Science.gov

Sample records for 8-harness satin weave

  1. Analytical Model of Shear of 4-harness Satin Weave Fabrics

    NASA Astrophysics Data System (ADS)

    Liu, Lu; Chen, Julie; Sherwood, James

    2004-06-01

    Trellis shear is the main deformation mode in the thermo-stamping process of woven fabric composites. To model the shear properties of woven fabrics analytically, the equilibrium equation of the unit cell of a 4-harness satin weave glass/polypropylene woven fabric is studied. Frictional resistance moment and lateral compaction resistance moment are then predicted by studying the geometry of the unit cell. Then the model is used to predict the load versus shear angle curves in the picture frame test to reduce or eliminate the test itself. A parametric study is carried out to determine the sensitivity of the friction coefficient. To validate the model, picture-frame experimental results are presented. A very close correlation is observed between the model predictions and the experimental results. Results of plain weave fabrics are included to show the analytical model's ability to predict the effect of weave pattern. Results from an international benchmark testing are also presented to help establish the test standards for experimental characterization of the shear properties of woven fabrics in the thermo-stamping process.

  2. Thermal-Mechanical Response of Cracked Satin Weave CFRP Composites at Cryogenic Temperatures

    NASA Astrophysics Data System (ADS)

    Watanabe, S.; Shindo, Y.; Narita, F.; Takeda, T.

    2008-03-01

    This paper examines the thermal-mechanical response of satin weave carbon fiber reinforced polymer (CFRP) laminates with internal and/or edge cracks subjected to uniaxial tension load at cryogenic temperatures. Cracks are considered to occur in the transverse fiber bundles and extend through the entire thickness of the fiber bundles. Two-dimentional generalized plane strain finite element models are developed to study the effects of residual thermal stresses and cracks on the mechanical behavior of CFRP woven laminates. A detailed examination of the Young's modulus and stress distributions near the crack tip is carried out which provides insight into material behavior at cryogenic temperatures.

  3. Cryogenic mechanical response of multilayer satin weave CFRP composites with cracks

    NASA Astrophysics Data System (ADS)

    Watanabe, S.; Shindo, Y.; Takeda, T.; Narita, F.

    2008-07-01

    We deal with the thermomechanical response of multilayer satin weave carbon-fiber-reinforced polymer (CFRP) laminates with internal and/or edge cracks and temperature-dependent material properties subjected to tensile loading at cryogenic temperatures. The composite material is assumed to be under the generalized plane strain. Cracks are located in the transverse fiber bundles and extend to the interfaces between two fiber bundles. A finite-element model is employed to study the influence of residual thermal stresses on the mechanical behavior of multilayer CFRP woven laminates with cracks. Numerical calculations are carried out, and Young's modulus and stress distributions near the crack tip are shown graphically.

  4. THERMAL-MECHANICAL RESPONSE OF CRACKED SATIN WEAVE CFRP COMPOSITES AT CRYOGENIC TEMPERATURES

    SciTech Connect

    Watanabe, S.; Shindo, Y.; Narita, F.; Takeda, T.

    2008-03-03

    This paper examines the thermal-mechanical response of satin weave carbon fiber reinforced polymer (CFRP) laminates with internal and/or edge cracks subjected to uniaxial tension load at cryogenic temperatures. Cracks are considered to occur in the transverse fiber bundles and extend through the entire thickness of the fiber bundles. Two-dimentional generalized plane strain finite element models are developed to study the effects of residual thermal stresses and cracks on the mechanical behavior of CFRP woven laminates. A detailed examination of the Young's modulus and stress distributions near the crack tip is carried out which provides insight into material behavior at cryogenic temperatures.

  5. Weaving.

    ERIC Educational Resources Information Center

    Counts, Rubynelle

    Developed at The Mountain School (Lookout Mountain, Georgia), a project funded under Title III of the Elementary and Secondary Education Act, 1974-75, this curriculum guide for an interdisciplinary minicourse in weaving provides for integration of environmental and career education goals with those in academic areas. Introductory material…

  6. Tablet Weaving

    ERIC Educational Resources Information Center

    Kren, Margo

    1976-01-01

    Article described a weaving technique called tablet weaving, an ancient textile process that provides opportunity for making a variety of items, such as guitar straps, belts, and decorative bands. (Author/RK)

  7. The Effect of Various Weave Designs on Mechanical Behavior of Lamina Intraply Composite Made from Kenaf Fiber Yarn

    NASA Astrophysics Data System (ADS)

    Yuhazri, M. Y.; Amirhafizan, M. H.; Abdullah, A.; Sihombing, H.; Saarah, A. B.; Fadzol, O. M.

    2016-11-01

    The development of lamina intraply composite is a novel approach that can be adopted to address the challenges of balance mechanical properties of polymer composite. This research will focuses on the effects of weave designs on the mechanical behavior of a single ply or also known as lamina intraply composite. The six (6) specimens of lamina intraply composites were made by kenaf fiber as a reinforcement and unsaturated polyester resin as a matrix in various weave designs which were plain, twill, satin, basket, mock leno and leno weave. The vacuum infusion technique was adopted due to advantages over hand lay-up. It was found that the plain, twill and satin weave exhibited better mechanical properties on tensile strength. The fiber content of the specimen was 40% and the result of the resin content of the specimen was 60% due to the higher permeability of natural fiber.

  8. Fabrication and physical testing of graphite composite panels utilizing woven graphite fabric with current and advanced state-of-the-art resin systems

    NASA Technical Reports Server (NTRS)

    Lee, S. C. S.

    1979-01-01

    Three weaves were evaluated; a balanced plain weave, a balanced 8-harness satin weave, and a semiunidirectional crowfoot satin weave. The current state-of-the-art resin system selected was Fiberite's 934 Epoxy; the advanced resin systems evaluated were Phenolic, Phenolic/Novolac, Benzyl and Bismaleimide. The panels were fabricated for testing on NASA/Ames Research Center's Composites Modification Program. Room temperature mechanical tests only were performed by Hitco; the results are presented.

  9. In-plane and interlaminar Iosipescu shear properties of various graphite fabric/epoxy laminates

    NASA Technical Reports Server (NTRS)

    Adams, Donald F.; Walrath, David E.

    1987-01-01

    The Iosipescu shear test method was used to measure the in-plane and interlaminar shear properties of four T300 graphite fabric/Fiberite 934 epoxy composite materials. Weave geometries tested included an Oxford weave, a 5-harness satin weave, an 8-harness satin weave, and a plain weave with auxiliary warp yarns. Both orthogonal and quasi-isotropic layup laminates were tested. In-plane and interlaminar shear properties were obtained for laminates of all four fabric types. Overall, few differences in shear properties attributable to the fabric weave pattern were observed. However, the auxiliary warp material was significantly weaker and less stiff in interlaminar shear parallel to its fill direction.

  10. Computational modeling of the electromagnetic characteristics of carbon fiber-reinforced polymer composites with different weave structures

    NASA Astrophysics Data System (ADS)

    Hassan, A. M.; Douglas, J. F.; Garboczi, E. J.

    2014-02-01

    Carbon fiber reinforced polymer composites (CFRPC) are of great interest in the aerospace and automotive industries due to their exceptional mechanical properties. Carbon fibers are typically woven and inter-laced perpendicularly in warps and wefts to form a carbon fabric that can be embedded in a binding matrix. The warps and wefts can be interlaced in different patterns called weaving structures. The primary weaving structures are the plain, twill, and satin weaves, which give different mechanical composite properties. The goal of this work is to computationally investigate the dependence of CFRPC microwave and terahertz electromagnetic characteristics on weave structure. These bands are good candidates for the Nondestructive Evaluation (NDE) of CFRPC since their wavelengths are comparable to the main weave features. 3D full wave electromagnetic simulations of several different weave models have been performed using a finite element (FEM) simulator, which is able to accurately model the complex weave structure. The computational experiments demonstrate that the reflection of electromagnetic waves from CFRPC depend sensitively on weave structure. The reflection spectra calculated in this work can be used to identify the optimal frequencies for the NDE of each weave structure.

  11. Influence of weave structures on the tribological properties of hybrid Kevlar/PTFE fabric composites

    NASA Astrophysics Data System (ADS)

    Gu, Dapeng; Yang, Yulin; Qi, Xiaowen; Deng, Wei; Shi, Lei

    2012-09-01

    The existing research of the woven fabric self-lubricating liner mainly focus on the tribological performance improvements and the service life raised by changing different fiber type combinations, adding additive modification, and performing fiber surface modification. As fabric composites, the weave structures play an important role in the mechanical and tribological performances of the liners. However, hardly any literature is available on the friction and wear behavior of such composites with different weave structures. In this paper, three weave structures (plain, twill 1/3 and satin 8/5) of hybrid Kevlar/PTFE fabric composites are selected and pin-on-flat linear reciprocating wear studies are done on a CETR tester under different pressures and different frequencies. The relationship between the tensile strength and the wear performance are studied. The morphologies of the worn surfaces under the typical test conditions are analyzed by means of scanning electron microscopy (SEM). The analysis results show that at 10 MPa, satin 8/5 performs the best in friction-reduction and antiwear performance, and plain is the worst. At 30 MPa, however, the antiwear performance is reversed and satin 8/5 does not even complete the 2 h wear test at 16 Hz. There is no clear evidence proving that the tensile strength has an influence on the wear performance. So the different tribological performance of the three weave structures of fabric composites may be attributed to the different PTFE proportions in the fabric surface and the different wear mechanisms. The fabric composites are divided into three regions: the lubrication region, the reinforced region and the bonding region. The major mechanisms are fatigue wear and the shear effects of the friction force in the lubrication region. In the reinforced region fiber-matrix de-bonding and fiber breakage are involved. The proposed research proposes a regional wear model and further indicates the wear process and the wear mechanism

  12. Wow Them with Weaving.

    ERIC Educational Resources Information Center

    Reddick, Laura McCants

    1998-01-01

    Describes an art lesson for seventh-grade students where they learned the craft of weaving using paper as their weaving logs. Explains that in order to evaluate the activity, the students discussed their work and participated in a discussion on non-objective art and the difference between art and crafts. Provides instructions for making weavers.…

  13. The Effect of Lamina Intraply Hybrid Composites on the Tensile Properties of Various Weave Designs

    NASA Astrophysics Data System (ADS)

    Yuhazri, M. Y.; Amirhafizan, M. H.; Abdullah, A.; Sihombing, H.; Nirmal, U.; Saarah, A. B.; Fadzol, O. M.

    2016-11-01

    The topic of natural fiber is one of the most active areas in thermoset composite research today. This paper will focuses on the effect of weave designs on the mechanical behaviour of lamina intraply hybrid composites. Twelve specimens were used and they were made of kenaf fibre and glass fibre as a reinforcement and unsaturated polyester resin as a matrix in various weave designs which were plain, twill, satin, basket, mock leno, and leno weave. Vacuum infusion technique was used due to its superior advantages over hand lay-up. The specimens were produced in two types which were kenaf fibre in warp direction interlace with glass fibre in weft direction (WK-WG) and glass fibre in warp direction interlace with kenaf fibre in weft direction (WG-WK). Various weave designs were found to affect the tensile properties. Glass fibre in warp direction has a greater effect on tensile strength compared to kenaf fibre in warp direction. Mock leno weave exhibited better mechanical properties for WK-WG and WG-WK, about 54.74 MPa and 99.46 MPa respectively.

  14. The interlaminar fracture toughness of woven graphite/epoxy composites

    NASA Technical Reports Server (NTRS)

    Funk, Joan G.; Deaton, Jerry W.

    1989-01-01

    The interlaminar fracture toughness of 2-D graphite/epoxy woven composites was determined as a function of stacking sequence, thickness, and weave pattern. Plain, oxford, 5-harness satin, and 8-harness satin weaves of T300/934 material were evaluated by the double cantilever beam test. The fabric material had a G (sub Ic) ranging from 2 to 8 times greater than 0 degrees unidirectional T300/934 tape material. The interlaminar fracture toughness of a particular weave style was dependent on whether the stacking sequence was symmetric or asymmetric and, in some cases, on the fabric orientation.

  15. Adjustable Reeds For Weaving

    NASA Technical Reports Server (NTRS)

    Farley, Gary L.

    1994-01-01

    Local characteristics of fabrics varied to suit special applications. Adjustable reed machinery proposed for use in weaving fabrics in various net shapes, widths, yarn spacings, and yarn angles. Locations of edges of fabric and configuration of warp and filling yarns varied along fabric to obtain specified properties. In machinery, reed wires mounted in groups on sliders, mounted on lengthwise rails in reed frame. Mechanisms incorporated to move sliders lengthwise, parallel to warp yarns, by sliding them along rails; move sliders crosswise by translating reed frame rails perpendicular to warp yarns; and crosswise by spreading reed rails within group. Profile of reed wires in group on each slider changed.

  16. Iosipescu shear properties of graphite fabric/epoxy composite laminates

    NASA Technical Reports Server (NTRS)

    Walrath, D. E.; Adams, D. F.

    1985-01-01

    The Iosipescu shear test method is used to measure the in-plane and interlaminar shear properties of four T300 graphite fabric/934 epoxy composite materials. Different weave geometries tested include an Oxford weave, a 5-harness satin weave, an 8-harness satin weave, and a plain weave with auxiliary warp yarns. Both orthogonal and quasi-isotropic layup laminates were tested. In-plane and interlaminar shear properties are obtained for laminates of all four fabric types. Overall, little difference in shear properties attributable to the fabric weave pattern is observed. The auxiliary warp material is significantly weaker and less stiff in interlaminar shear parallel to its fill direction. A conventional strain gage extensometer is modified to measure shear strains for use with the Iosipescu shear test. While preliminary results are encouraging, several design iterations failed to produce a reliable shear transducer prototype. Strain gages are still the most reliable shear strain transducers for use with this test method.

  17. The WEAVE-LOFAR Survey

    NASA Astrophysics Data System (ADS)

    Smith, D. J. B.; Best, P. N.; Duncan, K. J.; Hatch, N. A.; Jarvis, M. J.; Röttgering, H. J. A.; Simpson, C. J.; Stott, J. P.; Cochrane, R. K.; Coppin, K. E.; Dannerbauer, H.; Davis, T. A.; Geach, J. E.; Hale, C. L.; Hardcastle, M. J.; Hatfield, P. W.; Houghton, R. C. W.; Maddox, N.; McGee, S. L.; Morabito, L.; Nisbet, D.; Pandey-Pommier, M.; Prandoni, I.; Saxena, A.; Shimwell, T. W.; Tarr, M.; van Bemmel, I.; Verma, A.; White, G. J.; Williams, W. L.

    2016-12-01

    In these proceedings we highlight the primary scientific goals and design of the WEAVE-LOFAR survey, which will use the new WEAVE spectrograph on the 4.2m William Herschel Telescope to provide the primary source of spectroscopic information for the LOFAR Surveys Key Science Project. Beginning in 2018, WEAVE-LOFAR will generate more than 10^6 R=5000 365-960nm spectra of low-frequency selected radio sources, across three tiers designed to efficiently sample the redshift-luminosity plane, and produce a data set of enormous legacy value. The radio frequency selection, combined with the high multiplex and throughput of the WEAVE spectrograph, make obtaining redshifts in this way very efficient, and we expect that the redshift success rate will approach 100 per cent at z < 1. This unprecedented spectroscopic sample - which will be complemented by an integral field component - will be transformational in key areas, including studying the star formation history of the Universe, the role of accretion and AGN-driven feedback, properties of the epoch of reionisation, cosmology, cluster haloes and relics, as well as the nature of radio galaxies and protoclusters. Each topic will be addressed in unprecedented detail, and with the most reliable source classifications and redshift information in existence.

  18. Knitting and weaving artificial muscles

    PubMed Central

    Maziz, Ali; Concas, Alessandro; Khaldi, Alexandre; Stålhand, Jonas; Persson, Nils-Krister; Jager, Edwin W. H.

    2017-01-01

    A need exists for artificial muscles that are silent, soft, and compliant, with performance characteristics similar to those of skeletal muscle, enabling natural interaction of assistive devices with humans. By combining one of humankind’s oldest technologies, textile processing, with electroactive polymers, we demonstrate here the feasibility of wearable, soft artificial muscles made by weaving and knitting, with tunable force and strain. These textile actuators were produced from cellulose yarns assembled into fabrics and coated with conducting polymers using a metal-free deposition. To increase the output force, we assembled yarns in parallel by weaving. The force scaled linearly with the number of yarns in the woven fabric. To amplify the strain, we knitted a stretchable fabric, exhibiting a 53-fold increase in strain. In addition, the textile construction added mechanical stability to the actuators. Textile processing permits scalable and rational production of wearable artificial muscles, and enables novel ways to design assistive devices. PMID:28138542

  19. Knitting and weaving artificial muscles.

    PubMed

    Maziz, Ali; Concas, Alessandro; Khaldi, Alexandre; Stålhand, Jonas; Persson, Nils-Krister; Jager, Edwin W H

    2017-01-01

    A need exists for artificial muscles that are silent, soft, and compliant, with performance characteristics similar to those of skeletal muscle, enabling natural interaction of assistive devices with humans. By combining one of humankind's oldest technologies, textile processing, with electroactive polymers, we demonstrate here the feasibility of wearable, soft artificial muscles made by weaving and knitting, with tunable force and strain. These textile actuators were produced from cellulose yarns assembled into fabrics and coated with conducting polymers using a metal-free deposition. To increase the output force, we assembled yarns in parallel by weaving. The force scaled linearly with the number of yarns in the woven fabric. To amplify the strain, we knitted a stretchable fabric, exhibiting a 53-fold increase in strain. In addition, the textile construction added mechanical stability to the actuators. Textile processing permits scalable and rational production of wearable artificial muscles, and enables novel ways to design assistive devices.

  20. Community collaboration--a weaving.

    PubMed

    Cavanaugh, Nancy; Cheney, Kaats Saa Waa Della

    2002-01-01

    This article describes the collaborative efforts of the Sitka Turning Point Towards Health partnership in Sitka, Alaska. Key steps to its success include defining our terms, finding consensus, maintaining an attitude of respect, engaging people--building relationships, creating work groups, sharing leadership, committing to collaborative leadership, building in sustainability, and telling our story. We have chosen to interlace a weaving metaphor to reflect our Alaskan Native American culture and the vision of our partnership.

  1. The WEAVE disk dynamics survey

    NASA Astrophysics Data System (ADS)

    Famaey, B.; Antoja, T.; Romero-Gomez, M.; Siebert, A.; Babusiaux, C.; Di Matteo, P.; Figueras, F.; Fragkoudi, F.; Garzon-Lopez, F.; Gonzalez-Fernandez, C.; Martinez-Valpuesta, I.; Monari, G.; Mor-Crespo, R.; Hill, V.

    2016-12-01

    WEAVE is the next-generation wide-field survey facility for the William Herschel Telescope. It consists of a multi-object fibre spectrograph with a 2°-diameter field of view that can obtain ˜ 1000 spectra simultaneously. The "WEAVE Galactic Archaeology survey" is the survey focused on the Milky Way, as a complement to the Gaia space mission, and will start operating in early 2018. This survey is subdivided in four sub-surveys, among which the "WEAVE disk dynamics survey". This survey plans to measure the radial velocities (and abundances as far as possible) of ˜ 10^6 stars with magnitude 15

  2. Some remarks on static, creep and fatigue flexural strength of satin woven CFRP laminates

    SciTech Connect

    Miyano, Y.; McMurry, M.K.; Muki, R.

    1995-12-31

    This paper deals with the time-temperature dependent flexural strength of a satin-woven CFRP laminate having a matrix resin with a high glass transition temperature of T{sub g} = 236/C under static, creep and fatigue loading by 3-point bending tests. Static tests were conducted at various points in a wide range of deflection rates and temperatures. The creep and fatigue tests were carried out at various constant temperatures; the fatigue test was conducted at two frequencies. The results of the experimental study are as follows. The flexural strength of the CFRP laminates for all three loading types is time-temperature dependent even near room temperature well below T{sub g}. The time and temperature superposition principle for the matrix resin also holds for the flexural strength of the CFRP laminates. The fracture modes are almost the same for the three loading types under all conditions tested. Finally, we propose a method for predicting the flexural fatigue strength for a given number of cycles to failure at an arbitrary temperature, frequency and stress ratio based on the current experimental findings and considering the relationships among the static, creep and fatigue flexural strengths.

  3. On Weaving: Past to Present to Idea.

    ERIC Educational Resources Information Center

    Van Dommelen, David B.

    1979-01-01

    This article gives a very brief history of weaving and discusses using a primitive loom in the art classroom. Particular attention is given to construction of the loom and the design concerns in weaving. One of seven articles in this issue on fiber arts. (SJL)

  4. Aerobic capacity in wild satin bowerbirds: repeatability and effects of age, sex and condition.

    PubMed

    Chappell, Mark A; Savard, Jean-Francois; Siani, Jennifer; Coleman, Seth W; Keagy, Jason; Borgia, Gerald

    2011-10-01

    Individual variation in aerobic capacity has been extensively studied, especially with respect to condition, maturity or pathogen infection, and to gain insights into mechanistic foundations of performance. However, its relationship to mate competition is less well understood, particularly for animals in natural habitats. We examined aerobic capacity [maximum rate of O2 consumption (VO2,max) in forced exercise] in wild satin bowerbirds, an Australian passerine with a non-resource based mating system and strong intermale sexual competition. We tested for repeatability of mass and VO2,max, differences among age and sex classes, and effects of several condition indices. In adult males, we examined interactions between aerobic performance and bower ownership (required for male mating success). There was significant repeatability of mass and VO2,max within and between years, but between-year repeatability was lower than within-year repeatability. VO2,max varied with an overall scaling to mass(0.791), but most variance in VO2,max was not explained by mass. Indicators of condition (tarsus and wing length asymmetry, the ratio of tarsus length to mass) were not correlated to VO2,max. Ectoparasite counts were weakly correlated to VO2,max across all age-sex classes but not within any class. Adult males, the cohort with the most intense levels of mating competition, had higher VO2,max than juvenile birds or adult females. However, there was no difference between the VO2,max of bower-owning males and that of males not known to hold bowers. Thus one major factor determining male reproductive success was not correlated to aerobic performance.

  5. Twofold orthogonal weavings on cuboids

    PubMed Central

    Kovács, Flórián

    2016-01-01

    Some closed polyhedral surfaces can be completely covered by two-way, twofold (rectangular) weaving of strands of constant width. In this paper, a construction for producing all possible geometries for such weavable cuboids is proposed: a theorem on spherical octahedra is proven first that all further theory is based on. The construction method of weavable cuboids itself relies on successive truncations of an initial tetrahedron and is also extended for cases of degenerate (unbounded) polyhedra. Arguments are mainly based on the plane geometry of the development of the respective polyhedra, in connection with some of three-dimensional projective properties of the same. PMID:27118910

  6. WAS: Textures of the WEAVE Science Archive

    NASA Astrophysics Data System (ADS)

    Molinari, E.; Guerra, J.; Lodi, M.; Benn, C.; Domínguez, L.

    2016-10-01

    WAS is the WEAVE1 Science Archive, a part of the Science Data Processing of the spectrograph, which keeps a record of all the observations, calibrations, processed spectra and astrophysical metadata obtained with the WEAVE automatic pipelines. It will have connections with all the producers in the system flow, beginning with the surveys catalog compiler, through the Observing Control Software, the Core Processing Software and the Advanced Processing Software. Every version of the products will be recorded and made accessible, and the relevant database will allow basic and more complex searches, filtering and (meta)data retrieval.

  7. Spillmann's weaves are more resilient than Hermann's grid.

    PubMed

    Hamburger, Kai; Shapiro, Arthur G

    2009-07-01

    In a classic Hermann grid display, faint and transient (illusory) spots are produced at the intersections of a white grid superimposed on a black background (or vice versa). In a variant of the Hermann grid developed by Spillmann and Levine (Spillmann, L., & Levine, J. (1971). Contrast enhancement in a Hermann grid with variable figure-ground ratio. Experimental Brain Research, 13, 547-559), the vertical and horizontal bars have different reflectance levels. In previous studies, the illusory spots in the Hermann and Spillmann and Levine grids have been treated analogously. Here, we focus on differences by introducing two types of 'weaves': one type consists of intertwined vertical and horizontal bars with the same luminance levels (hereinafter referred to as 'equiluminant weaves'); the vertical bars in the other type of weave differ in luminance level from the horizontal bars (hereinafter referred to as 'luminance-mismatched weaves'). The Hermann grid is a type of equiluminant weave, and the portion of the Spillmann and Levine grid in which the bars have different reflectance levels is similar to the luminance-mismatched weave. We demonstrate differences between illusory spots produced by luminance-mismatched weaves (and therefore Spillmann and Levine displays) and spots produced by equiluminant weaves (and therefore the Hermann grid): (1) low-pass equiluminant weaves create scintillating patterns, whereas low-pass luminance-mismatched weaves do not; (2) unlike spots for equiluminant weaves, the spots for the luminance-mismatched weaves are not abolished by jagged bars, wavy bars, thick bars, or orientation changes; (3) unlike the spots for equiluminant weaves, the spots for luminance-mismatched weaves occur foveally; and (4) unlike the spots for equiluminant weaves, luminance-mismatched weaves can be created with contrast variation (contrast-contrast, or 2nd-order weaves). We suggest three possible explanations for these results: (1) equiluminant weaves are just a

  8. A Maori Pedagogy: Weaving the Strands Together

    ERIC Educational Resources Information Center

    Stucki, Paora

    2012-01-01

    Literature on Maori pedagogy up until now has been disparate, some dealing with methodological issues, some with learning theory, some with environment and so forth. This article seeks to build one comprehensive picture of Maori pedagogy by weaving the myriad disparate themes in the literature into one unifying model. It is based on an EdD study…

  9. Weaving in the Story of Science

    ERIC Educational Resources Information Center

    Kirchhoff, Allison

    2008-01-01

    Stories weave common elements of the nature of science between topics and activities, regardless of whether it's short historical narratives about scientists or current event articles that are read. Stories also can help students realize the important contributions of persons of color, women, and other traditionally underrepresented groups. In…

  10. Analysis of plain-weave composites

    NASA Astrophysics Data System (ADS)

    Soykasap, Ö.

    2011-05-01

    The paper analyzes the mechanical properties of plain-weave composites by employing different micromechanical models. Their in-plane and flexural properties are estimated using analytical approaches, including the rule of mixtures and one-dimensional composite beam and two-dimensional mosaic models. The expressions of effective material properties are obtained for one-, two-, and three-ply woven composites. The results obtained are in agreement with published data.

  11. Fibre positioning algorithms for the WEAVE spectrograph

    NASA Astrophysics Data System (ADS)

    Terrett, David L.; Lewis, Ian J.; Dalton, Gavin; Abrams, Don Carlos; Aguerri, J. Alfonso L.; Bonifacio, Piercarlo; Middleton, Kevin; Trager, Scott C.

    2014-07-01

    WEAVE is the next-generation wide-field optical spectroscopy facility for the William Herschel Telescope (WHT) in La Palma, Canary Islands, Spain. It is a multi-object "pick and place" fibre fed spectrograph with more than one thousand fibres, similar in concept to the Australian Astronomical Observatory's 2dF1 instrument with two observing plates, one of which is observing the sky while other is being reconfigured by a robotic fibre positioner. It will be capable of acquiring more than 10000 star or galaxy spectra a night. The WEAVE positioner concept uses two robots working in tandem in order to reconfigure a fully populated field within the expected 1 hour dwell-time for the instrument (a good match between the required exposure times and the limit of validity for a given configuration due to the effects of differential refraction). This presents additional constraints and complications for the software that determines the optimal path from one configuration to the next, particularly given the large number of fibre crossings implied by the 1000 fibre multiplex. This paper describes the algorithms and programming techniques used in the prototype implementations of the field configuration tool and the fibre positioner robot controller developed to support the detailed design of WEAVE.

  12. Size-Free Weaving of Cotton Fabrics on a Modern High-Speed Weaving Machine: An Updated Progress Report

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Weaving experiments to produce 1/2-twill fabrics of varied constructions, using a size-free (common) cotton warp, have been conducted under mill-like conditions on a modern, high-speed, flexible-rapier weaving machine. More than 100 yards of fabrics of the same warp density and different pick densit...

  13. Simplified Micromechanics of Plain Weave Composites

    NASA Technical Reports Server (NTRS)

    Mital, Subodh K.; Murthy, Pappu L. N.; Chamis, Christos C.

    1996-01-01

    A micromechanics based methodology to simulate the complete hygro-thermomechanical behavior of plain weave composites is developed. This methodology is based on micromechanics and the classical laminate theory. The methodology predicts a complete set of thermal, hygral and mechanical properties of plain woven composites, generates necessary data for use in a finite element structural analysis, and predicts stresses all the way from the laminate to the constituent level. This methodology is used in conjunction with a composite mechanics code to analyze and predict the properties/response of a generic graphite/epoxy woven textile composite and a plain weave ceramic composite. The fiber architecture, including the fiber waviness and fiber end distributions through the thickness, is properly accounted for. Predicted results compare reasonably well with those from detailed three-dimensional finite element analyses as well as available experimental data. However, the main advantage of the proposed methodology is its high computational efficiency as compared with three-dimensional finite element analyses.

  14. Characterization and development of materials for advanced textile composites

    NASA Technical Reports Server (NTRS)

    Hartness, J. Timothy; Greene, Timothy L.; Taske, Leo E.

    1993-01-01

    Work ongoing under the NASA Langley - Advanced Composite Technology (ACT) program is discussed. The primary emphasis of the work centers around the development and characterization of graphite fiber that has been impregnated with an epoxy powder. Four epoxies have been characterized in towpreg form as to their weaveability and braidability. Initial mechanical properties have been generated on each resin system. These include unidirectional as well as 8-harness satin cloth. Initial 2D and 3D weaving and braiding trials will be reported on as well as initial efforts to develop towpreg suitable for advanced tow placement.

  15. Creep of plain weave polymer matrix composites

    NASA Astrophysics Data System (ADS)

    Gupta, Abhishek

    Polymer matrix composites are increasingly used in various industrial sectors to reduce structural weight and improve performance. Woven (also known as textile) composites are one class of polymer matrix composites with increasing market share mostly due to their lightweight, their flexibility to form into desired shape, their mechanical properties and toughness. Due to the viscoelasticity of the polymer matrix, time-dependent degradation in modulus (creep) and strength (creep rupture) are two of the major mechanical properties required by engineers to design a structure reliably when using these materials. Unfortunately, creep and creep rupture of woven composites have received little attention by the research community and thus, there is a dire need to generate additional knowledge and prediction models, given the increasing market share of woven composites in load bearing structural applications. Currently, available creep models are limited in scope and have not been validated for any loading orientation and time period beyond the experimental time window. In this thesis, an analytical creep model, namely the Modified Equivalent Laminate Model (MELM), was developed to predict tensile creep of plain weave composites for any orientation of the load with respect to the orientation of the fill and warp fibers, using creep of unidirectional composites. The ability of the model to predict creep for any orientation of the load is a "first" in this area. The model was validated using an extensive experimental involving the tensile creep of plain weave composites under varying loading orientation and service conditions. Plain weave epoxy (F263)/ carbon fiber (T300) composite, currently used in aerospace applications, was procured as fabrics from Hexcel Corporation. Creep tests were conducted under two loading conditions: on-axis loading (0°) and off-axis loading (45°). Constant load creep, in the temperature range of 80-240°C and stress range of 1-70% UTS of the

  16. Stick-Weaving: Innovative Behavior in Tamarins (Saguinus oedipus).

    PubMed

    Snowdon, Charles T; Roskos, Thomas R

    2017-03-09

    Some captive cotton-top tamarins spontaneously weave sticks in the mesh of their enclosures so that the stick is lodged between two mesh openings. Sticks are broken from natural branches placed in the enclosures and often modified by biting them in the center before weaving through the mesh. To investigate this further, we systematically surveyed all animals in our colony and found that all successful stick-weaving tamarins were descendants from only 2 of the 16 breeding groups contributing to the colony membership at the time of surveying or were the mates of these descendants, suggesting stick-weaving is a socially learned behavior. Successful stick-weavers were presented with pipe cleaners, soda straws, and wooden dowels to see if they would generalize stick-weaving to novel objects. Seven of 10 animals successfully wove with straws or pipe cleaners, showing that they could generalize the behavior to objects that were physically different but had the same affordances as the sticks. Data from a father-daughter pair suggest a form of coaching. Innovative behavior is needed for the emergence of culture with subsequent social transmission. Although innovative behavior in primates is mainly associated with foraging and is more likely to occur among males, stick-weaving has no obvious reward and appeared equally in both sexes. Stick-weaving behavior and its probable social transmission across generations suggest the possibility of cultural traditions emerging in this species. (PsycINFO Database Record

  17. Weaving child psychoanalysis: Past, present, and future.

    PubMed

    Brinich, Paul M

    2013-01-01

    Using the metaphor of a fabric woven from many threads, this paper describes nine of the many conceptual strands that have contributed to the development of child psychoanalysis over its first century. It notes the unfortunate isolation (sometimes self-imposed) of child analysis from related fields (including adult analysis) and argues that we must recognize both the strengths and weaknesses of our psychoanalytic tools if we are to collaborate with and profit from the work of nonanalytic colleagues. It closes with the suggestion that the continued weaving of child analysis will require the creation of new looms, structures that are able to support a new generation of child analysts and the continued elaboration of the field.

  18. WAS: the data archive for the WEAVE spectrograph

    NASA Astrophysics Data System (ADS)

    Guerra, Jose; Molinari, Emilio; Lodi, Marcello; Martin, Adrian; Dalton, Gavin B.; Trager, Scott C.; Jin, Shoko; Abrams, Don Carlos; Bonifacio, Piercarlo; López Aguerri, Jose Alfonso; Vallenari, Antonella; Carrasco Licea, Esperanza E.; Middleton, Kevin F.

    2016-08-01

    The WAS1(WEAVE Archive System) is a software architecture for archiving and delivering the data releases for the WEAVE7 instrument at WHT (William Herschel Telescope). The WEAVE spectrograph will be mounted at the 4.2-m WHT telescope and will provide millions of spectra in a 5-year program, starting early 2018. The access and retrieval of information will be through its dedicated archive, the WEAVE Archive System (WAS). This will be developed and maintained at the TNG2 premises on the same island as the WHT. Its structure foresees the main axes of scalability, virtualization, and high availability. We present here the first performances on a simulated data set of 20M spectra, using different architectures and hardware choices.

  19. Progress report on the wisker weaving all-hexahedral meshing algorithm

    SciTech Connect

    Tautges, T.J.; Mitchell, S.A.

    1996-02-01

    In this paper, a review of the Spatial Twist Contiuum and the basic whisker weaving algorithm are given. Progress in the detection and resolution of several types of degeneracies formed by whisker weaving are discussed. These examples include so-called knife doublets, triple doublets, through-cells and through-chords. Knife doublets and triple doublets are resolved by preventing their formation a-priori, which forces whisker weaving to remove the element(s) causing the degeneracy. Through-chords and through-cells are left in the weave and resolved after the weave has been closed. The paper concludes with three examples of geometries ``closed`` by whisker weaving.

  20. Weaving of organic threads into a crystalline covalent organic framework.

    PubMed

    Liu, Yuzhong; Ma, Yanhang; Zhao, Yingbo; Sun, Xixi; Gándara, Felipe; Furukawa, Hiroyasu; Liu, Zheng; Zhu, Hanyu; Zhu, Chenhui; Suenaga, Kazutomo; Oleynikov, Peter; Alshammari, Ahmad S; Zhang, Xiang; Terasaki, Osamu; Yaghi, Omar M

    2016-01-22

    A three-dimensional covalent organic framework (COF-505) constructed from helical organic threads, designed to be mutually weaving at regular intervals, has been synthesized by imine condensation reactions of aldehyde functionalized copper(I)-bisphenanthroline tetrafluoroborate, Cu(PDB)2(BF4), and benzidine (BZ). The copper centers are topologically independent of the weaving within the COF structure and serve as templates for bringing the threads into a woven pattern rather than the more commonly observed parallel arrangement. The copper(I) ions can be reversibly removed and added without loss of the COF structure, for which a tenfold increase in elasticity accompanies its demetalation. The threads in COF-505 have many degrees of freedom for enormous deviations to take place between them, throughout the material, without undoing the weaving of the overall structure.

  1. Anomalous Stretchable Conductivity Using an Engineered Tricot Weave.

    PubMed

    Lee, Yong-Hee; Kim, Yoonseob; Lee, Tae-Ik; Lee, Inhwa; Shin, Jaeho; Lee, Hyun Soo; Kim, Taek-Soo; Choi, Jang Wook

    2015-12-22

    Robust electric conduction under stretching motions is a key element in upcoming wearable electronic devices but is fundamentally very difficult to achieve because percolation pathways in conductive media are subject to collapse upon stretching. Here, we report that this fundamental challenge can be overcome by using a parameter uniquely available in textiles, namely a weaving structure. A textile structure alternately interwoven with inelastic and elastic yarns, achieved via a tricot weave, possesses excellent elasticity (strain up to 200%) in diagonal directions. When this textile is coated with conductive nanomaterials, proper textile engineering allows the textile to obtain an unprecedented 7-fold conductivity increase, with conductivity reaching 33,000 S cm(-1), even at 130% strain, due to enhanced interyarn contacts. The observed stretching conductivity can be described well using a modified 3D percolation theory that reflects the weaving effect and is also utilized for stretchable electronic interconnects and supercapacitors with high performance.

  2. A prototype yarn evaluation tester to rapidly assess comparative weavability of warp yarns without weaving

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The art of weaving continues to be the most predominantly used method of converting textile fibers into fabrics for various end-use applications, including apparel. In fact, the weaving is by far the largest textile manufacturing sector, worldwide. However, the weaving process is complex and costly....

  3. Mechanical Analyses of Real Time Warp Yarn Tensions in Size-Free Weaving

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A 100% cotton, size-less common warp was used to study the real-time tensions of single strands of the warp during weaving on a high-speed weaving machine. The machine was operated under almost mill-like conditions. In order to investigate the independent effects of the weaving speed and fabric cons...

  4. The Circulation and Silence of Weaving Knowledge in Contemporary Navajo Life

    ERIC Educational Resources Information Center

    Yohe, Jill Ahlberg

    2012-01-01

    This article draws upon ethnographic fieldwork within a Navajo community to illustrate how weaving knowledge and practices shape contemporary notions of community identity and belonging. The ongoing exchange of Navajo weaving taboos and the careful management of weaving teachings offers community members various opportunities to share and keep…

  5. How to Weave a Cognitive Web

    NASA Astrophysics Data System (ADS)

    Morris, R. A.; Dungan, J. L.; Votava, P.

    2006-12-01

    interactions with the sensor and product web through technologies related to plan execution and monitoring. Finally, the process of transforming products to goals requires the development of visualization and goal generation tools based on the notion we call model-based goal-generation. We will highlight recent advances in these software technologies that are relevant to realizing the goal of weaving a cognitive web.

  6. Wissa Wassef's Experiment: The Phoenix of Egyptian Weaving.

    ERIC Educational Resources Information Center

    Court, Elsbeth

    1985-01-01

    The gallery and weaving workshops of the Wissa Wassef School, located near Cairo, Egypt, are described. The school was started 30 years ago by the Egyptian architect Wissa Wassef, who believed in innate creativity and the need to encourage artistic creation by the practice of the craft from early childhood. (RM)

  7. Oh What a Tangled Biofilm Web Bacteria Weave

    MedlinePlus

    ... a Tangled Biofilm Web Bacteria Weave Inside Life Science View All Articles | Inside Life Science Home Page Oh What a Tangled Biofilm Web ... Conversations Learning from Bacterial Chatter This Inside Life Science article also appears on LiveScience . Learn about related ...

  8. Career Unit. The Art of Navajo Rug Weaving.

    ERIC Educational Resources Information Center

    Robb, Edna; And Others

    This career exploration instructional unit on Navajo rug weaving is one of several resulting from the rural southwestern Colorado CEPAC Project (Career Education Process of Attitude Change). This unit consists of (1) five unit objectives (to recognize the importance of sheep in the Indians' life, to realize the time required to prepare wool for…

  9. How to Weave... the Web Into K-8 Science

    ERIC Educational Resources Information Center

    Wetzel, David R.

    2005-01-01

    Like a search engine for science teachers, How to... "Weave the Web into K-8 Science" is a custom-made guide to bringing the best of the Internet into the classroom. Author David Wetzel has done the work of locating online materials. The book offers resources for Web-based science teaching and learning plus online technical help for both…

  10. Snakes in the Grass: Weaving Success for Everyone.

    ERIC Educational Resources Information Center

    Ide, Janet L.

    2000-01-01

    Describes "Snakes in the Grass," a weaving project used with special needs students. Discusses the preliminary skill-building activities used, the process for creating the students' individual snakes, and the preparation and process for how the students wove the snakes. (CMK)

  11. When Sandpaper Is 'Kiki' and Satin Is 'Bouba': an Exploration of the Associations Between Words, Emotional States, and the Tactile Attributes of Everyday Materials.

    PubMed

    Etzi, Roberta; Spence, Charles; Zampini, Massimiliano; Gallace, Alberto

    2016-01-01

    Over the last decade, scientists working on the topic of multisensory integration, as well as designers and marketers involved in trying to understand consumer behavior, have become increasingly interested in the non-arbitrary associations (e.g., sound symbolism) between different sensorial attributes of the stimuli they work with. Nevertheless, to date, little research in this area has investigated the presence of these crossmodal correspondences in the tactile evaluation of everyday materials. Here, we explore the presence and nature of the associations between tactile sensations, the sound of non-words, and people's emotional states. Samples of cotton, satin, tinfoil, sandpaper, and abrasive sponge, were stroked along the participants' forearm at the speed of 5 cm/s. Participants evaluated the materials along several dimensions, comprising scales anchored by pairs of non-words (e.g., Kiki/Bouba) and adjectives (e.g., ugly/beautiful). The results revealed that smoother textures were associated with non-words made up of round-shaped sounds (e.g., Maluma), whereas rougher textures were more strongly associated with sharp-transient sounds (e.g., Takete). The results also revealed the presence of a number of correspondences between tactile surfaces and adjectives related to visual and auditory attributes. For example, smooth textures were associated with features evoked by words such as 'bright' and 'quiet'; by contrast, the rougher textures were associated with adjectives such as 'dim' and 'loud'. The textures were also found to be associated with a number of emotional labels. Taken together, these results further our understanding of crossmodal correspondences involving the tactile modality and provide interesting insights in the applied field of design and marketing.

  12. Three-dimensional stress analysis of plain weave composites

    NASA Technical Reports Server (NTRS)

    Whitcomb, John D.

    1989-01-01

    Techniques were developed and described for performing three-dimensional finite element analysis of plain weave composites. Emphasized here are aspects of the analysis which are different from analysis of traditional laminated composites, such as the mesh generation and representative unit cells. The analysis was used to study several different variations of plain weaves which illustrate the effects of tow waviness on composite moduli, Poisson's ratios, and internal strain distributions. In-plane moduli decreased almost linearly with increasing tow waviness. The tow waviness was shown to cause large normal and shear strain concentrations in composites subjected to uniaxial load. These strain concentrations may lead to earlier damage initiation than occurs in traditional cross-ply laminates.

  13. Fibre positioning concept for the WEAVE spectrograph at the WHT

    NASA Astrophysics Data System (ADS)

    Lewis, Ian J.; Dalton, Gavin B.; Brock, Matthew; Gilbert, James; Abrams, Don C.; Aguerri, J. Alfonso L.; Bonifacio, Piercarlo; Middleton, Kevin; Trager, Scott C.

    2014-07-01

    WEAVE is the next-generation wide-field optical spectroscopy facility for the William Herschel Telescope (WHT) in La Palma, Canary Islands, Spain. It is a multi-object "pick and place" fibre fed spectrograph with more than one thousand fibres behind a new dedicated 2° prime focus corrector, This is similar in concept to the Australian Astronomical Observatory's 2dF instrument1 with two observing plates, one of which is observing the sky while other is being reconfigured by a robotic fibre positioner. It will be capable of acquiring more than 10000 star or galaxy spectra a night. The WEAVE positioner concept uses two robots working in tandem in order to reconfigure a fully populated field within the expected 1 hour dwell-time for the instrument (a good match between the required exposure times and the limit of validity for a given configuration due to the effects of differential refraction).

  14. Gaia, PLATO and WEAVE: A Powerful combination for Exoplanet Characterisation

    NASA Astrophysics Data System (ADS)

    Walton, Nicholas

    2015-12-01

    This presentation will describe the powerful linkages between the Gaia and PLATO missions and the potential impact of the WHT’s WEAVE multi-object spectrograph in the study of exoplanet populations.ESA’s Gaia mission commenced its nominal operations phase in July 2014. Its first data release is expected summer 2016. Over the course of its (at least) five year mission, it will discover, via their astrometric signatures, upwards of 20,000 massive Jupiter sized long period planets at distances out to several hundred parsecs around all star types. In addition Gaia will discover a significant number of short period hot Jupiters around M stars. This presentation will discuss the form and content of the first Gaia Data Release. The ESA PLATO mission, planned to launch in 2024, will photometrically observe a million host stars, and will detect, via the transit technique, planets down to Earth masses. PLATO will observe two fields of over 2,000 square degrees for 2 to 3 years each. At least one of these will be in the northern hemisphere. where WEAVE (a new multi object high resolution spectrograph currently under construction for the 4.2m William Herschel Telescope) will have the potential to provide detailed chemical characterisation of the host stars of the Gaia and PLATO exoplanet systems. This will enable insights into, for instance, metallicity of the host star correlations against both massive exoplanets (perhaps confirming current relationships), and lower mass exoplanets.We note how the rapid exploitation of such a potential WEAVE survey could be achieved, utilising the WEAVE processing systems being developed at the IoA, Cambridge, coupled with efficient interfaces to the Cambridge Gaia and PLATO data processing centres.

  15. The WEAVE focus translation system: from design to construction

    NASA Astrophysics Data System (ADS)

    Canchado, Manuel; Romero, Antonio; Maroto, Óscar; Tomas, Albert; Martín-Nuño, Carlos; Casalta, Joan Manel; Prida, Joaquín.; L. Aguerri, J. Alfonso; Herreros, José Miguel; Delgado, José Miguel; Burgal, José Alonso; Abrams, Don Carlos; Dee, Kevin; Dalton, Gavin; Bonifacio, Piercarlo; Trager, Scott C.; Vallenari, Antonella

    2016-07-01

    WEAVE is a new wide-field spectroscopy facility proposed for the prime focus of the 4.2m William Herschel Telescope (WHT), placed in La Palma, Canary Islands, Spain. To allow for the compensation of the effects of temperature-induced and gravity-induced image degradation, the WEAVE prime focus assembly will be translated along the telescope optical axis. The assembly comprises the prime focus corrector with integrated ADC, a central mount for the corrector, an instrument rotator and a twin-focal-plane fibre positioner. Translation is accomplished through the use of a set of purpose-built actuators; collectively referred to as the Focus Translation System (FTS), formed by four independently-controlled Focus Translation Units (FTUs), eight vanes connecting the FTUs to a central can, and a central can hosting WEAVE Instrument. Each FTU is capable of providing a maximum stroke of +/-4mm with sufficient, combined force to move the five-tonne assembly with a positional accuracy of +/-20μm at a resolution of 5μm. The coordinated movement of the four FTUs allows +/-3mm WEAVE focus adjustment in the optical axis and +/-0.015° tilt correction in one axis. The control of the FTS is accomplished through a PLC-based subsystem that receives positional demands from the higher-level Instrument Control System. SENER has been responsible for designing, manufacturing and testing the FTS and the equipment required to manipulate and store the FTS together with the instrument. This manuscript describes the final design of the FTS along with the analyses and simulations that were performed, discusses the manufacturing procedures and the results of early verification prior to integration with the telescope. The plans for mounting the whole system on the telescope are also discussed.

  16. Weaving properties of generalized continuous frames generated by an iterated function system

    NASA Astrophysics Data System (ADS)

    Vashisht, L. K.; Deepshikha

    2016-12-01

    In this paper, we present some classes of generalized continuous weaving frames. It is shown that if the sets of lower frame bounds of discrete frames for a Hilbert space are bounded below, then the corresponding generalized continuous frames are woven. Necessary and sufficient conditions for generalized continuous weaving frames generated by an iterated function system are given.

  17. Textile Technologies and Tissue Engineering: A Path Toward Organ Weaving.

    PubMed

    Akbari, Mohsen; Tamayol, Ali; Bagherifard, Sara; Serex, Ludovic; Mostafalu, Pooria; Faramarzi, Negar; Mohammadi, Mohammad Hossein; Khademhosseini, Ali

    2016-04-06

    Textile technologies have recently attracted great attention as potential biofabrication tools for engineering tissue constructs. Using current textile technologies, fibrous structures can be designed and engineered to attain the required properties that are demanded by different tissue engineering applications. Several key parameters such as physiochemical characteristics of fibers, microarchitecture, and mechanical properties of the fabrics play important roles in the effective use of textile technologies in tissue engineering. This review summarizes the current advances in the manufacturing of biofunctional fibers. Different textile methods such as knitting, weaving, and braiding are discussed and their current applications in tissue engineering are highlighted.

  18. Textile Technologies and Tissue Engineering: A Path Towards Organ Weaving

    PubMed Central

    Akbari, Mohsen; Tamayol, Ali; Bagherifard, Sara; Serex, Ludovic; Mostafalu, Pooria; Faramarzi, Negar; Mohammadi, Mohammad Hossein

    2016-01-01

    Textile technologies have recently attracted great attention as potential biofabrication tools for engineering tissue constructs. Using current textile technologies, fibrous structures can be designed and engineered to attain the required properties that are demanded by different tissue engineering applications. Several key parameters such as physiochemical characteristics of fibers, pore size and mechanical properties of the fabrics play important role in the effective use of textile technologies in tissue engineering. This review summarizes the current advances in the manufacturing of biofunctional fibers. Different textile methods such as knitting, weaving, and braiding are discussed and their current applications in tissue engineering are highlighted. PMID:26924450

  19. Workstation design in carpet hand-weaving operation: guidelines for prevention of musculoskeletal disorders.

    PubMed

    Choobineh, Alireza; Lahmi, Mohammadali; Hosseini, Mostafa; Shahnavaz, Houshang; Jazani, Reza Khani

    2004-01-01

    Carpet weavers suffer from musculoskeletal problems mainly attributed to poor working postures. Their posture is mostly constrained by the design of workstations. This study was conducted to investigate the effects of 2 design parameters (weaving height and seat type) on postural variables and subjective experience, and to develop guidelines for workstation adjustments. At an experimental workstation, 30 professional weavers worked in 9 different conditions. Working posture and weavers' perceptions were measured. It was shown that head, neck and shoulder postures were influenced by weaving height. Both design parameters influenced trunk and elbows postures. The determinant factor for weavers' perception on the neck, shoulders and elbows was found to be weaving height, and on the back and knees it was seat type. Based on the results, the following guidelines were developed: (a) weaving height should be adjusted to 20 cm above elbow height; (b) a 10 degrees forward-sloping high seat is to be used at weaving workstations.

  20. Predicting Spacecraft Trajectories by the WeavEncke Method

    NASA Technical Reports Server (NTRS)

    Weaver, Jonathan K.; Adamo, Daniel R.

    2011-01-01

    A combination of methods is proposed of predicting spacecraft trajectories that possibly include multiple maneuvers and/or perturbing accelerations, with greater speed, accuracy, and repeatability than were heretofore achievable. The combination is denoted the WeavEncke method because it is based on unpublished studies by Jonathan Weaver of the orbit-prediction formulation of the noted astronomer Johann Franz Encke. Weaver evaluated a number of alternatives that arise within that formulation, arriving at an orbit-predicting algorithm optimized for complex trajectory operations. In the WeavEncke method, Encke's method of prediction of perturbed orbits is enhanced by application of modern numerical methods. Among these methods are efficient Kepler s-equation time-of-flight solutions and self-starting numerical integration with time as the independent variable. Self-starting numerical integration satisfies the requirements for accuracy, reproducibility, and efficiency (and, hence, speed). Self-starting numerical integration also supports fully analytic regulation of integration step sizes, thereby further increasing speed while maintaining accuracy.

  1. Analysis of woven and braided fabric reinforced composites

    NASA Technical Reports Server (NTRS)

    Naik, Rajiv A.

    1994-01-01

    A general purpose micromechanics analysis that discretely models the yarn architecture within the textile repeating unit cell, was developed to predict overall, three dimensional, thermal and mechanical properties. This analytical technique was implemented in a user-friendly, personal computer-based, windows compatible code called Textile Composite Analysis for Design (TEXCAD). TEXCAD was used to analyze plain, 5-harness satin, and 8-harness satin weave composites along with 2-D braided and 2x2, 2-D triaxial braided composites. The calculated overall stiffnesses correlated well with available 3-D finite element results and test data for both the woven and the braided composites. Parametric studies were performed to investigate the effects of yarn size on the yarn crimp and the overall thermal and mechanical constants for plain weave composites. The effects of braid angle were investigated for the 2-D braided composites. Finally, the effects of fiber volume fraction on the yarn undulations and the thermal and mechanical properties of 2x2, 2-D triaxial braided composites were also investigated.

  2. Towards an Integrated Model of the WEAVE Performance

    NASA Astrophysics Data System (ADS)

    Ham, S. J.; Dalton, G.

    2016-10-01

    WEAVE is a new facility instrument for the 4.2 m William Herschel Telescope (WHT). The instrument has a 2° field of view and covers a wavelength range of 366-950 nm with up to 960 simultaneous spectra in each observation. The spectrograph consists of a collimator mirror and two correcting lenses before a VPH grating and two 8-lens cameras. The two cameras have been designed to have the same lens shapes. Here we report on the development of detailed simulations for the verification of the whole data reduction procedure and analysis pipeline, and for the generation of high signal-to-noise reference images that can be used as fitting templates for fiber positions and PSF mapping.

  3. Systematics, phylogeny, and evolution of orb-weaving spiders.

    PubMed

    Hormiga, Gustavo; Griswold, Charles E

    2014-01-01

    The orb-weaving spiders (Orbiculariae) comprise more than 25% of the approximately 44,000 known living spider species and produce a remarkable variety of webs. The wheel-shaped orb web is primitive to this clade, but most Orbiculariae make webs hardly recognizable as orbs. Orb-weavers date at least to the Jurassic. With no evidence for convergence of the orb web, the monophyly of the two typical orb web taxa, the cribellate Deinopoidea and ecribellate Araneoidea, remains problematic, supported only weakly by molecular studies. The sister group of the Orbiculariae also remains elusive. Despite more than 15 years of phylogenetic scrutiny, a fully resolved cladogram of the Orbiculariae families is not yet possible. More comprehensive taxon sampling, comparative morphology, and new molecular markers are required for a better understanding of orb-weaver evolution.

  4. Weaves as an Interconnection Fabric for ASIM's and Nanosatellites

    NASA Technical Reports Server (NTRS)

    Gorlick, Michael M.

    1995-01-01

    Many of the micromachines under consideration require computer support, indeed, one of the appeals of this technology is the ability to intermix mechanical, optical, analog, and digital devices on the same substrate. The amount of computer power is rarely an issue, the sticking point is the complexity of the software required to make effective use of these devices. Micromachines are the nano-technologist's equivalent of 'golden screws'. In other words, they will be piece parts in larger assemblages. For example, a nano-satellite may be composed of stacked silicon wafers where each wafer contains hundreds to thousands of micromachines, digital controllers, general purpose computers, memories, and high-speed bus interconnects. Comparatively few of these devices will be custom designed, most will be stock parts selected from libraries and catalogs. The novelty will lie in the interconnections. For example, a digital accelerometer may be a component part in an adaptive suspension, a monitoring element embedded in the wrapper of a package, or a portion of the smart skin of a launch vehicle. In each case, this device must inter-operate with other devices and probes for the purposes of command, control, and communication. We propose a software technology called 'weaves' that will permit large collections of micromachines and their attendant computers to freely intercommunicate while preserving modularity, transparency, and flexibility. Weaves are composed of networks of communicating software components. The network, and the components comprising it, may be changed even while the software, and the devices it controls, are executing. This unusual degree of software plasticity permits micromachines to dynamically adapt the software to changing conditions and allows system engineers to rapidly and inexpensively develop special purpose software by assembling stock software components in custom configurations.

  5. Pulmonary toxicity of dust generated during weaving of carpets.

    PubMed

    Ameen, M; Ahmad, I; Rahman, Q

    2002-12-01

    The dust generated during weaving (carpet dust) tibbati, knotted and tuffted carpets in carpet industry was studied for its toxicity in vitro and in vivo. Carpet dust (0.5, 1.0, 2.5 and 5.0 mg/1 x 10(6) cells) caused in vitro cytotoxicity in rat alveolar macrophages (AM) in a concentration-dependent manner. The cytotoxic, inflammatory and oxidative responses were observed in bronchoalveolar lavage fluid (BALF) of rats at 1, 4, 8 and 16 days after exposure. Rats were intratracheally exposed at 5 mg/rat individually to all three types of carpet dust. All types of carpet dusts produced increased AM, lymphocytes (PMN) population in BALF suggesting their inflammatory reactions. Cytotoxic nature of carpet dust was shown by the increased activities of lactate dehydrogenase (LDH) and acid phosphatase (AP) in BALF. Increased AM population and in vitro cytotoxicity due to carpet dusts have shown some correlation with the levels of LDH and AP activities in BALF. The gradual enhanced profile of hydrogen peroxide (H2O2) and nitric oxide (NO) along with depletion of reduced glutathione (GSH) in AM due to these carpet dusts are suggestive of their oxidant nature. The enzyme activities of both glutathione peroxidase (GPx) and glutathione reductase (GR) in AM were marginally reduced in exposed rats. In conclusion, the data suggest the cytotoxic, inflammatory and oxidant nature of carpet dusts. It is extrapolated that health effects on carpet weavers would be associated with the concentration and nature of airborne dust generated during weaving of carpets.

  6. Study of some parameters affecting noise level in textile spinning and weaving mills.

    PubMed

    el-Dakhakhny, A A; Noweir, M H; Kamel, N R

    1975-01-01

    Noise was evaluated in six spinning and five weaving halls located in three textile mills in Egypt. Spindle speed (rpm) and loom speed (picks per minutes) were found to be important parameters affecting the noise level in these mills. Reduction of the number of spinning machines to five spindles per square meter of floor area will probably bring the noise level below the TLV. In the weaving departments, the decrease in the number of looms will not effectively reduce the noise level.

  7. Design of the calibration unit for the WEAVE multi-object spectrograph at the WHT

    NASA Astrophysics Data System (ADS)

    Domínquez, Lilian; Cano, Diego; O'Mahony, Neil; Martín, Carlos; Picó, Sergio; Benn, Chris; Trager, Scott; Lhomé, Émilie; Ridings, Andy; Fariña, Cecilia; Abrams, D. C.; Balcells, Marc; Irwin, Mike; Lewis, Jim; Dalton, Gavin; Aguerri, J. A.; Bonifacio, P.; Vallenari, A.; Carrasco, E.

    2016-08-01

    WEAVE is the next-generation spectroscopic facility for the William Herschel Telescope (WHT), offering multi-object (1000 fibres) and integral-field spectroscopy at two resolutions (R 5000, 20000) over a 2-deg field of view at prime focus. WEAVE will (mainly) provide optical follow up of ground-based (LOFAR) and space-based (GAIA) surveys. First light is expected in mid 2018. Here, we describe the calibration unit, which will be adapted from an existing unit for the AF2+WYFFOS spectrograph (WEAVE's precursor) at the WHT. We summarise the results from a thorough characterisation of current performance (e.g. intensity, stability and focal-plane coverage of illumination as a function of lamp type and wavelength). We then set out our plans for upgrading the unit and its control systems to meet the WEAVE science and operational requirements. We conclude from this assessment that the upgraded AF2+WYFFOS calibration unit will meet the requirements for WEAVE. The design of the WEAVE calibration unit is now complete.

  8. Continuous Forming of Weaving Guides Using a Reel-to-reel Thermal Roller Imprint

    NASA Astrophysics Data System (ADS)

    Ohtomo, Akihiro; Mekaru, Harutaka; Takagi, Hideki; Kokubo, Mitsunori; Goto, Hiroshi

    In the emerging fields related to healthcare, energy, and environment, realization of devices on large area flexible sheets is imminent. Weaving e-textile with fibrous devices comprising warp and weft is one of the methods to realize such devices. Especially with a display or with a 2-D matrix sensor, a distortion of image, or error in positional information can occur if these matrices get misaligned. Therefore securing of the matrix becomes necessary. However, in a traditional textile, due to weak binding force in shear direction at the intersection of warp and weft, the displacement of intersection often does take place. So we propose to make a weaving guide in a form of dent structure on the fiber substrate. To realize this strategy, we developed a system to produce such weaving guides onto a fiber with improved productivity. To maintain a constant press force onto the fiber substrate during imprint, and to stabilize deformation volume, we adopted a press force control mechanism. As a result we obtained a stable and uniform deformation of imprinted weaving guides. Finally, to validate the weaving guide, we made two samples using 3×3 fibers, with and without the weaving guides. We saw distinct difference between the two samples.

  9. Experimental Characterization and Micromechanical Modeling of Woven Carbon/Copper Composites

    NASA Technical Reports Server (NTRS)

    Bednarcyk, Brett A.; Pauly, Christopher C.; Pindera, Marek-Jerzy

    1997-01-01

    The results of an extensive experimental characterization and a preliminary analytical modeling effort for the elastoplastic mechanical behavior of 8-harness satin weave carbon/copper (C/Cu) composites are presented. Previous experimental and modeling investigations of woven composites are discussed, as is the evolution of, and motivation for, the continuing research on C/Cu composites. Experimental results of monotonic and cyclic tension, compression, and Iosipescu shear tests, and combined tension-compression tests, are presented. With regard to the test results, emphasis is placed on the effect of strain gauge size and placement, the effect of alloying the copper matrix to improve fiber-matrix bonding, yield surface characterization, and failure mechanisms. The analytical methodology used in this investigation consists of an extension of the three-dimensional generalized method of cells (GMC-3D) micromechanics model, developed by Aboudi (1994), to include inhomogeneity and plasticity effects on the subcell level. The extension of the model allows prediction of the elastoplastic mechanical response of woven composites, as represented by a true repeating unit cell for the woven composite. The model is used to examine the effects of refining the representative geometry of the composite, altering the composite overall fiber volume fraction, changing the size and placement of the strain gauge with respect to the composite's reinforcement weave, and including porosity within the infiltrated fiber yarns on the in-plane elastoplastic tensile, compressive, and shear response of 8-harness satin C/Cu. The model predictions are also compared with the appropriate monotonic experimental results.

  10. First results of tests on the WEAVE fibres

    NASA Astrophysics Data System (ADS)

    Sayède, Frédéric; Younes, Youssef; Fasola, Gilles; Dorent, Stéphane; Abrams, Don Carlos; Aguerri, J. Alphonso L.; Bonifacio, Piercarlo; Carrasco, Esperanza; Dalton, Gavin; Dee, Kevin; Laporte, Philippe; Lewis, Ian; Lhome, Emilie; Middleton, Kevin; Pragt, Johan H.; Rey, Juerg; Stuik, Remko; Trager, Scott C.; Vallenari, Antonella

    2016-07-01

    WEAVE is a new wide-field spectroscopy facility proposed for the prime focus of the 4.2m William Herschel Telescope. The facility comprises a new 2-degree field of view prime focus corrector with a 1000-multiplex fibre positioner, a small number of individually deployable integral field units, and a large single integral field unit. The IFUs (Integral Field Units) and the MOS (Multi Object Spectrograph) fibres can be used to feed a dual-beam spectrograph that will provide full coverage of the majority of the visible spectrum in a single exposure at a spectral resolution of 5000 or modest wavelength coverage in both arms at a resolution 20000. The instrument is expected to be on-sky by the first quarter of 2018 to provide spectroscopic sampling of the fainter end of the Gaia astrometric catalogue, chemical labeling of stars to V 17, and dedicated follow up of substantial numbers of sources from the medium deep LOFAR surveys. After a brief description of the Fibre System, we describe the fibre test bench, its calibration, and some test results. We have to verify 1920 fibres from the MOS bundles and 740 fibres from the mini-IFU bundles with the test bench. In particular, we present the Focal Ratio Degradation of a cable.

  11. Weaving and bonding method to prevent warp and fill distortion

    NASA Technical Reports Server (NTRS)

    Farley, Gary L. (Inventor)

    1997-01-01

    A method to prevent fiber distortion in textile materials employed in a modified weaving process. In a first embodiment, a tacifier in powder form is applied to the yarn and melted while on the fabric. Cool air is then supplied after the tacifier has melted to expedite the solidification of the tacifier. In a second embodiment, a solution form of a tacifier is used by dissolving the tacifier into a solvent that has a high evaporation rate. The solution is then sprayed onto the fabric or fill yarn as each fill yarn is inserted into a shed of the fabric. A third embodiment applies the tacifier in a liquid form that has not been dissolved in a solvent. That is, the tacifier is melted and is sprayed as a liquid onto the fabric or fill yarn as it is being extracted from a fill yarn spool prior to the fill yarn being inserted into the shed of the fabric. A fourth embodiment employs adhesive yarns contained as an integral part of the warp or fill yarn. Additional tacifier material is not required because a matrix is used as the tacifier. The matrix is then locally melted using heating elements on clamping bars or take-up rollers, is cooled, if necessary, and solidified.

  12. Method and apparatus for weaving curved material preforms

    NASA Technical Reports Server (NTRS)

    Farley, Gary L. (Inventor)

    1995-01-01

    A method and apparatus for fabricating straight or curved planar or three-dimensional (C channel, for example) fabric for fabrication into composite structures is presented. In the first embodiment, the fill yarns are inserted between layers of warp yarns, and a canted or curved reed, depending on the desired orientation of the fill yarns, is used to compact or 'beat-up' the fill yarns. In the second embodiment, the warp yarns of the fabric are curved using a conical or a combination of conical and cylindrical rollers to effect differential fabric take-up of the warp yarns for obtaining a constant radius of curvature of the warp yarns. In a third embodiment, a clamping bar fabric take-up device is used to effect the differential fabric take-up of the warp yarns for obtaining straight warp yarns, curved warp yarns with a constant radius of curvature, curved warp yarns with a non-contant radius of curvature, or some combinations of straight and curved warp yarns. In a fourth embodiment, for forming the flanges of the curved C channel, the warp yarns are alternately inserted through adjacent dent wires of the reed to permit vertical weaving of the flanges.

  13. Oldest true orb-weaving spider (Araneae: Araneidae)

    PubMed Central

    Penney, David; Ortuño, Vicente M

    2006-01-01

    The aerial orb web woven by spiders of the family Araneidae typifies these organisms to laypersons and scientists alike. Here we describe the oldest fossil species of this family, which is preserved in amber from Álava, Spain and represents the first record of Araneidae from the Lower Cretaceous. The fossils provide direct evidence that all three major orb web weaving families: Araneidae, Tetragnathidae and Uloboridae had evolved by this time, confirming the antiquity of the use of this remarkable structure as a prey capture strategy by spiders. Given the complex and stereotyped movements that all orb weavers use to construct their webs, there is little question regarding their common origin, which must have occurred in the Jurassic or earlier. Thus, various forms of this formidable prey capture mechanism were already in place by the time of the explosive Cretaceous co-radiation of angiosperms and their flying insect pollinators. This permitted a similar co-radiation of spider predators with their flying insect prey, presumably without the need for a ‘catch-up lag phase’ for the spiders. PMID:17148427

  14. Weaving single photon imaging into new drug development.

    PubMed

    Mozley, P David

    2005-01-01

    The specific aim of this review is to assess the potential contribution of single photon emitting radiopharmaceutical technologies to new drug development. For each phase of therapeutic drug development, published literature was sought that shows single photon emitters can add value by quantifying pharmacokinetics, visualizing mechanisms of drug action, estimating therapeutic safety indices, or measuring dose-dependent pharmacodynamic effects. Not any published reports were found that describe using nuclear medicine techniques to help manage the progress of a new drug development program. As a consequence, most of the case in favor of weaving single photon imaging into the process had to be built on extrapolations from studies that showed feasibility post hoc. The strongest evidence of potential value was found for drug candidates that hope to influence diseases characterized by cell proliferation or cell death, particularly in the fields of oncology, cardiology, nephrology, and inflammation. Receptor occupancy studies were observed to occasionally offer unique advantages over analogous studies with positron emission tomography (PET). Enough hard data sets were found to justify the costs of using single photon imaging in a variety of new drug development paradigms.

  15. Impact Strength of Different Weaving Patterns of Woven Kenaf Reinforced Polyester Composites

    NASA Astrophysics Data System (ADS)

    Khalid, S. N. A.; Ismail, A. E.; Zainulabidin, M. H.

    2017-01-01

    This paper focuses on the effect of weaving patterns and orientations on the energy absorption of woven kenaf reinforced polyester composites. Kenaf fiber in the form of yarn is weaved to produce different weaving patterns such as plain, twill and basket. Three woven mats are stacked together and mixed with polyester resin before it is compressed to squeeze out any excessive resin. There is 9 different orientations are used during stacking processes. The hardened composites are cured for 24 hours before it is shaped according to specific dimensions for imp act tests. The composites are perforated with 1m/s blunted projectile. According to the experimental findings, both weaving patterns and orientations have distinct potential effects on the force-displacement diagrams. However, fiber orientations have insignificant effect for plain woven especially in the first stage of deformations. Energy absorption performances for each composite condition are calculated and then plotted against fiber orientations for different weaving patterns. It is found there is no strong relationship between energy absorption and fiber orientations. However for each case of composites, higher energy absorption is found for the composites orientated using [+40°/-15°/+40°/+75°]. Based on the fracture observation, both plain and basket-type woven composites reveal large fragmentations occurred indicating lower energy absorption performances. While for twill condition, no obvious fragmentation is observed where the impact damage around the perforated hole is uniformly distributed leading to higher capability of energy absorptions.

  16. Dynamic Data Visualization with Weave and Brain Choropleths

    PubMed Central

    Patterson, Dianne; Hicks, Thomas; Dufilie, Andrew; Grinstein, Georges; Plante, Elena

    2015-01-01

    This article introduces the neuroimaging community to the dynamic visualization workbench, Weave (https://www.oicweave.org/), and a set of enhancements to allow the visualization of brain maps. The enhancements comprise a set of brain choropleths and the ability to display these as stacked slices, accessible with a slider. For the first time, this allows the neuroimaging community to take advantage of the advanced tools already available for exploring geographic data. Our brain choropleths are modeled after widely used geographic maps but this mashup of brain choropleths with extant visualization software fills an important neuroinformatic niche. To date, most neuroinformatic tools have provided online databases and atlases of the brain, but not good ways to display the related data (e.g., behavioral, genetic, medical, etc). The extension of the choropleth to brain maps allows us to leverage general-purpose visualization tools for concurrent exploration of brain images and related data. Related data can be represented as a variety of tables, charts and graphs that are dynamically linked to each other and to the brain choropleths. We demonstrate that the simplified region-based analyses that underlay choropleths can provide insights into neuroimaging data comparable to those achieved by using more conventional methods. In addition, the interactive interface facilitates additional insights by allowing the user to filter, compare, and drill down into the visual representations of the data. This enhanced data visualization capability is useful during the initial phases of data analysis and the resulting visualizations provide a compelling way to publish data as an online supplement to journal articles. PMID:26418012

  17. 25 CFR 309.13 - What are examples of other weaving and textiles that are Indian products?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false What are examples of other weaving and textiles that are Indian products? 309.13 Section 309.13 Indians INDIAN ARTS AND CRAFTS BOARD, DEPARTMENT OF THE INTERIOR PROTECTION OF INDIAN ARTS AND CRAFTS PRODUCTS § 309.13 What are examples of other weaving and textiles...

  18. 25 CFR 309.13 - What are examples of other weaving and textiles that are Indian products?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 2 2014-04-01 2014-04-01 false What are examples of other weaving and textiles that are Indian products? 309.13 Section 309.13 Indians INDIAN ARTS AND CRAFTS BOARD, DEPARTMENT OF THE INTERIOR PROTECTION OF INDIAN ARTS AND CRAFTS PRODUCTS § 309.13 What are examples of other weaving and textiles...

  19. 25 CFR 309.13 - What are examples of other weaving and textiles that are Indian products?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 2 2012-04-01 2012-04-01 false What are examples of other weaving and textiles that are Indian products? 309.13 Section 309.13 Indians INDIAN ARTS AND CRAFTS BOARD, DEPARTMENT OF THE INTERIOR PROTECTION OF INDIAN ARTS AND CRAFTS PRODUCTS § 309.13 What are examples of other weaving and textiles...

  20. 25 CFR 309.13 - What are examples of other weaving and textiles that are Indian products?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 2 2013-04-01 2013-04-01 false What are examples of other weaving and textiles that are Indian products? 309.13 Section 309.13 Indians INDIAN ARTS AND CRAFTS BOARD, DEPARTMENT OF THE INTERIOR PROTECTION OF INDIAN ARTS AND CRAFTS PRODUCTS § 309.13 What are examples of other weaving and textiles...

  1. 25 CFR 309.13 - What are examples of other weaving and textiles that are Indian products?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false What are examples of other weaving and textiles that are Indian products? 309.13 Section 309.13 Indians INDIAN ARTS AND CRAFTS BOARD, DEPARTMENT OF THE INTERIOR PROTECTION OF INDIAN ARTS AND CRAFTS PRODUCTS § 309.13 What are examples of other weaving and textiles...

  2. A WEAVE Radial Velocity Survey to Unravel the Nature of the Milky Way's Spiral Arms

    NASA Astrophysics Data System (ADS)

    Monguió, M.; Figueras, F.; Grosbøl, P.

    2016-10-01

    The nature of the spiral arms of our Milky Way Galaxy is still a matter of debate. Different theories have been suggested (density waves, swing amplification, invariant manifolds...) which impose several constraints on the observables. For the first time it will be possible to disentangle these theories by combining Gaia and WEAVE data. Great advantage comes from the fact that WEAVE is in the Northern Hemisphere, that is with good coverage towards the galactic anticenter. We plan to quantify the kinematic perturbation induced by the Perseus spiral arm through radial velocity measurements. We show how, for the first time, we have detected the stellar overdensity associated with the Perseus arm using a Strömgren photometric survey with the Wide Field Camera on the Isaac Newton Telescope. This survey has allowed us to perform first tests on WEAVE capabilities.

  3. Investigating Cultural Evolution Using Phylogenetic Analysis: The Origins and Descent of the Southeast Asian Tradition of Warp Ikat Weaving

    PubMed Central

    Buckley, Christopher D.

    2012-01-01

    The warp ikat method of making decorated textiles is one of the most geographically widespread in southeast Asia, being used by Austronesian peoples in Indonesia, Malaysia and the Philippines, and Daic peoples on the Asian mainland. In this study a dataset consisting of the decorative characters of 36 of these warp ikat weaving traditions is investigated using Bayesian and Neighbornet techniques, and the results are used to construct a phylogenetic tree and taxonomy for warp ikat weaving in southeast Asia. The results and analysis show that these diverse traditions have a common ancestor amongst neolithic cultures the Asian mainland, and parallels exist between the patterns of textile weaving descent and linguistic phylogeny for the Austronesian group. Ancestral state analysis is used to reconstruct some of the features of the ancestral weaving tradition. The widely held theory that weaving motifs originated in the late Bronze Age Dong-Son culture is shown to be inconsistent with the data. PMID:23272211

  4. Investigating cultural evolution using phylogenetic analysis: the origins and descent of the southeast Asian tradition of warp ikat weaving.

    PubMed

    Buckley, Christopher D

    2012-01-01

    The warp ikat method of making decorated textiles is one of the most geographically widespread in southeast Asia, being used by Austronesian peoples in Indonesia, Malaysia and the Philippines, and Daic peoples on the Asian mainland. In this study a dataset consisting of the decorative characters of 36 of these warp ikat weaving traditions is investigated using Bayesian and Neighbornet techniques, and the results are used to construct a phylogenetic tree and taxonomy for warp ikat weaving in southeast Asia. The results and analysis show that these diverse traditions have a common ancestor amongst neolithic cultures the Asian mainland, and parallels exist between the patterns of textile weaving descent and linguistic phylogeny for the Austronesian group. Ancestral state analysis is used to reconstruct some of the features of the ancestral weaving tradition. The widely held theory that weaving motifs originated in the late Bronze Age Dong-Son culture is shown to be inconsistent with the data.

  5. Weaving Wisdom with Hard Work: Accomplished Student Learns, Grows, and Gives Back

    ERIC Educational Resources Information Center

    Kuhl, Eleanor

    2010-01-01

    Linda Taylor (Dine) raises sheep and horses, creates sculpture, paints, teaches traditional weaving classes, hunts solo for elk and deer, and volunteers at the Methodist Thrift Shop. In the past, she has also cared for Native children in need, and she is currently applying to foster a Navajo girl. On weekends, she sells bales of hay at the…

  6. Learning to Weave the Threads of Honor: Understanding the Value of Female Schooling in Southern Morocco

    ERIC Educational Resources Information Center

    Naji, Myriem

    2012-01-01

    This article is concerned with the role of formal education in the upward social mobility of women in the Sirwa, a marginal Berber region of southern Morocco where carpets are produced by women, and marketed by men. To explore why girls' education in weaving takes precedence over formal education, the article considers the place of women's…

  7. The Weaving of a Tapestry: A Metaphor for Teacher Education Curriculum Development

    ERIC Educational Resources Information Center

    Simon, Susan E

    2013-01-01

    Teacher educators rightfully dream of delivering inspiring programs to benefit future teachers and the students they will in turn inspire. However, in the current teacher education environment in Australia, the artisan's craft of weaving rich texture and producing a masterpiece is potentially over-shadowed by the educational administrator's…

  8. Insertion of Dye-Sensitized Solar Cells in Textiles using a Conventional Weaving Process.

    PubMed

    Yun, Min Ju; Cha, Seung I; Seo, Seon Hee; Kim, Han Seong; Lee, Dong Y

    2015-06-18

    Increasing demands for wearable energy sources and highly flexible, lightweight photovoltaic devices have stimulated the development of textile-structured solar cells. However, the former approach of wire-type solar cell fabrication, followed by weaving of these devices, has had limited success, due to device failure caused by high friction forces and tension forces during the weaving process. To overcome this limitation, we present a new approach for textile solar cell fabrication, in which dye-sensitized solar cell (DSSC) electrodes are incorporated into the textile during the weaving process, using the textile warp as a spacer to maintain the DSSC structure. Porous, dye-loaded TiO2-coated holed metal ribbon and Pt nanoparticle-loaded carbon yarn were used as the photoanode and counterelectrode, respectively. The highly flexible textile-based solar cell was fabricated using a common weaving process with a loom. The inserted DSSCs in the textile demonstrated an energy conversion efficiency of 2.63% (at 1 sun, 1.5 A.M.). Our results revealed that additional performance enhancement was possible by considering other electrode materials and textile structures, as well as where and how the DSSC electrodes are inserted. In addition, we demonstrated that the inserted DSSCs could be electrically connected using a parallel configuration.

  9. Insertion of Dye-Sensitized Solar Cells in Textiles using a Conventional Weaving Process

    NASA Astrophysics Data System (ADS)

    Yun, Min Ju; Cha, Seung I.; Seo, Seon Hee; Kim, Han Seong; Lee, Dong Y.

    2015-06-01

    Increasing demands for wearable energy sources and highly flexible, lightweight photovoltaic devices have stimulated the development of textile-structured solar cells. However, the former approach of wire-type solar cell fabrication, followed by weaving of these devices, has had limited success, due to device failure caused by high friction forces and tension forces during the weaving process. To overcome this limitation, we present a new approach for textile solar cell fabrication, in which dye-sensitized solar cell (DSSC) electrodes are incorporated into the textile during the weaving process, using the textile warp as a spacer to maintain the DSSC structure. Porous, dye-loaded TiO2-coated holed metal ribbon and Pt nanoparticle-loaded carbon yarn were used as the photoanode and counterelectrode, respectively. The highly flexible textile-based solar cell was fabricated using a common weaving process with a loom. The inserted DSSCs in the textile demonstrated an energy conversion efficiency of 2.63% (at 1 sun, 1.5 A.M.). Our results revealed that additional performance enhancement was possible by considering other electrode materials and textile structures, as well as where and how the DSSC electrodes are inserted. In addition, we demonstrated that the inserted DSSCs could be electrically connected using a parallel configuration.

  10. Gaia and WEAVE/WxES: Supporting the PLATO Exoplanet Hunter

    NASA Astrophysics Data System (ADS)

    Walton, N. A.

    2016-10-01

    This paper briefly describes the powerful linkages between the Gaia and PLATO missions and the potential for WEAVE in the study of exoplanet populations, for instance through the proposed WxES survey. Gaia successfully launched in December 2013, and over the course of its nominal five year mission will discover, via their astrometric signatures, upwards of 20 000 massive Jupiter sized long period planets at distances out to several hundred parsecs around all star types. In addition Gaia will discover up to a thousand short period hot Jupiters around M stars. PLATO, to launch in 2024, will through precision photometry, observe in detail some million host stars, and will detect, via the transit technique, planets down to Earth masses. PLATO will observe two fields of over 2 000 square degrees for 2-3 years each. At least one of these will be in the northern hemisphere. WEAVE has the potential to provide detailed chemical characterization of the host stars of the Gaia and PLATO exoplanet systems. This will enable insights into, for instance, metallicity of the host star correlations against both massive exoplanets (perhaps confirming current relationships), and lower mass exoplanets. We note how the rapid exploitation of such a potential WEAVE survey could be achieved, utilizing the WEAVE processing systems being developed at the IoA, Cambridge, coupled with efficient interfaces to both Gaia and PLATO data products, that are also being generated at the IoA.

  11. Weaving the Cloth of Literacy: The Relationship between Braille and Reading.

    ERIC Educational Resources Information Center

    Zago, P. A.

    1996-01-01

    This brief article uses a weaving metaphor to address the relationship between braille and reading, with prior knowledge (the warp threads) interacting with reading content (the weft threads) by means of braille (the shuttle). Reading is seen to be an interactive process between reader, text, and the context of the reading situation. (DB)

  12. Weaving the tapestry of learning: simulation, standardized patients, and virtual communities.

    PubMed

    Holland, Brian; Landry, Karen; Mountain, Angela; Middlebrooks, Mary Alice; Heim, Deborah; Missildine, Kathy

    2013-01-01

    Using situated cognition learning theory, nursing faculty developed simulated clinical learning experiences integrating virtual communities and standardized patients. These learning experiences provide authenticity and realism not easily achieved using the individual techniques in isolation. The authors describe the process of weaving these strategies into a rich learning experience for students.

  13. Insertion of Dye-Sensitized Solar Cells in Textiles using a Conventional Weaving Process

    PubMed Central

    Yun, Min Ju; Cha, Seung I.; Seo, Seon Hee; kim, Han Seong; Lee, Dong Y.

    2015-01-01

    Increasing demands for wearable energy sources and highly flexible, lightweight photovoltaic devices have stimulated the development of textile-structured solar cells. However, the former approach of wire-type solar cell fabrication, followed by weaving of these devices, has had limited success, due to device failure caused by high friction forces and tension forces during the weaving process. To overcome this limitation, we present a new approach for textile solar cell fabrication, in which dye-sensitized solar cell (DSSC) electrodes are incorporated into the textile during the weaving process, using the textile warp as a spacer to maintain the DSSC structure. Porous, dye-loaded TiO2-coated holed metal ribbon and Pt nanoparticle-loaded carbon yarn were used as the photoanode and counterelectrode, respectively. The highly flexible textile-based solar cell was fabricated using a common weaving process with a loom. The inserted DSSCs in the textile demonstrated an energy conversion efficiency of 2.63% (at 1 sun, 1.5 A.M.). Our results revealed that additional performance enhancement was possible by considering other electrode materials and textile structures, as well as where and how the DSSC electrodes are inserted. In addition, we demonstrated that the inserted DSSCs could be electrically connected using a parallel configuration. PMID:26087134

  14. Microstructure and Tensile Properties of BN/SiC Coated Hi-Nicalon, and Sylramic SiC Fiber Preforms. Revised

    NASA Technical Reports Server (NTRS)

    Bhatt, Ramakrishna T.; Chen, Yuan L.; Morscher, Gregory N.

    2002-01-01

    Batch to batch and within batch variations, and the influence of fiber architecture on room temperature physical and tensile properties of BN/SiC coated Hi-Nicalon and Sylramic SiC fiber preform specimens were determined. The three fiber architectures studied were plain weave (PW), 5-harness satin (5HS), and 8-harness satin (8HS). Results indicate that the physical properties vary up to 10 percent within a batch, and up to 20 percent between batches of preforms. Load-reload (Hysteresis) and acoustic emission methods were used to analyze damage accumulation occurring during tensile loading. Early acoustic emission activity, before observable hysteretic behavior, indicates that the damage starts with the formation of nonbridged tunnel cracks. These cracks then propagate and intersect the load bearing "0 deg" fibers giving rise to hysteretic behavior. For the Hi-Nicalon preform specimens, the onset of "0 deg" bundle cracking stress and strain appeared to be independent of the fiber architecture. Also, the "0 deg" fiber bundle cracking strain remained nearly the same for the preform specimens of both fiber types. TEM analysis indicates that the CVI BN interface coating is mostly amorphous and contains carbon and oxygen impurities, and the CVI SiC coating is crystalline. No reaction exists between the CVI BN and SiC coating.

  15. Microstructure and Tensile Properties of BN/SiC Coated Hi-Nicalon, and Sylramic SiC Fiber Preforms

    NASA Technical Reports Server (NTRS)

    Bhatt, Ramakrishna T.; Chen, Yuan L.; Morscher, Gregory N.

    2001-01-01

    Batch to batch and within batch variations, and the influence of fiber architecture on room temperature physical and tensile properties of BN/SiC coated Hi-Nicalon and Sylramic SiC fiber preform specimens were determined. The three fiber architectures studied were plain weave (PW), 5-harness satin (5HS) and 8-harness satin (8HS) Results indicate that the physical properties vary up to 10 percent within a batch, and up to 20 percent between batches of preforms. Load-reload (Hysteresis) and acoustic emission methods were used to analyze damage accumulation occurring during tensile loading. Early acoustic emission activity, before observable hysteretic behavior, indicates that the damage starts with the formation of nonbridged tunnel cracks. These cracks then propagate and intersect the load bearing "0" fibers giving rise to hysteretic behavior, For the Hi-Nicalon preform specimens, the onset of "0" bundle cracking stress and strain appeared to be independent of the fiber architecture. Also, the "0" fiber bundle cracking strain remained nearly the same for the preform specimens of both fiber types. Transmission Electron Microscope (TEM) analysis indicates that the Chemical Vapor Infiltration (CVI) Boron Nitride (BN) interface coating is mostly amorphous and contains carbon and oxygen impurities, and the CVI SiC coating is crystalline. No reaction exists between the CVI BN and SiC coating.

  16. Verification and application of the Iosipescu shear test method

    NASA Technical Reports Server (NTRS)

    Walrath, D. E.; Adams, D. F.

    1984-01-01

    Finite element models were used to study the effects of notch angle variations on the stress state within an Iosipescu shear test speciment. These analytical results were also studied to determine the feasibility of using strain gage rosettes and a modified extensometer to measure shear strains in this test specimen. Analytical results indicate that notch angle variations produced only small differences in simulated shear properties. Both strain gage rosettes and the modified extensometer were shown to be feasible shear strain transducers for the test method. The Iosipoescu shear test fixture was redesigned to incorporate several improvements. These improvements include accommodation of a 50 percent larger specimen for easier measurement of shear train, a clamping mechanism to relax strict tolerances on specimen width, and a self contained alignment tool for use during specimen installation. A set of in-plane and interlaminar shear properties were measured for three graphite fabric/epoxy composites of T300/934 composite material. The three weave patterns were Oxford, 5-harness satin, and 8-harness satin.

  17. Developments in fiber-positioning technology for the WEAVE instrument at the William Herschel Telescope

    NASA Astrophysics Data System (ADS)

    Schallig, Ellen; Lewis, Ian J.; Gilbert, James; Dalton, Gavin; Brock, Matthew; Abrams, Don Carlos; Middleton, Kevin; Aguerri, J. Alfonso L.; Bonifacio, Piercarlo; Carrasco, Esperanza; Trager, Scott C.; Vallenari, Antonella

    2016-08-01

    WEAVE is the next-generation wide-field optical spectroscopy facility for the William Herschel Telescope (WHT) on La Palma in the Canary Islands, Spain. It is a multi-object "pick-and-place" fibre-fed spectrograph with a 1000 fibre multiplex behind a new dedicated 2° prime focus corrector. The WEAVE positioner concept uses two robots working in tandem in order to reconfigure a fully populated field within the expected 1 hour dwell-time for the instrument (a good match between the required exposure times and the limit of validity for a given configuration due to the effects of differential refraction). In this paper we describe some of the final design decisions arising from the prototyping phase of the instrument design and provide an update on the current manufacturing status of the fibre positioner system.

  18. "Lungisa"-weaving relationships and social space to restore health in rural KwaZulu Natal.

    PubMed

    Wickström, Anette

    2014-06-01

    Many Zulu people who live in big cities in South Africa return to their rural homestead when they fall ill. Although the health care offered in rural areas is not efficient, people wish to connect to their family and ancestors. My aim is to explore acts of lungisa ("to put in order") and what they say about health, agency, and the circumstances under which people live. Returning home means weaving oneself firmly within a web of relationships that are located in material things and places. Healing involves imperfect strategies used to better connect bodies, relationships, and places. I theorize the acts of returning using Adriana Cavarero's concept of weaving together and argue that people produce space and relationships over time to exert some control over a life lived under political and economic circumstances that have created separation. Six months of ethnographic fieldwork make up the material for my analysis.

  19. Air-condition Control System of Weaving Workshop Based on LabVIEW

    NASA Astrophysics Data System (ADS)

    Song, Jian

    The project of air-condition measurement and control system based on LabVIEW is put forward for the sake of controlling effectively the environmental targets in the weaving workshop. In this project, which is based on the virtual instrument technology and in which LabVIEW development platform by NI is adopted, the system is constructed on the basis of the virtual instrument technology. It is composed of the upper PC, central control nodes based on CC2530, sensor nodes, sensor modules and executive device. Fuzzy control algorithm is employed to achieve the accuracy control of the temperature and humidity. A user-friendly man-machine interaction interface is designed with virtual instrument technology at the core of the software. It is shown by experiments that the measurement and control system can run stably and reliably and meet the functional requirements for controlling the weaving workshop.

  20. Effect of Shear, Compaction and Nesting on Permeability of the Orthogonal Plain-Weave Fabric Preforms

    DTIC Science & Technology

    2004-01-01

    processes such as resin transfer molding ( RTM ), vacuum assisted resin transfer molding ( VARTM ) and structural reaction injection molding (SRIM) have a...composite liquid-molding manufactur- ing processes (e.g. in the RTM and the VARTM processes), the porous medium consists of woven- or weaved-fabric...single-layer fabric preform. In typical RTM and VARTM processes, the preforms may contain several fabric layers. In such multi-layer preforms, nesting

  1. Group and insidious tetraethyl lead poisoning occurred in industry of plastic weaving: a case report

    PubMed Central

    Zhang, Feng; Bai, Ying; Zhu, Wenjing; Ye, Mingxian

    2016-01-01

    Tetraethyl lead (TEL) poisoning has declined sharply with decreasing consumption of gasoil and other chemicals contained TEL. Here we reported group TEL poisoning in the plastic weaving factory. We investigated 16 cases with the typical nerves disorder which is similar to organotin poisoning, and the result suggested that the poisoning may cause by applied “white oil” contented TEL. Despite its rareness, our cases emphasize that clinicians should pay attention to the difference from the treatment of organic tin poisoning. PMID:27162692

  2. WEAVE-QSO: A Massive Intergalactic Medium Survey for the William Herschel Telescope

    NASA Astrophysics Data System (ADS)

    Pieri, M. M.; Bonoli, S.; Chaves-Montero, J.; Pâris, I.; Fumagalli, M.; Bolton, J. S.; Viel, M.; Noterdaeme, P.; Miralda-Escudé, J.; Busca, N. G.; Rahmani, H.; Peroux, C.; Font-Ribera, A.; Trager, S. C.

    2016-12-01

    In these proceedings we describe the WEAVE-QSO survey, which will observe around 400,000 high redshift quasars starting in 2018. This survey is part of a broader WEAVE survey to be conducted at the 4.2m William Herschel Telescope. We will focus on chiefly on the science goals, but will also briefly summarise the target selection methods anticipated and the expected survey plan. Understanding the apparent acceleration in the expansion of the Universe is one of the key scientific challenges of our time. Many experiments have been proposed to study this expansion, using a variety of techniques. Here we describe a survey that can measure this acceleration and therefore help elucidate the nature of dark energy: a survey of the Lyα forest (and quasar absorption in general) in spectra towards z>2 quasars (QSOs). Further constraints on neutrino masses and warm dark matter are also anticipated. The same data will also shed light on galaxy formation via study of the properties of inflowing/outflowing gas associated with nearby galaxies and in a cosmic web context. Gas properties are sensitive to density, temperature, UV radiation, metallicity and abundance pattern, and so constraint galaxy formation in a variety of ways. WEAVE-QSO will study absorbers with a dynamic range spanning more than 8 orders of magnitude in column density, their thermal broadening, and a host of elements and ionization species. A core principal of the WEAVE-QSO survey is the targeting of QSOs with near 100% efficiency principally through use of the J-PAS (r < 23.2) and Gaia (r ≲ 20) data.

  3. Full-thickness Scalp Injury Due to Hair Braiding and Weave

    PubMed Central

    Grunzweig, Katherine

    2015-01-01

    Summary: Full-thickness scalp necrosis secondary to hair weave placement is a rare but serious complication of a common hairstyle. The defects can be large and may necessitate complex reconstruction with hair-bearing tissue. We report on the case of a young woman with extensive scalp loss following tight spiral braiding. The case description illustrates this relatively unknown complication, its treatment, and possible preventative measures. PMID:26495190

  4. The hardware control system for WEAVE at the William Herschel telescope

    NASA Astrophysics Data System (ADS)

    Delgado Hernandez, Jose M.; Rodríguez-Ramos, Luis F.; Cano Infantes, Diego; Martin, Carlos; Bevil, Craige; Picó, Sergio; Dee, Kevin M.; Abrams, Don Carlos; Lewis, Ian J.; Pragt, Johan; Stuik, Remko; Tromp, Niels; Dalton, Gavin; L. Aguerri, J. Alfonso; Bonifacio, Piercarlo; Middleton, Kevin F.; Trager, Scott C.

    2014-07-01

    This work describes the hardware control system of the Prime Focus Corrector (PFC) and the Spectrograph, two of the main parts of WEAVE, a multi-object fiber spectrograph for the WHT Telescope. The PFC and Spectrograph control system hardware is based on the Allen Bradley's Programmable Automation Controller and its modules. Mechanisms, sensors and actuators of both systems are summarized and their functionality described, showing how they meet the instrument requirements.

  5. Simulation of Complex Cracking in Plain Weave C/SiC Composite under Biaxial Loading

    NASA Technical Reports Server (NTRS)

    Cheng, Ron-Bin; Hsu, Su-Yuen

    2012-01-01

    Finite element analysis is performed on a mesh, based on computed geometry of a plain weave C/SiC composite with assumed internal stacking, to reveal the pattern of internal damage due to biaxial normal cyclic loading. The simulation encompasses intertow matrix cracking, matrix cracking inside the tows, and separation at the tow-intertow matrix and tow-tow interfaces. All these dissipative behaviors are represented by traction-separation cohesive laws. Not aimed at quantitatively predicting the overall stress-strain relation, the simulation, however, does not take the actual process of fiber debonding into account. The fiber tows are represented by a simple rule-of-mixture model where the reinforcing phase is a hypothetical one-dimensional material. Numerical results indicate that for the plain weave C/SiC composite, 1) matrix-crack initiation sites are primarily determined by large intertow matrix voids and interlayer tow-tow contacts, 2) the pattern of internal damage strongly depends on the loading path and initial stress, 3) compressive loading inflicts virtually no damage evolution. KEY WORDS: ceramic matrix composite, plain weave, cohesive model, brittle failure, smeared crack model, progressive damage, meso-mechanical analysis, finite element.

  6. Effects of grassland succession on communities of orb-weaving spiders.

    PubMed

    Richardson, M L; Hanks, L M

    2009-12-01

    Native grasslands are among the most imperiled of the North American ecosystems, but abandoned agricultural areas may provide suitable habitat for animal taxa that are endemic to grasslands. We studied how species diversity of orb-weaving spiders was influenced by secondary succession of a grassland plant community by monitoring the abundance and species diversity in study plots that were cultivated at 6-yr intervals and left uncultivated in the interim. We tested the hypothesis that local abundance and species diversity of spiders would be positively associated with time since cultivation because plant communities in older habitats would be more architecturally complex. Local abundance of spiders in general was not associated with time since cultivation, but abundance of Mangora gibberosa (Hentz) was positively associated with the abundance of perennial plants. Species richness and diversity of spiders also were positively associated with the abundance of perennial plants and reached a threshold a few years after cultivation. Species diversity of orb-weaving spiders seems to be strongly influenced by species composition of the plant community. Therefore, effective restoration of the structure and function of endemic communities of orb-weaving spiders may depend on preserving endemic grassland plant communities.

  7. Vibration characteristics of Ni-Ti pseudo-elastic wire inter-weaved fabric composites

    NASA Astrophysics Data System (ADS)

    Xu, Lei; Wang, Rui; Yang, Qiuhong; Dong, Li

    2009-07-01

    This paper presents a study on the vibration characteristics of Ni-Ti wire inter-weaved glass fabric/epoxy composites. The Ni-Ti pseudo-elastic wires were used as warp yarns and embedded in the fabric preforms with various weaving methods. Dynamic Mechanical Analyzer (DMA) and vibration test technique were used to reveal the dynamical behaviors of specimens in different frequencies of vibration. The storage modulus E', the loss tanδ, the natural frequency f and damping ratio η were examined. The energy dissipation behaviors of the Ni-Ti pseudo-elastic wire, the geometry of textile fabric was also studied. The effect of weaving method on the vibration behavior in Shape Memory Alloy (SMA) based textile composites was considered. The results showed that: (I) the energy dissipation capacity of the wire could be significantly improved by increasing the tensile strain and speed, but slightly affected by loading frequency; (II) the woven of few Ni-Ti warps caused the increase of the storage modulus and the change of the loss tanδ. In the buckling vibration, the damping effects of Ni-Ti pseudo-elastic wires vary with the woven structures. The compact woven structure with proper Ni-Ti warp architectures would receive a small amplitude and good damping.

  8. Analysis of major ampullate silk cDNAs from two non-orb-weaving spiders.

    PubMed

    Tian, Maozhen; Liu, Congzhou; Lewis, Randolph

    2004-01-01

    Compared to other arthropods, spiders are unique in their use of silk throughout their life span and the extraordinary mechanical properties of the silk threads they produce. Studies on orb-weaving spider silk proteins have shown that silk proteins are composed of highly repetitive regions, characterized by alanine and glycine-rich units. We have isolated and sequenced four partial cDNA clones representing major ampullate spider silk gene transcripts from two non-orb weavers: three for Kukulcania hibernalis and one for Agelenopsis aperta. These cDNA sequences were compared to each other, as well as to the previously published orb-weaver silk gene sequences. The results indicate that the repeats encoding conserved amino acid motifs such as polyA and polyGA that are characteristic of some orb-weaving spider silks are also found in some of the cDNAs reported in this study. However, we also found other motifs such as polyGS and polyGV in the cDNA sequences from the two non-orb-weaving spiders. The amino acid composition of the silk gland extracts shows that alanine and glycine are the major components of the silk of these two non-orb weavers as is the case in orb-weaver silks. Sequence alignment shows that A. aperta's cDNA displays a C-terminal encoding region that is about 44% similar to the one present in N. clavipes's MaSp1 cDNA. In addition, as previously observed for spider silk sequences, the analysis of the codon usage for these four cDNAs demonstrates a bias for A or T in the wobble base position.

  9. The meaning and value of traditional occupational practice: a Karen woman's story of weaving in the United States.

    PubMed

    Smith, Yda J; Stephenson, Stephanie; Gibson-Satterthwaite, Michelle

    2013-01-01

    This case study sought to understand the meaning of restoring traditional weaving as an occupation among Karen women from Burma who now live in an urban city in the United States and to examine the impact of weaving on their daily lives in terms of identity, empowerment, social support, and opportunities for entrepreneurship. The story of one Karen woman, Paw Law Eh, is described. Her story exemplifies the negative consequences of restricted access to familiar and meaningful daily activities, or "occupations", the relationship between occupation and self-identity, how participation in valued occupations can enhance social networks, and the restorative effects that are possible when engagement in meaningful occupations are maintained or restored. Her story demonstrates that occupational therapists have the skills and opportunity to contribute significantly to the well-being of Karen women by supporting the restoration of the occupation of weaving.

  10. Effect of various approximations on predicted progressive failure in plain weave composites

    NASA Technical Reports Server (NTRS)

    Whitcomb, John; Srirengan, Kanthikannan

    1995-01-01

    Three-dimensional finite element analysis was used to simulate progressive failure of a plain weave composite subjected to in-plane extension. The loading was parallel to one of the tow directions. The effects of various characteristics of the finite element model on predicted behavior were examined. The predicted behavior was found to be sensitive to quadrature order, mesh refinement, and the material degradation model. Also the sensitivity of the predictions to the tow waviness was studied. The predicted strength decreased considerably with increased waviness. More numerical studies and comparisons with experimental data are needed to establish reliable guidelines for accurate progressive failure prediction.

  11. Modeling Geometry and Progressive Failure of Material Interfaces in Plain Weave Composites

    NASA Technical Reports Server (NTRS)

    Hsu, Su-Yuen; Cheng, Ron-Bin

    2010-01-01

    A procedure combining a geometrically nonlinear, explicit-dynamics contact analysis, computer aided design techniques, and elasticity-based mesh adjustment is proposed to efficiently generate realistic finite element models for meso-mechanical analysis of progressive failure in textile composites. In the procedure, the geometry of fiber tows is obtained by imposing a fictitious expansion on the tows. Meshes resulting from the procedure are conformal with the computed tow-tow and tow-matrix interfaces but are incongruent at the interfaces. The mesh interfaces are treated as cohesive contact surfaces not only to resolve the incongruence but also to simulate progressive failure. The method is employed to simulate debonding at the material interfaces in a ceramic-matrix plain weave composite with matrix porosity and in a polymeric matrix plain weave composite without matrix porosity, both subject to uniaxial cyclic loading. The numerical results indicate progression of the interfacial damage during every loading and reverse loading event in a constant strain amplitude cyclic process. However, the composites show different patterns of damage advancement.

  12. Scale-up of nature’s tissue weaving algorithms to engineer advanced functional materials

    PubMed Central

    Ng, Joanna L.; Knothe, Lillian E.; Whan, Renee M.; Knothe, Ulf; Tate, Melissa L. Knothe

    2017-01-01

    We are literally the stuff from which our tissue fabrics and their fibers are woven and spun. The arrangement of collagen, elastin and other structural proteins in space and time embodies our tissues and organs with amazing resilience and multifunctional smart properties. For example, the periosteum, a soft tissue sleeve that envelops all nonarticular bony surfaces of the body, comprises an inherently “smart” material that gives hard bones added strength under high impact loads. Yet a paucity of scalable bottom-up approaches stymies the harnessing of smart tissues’ biological, mechanical and organizational detail to create advanced functional materials. Here, a novel approach is established to scale up the multidimensional fiber patterns of natural soft tissue weaves for rapid prototyping of advanced functional materials. First second harmonic generation and two-photon excitation microscopy is used to map the microscopic three-dimensional (3D) alignment, composition and distribution of the collagen and elastin fibers of periosteum, the soft tissue sheath bounding all nonarticular bone surfaces in our bodies. Then, using engineering rendering software to scale up this natural tissue fabric, as well as multidimensional weaving algorithms, macroscopic tissue prototypes are created using a computer-controlled jacquard loom. The capacity to prototype scaled up architectures of natural fabrics provides a new avenue to create advanced functional materials. PMID:28074876

  13. Scale-up of nature’s tissue weaving algorithms to engineer advanced functional materials

    NASA Astrophysics Data System (ADS)

    Ng, Joanna L.; Knothe, Lillian E.; Whan, Renee M.; Knothe, Ulf; Tate, Melissa L. Knothe

    2017-01-01

    We are literally the stuff from which our tissue fabrics and their fibers are woven and spun. The arrangement of collagen, elastin and other structural proteins in space and time embodies our tissues and organs with amazing resilience and multifunctional smart properties. For example, the periosteum, a soft tissue sleeve that envelops all nonarticular bony surfaces of the body, comprises an inherently “smart” material that gives hard bones added strength under high impact loads. Yet a paucity of scalable bottom-up approaches stymies the harnessing of smart tissues’ biological, mechanical and organizational detail to create advanced functional materials. Here, a novel approach is established to scale up the multidimensional fiber patterns of natural soft tissue weaves for rapid prototyping of advanced functional materials. First second harmonic generation and two-photon excitation microscopy is used to map the microscopic three-dimensional (3D) alignment, composition and distribution of the collagen and elastin fibers of periosteum, the soft tissue sheath bounding all nonarticular bone surfaces in our bodies. Then, using engineering rendering software to scale up this natural tissue fabric, as well as multidimensional weaving algorithms, macroscopic tissue prototypes are created using a computer-controlled jacquard loom. The capacity to prototype scaled up architectures of natural fabrics provides a new avenue to create advanced functional materials.

  14. Colourful orb-weaving spiders, Nephila pilipes, through a bee's eyes.

    PubMed

    Tso, I-Min; Lin, Chih-Wei; Yang, En-Cheng

    2004-07-01

    Many orb-weaving spiders in the tropics forage in open sites during the day and some of them have both bright and dark colourations. The conspicuous UV-reflective colour markings of these spiders have been reported to be attractive to visually oriented prey and thus could increase the spiders' foraging success. Using a combination of field and laboratory studies, we examine whether or not the body colouration of orb-weaving spiders exhibits optical properties that are attractive to insect prey from the viewpoint of insect visual physiology. We compared the prey interception rates and colour contrasts of the typical and melanic morphs of the giant wood spider, Nephila pilipes. Results of the field study showed that the typical morph caught significantly more insects than the melanic morph. Colour contrasts calculated from spectral reflectances of the background and body surface of spiders showed that the brightly coloured body parts of the typical morph exhibited rather high values, but those of the dark body parts were below the discrimination threshold. The differential colour contrasts of body parts generated a visual signal unlike that of a spider but rather like certain forms of food resources. On the other hand, the melanic morphs did not have bright colouration and the colour contrasts of every part of the body were significantly higher than the threshold, making the contour of spiders quite clear to bees.

  15. Scale-up of nature's tissue weaving algorithms to engineer advanced functional materials.

    PubMed

    Ng, Joanna L; Knothe, Lillian E; Whan, Renee M; Knothe, Ulf; Tate, Melissa L Knothe

    2017-01-11

    We are literally the stuff from which our tissue fabrics and their fibers are woven and spun. The arrangement of collagen, elastin and other structural proteins in space and time embodies our tissues and organs with amazing resilience and multifunctional smart properties. For example, the periosteum, a soft tissue sleeve that envelops all nonarticular bony surfaces of the body, comprises an inherently "smart" material that gives hard bones added strength under high impact loads. Yet a paucity of scalable bottom-up approaches stymies the harnessing of smart tissues' biological, mechanical and organizational detail to create advanced functional materials. Here, a novel approach is established to scale up the multidimensional fiber patterns of natural soft tissue weaves for rapid prototyping of advanced functional materials. First second harmonic generation and two-photon excitation microscopy is used to map the microscopic three-dimensional (3D) alignment, composition and distribution of the collagen and elastin fibers of periosteum, the soft tissue sheath bounding all nonarticular bone surfaces in our bodies. Then, using engineering rendering software to scale up this natural tissue fabric, as well as multidimensional weaving algorithms, macroscopic tissue prototypes are created using a computer-controlled jacquard loom. The capacity to prototype scaled up architectures of natural fabrics provides a new avenue to create advanced functional materials.

  16. Effect of Weaving Direction of Conductive Yarns on Electromagnetic Performance of 3D Integrated Microstrip Antenna

    NASA Astrophysics Data System (ADS)

    Xu, Fujun; Yao, Lan; Zhao, Da; Jiang, Muwen; Qiu, Yipping

    2013-10-01

    A three-dimensionally integrated microstrip antenna (3DIMA) is a microstrip antenna woven into the three-dimensional woven composite for load bearing while functioning as an antenna. In this study, the effect of weaving direction of conductive yarns on electromagnetic performance of 3DIMAs are investigated by designing, simulating and experimental testing of two microstrip antennas with different weaving directions of conductive yarns: one has the conductive yarns along the antenna feeding direction (3DIMA-Exp1) and the other has the conductive yarns perpendicular the antenna feeding direction (3DIMA-Exp2). The measured voltage standing wave ratio (VSWR) of 3DIMA-Exp1 was 1.4 at the resonant frequencies of 1.39 GHz; while that of 3DIMA-Exp2 was 1.2 at the resonant frequencies of 1.35 GHz. In addition, the measured radiation pattern of the 3DIMA-Exp1 has smaller back lobe and higher gain value than those of the 3DIMA-Exp2. This result indicates that the waving direction of conductive yarns may have a significant impact on electromagnetic performance of textile structural antennas.

  17. Effect of Yarn Distortion on the Mechanical Properties of Fiber-Bar Composites Reinforced by Three-Dimensional Weaving

    NASA Astrophysics Data System (ADS)

    Kang, Huairong; Shan, Zhongde; Zang, Yong; Liu, Feng

    2016-04-01

    A meso-structure model of fiber-bar composites reinforced by three-dimensional weaving (FBCR3DW) is proposed. Optical microscopy images of the preform structure revealed that the fibers along the circumference of the yarn cross-weave were twisted randomly due to alternating yarn winding on either side of the fiber bars during the manufacturing process. Sections of the cross-woven yarn were divided into five regions based on the twist characteristics. Stochastic function theory was used to describe the twist characteristics and to calculate the compliance tensor for each twisted yarn region. The twist characteristics and compliance tensor of each region were then introduced into a finite element model to calculate the elastic properties of the twisted yarn and FBCR3DW; unidirectional tensile stress-strain curves were generated based on the Tsai-Wu failure criterion. Several FBCR3DW specimens with randomly twisted yarns inside the weave structure were used in experimental tests. Our numerical results were in good agreement with the experimental values. Yarn distortion had a significant effect on the elastic properties and axial tensile strength of the yarn; specifically, the influence of yarn distortion on the transverse elastic modulus and transverse shear modulus of FBCR3DW was severe, whereas only a slight effect occurred with regard to the other elastic constants and unidirectional tensile properties. Thus, the proposed method provides an effective reference for modeling fiber composites with a weave structure.

  18. Wondering, Wiggling, and Weaving: A New Model for Project- and Community-Based Learning on the Web.

    ERIC Educational Resources Information Center

    Lamb, Annette; And Others

    1997-01-01

    Describes an eight-phase model for project-based learning via the Internet: watching, wondering, webbing, wiggling, weaving, wrapping, waving, and wishing. Highlights Internet research tools as well as Internet and print resources for an investigation of homelessness, hunger, and poverty; and provides introductory activities using Internet…

  19. Design and optimization of a novel bio-loom to weave melt-spun absorbable polymers for bone tissue engineering.

    PubMed

    Gilmore, Jordon; Burg, Timothy; Groff, Richard E; Burg, Karen J L

    2016-05-05

    Bone graft procedures are currently among the most common surgical procedures performed worldwide, but due to high risk of complication and lack of viable donor tissue, there exists a need to develop alternatives for bone defect healing. Tissue engineering, for example, combining biocompatible scaffolds with mesenchymal stem cells to achieve new bone growth, is a possible solution. Recent work has highlighted the potential for woven polymer meshes to serve as bone tissue engineering scaffolds; since, scaffolds can be iteratively designed by adjusting weave settings, material types, and mesh parameters. However, there are a number of material and system challenges preventing the implementation of such a tissue engineering strategy. Fiber compliance, tensile strength, brittleness, cross-sectional geometry, and size present specific challenges for using traditional textile weaving methods. In the current work, two potential scaffold materials, melt-spun poly-l-lactide, and poly-l-lactide-co-ε-caprolactone, were investigated. An automated bio-loom was engineered and built to weave these materials. The bio-loom was used to successfully demonstrate the weaving of these difficult-to-handle fiber types into various mesh configurations and material combinations. The dobby-loom design, adapted with an air jet weft placement system, warp tension control system, and automated collection spool, provides minimal damage to the polymer fibers while overcoming the physical constraints presented by the inherent material structure. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2016.

  20. [Evaluation of work environment in the flax textile industry. V. Air microflora in the flax spinning and flax weaving rooms].

    PubMed

    Gościcki, J; Włodarczyk, L; Bielichowska, G

    1980-01-01

    Microbiological air pollution in spinning and weaving rooms was determined by aspiration impinger using an aeroscop (Chirana, Czechoslovakia). The air samples were taken on Petri dishes with Bacto-broth-agar (Difco) or Bacto-blood-agar (Difco). After incubation at 37 degrees C for 24 h the number of bacterial or mould colonies and bacterial cells per 1 m3 of the air was calculated. The number of bacterial cells in flax spinning rooms ranged from 10.5 X 10(3) to 12,5 X 10(4), while in flax weaving rooms--from 2,4 X 10(3) to 10(4) per 1 m3 of air. In the examined samples of the air the bacterial pollution was found to dominate (45,1--95%). Gram-positive sporing bacteria were most frequently recognized. In the air of weaving rooms some moulds: Mucor sp., Circinella sp., Hormodendrum sp., Vetricillum sp., Aspergillus sp. and Penicillum sp. were also found (16.8--54%). It was observed that the microbiological air pollution in spinning and weaving rooms of flax industry was greater than in cotton industry. A wet technology of flax spinning promotes microbiological pollution in the air of this kind of workposts. A high level of mould cells in the air at workposts enhances the risk of workers' exposure to mycotoxins.

  1. PEDOT:PSS-based piezo-resistive sensors applied to reinforcement glass fibres for in situ measurement during the composite material weaving process.

    PubMed

    Trifigny, Nicolas; Kelly, Fern M; Cochrane, Cédric; Boussu, François; Koncar, Vladan; Soulat, Damien

    2013-08-16

    The quality of fibrous reinforcements used in composite materials can be monitored during the weaving process. Fibrous sensors previously developed in our laboratory, based on PEDOT:PSS, have been adapted so as to directly measure the mechanical stress on fabrics under static or dynamic conditions. The objective of our research has been to develop new sensor yarns, with the ability to locally detect mechanical stresses all along the warp or weft yarn. This local detection is undertaken inside the weaving loom in real time during the weaving process. Suitable electronic devices have been designed in order to record in situ measurements delivered by this new fibrous sensor yarn.

  2. PEDOT:PSS-Based Piezo-Resistive Sensors Applied to Reinforcement Glass Fibres for in Situ Measurement during the Composite Material Weaving Process

    PubMed Central

    Trifigny, Nicolas; Kelly, Fern M.; Cochrane, Cédric; Boussu, François; Koncar, Vladan; Soulat, Damien

    2013-01-01

    The quality of fibrous reinforcements used in composite materials can be monitored during the weaving process. Fibrous sensors previously developed in our laboratory, based on PEDOT:PSS, have been adapted so as to directly measure the mechanical stress on fabrics under static or dynamic conditions. The objective of our research has been to develop new sensor yarns, with the ability to locally detect mechanical stresses all along the warp or weft yarn. This local detection is undertaken inside the weaving loom in real time during the weaving process. Suitable electronic devices have been designed in order to record in situ measurements delivered by this new fibrous sensor yarn. PMID:23959238

  3. Numerical and experimental investigation of passive rider effects on motorcycle weave

    NASA Astrophysics Data System (ADS)

    Massaro, Matteo; Lot, Roberto; Cossalter, Vittore; Brendelson, James; Sadauckas, James

    2012-01-01

    Despite the importance of rider passive response to the lateral dynamics of motorcycles, there is very little literature on the subject. Even more uncommon are works that consider rider passive steering impedance and its effect on motorcycle stability. Moreover, until this time, there have been no published studies on steering impedance that include correlation to on-road motorcycle stability testing. This paper explores these topics using an advanced motorcycle simulation model which includes rider torso and steering impedance values derived from experimental characterisation and anthropometric modelling. A novel method for quantitatively evaluating on-road stability is discussed and utilised to compare the simulation results to on-road weave stability testing for two different riders in the 'hands-off' and 'hands-on' the handlebars conditions. Good correlation is achieved between simulation and test indicating stability differences between riders and highlighting hands-off/on effects.

  4. Investigation of the Thermomechanical Behavior of a 2 × 2 TWILL Weave Fabric Advanced Textile Composite

    NASA Astrophysics Data System (ADS)

    Dixit, A.; Mali, H. S.; Misra, R. K.

    2015-05-01

    The thermomechanical performance of a 2 × 2 twill weave fabric advanced textile composite was evaluated. The tensile, compressive, and flexural properties of flat beam specimens of the composite were tested at room temperature, in water (24.9 to 96.7°C), and in liquid nitrogen (-96.9 to 99.4°C) by using a high-precision instrument called the dynamic mechanical analyzer (DMA). The storage modulus and tanδ of the carbonfiber-reinforced plastic (CFRP) specimens at various temperatures were evaluated. The scanning electron micrograph (SEMs) of deformed composite specimens revealed their failure mode (fiber pull-out, debonding, crack propagation, delamination, matrix cracking, and kinking of fibers).

  5. Thermoelastic properties of plain weave composites for circuit board applications: A comparison of models and experiments

    SciTech Connect

    Ockers, J.M.; Sottos, N.R.

    1994-12-31

    The results of several micromechanical models are presented for predicting the properties of woven glass epoxy substrates used in multilayer circuit boards. Two new models are formulated and the predictions of the elastic moduli, Poisson`s ratios, and expansion coefficients are compared with the results of previously developed one and two dimensional models. The properties of several commercially pressed circuit boards are determined experimentally and compared with all of the different models. One of the newly proposed models, which does not use classical lamination theory, results in a significant improvement for the prediction of the Poisson`s ratios. Finally, parametric studies are performed to predict the influence of fabric geometry on the in-plane thermal expansion coefficients and elastic moduli. Optimal weaving parameters are identified which lead to improved dimensional stability.

  6. Verification of Commercial Motor Performance for WEAVE at the William Herschel Telescope

    NASA Astrophysics Data System (ADS)

    Gilbert, J.; Dalton, G.; Lewis, I.

    2016-10-01

    WEAVE is a 1000-fiber multi-object spectroscopic facility for the 4.2 m William Herschel Telescope. It will feature a double-headed pick-and-place fiber positioning robot comprising commercially available robotic axes. This paper presents results on the performance of these axes, obtained by testing a prototype system in the laboratory. Positioning accuracy is found to be better than the manufacturer's published values for the tested cases, indicating that the requirement for a maximum positioning error of 8.0 microns is achievable. Field reconfiguration times well within the planned 60 minute observation window are shown to be likely when individual axis movements are combined in an efficient way.

  7. Weaving meanings from the deliberative process of collegiate management in nursing1

    PubMed Central

    Higashi, Giovana Dorneles Callegaro; Erdmann, Alacoque Lorenzini

    2014-01-01

    Objective to understand the meanings of the collegiate deliberations attributed by its members on an undergraduate nursing course. Method Grounded Theory, interviews being held with 30 participants, making up 4 sample groups, between January and June 2012, in a public higher education institution. Result 5 categories emerged, indicating the phenomenon and weaving the paradigmatic model: Understanding the experience of the complex relationships and interactions in the deliberations of collegiate management in nursing: intertwining divergences, convergences, dialogs, collectivities and diversities. This deliberative process presents various meanings involving discussion, and divergent, convergent and complementary positions, through dialog, commitment and negotiation. Conclusion the deliberations in the collegiate of nursing, intertwining dialogs, collectivities and diversities, mold the complex relational fabrics. PMID:26107835

  8. Loss of legs: is it or not a handicap for an orb-weaving spider?

    NASA Astrophysics Data System (ADS)

    Pasquet, Alain; Anotaux, Mylène; Leborgne, Raymond

    2011-07-01

    Leg loss is a common phenomenon in spiders, and according to the species 5% to 40% of the adults can present at least one missing leg. There is no possibility of regeneration after adult moult and the animal must manage with its missing appendages until its death. With the loss of one or more legs, female orb-weaving spiders can be penalized twice: firstly, because the legs are necessary for web construction and secondly, the legs are essential for the control of the prey after its interception by the web. During development, spiders may be also penalized because regeneration has energetic costs that take away resources for survival, growth and reproduction. All these consequences should influence negatively the development of the spider and thus its fitness. We investigated the impact of leg loss in the orb-weaving spider, Zygiella x-notata by studying its frequency in a natural population and web building and prey capture behaviours in laboratory. In field populations, 9.5% to 13%, of the adult females presented the loss of one or more legs; the majority of individuals had lost only one leg (in 48% of cases, a first one). Leg loss seems to affect all the adult spiders, as there is no difference of mass between intact spiders and those with missing leg. Data obtained with laboratory-reared spiders, showed that the loss of legs due to the moult is rare (less than 1%). Considering changes in web design, spiders with missing legs decreased their silk investment, increased the distance between spiral turns but did not change the capture surface of the web. Under our laboratory experimental conditions, spiders with one or two lost legs did not present any difference in prey capture efficiency. In laboratory conditions, spiders with lost leg(s) did not show any difference in egg sac production or in longevity (adult lifespan) compared to intact spiders.

  9. Effect of weave tightness and structure on the in-plane and through-plane air permeability of woven carbon fibers for gas diffusion layers

    NASA Astrophysics Data System (ADS)

    Caston, Terry B.; Murphy, Andrew R.; Harris, Tequila A. L.

    In this study, woven gas diffusion layers (GDLs) with varying weave type and tightness are investigated. Plain and twill weave patterns were manufactured in-house. The in-plane and through-plane air permeability of the woven samples were tested, and mercury intrusion porosimetry (MIP) tests were performed to study the pore structure. It was found that the twill weave has a higher permeability than the plain weave, which is consistent with literature. Like non-woven carbon papers, woven GDLs have higher in-plane permeability than through-plane permeability; however it has been shown that it is possible to manufacture a GDL with higher through-plane permeability than in-plane permeability. It was also concluded that the percentage of macropores in the weave is the driving factor in determining the through-plane air permeability. This work lays the groundwork for future studies to attempt to characterize the relationship between the weave structure and the air permeability in woven GDLs.

  10. Effect of pad location relative to glass weave on cratering and underfill process improvement and material evaluation

    NASA Astrophysics Data System (ADS)

    Quran, Mohammad M.

    This research contains two studies. First study investigated one of the factors that affect the performance of pads; the locations of pads relative to glass weave. Dage 4000plus bond tester was used in conducting a joint-level testing of pads on 370HR printed circuit board that has 1080 glass fabric. Scanning acoustic microscopy (SAM) was utilized to image pads with respect to upper layer of glass weave. It was found that locations of pads do not affect their strength, but it has a weak effect on fatigue performance. The second part of this research is underfill process improvement and material selection. This study evaluated four underfill materials against a flow model. Assemblies were made of transparent glass slides and then underfilled. Different factors that affect this flow were investigated: substrate temperature, standoff, and material age. In addition, the materials' tendency to form voids during flow or curing was observed.

  11. Machine-Washable Textile Triboelectric Nanogenerators for Effective Human Respiratory Monitoring through Loom Weaving of Metallic Yarns.

    PubMed

    Zhao, Zhizhen; Yan, Casey; Liu, Zhaoxian; Fu, Xiuli; Peng, Lian-Mao; Hu, Youfan; Zheng, Zijian

    2016-12-01

    Textile triboelectric nanogenerators for human respiratory monitoring with machine washability are developed through loom weaving of Cu-PET and PI-Cu-PET yarns. Triboelectric charges are generated at the yarn crisscross intersections to achieve a maximum short circuit current density of 15.50 mA m(-2) . By integrating into a chest strap, human respiratory rate and depth can be monitored.

  12. Final design and progress of WEAVE: the next generation wide-field spectroscopy facility for the William Herschel Telescope

    NASA Astrophysics Data System (ADS)

    Dalton, Gavin; Trager, Scott; Abrams, Don Carlos; Bonifacio, Piercarlo; Aguerri, J. Alfonso L.; Middleton, Kevin; Benn, Chris; Dee, Kevin; Sayède, Frédéric; Lewis, Ian; Pragt, Johannes; Pico, Sergio; Walton, Nic; Rey, Jeurg; Allende Prieto, Carlos; Peñate, José; Lhome, Emilie; Agócs, Tibor; Alonso, José; Terrett, David; Brock, Matthew; Gilbert, James; Schallig, Ellen; Ridings, Andy; Guinouard, Isabelle; Verheijen, Marc; Tosh, Ian; Rogers, Kevin; Lee, Martin; Steele, Iain; Stuik, Remko; Tromp, Niels; Jaskó, Attila; Carrasco, Esperanza; Farcas, Szigfrid; Kragt, Jan; Lesman, Dirk; Kroes, Gabby; Mottram, Chris; Bates, Stuart; Rodriguez, Luis Fernando; Gribbin, Frank; Delgado, José Miguel; Herreros, José Miguel; Martin, Carlos; Cano, Diego; Navarro, Ramon; Irwin, Mike; Lewis, Jim; Gonzalez Solares, Eduardo; Murphy, David; Worley, Clare; Bassom, Richard; O'Mahoney, Neil; Bianco, Andrea; Zurita, Christina; ter Horst, Rik; Molinari, Emilio; Lodi, Marcello; Guerra, José; Martin, Adrian; Vallenari, Antonella; Salasnich, Bernardo; Baruffolo, Andrea; Jin, Shoko; Hill, Vanessa; Smith, Dan; Drew, Janet; Poggianti, Bianca; Pieri, Mat; Dominquez Palmero, Lillian; Farina, Cecilia

    2016-08-01

    We present the Final Design of the WEAVE next-generation spectroscopy facility for the William Herschel Telescope (WHT), together with a status update on the details of manufacturing, integration and the overall project schedule now that all the major fabrication contracts are in place. We also present a summary of the current planning behind the 5-year initial phase of survey operations. WEAVE will provide optical ground-based follow up of ground-based (LOFAR) and space-based (Gaia) surveys. WEAVE is a multi-object and multi-IFU facility utilizing a new 2-degree prime focus field of view at the WHT, with a buffered pick-and-place positioner system hosting 1000 multi-object (MOS) fibres, 20 integral field units, or a single large IFU for each observation. The fibres are fed to a single (dual-beam) spectrograph, with total of 16k spectral pixels, located within the WHT GHRIL enclosure on the telescope Nasmyth platform, supporting observations at R 5000 over the full 370-1000nm wavelength range in a single exposure, or a high resolution mode with limited coverage in each arm at R 20000. The project is now in the manufacturing and integration phase with first light expected for early of 2018.

  13. Multi-scale Model of Residual Strength of 2D Plain Weave C/SiC Composites in Oxidation Atmosphere

    NASA Astrophysics Data System (ADS)

    Chen, Xihui; Sun, Zhigang; Sun, Jianfen; Song, Yingdong

    2017-02-01

    Multi-scale models play an important role in capturing the nonlinear response of woven carbon fiber reinforced ceramic matrix composites. In plain weave carbon fiber/silicon carbon (C/SiC) composites, the carbon fibers and interphases will be oxidized at elevated temperature and the strength of the composite will be degraded when oxygen enters micro-cracks formed in the as-produced parts due to the mismatch in thermal properties between constituents. As a result of the oxidation on fiber surface, fiber shows a notch-like morphology. In this paper, the change rule of fiber notch depth is fitted by circular function. And a multi-scale model based upon the change rule of fiber notch depth is developed to simulate the residual strength and post-oxidation stress-strain curves of the composite. The multi-scale model is able to accurately predict the residual strength and post-oxidation stress-strain curves of the composite. Besides, the simulated residual strength and post-oxidation stress-strain curves of 2D plain weave C/SiC composites in oxidation atmosphere show good agreements with experimental results. Furthermore, the oxidation time and temperature of the composite are investigated to show their influences upon the residual strength and post-oxidation stress-strain curves of plain weave C/SiC composites.

  14. ZnO nanosheet arrays constructed on weaved titanium wire for CdS-sensitized solar cells

    PubMed Central

    2014-01-01

    Ordered ZnO nanosheet arrays were grown on weaved titanium wires by a low-temperature hydrothermal method. CdS nanoparticles were deposited onto the ZnO nanosheet arrays using the successive ionic layer adsorption and reaction method to make a photoanode. Nanoparticle-sensitized solar cells were assembled using these CdS/ZnO nanostructured photoanodes, and their photovoltaic performance was studied systematically. The best light-to-electricity conversion efficiency was obtained to be 2.17% under 100 mW/cm2 illumination, and a remarkable short-circuit photocurrent density of approximately 20.1 mA/cm2 was recorded, which could attribute to the relatively direct pathways for transportation of electrons provided by ZnO nanosheet arrays as well as the direct contact between ZnO and weaved titanium wires. These results indicate that CdS/ZnO nanostructures on weaved titanium wires would open a novel possibility for applications of low-cost solar cells. PMID:24618047

  15. Multi-scale Model of Residual Strength of 2D Plain Weave C/SiC Composites in Oxidation Atmosphere

    NASA Astrophysics Data System (ADS)

    Chen, Xihui; Sun, Zhigang; Sun, Jianfen; Song, Yingdong

    2016-06-01

    Multi-scale models play an important role in capturing the nonlinear response of woven carbon fiber reinforced ceramic matrix composites. In plain weave carbon fiber/silicon carbon (C/SiC) composites, the carbon fibers and interphases will be oxidized at elevated temperature and the strength of the composite will be degraded when oxygen enters micro-cracks formed in the as-produced parts due to the mismatch in thermal properties between constituents. As a result of the oxidation on fiber surface, fiber shows a notch-like morphology. In this paper, the change rule of fiber notch depth is fitted by circular function. And a multi-scale model based upon the change rule of fiber notch depth is developed to simulate the residual strength and post-oxidation stress-strain curves of the composite. The multi-scale model is able to accurately predict the residual strength and post-oxidation stress-strain curves of the composite. Besides, the simulated residual strength and post-oxidation stress-strain curves of 2D plain weave C/SiC composites in oxidation atmosphere show good agreements with experimental results. Furthermore, the oxidation time and temperature of the composite are investigated to show their influences upon the residual strength and post-oxidation stress-strain curves of plain weave C/SiC composites.

  16. ZnO nanosheet arrays constructed on weaved titanium wire for CdS-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Wu, Cuncun; Wei, Lin; Li, Yitan; Liu, Chang; Jiao, Jun; Chen, Yanxue; Mei, Liangmo

    2014-03-01

    Ordered ZnO nanosheet arrays were grown on weaved titanium wires by a low-temperature hydrothermal method. CdS nanoparticles were deposited onto the ZnO nanosheet arrays using the successive ionic layer adsorption and reaction method to make a photoanode. Nanoparticle-sensitized solar cells were assembled using these CdS/ZnO nanostructured photoanodes, and their photovoltaic performance was studied systematically. The best light-to-electricity conversion efficiency was obtained to be 2.17% under 100 mW/cm2 illumination, and a remarkable short-circuit photocurrent density of approximately 20.1 mA/cm2 was recorded, which could attribute to the relatively direct pathways for transportation of electrons provided by ZnO nanosheet arrays as well as the direct contact between ZnO and weaved titanium wires. These results indicate that CdS/ZnO nanostructures on weaved titanium wires would open a novel possibility for applications of low-cost solar cells.

  17. Health hazards, injury problems, and workplace conditions of carpet-weaving children in three districts of Punjab, Pakistan.

    PubMed

    Awan, Saeed; Nasrullah, Muazzam; Cummings, Kristin J

    2010-01-01

    Carpet weaving among children is common in rural Pakistan, but little information is available on the health effects of this work. A total of 628 carpet-weaving children and 292 non-working children from 10 rural villages were evaluated with questionnaires and physical exams. Fifty-five home-based and 30 shed-based worksites in these villages were assessed. Girls comprised the majority of working (73%) and non-working (69%) children; the mean age for both boys and girls was 10 years. The mean number of hours worked daily was 7.2 for males and 6.8 for females. Dust exposure in homes was generally higher than in sheds. Working children had significantly greater odds of joint pain (OR = 2.8), dry cough (OR = 2.5), cuts/bruises (OR = 22.1), Phalen's sign (OR = 17.2), and neck/shoulder abnormalities (OR = 14.2). Symptoms and signs of acute and repetitive injury and respiratory symptoms were more common among carpet-weaving children than their non-working peers.

  18. Micromechanical Modeling of Woven Metal Matrix Composites

    NASA Technical Reports Server (NTRS)

    Bednarcyk, Brett A.; Pindera, Marek-Jerzy

    1997-01-01

    This report presents the results of an extensive micromechanical modeling effort for woven metal matrix composites. The model is employed to predict the mechanical response of 8-harness (8H) satin weave carbon/copper (C/Cu) composites. Experimental mechanical results for this novel high thermal conductivity material were recently reported by Bednarcyk et al. along with preliminary model results. The micromechanics model developed herein is based on an embedded approach. A micromechanics model for the local (micro-scale) behavior of the woven composite, the original method of cells (Aboudi), is embedded in a global (macro-scale) micromechanics model (the three-dimensional generalized method of cells (GMC-3D) (Aboudi). This approach allows representation of true repeating unit cells for woven metal matrix composites via GMC-3D, and representation of local effects, such as matrix plasticity, yarn porosity, and imperfect fiber-matrix bonding. In addition, the equations of GMC-3D were reformulated to significantly reduce the number of unknown quantities that characterize the deformation fields at the microlevel in order to make possible the analysis of actual microstructures of woven composites. The resulting micromechanical model (WCGMC) provides an intermediate level of geometric representation, versatility, and computational efficiency with respect to previous analytical and numerical models for woven composites, but surpasses all previous modeling work by allowing the mechanical response of a woven metal matrix composite, with an elastoplastic matrix, to be examined for the first time. WCGMC is employed to examine the effects of composite microstructure, porosity, residual stresses, and imperfect fiber-matrix bonding on the predicted mechanical response of 8H satin C/Cu. The previously reported experimental results are summarized, and the model predictions are compared to monotonic and cyclic tensile and shear test data. By considering appropriate levels of porosity

  19. Monitoring of cotton dust and health risk assessment in small-scale weaving industry.

    PubMed

    Tahir, Muhammad Wajid; Mumtaz, Muhammad Waseem; Tauseef, Shanza; Sajjad, Muqadas; Nazeer, Awais; Farheen, Nazish; Iqbal, Muddsar

    2012-08-01

    The present study describes the estimation of particulate matter (cotton dust) with different sizes, i.e., PM(1.0), PM(2.5), PM(4.0), and PM(10.0 μm) in small-scale weaving industry (power looms) situated in district Hafizabad, Punjab, Pakistan, and the assessment of health problems of workers associated with these pollutants. A significant difference was found in PM(1.0), PM(2.5), PM(4.0), and PM(10.0) with reference to nine different sampling stations with p values <0.05. Multiple comparisons of particulate matter with respect to size, i.e. PM(1.0), PM(2.5), PM(4.0), and PM(10.0), depict that PM(1.0) differs significantly from PM(2.5), PM(4.0), and PM(10.0), with p values <0.05 and that PM(2.5) differs significantly from PM(1.0) and PM(10.0), with p values <0.05, whereas PM(2.5) differs non-significantly from PM(4.0), with a p value >0.05 in defined sampling stations on an average basis. Majority of the workers were facing several diseases due to interaction with particulate matter (cotton dust) during working hours. Flue, cough, eye, and skin infections were the most common diseases among workers caused by particulate matter (cotton dust).

  20. The effect of weave orientation on the BRDF of tarp samples

    NASA Astrophysics Data System (ADS)

    Georgiev, Georgi; Butler, James J.

    2003-10-01

    The results of bi-directional reflectance distribution function (BRDF) measurements of four tarp samples obtained from NASA"s Stennis Space Center (SSC) are presented. The measurements were performed in the Diffuser Calibration Facility (DCaF) at NASA"s Goddard Space Flight Center (GSFC). The samples are of similar material structure but different reflectance. The experimental data were obtained with a Xe arc lamp/monochromator light source as well as laser light sources in the ultraviolet, visible, and near infrared spectral regions. The BRDF data were recorded at four incident zenith angles and at five incident azimuth angles. The dependence of the measured BRDF on weave orientation was analyzed and presented. 8 degree irectional/hemispherical reflectance data were also measured for each tarp sample, and those results are also reported. All results are NIST traceable through calibrated standard plates. The specular and diffuse scatter data obtained from these studies are used by NASA"s SSC in their field-based, vicarious calibration of satellite and airborne remote sensing instruments.

  1. Using active colloids as machines to weave and braid on the micrometer scale

    NASA Astrophysics Data System (ADS)

    Goodrich, Carl P.; Brenner, Michael P.

    2017-01-01

    Controlling motion at the microscopic scale is a fundamental goal in the development of biologically inspired systems. We show that the motion of active, self-propelled colloids can be sufficiently controlled for use as a tool to assemble complex structures such as braids and weaves out of microscopic filaments. Unlike typical self-assembly paradigms, these structures are held together by geometric constraints rather than adhesive bonds. The out-of-equilibrium assembly that we propose involves precisely controlling the 2D motion of active colloids so that their path has a nontrivial topology. We demonstrate with proof-of-principle Brownian dynamics simulations that, when the colloids are attached to long semiflexible filaments, this motion causes the filaments to braid. The ability of the active particles to provide sufficient force necessary to bend the filaments into a braid depends on a number of factors, including the self-propulsion mechanism, the properties of the filament, and the maximum curvature in the braid. Our work demonstrates that nonequilibrium assembly pathways can be designed using active particles.

  2. Mechanical and wet tribological properties of carbon fabric/phenolic composites with different weave filaments counts

    NASA Astrophysics Data System (ADS)

    Wenbin, Li; Jianfeng, Huang; Jie, Fei; Liyun, Cao; Chunyan, Yao

    2015-10-01

    Carbon fabric/phenolic composites with different weave filaments counts were prepared by dip-coating and hot-press techniques, and then their mechanical and wet tribological properties were investigated based on the analysis of the three-dimensional surface profiles and the pore structures. Results show that the mechanical properties (elastic modulus, flexural modulus, tensile modulus, flexural strength and tensile strength) of the 3K carbon fabric/phenolic composites (Composite A) are better than that of the 12K carbon fabric/phenolic composites (Composite B). Fractured surfaces observation suggests that the dominant tensile failure mechanism is fiber breakage for Composite A and matrix fracture for Composite B. Compared with Composite B, Composite A possesses high friction coefficient in different loads and at different sliding speeds, and the friction coefficient of Composite A is more sensitive to load and sliding speed. The wear rate of Composite B is 39% greater than that of Composite A and the wear features of worn surfaces demonstrate the excellent wear resistance for Composite A. Based on the observation of worn surface, the wear mechanisms are presented.

  3. "Productivity on the cheap"? The "more looms" experiment and the Lancashire weaving industry during the inter-war years.

    PubMed

    Bowden, S; Higgins, D M

    1999-01-01

    Two major debates in the literature, productivity performance and the decline of the cotton industry, are joined in the analysis presented in this article on the attempts to raise productivity through the introduction of the more looms per weaver system in cotton weaving in the inter-war years. We find that the limited resultant changes were the outcome of understandable predisposition to maintain co-operative behaviour which meant that productivity enhancing schemes with long term potential were sacrificed for more modest schemes which preserved consensus in the short term.

  4. The male of the orb-weaving spider Plebs mitratus (Simon, 1895) and a redescription of the female (Araneae, Araneidae).

    PubMed

    Paul, Jimmy; Sankaran, Pradeep M; Joseph, Mathew M; Sebastian, Pothalil A

    2016-10-28

    The orb-weaving spider genus Plebs Joseph & Framenau, 2012 currently has only two representatives in India: Plebs himalayaensis (Tikader, 1975) from the Himalayas and Plebs mitratus (Simon, 1895) from the Nilgiris and Anamudi Shola National Park (World Spider Catalog 2016), both are found in high altitude mountainous habitats (Joseph & Framenau 2012). Both species were known only from females (World Spider Catalog 2016), although Sherriffs (1918, 1919) provided a description of an immature male of P. mitratus. In the present paper, we provide the first description of the adult male of P. mitratus, together with the detailed redescription of its female demonstrating considerable intraspecific variation.

  5. A new giant species of placented worm and the mechanism by which onychophorans weave their nets (Onychophora: Peripatidae).

    PubMed

    Morera-Brenes, Bernal; Monge-Nájera, Julián

    2010-12-01

    Onychophorans, or velvet worms, are poorly known and rare animals. Here we report the discovery of a new species that is also the largest onychophoran found so far, a 22 cm long female from the Caribbean coastal forest of Costa Rica. Specimens were examined with Scanning Electron Microscopy; Peripatus solorzanoi sp. nov., is diagnosed as follows: primary papillae convex and conical with rounded bases, with more than 18 scale ranks. Apical section large, spherical, with a basal diameter of at least 20 ranks. Apical piece with 6-7 scale ranks. Outer blade 1 principal tooth, 1 accessory tooth, 1 vestigial accessory tooth (formula: 1/1/1); inner blade 1 principal tooth, 1 accessory tooth, 1 rudimentary accessory tooth, 9 to 10 denticles (formula: 1/1/1/9-10). Accessory tooth blunt in both blades. Four pads in the fourth and fifth oncopods; 4th. pad arched. The previously unknown mechanism by which onychophorans weave their adhesive is simple: muscular action produces a swinging movement of the adhesive-spelling organs; as a result, the streams cross in mid air, weaving the net. Like all onychophorans, P. solorzanoi is a rare species: active protection of the habitat of the largest onychophoran ever described, is considered urgent.

  6. An investigation to determine the producibility of a 3-D braider and bias direction weaving loom

    NASA Technical Reports Server (NTRS)

    Huey, Cecil O., Jr.

    1991-01-01

    The development of prototype machines for the production of generalized braid patterns is described. Mechanical operating principles and control strategies are presented for two prototype machines which were fabricated and evaluated. Both machines represent advances over current techniques for forming composite material preforms by enabling near ideal control of fiber orientation. Furthermore, they overcome both the lack of general control of produced fiber architectures and the complexity of other weaving processes that were produced for the same purpose. One prototype, the modified Farley braider, consists of an array of turntables which can be rotated 90 degrees and returned; hence, they can form tracks in the x and y axis. Yarn ends are transported about the surface formed by the turntables using motorized tractors. These tractors are controlled using an optical link with a control circuit and host computer. The tractors are powered through electrical contact with the turntables. The necessary relative motions are produced by a series of linear tractor moves combined with a sequence of turntable rotations. The movement of the tractors about the surface causes the yarns to produce the desired braiding pattern. The second device, the shuttle plate braider, consists of a braiding surface formed by an array of square elements, each separated from its neighbor by a gap. Beneath this surface lies a shuttle plate, which reciprocates first in one axis and then in the other. As this movement takes place, yarn carrying shuttles engage and disengage the plate by means of solenoid activated pins. By selective engagement and disengagement, the shuttles can move the yarn ends in any desired pattern, forming the desired braid. Control power, and control signals, are transmitted from the electronic interface circuit and host computer, via the braiding surface through electrical contact with the shuttles. Motive power is proved to the shuttles by motion of the shuttle plate

  7. An investigation to determine the producibility of a 3-D braider and bias direction weaving loom

    NASA Astrophysics Data System (ADS)

    Huey, Cecil O., Jr.

    1991-09-01

    The development of prototype machines for the production of generalized braid patterns is described. Mechanical operating principles and control strategies are presented for two prototype machines which were fabricated and evaluated. Both machines represent advances over current techniques for forming composite material preforms by enabling near ideal control of fiber orientation. Furthermore, they overcome both the lack of general control of produced fiber architectures and the complexity of other weaving processes that were produced for the same purpose. One prototype, the modified Farley braider, consists of an array of turntables which can be rotated 90 degrees and returned; hence, they can form tracks in the x and y axis. Yarn ends are transported about the surface formed by the turntables using motorized tractors. These tractors are controlled using an optical link with a control circuit and host computer. The tractors are powered through electrical contact with the turntables. The necessary relative motions are produced by a series of linear tractor moves combined with a sequence of turntable rotations. The movement of the tractors about the surface causes the yarns to produce the desired braiding pattern. The second device, the shuttle plate braider, consists of a braiding surface formed by an array of square elements, each separated from its neighbor by a gap. Beneath this surface lies a shuttle plate, which reciprocates first in one axis and then in the other. As this movement takes place, yarn carrying shuttles engage and disengage the plate by means of solenoid activated pins. By selective engagement and disengagement, the shuttles can move the yarn ends in any desired pattern, forming the desired braid. Control power, and control signals, are transmitted from the electronic interface circuit and host computer, via the braiding surface through electrical contact with the shuttles. Motive power is proved to the shuttles by motion of the shuttle plate

  8. Outdoor Education across America: "Weaving the Web." Selected Papers, Activities, and Resources from the 1987 National Outdoor Education Conference (Cortland, New York, October 9-12, 1987).

    ERIC Educational Resources Information Center

    Yerkes, Rita, Comp.; And Others

    Selected through a refereed process from presentations given by speakers at the "1987 Outdoor Education across America: Weaving the Web" Conference, the content represents philosophy, ideas, program activities, and research of outdoor practitioners and leaders across America. The 25 presentations/workshops are summarized under the broad…

  9. Comparative evaluation of woven graphite-epoxy composites

    NASA Technical Reports Server (NTRS)

    Hanagud, S.; Tayebi, A.; Clinton, R. G., Jr.; Nayak, B. M.

    1979-01-01

    A comparative evaluation of some of the mechanical properties of woven graphite-epoxy composites are discussed. In particular, the types of weaves and the resin contents were chosen for comparison. The types of weaves selected are plain weave, satin weave, and tridirectional weave. The composites made of the fabrics are compared to composites made from unidirectional tapes under static and fatigue loading. During static loading, acoustic emission events were monitored. Also, examinations of fracture surfaces and polished sections both away from the fracture surface, and of virgin specimens under an electron microscope are discussed.

  10. Comparative evaluation of woven graphite-epoxy composites

    NASA Technical Reports Server (NTRS)

    Hanagud, S.; Tayebi, A.; Clinton, R. G.; Nayak, B. M.

    1979-01-01

    A comparative evaluation of some of the mechanical properties of woven graphite-epoxy composites have been discussed in this report. In particular the types of weaves and the resin contents have been chosen for comparison. The types of weaves selected are plain weaves, satin weave and tri-directional weave. The composites made of these fabrics have been compared to composites made from unidirectional tapes under static and fatigue loading. During static loading acoustic emission events have been monitored. Also, examinations of fracture surface and polished sections of specimens away from the fracture surface under an electron microscope have been discussed.

  11. Fiber and fabric solar cells by directly weaving carbon nanotube yarns with CdSe nanowire-based electrodes.

    PubMed

    Zhang, Luhui; Shi, Enzheng; Ji, Chunyan; Li, Zhen; Li, Peixu; Shang, Yuanyuan; Li, Yibin; Wei, Jinquan; Wang, Kunlin; Zhu, Hongwei; Wu, Dehai; Cao, Anyuan

    2012-08-21

    Electrode materials are key components for fiber solar cells, and when combined with active layers (for light absorption and charge generation) in appropriate ways, they enable design and fabrication of efficient and innovative device structures. Here, we apply carbon nanotube yarns as counter electrodes in combination with CdSe nanowire-grafted primary electrodes (Ti wire) for making fiber and fabric-shaped photoelectrochemical cells with power conversion efficiencies in the range 1% to 2.9%. The spun-twist long nanotube yarns possess both good electrical conductivity and mechanical flexibility compared to conventional metal wires or carbon fibers, which facilitate fabrication of solar cells with versatile configurations. A unique feature of our process is that instead of making individual fiber cells, we directly weave single or multiple nanotube yarns with primary electrodes into a functional fabric. Our results demonstrate promising applications of semiconducting nanowires and carbon nanotubes in woven photovoltaics.

  12. PDF Weaving - Linking Inventory Data and Monte Carlo Uncertainty Analysis in the Study of how Disturbance Affects Forest Carbon Storage

    NASA Astrophysics Data System (ADS)

    Healey, S. P.; Patterson, P.; Garrard, C.

    2014-12-01

    Altered disturbance regimes are likely a primary mechanism by which a changing climate will affect storage of carbon in forested ecosystems. Accordingly, the National Forest System (NFS) has been mandated to assess the role of disturbance (harvests, fires, insects, etc.) on carbon storage in each of its planning units. We have developed a process which combines 1990-era maps of forest structure and composition with high-quality maps of subsequent disturbance type and magnitude to track the impact of disturbance on carbon storage. This process, called the Forest Carbon Management Framework (ForCaMF), uses the maps to apply empirically calibrated carbon dynamics built into a widely used management tool, the Forest Vegetation Simulator (FVS). While ForCaMF offers locally specific insights into the effect of historical or hypothetical disturbance trends on carbon storage, its dependence upon the interaction of several maps and a carbon model poses a complex challenge in terms of tracking uncertainty. Monte Carlo analysis is an attractive option for tracking the combined effects of error in several constituent inputs as they impact overall uncertainty. Monte Carlo methods iteratively simulate alternative values for each input and quantify how much outputs vary as a result. Variation of each input is controlled by a Probability Density Function (PDF). We introduce a technique called "PDF Weaving," which constructs PDFs that ensure that simulated uncertainty precisely aligns with uncertainty estimates that can be derived from inventory data. This hard link with inventory data (derived in this case from FIA - the US Forest Service Forest Inventory and Analysis program) both provides empirical calibration and establishes consistency with other types of assessments (e.g., habitat and water) for which NFS depends upon FIA data. Results from the NFS Northern Region will be used to illustrate PDF weaving and insights gained from ForCaMF about the role of disturbance in carbon

  13. Fiber and fabric solar cells by directly weaving carbon nanotube yarns with CdSe nanowire-based electrodes

    NASA Astrophysics Data System (ADS)

    Zhang, Luhui; Shi, Enzheng; Ji, Chunyan; Li, Zhen; Li, Peixu; Shang, Yuanyuan; Li, Yibin; Wei, Jinquan; Wang, Kunlin; Zhu, Hongwei; Wu, Dehai; Cao, Anyuan

    2012-07-01

    Electrode materials are key components for fiber solar cells, and when combined with active layers (for light absorption and charge generation) in appropriate ways, they enable design and fabrication of efficient and innovative device structures. Here, we apply carbon nanotube yarns as counter electrodes in combination with CdSe nanowire-grafted primary electrodes (Ti wire) for making fiber and fabric-shaped photoelectrochemical cells with power conversion efficiencies in the range 1% to 2.9%. The spun-twist long nanotube yarns possess both good electrical conductivity and mechanical flexibility compared to conventional metal wires or carbon fibers, which facilitate fabrication of solar cells with versatile configurations. A unique feature of our process is that instead of making individual fiber cells, we directly weave single or multiple nanotube yarns with primary electrodes into a functional fabric. Our results demonstrate promising applications of semiconducting nanowires and carbon nanotubes in woven photovoltaics.Electrode materials are key components for fiber solar cells, and when combined with active layers (for light absorption and charge generation) in appropriate ways, they enable design and fabrication of efficient and innovative device structures. Here, we apply carbon nanotube yarns as counter electrodes in combination with CdSe nanowire-grafted primary electrodes (Ti wire) for making fiber and fabric-shaped photoelectrochemical cells with power conversion efficiencies in the range 1% to 2.9%. The spun-twist long nanotube yarns possess both good electrical conductivity and mechanical flexibility compared to conventional metal wires or carbon fibers, which facilitate fabrication of solar cells with versatile configurations. A unique feature of our process is that instead of making individual fiber cells, we directly weave single or multiple nanotube yarns with primary electrodes into a functional fabric. Our results demonstrate promising applications

  14. Visualization of the spatial and spectral signals of orb-weaving spiders, Nephila pilipes, through the eyes of a honeybee.

    PubMed

    Chiao, Chuan-Chin; Wu, Wen-Yen; Chen, Sheng-Hui; Yang, En-Cheng

    2009-07-01

    It is well known that the honeybee has good color vision. However, the spectral range in which the bee can see is different from that of the human eye. To study how bees view their world of colors, one has to see through the eyes of the bee, not the eyes of a human. A conventional way to examine the color signals that animals can detect is to measure the surface reflectance spectra and compute the quantum catches of each photoreceptor type based on its known spectral sensitivity. Color signal and color contrast are then determined from the loci of these quantum catches in the color space. While the point-by-point measurements of the reflectance spectra using a standard spectrometer have yielded a significant amount of data for analyzing color signals, the lack of spatial information and low sampling efficiency constrain their applications. Using a special filter coating technique, a set of filters with transmission spectra that were closely matched to the bee's sensitivity spectra of three photoreceptor types (UV, blue, and green) was custom made. By placing these filters in front of a UV/VIS-sensitive CCD camera and acquiring images sequentially, we could collect images of a bee's receptor with only three shots. This allowed a direct visualization of how bees view their world in a pseudo-color RGB display. With this imaging system, spatial and spectral signals of the orb-weaving spider, Nephila pilipes, were recorded, and color contrast images corresponding to the bee's spatial resolution were constructed and analyzed. The result not only confirmed that the color markings of N. pilipes are of high chromatic contrast to the eyes of a bee, but it also indicated that the spatial arrangement of these markings resemble flower patterns which may attract bees to visit them. Thus, it is likely that the orb-weaving spider (N. pilipes) deploys a similar strategy to that of the Australian crab spider (Thomisus spectabilis) to exploit the bee's pre-existing preference for

  15. Mercury bioaccumulation, speciation, and influence on web structure in orb-weaving spiders from a forested watershed.

    PubMed

    Wyman, Katherine E; Rodenhouse, Nicholas L; Bank, Michael S

    2011-08-01

    Atmospheric deposition is an important source of Hg in remote terrestrial ecosystems of northeastern North America. As high-level invertebrate consumers, orb-weaving spiders (family Araneidae) are excellent subjects for studying the impact of sublethal levels of Hg on forest animals because their webs provide snapshots of behavior and neurological function. Spiders of the diadematus group of the genus Araneus were collected from the Jeffers Brook watershed in the White Mountain National Forest, New Hampshire (USA), and analyzed for Hg content. Webs were photographed and measured to test for correlations between Hg body burden and web structure. Collected spiders contained concentrations of total Hg averaging 44.7 ± 10.0 ng/g Hg (wet mass; mean ± standard deviation), with 37 ± 6% of the total Hg present in the methylmercury form. Mercury loads were likely accumulated through diet (potential prey items contained an average of 43% of the Hg load in collected spiders) and possibly web ingestion. The present study found no direct evidence that the web structure-and thus the prey-capture ability-of spiders in the study area was affected by their Hg body burden.

  16. Manufacturing process for the WEAVE prime focus corrector optics for the 4.2m William Hershel Telescope

    NASA Astrophysics Data System (ADS)

    Lhomé, Emilie; Agócs, Tibor; Abrams, Don Carlos; Dee, Kevin M.; Middleton, Kevin F.; Tosh, Ian A.; Jaskó, Attila; Connor, Peter; Cochrane, Dave; Gers, Luke; Jonas, Graeme; Rakich, Andrew; Benn, Chris R.; Balcells, Marc; Trager, Scott C.; Dalton, Gavin B.; Carrasco, Esperanza; Vallenari, Antonella; Bonifacio, Piercarlo; Aguerri, J. Alfonso L.

    2016-07-01

    In this paper, we detail the manufacturing process for the lenses that will constitute the new two-degree field-of-view Prime Focus Corrector (PFC) for the 4.2m William Herschel Telescope (WHT) optimised for the upcoming WEAVE Multi-Object Spectroscopy (MOS) facility. The corrector, including an Atmospheric Dispersion Corrector (ADC), is made of six large lenses, the largest being 1.1-meter diameter. We describe how the prescriptions of the optical design were translated into manufacturing specifications for the blanks and lenses. We explain how the as-built glass blank parameters were fed back into the optical design and how the specifications for the lenses were subsequently modified. We review the critical issues for the challenging manufacturing process and discuss the trade-offs that were necessary to deliver the lenses while maintaining the optimal optical performance. A short description of the lens optical testing is also presented. Finally, the subsequent manufacturing steps, including assembly, integration, and alignment are outlined.

  17. Weaving hypothesis of cardiomyocyte sarcomeres: discovery of periodic broadening and narrowing of intercalated disk during volume-load change.

    PubMed

    Yoshida, Makoto; Sho, Eiketsu; Nanjo, Hiroshi; Takahashi, Masato; Kobayashi, Mikio; Kawamura, Kouiti; Honma, Makiko; Komatsu, Masayo; Sugita, Akihiro; Yamauchi, Misa; Hosoi, Takahiro; Ito, Yukinobu; Masuda, Hirotake

    2010-02-01

    To investigate how cardiomyocytes change their length, echocardiographic and morphological studies were performed on rabbit hearts that were subjected to volume overload, overload removal, and repeated cycles of overload and overload removal. These conditions were created by arterio-venous fistula between the carotid artery and jugular vein, closure of the fistula, and cycles of repeatedly forming and closing fistula, respectively. After overload, hearts dilated and myocytes elongated. Intercalated disks repeatedly broadened and narrowed with a 2-day cycle, which continued for 8 weeks in many animals. The cycle consisted of shifts between five modes characterized by two interdigitation elongation-and-shortenings as follows: (I) flat with short ( approximately 1/4 to approximately 1/3 sarcomere long) interdigitations; (II) flat with long (one sarcomere long) interdigitations; (III) grooved with short interdigitations; (IV) grooved with long interdigitations; (V) flat with short interdigitations intermingled by sporadic long interdigitations; and return to (I). After overload removal, hearts contracted and myocytes shortened with similar 2-day broadening and narrowing cycle of intercalated disks, in which the five modes were reversed. Repeated overload and overload removal resulted in the repetition of myocyte elongation and shortening. We hypothesize that a single elongation-and-shortening event creates or disposes one sarcomere layer, and the two consecutive elongation-and-shortenings occur complementarily to each other so that the disks return to their original state after each cycle. Our hypothesis predicts that intercalated disks weave and unravel one sarcomere per myocyte per day.

  18. "The story God is weaving us into": narrativizing grief, faith, and infant loss in US evangelical women's blog communities

    NASA Astrophysics Data System (ADS)

    Whitehead, Deborah

    2015-04-01

    This case study explores how US evangelical Christian "mommy blog" communities constitute spaces for the collective memorialization of infant loss. Personal religious blogs feature a rich combination of esthetics, narrative structure, description of religious practices and beliefs, reader interaction, and linked networks. Using a textual approach, I illustrate distinctive features in how pregnancy and infant loss and grief are experienced, shared and memorialized in US women's evangelical blogging communities. I argue that the blog format allows for a (re)narrativization of the devastating experience of infant loss as grieving mothers situate their traumatic personal experiences within the context of an ongoing religious narrative in which blog readers also come to participate. As the blogger tells the story of her own loss to a listening public, it becomes a larger shared story, so that it is not just the child's story but also the author's story, their family's story, and "our story" inclusive of the blog community of readers, "the story God is weaving us into," post by post, day by day. Personal religious blogs and their reading publics, therefore, can provide a medium for the ongoing creation of meaning, faith and community in the context of infant loss.

  19. The influence of varied gravito-inertial fields on the cardiac response of orb-weaving spiders

    NASA Technical Reports Server (NTRS)

    Finck, A.

    1982-01-01

    The Gz transfer function was described for the orb weaving spider A. sericatus. The functional relationship between the heartrate and the intensity of G is linear in the form of: Y = a Log Gz-1 +k. The heartrate in unrestrained animals was recorded by a laser plethysmograph developed specifically for this purpose. Following a control, sample heartrate were taken postrotation between 1.001 and 1.5 Gz in 6 steps. The underlying distribution of heartrates does not appear significantly different from a Gaussian distribution. A method of varnishing the legs of the spider was developed. This was done in order to compromise the lyriform organs, especially those located on the patellae. The lyriform organ is hypothesized to serve the receptor role in the transduction of gravity related stimuli. In preliminary animals the Gz function, post varnishing of the patellae, appears to be changed in the direction of poorer discrimination. We also observed that the resting heartrate following the varnish procedure is substantially increased.

  20. The fatal wound of Hector, according to a drawing by Peter Paul Rubens designed for tapestry weaving.

    PubMed

    Rubino, M; Viale, G L

    2001-02-01

    According to the Iliad(Chapter XXII, Verses 322-329), Hector, while fighting his last duel, was almost entirely protected by bronze armor, with only a small area "where the clavicle marks the boundary between neck and thorax" exposed. It was precisely into this area, "the shorter way to death," that Achilles thrust his lance. This fatal wound, although covering Hector with blood, allowed the victim to pronounce a few words. In designing the Story of Achilles, his fourth and last series of drawings especially designed for tapestry weaving, Rubens depicted Achilles stabbing Hector near the midline of his neck. There is evidence that Rubens was always well acquainted with the literary sources of his pictures. It is also likely that he became familiar with contemporary editions of the Iliad that were enhanced with commentaries. Realizing that the wound depicted in his original drawing should have prevented Hector from speaking, Rubens altered the scene, then showing the lance piercing the cervical vascular bundle. The careful scrutiny for literary accuracy that was typical of Rubens' artistic behavior did not prevent an additional minor imprecision in the final tapestry. Nevertheless, his outstanding expressive power enabled him to give form to a gigantic baroque representation of the death of Hector in masterly fashion.

  1. Porous ZnO nanosheet arrays constructed on weaved metal wire for flexible dye-sensitized solar cells.

    PubMed

    Dai, Hui; Zhou, Yong; Chen, Liang; Guo, Binglei; Li, Aidong; Liu, Jianguo; Yu, Tao; Zou, Zhigang

    2013-06-07

    Porous zinc oxide (ZnO) nanosheet (NS) arrays constructed by connected nanocrystallites were built on weaved metal wire (WMW) via hydrothermal treatment followed by calcination, and used as photoanodes for flexible dye-sensitized solar cells (DSSCs). An overall light-to-electricity conversion efficiency (η) of 2.70% was achieved for the DSSC under 100 mW cm(-2) illumination, and this η was found to be much higher than that of the DSSC with ZnO nanowire (NW) as the photoanode (0.71%). The far superior performance of the DSSC with ZnO-NS is essentially attributed to: (i) the film consisting of nanosheets with interconnected nanocrystallites can allow relatively direct pathways for the transportation of electrons as the nanosheets have a regular structure with the sheets being oriented to the electrode; (ii) the nanocrystallites assembly and porous character of the nanosheets can provide a large surface area for dye adsorption, which is in favor of enhancing the light absorption and the light propagation; (iii) the nanopores embedded in the nanosheet can act as "branch lines" for more efficient electrolyte diffusion into the interstice of the densely packed nanosheets in the array. A further improvement in the efficiency of the DSSC with ZnO-NS was achieved through the atomic layer deposition (ALD) of an ultrathin titanium oxide (TiO2) layer onto the ZnO-NS layer. The larger charge transfer resistance along with the introduction of a TiO2 shell is thought to reduce the surface recombination and thus contribute to the increase in the open circuit voltage (Voc) of the DSCs and higher conversion efficiency (3.09%).

  2. Transply crack density detection by acousto-ultrasonics

    NASA Technical Reports Server (NTRS)

    Hemann, John H.; Bowles, Kenneth J.; Kautz, Harold; Cavano, Paul

    1987-01-01

    The acousto-ultrasonic method was applied to a PMR-15 8-harness, satin Celion 3000 fabric composite to determine the extent of transply cracking. A six-ply 0/90 laminate was also subjected to mechanical loading, which induced transply cracking. The stress wave factor (SWF) is defined as the energy contained in the received signal from a 2.25-MHz center frequency transducer. The correlation of the SWF with transply crack density is shown.

  3. Pressure Drop Across Woven Screens Under Uniform and Nonuniform Flow Conditions. [flow characteristics of water through Dutch twill and square weave fabrics

    NASA Technical Reports Server (NTRS)

    Ludewig, M.; Omori, S.; Rao, G. L.

    1974-01-01

    Tests were conducted to determine the experimental pressure drop and velocity data for water flowing through woven screens. The types of materials used are dutch twill and square weave fabrics. Pressure drop measures were made at four locations in a rectangular channel. The data are presented as change in pressure compared with the average entry velocity and the numerical relationship is determined by dividing the volumetric flow rate by the screen area open to flow. The equations of continuity and momentum are presented. A computer program listing an extension of a theoretical model and data from that computer program are included.

  4. Analysis of Microdamage in Thermally Aged CF/Polyimide Laminates

    NASA Astrophysics Data System (ADS)

    Varna, J.; Zrida, H.

    2017-03-01

    Microdamage in the layers of CF Thornel® T650 8-harness satin-weave composites with a thermosetting NEXIMID® MHT-R polyimide resin, designed for high service temperatures, is analyzed. After cooling down to room temperature (RT), a multiple intrabundle cracking due to tensile transverse thermal stresses was observed in the [(+45/-45)/(90/0)]2s laminates studied. Then, the composite was subjected to two ramps of thermal cycling quantifying the increase in crack density in its layers. A comparison of two ramps with the same lowest temperature showed that the highest temperature in the cycle where thermal stresses were low had a significant detrimental effect on the thermal fatigue resistance of the composite. The effect of holding it at 288°C for 40 days was also studied: many new cracks formed in it after cooling down to RT. During the time at the high temperature, the mechanical properties degraded with time, and the crack density versus aging time was measured at RT. Then, both aged and nonaged specimens were tested in uniaxial quasi-static tension quantifying the damage development in layers of different orientation. Cracking in the layers was analyzed using fracture mechanics arguments and probabilistic approaches: a) a simple one, not considering crack interaction; b) Monte Carlo simulations. It is shown that cracking in the off-axis layers which are not in contact with the damaged 90°-layer can be predicted based on the Weibull analysis of the 90°-layer, whereas in the off-axis layer contacting the 90°-layer, the crack density is much higher due to the local stress concentrations caused by cracks in the 90°-layer. The thermal treatment degraded the cracking resistance in the surface and adjacent layer, whereas the composite close to the midplane was not changed.

  5. Bioaccumulation of mercury and its effects on survival, development and web-weaving in the funnel-web spider Agelena labyrinthica (Araneae: Agelenidae).

    PubMed

    Liu, Jin; Gao, Jin; Yun, Yueli; Hu, Zhiyong; Peng, Yu

    2013-05-01

    This study investigated the bioaccumulation and effects of mercury (Hg) in funnel-web spiders, Agelena labyrinthica, following exposure to sublethal concentrations of Hg(NO3)2 in their drinking water. The results showed that the Hg content in adult A. labyrinthica increased rapidly with the number of days exposed to the Hg(NO3)2 solution, and the mortality of adult spiders within 30 days increased with increased concentrations of Hg(NO3)2 in the drinking water. The total developmental duration of A. labyrinthica exposed to Hg(NO3)2 was significantly longer than in the control spiders, but there were no significant differences in the total developmental duration of spiders among the three treatment groups (exposed to 10, 20 and 50 mg/L Hg(NO3)2 solution). We also compared the web-weaving of the control and treated spiders, and found no significant differences in shape, structure, color, or size of the webs between the control and treated spiders; however, there was a significant difference in web placement between the treatment and control groups. The spiders in the control group appeared to have an episodic-like memory, choosing to weave their five webs in the same corner in the five time periods allowed.

  6. [Evaluation of working environment in the textile industry. IV. Dust concentration in the air of the flax spinning and weaving plants].

    PubMed

    Gościcki, J; Wiecek, E; Matecki, W; Bielichowska, G

    1980-01-01

    Evaluation of dust concentration in the air of spinning and weaving rooms was made by gravimetric sampling of dust in 3 flax plants, where short flax fibres (flax--tow) and long flax fibres were manufactured. Besides, the dispersion of dusts and concentration of free silica were determined. The highest concentration of dust (10 mg/m3) was found in hackling room, mixing mill, and the one where spreading machines are operated, while in the carding room it was - 7.0 mg/m3. In other shops the concentration was - 5.5 mg/m3. The dust in the air of spinning rooms contained 2.3% of free silica and 53% of its particles were smaller than 5 micrometers. In the weaving rooms it contained 1.6% of free silica and 57% particles were smaller than 5 micrometers. The geometric mean of dust concentration higher than MAC for vegetable dusts (4 mg/m3) was found in hackling mill, mixing mill and the one where spreading machines are operated.

  7. Structure-activity relationships of pyrrolizidine alkaloids in insect chemical defense against the orb-weaving spider Nephila clavipes.

    PubMed

    Silva, Karina Lucas; Trigo, José Roberto

    2002-04-01

    Pyrrolizidine alkaloids (PAs) are known to protect Arctiidae moths and Danainae and Ithomiinae butterflies against the orb-weaving spider Nephila clavipes (Araneae, Araneidae, Tetragnathinae), which liberates adults of these insects unharmed from its web. We tested against this spider the role of eight PAs and one derived structure [an 89:11 mixture of the 12-membered macrocyclic diester free base integerrimine and senecionine and the respective N-oxide; two hydrolysis products from this mixture (the necine base retronecine, its respective N-oxide, and a mixture of integerriminic and senecionic necic acids); the 12-membered macrocyclic senkirkine; the 9-O-monoester free base senecioylretronecine and its respective N-oxide; and the 9-O-monoester free base callimorphine (a PA biosynthesized only by insects from retronecine)]. The mixture integerrimine-senecionine N-oxide seems to be more active than the respective free base [LibD50 (liberation dose 50) = 0.042 and 0.153 microg/dry weight of prey, respectively], but the difference in activity between the N-oxide and free base of the 9-O-monoester senecioylretronecine was slight (LibD50 = 0.167 and 0.104, respectively). Senkirkine, an otonecine base PA that does not form N-oxide and is not found in insects, was the less active, showing the highest LibD50 (0.354). The difference in antipredator activity between N-oxides and free bases from macrocyclic diesters and monoesters may be correlated with physicochemical properties of these molecules in interaction with the Nephila receptors. For the active structures, there was a significant correlation between dosage and antipredator activity. Both forms of retronecine and a necic acid mixture were inactive, supporting the hypothesis that PAs biosynthesized by insects from retronecine were originally produced and stored in order to optimize chemical defense. Comparison of dose/activity data with reported amounts of PAs in butterflies suggested that, in general, PA

  8. Weaving Together Student Supports

    ERIC Educational Resources Information Center

    Benigni, Mark D.; Miller, Bruce A.

    2010-01-01

    Public schools must be the catalyst for achieving equity in education. Real equity is not simply achieving equality or about ensuring that everyone gets the same resources and receives the same instruction. Equity is about ensuring that all students get what they need to be successful. Fairness is not providing the same resources, instruction, and…

  9. Characterisation of the mechanical and fracture properties of a uni-weave carbon fibre/epoxy non-crimp fabric composite.

    PubMed

    Bru, Thomas; Hellström, Peter; Gutkin, Renaud; Ramantani, Dimitra; Peterson, Göran

    2016-03-01

    A complete database of the mechanical properties of an epoxy polymer reinforced with uni-weave carbon fibre non-crimp fabric (NCF) is established. In-plane and through-the-thickness tests were performed on unidirectional laminates under normal loading and shear loading. The response under cyclic shear loading was also measured. The material has been characterised in terms of stiffness, strength, and failure features for the different loading cases. The critical energy release rates associated with different failure modes in the material were measured from interlaminar and translaminar fracture toughness tests. The stress-strain data of the tensile, compressive, and shear test specimens are included. The load-deflection data for all fracture toughness tests are also included. The database can be used in the development and validation of analytical and numerical models of fibre reinforced plastics (FRPs), in particular FRPs with NCF reinforcements.

  10. Characterisation of the mechanical and fracture properties of a uni-weave carbon fibre/epoxy non-crimp fabric composite

    PubMed Central

    Bru, Thomas; Hellström, Peter; Gutkin, Renaud; Ramantani, Dimitra; Peterson, Göran

    2016-01-01

    A complete database of the mechanical properties of an epoxy polymer reinforced with uni-weave carbon fibre non-crimp fabric (NCF) is established. In-plane and through-the-thickness tests were performed on unidirectional laminates under normal loading and shear loading. The response under cyclic shear loading was also measured. The material has been characterised in terms of stiffness, strength, and failure features for the different loading cases. The critical energy release rates associated with different failure modes in the material were measured from interlaminar and translaminar fracture toughness tests. The stress–strain data of the tensile, compressive, and shear test specimens are included. The load–deflection data for all fracture toughness tests are also included. The database can be used in the development and validation of analytical and numerical models of fibre reinforced plastics (FRPs), in particular FRPs with NCF reinforcements. PMID:26958626

  11. Physical and Biological Determinants of Collective Behavioural Dynamics in Complex Systems: Pulling Chain Formation in the Nest-Weaving Ant Oecophylla smaragdina

    PubMed Central

    2014-01-01

    The evolution of nest weaving, the inclusion of larval silk in the nest walls, is considered one of the pinnacles of cooperative behaviour in social insects. Within the four ant genera in which this has evolved, Oecophylla are unique in being the only group that precedes the deposition of larval silk by actively manipulating the leaf substrate to form a nest chamber. Here we provide the first descriptions of the manipulation process within a complex-systems framework. Substrate manipulation involves individual ants selecting, grasping and attempting to pull the edge of the substrate. These individuals are then joined by nest mates at the work site, who either select a site beside the first individual or grasp the body of the first or preceding worker to form a chain of pulling ants that together drag and bend the substrate. Site selection by individual workers is not random when confronted with an artificial leaf, with individuals more likely to grasp a substrate at its tip rather than along a more broad edge. The activity of additional individuals is also not random, with their activity being grouped in both space and time. Additional individuals are more likely to join an existing biting individual or pulling group. The positive feedback associated with the early stages of pulling behaviour appears typical for many of the collective actions observed in social insects. PMID:24759886

  12. Dynamic optimization over infinite-time horizon: web-building strategy in an orb-weaving spider as a case study.

    PubMed

    Venner, Samuel; Chadès, Iadine; Bel-Venner, Marie-Claude; Pasquet, Alain; Charpillet, François; Leborgne, Raymond

    2006-08-21

    Dynamic state-dependent models have been widely developed since 1990s for solving questions in evolutionary ecology. Up to now, these models were mainly run over finite-time horizon. However, for many biological questions an infinite-time horizon perspective could be more appropriate, especially when the end of the modeled period is state- rather than time-dependent. Despite this approach is widely used in the field of economics and operational research, thus far no work has been providing biologists with a general method to solve infinite-time horizon problems. Here we present such a method, through the exhaustive description of an algorithm that we implement to determine the strategy an organism should follow to reach a particular state as fast as possible while limiting mortality risk. To illustrate that method we explored web-building behavior in an orb-weaving spider. How are adult females predicted to build their successive webs to gain energy, grow, and lay their first clutch as fast as possible, without suffering from either predation or starvation? From this example, we first show how an optimal strategy over infinite-time horizon can be processed and selected. Second, we analyse variations of the optimal web-building strategy along with the spider's body weight and predation risk during web building. Our model yields two main predictions: (1) spiders reduce their web size as they are gaining weight due to body-mass-dependent cost of web-building behavior, and (2) this reduction in web size starts at lower weight under higher predation risk.

  13. An occupational health programme for adults and children in the carpet weaving industry, Mirzapur, India: a case study in the informal sector.

    PubMed

    Das, P K; Shukla, K P; Ory, F G

    1992-11-01

    tiles for light improvement in the loom sheds, training of community health volunteers and house-to-house health education. Another essential part of the programme is the provision of functional literacy classes for child and adult labourers in the carpet weaving industry. Occupational health as an entry point proved to be a successful approach in this segment of the informal sector, where child labour plays an important role.

  14. Technology of Aircraft Construction (Selected Chapters)

    DTIC Science & Technology

    1988-10-13

    fulfilled in the following order. Are established/installed and fixed in the device by adjusting and clamping elements the shock strut I, braces II...assemblies of these systems. In blank production shops in walls of frames/formers, ribs, beams and diaphragms under cable guide and rigid control...characterized by diagonal arrangement of overlaps of filaments. Fabrics of linen weave possess greatest density and low flexibility. The fabrics of satin

  15. Springback Angle of a C/PPS Laminate with a Textile Reinforcement

    NASA Astrophysics Data System (ADS)

    Padovec, Z.; Růžička, M.

    2013-05-01

    The residual stresses arising in fiber-reinforced laminates during their curing in closed molds lead to changes in the composites after their removal from the molds and cooling. One of these dimensional changes of angle sections is called springback. The article compares the springback angles computed by a model representating the weave geometry (for plain and satin weaves) and by a model with straight fibers with values measured after the manufacturing process. A comparison between the thermoelastic characteristics of composites computed by both the models also presented.

  16. Weaving Nanotechnology Dreams with Nanotubes

    SciTech Connect

    Tomanek, David

    2003-01-15

    The continuous reduction of device sizes, which is rapidly approaching the atomic level, calls for new approaches to design and test future building blocks of nanotechnology. Computers will become the most powerful tools to interpret what happens on the nanometer scale, where as I will illustrate, structures of carbon may become stronger than steel, yet turn into quantum conductors or even efficient heat conductors. In nanostructures that form during a hierarchical self-assembly process, even defects may play a different, often helpful role. An efficient self-healing process may convert less stable atomic assemblies into other, more perfect structures, thus answering an important concern in molecular electronics. Defects may even be used in nano-scale engineering to form complex systems such as carbon foam or nanotube peapods. I will show how some of these challenging problems can be most efficiently addressed in simulations on recently available massively parallel supercomputers.

  17. Weaving an Integrated Information Web.

    ERIC Educational Resources Information Center

    Fickes, Michael

    2000-01-01

    Examines Texas Christian University's integration of individual information systems used in various university departments into a single information backbone providing controlled levels of access to all interested audiences. Early results of the integration are discussed. (GR)

  18. The Weave of the World.

    ERIC Educational Resources Information Center

    Jarrett, Denise

    1999-01-01

    A three-week geometry unit at a Portland (Oregon) middle school integrated mathematics, dance, and visual art. Studying the graphic art of M.C. Escher and the geometric dance patterns of the dance company Pilobolus helped students appreciate the relevance of mathematics to art and life. Students then choreographed brief dances involving geometric…

  19. Weaving Geometry and Algebra Together

    ERIC Educational Resources Information Center

    Cetner, Michelle

    2015-01-01

    When thinking about student reasoning and sense making, teachers must consider the nature of tasks given to students along with how to plan to use the tasks in the classroom. Students should be presented with tasks in a way that encourages them to draw connections between algebraic and geometric concepts. This article focuses on the idea that it…

  20. Weaving History through the Major

    ERIC Educational Resources Information Center

    Mayfield, Betty

    2014-01-01

    The benefits of including the study of the history of mathematics in the education of mathematics majors have been discussed at length elsewhere. Many colleges and universities now offer a History of Mathematics course for mathematics majors, for mathematics education majors, or for general credit. At Hood College, we emphasize our commitment to…

  1. Analysis of two-dimensional flow of epoxy fluids through woven glass fabric

    SciTech Connect

    Schutz, J.B.; Smith, K.B.

    1997-06-01

    Fabrication of magnet coils for the International Thermonuclear Experimental Reactor will require vacuum pressure impregnation of epoxy resin into the glass fabric of the insulation system. Flow of a fluid through a packed bed of woven glass fabric is extremely complicated, and semiempirical methods must be used to analyze these flows. The previous one-dimensional model has been modified for analysis of two-dimensional isotropic flow of epoxy resins through woven glass fabric. Several two-dimensional flow experiments were performed to validate the analysis, and to determine permeabilities of several fabric weave types. The semiempirical permeability is shown to be a characteristic of the fabric weave, and once determined, may be used to analyze flow of fluids of differing viscosities. Plain weave has a lower permeability than satin weave fabric, possibly due to the increased tortuosity of the preferential flow paths along fiber tows. A flow radius of approximately 2 meters through satin weave fabric is predicted for fluid viscosities of 0.10 Pa s (100 cps) in 20 hours, characteristic of VPI resins.

  2. Low-temperature mechanical properties of glass/epoxy laminates

    NASA Astrophysics Data System (ADS)

    Reed, R. P.; Madhukar, M.; Thaicharoenporn, B.; Martovetsky, N. N.

    2014-01-01

    Selected mechanical properties of glass/epoxy laminate candidates for use in the electrical turn and ground insulation of the ITER Central solenoid (CS) modules were measured. Short-beam shear and flexural tests have been conducted on various E-glass cloth weaves/epoxy laminates at 295 and 77 K. Types of glass weave include 1581, 7500, 7781, and 38050, which represent both satin and plain weaves. The epoxy, planned for use for vacuum-pressure impregnation of the CS module, consists of an anhydride-cured bisphenol F resin system. Inter-laminar shear strength, flexural elastic modulus, and flexural strength have been measured. The data indicate that these properties are dependent on the volume percent of glass. Short-beam shear strength was measured as a function of the span-to-thickness ratio for all laminates at 77 K. Comprehensive fractography was conducted to obtain the failure mode of each short-beam shear test sample.

  3. Predicting the Failure Behavior of Textile Composite Laminates by Using a Multi-Scale Correlating Approach

    NASA Astrophysics Data System (ADS)

    Deng, Yan; Chen, Xiuhua; Wang, Hai

    2015-12-01

    This paper investigates the elastic and failure behavior of textile composite laminates by using an analytical multi-scale correlating approach. The analyses are performed under the four scale levels, i.e. the laminate scale, representative unit cell (RUC) scale, tow architecture scale and fiber/matrix scale levels. The correlation between different scales is derived based on the continuum mechanics and homogenization method from which the stress and strain fields in multiple scales can be obtained concurrently. Effective modulus and ultimate failure strengths of different textile composite (plain weave, twill weave and satin weave) laminates are predicted solely from the corresponding constituent properties, braid geometrical parameters and lay-up. The damage and failure mechanisms at the constituent level are also determined by the micromechanical failure criteria. All the predicted results compare favorably with available experimental data. Parametric studies are also performed to examine the effect of various mechanical and geometrical parameters on the resulting mechanical properties.

  4. Low-temperature mechanical properties of glass/epoxy laminates

    SciTech Connect

    Reed, R. P.; Madhukar, M.; Thaicharoenporn, B.; Martovetsky, N. N.

    2014-01-27

    Selected mechanical properties of glass/epoxy laminate candidates for use in the electrical turn and ground insulation of the ITER Central solenoid (CS) modules were measured. Short-beam shear and flexural tests have been conducted on various E-glass cloth weaves/epoxy laminates at 295 and 77 K. Types of glass weave include 1581, 7500, 7781, and 38050, which represent both satin and plain weaves. The epoxy, planned for use for vacuum-pressure impregnation of the CS module, consists of an anhydride-cured bisphenol F resin system. Inter-laminar shear strength, flexural elastic modulus, and flexural strength have been measured. The data indicate that these properties are dependent on the volume percent of glass. Short-beam shear strength was measured as a function of the span-to-thickness ratio for all laminates at 77 K. Comprehensive fractography was conducted to obtain the failure mode of each short-beam shear test sample.

  5. Stress and failure analysis of textile composites using a global/local finite element method. Ph.D. Thesis

    SciTech Connect

    Woo, K.

    1993-01-01

    Textile composites are known to have improved out-of-plane properties and impact resistance. However, detailed analysis of textile composites is very difficult to perform due to the geometric complexity. In the present study, a practical computational procedure based on a global/local finite element method was developed for detailed analysis of textile composites. This procedure utilizes two problem levels: global and local levels. At the global level, an initial solution was obtained using a coarse global mesh. At the local level, a small portion of the textile composite was refined in a local mesh and analyzed in a great detail. In this study, single-field and multi-field macro elements were used in the global analysis. The macro elements are defined herein to be elements with microstructure within each element. Both the conventional finite element method and the global/local finite element method with macro elements were used to study the variation of effective properties and failure behavior of plain weave and satin weave textile composites. Results indicated that the global/local procedure was very efficient for the detailed analysis of the textile composites. The use of macro elements in the global mesh predicted the global response well and the detailed local stress distribution was obtained by the refined local mesh with discrete material modeling. With a small loss of accuracy, the global/local procedure was able to provide a reasonable solution where the conventional finite element analysis was not possible due to huge computer resource requirements. The effective properties of plain weave and satin weave textile composites were dependent on waviness. The effective properties also showed strong dependency on the number of layers. Quick convergence was obtained, however, as the number of layers increased. The stress and failure index distribution of thin plain weave textile composites were different from that of thick plain weave textile composites.

  6. Modeling of woven fabric structures based on fourier image analysis.

    PubMed

    Escofet, J; Millán, M S; Ralló, M

    2001-12-01

    The periodic woven structures of fabrics can be defined on the basis of the convolution theorem. Here an elementary unit with the minimum number of thread crossings and a nonrectangular two-dimensional comb function for the pattern of repetition is used to define woven structures. The expression derived is more compact than the conventional diagram for weaving, and the parameters that one needs to determine a given fabric can easily be extracted from its Fourier transform. Several results with real samples of the most common structures-plain, twill, and satin-are presented.

  7. Notch Sensitivity of Fatigue Behavior of a Hi-Nicalon/SiC Ceramic Composite with an Oxidation Inhibited Matrix at 1200 degree C in Air and in Steam

    DTIC Science & Technology

    2011-03-24

    Silicon Carbide / Silicon Carbide (SiC/SiC) ceramic matrix composite (CMC) was investigated at 1200 deg C in laboratory air and in steam environment. The composite consisted of an oxidation inhibited HyprSiC matrix reinforced with laminated Hi-Nicalon fibers woven in an eight-harness-satin weave (8HSW). Fiber preforms were coated with pyrolytic carbon (PyC) fiber coating with boron carbide overlay and were then densified with HyprSiC matrix via chemical vapor infiltration (CVI). Effects if center hole on tensile stress-strain behavior and tensile

  8. Fatigue damage development of various CFRP-laminates

    NASA Technical Reports Server (NTRS)

    Schulte, K.; Baron, CH.

    1988-01-01

    The chronic strength and fatigue behavior of a woven carbon-fiber reinforced laminate in a balanced eight-shaft satin weave style was compared to nonwoven laminates with an equivalent cross-ply layup. Half the fibers were arranged in the direction of the load and the other half perpendicular to it. Two types of nonwoven laminates consisting of continuous fibers and aligned discontinuous fibers, both produced from carbon fiber prepregs, were studied. The cross-ply laminate with continuous fiber showed the best characteristics with regard to both static strength and fatigue. The similarities and differences in damage mechanisms in the laminates are described.

  9. WEAVE an overview and status update

    NASA Astrophysics Data System (ADS)

    Bonifacio, P.; Dalton, G.; Trager, S.; Aguerri, A. L.; Carrasco, E.; Vallenari, A.; Abrams, D. C.; Middleton, K.; Sayède, F.

    2016-12-01

    The WHT Enhanced Area Velocity Explorer is a high multiplex, multi-object spectrograph that will equip the prime focus of the WHT 4.2m telescope. The instrument is currently in the construction phase and several components have already been procured. I will give a short overview of the instrument and of the project and its status. The French participation is done through CNRS - Institut National des Sciences de l'Univers and the technical activity is carried out, at this stage, at GEPI, Observatoire de Paris.

  10. Weaving a Stronger Fabric for Improved Outcomes

    ERIC Educational Resources Information Center

    Lobry de Bruyn, Lisa; Prior, Julian; Lenehan, Jo

    2014-01-01

    Purpose: To explain how training and education events (TEEs) can be designed to increase the likelihood of achieving behavioural objectives. Approach: The approach combined both a quantitative review of evaluation surveys undertaken at the time of the TEE, and qualitative telephone interviews with selected attendees (2025% of the total population…

  11. Weaving Clinical Expertise in Online Health Communities.

    PubMed

    Huh, Jina; Pratt, Wanda

    Many patients visit online health communities to receive support. In face-to-face support groups, health professionals facilitate peer-patients exchanging experience while adding their clinical expertise when necessary. However, the large scale of online health communities makes it challenging for such health professional moderators' involvement to happen. To address this challenge of delivering clinical expertise to where patients need them, we explore the idea of semi-automatically providing clinical expertise in online health communities. We interviewed 14 clinicians showing them example peer-patient conversation threads. From the interviews, we examined the ideal practice of clinicians providing expertise to patients. The clinicians continuously assessed when peer-patients were providing appropriate support, what kinds of clinical help they could give online, and when to defer to patients' healthcare providers. The findings inform requirements for building a semi-automated system delivering clinical expertise in online health communities.

  12. Homecoming rituals: weaving multicultural funeral narratives.

    PubMed

    Kwon, Soo-Young

    2003-01-01

    Using the personal experience of "homecoming" funcrary journey from the U.S. to Korea the author of this article probes the cultural construction of familial bond in Korean and biblical (Genesis) tuneral narratives. He highlights the cultural differences between American and Korean funeral traditions--(1) dying at hospital vs. dying at home, (2) embalming vs sup/yom (washing/binding of the corpse), (3) metal casket vs. wooden coffin, (4) committal vs. banhon (returning of the spirit)--to explore the religious and practical implications of the multicultural grieving process for pastoral care and grief ministry in which death is conceived as returning to the familial, cultural, and spiritual homes.

  13. Weaving Webs: School, Community, and Home

    ERIC Educational Resources Information Center

    Thweatt, Mary

    2012-01-01

    School librarians are collaborators, making connections with community, school, technology, jobseekers, and individuals with language barriers. They have served as a resource of information to the community and students. As an elementary school librarian, the author has become more creative by seriously listening to school community members. What…

  14. Theories, relationships and interprofessionalism: learning to weave.

    PubMed

    Hall, Pippa; Weaver, Lynda; Grassau, Pamela Anne

    2013-01-01

    In this article, we illustrate the application of a number of theoretical frameworks we have used to guide our work in interprofessional education (IPE) and collaborative interprofessional care (IPC). Although we do not claim to be experts in any one of these theories, each has offered important insights that have broadened our understanding of the complexities of interprofessional learning and practice. We have gained an appreciation for an increasing number of theories relevant to IPE and IPC, and, as a result, we have woven together more key principles from different theories to develop activities for all levels of interprofessional learners and clinicians. We pay particular attention to relational competencies, knotworking/idea dominance, targeted tension and situational awareness. We are now drawing on the arts and humanities and complexity theory to foster relationship-building learning. Evaluation of our endeavors will eventually follow these latter theories for methods that better match the human and social experiences that underpin learning. Our "theoretical toolbox" therefore may be of value to educators who develop and implement creative interprofessional learning activities, as well as clinicians interested in moving toward more effective collaboration.

  15. Bridging the Gap: Weaving Humanism and Poststructuralism

    ERIC Educational Resources Information Center

    Cornforth, Sue

    2010-01-01

    This case study documents an attempt to teach counselling approaches differently in order to scaffold a bridge between humanistic and poststructural perspectives. It focuses on the experience of one postgraduate class, drawing on material written in class and a later reflective focus group. The study locates counselling within current…

  16. Assessment of Angular Weaving for Turbine Components.

    DTIC Science & Technology

    1987-01-23

    including foreign nations. This technical report has been reviewed and is approved for publication. RAYMONDP.VIN F. SCHMIDT, Chief Project Engineer ... Engine Assessment Branch Engine Assessment Branch Turbine Engine Division Turbine Engine Division Aero Propulsion Laboratory Aero Propulsion Laboratory FOR...F ....:. . . ......, . . iT u iepu t yie D i i s o .... .................... ......... .. Turbine Engine Di vision Jt. ib .tion ) Aero Propulsion

  17. Beyond Earth: Weaving Science and Indigenous Culture

    NASA Astrophysics Data System (ADS)

    Young, Timothy; Guy, M.; Baker-Big Back, C.; Froelich, K.; Munski, L.; Johnson, T.

    2010-01-01

    Beyond Earth is an NSF planning grant designed to engage urban and rural families in science learning while piloting curriculum development and implementation that incorporates both Native and Western epistemologies. Physical, earth, and space science content is juxtaposed with indigenous culture, stories, language and epistemology in after-school programs and teacher training. Project partners include the Dakota Science Center, Fort Berthold Community College, and Sitting Bull College. The Native American tribes represented in this initiative illustrate partnerships between the Dakota, Lakota, Nakota, Hidatsa, Mandan, and Arikara. The primary project deliverables include a culturally responsive curriculum Beyond Earth Moon Module, teacher training workshops, a project website. The curriculum module introduces students to the moon's appearance, phases, and positions in the sky using the Night Sky Planetarium Experience Station to explore core concepts underlying moon phases and eclipses using the interactive Nature Experience Station before engaging in the culminating Mission Challenge in which they apply their knowledge to problem solving situations and projects. The website and developed explorations are presented.

  18. Weaving Multicultural Literature into Middle School Curricula

    ERIC Educational Resources Information Center

    Landt, Susan M.

    2007-01-01

    Middle school students are acutely aware of their social surroundings. In the process of emerging from childhood they attentively observe one another, looking for clues to belonging. Striving for independence from adult authority, young adolescents endeavor to blend in with their contemporaries. From clothes to music, from posture to attitude,…

  19. The Social Weaving of a Reading Atmosphere

    ERIC Educational Resources Information Center

    Sequeiros, Paula

    2011-01-01

    This paper discusses how public library readers in Almeida Garrett, Porto, create a reading atmosphere, focusing on meanings associated with aural conditions. Through a qualitative, single case study, ethnographic and interview techniques were applied. Readers' actual practices and discourses, through a theoretical sample, and those of managers,…

  20. Miami thrives: weaving a poverty reduction coalition.

    PubMed

    Evans, Scotney D; Rosen, Adam D; Kesten, Stacey M; Moore, Wendy

    2014-06-01

    In an environment where community based organizations are asked to do increasingly more to alleviate the effects of complex social problems, networks and coalitions are becoming the answer for increasing scale, efficiency, coordination, and most importantly, social impact. This paper highlights the formation of a poverty reduction coalition in south Florida. Our case study approach chronicles a developing coalition in Miami-Dade County and the role of one organization acting as lead to the initiative. Drawing on interviews with lead organization staff, participant observation field notes, network mapping and analysis of documents and artifacts from the initiative, we analyze the local organizational context and illuminate important processes associated with supporting a developing coalition. Findings offer a picture of the interorganizational relationships in the community using social network analysis and identify the organizational capacity factors that contribute to and inhibit the formation of a cohesive and effective coalition in this context. This study also highlights the utility of an action research approach to organizational learning about coalition-building in such a way that informs decision making.

  1. Basket Weaving Inspired by the Gullah

    ERIC Educational Resources Information Center

    Baker, Rita

    2010-01-01

    Many different cultures created and used the basket not only for utilitarian purposes, but also for ceremonial uses. In this article, the author describes an eighth-grade project inspired by the basket making of the Gullah people, who live along the coast of South Carolina, Georgia and Florida.

  2. Weaving the Web into Course Integrated Instruction.

    ERIC Educational Resources Information Center

    Wallach, Ruth; McCann, Linda

    In the fall 1995, a professor teaching an undergraduate course asked the Reference Center at the University of Southern California to conduct a research session on Dante related resources on the Internet, and to show her students how to search the Dartmouth Dante Project. A simple homepage was created for the class, which listed the course…

  3. Weaving the Web into legacy information systems.

    PubMed Central

    Schoenberg, R.; Nathanson, L.; Safran, C.; Sands, D. Z.

    2000-01-01

    For many years, client-server systems were developed as the backbone of clinical computing in leading hospitals around the country. Beth Israel Deaconess Medical Center now faces the challenge of bridging the technology gap between such systems and the Internet. While developing Web interfaces to legacy clinical systems gives a taste of the future, it is clear that complete institutional migration to the Web is not imminent. Asking clinicians to utilize two different systems, Web-based and legacy, in the interim phase is just one of the difficulties in such transition. This paper describes "Mbridge", a solution that allows legacy system users to exploit the benefits of the Internet in a fashion that does not interfere with their workflow and is both simple and affordable to implement. The service allows clinicians to work on the legacy platform while context-sensitive clinical content is streamed to the browser without their intervention. Using the system, we can gradually expose clinicians to new Web-based applications and resources without forcing them to operate two computing environments simultaneously. The service achieves these goals by means of linkage and coordination rather than by code-translation, data exchange or replication. PMID:11079988

  4. Weaving the Web into Your Campaign

    ERIC Educational Resources Information Center

    Broman, Claudia

    2009-01-01

    Like anything else, there are good fundraising campaign Web sites and bad fundraising campaign Web sites. The author took a closer look at fundraising campaign sites to see if her intuitive judgments about these could be translated into a logical, research-supported set of best practices. She set up a study that gauged the ease of use and…

  5. Ethynylated aromatics as high temperature matrix resins

    NASA Technical Reports Server (NTRS)

    Hurwitz, Frances I.

    1986-01-01

    Difunctional and trifunctional arylacetylenes were used as monomers to form thermoset matrix resin composites. Composites can be hot pressed at 180 C to react 80 percent of the acetylene groups. Crosslinking is completed by postcuring at 350 C. The postcured resins are thermally stable to nominally 460 C in air. As a result of their high crosslink density, the matrix exhibits brittle failure when unaxial composites are tested in tension. Failure of both uniaxial tensile and flexural specimens occurs in shear at the fiber matrix interface. Tensile fracture stresses for 0 deg composites fabricated with 60 v/o Celion 6K graphite fiber were 827 MPa. The strain to failure was 0.5 percent. Composites fabricated with 8 harness satin Celion cloth (Fiberite 1133) and tested in tension also failed in shear at tensile stresses of 413 MPa.

  6. Experimental Investigation of the Interface Behavior of Balanced and Unbalanced E-Glass/Polyester Woven Fabric Composite Laminates

    NASA Astrophysics Data System (ADS)

    Triki, E.; Zouari, B.; Jarraya, A.; Dammak, F.

    2013-12-01

    The aim of this work is to study the influence of weave structure on the crack growth behavior of thick E-glass/polyester woven fabric composites laminates. Two different types of laminates were fabricated: (i) balanced: plain weave (taffetas T)/chopped strand mat weave (M) [T/M]6 and (ii) unbalanced: 4-hardness satin weave (S)/chopped strand mat weave [S/M]7. In order to accurately predict damage criticality in such structures, mixed mode fracture toughness data is required. So, the experiments were conducted using standards delamination tests under mixed mode loading and pure mode loading. These tests were carried out in mode II using End Load Split (ELS) tests and in mixed-mode I+II by Mixed Mode Flexure (MMF) tests under static conditions. The test methodology used for the experiments will be presented. The experimental results have been expressed in terms of total strain energy release rate and R-curves. The fracture toughness results show that the T/M interface is more resistant to delamination than the S/M interface.

  7. Ballistic damage in hybrid composite laminates

    NASA Astrophysics Data System (ADS)

    Phadnis, Vaibhav A.; Pandya, Kedar S.; Naik, Niranjan K.; Roy, Anish; Silberschmidt, Vadim V.

    2015-07-01

    Ballistic damage of hybrid woven-fabric composites made of plain-weave E-glass- fabric/epoxy and 8H satin-weave T300 carbon-fabric/epoxy is studied using a combination of experimental tests, microstructural studies and finite-element (FE) analysis. Ballistic tests were conducted with a single-stage gas gun. Fibre damage and delamination were observed to be dominating failure modes. A ply-level FE model was developed, with a fabric-reinforced ply modelled as a homogeneous orthotropic material with capacity to sustain progressive stiffness degradation due to fibre/matrix cracking, fibre breaking and plastic deformation under shear loading. Simulated damage patterns on the front and back faces of fabric-reinforced composite plates provided an insight into their damage mechanisms under ballistic loading.

  8. SUBCRITICAL CRACK PROPAGATION STUDIES IN HI-NICALON AND HI-NICALON TYPE-S FIBER SiC/SiC COMPOSITES USING COMPACT TENSION SPECIMENS

    SciTech Connect

    Henager, Charles H.

    2007-10-02

    PNNL has performed subcritical crack growth tests under constant applied load at various elevated temperatures in inert environments using subscale compact tension (CT) specimens of two types of SiC-composite materials. The use of CT specimens is preferred over the usual dingle-edge notched beam (SENB) specimens due to more uniform applied stresses over the crack growth region. This study will compare crack growth data taken between two materials as well as specimen geometry types, CT compared to SENB. Plain weave [0/90] Hi-Nicalon CT specimens were tested in argon atmospheres and compared to similar tests of 5-harness satin weave [0/90] Hi-Nicalon Type-S composites. We report here some of the preliminary fractographic examinations of the two materials and an initial assessment of the crack growth data. Additional information on this study will be presented later and also at ICFRM-13 in December.

  9. Weavability of dry polymer powder towpreg

    NASA Technical Reports Server (NTRS)

    Hugh, Maylene K.; Marchello, Joseph M.; Maiden, Janice R.; Johnston, Norman J.

    1993-01-01

    Carbon fiber yarns (3k, 6k, 12k) were impregnated with LARC (tm) thermoplastic polyimide dry powder. Parameters for weaving these yarns were established. Eight-harness satin fabrics were successfully woven from each of the three classes of yarns and consolidated into test specimens to determine mechanical properties. It was observed that for optimum results warp yarns should have flexural rigidities between 10,000 and 100,000 mg-cm. Tow handling minimization, low tensioning, and tow bundle twisting were used to reduce fiber breakage, the separation of filaments, and tow-to-tow abrasion. No apparent effect of tow size or twist was observed on either tension or compression modulus. However, fiber damage and processing costs favor the use of 12k yarn bundles versus 3k or 6k yarn bundles in the weaving of powder-coated towpreg.

  10. Mechanical Characterization and Micromechanical Modeling of Woven Carbon/Copper Composites

    NASA Technical Reports Server (NTRS)

    Bednarcyk, Brett A.; Pindera, Marek-Jerzy; Ellis, David L.; Miner, Robert V.

    1997-01-01

    The present investigation examines the in-plane mechanical behavior of a particular woven metal matrix composite (MMC); 8-harness (8H) satin carbon/copper (C/Cu). This is accomplished via mechanical testing as well as micromechanical modeling. While the literature is replete with experimental and modeling efforts for woven and braided polymer matrix composites, little work has been done on woven and braided MMC's. Thus, the development and understanding of woven MMC's is at an early stage. 8H satin C/Cu owes its existence to the high thermal conductivity of copper and low density and thermal expansion of carbon fibers. It is a candidate material for high heat flux applications, such as space power radiator panels. The experimental portion of this investigation consists of monotonic and cyclic tension, compression, and Iosipescu shear tests, as well as combined tension-compression tests. Tests were performed on composite specimens with three copper matrix alloy types: pure Cu, Cu-0.5 weight percent Ti (Cu-Ti), and Cu-0.7 weight percent Cr (Cu-Cr). The small alloying additions are present to promote fiber/matrix interfacial bonding. The analytical modeling effort utilizes an approach in which a local micromechanical model is embedded in a global micromechanical model. This approach differs from previously developed analytical models for woven composites in that a true repeating unit cell is analyzed. However, unlike finite element modeling of woven composites, the geometry is sufficiently idealized to allow efficient geometric discretization and efficient execution.

  11. Micromechanics Based Multiscale Modeling of the Inelastic Response and Failure of Complex Architecture Composites

    NASA Astrophysics Data System (ADS)

    Liu, Kuang

    Advanced composites are being widely used in aerospace applications due to their high stiffness, strength and energy absorption capabilities. However, the assurance of structural reliability is a critical issue because a damage event will compromise the integrity of composite structures and lead to ultimate failure. In this dissertation a novel homogenization based multiscale modeling framework using semi-analytical micromechanics is presented to simulate the response of textile composites. The novelty of this approach lies in the three scale homogenization/localization framework bridging between the constituent (micro), the fiber tow scale (meso), weave scale (macro), and the global response. The multiscale framework, named Multiscale Generalized Method of Cells (MSGMC), continuously bridges between the micro to the global scale as opposed to approaches that are top-down and bottom-up. This framework is fully generalized and capable of modeling several different weave and braids without reformulation. Particular emphasis in this dissertation is placed on modeling the nonlinearity and failure of both polymer matrix and ceramic matrix composites. Results are presented for the cases of plain, twill, satin, and triaxially braided composites. Inelastic, failure, strain rate and damage effects are included at the microscale and propagated to the global scale. MSGMC was successfully used to predict the in-plane material response plain and five harness satin woven polymer composites, triaxially braided polymer composite and both the in-plane and out-of-plane response of silicon carbide ceramic matrix composites.

  12. Optimization of the Composite Repair Work using 5H Satin Dry Glass Fabric and Epoxy Resin LY5052/HY5052 Materials through the Vacuum Bagging Technique

    NASA Astrophysics Data System (ADS)

    Hartono; Rifai, Mochammad; Subawi, Handoko

    2016-08-01

    In composite repair terminology, the intermingled fiber joints (IFJs) concept is clearly identified as the most effective in transferring stress. However, the practical application leads to apply the laminated fiber joints (LFJs) concept for composite repair. The LFJs become almost as strong as the IFJs as the jointed zone length increases. The LFJs concept was implemented to set up the repair configuration for this work. It is identified that fracture tendency as the result of crack propagation starts from the free edges. This tendency is alleviated by applying vacuum bag to compact the laminate system. If necessary, additional accelerated curing was performed at low temperature for short time. However, this repair work preferably applying natural overnight cure to ensure the structure stability. Additionally, the repair handling and waiting purposes take 40% out of the effectively repair time. The waiting time should be anticipated in the composite repair to reduce wasting time for unproductive output.

  13. Effects of Nesting on Compression-Loaded 2-D Woven Textile Composites

    NASA Technical Reports Server (NTRS)

    Adams, Daniel OHare; Breiling, Kurtis B.; Verhulst, Mark A.

    1995-01-01

    Layer nesting was investigated in five harness satin weave textile composite laminates under static compression loading. Two carbon/epoxy material systems, AS4/3501-6 and IM7/8551-7A were considered. Laminates were fabricated with three idealized nesting cases: stacked, split-span and diagonal. Similar compression strength reductions due to the effects of idealized nesting were identified for each material. The diagonal nesting geometry produced the largest reduction in static strength when compared to the compression strength of a conventional textile composite. All three nesting cases produced reductions in strength and ultimate strain due to the effects of idealized nesting. Finite element results showed consistent strength reduction trends for the idealized nesting cases, however the magnitudes of compressive strengths were overpredicted.

  14. High Dose Neutron Irradiation of Hi-Nicalon Type S Silicon Carbide Composites, Part 2. Mechanical and Physical Properties

    SciTech Connect

    Katoh, Yutai; Nozawa, Takashi; Shih, Chunghao Phillip; Ozawa, Kazumi; Koyanagi, Takaaki; Porter, Wallace D; Snead, Lance Lewis

    2015-01-07

    Nuclear-grade silicon carbide (SiC) composite material was examined for mechanical and thermophysical properties following high-dose neutron irradiation in the High Flux Isotope Reactor at a temperature range of 573–1073 K. Likewise, the material was chemical vapor-infiltrated SiC-matrix composite with a two-dimensional satin weave Hi-Nicalon Type S SiC fiber reinforcement and a multilayered pyrocarbon/SiC interphase. Moderate (1073 K) to very severe (573 K) degradation in mechanical properties was found after irradiation to >70 dpa, whereas no evidence was found for progressive evolution in swelling and thermal conductivity. The swelling was found to recover upon annealing beyond the irradiation temperature, indicating the irradiation temperature, but only to a limited extent. Moreover, the observed strength degradation is attributed primarily to fiber damage for all irradiation temperatures, particularly a combination of severe fiber degradation and likely interphase damage at relatively low irradiation temperatures.

  15. A study of elevated temperature testing techniques for the fatigue behavior of PMCS: Application to T650-35/AMB21

    NASA Technical Reports Server (NTRS)

    Gyekenyesi, Andrew L.; Gastelli, Michael G.; Ellis, John R.; Burke, Christopher S.

    1995-01-01

    An experimental study was conducted to investigate the mechanical behavior of a T650-35/AMB21 eight-harness satin weave polymer composite system. Emphasis was placed on the development and refinement of techniques used in elevated temperature uniaxial PMC testing. Issues such as specimen design, gripping, strain measurement, and temperature control and measurement were addressed. Quasi-static tensile and fatigue properties (R(sub sigma) = 0.1) were examined at room and elevated temperatures. Stiffness degradation and strain accumulation during fatigue cycling were recorded to monitor damage progression and provide insight for future analytical modeling efforts. Accomplishments included an untabbed dog-bone specimen design which consistently failed in the gage section, accurate temperature control and assessment, and continuous in-situ strain measurement capability during fatigue loading at elevated temperatures. Finally, strain accumulation and stiffness degradation during fatigue cycling appeared to be good indicators of damage progression.

  16. Effects of Microstructural Variability on Thermo-Mechanical Properties of a Woven Ceramic Matrix Composite

    NASA Technical Reports Server (NTRS)

    Goldsmith, Marlana B.; Sankar, Bhavani V.; Haftka, Raphael T.; Goldberg, Robert K.

    2013-01-01

    The objectives of this paper include identifying important architectural parameters that describe the SiC/SiC five-harness satin weave composite and characterizing the statistical distributions and correlations of those parameters from photomicrographs of various cross sections. In addition, realistic artificial cross sections of a 2D representative volume element (RVE) are generated reflecting the variability found in the photomicrographs, which are used to determine the effects of architectural variability on the thermo-mechanical properties. Lastly, preliminary information is obtained on the sensitivity of thermo-mechanical properties to architectural variations. Finite element analysis is used in combination with a response surface and it is shown that the present method is effective in determining the effects of architectural variability on thermo-mechanical properties.

  17. Functional finishes of stretch cotton fabrics.

    PubMed

    Ibrahim, N A; Amr, A; Eid, B M; Almetwally, A A; Mourad, M M

    2013-11-06

    Functionalized cotton cellulose/spandex woven fabrics with different structures namely plain (1/1), twill (2/2) and satin were produced. Factors affecting the imparted functional properties such as weave structure and constituents of the finishing formulations including ether or ester cross-linker and catalyst type, silicone-micro-emulsion, water/oil repellent, Ag-NP(,)s and TiO2-NP(,)s were studied. The treated fabrics were found to have easy care property together with one or more of the imparted functional properties such as soft-handle, water/oil repellence, antibacterial, UV-protection and self cleaning. The effectiveness of the imparted properties is not seriously affected even after 10 washing cycles. Surface modifications as well as the composition of certain samples were confirmed by SEM images and EDX spectra. Mode of interactions was also suggested.

  18. Rubber-toughened polyfunctional epoxies - Brominated vs nonbrominated formulated for graphite composites

    NASA Technical Reports Server (NTRS)

    Nir, Z.; Gilwee, W. J.; Kourtides, D. A.; Parker, J. A.

    1983-01-01

    A new, commercially available, trifunctional epoxy resin (tris-(hydroxyphenyl)-methane triglycidyl ether) was modified with synthetic rubber to increase the impact resistance of epoxy/graphite composites. These composites were reinforced with commercially available satin-weave carbon cloth using two formulations of epoxies (brominated and nonbrominated) containing various amounts of carboxy-terminated butadience acrylonitrile (CTBN) rubber that had been prereacted with epoxy resin. The impact resistance was determined by measuring the interlaminar shear strength of the composites after impact. The mechanical properties, such as flexural strength and modulus at room temperature and at 93 C, were also determined. Measurements were taken of the flammability and glass transition temperature (Tg); and a thermal-gravimetric analysis was made.

  19. Polymeric routes to silicon carbide and silicon oxycarbide CMC

    NASA Technical Reports Server (NTRS)

    Hurwitz, Frances I.; Heimann, Paul J.; Gyekenyesi, John Z.; Masnovi, John; Bu, Xin YA

    1991-01-01

    An overview of two approaches to the formation of ceramic composite matrices from polymeric precursors is presented. Copolymerization of alkyl- and alkenylsilanes (RSiH3) represents a new precursor system for the production of Beta-SiC on pyrolysis, with copolymer composition controlling polymer structure, char yield, and ceramic stoichiometry and morphology. Polysilsesquioxanes which are synthesized readily and can be handled in air serve as precursors to Si-C-O ceramics. Copolymers of phenyl and methyl silsesquioxanes display rheological properties favorable for composite fabrication; these can be tailored by control of pH, water/methoxy ratio and copolymer composition. Composites obtained from these utilize a carbon coated, eight harness satin weave Nicalon cloth reinforcement. The material exhibits nonlinear stress-strain behavior in tension.

  20. Development of new and improved polymer matrix resin systems, phase 1

    NASA Technical Reports Server (NTRS)

    Hsu, M. S.

    1983-01-01

    Vinystilbazole (vinylstryrylpyridine) and vinylpolystyrulpyridine were prepared for the purpose of modifying bismaleimide composite resins. Cure studies of resins systems were investigated by differential scanning calorimetry. The vinylstyrylpyridine-modified bismaleimide composite resins were found to have lower cure and gel temperatures, and shorter cure times than the corresponding unmodified composite resins. The resin systems were reinforced with commercially avialable satin-weave carbon cloth. Prepregs were fabricated by solvent or hot melt techniques. Thermal stability, flammability, moisture absorption, and mechanical properties of the composites (such as flexural strength, modulus, tensile and short beam shear strength) were determined. Composite laminates showed substantial improvements in both processability and mechanical properties compared to he bismaleimide control systems. The vinylstyrylpyridine modified bismaleimide resins can be used as advanced matrix resins for graphite secondary structures where ease of processing, fireworthiness, and high temperature stability are required for aerospace applications.

  1. Weaving Social Media into a Business Proposal Project

    ERIC Educational Resources Information Center

    Li, Xiaoli

    2012-01-01

    Given that students are enthusiastic about social media or even have expertise in some social media tools, the author decided to design a class project in her Writing for Careers (Business Communication) class that integrates social media in terms of content and project management. This article intends to describe such a class project design as…

  2. Image analysis of weaverbird nests reveals signature weave textures.

    PubMed

    Bailey, Ida E; Backes, André; Walsh, Patrick T; Morgan, Kate V; Meddle, Simone L; Healy, Susan D

    2015-06-01

    In nature, many animals build structures that can be readily measured at the scale of their gross morphology (e.g. length, volume and weight). Capturing individuality as can be done with the structures designed and built by human architects or artists, however, is more challenging. Here, we tested whether computer-aided image texture classification approaches can be used to describe textural variation in the nests of weaverbirds (Ploceus species) in order to attribute nests to the individual weaverbird that built them. We found that a computer-aided texture analysis approach does allow the assignment of a signature to weaverbirds' nests. We suggest that this approach will be a useful tool with which to examine individual variation across a range of animal constructions, not just for nests.

  3. Masters of Weaving: The Complex Role of Special Education Teachers

    ERIC Educational Resources Information Center

    Hillel Lavian, Rivka

    2015-01-01

    Special education teachers work under more difficult, more intense, and more demanding conditions than mainstream teachers. Relations between teachers, pupils, and parents are more complex than in mainstream education due to the intensity, intimacy, vulnerability, and commitment involved. Teachers require special skills so they can practice…

  4. Helping Students Weave Their Way through the World Wide Web.

    ERIC Educational Resources Information Center

    Elliott, Catherine B.

    2000-01-01

    Discusses six strategies to help both students and teachers learn to make wise use of information on the World Wide Web: teaching the value of key word skills; using online sources available in the media center; creating pathfinders; teaching students sound searching skills that include Boolean logic; directing students to the best search engines;…

  5. True Teaching Expertise: The Weaving Together of Theory and Practice

    ERIC Educational Resources Information Center

    Mascio, Bryan

    2016-01-01

    How do we strengthen the teaching profession? This question weighs on many educators, researchers, politicians, and parents. The public discourse around teaching often feels very negative; it does not clearly define teaching expertise, but it does reflect a very clear belief that many teachers just do not have it. In this article, a former…

  6. Educating for Vocation: Weaving Educational Ideas with Institutional Practices

    ERIC Educational Resources Information Center

    Roels, Shirley J.

    2017-01-01

    Theologies of vocation are essential in order to explore questions of purpose, values, and direction with college and university students. Given that educational institutions have embedded values and perspectives, some higher education cultures are more effective than others in fostering a student's sense of life calling. In this article, I…

  7. Weaving Imagination into an Academic Framework: Attitudes, Assignments, and Assessments

    ERIC Educational Resources Information Center

    Miller, Jeanetta

    2009-01-01

    The author believes that imagination is alive in the high school classroom, but it is pale and sickly, suffering from a long decline in which teachers have confined it to its most decorous forms of expression--inference and interpretation--and become ambiguous about whether or not it is truly welcome. To rouse imagination in the high school…

  8. Weaving a Virtual Story--Creating Book Trailers 101

    ERIC Educational Resources Information Center

    Bates, Naomi

    2012-01-01

    Book trailers are fast becoming today's marketing technique for newly published books. They have changed the way students select books, and trailers meet the expectations of today's teens who have been brought up on graphic visuals. Book trailers are also quite new, starting as a trend only about four years ago. Since then, they have proliferated,…

  9. Weaving Authenticity and Legitimacy: Latina Faculty Peer Mentoring

    ERIC Educational Resources Information Center

    Núñez, Anne-Marie; Murakami, Elizabeth T.; Gonzales, Leslie D.

    2015-01-01

    As an alternative to typical top-down mentoring models, the authors advance a conception of peer mentoring that is based on research about collectivist strategies that Latina faculty employ to navigate the academy. The authors advance recommendations for institutional agents to support mentoring for faculty who are members of historically…

  10. Weaving Social Foundations through Dance Pedagogy: A Pedagogy of Uncovering

    ERIC Educational Resources Information Center

    Barr, Sherrie; Risner, Doug

    2014-01-01

    Today's dance educators enter classrooms populated by increasingly diverse students in which teachers' pedagogical knowledge necessitates heightened understandings of race, ethnicity, social class, gender, and sexuality. Uncovering taken-for-granted assumptions, dominant stereotypes, and educational structures that reproduce social…

  11. Weaving New Retail and Consumer Landscapes in the Scottish Borders

    ERIC Educational Resources Information Center

    Findlay, Anne; Sparks, Leigh

    2008-01-01

    New retail locations and formats and changing consumer capabilities and behaviours (including "switching") have encouraged "outshopping" from rural to urban areas. Rural areas have been suffering from a decline in the provision of services, including retailing. One "solution" has been the strengthening of market towns…

  12. Image analysis of weaverbird nests reveals signature weave textures

    PubMed Central

    Bailey, Ida E.; Backes, André; Walsh, Patrick T.; Morgan, Kate V.; Meddle, Simone L.; Healy, Susan D.

    2015-01-01

    In nature, many animals build structures that can be readily measured at the scale of their gross morphology (e.g. length, volume and weight). Capturing individuality as can be done with the structures designed and built by human architects or artists, however, is more challenging. Here, we tested whether computer-aided image texture classification approaches can be used to describe textural variation in the nests of weaverbirds (Ploceus species) in order to attribute nests to the individual weaverbird that built them. We found that a computer-aided texture analysis approach does allow the assignment of a signature to weaverbirds' nests. We suggest that this approach will be a useful tool with which to examine individual variation across a range of animal constructions, not just for nests. PMID:26543586

  13. Weaving multi-layer fabrics for reinforcement of engineering components

    NASA Technical Reports Server (NTRS)

    Hill, B. J.; Mcilhagger, R.; Mclaughlin, P.

    1993-01-01

    The performance of interlinked, multi-layer fabrics and near net shape preforms for engineering applications, woven on a 48 shaft dobby loom using glass, aramid, and carbon continuous filament yarns is assessed. The interlinking was formed using the warp yarns. Two basic types of structure were used. The first used a single warp beam and hence each of the warp yarns followed a similar path to form four layer interlinked reinforcements and preforms. In the second two warp beams were used, one for the interlinking yarns which pass from the top to the bottom layer through-the-thickness of the fabric and vice versa, and the other to provide 'straight' yarns in the body of the structure to carry the axial loading. Fabrics up to 15mm in thickness were constructed with varying amounts of through-the-thickness reinforcement. Tapered T and I sections were also woven, with the shaping produced by progressive removal of ends during construction. These fabrics and preforms were impregnated with resin and cured to form composite samples for testing. Using these two basic types of construction, the influence of reinforcement construction and the proportion and type of interlinking yarn on the performance of the composite was assessed.

  14. Basket-Weave Technique for Medial Patellofemoral Ligament Reconstruction

    PubMed Central

    Kodkani, Pranjal S.

    2015-01-01

    The anatomy of the medial patellofemoral ligament (MPFL) has been well defined, with parts of its uppermost fibers having a soft-tissue insertion onto the vastus intermedius. Bone tunnels and implants on the patellar side therefore cannot replicate this anatomic construct precisely. Because of implants and tunnels, complications have been reported with bone tunnel fracture. Similarly, on the femoral side, rigid fixation with implants can result in over-constraint with compromised results. Moreover, bone tunnels cannot be used in skeletally immature cases. To overcome issues related to bone tunneling and implants, as well as to reconstruct the MPFL in a precise anatomic manner, an all–soft-tissue fixation technique was devised. Bony landmarks were used as reference points instead of radiologic markers to achieve a more precise construct and to eliminate intraoperative radiography. Hamstring graft was used to reconstruct the MPFL. Special suturing techniques were used to achieve optimal graft fixation with minimal suture knots. A special tissue elevator–suture passer device was designed to facilitate graft passage and ease in performing the procedure. This technique permits differential tensioning, and therefore one achieves stability throughout the range of motion. PMID:26258044

  15. Adjustable reed for weaving net-shaped tailored fabrics

    NASA Astrophysics Data System (ADS)

    Farley, Gary L.

    1994-06-01

    The invention is an apparatus and method for forming woven fabrics through the use of an adjustable reed. The adjustable reed has multiple groups of reed wires that guide the warp yarns. The groups of reed wires move on reed rails parallel to the warp direction. In addition, rail expanders permit the space between the reed wires to be modified and telescoping rods attached to the rail sliders can be turned to permit the reed wires to be skewed to alter the fill yarn angle. These adjustments to the reed permit simultaneous variation of fill yarn angles and fabric widths and allow these variations to be made during fabrication, without the need to halt production.

  16. Weaving the Net: Linking Space Systems to Theater Operations

    DTIC Science & Technology

    2007-11-02

    However, like the video arcade "shoot-em-up" game in which the player has "infinite" bullets, the information grid concept assumes bandwidth on demand...22 The FLTSATCOM, UHF Follow-On ( UFO ) and LEASAT programs provide UHF communications. These systems cover the region between 70°N and 70°S Latitudes...such as point-to-point, broadcast, and netted single channel applications.23 The MILSTAR constellation and certain FLTSATCOM and UFO vehicles fitted

  17. SDI: O, what a tangled web we weave

    SciTech Connect

    Keeny, S.M. Jr.

    1993-11-01

    The ghost of the Strategic Defense Initiative (SDI) still haunts the Pentagon. The recent relevation that the highly publicized 1984 intercept of a mock Soviet reentry vehicle (RV) was rigged - as part of a highly secret deception plan to mislead the Soviet Union - has raised questions about the integrity and wisdom of defense development and policy processes.

  18. States Seek High School Pathways Weaving Academic, Career Options

    ERIC Educational Resources Information Center

    Sawchuk, Stephen

    2013-01-01

    Every student at Wheeling High School takes a full academic courseload. Many of the graduates of this 2,000-student school in Wheeling, Illinois, however, also emerge with significant experience in a career field. Those interested in health careers, for example, can work with student-athletes in the school's athletic training facility, earn a…

  19. Arts-Based Research: Weaving Magic and Meaning

    ERIC Educational Resources Information Center

    Greenwood, Janinka

    2012-01-01

    What kinds of things do we research when we use arts-based research? And when we apply arts-based research to educational contexts, what kinds of contributions to the scholarship of learning and teaching can we make? Taking as its basis three case studies in which art processes were used to investigate culture and identity, this essay examines the…

  20. Adjustable reed for weaving net-shaped tailored fabrics

    NASA Technical Reports Server (NTRS)

    Farley, Gary L. (Inventor)

    1995-01-01

    An apparatus and method for forming woven fabrics through the use of an adjustable reed. The adjustable reed has multiple groups of reed wires that guide the warp yarns. The groups of reed wires move on reed rails parallel to the warp direction. In addition, rail expanders permit the space between the reed wires to be modified and telescoping rods attached to the rail sliders can be turned to permit the reed wires to be skewed to alter the fill yarn angle. These adjustments to the reed permit simultaneous variation of fill yarn angles and fabric widths and allow these variations to be made during fabrication, without the need to halt production.

  1. Weaving the Foundation into the Culture of a Community College

    ERIC Educational Resources Information Center

    Carlsen, Charles J.

    2003-01-01

    This chapter explores the role of the president as enabler and leader in promoting a foundation that is engaged with the community and responsive to the college mission. It uses as its foundation a case study of Johnson County Community College (JCCC), where the president's involvement in the community educates the community about the college,…

  2. Weaving a Virtual Web: Practical Approaches to New Information Technologies.

    ERIC Educational Resources Information Center

    Gruber, Sibylle, Ed.

    With sections on using the Web to plan and structure courses, conduct research, and publish student work, as well as a reference essay that reviews Web sites for educators and students, this book reveals the rich variety of ways in which this technology can be used by English and language arts teachers at all levels. The 20 essays in the book…

  3. Weaving Connections: Educating for Peace, Social and Environmental Justice.

    ERIC Educational Resources Information Center

    Goldstein, Tara, Ed.; Selby, David, Ed.

    This collection of essays by Canadian educators seeks to achieve two goals. First, it documents educational philosophies and approaches that are directed toward equity, justice, peacefulness, and earth awareness. Second, it challenges current directions in Canadian school reform that promote "back to basics," centralization of control, a…

  4. Nrf2 Weaves an Elaborate Network of Neuroprotection Against Stroke.

    PubMed

    Jiang, Shuai; Deng, Chao; Lv, Jianjun; Fan, Chongxi; Hu, Wei; Di, Shouyin; Yan, Xiaolong; Ma, Zhiqiang; Liang, Zhenxing; Yang, Yang

    2017-03-01

    Nuclear factor erythroid 2-related factor 2 (Nrf2) is a neuroprotective transcription factor that has recently attracted increased attention. Stroke, a common and serious neurological disease, is currently a leading cause of death in the USA so far. It is therefore of vital importance to explore how Nrf2 behaves in stroke. In this review, we first introduce the structural features of Nrf2 and Kelch-like ECH-associated protein 1 (Keap1) and briefly depict the activation, inactivation, and regulation processes of the Nrf2 pathway. Next, we discuss the physiopathological mechanisms, upstream modulators, and downstream targets of the Nrf2 pathway. Following this background, we expand our discussion to the roles of Nrf2 in ischemic and hemorrhagic stroke and provide several potential future directions. The information presented here may be useful in the design of future experimental research and increase the likelihood of using Nrf2 as a therapeutic target for stroke in the future.

  5. Weaving the (neuronal) web: fear learning in spider phobia.

    PubMed

    Schweckendiek, Jan; Klucken, Tim; Merz, Christian J; Tabbert, Katharina; Walter, Bertram; Ambach, Wolfgang; Vaitl, Dieter; Stark, Rudolf

    2011-01-01

    Theories of specific phobias consider classical conditioning as a central mechanism in the pathogenesis and maintenance of the disorder. Although the neuronal network underlying human fear conditioning is understood in considerable detail, no study to date has examined the neuronal correlates of fear conditioning directly in patients with specific phobias. Using functional magnet resonance imaging (fMRI) we investigated conditioned responses using phobia-relevant and non-phobia-relevant unconditioned stimuli in patients with specific phobias (n=15) and healthy controls (n=14) by means of a differential picture-picture conditioning paradigm: three neutral geometric figures (conditioned stimuli) were followed by either pictures of spiders, highly aversive scenes or household items (unconditioned stimuli), respectively. Enhanced activations within the fear network (medial prefrontal cortex, anterior cingulate cortex, amygdala, insula and thalamus) were observed in response to the phobia-related conditioned stimulus. Further, spider phobic subjects displayed higher amygdala activation in response to the phobia-related conditioned stimulus than to the non-phobia-related conditioned stimulus. Moreover, no differences between patients and healthy controls emerged regarding the non-phobia-related conditioned stimulus. The results imply that learned phobic fear is based on exaggerated responses in structures belonging to the fear network and emphasize the importance of the amygdala in the processing of phobic fear. Further, altered responding of the fear network in patients was only observed in response to the phobia-related conditioned stimulus but not to the non-phobia-related conditioned stimulus indicating no differences in general conditionability between patients with specific phobias and healthy controls.

  6. Gender differences, work stressors and musculoskeletal disorders in weaving industries.

    PubMed

    Nag, Anjali; Vyas, H; Nag, P K

    2010-01-01

    A study was undertaken to identify the work stressors among male and female weavers (N=516) in powerloom and handloom and examine the association of work stressors with the prevalence of work related musculo-skeletal disorders (MSDs). Physical and psychosocial stresses of work, job diagnostics, hazards of workplace, working environment and MSDs prevalence were assessed. There is high prevalence of MSDs among weavers. Female weavers in powerloom and handloom were more prone to developing MSDs in upper back (OR 1.8; p<0.05 and OR 2.1; p<0.01) and lower back (OR 1.9; p<0.05 and OR 1.8; p<0.05). Male weavers were more prone to developing pain in the knee (OR 2.9; p<0.001), and hand (OR 2.2; p<0.05). Multivariate analysis indicated that job duration >10 yr (OR 3.7, p<0.05), manual material handling (OR 3, p<0.05), and poor machinery safety (OR 11, p<0.05), contributed to occurrence of MSDs amongst powerloom weavers. Among the handloom weavers, age >25 yr (OR 3.2, p<0.05), poor machinery design (OR 2.2, p<0.01), mental overload (OR 5.7, p<0.001), skill requirement to perform jobs (OR 20.7, p<0.05) had significant influence in the occurrence of pain. Gender differences exist in the prevalence of MSDs and the perception of work and psycho-social stresses among the weavers.

  7. Quantum information processing by weaving quantum Talbot carpets

    NASA Astrophysics Data System (ADS)

    Farías, Osvaldo Jiménez; de Melo, Fernando; Milman, Pérola; Walborn, Stephen P.

    2015-06-01

    Single-photon interference due to passage through a periodic grating is considered in a novel proposal for processing D -dimensional quantum systems (quDits) encoded in the spatial degrees of freedom of light. We show that free-space propagation naturally implements basic single-quDit gates by means of the Talbot effect: an intricate time-space carpet of light in the near-field diffraction regime. By adding a diagonal phase gate, we show that a complete set of single-quDit gates can be implemented. We then introduce a spatially dependent beam splitter that allows for projective measurements in the computational basis and can be used for the implementation of controlled operations between two quDits. Universal quantum information processing can then be implemented with linear optics and ancilla photons via postselection and feed-forward following the original proposal of Knill-Laflamme and Milburn. Although we consider photons, our scheme should be directly applicable to a number of other physical systems. Interpretation of the Talbot effect as a quantum logic operation provides a beautiful and interesting way to visualize quantum computation through wave propagation and interference.

  8. An evaluation of composites fabricated from powder epoxy towpreg

    NASA Technical Reports Server (NTRS)

    Hartness, J. Timothy; Greene, Tim

    1992-01-01

    BASF has developed a unique process for applying powdered resin systems to continuous reinforcement fibers in order to produce flexible towpreg material. Evaluation of three powder epoxy resins using this towpregging process is in progress under NASA contract NAS1-18834. Shell RSS-1952, Dow CET-3, and 3M PR 500 powder epoxy systems have been successfully towpregged with G30-500 6K carbon fiber. Both neat resin and basic unidirectional composite properties have been developed to compare performance. Cure cycles for each system have also been developed for repeatable fabrication of high-quality composite laminates. Evaluations of the powder towpreg material for use in textiles processes such as weaving and braiding are underway. Traditional 8-harness weaving has been successfully performed with one system (PR500/G30-500) to date, with some basic composite properties generated. Ongoing work will demonstrate scaleup of the towpregging process for higher throughput, as well as evaluation of the powder towpreg material in advanced preforming processes such as 3-D braiding and weaving. An outline and figures summarize the research results.

  9. Evaluation of Solid Modeling Software for Finite Element Analysis of Woven Ceramic Matrix Composites

    NASA Technical Reports Server (NTRS)

    Nemeth, Noel N.; Mital, Subodh; Lang, Jerry

    2010-01-01

    Three computer programs, used for the purpose of generating 3-D finite element models of the Repeating Unit Cell (RUC) of a textile, were examined for suitability to model woven Ceramic Matrix Composites (CMCs). The programs evaluated were the open-source available TexGen, the commercially available WiseTex, and the proprietary Composite Material Evaluator (COMATE). A five-harness-satin (5HS) weave for a melt-infiltrated (MI) silicon carbide matrix and silicon carbide fiber was selected as an example problem and the programs were tested for their ability to generate a finite element model of the RUC. The programs were also evaluated for ease-of-use and capability, particularly for the capability to introduce various defect types such as porosity, ply shifting, and nesting of a laminate. Overall, it was found that TexGen and WiseTex were useful for generating solid models of the tow geometry; however, there was a lack of consistency in generating well-conditioned finite element meshes of the tows and matrix. TexGen and WiseTex were both capable of allowing collective and individual shifting of tows within a ply and WiseTex also had a ply nesting capability. TexGen and WiseTex were sufficiently userfriendly and both included a Graphical User Interface (GUI). COMATE was satisfactory in generating a 5HS finite element mesh of an idealized weave geometry but COMATE lacked a GUI and was limited to only 5HS and 8HS weaves compared to the larger amount of weave selections available with TexGen and WiseTex.

  10. Fracture morphology of 2-D carbon-carbon composition

    NASA Technical Reports Server (NTRS)

    Avery, W. B.; Herakovich, C. T.

    1985-01-01

    Out-of-plane tensile tests of a woven fabric carbon-carbon composite were performed in a scanning electron microscope equipped with a tensile stage and a videotape recording system. The composite was prepared from T-300 8-harness satin graphite fabric and a phenolic resin. The (0/90/0/90/0 sub 1/2) sub 2 laminate, with a Theta describing the orientation of the warp fibers of the fabric, was cured at 160 C and pyrolized at 871 C. This was followed by four cycles of resin impregnation, curing, and pyrolysis. A micrograph of the cross section of the composite is presented. Inspection of the specimen fracture surface revealed that the filaments had no residual matrix bonded to them. Further inspection revealed that the fracture was interlaminar in nature. Failure occurred where filaments of adjacent plies had the same orientation. Thus it is postulated that improvement in transverse tensile strength of 2-D carbon-carbon depends on the improvement of the filament-matrix bond strength.

  11. Microdamage analysis in thermally aged CF/polyimide laminates

    NASA Astrophysics Data System (ADS)

    Varna, J.; Zrida, H.; Fernberg, P.

    2016-07-01

    Microdamage in layers of CF Thornel® T650 8-harness satin woven composite with thermosetting polyimide NEXIMID® MHT-R resin was analysed. After cooling to room temperature multiple intra-bundle cracking due to tensile transverse thermal stresses was observed in the studied [(+45/-45)/(90/0)]2s composite. The composite was subjected to thermal cycling quantifying the increase of crack density in layers. Comparison of two ramps with the same lowest temperature shows that the highest temperature in the cycle has a significant detrimental effect. Exposure for 40 days to 288°C caused many new cracks after cooling down to room temperature. Both aged and not aged specimens were tested in uniaxial quasi-static tension. Cracking was analysed using fracture mechanics and probabilistic approaches. Cracking in off-axis layers was predicted based on Weibull analysis of the 90- layer. The thermal treatment degraded the cracking resistance of the surface layer and of the next layer.

  12. Impact of Material and Architecture Model Parameters on the Failure of Woven Ceramic Matrix Composites (CMCs) via the Multiscale Generalized Method of Cells

    NASA Technical Reports Server (NTRS)

    Liu, Kuang C.; Arnold, Steven M.

    2011-01-01

    It is well known that failure of a material is a locally driven event. In the case of ceramic matrix composites (CMCs), significant variations in the microstructure of the composite exist and their significance on both deformation and life response need to be assessed. Examples of these variations include changes in the fiber tow shape, tow shifting/nesting and voids within and between tows. In the present work, the effects of many of these architectural parameters and material scatter of woven ceramic composite properties at the macroscale (woven RUC) will be studied to assess their sensitivity. The recently developed Multiscale Generalized Method of Cells methodology is used to determine the overall deformation response, proportional elastic limit (first matrix cracking), and failure under tensile loading conditions. The macroscale responses investigated illustrate the effect of architectural and material parameters on a single RUC representing a five harness satin weave fabric. Results shows that the most critical architectural parameter is weave void shape and content with other parameters being less in severity. Variation of the matrix material properties was also studied to illustrate the influence of the material variability on the overall features of the composite stress-strain response.

  13. Fatigue of a 3D Orthogonal Non-crimp Woven Polymer Matrix Composite at Elevated Temperature

    NASA Astrophysics Data System (ADS)

    Wilkinson, M. P.; Ruggles-Wrenn, M. B.

    2017-02-01

    Tension-tension fatigue behavior of two polymer matrix composites (PMCs) was studied at elevated temperature. The two PMCs consist of the NRPE polyimide matrix reinforced with carbon fibers, but have different fiber architectures: the 3D PMC is a singly-ply non-crimp 3D orthogonal weave composite and the 2D PMC, a laminated composite reinforced with 15 plies of an eight harness satin weave (8HSW) fabric. In order to assess the performance and suitability of the two composites for use in aerospace components designed to contain high-temperature environments, mechanical tests were performed under temperature conditions simulating the actual operating conditions. In all elevated temperature tests performed in this work, one side of the test specimen was at 329 °C while the other side was open to ambient laboratory air. The tensile stress-strain behavior of the two composites was investigated and the tensile properties measured for both on-axis (0/90) and off-axis (±45) fiber orientations. Elevated temperature had little effect on the on-axis tensile properties of the two composites. The off-axis tensile strength of both PMCs decreased slightly at elevated temperature. Tension-tension fatigue tests were conducted at elevated temperature at a frequency of 1.0 Hz with a ratio of minimum stress to maximum stress of R = 0.05. Fatigue run-out was defined as 2 × 105 cycles. Both strain accumulation and modulus evolution during cycling were analyzed for each fatigue test. The laminated 2D PMC exhibited better fatigue resistance than the 3D composite. Specimens that achieved fatigue run-out were subjected to tensile tests to failure to characterize the retained tensile properties. Post-test examination under optical microscope revealed severe delamination in the laminated 2D PMC. The non-crimp 3D orthogonal weave composite offered improved delamination resistance.

  14. Reversible dielectric property degradation in moisture-contaminated fiber-reinforced laminates

    NASA Astrophysics Data System (ADS)

    Rodriguez, Luis A.; García, Carla; Fittipaldi, Mauro; Grace, Landon R.

    2016-03-01

    The potential for recovery of dielectric properties of three water-contaminated fiber-reinforced laminates is investigated using a split-post dielectric resonant technique at X-band (10 GHz). The three material systems investigated are bismaleimide (BMI) reinforced with an eight-harness satin weave quartz fabric, an epoxy resin reinforced with an eight- harness satin weave glass fabric (style 7781), and the same epoxy reinforced with a four-harness woven glass fabric (style 4180). A direct correlation between moisture content, dielectric constant, and loss tangent was observed during moisture absorption by immersion in distilled water at 25 °C for five equivalent samples of each material system. This trend is observed through at least 0.72% water content by weight for all three systems. The absorption of water into the BMI, 7781 epoxy, and 4180 epoxy laminates resulted in a 4.66%, 3.35%, and 4.01% increase in dielectric constant for a 0.679%, 0.608%, and 0.719% increase in water content by weight, respectively. Likewise, a significant increase was noticed in loss tangent for each material. The same water content is responsible for a 228%, 71.4%, and 64.1% increase in loss tangent, respectively. Subsequent to full desorption through drying at elevated temperature, the dielectric constant and loss tangent of each laminate exhibited minimal change from the dry, pre-absorption state. The dielectric constant and loss tangent change after the absorption and desorption cycle, relative to the initial state, was 0.144 % and 2.63% in the BMI, 0.084% and 1.71% in the style 7781 epoxy, and 0.003% and 4.51% in the style 4180 epoxy at near-zero moisture content. The similarity of dielectric constant and loss tangent in samples prior to absorption and after desorption suggests that any chemical or morphological changes induced by the presence of water have not caused irreversible changes in the dielectric properties of the laminates.

  15. Out-of-Autoclave Manufacturing of Aerospace Representative Parts

    NASA Astrophysics Data System (ADS)

    Cauberghs, Julien

    The use of carbon fibre reinforced composites for aerospace structures has seen a high increase in recent years, and is still growing. The high stiffness-to-weight ratio of these materials makes them ideal for primary structures on airplanes, satellites, and spacecrafts. Nevertheless, the manufacturing of composites remains very costly since it requires equipment investment such as an autoclave, and very qualified workers. Out-of-autoclave manufacturing technology is very promising since it only requires a traditional oven, while still aiming at similar part quality. However, the absence of positive pressure compared with an autoclave makes it more difficult to achieve low porosity parts. This research investigates the manufacturing of complex features with out-of autoclave prepreg technology. The features studied are tight-radius corners with a curvature change, and ply drop-offs. Ply drop-offs tests were conducted to identify if porosity is higher at ply terminations. In corners, the bagging arrangement was modified to achieve the most uniform thickness in areas of curvature change, even with small radii. The conclusions from these studies provided us with guidelines to manufacture larger representative parts, which included these features. The representative parts were tested for porosity, thickness uniformity, mechanical performance, and glass transition temperature (Tg). A total of four representative parts were manufactured with out-of-autoclave technology, and one more was manufactured with an autoclave to allow for a proper comparison between the two processes. The materials used were MTM45-1 5 harness satin and CYCOM5320 plain weave for the out-of-autoclave parts, and CYCOM5276-1 plain weave for the autoclave part. The effect of ply drop-offs on porosity was found to be negligible. Thickness deviation in corners was attributed to a combination of consumable bridging, prepreg's bulk factor and inter-ply shear. Overall, out-of-autoclave prepregs showed

  16. Tension-Compression Fatigue of a Nextel™720/alumina Composite at 1200 °C in Air and in Steam

    NASA Astrophysics Data System (ADS)

    Lanser, R. L.; Ruggles-Wrenn, M. B.

    2016-08-01

    Tension-compression fatigue behavior of an oxide-oxide ceramic-matrix composite was investigated at 1200 °C in air and in steam. The composite is comprised of an alumina matrix reinforced with Nextel™720 alumina-mullite fibers woven in an eight harness satin weave (8HSW). The composite has no interface between the fiber and matrix, and relies on the porous matrix for flaw tolerance. Tension-compression fatigue behavior was studied for cyclical stresses ranging from 60 to 120 MPa at a frequency of 1.0 Hz. The R ratio (minimum stress to maximum stress) was -1.0. Fatigue run-out was defined as 105 cycles and was achieved at 80 MPa in air and at 70 MPa in steam. Steam reduced cyclic lives by an order of magnitude. Specimens that achieved fatigue run-out were subjected to tensile tests to failure to characterize the retained tensile properties. Specimens subjected to prior cyclic loading in air retained 100 % of their tensile strength. The steam environment severely degraded tensile properties. Tension-compression cyclic loading was considerably more damaging than tension-tension cyclic loading. Composite microstructure, as well as damage and failure mechanisms were investigated.

  17. Creep Behavior in Interlaminar Shear of a SiC/SiC Ceramic Composite with a Self-healing Matrix

    NASA Astrophysics Data System (ADS)

    Ruggles-Wrenn, M. B.; Pope, M. T.

    2014-02-01

    Creep behavior in interlaminar shear of a non-oxide ceramic composite with a multilayered matrix was investigated at 1,200 °C in laboratory air and in steam environment. The composite was produced via chemical vapor infiltration (CVI). The composite had an oxidation inhibited matrix, which consisted of alternating layers of silicon carbide and boron carbide and was reinforced with laminated Hi-Nicalon™ fibers woven in a five-harness-satin weave. Fiber preforms had pyrolytic carbon fiber coating with boron carbide overlay applied. The interlaminar shear properties were measured. The creep behavior was examined for interlaminar shear stresses in the 16-22 MPa range. Primary and secondary creep regimes were observed in all tests conducted in air and in steam. In air and in steam, creep run-out defined as 100 h at creep stress was achieved at 16 MPa. Larger creep strains were accumulated in steam. However, creep strain rates and creep lifetimes were only moderately affected by the presence of steam. The retained properties of all specimens that achieved run-out were characterized. Composite microstructure, as well as damage and failure mechanisms were investigated.

  18. Modeling of Damage Initiation and Progression in a SiC/SiC Woven Ceramic Matrix Composite

    NASA Technical Reports Server (NTRS)

    Mital, Subodh K.; Goldberg, Robert K.; Bonacuse, Peter J.

    2012-01-01

    The goal of an ongoing project at NASA Glenn is to investigate the effects of the complex microstructure of a woven ceramic matrix composite and its variability on the effective properties and the durability of the material. Detailed analysis of these complex microstructures may provide clues for the material scientists who `design the material? or to structural analysts and designers who `design with the material? regarding damage initiation and damage propagation. A model material system, specifically a five-harness satin weave architecture CVI SiC/SiC composite composed of Sylramic-iBN fibers and a SiC matrix, has been analyzed. Specimens of the material were serially sectioned and polished to capture the detailed images of fiber tows, matrix and porosity. Open source analysis tools were used to isolate various constituents and finite elements models were then generated from simplified models of those images. Detailed finite element analyses were performed that examine how the variability in the local microstructure affected the macroscopic behavior as well as the local damage initiation and progression. Results indicate that the locations where damage initiated and propagated is linked to specific microstructural features.

  19. Two-Dimensional Nonlinear Finite Element Analysis of CMC Microstructures

    NASA Technical Reports Server (NTRS)

    Mital, Subodh K.; Goldberg, Robert K.; Bonacuse, Peter J.

    2012-01-01

    A research program has been developed to quantify the effects of the microstructure of a woven ceramic matrix composite and its variability on the effective properties and response of the material. In order to characterize and quantify the variations in the microstructure of a five harness satin weave, chemical vapor infiltrated (CVI) SiC/SiC composite material, specimens were serially sectioned and polished to capture images that detailed the fiber tows, matrix, and porosity. Open source quantitative image analysis tools were then used to isolate the constituents, from which two dimensional finite element models were generated which approximated the actual specimen section geometry. A simplified elastic-plastic model, wherein all stress above yield is redistributed to lower stress regions, is used to approximate the progressive damage behavior for each of the composite constituents. Finite element analyses under in-plane tensile loading were performed to examine how the variability in the local microstructure affected the macroscopic stress-strain response of the material as well as the local initiation and progression of damage. The macroscopic stress-strain response appeared to be minimally affected by the variation in local microstructure, but the locations where damage initiated and propagated appeared to be linked to specific aspects of the local microstructure.

  20. Investigation of Effects of Material Architecture on the Elastic Response of a Woven Ceramic Matrix Composite

    NASA Technical Reports Server (NTRS)

    Goldberg, Robert K.; Bonacuse, Peter J.; Mital, Subodh K.

    2012-01-01

    To develop methods for quantifying the effects of the microstructural variations of woven ceramic matrix composites on the effective properties and response of the material, a research program has been undertaken which is described in this paper. In order to characterize and quantify the variations in the microstructure of a five harness satin weave, CVI SiC/SiC, composite material, specimens were serially sectioned and polished to capture images that detailed the fiber tows, matrix, and porosity. Open source quantitative image analysis tools were then used to isolate the constituents and collect relevant statistics such as within ply tow spacing. This information was then used to build two dimensional finite element models that approximated the observed section geometry. With the aid of geometrical models generated by the microstructural characterization process, finite element models were generated and analyses were performed to quantify the effects of the microstructure and its variation on the effective stiffness and areas of stress concentration of the material. The results indicated that the geometry and distribution of the porosity appear to have significant effects on the through-thickness modulus. Similarly, stress concentrations on the outer surface of the composite appear to correlate to regions where the transverse tows are separated by a critical amount.

  1. High Dose Neutron Irradiation of Hi-Nicalon Type S Silicon Carbide Composites, Part 2. Mechanical and Physical Properties

    DOE PAGES

    Katoh, Yutai; Nozawa, Takashi; Shih, Chunghao Phillip; ...

    2015-01-07

    Nuclear-grade silicon carbide (SiC) composite material was examined for mechanical and thermophysical properties following high-dose neutron irradiation in the High Flux Isotope Reactor at a temperature range of 573–1073 K. Likewise, the material was chemical vapor-infiltrated SiC-matrix composite with a two-dimensional satin weave Hi-Nicalon Type S SiC fiber reinforcement and a multilayered pyrocarbon/SiC interphase. Moderate (1073 K) to very severe (573 K) degradation in mechanical properties was found after irradiation to >70 dpa, whereas no evidence was found for progressive evolution in swelling and thermal conductivity. The swelling was found to recover upon annealing beyond the irradiation temperature, indicating themore » irradiation temperature, but only to a limited extent. Moreover, the observed strength degradation is attributed primarily to fiber damage for all irradiation temperatures, particularly a combination of severe fiber degradation and likely interphase damage at relatively low irradiation temperatures.« less

  2. Processing, properties and applications of composites using powder-coated epoxy towpreg technology

    NASA Technical Reports Server (NTRS)

    Bayha, T. D.; Osborne, P. P.; Thrasher, T. P.; Hartness, J. T.; Johnston, N. J.; Marchello, J. M.; Hugh, M. K.

    1993-01-01

    Composite manufacturing using the current prepregging technology of impregnating liquid resin into three-dimensionally reinforced textile preforms can be a costly and difficult operation. Alternatively, using polymer in the solid form, grinding it into a powder, and then depositing it onto a carbon fiber tow prior to making a textile preform is a viable method for the production of complex textile shapes. The powder-coated towpreg yarn is stable, needs no refrigeration, contains no solvents and is easy to process into various woven and braided preforms for later consolidation into composite structures. NASA's Advanced Composites Technology (ACT) program has provided an avenue for developing the technology by which advanced resins and their powder-coated preforms may be used in aircraft structures. Two-dimensional braiding and weaving studies using powder-coated towpreg have been conducted to determine the effect of resin content, towpreg size and twist on textile composite properties. Studies have been made to customize the towpreg to reduce friction and bulk factor. Processing parameters have been determined for three epoxy resin systems on eight-harness satin fabric, and on more advanced 3-D preform architectures for the downselected resin system. Processing effects and the resultant mechanical properties of these textile composites will be presented and compared.

  3. Analysis of the Numerical and Geometrical Parameters Influencing the Simulation of Mode I and Mode II Delamination Growth in Unidirectional and Textile Composites

    NASA Astrophysics Data System (ADS)

    Jacques, S.; De Baere, I.; Van Paepegem, W.

    2015-12-01

    The reliability of composite structures depends, among other damage mechanisms, on their ability to withstand delaminations. In order to have a better understanding of the cohesive zone method technique for delamination simulations, a complete analysis of the multiple parameters influencing the results is necessary. In this paper the work is concentrated on the cohesive zone method using cohesive elements. First a summary of the theory of the cohesive zone method is given. A numerical investigation on the multiple parameters influencing the numerical simulation of the mode I and mode II delamination tests has been performed. The parameters such as the stabilization method, the output frequency, the friction and the computational efficiency have been taken into account. The results will be compared to an analytical solution obtained by linear elastic fracture mechanics. Additionally the numerical simulation results will be compared to the experimental results of a glass-fibre reinforced composite material for the mode I Double Cantilever Beam (DCB) and to a carbon fibre 5-harness satin weave reinforced polyphenylene sulphide composite for the mode I DCB and mode II End Notched Flexure (ENF).

  4. Cob-Weaving Spiders Design Attachment Discs Differently for Locomotion and Prey Capture

    NASA Astrophysics Data System (ADS)

    Sahni, Vasav; Harris, Jared; Blackledge, Todd; Dhinojwala, Ali

    2013-03-01

    Spiders' cobwebs ensnare both walking and flying prey. While the scaffolding silk can entangle flying insects, gumfoot silk threads pull walking prey off the ground and into the web. Therefore, scaffolding silk needs to withstand the impact of the prey, whereas gumfoot silk needs to easily detach from the substrate when contacted by prey. Here, we show that spiders accomplish these divergent demands by creating attachment discs of two distinct architectures using the same pyriform silk. A ``staple-pin'' architecture firmly attaches the scaffolding silk to the substrate and a previously unknown ``dendritic'' architecture weakly attaches the gumfoot silk to the substrate. Gumfoot discs adhere weakly, triggering a spring-loaded trap, while the strong adhesion of scaffolding discs compels the scaffolding threads to break instead of detaching. We describe the differences in adhesion for these two architectures using tape-peeling models and design synthetic attachments that reveal important design principles for controlled adhesion. National Science Foundation

  5. In Practice: Weaving the Campus Safety Net by Integrating Student Health Issues into the Curriculum

    ERIC Educational Resources Information Center

    Olson, Todd A.; Riley, Joan B.

    2009-01-01

    Georgetown University has developed an innovative approach to addressing student health and wellness issues through curriculum infusion--a collaborative pedagogy that introduces real-life health issues faced by college students into their academic courses.

  6. Molecular weaving via surface-templated epitaxy of crystalline coordination networks.

    PubMed Central

    Wang, Zhengbang; Błaszczyk, Alfred; Fuhr, Olaf; Heissler, Stefan; Wöll, Christof; Mayor, Marcel

    2017-01-01

    One of the dream reactions in polymer chemistry is the bottom-up, self-assembled synthesis of polymer fabrics, with interwoven, one-dimensional fibres of monomolecular thickness forming planar pieces of textiles. We have made a major step towards realizing this goal by assembling sophisticated, quadritopic linkers into surface-mounted metal-organic frameworks. By sandwiching these quadritopic linkers between sacrificial metal-organic framework thin films, we obtained multi-heteroepitaxial, crystalline systems. In a next step, Glaser–Hay coupling of triple bonds in the quadritopic linkers yields linear, interwoven polymer chains. X-ray diffraction studies revealed that this topochemical reaction leaves the MOF backbone completely intact. After removing the metal ions, the textile sheets can be transferred onto different supports and imaged using scanning electron microscopy and atomic-force microscopy. The individual polymer strands forming the two-dimensional textiles have lengths on the order of 200 nm, as evidenced by atomic-force microscopy images recorded from the disassembled textiles. PMID:28198388

  7. History of psychological knowledge in Brazilian culture: Weaving threads on the loom of time.

    PubMed

    Massimi, Marina; Gontijo, Sandro R

    2015-05-01

    After a brief presentation of the research program on the "history of psychological knowledge in the ambit of cultural history," this article addresses 2 issues that we consider particularly important from the methodological point of view: the notion of multiple temporalities (regimes of historicity) and of complexity as characteristics of the contexture of Brazilian culture. It will be shown how both require specific attention from the researcher, because the process of incorporation of psychology in Brazil over time is complex and articulated according to various regimes of historicity that intersect and interpenetrate each other, without being exclusive. Our approach will be exemplified by the concept of memory, showing how this can be grasped in its constitution in Brazilian culture, which is composed of several sedimented layers according to different temporalities.

  8. Weaving the astronomy web. Proceedings. Conference, Strasbourg (France), 6 - 7 Apr 1995.

    NASA Astrophysics Data System (ADS)

    The following topics were dealt with: the Electronic Astrophysical Journal Letters project; astronomical information infrastructure; electronic publication; data distribution; dynamic form generation and image map techniques; on-line image archive; library services; Astrophysics Data System; solar information; HST and ESO archives; digital sky surveys; WWW interfaces and access; databases and astronomical resources; astronomical catalogues; multimedia astronomy using CD-ROMs; and observing applications.

  9. Weaving Dreamcatchers: Mothering among American Indian Women who were Teen Mothers

    PubMed Central

    Palacios, Janelle F.; Strickland, Carolyn J.; Chesla, Catherine A.; Kennedy, Holly P.; Portillo, Carmen J.

    2013-01-01

    Aims The aim of this study was to explore the mothering experience and practice among reservation based adult American Indian women who had been adolescent mothers. Background Adolescent American Indian women are at an elevated risk for teen pregnancy and poor maternal/child outcomes. Identifying mothering practices among this population may help guide intervention development that will improve health outcomes. Design A collaborative orientation to community based participatory research approach. Methods Employing interpretive phenomenology, 30 adult American Indian women who resided on a Northwestern reservation were recruited. In-depth, face-to-face and telephone interviews were conducted between 2007 and 2008. Findings Women shared their mothering experience and practice which encompassed a lifespan perspective grounded in their American Indian cultural tradition. Four themes were identified: mother hen, interrupted mothering and second chances, breaking cycles and mothering a community. Mothering originated in childhood, extended across their lifespan and moved beyond mothering their biological offspring. Conclusion These findings challenge the Western construct of mothering and charge nurses to seek culturally sensitive interventions that reinforce positive mothering practices and identify when additional mothering support is needed across a woman’s lifespan. PMID:23713884

  10. Weaving RIE with "Te Whariki": Re-Thinking Family Involvement in Assessment of Learning Dispositions

    ERIC Educational Resources Information Center

    Cooper, Maria; Hedges, Helen; Dixon, Helen

    2014-01-01

    Families play important roles in children's learning. Yet, teachers' values and beliefs may sway how families may participate in assessment of their child's learning within early childhood education. This paper reports on a qualitative case study in a New Zealand early childhood setting that explored teachers' views about involving families in…

  11. What a Tangled Web We Weave: Hermus as the Northern Extension of the Phoenix Stream

    NASA Astrophysics Data System (ADS)

    Grillmair, Carl J.; Carlberg, Raymond G.

    2016-04-01

    We investigate whether the recently discovered Phoenix stream may be part of a much longer stream that includes the previously discovered Hermus stream. Using a simple model of the Galaxy with a disk, bulge, and a spherical dark matter halo, we show that a nearly circular orbit, highly inclined with respect to the disk, can be found that fits the positions, orientations, and distances of both streams. While the two streams are somewhat misaligned in the sense that they do not occupy the same plane, nodal precession due to the Milky Way disk potential naturally brings the orbit into line with each stream in the course of half an orbit. We consequently consider a common origin for the two streams as plausible. Based on our best-fitting orbit, we make predictions for the positions, distances, radial velocities, and proper motions along each stream. If our hypothesis is borne out by measurements, then at ≈183° (≈235° with respect to the Galactic center) and ≈76 kpc in length, Phoenix-Hermus would become the longest cold stream yet found. This would make it a particularly valuable new probe of the shape and mass of the Galactic halo out to ≈20 kpc.

  12. Weaving New Meanings: Evaluating Children's Written Responses to a Story Telling Resource Package

    ERIC Educational Resources Information Center

    Brady, Josephine; Millard, Elaine

    2012-01-01

    This paper documents an evaluation of children's written responses to a story telling package used in an intervention project set up by the National Association for the Teaching of English as part of the larger "Inspire Rotherham" literacy campaign. The brief was to provide a group of primary teachers with innovative and inspirational approaches…

  13. Weaving the Web of Democracy: Confronting Conflicting Expectations for Teachers and Schools.

    ERIC Educational Resources Information Center

    Vavrus, Michael; Walton, Sherry; Kido, Janice; Diffendal, Elizabeth; King, Pauletta

    1999-01-01

    Shares Evergreen State College's attempts to create and provide a teacher-preparation program that examines what it means to teach in a democratic, pluralistic society, presenting six provocative declaratives about democratic education that the program uses for its internal program discussions and explaining how the program contends with each…

  14. Our North Carolina Stories Weaving Standards into a Fourth Grade Digital History Project

    ERIC Educational Resources Information Center

    Luke, Nancy; Binkley, Russell; Marotta, Naomi; Pirkl, Melissa

    2014-01-01

    This article describes a project that helped fourth-grade students connect personally with and bring North Carolina history to life. Over the months of this project, students asked questions, investigated topics of interest that they chose, conducted in-depth research that included interviewing experts, learned to use a video editor to combine…

  15. The ABCs of Teaching Alphabet Knowledge: Affordances and Challenges of "Weaving" Visible and Invisible Pedagogies

    ERIC Educational Resources Information Center

    Exley, Beryl; Richard-Bossez, Ariane

    2013-01-01

    As researchers interested in the pursuit of high-quality/high-equity literacy learning outcomes, the authors focus on the learning experiences of five early years French students, with a special regard for those who are already considered as being at risk of educational failure. The authors narrow the empirical focus to a single lesson on a…

  16. Modular evolution of egg case silk genes across orb-weaving spider superfamilies

    PubMed Central

    Garb, Jessica E.; Hayashi, Cheryl Y.

    2005-01-01

    Spider silk proteins (fibroins) are renowned for their extraordinary mechanical properties and biomimetic potential. Despite extensive evolutionary, ecological, and industrial interest in these fibroins, only a fraction of the known silk types have been characterized at the molecular level. Here we report cDNA and genomic sequences of the fibroin TuSp1, which appears to be the major component of tubuliform gland silk, a fiber exclusively synthesized by female spiders for egg case construction. We obtained TuSp1 sequences from 12 spider species that represent the extremes of phylogenetic diversity within the Orbicularia (orb-weaver superfamilies, Araneoidea and Deinopoidea) and finer scale sampling within genera. TuSp1 encodes tandem arrays of an ≈200-aa-long repeat unit and individual repeats are readily aligned, even among species that diverged >125 million years ago. Analyses of these repeats across species reveal the strong influence of concerted evolution, resulting in intragenic homogenization. However, deinopoid TuSp1 repeats also contain insertions of coding, minisatellite-like sequences, an apparent result of replication slippage and nonreciprocal recombination. Phylogenetic analyses of 37 spider fibroin sequences support the monophyly of TuSp1 within the spider fibroin gene family, consistent with a single origin of this ortholog group. The diversity of taxa and silks examined here confirms that repetitive architecture is a general feature of this gene family. Moreover, we show that TuSp1 provides a clear example of modular evolution across a range of phylogenetic levels. PMID:16061817

  17. Indians Weaving in Cyberspace Indigenous Urban Youth Cultures, Identities and Politics of Languages

    ERIC Educational Resources Information Center

    Jimenez Quispe, Luz

    2013-01-01

    This study is aimed at analyzing how contemporary urban Aymara youth hip hoppers and bloggers are creating their identities and are producing discourses in texts and lyrics to contest racist and colonial discourses. The research is situated in Bolivia, which is currently engaged in a cultural and political revolution supported by Indigenous…

  18. Chains, necklaces and weaving chain-link grids from self-assembly reactions.

    PubMed

    Alvariño, Cristina; Simond, Damien; Lorente, Pau Moneva; Besnard, Céline; Williams, Alan F

    2015-06-08

    Assembly of two ditopic units, a phenanthroline substituted by 4-ethynyl pyridines at the 2-and 9-positions and a dimetallic paddlewheel, gives a linear chain polymer rather than a closed cyclic species, which would appear equally possible. The chain may be decorated by binding a copper-containing macrocycle around the phenanthroline units to form a polypseudorotaxane. When two phenanthroline ligands are assembled in a first step around copper(I), the paddlewheel acceptor can link them in a second step to form a two-dimensional interwoven grid that resembles the form of a chain-link fence. Each copper(I) centre in this structure is chiral, and the crystal shows complete homochirality, implying selection during the assembly process.

  19. Pore geometry in woven fiber structures: 0{degree}/90{degree} plain-weave cloth layup preform

    SciTech Connect

    Lee, S.; Stock, S.R.; Butts, M.D.; Starr, T.L.; Breunig, T.M.; Kinney, J.H.

    1998-05-01

    Composite preform fiber architectures range from the very simple to the complex, and the extremes are typified by parallel continuous fibers and complicated three-dimensional woven structures. Subsequent processing of these preforms to produce dense composites may depend critically on the geometry of the interfiber porosity. The goal of this study is to fully characterize the structure of a 0{degree}/90{degree} cloth layup preform using x-ray tomographic microscopy (XTM). This characterization includes the measurement of intercloth channel widths and their variability, the transverse distribution of through-cloth holes, and the distribution of preform porosity. The structure of the intercloth porosity depends critically on the magnitude and direction of the offset between adjacent cloth layers. The structures observed include two-dimensional networks of open pipes linking adjacent holes, arrays of parallel one-dimensional pipes linking holes, and relatively closed channels exhibiting little structure, and these different structures would appear to offer very different resistances to gas flow through the preform. These measurements, and future measurements for different fiber architectures, will yield improved understanding of the role of preform structure on processing. {copyright} {ital 1998 Materials Research Society.}

  20. Molecular weaving via surface-templated epitaxy of crystalline coordination networks.

    NASA Astrophysics Data System (ADS)

    Wang, Zhengbang; Błaszczyk, Alfred; Fuhr, Olaf; Heissler, Stefan; Wöll, Christof; Mayor, Marcel

    2017-02-01

    One of the dream reactions in polymer chemistry is the bottom-up, self-assembled synthesis of polymer fabrics, with interwoven, one-dimensional fibres of monomolecular thickness forming planar pieces of textiles. We have made a major step towards realizing this goal by assembling sophisticated, quadritopic linkers into surface-mounted metal-organic frameworks. By sandwiching these quadritopic linkers between sacrificial metal-organic framework thin films, we obtained multi-heteroepitaxial, crystalline systems. In a next step, Glaser-Hay coupling of triple bonds in the quadritopic linkers yields linear, interwoven polymer chains. X-ray diffraction studies revealed that this topochemical reaction leaves the MOF backbone completely intact. After removing the metal ions, the textile sheets can be transferred onto different supports and imaged using scanning electron microscopy and atomic-force microscopy. The individual polymer strands forming the two-dimensional textiles have lengths on the order of 200 nm, as evidenced by atomic-force microscopy images recorded from the disassembled textiles.

  1. Second Language Learning with the Story Maze Task: Examining the Training Effect of Weaving through Stories

    ERIC Educational Resources Information Center

    Enkin, Elizabeth

    2016-01-01

    The maze task is a psycholinguistic experimental procedure that measures real-time incremental sentence processing. The task has recently been tested as a language learning tool with promising results. Therefore, the present study examines the merits of a contextualized version of this task: the story maze. The findings are consistent with…

  2. Cryogenic fatigue behavior of plain weave glass/epoxy composite laminates under tension tension cycling

    NASA Astrophysics Data System (ADS)

    Shindo, Yasuhide; Takano, Satoru; Horiguchi, Katsumi; Sato, Takashi

    2006-11-01

    This paper focuses on understanding the tension-tension fatigue behavior of woven glass fiber reinforced polymer laminates at cryogenic temperatures. Tension-tension fatigue tests at frequencies of 4 and 10 Hz with a stress ratio of 0.1 were conducted at room temperature, 77 and 4 K. The fatigue stress versus cycles to failure ( S- N) relationships and fatigue limits for 10 6 cycles were obtained. Fractured specimens tested under fatigue tests were also examined with optical microscope.

  3. Weaving the Tapestry: A First Grade Teacher Integrates Teaching and Learning

    ERIC Educational Resources Information Center

    Hurless, Bonnie; Gittings, Susan

    2008-01-01

    In Susan Gitting's classroom, writing is woven into every activity, whether it is a walk to the nature preserve or a science experiment. Authentic, shared experiences around engaging themes help the children connect their learning to existing knowledge, and learning standards guide Susan's planning. The authors describe the implementation of an…

  4. Weaving a Secure Web around Education: A Guide to Technology Standards and Security.

    ERIC Educational Resources Information Center

    National Forum on Education Statistics (ED/OERI), Washington, DC.

    The purpose of this guidebook is to assist education agencies and organizations--which include state education agencies or state departments of education, school districts, and schools--in the development, maintenance, and standardization of effective Web sites. Also included is a detailed examination of the procedures necessary to provide…

  5. Molecular weaving via surface-templated epitaxy of crystalline coordination networks.

    PubMed

    Wang, Zhengbang; Błaszczyk, Alfred; Fuhr, Olaf; Heissler, Stefan; Wöll, Christof; Mayor, Marcel

    2017-02-15

    One of the dream reactions in polymer chemistry is the bottom-up, self-assembled synthesis of polymer fabrics, with interwoven, one-dimensional fibres of monomolecular thickness forming planar pieces of textiles. We have made a major step towards realizing this goal by assembling sophisticated, quadritopic linkers into surface-mounted metal-organic frameworks. By sandwiching these quadritopic linkers between sacrificial metal-organic framework thin films, we obtained multi-heteroepitaxial, crystalline systems. In a next step, Glaser-Hay coupling of triple bonds in the quadritopic linkers yields linear, interwoven polymer chains. X-ray diffraction studies revealed that this topochemical reaction leaves the MOF backbone completely intact. After removing the metal ions, the textile sheets can be transferred onto different supports and imaged using scanning electron microscopy and atomic-force microscopy. The individual polymer strands forming the two-dimensional textiles have lengths on the order of 200 nm, as evidenced by atomic-force microscopy images recorded from the disassembled textiles.

  6. Beyond Earth: Weaving Science and Indigenous Culture - A 1-year NSF Planning Grant

    NASA Astrophysics Data System (ADS)

    Young, Timothy; Guy, M.; Baker Big-Back, C.; Froelich, K.

    2011-01-01

    We present results of a 1-year NSF planning grant called Beyond Earth. The project is designed to engage Native American, urban, and rural families in science learning while piloting curriculum development and implementation that incorporates both Native and Western epistemologies. Physical, earth, and space science content is juxtaposed with indigenous culture, stories, language and epistemology in after-school programs and teacher training. Project partners include the Dakota Science Center, Fort Berthold Community College, and Sitting Bull College. The Native American tribes represented in this initiative illustrate partnerships between the Dakota, Lakota, Nakota, Hidatsa, Mandan, and Arikara. Over the past year the primary project deliverables include a culturally responsive curriculum Beyond Earth Moon Module, teacher training workshops, a project website. The curriculum module introduces students to the moon's appearance, phases, and positions in the sky using the Night Sky Planetarium Experience Station to explore core concepts underlying moon phases and eclipses using the interactive Nature Experience Station before engaging in the culminating Mission Challenge in which they apply their knowledge to problem solving situations and projects. The Native Science and Western Science activities developed, planetarium explorations created, and website toolkit utilizations are presented.

  7. Weaving Web 2.0 and the Writing Process with Feminist Pedagogy

    ERIC Educational Resources Information Center

    Zhao, Ruijie

    2010-01-01

    This dissertation, as a theoretical study, focused on how Web 2.0 technology potentially helps students gain power, knowledge, and agency in the networked learning environment and how feminist pedagogy conceivably facilitates the implementation of Web 2.0 technology to produce an opportune learning environment. Primarily, this study used feminist…

  8. Mathematics and Water in the Garden: Weaving Mathematics into the Students' Lived Environment

    ERIC Educational Resources Information Center

    Clarkson, Philip

    2010-01-01

    In an earlier issue of "Australian Primary Mathematics Classroom," Sparrow discussed the concept of real-world mathematics and the use of mathematics to explore problems in real-life situations. Environmental issues have provided a context that some teachers have used for teaching mathematics. An example of a particular environmental…

  9. A Tangled Weave: Tracing Outcomes of Education in Rural Women's Lives in North India

    ERIC Educational Resources Information Center

    Ghose, Malini; Mullick, Disha

    2015-01-01

    This paper is based on the findings of a research study which traced 56 rural women learners 15 years after they had participated in an empowerment and education programme in North India. It attempts to understand, from the perspectives of women from marginalised communities, the ways in which participating in the programme had been empowering for…

  10. A Tapestry of Inquiry and Action: Cycle of Learning Weaves Its Way through Washington District

    ERIC Educational Resources Information Center

    Rasmussen, Harriette Thurber; Karschney, Kathryn

    2012-01-01

    Welcome to the West Valley School District in eastern Washington. Home to almost 4,000 students, West Valley made a public commitment more than seven years ago that all students would graduate with the option to attend college. This daunting goal--made even more so by the fact that almost half of the district's high school students come from…

  11. Weaving Together Science and English: An Interconnected Model of Language Development for Emergent Bilinguals

    ERIC Educational Resources Information Center

    Ciechanowski, Kathryn M.

    2014-01-01

    This research explores third-grade science and language instruction for emergent bilinguals designed through a framework of planning, lessons, and assessment in an interconnected model including content, linguistic features, and functions. Participants were a team of language specialist, classroom teacher, and researcher who designed…

  12. High Temperature Mechanical Testing of a Cylindrical Weave Carbon-Carbon Composite.

    DTIC Science & Technology

    2014-09-26

    9. Schematic Representation of the Calcination 44 *-"-"Fixture Inside the Tube Furnace. -’’.-. 10. Block Diagram of Calcination Furnace 45 and Instr...umentation. 11. Photograph of the Calcination Furnace 46 and Automatic Controller/"Recorder. 12. Shear-Lao Specimen for both Axial 47 and Radial Fiber...concentrations that can lead to premature failure when the fully processed specimens are loaded. The calcination process is the longest of all the specimen

  13. Weaving time into system architecture: satellite cost per operational day and optimal design lifetime

    NASA Astrophysics Data System (ADS)

    Saleh, Joseph H.; Hastings, Daniel E.; Newman, Dava J.

    2004-03-01

    An augmented perspective on system architecture is proposed (diachronic) that complements the traditional views on system architecture (synchronic). This paper proposes to view in a system architecture the flow of service (or utility) that the system will provide over its design lifetime. It suggests that the design lifetime is a fundamental component of system architecture although one cannot see it or touch it. Consequently, cost, utility, and value per unit time metrics are introduced. A framework is then developed that identifies optimal design lifetimes for complex systems in general, and space systems in particular, based on this augmented perspective of system architecture and on these metrics. It is found that an optimal design lifetime for a satellite exists, even in the case of constant expected revenues per day over the system's lifetime, and that it changes substantially with the expected Time to Obsolescence of the system and the volatility of the market the system is serving in the case of a commercial venture. The analysis thus proves that it is essential for a system architect to match the design lifetime with the dynamical characteristics of the environment the system is/will be operating in. It is also shown that as the uncertainty in the dynamical characteristics of the environment the system is operating in increases, the value of having the option to upgrade, modify, or extend the lifetime of a system at a later point in time increases depending on how events unfold.

  14. Weaving together peer assessment, audios and medical vignettes in teaching medical terms

    PubMed Central

    Khan, Lateef M.

    2015-01-01

    Objectives The current study aims at exploring the possibility of aligning peer assessment, audiovisuals, and medical case-report extracts (vignettes) in medical terminology teaching. In addition, the study wishes to highlight the effectiveness of audio materials and medical history vignettes in preventing medical students' comprehension, listening, writing, and pronunciation errors. The study also aims at reflecting the medical students' attitudes towards the teaching and learning process. Methods The study involved 161 medical students who received an intensive medical terminology course through audio and medical history extracts. Peer assessment and formative assessment platforms were applied through fake quizzes in a pre- and post-test manner. An 18-item survey was distributed amongst students to investigate their attitudes and feedback towards the teaching and learning process. Quantitative and qualitative data were analysed using the SPSS software. Results The students did better in the posttests than on the pretests for both the quizzes of audios and medical vignettes showing a t-test of -12.09 and -13.60 respectively. Moreover, out of the 133 students, 120 students (90.22%) responded to the survey questions. The students gave positive attitudes towards the application of audios and vignettes in the teaching and learning of medical terminology and towards the learning process. Conclusions The current study revealed that the teaching and learning of medical terminology have more room for the application of advanced technologies, effective assessment platforms, and active learning strategies in higher education. It also highlights that students are capable of carrying more responsibilities of assessment, feedback, and e-learning. PMID:26637986

  15. Weaving Diversity into LIS: An Examination of Diversity Course Offerings in iSchool Programs

    ERIC Educational Resources Information Center

    Subramaniam, Mega M.; Jaeger, Paul T.

    2011-01-01

    This study examines the current state of diversity course offerings in Library and Information Science (LIS) programs through the analysis of syllabi of diversity-related courses offered in the American Library Association accredited Master of Library and Information Science (MLS) programs at iSchools (a group of information schools that include…

  16. Weft, warp, and weave: the intricate tapestry of calcium channels regulating T lymphocyte function.

    PubMed

    Omilusik, Kyla D; Nohara, Lilian L; Stanwood, Shawna; Jefferies, Wilfred A

    2013-01-01

    Calcium (Ca(2+)) is a universal second messenger important for T lymphocyte homeostasis, activation, proliferation, differentiation, and apoptosis. The events surrounding Ca(2+) mobilization in lymphocytes are tightly regulated and involve the coordination of diverse ion channels, membrane receptors, and signaling molecules. A mechanism termed store-operated Ca(2+) entry (SOCE), causes depletion of endoplasmic reticulum (ER) Ca(2+) stores following T cell receptor (TCR) engagement and triggers a sustained influx of extracellular Ca(2+) through Ca(2+) release-activated Ca(2+) (CRAC) channels in the plasma membrane. The ER Ca(2+) sensing molecule, stromal interaction molecule 1 (STIM1), and a pore-forming plasma membrane protein, ORAI1, have been identified as important mediators of SOCE. Here, we review the role of several additional families of Ca(2+) channels expressed on the plasma membrane of T cells that likely contribute to Ca(2+) influx following TCR engagement, particularly highlighting an important role for voltage-dependent Ca(2+) channels (CaV) in T lymphocyte biology.

  17. Old warp, new weft: weaving a new life fabric after anoxia.

    PubMed

    Kelleher, J A

    1998-04-01

    A young New Zealander reweaves a new life after a severe anoxic brain injury. His mother, a teacher, works from an educational perspective to construct an individualized lifestyle plan (ILP), implemented in the community by a team of support workers. This approach to learning is holistic and encompasses the physical, cognitive, emotional and spiritual dimensions of human healing. This article, part of the requirements for a Master's degree in Special Education, recounts part of the new journey, which is described in the language of capacity, achievement and love, rather than that of dysfunction, disability and disappointment.

  18. Quantifying Damage at Multiple Loading Rates to Kevlar KM2 Fibers Due to Weaving and Finishing

    DTIC Science & Technology

    2013-06-01

    stress is calculated using = 0 , (3) where Ao is the initial cross-sectional area, and P is the force measured by the load cell. 2.3...acting piezoelectric quartz load cell is used to collect the force history. Figure 2. Modified fiber-SHTB and the fiber specimen for high-rate...calculating the strain of the specimen using the strain gage signal, a noncontact high-rate laser method was used to measure the strain history of the

  19. Brackish Bayou Blood: Weaving Mixed-Blood Indian-Creole Identity outside the Written Record

    ERIC Educational Resources Information Center

    Cranford-Gomez, L. Rain

    2008-01-01

    As a child on the Gulf of Mexico, evacuation to higher ground for floods, hurricanes, and tornado warnings were common. At the end of August 2005, Hurricane Katrina ravaged the homelands of this author's father and grandfather in Louisiana. Hundreds of miles of wetlands, already threatened, were turned to open water; vital brackish waters were…

  20. Weaving Language and Culture: Latina Adolescent Writers in an After-School Writing Project

    ERIC Educational Resources Information Center

    Garcia, Andrea; Gaddes, Amy

    2012-01-01

    A decade ago, the subtractive schooling of many Latino youth in the United States resulted in a devaluing of cultural identity and heritage as resources to support learning. Today, educators are urged to revalue cultural resources toward literacy development. This study explores the experiences of Latina adolescent students as writers during an…

  1. Wnt Drug Discovery: Weaving Through the Screens, Patents and Clinical Trials

    PubMed Central

    Lu, Benjamin; Green, Brooke A.; Farr, Jacqueline M.; Lopes, Flávia C.M.; Van Raay, Terence J.

    2016-01-01

    The Wnt signaling pathway is intricately involved in many aspects of development and is the root cause of an increasing number of diseases. For example, colorectal cancer is the second leading cause of death in the industrialized world and aberration of Wnt signaling within the colonic stem cell is the cause of more than 90% of these cancers. Despite our advances in successfully targeting other pathways, such as Human Epidermal Growth Factor Receptor 2 (HER2), there are no clinically relevant therapies available for Wnt-related diseases. Here, we investigated where research activities are focused with respect to Wnt signaling modulators by searching the United States Patent and Trade Office (USPTO) for patents and patent applications related to Wnt modulators and compared this to clinical trials focusing on Wnt modulation. We found that while the transition of intellectual property surrounding the Wnt ligand-receptor interface to clinical trials is robust, this is not true for specific inhibitors of β-catenin, which is constitutively active in many cancers. Considering the ubiquitous use of the synthetic T-cell Factor/Lymphoid Enhancer Factor (TCF/Lef) reporter system and its success in identifying novel modulators in vitro, we speculate that this model of drug discovery does not capture the complexity of in vivo Wnt signaling that may be required if we are to successfully target the Wnt pathway in the clinic. Notwithstanding, increasingly more complex models are being developed, which may not be high throughput, but more pragmatic in our pursuit to control Wnt signaling. PMID:27598201

  2. High-Poverty Urban High School Students' Plans for Higher Education: Weaving Their Own Safety Nets

    ERIC Educational Resources Information Center

    Cilesiz, Sebnem; Drotos, Stephanie M.

    2016-01-01

    This qualitative study investigates high-poverty urban high school students' views of and plans regarding higher education, using Bourdieu's theory of reproduction in education as theoretical framework. Interview data from 76 students from six high-poverty urban schools in a metropolitan area in the Midwestern United States were analyzed using…

  3. Weaving a Syllaweb: Consideration before Constructing an On-line Syllabus.

    ERIC Educational Resources Information Center

    Johnston, Joyce P.

    This paper explores the practical and philosophical issues involved in Web site construction so that the finished site truly reflects its creator. The author uses the term "syllaweb" for a hyperlinked syllabus and declares that it was an outgrowth of Vannevar Bush's original description of computerized graphical communication as a web,…

  4. “Basket weave technique” for medial patellofemoral ligament reconstruction: Clinical outcome of a prospective study

    PubMed Central

    Kodkani, Pranjal S

    2016-01-01

    Background: Bone tunneling and implants with rigid fixations for medial patellofemoral ligament (MPFL) reconstruction are known to compromise results and are avoidable, especially in skeletally immature subjects. This study was to assess if these deficiencies were overcome with the technique devised by the author which avoids implants and bone tunnels. Results were assessed for complication rate and outcome. Materials and Methods: Fifty six knees of recurrent lateral patellar dislocation were treated in the past 49 months by MPFL reconstruction. Thirty nine were female and 17 male knees. The mean age was 20.6 years (range 9-48 years). Mean followup was 26 months. Five knees had previously failed stabilization procedures. Thirty one cases had Dejours Type A or B and 12 had Type C trochlear dysplasia. Arthroscopy was performed for associated injuries and loose bodies. Seven knees required loose body removal. Five knees underwent lateral retinacular release. Four knees had tibial tuberosity transfer. One knee had an associated anterior cruciate ligament reconstruction. An anatomical MPFL reconstruction was performed using hamstring autograft without the need for intraoperative fluoroscopy. Only soft tissue fixation was necessary with this newly devised technique and suturing. A rapid rehabilitation protocol was implemented with monthly followup until normalcy and 6 monthly thereafter. Results: All achieved full range of motion and normal mediolateral stability. There was no recurrence of dislocation. No major surgery related complications. One patella fracture at 8 months was due to a fall developed terminal restriction of flexion. Those in sports could return to their sporting activities (Tegner 1–9). Cases with osteochondral fractures had occasional pain that subsided in 1 year. Mean Kujala score improved from 64.3 to 99.69 with KOOS score near normal in all. Conclusion: This new method of MPFL reconstruction gives excellent results. It avoids complications related to bone tunneling and implants. It is a safe, effective, reliable and reproducible technique. PMID:26952121

  5. Weaving public health education into the fabric of a family medicine residency.

    PubMed

    Potts, Stacy E; Deligiannidis, Konstantinos E; Cashman, Suzanne B; Caggiano, Marie E; Carter, Lisa H; Haley, Heather-Lyn; Ferguson, Warren J

    2011-10-01

    Policymakers and accrediting bodies have recognized the importance of integrating public health, population health, and prevention into graduate medical education programs. The high prevalence of chronic illness, coupled with the impact of behavioral and societal determinants of health, necessitate an urgent call for family medicine residencies to prepare future leaders to meet these challenges. The University of Massachusetts Worcester Family Medicine Residency recently developed an integrated curriculum that strives to develop a culture of incorporating fundamental public health principles into everyday practice. This public health curriculum was designed to integrate new topics within the current residency structure through longitudinal and concentrated experiences. This strategy has substantially improved public health and prevention education without substantial impact on the already strained residency curricular structure. This paper describes the integration of public health and prevention education into a family medicine residency to help residents acquire the fundamental skills necessary to improve a population's health.

  6. Progressive Failure Analysis of Plain Weaves Using Damage Mechanics Based Constitutive Laws

    DTIC Science & Technology

    2006-01-01

    2 7 2 7 1 6, ( A4a ) where ε ε ε ε ε ε s d = + = − 2 3 2 3 (A4b,c) k is the plane strain bulk modulus and GA and GT are the axial and transverse shear...ε ε ε α ε α α 1 1 12 21 1 12 12 11 21 12 * * / / = + = + = = s s s C C C k (A5b-e) Use of ( A4a -i) yields a transversely isotropic material with the

  7. Connecting Readers and Writers with Books: Weaving Literature into the School Community.

    ERIC Educational Resources Information Center

    Afromsky, Ellen; Davis, Judy; Harwayne, Shelley; Hudes, Layne; Lederman, Diane; Mayer, Pam; Rhodes, Roberta Pantal; Siegman, Lisa

    1998-01-01

    Offers descriptions of 34 books for children and young adolescents (many of them illustrated books), in the following categories: books for the youngest readers; poems for young writers; books about the moon; books celebrating city life; books for older readers; and books of multicultural folktales. (SR)

  8. Multimodal Literacy Narratives: Weaving the Threads of Young Children's Identity through the Arts

    ERIC Educational Resources Information Center

    Binder, Marni; Kotsopoulos, Sally

    2011-01-01

    The current study examines how children develop multimodal narratives through the construction of quilt squares and I Am poetry. Creating visual narratives through the use of personal artifacts lays the foundation for this artistic multiple literacy experience. The study focuses on the process and growth that a diverse group of kindergarten…

  9. [Evaluation of energy metabolism of women working at the silk weaving factory, Dushanbe, Tajikistan ].

    PubMed

    Khaĭrov, Kh S

    1998-01-01

    Evaluation of energy expenses and energy needs of the 19-23 years old women was carried out. It was shown average energy expenses of women-weavers were 2035 kkal per day. The professional activity accounts for 25.2% of all energy expenses, sleep--24.6% and other kinds of activity--34.2%.

  10. Weave and Fiber Volume Effects in a PIP CMC Material System (Preprint)

    DTIC Science & Technology

    2012-02-01

    Whitney U. Santhosh Structural Analystics, Inc. D. C. Jarmon United Technologies Research Center FEBRUARY 2012 Approved for...G. Ojard, E. Prevost, and R. Naik (Pratt & Whitney) U. Santhosh (Structural Analystics, Inc.) D. C. Jarmon (United Technologies Research Center) 5d...Ojard, G.1, Prevost, E.1, Santhosh , U.2, Naik, R.1, and Jarmon, D. C.3 1 Pratt & Whitney, East Hartford, CT 2 Structural Analystics, Inc., San

  11. The Common Thread: Tips for Weaving Philanthropy into the Campus Fabric

    ERIC Educational Resources Information Center

    Bennett, Gayle

    2013-01-01

    Like any profession, advancement has its terms of art: "the ask," "prospects," "quiet phase." A relatively new one is "culture of philanthropy." As in, "We need to build a culture of philanthropy at this institution." The general idea is that everyone from the campus CEO to the students understands…

  12. How the OCLC CORC Service Is Helping Weave Libraries into the Web.

    ERIC Educational Resources Information Center

    Covert, Kay

    2001-01-01

    Describes OCLC's CORC (Cooperative Online Resource Catalog) service. As a state-of-the-art Web-based metadata creation system, CORC is optimized for creating bibliographic records and pathfinders for electronic resources. Discusses how libraries are using CORC in technical services, public services, and collection development and explains the…

  13. A tangled weave: Tracing outcomes of education in rural women's lives in North India

    NASA Astrophysics Data System (ADS)

    Ghose, Malini; Mullick, Disha

    2015-06-01

    This paper is based on the findings of a research study which traced 56 rural women learners 15 years after they had participated in an empowerment and education programme in North India. It attempts to understand, from the perspectives of women from marginalised communities, the ways in which participating in the programme had been empowering for them, or not. While most of the women were indeed able to transform several areas in their lives, this study illustrates that empowering outcomes cannot be assumed or articulated in categorical terms and that bringing about change requires the negotiation of power at various levels. The women's narratives stand in contrast to the prevalent discourses around women's literacy and empowerment, which highlight the importance of literacy only in terms of its positive impact on attaining development goals. Despite the vigorously discussed de-politicisation of the concept of empowerment, the authors show in this paper that empowerment, when informed by a critical feminist understanding, continues to provide a useful framework to analyse women's experiences related to education, as a process enabling women to understand and negotiate structures of power - which are neither static nor wholly dominating - and to find spaces to exercise agency. There are few longitudinal studies which trace the long-term impact of educational programmes on adult women, and most studies are in the nature of impact assessments of programmes. Through this paper the authors argue for the need to analyse the complexities around the relationship between women's education and empowerment.

  14. Thermostructural Properties Of Sic/Sic Panels With 2.5d And 3d Fiber Architectures

    NASA Technical Reports Server (NTRS)

    Yun, H. M.; DeCarlo, J. A.; Bhatt, R. H.; Jaskowiak, M. H.

    2005-01-01

    CMC hot-section components in advanced engines for power and propulsion will typically require high cracking strength, high ultimate strength and strain, high creep- rupture resistance, and high thermal conductivity in all directions. In the past, NASA has demonstrated fabrication of a variety of SiC/SiC flat panels and round tubes with various 2D fiber architectures using the high-modulus high-performance Sylramic-iBN Sic fiber and Sic-based matrices derived by CVI, MI, and/or PIP processes. The thermo- mechanical properties of these CMC have shown state-of-the-art performance, but primarily in the in-plane directions. Currently NASA is extending the thermostructural capability of these SiC/SiC systems in the thru-thickness direction by using various 2.5D and 3D fiber architectures. NASA is also using specially designed fabrication steps to optimize the properties of the BN-based interphase and Sic-based matrices. In this study, Sylramic-iBN/SiC panels with 2D plain weave, 2.5D satin weave, 2.5D ply-to-ply interlock weave, and 3D angle interlock fiber architectures, all woven at AITI, were fabricated using matrix densification routes previously established between NASA and GEPSC for CVI-MI processes and between NASA and Starfire-Systems for PIP processes. Introduction of the 2.5 D fiber architecture along with an improved matrix process was found to increase inter-laminar tensile strength from 1.5 -2 to 3 - 4 ksi and thru-thickness thermal conductivity from 15-20 to 30-35 BTU/ft.hr.F with minimal reduction in in-plane strength and creep-rupture properties. Such improvements should reduce thermal stresses and increase the thermostructural operating envelope for SiC/SiC engine components. These results are analyzed to offer general guidelines for selecting fiber architectures and constituent processes for high-performance SiC/SiC engine components.

  15. New design of textile light diffusers for photodynamic therapy.

    PubMed

    Cochrane, Cédric; Mordon, Serge R; Lesage, Jean Claude; Koncar, Vladan

    2013-04-01

    A homogeneous and reproducible fluence delivery rate during clinical photodynamic therapy (PDT) plays a determinant role in preventing under- or overtreatment. PDT applied in dermatology has been carried out with a wide variety of light sources delivering a broad range of more or less adapted light doses. Due to the complexities of the human anatomy, these light sources do not in fact deliver a uniform light distribution to the skin. Therefore, the development of flexible light sources would considerably improve the homogeneity of light delivery. The integration of plastic optical fiber (POF) into textile structures could offer an interesting alternative. In this article, a textile light diffuser (TLD) has been developed using POF and Polyester yarns. Predetermined POF macrobending leads to side emission of light when the critical angle is exceeded. Therefore, a specific pattern based on different satin weaves has been developed in order to improve light emission homogeneity and to correct the decrease of side emitted radiation intensity along POF. The prototyped fabrics (approximately 100 cm(2): 5×20 cm) were woven using a hand loom, then both ends of the POF were coupled to a laser diode (5 W, 635 nm). The fluence rate (mW/ cm(2)) and the homogeneity of light delivery by the TLD were evaluated. Temperature evolution, as a function of time, was controlled with an infrared thermographic camera. When using a power source of 5 W, the fluence rate of the TLD was 18±2.5 mw/cm(2). Due to the high efficiency of the TLD, the optical losses were very low. The TLD temperature elevation was 0.6 °C after 10 min of illumination. Our TLD meets the basic requirements for PDT: homogeneous light distribution and flexibility. It also proves that large (500 cm(2)) textile light diffusers adapted to skin, but also to peritoneal or pleural cavity, PDTs can be easily produced by textile manufacturing processes.

  16. Effects of Steam Environment on Creep Behavior of Nextel™610/Monazite/Alumina Composite at 1,100°C

    NASA Astrophysics Data System (ADS)

    Ruggles-Wrenn, Marina B.; Yeleser, Tufan; Fair, Geoff E.; Davis, Janet B.

    2009-12-01

    The tensile creep behavior of a N610™/LaPO4/Al2O3 composite was investigated at 1,100°C in laboratory air and in steam. The composite consists of a porous alumina matrix reinforced with Nextel 610 fibers woven in an eight-harness satin weave fabric and coated with monazite. The tensile stress-strain behavior was investigated and the tensile properties measured at 1,100°C. The addition of monazite coating resulted in ~33% improvement in ultimate tensile strength (UTS) at 1,100°C. Tensile creep behavior was examined for creep stresses in the 32-72 MPa range. Primary and secondary creep regimes were observed in all tests. Minimum creep rate was reached in all tests. In air, creep strains remained below 0.8% and creep strain rates approached 2 × 10-8 s-1. Creep run-out defined as 100 h at creep stress was achieved in all tests conducted in air. The presence of steam accelerated creep rates and significantly reduced creep lifetimes. In steam, creep strain reached 2.25%, and creep strain rate approached 2.6 × 10-6 s-1. In steam, creep run-out was not achieved. The retained strength and modulus of all specimens that achieved run-out were characterized. Comparison with results obtained for N610™/Al2O3 (control) specimens revealed that the use of the monazite coating resulted in considerable improvement in creep resistance at 1,100°C both in air and in steam. Composite microstructure, as well as damage and failure mechanisms were investigated.

  17. Impact response of graphite/epoxy fabric structures

    NASA Technical Reports Server (NTRS)

    Lagace, Paul A.; Kraft, Michael J.

    1990-01-01

    The impact damage resistance and damage tolerance of graphite/epoxy fabric plate (coupon) and cylinder structures were investigated and compared in an analytical and experimental study. Hercules A370-5H/3501-6 five-harness satin weave cloth in a quasi-isotropic (0,45)(sub s) laminate configuration was utilized. Specimens were impacted with 12.7 mm diameter steel spheres at velocities ranging from 10 m/s to 100 m/s. Damage resistance of the specimens was determined through the use of dye penetrant enhanced x-radiography, sectioning, epoxy burnoff, and visual methods. Damage tolerance of the flat plate structures was assessed in a residual tensile test while damage tolerance of the cylinder structures was assessed via pressurization tests. Impacted fabric laminates exhibited matrix crushing, fiber breakage, delamination, and fiber bundle disbonds; the latter being a unique damage mode for fabric laminates. Plate delamination and bundle disbonding was found to be more extensive around the central core area of fiber damage in the coupon specimens than in the cylinder specimens which showed a cleaner damage area due to impact. Damage resistance and damage tolerance were predicted by utilizing a five-step analysis approach previously utilized for coupon configurations. Two of the five steps were adapted to account for the effects of the structural configuration of the pressurized cylinder. The damage resistance analysis provided good correlation to the fiber damage region of both the coupon and cylinder specimens. There was little difference in the size of this region in the two specimen types. However, the analysis was not able to predict the distribution of damage through-the-thickness. This was important in assessing the damage tolerance of the cylinders. The damage tolerance analysis was able to predict the residual tensile strength of the coupons. A general methodology to predict the impact damage resistance and damage tolerance of composite structures utilizing

  18. Modeling of fracture and durability of paste-bonded composite joints subjected to hygro-thermal-mechanical loading

    NASA Astrophysics Data System (ADS)

    Harris, David Lee

    The objective of the research is to characterize the behavior of composite/composite joints with paste adhesive using both experimental testing and analytical modeling. In comparison with the conventional tape adhesive, joining composites using paste adhesive provides several advantages. The carbon fiber laminate material systems employed in this study included IM7 carbon fibers and 977-3 epoxy matrix assembled in prepreg tape, and AS4 carbon fibers and 977-3 epoxy matrix as a five-harness satin weave. The adhesive employed was EA 9394 epoxy. All laminates and test specimens were fabricated and inspected by Boeing using their standard propriety procedures. Three types of test specimens were used in the program. They were bonded double-lap shear (DLS), bonded double cantilever beam (DCB) and bonded interlaminar tension (ILT) specimens. A group of specimens were conditioned at elevated temperature and humidity in an environmental chamber at Boeing's facility and their moisture absorption recorded with time. Specimens were tested at room temperature dry and elevated temperatures. DCB and DLS specimens were tested in fatigue as well as static conditions. Two-dimensional finite element models of the three configurations were developed for determining stresses and strains using the ABAQUS finite element package code. Due to symmetry, only the one-half of the specimen needed to be considered thus reducing computational time. The effect of the test fixture is not taken into account instead equivalent distributed stresses are applied directly on the composite laminates. For each of the specimen, the distribution of Mises stress and the first strain invariant J1 are obtained to identify potential failure locations within a specimen.

  19. An Evaluation of the Iosipescu Specimen for Composite Materials Shear Property Measurement. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Ho, Henjen

    1991-01-01

    accuracy of the shear modulus values are made, and the implications for shear strength measurement discussed. Further application of the Iosipescu shear test to woven fabric composites is presented. The limitations of the traditional strain gage instrumentation on the satin weave and high tow plain weave fabrics is discussed. Test results of a epoxy based aluminum particulate composite is also presented. A modification of the Iosipescu specimen is proposed and investigated experimentally and numerically. It is shown that the proposed new specimen design provides a more uniform shear stress field in the test section and greatly reduces the normal and shear stress concentrations in the vicinity of the notches. While the fabrication and the material cost of the proposed specimen is tremendously reduced, it is shown the accuracy of the shear modulus measurement is not sacrificed.

  20. Ultrasonic evaluation of ballistic impact damage in thick section twill weave S2-glass/vinyl ester laminates

    NASA Astrophysics Data System (ADS)

    Hosur, M. V.; Vaidya, U. K.; Gillespie, J. W.; Jeelani, S.

    2000-05-01

    This paper presents the ultrasonic nondestructive evaluation of impact damage composite panels subjected to both low-velocity and ballistic impact. In low-velocity impact test, the specimens were subjected to impact at 40, 60 and 80 J. Results of the c-scans using a 2.25 MHz sensor indicate that the size and distribution of delamination is almost the same at 40 and 60 J of impact, whereas at 80J there is considerable increase. For ballistic impact testing, a 12″ square specimen made of 45 layers was used. The panels were made adopting different combinations of vacuum Assisted Resin Infusion (VARIM) and Transfer Molding (VARTM) processes. Both 2D plain and 3D reinforced laminates were subjected to ballistic impact using 50 cal. projectile. Results of the c-scan using 1 MHz sensor indicate damage through penetration at the point of impact and by the creation of multiple delaminations which are predominant beyond the depth of penetration and increase in size with depth.

  1. Combining morphology, DNA sequences, and morphometrics: revising closely related species in the orb-weaving spider genus Araniella (Araneae, Araneidae).

    PubMed

    Spasojevic, Tamara; Kropf, Christian; Nentwig, Wolfgang; Lasut, Liana

    2016-05-17

    The integration of independent data sets could solve problems in both traditional and DNA-based taxonomy. The aim of this study is to investigate the power of CO1 sequences and of morphometrics to distinguish closely related species in the spider genus Araniella. We put special emphasis on the species pair A. cucurbitina (Clerck, 1757) and A. opisthographa (Kulczyński, 1905) since the females are morphologically difficult to distinguish and often misidentified. A total of 216 sequences of eight Araniella species from seven European countries, North America and Asia were included in the molecular analysis. The results from both maximum likelihood and Bayesian phylogenetic inference indicate successful separation of six out of eight Araniella species, including A. cucurbitina and A. opisthographa. For the same six species, we detect no overlap of intra- and interspecific genetic divergence, leading to successful species identification with a threshold approach. In addition, morphometric analysis of the epigyna of A. cucurbitina and A. opisthographa supports species separation by two best explanatory ratios: receptaculum length and distance between receptaculum and copulatory duct. Although a small overlap in the ratios exists, the species identification rate increases when combining morphometric and molecular data, which demonstrates the efficiency of integrative approaches for distinguishing closely related species. However, none of the molecular approaches was able to separate closely related A. alpica (L. Koch, 1869) and A. inconspicua (Simon, 1874) due to shared CO1 haplotypes. Considering the clear morphological separation of the males and different habitat preferences, incomplete lineage sorting or introgressive hybridization could have led to identical CO1 sequences. Therefore, DNA-barcoding must be thoroughly tested even within small homogenous genera of spiders.

  2. Weaving Transnational Feminist(s) Methodologies: (Re)Examining Early Childhood Linguistic Diversity Teacher Training and Research

    ERIC Educational Resources Information Center

    Saavedra, Cinthya M.; Chakravarthi, Swetha; Lower, Joanna K.

    2009-01-01

    The purpose of this article is to engender a space where a variety of critical feminist(s) lenses are interwoven to problematize current discursive practices in linguistic diversity training and to (re)imagine "nueavas posibilidades" for linguistic diversity research/training for pre-kindergarten teachers. Transnational feminists' projects have…

  3. Weaving Webs of Intrigue: Classical Mythology and Analytic Crime Fiction in Rubem Fonseca's "A grande arte"

    ERIC Educational Resources Information Center

    Ginway, M. Elizabeth

    2013-01-01

    This study focuses on some of the classical features of Rubem Fonseca's "A grande arte" (1983) in order to emphasize the puzzle-solving tradition of the detective novel that is embedded within Fonseca's crime thriller, producing a work that does not entirely fit into traditional divisions of detective, hardboiled, or crime…

  4. Weaving Common Threads: Reaching out to American Indians and Native Peoples of Alaska and the Pacific Islands

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This report outlines the activities of the GLOBE (Global Learning and Observations to Benefit the Environment) Train-the-Trainer Workshop. Educators were introduced to the GLOBE protocols for Atmosphere, Hydrology, Soil and Land Cover. These protocols included measurement of pH, temperature, precipitation, salinity, and soil moisture content. Each topic included implementation plans and learning activities.

  5. Geographical Distribution of the Space-Weaving Spider, Chibchea salta, from Northwestern Argentina: New Records and Bioclimatic Modeling

    PubMed Central

    Rubio, Gonzalo D.; Acosta, Luis E.

    2011-01-01

    New records of the spider Chibchea salta Huber 2000 (Araneae, Pholcidae) from northwestern Argentina are provided, and the potential range of this species is modeled. Two presence-only methods, Maxent and Bioclim, were run using 19 bioclimatic parameters at a resolution of 30 arc seconds. The climatic profile of C. salta is described, and the relative importance of the bioclimatic variables is explored. Temperature variables proved to be more decisive to the final range shape. The range predicted with Maxent is slightly larger than with Bioclim, but the latter appears to be more sensitive to the record set bias. Both methods performed well, resulting in predictive ranges consistent with the yungas ecoregion. These results provide an initial insight into the bioclimatic tolerance of C. salta, and by identifying potential areas with no records, such as the sierras on the Salta-Jujuy border, they also help in identifying sites for future sampling efforts. PMID:21861658

  6. The Wisdom of Webs A-Weaving: Adult Education and the Paradoxes of Complexity in Changing Times

    ERIC Educational Resources Information Center

    Tisdell, Elizabeth J.

    2011-01-01

    In this article, the author begins by providing an overview of the literature on wisdom itself and then considers what some of its insights might suggest for dealing with a few current challenges facing the field of adult education. This article is grounded in two basic assumptions: (1) that there is an integration quality to wisdom that attends…

  7. Weaving Intergenerational Engagement into ESL Instruction: Case Study of a University-Based Program in Hong Kong

    ERIC Educational Resources Information Center

    Lai, Alan; Kaplan, Matthew

    2016-01-01

    This article aims to address the practical question of whether there is educational value to embedding second-language (L2) learning experiences in intergenerational contexts. In particular, a case study was conducted of a novel, university-based ESL program in Hong Kong in which a group of older adult volunteers with a high level of English…

  8. Folk Arts--Traditional Arts of Greece: Art Activities with Fibers, Fabrics and Weaving for Young Children.

    ERIC Educational Resources Information Center

    Nikoltsos, Catherine

    This paper describes a developmental arts activities program for preschool children centered on traditional Greek arts. The program's elements include discussion and observation of traditional arts, collection and categorization of textile materials, manipulation of the materials, production and work with the materials to construct various designs…

  9. [Hygienic characteristics of the air and air microflora in the weaving mill of the wool textile industry].

    PubMed

    Garas'ko, E V; Zhuravleva, L T; Sedova, E A; Milovanova, M A

    1990-01-01

    Modern wool textile factories are characterized by hygienically inadequate labour conditions which include exceeding dust and microbe contamination of the air in the working zone and poor microclimate conditions in some shops. Basing on the studies of the air contamination sources, the contributors propose recommendations for health-related improvement of the air conditions.

  10. Weaving a Fabric of World History? An Analysis of U.S. State High School World History Standards

    ERIC Educational Resources Information Center

    Marino, Michael; Bolgatz, Jane

    2010-01-01

    Understanding world history is critical for our development as citizens in our interconnected society. Yet it is not clear that the standards for world history courses in the U.S. foster understanding of the whole world or of its history. The authors argue that the high school world history standards mapped out by various states promulgate a…

  11. Weaving the Native Web: Using Social Network Analysis to Demonstrate the Value of a Minority Career Development Program

    PubMed Central

    Buchwald, Dedra; Dick, Rhonda Wiegman

    2011-01-01

    Purpose American Indian and Alaska Native scientists are consistently among the most underrepresented minority groups in health research. The authors used social network analysis (SNA) to evaluate the Native Investigator Development Program (NIDP), a career development program for junior Native researchers established as a collaboration between the University of Washington and the University of Colorado Denver. Method The study focused on 29 trainees and mentors who participated in the NIDP. Data were collected on manuscripts and grant proposals produced by participants from 1998 to 2007. Information on authorship of manuscripts and collaborations on grant applications was used to conduct social network analyses with 3 measures of centrality and 1 measure of network reach. Both visual and quantitative analyses were performed. Results Participants in the NIDP collaborated on 106 manuscripts and 83 grant applications. Although 3 highly connected individuals, with critical and central roles in the program, accounted for much of the richness of the network, both current core faculty and “graduates” of the program were heavily involved in collaborations on manuscripts and grants. Conclusions This study’s innovative application of SNA demonstrates that collaborative relationships can be an important outcome of career development programs for minority investigators, and that an analysis of these relationships can provide a more complete assessment of the value of such programs. PMID:21512364

  12. More data, fewer shifts: molecular insights into the evolution of the spinning apparatus in non-orb-weaving spiders.

    PubMed

    Spagna, Joseph C; Gillespie, Rosemary G

    2008-01-01

    All spiders produce silk and use it for various functions throughout their lives, but not all spiders produce the same silks, or use them for the same functions. These functions may include building shelters, protecting eggs, and trapping prey. The "RTA clade" of spiders (grass spiders, jumping-spiders, wolf spiders, hackled-band weavers, etc.) is an extremely diverse group ( approximately 18,000 species, representing nearly half of all described species), with great variation in ecology and morphology, including variation in the cribellum, a specialized silk-producing organ. The loss of the cribellum, a structure that produces fibers contributing stickiness to prey snares and which is invariably associated with a set of accessory structures, has been studied in orb-web-weavers and shown to have been lost once during the evolutionary history of the group, but never regained. Relative to the orb-weavers, evolution of the structure remains less-thoroughly studied in the RTA clade. As the cribellum is one member of a suite of traits, the combined action of which is essential in prey-capture, its loss should have ecological correlates or physiological trade-offs of evolutionary interest. Using molecular data from nuclear genes (ribosomal DNAs 18S and 28S, and protein-coding Histone H3), as well as mitochondrial data (Cytochrome oxidase I) totaling approximately 3400 base pairs, we developed a phylogenetic hypothesis for three-clawed lineages in this group, focusing on families where taxonomy and previous cladistic analyses suggest multiple losses, or possibly loss and secondary gain, of the cribellum. Results of Bayesian and direct-optimization (POY) analyses agree on a well-resolved and robust agelenid clade that includes the putative subfamilies Ageleninae, Tegenariinae, Textricinae and Coelotinae, but excludes the cribellate New Zealand genus Neoramia. Optimizing the pattern of cribellum evolution onto these trees shows that the cribellate state is conserved in large clades and has undergone fewer shifts than current taxonomy implies. The dominant pattern is one of repeated loss of the cribellum, though loss and regain remains a possibility in some groups.

  13. RU SciTech: Weaving Astronomy and Physics into a University-sponsored Summer Camp for Middle School Students

    NASA Astrophysics Data System (ADS)

    Hart, Quyen N.

    2015-01-01

    We present a successful model for organizing a small University-sponsored summer camp that integrates astronomy and physics content with other science disciplines and computer programming content. The aim of our science and technology camp is to engage middle school students in a wide array of critical thinking tasks and hands-on activities centered on science and technology. Additionally, our program seeks to increase and maintain STEM interest among children, particularly in under-represented populations (e.g., Hispanic, African-American, women, and lower socioeconomic individuals) with hopes of decreasing disparities in diversity across many STEM fields.During this four-day camp, organized and facilitated by faculty volunteers, activities rotated through many STEM modules, including optics, telescopes, circuit building, computer hardware, and programming. Specifically, we scaffold camp activities to build upon similar ideas and content if possible. Using knowledge and skills gained through the AAS Astronomy Ambassadors program, we were able to integrate several astronomy activities into the camp, leading students through engaging activities, and conduct educational research. We present best practices on piloting a similar program in a university environment, our efforts to connect the learning outcomes common across all the modules, specifically in astronomy and physics, outline future camp activities, and the survey results on the impact of camp activities on attitudes toward science, technology, and science careers.

  14. The Effect of Weaving on the Strength of Kevlar KM2 Single Fibers at Different Loading Rates

    DTIC Science & Technology

    2012-12-01

    mechanical properties of single fibers at different strain rates is important for high-fidelity simulation of fibrous bodies in composite laminates in...DIR USARL RDRL CIH C P CHUNG RDRL HRS C K MCDOWELL K OIE B LANCE W HAIRSTON J VETTEL RDRL SL R COATES RDRL SLB

  15. Biphasic Effect of Phyllanthus emblica L. Extract on NSAID-Induced Ulcer: An Antioxidative Trail Weaved with Immunomodulatory Effect.

    PubMed

    Chatterjee, Ananya; Chattopadhyay, Subrata; Bandyopadhyay, Sandip K

    2011-01-01

    Amla (Phyllanthus emblica L.), apart from its food value, can be used as a gastroprotective agent in non steroidal anti-inflammatory drug (NSAID)-induced gastropathy. It has been suggested that the antioxidative property of amla is the key to its therapeutic effect. Hence, on the basis of in vitro antioxidative potential, the ethanolic extract of amla (eAE) was selected for in vivo study in NSAID-induced ulcer. Intriguingly, eAE showed biphasic activity in ulcerated mice, with healing effect observed at 60 mg/kg and an adverse effect at 120 mg/kg.The dose-dependent study revealed that switching from anti-oxidant to pro-oxidant shift and immunomodulatory property could be the major cause for its biphasic effect, as evident from the total antioxidant status, thiol concentration, lipid peroxidation, protein carbonyl content followed by mucin content, PGE(2) synthesis and cytokine status. Further, Buthionine sulfoxamine (BSO) pretreatment established the potential impact of antioxidative property in the healing action of eAE. However, eAE efficiently reduced pro-inflammatory cytokine (TNF-α and IL-1β) levels and appreciably upregulate anti-inflammatory cytokine (IL-10) concentration. In conclusion, gastric ulcer healing induced by eAE was driven in a dose-specific manner through the harmonization of the antioxidative property and modulation of anti-inflammatory cytokine level.

  16. Weaving Colors into a White Landscape: Unpacking the Silences in Karen Hesse's Children's Novel "Out of the Dust"

    ERIC Educational Resources Information Center

    Simon, Lisa

    2008-01-01

    The children's novel "Out of the Dust" (Hesse, 1997) is an evocative portrayal of the drought and dust storms that devastated Midwestern farms in the 1930s. Through the voice of her 13-year-old narrator, Karen Hesse intertwines history and free verse poetry to create what many readers find to be a moving depiction of the Oklahoma…

  17. Self-sealing of thermal fatigue and mechanical damage in fiber-reinforced composite materials

    NASA Astrophysics Data System (ADS)

    Moll, Jericho L.

    Fiber reinforced composite tanks provide a promising method of storage for liquid oxygen and hydrogen for aerospace applications. The inherent thermal fatigue of these vessels leads to the formation of microcracks, which allow gas phase leakage across the tank walls. In this dissertation, self-healing functionality is imparted to a structural composite to effectively seal microcracks induced by both mechanical and thermal loading cycles. Two different microencapsulated healing chemistries are investigated in woven glass fiber/epoxy and uni-weave carbon fiber/epoxy composites. Self-healing of mechanically induced damage was first studied in a room temperature cured plain weave E-glass/epoxy composite with encapsulated dicyclopentadiene (DCPD) monomer and wax protected Grubbs' catalyst healing components. A controlled amount of microcracking was introduced through cyclic indentation of opposing surfaces of the composite. The resulting damage zone was proportional to the indentation load. Healing was assessed through the use of a pressure cell apparatus to detect nitrogen flow through the thickness direction of the damaged composite. Successful healing resulted in a perfect seal, with no measurable gas flow. The effect of DCPD microcapsule size (51 microm and 18 microm) and concentration (0--12.2 wt%) on the self-sealing ability was investigated. Composite specimens with 6.5 wt% 51 microm capsules sealed 67% of the time, compared to 13% for the control panels without healing components. A thermally stable, dual microcapsule healing chemistry comprised of silanol terminated poly(dimethyl siloxane) plus a crosslinking agent and a tin catalyst was employed to allow higher composite processing temperatures. The microcapsules were incorporated into a satin weave E-glass fiber/epoxy composite processed at 120°C to yield a glass transition temperature of 127°C. Self-sealing ability after mechanical damage was assessed for different microcapsule sizees (25 microm and 42

  18. Mechanical Properties of T650-35/AFR-PE-4 at Elevated Temperatures for Lightweight Aeroshell Designs

    NASA Technical Reports Server (NTRS)

    Whitley, Karen S.; Collins, TImothy J.

    2006-01-01

    Considerable efforts have been underway to develop multidisciplinary technologies for aeroshell structures that will significantly increase the allowable working temperature for the aeroshell components, and enable the system to operate at higher temperatures while sustaining performance and durability. As part of these efforts, high temperature polymer matrix composites and fabrication technologies are being developed for the primary load bearing structure (heat shield) of the spacecraft. New high-temperature resins and composite material manufacturing techniques are available that have the potential to significantly improve current aeroshell design. In order to qualify a polymer matrix composite (PMC) material as a candidate aeroshell structural material, its performance must be evaluated under realistic environments. Thus, verification testing of lightweight PMC's at aeroshell entry temperatures is needed to ensure that they will perform successfully in high-temperature environments. Towards this end, a test program was developed to characterize the mechanical properties of two candidate material systems, T650-35/AFR-PE-4 and T650-35/RP46. The two candidate high-temperature polyimide resins, AFR-PE-4 and RP46, were developed at the Air Force Research Laboratory and NASA Langley Research Center, respectively. This paper presents experimental methods, strength, and stiffness data of the T650-35/AFR-PE-4 material as a function of elevated temperatures. The properties determined during the research test program herein, included tensile strength, tensile stiffness, Poisson s ratio, compressive strength, compressive stiffness, shear modulus, and shear strength. Unidirectional laminates, a cross-ply laminate and two eight-harness satin (8HS)-weave laminates (4-ply and 10-ply) were tested according to ASTM standard methods at room and elevated temperatures (23, 316, and 343 C). All of the relevant test methods and data reduction schemes are outlined along with

  19. The Calling Canvas, Weaving Together Words and Images: A Narrative Inquiry into the Creative Voice of Students with Autism Participating in a Creative Lunchtime Program

    ERIC Educational Resources Information Center

    Kotowski, Kelly

    2013-01-01

    This narrative chronicles the story of the Lunch Bunch, a group of 4 students with autism, 1 student with a specific learning disability and their art educator/researcher as they ate lunch together and discussed creativity and at times made art. A chronological story of the Lunch Bunch was crafted utilizing narrative inquiry as the overarching…

  20. Weaving a two-dimensional fishing net from titanoniobate nanosheets embedded with Fe3O4 nanocrystals for highly efficient capture and isotope labeling of phosphopeptides

    NASA Astrophysics Data System (ADS)

    Chen, Xueqin; Li, Siyuan; Zhang, Xiaoxia; Min, Qianhao; Zhu, Jun-Jie

    2015-03-01

    Qualitative and quantitative characterization of phosphopeptides by means of mass spectrometry (MS) is the main goal of MS-based phosphoproteomics, but suffers from their low abundance in the large haystack of various biological molecules. Herein, we introduce two-dimensional (2D) metal oxides to tackle this biological separation issue. A nanocomposite composed of titanoniobate nanosheets embedded with Fe3O4 nanocrystals (Fe3O4-TiNbNS) is constructed via a facile cation-exchange approach, and adopted for the capture and isotope labeling of phosphopeptides. In this nanoarchitecture, the 2D titanoniobate nanosheets offer enlarged surface area and a spacious microenvironment for capturing phosphopeptides, while the Fe3O4 nanocrystals not only incorporate a magnetic response into the composite but, more importantly, also disrupt the restacking process between the titanoniobate nanosheets and thus preserve a greater specific surface for binding phosphopeptides. Owing to the extended active surface, abundant Lewis acid sites and excellent magnetic controllability, Fe3O4-TiNbNS demonstrates superior sensitivity, selectivity and capacity over homogeneous bulk metal oxides, layered oxides, and even restacked nanosheets in phosphopeptide enrichment, and further allows in situ isotope labeling to quantify aberrantly-regulated phosphopeptides from sera of leukemia patients. This composite nanosheet greatly contributes to the MS analysis of phosphopeptides and gives inspiration in the pursuit of 2D structured materials for separation of other biological molecules of interests.Qualitative and quantitative characterization of phosphopeptides by means of mass spectrometry (MS) is the main goal of MS-based phosphoproteomics, but suffers from their low abundance in the large haystack of various biological molecules. Herein, we introduce two-dimensional (2D) metal oxides to tackle this biological separation issue. A nanocomposite composed of titanoniobate nanosheets embedded with Fe3O4 nanocrystals (Fe3O4-TiNbNS) is constructed via a facile cation-exchange approach, and adopted for the capture and isotope labeling of phosphopeptides. In this nanoarchitecture, the 2D titanoniobate nanosheets offer enlarged surface area and a spacious microenvironment for capturing phosphopeptides, while the Fe3O4 nanocrystals not only incorporate a magnetic response into the composite but, more importantly, also disrupt the restacking process between the titanoniobate nanosheets and thus preserve a greater specific surface for binding phosphopeptides. Owing to the extended active surface, abundant Lewis acid sites and excellent magnetic controllability, Fe3O4-TiNbNS demonstrates superior sensitivity, selectivity and capacity over homogeneous bulk metal oxides, layered oxides, and even restacked nanosheets in phosphopeptide enrichment, and further allows in situ isotope labeling to quantify aberrantly-regulated phosphopeptides from sera of leukemia patients. This composite nanosheet greatly contributes to the MS analysis of phosphopeptides and gives inspiration in the pursuit of 2D structured materials for separation of other biological molecules of interests. Electronic supplementary information (ESI) available: Sequence of phosphopeptides from the digests of α- and β-casein percentages of the 4 methylated products from peptide β1 at different labeling reaction times; sequence of serum phosphopeptides; XPS spectra of Nb 3d and Ti 2p in layered oxides and H+-stacked nanosheets; phosphopeptide enrichment sensitivity of bulk oxides, layered oxides and H+-stacked nanosheets; AFM image of TiNbNS; saturated adsorption isotherm for pNPP adsorbed on bulk oxides, layered oxides and H+-stacked nanosheets; XPS spectra of Fe3O4-TiNbNS nitrogen adsorption-desorption isotherms and pore size distribution curves for the Fe3O4 nanocrystals; phosphopeptide enrichment sensitivity, capacity and selectivity of the Fe3O4-TiNbNS composites; MS/MS spectra of phosphopeptides enriched from serum; linear relationship between the logarithms of peak area ratio and loading volume ratio. See DOI: 10.1039/c4nr07041k

  1. Foxfire 2: Ghost Stories, Spring Wild Plant Foods, Spinning and Weaving, Midwifing, Burial Customs, Corn Shuckin's, Wagon Making and More Affairs of Plain Living.

    ERIC Educational Resources Information Center

    Wigginton, Eliot, Ed.

    Information about the rural Appalachian culture as told by longtime residents of Rabun Gap County, Georgia, is presented in this book. In many cases the material is in the words of the resident and additional commentary is provided by the high school student conducting the interview. Instructions are given for making items often made at home when…

  2. The Effect of Plain-Weaving on the Mechanical Properties of Warp and Weft P-Phenylene Terephthalamide (PPTA) Fibers/Yarns

    DTIC Science & Technology

    2014-08-15

    and (b) parameterize various components of the bead/bead force- field functions. In the second portion of the work, a simplified finite-element...various components of the bead/bead force- field functions. In the second portion of the work, a simplified finite-element analysis of the plain...including the construction of the computational model, formulation and parameterization of the force- fields , computational algorithms, problem formulation

  3. The Double-Weave of Self and Other: Ethnographic Acts and Autobiographical Occasions in Marilou Awiakta's "Selu: Seeking the Corn-Mother's Wisdom"

    ERIC Educational Resources Information Center

    Watkins, James H.

    2006-01-01

    In the opening pages of Marilou Awiakta's "Selu: Seeking the Corn-Mother's Wisdom," the author offers a metacommentary on her delightfully hybrid text, likening it to a "double-woven basket (Cherokee-style)." The image resonates on many levels with the author's tribal traditions and thus serves to foreshadow the text's wealth of material on…

  4. Artificial Skin – Culturing of Different Skin Cell Lines for Generating an Artificial Skin Substitute on Cross-Weaved Spider Silk Fibres

    PubMed Central

    Reimers, Kerstin; Kuhbier, Joern W.; Schäfer-Nolte, Franziska; Allmeling, Christina; Kasper, Cornelia; Vogt, Peter M.

    2011-01-01

    Background In the field of Plastic Reconstructive Surgery the development of new innovative matrices for skin repair is in urgent need. The ideal biomaterial should promote attachment, proliferation and growth of cells. Additionally, it should degrade in an appropriate time period without releasing harmful substances, but not exert a pathological immune response. Spider dragline silk from Nephila spp meets these demands to a large extent. Methodology/Principal Findings Native spider dragline silk, harvested directly out of Nephila spp spiders, was woven on steel frames. Constructs were sterilized and seeded with fibroblasts. After two weeks of cultivating single fibroblasts, keratinocytes were added to generate a bilayered skin model, consisting of dermis and epidermis equivalents. For the next three weeks, constructs in co-culture were lifted on an originally designed setup for air/liquid interface cultivation. After the culturing period, constructs were embedded in paraffin with an especially developed program for spidersilk to avoid supercontraction. Paraffin cross- sections were stained in Haematoxylin & Eosin (H&E) for microscopic analyses. Conclusion/Significance Native spider dragline silk woven on steel frames provides a suitable matrix for 3 dimensional skin cell culturing. Both fibroblasts and keratinocytes cell lines adhere to the spider silk fibres and proliferate. Guided by the spider silk fibres, they sprout into the meshes and reach confluence in at most one week. A well-balanced, bilayered cocultivation in two continuously separated strata can be achieved by serum reduction, changing the medium conditions and the cultivation period at the air/liquid interphase. Therefore spider silk appears to be a promising biomaterial for the enhancement of skin regeneration. PMID:21814557

  5. Weaving Indigenous Agricultural Knowledge with Formal Education to Enhance Community Food Security: School Competition as a Pedagogical Space in Rural Anchetty, India

    ERIC Educational Resources Information Center

    Shukla, Shailesh; Barkman, Janna; Patel, Kirit

    2017-01-01

    Like many socially and economically disadvantaged farming communities around the world, the Anchetty region of Tamil Nadu, India, has been experiencing serious food security challenges mainly due to the loss of traditional foods such as small millets and associated crops (SMAC) and associated indigenous agricultural knowledge (IAK). Drawing on…

  6. Weaving interdisciplinary and discipline-specific content into palliative care education: one successful model for teaching end-of-life care.

    PubMed

    Supiano, Katherine P

    2013-01-01

    While palliative care is best delivered in an interdisciplinary format, courses teaching the interdisciplinary approach to palliative care are rare in healthcare education. This article describes a graduate-level course in palliative care for students in nursing, pharmacy, social work, and gerontology taught by faculty from each discipline. The overarching goals of this course are to convey core palliative care knowledge across disciplines, articulate the essential contribution of each discipline in collaborative care, and to define interdisciplinary processes learners need to understand and navigate interdisciplinary palliative care. Learning outcomes included increased knowledge in palliative care, enhanced attitudes in practice and application of skills to clinical practice settings, increased ability to contribute discipline-specific knowledge to their teams' discussions, and a sense of increasing confidence in participating in the care of complex patients, communicating with families, and contributing to the team as a member of their own discipline.

  7. With All Strings Attached: Composer William C. Banfield Notes the Clash of Artistry and Commerce while Weaving Together a World of Music

    ERIC Educational Resources Information Center

    Hamilton, Kendra

    2004-01-01

    William Banfield is a composer with nine symphonies to his credit, as well as countless smaller scale works--concerti, chamber works, operas, choral and jazz works--that have been performed all over the nation. He has also performed with highly acclaimed jazz performers such as Patrice Rushen, Earl Klugh, Najee, Nelson Rangell and many others. He…

  8. Effects of Weave Styles and Crimp Gradients on Damage Tolerance and Energy-Absorption Capacities of Woven Kevlar/Epoxy Composites

    DTIC Science & Technology

    2015-09-01

    ORGANIZATION NAME(S) AND ADDRESS(ES) Naval Undersea Warfare Center Division 1176 Howell Street Newport, Rl 02841-1708 8. PERFORMING ORGANIZATION ...gradients (CGs) on the damage-tolerance levels and energy-absorption capacities of woven fabric-reinforced polymer (WFRP) composites. A comparative...Mechanics Fabrics Finite Element Analysis Functionally Graded Impact Fracture Kevlar Woven Composites Woven Fabric-Reinforced Polymer Composites 16

  9. Weaving Together Space Biology and the Human Research Program: Selecting Crops and Manipulating Plant Physiology to Produce High Quality Food for ISS Astronauts

    NASA Technical Reports Server (NTRS)

    Massa, Gioia; Hummerick, Mary; Douglas, Grace; Wheeler, Raymond

    2015-01-01

    Researchers from the Human Research Program (HRP) have teamed up with plant biologists at KSC to explore the potential for plant growth and food production on the international space station (ISS) and future exploration missions. KSC Space Biology (SB) brings a history of plant and plant-microbial interaction research for station and for future bioregenerative life support systems. JSC HRP brings expertise in Advanced Food Technology (AFT), Advanced Environmental Health (AEH), and Behavioral Health and Performance (BHP). The Veggie plant growth hardware on the ISS is the platform that first drove these interactions. As we prepared for the VEG-01 validation test of Veggie, we engaged with BHP to explore questions that could be asked of the crew that would contribute both to plant and to behavioral health research. AFT, AEH and BHP stakeholders were engaged immediately after the return of the Veggie flight samples of space-grown lettuce, and this team worked with the JSC human medical offices to gain approvals for crew consumption of the lettuce on ISS. As we progressed with Veggie testing we began performing crop selection studies for Veggie that were initiated through AFT. These studies consisted of testing and down selecting leafy greens, dwarf tomatoes, and dwarf pepper crops based on characteristics of plant growth and nutritional levels evaluated at KSC, and organoleptic quality evaluated at JSCs Sensory Analysis lab. This work has led to a successful collaborative proposal to the International Life Sciences Research Announcement for a jointly funded HRP-SB investigation of the impacts of light quality and fertilizer on salad crop productivity, nutrition, and flavor in Veggie on the ISS. With this work, and potentially with other pending joint projects, we will continue the synergistic research that will advance the space biology knowledge base, help close gaps in the human research roadmap, and enable humans to venture out to Mars and beyond.

  10. Rowing the Weaves of Community Participation: Good Practices in Early Childhood Development (ECD) Program in Rural Central Lombok, West Nusa Tenggara

    ERIC Educational Resources Information Center

    Abdillah, Ali

    2014-01-01

    This paper describes the rural community participation within the context of an integrated early childhood development program initiated by the government of Indonesia in partnership with UNICEF and AusAID in Central Lombok (2008-2010). Based on purposive interviews with relevant stakeholders, as well as an analysis of past documents, researchers'…

  11. Constraints on the adhesion of viscous threads spun by orb-weaving spiders: the tensile strength of glycoprotein glue exceeds its adhesion.

    PubMed

    Opell, Brent D; Schwend, Harold S; Vito, Stephen T

    2011-07-01

    In this study we tested the hypothesis that a viscous thread releases its hold on a surface because its glycoprotein glue pulls from the surface and not because its elongating droplets break near their attachment to the surface. We compared the values obtained when three species' viscous threads adhered to four smooth surfaces, which differed in their total surface energy and in the proportions of their dispersion and polar energy components. Although water comprised 43-70% of the volume of these viscous droplets, only the dispersion surface energies of test materials and not their polar surface energies impacted thread adhesion. These results support the droplet pull-off hypothesis and are consistent with a previous finding that capillary force contributes little to thread adhesion. Just as a viscous thread's stickiness is constrained by the tensile strength of its supporting axial fibers, our findings suggest that glycoprotein adhesion is constrained by glycoprotein tensile strength.

  12. "Ka ulana 'ana i ka piko" (In Weaving You Begin at the Center): Perspectives from a Culturally Specific Approach to Art Education

    ERIC Educational Resources Information Center

    Dewhurst, Marit; Keawe, Lia O'Neill Moanike'Ala Ah-Lan; MacDowell, Marsha; Okada-Carlson, Cherie N. K.; Wong, Annette Ku'Uipolani

    2013-01-01

    This essay examines the experiences of "lau hala" ("pandanus" leaf plaiting) weavers for the pedagogical philosophies and strategies embedded in this Hawaiian art form in an effort to broaden the ways in which we understand and practice art education in any setting. Drawing on personal experiences as "lau hala"…

  13. Flexible Weaving: Investigating the Teaching and Learning Opportunities in the Practices of Theatre-Makers and Performers from Selected Townships in Cape Town

    ERIC Educational Resources Information Center

    Morris, Gay

    2013-01-01

    In 2005-2009, the author researched the theatre-making practices of young people in selected black townships near Cape Town, South Africa. Township theatre groups comprised secondary school learners and out-of-school youth who join together to learn about and make theatre, perform and watch each other. These theatre practitioners do not describe…

  14. 10 CFR Appendix J1 to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Automatic and Semi-Automatic Clothes...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... cloth, made with a momie or granite weave, which is 50 percent cotton and 50 percent polyester and... type. Pure finished bleached cloth, made with a momie or granite weave, which is nominally 50...

  15. 40 CFR 410.31 - Specialized definitions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... STANDARDS TEXTILE MILLS POINT SOURCE CATEGORY Low Water Use Processing Subcategory § 410.31 Specialized... qualify under the water jet weaving subdivision. (b) The term water jet weaving shall mean the internal... woven greige goods through the water jet weaving process....

  16. Low-Velocity, Multi-Impact Durability Performance of Thick-Section 3WEAVE S2-Glass/SC-15 Composites Toughened with Thermoplastic Polyurethane Inter-Layer Films

    DTIC Science & Technology

    2013-08-01

    transfer molding ( VARTM ) process. Large panels (approximately 89-cm squares) were processed, cured, and post-cured according to manufacturers...infused with SC-15 using the VARTM method. Each sample was processed individually. After infusion, the resin was allowed to cure for 48 h at room...Thermoplastic polyurethane VARTM Vacuum assisted resin transfer molding 2-D Two-dimensional 3-D Three-dimensional LVI Low velocity impact ds

  17. Long-Wave Infrared (LWIR) Polarimetric and Radiometric Analysis for a Variety of Thermal and Electromagnetic Suppressing Materials

    DTIC Science & Technology

    2014-08-01

    shielding materials. Nine materials were examined: 3 forms of aluminum-coated heat-shield fabric, 2 samples of a nickel- Kevlar material, 2 samples of a...5 Fig. 4 Photographs a) and b) show swaths of a nickel- Kevlar woven fabric with slightly different weave patterns, i.e., Sample D’s weave pattern...materials (red), the nickel-coated Kevlar (blue), the silver- coated polyester (green), and the carbon-based NanoWeave materials (orange

  18. Composites from powder coated towpreg - Studies with variable tow sizes

    NASA Astrophysics Data System (ADS)

    Hugh, Maylene K.; Marchello, Joseph M.; Baucom, Robert M.; Johnston, Norman J.

    Part fabrication from composite materials usually costs less when larger fiber tow bundles are used. On the other hand, mechanical properties generally are lower for composites made using larger size tows. This situation gives rise to a choice between costs and properties in determining the best fiber tow bundle size to employ in preparing prepreg materials for part fabrication. To address this issue, unidirectional and eight harness satin fabric composite specimens were fabricated from 3k, 6k, and 12k carbon fiber reinforced LARC-TPI powder coated towpreg. Short beam shear strengths and longitudinal and transverse flexure properties were obtained for the unidirectional specimens. Tension properties were obtained for the eight harness satin woven towpreg specimens. Knowledge of the variation of properties with tow size may serve as a guide in material selection for part fabrication.

  19. Composites from powder coated towpreg - Studies with variable tow sizes

    NASA Technical Reports Server (NTRS)

    Hugh, Maylene K.; Marchello, Joseph M.; Baucom, Robert M.; Johnston, Norman J.

    1992-01-01

    Part fabrication from composite materials usually costs less when larger fiber tow bundles are used. On the other hand, mechanical properties generally are lower for composites made using larger size tows. This situation gives rise to a choice between costs and properties in determining the best fiber tow bundle size to employ in preparing prepreg materials for part fabrication. To address this issue, unidirectional and eight harness satin fabric composite specimens were fabricated from 3k, 6k, and 12k carbon fiber reinforced LARC-TPI powder coated towpreg. Short beam shear strengths and longitudinal and transverse flexure properties were obtained for the unidirectional specimens. Tension properties were obtained for the eight harness satin woven towpreg specimens. Knowledge of the variation of properties with tow size may serve as a guide in material selection for part fabrication.

  20. Fatigue Behavior of an Advanced SiC/SiC Composite at Elevated Temperature in Air and in Steam

    DTIC Science & Technology

    2009-12-01

    SV II optical microscope with a Zeiss AxioCam HRc digital camera. ... 24 Figure 16: Quanta 200 Scanning Electron Microscope...failed specimens were examined using both a Zeiss optical microscope and a Quanta scanning electron microscope. Figures 32-34 show the optical ...environments. The composite consisted of a SiC matrix reinforced with Boron Nitride (BN) coated Hi-Nicalon fibers woven into eight-harness-satin (8HS

  1. An Absorbing Look at Terry-Cloth Towels

    ERIC Educational Resources Information Center

    Moyer, Richard; Everett, Susan

    2010-01-01

    This article describes a lesson where students explore the absorbency of several towels with different weaves and weights. The lesson follows the 5E learning-cycle model and incorporates engineering in the sense of product testing with a focus on the relationship between the weave of a towel and its absorbency. The National Science Education…

  2. SRB thermal curtain design support

    NASA Technical Reports Server (NTRS)

    Dixon, Carl A.; Lundblad, Wayne E.; Koenig, John R.

    1992-01-01

    Improvements in SRB Thermal Curtain were identified by thermal design featuring: selection of materials capable of thermal protection and service temperatures by tri-layering quartz, S2 glass, and Kevlar in thinner cross section; weaving in single piece (instead of 24 sections) to achieve improved strength; and weaving to reduce manufacturing cost with angle interlock construction.

  3. SRB thermal curtain design support

    NASA Astrophysics Data System (ADS)

    Dixon, Carl A.; Lundblad, Wayne E.; Koenig, John R.

    1992-11-01

    Improvements in SRB Thermal Curtain were identified by thermal design featuring: selection of materials capable of thermal protection and service temperatures by tri-layering quartz, S2 glass, and Kevlar in thinner cross section; weaving in single piece (instead of 24 sections) to achieve improved strength; and weaving to reduce manufacturing cost with angle interlock construction.

  4. Making Skew-Resistant Fabrics For Composite Layups

    NASA Technical Reports Server (NTRS)

    Farley, Gary L.

    1994-01-01

    Fabrics used in curved composite-material structures prevented from skewing during composite layup by weaving them in modified process in which warp and fill yarns bonded together at their points of contact. (Bonding concept may prove similarly beneficial for braided and knitted fabrics.) In modified weaving process, adhesives prevent excessive shifting of warp and fill yarns with respect to each other.

  5. 75 FR 54599 - Notice of Solicitation of Applications for Allocation of Tariff Rate Quotas on the Import of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-08

    ... on the Import of Certain Worsted Wool Fabrics to Persons Who Weave Such Fabrics in the United States... wool fabric to persons who weave such fabrics in the United States. SUMMARY: The Department hereby solicits applications from persons (including firms, corporations, or other legal entities) who...

  6. 77 FR 58525 - Notice of Solicitation of Applications for Allocation of Tariff Rate Quotas on the Import of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-21

    ... on the Import of Certain Worsted Wool Fabrics to Persons Who Weave Such Fabrics in the United States... wool fabric to persons who weave such fabrics in the United States. SUMMARY: The Department hereby solicits applications from persons (including firms, corporations, or other legal entities) who...

  7. Optimization on Impact Strength of Woven Kenaf Reinforced Polyester Composites using Taguchi Method

    NASA Astrophysics Data System (ADS)

    Khalid, S. N. A.; Ismail, A. E.; Zainulabidin, M. H.

    2017-01-01

    This paper focuses on the effect of weaving patterns and orientations on the energy absorption of woven kenaf reinforced polyester composites. Kenaf fiber in the form of yarn is weaved to produce different weaving patterns such as plain, twill and basket. Three woven mats are stacked together and mixed with polyester resin before it is compressed to squeeze out any excessive resin. There is nine different orientations are used during stacking processes by following Taguchi orthogonal arrays method. The hardened composites are cured for 24 hours before it is shaped according to specific dimensions for impact tests. The composites are perforated with 1m/s blunted projectile. According to the experimental findings, weaving pattern and orientation have distinct potential effects on value of energy absorption. The optimization using Taguchi method reveals preferable orientation of each weaving pattern composites. Based on the fracture observation, the fragmentations after optimization indicating lower distance surface fracture perforated obtained.

  8. Determination of interlaminar shear strength for glass/epoxy and carbon/epoxy laminates at impact rates of strain

    NASA Astrophysics Data System (ADS)

    Harding, J.; Li, Y. L.

    A new technique is proposed for determining the interlaminar shear strength of fiber-reinforced polymer matrix composites using a double-lap shear specimen in which failure occurs on a predetermined plane. by using different ply layups in the double-lap shear specimen, the effect of loading rate on the interfacial shear strength is determined for (1) two plain-weave carbon/epoxy plies, (2) two plain-weave glass/epoxy plies, and (3) a plain-weave carbon/epoxy ply and a plain-weave carbon/epoxy ply and a plain-weave glass/epoxy ply. An increase in loading rate of about six orders of magnitude is found to raise the average value of the shear stress on the failure plane by about 70 percent for the carbon/carbon and glass/glass interfaces and by about 50 percent for the hybrid carbon/glass interface.

  9. Evaluation of the impact response of textile composites

    NASA Technical Reports Server (NTRS)

    Portanova, M. A.

    1995-01-01

    An evaluation of the impact damage resistance and impact damage tolerance of stitched and unstitched uniweaves, 2-D braids, and 3-D weaves was conducted. Uniweave laminates were tested at four thicknesses to determine the sensitivity of the tests to this parameter. Several braid and weave parameters were also varied to establish their velocity (large mass) impacts and then loaded in tension or compression to measure residual strength. Experimental results indicate that stitching significantly improves the uniweaves' damage resistance. The 2-D braids and 3-D weaves offered less damage resistance than the stitched materials. Stitching also improved the compression after impact (CAI) and tension after impact (TAI) strengths of the uniweave materials.

  10. Seam-Tracking for Friction Stir Welded Lap Joints

    NASA Astrophysics Data System (ADS)

    Fleming, Paul A.; Hendricks, Christopher E.; Cook, George E.; Wilkes, D. M.; Strauss, Alvin M.; Lammlein, David H.

    2010-11-01

    This article presents a method for automatic seam-tracking in friction stir welding (FSW) of lap joints. In this method, tracking is accomplished by weaving the FSW tool back-and-forth perpendicular to the direction of travel during welding and monitoring force and torque signals. Research demonstrates the ability of this method to automatically track weld seam positions. Additionally, tensile and S-bend test result comparisons demonstrate that weaving most likely does not reduce weld quality. Finally, benefits of this weave-based method to FSW of lap joints are discussed and methods for incorporating it into existing friction stir welding control algorithms (such as axial load control) are examined.

  11. Continuum Model Simulations and Experiments of Projectile Impact on Woven Fabric

    DTIC Science & Technology

    2008-12-01

    scale of the fabric and the “mesoscale” of the yarns that compose the weave . Here, we utilize a continuum-level modeling technique for woven fabrics (King...the fabric and the “mesoscale” of the yarns that compose the weave . In fact, there is no widely accepted computational model for fabric defor- mation...the litera- ture, either the fabric has been modeled at the level of the mesoscale, with detailed discretization of each fiber in the weave , or the

  12. Woven Thermal Protection System (Woven TPS) for Extreme Entry Environments

    NASA Video Gallery

    The Woven Thermal Protection System (WTPS) project explores an innovative way to design, develop and manufacture a family of ablative TPS materials using weaving technology and testing them in the ...

  13. Same Play, Different Actors: The Aquatic Community.

    ERIC Educational Resources Information Center

    Kanis, Ira B.; Saccente, Joseph

    1988-01-01

    Provided are background information, equipment lists, and procedures for four activities for teaching aquatic ecology. Activities include "The Aquatic Food Chain Game"; "Two-Liter Aqua-Vivariums"; "A Sealed World"; and "Weaving a Web: Evaluation." (CW)

  14. 25 CFR 170.121 - What is a cultural access road?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... example: (1) Sacred and medicinal sites; (2) Gathering medicines or materials such as grasses for basket weaving; or (3) Other traditional activities, including, but not limited to, subsistence hunting,...

  15. 25 CFR 170.121 - What is a cultural access road?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... example: (1) Sacred and medicinal sites; (2) Gathering medicines or materials such as grasses for basket weaving; or (3) Other traditional activities, including, but not limited to, subsistence hunting,...

  16. Preparing Students for the 21st Century through the Study of World Music

    ERIC Educational Resources Information Center

    Beegle, Amy Christine

    2014-01-01

    This column provides examples of activities that general music teachers might use to weave global awareness into web-based lessons to promote the development of information literacy, media literacy, and communication literacy through the study of world music.

  17. Learning Math: Exploring Relationships through Superheroes.

    ERIC Educational Resources Information Center

    Clyde, Jean Anne; Mills, Heidi

    1993-01-01

    Illustrates one seven-year-old boy's understanding of mathematical relationships through drawings of his favorite "superheroes." Also illustrates how he conveyed the qualities of his heroes by weaving together the three symbol systems of language, art, and mathematics. (BB)

  18. Chaos Theory: Self-Organization and Symbolic Representation in Family Systems.

    ERIC Educational Resources Information Center

    Butz, Michael R.; Carlson, J. Matthew; Carlson, Jon

    1998-01-01

    Proposes an integration of the use of symbols and metaphors that illustrates nonlinear dynamics through a case example weaving together contemporary science and human development in the context of family therapy. Discusses areas of future study. (Author/MKA)

  19. Be the Change You Wish to See: An Interview with Arun Gandhi.

    ERIC Educational Resources Information Center

    B'Hahn, Carmella

    2001-01-01

    Arun Gandhi was taught well by his legendary grandfather, Mohandas K. Ghandi. In this interview, he weaves his wisdom about facing adversity, anger, and prejudice with his personal stories of life's challenges, including the assassination of his grandfather. (BF)

  20. 15 CFR Supplement No. 2 to Part 740 - Items That May Be Donated To Meet Basic Human Needs Under the Humanitarian License Exception

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Medicines and Supplies (c) Clothes and Household Goods Bedding Clothes Cooking Utensils Fabric Personal Hygiene Items Soap-Making Equipment Weaving and Sewing Equipment (d) Shelter Building Materials Hand...

  1. 15 CFR Supplement No. 2 to Part 740 - Items That May Be Donated To Meet Basic Human Needs Under the Humanitarian License Exception

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Medicines and Supplies (c) Clothes and Household Goods Bedding Clothes Cooking Utensils Fabric Personal Hygiene Items Soap-Making Equipment Weaving and Sewing Equipment (d) Shelter Building Materials Hand...

  2. 15 CFR Supplement No. 2 to Part 740 - Items That May Be Donated To Meet Basic Human Needs Under the Humanitarian License Exception

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Medicines and Supplies (c) Clothes and Household Goods Bedding Clothes Cooking Utensils Fabric Personal Hygiene Items Soap-Making Equipment Weaving and Sewing Equipment (d) Shelter Building Materials Hand...

  3. 22 CFR 1104.2 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., contextual measurement, controlled collection, analysis, interpretation and explanation. (2) Material remains... ceramics, cordage, basketry and other weaving, bottles and other glassware, bone, ivory, shell, metal, wood... limited to, bone, teeth, mummified flesh, burials, cremations); (vii) Rock carvings, rock...

  4. 22 CFR 1104.2 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., contextual measurement, controlled collection, analysis, interpretation and explanation. (2) Material remains... ceramics, cordage, basketry and other weaving, bottles and other glassware, bone, ivory, shell, metal, wood... limited to, bone, teeth, mummified flesh, burials, cremations); (vii) Rock carvings, rock...

  5. 22 CFR 1104.2 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., contextual measurement, controlled collection, analysis, interpretation and explanation. (2) Material remains... ceramics, cordage, basketry and other weaving, bottles and other glassware, bone, ivory, shell, metal, wood... limited to, bone, teeth, mummified flesh, burials, cremations); (vii) Rock carvings, rock...

  6. 36 CFR 296.3 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., contextual measurement, controlled collection, analysis, interpretation and explanation. (2) Material remains... ceramics, cordage, basketry and other weaving, bottles and other glassware, bone, ivory, shell, metal, wood... limited to, bone, teeth, mummified flesh, burials, cremations); (vii) Rock carvings, rock...

  7. 18 CFR 1312.3 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., contextual measurement, controlled collection, analysis, interpretation and explanation. (2) Material remains... ceramics, cordage, basketry and other weaving, bottles and other glassware, bone, ivory, shell, metal, wood... limited to, bone, teeth, mummified flesh, burials, cremations); (vii) Rock carvings, rock...

  8. 18 CFR 1312.3 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., contextual measurement, controlled collection, analysis, interpretation and explanation. (2) Material remains... ceramics, cordage, basketry and other weaving, bottles and other glassware, bone, ivory, shell, metal, wood... limited to, bone, teeth, mummified flesh, burials, cremations); (vii) Rock carvings, rock...

  9. 25 CFR 700.805 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... or scholarly techniques such as controlled observation, contextual measurement, controlled collection... weaving, bottles and other glasseware, bone, ivory, shell, metal, wood, hide, feathers, pigments, and... animal remains, coprolites); (vi) Human remains (including, but not limited to, bone, teeth,...

  10. 25 CFR 700.805 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... or scholarly techniques such as controlled observation, contextual measurement, controlled collection... weaving, bottles and other glasseware, bone, ivory, shell, metal, wood, hide, feathers, pigments, and... animal remains, coprolites); (vi) Human remains (including, but not limited to, bone, teeth,...

  11. 36 CFR 296.3 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., contextual measurement, controlled collection, analysis, interpretation and explanation. (2) Material remains... ceramics, cordage, basketry and other weaving, bottles and other glassware, bone, ivory, shell, metal, wood... limited to, bone, teeth, mummified flesh, burials, cremations); (vii) Rock carvings, rock...

  12. 25 CFR 700.805 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... or scholarly techniques such as controlled observation, contextual measurement, controlled collection... weaving, bottles and other glasseware, bone, ivory, shell, metal, wood, hide, feathers, pigments, and... animal remains, coprolites); (vi) Human remains (including, but not limited to, bone, teeth,...

  13. 18 CFR 1312.3 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., contextual measurement, controlled collection, analysis, interpretation and explanation. (2) Material remains... ceramics, cordage, basketry and other weaving, bottles and other glassware, bone, ivory, shell, metal, wood... limited to, bone, teeth, mummified flesh, burials, cremations); (vii) Rock carvings, rock...

  14. 36 CFR 296.3 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., contextual measurement, controlled collection, analysis, interpretation and explanation. (2) Material remains... ceramics, cordage, basketry and other weaving, bottles and other glassware, bone, ivory, shell, metal, wood... limited to, bone, teeth, mummified flesh, burials, cremations); (vii) Rock carvings, rock...

  15. Uncommon Teaching in an Unexpected Place

    ERIC Educational Resources Information Center

    Shore, Rebecca

    2014-01-01

    Continued physical well-being is important, especially within the aging teacher ranks. The story of one veteran exercise instructor emphasizes fitness and weaves best classroom practices throughout the narrative.

  16. Microstructure of Matrix in UHTC Composites

    NASA Technical Reports Server (NTRS)

    Johnson, Sylvia; Stackpoole, Margaret; Gusman, Michael I.; Chavez-Garia Jose; Doxtad, Evan

    2011-01-01

    Approaches to controlling the microstructure of Ultra High Temperature Ceramics (UHTCs) are described.. One matrix material has been infiltrated into carbon weaves to make composite materials. The microstructure of these composites is described.

  17. Tailorable advanced blanket insulation using aluminoborosilicate and alumina batting

    NASA Technical Reports Server (NTRS)

    Calamito, Dominic P.

    1989-01-01

    Two types of Tailorable Advanced Blanket Insulation (TABI) flat panels for Advanced Space Transportation Systems were produced. Both types consisted of integrally woven, 3-D fluted core having parallel faces and connecting ribs of Nicalon yarns. The triangular cross section flutes of one type was filled with mandrels of processed Ultrafiber (aluminoborosilicate) stitchbonded Nextel 440 fibrous felt, and the second type wall filled with Saffil alumina fibrous felt insulation. Weaving problems were minimal. Insertion of the fragile insulation mandrels into the fabric flutes was improved by using a special insertion tool. An attempt was made to weave fluted core fabrics from Nextel 440 yarns but was unsuccessful because of the yarn's fragility. A small sample was eventually produced by an unorthodox weaving process and then filled with Saffil insulation. The procedures for setting up and weaving the fabrics and preparing and inserting insulation mandrels are discussed. Characterizations of the panels produced are also presented.

  18. NASA Ames Develops Woven Thermal Protection System (TPS)

    NASA Video Gallery

    The Woven Thermal Protection System (WTPS) project explores an innovative way to design, develop and manufacture a family of ablative TPS materials using weaving technology and testing them in the ...

  19. The Carry Loom.

    ERIC Educational Resources Information Center

    Mihalow, Paula

    1980-01-01

    Presents instructions for building a simple, inexpensive, one-piece loom that is easy for students and teachers to work with, transport, and store. A short list of books for weaving instruction is appended. (Author/SJL)

  20. Adult Learning, Transformative Education, and Indigenous Epistemology

    ERIC Educational Resources Information Center

    McEachern, Diane

    2016-01-01

    This chapter describes an innovative program that weaves together adult learning, transformative education, and indigenous epistemology in order to prepare Alaskan rural indigenous social service providers to better serve their communities.

  1. Measurement and Prediction of Effective Thermal Conductivity for Woven Fabric Composites

    NASA Astrophysics Data System (ADS)

    Goo, Nam Seo; Woo, Kyeongsik

    The current paper deals with the measurement and prediction of thermal conductivities for plain weave fabric composites. An experimental apparatus was setup to measure the temperature gradients from which the thermal conductivities were obtained. The thermal conductivities were also calculated using finite element analyses for plain weave unit cell models and then compared with experimental results. In addition, the effect of a phase shift and the fiber volume fraction in the tow on the thermal conductivities was addressed.

  2. Brookside Mills, Knox County, TN

    EPA Pesticide Factsheets

    Brookside Mills, located in Knox County, TN, was a textile mill that was founded in 1885 and at its peak employed over 1,000 people. Its former uses included fabric weaving, dying, and sewing operations. It was at some point a department store, and during a portion of its history, coal was used as an energy source. Weaving operations continued in some form at the Brookside factory until 1969. In 1996 the buildings were demolished.

  3. Optics of Spider Sticky Orb Webs

    DTIC Science & Technology

    2011-01-01

    silks of Australian orb web weaving spiders . Studies of both 1. REPORT DATE (DD-MM-YYYY) 4. TITLE AND SUBTITLE 06-10-2011 13. SUPPLEMENTARY NOTES The...thin film effects as the primary causes. We report systematic studies carried out using the silks of Australian orb web weaving spiders . Studies of... spiders . Studies of both white light and laser light scattering/propagation by natural spider silks have definitively determined the primary cause

  4. Antenna Patterns from Single Slots in Carbon Fibre Reinforced Plastic Waveguides

    DTIC Science & Technology

    2010-02-01

    manufactured from carbon fibre reinforced plastic (CFRP), specifically T650/F584 plain weave fabric prepreg . This cross-section is the same as that...sandwich panels Attenuation losses in waveguides manufactured from metal and typical CFRP prepregs (AS4/3501-6 and IM7/5250-4 unidirectional tape, and...CFRP waveguides were manufactured from Hexcel T650/F584 plain weave carbon/epoxy prepreg , with a [45 -45]s stacking sequence, in accordance with the

  5. The Prospects for Modernizing Soviet Industry.

    DTIC Science & Technology

    1990-01-01

    condi- tions under which weaving occurred in their plants. However, the manufacture of textiles is, in fact, one instance where it is possible to use... weaving plant. A Soviet textile producer may not be allowed even this simple expedient to use the new shuttleless looms more effectively. Delivery...system than appears likely at this time. ISteven W. Popper, Modernizing the Soviet Textile Industry: Implications for Peres- troika, R-3779, October

  6. Electrooptic Crystal Growth and Properties

    DTIC Science & Technology

    1994-02-04

    the Applications of Ferroelectnics. ISAF 󈨠, Greenville, SC, 374 (1993). 9. A . M . Gadalla , Texas A & M University, unpublished results (1991). 10. B. D...TEES) for this work; Grant no. NAGW- 1194. We express our sincere thanks to Dr. A . M . Gadalla for the DTA and TGA expreiments. We also express our...AD-A276 023 *Texs Eginerin Exprimnt Satin Th Teas AM U Ivers I ity IIIII !11111 IilI li "*Texas Engineering Experiment Station The Texas A & M

  7. Optimisation of Fabric Reinforced Polymer Composites Using a Variant of Genetic Algorithm

    NASA Astrophysics Data System (ADS)

    Axinte, Andrei; Taranu, Nicolae; Bejan, Liliana; Hudisteanu, Iuliana

    2017-03-01

    Fabric reinforced polymeric composites are high performance materials with a rather complex fabric geometry. Therefore, modelling this type of material is a cumbersome task, especially when an efficient use is targeted. One of the most important issue of its design process is the optimisation of the individual laminae and of the laminated structure as a whole. In order to do that, a parametric model of the material has been defined, emphasising the many geometric variables needed to be correlated in the complex process of optimisation. The input parameters involved in this work, include: widths or heights of the tows and the laminate stacking sequence, which are discrete variables, while the gaps between adjacent tows and the height of the neat matrix are continuous variables. This work is one of the first attempts of using a Genetic Algorithm (GA) to optimise the geometrical parameters of satin reinforced multi-layer composites. Given the mixed type of the input parameters involved, an original software called SOMGA (Satin Optimisation with a Modified Genetic Algorithm) has been conceived and utilised in this work. The main goal is to find the best possible solution to the problem of designing a composite material which is able to withstand to a given set of external, in-plane, loads. The optimisation process has been performed using a fitness function which can analyse and compare mechanical behaviour of different fabric reinforced composites, the results being correlated with the ultimate strains, which demonstrate the efficiency of the composite structure.

  8. Modeling yarn slip in woven fabric at the continuum level: Simulations of ballistic impact

    NASA Astrophysics Data System (ADS)

    Parsons, Ethan M.; King, Michael J.; Socrate, Simona

    2013-01-01

    Woven fabric is used in a wide variety of military and commercial products—both in neat form and as the reinforcement phase of composites. In many applications, yarn slip, the relative sliding of the yarns composing the weave, is an important mode of deformation or failure. Yarn slip can significantly change the energy absorption capacity and yarn density of the fabric and also cause yarns to unravel from the weave. Virtually all existing models for woven fabric that allow yarn slip are discrete in nature. They simulate every yarn in the weave and are therefore computationally expensive and difficult to integrate with other material models. A promising alternative to discrete models is the mesostructure-based continuum technique. With this technique, homogenized continuum properties are determined from a deforming analytic model of the fabric mesostructure at each material point. Yarn-level mechanisms of deformation are thus captured without the computational cost of simulating every yarn in the fabric. However, existing mesostructure-based continuum models treat the yarns as pinned together at the cross-over points of the weave, and an operative model that allows yarn slip has not been published. Here, we introduce a mesostructure-based continuum model that permits yarn slip and use the model to simulate the ballistic impact of woven fabric. In our approach, the weave is the continuum substrate on which the model is anchored, and slip of the yarns occurs relative to the weave continuum. The cross-over points of the weave act as the material points of the continuum, and the evolution of the local weave mesostructure at each point of the continuum is represented by state variables. At the same time, slip velocity fields simulate the slip of each yarn family relative to the weave continuum and therefore control the evolution of the yarn pitch. We found that simulating yarn slip significantly improves finite element predictions of the ballistic impact of a Kevlar

  9. The effect of woven and non-woven fiber structure on mechanical properties polyester composite reinforced kenaf

    NASA Astrophysics Data System (ADS)

    Ratim, S.; Bonnia, N. N.; Surip, S. N.

    2012-07-01

    The effects of woven and non-woven kenaf fiber on mechanical properties of polyester composites were studied at different types of perform structures. Composite polyester reinforced kenaf fiber has been prepared via hand lay-up process by varying fiber forms into plain weave, twill and mats structure. The reinforcing efficiency of different fiber structure was compared with control of unreinforced polyester sample. It was found that the strength and stiffness of the composites are largely affected by fiber structure. A maximum value for tensile strength of composite was obtained for twill weave pattern of fiber structure while no significant different for plain weave and mat structure. The elastic modulus of composite has shown some improvement on plain and twill weave pattern. Meanwhile, lower value of modulus elasticity achieved by mats structure composite as well as control sample. The modulus of rupture and impact resistance were also analyzed. The improvement of modulus of rupture value can be seen on plain and twill weave pattern. However impact resistance doesn't show significant improvement in all types of structure except for mat fiber. The mechanical properties of kenaf fiber reinforced polyester composite found to be increased with woven and non-woven fiber structures in composite.

  10. A sustainable slashing industry using biodegradable sizes from modified soy protein to replace petro-based poly(vinyl alcohol).

    PubMed

    Zhao, Yi; Zhao, Yuzhu; Xu, Helan; Yang, Yiqi

    2015-02-17

    Biodegradable sizing agents from triethanolamine (TEA) modified soy protein could substitute poly(vinyl alcohol)(PVA) sizes for high-speed weaving of polyester and polyester/cotton yarns to substantially decrease environmental pollution and impel sustainability of textile industry. Nonbiodegradable PVA sizes are widely used and mainly contribute to high chemical oxygen demand (COD) in textile effluents. It has not been possible to effectively degrade, reuse or replace PVA sizes so far. Soy protein with good biodegradability showed potential as warp sizes in our previous studies. However, soy protein sizes lacked film flexibility and adhesion for required high-speed weaving. Additives with multiple hydroxyl groups, nonlinear molecule, and electric charge could physically modify secondary structure of soy protein and lead to about 23.6% and 43.3% improvement in size adhesion and ability of hair coverage comparing to unmodified soy protein. Industrial weaving results showed TEA-soy protein had relative weaving efficiency 3% and 10% higher than PVA and chemically modified starch sizes on polyester/cotton fabrics, and had relative weaving efficiency similar to PVA on polyester fabrics, although with 3- 6% lower add-on. In addition, TEA-soy sizes had a BOD5/COD ratio of 0.44, much higher than 0.03 for PVA, indicating that TEA-soy sizes were easily biodegradable in activated sludge.

  11. Transport properties of ceramic composites

    SciTech Connect

    Starr, T.L.

    1995-08-01

    This project involves experimental and modeling investigation of the transport properties of chemical vapor infiltration (CVI) preforms and densified composites, with particular emphasis on gas permeability and mass diffusivity. The results of this work will be useful both for on-going CVI process development and for evaluation and optimization of composite materials for fossil energy applications. With preforms made with 500 filaments/tow Nicalon at 40 vol% fiber loading, permeability values are similar for square-weave cloth layup and 3-D weave at low density. At greater densification the 3-D weave permeability is lower and approaches zero with significantly more closed porosity than the cloth layup. For filament wound preforms we were unable to make reliable measurements with the available materials. A model for gas transport in these materials utilizes percolation theory concepts. The ultimate achievable density is related to the closing of a continuous gas path through the preform. As the density approaches this limit the gas permeability and diffusivity vanish exponentially. The value of this limit is controlled primarily by the preform fiber architecture. The observed difference between the cloth layup and 3-D weave materials is due to the larger pores at tow crossing points found in the 3-D weave.

  12. Woven fiber optics.

    PubMed

    Schmidt, A C; Courtney-Pratt, J S; Ross, E A

    1975-02-01

    In this paper we describe how the art of weaving can be applied to fiber optics in order to produce precisely controlled reproducible image guides and image dissectors. As examples of the types of device for which woven fiber optics are applicable, we describe a 3:1 interleaver for use with a cathode-ray tube to produce color images, and a high speed alpha numeric output device. The techniques of weaving fiber optics are discussed in sufficient detail in order to allow for further work. Although, in principle, one might be able to weave glass optical fibers, all the work described here made use of plastic optical fibers 0.25 mm in diameter.

  13. The effect of fiber architecture on the mechanical properties of carbon/carbon fiber composites

    SciTech Connect

    Neumeister, J.; Jansson, S.; Leckie, F.

    1996-02-01

    The mechanical performance of carbon-fiber matrix composites with different fiber architectures is investigated for various loading modes. All the composites were fabricated from nominally equal constituents and identical consolidation processes, leaving as the only variables, the variations caused by the different fiber weave structures. The fiber architecture drastically affects both composite strength and deformation characteristics. Some systems are almost linear up to a final brittle failure while others exhibit a pronounced non-linearity prior to failure. It is found that the composite tensile strength is dictated by both fiber volume and fraction and weave architecture. The weaving can have a beneficial effect in spite of introducing new fiber flaws and stress concentrations, because it causes the composite to be less flaw sensitive. These features are addressed analytically by considering the statistical aspects of the fiber strength and the formation of critical defects.

  14. Thermal blanket insulation for advanced space transportation systems

    NASA Technical Reports Server (NTRS)

    Pusch, Richard H.

    1985-01-01

    The feasibility of weaving Nextel ceramic and Nicalon silicon carbide yarns into integrally woven, three dimensional fluted core fabrics was demonstrated. Parallel face fabrics joined with woven fabric ribs to form triangular cross section flutes between the faces were woven into three single and one double layer configuration. High warp yarn density in the double layer configuration caused considerable yarn breakage during weaving. The flutes of all four fabrics were filled with mandrels made from Q-Fiber Felt and FRCI-20-12 to form candidate insulation panels for advanced Space Transportation Systems. Procedures for preparing and inserting the mandrels were developed. Recommendations are made on investigating alternate methods for filling the flutes with insulation, and for improving the weaving of these types of fabrics.

  15. Hemp reinforced composites: surface treatment, manufacturing method and fabric type effects

    SciTech Connect

    Cicala, G.; Cristaldi, G.; Recca, G.

    2010-06-02

    Hemp mats and weaved fabrics were used as received and after surface treatment as reinforcement for composites. Mercerization and amino silane surface treatments improved fibre/matrix adhesion and, as results, the mechanical properties of the composites were also improved. However, if surface treatment was too severe degradation of the mechanical properties of the single fibre was observed and this resulted in a reinforcing efficiency loss. Weaved fabrics obtained from twisted fibres in unidirectional and 0/90 deg. architecture were used. The use of weaved fabrics lead to high improvements of composite mechanical properties despite the absence of fibre's surface treatment. The specimens manufactured by LRTM (Light Resin Transfer Moulding) showed enhanced mechanical properties compared to specimens made by hand lay up. Mechanical models were also used to predict the mechanical properties of the composites.

  16. Influence of Fibre Architecture on Impact Damage Tolerance in 3D Woven Composites

    NASA Astrophysics Data System (ADS)

    Potluri, P.; Hogg, P.; Arshad, M.; Jetavat, D.; Jamshidi, P.

    2012-10-01

    3D woven composites, due to the presence of through-thickness fibre-bridging, have the potential to improve damage tolerance and at the same time to reduce the manufacturing costs. However, ability to withstand damage depends on weave topology as well as geometry of individual tows. There is an extensive literature on damage tolerance of 2D prepreg laminates but limited work is reported on the damage tolerance of 3D weaves. In view of the recent interest in 3D woven composites from aerospace as well as non-aerospace sectors, this paper aims to provide an understanding of the impact damage resistance as well as damage tolerance of 3D woven composites. Four different 3D woven architectures, orthogonal, angle interlocked, layer-to-layer and modified layer-to-layer structures, have been produced under identical weaving conditions. Two additional structures, Unidirectional (UD) cross-ply and 2D plain weave, have been developed for comparison with 3D weaves. All the four 3D woven laminates have similar order of magnitude of damage area and damage width, but significantly lower than UD and 2D woven laminates. Damage Resistance, calculated as impact energy per unit damage area, has been shown to be significantly higher for 3D woven laminates. Rate of change of CAI strength with impact energy appears to be similar for all four 3D woven laminates as well as UD laminate; 2D woven laminate has higher rate of degradation with respect to impact energy. Undamaged compression strength has been shown to be a function of average tow waviness angle. Additionally, 3D weaves exhibit a critical damage size; below this size there is no appreciable reduction in compression strength. 3D woven laminates have also exhibited a degree of plasticity during compression whereas UD laminates fail instantly. The experimental work reported in this paper forms a foundation for systematic development of computational models for 3D woven architectures for damage tolerance.

  17. Woven TPS Mechanical Property Evaluation

    NASA Technical Reports Server (NTRS)

    Gonzales, Gregory Lewis; Kao, David Jan-Woei; Stackpoole, Margaret M.

    2013-01-01

    Woven Thermal Protection Systems (WTPS) is a relatively new program funded by the Office of the Chief Technologist (OCT). The WTPS approach to producing TPS architectures uses precisely engineered 3-D weaving techniques that allow tailoring material characteristics needed to meet specific mission requirements. A series of mechanical tests were performed to evaluate performance of different weave types, and get a better understanding of failure modes expected in these three-dimensional architectures. These properties will aid in material down selection and guide selection of the appropriate WTPS for a potential mission.

  18. Comparative Studies on the Mechanical Properties of Nonwoven- and Woven-Flax-Fiber-Reinforced Poly(Butylene Adipate-Co-Terephthalate)-Based Composite Laminates

    NASA Astrophysics Data System (ADS)

    Phongam, N.; Dangtungee, R.; Siengchin, S.

    2015-03-01

    Textile biocomposites made from woven- and nonwoven-flax-fiber-reinforced poly(butylene adipate-co-terephthalate) (PBAT) were prepared by compression molding using the film stacking method, and their tensile strength and stiffness, flexural strength and modulus, and impact strength were determined experimentally. The PBAT-based composites were subjected to water absorption tests. The mechanical properties of pure PBAT and the textile composites were compared, and the influence of flax weave styles on the properties were evaluated. The biocomposite reinforced with 4 × 4-plain weave fibers showed the highest strength and stiffness compared with those of the other textile biocomposites and pure PBAT.

  19. A model for frictional slip in woven fabrics

    NASA Astrophysics Data System (ADS)

    Nadler, Ben; Steigmann, David J.

    2003-12-01

    A continuum model for frictional slip of the yarns of a plain-weave fabric is presented. The model is based on the assumption that the weave is composed of two families of continuously distributed yarns constrained at all times to occupy a common evolving surface in three-dimensional space. The two families may slide relative to one another on the surface, subject to their respective equations of motion, fiber constitutive equations, and frictional slip rules. The theory is intended for the quantitative analysis of deformation, slip and energy dissipation during a ballistic impact event. To cite this article: B. Nadler, D.J. Steigmann, C. R. Mecanique 331 (2003).

  20. Effect of Architecture on the Resistivity of Carbon Fiber Polymer Composites

    NASA Technical Reports Server (NTRS)

    Gaier, James R.; Opaluch, Amanda

    2005-01-01

    The electrical resistivity of carbon fiber laminar composites can be tailored by weave direction, fiber composition, resin composition, applied pressure, and fiber fraction. Although the weave direction was only found to be important in the case of high aspect ratio composites, the other factors were found to influence the resistivity generally. Most intriguing, the resistivity of composites with lamina of different fiber compositions follows a parallel resistor model. This opens the door for higher performance, lower cost composites to be fabricated from these mixed fiber composites.

  1. Triaxial Fabrics

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Gentax Corporation's triaxal fabrics are woven from three separate yarn sets whose intersections form equilateral triangles. This type of weave, derived from space shuttle pressure suits, assures practically equal strength in every direction; has essentially no bias, or weak dimension offering greater resistance to tear and shear along with significant weight reduction. Applications of the Triax line include inflatable equipment, life vests, aircraft evacuation slides, helicopter flotation devices, tension structures, safety clothing and sailcloth for boats. Ability to accept compound curvatures with no distortion of the weave configuration makes it useful in manufacturing molded composites.

  2. Psychological Evaluation of Frisky Robot Motion

    NASA Astrophysics Data System (ADS)

    Hashimoto, Hiroshi; Takeda, Daisuke; Ohyama, Yasuhiro; Ishii, Chiharu; Niitsuma, Mihoko; Hashimoto, Hideki

    This paper describes the emotional evaluation of a frisky robot that weaves around its human owner; the evaluation is based on the SD (Semantic Differential) method and the RRV(R-R wave variance) method using electrocardiograms (ECG) as the biosignal source. The SD method is effective to measure emotion, and the RRV method is suitable for investigating the physiological state from the heartbeat. The SD method shows that humans show a significant response only when the robot weaves, not when it simply shadows the human. Furthermore, we revealed that these methods are correlated which suggests that the RRV method supports real time evaluation.

  3. Development of 3D Woven Ablative Thermal Protection Systems (TPS) for NASA Spacecraft

    NASA Technical Reports Server (NTRS)

    Feldman, Jay D.; Ellerby, Don; Stackpoole, Mairead; Peterson, Keith; Venkatapathy, Ethiraj

    2015-01-01

    The development of a new class of thermal protection system (TPS) materials known as 3D Woven TPS led by the Entry Systems and Technology Division of NASA Ames Research Center (ARC) will be discussed. This effort utilizes 3D weaving and resin infusion technologies to produce heat shield materials that are engineered and optimized for specific missions and requirements. A wide range of architectures and compositions have been produced and preliminarily tested to prove the viability and tailorability of the 3D weaving approach to TPS.

  4. Musculoskeletal problems in Iranian hand-woven carpet industry: guidelines for workstation design.

    PubMed

    Choobineh, Alireza; Hosseini, Mostafa; Lahmi, Mohammadali; Khani Jazani, Reza; Shahnavaz, Houshang

    2007-09-01

    Long hours of static work with awkward posture at traditionally designed looms can cause high prevalence of musculoskeletal disorders (MSDs) among carpet weavers. A comprehensive study was conducted in this industry with the objectives of determination of MSDs symptoms prevalence; identification of major factors associated with MSDs symptoms in carpet weaving occupation; and development of guidelines for weaving workstation design. In the present paper, this ergonomics study is presented. The study consisted of two phases. In the first phase, MSDs symptoms in nine Iranian provinces were surveyed by questionnaire among 1439 randomly selected weavers. Working posture and weaving workstations were ergonomically assessed as well. The results of this phase revealed that symptoms from the musculoskeletal system occurred in high rate among weavers with the prevalence significantly higher than that of the general Iranian population (P<0.001). It was found that the majority of ergonomics shortcomings originated from ill-designed weaving workstation. Based on the findings, some general guidelines for workstation design were presented. In the second phase, considering the general guidelines, an adjustable workstation was designed and constructed. To develop quantitative guidelines for optimizing workstation set-up, in the laboratory, nine sets of experimental conditions were tested, and working posture and weavers' perceptions were measured. The results of this lab work showed that working posture was acceptable for both the researchers and the weavers when the weaving height was adjusted 20 cm above the elbow height and a high seat with forward slope was used. By combining the results of the two phases, guidelines for weaving workstation design were presented. In this ergonomics-oriented workstation, loom is vertical. Seat, loom and weaving heights are adjustable. There is enough leg room under the loom. The seat with 10 degrees forward slope is adjusted 15 cm above the

  5. Noise levels and hearing ability of female workers in a textile factory in Vietnam.

    PubMed

    Nguyen, A L; Nguyen, T C; Van, T L; Hoang, M H; Nguyen, S; Jonai, H; Villanueva, M B; Matsuda, S; Sotoyama, M; Sudo, A

    1998-01-01

    Noise and hearing ability profiles were determined in a textile factory in Vietnam. Noise mapping done in the weaving section showed that the noise levels exceeded the Vietnamese standard of 90 dBA by as much as 9 dBA in some areas. Audiometric tests performed on 69 female workers from the weaving section revealed that workers with more than 10 years of noise exposure had the worst hearing threshold levels at 1,000 and 4,000 Hz. Similar findings were observed for workers greater than 35 years old. The 4,000 Hz notch, suggestive of exposure to intense noise, was noted in the audiograms of 26 subjects.

  6. Ultrasonic Air-Coupled Inspection of Textile Materials Using Ferroelectret-Based Phased Arrays

    NASA Astrophysics Data System (ADS)

    Ealo, J.; Camacho, J.; Seco, F.; Fritsch, C.

    2010-02-01

    Most common defects in textile manufacturing processes include weaving errors (such as missing threads), oil spots and material inhomogeneities. In this work, we demonstrate the feasibility of using ferroelectret-based transducers for the inspection of woven material. A linear array of 32 elements was built for this purpose following an easy fabrication procedure recently proposed. Electronic focusing at the textile sample position allowed us to detect weaving errors and oil spots of up to ˜1 mm of width in through transmission mode, at normal incidence and with a good signal-to-noise ratio.

  7. Polymer infiltration studies

    NASA Technical Reports Server (NTRS)

    Marchello, Joseph M.

    1991-01-01

    Progress was made on the preparation of carbon fiber composites using advanced polymer resins. Processes reported include powder towpreg process, weaving towpreg made from dry powder prepreg, composite from powder coated towpreg, and toughening of polyimide resin (PMR) composites by semi-interpenetrating networks. Several important areas of polymer infiltration into fiber bundles will be researched. Preparation to towpreg for textile preform weaving and braiding and for automated tow placement is a major goal, as are the continued development of prepregging technology and the various aspects of composite part fabrication.

  8. Damage and failure mechanisms of a 3-directional carbon/carbon composite under uniaxial tensile and shear loads

    SciTech Connect

    Siron, O.; Lamon, J.

    1998-11-20

    The mechanical behavior of a three-directional carbon/carbon (C/C) composite under tensile and shear loads is investigated in relation with the failure mechanisms and, the fiber architecture. This three-directional C/C composite was produced by Chemical Vapor Infiltration of a needled fiber preform of multiple layers of satin woven tows. The C/C composite exhibited several interesting features including an essentially non-linear stress-strain behavior and permanent deformations. Three families of matrix cracks were identified under tensile and shear loads, including microcracks in the tows, intertow delamination and cracks across the longitudinal tows. It was found that the delamination cracks affect preponderantly the stress-strain behavior and the mechanical properties. Similar features in the mechanical behavior and the failure mechanisms were highlighted under tension and under shear loading.

  9. Filler/ Polycarbosilane Systems as CMC Matrix Precursors

    NASA Technical Reports Server (NTRS)

    Hurwitz, Frances I.

    1998-01-01

    Pyrolytic conversion of polymeric precursors to ceramics is accompanied by loss of volatiles and large volume changes. Infiltration of a low viscosity polymer into a fiber preform will fill small spaces within fiber tows by capillary forces, but create large matrix cracks within large, intertow areas. One approach to minimizing shrinkage and reducing the number of required infiltration cycles is to use particulate fillers. In this study, Starfire allylhydridopolycarbosilane (AHPCS) was blended with a silicon carbide powder, with and without dispersant, using shear mixing. The polymer and polymer/particle interactions were characterized using nuclear magnetic resonance, differential scanning calorimetry, thermogravimetric analysis and rheometry. Polymer/particulate slurries and suspensions were used to infiltrate a figidized preform of an eight ply five harness satin CG Nicalon fiber having a dual layer BN/SiC interface coating, and the resulting composites characterized by optical and scanning electron microscopy.

  10. Final matches of the FIRST regional robotic competition at KSC

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Student teams behind protective walls operate remote controls to maneuver their robots around the playing field during the 1999 FIRST Southeastern Regional robotic competition held at KSC. The robotic gladiators spent two minutes each trying to grab, claw and hoist large, satin pillows onto their machines. Teams played defense by taking away competitors' pillows and generally harassing opposing machines. On the side of the field are the judges, including (far left) Deputy Director for Launch and Payload Processing Loren Shriver and former KSC Director of Shuttle Processing Robert Sieck. A giant screen TV displays the action on the field. The competition comprised 27 teams, pairing high school students with engineer mentors and corporations. The FIRST robotics competition is designed to provide students with a hands-on, inside look at engineering and other professional careers.

  11. Final matches of the FIRST regional robotic competition at KSC

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Watching the 1999 FIRST Southeastern Regional robotic competition held at KSC are (left to right) FIRST representative Vince Wilczynski and Executive Director of FIRST David Brown, Center Director Roy Bridges, former KSC Director of Shuttle Processing Robert Sieck (pointing), and astronaut David Brown. FIRST is a nonprofit organization, For Inspiration and Recognition of Science and Technology. The competition comprised 27 teams, pairing high school students with engineer mentors and corporations. Brown and Sieck served as judges for the event that pits gladiator robots against each other in an athletic-style competition. Powered by 12-volt batteries and operated by remote control, the robotic gladiators spend two minutes each trying to grab, claw and hoist large, satin pillows onto their machines. Teams play defense by taking away competitors' pillows and generally harassing opposing machines. The FIRST robotics competition is designed to provide students with a hands-on, inside look at engineering and other professional careers.

  12. Final matches of the FIRST regional robotic competition at KSC

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Four robots vie for position on the playing field during the 1999 FIRST Southeastern Regional robotic competition held at KSC. Powered by 12-volt batteries and operated by remote control, the robotic gladiators spent two minutes each trying to grab, claw and hoist large, satin pillows onto their machines. Student teams, shown behind protective walls, play defense by taking away competitors' pillows and generally harassing opposing machines. Two of the robots have lifted their caches of pillows above the field, a movement which earns them points. Along with the volunteer referees, at the edge of the playing field, judges at right watch the action. FIRST is a nonprofit organization, For Inspiration and Recognition of Science and Technology. The competition comprised 27 teams, pairing high school students with engineer mentors and corporations. The FIRST robotics competition is designed to provide students with a hands-on, inside look at engineering and other professional careers.

  13. Preliminary study to establish a relationship between tactile sensation and surface roughness.

    PubMed

    Ando, M; Eckert, G J; Zero, D T

    2010-01-01

    This study evaluated the ability of tactile sensations to distinguish roughness. Five examiners experienced in visual examination participated. Tactile sensation was assessed by 3 standard references, the average roughnesses 0.49, 0.92 and 1.54 mum. The examiners evaluated the roughness using 2 different ends of sharp explorers (TU 17 SE and 23 SE), each with 2 different handles (Standard Handle and No. 6 Handle-Satin Steel), and 1 WHO probe using a 5-point response score. The examiners performed 3 evaluations to establish repeatability. Using the 23 SE explorer with the steel handle was the best option to distinguish between 3 roughnesses (p < 0.05). The intraexaminer intraclass correlation coefficients (ICC) were between 0.90 and 0.98, but the interexaminer ICC were only between 0 and 0.04, indicating that, although trained examiners could repeat their own scores, they were not consistent with each other in grading roughness.

  14. Graphite/Polyimide Composites Subjected to Biaxial Loads at Elevated Temperatures

    NASA Technical Reports Server (NTRS)

    Kumosa, Maciej S.; Sutter, J. K.

    2007-01-01

    First, we will review our most important research accomplishments from a five year study concerned with the prediction of mechanical properties of unidirectional and woven graphite/polyimide composites based on T650-35, M40J and M60J fibers embedded in either PMR-15 or PMR-II-50 polyimide resins. Then, an aging model recently developed for the composites aged in nitrogen will be proposed and experimentally verified on an eight harness satin (8HS) woven T650-35/PMR-15 composite aged in nitrogen at 315 C for up to 1500 hours. The study was supported jointly between 1999 and 2005 by the AFOSR, the NASA Glenn Research Center, and the National Science Foundation.

  15. Evaluating Evaporation with Satellite Thermal Data.

    DTIC Science & Technology

    1987-11-01

    satin11±m - mitted tuml Jbiftwe zadatcu mn a zopiar bmis oww =% of tho 9, Is wzam tvputin is &cmqi~n by th rat =u:pwt Of -ftm tho VOW OZfa to tt ~e. vmW f...Bay Monthly Evaporation at Tefferablre = 200C Epa = -10.819 + 1.416(20) = 17.501 E’I lake - (17.501) (0.7) (0.95) = 116 Eae= -6.709 + 0.917 (20) =1.3...Bear River Bay Day-Before Average Evaporation at Telperatiure =20 0 C Epa = -0.386 + 0.056(20) - 0.734 E ake (0.734) (0.7) (0.95) = 0.49~1 =lk -0.266

  16. Female preferences drive the evolution of mimetic accuracy in male sexual displays.

    PubMed

    Coleman, Seth William; Patricelli, Gail Lisa; Coyle, Brian; Siani, Jennifer; Borgia, Gerald

    2007-10-22

    Males in many bird species mimic the vocalizations of other species during sexual displays, but the evolutionary and functional significance of interspecific vocal mimicry is unclear. Here we use spectrographic cross-correlation to compare mimetic calls produced by male satin bowerbirds (Ptilonorhynchus violaceus) in courtship with calls from several model species. We show that the accuracy of vocal mimicry and the number of model species mimicked are both independently related to male mating success. Multivariate analyses revealed that these mimetic traits were better predictors of male mating success than other male display traits previously shown to be important for male mating success. We suggest that preference-driven mimetic accuracy may be a widespread occurrence, and that mimetic accuracy may provide females with important information about male quality. Our findings support an alternative hypothesis to help explain a common element of male sexual displays.

  17. Finding the Cracks: Progressive, Democratic Education in an Era of Standardization

    ERIC Educational Resources Information Center

    Elliott, Shanti; Bradbury, Joan; Gardner, Joseph

    2014-01-01

    In the spring of 2014, Chicago educators met to reflect on the opportunities and challenges for progressive, democratic education in Chicago-area schools. This article weaves together the writings of teachers and principals from over 15 public schools and a couple of private and parochial schools who are thinking about their own experiences in…

  18. New Paper Words: Historical Images of Navajo Literacy.

    ERIC Educational Resources Information Center

    Lockard, Louise

    1996-01-01

    Weaves a Navajo elementary teacher's anecdotes from her own and her father's educational experiences with archival materials to provide a historical context for Navajo literacy. Discusses early written Navajo; the role of schools and churches in the expansion of written Navajo; and the advancement of Navajo linguistics during John Collier's…

  19. Thermal insulation blanket material

    NASA Technical Reports Server (NTRS)

    Pusch, R. H.

    1982-01-01

    A study was conducted to provide a tailorable advanced blanket insulation based on a woven design having an integrally woven core structure. A highly pure quartz yarn was selected for weaving and the cells formed were filled with a microquartz felt insulation.

  20. Enchanting Teachers among Us

    ERIC Educational Resources Information Center

    Richards, Jan

    2004-01-01

    The amazing power to enchant students often is a defining hallmark of great teachers. Enchanting teachers, those who make learning exciting and attractive, are all around, and each is effective and inspiring in his or her own unique way. Wonderful teachers generally weave their magic behind closed doors, however, where only their students can…

  1. Get 'Em outside

    ERIC Educational Resources Information Center

    Weise, Lisa

    2012-01-01

    There is a movement afoot in the nation--one that goes against the trend toward more testing, less recess, and too many standards to fit into the school day. This movement does not ignore standards; rather, it weaves the standards with the places and meanings that are ever-present outside of the classrooms. Place-based education connects students…

  2. 40 CFR 63.4281 - Am I subject to this subpart?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) National Emission Standards for Hazardous Air Pollutants: Printing, Coating, and Dyeing of Fabrics and... printing, coating, slashing, dyeing or finishing of fabric and other textiles, and it includes the... to provide abrasion resistance during weaving. (3) The dyeing and finishing subcategory includes...

  3. 40 CFR 63.4281 - Am I subject to this subpart?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) National Emission Standards for Hazardous Air Pollutants: Printing, Coating, and Dyeing of Fabrics and... printing, coating, slashing, dyeing or finishing of fabric and other textiles, and it includes the... to provide abrasion resistance during weaving. (3) The dyeing and finishing subcategory includes...

  4. 40 CFR 63.4281 - Am I subject to this subpart?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Standards for Hazardous Air Pollutants: Printing, Coating, and Dyeing of Fabrics and Other Textiles What..., slashing, dyeing or finishing of fabric and other textiles, and it includes the subcategories listed in... abrasion resistance during weaving. (3) The dyeing and finishing subcategory includes any operation...

  5. 40 CFR 63.4281 - Am I subject to this subpart?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) National Emission Standards for Hazardous Air Pollutants: Printing, Coating, and Dyeing of Fabrics and... printing, coating, slashing, dyeing or finishing of fabric and other textiles, and it includes the... to provide abrasion resistance during weaving. (3) The dyeing and finishing subcategory includes...

  6. 1. EXTERIOR VIEW OF HILLSIDE PLANT FROM INTERSECTION OF LINCOLN ...

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

    1. EXTERIOR VIEW OF HILLSIDE PLANT FROM INTERSECTION OF LINCOLN STREET AND 2ND AVENUE. HILLSIDE PLANT WAS BUILT AS CALLAWAY MILLS HILLSIDE COTTON MILL (PARK A. DALLIS, 1914-15). THIS TWO-STORY SECTION WAS BUILT AS A WEAVE SHED. - Hillside Cotton Mill, 1300 Brownwood Avenue, La Grange, Troup County, GA

  7. Improved linings for integrating spheres

    NASA Technical Reports Server (NTRS)

    Fergerson, P. O.; French, B. O.

    1970-01-01

    Sphere surface is covered with plain weave of glass fibers coated with polytetrafluoroethylene and one or two layers of magnesium oxide vapor. The resultant lining is suitable for measurement of radiation in the ultraviolet, visible, and near-infrared wavelengths, is not damage prone, and is easily cleaned.

  8. Understanding Early Childhood Mental Health: A Practical Guide for Professionals

    ERIC Educational Resources Information Center

    Summers, Susan Janko, Ed.; Chazan-Cohen, Rachel, Ed.

    2012-01-01

    Integrating infant mental health services into early education programs leads to better child outcomes and stronger parent-child relationships--the big question is how to do it appropriately and effectively. Clear answers are in this accessible textbook, created to prepare early childhood professionals and programs to weave best practices in…

  9. Transsexuals: Teaching Your Children

    ERIC Educational Resources Information Center

    Krywanczyk, Loren

    2010-01-01

    The main point the author hopes to impart in this article is how essential it is for educators to create an environment in classrooms where they and their students are comfortable talking about issues of gender. In order for this to happen, it is important to weave concepts of gender into the curricula and refrain from a tokenizing approach that…

  10. Identifying, Confronting and Disrupting Stereotypes: Role on the Wall in an Intergenerational LGBTQ Applied Theatre Project

    ERIC Educational Resources Information Center

    Houseal, Jennifer; Ray, Kevin; Teitelbaum, Sherry

    2013-01-01

    In New York City, LGBTQ people from different generations have had few opportunities to connect. They have splintered into age-segregated micro-communities, robbing them of opportunities to weave a common history and share strategies that community members have used to survive and thrive. "Bridging the Gap" was a community-based…

  11. Funds of Knowledge and Community Cultural Wealth: Exploring How Pre-Service Teachers Can Work Effectively with Mexican and Mexican American Students

    ERIC Educational Resources Information Center

    Saathoff, Stacy D.

    2015-01-01

    This article examines how pre-service teachers can work effectively with Mexican and Mexican American students. Using the foundation of funds of knowledge (González, Moll, & Amanti, 2005) and the critical race theory concept of community cultural wealth (Yosso, 2005), the article weaves together these ideas to discuss how they can be…

  12. A Rainbow of Threads

    ERIC Educational Resources Information Center

    Mack, Stevie

    2011-01-01

    In the highlands of Guatemala, the Maya Indians weave colorful, vibrant textiles. Many of these beautiful fabrics are used to make traditional clothing for the men, women, and children who live in the rural villages. In Mayan culture, dress is important for more than just keeping warm and covered. It serves as a sort of uniform that immediately…

  13. Representing Latino/a Culture in Introductory Spanish Textbooks.

    ERIC Educational Resources Information Center

    Elissondo, Guillermina

    This paper examines the kinds of visuals that Spanish language textbooks use to legitimize Latino/a culture, noting how different groups are presented and represented by the narratives; how ethnicity, class, gender, age, and sexual inclinations interplay with power relations, and what ideologies weave the textual fabric of foreign language books.…

  14. Meaningful confusions and confusing meanings in communication in schizophrenia

    PubMed Central

    Elvevåg, Brita; Wynn, Rolf; Covington, Michael A.

    2010-01-01

    Unconventional discourse in schizophrenia has been speculated to be attributable to the mixing up of symbols and signs. We illustrate how a series of scientific images, cartoons, and prose are used by a patient to weave disparate - and objectively unrelated -concepts. The resulting prose is incoherent science. PMID:20843559

  15. A Body of Writing, 1990-1999.

    ERIC Educational Resources Information Center

    Davies, Bronwyn

    This book weaves together some of the author's most influential writings of the 1990s to offer a unique engagement with poststructuralism that defies the boundaries between theory and embodied practice. The sophisticated and nuanced discussions of subjectivity, agency, epistemology, feminism, and power are embedded in vital depictions of life…

  16. Working with Corn: Two Conversations. Interview with Mohawk Midwife Katsi Cook in Her Home on June 6, 1992.

    ERIC Educational Resources Information Center

    Cornelius, Carol

    1992-01-01

    Presents interviews with a Mohawk midwife and an Onondaga chief concerning the importance of corn in Native American culture. Compares gestational cycle of corn to that of women. Describes the numerous uses of corn from eating and weaving. Explains how Native Americans and non-Native Americans can be taught about corn by incorporating art,…

  17. The Electronic FERPA: Access in the Digital Age

    ERIC Educational Resources Information Center

    McConahay, Mark; Hanson, Karen; West, Ann; Woodbeck, Dean

    2009-01-01

    On every college and university campus, common themes weave throughout identity and access management (IAM) and its relationship to Family Educational Rights and Privacy Act (FERPA). Institutions approach IAM differently as there is not a one-size-fits-all solution. Nevertheless, all face common elements. Over the past few years, a number of…

  18. Blurred Lines: The School Librarian and the Instructional Technology Specialist

    ERIC Educational Resources Information Center

    Johnston, Melissa P.

    2015-01-01

    "Empowering Learners: Guidelines for School Library Media Programs" (AASL, 2009) charges school librarians "to play a leading role in weaving such skills throughout the curriculum so that all members of the school community are effective users of ideas and information" (p. 46). Providing leadership in technology integration for…

  19. Troublemaker: The Education of Chester Finn

    ERIC Educational Resources Information Center

    Finn, Chester E., Jr.

    2008-01-01

    "Troublemaker," the memoir of "Education Next" senior editor and veteran education reformer Chester E. "Checker" Finn Jr., weaves into the chronicle of Finn's life and career the broader history of education reform, in which he has played a vital and sometimes rambunctious role. Currently president of the Thomas B.…

  20. Bearing Witness: Poetry by Teachers about Teaching.

    ERIC Educational Resources Information Center

    Hatcher, Margaret, Ed.

    The purpose of this poetry anthology is to create a positive inspirational yet realistic picture of teachers and the very challenging and complex contexts within which they "weave their magic in students' lives" and make contributions to the world. The anthology aims to show how teachers think and feel about teaching, learning, and their…

  1. Performing Narrative Medicine

    ERIC Educational Resources Information Center

    Langellier, Kristin M.

    2009-01-01

    In this article, the author weaves narrative medicine and performance together to consider what might it mean to call narrative medicine a performance. To name narrative medicine as performance is to recognize the texts and bodies, the stories and selves, that participate in its practice--patients' and physicians' embodied stories as well as the…

  2. "EMERGING" POLLUTANTS, AND COMMUNICATING THE SCIENCE OF ENVIRONMENTAL CHEMISTRY AND MASS SPECTROMETRY: PHARMACEUTICALS IN THE ENVIRONMENT

    EPA Science Inventory

    This paper weaves a rnulti-dimensioned perspective of mass spectrometry as a career against the backdrop of mass spectrometry's key role in the past and future of environmental chemistry. Along the way, some insights are offered for better focusing the spotlight on the discipline...

  3. Attitude and Passion: Becoming a Teacher in Early Childhood Education and Care

    ERIC Educational Resources Information Center

    Maier-Höfer, Claudia

    2015-01-01

    By focusing on a collective aesthetics based on sensation and affect, researchers, especially in Stockholm, Sweden, are exploring a pedagogy that opens up space for assemblages of desire, acknowledging the expressions of children who transform themselves and their milieus into a weave of bodies, spaces, signs and media. By analysing this pedagogy,…

  4. Measurement of gas transport through fiber preforms and densified composites for chemical vapor infiltration

    SciTech Connect

    Starr, T.L.; Hablutzel, N.

    1998-05-01

    Gas transport via pressure-driven permeation or via concentration-driven diffusion is a key step in the chemical vapor infiltration (CVI) process. This paper describes methods for the measurement of these properties for CVI preforms and partially infiltrated composites. Results are presented for Nicalon-fiber cloth layup preforms and composites, Nextel-fiber braid preforms and composites, and a Nicalon-fiber three-dimensional (3-D) weave composite. The permeability of Nicalon cloth layup preforms is strongly dependent on the packing density over the range of 29--40 vol% but is only weakly dependent on the orientation of the alternating cloth layers. The permeability of Nextel braid preforms is dependent on the thread count and the weight for cloths with similar construction and packing density. The gas permeability of the finer wave (6.3 tows/cm (16 tows/in.)) is approximately one-half that of the coarser weave (3.5 tows/cm (9 tows/in.)). Results are reported for a small number of infiltrated composites with Nextel fiber reinforcement. Attempts to mount a Nicalon-fiber 3-D weave preform specimen have been unsuccessful. Results for a small number of composite specimens with 3-D weave reinforcement are reported.

  5. Across the Curriculum: Hands-on Science [and] Math in Action [and] Social Studies Now.

    ERIC Educational Resources Information Center

    VanCleve, Janice; Burns, Marilyn; Lindquist, Tarry

    1997-01-01

    Three articles present elementary science, mathematics, and social studies activities. A hands-on science activity introduces students to microscopic water creatures. A math in action game has students build logic and number-sense skills. A social studies activity has students weave story cloths into conflict resolution. (SM)

  6. Laban Movement Analysis Approach to Classical Ballet Pedagogy

    ERIC Educational Resources Information Center

    Whittier, Cadence

    2006-01-01

    As a Certified Laban Movement Analyst and a classically trained ballet dancer, I consistently weave the Laban Movement Analysis/Bartenieff Fundamentals (LMA/BF) theories and philosophies into the ballet class. This integration assists in: (1) Identifying the qualitative movement elements both in the art of ballet and in the students' dancing…

  7. There-apy: The Use of Task, Imagery, and Symbolism To Connect the Inner and Outer Worlds.

    ERIC Educational Resources Information Center

    Eisenstein-Naveh, A. Rosa

    2001-01-01

    Presents a model of therapy called there-apy, which weaves together the use of task, symbolism, and imagery into an ongoing process. Concrete tasks take on symbolic meaning, and symbolism gets actualized through achieving concrete tasks. There-apy connects the individual's outside and inside worlds and often involves the partner or family in the…

  8. The hydroentanglement system of producing nonwoven fabrics of certain specific attributes and functionalities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although the traditional technologies and processes of producing fabric structures, via yarn spinning, weaving, knitting, lacing, tufting, or the like, continue to be the ‘major league’ players in textile manufacturing today, the modern hydroentanglement system, commonly known as “spunlacing,” has a...

  9. fibmeasure: Python/Cython module to find the center of back-illuminated optical fibers in metrology images

    NASA Astrophysics Data System (ADS)

    Gilbert, James

    2016-03-01

    fibmeasure finds the precise locations of the centers of back-illuminated optical fibers in images. It was developed for astronomical fiber positioning feedback via machine vision cameras and is optimized for high-magnification images where fibers appear as resolvable circles. It was originally written during the design of the WEAVE pick-and-place fiber positioner for the William Herschel Telescope.

  10. Molding Helmet Liners from Nylon Cloth Made from 1050 Denier Type 700 Nylon Yarns

    DTIC Science & Technology

    Helmet liners were satisfactorily molded from 14 ounce, 2 x 2 basket- weave nylon fabric made of 1050 denier, 168 filaments, 3 to 4 Z turns per inch...type 700 nylon yarn. These helmets liners satisfied the autoclave and the ballistics resistant requirements of Military Specification MIL-L-41800, Liner , Soldier’s Steel Helmet, 1 May 1961.

  11. Teaching as Jazz

    ERIC Educational Resources Information Center

    Tomlinson, Carol Ann; Germundson, Amy

    2007-01-01

    Tomlinson and Germundson compare teaching well to playing jazz well. Excellent teaching involves a blend of techniques and theory; expressiveness; syncopation; call and response, and, frequently, improvisation. Weaving in analogies to jazz, the authors delineate four elements of such teaching: curriculum that helps students connect to big ideas,…

  12. Risk-Taker, Role Model, Muse, and "Charlatan": Stories of Ellen--An Atypical Giant

    ERIC Educational Resources Information Center

    Connor, David J.

    2013-01-01

    This narrative essay weaves personal recollections of my encounters with Ellen Brantlinger and a sampling of her works that continue to exert a profound influence on my own thinking and writing within Disability Studies in Education. I begin by describing how, as a first-year doctoral student, I encountered the scholarly work of Ellen and…

  13. Higher Order Thinking in the Dance Studio

    ERIC Educational Resources Information Center

    Moffett, Ann-Thomas

    2012-01-01

    The author identifies higher order thinking as an essential component of dance training for students of all ages and abilities. Weaving together insights from interviews with experts in the field of dance education with practical pedagogical applications within an Improvisation and Composition class for talented and gifted youth, this article…

  14. 19 CFR 10.222 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...,” when used with reference to yarns, means that all of the production processes, starting with the... country, and, when used with reference to fabric(s), means that all of the production processes, starting... ending with a fabric by a weaving, knitting, needling, tufting, felting, entangling or other...

  15. 75 FR 45603 - Determination by the Department of Commerce on the Wholly Formed Requirement for Qualifying Woven...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-03

    ... definition of `qualifying woven fabric' to require that all production processes and finishing operations... woven fabric'' to require that all production processes and finishing operations, starting with weaving... definition of ``qualifying woven fabric'' to require that all production processes and finishing...

  16. Death, Murder, and Mayhem: Stories of Violence and Healing on the Plains

    ERIC Educational Resources Information Center

    Maher, Susan Naramore

    2009-01-01

    Unexpected, dramatic stories of death have left deep marks on the physical landscape and in the cultural psyche since humans first began to weave narrative from the Plains. When scholars and writers converged in Omaha, Nebraska for the 34th Interdisciplinary Symposium of the Center for Great Plains Center, many stories received scholarly and…

  17. When the Familiar Is Strange: Encountering the Cultural Politics of Hawaii in the College Classroom

    ERIC Educational Resources Information Center

    Tavares, Hannah M.

    2008-01-01

    Weaving feminist, psychoanalytic, and postcolonial strands of social criticism, I recount an incident that is emblematic of the complex arrangements or dispositions of space in the Pacific. The specific moment--an encounter in the college classroom where an entangled racial-ethnic-gender dynamic of identification surfaced--acts as a catalyst for…

  18. Discourses of Legitimacy: A Love Song to Our Mongrel Selves

    ERIC Educational Resources Information Center

    Filmer, Alice A.

    2009-01-01

    In an intervention that blurs methodological boundaries traditionally separating the researcher from the researched, history from poetry, and the personal from the political, the author weaves a narrative account of her Euro-American family's early history in California into a larger set of social and historical events taking place during the…

  19. Wisconsin's Model Academic Standards for Dance.

    ERIC Educational Resources Information Center

    Wisconsin State Dept. of Public Instruction, Madison.

    Wisconsin's Department of Public Instruction, in collaboration with Wisconsin citizens, developed academic standards in 12 curricular areas. The dance education standards go beyond emphasizing mastery of individual student areas--they weave five essential characteristics of literate individuals throughout: application of the basics, ability to…

  20. Let Me Do It: Children's Art with Less Stress and More Success.

    ERIC Educational Resources Information Center

    Spears, Jo Ann Lohl

    2002-01-01

    Offers suggestions for incorporating inexpensive art activities into early childhood classrooms. Suggests activities for children over 3 years in the areas of art using: paint and food coloring, drawing or scribbling, sculpture or construction, weaving and stitching, clay and dough, paper scraps, and broken crayons. Suggests craft activities for…

  1. Artificial intelligence and tutoring systems: Computational and cognitive approaches to the communication of knowledge

    SciTech Connect

    Wenger, E.

    1987-01-01

    Adopting the perspective of the communication of knowledge, the author addresses practical issues involved in designing instructional systems as well as theoretical questions raised by investigating computational methods of knowledge communication. By weaving together the goals, contributions, and fascinating challenges of intelligent tutoring system development, this book reveals the emergence of an important field.

  2. Waldorf Education: An Innovative Tradition.

    ERIC Educational Resources Information Center

    Harrington, Sheila

    1993-01-01

    Waldorf Schools represent the largest nonsectarian school movement in the world, shunning fads and technology and relying on the creative gifts of teachers and students. Studies include eurythmy, woodworking, weaving, and traditional academic subjects, and no commercial textbooks are used. Despite teacher/funding shortages, the system continues to…

  3. Helping the Homeless in School and out

    ERIC Educational Resources Information Center

    Holgersson-Shorter, Helena

    2010-01-01

    Homeless children can be hard to identify and even harder to help. But teachers can do a great deal to make sure that they do not fall through the cracks. Teachers of highly mobile students must develop the skills to make these children and youth feel welcome while quickly weaving them into classroom routines. They must rapidly assess new…

  4. Trajectories of At-Homeness and Health in Usual Care and Small House Nursing Homes

    ERIC Educational Resources Information Center

    Molony, Sheila L.; Evans, Lois K.; Jeon, Sangchoon; Rabig, Judith; Straka, Leslie A.

    2011-01-01

    Background: Long-term care providers across the United States are building innovative environments called "Green House" or small-house nursing homes that weave humanistic person-centered philosophies into clinical care, organizational policies, and built environments. Purpose: To compare and contrast trajectories of at-homeness and health over…

  5. Science Fair Report: Flight of the Split-Fingered Fastball.

    ERIC Educational Resources Information Center

    Mitchell, Richard J.

    1991-01-01

    Reports on the results of an eighth grade student's experiments, conducted with a moving car, concerning the aerodynamics of a baseball in flight. Describes the peculiar diving ability of the split-fingered fastball, as well as the dancing and weaving effect of the knuckleball. (JJK)

  6. 76 FR 48804 - Grants to Manufacturers of Certain Worsted Wool Fabrics

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-09

    ... HTS 9902.51.11 or HTS 9902.51.15 was woven by the applicant in 1999, 2000 and 2001; (4) the name and address of each plant or location in the United States where the applicant is weaving worsted wool fabrics... appropriate, woven in the United States in each of calendar years 1999, 2000 and 2001; and (6) the value...

  7. 10. View of the Monadnock Mills complex showing (left to ...

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

    10. View of the Monadnock Mills complex showing (left to right) Mill No. 3 (1892), the Weave Shed (1876), and Mill No. 2 (1853). The Office Building is visible in the foreground, with Mill No. 5 to its left. - Monadnock Mills, 15 Water Street, Claremont, Sullivan County, NH

  8. Inspired by Deschooling: An Appreciation of Ivan Illich.

    ERIC Educational Resources Information Center

    Spaventa, Lou

    2003-01-01

    Discusses the work and beliefs of Ivan Illich and how these have influenced one English-as-a-Second-Language teacher's and kept him thinking about his work as an educator. Uses Illich's favorite metaphor--that of weaving a web--to illustrate how he tries to find an interconnectedness between himself and each of his students. (Author/VWL)

  9. Rhetoric as Preventive Medicine: The Essays of E. M. Forster.

    ERIC Educational Resources Information Center

    McGuiness, Ilona M.

    Through the art of the essay, as conceived by E. M. Forster, Virginia Woolf and others, college readers and writers can play a role in the continual weaving of the fabric of civilization--not by delivering lessons, or sermons, or polemical arguments, but by participating in the essayistic dialogue about what comprises a healthy human community…

  10. Proceedings of the Annual Technology Literacy Conference. (7th, Alexandria, Virginia, February 6-9, 1992).

    ERIC Educational Resources Information Center

    Cheek, Dennis, Ed.

    The following papers are included in these proceedings: "Weaving Technology and Human Affairs" (B. Hazeltine); "Positivist and Constructivist Understandings about Science and Their Implications for STS Teaching and Learning" (B. Reeves; C. Ney); "A Modular Conceptual Framework for Technology and Work" (D. Blandow); "A Time of Uncertainty: The…

  11. Establishing a Framework for Quality

    ERIC Educational Resources Information Center

    Lehman, Kirby

    2006-01-01

    The Jenks School District applies a continuous improvement approach that focuses on academics, arts, activities, athletics and attitude, weaving in leadership, professional development, technology and data-based decision making to prepare all learners to be productive, responsible citizens. Since 1998, the Jenks School District has embraced a…

  12. A Critical Foundation for Bilingual Education

    ERIC Educational Resources Information Center

    Smith, Matthew David; Rodriguez, Arturo

    2011-01-01

    In this paper we weave lived experiences, those of a bilingual social studies teacher at a middle school in a large city in the Southwestern US, with critical theory/pedagogy and bilingual education. The purpose of this paper is to present an articulation of the practice of critical pedagogy in a bilingual educational context principally under the…

  13. "Green" School Programs. Research Brief

    ERIC Educational Resources Information Center

    Johnston, J. Howard

    2009-01-01

    What are "Green School" programs and how do they benefit students, teachers and the community? Green School programs seek to weave concepts of sustainability and environmental awareness into the social and academic culture of the school community. Green schools are high performance facilities that have been designed, built, renovated operated or…

  14. 13. Photocopy of engraving from History of Westchester County, Vol. ...

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

    13. Photocopy of engraving from History of Westchester County, Vol. 2, by J. Thomas Scharf, published by L.E. Preston & Company, Philadelphia, 1886 ALEXANDER SMITH AND SONS CARPET COMPANY, MOQUETTE MILLS, WEAVING MILLS, SPINNING AND PRINT MILLS - Moquette Row Housing, Moquette Row North & Moquette Row South, Yonkers, Westchester County, NY

  15. A Computational Lens on Design Research

    ERIC Educational Resources Information Center

    Hoyles, Celia; Noss, Richard

    2015-01-01

    In this commentary, we briefly review the collective effort of design researchers to weave theory with empirical results, in order to gain a better understanding of the processes of learning. We seek to respond to this challenging agenda by centring on the evolution of one sub-field: namely that which involves investigations within a…

  16. 1. EXTERIOR VIEW OF BOILER HOUSE FROM SOUTHWEST. THE BOILER ...

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

    1. EXTERIOR VIEW OF BOILER HOUSE FROM SOUTHWEST. THE BOILER HOUSE WAS USED FOR HEATING THE MILL; HYDRO-ELECTRIC POWER FOR PRODUCTION WAS PURCHASED FROM THE COLUMBUS LIGHT & POWER COMPANY. NORTH END OF 1924 MILL TO RIGHT, c. 1970 WINDOWLESS WEAVE ROOM ADDITION TO LEFT. - Stark Mill, Boiler House, 117 Corinth Road, Hogansville, Troup County, GA

  17. Language of Physics, Language of Math: Disciplinary Culture and Dynamic Epistemology

    ERIC Educational Resources Information Center

    Redish, Edward F.; Kuo, Eric

    2015-01-01

    Mathematics is a critical part of much scientific research. Physics in particular weaves math extensively into its instruction beginning in high school. Despite much research on the learning of both physics and math, the problem of how to effectively include math in physics in a way that reaches most students remains unsolved. In this paper, we…

  18. Poetry, Literacy, and Creativity: Fostering Effective Learning Strategies in an Urban Classroom

    ERIC Educational Resources Information Center

    Kinloch, Valerie F.

    2005-01-01

    In this essay, the author argues for a democratized way of developing a consciousness of differences by describing two abbreviated creative writing classroom experiences with urban sixth grade middle school students during the 2002-2003 academic year. She draws on Tony Medina's (2001) claim that poetry and writing weave people and worlds together…

  19. Handbook of Research on Literacy and Diversity

    ERIC Educational Resources Information Center

    Morrow, Lesley Mandel, Ed.; Rueda, Robert, Ed.; Lapp, Diane, Ed.

    2009-01-01

    This is the first research handbook to address all dimensions of diversity that have an impact on literacy achievement. Leading experts examine how teaching and learning intersect with cultural and language differences and socioeconomic disparities in today's increasingly diverse schools and communities. The volume weaves compelling research…

  20. Beyond the Core: Peer Observation Brings Common Core to Vocational and Electives Classes

    ERIC Educational Resources Information Center

    Thurber Rasmussen, Harriette

    2014-01-01

    This article describes how a Washington State School District increased professional learning around the Common Core State Standards. The challenge was how to establish a way for career and technical education and electives teachers to learn and apply Common Core in their classes. Weaving Common Core literacy standards into vocational and…