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Sample records for modified tile mortar

  1. Solid state NMR and LVSEM studies on the hardening of latex modified tile mortar systems

    SciTech Connect

    Rottstegge, J.; Arnold, M.; Herschke, L.; Glasser, G.; Wilhelm, M.; Spiess, H.W. . E-mail: spiess@mpip-mainz.mpg.de; Hergeth, W.D.

    2005-12-15

    Construction mortars contain a broad variety of both inorganic and organic additives beside the cement powder. Here we present a study of tile mortar systems based on portland cement, quartz, methyl cellulose and different latex additives. As known, the methyl cellulose stabilizes the freshly prepared cement paste, the latex additive enhances final hydrophobicity, flexibility and adhesion. Measurements were performed by solid state nuclear magnetic resonance (NMR) and low voltage scanning electron microscopy (LVSEM) to probe the influence of the latex additives on the hydration, hardening and the final tile mortar properties. While solid state NMR enables monitoring of the bulk composition, scanning electron microscopy affords visualization of particles and textures with respect to their shape and the distribution of the different phases. Within the alkaline cement paste, the poly(vinyl acetate) (VAc)-based latex dispersions stabilized by poly(vinyl alcohol) (PVA) were found to be relatively stable against hydrolysis. The influence of the combined organic additives methyl cellulose, poly(vinyl alcohol) and latexes stabilized by poly(vinyl alcohol) on the final silicate structure of the cement hydration products is small. But even small amounts of additives result in an increased ratio of ettringite to monosulfate within the final hydrated tile mortar as monitored by {sup 27}Al NMR. The latex was found to be adsorbed to the inorganic surfaces, acting as glue to the inorganic components. For similar latex water interfaces built up by poly(vinyl alcohol), a variation in the latex polymer composition results in modified organic textures. In addition to the networks of the inorganic cement and of the latex, there is a weak network build up by thin polymer fibers, most probably originating from poly(vinyl alcohol). Besides the weak network, polymer fibers form well-ordered textures covering inorganic crystals such as portlandite.

  2. Influence of Prepackaged Polymer-Modified Mortar as a Modifier on Strength of Concrete

    NASA Astrophysics Data System (ADS)

    Saand, Abdullah; Ismail, Mohammad; Radin Sumadi, Salihuddin

    This study introduce a new trend of utilising Prepackaged Polymer-Modified Mortar (PPMM) as a modifier to ordinary concrete for producing Polymer-Modified Concrete (PMC). The experimental study articulates the strength development of proposed polymer-modified concrete. A range of quantities of PPMM, as 5 to 50%, were mixed with ordinary concrete of 30 N mmG2 characteristic strength to produce polymer-modified concrete and to evaluate for compressive strength, tensile strength, density and workability. The material behaviour in terms of compressive strength and tensile strength, together with density and slump was investigated by casting and testing cubes of 100 mm size, cylinders 100 mm dia and 200 mm height. This Preliminary study shows that compressive strength and tensile strength is improved significantly by inclusion of various quantities as percentages of PPMM to ordinary concrete and curing regime as specified by JIS. PPMM dosages of 5 to 20% resulted considerably higher compressive and tensile strength than that of ordinary concrete, on the other hand further increase in percentage of PPMM gave less strengths. Results demonstrated more prominent percentage increase in tensile strength than compressive strength of produced polymer-modified concrete. Polymer-mod fied concrete mixes with all percentage dosages of PPMM were found cohesive and workable.

  3. Influence of viscosity modifying admixtures on the rheological behavior of cement and mortar pastes

    NASA Astrophysics Data System (ADS)

    Bouras, R.; Kaci, A.; Chaouche, M.

    2012-03-01

    The influence of Viscosity-modifying admixtures (VMA) dosage rate on the steady state rheological properties, including the yield stress, fluid consistency index and flow behaviour index, of cementitious materials is considered experimentally. The investigation is undertaken both at cement paste and mortar scales. It is found that the rheological behaviour of the material is in general dependent upon shear-rate interval considered. At sufficiently low shear-rates the materials exhibit shear-thinning. This behaviour is attributed to flow-induced defloculation of the solid particles and VMA polymer disentanglement and alignment. At relatively high shear-rates the pastes becomes shear-thickening, due to repulsive interactions among the solid particles. There is a qualitative difference between the influence of VMA dosage at cement and mortar scales: at cement scale we obtain a monotonic increase of the yield stress, while at mortar scale there exists an optimum VMA dosage for which the yield stress is a minimum. The flow behaviour index exhibit a maximum in the case of cement pastes and monotonically decreases in the case of mortars. On the other hand, the fluid consistency index presents a minimum for both cement pastes and mortars.

  4. The effect of different surfactants/plastisizers on the electrical behavior of CNT nano-modified cement mortars

    NASA Astrophysics Data System (ADS)

    Dalla, P. T.; Alafogianni, P.; Tragazikis, I. K.; Exarchos, D. A.; Dassios, K.; Barkoula, N.-M.; Matikas, T. E.

    2015-03-01

    Cement-based materials have in general low electrical conductivity. Electrical conductivity is the measure of the ability of the material to resist the passage of electrical current. The addition of a conductive admixture such as Multi-Walled Carbon Nanotubes (MWCNTs) in a cement-based material increases the conductivity of the structure. This research aims to characterize nano-modified cement mortars with MWCNT reinforcements. Such nano-composites would possess smartness and multi-functionality. Multifunctional properties include electrical, thermal and piezo-electric characteristics. One of these properties, the electrical conductivity, was measured using a custom made apparatus that allows application of known D.C. voltage on the nano-composite. In this study, the influence of different surfactants/plasticizers on CNT nano-modified cement mortar specimens with various concentrations of CNTs (0.2% wt. cement CNTs - 0.8% wt. cement CNTs) on the electrical conductivity is assessed.

  5. Effects of a new modifier on the water-resistance of magnesite cement tiles

    NASA Astrophysics Data System (ADS)

    Xu, Kejing; Xi, Jintao; Guo, Yanqing; Dong, Shuhua

    2012-01-01

    The magnesium oxychloride composite is an inorganic cementitious material with high bending and compression strength in air characteristics. However its strength decreases significantly after immersion in water. The preparing process of a new magnesite cement tile using nano rice husk ashes and a complex water-resistance agent as modifiers was described in the paper. The effects of low-temperature rice husk ashes (RHAs) and the complex water-resistance agent constituted with phosphoric acid, calcium superphosphate, wooden calcium and styrene-acrylic emulsion on the water-resistance of magnesite materials were mainly studied. The samples properties were characterized by XRD, SEM, BET, a laser particle size analyzer and bending test. The experiments show that the proportional addition of nano RHAs markedly increases the water-resistance of magnesite materials without reducing the bending strength and promotes the softening coefficient from 0.29 to 0.78, while the softening coefficient reaches up to 0.97 combined with the use of complex water-resistance agent. The new magnesite cement tiles prepared were not scumming, not warping, and not contracting at room temperature for 360 d.

  6. 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…

  7. Compatibility of repair mortar with migrating corrosion inhibiting admixtures

    SciTech Connect

    Bjegovic, D.; Ukrainczyk, V.; Ukrainczyk, B.; Miksic, B.

    1997-08-01

    One of the methods for corrosion protection of reinforced concrete is the use of migrating corrosion inhibitor as an admixture in repair mortars. The admixture must be effective for corrosion protection and compatible with polymers added to repair mortar to improve properties of fresh and hardened mortar. This paper presents experimental results on compatibility of a migrating corrosion inhibitor added to two repair mortars based on an inorganic binder modified with polymers. The influence of a migrating inhibitor on the properties of fresh and hardened mortars was tested. The effectiveness on reinforcement corrosion protection has been tested according to ASTM G 109. Test results prove that the investigated migrating inhibitor is compatible with repair mortars and that it delays corrosion of the reinforcement.

  8. Mortar launched surveillance system

    NASA Astrophysics Data System (ADS)

    Lewis, Carl E.; Carlton, Lindley A.

    2001-02-01

    Accurate Automation Corporation has completed the conceptual design of a mortar launched air vehicle system to perform close range or over-the-horizon surveillance missions. Law enforcement and military units require an organic capability to obtain real time intelligence information of time critical targets. Our design will permit law enforcement to detect, classify, locate and track these time critical targets. The surveillance system is a simple, unmanned fixed-winged aircraft deployed via a conventional mortar tube. The aircraft's flight surfaces are deployed following mortar launch to permit maximum range and time over target. The aircraft and sensor system are field retrievable. The aircraft can be configured with an engine to permit extended time over target or range. The aircraft has an integrated surveillance sensor system; a programmable CMOS sensor array. The integrated RF transmitted to capable of down- linking real-time video over line-of-sight distances exceeding 10 kilometers. The major benefit of the modular design is the ability to provide surveillance or tracking quickly at a low cost. Vehicle operational radius and sensor field coverage as well as design trade results of vehicle range and endurance performance and payload capacity at operational range are presented for various mortar configurations.

  9. Domain decomposition methods for mortar finite elements

    SciTech Connect

    Widlund, O.

    1996-12-31

    In the last few years, domain decomposition methods, previously developed and tested for standard finite element methods and elliptic problems, have been extended and modified to work for mortar and other nonconforming finite element methods. A survey will be given of work carried out jointly with Yves Achdou, Mario Casarin, Maksymilian Dryja and Yvon Maday. Results on the p- and h-p-version finite elements will also be discussed.

  10. 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.

  11. 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.

  12. 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.

  13. Properties of Cement Mortar Produced from Mixed Waste Materials with Pozzolanic Characteristics

    PubMed Central

    Yen, Chi-Liang; Tseng, Dyi-Hwa; Wu, Yue-Ze

    2012-01-01

    Abstract Waste materials with pozzolanic characteristics, such as sewage sludge ash (SSA), coal combustion fly ash (FA), and granulated blast furnace slag (GBS), were reused as partial cement replacements for making cement mortar in this study. Experimental results revealed that with dual replacement of cement by SSA and GBS and triple replacement by SSA, FA, and GBS at 50% of total cement replacement, the compressive strength (Sc) of the blended cement mortars at 56 days was 93.7% and 92.9% of the control cement mortar, respectively. GBS had the highest strength activity index value and could produce large amounts of CaO to enhance the pozzolanic activity of SSA/FA and form calcium silicate hydrate gels to fill the capillary pores of the cement mortar. Consequently, the Sc development of cement mortar with GBS replacement was better than that without GBS, and the total pore volume of blended cement mortars with GBS/SSA replacement was less than that with FA/SSA replacement. In the cement mortar with modified SSA and GBS at 70% of total cement replacement, the Sc at 56 days was 92.4% of the control mortar. Modifying the content of calcium in SSA also increased its pozzolanic reaction. CaCl2 accelerated the pozzolanic activity of SSA better than lime did. Moreover, blending cement mortars with GBS/SSA replacement could generate more monosulfoaluminate to fill capillary pores. PMID:22783062

  14. Properties of Cement Mortar Produced from Mixed Waste Materials with Pozzolanic Characteristics.

    PubMed

    Yen, Chi-Liang; Tseng, Dyi-Hwa; Wu, Yue-Ze

    2012-07-01

    Waste materials with pozzolanic characteristics, such as sewage sludge ash (SSA), coal combustion fly ash (FA), and granulated blast furnace slag (GBS), were reused as partial cement replacements for making cement mortar in this study. Experimental results revealed that with dual replacement of cement by SSA and GBS and triple replacement by SSA, FA, and GBS at 50% of total cement replacement, the compressive strength (Sc) of the blended cement mortars at 56 days was 93.7% and 92.9% of the control cement mortar, respectively. GBS had the highest strength activity index value and could produce large amounts of CaO to enhance the pozzolanic activity of SSA/FA and form calcium silicate hydrate gels to fill the capillary pores of the cement mortar. Consequently, the Sc development of cement mortar with GBS replacement was better than that without GBS, and the total pore volume of blended cement mortars with GBS/SSA replacement was less than that with FA/SSA replacement. In the cement mortar with modified SSA and GBS at 70% of total cement replacement, the Sc at 56 days was 92.4% of the control mortar. Modifying the content of calcium in SSA also increased its pozzolanic reaction. CaCl(2) accelerated the pozzolanic activity of SSA better than lime did. Moreover, blending cement mortars with GBS/SSA replacement could generate more monosulfoaluminate to fill capillary pores. PMID:22783062

  15. 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…

  16. Chloride ingress in cement paste and mortar

    SciTech Connect

    Jensen, O.M.; Hansen, P.F.; Coats, A.M.; Glasser, F.P.

    1999-09-01

    In this paper chloride ingress in cement paste and mortar is followed by electron probe microanalysis. The influence of several paste and exposure parameters on chloride ingress are examined (e.g., water-cement ratio, silica fume addition, exposure time, and temperature). The measurements are modelled on Fick's law modified by a term for chloride binding. Inclusion of chloride binding significantly improves the profile shape of the modelled ingress profiles. The presence of fine aggregate and formation of interfacial transition zones at paste-aggregate boundaries does not significantly affect diffusion rates.

  17. NMR relaxometry study of plaster mortar with polymer additives

    SciTech Connect

    Jumate, E.; Manea, D.; Moldovan, D.; Fechete, R.

    2013-11-13

    The cement mixed with water forms a plastic paste or slurry which stiffness in time and finally hardens into a resistant stone. The addition of sand aggregates, polymers (Walocel) and/or calcium carbonate will modify dramatically the final mortar mechanic and thermal properties. The hydration processes can be observed using the 1D NMR measurements of transverse T{sub 2} relaxation times distributions analysed by a Laplace inversion algorithm. These distributions were obtained for mortar pasta measured at 2 hours after preparation then at 3, 7 and 28 days after preparation. Multiple components are identified in the T{sub 2} distributions. These can be associated with the proton bounded chemical or physical to the mortar minerals characterized by a short T{sub 2} relaxation time and to water protons in pores with three different pore sizes as observed from SEM images. The evaporation process is faster in the first hours after preparation, while the mortar hydration (bonding of water molecules to mortar minerals) can be still observed after days or months from preparation. Finally, the mechanic resistance was correlated with the transverse T{sub 2} relaxation rates corresponding to the bound water.

  18. 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.

  19. Mortar-launched surveillance system

    NASA Astrophysics Data System (ADS)

    Lewis, Carl E.; Cooper, Steve; Carlton, Lindley A.

    2001-09-01

    Accurate Automation Corporation has completed the conceptual design of a mortar launched air vehicle system to perform close range or over-the-horizon surveillance missions. Law enforcement and military units require an organic capability to obtain real time intelligence information of time critical targets. Our design will permit law enforcement to detect, classify, locate and track these time critical targets. The surveillance system is a simple, unmanned fixed-winged aircraft deployed via a conventional mortar tube. The aircraft's flight surfaces are deployed following mortar launch to permit maximum range and time over target. The aircraft and sensor system are field retrievable. The aircraft can be configured with an engine to permit extended time over target or range. The aircraft has an integrated surveillance sensor system; a programmable CMOS sensor array. The integrated RF transmitter is capable of down- linking real-time video over line-of-sight distances exceeding 10 kilometers. The major benefit of the modular design is the ability to provide surveillance or tracking quickly at a low cost. Vehicle operational radius and sensor field coverage as well as design trade results of vehicle range and endurance performance and payload capacity at operational range are presented for various mortar configurations.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. 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.

  6. 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)

  7. Simple Analysis of Historical Lime Mortars

    ERIC Educational Resources Information Center

    Pires, Joa~o

    2015-01-01

    A laboratory experiment is described in which a simple characterization of a historical lime mortar is made by the determination of its approximate composition by a gravimetric method. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) are also used for the qualitative characterization of the lime mortar components. These…

  8. 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

  9. 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.

  10. Use of cactus in mortars and concrete

    SciTech Connect

    Chandra, S.; Eklund, L.; Villarreal, R.R.

    1998-01-01

    Natural polymers have been used in ancient times to improve the durability of lime-based mortars and concretes. The natural polymers used were locally available. In this work, cactus extract from Mexico has been tested in a Portland cement mortar. It is seen that cactus extract increases the plasticity of the mortar and improves water absorption and freeze-salt resistance. Calcium hydroxide produced by Portland cement hydration interacts with the components of cactus extract, polysaccharides or proteins, and forms complexes. It affects the crystallization process. Painting of the concrete with this extract has also shown improved water resistance.

  11. 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

  12. Modeling and numerical simulation of interior ballistic processes in a 120mm mortar system

    NASA Astrophysics Data System (ADS)

    Acharya, Ragini

    by using a high-resolution Godunov-type shock-capturing approach was used where the discretization is done directly on the integral formulation of the conservation laws. A linearized approximate Riemann Solver was modified in this work for the two-phase flows to compute fully non-linear wave interactions and to directly provide upwinding properties in the scheme. An entropy fix based on Harten-Heyman method was used with van Leer flux limiter for total variation diminishing. The three dimensional effects were simulated by incorporating an unsplit multi-dimensional wave propagation method, which accounted for discontinuities traveling in both normal and oblique coordinate directions. For each component, the predicted pressure-time traces showed significant pressure wave phenomena, which closely simulated the measured pressure-time traces obtained at PSU. The pressure-time traces at the breech-end of the mortar tube were obtained at Aberdeen Test Center with 0, 2, and 4 charge increments. The 3D-MIB code was also used to simulate the effect of flash tube vent-hole pattern on the pressure-wave phenomenon in the ignition cartridge. A comparison of the pressure difference between primer-end and projectile-end locations of the original and modified ignition cartridges with each other showed that the early-phase pressure-wave phenomenon can be significantly reduced with the modified pattern. The flow property distributions predicted by the 3D-MIB for 0, 2, and 4 charge increment cases as well the projectile dynamics predictions provided adequate validation of theory by experiments.

  13. 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.

  14. 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

  15. Energy absorption at high strain rate of glass fiber reinforced mortars

    NASA Astrophysics Data System (ADS)

    Fenu, Luigi; Forni, Daniele; Cadoni, Ezio

    2015-09-01

    In this paper, the dynamic behaviour of cement mortars reinforced with glass fibers was studied. The influence of the addition of glass fibers on energy absorption and tensile strength at high strain-rate was investigated. Static tests in compression, in tension and in bending were first performed. Dynamic tests by means of a Modified Hopkinson Bar were then carried out in order to investigate how glass fibers affected energy absorption and tensile strength at high strain-rate of the fiber reinforced mortar. The Dynamic Increase Factor (DIF) was finally evaluated.

  16. 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.

  17. 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.

  18. 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)

  19. 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.

  20. Characterization of historical mortars in Jordan

    NASA Astrophysics Data System (ADS)

    Gomez-Heras, M.; Arce, I.; Lopez-Arce, P.; Alvarez de Buergo, M.; Fort, R.

    2012-04-01

    This paper presents the petrographic and mineralogical characterization of mortars from different archaeological sites in Jordan which encompass Nabatean, Late-Antique and Early Islamic (Umayyad) sites, in some cases offering a sequence of different period mortars from the same building. These sites include the Nabataean city of Petra, the Late Antique town of Umm al Jimal and the castle of Qasr Al Hallabat. These mortars were produced with different raw materials and manufacturing technologies, which are reflected on distinctive variations of mineralogy, texture and crystal size and aggregates composition (including volcanic ashes, ceramic fragments, burnt organic material) size and their puzzolanic properties. As a consequence these mortars present different physical properties and reveal nowadays very different states of conservation. There is a dramatic change in mortar properties between those manufactured in pre-Islamic period and those from early Islamic - Ummayad times with a general trend in which these last ones present coarser crystal and aggregate sizes with less puzzolanic aggregates that result in less durable mortars. All of this reflects changes in the different stages of production of the mortar, from the use of either hydraulic, lime putty or slaked lime and the selection of aggregates to the application techniques (polishing). This reflects the evolution of building technology that took place in this area during early Islamic period and how petrological information can shed light on historical interpretation of building technologies. Research funded by AECID (PCI A/032184/10), GEOMATERIALES (S2009/MAT-16) and MCU (Analisis y Documentación de tipología arquitectónica y técnicas constructivas en el periodo de transición Bizantino-Omeya en Jordania)

  1. 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

  2. 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.

  3. Immobilization of IFR salt wastes in mortar

    SciTech Connect

    Fischer, D.F.; Johnson, T.R.

    1988-01-01

    Portland cement-base mortars are being considered for immobilizing chloride salt wastes produced by the fuel cycles of Integral Fast Reactors (IFR). The IFR is a sodium-cooled fast reactor with metal alloy fuels. It has a close-coupled fuel cycle in which fission products are separated from the actinides in an electrochemical cell operating at 500/degree/C. This cell has a liquid cadmium anode in which the fuels are dissolved and a liquid salt electrolyte. The salt will be a mixture of either lithium, potassium, and sodium chlorides or lithium, calcium, barium, and sodium chlorides. One method being considered for immobilizing the treated nontransuranic salt waste is to disperse the salt in a portland cement-base mortar that will be sealed in corrosion-resistant containers. For this application, the grout must be sufficiently fluid that it can be pumped into canister-molds where it will solidify into a strong, leach-resistant material. The set times must be longer than a few hours to allow sufficient time for processing, and the mortar must reach a reasonable compressive strength (/approximately/7 MPa) within three days to permit handling. Because fission product heating will be high, about 0.6 W/kg for a mortar containing 10% waste salt, the effects of elevated temperatures during curing and storage on mortar properties must be considered.

  4. 46. DETAIL VIEW OF THE MORTAR BOXES, STAMP BATTERIES AND ...

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

    46. DETAIL VIEW OF THE MORTAR BOXES, STAMP BATTERIES AND AMALGAMATION TABLES. NOTE FULTON IRON WORKS, SAM FRANCISCO 1908 STAMPED INTO THE MORTAR BOX. ALSO NOTE THE DIES RESTING ON THE OUTSIDE OF THE MORTAR BOX BY THE SECOND STAMP BATTERY FROM THE CAMERA POSITION. - Standard Gold Mill, East of Bodie Creek, Northeast of Bodie, Bodie, Mono County, CA

  5. 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.

  6. 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.

  7. 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

  8. [The Analysis of Traditional Lime Mortars from Zhejiang Province, China].

    PubMed

    Liu, Xiao-bin; Cui, Biao; Zhang, Bing-jian

    2016-01-01

    The components of ancient mortars have always been an important research field in historic building conservation. It has been well known that using traditional mortars in conservation projects have many advantages, such as compatibility and stability. So, developing new binding materials based on traditional mortar has become an international study hotspot. With China's economic development, the protection of ancient buildings also began to put on the agenda, but the understanding on Chinese traditional mortar is limited, and rare literatures are reported. In the present work, the authors investigate seven ancient city wall sites in Zhejiang Province in situ, and subsequently laboratory analysis were carried out on collected mortar samples. The characterizations of mortar samples were made by multi-density gauge, XRD, FTIR, TG-DSC and wet chemical analysis. The experimental results showed that: the main component of masonry mortars is calcium carbonate, the content between 75% - 90%, and they should be made from relatively pure lime mortar. The raw materials of mortar samples were mainly calcareous quick lime, and sample from Taizhou city also contained magnesium quick lime. There are four city walls were built by sticky-rice mortars. It suggests that the technology of adding the sticky rice soup into mortar was universal in the Ming Dynasties. These mortars have lower density between 1.2 and 1.9 g x cm(-3); this outcome should be the result of long-term natural erosion. We have also analyzed other chemical and physical characteristics of these masonry mortars. The results can afford the basic data for the future repairmen programs, development of new protective materials, and comparative study of mortars. PMID:27228774

  9. ASR potential of quartz based on expansion values and microscopic characteristics of mortar bars

    NASA Astrophysics Data System (ADS)

    Stastna, Aneta; Sachlova, Sarka; Kuchynova, Marketa; Pertold, Zdenek; Prikryl, Richard

    2016-04-01

    The alkali-silica reaction (ASR) is one of the most damaging factors for concrete structures. Different analytical techniques are used to quantify ASR potential of aggregates. The accelerated mortar bar test (ASTM C1260) in combination with the petrographic examination of aggregates by microscopic techniques belongs to the frequently employed methods. Such a methodical approach enables quantification of the ASR potential, based on the expansion values of accelerated mortar bars; and also to identify deleterious components in aggregates. In this study, the accelerated mortar bar test (ASTM C1260) was modified and combined with the scanning electron microscopy of polished sections prepared from mortar bars. The standard 14-day test period of mortar bars was prolonged to 1-year. ASR potential of aggregates was assessed based on expansion values (both 14-day and 1-year) of mortar bars and microscopic analysis of ASR products (alkali silica gels, microcracks, dissolution gaps) detected in the sections. Different varieties of quartz-rich rocks including chert, quartz meta-greywacke, three types of quartzite and pegmatite were used as aggregate. Only quartz from pegmatite was assessed to be non reactive (14-day expansion of 0.08%, 1-year expansion of 1.25%). Aggregate sections exhibited minor ASR products even after 1-year of mortar bar immersion in 1 M NaOH. Expansion values of the rest of samples exceeded the limit of 0.10% after 14-day test period indicating aggregates as reactive. The highest ASR potential was detected in mortar bars containing chert (14-day expansion of 0.55%, 1-year expansion of 2.70%) and quartz meta-greywacke (14-day expansion of 0.46%, 1-year expansion of 2.41%). The high ASR potential was explained by presence of cryptocrystalline matrix in significant volumes (24 - 65 vol%). Influence of the lengths of the immersion in the alkaline solution was observed mainly in the microstructure of the cement paste and on the extension of ASR products. The

  10. 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

  11. 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.

  12. Sulfate and acid resistant concrete and mortar

    DOEpatents

    Liskowitz, John W.; Wecharatana, Methi; Jaturapitakkul, Chai; Cerkanowicz, deceased, Anthony E.

    1998-01-01

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction and other applications, which hardenable mixtures demonstrate significant levels of acid and sulfate resistance while maintaining acceptable compressive strength properties. The acid and sulfate hardenable mixtures of the invention containing fly ash comprise cementitious materials and a fine aggregate. The cementitous materials may comprise fly ash as well as cement. The fine aggregate may comprise fly ash as well as sand. The total amount of fly ash in the hardenable mixture ranges from about 60% to about 120% of the total amount of cement, by weight, whether the fly ash is included as a cementious material, fine aggregate, or an additive, or any combination of the foregoing. In specific examples, mortar containing 50% fly ash and 50% cement in cementitious materials demonstrated superior properties of corrosion resistance.

  13. Sulfate and acid resistant concrete and mortar

    DOEpatents

    Liskowitz, J.W.; Wecharatana, M.; Jaturapitakkul, C.; Cerkanowicz, A.E.

    1998-06-30

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction and other applications, which hardenable mixtures demonstrate significant levels of acid and sulfate resistance while maintaining acceptable compressive strength properties. The acid and sulfate hardenable mixtures of the invention containing fly ash comprise cementitious materials and a fine aggregate. The cementitous materials may comprise fly ash as well as cement. The fine aggregate may comprise fly ash as well as sand. The total amount of fly ash in the hardenable mixture ranges from about 60% to about 120% of the total amount of cement, by weight, whether the fly ash is included as a cementious material, fine aggregate, or an additive, or any combination of the foregoing. In specific examples, mortar containing 50% fly ash and 50% cement in cementitious materials demonstrated superior properties of corrosion resistance. 6 figs.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. Estimating transport properties of mortars using image analysis on backscattered electron images

    SciTech Connect

    Wong, H.S. . E-mail: hong.wong@imperial.ac.uk; Buenfeld, N.R.; Head, M.K.

    2006-08-15

    The pore structure of two ordinary Portland cement mortars at water-cement ratio of 0.35 and 0.70 was characterised using quantitative backscattered electron imaging. The mortars were cured and conditioned to produce a range of pore structure characteristics. Image analysis was used to characterise the pore structure in terms of simple morphological parameters such as resolvable porosity and the specific surface area. These were found to be correlated to measured transport coefficients (diffusivity, permeability and sorptivity), suggesting the feasibility of image analysis to derive valuable quantitative information describing the pore structure that can be used as input values for a transport prediction model. A simple analytical model incorporating tortuosity and constrictivity was used to predict oxygen diffusivity and a variant of the Kozeny-Carman model was used to predict oxygen permeability. The diffusion model tended to over-predict for the lower w/c ratio mortar, but the general agreement was reasonable, with 90% of the estimated values within a factor of two from the measured values. The modified Kozeny-Carman model, however, over-predicted all permeability values with an error of between half to one order of magnitude.

  20. Application of antifungal CFB to increase the durability of cement mortar.

    PubMed

    Park, Jong-Myong; Park, Sung-Jin; Kim, Wha-Jung; Ghim, Sa-Youl

    2012-07-01

    Antifungal cement mortar or microbiological calcium carbonate precipitation on cement surface has been investigated as functional concrete research. However, these research concepts have never been fused with each other. In this study, we introduced the antifungal calciteforming bacteria (CFB) Bacillus aryabhattai KNUC205, isolated from an urban tunnel (Daegu, South Korea). The major fungal deteriogens in urban tunnel, Cladosporium sphaerospermum KNUC253, was used as a sensitive fungal strain. B. aryabhattai KNUC205 showed CaCO3 precipitation on B4 medium. Cracked cement mortar pastes were made and neutralized by modified methods. Subsequently, the mixture of B. aryabhattai KNUC205, conidiospore of C. sphaerospermum KNUC253, and B4 agar was applied to cement cracks and incubated at 18 degrees C for 16 days. B. aryabhattai KNUC205 showed fungal growth inhibition against C. sphaerospermum. Furthermore, B. aryabhattai KNUC205 showed crack remediation ability and water permeability reduction of cement mortar pastes. Taken together, these results suggest that the CaCO3 precipitation and antifungal properties of B. aryabhattai KNUC205 could be used as an effective sealing or coating material that can also prevent deteriorative fungal growth. This study is the first application and evaluation research that incorporates calcite formation with antifungal capabilities of microorganisms for an environment-friendly and more effective protection of cement materials. In this research, the conception of microbial construction materials was expanded. PMID:22580322

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. Study of outgassing and decomposition of space shuttle heat protection tiles, fillers and adhesive

    NASA Technical Reports Server (NTRS)

    Proctor, B. L.; Hoffman, J. H.

    1982-01-01

    The purpose of this project was to determine the chemicals desorbing from the space shuttle heat protection tiles. The original protocol for this project involved direct insertion probe mass spectrometry (DIPMS) analysis of the outgassing products from the tiles. However, this method proved unsatisfactory due to the large number of compounds desorbing from the tiles. A purge and trap technique was then employed to collect and separate the chemicals desorbing from the tiles. The maximum temperature in this analysis was 180 C which is the gas chromatograph fused silica capillary column's temperature limit. The desorption was also carried out at atmospheric pressure with helium as the purge gas. A description of the modified protocol is given. All compounds are tentatively identified.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Early age monitoring of cement mortar using embedded piezoelectric sensors

    NASA Astrophysics Data System (ADS)

    Narayanan, Arun; Subramaniam, Kolluru V. L.

    2016-04-01

    A piezoceramic based sensor consisting of embedded Lead Zirconate Titanate (PZT) patch is developed for assessing the progression of hydration and evolution of properties of cement mortar. A method for continuous assessment of cement mortar with different water to cement ratios after casting is presented. The method relies on monitoring changes in the electromechanical (EM) conductance of a PZT patch embedded in mortar. Changes in conductance are shown to sensitively reflect the changes in the mechanical impedance of the cementitious material as it transforms from fluid to solid state.

  13. 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

  14. 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.

  15. 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.

  16. Atmospheric deterioration of ancient and modern hydraulic mortars

    NASA Astrophysics Data System (ADS)

    Sabbioni, C.; Zappia, G.; Riontino, C.; Blanco-Varela, M. T.; Aguilera, J.; Puertas, F.; Balen, K. Van; Toumbakari, E. E.

    Different types of ancient and recent hydraulic mortars were collected from well-documented archaeological, historic and modern buildings in various geographical locations (urban, suburban, rural and maritime) of Italy, Spain and Belgium, representative of different environmental impacts, types and degrees of deterioration. A synthesis of the characteristics of the collected samples is presented, along with the identification of the formation products that occurred on the sample surfaces as a result of the reaction of the mortars with atmospheric pollutants. The analyses were performed by means of optical microscopy (OM), X-ray diffractometry (XRD), scanning electron microscopy (SEM-EDX) and ion chromatography (IC). The results obtained prove that sulphation processes takes place on hydraulic mortars, leading to gypsum formation on the external surface of the samples. Through the reaction of gypsum with the aluminate hydrate of the binder, ettringite formation was found to occur on a cement-based restoration mortar sampled in Antwerp.

  17. VIEW OF MORTARED ROCK FOOTING THAT ONCE SUPPORTED THE TWIN ...

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

    VIEW OF MORTARED ROCK FOOTING THAT ONCE SUPPORTED THE TWIN FLUME'S OUTLET TO TUMALO FEED CANAL, WITH BRIDGE. LOOKING NORTHWEST - Tumalo Irrigation District, Tumalo Project, West of Deschutes River, Tumalo, Deschutes County, OR

  18. A chemometric approach to the characterisation of historical mortars

    SciTech Connect

    Rampazzi, L. . E-mail: laura.rampazzi@uninsubria.it; Pozzi, A.; Sansonetti, A.; Toniolo, L.; Giussani, B.

    2006-06-15

    The compositional knowledge of historical mortars is of great concern in case of provenance and dating investigations and of conservation works since the nature of the raw materials suggests the most compatible conservation products. The classic characterisation usually goes through various analytical determinations, while conservation laboratories call for simple and quick analyses able to enlighten the nature of mortars, usually in terms of the binder fraction. A chemometric approach to the matter is here undertaken. Specimens of mortars were prepared with calcitic and dolomitic binders and analysed by Atomic Spectroscopy. Principal Components Analysis (PCA) was used to investigate the features of specimens and samples. A Partial Least Square (PLS1) regression was done in order to predict the binder/aggregate ratio. The model was applied to historical mortars from the churches of St. Lorenzo (Milan) and St. Abbondio (Como). The accordance between the predictive model and the real samples is discussed.

  19. 7. Detail, beaded mortar joint, stepped wingwall coping at the ...

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

    7. Detail, beaded mortar joint, stepped wingwall coping at the east portal of Tunnel 18, 135mm lens with electronic flash fill. - Southern Pacific Railroad Natron Cutoff, Tunnel No. 18, Milepost 410, Dorris, Siskiyou County, CA

  20. VIEW OF MORTARED ROCK AND CONCRETE INLET TO COUCH LATERAL ...

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

    VIEW OF MORTARED ROCK AND CONCRETE INLET TO COUCH LATERAL CANAL, UPSTREAM OF COLLINS ROAD. LOOKING NORTH/NORTHEAST - Tumalo Irrigation District, Tumalo Project, West of Deschutes River, Tumalo, Deschutes County, OR

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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…

  6. 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.

  7. Properties of wastepaper sludge in geopolymer mortars for masonry applications.

    PubMed

    Yan, Shiqin; Sagoe-Crentsil, Kwesi

    2012-12-15

    This paper presents the results of an investigation into the use of wastepaper sludge in geopolymer mortar systems for manufacturing construction products. The investigation was driven by the increasing demand for reuse options in paper-recycling industry. Both fresh and hardened geopolymer mortar properties are evaluated for samples incorporating dry wastepaper sludge, and the results indicate potential end-use benefits in building product manufacture. Addition of wastepaper sludge to geopolymer mortar reduces flow properties, primarily due to dry sludge absorbing water from the binder mix. The average 91-day compressive strength of mortar samples incorporating 2.5 wt% and 10 wt% wastepaper sludge respectively retained 92% and 52% of the reference mortar strength. However, contrary to the normal trend of increasing drying shrinkage with increasing paper sludge addition to Portland cement matrices, the corresponding geopolymer drying shrinkage decreased by 34% and 64%. Equally important, the water absorption of hardened geopolymer mortar decreased with increasing paper sludge content at ambient temperatures, providing good prospects of overall potential for wastepaper sludge incorporation in the production of building and masonry elements. The results indicate that, despite its high moisture absorbance due to the organic matter and residual cellulose fibre content, wastepaper sludge appears compatible with geopolymer chemistry, and hence serves as a potential supplementary additive to geopolymer cementitious masonry products. PMID:22868380

  8. Applicability of Carbonated Electric Arc Furnace Slag to Mortar

    NASA Astrophysics Data System (ADS)

    Yokoyama, S.; Arisawa, R.; Hisyamudin, M. N. N.; Murakami, K.; Maegawa, A.; Izaki, M.

    2012-03-01

    Authors have been studying the absorption of CO2 in the steelmaking slag. In this study, an application of the electric arc furnace slag after the carbonation to admixture of mortar was investigated with the JIS (A6206-1997) method for ground granulated blast-furnace slag for concrete. The percent flows for the test mortar were smaller than that for the standard mortar. The percent flow of the carbonated slag whose average particle size of more than approximately 4 μm increased with an increase in the average size of the particles. Because the compressive strengths of the test mortar cured for 91 days were almost the same as those cured 28 days, the slag after the carbonation was thought not to have self-hardening property for a medium and long term. The compressive strength for the test mortar was almost unchanged within a range of approximately 2 to 7 μm of the average particle size, and it in this range was highest. The activity indexes for the test mortar prepared with the slag after the carbonation ranged from approximately 40 to 60 %.

  9. 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.

  10. 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.

  11. Properties of microcement mortar with nano particles

    NASA Astrophysics Data System (ADS)

    Alimeneti, Narasimha Reddy

    Carbon nanotubes (CNT) and Carbon nanofibers (CNF) are one of the toughest and stiffest materials in the world presently with extreme properties yet to be discovered in terms of elastic modulus and tensile strength. Due to the advanced properties of these materials they are being used in almost all fields of science at nanolevel and are being used in construction industry recently for improvement of material properties. Microcement is fine ground cement which as half the particle size of ordinary Portland cement. In this research the behavior of cement mortar of micro cement with the addition of nanoparticles is studied. Due to high aspect ratio and strong van der Waal forces between the particles of CNT and CNF, they agglomerate and form bundles when mixed with water, sonication method is used to mix nanoparticles with few drops of surfactant and super plasticizer. Mechanical properties such as compressive strength and flexural strength with CNT and CNF composites are examined and compared with control samples. 0.1% and 0.05 % of nanoparticles (both CNT and CNF) by the weight of cement are used in this research and 0.8% of super plasticizer by weight of cement was also used along with 0.4, 0.45 and 0.50 water cement ratios for making specimens for compression test. The compressive strength results are not satisfactory as there was no constant increase in strength with all the composites, however strength of few nanocomposites increased by a good percentage. 0.5 water cement ratio cement mortar had compressive strength of 7.15 ksi (49.3 MPa), whereas sample with 0.1% CNT showed 8.38 ksi (57.8 MPa) with 17% increase in strength after 28 days. Same trend was followed by 0.4 water cement ratio as the compressive strength of control sample was 8.89 ksi (61.3 MPa), with 0.05% of CNT strength increased to 10.90 ksi (75.2 MPa) with 23% increase in strength. 0.4 water cement ratio was used for flexural tests including 0.1%, 0.05% of CNT and 0.1%, 0.05% of CNF with 0

  12. Micro- and meso-scale pore structure in mortar in relation to aggregate content

    SciTech Connect

    Gao, Yun; De Schutter, Geert; Ye, Guang

    2013-10-15

    Mortar is often viewed as a three-phase composite consisting of aggregate, bulk paste, and an interfacial transition zone (ITZ). However, this description is inconsistent with experimental findings because of the basic assumption that larger pores are only present within the ITZ. In this paper, we use backscattered electron (BSE) imaging to investigate the micro- and meso-scale structure of mortar with varying aggregate content. The results indicate that larger pores are present not only within the ITZ but also within areas far from aggregates. This phenomenon is discussed in detail based on a series of analytical calculations, such as the effective water binder ratio and the inter-aggregate spacing. We developed a modified computer model that includes a two-phase structure for bulk paste. This model interprets previous mercury intrusion porosimetry data very well. -- Highlights: •Based on BSE, we examine the HCSS model. •We develop the HCSS-DBLB model. •We use the modified model to interpret the MIP data.

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. Modeling the impact of nitrogen fertilizer application and tile drain configuration on nitrate leaching using SWAT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recently, the Soil and Water Assessment Tool (SWAT) was revised to improve the partitioning of runoff and tile drainage in poorly drained soils by modifying the algorithm for computing the soil moisture retention parameter. In this study, the revised SWAT model was used to evaluate the sensitivity a...

  1. 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.

  2. 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.

  3. 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

  4. Use of rubble from building demolition in mortars.

    PubMed

    Corinaldesi, V; Giuggiolini, M; Moriconi, G

    2002-01-01

    Because of increasing waste production and public concerns about the environment, it is desirable to recycle materials from building demolition. If suitably selected, ground, cleaned and sieved in appropriate industrial crushing plants, these materials can be profitably used in concrete. Nevertheless, the presence of masonry instead of concrete rubble is particularly detrimental to the mechanical performance and durability of recycled-aggregate concrete and the same negative effect is detectable when natural sand is replaced by fine recycled aggregate fraction. An alternative use of both masonry rubble and fine recycled material fraction could be in mortars. These could contain either recycled instead of natural sand or powder obtained by bricks crushing as partial cement substitution. In particular, attention is focused on the modification that takes place when either polypropylene or stainless steel fibers are added to these mortars. Polypropylene fibers are added in order to reduce shrinkage of mortars, stainless steel fibers for improving their flexural strength. The combined use of polypropylene fibers and fine recycled material from building demolition could allow the preparation of mortars showing good performance, in particular when coupled with bricks. Furthermore, the combined use of stainless steel fibers and mortars containing brick powder seems to be an effective way to guarantee a high flexural strength. PMID:12423051

  5. Mortar radiocarbon dating: preliminary accuracy evaluation of a novel methodology.

    PubMed

    Marzaioli, Fabio; Lubritto, Carmine; Nonni, Sara; Passariello, Isabella; Capano, Manuela; Terrasi, Filippo

    2011-03-15

    Mortars represent a class of building and art materials that are widespread at archeological sites from the Neolithic period on. After about 50 years of experimentation, the possibility to evaluate their absolute chronology by means of radiocarbon ((14)C) remains still uncertain. With the use of a simplified mortar production process in the laboratory environment, this study shows the overall feasibility of a novel physical pretreatment for the isolation of the atmospheric (14)CO(2) (i.e., binder) signal absorbed by the mortars during their setting. This methodology is based on the assumption that an ultrasonic attack in liquid phase isolates a suspension of binder carbonates from bulk mortars. Isotopic ((13)C and (14)C), % C, X-ray diffractometry (XRD), and scanning electron microscopy (SEM) analyses were performed to characterize the proposed methodology. The applied protocol allows suppression of the fossil carbon (C) contamination originating from the incomplete burning of the limestone during the quick lime production, providing unbiased dating for "laboratory" mortars produced operating at historically adopted burning temperatures. PMID:21338118

  6. Artillery/mortar type classification based on detected acoustic transients

    NASA Astrophysics Data System (ADS)

    Morcos, Amir; Grasing, David; Desai, Sachi

    2008-04-01

    Feature extraction methods based on the statistical analysis of the change in event pressure levels over a period and the level of ambient pressure excitation facilitate the development of a robust classification algorithm. The features reliably discriminates mortar and artillery variants via acoustic signals produced during the launch events. Utilizing acoustic sensors to exploit the sound waveform generated from the blast for the identification of mortar and artillery variants as type A, etcetera through analysis of the waveform. Distinct characteristics arise within the different mortar/artillery variants because varying HE mortar payloads and related charges emphasize varying size events at launch. The waveform holds various harmonic properties distinct to a given mortar/artillery variant that through advanced signal processing and data mining techniques can employed to classify a given type. The skewness and other statistical processing techniques are used to extract the predominant components from the acoustic signatures at ranges exceeding 3000m. Exploiting these techniques will help develop a feature set highly independent of range, providing discrimination based on acoustic elements of the blast wave. Highly reliable discrimination will be achieved with a feed-forward neural network classifier trained on a feature space derived from the distribution of statistical coefficients, frequency spectrum, and higher frequency details found within different energy bands. The processes that are described herein extend current technologies, which emphasis acoustic sensor systems to provide such situational awareness.

  7. Oyster shell as substitute for aggregate in mortar.

    PubMed

    Yoon, Hyunsuk; Park, Sangkyu; Lee, Kiho; Park, Junboum

    2004-06-01

    Enormous amounts of oyster shell waste have been illegally disposed of at oyster farm sites along the southern coast of Korea. In this study to evaluate the possibility of recycling this waste for use as a construction material, the mechanical characteristics of pulverized oyster shell were investigated in terms of its potential utilization as a substitute for the aggregates used in mortar. The unconfined compressive strengths of various soil mortar specimens, with varying blending ratios of cement, water and oyster shell, were evaluated by performing unconfined compression tests, and the results were compared with the strengths of normal cement mortar made with sand. In addition, the effect of organic chemicals on the hardening of concrete was evaluated by preparing ethyl-benzene-mixed mortar specimens. The long-term strength improvement resulting from the addition of fly ash was also examined by performing unconfined compression tests on specimens with fly-ash content. There was no significant reduction in the compressive strength of the mortars containing small oyster shell particles instead of sand. From these test data, the possible application of oyster shells in construction materials could be verified, and the change in the strength parameters according to the presence of organic compounds was also evaluated. PMID:15253499

  8. Strength and pore structure of ternary blended cement mortars containing blast furnace slag and silica fume

    SciTech Connect

    Bagel, L.

    1998-07-01

    Blended cement mortars with fixed workability and incorporating blast furnace slag and silica fume, were tested for compressive strength and mercury intrusion, with a view to comparing their performance with that of plain Portland cement mortar and/or slag-cement mortar. The obtained results showed that with high portions of slag and silica fume in the binding system, the mortars reached relatively satisfactory level of compressive strength and contributed to the significantly denser pore structure.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Assesment of uniaxial compressive strenght of repair mortars by using in situ non destructive techniques

    NASA Astrophysics Data System (ADS)

    Szemerey-Kiss, Balázs; Török, Ákos

    2014-05-01

    The present paper provides information on the strength assessment of restoration mortars by using ultrasonic pulse velocity. The aims of the tests were to determine the compressive strength of the mortars by using non destructive test methods. Four commercially available types of restoration mortars were tested. Besides the pure mortars, specimens with 30 and 50 wt% of limestone sand aggregate (from Sóskút quarry) were also made. The material properties of the tested mortars have been described in details previously (Szemerey-Kiss et al. 2013). Cubic test specimens of 3cm x 3cm x 3cm were prepared from the mortars and after casting and consolidation 10 cubes of each mortar type were tested. Ultrasonic pulse velocity was measured according to the guidelines given by EN 14579:2005. Uniaxial compressive strength of test specimens were measured following the instructions of EN 1015-11:2000. An exponential mathematical formula was outlined that describes the uniaxial compressive strength of mortars based on ultrasonic pulse velocity data. The best fit was found for two mortars while the formula with different constants could be also used for other mortars, too. These experiments have proved that non destructive tests can be used in the assessment of the strength of historic mortars. References: Szemerey-Kiss, B., Török, Á., Siegesmund S 2013. The influence of binder/aggregate ratio on the properties and strength of repair mortars. Environmental Earth Sciences, 69:1439-1449.

  15. Influence of pore structure on compressive strength of cement mortar.

    PubMed

    Zhao, Haitao; Xiao, Qi; Huang, Donghui; Zhang, Shiping

    2014-01-01

    This paper describes an experimental investigation into the pore structure of cement mortar using mercury porosimeter. Ordinary Portland cement, manufactured sand, and natural sand were used. The porosity of the manufactured sand mortar is higher than that of natural sand at the same mix proportion; on the contrary, the probable pore size and threshold radius of manufactured sand mortar are finer. Besides, the probable pore size and threshold radius increased with increasing water to cement ratio and sand to cement ratio. In addition, the existing models of pore size distribution of cement-based materials have been reviewed and compared with test results in this paper. Finally, the extended Bhattacharjee model was built to examine the relationship between compressive strength and pore structure. PMID:24757414

  16. Durability of waste glass flax fiber reinforced mortar

    SciTech Connect

    Aly, M.; Hashmi, M. S. J.; Olabi, A. G.; Messeiry, M.

    2011-01-17

    The main concern for natural fibre reinforced mortar composites is the durability of the fibres in the alkaline environment of cement. The composites may undergo a reduction in strength as a result of weakening of the fibres by a combination of alkali attack and fibre mineralisation. In order to enhance the durability of natural fiber reinforced cement composites several approaches have been studied including fiber impregnation, sealing of the matrix pore system and reduction of matrix alkalinity through the use of pozzolanic materials. In this study waste glass powder was used as a pozzolanic additive to improve the durability performance of flax fiber reinforced mortar (FFRM). The durability of the FFRM was studied by determining the effects of ageing in water and exposure to wetting and drying cycles; on the microstructures and flexural behaviour of the composites. The mortar tests demonstrated that the waste glass powder has significant effect on improving the durability of FFRM.

  17. Durability of Waste Glass Flax Fiber Reinforced Mortar

    NASA Astrophysics Data System (ADS)

    Aly, M.; Hashmi, M. S. J.; Olabi, A. G.; Messeiry, M.

    2011-01-01

    The main concern for natural fibre reinforced mortar composites is the durability of the fibres in the alkaline environment of cement. The composites may undergo a reduction in strength as a result of weakening of the fibres by a combination of alkali attack and fibre mineralisation. In order to enhance the durability of natural fiber reinforced cement composites several approaches have been studied including fiber impregnation, sealing of the matrix pore system and reduction of matrix alkalinity through the use of pozzolanic materials. In this study waste glass powder was used as a pozzolanic additive to improve the durability performance of flax fiber reinforced mortar (FFRM). The durability of the FFRM was studied by determining the effects of ageing in water and exposure to wetting and drying cycles; on the microstructures and flexural behaviour of the composites. The mortar tests demonstrated that the waste glass powder has significant effect on improving the durability of FFRM.

  18. Ancient mortars from Cape Verde: mineralogical and physical characterization

    NASA Astrophysics Data System (ADS)

    Rocha, Fernando; Costa, Cristiana; Velosa, Ana; Quintela, Ana; Terroso, Denise; Marques, Vera

    2014-05-01

    Times and locations of different building constructions means different knowledge, habits, different construction methods and materials. The study and safeguarding of the architectural heritage takes nowadays a progressive importance as a vehicle for transmission of cultures and history of nations. The coatings are of great importance in the durability of a building due to the protective role of the masonry. The compatibility between the materials with which they are executed (masonry, mortar and grout settlement) promotes the proper functioning of the wall and a consequent increase in durability. Therefore, it becomes important to study and characterize the mortar coating of buildings to know its characteristics and to use compatible materials in the rehabilitation and maintenance of buildings. This study aims to characterize the chemical, physical, mechanical and mineralogical mortar samples collected in buildings in three islands of Cape Verde, for the conservation, rehabilitation and preservation of them. The collected samples belong to buildings constructed in the end of XIX century and in the beginning of XX century. In order to characterize the mortar samples some tests was made, such as X-Ray Diffraction, X- Ray Fluorescence, acid attack and mechanical strength. The samples were divided into three groups depending on origin; so we have a first group collected on the island of Santiago, the second on the island of Saint Vincent and the third on the island of Santo Antao. The samples are all carbonated, but Santiago samples have a lower carbonates content. In terms of insoluble residue (from the acid attack) it was concluded that the samples have similar value ranging from 9 to 26%. The compressive strength of the mortars have a range between 1.36 and 4.55 MPa, which is related to the presence of more binder in samples with higher resistance. The chemical and mineralogical analyzes showed that these consist of lime mortars (binder), natural pozzolan and

  19. Various mortars for anti-fouling purposes in marine environments

    SciTech Connect

    Kanematsu, Hideyuki; Masuda, Tomoka; Miura, Yoko; Kuroda, Daisuke; Hirai, Nobumitsu; Yokoyama, Seiji

    2014-02-20

    The antifouling properties for some mortars with steel making slags were investigated by real marine immersion tests and a unique laboratory acceleration tests with a specially devised biofilm acceleration reactors. Mortars mixed with steel making slags containing abundant iron elements tended to form biofilm and also bifouling. The two kinds of biofilm formation tests were used in this study. Real immersion in marine environments and laboratory test with a specially devised biofilm acceleration reactor. The former evaluated the biofouling characteristics more properly, while the latter did the biofilm formation characteristics more effectively.

  20. Study on basalt fiber parameters affecting fiber-reinforced mortar

    NASA Astrophysics Data System (ADS)

    Orlov, A. A.; Chernykh, T. N.; Sashina, A. V.; Bogusevich, D. V.

    2015-01-01

    This article considers the effect of different dosages and diameters of basalt fibers on tensile strength increase during bending of fiberboard-reinforced mortar samples. The optimal dosages of fiber, providing maximum strength in bending are revealed. The durability of basalt fiber in an environment of cement, by means of microscopic analysis of samples of fibers and fiberboard-reinforced mortar long-term tests is examined. The article also compares the behavior of basalt fiber in the cement stone environment to a glass one and reveals that the basalt fiber is not subject to destruction.

  1. Overland flow and sediment transport in an agricultural lowland catchments: a focus on tile drain export

    NASA Astrophysics Data System (ADS)

    Vandromme, Rosalie; Grangeon, Thomas; Cerdan, Olivier; Manière, Louis; Salvador Blanes, Sébastien; Foucher, Anthony; Chapalain, Marion; Evrard, Olivier; Le Gall, Marion

    2016-04-01

    Rural landscapes have been extensively modified by human activities in Western Europe since the beginning of the 20th century in order to intensify agricultural production. Cultivated areas often expanded at the expense of grassland and wetlands located in lowland areas (de Groot et al., 2002). Therefore, large modifications were made to the agricultural landscapes: stream redesign, land consolidation, removal of hedges, and installation of tile drainage networks to drain the hydromorphic soils. These changes modified sediment processes and resulted in large morphological alterations (e.g. channel bed incision, deposition of fine sediment, channel bank erosion). Accordingly, these alterations threaten water quality and prevent to meet the requirements of the European directives. Improving water quality requires a clear understanding of the hydrosedimentary dynamics in these lowland cultivated catchments. However, few studies were conducted in drained environments. To fill this research gap, a pilot study was started in cultivated catchment of the Loire River basin, France, where tile drain densities are very high (> 1.5 km/km²). Six hydro-sedimentary monitoring stations were installed in the Louroux catchment (24 km²). One of them was specifically dedicated to measuring water/sediment fluxes from tile drains. Water level and turbidity were continuously monitored and sediments were sampled during floods and low stage periods. Samples were measured for particle size distribution, and sediment tracing studies are currently being developed to quantify the contribution of potential sources (e.g. surface vs subsurface, lithologies) to river sediment. Hydro-sedimentary fluxes were quantified and modelled for some selected events. The catchment hydrosedimentary fluxes and their properties were shown to be impacted by tile drain sediment transport, especially regarding particle size distribution, with the dominant export of very fine particles (< 2 μm) from tile drains

  2. On the relationship between the formation factor and propan-2-ol diffusivity in mortars

    SciTech Connect

    Tumidajski, P.J.; Schumacher, A.S.

    1996-09-01

    For porous rocks saturated with saltwater and with solid phases of high resistivity, early work showed that the ratio of the saltwater saturated rock resistivity to the resistivity of the saltwater was inversely related to the respective diffusivities (or permeabilities). The applicability of resistivity-diffusivity relationships for mortars is addressed. The following equation: F = R(mortar)/R(porewater) = D(porewater)/D(mortar) relating the formation factor (F) to the resistivity (R) and diffusivity (D) was investigated for Portland cement mortars and for mortars incorporating silica fume, fly ash and blast furnace slag.

  3. 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.

  4. Seismic augmentation of acoustic monitoring of mortar fire

    NASA Astrophysics Data System (ADS)

    Anderson, Thomas S.

    2007-10-01

    The US Army Corps of Engineers Research and Development Center participated in a joint ARL-NATO TG-53 field experiment and data collect at Yuma Proving Ground, AZ in early November 2005. Seismic and acoustic signatures from both muzzle blasts and impacts of small arms fire and artillery were recorded using 7 seismic arrays and 3 acoustic arrays. Arrays comprised of 12 seismic and 12 acoustic sensors each were located from 700 m to 18 km from gun positions. Preliminary analysis of signatures attributed to 60mm, 81mm, 120 mm mortars recorded at a seismic-acoustic array 1.1 km from gun position are presented. Seismic and acoustic array f-k analysis is performed to detect and characterize the source signature. Horizontal seismic data are analyzed to determine efficacy of a seismic discriminant for mortar and artillery sources. Rotation of North and East seismic components to radial and transverse components relative to the source-receiver path provide maximum surface wave amplitude on the transverse component. Angles of rotation agree well with f-k analysis of both seismic and acoustic signals. The spectral energy of the rotated transverse surface wave is observable on the all caliber of mortars at a distance of 1.1 km and is a reliable source discriminant for mortar sources at this distance. In a step towards automation, travel time stencils using local seismic and acoustic velocities are applied to seismic data for analysis and determination of source characteristics.

  5. Do Schools Still Need Brick-and-Mortar Libraries?

    ERIC Educational Resources Information Center

    Johnson, Doug; Mastrion, Keith

    2009-01-01

    Do all schools need brick-and-mortar libraries? In this article, Johnson and Mastrion share their contradictory thoughts to the question. Johnson says some schools don't need library facilities or programs or librarians. These schools' teachers and administrators: (1) feel no need for a collaborative learning space; (2) feel the ability to process…

  6. Modeling the thermal characteristics of masonry mortar containing recycled materials

    NASA Astrophysics Data System (ADS)

    Laney, Morgan Gretchen

    As the building industry in the United States rapidly expands, the reuse of recycled demolition waste aggregates is becoming increasingly more important. Currently, the building industry is the largest consumer of natural resources. The constant use of raw virgin aggregate is resulting in depleting resources, lack of space for landfills, increasing costs, and heightened levels of pollution. The use of these recycled aggregates in building envelopes and the study of thermal properties are becoming a popular area of research in order to improve building energy usage. The construction of Zero Energy Buildings (ZEB) is encouraged by the United States government as a result of the unresolved finite resources and environmental pollution. The focus of this research is on the impact of using recycled demolition waste aggregates on thermal properties, including specific heat capacity and thermal conductivity, in masonry mortar applications. The new forms of aggregate were analyzed for efficiency and practical utilization in construction in seven locations across the United States by embedding the new material into the building envelope of a strip mall mercantile build model from the National Renewable Energy Laboratory (NREL) in the EnergyPlus Building Energy Simulation Program (BESP). It was determined that the recycled aggregate mortar mixtures performed as well as or better than the traditional mortar mix. Opportunities for future research in recycled aggregate mortar mixtures exist in a regional analysis, a regional recycled aggregate cost analysis, and a life cycled cost analysis (LCCA).

  7. 2. VIEW, LOOKING FROM THE NORTHEAST. THESE THREE CONCRETE MORTAR ...

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

    2. VIEW, LOOKING FROM THE NORTHEAST. THESE THREE CONCRETE MORTAR BLOCKS WERE FOR THE MILL'S 3-STAMP BATTERIES ERECTED IN 1903, NORTH OF THE TWO 1901 BATTERIES WHICH WERE MOUNTED ON WOODEN TIMBERS - Wilbur-Womble Mill, Southern Edge Of Salt Spring Valley, Copperopolis, Calaveras County, CA

  8. Workability and strength of lignite bottom ash geopolymer mortar.

    PubMed

    Sathonsaowaphak, Apha; Chindaprasirt, Prinya; Pimraksa, Kedsarin

    2009-08-30

    In this paper, the waste lignite bottom ash from power station was used as a source material for making geopolymer. Sodium silicate and sodium hydroxide (NaOH) were used as liquid for the mixture and heat curing was used to activate the geopolymerization. The fineness of bottom ash, the liquid alkaline/ash ratio, the sodium silicate/NaOH ratio and the NaOH concentration were studied. The effects of the additions of water, NaOH and napthalene-based superplasticizer on the workability and strength of the geopolymer mortar were also studied. Relatively high strength geopolymer mortars of 24.0-58.0 MPa were obtained with the use of ground bottom ash with 3% retained on sieve no. 325 and mean particle size of 15.7 microm, using liquid alkaline/ash ratios of 0.429-0.709, the sodium silicate/NaOH ratios of 0.67-1.5 and 7.5-12.5M NaOH. The incorporation of water improved the workability of geopolymer mortar more effectively than the use of napthalene-based superplasticizer with similar slight reduction in strengths. The addition of NaOH solution slightly improves the workability of the mix while maintaining the strength of the geopolymer mortars. PMID:19264400

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. Comparing the Environmental Impacts of Alkali Activated Mortar and Traditional Portland Cement Mortar using Life Cycle Assessment

    NASA Astrophysics Data System (ADS)

    Matheu, P. S.; Ellis, K.; Varela, B.

    2015-11-01

    Since the year 1908 there has been research into the use alkali activated materials (AAM) in order to develop cementitious materials with similar properties to Ordinary Portland Cement. AAMs are considered green materials since their production and synthesis is not energy intensive. Even though AAMs have a high compressive strength, the average cost of production among other issues limits its feasibility. Previous research by the authors yielded a low cost AAM that uses mine tailings, wollastonite and ground granulated blast furnace slag (GGBFS). This mortar has an average compressive strength of 50MPa after 28 days of curing. In this paper the software SimaPro was used to create a product base cradle to gate Life Cycle Assessment (LCA). This compared the environmental impact of the AAM mortar to an Ordinary Portland Cement mortar (PCHM) with similar compressive strength. The main motivation for this research is the environmental impact of producing Ordinary Portland Cement as compared to alkali activated slag materials. The results of this LCA show that the Alkali Activated Material has a lower environmental impact than traditional Portland cement hydraulic mortar, in 10 out of 12 categories including Global Warming Potential, Ecotoxicity, and Smog. Areas of improvement and possible future work were also discovered with this analysis.

  15. 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

  16. 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

  17. 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

  18. 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.''

  19. 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.”

  20. 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...

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. Surface analysis of 1984/1985 Tokamak Fusion Test Reactor 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.

    1986-05-01

    Bare POCO AXF-5Q graphite tiles were installed as the plasma-facing surface of the Tokamak Fusion Test Reactor (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 2400/sup 0/C, only small amounts of metallic impurities (<5 x 10/sup 16/ atoms/cm/sup 2/) 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 diam) presumed to originate from melted internal hardware. In regions more removed from direct plasma contact, thicker metallic deposits are observed (approx. 2 x 10/sup 18/ atoms/cm/sup 2/). There are more of these deposits on the side facing the electron drift direction than on the ion drift side. The metallic deposits are composed of approx. 55% Ni, 25% Cr, and 20% Fe and several trace elements. Near-surface retained deuterium levels vary from 10/sup 16/ to 10/sup 18//cm/sup 2/ along one ion-side/electron-side pair of tiles. Deuterium from TFTR operations in the bulk of a tile may have been as much as 5 ppm. Hydrogen in the tile was approx.1 at. %. 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.

  7. 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

  8. 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;…

  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. 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...

  11. 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

  12. 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

  13. 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.

  14. Chemical composition influence of cement based mortars on algal biofouling

    NASA Astrophysics Data System (ADS)

    Estelle, Dalod; Alexandre, Govin; Philippe, Grosseau; Christine, Lors; René, Guyonnet; Denis, Damidot

    2013-04-01

    The main cause of building-facade biodegradation is the growth of microorganisms. This phenomenon depends on several parameters such as the geographical situation, the environmental conditions and the surface state of the substrate. Several researches have been devoted to the study of the effect of porosity and roughness on the biofouling of stones and mortars. However, none of them have addressed the influence of the mortar chemistry on the microorganism growth kinetic. The main objective of this study is to highlight the influence of the mortar chemistry in relationship with its physical properties on biological weathering. Earlier work showed a good resistance of Calcium Aluminate Cements to biodeterioration by acidogenic bacteria (Thiobacillus) and fungi (Alternaria alternata, Aspergillus Niger and Coniosporium uncinatum). In order to characterize the influence of the mortar chemistry on biofouling, two Portland cements and two alumina cements are used. Among micro-organisms able to grow, green algae are most involved in the aesthetic deterioration of facades. Indeed, they can colonize any type of media and can be a source of nutrients for other micro-organisms such as fungi. The green algae Klebsormidium flaccidum is chosen because of its representativeness. It is indeed the species the most frequently identified and isolated from samples taken on sites. The biofouling kinetic is followed on samples exposed outdoor and on samples tested in a laboratory bench which consists in spraying an algae culture on mortar specimens. The results obtained by in situ trials are compared with the results obtained on the laboratory bench. The microorganism growth kinetic is measured by image analysis. To improve the detection of algae on the surface of the cementitious samples, the raw image is converted in the YIQ color space. Y, I and Q correspond respectively to luminance, in-phase, and quadrature. On the Q channel, the areas covered by algae and the areas of clean mortar

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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…

  20. 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…

  1. 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.

  2. Plastic shrinkage of mortars with shrinkage reducing admixture and lightweight aggregates studied by neutron tomography

    SciTech Connect

    Wyrzykowski, Mateusz; Trtik, Pavel; Münch, Beat; Weiss, Jason; Vontobel, Peter; Lura, Pietro

    2015-07-15

    Water transport in fresh, highly permeable concrete and rapid water evaporation from the concrete surface during the first few hours after placement are the key parameters influencing plastic shrinkage cracking. In this work, neutron tomography was used to determine both the water loss from the concrete surface due to evaporation and the redistribution of fluid that occurs in fresh mortars exposed to external drying. In addition to the reference mortar with a water to cement ratio (w/c) of 0.30, a mortar with the addition of pre-wetted lightweight aggregates (LWA) and a mortar with a shrinkage reducing admixture (SRA) were tested. The addition of SRA reduced the evaporation rate from the mortar at the initial stages of drying and reduced the total water loss. The pre-wetted LWA released a large part of the absorbed water as a consequence of capillary pressure developing in the fresh mortar due to evaporation.

  3. Effects of fly ash particle size on strength of Portland cement fly ash mortars

    SciTech Connect

    Erdogdu, K.; Tuerker, P.

    1998-09-01

    Fly ashes do not have the same properties for different size fractions. It can be accepted that the effect of a fly ash on mortar strength is a combined effect of its size fractions. Therefore, it was concluded that by separating the size fractions and replacing cement with them, the combined bulk effect of a fly ash on strength can be better analyzed. In this study, different size fractions of fly ash were used to replace cement partially in standard compressive strength mortars. The authors attempted to interpret the strength of Portland cement-fly ash mortars in terms of the chemical, mineralogical, morphological, and physical properties of different fly ash size fractions used. Strengths of the mortars were compared at 2, 7, 28, and 90 days. Also strength of mortars with all-in ash (original ash containing all the fractions) were estimated by using strength of mortars with size fractions and the suitability of this estimation was discussed.

  4. Strength, porosity, and chloride resistance of mortar using the combination of two kinds of pozzolanic materials

    NASA Astrophysics Data System (ADS)

    Rukzon, Sumrerng; Chindaprasirt, Prinya

    2013-08-01

    This article presents a study on the resistance to chloride penetration, corrosion, porosity, and strength of mortar containing fine fly ash (FA), ground rice husk-bark ash (RB), and ground bagasse ash (BA). Ordinary Portland cement (CT) was blended with a single pozzolan and two pozzolans. Strength, porosity, rapid chloride penetration, immersion, and corrosion tests were performed to characterize the mortar. Test results showed that the use of ternary blends of CT, FA, and RB or BA decreased the porosity of the mortar, as compared with binary blended mortar containing CT and RB or BA. The resistance to chloride penetration of the mortar improved substantially with partial replacement of CT with FA, RB, and BA. The use of ternary blends of CT, FA and RB or BA produced the mortar with good strength and resistance to chloride penetration. The resistance to chloride penetration was higher with an increase in the replacement level due to the reduced calcium hydroxide.

  5. 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.

  6. A three-level BDDC algorithm for Mortar discretizations

    SciTech Connect

    Kim, H.; Tu, X.

    2007-12-09

    In this paper, a three-level BDDC algorithm is developed for the solutions of large sparse algebraic linear systems arising from the mortar discretization of elliptic boundary value problems. The mortar discretization is considered on geometrically non-conforming subdomain partitions. In two-level BDDC algorithms, the coarse problem needs to be solved exactly. However, its size will increase with the increase of the number of the subdomains. To overcome this limitation, the three-level algorithm solves the coarse problem inexactly while a good rate of convergence is maintained. This is an extension of previous work, the three-level BDDC algorithms for standard finite element discretization. Estimates of the condition numbers are provided for the three-level BDDC method and numerical experiments are also discussed.

  7. Ancient gypsum mortars from Cyprus: characterization and reinvention

    NASA Astrophysics Data System (ADS)

    Theodoridou, M.; Ioannou, I.

    2012-04-01

    Mortars with various binding materials have been used across different pre-historic and historic periods to meet several construction applications, such as jointing masonry blocks, finishing walls and isolating water bearing structures. In the framework of an ongoing research programme (NEA ΥΠOΔOMH/NEKΥΠ/0308/17) funded by the Cyprus Research Promotion Foundation, the Republic of Cyprus and the European Union Regional Development Fund, 25 samples of gypsum mortars from different archaeological sites in Cyprus were collected and characterized following a systematic analytical approach. Petrographic observations of thin sections were carried out using polarizing optical microscope. Scanning electron microscopy equipped with energy dispersive X-ray microanalyser (SEM-EDX) was used to examine the microstructure and texture of the mortar samples and to determine semi-quantitatively the chemical composition and interface of their binders. X-ray diffraction (XRD) was performed to identify the main mineral crystalline phases of the specimens' binder and aggregates. Thermal analyses (TG/DTA) were used as a further confirmation of the material composition. The pore structure and volume of the ancient mortars were also determined by mercury intrusion porosimetry (MIP) analysis. Last but not least, a portable drilling resistance measurement system (DRMS) was used for micro-destructive assessment of the mechanical state of the samples. The results confirmed the predominant presence of hydrous calcium sulphate in all samples. Calcite was also found both in the binder and aggregates. Small proportions of SiO2 were also detected. The common ratio of binder to aggregates was 1:2.5. MIP showed porosity values between 14-48% and real densities between 1-1.7 g/cm3. The average pore diameters were smaller in the case of mortars with lower porosity. The use of DRMS indicated lower resistance to drilling for the case of joint mortars (as opposed to analysed gypsum plasters). This

  8. Compressive strength of concrete and mortar containing fly ash

    DOEpatents

    Liskowitz, J.W.; Wecharatana, M.; Jaturapitakkul, C.; Cerkanowicz, A.E.

    1998-12-29

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention includes a method for predicting the compressive strength of such a hardenable mixture, which is very important for planning a project. The invention also relates to hardenable mixtures comprising cement and fly ash which can achieve greater compressive strength than hardenable mixtures containing only concrete over the time period relevant for construction. In a specific embodiment, a formula is provided that accurately predicts compressive strength of concrete containing fly ash out to 180 days. In other specific examples, concrete and mortar containing about 15% to 25% fly ash as a replacement for cement, which are capable of meeting design specification required for building and highway construction, are provided. Such materials can thus significantly reduce construction costs. 33 figs.

  9. Compressive strength of concrete and mortar containing fly ash

    DOEpatents

    Liskowitz, J.W.; Wecharatana, M.; Jaturapitakkul, C.; Cerkanowicz, A.E.

    1997-04-29

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention includes a method for predicting the compressive strength of such a hardenable mixture, which is very important for planning a project. The invention also relates to hardenable mixtures comprising cement and fly ash which can achieve greater compressive strength than hardenable mixtures containing only concrete over the time period relevant for construction. In a specific embodiment, a formula is provided that accurately predicts compressive strength of concrete containing fly ash out to 180 days. In other specific examples, concrete and mortar containing about 15% to 25% fly ash as a replacement for cement, which are capable of meeting design specifications required for building and highway construction, are provided. Such materials can thus significantly reduce construction costs. 33 figs.

  10. Compressive strength of concrete and mortar containing fly ash

    DOEpatents

    Liskowitz, John W.; Wecharatana, Methi; Jaturapitakkul, Chai; Cerkanowicz, deceased, Anthony E.

    1998-01-01

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention includes a method for predicting the compressive strength of such a hardenable mixture, which is very important for planning a project. The invention also relates to hardenable mixtures comprising cement and fly ash which can achieve greater compressive strength than hardenable mixtures containing only concrete over the time period relevant for construction. In a specific embodiment, a formula is provided that accurately predicts compressive strength of concrete containing fly ash out to 180 days. In other specific examples, concrete and mortar containing about 15% to 25% fly ash as a replacement for cement, which are capable of meeting design specification required for building and highway construction, are provided. Such materials can thus significantly reduce construction costs.

  11. Compressive strength of concrete and mortar containing fly ash

    DOEpatents

    Liskowitz, John W.; Wecharatana, Methi; Jaturapitakkul, Chai; Cerkanowicz, deceased, Anthony E.

    1997-01-01

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction. The invention includes a method for predicting the compressive strength of such a hardenable mixture, which is very important for planning a project. The invention also relates to hardenable mixtures comprising cement and fly ash which can achieve greater compressive strength than hardenable mixtures containing only concrete over the time period relevant for construction. In a specific embodiment, a formula is provided that accurately predicts compressive strength of concrete containing fly ash out to 180 days. In other specific examples, concrete and mortar containing about 15% to 25% fly ash as a replacement for cement, which are capable of meeting design specifications required for building and highway construction, are provided. Such materials can thus significantly reduce construction costs.

  12. Nonconforming mortar element methods: Application to spectral discretizations

    NASA Technical Reports Server (NTRS)

    Maday, Yvon; Mavriplis, Cathy; Patera, Anthony

    1988-01-01

    Spectral element methods are p-type weighted residual techniques for partial differential equations that combine the generality of finite element methods with the accuracy of spectral methods. Presented here is a new nonconforming discretization which greatly improves the flexibility of the spectral element approach as regards automatic mesh generation and non-propagating local mesh refinement. The method is based on the introduction of an auxiliary mortar trace space, and constitutes a new approach to discretization-driven domain decomposition characterized by a clean decoupling of the local, structure-preserving residual evaluations and the transmission of boundary and continuity conditions. The flexibility of the mortar method is illustrated by several nonconforming adaptive Navier-Stokes calculations in complex geometry.

  13. 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

  14. Link between microstructure and tritiated water diffusivity in mortars

    NASA Astrophysics Data System (ADS)

    Larbi, B.; Dridi, W.; Le Bescop, P.; Dangla, P.; Petit, L.

    2013-07-01

    Ions and radionuclide diffusivity in concrete is one of the most important factors that determine service life and safety assessment of cement based structures in nuclear power plants and radioactive-waste repositories. Apart from the influence of cement paste microstructure, the presence of aggregates may have an impact on transport properties of the material. The well-known interfacial transition zone, denoted by ITZ, is created near the aggregates and characterized by a greater porosity. The goal of this study is to investigate the competition between the more diffusing ITZ zone and the less diffusing aggregates. To this end, several series of tritiated water diffusion tests are conducted on mortars characterized by different water-to-cement ratios and sand volume fractions. In parallel, microstructure of these materials is explored by mercury and water porosimetry. It was observed that at low sand content (0% - 50%), diffusion properties of mortars are dominated by aggregates dilution effect. At 60% sand, diffusion increases significantly suggesting that percolation's pores threshold has been reached. Results indicate also that sand particle size distribution has a great impact on the diffusivity of mortars.

  15. The Interfacial Transition Zone in Alkali-Activated Slag Mortars

    NASA Astrophysics Data System (ADS)

    San Nicolas, Rackel; Provis, John

    2015-12-01

    The interfacial transition zone (ITZ) is known to strongly influence the mechanical and transport properties of mortars and concretes. This paper studies the ITZ between siliceous (quartz) aggregates and alkali activated slag binders in the context of mortar specimens. Backscattered electron images (BSE) generated in an environmental scanning electron microscope (ESEM) are used to identify unreacted binder components, reaction products and porosity in the zone surrounding aggregate particles, by composition and density contrast. X-ray mapping is used to exclude the regions corresponding to the aggregates from the BSE image of the ITZ, thus enabling analysis of only the binder phases, which are segmented into binary images by grey level discrimination. A distinct yet dense ITZ region is present in the alkali-activated slag mortars, containing a reduced content of unreacted slag particles compared to the bulk binder. The elemental analysis of this region shows that it contains a (C,N)-A-S-H gel which seems to have a higher content of Na (potentially deposited through desiccation of the pore solution) and a lower content of Ca than the bulk inner and outer products forming in the main binding region. These differences are potentially important in terms of long-term concrete performance, as the absence of a highly porous interfacial transition zone region is expected to provide a positive influence on the mechanical and transport properties of alkali-activated slag concretes.

  16. Cement-mortar pipes as a source of aluminum

    SciTech Connect

    Berend, K.; Trouwborst, T.

    1999-07-01

    In 1996 in Curacao, acute aluminum (Al) intoxication sickened patients in a dialysis center that used tap water to prepare dialysate. The mortality rate was 32%. A new factory-lined cement-mortar water distribution pipe had recently been installed. It is known that substantial amounts of barium, cadmium, and chromium can leach from cement-mortar linings. This article shows that high concentrations of Al can leach from cement mortars for at least two years in soft, aggressive water. The newly installed pipe, cement containing four times as much Al as usual, corrosive water, the high pH and temperature of the water, long residence time, and perhaps the corrosion inhibitor polyphosphate may have promoted this leaching. Certification of cements used to line water pipes is warranted. Central water treatment plants must distribute noncorrosive water, especially plants that use membrane desalination or other reverse osmosis or nanofiltration processes. Dialysis units should be promptly informed of any impending change in water treatment that might increase the Al content of tap water and also of any accidental pollution of the water distributed. Dialysis centers should always practice extended purification of tap water used for dialysate. Although Al as a risk factor for Alzheimer`s disease in the general population is still debated, there is no doubt that Al causes dialysis encephalopathy.

  17. Analysis of main parameters affecting substrate/mortar contact area through tridimensional laser scanner.

    PubMed

    Stolz, Carina M; Masuero, Angela B

    2015-10-01

    This study assesses the influence of the granulometric composition of sand, application energy and the superficial tension of substrates on the contact area of rendering mortars. Three substrates with distinct wetting behaviors were selected and mortars were prepared with different sand compositions. Characterization tests were performed on fresh and hardened mortars, as well as the rheological characterization. Mortars were applied to substrates with two different energies. The interfacial area was then digitized with 3D scanner. Results show that variables are all of influence on the interfacial contact in the development area. Furthermore, 3D laser scanning proved to be a good method to contact area measurement. PMID:26046982

  18. Study of sticky rice-lime mortar technology for the restoration of historical masonry construction.

    PubMed

    Yang, Fuwei; Zhang, Bingjian; Ma, Qinglin

    2010-06-15

    Replacing or repairing masonry mortar is usually necessary in the restoration of historical constructions, but the selection of a proper mortar is often problematic. An inappropriate choice can lead to failure of the restoration work, and perhaps even further damage. Thus, a thorough understanding of the original mortar technology and the fabrication of appropriate replacement materials are important research goals. Many kinds of materials have been used over the years in masonry mortars, and the technology has gradually evolved from the single-component mortar of ancient times to hybrid versions containing several ingredients. Beginning in 2450 BCE, lime was used as masonry mortar in Europe. In the Roman era, ground volcanic ash, brick powder, and ceramic chip were added to lime mortar, greatly improving performance. Because of its superior properties, the use of this hydraulic (that is, capable of setting underwater) mortar spread, and it was adopted throughout Europe and western Asia. Perhaps because of the absence of natural materials such as volcanic ash, hydraulic mortar technology was not developed in ancient China. However, a special inorganic-organic composite building material, sticky rice-lime mortar, was developed. This technology was extensively used in important buildings, such as tombs, in urban constructions, and even in water conservancy facilities. It may be the first widespread inorganic-organic composite mortar technology in China, or even in the world. In this Account, we discuss the origins, analysis, performance, and utility in historic preservation of sticky rice-lime mortar. Mortar samples from ancient constructions were analyzed by both chemical methods (including the iodine starch test and the acid attack experiment) and instrumental methods (including thermogravimetric differential scanning calorimetry, X-ray diffraction, Fourier transform infrared, and scanning electron microscopy). These analytical results show that the ancient masonry

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. Modeling of ultrasonic and terahertz radiations in defective tiles for condition monitoring of thermal protection systems

    NASA Astrophysics Data System (ADS)

    Kabiri Rahani, Ehsan

    Condition based monitoring of Thermal Protection Systems (TPS) is necessary for safe operations of space shuttles when quick turn-around time is desired. In the current research Terahertz radiation (T-ray) has been used to detect mechanical and heat induced damages in TPS tiles. Voids and cracks inside the foam tile are denoted as mechanical damage while property changes due to long and short term exposures of tiles to high heat are denoted as heat induced damage. Ultrasonic waves cannot detect cracks and voids inside the tile because the tile material (silica foam) has high attenuation for ultrasonic energy. Instead, electromagnetic terahertz radiation can easily penetrate into the foam material and detect the internal voids although this electromagnetic radiation finds it difficult to detect delaminations between the foam tile and the substrate plate. Thus these two technologies are complementary to each other for TPS inspection. Ultrasonic and T-ray field modeling in free and mounted tiles with different types of mechanical and thermal damages has been the focus of this research. Shortcomings and limitations of FEM method in modeling 3D problems especially at high-frequencies has been discussed and a newly developed semi-analytical technique called Distributed Point Source Method (DPSM) has been used for this purpose. A FORTRAN code called DPSM3D has been developed to model both ultrasonic and electromagnetic problems using the conventional DPSM method. This code is designed in a general form capable of modeling a variety of geometries. DPSM has been extended from ultrasonic applications to electromagnetic to model THz Gaussian beams, multilayered dielectrics and Gaussian beam-scatterer interaction problems. Since the conventional DPSM has some drawbacks, to overcome it two modification methods called G-DPSM and ESM have been proposed. The conventional DPSM in the past was only capable of solving time harmonic (frequency domain) problems. Time history was

  9. Influence of recycled fine aggregates on the resistance of mortars to magnesium sulfate attack

    SciTech Connect

    Lee, Seung-Tae

    2009-08-15

    The influence of recycled fine aggregates, which had been reclaimed from field-demolished concretes, on the resistance of mortar specimens to magnesium sulfate attack was investigated. Mortar specimens were prepared with recycled fine aggregates at different replacement levels (0%, 25%, 50%, 75% and 100% of natural fine aggregate by mass). The mortar specimens were exposed to 4.24% magnesium sulfate solution for about 1 year at ambient temperature, and regularly monitored for visual appearance, compressive strength loss and expansion. Additionally, in order to identify products of magnesium sulfate attack, mortar samples incorporating 0%, 25% and 100% replacement levels of the recycled fine aggregates were examined by X-ray diffraction (XRD) technique. Experimental results confirmed that the use of recycled fine aggregates up to a maximum 50% replacement level is effective under severe magnesium sulfate environment, irrespective of type of recycled fine aggregates. However, the worse performance was observed in mortar specimens incorporating 100% replacement level. It was found that the water absorption of recycled fine aggregates affected deterioration of mortar specimens, especially at a higher replacement level. XRD results indicated that the main cause of deterioration of the mortar specimens was primarily due to the formation of gypsum and thaumasite by magnesium sulfate attack. In addition, it appeared that the conversion of C-S-H into M-S-H by the attack probably influenced mechanical deterioration of mortar specimens with recycled fine aggregates.

  10. 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.

  11. Effect of surfactants on pressure-sensitivity of CNT filled cement mortar composites

    NASA Astrophysics Data System (ADS)

    Han, Baoguo; Yu, Xun

    2014-11-01

    Sodium dodecyl sulfate (SDS) and sodium dodecylbenzene sulfonate (NaDDBS) were used as surfactants to disperse multi-walled carbon nanotubes (MWNT) in cement mortar and fabricate pressure-sensitive carbon nanotubes filled cement mortar composites. The pressure-sensitivity of cement mortar composites with different concentrations of MWNT and different surfactants was explored under repeated loading and impulsive loading, respectively. Experimental results indicate that the response of the electrical resistance of composites with NaDDBS to external force is more stable and sensitive than that of composites with SDS. Therefore, NaDDBS has higher efficiency than SDS for the dispersion of MWNT in cement mortar, and it is an effective surfactant for fabricating MWNT filled cement mortar composites with superior pressure-sensitivity.

  12. [Study on the traditional lime mortar from the memorial archway in the southern Anhui province].

    PubMed

    Wei, Guo-Feng; Sun, Sheng; Wang, Cheng-Xing; Zhang, Bing-Jian; Chen, Xi-Min

    2013-07-01

    The traditional lime mortar was investigated by means of scanning electron microscope (SEM), X-ray diffractometry and Fourier transform infrared spectrometry (FTIR). The results show that the mortar from the memorial archway in the southern Anhui province was the organic-inorganic composite materials composed of lime with tung oil or sticky rice. It was found that the excellent performance of the tung oil-lime mortar can be explained by the compact lamellar organic-inorganic composite structure that was produced by carbonization reaction of lime, cross-linking reactions of tung oil and oxygen and complexing reaction of Ca2+ and -COO-. The compact micro-structure of sticky rice-lime mortar, which was produced due to carbonation process of lime controlled by amylopectin, should be the cause of the good performance of this kind of organic-inorganic mortar. PMID:24059213

  13. 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

  14. 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

  15. Mechanical resilience and cementitious processes in Imperial Roman architectural mortar

    DOE PAGESBeta

    Jackson, Marie D.; Landis, Eric N.; Brune, Philip F.; Vitti, Massimo; Chen, Heng; Li, Qinfei; Kunz, Martin; Wenk, Hans -Rudolf; Monteiro, Paulo J. M.; Ingraffea, Anthony R.

    2014-12-15

    The pyroclastic aggregate concrete of Trajan’s Markets (110 CE), now Museo Fori Imperiali in Rome, has absorbed energy from seismic ground shaking and long-term foundation settlement for nearly two millenia while remaining largely intact at the structural scale. The scientific basis of this exceptional service record is explored through computed tomography of fracture surfaces and synchroton X-ray microdiffraction analyses of a reproduction of the standardized hydrated lime–volcanic ash mortar that binds decimeter-sized tuff and brick aggregate in the conglomeratic concrete. The mortar reproduction gains fracture toughness over 180 d through progressive coalescence of calcium–aluminum-silicate–hydrate (C-A-S-H) cementing binder with Ca/(Si+Al) ≈more » 0.8–0.9 and crystallization of strätlingite and siliceous hydrogarnet (katoite) at ≥90 d, after pozzolanic consumption of hydrated lime was complete. Platey strätlingite crystals toughen interfacial zones along scoria perimeters and impede macroscale propagation of crack segments. In the 1,900 year old mortar, C-A-S-H has low Ca/(Si+Al) ≈ 0.45–0.75. Dense clusters of 2- to 30-µm strätlingite plates further reinforce interfacial zones, the weakest link of modern cement-based concrete, and the cementitious matrix. These crystals formed during long-term autogeneous reaction of dissolved calcite from lime and the alkali-rich scoriae groundmass, clay mineral (halloysite), and zeolite (phillipsite and chabazite) surface textures from the Pozzolane Rosse pyroclastic flow, erupted from the nearby Alban Hills volcano. The clast-supported conglomeratic fabric of the concrete presents further resistance to fracture propagation at the structural scale.« less

  16. Mechanical resilience and cementitious processes in Imperial Roman architectural mortar.

    PubMed

    Jackson, Marie D; Landis, Eric N; Brune, Philip F; Vitti, Massimo; Chen, Heng; Li, Qinfei; Kunz, Martin; Wenk, Hans-Rudolf; Monteiro, Paulo J M; Ingraffea, Anthony R

    2014-12-30

    The pyroclastic aggregate concrete of Trajan's Markets (110 CE), now Museo Fori Imperiali in Rome, has absorbed energy from seismic ground shaking and long-term foundation settlement for nearly two millenia while remaining largely intact at the structural scale. The scientific basis of this exceptional service record is explored through computed tomography of fracture surfaces and synchroton X-ray microdiffraction analyses of a reproduction of the standardized hydrated lime-volcanic ash mortar that binds decimeter-sized tuff and brick aggregate in the conglomeratic concrete. The mortar reproduction gains fracture toughness over 180 d through progressive coalescence of calcium-aluminum-silicate-hydrate (C-A-S-H) cementing binder with Ca/(Si+Al) ≈ 0.8-0.9 and crystallization of strätlingite and siliceous hydrogarnet (katoite) at ≥ 90 d, after pozzolanic consumption of hydrated lime was complete. Platey strätlingite crystals toughen interfacial zones along scoria perimeters and impede macroscale propagation of crack segments. In the 1,900-y-old mortar, C-A-S-H has low Ca/(Si+Al) ≈ 0.45-0.75. Dense clusters of 2- to 30-µm strätlingite plates further reinforce interfacial zones, the weakest link of modern cement-based concrete, and the cementitious matrix. These crystals formed during long-term autogeneous reaction of dissolved calcite from lime and the alkali-rich scoriae groundmass, clay mineral (halloysite), and zeolite (phillipsite and chabazite) surface textures from the Pozzolane Rosse pyroclastic flow, erupted from the nearby Alban Hills volcano. The clast-supported conglomeratic fabric of the concrete presents further resistance to fracture propagation at the structural scale. PMID:25512521

  17. Mechanical resilience and cementitious processes in Imperial Roman architectural mortar

    SciTech Connect

    Jackson, Marie D.; Landis, Eric N.; Brune, Philip F.; Vitti, Massimo; Chen, Heng; Li, Qinfei; Kunz, Martin; Wenk, Hans -Rudolf; Monteiro, Paulo J. M.; Ingraffea, Anthony R.

    2014-12-15

    The pyroclastic aggregate concrete of Trajan’s Markets (110 CE), now Museo Fori Imperiali in Rome, has absorbed energy from seismic ground shaking and long-term foundation settlement for nearly two millenia while remaining largely intact at the structural scale. The scientific basis of this exceptional service record is explored through computed tomography of fracture surfaces and synchroton X-ray microdiffraction analyses of a reproduction of the standardized hydrated lime–volcanic ash mortar that binds decimeter-sized tuff and brick aggregate in the conglomeratic concrete. The mortar reproduction gains fracture toughness over 180 d through progressive coalescence of calcium–aluminum-silicate–hydrate (C-A-S-H) cementing binder with Ca/(Si+Al) ≈ 0.8–0.9 and crystallization of strätlingite and siliceous hydrogarnet (katoite) at ≥90 d, after pozzolanic consumption of hydrated lime was complete. Platey strätlingite crystals toughen interfacial zones along scoria perimeters and impede macroscale propagation of crack segments. In the 1,900 year old mortar, C-A-S-H has low Ca/(Si+Al) ≈ 0.45–0.75. Dense clusters of 2- to 30-µm strätlingite plates further reinforce interfacial zones, the weakest link of modern cement-based concrete, and the cementitious matrix. These crystals formed during long-term autogeneous reaction of dissolved calcite from lime and the alkali-rich scoriae groundmass, clay mineral (halloysite), and zeolite (phillipsite and chabazite) surface textures from the Pozzolane Rosse pyroclastic flow, erupted from the nearby Alban Hills volcano. The clast-supported conglomeratic fabric of the concrete presents further resistance to fracture propagation at the structural scale.

  18. Mechanical resilience and cementitious processes in Imperial Roman architectural mortar

    PubMed Central

    Landis, Eric N.; Brune, Philip F.; Vitti, Massimo; Chen, Heng; Li, Qinfei; Kunz, Martin; Wenk, Hans-Rudolf; Monteiro, Paulo J. M.; Ingraffea, Anthony R.

    2014-01-01

    The pyroclastic aggregate concrete of Trajan’s Markets (110 CE), now Museo Fori Imperiali in Rome, has absorbed energy from seismic ground shaking and long-term foundation settlement for nearly two millenia while remaining largely intact at the structural scale. The scientific basis of this exceptional service record is explored through computed tomography of fracture surfaces and synchroton X-ray microdiffraction analyses of a reproduction of the standardized hydrated lime–volcanic ash mortar that binds decimeter-sized tuff and brick aggregate in the conglomeratic concrete. The mortar reproduction gains fracture toughness over 180 d through progressive coalescence of calcium–aluminum-silicate–hydrate (C-A-S-H) cementing binder with Ca/(Si+Al) ≈ 0.8–0.9 and crystallization of strätlingite and siliceous hydrogarnet (katoite) at ≥90 d, after pozzolanic consumption of hydrated lime was complete. Platey strätlingite crystals toughen interfacial zones along scoria perimeters and impede macroscale propagation of crack segments. In the 1,900-y-old mortar, C-A-S-H has low Ca/(Si+Al) ≈ 0.45–0.75. Dense clusters of 2- to 30-µm strätlingite plates further reinforce interfacial zones, the weakest link of modern cement-based concrete, and the cementitious matrix. These crystals formed during long-term autogeneous reaction of dissolved calcite from lime and the alkali-rich scoriae groundmass, clay mineral (halloysite), and zeolite (phillipsite and chabazite) surface textures from the Pozzolane Rosse pyroclastic flow, erupted from the nearby Alban Hills volcano. The clast-supported conglomeratic fabric of the concrete presents further resistance to fracture propagation at the structural scale. PMID:25512521

  19. Thermographic measurement of the effect of humidity in mortar porosity

    NASA Astrophysics Data System (ADS)

    Poblete, A.; Acebes Pascual, M.

    2007-01-01

    The objective of this analysis is to examine the influence of the moisture in the porosity measurement by means of thermal non-destructive test and ultrasound techniques. It is possible to determine the concrete durability by the calculation of its porosity. Porosity is determined in an indirect way, measuring mortar diffusivity by means of active thermography. Using ultrasound techniques, the porosity is related with the ultrasonic propagation of velocity. The diffusivity has been calculated using the W.J. Parker equation. In the ultrasound technique, using the pulse transmission method, ultrasonic propagation velocity was measured as a function of the water content. The conclusions express the correlation between both methods.

  20. 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'.

  1. 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.

  2. Computational modeling of thin ceramic tiles backed by thin substrates

    SciTech Connect

    Walker, J.D.; Anderson, C.E. Jr.; Cox, P.A.

    1995-12-31

    Building on the work of Wilkins, Eulerian hydrocode calculations were performed with ceramic models to examine the behavior of thin ceramic tiles backed by a thin substrate. In order to match ballistic limit data it was necessary to include a pressure dependent flow stress for failed ceramic. Reasonable agreement is found between the modified model and ballistic limit data for a simulated armor piercing round impacting an AD-85 alumina/6061T6 aluminum laminate. Based upon this success, the modified model was used to examine the performance of a SiC/6061T6 aluminum laminate when impacted by an M80 ball round (7.62 mm) at muzzle velocity. The projectile undergoes large deformation, as does the aluminum backing sheet. The computational results indicate, for the M80 projectile impacting at muzzle velocity, that the ballistic limit thickness for the SiC/aluminum laminate should weigh 10% less than the ballistic limit thickness for steel. The talk will include a video tape of calculations.

  3. 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

  4. Differentiating seawater and groundwater sulfate attack in Portland cement mortars

    SciTech Connect

    Santhanam, Manu . E-mail: manus@iitm.ac.in; Cohen, Menashi; Olek, Jan

    2006-12-15

    The study reported in this article deals with understanding the physical, chemical and microstructural differences in sulfate attack from seawater and groundwater. Portland cement mortars were completely immersed in solutions of seawater and groundwater. Physical properties such as length, mass, and compressive strength were monitored periodically. Thermal analysis was used to study the relative amounts of phases such as ettringite, gypsum, and calcium hydroxide, and microstructural studies were conducted by scanning electron microscopy. Portland cement mortars performed better in seawater solution compared to groundwater solution. The difference in performance could be attributed to the reduction in the quantity of the expansive attack products (gypsum and ettringite). The high Cl concentration of seawater could have played an important role by binding the C{sub 3}A to form chloroaluminate compounds, such as Friedel's salt (detected in the microstructural studies), and also by lowering the expansive potential of ettringite. Furthermore, the thicker layer of brucite forming on the specimens in seawater could have afforded better protection against ingress of the solution than in groundwater.

  5. Effect of copolymer latexes on physicomechanical properties of mortar containing high volume fly ash as a replacement material of cement.

    PubMed

    Negim, El-Sayed; Kozhamzharova, Latipa; Gulzhakhan, Yeligbayeva; Khatib, Jamal; Bekbayeva, Lyazzat; Williams, Craig

    2014-01-01

    This paper investigates the physicomechanical properties of mortar containing high volume of fly ash (FA) as partial replacement of cement in presence of copolymer latexes. Portland cement (PC) was partially replaced with 0, 10, 20, 30 50, and 60% FA. Copolymer latexes were used based on 2-hydroxyethyl acrylate (2-HEA) and 2-hydroxymethylacrylate (2-HEMA). Testing included workability, setting time, absorption, chemically combined water content, compressive strength, and scanning electron microscopy (SEM). The addition of FA to mortar as replacement of PC affected the physicomechanical properties of mortar. As the content of FA in the concrete increased, the setting times (initial and final) were elongated. The results obtained at 28 days of curing indicate that the maximum properties of mortar occur at around 30% FA. Beyond 30% FA the properties of mortar reduce and at 60% FA the properties of mortar are lower than those of the reference mortar without FA. However, the addition of polymer latexes into mortar containing FA improved most of the physicomechanical properties of mortar at all curing times. Compressive strength, combined water, and workability of mortar containing FA premixed with latexes are higher than those of mortar containing FA without latexes. PMID:25254256

  6. Effect of Copolymer Latexes on Physicomechanical Properties of Mortar Containing High Volume Fly Ash as a Replacement Material of Cement

    PubMed Central

    Kozhamzharova, Latipa; Gulzhakhan, Yeligbayeva; Bekbayeva, Lyazzat; Williams, Craig

    2014-01-01

    This paper investigates the physicomechanical properties of mortar containing high volume of fly ash (FA) as partial replacement of cement in presence of copolymer latexes. Portland cement (PC) was partially replaced with 0, 10, 20, 30 50, and 60% FA. Copolymer latexes were used based on 2-hydroxyethyl acrylate (2-HEA) and 2-hydroxymethylacrylate (2-HEMA). Testing included workability, setting time, absorption, chemically combined water content, compressive strength, and scanning electron microscopy (SEM). The addition of FA to mortar as replacement of PC affected the physicomechanical properties of mortar. As the content of FA in the concrete increased, the setting times (initial and final) were elongated. The results obtained at 28 days of curing indicate that the maximum properties of mortar occur at around 30% FA. Beyond 30% FA the properties of mortar reduce and at 60% FA the properties of mortar are lower than those of the reference mortar without FA. However, the addition of polymer latexes into mortar containing FA improved most of the physicomechanical properties of mortar at all curing times. Compressive strength, combined water, and workability of mortar containing FA premixed with latexes are higher than those of mortar containing FA without latexes. PMID:25254256

  7. 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

  8. Compatibility study and adaption of stone repair mortars for the Lede stone (Belgium)

    NASA Astrophysics Data System (ADS)

    De Kock, T.; Vandevoorde, D.; Boone, M. A.; Dewanckele, J.; De Boever, W.; Lanzón, M.; De Schutter, G.; Van Hoorebeke, L.; Jacobs, P.; Cnudde, V.

    2012-04-01

    One of the main historic building materials in northern Belgium is the Lede stone. This arenaceous limestone from Lutetian age was excavated in the region of Ghent and Brussels and was transported northwards by main rivers such as the Scheldt and Zenne. Thanks to this natural transport route, the stone in also found in many cities which lie abroad the excavation area, such as Antwerp (Belgium) and various cities in the Netherlands (Breda, Zierikzee, …). Due to its dominant occurrence in our cultural heritage, it is frequently subjected to restoration and renovation works. Depending on the degree of decay, most frequent stone operations are cleaning, healing with mortar or replacing it by (often exotic) fresh blocks. Originally, this limestone has a greenish-gray colour, but when being exposed to atmospheric conditions it acquires a yellowish to rusty coloured patina. The origin of the latter is most likely the oxidation of glauconite minerals which are present in a few percent in the stone. In addition, the stone often demonstrates black crust formation due to sulphation. Cleaning of the stone often results in an excess removal of this black gypsum crusts and patina, thus exposing deeper parts of the stone which appear more greenish-gray again. When the stone is subsequently healed by adding repair mortar to damaged parts, the question rises which mortar colour is more appropriate. The choice of repair mortar is greatly depending on commercial aspects. When handling entire facades on monuments, a mineral mortar based on ZnCl is most often applied in Belgium. The big advantage of this mortar is its fast curing. Three colour types have been developed for the Lede stone in specific. However, the hardness of this mortar is sometimes in conflict with reversibility. For the handling of individual sculptures some conservators choose for the application of (hydraulic) lime mortars. The advantage of using such mortars is their high compatibility and reversibility. The

  9. Use of limestone obtained from waste of the mussel cannery industry for the production of mortars

    SciTech Connect

    Ballester, Paloma; Marmol, Isabel; Morales, Julian; Sanchez, Luis . E-mail: luis-sanchez@uco.es

    2007-04-15

    Various types of cement-SiO{sub 2}-CaCO{sub 3} mortar were prepared by replacing quarry limestone aggregate with limestone obtained as a by-product from waste of the mussel cannery industry. The CaCO{sub 3} aggregate consists mainly of elongated prismatic particles less than 4 {mu}m long rather than of the rounded particles of smaller size (2-6 {mu}m) obtained with quarry limestone. The mechanical and structural properties of the mortars were found to be influenced by aggregate morphology. Setting of the different types of mortar after variable curing times was evaluated by scanning electron microscopy (SEM), thermogravimetric analysis (TG) and mercury intrusion porosimetry (MIP) techniques. Mortars with a high content in mussel shell limestone exhibited a more packed microstructure, which facilitates setting of cement and results in improved mortar strength. The enhanced mechanical properties of the new mortars allow the cement content in the final mortar composition to be decreased and production costs to be reduced as a result.

  10. Reuse of de-inking sludge from wastepaper recycling in cement mortar products.

    PubMed

    Yan, Shiqin; Sagoe-Crentsil, Kwesi; Shapiro, Gretta

    2011-08-01

    This paper presents results of an investigation into the use of de-inking sludge from a paper recycling mill as feedstock material in the manufacture of cement mortar products, including masonry blocks and mortar renders. Both physical and mechanical properties of mortar specimens containing various amounts of de-inking sludge were investigated. It was observed that the addition of de-inking sludge to cement mortar at a fixed water-to-cement ratio significantly reduced flow properties and increased setting time. Water absorption and volume of permeable voids of cement mortar increased with increased dosage of de-inking sludge, with a corresponding reduction of bulk density. The 91-day compressive strength of mortar samples with 2.5 wt% and 20 wt% de-inking sludge loadings retained 83% and 62% respectively of the reference mortar strength. The corresponding drying shrinkage increased by up to 160% compared to reference samples. However, a de-inking sludge loading of up to 2.5 wt% did not significantly alter measured physical and mechanical properties. The results demonstrate that despite the high moisture absorbance of de-inking sludge due to its organic matter and residual cellulose fibre content, it serves as a potential supplementary additive and its cellulosic content proving to be an active set retardant to cementitious masonry products. PMID:21507557

  11. Resistance of biofilm-covered mortars to microbiologically influenced deterioration simulated by sulfuric acid exposure

    SciTech Connect

    Soleimani, Sahar Isgor, O. Burkan Ormeci, Banu

    2013-11-15

    Following the reported success of biofilm applications on metal surfaces to inhibit microbiologically influenced corrosion, effectiveness and sustainability of E. coli DH5α biofilm on mortar surface to prevent microbiologically influenced concrete deterioration (MICD) are investigated. Experiments simulating microbial attack were carried out by exposing incrementally biofilm-covered mortar specimens to sulfuric acid solutions with pH ranging from 3 to 6. Results showed that calcium concentration in control reactors without biofilm was 23–47% higher than the reactors with biofilm-covered mortar. Formation of amorphous silica gel as an indication of early stages of acid attack was observed only on the control mortar specimens without biofilm. During acidification, the biofilm continued to grow and its thickness almost doubled from ∼ 30 μm before acidification to ∼ 60 μm after acidification. These results demonstrated that E. coli DH5α biofilm was able to provide a protective and sustainable barrier on mortar surfaces against medium to strong sulfuric acid attack. -- Highlights: •Effectiveness of E.coli DH5α biofilm to prevent MICD was studied. •Conditions that lead to MICD were simulated by chemical acidification. •Biofilm-covered mortar specimens were exposed to sulfuric acid solutions. •The presence of biofilm helped reduce the chemically-induced mortar deterioration. •Biofilm remained alive and continued to grow during the acidification process.

  12. Carbonation and pH in mortars manufactured with supplementary cementitious materials

    SciTech Connect

    McPolin, D.O.; Basheer, P.A.M.; Long, A.E.

    2009-05-15

    An investigation of carbonation in mortars and methods of measuring the degree of carbonation and pH change is presented. The mortars were manufactured using ordinary portland cement, pulverized fuel ash, ground granulated blast-furnace slag, metakaolin, and microsilica. The mortars were exposed to a carbon dioxide-rich environment (5% CO{sub 2}) to accelerate carbonation. The resulting carbonation was measured using phenolphthalein indicator and thermogravimetric analysis. The pH of the pore fluid and a powdered sample, extracted from the mortar, was measured to give an accurate indication of the actual pH of the concrete. The pH of the extracted powder mortar sample was found to be similar to the pH of the pore fluid expressed from the mortars. The thermogravimetric analysis suggested two distinct regions of transport of CO{sub 2} within mortar, a surface region where convection was prevalent and a deeper region where diffusion was dominant. The use of microsilica has been shown to decrease the rate of carbonation, while pulverized fuel ash and ground granulated blast-furnace slag have a detrimental effect on carbonation. Metakaolin has little effect on carbonation.

  13. 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

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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...

  19. 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...

  20. 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.

  1. 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...

  2. 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...

  3. AMS radiocarbon dating of mortar: The case study of the medieval UNESCO site of Modena

    NASA Astrophysics Data System (ADS)

    Carmine, Lubritto; Caroselli, Marta; Lugli, Stefano; Marzaioli, Fabio; Nonni, Sara; Marchetti Dori, S.; Terrasi, Filippo

    2015-10-01

    The carbon dioxide contributing to binder formation during the set of a lime mortar reflects the atmospheric 14C content at the time of construction of a building. For this reason, the 14C dating of mortars is used with increasing frequencies in archaeological and architectural research. Mortars, however, may also contain carbonaceous contaminants potentially affecting radiocarbon dating. The Centre for Isotopic Research on Cultural and Environmental heritage (CIRCE) of the Second University of Naples (SUN) has recently obtained some promising results in mortar radiocarbon dating thanks to the development of a procedure (i.e. CryoSoniC/Cryo2SoniC) aiming to eliminate exogenous C contamination that may occur in a mortar. The construction history of the UNESCO World Heritage Site of Modena (Italy) is still controversial and represents a challenging case study for the application of absolute dating methodologies for different reasons. From the point of view of 14C dating, for example, given the high percentage of carbonate aggregates composing these samples, Modena mortars represent an experimental test particularly indicative of exogenous carbon sources suppression ensuring methodology accuracy. In this paper several AMS Radiocarbon dates were carried out on lime lumps with the aim to: (i) verify procedure accuracy by a comparison of the results obtainable from lime lumps dated after different treatments (i.e. bulk lime lumps vs. CryoSoniC purified lime lumps); (ii) compare different building phases absolute chronology for the medieval UNESCO site of Modena, with that assumed by historical sources in order to assess preliminary the 14C dating feasibility for of the site. Historical temporal constraints and mortar clustering, based on petrography, have been applied to define a temporal framework of the analyzed structure. Moreover, a detailed petrographic characterization of mortars was used both as a preliminary tool for the choice of samples and to infer about the

  4. 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.

  5. 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...

  6. Water transfer properties and shrinkage in lime-based rendering mortars

    NASA Astrophysics Data System (ADS)

    Arizzi, A.; Cultrone, G.

    2012-04-01

    Rendering is the practice of covering a wall or a building façade with one or more layers of mortar, with the main aim to protect the masonry structure against weathering. The render applied must show high flexibility, good adhesion and compatibility with the support (i.e. stone, brick) and, overall, it should be characterised by low water absorption and high water vapour permeability. Water (in the solid, liquid and vapour state) is one of the main factors that drive construction materials to deterioration. Therefore, to evaluate the quality and durability of a rendering mortar, thus ensuring its protective function in the masonry structure, it is fundamental to assess the behaviour of this mortar towards water. Mortars were elaborated with a calcitic dry hydrated lime, a calcareous aggregate, a pozzolan, a lightweight aggregate, a water-retaining agent and a plasticiser. Four types of lime mortars were prepared, in which the binder-to-aggregate ratios were 1:3, 1:4, 1:6 and 1:9 by weight, whilst the pozzolan was kept at 10% of the lime (by mass) and the total admixtures proportion was less than 2% of the total mass. The influence of the characteristics of mortars pore system on the amount of water absorbed and the kinetics of absorption was investigated by means of: free water absorption and drying; capillary uptake; water permeability; water vapour permeability. Interesting deductions can be made from the values of water and water vapour permeability found for mortars: the former increases exponentially with the sand volume of the mortar, whilst the latter increases almost exponentially with the initial water content added to the mortar mixes during their elaboration. However, the relationship obtained between porosity of mortars and permeability values is not really clear. This finding suggests that the permeability of a material cannot be estimated on the basis of its porosity as it can be made for the capillary uptake and free water absorption. Another

  7. Thermo-mechanical properties of polyester mortar using recycled PET

    SciTech Connect

    Rebeiz, K.S.; Craft, A.P.

    1997-07-01

    The thermo-mechanical properties of polyester mortar (PM) using unsaturated polyester resins based on recycled PET are investigated in this paper (the recycled PET waste is mainly obtained from used plastic beverage bottles). The use of recycled PET in PM formulation is important because it helps produce good quality PM at a relatively low cost, save energy and alleviate an environmental problem posed by plastic wastes. PM construction applications include the repair of dams, piers, runways, bridges and other structures. Test results show that the effective use of PM overlays on portland cement concrete slabs is best achieved by utilizing flexible resins with low modulus and high elongation capacity at failure. The use of flexible resins in PM production is especially important in situations involving large thermal movements.

  8. Mineralogical and microstructural studies of mortars from the bath complex of the Roman villa rustica near Mosnje (Slovenia)

    SciTech Connect

    Kramar, Sabina; Zalar, Vesna; Urosevic, Maja; Mauko, Alenka; Mirtic, Breda; Lux, Judita; Mladenovic, Ana

    2011-11-15

    This study deals with the characterization of mortars collected from bath complex of the Roman villa rustica from an archeological site near Mosnje (Slovenia). The mortar layers of the mosaics, wall paintings and mortar floors were investigated. A special aggregate consisting of brick fragments was present in the mortars studied. The mineralogical and petrographic compositions of the mortars were determined by means of optical microscopy, X-ray powder diffraction and FTIR spectroscopy. Analysis of aggregate-binder interfaces using SEM-EDS revealed various types of reactivity rims. In order to assess the hydraulic characteristics of the mortars, the acid-soluble fractions were determined by ICP-OES. Furthermore, the results of Hg-porosimetry and gas sorption isotherms showed that mortars with a higher content of brick fragments particles exhibited a higher porosity and a greater BET surface area but a lower average pore diameter compared to mortars lacking this special aggregate. - Highlights: {yields} Mineral and microstructural characterizations of brick-lime mortars. {yields} Hydraulic character of mortars in Roman baths complex. {yields} Reaction rims were observed around brick fragments and dolomitic grains. {yields} Higher content of brick particles yielded a higher BET surface area. {yields} Addition of brick particles increased porosity and diminished pore size diameter.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Effects of Surfactants on the Properties of Mortar Containing Styrene/Methacrylate Superplasticizer

    PubMed Central

    Negim, El-Sayed; Kozhamzharova, Latipa; Khatib, Jamal; Bekbayeva, Lyazzat; Williams, Craig

    2014-01-01

    The physical and mechanical properties of mortar containing synthetic cosurfactants as air entraining agent are investigated. The cosurfactants consist of a combination of 2% dodecyl benzene sodium sulfonate (DBSS) and either 1.5% polyvinyl alcohol (PVA) or 1.5% polyoxyethylene glycol monomethyl ether (POE). Also these cosurfactants were used to prepare copolymers latex: styrene/butyl methacrylate (St/BuMA), styrene/methyl methacrylate (St/MMA), and styrene/glycidyl methacrylate (St/GMA), in order to study their effects on the properties of mortar. The properties of mortar examined included flow table, W/C ratio, setting time, water absorption, compressive strength, and combined water. The results indicate that the latex causes improvement in mortar properties compared with cosurfactants. Also polymer latex containing DBSS/POE is more effective than that containing DBSS/PVA. PMID:24955426

  14. Practical Issues Associated with Mortar Projections in Large Deformation Contact/Impact Analysis

    SciTech Connect

    Laursen, T A; Puso, M A; Heinstein, M W

    2002-05-02

    Several recent works have considered variants of the mortar-finite element method for numerical treatment of contact phenomena. The method has shown considerable promise for the spatial discretization of contact interactions, particularly for kinematically linear applications where one or both of the contacting surfaces are flat. Desirable features already demonstrated for the method in this specialized setting include passage of patch tests, preservation of convergence rates that would be obtained with a perfectly conforming mesh, and accurate resolution of contact stresses on interfaces. This paper concerns itself with the successful extension of these methods to encompass contact of geometrically noncoincident surfaces. The issue of patch test passage over curved interfaces will be discussed. It will be shown that a generalization of the mortar projection method is required to pass patch tests in this instance. Issues relating to the exact numerical integration of the mortar projection integrals will also be outlined, and a convergence study for a mortar tying application will be presented.

  15. Mineralogical characterization of rendering mortars from decorative details of a baroque building in Kozuchow (SW Poland)

    SciTech Connect

    Bartz, W.; Filar, T.

    2010-01-15

    Optical microscopic observations, scanning electron microscopy and microprobe with energy dispersive X-ray analysis, X-ray diffraction and differential thermal/thermogravimetric analysis allowed detailed characterization of rendering mortars from decorative details (figures of Saints) of a baroque building in Kozuchow (Lubuskie Voivodship, Western Poland). Two separate coats of rendering mortars have been distinguished, differing in composition of their filler. The under coat mortar has filler composed of coarse-grained siliceous sand, whereas the finishing one has much finer grained filler, dominated by a mixture of charcoal and Fe-smelting slag, with minor amounts of quartz grains. Both mortars have air-hardening binder composed of gypsum and micritic calcite, exhibiting microcrystalline structure.

  16. 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

  17. 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.

  18. Tracing formation and durability of calcite in a Punic-Roman cistern mortar (Pantelleria Island, Italy).

    PubMed

    Dietzel, Martin; Schön, Frerich; Heinrichs, Jens; Deditius, Artur P; Leis, Albrecht

    2016-01-01

    Ancient hydraulic lime mortar preserves chemical and isotopic signatures that provide important information about historical processing and its durability. The distribution and isotopic composition of calcite in a mortar of a well-preserved Punic-Roman cistern at Pantelleria Island (Italy) was used to trace the formation conditions, durability, and individual processing periods of the cistern mortar. The analyses of stable carbon and oxygen isotopes of calcite revealed four individual horizons, D, E, B-1 and B-2, of mortar from the top to the bottom of the cistern floor. Volcanic and ceramic aggregates were used for the production of the mortar of horizons E/D and B-1/B-2, respectively. All horizons comprise hydraulic lime mortar characterized by a mean cementation index of 1.5 ± 1, and a constant binder to aggregate ratio of 0.31 ± 0.01. This suggests standardized and highly effective processing of the cistern. The high durability of calcite formed during carbonation of slaked lime within the matrix of the ancient mortar, and thus the excellent resistance of the hydraulic lime mortar against water, was documented by (i) a distinct positive correlation of δ(18)Ocalcite and δ(13)Ccalcite; typical for carbonation through a mortar horizon, (ii) a characteristic evolution of δ(18)Ocalcite and δ(13)Ccalcite through each of the four mortar horizons; lighter follow heavier isotopic values from upper to lower part of the cistern floor, and (iii) δ(18)Ocalcite varying from -10 to -5 ‰ Vienna Pee Dee belemnite (VPDB). The range of δ(18)Ocalcite values rule out recrystallization and/or neoformation of calcite through chemical attack of water stored in cistern. The combined studies of the chemical composition of the binder and the isotopic composition of the calcite in an ancient mortar provide powerful tools for elucidating the ancient techniques and processing periods. This approach helps to evaluate the durability of primary calcite and demonstrates the

  19. Effect of dry deposition of pollutants on the degradation of lime mortars with sepiolite

    SciTech Connect

    Martinez-Ramirez, S.; Thompson, G.E.; Puertas, F.; Blanco-Varela, M.T.

    1998-01-01

    The behavior of lime mortars containing sepiolite or sepiolite plus pentaclorophenol in atmospheric simulation chambers has been studied. The pollutant gases used in this study have been NO, NO{sub 2}, and SO{sub 2}. The studies have been done in wet and dry conditions as well as with and without ozone. In the case of NO and NO{sub 2}, the aggressive agent would be HNO{sub 3}, which reacts with lime mortar binder CaCO{sub 3}, producing Ca(NO{sub 3}){sub 2} formation. On this process, the influence of the presence of an oxidant as well as water has been studied. The catalyst effect of the oxidation is known to be accelerated by water presence, so mortars exposed to NO + O{sub 3} + H{sub 2}O and NO{sub 2} + O{sub 3} + H{sub 2}O environments undergo a greater salts formation than those exposed to the rest of he aggressive media. The three mortars` behaviors are similar and independent of their composition, producing small amount of salts in every case. When SO{sub 2} is the gas used, the aggressive agent of mortar will be H{sub 2}SO{sub 4} that reacts with mortar binder, CaCO{sub 3} to produce calcium sulfate in the form of gypsum. Oxidant and/or water influence has been studied, and the (SO{sub 2} + O{sub 3} + H{sub 2}O) chamber was found to be the one with greater aggressivity to mortars. However, in these conditions, sepiolite presence within the mortars delayed gypsum formation.

  20. 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.

  1. 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

  2. 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.

  3. Utilization of ground waste seashells in cement mortars for masonry and plastering.

    PubMed

    Lertwattanaruk, Pusit; Makul, Natt; Siripattarapravat, Chalothorn

    2012-11-30

    In this research, four types of waste seashells, including short-necked clam, green mussel, oyster, and cockle, were investigated experimentally to develop a cement product for masonry and plastering. The parameters studied included water demand, setting time, compressive strength, drying shrinkage and thermal conductivity of the mortars. These properties were compared with those of a control mortar that was made of a conventional Portland cement. The main parameter of this study was the proportion of ground seashells used as cement replacement (5%, 10%, 15%, or 20% by weight). Incorporation of ground seashells resulted in reduced water demand and extended setting times of the mortars, which are advantages for rendering and plastering in hot climates. All mortars containing ground seashells yielded adequate strength, less shrinkage with drying and lower thermal conductivity compared to the conventional cement. The results indicate that ground seashells can be applied as a cement replacement in mortar mixes and may improve the workability of rendering and plastering mortar. PMID:22841935

  4. A Study on the Properties of Carbon Black Mortar Using Granulated Blast Furnace Slag and Polymer.

    PubMed

    Jang, Hong-Seok; Jeon, Ui-Hyeon; So, Seung-Young

    2015-11-01

    White Portland Cement (WPC) and inorganic pigment have been used in colored concrete, but there are some physical problems such as increases in efflorescence, and poor workability and low economics. The aim of this study was to investigate the effects of GBFS and polymer (methyl cellulose) on the physical properties of carbon black mortar. For this purpose, a flow test, compressive strength test and color evaluation and was carried out on cement mortar mixed with polymer by changing the proportion of cement and ratio of GBFS. The results show that the addition of polymer influences significantly the color value efficiency in colored mortar. This is due to the reduction of overall amount of micro pore. This polymer films prevent the transport of soluble calcium towards the surface, and decreases efflorescence. And the flow of colored mortar was increased in proportion to the addition rate of the GBFS. In addition the strength of colored mortars with GBFS at the long-term aged (after 28 days) was higher than that of the general WPC mortar, although its strength was developed slowly at the early ages. PMID:26726652

  5. Concretes and mortars with waste paper industry: Biomass ash and dregs.

    PubMed

    Martínez-Lage, Isabel; Velay-Lizancos, Miriam; Vázquez-Burgo, Pablo; Rivas-Fernández, Marcos; Vázquez-Herrero, Cristina; Ramírez-Rodríguez, Antonio; Martín-Cano, Miguel

    2016-10-01

    This article describes a study on the viability of using waste from the paper industry: biomass boiler ash and green liquor dregs to fabricate mortars and concretes. Both types of ash were characterized by obtaining their chemical and mineralogical composition, their organic matter content, granulometry, adsorption and other common tests for construction materials. Seven different mortars were fabricated, one for reference made up of cement, sand, and water, three in which 10, 20, or 30% of the cement was replaced by biomass ash, and three others in which 10, 20, or 30% of the cement was replaced with dregs. Test specimens were fabricated with these mortars to conduct flexural and compression tests. Flexural strength is reduced for all the mortars studied. Compressive strength increases for the mortars fabricated with biomass ash and decreases for the mortar with dregs. Finally, 5 concretes were made, one of them as a reference (neither biomass ash nor dregs added), two of them with replacements of 10 and 20% of biomass ash instead of cement and another two with replacements of 10 and 20% of dregs instead of cement. The compressive and tensile splitting strength increase when a 10% of ash is replaced and decrease in all the other cases. The modulus of elasticity always decreases. PMID:27397843

  6. The Effect of Mortar Grade and Thickness on the Impact Resistance of Ferrocement Slab

    NASA Astrophysics Data System (ADS)

    Che Muda, Zakaria; Syamsir, Agusril; Nasharuddin Mustapha, Kamal; Sulleman, Sorefan; Beddu, Salmia; Thiruchelvam, Sivadass; Ismail, Firas B.; Usman, Fathoni; Liyana Mohd Kamal, Nur; Ashraful Alam, Md; Birima, Ahmed H.; Itam, Zarina; Zaroog, O. S.

    2016-03-01

    This paper investigate the effect of the thickness and mesh spacing on the impact of ferrocement for the concrete slab of 300mm × 300mm size reinforced subjected to low impact projectile test. A self-fabricated drop-weight impact test rig with a steel ball weight of 1.236 kg drop at height of 150 mm, 350mm, and 500mm has been used in this research work. The objective of this research is to study the relationship of impact resistance of ferrocement against the mortar grade and slab thickness. There is a good linear correlation between impact resistance of ferrocement against the mortar grade and the thickness of ferrocement slab. The first and ultimate crack impact resistance of mortar grade 43 (for 40 mm thick slab with mesh reinforcement) are 1.60 times and 1.53 times respectively against the mortar grade 17 slab (of same thickness with mesh reinforcement). The first and ultimate crack impact resistance for 40 mm thick slab (mortar grade 43 with mesh reinforcement) are 3.55 times and 4.49 times respectively against the 20 mm thick slab (of same mortar grade with mesh reinforcement).

  7. Use of Artificial Neural Network for the Simulation of Radon Emission Concentration of Granulated Blast Furnace Slag Mortar.

    PubMed

    Jang, Hong-Seok; Xing, Shuli; Lee, Malrey; Lee, Young-Keun; So, Seung-Young

    2016-05-01

    In this study, an artificial neural networks study was carried out to predict the quantity of radon of Granulated Blast Furnace Slag (GBFS) cement mortar. A data set of a laboratory work, in which a total of 3 mortars were produced, was utilized in the Artificial Neural Networks (ANNs) study. The mortar mixture parameters were three different GBFS ratios (0%, 20%, 40%). Measurement radon of moist cured specimens was measured at 3, 10, 30, 100, 365 days by sensing technology for continuous monitoring of indoor air quality (IAQ). ANN model is constructed, trained and tested using these data. The data used in the ANN model are arranged in a format of two input parameters that cover the cement, GBFS and age of samples and, an output parameter which is concentrations of radon emission of mortar. The results showed that ANN can be an alternative approach for the predicting the radon concentration of GBFS mortar using mortar ingredients as input parameters. PMID:27483913

  8. 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

  9. 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)

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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

  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. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. Parallel 3D Mortar Element Method for Adaptive Nonconforming Meshes

    NASA Technical Reports Server (NTRS)

    Feng, Huiyu; Mavriplis, Catherine; VanderWijngaart, Rob; Biswas, Rupak

    2004-01-01

    High order methods are frequently used in computational simulation for their high accuracy. An efficient way to avoid unnecessary computation in smooth regions of the solution is to use adaptive meshes which employ fine grids only in areas where they are needed. Nonconforming spectral elements allow the grid to be flexibly adjusted to satisfy the computational accuracy requirements. The method is suitable for computational simulations of unsteady problems with very disparate length scales or unsteady moving features, such as heat transfer, fluid dynamics or flame combustion. In this work, we select the Mark Element Method (MEM) to handle the non-conforming interfaces between elements. A new technique is introduced to efficiently implement MEM in 3-D nonconforming meshes. By introducing an "intermediate mortar", the proposed method decomposes the projection between 3-D elements and mortars into two steps. In each step, projection matrices derived in 2-D are used. The two-step method avoids explicitly forming/deriving large projection matrices for 3-D meshes, and also helps to simplify the implementation. This new technique can be used for both h- and p-type adaptation. This method is applied to an unsteady 3-D moving heat source problem. With our new MEM implementation, mesh adaptation is able to efficiently refine the grid near the heat source and coarsen the grid once the heat source passes. The savings in computational work resulting from the dynamic mesh adaptation is demonstrated by the reduction of the the number of elements used and CPU time spent. MEM and mesh adaptation, respectively, bring irregularity and dynamics to the computer memory access pattern. Hence, they provide a good way to gauge the performance of computer systems when running scientific applications whose memory access patterns are irregular and unpredictable. We select a 3-D moving heat source problem as the Unstructured Adaptive (UA) grid benchmark, a new component of the NAS Parallel

  4. 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%.

  5. 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.

  6. 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"

  7. 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

  8. Effects of the restoration mortar on chalk stone buildings

    NASA Astrophysics Data System (ADS)

    Ion, R. M.; Teodorescu, S.; Ştirbescu, R. M.; Dulamă, I. D.; Şuică-Bunghez, I. R.; Bucurică, I. A.; Fierăscu, R. C.; Fierscu, I.; Ion, M. L.

    2016-06-01

    The monument buildings as components of cultural heritage are exposed to degradation of surfaces and chemical and mechanical degradation, often associated to soiling and irreversible deterioration of the building. In many conservative and restorative works, a cement-based mortar was used without knowing all the adverse effects of this material on the building. This paper deals with the study of the effects of natural cement used in restorative works in the particular case of the Basarabi-Murfatlar Churches Ensemble. Cement-based materials exposed to sulfate present in the chalk stone - gypsum (CaSO4.2H2O), can induce signs of deterioration, due to ettringite ([Ca3Al (OH)612H2O]2(SO4)32H2O) or thaumasite (Ca3[Si(OH)612H2O](CO3)SO4) formation. These phases contribute to strain within the material, inducing expansion, strength loss, spalling and severe degradation. Several combined techniques (XRD, EDXRF, ICP-AES, SEM, EDS, sulphates content, FT-IR and Raman analysis were carried out to put into evidence the effects of them on the building walls.

  9. Analyses and design of underground reinforced plastic mortar pipelines

    SciTech Connect

    Abdel-Magid, B.M.

    1986-01-01

    A simplified design procedure for underground Reinforced Plastic Mortar (RPM) pipe is proposed. This procedure is based on finite-element analyses of the pipe-soil system and composite laminate analysis of the pipe. With the proposed method, the designer is able to select the best trench geometry and backfill conditions, to determine the construction effects, and to devise the constituent pipe materials according to the given installation conditions for a reliable and cost-effective design. Existing design methods of underground flexible pipes were evaluated. A thorough investigation of the problems encountered with the RPM pipe is made to study the possible modes and causes of failure. The new design method is based on a composite beam element model to account for the failure modes pertinent to fiberglass-reinforced plastic pipes. The design procedure and the required soil and pipe materials data are described. It is shown that simpler performance limits are needed and that the proposed design procedure can be fully implemented once these data are provided.

  10. Estimation of corrosion damage in steel reinforced mortar using waveguides

    NASA Astrophysics Data System (ADS)

    Reis, Henrique; Ervin, Benjamin L.; Kuchma, Daniel A.; Bernhard, Jennifer

    2005-05-01

    Corrosion of reinforced concrete is a chronic infrastructure problem, particularly in areas with deicing salt and marine exposure. To maintain structural integrity, a testing method is needed to identify areas of corroding reinforcement. For purposes of rehabilitation, the method must also be able to evaluate the degree, rate and location of damage. Towards the development of a wireless embedded sensor system to monitor and assess corrosion damage in reinforced concrete, reinforced mortar specimens were manufactured with seeded defects to simulate corrosion damage. Taking advantage of waveguide effects of the reinforcing bars, these specimens were then tested using an ultrasonic approach. Using the same ultrasonic approach, specimens without seeded defects were also monitored during accelerated corrosion tests. Both the ultrasonic sending and the receiving transducers were mounted on the steel rebar. Advantage was taken of the lower frequency (<250 kHz) fundamental flexural propagation mode because of its relatively large displacements at the interface between the reinforcing steel and the surrounding concrete. Waveform energy (indicative of attenuation) is presented and discussed in terms of corrosion damage. Current results indicate that the loss of bond strength between the reinforcing steel and the surrounding concrete can be detected and evaluated.

  11. Properties of mortars made by uncalcined FGD gypsum-fly ash-ground granulated blast furnace slag composite binder

    SciTech Connect

    Zhong Shiyun; Ni Kun; Li Jinmei

    2012-07-15

    Highlights: Black-Right-Pointing-Pointer The mortar with uncalcined FGD gypsum has suitable workability. Black-Right-Pointing-Pointer The strength of mortar with uncalcined FGD gypsum is higher than that of mortar without uncalcined FGD gypsum. Black-Right-Pointing-Pointer The dry shrinkage of mortar with uncalcined FGD gypsum is lower than that of mortar without uncalcined FGD gypsum. Black-Right-Pointing-Pointer The leaching of sulfate ion of mortar is studied. - Abstract: A series of novel mortars were developed from composite binder of uncalcined FGD gypsum, fly ash (FA) and ground granulated blast furnace slag (GGBFS) for the good utilization of flue gas desulphurization (FGD) gypsum. At a fixed ratio (20%) of GGBFS to the composite binder, keeping consistency of the mortar between 9.5 and 10.0 cm, the properties of the composite mortar were studied. The results show that higher water/binder (W/B) is required to keep the consistency when increasing the percentage of FGD gypsum. No obvious influences of the W/B and content of FGD gypsum on the bleeding of paste were observed which keeps lower than 2% under all experimental conditions tried. The highest compressive and flexural strengths (ratio is 20% FGD gypsum, 20% GGBFS and 60% FA) are 22.6 and 4.3 MPa at 28 days, respectively. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) results indicate that massive ettringite crystals and C-S-H gels exist in the hydration products. At 90 days the mortars with FGD gypsum is dramatically smaller drying shrinkage (563-938 micro strain) than that without FGD gypsum (about 2250 micro strain). The release of the SO{sub 4}{sup 2-} from the mortar was analyzed, indicating that the dissolution of sulfate increases with FGD gypsum. The concentration of SO{sub 4}{sup 2-} releasing from the mortar with 10% FGD gypsum is almost equal to that obtained from the mortar without FGD gypsum. The release of SO{sub 4}{sup 2-} from the mortar with 20% FGD gypsum is 9200 mg

  12. Addition of cement to lime-based mortars: Effect on pore structure and vapor transport

    SciTech Connect

    Mosquera, M.J. . E-mail: mariajesus.mosquera@uca.es; Silva, B.; Prieto, B.; Ruiz-Herrera, E.

    2006-09-15

    The main focus of this work is to determine the effect of cement addition, a common practice in many restorations, on the pore structure of lime-based mortars. A second target is to establish correlations between microstructure and water vapor transport across the mortar, which is a key characteristic of building decay. In order to achieve these objectives, we prepared a set of mortars consisting of air-hardening lime with a progressively increasing cement content, as well as a mortar containing hydraulic lime. Several different techniques, most notably mercury intrusion porosimetry and scanning electron microscopy in the backscatter mode, were used to investigate the pore structure. The results from these procedures led to the conclusion that porosity and pore size are progressively reduced as cement content increases. Moreover, an excellent correlation between pore radius parameter and the vapor diffusion coefficient was established. Hydraulic lime mortar exhibited textural parameters and diffusivity values halfway between those of the different lime/cement mixes studied.

  13. Use of waste brick as a partial replacement of cement in mortar

    SciTech Connect

    Naceri, Abdelghani Hamina, Makhloufi Chikouche

    2009-08-15

    The aim of this study is to investigate the use of waste brick as a partial replacement for cement in the production of cement mortar. Clinker was replaced by waste brick in different proportions (0%, 5%, 10%, 15% and 20%) by weight for cement. The physico-chemical properties of cement at anhydrous state and the hydrated state, thus the mechanical strengths (flexural and compressive strengths after 7, 28 and 90 days) for the mortar were studied. The microstructure of the mortar was investigated using scanning electron microscopy (SEM), the mineralogical composition (mineral phases) of the artificial pozzolan was investigated by the X-ray diffraction (XRD) and the particle size distributions was obtained from laser granulometry (LG) of cements powders used in this study. The results obtained show that the addition of artificial pozzolan improves the grinding time and setting times of the cement, thus the mechanical characteristics of mortar. A substitution of cement by 10% of waste brick increased mechanical strengths of mortar. The results of the investigation confirmed the potential use of this waste material to produce pozzolanic cement.

  14. Lime-pozzolana mortars in Roman catacombs: composition, structures and restoration

    SciTech Connect

    Sanchez-Moral, Sergio; Soler, Vicente; Garcia-Guinea, Javier

    2005-08-01

    Analyses of microsamples collected from Roman catacombs and samples of lime-pozzolana mortars hardened in the laboratory display higher contents in carbonated binder than other subaerial Roman monuments. The measured environmental data inside the Saint Callistus and Domitilla catacombs show a constant temperature of 15-17 deg C, a high CO{sub 2} content (1700 to 3500 ppm) and a relative humidity close to 100%. These conditions and particularly the high CO{sub 2} concentration speed-up the lime calcitization roughly by 500% and reduce the cationic diffusion to form hydrous calcium aluminosilicates. The structure of Roman catacomb mortars shows (i) coarser aggregates and thicker beds on the inside, (ii) thin, smoothed, light and fine-grained external surfaces with low content of aggregates and (iii) paintings and frescoes on the outside. The observed high porosity of the mortars can be attributed to cracking after drying linked with the high binder content. Hardened lime lumps inside the binder denote low water/mortar ratios for slaking. The aggregate tephra pyroclasts rich in aluminosilicate phases with accessorial amounts of Ba, Sr, Rb, Cu and Pb were analysed through X-ray diffraction (XRD), electron microprobe analysis (EMPA) and also by environmental scanning electron microscopy (ESEM) to identify the size and distribution of porosity. Results support procedures using local materials, special mortars and classic techniques for restoration purposes in hypogeal backgrounds.

  15. Neutron attenuation characteristics of polyethylene, polyvinyl chloride, and heavy aggregate concrete and mortars

    SciTech Connect

    Abdul-Majid, S.; Othman, F.

    1994-03-01

    Polyethylene and polyvinyl chloride pellets were introduced into concrete to improve its neutron attenuation characteristics while several types of heavy coarse aggregates were used to improve its gamma ray attenuation properties. Neutron and gamma ray attenuation were studied in concrete samples containing coarse aggregates of barite, pyrite, basalt, hematite, and marble as well as polyethylene and polyvinyl chloride pellets in narrow-beam geometry. The highest neutron attenuation was shown by polyethylene mortar, followed by polyvinyl chloride mortar; barite and pyrite concrete showed higher gamma ray attenuation than ordinary concrete. Broad-beam and continuous (infinite) medium geometries were used to study the neutron attenuation of samples containing polymers at different concentrations with and without heavy aggregates, the fitting equations were established, and from these the neutron removal coefficients were deduced. In a radiation field of neutrons and gamma rays, the appropriate concentration of polymer and heavy aggregate can be selected to give the optimum total dose attenuation depending on the relative intensities of each type of radiation. This would give much better design flexibility over ordinary concrete. The compressive strength tests performed on mortar and concrete samples showed that their value, in general, decreases as polymer concentration increases and that the polyvinyl chloride mortar showed higher values than the polyethylene mortar. For general construction purposes, the compression strength was considered acceptable in these samples. 34 refs., 16 figs., 4 tabs.

  16. Coupled Effect of Elevated Temperature and Cooling Conditions on the Properties of Ground Clay Brick Mortars

    NASA Astrophysics Data System (ADS)

    Ali Abd El Aziz, Magdy; Abdelaleem, Salh; Heikal, Mohamed

    2013-12-01

    When a concrete structure is exposed to fire and cooling, some deterioration in its chemical resistivity and mechanical properties takes place. This deterioration can reach a level at which the structure may have to be thoroughly renovated or completely replaced. In this investigation, four types of cement mortars, ground clay bricks (GCB)/sand namely 0/3, 1/2, 2/1 and 3/0, were used. Three different cement contents were used: 350, 400 and 450 kg/m3. All the mortars were prepared and cured in tap water for 3 months and then kept in laboratory atmospheric conditions up to 6 months. The specimens were subjected to elevated temperatures up to 700°C for 3h and then cooled by three different conditions: water, furnace, and air cooling. The results show that all the mortars subjected to fire, irrespective of cooling mode, suffered a significant reduction in compressive strength. However, the mortars cooled in air exhibited a relativity higher reduction in compressive strength rather than those water or furnace cooled. The mortars containing GCB/sand (3/0) and GCB/sand (1/2) exhibited a relatively higher thermal stability than the others.

  17. Strength and Density of Geopolymer Mortar Cured at Ambient Temperature for Use as Repair Material

    NASA Astrophysics Data System (ADS)

    Warid Wazien, A. Z.; Bakri Abdullah, Mohd Mustafa Al; Abd. Razak, Rafiza; Mohd Remy Rozainy, M. A. Z.; Faheem Mohd Tahir, Muhammad

    2016-06-01

    Geopolymers produced by synthesizing aluminosilicate source materials with an alkaline activator solution promised an excellent properties akin to the existing construction material. This study focused on the effect of various binder to sand ratio on geopolymer mortar properties. Mix design of geopolymer mortar was produced using NaOH concentration of 12 molars, ratio of fly ash/alkaline activator and ratio Na2SiO3/NaOH of 2.0 and 2.5 respectively. Samples subsequently ware cured at ambient temperature. The properties of geopolymer mortar were analysed in term of compressive strength and density at different period which are on the 3rd and 7th day of curing. Experimental results revealed that the addition of sand slightly increase the compressive strength of geopolymer. The optimum compressive strength obtained was up to 31.39 MPa on the 7th day. The density of geopolymer mortar was in the range between 2.0 g/cm3 to 2.23 g/cm3. Based on this findings, the special properties promoted by geopolymer mortar display high potential to be implemented in the field of concrete patch repair.

  18. Use of waste brick as a partial replacement of cement in mortar.

    PubMed

    Naceri, Abdelghani; Hamina, Makhloufi Chikouche

    2009-08-01

    The aim of this study is to investigate the use of waste brick as a partial replacement for cement in the production of cement mortar. Clinker was replaced by waste brick in different proportions (0%, 5%, 10%, 15% and 20%) by weight for cement. The physico-chemical properties of cement at anhydrous state and the hydrated state, thus the mechanical strengths (flexural and compressive strengths after 7, 28 and 90 days) for the mortar were studied. The microstructure of the mortar was investigated using scanning electron microscopy (SEM), the mineralogical composition (mineral phases) of the artificial pozzolan was investigated by the X-ray diffraction (XRD) and the particle size distributions was obtained from laser granulometry (LG) of cements powders used in this study. The results obtained show that the addition of artificial pozzolan improves the grinding time and setting times of the cement, thus the mechanical characteristics of mortar. A substitution of cement by 10% of waste brick increased mechanical strengths of mortar. The results of the investigation confirmed the potential use of this waste material to produce pozzolanic cement. PMID:19383569

  19. Immobilization in cement mortar of chromium removed from water using titania nanoparticles.

    PubMed

    Husnain, Ahmed; Qazi, Ishtiaq Ahmed; Khaliq, Wasim; Arshad, Muhammad

    2016-05-01

    Because of the high toxicity of chromium, particularly as Cr (VI), it is removed from industrial effluents before their discharge into water bodies by a variety of techniques, including adsorption. Ultimate disposal of the sludge or the adsorbate, however, is a serious problem. While titania, in nanoparticle form, serves as a very good adsorbent for chromium, as an additive, it also helps to increase the compressive strength of mortar and concrete. Combining these two properties of the material, titania nanoparticles were used to adsorb chromium and then added to mortar up to a concentration of 20% by weight. The compressive strength of the resulting mortar specimens that replaced 15% of cement with chromium laden titania showed an improved strength than that without titania, thus confirming that this material had positive effect on the mortar strength. Leachate tests using the Toxicity Characteristics Leaching Procedure (TCLP) confirmed that the mortar sample chromium leachate was well within the permissible limits. The proposed technique thus offers a safe and viable method for the ultimate disposal of toxic metal wastes, in general, and those laden waste chromium, in particular. PMID:26915979

  20. Superplasticized Portland cement: Production and compressive strength of mortars and concrete

    SciTech Connect

    Bouzoubaa, N.; Zhang, M.H.; Malhotra, V.M.

    1998-12-01

    This paper deals with the effect of intergrinding different percentages of a naphthalene-based superplasticizer with Portland cement clinker and gypsum on the fineness of the product, and on the water requirement and the compressive strength of the mortars made with the superplasticized cement. The properties of the fresh and hardened concrete made with the superplasticized cements were also investigated. The results showed that the intergrinding of a given amount of a naphthalene-based superplasticizer with Portland clinker and gypsum reduced the grinding time required for obtaining the same Blaine fineness as that of the control Portland cement without the superplasticizer. The water requirement of the mortars made with the superplasticized cements was similar to that of the mortars made with the control Portland cements when the same amount of the superplasticizer was added at the mortar mixer; for a given grinding time and a Blaine fineness of {approximately}4500 cm{sup 2}/g, the mortars made with the superplasticized cement had higher compressive strength than those made with the control Portland cement. For a given grinding time or Blaine fineness of cement {ge}5000 cm{sup 2}/g, the slump loss, air content stability, bleeding, autogenous temperature rise, setting times, and compressive strength of the concrete made with the superplasticized cements were generally comparable to those of the concrete made with the control Portland cements when the superplasticizer was added at the concrete mixer.

  1. Classifiers utilized to enhance acoustic based sensors to identify round types of artillery/mortar

    NASA Astrophysics Data System (ADS)

    Grasing, David; Desai, Sachi; Morcos, Amir

    2008-04-01

    Feature extraction methods based on the statistical analysis of the change in event pressure levels over a period and the level of ambient pressure excitation facilitate the development of a robust classification algorithm. The features reliably discriminates mortar and artillery variants via acoustic signals produced during the launch events. Utilizing acoustic sensors to exploit the sound waveform generated from the blast for the identification of mortar and artillery variants as type A, etcetera through analysis of the waveform. Distinct characteristics arise within the different mortar/artillery variants because varying HE mortar payloads and related charges emphasize varying size events at launch. The waveform holds various harmonic properties distinct to a given mortar/artillery variant that through advanced signal processing and data mining techniques can employed to classify a given type. The skewness and other statistical processing techniques are used to extract the predominant components from the acoustic signatures at ranges exceeding 3000m. Exploiting these techniques will help develop a feature set highly independent of range, providing discrimination based on acoustic elements of the blast wave. Highly reliable discrimination will be achieved with a feedforward neural network classifier trained on a feature space derived from the distribution of statistical coefficients, frequency spectrum, and higher frequency details found within different energy bands. The processes that are described herein extend current technologies, which emphasis acoustic sensor systems to provide such situational awareness.

  2. Artillery/mortar round type classification to increase system situational awareness

    NASA Astrophysics Data System (ADS)

    Desai, Sachi; Grasing, David; Morcos, Amir; Hohil, Myron

    2008-04-01

    Feature extraction methods based on the statistical analysis of the change in event pressure levels over a period and the level of ambient pressure excitation facilitate the development of a robust classification algorithm. The features reliably discriminates mortar and artillery variants via acoustic signals produced during the launch events. Utilizing acoustic sensors to exploit the sound waveform generated from the blast for the identification of mortar and artillery variants as type A, etcetera through analysis of the waveform. Distinct characteristics arise within the different mortar/artillery variants because varying HE mortar payloads and related charges emphasize varying size events at launch. The waveform holds various harmonic properties distinct to a given mortar/artillery variant that through advanced signal processing and data mining techniques can employed to classify a given type. The skewness and other statistical processing techniques are used to extract the predominant components from the acoustic signatures at ranges exceeding 3000m. Exploiting these techniques will help develop a feature set highly independent of range, providing discrimination based on acoustic elements of the blast wave. Highly reliable discrimination will be achieved with a feedforward neural network classifier trained on a feature space derived from the distribution of statistical coefficients, frequency spectrum, and higher frequency details found within different energy bands. The processes that are described herein extend current technologies, which emphasis acoustic sensor systems to provide such situational awareness.

  3. 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?

  4. 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.

  5. 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.

  6. Properties, characterization, and decay of sticky rice–lime mortars from the Wugang Ming dynasty city wall (China)

    SciTech Connect

    Xiao, Ya; Fu, Xuan; Gu, Haibing; Gao, Feng; Liu, Shaojun

    2014-04-01

    Urgent restoration of the Wugang Ming dynasty city wall brings about the need for a study of the formulation and properties of mortars. In the present paper, mortar samples from the Wugang Ming dynasty city wall were characterized in a combination of sheet polarized light optical microscopy, scanning electron microscopy with X-ray energy dispersive spectrometer, thermogravimetric/differential scanning calorimetry, X-ray powder diffraction, Fourier transform infrared spectroscopy, and inductively coupled plasma emission spectroscopy. Results show that mortars are mainly built up from inorganic calcium carbonate based organic–inorganic hybrid material with a small amount of sticky rice, which plays a crucial role in forming dense and compact microstructure of mortars and effectively hindering penetration of water and air into mortars. Analysis of decayed products shows that the detrimental soluble salts originates from ambient environment. - Highlights: • Mortars used in the Wugang city wall are a calcium carbonate-sticky rice hybrid bonding material. • Carbonation processing is extremely slow due to dense and compact microstructure of mortars. • Decying of mortars results from the appearance of soluble salt from ambient environment.

  7. The Impact of Involvement in Mortar Board Senior Honor Society on Lifelong Views of Civic Engagement and Leadership

    ERIC Educational Resources Information Center

    Turner, Daniel James

    2012-01-01

    This study examines the impact that involvement in Mortar Board National Senior Honor Society has on lifelong views of civic engagement and leadership. Mortar Board Senior Honor Society is a collegiate honor society established in 1918 that recognizes students for their outstanding contributions to their college or university community in the…

  8. 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%.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  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. Brick-and-Mortar Self-Assembly Approach to Graphitic Mesoporous Carbon Nanocomposites

    SciTech Connect

    Dai, Sheng; Fulvio, Pasquale F; Mayes, Richard T; Wang, Xiqing; Mahurin, Shannon Mark; Bauer, Christopher; Presser, Volker; Mcdonough, John; Gogotsi, Yury

    2011-01-01

    Mesoporous carbon materials do not have sufficient ordering at the atomic scale to exhibit good electronic conductivity. To date, mesoporous carbons having uniform mesopores and high surface areas have been prepared from partially-graphitizable precursors in the presence of templates. High temperature thermal treatments above 2000 C, which are usually required to increase conductivity, result in a partial or total collapse of the mesoporous structures and reduced surface areas induced by growth of graphitic domains, limiting their applications in electric double layer capacitors and lithium-ion batteries. In this work, we successfully implemented a 'brick-and-mortar' approach to obtain ordered graphitic mesoporous carbon nanocomposites with tunable mesopore sizes below 850 C without using graphitization catalysts or high temperature thermal treatments. Phenolic resin-based mesoporous carbons act as mortar to highly conductive carbon blacks and carbon onions (bricks). The capacitance and resistivity of final materials can be tailored by changing the mortar to brick ratios.

  17. Effect of brief heat-curing on microstructure and mechanical properties in fresh cement based mortars

    SciTech Connect

    Ballester, P.; Hidalgo, A.; Marmol, I.; Morales, J.; Sanchez, L.

    2009-07-15

    The effect of temperature on fresh mortar and cement paste was evaluated by simulating the curing conditions of external buildings plastering applied under extremely hot weather. The specimens were heated at controlled temperatures in the 40-80 {sup o}C range by exposure to IR radiation over short periods. The effect of soaking for a short time was also examined. The results of compressive strength tests, scanning electron microscopy, infrared spectroscopy and mercury porosimetry helped to characterize the mechanical and physico-chemical properties of the studied sample. Early age behaviour (28 days) in neat cement was barely affected by the temperature. By contrast, exposure to high temperatures caused significant microstructural changes in the mortar. However, successive soaking over short periods was found to reactivate the mechanism of curing and restore the expected mechanical properties. Based on the results, application of cement based mortar at high temperatures is effective when followed by a short, specific soaking process.

  18. Transient three-dimensional contact problems: mortar method. Mixed methods and conserving integration

    NASA Astrophysics Data System (ADS)

    Hesch, Christian; Betsch, Peter

    2011-10-01

    The present work deals with the development of an energy-momentum conserving method to unilateral contact constraints and is a direct continuation of a previous work (Hesch and Betsch in Comput Mech 2011, doi: 10.1007/s00466-011-0597-2) dealing with the NTS method. In this work, we introduce the mortar method and a newly developed segmentation process for the consistent integration of the contact interface. For the application of the energy-momentum approach to mortar constraints, we extend an approach based on a mixed formulation to the segment definition of the mortar constraints. The enhanced numerical stability of the newly proposed discretization method will be shown in several examples.

  19. Performance Characteristics of Waste Glass Powder Substituting Portland Cement in Mortar Mixtures

    NASA Astrophysics Data System (ADS)

    Kara, P.; Csetényi, L. J.; Borosnyói, A.

    2016-04-01

    In the present work, soda-lime glass cullet (flint, amber, green) and special glass cullet (soda-alkaline earth-silicate glass coming from low pressure mercury-discharge lamp cullet and incandescent light bulb borosilicate glass waste cullet) were ground into fine powders in a laboratory planetary ball mill for 30 minutes. CEM I 42.5N Portland cement was applied in mortar mixtures, substituted with waste glass powder at levels of 20% and 30%. Characterisation and testing of waste glass powders included fineness by laser diffraction particle size analysis, specific surface area by nitrogen adsorption technique, particle density by pycnometry and chemical analysis by X-ray fluorescence spectrophotometry. Compressive strength, early age shrinkage cracking and drying shrinkage tests, heat of hydration of mortars, temperature of hydration, X-ray diffraction analysis and volume stability tests were performed to observe the influence of waste glass powder substitution for Portland cement on physical and engineering properties of mortar mixtures.

  20. Effect of various superplasticizers on rheological properties of cement paste and mortars

    SciTech Connect

    Masood, I.; Agarwal, S.K. )

    1994-01-01

    The effect of eight commercial superplasticizers including one developed from Cashew Nut Shell Liquid (CNSL) at CBRI on the rheological properties viz. viscosity and flow of cement paste and mortars have been investigated. The viscosity measurements have been made at various shear rates (5--100 rpm). It is found that at higher rates (100 rpm) even with the low concentration of superplasticizers (0.1), the viscosity of the cement paste is more or less the same as that obtained with 0.6 % dosages of SPs at lesser shear rates. The effect of split addition (delayed addition) of superplasticizers on viscosity of cement paste and 1:3 cement sand mortar have also been studied. A decrease in viscosity due to split addition has been observed in the cement paste and there is an increase of 15--20 % in flow of mortars.

  1. Influence of limestone fillers on combustion characteristics of asphalt mortar for pavements

    NASA Astrophysics Data System (ADS)

    Wu, Ke; Zhu, Kai; Wu, Hao; Han, Jun; Wang, Jin-Chang; Huang, Zhi-Yi; Liang, Pei

    2014-07-01

    Asphalt materials will be ignited and release significant toxic fumes within tunnel fires. Thus, combustion characteristics of asphalt materials used in road tunnel should be studied in order to limit such an adverse effect. In the present work we study the influence of limestone fillers on combustion characteristics of asphalt mortar by thermogravimetric and kinetic analysis. It is shown that the combustion of asphalt mortar is not just a linear superposition of asphalt and limestone. The limestone will increase the ignition point and the activation energy of the primary volatile release, and will catalyze the char formation from the primary volatile release. Kinetic analysis shows that the primary volatile release stage of asphalt mortar combustion can be explained by a three-dimensional diffusion model, the secondary volatile release and char combustion stage can be explained by a model under the assumption of random nucleation and nuclei growth, whereas the limestone decomposition stage appears to follow the one-dimensional phase boundary model.

  2. Influence of bicarbonate ions on the deterioration of mortar bars in sulfate solutions

    SciTech Connect

    Kunther, W.; Lothenbach, B.; Scrivener, K.

    2013-02-15

    This work investigates the influence of bicarbonate ions on the deterioration of cementitious material exposed to sulfate ions. Mortars based on a CEM I and on a CEM III/B cement were investigated. Experimental investigations were compared to thermodynamic modeling and phase characterization to understand the differences in deterioration. The presence of bicarbonate ions significantly reduced the expansion of the CEM I mortars. Thermodynamic modeling showed that at high concentrations of bicarbonate ettringite and gypsum become unstable. Microstructural characterization combined with information from thermodynamic modeling suggests that conditions of high supersaturation with respect to ettringite are unlikely in the samples exposed in solutions containing bicarbonate. Consequently, expansive forces are not generated by the crystallization pressure of ettringite. There was little expansion of the CEM III/B sample even in the sodium sulfate solution. In the bicarbonate solution this mortar showed a highly leached zone at the surface in which calcite was observed.

  3. Stability Analysis of a mortar cover ejected at various Mach numbers and angles of attack

    NASA Astrophysics Data System (ADS)

    Schwab, Jane; Carnasciali, Maria-Isabel; Andrejczyk, Joe; Kandis, Mike

    2011-11-01

    This study utilized CFD software to predict the aerodynamic coefficient of a wedge-shaped mortar cover which is ejected from a spacecraft upon deployment of its Parachute Recovery System (PRS). Concern over recontact or collision between the mortar cover and spacecraft served as the impetus for this study in which drag and moment coefficients were determined at Mach numbers from 0.3 to 1.6 at 30-degree increments. These CFD predictions were then used as inputs to a two-dimensional, multi-body, three-DoF trajectory model to calculate the relative motion of the mortar cover and spacecraft. Based upon those simulations, the study concluded a minimal/zero risk of collision with either the spacecraft or PRS. Sponsored by Pioneer Aerospace.

  4. EXPERIMENTAL STUDY ON THE APPLICATION OF HIGH STRENGTH FIBER REINFORCED MORTAR TO PRESTRESSED CONCRETE STRUCTURES

    NASA Astrophysics Data System (ADS)

    Sakurada, Michihiro; Mori, Takuya; Ohyama, Hiroaki; Seki, Hiroshi

    In order to study the application of high strength fiber reinforced mortar which has design compressive strength 120N/mm2 to prestressed concrete structures, the authors carried out material tests, bending tests and shear tests of prestressed concrete beam specimens. From the material tests, we obtained material properties for the design of prestressed concrete structures such as compressive strength, tensile strength, Young's modulus, coefficient of creep, dry shrinkage and so on. The results of the bending tests and the shear tests of prestressed concrete beam specimen shows that experimental flexural strength and shear strength of prestressed concrete beam using high strength fiber reinforced mortar exceeds strength calculated by traditional design method. It is confirmed that high strength fiber reinforced mortar can be applied to prestressed concrete structures.

  5. Keratin film ablation for the fabrication of brick and mortar skin structure using femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Haq, Bibi Safia; Khan, Hidayat Ullah; Dou, Yuehua; Alam, Khan; Attaullah, Shehnaz; Zari, Islam

    2015-09-01

    The patterning of thin keratin films has been explored to manufacture model skin surfaces based on the "bricks and mortar" view of the relationship between keratin and lipids. It has been demonstrated that laser light is capable of preparing keratin-based "bricks and mortar" wall structure as in epidermis, the outermost layer of the human skin. "Bricks and mortar" pattern in keratin films has been fabricated using an ArF excimer laser (193 nm wavelength) and femtosecond laser (800 and 400 nm wavelength). Due to the very low ablation threshold of keratin, femtosecond laser systems are practical for laser processing of proteins. These model skin structures are fabricated for the first time that will help to produce potentially effective moisturizing products for the protection of skin from dryness, diseases and wrinkles.

  6. Segment-based vs. element-based integration for mortar methods in computational contact mechanics

    NASA Astrophysics Data System (ADS)

    Farah, Philipp; Popp, Alexander; Wall, Wolfgang A.

    2015-01-01

    Mortar finite element methods provide a very convenient and powerful discretization framework for geometrically nonlinear applications in computational contact mechanics, because they allow for a variationally consistent treatment of contact conditions (mesh tying, non-penetration, frictionless or frictional sliding) despite the fact that the underlying contact surface meshes are non-matching and possibly also geometrically non-conforming. However, one of the major issues with regard to mortar methods is the design of adequate numerical integration schemes for the resulting interface coupling terms, i.e. curve integrals for 2D contact problems and surface integrals for 3D contact problems. The way how mortar integration is performed crucially influences the accuracy of the overall numerical procedure as well as the computational efficiency of contact evaluation. Basically, two different types of mortar integration schemes, which will be termed as segment-based integration and element-based integration here, can be found predominantly in the literature. While almost the entire existing literature focuses on either of the two mentioned mortar integration schemes without questioning this choice, the intention of this paper is to provide a comprehensive and unbiased comparison. The theoretical aspects covered here include the choice of integration rule, the treatment of boundaries of the contact zone, higher-order interpolation and frictional sliding. Moreover, a new hybrid scheme is proposed, which beneficially combines the advantages of segment-based and element-based mortar integration. Several numerical examples are presented for a detailed and critical evaluation of the overall performance of the different schemes within several well-known benchmark problems of computational contact mechanics.

  7. Finite Element Analysis of Crack-Path Selection in a Brick and Mortar Structure

    NASA Astrophysics Data System (ADS)

    Sarrafi-Nour, Reza; Manoharan, Mohan; Johnson, Curtis A.

    Many natural composite materials rely on organized architectures that span several length scales. The structures of natural shells such as nacre (mother-of-pearl) and conch are prominent examples of such organizations where the calcium carbonate platelets, the main constituent of natural shells, are held together in an organized fashion within an organic matrix. At one or multiple length scales, these organized arrangements often resemble a brick-and-mortar structure, with calcium carbonate platelets acting as bricks connected through the organic mortar phase.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. Enhanced affordable methods for assessment of material characteristics and consolidation effects on stone and mortar

    NASA Astrophysics Data System (ADS)

    Drdacky, M.; Slizkova, Z.

    2012-04-01

    In situ considerate testing of surface cohesion of historic stone and mortar materials suffers from a lack of suitable affordable non-destructive methods. The problem is mainly important for assessment of surface degradation characteristics and/or evaluation of effectiveness of consolidation treatment of degraded historic materials. The paper presents two innovations of simple testing methods which provide reliable data on material cohesion and water uptake. The so called "Scotch Tape Test" or peeling test has been introduced into the field of conservation for testing the cohesion qualities of historic materials mainly stone and renders in sixties without any standards or reliably verified recommendations for the above mentioned application in the conservation practice. Licentious use without adequate knowledge and sufficient understanding leads to non-comparable and non-reproducible as well as in many cases incorrect and severely biased results and assessments. Therefore, the authors after a research and comparative testing have established limits for its application, reliable procedures and a "standard" protocol for testing of cohesion characteristics of brittle and quasi brittle materials mainly mortars and stones. This article presents a detailed analysis of the peeling test procedures, and suggests recommendations for performing peeling tests and for evaluating the obtained results. Also in situ testing of material water uptake is a very basic and indispensable technique in conservation practice and it correlates significantly with some other material characteristics. The capillary properties of porous materials can be measured in situ using a Karsten tube and modified tools or methods which are quite cumbersome, and cannot be performed on inclined surfaces, e.g. vaults or ceilings. There are other difficulties with Karsten tube measurements, e.g. problems with fixing a heavy glass tube on vertical surfaces, a need for two operators, and soiling of the surface

  13. 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.

  14. 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.

  15. 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

  16. Hierarchical Assembly of Plasmonic Nanostructures using Virus Capsid Scaffolds on DNA Origami Tiles

    SciTech Connect

    Wang, Debin; Capehart, Stacy L.; Pal, Suchetan; Liu, Minghui; Zhang, Lei; Schuck, P. J.; Liu, Yan; Yan, Hao; Francis, Matthew B.; De Yoreo, James J.

    2014-07-07

    Plasmonic nanoarchitectures using biological scaffolds have shown the potential to attain controllable plasmonic fluorescence via precise spatial arrangement of fluorophores and plasmonic antennae. However, previous studies report a predominance of fluorescence quenching for small metal nanoparticles (less than ~60 nm) due to their small scattering cross-sections. In this work, we report the design and performance of fluorescent plasmonic structures composed of fluorophore-modified virus capsids and gold nanoparticles (AuNPs) assembled on DNA origami tiles. The virus capsid creates a scaffold for control over the three dimensional arrangement of the fluorophores, whereas the DNA origami tile provides precise control over the distance between the capsid and the AuNP. Using finite-difference time-domain (FDTD) numerical simulations and multimodal single-particle imaging measurements, we show that the judicial design of these structures places the dye molecules near the hot spot of the AuNP. This effectively increases the fluorescence intensity in the quenching regime of the AuNP, with an enhancement factor that increases with increasing AuNP size. This strategy of using biological scaffolds to control fluorescence paves the way for exploring the parameters that determine plasmonic fluorescence. It may lead to a better understanding of the antenna effects of photon absorption and emission, enabling the construction of multicomponent plasmonic systems.

  17. Directed assembly of hierarchical light-harvesting complexes using virus capsid scaffolds and DNA origami tiles

    NASA Astrophysics Data System (ADS)

    Wang, Debin; Capehart, Stacy; Pal, Suchetan; Liu, Minghui; Lau, Jolene; Yan, Hao; Francis, Matthew; Deyoreo, Jim; LBNL Team; UCB Team; ASU Team

    2013-03-01

    Directed assembly of nanostructures with molecular precision is of great importance to develop an insightful understanding of assembly pathways and dynamics as well as to derive new functionalities. In this work, we explore the use of virus capsids and DNA origami tiles as 3D scaffolds and 2D templates for directed assembly of light-harvesting molecules and plasmonic gold nanoparticles to achieve tunable photoemission. Bacteriophage MS2 virus capsids with well-defined spherical macromolecular structures are genetically modified to provide predictable steric arrangements of light-harvesting molecules. DNA origami tiles act as programmable planar templates to provide higher-order organization of oligonucleotide-functionalized light-harvesting capsids and plasmonic gold nanoparticles. The direct observation of distance dependent photoluminescence emission is carried out by our correlative approach combining atomic force microscopy and confocal fluorescence microscopy, which is in good agreement with our numerical simulation and theoretical calculation. This work will facilitate the construction of multicomponent biological-metal hybrid plasmonic nanostructures for nanophotonics and biosensing applications.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

    Following the breakup of the Space Shuttle Columbia during reentry a NASA-wide investigation team was formed to examine the probable damage inflicted on Orbiter Thermal Protection System (TPS) elements by impact of External Tank insulating foam projectiles. Our team was to apply rigorous, physics-based analysis techniques to help determine parameters of interest for an experimental test program, utilize validated codes to investigate the full range of impact scenarios, and use analysis derived models to predict aero-thermal-structural responses to entry conditions. We were to operate on a non-interference basis with the j Team, and were to supply significant findings to that team and to the Orbiter Vehicle Engineering Working Group, being responsive to any solicitations for support from these entities. The authors formed a working sub-group within the larger team to apply the Smooth Particle Hydrodynamics code SPHC to the damage estimation problem. Numerical models of the LI-900 TPS tiles and of the BX-250 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 sub-groups 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 densified lower layer of LI-900 insulation, the Nomex felt Strain Isolation Pad (SIP) mounting layer, and the underlying 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 the Southwest Research Institute (SwRI) 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 ET foam projectiles on the TPS tile systems used

  3. 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.

  4. 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 ...

  5. 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.

  6. 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.

  7. 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...

  8. 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...

  9. 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...

  10. 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.

  11. 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.

  12. Experimental Study of the Possibility to Make a Mortar with Ternary Sand (Natural and Artificial Fine Aggregates)

    NASA Astrophysics Data System (ADS)

    Baali, L.; Naceri, A.; Rahmouni, Z.; Mehidi, M. W. Noui

    This experimental study investigates the possibility to make a mortar with a ternary sand (natural and artificial fine aggregates). This method is utilized to correct the particle size distribution of various sands used in mortar. For this investigation, three sands have been used: a dune sand (DS), a slag sand (SS), and brick sand (BS) at different proportions in mortar. After crushing, the artificial fine aggregate (blast furnace slag and waste brick fine aggregate) was sifted in order to use it as fine aggregate. The effect of the quality and grain size distribution of natural fine aggregate (i.e., DS) and artificial fine aggregates (i.e., SS and BS) on the physical properties of ternary sand confected (density, porosity, fineness modulus, equivalent sand, particle size distribution, water absorption) and properties of fresh and hardened mortar were analysed. In the same way for this study, the physical properties and chemical compositions of DS, SS, BS and cement were investigated. The results obtained show that the mechanical strength on mortar depends of the nature and particle size distribution of sand studied. The reuse of this recycled material (slag blast furnace and waste brick) in the industry would contribute to the protection of the environment. This study shows the potential of this method to make mortar with ternary sand (natural and artificial fine aggreagates) in order to improve the physical properties of sand. Utilising natural and artificial fine aggregates to produce quality mortar should yield significant environmental benefits.

  13. Microscopic characterisation of old mortars from the Santa Maria Church in Evora

    SciTech Connect

    Adriano, P.; Santos Silva, A.; Veiga, R.; Mirao, J.; Candeias, A.E.

    2009-07-15

    Evora Cathedral (one of the most emblematic monuments of Evora - Portugal) has suffered several conservation and restoration interventions through the ages, without, however, any type of previous knowledge about mortars and materials used. This work was carried out in order to identify the mortar's composition in different locations, which were attributed to different construction or conservation periods. The characterisation methodology involved a multidisciplinary set of chemical, physical, microstructural and mechanical techniques, and gave special attention to the use of microstructural characterisation techniques, particularly petrographical analysis and scanning electron microscopy for the identification of the mortar's constituents as well as in the evaluation of the state of conservation. The test results showed that two types of aerial binders were used, dolomitic and calcitic limes, the former being predominant. The aggregates used have a siliceous nature and are similar in composition to the granodiorites of the region around Evora. The mortars differ in the aggregate contents and, in some cases, crushed bricks were used as an additive.

  14. Use of polypropylene fibers coated with nano-silica particles into a cementitious mortar

    SciTech Connect

    Coppola, B. Di Maio, L.; Scarfato, P.; Incarnato, L.

    2015-12-17

    Fiber reinforced cementitious composite (FRCC) materials have been widely used during last decades in order to overcome some of traditional cementitious materials issues: brittle behaviour, fire resistance, cover spalling, impact strength. For composite materials, fiber/matrix bond plays an important role because by increasing fiber/matrix interactions is possible to increase the behaviour of the entire material. In this study, in order to improve fiber to matrix adhesion, two chemical treatments of polypropylene fibers were investigated: alkaline hydrolysis and nano-silica sol-gel particles deposition. Treatmtents effect on fibers morphology and mechanical properties was investigated by scanning electron microscopy (SEM) and tensile tests. SEM investigations report the presence of spherical nano-silica particles on fiber surface, in the case of sol-gel process, while alkaline hydrolysis leads to an increase of fibers roughness. Both treatments have negligible influence on fibers mechanical properties confirming the possibility of their use in a cementitious mortar. Pullout tests were carried out considering three embedded length of fibers in mortar samples (10, 20 and 30 mm, respectively) showing an increase of pullout energy for treated fibers. The influence on fiber reinforced mortar mechanical properties was investigated by three-point flexural tests on prismatic specimens considering two fibers length (15 and 30 mm) and two fibers volume fractions (0.50 and 1.00 %). A general increase of flexural strength over the reference mix was achieved and an overall better behaviour is recognizable for mortars containing treated fibers.

  15. Masonry repair lime-based mortars: factors affecting the mechanical behavior

    SciTech Connect

    Lanas, J.; Alvarez-Galindo, Jose I

    2003-11-01

    The increasing use of lime-based mortars for the restoration of historic buildings and structures justifies the research on these materials. The focus of this paper is the effect of technological variables on pore structure and mechanical properties of lime-based mortars. The influence of curing time, binder-aggregate (B/Ag) ratio, aggregate attributes and porosity is discussed. Mortars prepared with aerial lime, varying aggregate types and B/Ag ratios ranging from 1:1 to 1:5 by volume were tested. Compressive and flexural strength measurements, as well as X-ray diffraction (XRD) and thermal studies, were performed after 3, 7, 28, 91, 182 and 365 days. A strong increase in strength of mortar mixtures after 365 curing days (as compared to 28 curing days) is found. In spite of the fact that larger amounts of binder increase the total porosity, the strength of these mixtures is also increased. A good interlocked structure is obtained as binder contents increase. Also, higher porosities allow better portlandite carbonation. A relationship between mechanical properties and pore structure was established. However, in case of binder excess, the increase in voids leads to a strength reduction. The use of calcareous aggregates improves strength more as compared to the use of siliceous aggregates. Factors as grain size distribution and grain shape of the aggregates have also been considered.

  16. Determination of Chlorinated Solvent Sorption by Porous Material—Application to Trichloroethene Vapor on Cement Mortar

    PubMed Central

    Musielak, Marion; Brusseau, Mark L.; Marcoux, Manuel; Morrison, Candice; Quintard, Michel

    2014-01-01

    Experiments have been performed to investigate the sorption of trichloroethene (TCE) vapor by concrete material or, more specifically, the cement mortar component. Gas-flow experiments were conducted using columns packed with small pieces of cement mortar obtained from the grinding of typical concrete material. Transport and retardation of TCE at high vapor concentrations (500 mg L−1) was compared to that of a non-reactive gas tracer (Sulfur Hexafluoride, SF6). The results show a large magnitude of retardation (retardation factor = 23) and sorption (sorption coefficient = 10.6 cm3 g−1) for TCE, compared to negligible sorption for SF6. This magnitude of sorption obtained with pollutant vapor is much bigger than the one obtained for aqueous-flow experiments conducted for water-saturated systems. The considerable sorption exhibited for TCE under vapor-flow conditions is attributed to some combination of accumulation at the air-water interface and vapor-phase adsorption, both of which are anticipated to be significant for this system given the large surface area associated with the cement mortar. Transport of both SF6 and TCE was simulated successfully with a two-region physical non-equilibrium model, consistent with the dual-medium structure of the crushed cement mortar. This work emphasizes the importance of taking into account sorption phenomena when modeling transport of volatile organic compounds through concrete material, especially in regard to assessing vapor intrusion. PMID:25530647

  17. Removal of graffiti from the mortar by using Q-switched Nd:YAG laser

    NASA Astrophysics Data System (ADS)

    Sanjeevan, Poologanathan; Klemm, Agnieszka J.; Klemm, Piotr

    2007-08-01

    This paper presents part of the larger study on microstructural features of mortars and it's effects on laser cleaning process. It focuses on the influence of surface roughness, porosity and moisture content of mortars on the removal of graffiti by Nd:YAG laser. The properties of this laser are as follows: wavelength ( λ) 1.06 μm, energy: 500 mJ per pulse, pulse duration: 10 ns. The investigation shows that the variation of laser fluence with the number of pulses required for the laser cleaning can be divided into two zones, namely effective zone and ineffective zone. There is a linear relationship observed between number of pulses required for laser cleaning and the laser fluence in the effective zone, while the number of pulses required for the laser cleaning is almost constant even though the laser fluence increases in the ineffective zone. Moreover, surface roughness, porosity and moisture content of mortar samples have influence on the laser cleaning process. The effect of these parameters become however negligible at the high level of laser fluence. The number of pulses required for the laser cleaning is low for smooth surface or less porous mortar. Furthermore, the wetness of the samples facilitates the cleaning process.

  18. Use of polypropylene fibers coated with nano-silica particles into a cementitious mortar

    NASA Astrophysics Data System (ADS)

    Coppola, B.; Di Maio, L.; Scarfato, P.; Incarnato, L.

    2015-12-01

    Fiber reinforced cementitious composite (FRCC) materials have been widely used during last decades in order to overcome some of traditional cementitious materials issues: brittle behaviour, fire resistance, cover spalling, impact strength. For composite materials, fiber/matrix bond plays an important role because by increasing fiber/matrix interactions is possible to increase the behaviour of the entire material. In this study, in order to improve fiber to matrix adhesion, two chemical treatments of polypropylene fibers were investigated: alkaline hydrolysis and nano-silica sol-gel particles deposition. Treatmtents effect on fibers morphology and mechanical properties was investigated by scanning electron microscopy (SEM) and tensile tests. SEM investigations report the presence of spherical nano-silica particles on fiber surface, in the case of sol-gel process, while alkaline hydrolysis leads to an increase of fibers roughness. Both treatments have negligible influence on fibers mechanical properties confirming the possibility of their use in a cementitious mortar. Pullout tests were carried out considering three embedded length of fibers in mortar samples (10, 20 and 30 mm, respectively) showing an increase of pullout energy for treated fibers. The influence on fiber reinforced mortar mechanical properties was investigated by three-point flexural tests on prismatic specimens considering two fibers length (15 and 30 mm) and two fibers volume fractions (0.50 and 1.00 %). A general increase of flexural strength over the reference mix was achieved and an overall better behaviour is recognizable for mortars containing treated fibers.

  19. Application of AMDS mortar as a treatment agent for arsenic in subsurface environment

    NASA Astrophysics Data System (ADS)

    Choi, J.; Lee, H.; Choi, U. K.; Yang, I. J.

    2014-12-01

    Among the treatment technologies available for As in soil and groundwater, adsorption or precipitation using acid mine drainage (AMD) sludge has become a promised technique because of high efficiency, inexpensiveness and simple to handling. The adsorbents were prepared by addition of Cement, Joomoonjin sand, fly ash, and Ca(OH)2 to air dry AMD sludge. In this work, the adsorption of As (III) and As (V) on AMDS mortar has been studied as a function of kinetic, pH, and initial arsenic concentration. Results of batch study showed that 75-90% of both As (III) and As (V) were removed at pH 7. Arsenic adsorption capacities were the highest at neutral pH condition and the adsorption equilibrium time reached in 7 days using AMDS mortar. Additionally, the adsorption kinetic process is expressed well by pseudo-second-order model. The adsorption capacities of AMDS mortar for As(III) and As(V) were found 19.04 and 30.75 mg g-1, respectively. The results of As (III) adsorption isotherms were fitted well to the Freundlich model. Moreover, As (V) adsorption isotherms were fitted well to the Langmuir model rather than Freundlich model. Based on experimental results in this study, we could conclude that AMDS mortar can be effectively used for arsenic removal agent from subsurface environment.

  20. On the role of hydrophobic Si-based protective coatings in limiting mortar deterioration.

    PubMed

    Cappelletti, G; Fermo, P; Pino, F; Pargoletti, E; Pecchioni, E; Fratini, F; Ruffolo, S A; La Russa, M F

    2015-11-01

    In order to avoid both natural and artificial stone decay, mainly due to the interaction with atmospheric pollutants (both gases such as NOx and SO2 and particulate matter), polymeric materials have been widely studied as protective coatings enable to limit the penetration of fluids into the bulk material. In the current work, an air hardening calcic lime mortar (ALM) and a natural hydraulic lime mortar (HLM) were used as substrates, and commercially available Si-based resins (Alpha®SI30 and Silres®BS16) were adopted as protective agents to give hydrophobicity features to the artificial stones. Surface properties of coatings and their performance as hydrophobic agents were studied using different techniques such as contact angle measurements, capillary absorption test, mercury intrusion porosimetry, surface free energy, colorimetric measurements and water vapour permeability tests. Finally, some exposure tests to UV radiation and to real polluted atmospheric environments (a city centre and an urban background site) were carried out during a wintertime period (when the concentrations of the main atmospheric pollutants are higher) in order to study the durability of the coating systems applied. The effectiveness of the two commercial resins in reducing salt formation (sulphate and nitrate), induced by the interaction of the mortars with the atmospheric pollutants, was demonstrated in the case of the HLM mortar. Graphical Abstract ᅟ. PMID:26154039

  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. 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...

  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. 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...

  5. 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...

  6. 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.

  7. 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...

  8. 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 ...

  9. 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.

  10. 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.

  11. 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...

  12. 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.

  13. 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...

  14. 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...

  15. 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.

  16. 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.

  17. Properties of mortars made by uncalcined FGD gypsum-fly ash-ground granulated blast furnace slag composite binder.

    PubMed

    Zhong, Shiyun; Ni, Kun; Li, Jinmei

    2012-07-01

    A series of novel mortars were developed from composite binder of uncalcined FGD gypsum, fly ash (FA) and ground granulated blast furnace slag (GGBFS) for the good utilization of flue gas desulphurization (FGD) gypsum. At a fixed ratio (20%) of GGBFS to the composite binder, keeping consistency of the mortar between 9.5 and 10.0 cm, the properties of the composite mortar were studied. The results show that higher water/binder (W/B) is required to keep the consistency when increasing the percentage of FGD gypsum. No obvious influences of the W/B and content of FGD gypsum on the bleeding of paste were observed which keeps lower than 2% under all experimental conditions tried. The highest compressive and flexural strengths (ratio is 20% FGD gypsum, 20% GGBFS and 60% FA) are 22.6 and 4.3 MPa at 28 days, respectively. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) results indicate that massive ettringite crystals and C-S-H gels exist in the hydration products. At 90 days the mortars with FGD gypsum is dramatically smaller drying shrinkage (563-938 micro strain) than that without FGD gypsum (about 2250 micro strain). The release of the SO(4)(2-) from the mortar was analyzed, indicating that the dissolution of sulfate increases with FGD gypsum. The concentration of SO(4)(2-) releasing from the mortar with 10% FGD gypsum is almost equal to that obtained from the mortar without FGD gypsum. The release of SO(4)(2-) from the mortar with 20% FGD gypsum is 9200 mg·m(-2), which is lower than that from the mortar with 95% cement clinker and 5% FGD gypsum. PMID:22440404

  18. Binder characterisation of mortars used at different ages in the San Lorenzo church in Milan

    SciTech Connect

    Bertolini, Luca Carsana, Maddalena Gastaldi, Matteo Lollini, Federica Redaelli, Elena

    2013-06-15

    The paper describes a study on the mortars of the basilica of San Lorenzo in Milan, which was carried out to support an archaeological study aimed at dating and documenting the construction techniques used throughout the centuries. The church, which was founded between the 4th and 5th century, at the end of the period when Milan was the capital of the Roman Empire, was subjected in time to extensions, collapses and reconstructions that lasted until the Renaissance period and even later on. Thanks to the good state of conservation, San Lorenzo church is a collection of materials and construction techniques throughout a period of more than a millennium. Mortars were investigated in order to compare the binders used for structural elements built in different historical ages. From an archaeological study, samples of mortars attributed to the late Roman period, the Middle Ages and the Renaissance were available. The binder of each sample was separated by the aggregates and it was characterised on the basis of X-ray diffraction analysis, thermogravimetric analysis and scanning electron microscopy. Constituents of the binder were identified and their origin is discussed in order to investigate if they could be attributed to the original composition of the binder or to possible alteration in time due to atmospheric pollution. Results show that, even though the binder is mainly based on magnesian lime, there are significant differences in the microstructure of the binding matrix used in mortars ascribed to the different historical periods. In the Roman period, in correspondence of the structural elements that required higher strength, also hydraulic cocciopesto mortars were detected. Gypsum was found in most samples, which was maybe added intentionally. - Highlights: • Binders of mortars of San Lorenzo church in Milan were investigated. • Roman, Middle Ages and Renaissance samples were studied by XRD, TG and SEM. • Magnesian-lime binders containing silico

  19. 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.

  20. 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.

  1. 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...

  2. 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.

  3. Fly and bottom ashes from biomass combustion as cement replacing components in mortars production: rheological behaviour of the pastes and materials compression strength.

    PubMed

    Maschio, Stefano; Tonello, Gabriele; Piani, Luciano; Furlani, Erika

    2011-10-01

    In the present research mortar pastes obtained by replacing a commercial cement with the equivalent mass of 5, 10, 20 and 30 wt.% of fly ash or bottom ash from fir chips combustion, were prepared and rheologically characterized. It was observed that the presence of ash modifies their rheological behaviour with respect to the reference blend due to the presence, in the ashes, of KCl and K2SO4 which cause precipitation of gypsum and portlandite during the first hydration stages of the pastes. Hydrated materials containing 5 wt.% of ash display compression strength and absorption at 28 d of same magnitude as the reference composition; conversely, progressive increase of ash cause a continuous decline of materials performances. Conversely, samples tested after 180 d display a marked decline of compression strength, as a consequence of potassium elution and consequent alkali-silica reaction against materials under curing. PMID:21762950

  4. 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.

  5. 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.

  6. Scanning electron microscopic investigations of fresh mortars: Well-defined water-filled layers adjacent to sand grains

    SciTech Connect

    Diamond, S. Kjellsen, K.O.

    2008-04-15

    SEM examinations are reported of freshly-mixed and early age mortar specimens prepared by fast freezing in liquid nitrogen followed by epoxy impregnation, and of companion specimens of early aged mortars prepared conventionally. Freshly-mixed mortars reveal complex features that appear to influence subsequent development of the hardened state microstructure. In particular, layers of entirely water-filled space a few micrometers thick are found adjacent to many of the sand grain surfaces. After a few hours sparse deposits of calcium hydroxide crystals (and later C-S-H) are found within these layers, but the layers persist as recognizable features for at least 12 h. The layers are identically recognizable in both fast-frozen and conventionally-prepared specimens. Another feature found in freshly-mixed mortars is the existence of patchy local areas of sparsely-packed and other areas of densely-packed cement particles.

  7. The Market Gate of Miletus: damages, material characteristics and the development of a compatible mortar for restoration

    NASA Astrophysics Data System (ADS)

    Siegesmund, Siegfried; Middendorf, Bernhard

    2008-12-01

    The indoor exhibit of the Market Gate of Miletus is unique for an archaeological monument. The reconstruction of the gate was done in such a way that most marble fragments were removed leaving cored marble columns 3-4 cm in thickness. These cored columns were mounted on a steel construction and filled with different mortars or filled with specially shaped blocks of brick combined with mortar. All the missing marble elements were replaced by copies made of a Portland cement based concrete, which is compositionally similar to the original building materials. During the Second World War the monument was heavily damaged by aerial bombardment. For 2 years the Market Gate of Miletus was exposed to weathering, because a brick wall protecting the gate was also destroyed. The deterioration phenomena observed are microcracks, macroscopic fractures, flaking, sugaring, greying, salt efflorescence, calcitic-sinter layers and iron oxide formation etc. The rapid deterioration seems to be due to indoor atmospheric effects, and also by a combination of incompatible materials (e.g. marble, steel, mortar, concrete, bricks etc.). Compatible building materials like mortars or stone replacing materials have to be developed for the planned restoration. The requirements for restoration mortars are chemical-mineralogical and physical-mechanical compatibilities with the existing building materials. In detail this means that the mortar should ensure good bonding properties, adapted strength development and not stain the marble when in direct contact. The favoured mortar was developed with a hydraulic binder based on iron-free white cement and pozzolana based on activated clay. A special limestone and quartz sand mixture was used as an aggregate. The cement was adjusted using chemical additives. Specially designed tests were applied extensively to prove whether the developed mortar is suitable for the restoration of this precious monument.

  8. Effects of blended-cement paste chemical composition changes on some strength gains of blended-mortars.

    PubMed

    Kirgiz, Mehmet Serkan

    2014-01-01

    Effects of chemical compositions changes of blended-cement pastes (BCPCCC) on some strength gains of blended cement mortars (BCMSG) were monitored in order to gain a better understanding for developments of hydration and strength of blended cements. Blended cements (BC) were prepared by blending of 5% gypsum and 6%, 20%, 21%, and 35% marble powder (MP) or 6%, 20%, 21%, and 35% brick powder (BP) for CEMI42.5N cement clinker and grinding these portions in ball mill at 30 (min). Pastes and mortars, containing the MP-BC and the BP-BC and the reference cement (RC) and tap water and standard mortar sand, were also mixed and they were cured within water until testing. Experiments included chemical compositions of pastes and compressive strengths (CS) and flexural strengths (FS) of mortars were determined at 7th-day, 28th-day, and 90th-day according to TS EN 196-2 and TS EN 196-1 present standards. Experimental results indicated that ups and downs of silica oxide (SiO2), sodium oxide (Na2O), and alkali at MP-BCPCC and continuously rising movement of silica oxide (SiO2) at BP-BCPCC positively influenced CS and FS of blended cement mortars (BCM) in comparison with reference mortars (RM) at whole cure days as MP up to 6% or BP up to 35% was blended for cement. PMID:24587737

  9. Effects of Blended-Cement Paste Chemical Composition Changes on Some Strength Gains of Blended-Mortars

    PubMed Central

    Kirgiz, Mehmet Serkan

    2014-01-01

    Effects of chemical compositions changes of blended-cement pastes (BCPCCC) on some strength gains of blended cement mortars (BCMSG) were monitored in order to gain a better understanding for developments of hydration and strength of blended cements. Blended cements (BC) were prepared by blending of 5% gypsum and 6%, 20%, 21%, and 35% marble powder (MP) or 6%, 20%, 21%, and 35% brick powder (BP) for CEMI42.5N cement clinker and grinding these portions in ball mill at 30 (min). Pastes and mortars, containing the MP-BC and the BP-BC and the reference cement (RC) and tap water and standard mortar sand, were also mixed and they were cured within water until testing. Experiments included chemical compositions of pastes and compressive strengths (CS) and flexural strengths (FS) of mortars were determined at 7th-day, 28th-day, and 90th-day according to TS EN 196-2 and TS EN 196-1 present standards. Experimental results indicated that ups and downs of silica oxide (SiO2), sodium oxide (Na2O), and alkali at MP-BCPCC and continuously rising movement of silica oxide (SiO2) at BP-BCPCC positively influenced CS and FS of blended cement mortars (BCM) in comparison with reference mortars (RM) at whole cure days as MP up to 6% or BP up to 35% was blended for cement. PMID:24587737

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. 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

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. Dynamic tensile fracture of mortar at ultra-high strain-rates

    NASA Astrophysics Data System (ADS)

    Erzar, B.; Buzaud, E.; Chanal, P.-Y.

    2013-12-01

    During the lifetime of a structure, concrete and mortar may be exposed to highly dynamic loadings, such as impact or explosion. The dynamic fracture at high loading rates needs to be well understood to allow an accurate modeling of this kind of event. In this work, a pulsed-power generator has been employed to conduct spalling tests on mortar samples at strain-rates ranging from 2 × 104 to 4 × 104 s-1. The ramp loading allowed identifying the strain-rate anytime during the test. A power law has been proposed to fit properly the rate-sensitivity of tensile strength of this cementitious material over a wide range of strain-rate. Moreover, a specimen has been recovered damaged but unbroken. Micro-computed tomography has been employed to study the characteristics of the damage pattern provoked by the dynamic tensile loading.

  4. Dynamic tensile fracture of mortar at ultra-high strain-rates

    SciTech Connect

    Erzar, B. Buzaud, E.; Chanal, P.-Y.

    2013-12-28

    During the lifetime of a structure, concrete and mortar may be exposed to highly dynamic loadings, such as impact or explosion. The dynamic fracture at high loading rates needs to be well understood to allow an accurate modeling of this kind of event. In this work, a pulsed-power generator has been employed to conduct spalling tests on mortar samples at strain-rates ranging from 2 × 10{sup 4} to 4 × 10{sup 4} s{sup −1}. The ramp loading allowed identifying the strain-rate anytime during the test. A power law has been proposed to fit properly the rate-sensitivity of tensile strength of this cementitious material over a wide range of strain-rate. Moreover, a specimen has been recovered damaged but unbroken. Micro-computed tomography has been employed to study the characteristics of the damage pattern provoked by the dynamic tensile loading.

  5. Comparative investigation of corrosion resistance of steel reinforcement in alinite and Portland cement mortars

    SciTech Connect

    Kostogloudis, G.C.; Kalogridis, D.; Ftikos, C.; Malami, C.; Georgali, B.; Kaloidas, V.

    1998-07-01

    The corrosion resistance of steel-reinforced mortar specimens made from alinite cement was investigated using ordinary Portland cement (OPC) specimens as reference. The specimens were prepared and exposed in three different environments: continuous exposure in tap water, interrupted exposure in tap water, and interrupted exposure in 3.5% NaCl solution. The steel weight loss and the half cell potential were measured vs. exposure time, up to the age of 12 months. Pore solution extraction and analysis and porosity determination were also performed. In continuous exposure in tap water, alinite cement provided adequate protection against corrosion. In interrupted exposure in tap water, a higher corrosion was observed for alinite cement compared to OPC. In the case of interrupted exposure in 3.5% NaCl solution, the simultaneous action of free chlorides and oxygen resulted in the depassivation of steel reinforcing bars in alinite and Portland cement mortars, and led to severe corrosion effect.

  6. Effect of geothermal waste on strength and microstructure of alkali-activated slag cement mortars

    SciTech Connect

    Escalante-Garcia, J.I.; Gorokhovsky, A.V.; Mendoza, G.; Fuentes, A.F

    2003-10-01

    Mortars of blast furnace slag replaced with 10% of a geothermal silica waste were cured for 90 days. The binder was activated by 6 wt.% Na{sub 2}O equivalent of NaOH and water glass. The presence of the silica enhanced the formation of hydration products as shown by nonevaporable water (NEW) results. Backscattered electron images indicated that the microstructures of blended slag had less porosity than those of neat slag mortars and the interfacial zone between aggregate and hydration products was dense and of homogeneous composition similar to the matrix of hydration products. The main hydration products were C-S-H and for NaOH a hydrotalcite type phase was found as finely intermixed with the C-S-H.

  7. Application of a semi-empirical model for the evaluation of transmission properties of barite mortar.

    PubMed

    Santos, Josilene C; Tomal, Alessandra; Mariano, Leandro; Costa, Paulo R

    2015-06-01

    The aim of this study was to estimate barite mortar attenuation curves using X-ray spectra weighted by a workload distribution. A semi-empirical model was used for the evaluation of transmission properties of this material. Since ambient dose equivalent, H(⁎)(10), is the radiation quantity adopted by IAEA for dose assessment, the variation of the H(⁎)(10) as a function of barite mortar thickness was calculated using primary experimental spectra. A CdTe detector was used for the measurement of these spectra. The resulting spectra were adopted for estimating the optimized thickness of protective barrier needed for shielding an area in an X-ray imaging facility. PMID:25600506

  8. Monitoring general corrosion of rebar embedded in mortar using high-frequency guided mechanical waves

    NASA Astrophysics Data System (ADS)

    Ervin, Benjamin L.; Bernhard, Jennifer T.; Kuchma, Daniel A.; Reis, Henrique

    2007-04-01

    High-frequency guided mechanical waves were used to ultrasonically monitor reinforced mortar specimens undergoing accelerated general corrosion damage. Waves were invoked, using both single-cycle and high-cycle tonebursts, at frequencies where the attenuation is at a local minimum. Results show that the high-frequency waves were sensitive to irregularities in the reinforcing rebar profile caused by corrosion. The sensitivity is thought to be due to scattering, reflections, and mode conversion at the irregularities. Certain frequencies show promise for being insensitive to the surrounding mortar, ingress of water, presence of additional rebar, stirrups, and rust product accumulation. This lack of sensitivity allows for changes in guided wave behavior from bar profile deterioration to be isolated from the effects of other surrounding interfaces.

  9. Properties of Roman bricks and mortars used in Serapis temple in the city of Pergamon

    SciTech Connect

    Ozkaya, Ozlem Aslan; Boeke, Hasan

    2009-09-15

    Serapis temple, which was constructed in the Roman period in the city of Pergamon (Bergama/Turkey), is one of the most important monuments of the world heritage. In this study, the characteristics of bricks and mortars used in the temple have been determined in order to define the necessary characteristics of the intervention materials, which will be used in the conservation works of the temple. Several analyses were carried out to determine their basic physical properties, raw material compositions, mineralogical and microstructural properties using X-ray diffraction, Scanning Electron Microscope and a Thermo Gravimetric Analyzer. Analysis results indicated that the mortars are stiff, compact and hydraulic due to the use of natural pozzolanic aggregates. The Roman bricks are of low density, high porosity and were produced from raw materials containing calcium poor clays fired at low temperatures.

  10. Processing of Sugarcane Bagasse ash and Reactivity of Ash-blended Cement Mortar

    NASA Astrophysics Data System (ADS)

    Ajay, Goyal; Hattori, Kunio; Ogata, Hidehiko; Ashraf, Muhammad

    Sugarcane bagasse ash (SCBA), a sugar-mill waste, has the potential of a partial cement replacement material if processed and obtained under controlled conditions. This paper discusses the reactivity of SCBA obtained by control burning of sugarcane bagasse procured from Punjab province of India. X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques were employed to ascertain the amorphousness and morphology of the minerals ash particles. Destructive and non-destructive tests were conducted on SCBA-blended mortar specimens. Ash-blended cement paste specimens were analyzed by XRD, thermal analysis, and SEM methods to evaluate the hydration reaction of SCBA with cement. Results showed that the SCBA processed at 600°C for 5 hours was reactive as ash-blended mortar specimens with up to 15% substitution of cement gave better strength than control specimens.

  11. Rheology of Carbon Fibre Reinforced Cement-Based Mortar

    SciTech Connect

    Banfill, Phillip F. G.; Starrs, Gerry; McCarter, W. John

    2008-07-07

    Carbon fibre reinforced cement based materials (CFRCs) offer the possibility of fabricating 'smart' electrically conductive materials. Rheology of the fresh mix is crucial to satisfactory moulding and fresh CFRC conforms to the Bingham model with slight structural breakdown. Both yield stress and plastic viscosity increase with increasing fibre length and volume concentration. Using a modified Viskomat NT, the concentration dependence of CFRC rheology up to 1.5% fibre volume is reported.

  12. Rheology of Carbon Fibre Reinforced Cement-Based Mortar

    NASA Astrophysics Data System (ADS)

    Banfill, Phillip F. G.; Starrs, Gerry; McCarter, W. John

    2008-07-01

    Carbon fibre reinforced cement based materials (CFRCs) offer the possibility of fabricating "smart" electrically conductive materials. Rheology of the fresh mix is crucial to satisfactory moulding and fresh CFRC conforms to the Bingham model with slight structural breakdown. Both yield stress and plastic viscosity increase with increasing fibre length and volume concentration. Using a modified Viskomat NT, the concentration dependence of CFRC rheology up to 1.5% fibre volume is reported.

  13. An Investigation at Low Speed of the Spin Instability of Mortar-Shell Tails

    NASA Technical Reports Server (NTRS)

    Bird, John D.; Lichtenstein, Jacob H.

    1957-01-01

    An investigation was made in the Langley stability tunnel to study the influence of number of fins, fin shrouding, and fin aspect ratio on the spin instability of mortar-shell tail surfaces. It was found that the 12-fin tails tested spun less rapidly throughout the angle-of-yaw range than did the 6-fin tails and that fin shrouding reduced the spin encountered by a large amount.

  14. Practical aspects of the use of phosphate binding materials in refractory mixtures, mortars and putties

    NASA Technical Reports Server (NTRS)

    Soltysik, B.; Pawelek, A.; Witkowska, E.

    1983-01-01

    Phosphate binders, particularly acidic phosphates of Al and Cr, are used for binding Al silicate refractories used for lining of burners, SiC refractories, and refractory mortars. The binders have apparent d. 2.13-2.18 g/cu cm, porosity 21.4-23.8%, compressive strength 223 71 kg/ sq cm, total shrinkage 0.2-0.8%, and refractoriness 1240 deg.

  15. Effects of carbonation on the pore structure of non-hydraulic lime mortars

    SciTech Connect

    Lawrence, Robert M. . E-mail: mike@cc-w.co.uk; Mays, Timothy J.; Rigby, Sean P.; Walker, Peter; D'Ayala, Dina

    2007-07-15

    The pore structures of carbonated non-hydraulic lime mortars made with a range of different aggregates and concentrations of lime have been determined using mercury intrusion porosimetry (MIP). MIP data have been correlated with scanning electron microscopy images and other porosity data. During carbonation there is an increase in pore volume in the {approx} 0.1 {mu}m pore diameter range across all mortar types which is attributed to the transformation of portlandite to calcite. Also there is a monotonic increase in the volumes of pores with diameters below 0.03 {mu}m. A model is proposed for the changes in pore structure caused by carbonation. This attributes the increase in the volume of sub 0.03 {mu}m pores to the attachment of calcite crystals to the surface of aggregate particles, and in some cases to the surface of portlandite crystals. This phenomenon may explain the continuing presence of portlandite in mortars that, apparently, have fully carbonated.

  16. Comparative Effect of Bio-waste Ashes on Strength Properties of Cement Mortar

    NASA Astrophysics Data System (ADS)

    Ajay, Goyal; Hattori, Kunio; Ogata, Hidehiko; Ashraf, Muhammad; Ahmed, Mohamed Anwar

    Biomass fuels produce about 400 million tonnes of ashes as waste material. This paper discusses the pozzolanic character of bio-waste ashes obtained from dry tree leaves (AML), Korai grass (KRI) and Tifton grass (TFT). Ashes were obtained by control incineration of the wastes at 600°C for 5 hours and mortar specimens were prepared by substituting cement with 10, 20 and 30% ash. Strength development of ash-blended mortar specimens was evaluated by conducting destructive tests as well as non-destructive tests till 91 days. X-ray diffraction, scanning electron microscopic and thermo-gravimetric techniques were used to analyze the influence of ash substitution on strength properties of blended-mortar. Pozzolanic reactivity of AML- and KRI-ash was confirmed, but TFT-ash did not show enough reactivity. Overall results confirmed that up to 20% substitution of cement can be made with AML- or KRI-ash with strength approaching 90% of that of control.

  17. Strength and durability performance of alkali-activated rice husk ash geopolymer mortar.

    PubMed

    Kim, Yun Yong; Lee, Byung-Jae; Saraswathy, Velu; Kwon, Seung-Jun

    2014-01-01

    This paper describes the experimental investigation carried out to develop the geopolymer concrete based on alkali-activated rice husk ash (RHA) by sodium hydroxide with sodium silicate. Effect on method of curing and concentration of NaOH on compressive strength as well as the optimum mix proportion of geopolymer mortar was investigated. It is possible to achieve compressive strengths of 31 N/mm(2) and 45 N/mm(2), respectively for the 10 M alkali-activated geopolymer mortar after 7 and 28 days of casting when cured for 24 hours at 60°C. Results indicated that the increase in curing period and concentration of alkali activator increased the compressive strength. Durability studies were carried out in acid and sulfate media such as H2SO4, HCl, Na2SO4, and MgSO4 environments and found that geopolymer concrete showed very less weight loss when compared to steam-cured mortar specimens. In addition, fluorescent optical microscopy and X-ray diffraction (XRD) studies have shown the formation of new peaks and enhanced the polymerization reaction which is responsible for strength development and hence RHA has great potential as a substitute for ordinary Portland cement concrete. PMID:25506063

  18. Assessment and prediction of drying shrinkage cracking in bonded mortar overlays

    SciTech Connect

    Beushausen, Hans Chilwesa, Masuzyo

    2013-11-15

    Restrained drying shrinkage cracking was investigated on composite beams consisting of substrate concrete and bonded mortar overlays, and compared to the performance of the same mortars when subjected to the ring test. Stress development and cracking in the composite specimens were analytically modeled and predicted based on the measurement of relevant time-dependent material properties such as drying shrinkage, elastic modulus, tensile relaxation and tensile strength. Overlay cracking in the composite beams could be very well predicted with the analytical model. The ring test provided a useful qualitative comparison of the cracking performance of the mortars. The duration of curing was found to only have a minor influence on crack development. This was ascribed to the fact that prolonged curing has a beneficial effect on tensile strength at the onset of stress development, but is in the same time not beneficial to the values of tensile relaxation and elastic modulus. -- Highlights: •Parameter study on material characteristics influencing overlay cracking. •Analytical model gives good quantitative indication of overlay cracking. •Ring test presents good qualitative indication of overlay cracking. •Curing duration has little effect on overlay cracking.

  19. Application of nanoindentation testing to study of the interfacial transition zone in steel fiber reinforced mortar

    SciTech Connect

    Wang Xiaohui Jacobsen, Stefan; He Jianying; Zhang Zhiliang; Lee, Siaw Foon; Lein, Hilde Lea

    2009-08-15

    The characteristics of the profiles of elastic modulus and hardness of the steel fiber-matrix and fiber-matrix-aggregate interfacial zones in steel fiber reinforced mortars have been investigated by using nanoindentation and Scanning Electron Microscopy (SEM), where two sets of parameters, i.e. water/binder ratio and content of silica fume were considered. Different interfacial bond conditions in the interfacial transition zones (ITZ) are discussed. For sample without silica fume, efficient interfacial bonds across the steel fiber-matrix and fiber-matrix-aggregate interfaces are shown in low water/binder ratio mortar; while in high water/binder ratio mortar, due to the discontinuous bleeding voids underneath the fiber, the fiber-matrix bond is not very good. On the other hand, for sample with silica fume, the addition of 10% silica fume leads to no distinct presence of weak ITZ in the steel fiber-matrix interface; but the effect of the silica fume on the steel fiber-matrix-aggregate interfacial zone is not obvious due to voids in the vicinity of steel fiber.

  20. Monitoring accelerated carbonation on standard Portland cement mortar by nonlinear resonance acoustic test

    NASA Astrophysics Data System (ADS)

    Eiras, J. N.; Kundu, T.; Popovics, J. S.; Monzó, J.; Borrachero, M. V.; Payá, J.

    2015-03-01

    Carbonation is an important deleterious process for concrete structures. Carbonation begins when carbon dioxide (CO2) present in the atmosphere reacts with portlandite producing calcium carbonate (CaCO3). In severe carbonation conditions, C-S-H gel is decomposed into silica gel (SiO2.nH2O) and CaCO3. As a result, concrete pore water pH decreases (usually below 10) and eventually steel reinforcing bars become unprotected from corrosion agents. Usually, the carbonation of the cementing matrix reduces the porosity, because CaCO3 crystals (calcite and vaterite) occupy more volume than portlandite. In this study, an accelerated carbonation-ageing process is conducted on Portland cement mortar samples with water to cement ratio of 0.5. The evolution of the carbonation process on mortar is monitored at different levels of ageing until the mortar is almost fully carbonated. A nondestructive technique based on nonlinear acoustic resonance is used to monitor the variation of the constitutive properties upon carbonation. At selected levels of ageing, the compressive strength is obtained. From fractured surfaces the depth of carbonation is determined with phenolphthalein solution. An image analysis of the fractured surfaces is used to quantify the depth of carbonation. The results from resonant acoustic tests revealed a progressive increase of stiffness and a decrease of material nonlinearity.

  1. Strength and Durability Performance of Alkali-Activated Rice Husk Ash Geopolymer Mortar

    PubMed Central

    Kim, Yun Yong; Lee, Byung-Jae; Saraswathy, Velu

    2014-01-01

    This paper describes the experimental investigation carried out to develop the geopolymer concrete based on alkali-activated rice husk ash (RHA) by sodium hydroxide with sodium silicate. Effect on method of curing and concentration of NaOH on compressive strength as well as the optimum mix proportion of geopolymer mortar was investigated. It is possible to achieve compressive strengths of 31 N/mm2 and 45 N/mm2, respectively for the 10 M alkali-activated geopolymer mortar after 7 and 28 days of casting when cured for 24 hours at 60°C. Results indicated that the increase in curing period and concentration of alkali activator increased the compressive strength. Durability studies were carried out in acid and sulfate media such as H2SO4, HCl, Na2SO4, and MgSO4 environments and found that geopolymer concrete showed very less weight loss when compared to steam-cured mortar specimens. In addition, fluorescent optical microscopy and X-ray diffraction (XRD) studies have shown the formation of new peaks and enhanced the polymerization reaction which is responsible for strength development and hence RHA has great potential as a substitute for ordinary Portland cement concrete. PMID:25506063

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Na and Li ion diffusion in modified ASTM C 1260 test by Magnetic Resonance Imaging (MRI)

    SciTech Connect

    Feng, X. Balcom, B.J.; Thomas, M.D.A.; Bremner, T.W.

    2008-12-15

    In the current study, MRI was applied to investigate lithium and sodium ion diffusion in cement paste and mortars containing inert sand and borosilicate glass. Paste and mortars were treated by complying with ASTM C 1260. Lithium and sodium distribution profiles were collected at different ages after different treatments. Results revealed that sodium ions had a greater diffusion rate than lithium ions, suggesting that Na reaches the aggregate particle surface before Li. Results also showed that Na and Li ions had a competitive diffusion process in mortars; soaking in a solution with higher [Li] favored Li diffusion but hindered Na diffusion. In mortars containing glass, a substantial amount of Li was consumed by the formation of ASR products. When [Li] in soaking solution was reduced to 0.37 N, a distinctive Na distribution profile was observed, indicating the free-state Na ions were continuously transformed to solid reaction products by ASR. Hence, in the modified ASTM C 1260 test, [Li] in the storage solution should be controlled at 0.74 N, in order to completely prevent the consumption of Na ions and thus stop ASR.

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. Effect of the pre-treatment and the aggregate content on the adhesion strength of repair mortars on Miocene porous limestone

    NASA Astrophysics Data System (ADS)

    Szemerey-Kiss, Balázs; Török, Ákos

    2016-04-01

    The adhesion between porous limestone and newly prepared repair mortars are crucial in the preservation of historic stone structures. Besides mechanical compatibility other matches such as chemical composition and porosity are also essential, but the current research focuses on the adhesion strength of repair mortars that are used in the restoration of Hungarian porous limestone. 8 mortars (4 commercial and 4 specially prepared) were selected for the tests. Mortars with different amount of aggregate were prepared and caste to stone surface. The stone substrate was highly porous Miocene limestone. The strength was tested by standardized pull-out tests which method is commonly used for concrete testing. The limestone surfaces were either used in their natural conditions or were pre-treated (pre-wetting). The strength of the stone/mortar bond was tested. The failure mechanism was documented and various failure modes were identified. Strength test results suggest that especially pre-treatment influences strongly the pull-out strength at mortar/stone interface. Increasing aggregate content also reduces pull out strength of tested repair mortars, but at various rates depending on the mortar type. The financial support of OTKA post-doctoral grant to BSZK (reference number is: PD 112-955) and National Research, Development and Innovation (NKFI) Fund to ÁT (ref. no. K 116532) are appreciated.

  2. 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.

  3. 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.

  4. 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.

  5. 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…

  6. 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.

  7. 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...

  8. 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...

  9. 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...

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Mathematical model relating uniaxial compressive behavior of manufactured sand mortar to MIP-derived pore structure parameters.

    PubMed

    Tian, Zhenghong; Bu, Jingwu

    2014-01-01

    The uniaxial compression response of manufactured sand mortars proportioned using different water-cement ratio and sand-cement ratio is examined. Pore structure parameters such as porosity, threshold diameter, mean diameter, and total amounts of macropores, as well as shape and size of micropores are quantified by using mercury intrusion porosimetry (MIP) technique. Test results indicate that strains at peak stress and compressive strength decreased with the increasing sand-cement ratio due to insufficient binders to wrap up entire sand. A compression stress-strain model of normal concrete extending to predict the stress-strain relationships of manufactured sand mortar is verified and agreed well with experimental data. Furthermore, the stress-strain model constant is found to be influenced by threshold diameter, mean diameter, shape, and size of micropores. A mathematical model relating stress-strain model constants to the relevant pore structure parameters of manufactured sand mortar is developed. PMID:25133257

  20. The Properties of Mortar Mixtures Blended with Natural, Crushed, and Recycled Fine Aggregates for Building Construction Materials

    SciTech Connect

    Yu, Myoung-Youl; Lee, Jae-Yong; Chung, Chul-Woo

    2012-01-12

    In this research, the possible applicability of fine aggregates blended with natural, crushed, and recycled fine aggregate are discussed. The fresh and hardened properties of mortar using blended fine aggregates are monitored depending on various blending ratio of fine aggregates. Newly developed ternary diagram was also utilized for better interpretation of the data. It was found that air content increased and unit weight decreased as recycled fine aggregate content increased. With moisture type processing of recycled fine aggregate, the mortar flow was not negatively affected by increase in the recycled fine aggregate content. The ternary diagram is found to be an effective graphical presentation tool that can be used for the quality evaluation of mortar using blended fine aggregate.

  1. Incorporation of titanium dioxide nanoparticles in mortars - Influence of microstructure in the hardened state properties and photocatalytic activity

    SciTech Connect

    Lucas, S.S.

    2013-01-15

    The environmental pollution in urban areas is one of the causes for poor indoor air quality in buildings, particularly in suburban areas. The development of photocatalytic construction materials can contribute to clean the air and improve sustainability levels. Previous studies have focused mainly in cement and concrete materials, disregarding the potential application in historic buildings. In this work, a photocatalytic additive (titanium dioxide) was added to mortars prepared with aerial lime, cement and gypsum binders. The main goal was to study the way that microstructural changes affect the photocatalytic efficiency. The photocatalytic activity was determined using a reactor developed to assess the degradation rate with a common urban pollutant, NO{sub x}. The laboratory results show that all the compositions tested exhibited high photocatalytic efficiency. It was demonstrated that photocatalytic mortars can be applied in new and old buildings, because the nanoadditives do not compromise the mortar hardened state properties.

  2. Mathematical Model Relating Uniaxial Compressive Behavior of Manufactured Sand Mortar to MIP-Derived Pore Structure Parameters

    PubMed Central

    Tian, Zhenghong; Bu, Jingwu

    2014-01-01

    The uniaxial compression response of manufactured sand mortars proportioned using different water-cement ratio and sand-cement ratio is examined. Pore structure parameters such as porosity, threshold diameter, mean diameter, and total amounts of macropores, as well as shape and size of micropores are quantified by using mercury intrusion porosimetry (MIP) technique. Test results indicate that strains at peak stress and compressive strength decreased with the increasing sand-cement ratio due to insufficient binders to wrap up entire sand. A compression stress-strain model of normal concrete extending to predict the stress-strain relationships of manufactured sand mortar is verified and agreed well with experimental data. Furthermore, the stress-strain model constant is found to be influenced by threshold diameter, mean diameter, shape, and size of micropores. A mathematical model relating stress-strain model constants to the relevant pore structure parameters of manufactured sand mortar is developed. PMID:25133257

  3. Characterization and modeling of major constituent equilibrium chemistry of a blended cement mortar

    NASA Astrophysics Data System (ADS)

    Arnold, J.; Kosson, D. S.; Brown, K. G.; Garrabrants, A. C.; Meeussen, J. C. L.; van der Sloot, H. A.

    2013-07-01

    Cementitious materials containing ground granulated iron blast furnace slag and coal combustion fly ash as admixtures are being used extensively for nuclear waste containment applications. Whereas the solid phases of ordinary Portland cement (OPC) have been studied in great detail, the chemistry of cement, fly ash and slag blends has received relatively less study. Given that OPC is generally more reactive than slag and fly ash, the mineralogy of OPC provides a logical starting point for describing the major constituent chemistry of blended cement mortars. To this end, a blended cement mortar containing Portland cement, granulated blast furnace slag, fly ash and quartz sand was modeled using a set of solid phases known to form in hydrated OPC with the geochemical speciation solver LeachXS/ORCHESTRA. Comparison of modeling results to the experimentally determined pH-dependent batch leaching concentrations (USEPA Method 1313) indicates that major constituent concentrations are described reasonably well with the Portland cement mineral set; however, modeled and measured aluminum concentrations differ greatly. Scanning electron microscopic analysis of the mortar reveals the presence of Al-rich phyllosilicate minerals heretofore unreported in similar cementitious blends: kaolinite and potassic phyllosilicates similar in composition to illite and muscovite. Whereas the potassic phyllosilicates are present in the quartz sand aggregate, the formation of kaolinite appears to be authigenic. The inclusion of kaolinite in speciation modeling provides a substantially improved description of the release of Al and therefore, suggests that the behavior of phyllosilicate phases may be important for predicting long-term physico-chemical behavior of such systems.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Effect of shrinkage and moisture content on the physical characteristics of blended cement mortars

    SciTech Connect

    Kanna, V.; Olson, R.A.; Jennings, H.M.

    1998-10-01

    The effects of drying on mortars containing Portland cement blended with fly ash or slag on the shrinkage, extent of surface cracking, pore size distribution as measured by mercury intrusion porosimetry, flexural strength, fracture toughness, and Young`s modulus are reported. Specimens were exposed to conditions of 100% relative humidity (RH), 50% RH, and/or oven-drying at 105 C. Drying coarsened the pore structure and increased the density of surface cracks, but surprisingly increased the flexural strength and the fracture toughness, and as anticipated lowered the Young`s modulus. This was regardless of the content of mineral admixture.

  13. Mechanical properties, pore size distribution, and pore solution of fly ash-belite cement mortars

    SciTech Connect

    Guerrero, A.; Goni, S.; Macias, A.; Luxan, M.P.

    1999-11-01

    The mechanical properties, pore size distribution, and extracted pore solution of fly ash-belite cement (FABC) mortars were studied for a period of 200 days. The influence of the calcination temperature, which ranged from 700 to 900 C, of the fly ash-belite cement was discussed. The evolution with hydration time of the pore size distribution was followed by mercury intrusion porosimetry, and the results correlated with those of flexural and compressive strength. The pore solution was expressed and analyzed at different times of hydration.

  14. Analysis of total least squares in estimating the parameters of a mortar trajectory

    SciTech Connect

    Lau, D.L.; Ng, L.C.

    1994-12-01

    Least Squares (LS) is a method of curve fitting used with the assumption that error exists in the observation vector. The method of Total Least Squares (TLS) is more useful in cases where there is error in the data matrix as well as the observation vector. This paper describes work done in comparing the LS and TLS results for parameter estimation of a mortar trajectory based on a time series of angular observations. To improve the results, we investigated several derivations of the LS and TLS methods, and early findings show TLS provided slightly, 10%, improved results over the LS method.

  15. Field evaluation of an engineering control for respirable crystalline silica exposures during mortar removal.

    PubMed

    Collingwood, Scott; Heitbrink, William A

    2007-11-01

    During mortar removal with a right angle grinder, a building renovation process known as "tuck pointing," worker exposures to respirable crystalline silica can be as high as 5 mg/m(3), 100 times the recommended exposure limit developed by the National Institute for Occupational Safety and Health. To reduce the risk of silicosis among these workers, a vacuum cleaner can be used to exhaust 80 ft(3)/min (2.26 m(3)/min) from a hood mounted on the grinder. Field trials examined the ability of vacuum cleaners to maintain adequate exhaust ventilation rates and measure exposure outcomes when using this engineering control. These field trials involved task-based exposure measurement of respirable dust and crystalline silica exposures during mortar removal. These measurements were compared with published exposure data. Vacuum cleaner airflows were obtained by measuring and digitally logging vacuum cleaner static pressure at the inlet to the vacuum cleaner motor. Static pressures were converted to airflows based on experimentally determined fan curves. In two cases, video exposure monitoring was conducted to study the relationship between worker activities and dust exposure. Worker activities were video taped concurrent with aerosol photometer measurement of dust exposure and vacuum cleaner static pressure as a measure of airflow. During these field trials, respirable crystalline silica exposures for 22 samples had a geometric mean of 0.06 mg/m(3) and a range of less than 0.01 to 0.86 mg/m(3). For three other studies, respirable crystalline silica exposures during mortar removal have a geometric means of 1.1 to 0.35. Although this field study documented noticeably less exposure to crystalline silica, video exposure monitoring found that the local exhaust ventilation provided incomplete dust control due to low exhaust flow rates, certain work practices, and missing mortar. Vacuum cleaner airflow decrease had a range of 3 to 0.4 ft(3)/min (0.08 to 0.01 m(3)/sec(2)) over a range

  16. Electronic microscopy and EDX characterization of Teotihuacan prehispanic mortar from the cave under the Sun Pyramid.

    PubMed

    Martinez, T; Martinez, G; Mendoza, D; Juarez, F; Cabrera, L

    2005-01-01

    A cave (102 m long) under the structure of the Sun pyramid of the prehispanic Teotihuacan City indicates the importance of the pyramid. Studies of the cave mortar samples using energy dispersive X-ray (EDX) fluorescence, scanning electron microscopy (SEM) and X-ray diffraction (XRD) showed no difference in the chemical elemental composition. The elements can be distributed in three groups: major, minor and trace elements. The minerals identified were compatible with the origins of the cave and with the magnetic pattern. PMID:15996472

  17. Innovative method and apparatus for the deep cleaning of soluble salts from mortars and lithic materials

    NASA Astrophysics Data System (ADS)

    Gaggero, Laura; Ferretti, Maurizio; Torrielli, Giulia; Caratto, Valentina

    2016-04-01

    Porous materials (e.g. plasters, mortars, concrete, and the like) used in the building industry or in artworks fail to develop, after their genesis, salts such as nitrates, carbonates (e.g. potassium carbonate, magnesium carbonate, calcium carbonate), chlorides (e.g. sodium chloride) and/or others, which are a concurrent cause of material deterioration phenomena. In the case of ancient or cultural heritage buildings, severe damage to structures and works of art, such as fresco paintings are possible. In general, in situ alteration pattern in mortars and frescoes by crystallization of soluble salts from solutions is caused by capillar rise or circulation in damp walls. Older buildings can be more subject to capillary rise of ion-rich waters, which, as water evaporates, create salt crystals inside the walls. If this pattern reveals overwhelming upon other environmental decay factors, the extraction of salts is the first restoration to recover the artpiece after the preliminary assessment and mitigation of the causes of soaking. A new method and apparatus, patented by University of Genoa [1] improves the quality and durability of decontamination by soluble salts, compared with conventional application of sepiolite or cellulose wraps. The conventional application of cellulose or sepiolite requires casting a more or less thick layer of wrap on the mortar, soaking with distilled water, and waiting until dry. The soluble salts result trapped within the wrap. A set of artificial samples reproducing the stratigraphy of frescoes was contaminated with saline solution of known concentration. The higher quality of the extraction was demonstrated by trapping the salts within layers of Japanese paper juxtaposed to the mortar; the extraction with the dedicated apparatus was operated in a significantly shorter time than with wraps (some hours vs. several days). Two cycles of about 15 minutes are effective in the deep cleaning from contaminant salts. The decontamination was

  18. [Based on Curing Age of Calcined Coal Gangue Fine Aggregate Mortar of X-Ray Diffraction and Scanning Electron Microscopy Analysis].

    PubMed

    Dong, Zuo-chao; Xia, Jun-wu; Duan, Xiao-mu; Cao, Ji-chang

    2016-03-01

    By using X-ray diffraction (XRD) and environmental scanning electron microscope (SEM) analysis method, we stud- ied the activity of coal gangue fine aggregate under different calcination temperature. In view of the activity of the highest-700 degrees C high temperature calcined coal gangue fine aggregate mortar of hydration products, microstructure and strength were discussed in this paper, and the change laws of mortar strength with curing age (3, 7, 14, 28, 60 and 90 d) growth were analyzed. Test results showed that coal gangue fine aggregate with the increase of calcination temperature, the active gradually increases. When the calcination temperature reaches 700 degrees C, the activity of coal gangue fine aggregate is the highest. When calcining temperature continues to rise, activity falls. After 700 degrees C high temperature calcined coal gangue fine aggregate has obvious ash activity, the active components of SiO2 and Al2 O3 can be with cement hydration products in a certain degree of secondary hydration reaction. Through on the top of the activity of different curing age 700 degrees C high temperature calcined coal gangue fine aggregate mortar, XRD and SEM analysis showed that with the increase of curing age, secondary hydration reaction will be more fully, and the amount of hydration products also gradually increases. Compared with the early ages of the cement mortar, the products are more stable hydration products filling in mortar microscopic pore, which can further improve the microstructure of mortar, strengthen the interface performance of the mortar. The mortar internal structure is more uniform, calcined coal gangue fine aggregate and cement mortar are more of a strong continuous whole, which increase the later strength of hardened cement mortar, 700 degrees C high temperature calcined coal gangue fine aggregate pozzolanic effect is obvious. PMID:27400535

  19. Tile Drainage Management Influences on Surface-Water and Groundwater Quality following Liquid Manure Application.

    PubMed

    Frey, Steven K; Topp, Ed; Ball, Bonnie R; Edwards, Mark; Gottschall, Natalie; Sunohara, Mark; Zoski, Erin; Lapen, David R

    2013-01-01

    This study investigated the potential for controlled tile drainage (CD) to reduce bacteria and nutrient loading to surface water and groundwater from fall-season liquid manure application (LMA) on four macroporous clay loam plots, of which two had CD and two had free-draining (FD) tiles. Rhodamine WT (RWT) was mixed into the manure and monitored in the tile water and groundwater following LMA. Tile water and groundwater quality were influenced by drainage management. Following LMA on the FD plots, RWT, nutrients, and bacteria moved rapidly via tiles to surface water; at the CD plots, tiles did not flow until the first post-LMA rainfall, so the immediate risk of LMA-induced contamination of surface water was abated. During the 36-d monitoring period, flow-weighted average specific conductance, redox potential, and turbidity, as well as total Kjeldahl N (TKN), total P (TP), NH-N, reactive P, and RWT concentrations, were higher in the CD tile effluent; however, because of lower tile discharge from the CD plots, there was no significant ( ≤ 0.05) difference in surface water nutrient and RWT loading between the CD and FD plots when all tiles were flowing. The TKN, TP, and RWT concentrations in groundwater also tended to be higher at the CD plots. Bacteria behaved differently than nutrients and RWT, with no significant difference in total coliform, , fecal coliform, fecal streptococcus, and concentrations between the CD and FD tile effluent; however, for all but , hourly loading was higher from the FD plots. Results indicate that CD has potential for mitigating bacteria movement to surface water. PMID:23673956

  20. Thermodynamics and Kinetics of DNA Tile-Based Self-Assembly

    NASA Astrophysics Data System (ADS)

    Jiang, Shuoxing

    Deoxyribonucleic acid (DNA) has emerged as an attractive building material for creating complex architectures at the nanometer scale that simultaneously affords versatility and modularity. Particularly, the programmability of DNA enables the assembly of basic building units into increasingly complex, arbitrary shapes or patterns. With the expanding complexity and functionality of DNA toolboxes, a quantitative understanding of DNA self-assembly in terms of thermodynamics and kinetics, will provide researchers with more subtle design guidelines that facilitate more precise spatial and temporal control. This dissertation focuses on studying the physicochemical properties of DNA tile-based self-assembly process by recapitulating representative scenarios and intermediate states with unique assembly pathways. First, DNA double-helical tiles with increasing flexibility were designed to investigate the dimerization kinetics. The higher dimerization rates of more rigid tiles result from the opposing effects of higher activation energies and higher pre-exponential factors from the Arrhenius equation, where the pre-exponential factor dominates. Next, the thermodynamics and kinetics of single tile attachment to preformed "multitile" arrays were investigated to test the fundamental assumptions of tile assembly models. The results offer experimental evidences that double crossover tile attachment is determined by the electrostatic environment and the steric hindrance at the binding site. Finally, the assembly of double crossover tiles within a rhombic DNA origami frame was employed as the model system to investigate the competition between unseeded, facet and seeded nucleation. The results revealed that preference of nucleation types can be tuned by controlling the rate-limiting nucleation step. The works presented in this dissertation will be helpful for refining the DNA tile assembly model for future designs and simulations. Moreover, The works presented here could also be

  1. Classification of Voronoi and Delone tiles in quasicrystals: I. General method

    NASA Astrophysics Data System (ADS)

    Masáková, Z.; Patera, J.; Zich, J.

    2003-02-01

    A new general method is presented which allows one to find all distinct Voronoi and Delone tiles in any quasicrystal from a large family. This includes the tiles which may be present with arbitrarily low density >0. At all stages, the method requires only consideration of a (possibly large) finite number of cases. Our method is applicable, in principle, to quasicrystals in any dimension and with any irrationality. This is the first of three papers where the Voronoi and Delone tilings are studied. Two-dimensional point sets, 'quasicrystals', arising from the A4-root lattice by means of the standard projection to a two-dimensional plane with the irrationality tau = 1/2(1 + surd5), are considered. In general, we require that the acceptance window be bounded with non-empty interior. Specific results are provided here for rhombic acceptance windows of any size oriented along the direction of simple roots of the Coxeter group H2. Within one quasicrystal the tiles are distinguished by their shape, size and orientation. The rhombic window case is indispensable for subsequent classification of Voronoi and Delone tiles in quasicrystals with general shape of the acceptance window. Voronoi and Delone tiles of quasicrystals with circular and decagonal windows of any size are given in subsequent papers. Let VT denote the set of distinct Voronoi tiles making up a quasicrystal with a given acceptance window. There are three VT sets of the 'generic' type and three of the 'singular' type. The latter occur for one precise value of the size of the acceptance window. Any other VT set is a uniform scaling of the tiles listed here. Similar results, differing in detail, are provided for the sets of distinct Delone tiles DT. Altogether there are four different sets DT of Delone tiles.

  2. Nitrate and Pesticide Transport From Tile-Drained Fields in the Willamette Valley, Oregon

    NASA Astrophysics Data System (ADS)

    Warren, K. L.; Rupp, D. E.; Selker, J. S.; Dragila, M. I.; Peachey, R. E.

    2002-12-01

    Tile drainage affects the hydrology and thus the solute transport on agricultural fields by increasing the volume of water that drains from the subsurface. Previous NAWQA studies have shown elevated nitrate levels in wells and high detection frequencies for selected pesticides in Willamette Valley streams. As a substantial area of Willamette Valley agricultural land is tile-drained, it is important to determine the role of tile drains in surface water and ground water pollution. Four fields in the Willamette Valley were instrumented to monitor tile effluent for two winter seasons. On two fields, surface runoff was also monitored for the second season. Field areas ranged from 3 to 30 acres and were cropped in grass, corn, or a grass/corn rotation. Tile effluent nitrate concentrations frequently exceeded 10 ppm on some fields. Flow-weighted averages for each field were 0.87 ppm and 1.36 ppm for two established grass fields, and 8.1 ppm and 14.4 ppm for grass fields that had recently grown corn. Mass losses ranged from 1.15%-6.45% of the applied nitrate through the tile drains. Diuron, Metolachlor, and Chlorpyrifos were tested in selected surface runoff and tile effluent samples. On one field, Metolachlor concentrations were similar in the tile drains and surface runoff. Concentrations in both sources were 10 times lower than the drinking water advisory for Metolachlor. In a second field, Chlorpyrifos concentrations were two orders of magnitude lower than drinking water advisories in both sources. On the same field, Diuron concentrations were significantly higher in the surface runoff than in the tile effluent. Diuron concentrations were 1-2 orders of magnitude higher during the first precipitation events after application in the surface runoff. On a third field, Diuron was at least 10 times lower than drinking water advisories in the tile effluent, with the highest concentrations found in samples collected within 21 days of pesticide application.

  3. Using stable isotope tracers to assess flow pathways for P transport in tile-drained landscapes

    NASA Astrophysics Data System (ADS)

    Williams, M. R.; King, K.; Ford, W. I., III; Buda, A. R.; Kennedy, C. D.

    2015-12-01

    Throughout the Midwestern US and other poorly drained agricultural regions, phosphorus (P) transport in tile drainage is of increasing environmental concern. Significant P loads are often measured in subsurface drainage water despite the normally high P adsorption capacity of subsoils, which suggest that the high P loadings observed in tile drainage water during storm events are the result of P bypassing the soil matrix via macropore flow. The objectives of this study were to quantify event water delivery to tile drains via macropore flow paths during storm events and to determine the effect of tillage practices on event water and P delivery to tiles. Tile discharge, total dissolved P (DP) and total P (TP) concentrations, and stable oxygen and deuterium isotopic signatures were measured from two adjacent tile-drained fields in Ohio, USA during seven spring storms. Fertilizer was surface-applied to both fields and disk tillage was used to incorporate the fertilizer on one field while the other remained in no-till. Results showed that event water accounted for between 26 and 69% of total tile discharge from both fields, with tillage substantially reducing the maximum contributions of event water. Following fertilizer application, median DP concentration was significantly greater in the no-tilled fields (1.19 mg/L) compared to the tilled field (0.66 mg/L). Concentrations remained significantly greater in the no-tilled field compared to the tilled field for the five monitored storms (>1 month) after fertilizer application. Both DP and TP concentrations in the no-tilled fields were significantly related to event water contributions to tile discharge, while only TP concentration was significantly related to event water in the tilled field. Collectively, results suggest that macropore flow is an important flow pathway in tile-drained landscapes and that incorporating surface-applied fertilizers has the potential to substantially reduce the risk of P loss from tile

  4. "Bricks and mortar" self-assembly approach to graphitic mesoporous carbon nanocomposites

    SciTech Connect

    Fulvio, P. F.; Mayes, R.; Wang, X. Q.; Mahurin, S., M.; Bauer, J. C.; Presser, V.; McDonough, J.; Gogotsi, Y.; Dai, S.

    2011-04-20

    Mesoporous carbon materials do not have sufficient ordering at the atomic scale to exhibit good electronic conductivity. To date, mesoporous carbons having uniform mesopores and high surface areas have been prepared from partially-graphitizable precursors in the presence of templates. High temperature thermal treatments above 2000 °C, which are usually required to increase conductivity, result in a partial or total collapse of the mesoporous structures and reduced surface areas induced by growth of graphitic domains, limiting their applications in electric double layer capacitors and lithium-ion batteries. In this work, we successfully implemented a “brick-and-mortar” approach to obtain ordered graphitic mesoporous carbon nanocomposites with tunable mesopore sizes below 850 °C without using graphitization catalysts or high temperature thermal treatments. Phenolic resin-based mesoporous carbons act as mortar to highly conductive carbon blacks and carbon onions (bricks). The capacitance and resistivity of final materials can be tailored by changing the mortar to brick ratios.

  5. Comparative experimental study of dynamic compressive strength of mortar with glass and basalt fibres

    NASA Astrophysics Data System (ADS)

    Kruszka, Leopold; Moćko, Wojciech; Fenu, Luigi; Cadoni, Ezio

    2015-09-01

    Specimen reinforced with glass and basalt fibers were prepared using Standard Portland cement (CEM I, 52.5 R as prescribed by EN 197-1) and standard sand, in accordance with EN 196-1. From this cementitious mixture, a reference cement mortar without fibers was first prepared. Compressive strength, modulus of elasticity, and mod of fracture were determined for all specimens. Static and dynamic properties were investigated using Instron testing machine and split Hopkinson pressure bar, respectively. Content of the glass fibers in the mortar does not influence the fracture stress at static loading conditions in a clearly observed way. Moreover at dynamic range 5% content of the fiber results in a significant drop of fracture stress. Analysis of the basalt fibers influence on the fracture stress shows that optimal content of this reinforcement is equal to 3% for both static and dynamic loading conditions. Further increase of the fiber share gives the opposite effect, i.e. drop of the fracture stress.

  6. Dimensional stability under wet curing of mortars containing high amounts of nitrates and phosphates

    SciTech Connect

    Benard, P.

    2008-10-15

    Investigations were carried out in order to solidify in cement some aqueous streams resulting from nuclear decommissioning processes and characterized by a high salinity (300 g/L), as well as important concentrations of nitrate (150-210 g/L) and phosphate ions (0-50 g/L). Special attention was paid to the influence of these compounds on the dimensional variations under wet curing of simulated solidified waste forms. The length changes of mortars containing nitrate salts only (KNO{sub 3}, NaNO{sub 3}) were shown to be governed by a concentration effect which involved osmosis: the higher their concentration in the mixing solution, the higher the swelling. The expansion of mortars containing high amounts of phosphates ({>=} 30 g/L in the mixing solution) was preceded by a shrinkage which increased with the phosphate concentration, and which could be suppressed by seeding the cement used with hydroxyapatite crystals. This transitory shrinkage was attributed to the conversion into hydroxyapatite of a precursor readily precipitated in the cement paste after mixing.

  7. Monitoring the self-healing process of biomimetic mortar using coda wave interferometry method

    NASA Astrophysics Data System (ADS)

    Liu, Shukui; Basaran, Zeynep; Zhu, Jinying; Ferron, Raissa

    2014-02-01

    Internal stresses might induce microscopic cracks in concrete, which can provide pathways for ingress of harmful chemicals and can lead to loss of strength. Recent research in concrete materials suggests that it might be possible to develop a smart cement-based material that is capable of self-healing by leveraging the metabolic activity of microorganisms to provide biomineralization. Limited research on biomineralization in cement-based systems has shown promising results that healing of cracks can occur on the surface of concrete and reduce permeability. This paper presents the results from an investigation regarding the potential for a cement-based material to repair itself internally through biomineralization. Compressive strength test and coda wave interferometry (CWI) analyses were conducted on mortar samples that were loaded to 70% of their compressive strength and cured in different conditions. Experimental results indicate that the damaged mortar samples with microorganisms showed significantly higher strength development and higher increase of ultrasonic wave velocity compared to samples without microorganisms at 7 and 28 days.

  8. A New Test Method for Determining the Strength and Fracture Toughness of Cement Mortar and Concrete

    SciTech Connect

    Wang, Jy-An John; Liu, Ken C; Naus, Dan J

    2010-01-01

    The Spiral Notch Torsion Fracture Toughness Test (SNTT) was developed recently to determine the intrinsic fracture toughness (KIC) of structural materials. The SNTT system operates by applying pure torsion to uniform cylindrical specimens with a notch line that spirals around the specimen at a 45 a pitch. KIC values are obtained with the aid of a three-dimensional finite-element computer code, TOR3D-KIC. The SNTT method is uniquely suitable for testing a wide variety of materials used extensively in pressure vessel and piping structural components and weldments. Application of the method to metallic, ceramic, and graphite materials has been demonstrated. One important characteristic of SNTT is that neither a fatigue precrack or a deep notch are required for the evaluation of brittle materials, which significantly reduces the sample size requirement. In this paper we report results for a Portland cement-based mortar to demonstrate applicability of the SNTT method to cementitious materials. The estimated KIC of the tested mortar samples with compressive strength of 34.45 MPa was found to be 0.19 MPa m^(1/2).

  9. Nondestructive evaluation of notched cracks in mortars by nonlinear ultrasonic technique

    NASA Astrophysics Data System (ADS)

    Chen, Jun; Ren, Jun; Yin, Tingyuan

    2016-04-01

    In this paper, a nonlinear ultrasonic technique is used to nondestructively characterise concentrated defects in cement-based materials. Cracks are artificially notched in mortar samples and five different crack widths are used to simulate increased damage of samples. The relative ratio of second harmonic amplitude to the square of fundamental ultrasonic signal amplitude is defined as the damage indicator of the nonlinear ultrasonic technique, which is measured for mortar samples in conjunction with a typical linear nondestructive evaluation parameter - ultrasonic pulse velocity. It is found that both linear and nonlinear damage parameters have a good correlation with the change of crack width, while the nonlinearity parameter shows a better sensitivity to the width increase. In addition, the nonlinearity parameter presents an exponential increase with the crack growth, indicating an accelerating nonlinear ultrasonic response of materials to increased internal damage in the late phase. The results demonstrate that the nonlinear ultrasonic technique based on the second harmonic principle keeps the high sensitivity to the isolated cracks in cement-based materials, similarly to the case of distributed cracks in previous studies. The developed technique could thus be a useful experimental tool for the assessment of concentrated damage of concrete structures.

  10. A novel method for a multi-level hierarchical composite with brick-and-mortar structure

    NASA Astrophysics Data System (ADS)

    Brandt, Kristina; Wolff, Michael F. H.; Salikov, Vitalij; Heinrich, Stefan; Schneider, Gerold A.

    2013-07-01

    The fascination for hierarchically structured hard tissues such as enamel or nacre arises from their unique structure-properties-relationship. During the last decades this numerously motivated the synthesis of composites, mimicking the brick-and-mortar structure of nacre. However, there is still a lack in synthetic engineering materials displaying a true hierarchical structure. Here, we present a novel multi-step processing route for anisotropic 2-level hierarchical composites by combining different coating techniques on different length scales. It comprises polymer-encapsulated ceramic particles as building blocks for the first level, followed by spouted bed spray granulation for a second level, and finally directional hot pressing to anisotropically consolidate the composite. The microstructure achieved reveals a brick-and-mortar hierarchical structure with distinct, however not yet optimized mechanical properties on each level. It opens up a completely new processing route for the synthesis of multi-level hierarchically structured composites, giving prospects to multi-functional structure-properties relationships.

  11. A novel method for a multi-level hierarchical composite with brick-and-mortar structure.

    PubMed

    Brandt, Kristina; Wolff, Michael F H; Salikov, Vitalij; Heinrich, Stefan; Schneider, Gerold A

    2013-01-01

    The fascination for hierarchically structured hard tissues such as enamel or nacre arises from their unique structure-properties-relationship. During the last decades this numerously motivated the synthesis of composites, mimicking the brick-and-mortar structure of nacre. However, there is still a lack in synthetic engineering materials displaying a true hierarchical structure. Here, we present a novel multi-step processing route for anisotropic 2-level hierarchical composites by combining different coating techniques on different length scales. It comprises polymer-encapsulated ceramic particles as building blocks for the first level, followed by spouted bed spray granulation for a second level, and finally directional hot pressing to anisotropically consolidate the composite. The microstructure achieved reveals a brick-and-mortar hierarchical structure with distinct, however not yet optimized mechanical properties on each level. It opens up a completely new processing route for the synthesis of multi-level hierarchically structured composites, giving prospects to multi-functional structure-properties relationships. PMID:23900554

  12. On the relevance of volume increase for the length changes of mortar bars in sulfate solutions

    SciTech Connect

    Kunther, Wolfgang; Lothenbach, Barbara; Scrivener, Karen L.

    2013-04-01

    The ingress of sulfate ions into cementitious materials leads to the formation of ettringite, gypsum and other phases. The increase in solid volume through the formation of these phases is often assumed to be the only reason for expansion. In this paper we systematically compare the volume increase predicted by thermodynamic modeling to macroscopic expansion for mortars made with CEM I in different sulfate solutions and for mortars made with a range of blended cements in sodium sulfate solution. It is shown that the length changes cannot be explained by simple volume increase alone. A more plausible explanation of expansion lies in the theory of crystallization pressure, in which crystals forming from a supersaturated solution may exert pressure on their surroundings. It is observed that expansion occurs in systems where thermodynamic modeling predicts the co-existence of ettringite with gypsum. In such a case, if monosulfate and gypsum are both present locally, the solution can be highly supersaturated with respect to ettringite, whose formation in confined conditions (such as within C–S–H) can then exert expansive forces.

  13. Study on cement mortar and concrete made with sewage sludge ash.

    PubMed

    Chang, F C; Lin, J D; Tsai, C C; Wang, K S

    2010-01-01

    This study investigated the feasibility of reusing wastewater sludge ash in construction materials to replace partial materials. Wastewater sludge sampled from thermal power plant was burned into sludge ash at 800°C in the laboratory. The sludge incineration ash has low heavy metal including Pb, Cd, Cr and Cu, so it belongs to general enterprise waste. The chemical composition of sludge incineration ash was summed up in SiO₂, CaO, Fe₂O₃ and MgO. Then the wastewater sludge ash is also found to be a porous material with irregular surface. When the sludge ash was used to replace mortar or concrete cement, its water-adsorption capability will result in the reduction of mortar workability and compressive strength. Cement is being substituted for sludge ash, and 10 percent of sludge ash is more appropriate. Sludge ash is reused to take the place of construction materials and satisfies the requests of standard specification except for higher water absorption. PMID:20935389

  14. [Dynamic leaching behavior of heavy metals in eco-cement mortar block].

    PubMed

    Li, Cheng; Liu, Jian-Guo; Zhang, Jun-Li; Yue, Dong-Bei; Nie, Yong-Feng; Wang, Chang-Hai

    2008-03-01

    A dynamic leaching test with the renewal of acidic leaching medium was designed to study the leaching behavior of the seven heavy metals (As, Cd, Cr, Cu, Ni, Pb, Zn) in three solidified eco-cement mortar samples with different particle size (fine granule, coarse granule, block) under a long-term leaching condition. It was demonstrated that all the heavy metals were detected in the leachate except Cd. The leaching ratio of Cr was the highest when compared with other metals in the same sample, and the leaching ratio of every metal showed an identical tendency: fine granule> coarse granule > block. The on-going leaching part of the relationship curve of accumulative leaching point (Pt) and t1/2 of each metal presented a fairly good linearity, which indicated that the leaching process was under the control of diffusion mechanism by the Fick Law. To each metal, the effective diffusion coefficient (Deff) showed a tendency of fine granule < coarse granule < block, which was opposite to the tendency of leaching ratio. It could be concluded that the solidified eco-cement mortar with a bigger size would have a lower leaching ratio and a shorter period to finish the leaching test. To all the metals, the Deff was very low, with the magnitude around 10(-10) cm2/s, which meant the leaching process would take a relatively long time. PMID:18649553

  15. Transparent, Ultrahigh-Gas-Barrier Films with a Brick-Mortar-Sand Structure.

    PubMed

    Dou, Yibo; Pan, Ting; Xu, Simin; Yan, Hong; Han, Jingbin; Wei, Min; Evans, David G; Duan, Xue

    2015-08-10

    Transparent and flexible gas-barrier materials have shown broad applications in electronics, food, and pharmaceutical preservation. Herein, we report ultrahigh-gas-barrier films with a brick-mortar-sand structure fabricated by layer-by-layer (LBL) assembly of XAl-layered double hydroxide (LDH, X=Mg, Ni, Zn, Co) nanoplatelets and polyacrylic acid (PAA) followed by CO2 infilling, denoted as (XAl-LDH/PAA)n-CO2. The near-perfectly parallel orientation of the LDH "brick" creates a long diffusion length to hinder the transmission of gas molecules in the PAA "mortar". Most significantly, both the experimental studies and theoretical simulations reveal that the chemically adsorbed CO2 acts like "sand" to fill the free volume at the organic-inorganic interface, which further depresses the diffusion of permeating gas. The strategy presented here provides a new insight into the perception of barrier mechanism, and the (XAl-LDH/PAA)n-CO2 film is among the best gas barrier films ever reported. PMID:26110398

  16. A novel method for a multi-level hierarchical composite with brick-and-mortar structure

    PubMed Central

    Brandt, Kristina; Wolff, Michael F. H.; Salikov, Vitalij; Heinrich, Stefan; Schneider, Gerold A.

    2013-01-01

    The fascination for hierarchically structured hard tissues such as enamel or nacre arises from their unique structure-properties-relationship. During the last decades this numerously motivated the synthesis of composites, mimicking the brick-and-mortar structure of nacre. However, there is still a lack in synthetic engineering materials displaying a true hierarchical structure. Here, we present a novel multi-step processing route for anisotropic 2-level hierarchical composites by combining different coating techniques on different length scales. It comprises polymer-encapsulated ceramic particles as building blocks for the first level, followed by spouted bed spray granulation for a second level, and finally directional hot pressing to anisotropically consolidate the composite. The microstructure achieved reveals a brick-and-mortar hierarchical structure with distinct, however not yet optimized mechanical properties on each level. It opens up a completely new processing route for the synthesis of multi-level hierarchically structured composites, giving prospects to multi-functional structure-properties relationships. PMID:23900554

  17. Automation Of Shuttle Tile Inspection: Engineering Methodology For Space Station

    NASA Astrophysics Data System (ADS)

    Wiskerchen, M. J.; Mollakarimi, C.

    1987-10-01

    The Space Systems Integration and Operations Research Applications (SIORA) Program was initiated in late 1986 as a cooperative applications research effort between Stanford University, NASA Kennedy Space Center (KSC), and Lockheed Space Operations Company (LSOC). One of the major initial SIORA tasks was the application of automation and robotics technology to all aspects of the Shuttle tile processing and inspection system. This effort has adobted a systems engineering approach consisting of an integrated set of rapid prototyping testbeds in which a government/university/industry team of users, technologists, and engineers test and evaluate new concepts and technologies within the operational world of Shuttle. These integrated testbeds include speech recognition and synthesis, laser imaging inspection systems, distributed Ada programming environments, distributed relational database architectures, distributed computer network architectures, multi-media workbenches, and human factors considerations.

  18. Topology-aware Tile Mapping for Clusters of SMPs

    SciTech Connect

    Chavarría-Miranda, Daniel; Nieplocha, Jarek; Tipparaju, Vinod

    2006-05-01

    We propose a technique to optimize the performance of applications using distributed dense arrays and characterized by a nearest-neighbor communication profile by exploiting the topology of SMP clusters. The topological information is exploited for mapping array tiles to processors to reduce the network communication and improve utilization of shared memory for inter-process communication. The potential benefits of using the SMP-aware mapping are demonstrated through a simulation, as well as a real application solving a wind-driven ocean circulation model on an IBM SP. On 128 processors, the execution time was reduced by almost 20 percent without any changes to the original application source code. The proposed mapping approach is applicable to multiple programming models and distributed array management systems.

  19. Automation of Shuttle Tile Inspection - Engineering methodology for Space Station

    NASA Technical Reports Server (NTRS)

    Wiskerchen, M. J.; Mollakarimi, C.

    1987-01-01

    The Space Systems Integration and Operations Research Applications (SIORA) Program was initiated in late 1986 as a cooperative applications research effort between Stanford University, NASA Kennedy Space Center, and Lockheed Space Operations Company. One of the major initial SIORA tasks was the application of automation and robotics technology to all aspects of the Shuttle tile processing and inspection system. This effort has adopted a systems engineering approach consisting of an integrated set of rapid prototyping testbeds in which a government/university/industry team of users, technologists, and engineers test and evaluate new concepts and technologies within the operational world of Shuttle. These integrated testbeds include speech recognition and synthesis, laser imaging inspection systems, distributed Ada programming environments, distributed relational database architectures, distributed computer network architectures, multimedia workbenches, and human factors considerations.

  20. 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.

  1. Complex Multicolor Tilings and Critical Phenomena in Tetraphilic Liquid Crystals

    NASA Astrophysics Data System (ADS)

    Zeng, Xiangbing; Kieffer, Robert; Glettner, Benjamin; Nürnberger, Constance; Liu, Feng; Pelz, Karsten; Prehm, Marko; Baumeister, Ute; Hahn, Harald; Lang, Heinrich; Gehring, Gillian A.; Weber, Christa H. M.; Hobbs, Jamie K.; Tschierske, Carsten; Ungar, Goran

    2011-03-01

    T-shaped molecules with a rod-like aromatic core and a flexible side chain form liquid crystal honeycombs with aromatic cell walls and a cell interior filled with the side chains. Here, we show how the addition of a second chain, incompatible with the first (X-shaped molecules), can form honeycombs with highly complex tiling patterns, with cells of up to five different compositions (“colors”) and polygonal shapes. The complexity is caused by the inability of the side chains to separate cleanly because of geometric frustration. Furthermore, a thermoreversible transition was observed between a multicolor (phase-separated) and a single-color (mixed) honeycomb phase. This is analogous to the Curie transition in simple and frustrated ferro- and antiferromagnets; here spin flips are replaced by 180° reorientations of the molecules.

  2. In-flight investigation of shuttle tile pressure orifice installations

    NASA Astrophysics Data System (ADS)

    Moes, Timothy R.; Meyer, Robert R., Jr.

    1990-09-01

    To determine shuttle orbiter wing loads during ascent, wing load instrumentation was added to Columbia (OV-102). This instrumentation included strain gages and pressure orifices on the wing. The loads derived from wing pressure measurements taken during STS 61-C did not agree with those derived from strain gage measurements or with the loads predicted from the aerodynamic database. Anomalies in the surface immediately surrounding the pressure orifices in the thermal protection system (TPS) tiles were one possible cause of errors in the loads derived from wing pressure measurements. These surface anomalies were caused by a ceramic filler material which was installed around the pressure tubing. The filler material allowed slight movement of the TPS tile and pressure tube as the airframe flexed and bent under aerodynamic loads during ascent and descent. Postflight inspection revealed that this filler material had protruded from or receeded beneath the surface, causing the orifice to lose its flushness. Flight tests were conducted at NASA Ames Research Center Dryden Flight Research Facility to determine the effects of any anomaly in surface flushness of the orifice installation on the measured pressures at Mach numbers between 0.6 and 1.4. An F-104 aircraft with a flight test fixture mounted beneath the fuselage was used for these flights. Surface flushness anomalies typical of those on the orbiter after flight (STA 61-C) were tested. Also, cases with excessive protrusion and recession of the filler material were tested. This report shows that the anomalies in STS 61-C orifice installations adversely affected the pressure measurements. But the magnitude of the affect was not great enough to account for the discrepancies with the strain gage measurements and the aerodynamic predictions.

  3. In-flight investigation of shuttle tile pressure orifice installations

    NASA Technical Reports Server (NTRS)

    Moes, Timothy R.; Meyer, Robert R., Jr.

    1990-01-01

    To determine shuttle orbiter wing loads during ascent, wing load instrumentation was added to Columbia (OV-102). This instrumentation included strain gages and pressure orifices on the wing. The loads derived from wing pressure measurements taken during STS 61-C did not agree with those derived from strain gage measurements or with the loads predicted from the aerodynamic database. Anomalies in the surface immediately surrounding the pressure orifices in the thermal protection system (TPS) tiles were one possible cause of errors in the loads derived from wing pressure measurements. These surface anomalies were caused by a ceramic filler material which was installed around the pressure tubing. The filler material allowed slight movement of the TPS tile and pressure tube as the airframe flexed and bent under aerodynamic loads during ascent and descent. Postflight inspection revealed that this filler material had protruded from or receeded beneath the surface, causing the orifice to lose its flushness. Flight tests were conducted at NASA Ames Research Center Dryden Flight Research Facility to determine the effects of any anomaly in surface flushness of the orifice installation on the measured pressures at Mach numbers between 0.6 and 1.4. An F-104 aircraft with a flight test fixture mounted beneath the fuselage was used for these flights. Surface flushness anomalies typical of those on the orbiter after flight (STA 61-C) were tested. Also, cases with excessive protrusion and recession of the filler material were tested. This report shows that the anomalies in STS 61-C orifice installations adversely affected the pressure measurements. But the magnitude of the affect was not great enough to account for the discrepancies with the strain gage measurements and the aerodynamic predictions.

  4. Differential analysis for high density tiling microarray data

    PubMed Central

    Ghosh, Srinka; Hirsch, Heather A; Sekinger, Edward A; Kapranov, Philipp; Struhl, Kevin; Gingeras, Thomas R

    2007-01-01

    Background High density oligonucleotide tiling arrays are an effective and powerful platform for conducting unbiased genome-wide studies. The ab initio probe selection method employed in tiling arrays is unbiased, and thus ensures consistent sampling across coding and non-coding regions of the genome. These arrays are being increasingly used to study the associated processes of transcription, transcription factor binding, chromatin structure and their association. Studies of differential expression and/or regulation provide critical insight into the mechanics of transcription and regulation that occurs during the developmental program of a cell. The time-course experiment, which comprises an in-vivo system and the proposed analyses, is used to determine if annotated and un-annotated portions of genome manifest coordinated differential response to the induced developmental program. Results We have proposed a novel approach, based on a piece-wise function – to analyze genome-wide differential response. This enables segmentation of the response based on protein-coding and non-coding regions; for genes the methodology also partitions differential response with a 5' versus 3' versus intra-genic bias. Conclusion The algorithm built upon the framework of Significance Analysis of Microarrays, uses a generalized logic to define regions/patterns of coordinated differential change. By not adhering to the gene-centric paradigm, discordant differential expression patterns between exons and introns have been identified at a FDR of less than 12 percent. A co-localization of differential binding between RNA Polymerase II and tetra-acetylated histone has been quantified at a p-value < 0.003; it is most significant at the 5' end of genes, at a p-value < 10-13. The prototype R code has been made available as supplementary material [see Additional file 1]. PMID:17892592

  5. Nondeterministic self-assembly of two tile types on a lattice

    NASA Astrophysics Data System (ADS)

    Tesoro, S.; Ahnert, S. E.

    2016-04-01

    Self-assembly is ubiquitous in nature, particularly in biology, where it underlies the formation of protein quaternary structure and protein aggregation. Quaternary structure assembles deterministically and performs a wide range of important functions in the cell, whereas protein aggregation is the hallmark of a number of diseases and represents a nondeterministic self-assembly process. Here we build on previous work on a lattice model of deterministic self-assembly to investigate nondeterministic self-assembly of single lattice tiles and mixtures of two tiles at varying relative concentrations. Despite limiting the simplicity of the model to two interface types, which results in 13 topologically distinct single tiles and 106 topologically distinct sets of two tiles, we observe a wide variety of concentration-dependent behaviors. Several two-tile sets display critical behaviors in the form of a sharp transition from bound to unbound structures as the relative concentration of one tile to another increases. Other sets exhibit gradual monotonic changes in structural density, or nonmonotonic changes, while again others show no concentration dependence at all. We catalog this extensive range of behaviors and present a model that provides a reasonably good estimate of the critical concentrations for a subset of the critical transitions. In addition, we show that the structures resulting from these tile sets are fractal, with one of two different fractal dimensions.

  6. Analytical and experimental evaluations of Space Shuttle TPS tile vibration response

    NASA Technical Reports Server (NTRS)

    Piersol, A. G.; Pope, L. D.

    1982-01-01

    Analytical studies and laboratory experiments have been performed to evaluate the vibration response of the Space Shuttle Thermal Protection System (TPS) tiles due to the intense rocket generated acoustic noise during lift-off. The TPS tiles are mounted over the exterior of the Space Shuttle Orbiter structure through Strain Isolation Pads (SIP) which protect the tiles from thermal induced shear loads at their interface. The analytical predictions indicate that the response of a typical tile is governed by the structural vibration inputs through the SIP under the tile at frequencies below 250 Hz, and by the direct acoustic excitation over the exterior surface of the tile at frequencies above 250 Hz. An evaluation of the laboratory test data for this same tile, in which conditioned (partial) coherent output spectral analysis procedures were used, leads to exactly the same conclusion. The results demonstrate the power of conditioned spectral analysis procedures in identifying vibration response mechanisms when two or more of the inputs are highly correlated.

  7. Detecting Subsurface Agricultural Tile Drainage using GIS and Remote Sensing Technique

    NASA Astrophysics Data System (ADS)

    Budhathoki, M.; Gokkaya, K.; Tank, J. L.; Christopher, S. F.; Hanrahan, B.

    2015-12-01

    Subsurface tile drainage is a common practice in many of the row crop dominated agricultural lands in the Upper Midwest, which increases yield by making the soil more productive. It is reported that nearly half of all cropland in Indiana benefits from some sort of artificial drainage. However, subsurface tile has a significant negative impact on surface water quality by providing a fast means of transport for nutrients from fertilizers. Therefore, generating spatial data of tile drainage in the field is important and useful for agricultural landscape and hydrological studies. Subsurface tile drains in Indiana's croplands are not widely mapped. In this study, we will delineate subsurface tile drainage in agricultural land in Shatto Ditch watershed, located in Kosciusko County, Indiana. We will use geo-spatial methodology, which was purposed by earlier researchers to detect tile drainage. We will use aerial color-infrared and satellite imagery along with Light Detection and Ranging (LiDAR) data. In order to map tile lines with possible accuracy, we will use GIS-based analysis in combination with remotely sensed data. This research will be comprised of three stages: 1) masking out the potential drainage area using a decision tree rule based on land cover information, soil drainage category, surface slope, and satellite image differencing technique, 2) delineate tile lines using image processing techniques, and 3) check the accuracy of mapped tile lines with ground control points. To our knowledge, this study will be the first to check the accuracy of mapping with ground truth data. Based on the accuracy of results, we will extend the methodology to greater spatial scales. The results are expected to contribute to better characterizing and controlling water pollution sources in Indiana, which is a major environmental problem.

  8. Spatiotemporal scaling of hydrological and agrochemical export dynamics in a tile-drained Midwestern watershed

    NASA Astrophysics Data System (ADS)

    Guan, K.; Thompson, S. E.; Harman, C. J.; Basu, N. B.; Rao, P. S. C.; Sivapalan, M.; Packman, A. I.; Kalita, P. K.

    2011-10-01

    Conceptualizing catchments as physicochemical filters is an appealing way to link streamflow discharge and concentration time series to hydrological and biogeochemical processing in hillslopes and drainage networks. Making these links explicit is challenging in complex watersheds but may be possible in highly modified catchments where hydrological and biogeochemical processes are simplified. Linking hydrological and biogeochemical filtering in highly modified watersheds is appealing from a water quality perspective in order to identify the major controls on chemical export at different spatial and temporal scales. This study investigates filtering using a 10 year data set of hydrological and biogeochemical export from a small (<500 km2) agricultural watershed in Illinois, the Little Vermilion River (LVR) Watershed. A number of distinct scaling regimes were identified in the Fourier power spectrum of discharge and nitrate, phosphate, and atrazine concentrations. These scaling regimes were related to different runoff pathways and spatial scales throughout the catchment (surface drainage, tile drains, and channel flow in the river). Wavelet analysis indicated increased coupling between discharge and in-stream concentrations at seasonal-annual time scales. Using a multiresolution analysis, nitrate, phosphate, and atrazine loads exported at annual scales were found to exhibit near-linear scaling with annual streamflow, suggesting that at these scales the export dynamics could be approximated as chemostatic responses. This behavior was pronounced for nitrate and less so for phosphate and atrazine. The analysis suggests that biogeochemical inputs built up legacy loads, leading to the emergence of chemostatic behavior at annual time scales, even at the relatively small scale of the LVR.

  9. Radioactively contaminated electric arc furnace dust as an addition to the immobilization mortar in low- and medium-activity repositories.

    PubMed

    Castellote, Marta; Menéndez, Esperanza; Andrade, Carmen; Zuloaga, Pablo; Navarro, Mariano; Ordóñez, Manuel

    2004-05-15

    Electric arc furnace dust (EAFD), generated by the steel-making industry, is in itself an intrinsic hazardous waste; however, the case may also be that scrap used in the process is accidentally contaminated by radioactive elements such as cesium. In this case the resulting EAFD is to be handled as radioactive waste, being duly confined in low- and medium-activity repositories (LMAR). What this paper studies is the reliability of using this radioactive EAFD as an addition in the immobilization mortar of the containers of the LMAR, that is, from the point of view of the durability. Different mixes of mortar containing different percentages of EAFD have been subjected to flexural and compressive strength, initial and final setting time, XRD study, total porosity and pore size distribution, determination of the chloride diffusion coefficient, dimensional stability tests, hydration heat, workability of the fresh mix, and leaching behavior. What is deduced from the results is that for the conditions used in this research, (cement + sand) can be replaced by EAFD upto a ratio [EAFD/(cement + EAFD)] of 46% in the immobilization mortar of LMAR, apparently without any loss in the long-term durability properties of the mortar. PMID:15212272

  10. Green and early age compressive strength of extruded cement mortar monitored with compression tests and ultrasonic techniques

    SciTech Connect

    Voigt, Thomas . E-mail: mail@tvoigt.com; Malonn, Tim; Shah, Surendra P.

    2006-05-15

    Knowledge about the early age compressive strength development of cementitious materials is an important factor for the progress and safety of many construction projects. This paper uses cylindrical mortar specimens produced with a ram extruder to investigate the transition of the mortar from plastic and deformable to hardened state. In addition, wave transmission and reflection measurements with P- and S-waves were conducted to obtain further information about the microstructural changes during the setting and hardening process. The experiments have shown that uniaxial compression tests conducted on extruded mortar cylinders are a useful tool to evaluate the green strength as well as the initiation and further development of the compressive strength of the tested material. The propagation of P-waves was found to be indicative of the internal structure of the tested mortars as influenced, for example, by the addition of fine clay particles. S-waves used in transmission and reflection mode proved to be sensitive to the inter-particle bonding caused by the cement hydration and expressed by an increase in compressive strength.

  11. Impact of superplasticizer concentration and of ultra-fine particles on the rheological behaviour of dense mortar suspensions

    SciTech Connect

    Artelt, C. Garcia, E.

    2008-05-15

    This work aims at investigating the impact of the addition of superplasticizer and of ultra-fine particles, namely of silica fume and of precipitated titania, on the rheological behaviour of water-lean mortar pastes. The pastes are characterised in terms of their spread, their flowing behaviour and by means of performing a shear test, giving access to viscosity/shear gradient correlations. Adding superplasticizer is shown to shift the onset of shear thickening of the referring pastes to higher shear rates and to attenuate its otherwise rapid evolution, possibly by means of favouring steric particle-particle interactions. The workability of these mortars, which is characterised in terms of spread values and draining, is also improved. For the case of fly ash based mortars, adding ultra-fine particles is another way of (slightly) 'retarding' shear thickening and of attenuating its evolution, possibly because of resulting in - on the average - lower hydrodynamic forces and reduced attractive Van der Waals interactions between particles. However, at the same time these mortars are characterised by a worsening in workability which is attributed to the huge amount of surface area provided by the ultra-fines.

  12. Modified cyanobacteria

    DOEpatents

    Vermaas, Willem F J.

    2014-06-17

    Disclosed is a modified photoautotrophic bacterium comprising genes of interest that are modified in terms of their expression and/or coding region sequence, wherein modification of the genes of interest increases production of a desired product in the bacterium relative to the amount of the desired product production in a photoautotrophic bacterium that is not modified with respect to the genes of interest.

  13. Duplication of a Single Neuron in C. elegans Reveals a Pathway for Dendrite Tiling by Mutual Repulsion.

    PubMed

    Yip, Zhiqi Candice; Heiman, Maxwell G

    2016-06-01

    Simple cell-cell interactions can give rise to complex cellular patterns. For example, neurons of the same type can interact to create a complex patchwork of non-overlapping dendrite arbors, a pattern known as dendrite tiling. Dendrite tiling often involves mutual repulsion between neighboring neurons. While dendrite tiling is found across nervous systems, the nematode Caenorhabditis elegans has a relatively simple nervous system with few opportunities for tiling. Here, we show that genetic duplication of a single neuron, PVD, is sufficient to create dendrite tiling among the resulting ectopic neurons. We use laser ablation to show that this tiling is mediated by mutual repulsion between neighbors. Furthermore, we find that tiling requires a repulsion signal (UNC-6/Netrin and its receptors UNC-40/DCC and UNC-5) that normally patterns the PVD dendrite arbor. These results demonstrate that an apparently complex cellular pattern can emerge in a simple nervous system merely by increasing neuron number. PMID:27239028

  14. Conduction in a two-phase plane with diamond-shaped tiling

    NASA Astrophysics Data System (ADS)

    Helsing, Johan; Grimvall, Göran; Bao, Ke-da

    1991-07-01

    The effective conductivity of a two-phase two-dimensional composite with diamond-shaped tiling is considered. This analysis, based on a projection of the boundary conditions on linear combinations of solutions to the electrostatic equation that are orthonormal on the boundary, generalizes results by Keller [J. Math. Phys. 28, 2516 (1987)] and others. Numerical results are given for several conductivity ratios of the two phases and for varying obtuse angles of the tiles. Special emphasis is given to very large and very small conductivity differences, and very elongated tiles.

  15. 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.

  16. Electrospun SiO2 "necklaces" on unglazed ceramic tiles: a planarizing strategy

    NASA Astrophysics Data System (ADS)

    Di Mauro, Alessandro; Fragalà, Maria Elena

    2015-05-01

    Silica based nanofibres have been deposited on unglazed ceramic tiles by combining electrospinning and sol-gel processes. Poly(vinyl pyrrolidone) (PVP) alcoholic solutions and commercial spin on glass (Accuglass) mixtures have been used to obtain composite fibrous non-woven mats totally converted, after thermal annealing at 600 °C, to SiO2 microsphere "necklaces". The possibility to get an uniform fibres coverage onto the tile surface confirms the validity of electrospinning (easily scalable to large surface samples) as coating strategy to cover the macroscopic defects typical of the polished unglazed tile surface and improve surface planarization.

  17. A prediction method for flow in the Shuttle tile strain isolation pad

    NASA Technical Reports Server (NTRS)

    Lawing, Pierce L.

    1987-01-01

    The Shuttle Orbiter thermal protection system uses a Strain Isolation Pad (SIP) between the tile and the Orbiter. This paper presents experimental measurements of the pressure drop and associated flow rate through a sample of the SIP material. Included are data for a range of air densities representative of Shuttle ascent and re-entry trajectories. Also presented are new theoretical and correlative methods which predict the experimental data. These methods will help in predicting venting characteristics of tile assemblies during ascent, and hot gas leak under the tiles during descent. The predictive philosophy developed is useful in the study of fibrous and porous media fluid mechanics.

  18. Gap heating with pressure gradients. [for Shuttle Orbiter thermal protection system tiles

    NASA Technical Reports Server (NTRS)

    Scott, C. D.; Maraia, R. J.

    1979-01-01

    The heating rate distribution and temperature response on the gap walls of insulating tiles is analyzed to determine significant phenomena and parameters in flows where there is an external surface pressure gradient. Convective heating due to gap flow, modeled as fully developed pipe flow, is coupled with a two-dimensional thermal model of the tiles that includes conduction and radiative heat transfer. To account for geometry and important environmental parameters, scale factors are obtained by curve-fitting measured temperatures to analytical solutions. These scale factors are then used to predict the time-dependent gap heat flux and temperature response of tile gaps on the Space Shuttle Orbiter during entry.

  19. Thermal insulation attaching means. [adhesive bonding of felt vibration insulators under ceramic tiles

    NASA Technical Reports Server (NTRS)

    Leger, L. J. (Inventor)

    1978-01-01

    An improved isolation system is provided for attaching ceramic tiles of insulating material to the surface of a structure to be protected against extreme temperatures of the nature expected to be encountered by the space shuttle orbiter. This system isolates the fragile ceramic tiles from thermally and mechanically induced vehicle structural strains. The insulating tiles are affixed to a felt isolation pad formed of closely arranged and randomly oriented fibers by means of a flexible adhesive and in turn the felt pad is affixed to the metallic vehicle structure by an additional layer of flexible adhesive.

  20. The central tower of the cathedral of Schleswig - New investigations to understand the alcali-silica reaction of historical mortars

    NASA Astrophysics Data System (ADS)

    Wedekind, Wanja; Protz, Andreas

    2016-04-01

    The damaging alcali-silica reaction leads to crack-formation and structural destruction at noumerous, constructed with cement mortar, buildings worldwide. The ASR-reaction causes the expansion of altered aggregates by the formation of a swelling gel. This gel consists of calcium silicate hydrate (C-S-H) that increases in volume with water, which exerts an expansive pressure inside the material. The cathedral of Schleswig is one of the oldest in northern Germany. The first church was built in 985-965. The Romanesque building part was erected around 1180 and the Gothic nave at the end of the 13th century. The central tower was constructed between 1888 and 1894 with brick and cement mortar. With 112 meters, the tower is the second-largest church spire of the country of Schleswig-Holstein in northern Germany. Due to the formation of cracks and damages from 1953 to 1956 first restoration works took place. Further developments of cracks are making restoration necessary again today. For developing a suitable conservation strategy, different investigations were done. The investigation included the determination of the pore space properties, the hygric and thermal dilatation and mercury porosimetry measurements. Furthermore, the application of cathodoluminescence microscopy may give information about the alteration process and microstructures present and reveal the differences between unaltered and altered mortars. An obvious relation between the porosity and the swelling intensity could be detected. Furthermore it becomes apparent, that a clear zonation of the mortar took place. The mortar near the surface is denser with a lower porosity and has a significantly lower swelling or dilatation.