connect

    S. Lami

    2004-08-12

    The front face of the CDF central calorimeter is being equipped with a new Preshower detector, based on scintillator tiles read out by WLS fibers. A light yield of about 40 pe/MIP at the tile exit was obtained, exceeding the design requirements.

  15. Effect of strain isolator pad modulus on inplane strain in Shuttle Orbiter thermal protection system tiles

    NASA Technical Reports Server (NTRS)

    Sawyer, J. W.

    1983-01-01

    The thermal protection system used on the Space Shuttle orbiter to determine strains in the reusable surface insulation tiles under simulated flight loads was investigated. The effects of changes in the strain isolator pad (SIP) moduli on the strains in the tile were evaluated. To analyze the SIP/tile system, it was necessary to conduct tests to determine inplane tension and compression modulus and inplane failure strain for the densified layer of the tiles. It is shown that densification of the LI-900 tile material increases the modulus by a factor of 6 to 10 and reduces the failure strain by about 50%. It is indicated that the inplane strain levels in the Shuttle tiles in the highly loaded regions are approximately 2 orders of magnitude lower than the failure strain of the material. It is concluded that most of the LI-900 tiles on the Shuttle could be mounted on a SIP with tensile and shear stiffnesses 10 times those of the present SIP without inplane strain failure in the tile.

  16. Tritium distributions on tungsten and carbon tiles used in the JET divertor

    NASA Astrophysics Data System (ADS)

    Hatano, Y.; Yumizuru, K.; Likonen, J.; Koivuranta, S.; Ikonen, J.; Contributors, JET

    2016-02-01

    Tritium distributions on the W-coated divertor tiles used with Be wall in JET 2011-2012 ITER-like wall (JET-ILW) campaign were measured using an imaging plate (IP) technique. The high intensity of photo-stimulated luminescence (PSL) from IP was observed at the regions covered by deposited Be layers. However, the PSL intensity was not simply proportional to the thickness of the deposited Be layers; the shadowed region of Tile 4 showed the highest PSL intensity though the thickness of deposited Be layer on this region was smaller than that on Tile 0 and the apron of Tile 1 by an order of magnitude. These observations indicated the influence of impurities such as oxygen on tritium retention in the deposited Be layers. The C tiles used in the 2007-2009 JET carbon wall (JET-C) campaign were also examined. The high PSL intensity was observed for the regions covered with deposited C layers in this case. The area of tile surfaces covered by the deposited tritium-rich layers on the W-coated-tiles used in the JET-ILW campaign was significantly smaller than that on the C tiles used in the JET-C campaign.

  17. Automated 3D Damaged Cavity Model Builder for Lower Surface Acreage Tile on Orbiter

    NASA Technical Reports Server (NTRS)

    Belknap, Shannon; Zhang, Michael

    2013-01-01

    The 3D Automated Thermal Tool for Damaged Acreage Tile Math Model builder was developed to perform quickly and accurately 3D thermal analyses on damaged lower surface acreage tiles and structures beneath the damaged locations on a Space Shuttle Orbiter. The 3D model builder created both TRASYS geometric math models (GMMs) and SINDA thermal math models (TMMs) to simulate an idealized damaged cavity in the damaged tile(s). The GMMs are processed in TRASYS to generate radiation conductors between the surfaces in the cavity. The radiation conductors are inserted into the TMMs, which are processed in SINDA to generate temperature histories for all of the nodes on each layer of the TMM. The invention allows a thermal analyst to create quickly and accurately a 3D model of a damaged lower surface tile on the orbiter. The 3D model builder can generate a GMM and the correspond ing TMM in one or two minutes, with the damaged cavity included in the tile material. A separate program creates a configuration file, which would take a couple of minutes to edit. This configuration file is read by the model builder program to determine the location of the damage, the correct tile type, tile thickness, structure thickness, and SIP thickness of the damage, so that the model builder program can build an accurate model at the specified location. Once the models are built, they are processed by the TRASYS and SINDA.

  18. 40 CFR 427.70 - Applicability; description of the asbestos floor tile subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... asbestos floor tile subcategory. 427.70 Section 427.70 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Asbestos Floor Tile Subcategory § 427.70 Applicability; description of the asbestos floor...

  19. 40 CFR 427.70 - Applicability; description of the asbestos floor tile subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... asbestos floor tile subcategory. 427.70 Section 427.70 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Asbestos Floor Tile Subcategory § 427.70 Applicability; description of the asbestos floor...

  20. 40 CFR 427.70 - Applicability; description of the asbestos floor tile subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... asbestos floor tile subcategory. 427.70 Section 427.70 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Asbestos Floor Tile Subcategory § 427.70 Applicability; description of the asbestos floor...

  1. Tiled-grating compressor with uncompensated dispersion for near-field-intensity smoothing.

    PubMed

    Huang, H; Kessler, Terrance

    2007-07-01

    A tiled-grating compressor, in which the spatial dispersion is not completely compensated, reduces the near-field-intensity modulation caused by tiling gaps and provides near-field spatial filtering of the input laser beam, thus reducing the laser damage to the final optics. PMID:17603592

  2. Preferential flow estimates to an agricultural tile drain with implications for glyphosate transport

    USGS Publications Warehouse

    Stone, W.W.; Wilson, J.T.

    2006-01-01

    Agricultural subsurface drains, commonly referred to as tile drains, are potentially significant pathways for the movement of fertilizers and pesticides to streams and ditches in much of the Midwest. Preferential flow in the unsaturated zone provides a route for water and solutes to bypass the soil matrix and reach tile drains faster than predicted by traditional displacement theory. This paper uses chloride concentrations to estimate preferential flow contributions to a tile drain during two storms in May 2004. Chloride, a conservative anion, was selected as the tracer because of differences in chloride concentrations between the two sources of water to the tile drain, preferential and matrix flow. A strong correlation between specific conductance and chloride concentration provided a mechanism to estimate chloride concentrations in the tile drain throughout the storm hydrographs. A simple mixing analysis was used to identify the preferential flow component of the storm hydrograph. During two storms, preferential flow contributed 11 and 51% of total storm tile drain flow; the peak contributions, 40 and 81%, coincided with the peak tile drain flow. Positive relations between glyphosate [N-(phosphonomethyl)glycine] concentrations and preferential flow for the two storms suggest that preferential flow is an important transport pathway to the tile drain. ?? ASA, CSSA, SSSA.

  3. Space Shuttle Communications Coverage Analysis for Thermal Tile Inspection

    NASA Technical Reports Server (NTRS)

    Kroll, Quin D.; Hwu, Shian U.; Upanavage, Matthew; Boster, John P.; Chavez, Mark A.

    2009-01-01

    The space shuttle ultra-high frequency Space-to-Space Communication System has to provide adequate communication coverage for astronauts who are performing thermal tile inspection and repair on the underside of the space shuttle orbiter (SSO). Careful planning and quantitative assessment are necessary to ensure successful system operations and mission safety in this work environment. This study assesses communication systems performance for astronauts who are working in the underside, non-line-of-sight shadow region on the space shuttle. All of the space shuttle and International Space Station (ISS) transmitting antennas are blocked by the SSO structure. To ensure communication coverage at planned inspection worksites, the signal strength and link margin between the SSO/ISS antennas and the extravehicular activity astronauts, whose line-of-sight is blocked by vehicle structure, was analyzed. Investigations were performed using rigorous computational electromagnetic modeling techniques. Signal strength was obtained by computing the reflected and diffracted fields along the signal propagation paths between transmitting and receiving antennas. Radio frequency (RF) coverage was determined for thermal tile inspection and repair missions using the results of this computation. Analysis results from this paper are important in formulating the limits on reliable communication range and RF coverage at planned underside inspection and repair worksites.

  4. Tiling analysis of melting in strongly-coupled dusty plasma*

    NASA Astrophysics Data System (ADS)

    Suranga Ruhunusiri, W. D.; Feng, Yan; Liu, Bin; Goree, John

    2010-11-01

    A dusty plasma is an ionized gas containing micron-size particles of solid matter, which collect electrons and ions and become negatively charged. Due to large Coulomb interparticle potential energies, the microparticles represent a strongly-coupled plasma. In the absence of an external disturbance, the microparticles self-organize, arranging themselves in a crystalline lattice, due to their Coulomb interaction. If kinetic energy is added, the arrangement of microparticles becomes disordered, like atoms in a liquid. This melting process can be characterized by a proliferation of defects, which previous experimenters measured using Voronoi analysis. Here we use another method, tiling [1] to quantify defects. We demonstrate this method, which until now has been used only in simulations, in a dusty plasma experiment. A single layer of 4.83 μm polymer microparticles was electrically levitated in a glow discharge argon plasma. The lattice was melted by applying random kicks to the micoparticles from rastered laser beams. We imaged the particle positions and computed the corresponding tiling for both the crystalline lattice and liquid states. [1] Matthew A. Glaser, Phys. Rev A 41, 4585 (1990) ^*Work supported by NSF and NASA.

  5. Emergence of limit-periodic order in tiling models

    NASA Astrophysics Data System (ADS)

    Marcoux, Catherine; Byington, Travis W.; Qian, Zongjin; Charbonneau, Patrick; Socolar, Joshua E. S.

    2014-07-01

    A two-dimensional (2D) lattice model defined on a triangular lattice with nearest- and next-nearest-neighbor interactions based on the Taylor-Socolar monotile is known to have a limit-periodic ground state. The system reaches that state during a slow quench through an infinite sequence of phase transitions. We study the model as a function of the strength of the next-nearest-neighbor interactions and introduce closely related 3D models with only nearest-neighbor interactions that exhibit limit-periodic phases. For models with no next-nearest-neighbor interactions of the Taylor-Socolar type, there is a large degenerate class of ground states, including crystalline patterns and limit-periodic ones, but a slow quench still yields the limit-periodic state. For the Taylor-Socolar lattic model, we present calculations of the diffraction pattern for a particular decoration of the tile that permits exact expressions for the amplitudes and identify domain walls that slow the relaxation times in the ordered phases. For one of the 3D models, we show that the phase transitions are first order, with equilibrium structures that can be more complex than in the 2D case, and we include a proof of aperiodicity for a geometrically simple tile with only nearest-neighbor matching rules.

  6. Close-up of Shuttle Thermal Tiles in Space

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Launched on July 26, 2005 from the Kennedy Space Center in Florida, STS-114 was classified as Logistics Flight 1. Among the Station-related activities of the mission were the delivery of new supplies and the replacement of one of the orbital outpost's Control Moment Gyroscopes (CMGs). STS-114 also carried the Raffaello Multi-Purpose Logistics Module and the External Stowage Platform-2. A major focus of the mission was the testing and evaluation of new Space Shuttle flight safety, which included new inspection and repair techniques. Upon its approach to the International Space Station (ISS), the Space Shuttle Discovery underwent a photography session in order to assess any damages that may have occurred during its launch and/or journey through Space. The mission's third and final Extra Vehicular Activity (EVA) included taking a close-up look and the repair of the damaged heat shield. Gap fillers were removed from between the orbiter's heat-shielding tiles located on the craft's underbelly. Never before had any repairs been done to an orbiter while still in space. This particular photo was taken by astronaut Stephen K. Robinson, STS-114 mission specialist, whose shadow is visible on the thermal protection tiles, and a portion of the Canadian built Remote Manipulator System (RMS) robotic arm and the Nile River is visible at the bottom.

  7. Non isothermal drying process optimisation - Drying of clay tiles

    NASA Astrophysics Data System (ADS)

    Vasić, M.; Radojević, Z.

    2015-11-01

    In our previous studies we have developed a model for determination of the variable effective diffusivity and identification of the exact transition points between possible drying mechanisms. The next goal was to develop a drying regime which could in advance characterize the real non isothermal process of drying clay tiles. In order to do this four isothermal experiments were recorded. Temperature and humidity were maintained at 350C / 75%; 450C / 70%; 450C / 60% and 500C / 60%; respectively in each experiment. All experimentally collected data were analyzed and the exact transition points between possible drying mechanisms were detected. Characteristic drying period (time) for each isothermal drying mechanism was also detected. The real, non-isothermal drying process was approximated by 5 segments. In each of these segments approximately isothermal drying condition were maintained. Temperature and humidity of the drying air, in the first four segments, was maintained on the same level as in recorded isothermal experiments while in the fifth segment, it were maintained at 700C / 40%. The duration of the first four segments were calculated from the diagrams Deff - t respectively for each experiment. The clay tile in experiment five was dried without cracking using the proposed non isothermal drying regime.

  8. Numerical methods for analysis of clay tile infills

    SciTech Connect

    Flanagan, R.D.; Tenbus, M.A.; Bennett, R.M.

    1993-10-20

    Recent Department of Energy requirements have led to a comprehensive evaluation of the industrial facilities at the Oak Ridge Y-12 Plant. The structures consist of simply connected steel frames infilled with structural clay tile walls. The objective of the evaluation was to determine the stability of the unreinforced infills, and whether they provide the lateral capacity necessary to resist the moderate seismic hazard at the site. Due to lack of information on the behavior of structural clay tile infills, various large-scale tests were performed to investigate the in-plane, out-of-plane and combined in-plane and out-of-plane behavior. The results of these tests are briefly summarized, and the development of analytical guidelines based on these tests is given. Little interaction between in-plane and out-of-plane loads was observed, both in terms of stiffness and strength. Out-of-plane stability can be examined panel by panel based on arching action. Inter-story drift does not appear to present a stability problem for the type of infill construction investigated. In-plane behavior may be adequately modeled with a nonlinear compression strut. A typical building is chosen for an illustrative application. The methodology and results of the seismic analysis are presented for this structure.

  9. Surface analysis of 1984/85 TFTR limiter tiles

    SciTech Connect

    Pontau, A.E.; Wampler, W.R.; Mills, B.E.; Doyle, B.L.; Wright, A.F.; Ulrickson, M.A.; LaMarche, P.H.; Dylla, H.F.; Fukuda, S.

    1985-01-01

    Bare POCO AXF-5Q graphite titles were installed as the plasma-facing surface of the TFTR movable limiter for a series of approx.2700 high power discharges (600 with up to 6 MW neutral beams). During this operating phase, erosion and deposition processes modified the surface of the limiter. In the regions of the most intense plasma contact, which reached temperatures over 2400C, only small amounts of metallic impurities (<5 x 10 W atoms/cmS) are observed during subsequent beta backscattering and proton-induced x-ray emission (PIXE) analysis. Also observed in these regions are several small areas of surface crazing, and scattered droplets of metals (approx.1 mm diameter) presumed to originate from melted internal hardware. In regions more removed from direct plasma contact, thicker metallic deposits are observed (approx.2 x 10 Y atoms/cmS). Surface roughness measured outside the intense plasma contact region is much more than the original POCO AXF-5Q graphite whereas within the plasma contact region, tile surfaces are somewhat smoother than they were initially. Two of the tiles in high heat flux regions broke during operation. The resulting geometry change led to areas of enhanced erosion and nearby redeposition of carbon. 5 figs.

  10. Size-Topology Correlations and Crystallization in Tilings and Packings

    NASA Astrophysics Data System (ADS)

    Hilgenfeldt, Sascha

    2014-03-01

    Ever since its empirical formulation in 1928, Lewis`s law has intrigued scientists, postulating a linear correlation between the average in-plane area and the number of neighbors in a two-dimensional tiling. Many supporting and dissenting results have been reported in systems as diverse as foams, Voronoi tilings in glass models, and nanocrystals. A strong size-topology correlation is consistently observed, but it is often pronouncedly nonlinear. Recently, a variant of the granocentric model explained numerous cases of nonlinear correlations, but cannot account for the linear version of the law. We revisit Lewis's original work by conducting more extensive experiments on cucumber epidermis tissue. The data confirms the linear law, but also shows that the individual cells have a pronounced anisotropy, not present in systems with nonlinear correlation laws. We demonstrate how the granocentric model can be modified taking into account the cell anisotropy, and how this feature is capable of reproducing the linear Lewis law, as well as other characteristic differences in size-topology statistical quantities. The model should be generally applicable to jammed, plane-filling systems and identifies domain anisotropy as an important ingredient in their statistical description.

  11. [Chemical composition analysis of bluish-white porcelain unearthed from Fanchang kiln, Anhui province by wave disperse X-ray fluorescence].

    PubMed

    Yang, Yu-zhang; Zhang, Ju-zhong; Zan, Yi

    2010-08-01

    Fanchang kiln was the earliest Chinese bluish-white porcelain kiln which first fired this special porcelain class as early as in Five Dynasties (AD 907-960). However, this important kiln declined rapidly in the middle North Song dynasty (AD 1023-1085). As to the decline reason, it is still not clearly identified till now. In order to find the truth, wavelength-dispersive X-ray fluorescence (WDXRF) was used to determine the elemental abundance patterns of its porcelain bodies in Five Dynasties, the early North Song dynasty and the middle North Song dynasty. The analytical results indicate that the chemical compositions of major, minor and trace elements in porcelain bodies changed greatly in the middle North Song dynasty. Combined with the results of INAA and glaze study, this change in elemental composition should be caused by the change in porcelain raw materials or body-making crafts. Meanwhile, it was just this change that led to the quality decline of raw material and rapid collapse of Fan-chang kiln in the middle North Song dynasty shortly after its establishment. PMID:20939361

  12. Direct determination of trace rare earth elements in ancient porcelain samples with slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry

    NASA Astrophysics Data System (ADS)

    Xiang, Guoqiang; Jiang, Zucheng; He, Man; Hu, Bin

    2005-10-01

    A method for the direct determination of trace rare earth elements in ancient porcelain samples by slurry sampling fluorinating electrothermal vaporization inductively coupled plasma mass spectrometry was developed with the use of polytetrafluoroethylene as fluorinating reagent. It was found that Si, as a main matrix element in ancient porcelain sample, could be mostly removed at the ashing temperature of 1200 °C without considerable losses of the analytes. However, the chemical composition of ancient porcelain sample is very complicated, which makes the influences resulting from other matrix elements not be ignored. Therefore, the matrix effect of ancient porcelain sample was also investigated, and it was found that the matrix effect is obvious when the matrix concentration was larger than 0.8 g l - 1 . The study results of particle size effect indicated that when the sample particle size was less than 0.057 mm, the particle size effect is negligible. Under the optimized operation conditions, the detection limits for rare earth elements by fluorinating electrothermal vaporization inductively coupled plasma mass spectrometry were 0.7 ng g - 1 (Eu)-33.3 ng g - 1 (Nd) with the precisions of 4.1% (Yb)-10% (La) ( c = 1 μg l - 1 , n = 9). The proposed method was used to directly determine the trace rare earth elements in ancient porcelain samples produced in different dynasty (Sui, Ming and Qing), and the analytical results are satisfactory.

  13. Aerodynamic heating in large cavities in an array of RSI tiles. [for space shuttles

    NASA Technical Reports Server (NTRS)

    Hunt, L. R.

    1977-01-01

    A large panel of reusable surface insulation (RSI) tiles including lost tile cavities was aerothermally tested in the Langley 8 foot high temperature structures tunnel to determine both the heat load within the cavities and the structural performance of the RSI surrounding the cavities. Tests were conducted with a turbulent boundary layer at a nominal free stream Mach number of 6.6, a total temperature of 1800 K, a Reynolds number per meter of 5 million, and a dynamic pressure of 62 kPa. The maximum aerodynamic heating to the floor of the cavity was two to three times the normal surface heating. The cavity heating rates agreed with data from other facilities and were successfully correlated with an empirical equation. A zippering failure occurred to a tile downstream of a double tile cavity when the separated flow attached to the floor of the cavity and forced the tile from its position.

  14. Porosity Detection in Ceramic Armor Tiles via Ultrasonic Time-Of

    NASA Astrophysics Data System (ADS)

    Margetan, Frank J.; Richter, Nathaniel; Jensen, Terrence

    2011-06-01

    Some multilayer armor panels contain ceramic tiles as one constituent, and porosity in the tiles can affect armor performance. It is well known that porosity in ceramic materials leads to a decrease in ultrasonic velocity. We report on a feasibility study exploring the use of ultrasonic time-of-flight (TOF) to locate and characterize porous regions in armor tiles. The tiles in question typically have well-controlled thickness, thus simplifying the translation of TOF data into velocity data. By combining UT velocity measurements and X-ray absorption measurements on selected specimens, one can construct a calibration curve relating velocity to porosity. That relationship can then be used to translate typical ultrasonic C-scans of TOF-versus-position into C-scans of porosity-versus-position. This procedure is demonstrated for pulse/echo, focused-transducer inspections of silicon carbide (SiC) ceramic tiles.

  15. Advanced Modeling Strategies for the Analysis of Tile-Reinforced Composite Armor

    NASA Technical Reports Server (NTRS)

    Davila, Carlos G.; Chen, Tzi-Kang

    1999-01-01

    A detailed investigation of the deformation mechanisms in tile-reinforced armored components was conducted to develop the most efficient modeling strategies for the structural analysis of large components of the Composite Armored Vehicle. The limitations of conventional finite elements with respect to the analysis of tile-reinforced structures were examined, and two complementary optimal modeling strategies were developed. These strategies are element layering and the use of a tile-adhesive superelement. Element layering is a technique that uses stacks of shear deformable shell elements to obtain the proper transverse shear distributions through the thickness of the laminate. The tile-adhesive superelement consists of a statically condensed substructure model designed to take advantage of periodicity in tile placement patterns to eliminate numerical redundancies in the analysis. Both approaches can be used simultaneously to create unusually efficient models that accurately predict the global response by incorporating the correct local deformation mechanisms.

  16. Tony Rollins prepares a new tile for the Space Shuttle orbiter

    NASA Technical Reports Server (NTRS)

    1998-01-01

    In the Tile Fabrication Shop, Tony Rollins, with United Space Alliance, cuts a High-Temperature Reusable Surface Insulation (HRSI) tile on a gun stock contour milling machine. About 70 percent of a Space Shuttle orbiter's external surface is shielded from heat by a network of more than 24,000 tiles formed from a silica fiber compound. HRSI tiles cover the lower surface of the orbiter, areas around the forward windows, upper body flap, the base heat shield, the 'eyeballs' on the front of the Orbital Maneuvering System (OMS) pods, and the leading and trailing edges of the vertical stabilizer and the rudder speed brake. They are generally 6 inches square, but may also be as large as 12 inches square in some areas, and 1 to 5 inches thick. More advanced materials such as Flexible Insulation Blankets have replaced tiles on some upper surfaces of the orbiter.

  17. Porosity detection in ceramic armor tiles via ultrasonic time-of-flight

    SciTech Connect

    Margetan, Frank J.; Richter, Nathaniel; Jensen, Terrence

    2011-06-23

    Some multilayer armor panels contain ceramic tiles as one constituent, and porosity in the tiles can affect armor performance. It is well known that porosity in ceramic materials leads to a decrease in ultrasonic velocity. We report on a feasibility study exploring the use of ultrasonic time-of-flight (TOF) to locate and characterize porous regions in armor tiles. The tiles in question typically have well-controlled thickness, thus simplifying the translation of TOF data into velocity data. By combining UT velocity measurements and X-ray absorption measurements on selected specimens, one can construct a calibration curve relating velocity to porosity. That relationship can then be used to translate typical ultrasonic C-scans of TOF-versus-position into C-scans of porosity-versus-position. This procedure is demonstrated for pulse/echo, focused-transducer inspections of silicon carbide (SiC) ceramic tiles.

  18. K-Theory of Crossed Products of Tiling C*-Algebras by Rotation Groups

    NASA Astrophysics Data System (ADS)

    Starling, Charles

    2015-02-01

    Let Ω be a tiling space and let G be the maximal group of rotations which fixes Ω. Then the cohomology of Ω and Ω/ G are both invariants which give useful geometric information about the tilings in Ω. The noncommutative analog of the cohomology of Ω is the K-theory of a C*-algebra associated to Ω, and for translationally finite tilings of dimension 2 or less, the K-theory is isomorphic to the direct sum of cohomology groups. In this paper we give a prescription for calculating the noncommutative analog of the cohomology of Ω/ G, that is, the K-theory of the crossed product of the tiling C*-algebra by G. We also provide a table with some calculated K-groups for many common examples, including the Penrose and pinwheel tilings.

  19. Terahertz NDE Application for Corrosion Detection and Evaluation under Shuttle Tiles

    NASA Technical Reports Server (NTRS)

    Anastasi, Robert F.; Madaras, Eric I.; Seebo, Jeffrey P.; Smith, Stephen W.; Lomness, Janice K.; Hintze, Paul E.; Kammerer, Catherine C.; Winfree, William P.; Russell, Richard W.

    2007-01-01

    Pulsed Terahertz NDE is being examined as a method to inspect for possible corrosion under Space Shuttle Tiles. Other methods such as ultrasonics, infrared, eddy current and microwave technologies have demonstrable shortcomings for tile NDE. This work applies Terahertz NDE, in the frequency range between 50 GHz and 1 THz, for the inspection of manufactured corrosion samples. The samples consist of induced corrosion spots that range in diameter (2.54 to 15.2 mm) and depth (0.036 to 0.787 mm) in an aluminum substrate material covered with tiles. Results of these measurements are presented for known corrosion flaws both covered and uncovered and for blind tests with unknown corrosion flaws covered with attached tiles. The Terahertz NDE system is shown to detect all artificially manufactured corrosion regions under a Shuttle tile with a depth greater than 0.13 mm.

  20. Electrical performance of RTV silicone rubber coating of different thicknesses on porcelain

    SciTech Connect

    Deng, H.; Hackam, R.

    1997-04-01

    A study of the effects of coating thickness of room temperature vulcanizing (RTV) silicone rubber on its electrical performance in salt-fog of 250 {micro}S/cm and 1,000 {micro}S/cm at 0.5 kV{sub rms}/cm is presented. Porcelain rods coated with RTV silicone rubber to a thickness from 0.17 to 0.99 mm were studied. The dependence of current pulse rate and cumulative number of current pulses on coating thickness were determined as a function of time of exposure to combined electric stress and salt-fog. The surface roughness and the total content of low molecular weight (LMW) silicone fluid in the coating were measured before and after the salt-fog test as a function of coating thickness. The effects of heating the RTV in an electric oven on the production and loss of LMW silicone fluid were investigated in order to elucidate the influence of the heat generated by dry band discharges. The loss of weight of RTV at high temperatures (370 C) due to the decomposition of the alumina trihydrate filler into alumina and water was measured and found to be close to the theoretical value.