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Sample records for accessory glass fiber

  1. Oxynitride glass fibers

    NASA Technical Reports Server (NTRS)

    Patel, Parimal J.; Messier, Donald R.; Rich, R. E.

    1991-01-01

    Research at the Army Materials Technology Laboratory (AMTL) and elsewhere has shown that many glass properties including elastic modulus, hardness, and corrosion resistance are improved markedly by the substitution of nitrogen for oxygen in the glass structure. Oxynitride glasses, therefore, offer exciting opportunities for making high modulus, high strength fibers. Processes for making oxynitride glasses and fibers of glass compositions similar to commercial oxide glasses, but with considerable enhanced properties, are discussed. We have made glasses with elastic moduli as high as 140 GPa and fibers with moduli of 120 GPa and tensile strengths up to 2900 MPa. AMTL holds a U.S. patent on oxynitride glass fibers, and this presentation discusses a unique process for drawing small diameter oxynitride glass fibers at high drawing rates. Fibers are drawn through a nozzle from molten glass in a molybdenum crucible at 1550 C. The crucible is situated in a furnace chamber in flowing nitrogen, and the fiber is wound in air outside of the chamber, making the process straightforward and commercially feasible. Strengths were considerably improved by improving glass quality to minimize internal defects. Though the fiber strengths were comparable with oxide fibers, work is currently in progress to further improve the elastic modulus and strength of fibers. The high elastic modulus of oxynitride glasses indicate their potential for making fibers with tensile strengths surpassing any oxide glass fibers, and we hope to realize that potential in the near future.

  2. Glass fiber insulation

    SciTech Connect

    Griffith, E.J.; Ngo, T.M.

    1993-06-29

    A composition for a glass fiber insulation is described comprising a loose mat of glass fibers having at least a portion of the surface coated with a water insoluble, non-hygroscopic, amorphous aluminum phosphate polymer having a molar ratio of Al[sub 2]O[sub 3] to P[sub 2]O[sub 5] of less than 1 and providing a substantial thermal resistance.

  3. Containerless glass fiber processing

    NASA Technical Reports Server (NTRS)

    Ethridge, E. C.; Naumann, R. J.

    1986-01-01

    An acoustic levitation furnace system is described that was developed for testing the feasibility of containerless fiber pulling experiments. It is possible to levitate very dense materials such as platinum at room temperature. Levitation at elevated temperatures is much more difficult. Samples of dense heavy metal fluoride glass were levitated at 300 C. It is therefore possible that containerless fiber pulling experiments could be performed. Fiber pulling from the melt at 650 C is not possible at unit gravity but could be possible at reduced gravities. The Acoustic Levitation Furnace is described, including engineering parameters and processing information. It is illustrated that a shaped reflector greatly increases the levitation force aiding the levitation of more dense materials.

  4. Photochromic glass optical fiber

    NASA Astrophysics Data System (ADS)

    Alvi, Bilal A.; Israr, Amber; Asif, Muhammad; Aamir, Muhammad; Rehan, Muhammad

    2016-02-01

    This paper describes the fabrication and analysis of novel twin cored fiber which contains a transparent and silver halide doped photochromic core in same cladding. The Photochromic core fibers were fabricated in twin cored structure by rode and tube method. The diameter of photochromic core and transparent core is around 15 m. The distance between two cores is 1.5m. The transparent core was used to guide the probe beam and photochromic core was excited by UV source. The interaction of the probe beam with the excited photochromic core showed the photochromic behavior of the fiber.

  5. Containerless Manufacture of Glass Optical Fibers

    NASA Technical Reports Server (NTRS)

    Naumann, R. J.; Ethridge, E. C.

    1985-01-01

    Contamination and crystallization reduced in proposed process. Solid optical fiber drawn from an acoustically levitated lump of molten glass. New material added in solid form, melted and then moved into main body of molten glass. Single axis acoustic levitation furnances levitate glass melts at temperature up to about 700 degrees C. Processing in unit limited to low-melting temperature glasses.

  6. Development of porous glass fiber optic sensors

    NASA Astrophysics Data System (ADS)

    Macedo, P. B.; Barkatt, A.; Feng, X.; Finger, S. M.; Hojaji, H.

    1989-06-01

    Porous glass fiber optic sensors in which the porous sensor tip is an integral part of the fiber optic, have been developed and found to be rugged and reliable, due to their monolithic structure and large interior surface area for attachment of active species. The sensor portion of the fiber is made porous by selective leaching of a specially formulated borosilicate glass fiber, resulting in a strong, monolithic structure where the sensor portion of the fiber remains integrally attached to the rest of the fiber, essentially eliminating losses at the sensor-light pipe interface. The process for constructing porous glass fiber optic sensors involves fiber pulling, phase separation, selective leaching, attachment of the active reagent, and integration with other optical elements. A broad range of sensors based on this technology could be developed by using different active species, such as enzymes and other biochemicals, which could be bonded to the interior surface of the porous glass sensor.

  7. High modulus high temperature glass fibers

    NASA Technical Reports Server (NTRS)

    Bacon, J. F.

    1973-01-01

    The search for a new high-modulus, high-temperature glass fiber involved the preparation of 500 glass compositions lying in 12 glass fields. These systems consisted primarily of low atomic number oxides and rare-earth oxides. Direct optical measurements of the kinetics of crystallization of the cordierite-rare earth system, for example, showed that the addition of rare-earth oxides decreased the rate of formation of cordierite crystals. Glass samples prepared from these systems proved that the rare-earth oxides made large specific contributions to the Young's modulus of the glasses. The best glasses have moduli greater than 21 million psi, the best glass fibers have moduli greater than 18 million psi, and the best glass fiber-epoxy resin composites have tensile strengths of 298,000 psi, compressive strengths of at least 220,000 psi, flexural strengths of 290,000 psi, and short-beam shear strengths of almost 17,000 psi.

  8. Inert strength of pristine silica glass fibers

    SciTech Connect

    Smith, W.L.; Michalske, T.A.

    1993-11-01

    Silica glass fibers have been produced and tested under ultra high vacuum (UHV) conditions to investigate the inert strength of pristine fibers in absence of reactive agents. Analysis of the coefficient of variation in diameter ({upsilon}{sub d}) vs the coefficient of variation of breaking strength ({upsilon}{sub {sigma}}) does not adequately explain the variation of breaking stress. Distribution of fiber tensile strength data suggests that the inert strength of such fibers is not single valued and that the intrinsic strength is controlled by defects in the glass. Furthermore, comparison of room temperature UHV data with LN{sub 2} data indicates that these intrinsic strengths are not temperature dependent.

  9. Chalcogenide glass hollow core photonic crystal fibers

    NASA Astrophysics Data System (ADS)

    Désévédavy, Frédéric; Renversez, Gilles; Troles, Johann; Houizot, Patrick; Brilland, Laurent; Vasilief, Ion; Coulombier, Quentin; Traynor, Nicholas; Smektala, Frédéric; Adam, Jean-Luc

    2010-09-01

    We report the first hollow core photonic crystal fibers (HC PCF) in chalcogenide glass. To design the required HC PCF profiles for such high index glass, we use both band diagram analysis to define the required photonic bandgap and numerical simulations of finite size HC PCFs to compute the guiding losses. The material losses have also been taken into account to compute the overall losses of the HC PCF profiles. These fibers were fabricated by the stack and draw technique from TeAsSe (TAS) glass. The fibers we drew in this work are composed of six rings of holes and regular microstructures. Two profiles are presented, one is known as a kagome lattice and the other one corresponds to a triangular lattice. Geometrical parameters are compared to the expected parameters obtained by computation. Applications of such fibers include power delivery or fiber sensors among others.

  10. New glass developments for fiber optics

    NASA Astrophysics Data System (ADS)

    Higby, Paige L.; Holst, Karen; Tabor, Kevin; James, William; Chase, Elizabeth; Pucilowski, Sally; Gober-Mangan, Elizabeth; Klimek, Ronald; Karetta, Frank; Schreder, Bianca

    2014-02-01

    Fiber optic components for lighting and imaging applications have been in use for decades. Recent requirements such as a need for RoHS compliance, attractive market pricing, or particular optical properties, such as numerical aperture (NA) or transmission, have required SCHOTT to develop and implement new glasses for these applications. From Puravis™ lead-free fibers for lighting applications, to new glasses for digital X-ray imaging and sensor applications, the challenges for SCHOTT scientists are considerable. Pertinent properties of these glasses and methods of determination for suitability will be discussed.

  11. Scintillating glass fiber-optic neutron sensors

    NASA Astrophysics Data System (ADS)

    Abel, K. H.; Arthur, R. J.; Bliss, M.

    1994-04-01

    Pacific Northwest Laboratory (PNL) has fabricated cerium-activated lithium silicate scintillating fibers via a hot-downdraw process. These fibers, which, as produced, typically have a transmission length (e(sup -1) length) of greater than 2 meters, are found to undergo aging when subjected to room air. The aging, which is complete in a few weeks, reduces the transmission length to the order of 0.5 meter. Because of the high alkali content of the glass (on the order of 20-30 mole percent lithia), we have attributed this aging to aqueous corrosion at the polymer cladding/glass interface. Changes in transmission with chemical treatment of the surface support the corrosion model. Fiber transmission performance has been preserved by modifying the hot-downdraw to a double crucible to produce glass-on-glass waveguides.

  12. In vitro evaluation of glass fiber post

    PubMed Central

    Sharma, Navneet; Singh, Harpal

    2012-01-01

    Statement of problem: Techniques and recommendations for the restoration of endodontically treated teeth have changed from the use of custom cast metal post and core system to glass fiber-reinforced (GFRC) post and composite core system. Has this latest prefabricated glass fiber reinforced post and composite core system increased the fracture resistance of teeth and reduced the incidence of unrestorable root fractures. Purpose: The purpose of this study was to evaluate the incidence of root fracture and mode of failure of endodontically treated teeth restored with two different post and core systems. Material and Methods: Forty maxillary central incisors were randomly divided into two groups. (n=20). All teeth received endodontic treatment. First group was restored with custom cast post and core system. Second group was restored with glass fiber post and composite core system. In Both the groups posts were cemented with adhesive resin cement. Compressive load was applied at an angle of 130 to the long axis of teeth at a cross head speed of 1 mm/min until fracture occurred. Data were analyzed with student “t” test P<.001. Results: The mean value for fracture resistance was (331.4025) N in Group -I Custom cast Ni-Cr post and core and (237.0625) N in Group -II Glass fiber reinforced post and composite core system. Students “t” test shows the significant difference in fracture resistance of two groups. Conclusion: This study showed that the incidence of root fracture was significantly higher in custom cast Ni-Cr post and core system than glass fiber post and composite core system. A more favourable mode of failure was observed in teeth restored with Group II glass fiber post system. Key words:Post-and-core technique, glass fiber post, cast post and-core system, fracture resistance, endodontically treated teeth. PMID:24558556

  13. Scintillating-glass-fiber neutron sensors

    NASA Astrophysics Data System (ADS)

    Abel, K. H.; Arthur, R. J.; Bliss, M.; Brite, D. W.; Brodzinski, R. L.; Craig, R. A.; Geelhood, B. D.; Goldman, D. S.; Griffin, J. W.; Perkins, R. W.; Reeder, P. L.; Richey, W. R.; Stahl, K. A.; Sunberg, D. S.; Warner, R. A.; Wogman, N. A.; Weber, M. J.

    1994-12-01

    Cerium-doped lithium-silicate glass fibers have been developed at Pacific Northwest Laboratory (PNL) for use as thermal neutron detectors. By using highly-enriched 6Li, these fibers efficiently capture thermal neutrons and produce scintillation light that can be detected at the ends of the fibers. Advantages of scintillating fibers over 3He or BF 3 proportional tubes include flexibility in geometric configuration, ruggedness in high-vibration environments, and less detector weight for the same neutron sensitivity. This paper describes the performance of these scintillating fibers with regard to count rates, pulse height spectra, absolute efficiencies, and neutron/gamma discrimination. Fibers with light transmission lengths ( {1}/{e}) of greater than 2 m have been produced at PNL. Neutron sensors in fiber form allow development of a variety of neutron detectors packaged in previously unavailable configurations. Brief descriptions of some of the devices already produced are included to illustrate these possibilities.

  14. Single-mode fluorotellurite glass fiber

    NASA Astrophysics Data System (ADS)

    Zhan, Huan; Huang, Zhihua; Wen, Jing; Jiang, Lei; Wang, Jianjun; Jing, Feng; Lin, Aoxiang

    2016-03-01

    By multi-stage rod-in-tube fiber drawing process, a single-mode fluorotellurite glass fiber was fabricated and reported for the first time. Benefiting from chemical-physical dehydration process to remove water and OH- groups, the propagation loss was decreased to 1.9 dB/m at 1550 nm and the infrared window is extended from 2.8 μm to 4.2 μm, i.e. a new kind of mid-infrared glass fiber. The fiber is with a small core of 3.52 μm in diameter to meet single-mode condition, and the effective nonlinear parameter γ was estimated to be 236.7 W-1 km-1 at 1550 nm by using continuous-wave self-phase modulation method. © 2015 Elsevier B.V.

  15. Development of new radiopaque glass fiber posts.

    PubMed

    Furtos, Gabriel; Baldea, Bogdan; Silaghi-Dumitrescu, Laura

    2016-02-01

    The aim of this study was to analyze the radiopacity and filler content of three experimental glass fiber posts (EGFP) in comparison with other glass/carbon fibers and metal posts from the dental market. Three EGFP were obtained by pultrusion of glass fibers in a polymer matrix based on 2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy)-phenyl]propane (bis-GMA) and triethyleneglycol dimethacrylate (TEGDMA) monomers. Using intraoral sensor disks 27 posts, as well as mesiodistal sections of human molar and aluminum step wedges were radiographed for evaluation of radiopacity. The percentage compositions of fillers by weight and volume were investigated by combustion analysis. Two EGFP showed radiopacity higher than enamel. The commercial endodontic posts showed radiopacity as follows: higher than enamel, between enamel and dentin, and lower than dentin. The results showed statistically significant differences (p b 0.05)when evaluatedwith one-way ANOVA statistical analysis. According to combustion analyses, the filler content of the tested posts ranges between 58.84wt.% and 86.02wt.%. The filler content of the tested EGFP ranged between 68.91 wt.% and 79.04 wt.%. EGFP could be an alternative to commercial glass fiber posts. Futureglass fiber posts are recommended to present higher radiopacity than dentin and perhaps ideally similar to or higher than that of enamel, for improved clinical detection. The posts with a lower radiopacity than dentin should be considered insufficiently radiopaque. The radiopacity of some glass fiber posts is not greatly influenced by the amount of filler. PMID:26652441

  16. Development of new radiopaque glass fiber posts.

    PubMed

    Furtos, Gabriel; Baldea, Bogdan; Silaghi-Dumitrescu, Laura

    2016-02-01

    The aim of this study was to analyze the radiopacity and filler content of three experimental glass fiber posts (EGFP) in comparison with other glass/carbon fibers and metal posts from the dental market. Three EGFP were obtained by pultrusion of glass fibers in a polymer matrix based on 2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy)-phenyl]propane (bis-GMA) and triethyleneglycol dimethacrylate (TEGDMA) monomers. Using intraoral sensor disks 27 posts, as well as mesiodistal sections of human molar and aluminum step wedges were radiographed for evaluation of radiopacity. The percentage compositions of fillers by weight and volume were investigated by combustion analysis. Two EGFP showed radiopacity higher than enamel. The commercial endodontic posts showed radiopacity as follows: higher than enamel, between enamel and dentin, and lower than dentin. The results showed statistically significant differences (p b 0.05)when evaluatedwith one-way ANOVA statistical analysis. According to combustion analyses, the filler content of the tested posts ranges between 58.84wt.% and 86.02wt.%. The filler content of the tested EGFP ranged between 68.91 wt.% and 79.04 wt.%. EGFP could be an alternative to commercial glass fiber posts. Futureglass fiber posts are recommended to present higher radiopacity than dentin and perhaps ideally similar to or higher than that of enamel, for improved clinical detection. The posts with a lower radiopacity than dentin should be considered insufficiently radiopaque. The radiopacity of some glass fiber posts is not greatly influenced by the amount of filler.

  17. Natural Fiber or Glass Reinforced Polypropylene Composites?

    NASA Astrophysics Data System (ADS)

    Lorenzi, W.; Di Landro, L.; Casiraghi, A.; Pagano, M. R.

    2008-08-01

    Problems related to the recycle of conventional composite materials are becoming always more relevant for many industrial fields. Natural fiber composites (NFC) have recently gained much attention due to their low cost, environmental gains (eco-compatibility), easy disposal, reduction in volatile organic emissions, and their potential to compete with glass fiber composites (GFC). Interest in natural fibers is not only based over ecological aspects. NFC have good mechanical performances in relation to their low specific weight and low price. A characterization of mechanical properties, dynamic behavior, and moisture absorption is presented.

  18. NATURAL FIBER OR GLASS REINFORCED POLYPROPYLENE COMPOSITES?

    SciTech Connect

    Lorenzi, W.; Di Landro, L.; Casiraghi, A.; Pagano, M. R.

    2008-08-28

    Problems related to the recycle of conventional composite materials are becoming always more relevant for many industrial fields. Natural fiber composites (NFC) have recently gained much attention due to their low cost, environmental gains (eco-compatibility), easy disposal, reduction in volatile organic emissions, and their potential to compete with glass fiber composites (GFC). Interest in natural fibers is not only based over ecological aspects. NFC have good mechanical performances in relation to their low specific weight and low price. A characterization of mechanical properties, dynamic behavior, and moisture absorption is presented.

  19. Making Glass-Fiber-Reinforced Coolant Tubes

    NASA Technical Reports Server (NTRS)

    Curtin, F.

    1985-01-01

    New use found for heat-shrinkable sleeves. Smooth, noncontaminating channels for transporting cooling water in Space Shuttle Extravehicularmobility unit made of fiberglass tubing with aid of heat-shrinkable sleeves. Previously, glass fibers from inner walls of tubes contaminate water.

  20. Nonwoven glass fiber mat reinforces polyurethane adhesive

    NASA Technical Reports Server (NTRS)

    Roseland, L. M.

    1967-01-01

    Nonwoven glass fiber mat reinforces the adhesive properties of a polyurethane adhesive that fastens hardware to exterior surfaces of aluminum tanks. The mat is embedded in the uncured adhesive. It ensures good control of the bond line and increases the peel strength.

  1. Glass-clad semiconductor core optical fibers

    NASA Astrophysics Data System (ADS)

    Morris, Stephanie Lynn

    Glass-clad optical fibers comprising a crystalline semiconductor core have garnered considerable recent attention for their potential utility as novel waveguides for applications in nonlinear optics, sensing, power delivery, and biomedicine. As research into these fibers has progressed, it has become evident that excessive losses are limiting performance and so greater understanding of the underlying materials science, coupled with advances in fiber processing, is needed. More specifically, the semiconductor core fibers possess three performance-limiting characteristics that need to be addressed: (a) thermal expansion mismatches between crystalline core and glass cladding that lead to cracks, (b) the precipitation of oxide species in the core upon fiber cooling, which results from partial dissolution of the cladding glass by the core melt, and (c) polycrystallinity; all of which lead to scattering and increased transmission losses. This dissertation systematically studies each of these effects and develops both a fundamental scientific understanding of and practical engineering methods for reducing their impact. With respect to the thermal expansion mismatch and, in part, the dissolution of oxides, for the first time to our knowledge, oxide and non-oxide glass compositions are developed for a series of semiconductor cores based on two main design criteria: (1) matching the thermal expansion coefficient between semiconductor core and glass cladding to minimize cracking and (2) matching the viscosity-temperature dependences, such that the cladding glass draws into fiber at a temperature slightly above the melting point of the semiconductor in order to minimize dissolution and improve the fiber draw process. The x[Na 2O:Al2O3] + (100 - 2x)SiO2 glass compositional family was selected due to the ability to tailor the glass properties to match the aforementioned targets through slight variations in composition and adjusting the ratios of bridging and non-bridging oxygen

  2. Development Of Porous Glass Fiber Optic Sensors

    NASA Astrophysics Data System (ADS)

    Macedo, P. B.; Barkatt, Aa.; Feng, X.; Finger, S. M.; Hojaji, H.; Laberge, N.; Mohr, R.; Penafiel, M.; Saad, E.

    A method for producing rugged, continuous porous glass fiber optic sensors was developed. pH and temperature sensors based on this technology have been successfully produced. The sensor portion of the fiber is made porous by selective leaching of a specially formulated borosilicate glass fiber. This results in a strong, monolithic structure where the sensor portion of the fiber remains integrally attached to the rest of the fiber (which acts as a light pipe), essentially eliminating losses at the sensor-light pipe interface. Pore size in the sensor can be controllably varied by modifying heat treatment conditions, making these sensors suitable for chemical concentration measurements in liquids and gases. Appropriate dyes were chemically bonded by silanization to the large interior surface area of the porous sensors to produce the pH and temperature sensors. Cresol red and phenol red were used for pH and pinacyanol chloride was used for temperature sensing. The sensitivity of these devices can be controlled by varying the concentration of the chemically bonded dye and the length of the porous region. Optical absorbance measurements were made in the visible range. The tip of the sensors was coated with a thin, porous layer of gold to reflect the incident light, resulting in a double pass across the porous sensor. Experimental measurements were made over a pH range of 3 to 8 and a temperature range of 28-70 C. These porous glass fiber optic sensors were found to be rugged and reliable due to their monolithic structure and large interior surface area for attachment of active species. A broad range of sensors based on this technology could be developed by using different active species, such as enzymes and other biochemicals, which could be bonded to the interior surface of the porous glass sensor.

  3. Photonic crystal fibers based on chalcogenide glasses

    NASA Astrophysics Data System (ADS)

    Adam, J. L.; Troles, J.; Brilland, L.; Coulombier, Q.; Chartier, T.

    2010-10-01

    Chalcogenide glasses are known for their large transparency in the mid-infrared and their high refractive index (>2). They present also a high non-linear coefficient (n2), 100 to 1000 times larger than for silica, depending on the composition. An original way to obtain single-mode fibers is to design microstructured optical fibers (MOFs). These fibers present unique optical properties thanks to the high degree of freedom in the design of their geometrical structure. A classical method to realize MOFs is the stack-and-draw technique. However, with chalcogenide glasses, that technique induces optical losses at the interfaces in the stack of capillaries. In consequence, we have developed a new casting method to fabricate the chalcogenide preform. This method permits to obtain optical losses around 1 dB/m at 1.55 μm and 0.3 dB/m in the mid-IR region. Various chalcogenide microstructured fibers working in the IR range were prepared in order to take advantage of the non-linear properties of these glasses and of the original MOF properties. For example, fibers with small effective mode area (Aeff < 10 μm2) have been realized to exacerbate the non-linear optical properties. Such fibers will find applications for signal regeneration in telecom, and for the generation of supercontinuum sources. On the contrary, for military applications in the 3-5 and 8-12 μm windows, large effective mode area and single mode fibers have been designed to permit the propagation of high-power gaussian laser beams.

  4. Glass fiber manufacturing and fiber safety: the producer's perspective.

    PubMed Central

    Bender, J R; Hadley, J G

    1994-01-01

    Historically, the potential health effects of airborne fibers have been associated with the dose, dimension, and durability. Increasing focus is being placed on the latter category. Concern about airborne fiber safety could be reduced by manufacturing fibers that are not respirable; however, due to performance and manufacturing constraints on glasswool insulations, this is not possible today. These products are an important part of today's economy and as a major manufacturer, Owens-Corning is committed to producing and marketing materials that are both safe and effective in their intended use. To this end, manufacturing technology seeks to produce materials that generate low concentrations of airborne fibers, thus minimizing exposure and irritation. The range of fiber diameters is controlled to assure effective product performance and, as far as possible, to minimize respirability. Glass compositions are designed to allow effective fiber forming and ultimate product function. Fiber dissolution is primarily a function of composition; this too, can be controlled within certain constraints. Coupled with these broad parameters is an extensive product stewardship program to assure the safety of these materials. This article will discuss the factors that influence glasswool insulation production, use, and safety. PMID:7882953

  5. FIBER LENGTH DISTRIBUTION MEASUREMENT FOR LONG GLASS AND CARBON FIBER REINFORCED INJECTION MOLDED THERMOPLASTICS

    SciTech Connect

    Kunc, Vlastimil; Frame, Barbara J; Nguyen, Ba N.; TuckerIII, Charles L.; Velez-Garcia, Gregorio

    2007-01-01

    Procedures for fiber length distribution (FLD) measurement of long fiber reinforced injection molded thermoplastics were refined for glass and carbon fibers. Techniques for sample selection, fiber separation, digitization and length measurement for both fiber types are described in detail. Quantitative FLD results are provided for glass and carbon reinforced polypropylene samples molded with a nominal original fiber length of 12.7 mm (1/2 in.) using equipment optimized for molding short fiber reinforced thermoplastics.

  6. Development of silica glass microstructured optical fibers technology in Poland

    NASA Astrophysics Data System (ADS)

    Wójcik, J.; Janoszczyk, B.; Poturaj, K.; Makara, M.; Walewski, A.; Mergo, P.; Klimek, J.; Skorupski, K.; Czyżewska, L.

    2007-04-01

    Paper presents the state of advance of the silica glass microstructured optical fibers technology n Poland especially in Department of Optical Fibers Technology Maria Curie Sklodowska University. Only in this Department there are the technological apparatus for advanced investigations on the technology of the silica glass optical fibers. In paper was describe the technology of optical fiber photonic structure manufacturing, high silica glass synthesis from vapor phase with MCVD and OVD methods. Next was describe some kinds of microstructured optical fibers witch technologies elaborated in UMCS in support of own and received from cooperated research teams optical fibers structures, modeling and measurements results.

  7. Reinforcement of conventional glass-ionomer restorative material with short glass fibers.

    PubMed

    Hammouda, Ibrahim M

    2009-01-01

    This study investigated the strengthening effect of glass fibers when added to conventional glass-ionomer restorative material. Glass fibers were incorporated into glass-ionomer powder in 3 wt% and 5 wt%. The fibers used had 1 mm length and 10 microm thickness. These criteria of fiber length, diameter, and concentration represent a new approach for reinforcing conventional glass-ionomer [Medifill, conventional restorative glass-ionomer]. The mechanical properties tested were diametral tensile strength, hardness, flexural strength, flexural modulus and fracture toughness after 24-h and 7-days of storage in deionized water. Glass short fibers were mixed thoroughly into the glass-ionomer powder before mixing with the cement liquid. Samples of specific dimensions were prepared for each time interval and fiber loading according to the manufacturer's instructions and international standards. Hardness was measured using a micro-hardness tester at 100 gram applied load for 15 s. The other mechanical properties were measured using a Lloyd universal testing machine. The results showed increased diametral tensile strength, flexural strength, flexural modulus, and fracture toughness by the addition of glass fibers. There was an appreciable increase of the tested mechanical properties of glass-ionomer restorative material as a result of increasing fiber loading and water storage for 1 week. It was concluded that conventional glass-ionomer can be reinforced by the addition of short glass fibers.

  8. Mechanical properties of woven glass fiber-reinforced composites.

    PubMed

    Kanie, Takahito; Arikawa, Hiroyuki; Fujii, Koichi; Ban, Seiji

    2006-06-01

    The aim of this investigation was to measure the flexural and compressive strengths and the corresponding moduli of cylindrical composite specimens reinforced with woven glass fiber. Test specimens were made by light-curing urethane dimethacrylate oligomer with woven glass fiber of 0.18-mm standard thickness. Tests were conducted using four reinforcement methods and two specimen diameters. Flexural strength and modulus of woven glass fiber-reinforced specimens were significantly greater than those without woven glass fiber (p < 0.01). Likewise, compressive strength of reinforced specimens was significantly greater than those without woven glass fiber (p < 0.01), except for specimens reinforced with woven glass fiber oriented at a tilt direction in the texture (p > 0.05). In terms of comparison between the two specimen diameters, no statistically significant differences in flexural strength and compressive strength (p > 0.05) were observed.

  9. Interactions between the glass fiber coating and oxidized carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Ku-Herrera, J. J.; Avilés, F.; Nistal, A.; Cauich-Rodríguez, J. V.; Rubio, F.; Rubio, J.; Bartolo-Pérez, P.

    2015-03-01

    Chemically oxidized multiwall carbon nanotubes (MWCNTs) were deposited onto commercial E-glass fibers using a dipping procedure assisted by ultrasonic dispersion. In order to investigate the role of the fiber coating (known as "sizing"), MWCNTs were deposited on the surface of as-received E-glass fibers preserving the proprietary coating as well as onto glass fibers which had the coating deliberately removed. Scanning electron microscopy and Raman spectroscopy were used to assess the distribution of MWCNTs onto the fibers. A rather homogeneous coverage with high density of MWCNTs onto the glass fibers is achieved when the fiber coating is maintained. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and nuclear magnetic resonance (NMR) analyses of the chemical composition of the glass fiber coating suggest that such coating is a complex mixture with multiple oxygen-containing functional groups such as hydroxyl, carbonyl and epoxy. FTIR and XPS of MWCNTs over the glass fibers and of a mixture of MWCNTs and fiber coating provided evidence that the hydroxyl and carboxyl groups of the oxidized MWCNTs react with the oxygen-containing functional groups of the glass fiber coating, forming hydrogen bonding and through epoxy ring opening. Hydrogen bonding and ester formation between the functional groups of the MWCNTs and the silane contained in the coating are also possible.

  10. Ultraflat supercontinuum generation in soft-glass photonic crystal fibers

    NASA Astrophysics Data System (ADS)

    Miret, J. J.; Silvestre, E.; Andrés, P.

    2009-05-01

    We recognize some photonic-crystal-fiber structures, made up of soft glass, that generate ultrawide (over an octave), very smooth and highly coherent supercontinuum spectrum when illuminated with femtosecond pulsed light around 1.55 μm. The design of soft-glass microstructured fiber geometry with nearly ultraflattened, positive and low dispersion is crucial to accomplish the above goals.

  11. Phosphate-based glass fiber vs. bulk glass: Change in fiber optical response to probe in vitro glass reactivity.

    PubMed

    Massera, J; Ahmed, I; Petit, L; Aallos, V; Hupa, L

    2014-04-01

    This paper investigates the effect of fiber drawing on the thermal and structural properties as well as on the glass reactivity of a phosphate glass in tris(hydroxymethyl)aminomethane-buffered (TRIS) solution and simulated body fluid (SBF). The changes induced in the thermal properties suggest that the fiber drawing process leads to a weakening and probable re-orientation of the POP bonds. Whereas the fiber drawing did not significantly impact the release of P and Ca, an increase in the release of Na into the solution was noticed. This was probably due to small structural reorientations occurring during the fiber drawing process and to a slight diffusion of Na to the fiber surface. Both the powders from the bulk and the glass fibers formed a Ca-P surface layer when immersed in SBF and TRIS. The layer thickness was higher in the calcium and phosphate supersaturated SBF than in TRIS. This paper for the first time presents the in vitro reactivity and optical response of a phosphate-based bioactive glass (PBG) fiber when immersed in SBF. The light intensity remained constant for the first 48h after which a decrease with three distinct slopes was observed: the first decrease between 48 and 200h of immersion could be correlated to the formation of the Ca-P layer at the fiber surface. After this a faster decrease in light transmission was observed from 200 to ~425h in SBF. SEM analysis suggested that after 200h, the surface of the fiber was fully covered by a thin Ca-P layer which is likely to scatter light. For immersion times longer than ~425h, the thickness of the Ca-P layer increased and thus acted as a barrier to the dissolution process limiting further reduction in light transmission. The tracking of light transmission through the PBG fiber allowed monitoring of the fiber dissolution in vitro. These results are essential in developing new bioactive fiber sensors that can be used to monitor bioresponse in situ.

  12. Preparation of chalcogenide glass fiber using an improved extrusion method

    NASA Astrophysics Data System (ADS)

    Jiang, Chen; Wang, Xunsi; Zhu, Minming; Xu, Huijuan; Nie, Qiuhua; Dai, Shixun; Tao, Guangming; Shen, Xiang; Cheng, Ci; Zhu, Qingde; Liao, Fangxing; Zhang, Peiquan; Zhang, Peiqing; Liu, Zijun; Zhang, Xianghua

    2016-05-01

    We developed the extrusion method to prepare arsenic-free chalcogenide glass fibers with glass cladding. By using the double nested extrusion molds and the corresponding isolated stacked extrusion method, the utilization rate of glass materials was greatly improved compared with the conventional extrusion method. Fiber preforms with optimal stability of core/cladding ratio throughout the 160 mm length were prepared using the developed extrusion method. Typical fiber structure defects between the core/cladding interface, such as bubbles, cracks, and core diameter variation, were effectively eliminated. Ge-Sb-Se/S chalcogenide glasses were used to form a core/cladding pair and fibers with core/cladding structure were prepared by thermally drawing the extruded preforms. The transmission loss, fiber bending loss, and other optical characters of the fibers were also investigated.

  13. Electrospun submicron bioactive glass fibers for bone tissue scaffold.

    PubMed

    Lu, H; Zhang, T; Wang, X P; Fang, Q F

    2009-03-01

    Submicron bioactive glass fibers 70S30C (70 mol% SiO(2), 30 mol% CaO) acting as bone tissue scaffolds were fabricated by electrospinning method. The scaffold is a hierarchical pore network that consists of interconnected fibers with macropores and mesopores. The structure, morphological characterization and mechanical properties of the submicron bioactive glass fibers were studied by XRD, EDS, FIIR, SEM, N(2) gas absorption analyses and nanoindentation. The effect of the voltage on the morphology of electrospun bioactive glass fibers was investigated. It was found that decreasing the applied voltage from 19 to 7 kV can facilitate the formation of finer fibers with fewer bead defects. The hardness and Young's modulus of submicron bioactive glass fibers were measured as 0.21 and 5.5 GPa, respectively. Comparing with other bone tissue scaffolds measured by nanoindentation, the elastic modulus of the present scaffold was relatively high and close to the bone.

  14. Apparatus For Making Glass Fibers Without The Aid Of Gravity

    NASA Technical Reports Server (NTRS)

    Tucker, Dennis; Smith, Guy A.; Workman, Gary

    1995-01-01

    Report describes apparatus for making optical fibers in microgravity. Includes sting that makes initial contact with softened glass to start drawing fiber. Absence of gravity helps to suppress nucleation of crystallites, which increase scattering of light and thus reduce transmission of light along fiber.

  15. Fiber reinforced glasses and glass-ceramics for high performance applications

    NASA Technical Reports Server (NTRS)

    Prewo, K. M.; Brennan, J. J.; Layden, G. K.

    1986-01-01

    The development of fiber reinforced glass and glass-ceramic matrix composites is described. The general concepts involved in composite fabrication and resultant composite properties are given for a broad range of fiber and matrix combinations. It is shown that composite materials can be tailored to achieve high levels of toughness, strength, and elastic stiffness, as well as wear resistance and dimensional stability.

  16. Optical Properties Of Low Loss Fluoride Glass-Cladded Fibers

    NASA Astrophysics Data System (ADS)

    Burk, M. J.; Tran, D. C.; Fisher, C. F.; Levin, K. H.; Hart, Patricia; Sigel, G. H.

    1984-12-01

    Recent improvements in preform processing and fiber drawing techniques have resulted in glass-cladded fluoride glass fibers having losses under 10 dB/km. Multicomponent zirconium fluoride glass was used, and care was taken to reduce impurities such as transition metals and water. The reduction of scattering centers was also a major concern. Preforms were made using the rotational casting approach, which resulted in glass-cladded preforms having no observable core-clad defects. The preforms were coated with teflon, and drawn into fibers using an r.f. induction furnace. The optical attenuation of the fibers was measured in the infrared region. The minimum loss occurred around 2.5 microns. The fiber scattering loss was also measured. A variety of lasers were used for this measurement, including an infrared color-center laser to obtain scattering data directly in the infrared region.

  17. Fracture behavior of glass fiber reinforced polymer composite

    SciTech Connect

    Avci, A.; Arikan, H.; Akdemir, A

    2004-03-01

    Chopped strand glass fiber reinforced particle-filled polymer composite beams with varying notch-to-depth ratios and different volume fractions of glass fibers were investigated in Mode I fracture using three-point bending tests. Effects of polyester resin content and glass fiber content on fracture behavior was also studied. Polyester resin contents were used 13.00%%, 14.75%, 16.50%, 18.00% and 19.50%, and glass fiber contents were 1% and 1.5% of the total weight of the polymer composite system. Flexural strength of the polymer composite increases with increase in polyester and fiber content. The critical stress intensity factor was determined by using several methods such as initial notch depth method, compliance method and J-integral method. The values of K{sub IC} obtained from these methods were compared.

  18. Production of Bulk and Fiber Glass in Space

    NASA Technical Reports Server (NTRS)

    Tucker, Dennis S.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    The production of bulk glass and fiber glass in space and on the moon and Mars should lead to superior products. Specifically glass plates for windows and optical elements could be produced with theoretical strengths by production in vacuum. Water vapor is known to decrease glass strength by up to two orders of magnitude from theoretical. A low gravity glass plate apparatus prototype has been designed and built which uses centrifugal force to shape the glass and solar energy to melt the glass. Glass fiber could be produced on the moon or Mars from in-situ materials using standard technologies. This material could then be used as reinforcement in composite materials in construction of bases. Also, it has been shown that processing in reduced gravity suppresses crystallization in certain heavy metal fluoride glasses. It is proposed to reprocess optical fiber preforms on the space station and then pull these into optical fiber. It is estimated that the attenuation coefficient should be reduced by two orders of magnitude.

  19. Deformation, Stress Relaxation, and Crystallization of Lithium Silicate Glass Fibers Below the Glass Transition Temperature

    NASA Technical Reports Server (NTRS)

    Ray, Chandra S.; Brow, Richard K.; Kim, Cheol W.; Reis, Signo T.

    2004-01-01

    The deformation and crystallization of Li(sub 2)O (center dot) 2SiO2 and Li(sub 2)O (center dot) 1.6SiO2 glass fibers subjected to a bending stress were measured as a function of time over the temperature range -50 to -150 C below the glass transition temperature (Tg). The glass fibers can be permanently deformed at temperatures about 100 C below T (sub)g, and they crystallize significantly at temperatures close to, but below T,, about 150 C lower than the onset temperature for crystallization for these glasses in the no-stress condition. The crystallization was found to occur only on the surface of the glass fibers with no detectable difference in the extent of crystallization in tensile and compressive stress regions. The relaxation mechanism for fiber deformation can be best described by a stretched exponential (Kohlrausch-Williams-Watt (KWW) approximation), rather than a single exponential model.The activation energy for stress relaxation, Es, for the glass fibers ranges between 175 and 195 kJ/mol, which is considerably smaller than the activation energy for viscous flow, E, (about 400 kJ/mol) near T, for these glasses at normal, stress-free condition. It is suspected that a viscosity relaxation mechanism could be responsible for permanent deformation and crystallization of the glass fibers below T,

  20. Ceramic fiber reinforced glass-ceramic matrix composite

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P. (Inventor)

    1993-01-01

    A slurry of BSAS glass powders is cast into tapes which are cut to predetermined sizes. Mats of continuous chemical vapor deposition (CVD)-SiC fibers are alternately stacked with these matrix tapes. This tape-mat stack is warm-pressed to produce a 'green' composite which is heated to burn out organic constituents. The remaining interim material is then hot-pressed to form a BSAS glass-ceramic fiber-reinforced composite.

  1. Lithium Loaded Glass Fiber Neutron Detector Tests

    SciTech Connect

    Ely, James H.; Erikson, Luke E.; Kouzes, Richard T.; Lintereur, Azaree T.; Stromswold, David C.

    2009-11-12

    Radiation portal monitors used for interdiction of illicit materials at borders include highly sensitive neutron detection systems. The main reason for having neutron detection capability is to detect fission neutrons from plutonium. The currently deployed radiation portal monitors (RPMs) from Ludlum and Science Applications International Corporation (SAIC) use neutron detectors based upon 3He-filled gas proportional counters, which are the most common large neutron detector. There is a declining supply of 3He in the world and, thus, methods to reduce the use of this gas in RPMs with minimal changes to the current system designs and sensitivity to cargo-borne neutrons are being investigated. Four technologies have been identified as being currently commercially available, potential alternative neutron detectors to replace the use of 3He in RPMs. Reported here are the results of tests of the lithium-loaded glass fibers option. This testing measured the neutron detection efficiency and gamma ray rejection capabilities of a small system manufactured by Nucsafe (Oak Ridge, TN).

  2. Soft-glass hollow-core photonic crystal fibers

    NASA Astrophysics Data System (ADS)

    Melnikov, Leonid; Khromova, Irina; Scherbakov, Andrey; Nikishin, Nikolay

    2005-09-01

    The results of numerical modeling and experimental investigations of manufactured diamond-shaped and large area hollow core photonic crystal fibers with periodical cladding (kagome-lattice and closely packed tubes) are presented. The use of soft glasses allows to fabricate high-quality structures with moderate losses. Numerical methods, designing strategies and fabrication issues of these promising fiber structures are discussed.

  3. Fretting maps of glass fiber-reinforced composites

    SciTech Connect

    Turki, C.; Salvia, M.; Vincent, L.

    1993-12-31

    Industrial development of new materials are often limited due to an insufficient knowledge in their functional properties. The paper deals with fretting behavior of glass fiber reinforced epoxy/metal contacts. Fretting is a plague for all industries, especially in the case of quasi-static loadings. Furthermore friction testing under small displacements appeared well fitted to understand the effect of fiber orientations and to relate results to microstructure (fiber, matrix and interface).

  4. Monitoring Fiber Stress During Curing of Single Fiber Glass- and Graphite-Epoxy Composites

    NASA Technical Reports Server (NTRS)

    Madhukar, Madhu S.; Kosuri, Ranga P.; Bowles, Kenneth J.

    1994-01-01

    The difference in thermal expansion characteristics of epoxy matrices and graphite fibers can produce significant residual stresses in the fibers during curing of composite materials. Tests on single fiber glass-epoxy and graphite-epoxy composite specimens were conducted in which the glass and graphite fibers were preloaded in tension, and the epoxy matrix was cast around the fibers. The fiber tension was monitored while the matrix was placed around the fiber and subjected to the temperature-time curing cycle. Two mechanisms responsible for producing stress in embedded fibers were identified as matrix thermal expansion and contraction and matrix cure shrinkage. A simple analysis based on the change in fiber tension during the curing cycle was conducted to estimate the produced stresses. Experimental results on single fiber glass- and graphite-epoxy composites show that the fiber was subjected to significant tensile stresses when the temperature was raised from the first to the second dwell period. When initial fiber pretension is about 60 percent of the fiber failure load, these curing-induced stresses can cause tensile fracture of the embedded fiber.

  5. Laser transmission welding of long glass fiber reinforced thermoplastics

    NASA Astrophysics Data System (ADS)

    van der Straeten, Kira; Engelmann, Christoph; Olowinsky, Alexander; Gillner, Arnold

    2015-03-01

    Joining fiber reinforced polymers is an important topic for lightweight construction. Since classical laser transmission welding techniques for polymers have been studied and established in industry for many years joint-strengths within the range of the base material can be achieved. Until now these processes are only used for unfilled and short glass fiber-reinforced thermoplastics using laser absorbing and laser transparent matrices. This knowledge is now transferred to joining long glass fiber reinforced PA6 with high fiber contents without any adhesive additives. As the polymer matrix and glass fibers increase the scattering of the laser beam inside the material, their optical properties, changing with material thickness and fiber content, influence the welding process and require high power lasers. In this article the influence of these material properties (fiber content, material thickness) and the welding parameters like joining speed, laser power and clamping pressure are researched and discussed in detail. The process is also investigated regarding its limitations. Additionally the gap bridging ability of the process is shown in relation to material properties and joining speed.

  6. Hybrid polymer photonic crystal fiber with integrated chalcogenide glass nanofilms

    NASA Astrophysics Data System (ADS)

    Markos, Christos; Kubat, Irnis; Bang, Ole

    2014-08-01

    The combination of chalcogenide glasses with polymer photonic crystal fibers (PCFs) is a difficult and challenging task due to their different thermo-mechanical material properties. Here we report the first experimental realization of a hybrid polymer-chalcogenide PCF with integrated As2S3 glass nanofilms at the inner surface of the air-channels of a poly-methyl-methacrylate (PMMA) PCF. The integrated high refractive index glass films introduce distinct antiresonant transmission bands in the 480-900 nm wavelength region. We demonstrate that the ultra-high Kerr nonlinearity of the chalcogenide glass makes the polymer PCF nonlinear and provides a possibility to shift the transmission band edges as much as 17 nm by changing the intensity. The proposed fabrication technique constitutes a new highway towards all-fiber nonlinear tunable devices based on polymer PCFs, which at the moment is not possible with any other fabrication method.

  7. Chemical cleaning agents and bonding to glass-fiber posts.

    PubMed

    Gonçalves, Ana Paula Rodrigues; Ogliari, Aline de Oliveira; Jardim, Patrícia dos Santos; Moraes, Rafael Ratto de

    2013-01-01

    The influence of chemical cleaning agents on the bond strength between resin cement and glass-fiber posts was investigated. The treatments included 10% hydrofluoric acid, 35% phosphoric acid, 50% hydrogen peroxide, acetone, dichloromethane, ethanol, isopropanol, and tetrahydrofuran. Flat glass-fiber epoxy substrates were exposed to the cleaners for 60 s. Resin cement cylinders were formed on the surfaces and tested in shear. All treatments provided increased bond strength compared to untreated control specimens. All failures were interfacial. Although all agents improved the bond strength, dichloromethane and isopropanol were particularly effective.

  8. Self-Frequency-Doubling Glass-Fiber Laser

    NASA Technical Reports Server (NTRS)

    Selker, Mark D.; Dallas, Joseph L.

    1993-01-01

    Specially prepared germanium and phosphorous-doped glass optical fiber doped with neodymium shown to act as self-frequency-doubling laser. Self-frequency-doubling fiber laser with further refinements, eliminates need for expensive, easily damaged, nonlinear crystals currently used. Enables one to avoid loss and damage mechanisms associated with interfaces of nonlinear crystals as well as to eliminate angle/temperature phase-matching tuning.

  9. [Biological effects of mineral fibers on lymphocytes in vitro. Comparative studies of asbestos and glass fibers].

    PubMed

    Nakatani, Y

    1983-09-01

    The biological effects of asbestos and glass fibers on lymphocytes in vitro were investigated. Blastoid transformation and beta 2 microglobulin production of human peripheral blood lymphocytes (PBL) induced by phytohemagglutinin were inhibited by Canadian chrysotile B (Standard sample of the Union Internationale Contre le Cancer; UICC standard sample) but it was not the case for crocidolite (UICC standard sample) and small and large glass fibers (John Manville, Canada). Cytotoxic activities of natural killer and killer cells of PBL were investigated using K562 cells and Chang liver cells as target cells respectively. Chrysotile inhibited the both activities but crocidolite and two kind of glass fibers not. In regard to release of lactic dehydrogenase and beta-glucuronidase from mouse peritoneal macrophages exposed to mineral fibers, chrysotile showed more effective reaction compared to crocidolite and amosite (UICC standard sample), on the other hand large glass fiber showed the similar reaction to chrysotile but small glass fiber and milled amosite did not induce any more enzymatic release than the control. In addition to chemical compositions of mineral fibers, the morphological characteristics were also discussed in relation to their biological effects.

  10. Adhesion between thermoplastic polymer particles and carbon and glass fibers

    SciTech Connect

    Colton, J.S.

    1996-12-31

    High performance composites consist of polymer matrices reinforced with continuous fibers. Polymer powders can be coated and fused onto the fibers by various techniques to produce these composites. One such technique consists of spreading the fibers with an air banding jet, and then running the fibers through a fluidized bed of the powder. The fluidizing air is typically charged, imparting a charge to the powder particles. The fibers are grounded which leads to an attraction between the particles and the fibers. The particle-coated fibers then go through a tunnel oven, sintering the particles onto the fibers, leaving a flexible {open_quotes}tow-preg{close_quotes} which can then be processed into a preform for manufacture into a final part. To develop an initial understanding of the powder coating process, the adhesion of uncharged particles and fibers was studied. Contact mechanics predicts that the adhesion force between uncharged particles depends on the mutual (or equivalent) radius of curvature between the contacting objects, as well as their surface energies. For the materials of interest, the Derjaguin approximation is appropriate and is applied. PEEK (poly ether ether ketone) and PET (poly ethylene terephthalate) particles, cryogenically ground to nominal diameters of 10 to 100 {mu}m were brought into contact with themselves, with E-glass fibers (nominal diameter of 20 {mu}m), carbon fibers (nominal diameter of 8 {mu}m), and glass microscope slides using an AFM. Adhesion forces were measured and compared to predictions using Derjaguin`s approximation. SEM micrographs were used to determine the scale of the radii of curvature of contacting sites.

  11. Design Guide for glass fiber reinforced metal pressure vessel

    NASA Technical Reports Server (NTRS)

    Landes, R. E.

    1973-01-01

    Design Guide has been prepared for pressure vessel engineers concerned with specific glass fiber reinforced metal tank design or general tank tradeoff study. Design philosophy, general equations, and curves are provided for safelife design of tanks operating under anticipated space shuttle service conditions.

  12. Liquid crystals detect voids in fiber glass laminates

    NASA Technical Reports Server (NTRS)

    Hollar, W. T.

    1967-01-01

    Liquid crystal solution nondestructively detects voids or poor bond lines in fiber glass laminates. A thin coating of the solution is applied by spray or brush to the test article surface, and when heated indicates the exact location of defects by differences in color.

  13. Durability of waste glass flax fiber reinforced mortar

    SciTech Connect

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

    2011-01-17

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

  14. Characterization and reactivity of sodium aluminoborosilicate glass fiber surfaces

    NASA Astrophysics Data System (ADS)

    Ortiz Rivera, Lymaris; Bakaev, Victor A.; Banerjee, Joy; Mueller, Karl T.; Pantano, Carlo G.

    2016-05-01

    Multicomponent complex oxides, such as sodium aluminoborosilicate glass fibers, are important materials used for thermal insulation in buildings and homes. Although the surface properties of single oxides, such as silica, have been extensively studied, less is known about the distribution of reactive sites at the surface of multicomponent oxides. Here, we investigated the reactivity of sodium aluminoborosilicate glass fiber surfaces for better understanding of their interface chemistry and bonding with acrylic polymers. Acetic acid (with and without a 13C enrichment) was used as a probe representative of the carboxylic functional groups in many acrylic polymers and adhesives. Inverse gas chromatography coupled to a mass spectrometer (IGC-MS), and solid state nuclear magnetic resonance (NMR), were used to characterize the fiber surface reactions and surface chemical structure. In this way, we discovered that both sodium ions in the glass surface, as well as sodium carbonate salts that formed on the surface due to the intrinsic reactivity of this glass in humid air, are primary sites of interaction with the carboxylic acid. Surface analysis by X-ray photoelectron spectroscopy (XPS) confirmed the presence of sodium carbonates on these surfaces. Computer simulations of the interactions between the reactive sites on the glass fiber surface with acetic acid were performed to evaluate energetically favorable reactions. The adsorption reactions with sodium in the glass structure provide adhesive bonding sites, whereas the reaction with the sodium carbonate consumes the acid to form sodium-carboxylate, H2O and CO2 without any contribution to chemical bonding at the interface.

  15. INFLUENCE OF DIFFERENT ADHESIVE SYSTEMS ON THE PULL-OUT BOND STRENGTH OF GLASS FIBER POSTS

    PubMed Central

    da Silva, Luciana Mendonça; de Andrade, Andréa Mello; Machuca, Melissa Fernanda Garcia; da Silva, Paulo Maurício Batista; da Silva, Ricardo Virgolino C.; Veronezi, Maria Cecília

    2008-01-01

    This in vitro study evaluated the tensile bond strength of glass fiber posts (Reforpost – Angelus-Brazil) cemented to root dentin with a resin cement (RelyX ARC – 3M/ESPE) associated with two different adhesive systems (Adper Single Bond - 3M/ESPE and Adper Scotchbond Multi Purpose (MP) Plus – 3M/ESPE), using the pull-out test. Twenty single-rooted human teeth with standardized root canals were randomly assigned to 2 groups (n=10): G1- etching with 37% phosphoric acid gel (3M/ESPE) + Adper Single Bond + #1 post (Reforpost – Angelus) + four #1 accessory posts (Reforpin – Angelus) + resin cement; G2- etching with 37% phosphoric acid gel + Adper Scotchbond MP Plus + #1 post + four #1 accessory posts + resin cement. The specimens were stored in distilled water at 37°C for 7 days and submitted to the pull-out test in a universal testing machine (EMIC) at a crosshead speed of 0.5 mm/min. The mean values of bond strength (kgf) and standard deviation were: G1- 29.163 ± 7.123; G2- 37.752 ±13.054. Statistical analysis (Student's t-test; α=0.05 showed no statistically significant difference (p<0.05) between the groups. Adhesive bonding failures between resin cement and root canal dentin surface were observed in both groups, with non-polymerized resin cement in the apical portion of the post space when Single Bond was used (G1). The type of adhesive system employed on the fiber post cementation did not influence the pull-out bond strength. PMID:19089224

  16. Infrared glass fiber cables for CO laser medical applications

    NASA Astrophysics Data System (ADS)

    Arai, Tsunenori; Mizuno, Kyoichi; Sensaki, Koji; Kikuchi, Makoto; Watanabe, Tamishige; Utsumi, Atsushi; Takeuchi, Kiyoshi; Akai, Yoshiro

    1993-05-01

    We developed the medical fiber cables which were designed for CO laser therapy, i.e., angioplasty and endoscopic therapy. As-S chalcogenide glass fibers were used for CO laser delivery. A 230 micrometers core-diameter fiber was used for the angioplasty laser cable. The outer diameter of this cable was 600 micrometers . The total length and insertion length of the angioplasty laser cable were 2.5 m and 1.0 m, respectively. Typically, 2.0 W of fiber output was used in the animal experiment in vivo for the ablation of the model plaque which consisted of human atheromatous aorta wall. The transmission of the angioplasty laser cable was approximately 35%, because the reflection loss occurred at both ends of the fiber and window. Meanwhile, the core diameter of the energy delivery fiber for the endoscopic therapy was 450 micrometers . The outer diameter of this cable was 1.7 mm. Approximately 4.5 W of fiber output was used for clinical treatment of pneumothorax through a pneumoscope. Both types of the cables had the ultra-thin thermocouples for temperature monitoring at the tip of the cables. This temperature monitoring was extremely useful to prevent the thermal destruction of the fiber tip. Moreover, the As-S glass fibers were completely sealed by the CaF2 windows and outer tubes. Therefore, these cables were considered to have sufficient safety properties for medical applications. These laser cables were successfully used for the in vivo animal experiments and/or actual clinical therapies.

  17. Remote Fiber Laser Cutting System for Dismantling Glass Melter - 13071

    SciTech Connect

    Mitsui, Takashi; Miura, Noriaki; Oowaki, Katsura; Kawaguchi, Isao; Miura, Yasuhiko; Ino, Tooru

    2013-07-01

    Since 2008, the equipment for dismantling the used glass melter has been developed in High-level Liquid Waste (HLW) Vitrification Facility in the Japanese Rokkasho Reprocessing Plant (RRP). Due to the high radioactivity of the glass melter, the equipment requires a fully-remote operation in the vitrification cell. The remote fiber laser cutting system was adopted as one of the major pieces of equipment. An output power of fiber laser is typically higher than other types of laser and so can provide high-cutting performance. The fiber laser can cut thick stainless steel and Inconel, which are parts of the glass melter such as casings, electrodes and nozzles. As a result, it can make the whole of the dismantling work efficiently done for a shorter period. Various conditions of the cutting test have been evaluated in the process of developing the remote fiber cutting system. In addition, the expected remote operations of the power manipulator with the laser torch have been fully verified and optimized using 3D simulations. (authors)

  18. Silver metaphosphate glass wires inside silica fibers--a new approach for hybrid optical fibers.

    PubMed

    Jain, Chhavi; Rodrigues, Bruno P; Wieduwilt, Torsten; Kobelke, Jens; Wondraczek, Lothar; Schmidt, Markus A

    2016-02-22

    Phosphate glasses represent promising candidates for next-generation photonic devices due to their unique characteristics, such as vastly tunable optical properties, and high rare earth solubility. Here we show that silver metaphosphate wires with bulk optical properties and diameters as small as 2 µm can be integrated into silica fibers using pressure-assisted melt filling. By analyzing two types of hybrid metaphosphate-silica fibers, we show that the filled metaphosphate glass has only negligible higher attenuation and a refractive index that is identical to the bulk material. The presented results pave the way towards new fiber-type optical devices relying on metaphosphate glasses, which are promising materials for applications in nonlinear optics, sensing and spectral filtering. PMID:26906989

  19. Biological glass fibers: Correlation between optical and structural properties

    PubMed Central

    Aizenberg, Joanna; Sundar, Vikram C.; Yablon, Andrew D.; Weaver, James C.; Chen, Gang

    2004-01-01

    Biological systems have, through the course of time, evolved unique solutions for complex optical problems. These solutions are often achieved through a sophisticated control of fine structural features. Here we present a detailed study of the optical properties of basalia spicules from the glass sponge Euplectella aspergillum and reconcile them with structural characteristics. We show these biosilica fibers to have a distinctive layered design with specific compositional variations in the glass/organic composite and a corresponding nonuniform refractive index profile with a high-index core and a low-index cladding. The spicules can function as single-mode, few-mode, or multimode fibers, with spines serving as illumination points along the spicule shaft. The presence of a lens-like structure at the end of the fiber increases its light-collecting efficiency. Although free-space coupling experiments emphasize the similarity of these spicules to commercial optical fibers, the absence of any birefringence, the presence of technologically inaccessible dopants in the fibers, and their improved mechanical properties highlight the advantages of the low-temperature synthesis used by biology to construct these remarkable structures. PMID:14993612

  20. Electrical Insulation Characteristics of Glass Fiber Reinforced Resins

    SciTech Connect

    Tuncer, Enis; Sauers, Isidor; James, David Randy; Ellis, Alvin R

    2009-01-01

    Non-metallic structural materials that act as an electrical insulation are needed for cryogenic power applications. One of the extensively utilized materials is glass fiber reinforced resins (GFRR) and may also be known as GFRP and FRP. They are created from glass fiber cloth that are impregnated with an epoxy resin under pressure and heat. Although the materials based on GFRR have been employed extensively, reports about their dielectric properties at cryogenic temperatures and larger thicknesses are generally lacking in the literature. Therefore to guide electrical apparatus designers for cryogenic applications, GFRR samples with different thicknesses are tested in a liquid nitrogen bath. Scaling relation between the dielectric breakdown strength and the GFFR thickness is established. Their loss tangents are also reported at various frequencies.

  1. Lung burden of a glass fiber by inhalation.

    PubMed

    Tanaka, I; Akiyama, T; Kido, M

    1991-01-01

    Pulmonary deposition and clearance of deposited particles from lungs are very important factors in order to induce pneumoconioses. In this paper, five Wistar male rats were exposed to glass fiber particles (mass median aerodynamic diameter (MMAD), 2.8 microns) for 6 hrs/day, 5 days/week for 4 weeks. The average exposure concentration was controlled by a continuous fluidized bed with a screw feeder and an overflow pipe at 0.79 mg/m3 during the exposure period. The fibrous particles concentrations in the exposure chamber were monitored by a light scattering method and showed to be constant during the exposure. The rats were sacrificed at 24 hours after the termination of the exposure and then the wet lung weight and the silica concentration in the lungs were measured. The lungs were treated for low temperature ashing (ca. 150 degrees C) by a plasma asher. After ashing, these samples were melted with sodium carbonate in platinum pot for the measurement of the silica content by the absorption spectrophotometry. The maximum content of SiO2 was 45 micrograms in the exposed rats and 20 micrograms in the control. The deposited amount of SiO2 by the exposure to glass fiber was 25 micrograms. The apparent deposition fraction defined as the deposited amount in the lungs to the amount of the inhaled glass fiber during the exposure was 6.8%. There was no significant difference of the apparent deposition fraction at same MMAD between glass fiber in this study and non-fibrous particles.

  2. Dynamic tensile strength of glass fiber reinforced pultruded composites

    SciTech Connect

    Dutta, P.K.; Kumar, M.M.; Hui, D.

    1994-12-31

    This paper discusses the stress-strain behavior, fracture strength, influence of low temperature, and energy absorption in the diametral tensile splitting fracturing of a Glass Fiber Reinforced Polymer Composite. Experiments were conducted at low-temperature in a thermal chamber installed on a servo-hydraulic universal testing machine. The tensile strength was determined by diametral compression of disc samples at 24, {minus}5 and {minus}40 C.

  3. All-glass optical fibers derived from sapphire

    NASA Astrophysics Data System (ADS)

    Dragic, Peter D.; Hawkins, Thomas; Foy, Paul; Morris, Stephanie; Ballato, John

    2013-02-01

    Increasing power levels and novel applications are demanding from fibers performance capabilities that have, to date, not been realized. One such example arises from the nascent push towards the 10-kW power threshold for narrow linewidth fiber lasers designed for applications including coherently-phased laser arrays and spectroscopic lidars. It is well-known that Brillouin scattering still restricts continued power scaling in these systems, despite several recent advances in acoustic-wave Brillouin management. Accordingly, novel fibers possessing a Brillouin gain coefficient 10 dB or more less than previously demonstrated would be of great practical benefit if they comprise novel materials in simple geometries and are manufactured using industry-accepted methods. Introducing a new and effective approach to the management of Brillouin scattering, we present on all-glass optical fibers derived from silica-clad sapphire with alumina concentrations up to 55 mole percent; considerably greater than conventionally possible enabling the design of optical fiber possessing a series of essential properties. Markedly, a Brillouin gain coefficient of 3.1 × 10-13 m/W was measured for a fiber with an average alumina concentration of 54 mole percent. This value is nearly 100 times lower than standard commercial single-mode fiber and is likely the lowest ever specified value. This reduction in Brillouin gain is enabled by a number of key material properties of the alumina-silica system, amazingly even leading to a predicted, but not yet demonstrated, composition with zero Brillouin gain. Optical fiber materials with these and other crucial properties will be discussed in the context high energy fiber laser systems.

  4. Interference phenomena in fraunhofer holograms and in their reconstructions of tapered glass fibers.

    PubMed

    Lomas, G M

    1969-10-01

    Fraunhofer holograms and their reconstructions show interference fringes when applied to tapered glass fibers, which do not occur with opaque fibers. The fringes are shown to be quantitatively related to fiber profile. The phase lag of fiber transmitted light is recorded as identifiable hologram fringes by interference with fiber-diffracted light. This also results in fringes in the reconstructed image. One fringe of both types, for a fiber refractive index n, represents a diameter change lambda/(n-1). Shape changes along a fiber not directly resolved by the optics are measurable. Profile measurement of attenuating glass fibers in the continuous filament process is described.

  5. Optimization of the contents of hollow glass microsphere and sodium hexametaphosphate for glass fiber vacuum insulation panel

    NASA Astrophysics Data System (ADS)

    Li, C. D.; Chen, Z. F.; Zhou, J. M.

    2016-07-01

    In this paper, various additive amounts of hollow glass microspheres (HGMs) and sodium hexametaphosphate (SHMP) powders were blended with flame attenuated glass wool (FAGW) to form hybrid core materials (HCMs) through the wet method. Among them, the SHMP was dissolved in the glass fiber suspension and coated on the surface of glass fibers while the HGMs were insoluble in the glass fiber suspension and filled in the fiber-fiber pores. The average pore diameter of the FAGW/HGM HCMs was 8-11 μm which was near the same as that of flame attenuated glass fiber mats (FAGMs, i.e., 10.5 µm). The tensile strength of the SHMP coated FAGMs was enhanced from 160 N/m to 370 N/m when SHMP content increased from 0 wt.% to 0.2 wt.%. By contrast, the tensile strength of the FAGW/HGM HCMs decreased from 160 N/m to 40 N/m when HGM content increased from 0 wt.% to 50 wt.%. Both the FAGW/HGM HCMs and SHMP coated FAGMs were vacuumed completely to form vacuum insulation panels (VIPs). The results showed that both the addition of SHMP and HGM led a slight increase in the thermal conductivity of the corresponding VIPs. To obtain a high-quality VIP, the optimal SHMP content and HGM content in glass fiber suspension was 0.12-0.2 wt.% and 0 wt.%.

  6. Synthesis of nanocrystals in KNb(Ge,Si)O{sub 5} glasses and chemical etching of nanocrystallized glass fibers

    SciTech Connect

    Enomoto, Itaru; Benino, Yasuhiko; Fujiwara, Takumi; Komatsu, Takayuki . E-mail: komatsu@chem.nagaokaut.ac.jp

    2006-06-15

    The nanocrystallization behavior of 25K{sub 2}O-25Nb{sub 2}O{sub 5}-(50-x)GeO{sub 2}-xSiO{sub 2} glasses with x=0,25,and50 (i.e., KNb(Ge,Si)O{sub 5} glasses) and the chemical etching behavior of transparent nanocrystallized glass fibers have been examined. All glasses show nanocrystallization, and the degree of transparency of the glasses studied depends on the heat treatment temperature. Transparent nanocrystallized glasses can be obtained if the glasses are heat treated at the first crystallization peak temperature. Transparent nanocrystallized glass fibers with a diameter of about 100{mu}m in 25K{sub 2}O-25Nb{sub 2}O{sub 5}-50GeO{sub 2} are fabricated, and fibers with sharpened tips (e.g., the taper length is about 450{mu}m and the tip angle is about 12{sup o}) are obtained using a meniscus chemical etching method, in which etching solutions of 10wt%-HF/hexane and 10M-NaOH/hexane are used. Although the tip (aperture size) has not a nanoscaled size, the present study suggests that KNb(Ge,Si)O{sub 5} nanocrystallized glass fibers have a potential for new near-field optical fiber probes with high refractive indices of around n=1.8 and high dielectric constants of around {epsilon}=58 (1kHz, room temperature)

  7. Durability-Based Design Criteria for a Chopped-Glass-Fiber Automotive Structural Composite

    SciTech Connect

    Battiste, R.L.; Corum, J.M.; Ren, W.; Ruggles, M.B.

    1999-11-01

    This report provides recommended durability-based design criteria for a chopped-glass-fiber reinforced polymeric composite for automotive structural applications. The criteria closely follow the framework of an earlier criteria document for a continuous-strand-mat (CSM) glass-fiber reference composite. Together these design criteria demonstrate a framework that can be adapted for future random-glass-fiber composites for automotive structural applications.

  8. Development of Cu-E-Glass Fiber Composites by Powder Metallurgy Route

    NASA Astrophysics Data System (ADS)

    Bhuyan, Pallabi; Singh, Harspreet; Kumar, Lailesh; Sharma, Nidhi; Panda, Deepankar; Verma, Deepanshu; NasmulAlam, Syed

    2016-02-01

    Cu-E glass fiber composites were developed with different vol. % of E-glass fiber (10, 20, 30 and 40 vol. %) by powder metallurgy route. Both as-received Cu and nanostructured Cu developed by milling as-received Cu powder for 20 h were used to develop various Cu-E-glass fiber composites. The effect of using as-received Cu powder and nanostructured Cu powder on the properties of the various Cu-E-glass fiber composites was analysed. The samples were sintered at 900oC for 1 h in inert atmosphere. The results show good bonding between the matrix and the reinforcement and there is homogeneous distribution of the reinforcement in the matrix.. The hardness of the Cu-E-glass fiber composites was found to increase from 0.8GPa to 2.7GPa with increase in vol. % of the glass fiber in case of unmilled and from 1.2GPa to 2.9GPa for the milled Cu-E-glass fiber composites. The as-milled Cu-E- glass fiber composites shows better densification and sinterability compared to the unmilled CuE-glass fiber composites

  9. Characterization of Glass Fiber Separator Material for Lithium Batteries

    NASA Technical Reports Server (NTRS)

    Subbarao, S.; Frank, H.

    1984-01-01

    Characterization studies were carried out on a glass fiber paper that is currently employed as a separator material for some LiSOCl2 primary cells. The material is of the non-woven type made from microfilaments of E-type glass and contains an ethyl acrylate binder. Results from extraction studies and tensile testing revealed that the binder content and tensile strength of the paper were significantly less than values specified by the manufacturer. Scanning electron micrographs revealed the presence of clusters of impurities many of which were high in iron content. Results of emission spectroscopy revealed high overall levels of iron and leaching, followed by atomic absorption measurements, revealed that essentially all of this iron is soluble in SOCl2.

  10. Glass fiber reinforced concrete for terrestrial photovoltaic arrays

    NASA Technical Reports Server (NTRS)

    Maxwell, H.

    1979-01-01

    The use of glass-fiber-reinforced concrete (GRC) as a low-cost structural substrate for terrestrial solar cell arrays is discussed. The properties and fabrication of glass-reinforced concrete structures are considered, and a preliminary design for a laminated solar cell assembly built on a GRC substrate is presented. A total cost for such a photovoltaic module, composed of a Korad acrylic plastic film front cover, an aluminum foil back cover, an ethylene/vinyl acetate pottant/adhesive and a cotton fabric electrical isolator in addition to the GRC substrate, of $9.42/sq m is projected, which is less than the $11.00/sq m cost goal set by the Department of Energy. Preliminary evaluations are concluded to have shown the design capabilities and cost effectiveness of GRC; however, its potential for automated mass production has yet to be evaluated.

  11. Study of glass preforms for glass fiber optics applications (study of space processing of ceramic materials). [light transmission

    NASA Technical Reports Server (NTRS)

    Wang, F. F. Y.

    1974-01-01

    The feasibility, and technical and economic desirability was studied of space processing of glass preforms for optical fiber transmission applications. The results indicate that space processing can produce glass preforms of equal quality at lower cost than earth bound production, and can produce diameter modulation in the glass preform which promotes mode coupling and lowers the dispersion. The glass composition can be modified through the evaporative and diffusion processes, and graded refractive index profiles can be produced. A brief summary of the state of the art in optical fiber transmission is included.

  12. Low thermal flux glass-fiber tubing for cryogenic service.

    NASA Technical Reports Server (NTRS)

    Hall, C. A.; Pharo, T. J., Jr.; Phillips, J. M.

    1972-01-01

    Study of thin metallic liners which provide leak-free service in cryogenic propulsion plumbing systems and are overwrapped with a glass-fiber composite that provides strength and protection from handling damage. The composite tube is lightweight, strong, and has a very low thermal flux. The resultant reduced boiloff of stored cryogenic propellants yields a substantial weight savings for long-term missions (seven days or greater). Twelve styles of tubing ranging from 1/2 to 5 in. in diameter were fabricated and tested with excellent results for most of the concepts at operating temperatures from +70 to -423 F and operating pressures up to 3000 psi.

  13. Bond strength of glass fiber reinforced plastics (GFRP) grouted anchors

    SciTech Connect

    Bellavance, E.; Xu, H.; Benmokrane, B.

    1995-11-01

    This paper describes the results of laboratory and field pull-out tests on cement grouted glass fiber reinforced plastic (GFRP) anchors. As an alternative for grouted steel anchors, GFRP bars have many advantages over steel tendons, and can avoid corrosion and some difficulties in transportation, handling, and installation. Three types of 36 GFRP anchors and 20 steel anchors installed in three types of host media: steel pipe, concrete block, and rock mass were tested in the laboratory as well as in the field. The bond strength, load carrying capacity, load-displacement behavior, and critical bond length of cement grouted GFRP anchors were examined in comparison with conventional steel anchors.

  14. Cold plasma activation of continuously moving fiber glass strand

    SciTech Connect

    Das, B.

    1992-03-01

    A few selectively activated products were made using 13.6 MHz radio frequency cold plasma induced gases; such as, argon, oxygen, ammonia, Freon{trademark}, and the 30:70 mixture of Freon{trademark} and oxygen. Surface wetting force measurements of random filaments drawn from the activated strands were made using a Wilhelmy Balance. These measurements indicated that chemical modifications of filaments had indeed occurred on all the filaments drawn either from the interior or the surface of the activated strand bundle. In some cases, Ion Scattering Spectrometry was used at Pennsylvania State University to confirm that surface modification of the fiber glass surface had, in fact, taken place during cold plasma activation. While argon and ammonia induced plasma activation did not cause any strength degradation of Emery or organic size coated fibers, the oxygen and Freon{trademark} induced activation did. 16 refs., 7 figs., 3 tabs.

  15. Nucleation and Crystallization as Induced by Bending Stress in Lithium Silicate Glass Fibers

    NASA Technical Reports Server (NTRS)

    Reis, Signo T.; Kim, Cheol W.; Brow, Richard K.; Ray, Chandra S.

    2003-01-01

    Glass Fibers of Li2O.2SiO2 (LS2) and Li2O.1.6SiO2 (LS1.6) compositions were heated near, but below, the glass transition temperature for different times while subjected to a constant bending stress of about 1.2 GPa. The nucleation density and the crystallization tendency estimated by differential thermal analysis (DTA) of a glass sample in the vicinity of the maximum of the bending stress increased relative to that of stress-free glass fibers. LS2 glass fibers were found more resistant to nucleation and crystallization than the Ls1.6 glass fibers. These results are discussed in regards to shear thinning effects on glass stability.

  16. Ytterbium-doped all glass leakage channel fibers with highly fluorine-doped silica pump cladding.

    PubMed

    Dong, Liang; McKay, Hugh A; Fu, Libin; Ohta, Michiharu; Marcinkevicius, Andrius; Suzuki, Shigeru; Fermann, Martin E

    2009-05-25

    All glass leakage channel fibers have been demonstrated to be a potential practical solution for power scaling in fiber lasers beyond the nonlinear limits in conventional large mode area fibers. The all glass nature with absence of any air holes is especially useful for allowing the fibers to be used and fabricated much like conventional fibers. Previously, double clad active all glass leakage channel fibers used low index polymer as a pump guide with the drawbacks of being less reliable at high pump powers and not being able to change fiber outer diameter independent of pump guide dimension. In this work, we demonstrate, for the first time, ytterbium-doped double clad all glass leakage channel fibers with highly fluorine-doped silica as pump cladding. The new all glass leakage channel fibers have no polymer in the pump path and have independent control of fiber outer diameters and pump cladding dimension, and, therefore, enable designs with smaller pump guide for high pump absorption and, at the same time, with large fiber diameters to minimize micro and macro bending effects, a much desired features for large core fibers where intermodal coupling can be an issue due to a much increased mode density. An ytterbium-doped double clad PM fiber with core diameter of 80 microm is also reported, which can be coiled in 76 cm diameter coils.

  17. A Comparative Study of Natural Fiber and Glass Fiber Fabrics Properties with Metal or Oxide Coatings

    NASA Astrophysics Data System (ADS)

    Lusis, Andrej; Pentjuss, Evalds; Bajars, Gunars; Sidorovicha, Uljana; Strazds, Guntis

    2015-03-01

    Rapidly growing global demand for technical textiles industries is stimulated to develop new materials based on hybrid materials (yarns, fabrics) made from natural and glass fibres. The influence of moisture on the electrical properties of metal and metal oxide coated bast (flax, hemp) fibre and glass fibre fabrics are studied by electrical impedance spectroscopy and thermogravimetry. The bast fibre and glass fiber fabrics are characterized with electrical sheet resistance. The method for description of electrical sheet resistance of the metal and metal oxide coated technical textile is discussed. The method can be used by designers to estimate the influence of moisture on technical data of new metal coated hybrid technical textile materials and products.

  18. Recent advances in the development of holey optical fibers based on sulphide glasses

    NASA Astrophysics Data System (ADS)

    Smektala, F.; Brilland, L.; Chartier, T.; Nguyen, T. N.; Troles, J.; Niu, Y. F.; Danto, S.; Traynor, N.; Jouan, T.

    2006-02-01

    Microstructured optical fibers as new optical objects have been developed in the recent past years, firstly from silica glass and then from other oxide glasses such as tellurite or different heavy cations oxide glasses. However very few results have been reported concerning non-oxide glasses and more particularly chalcogenide glasses. In a photonic crystal fiber the arrangement of air holes along the transverse section of the fiber around a solid glassy core leads to unique optical properties, such as for example broadband single-mode guidance, adjustable dispersion, nonlinear properties. Since the effective modal area is adjustable thanks to geometrical parameters, chalcogenide microstructured fibers with small mode area are of interest for nonlinear components because of the intrinsic non linearity of chalcogenide glasses, several order of magnitude above these of the reference silica glass (100 to 1000 times the non linearity of silica glass). On the other hand, chalcogenide holey fibers with large mode area are of interest for infrared power transmission, in a wavelength range out of reach of silica fibers, and more particularly in the 3-5 μm atmospheric window. The aim of this paper is to present more specifically the recent results that have been achieved in the elaboration, light guidance and characterization of photonic crystal fibers from the sulfide Ge 20Ga 5Sb 10S 65 glass, which presents a large transparency window from 600 nm to 11 μm.

  19. Ceramic fiber-reinforced monoclinic celsian phase glass-ceramic matrix composite material

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P. (Inventor); Dicarlo, James A. (Inventor)

    1994-01-01

    A hyridopolysilazane-derived ceramic fiber reinforced monoclinic celsian phase barium aluminum silicate glass-ceramic matrix composite material is prepared by ball-milling an aqueous slurry of BAS glass powder and fine monoclinic celsian seeds. The fibers improve the mechanical strength and fracture toughness and with the matrix provide superior dielectric properties.

  20. R&D on glass fiber reinforced epoxy resin composites for superconducting Tokamak.

    PubMed

    Hu, Nannan; Wang, Ke; Ma, Hongming; Pan, Wanjiang; Chen, Qingqing

    2016-01-01

    The glass fiber reinforced epoxy resin composites play an important role in superconducting Tokamak, which are used to insulate the metal components, such as superconducting winding, cooling pipes, metal electrodes and so on. For the components made of metal and glass fiber reinforced epoxy resin composites, thermal shrinkage leads to non-ignorable thermal stress, therefore, much attention should be paid on the thermal shrinkage rate of glass fiber reinforced epoxy resin composites. The structural design of glass fiber reinforced epoxy resin composites should aim at reducing thermal stress. In this paper, the density, glass fiber content and thermal shrinkage rate of five insulation tubes were tested. The testing results will be applied in structural design and mechanical analysis of isolators for superconducting Tokamak. PMID:27652137

  1. R&D on glass fiber reinforced epoxy resin composites for superconducting Tokamak.

    PubMed

    Hu, Nannan; Wang, Ke; Ma, Hongming; Pan, Wanjiang; Chen, Qingqing

    2016-01-01

    The glass fiber reinforced epoxy resin composites play an important role in superconducting Tokamak, which are used to insulate the metal components, such as superconducting winding, cooling pipes, metal electrodes and so on. For the components made of metal and glass fiber reinforced epoxy resin composites, thermal shrinkage leads to non-ignorable thermal stress, therefore, much attention should be paid on the thermal shrinkage rate of glass fiber reinforced epoxy resin composites. The structural design of glass fiber reinforced epoxy resin composites should aim at reducing thermal stress. In this paper, the density, glass fiber content and thermal shrinkage rate of five insulation tubes were tested. The testing results will be applied in structural design and mechanical analysis of isolators for superconducting Tokamak.

  2. Mechanical and thermal expansion properties of glass fibers reinforced PEEK composites at cryogenic temperatures

    NASA Astrophysics Data System (ADS)

    Chu, X. X.; Wu, Z. X.; Huang, R. J.; Zhou, Y.; Li, L. F.

    2010-02-01

    Polyetheretherketone (PEEK) has been widely used as matrix material for high performance composites. In this work, 30% chopped glass fibers reinforced PEEK composites were prepared by injection molding, and then the tensile, flexural and impact properties were tested at different temperatures. The modulus, strength and specific elongation of glass fibers reinforced PEEK at room temperature, 77 K and 20 K have been compared. And the fracture morphologies of different samples were investigated by scanning electron microscopy (SEM). The results showed a dependence of mechanical properties of glass fibers reinforced PEEK composites on temperature. The coefficient of thermal expansion of unfilled PEEK and glass fibers reinforced PEEK were also investigated from 77 K to room temperature. The results indicated that the thermal expansion coefficient (CTE) of PEEK matrix was nearly a constant in this temperature region, and it can be significantly decreased by adding glass fibers.

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

    NASA Astrophysics Data System (ADS)

    Fenu, Luigi; Forni, Daniele; Cadoni, Ezio

    2015-09-01

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

  4. Glass Fiber Reinforced Metal Pressure Vessel Design Guide

    NASA Technical Reports Server (NTRS)

    Landes, R. E.

    1972-01-01

    The Engineering Guide presents curves and general equations for safelife design of lightweight glass fiber reinforced (GFR) metal pressure vessels operating under anticipated Space Shuttle service conditions. The high composite vessel weight efficiency is shown to be relatively insensitive to shape, providing increased flexibility to designers establishing spacecraft configurations. Spheres, oblate speroids, and cylinders constructed of GFR Inconel X-750, 2219-T62 aluminum, and cryoformed 301 stainless steel are covered; design parameters and performance efficiencies for each configuration are compared at ambient and cryogenic temperature for an operating pressure range of 690 to 2760 N/sq cm (1000 to 4000 psi). Design variables are presented as a function of metal shell operating to sizing (proof) stress ratios for use with fracture mechanics data generated under a separate task of this program.

  5. Thermal fatigue of ceramic fiber glass matrix composites

    SciTech Connect

    Zawada, L.P.; Wetherhold, R.C.

    1989-10-01

    The thermal fatigue (TF) of ceramic matrix composites (CMC) introduces stresses within the composite due to the inevitable thermal expansion mismatch of fiber and matrix; this will affect the lifetime and dimensional stability of the composite. A Nicalon/glass composite has been subjected to rapid, controlled TF from 250-700 C and 250-800 C under no load and dead load conditions in order to illustrate a variety of elastic and inelastic cyclic strain conditions. After TF, the surfaces of the composites were characterized using SEM for evidence of thermal damage and microcracking. The composites were then tested for flexural modulus and strength. Results from the mechanical properties tests are present and correlated with observed thermal degradation. 7 refs.

  6. Kenaf-glass fiber reinforced unsaturated polyester hybrid composites: Tensile properties

    NASA Astrophysics Data System (ADS)

    Zhafer, S. F.; Rozyanty, A. R.; Shahnaz, S. B. S.; Musa, L.; Zuliahani, A.

    2016-07-01

    The use of natural fibers in composite is rising in recent years due their lightweight, non-abrasive, combustible, non-toxic, low cost and biodegradable properties. However, in comparison with synthetic fibers, the mechanical properties of natural fibers are lower. Therefore, the inclusion of synthetic fibers could improve the mechanical performance of natural fiber based composites. In this study, kenaf bast fiber and glass fiber at different weight percentage loading were used as reinforcement to produce hybrid composites. Unsaturated polyester (UP) resin was used as matrix and hand lay-up process was performed to apply the UP resin on the hybrid kenaf bast/glass fiber composite. Effect of different fiber loading on tensile strength, tensile modulus and elongation at break of the hybrid composite was studied. It has been found that the highest value of tensile strength and modulus was achieved at 10 wt.% kenaf/10 wt.% glass fiber loading. It was concluded that addition of glass fiber has improved the tensile properties of kenaf bast fiber based UP composites.

  7. Silicone polymer waveguide bridge for Si to glass optical fibers

    NASA Astrophysics Data System (ADS)

    Kruse, Kevin L.; Riegel, Nicholas J.; Middlebrook, Christopher T.

    2015-03-01

    Multimode step index polymer waveguides achieve high-speed, (<10 Gb/s) low bit-error-rates for onboard and embedded circuit applications. Using several multimode waveguides in parallel enables overall capacity to reach beyond 100 Gb/s, but the intrinsic bandwidth limitations due to intermodal dispersion limit the data transmission rates within multimode waveguides. Single mode waveguides, where intermodal dispersion is not present, have the potential to further improve data transmission rates. Single mode waveguide size is significantly less than their multimode counterparts allowing for greater density of channels leading to higher bandwidth capacity per layer. Challenges in implementation of embedded single mode waveguides within printed circuit boards involves mass production fabrication techniques to create precision dimensional waveguides, precision alignment tolerances necessary to launch a mode, and effective coupling between adjoining waveguides and devices. An emerging need in which single mode waveguides can be utilized is providing low loss fan out techniques and coupling between on-chip transceiver devices containing Si waveguide structures to traditional single mode optical fiber. A polymer waveguide bridge for Si to glass optical fibers can be implemented using silicone polymers at 1310 nm. Fabricated and measured prototype devices with modeling and simulation analysis are reported for a 12 member 1-D tapered PWG. Recommendations and designs are generated with performance factors such as numerical aperture and alignment tolerances.

  8. Commercial Production of Heavy Metal Fluoride Glass Fiber in Space

    NASA Technical Reports Server (NTRS)

    Tucker, Dennis S.; Workman, Gary L.; Smith, Guy A.

    1998-01-01

    International Space Station Alpha (ISSA) will provide a platform not only for materials research but also a possible means to produce products in space which cannot be easily produced on the ground. Some products may even be superior to those now produced in unit gravity due to the lack of gravity induced convection effects. Our research with ZrF4-BaF2-LaF3-AlF3-NaF (ZBLAN glass) has shown that gravity does indeed play a major role in the crystallization behavior of this material. At the present time ZBLAN is being produced on earth in fiber optic form for use in surgical lasers and fiber optic lasers among other applications. High attenuation coefficients, however, have kept this material from being used in other applications such as long haul data transmission links. The high attenuation coefficients are due to impurities which can be removed through improved processing techniques and crystals which can only be removed or prevented from forming by processing in a reduced gravity environment.

  9. Ni(2+) doped glass ceramic fiber fabricated by melt-in-tube method and successive heat treatment.

    PubMed

    Fang, Zaijin; Zheng, Shupei; Peng, Wencai; Zhang, Hang; Ma, Zhijun; Dong, Guoping; Zhou, Shifeng; Chen, Danping; Qiu, Jianrong

    2015-11-01

    Glass ceramic fibers containing Ni(2+) doped LiGa(5)O(8) nanocrystals were fabricated by a melt-in-tube method and successive heat treatment. Fiber precursors were prepared by drawing at high temperature where fiber core glass was melted while fiber clad glass was softened. After heat treatment, LiGa(5)O(8) nanocrystals were precipitated in the fiber core. Excited by 980 nm laser, efficient broadband near-infrared emission was observed in the glass ceramic fiber compared to that of precursor fiber. The melt-in-tube method can realize controllable crystallization and is suitable for fabrication of novel glass ceramic fibers. The Ni(2+)-doped glass ceramic fiber is promising for broadband optical amplification. PMID:26561096

  10. Ni(2+) doped glass ceramic fiber fabricated by melt-in-tube method and successive heat treatment.

    PubMed

    Fang, Zaijin; Zheng, Shupei; Peng, Wencai; Zhang, Hang; Ma, Zhijun; Dong, Guoping; Zhou, Shifeng; Chen, Danping; Qiu, Jianrong

    2015-11-01

    Glass ceramic fibers containing Ni(2+) doped LiGa(5)O(8) nanocrystals were fabricated by a melt-in-tube method and successive heat treatment. Fiber precursors were prepared by drawing at high temperature where fiber core glass was melted while fiber clad glass was softened. After heat treatment, LiGa(5)O(8) nanocrystals were precipitated in the fiber core. Excited by 980 nm laser, efficient broadband near-infrared emission was observed in the glass ceramic fiber compared to that of precursor fiber. The melt-in-tube method can realize controllable crystallization and is suitable for fabrication of novel glass ceramic fibers. The Ni(2+)-doped glass ceramic fiber is promising for broadband optical amplification.

  11. Flexural Strength of Glass and Polyethylene Fiber Combined with Three Different Composites

    PubMed Central

    Sharafeddin, F; Alavi, AA; Talei, Z

    2013-01-01

    Statement of Problem: The flexure of the fiber- reinforced composites (FRC) which can be generally used instead of fixed metal- framework prostheses have been more advocated due to the enormous demands for the conservative and esthetic restoration. The flexure of the fiber should be well-fitted to its covering composite. No study has been reported the comparison of the combination of glass and polyethylene fiber with particulate filled composite and fiber reinforced composite yet. Purpose: This study compared the flexural strength of two types of fibers combined with three types of composites. Materials and Method: Sixty-six specimens were prepared in a split mold (25×2×2 mm). The specimens were divided into six groups according to the type of resin and the fiber (N = 11): group 1: Z250 composite + Polyethylene fiber; group 2: Build It composite + Polyethylene fiber; group 3: Nulite F composite+ Polyethylene fiber; group 4: glass fiber + Z250 composite; group 5: glass fiber + Build-It composite and group 6: glass fiber + Nulite F. The mean flexural strengths (MPa) values were determined in a 3-point bending test at a crosshead speed of 1 mm/min by a universal testing machine (Zwick/Roell Z020, Germany). The results were statistically analyzed, using one and two- way ANOVA and LSD post-hoc tests (p< 0.05). Results: The highest flexural strength was registered for glass fiber in combination with Z250 composite (500 MPa) and the lowest for polyethylene fiber in combination with Build-It composite (188 MPa). One-way ANOVA test revealed that there was no statistically significant difference between polyethylene fiber combinations (p= 0.62) but there was a significant difference between glass fiber combinations (p= 0.0001). Two-way ANOVA revealed that the fiber type had a significant effect on flexural strength (p= 0.0001). Conclusion: The choice of fiber and composite type was shown to have a significant positive influence on the flexural properties of the

  12. Glass fiber processing for the Moon/Mars program: Center director's discretionary fund final report

    NASA Technical Reports Server (NTRS)

    Tucker, D. S.; Ethridge, E.; Curreri, P.

    1992-01-01

    Glass fiber has been produced from two lunar soil simulants. These two materials simulate lunar mare soil and lunar highland soil compositions, respectively. Short fibers containing recrystallized areas were produced from the as-received simulants. Doping the highland simulant with 8 weight percent B2-O3 yielded a material which could be spun continuously. The effects of lunar gravity on glass fiber formation were studied utilizing NASA's KC-135 aircraft. Gravity was found to play a major role in final fiber diameter.

  13. Extrinsic fiber-optic Fabry-Perot interferometer sensor for refractive index measurement of optical glass

    SciTech Connect

    Chen Jihuan; Zhao Jiarong; Huang Xuguang; Huang Zhenjian

    2010-10-10

    A simple fiber-optic sensor based on Fabry-Perot interference for refractive index measurement of optical glass is investigated both theoretically and experimentally. A broadband light source is coupled into an extrinsic fiber Fabry-Perot cavity formed by the surfaces of a sensing fiber end and the measured sample. The interference signals from the cavity are reflected back into the same fiber. The refractive index of the sample can be obtained by measuring the contrast of the interference fringes. The experimental data meet with the theoretical values very well. The proposed technique is a new method for glass refractive index measurement with a simple, solid, and compact structure.

  14. Impact tensile properties and strength development mechanism of glass for reinforcement fiber

    NASA Astrophysics Data System (ADS)

    Kim, T.; Oshima, K.; Kawada, H.

    2013-07-01

    In this study, impact tensile properties of E-glass were investigated by fiber bundle testing under a high strain rate. The impact tests were performed employing two types of experiments. One is the tension-type split Hopkinson pressure bar system, and the other is the universal high-speed tensile-testing machine. As the results, it was found that not only the tensile strength but also the fracture strain of E-glass fiber improved with the strain rate. The absorbed strain energy of this material significantly increased. It was also found that the degree of the strain rate dependency of E-glass fibers on the tensile strength was varied according to fiber diameter. As for the strain rate dependency of the glass fiber under tensile loading condition, change of the small crack-propagation behaviour was considered to clarify the development of the fiber strength. The tensile fiber strength was estimated by employing the numerical simulation based on the slow crack-growth model (SCG). Through the parametric study against the coefficient of the crack propagation rate, the numerical estimation value was obtained for the various testing conditions. It was concluded that the slow crack-growth behaviour in the glass fiber was an essential for the increase in the strength of this material.

  15. Ultrasonic assisted consolidation of commingled thermoplastic/glass fibers rovings

    NASA Astrophysics Data System (ADS)

    Lionetto, Francesca; Dell'Anna, Riccardo; Montagna, Francesco; Maffezzoli, Alfonso

    2015-04-01

    Thermoplastic matrix composites are finding new applications in different industrial area thanks to their intrinsic advantages related to environmental compatibility and processability. The approach presented in this work consists in the development of a technology for the simultaneous deposition and consolidation of commingled thermoplastic rovings through to the application of high energy ultrasound. An experimental equipment, integrating both fiber impregnation and ply consolidation in a single process, has been designed and tested. It is made of an ultrasonic welder, whose titanium sonotrode is integrated on a filament winding machine. During winding, the commingled roving is at the same time in contact with the mandrel and the horn. The intermolecular friction generated by ultrasound is able to melt the thermoplastic matrix and impregnate the reinforcement fibers. The heat transfer phenomena occurring during the in situ consolidation were simulated solving by finite element (FE) analysis an energy balance accounting for the heat generated by ultrasonic waves and the melting characteristics of the matrix. To this aim, a calorimetric characterization of the thermoplastic matrix has been carried out to obtain the input parameters for the model. The FE analysis has enabled to predict the temperature distribution in the composite during heating and cooling The simulation results have been validated by the measurement of the temperature evolution during ultrasonic consolidation. The reliability of the developed consolidation equipment was proved by producing hoop wound cylinder prototypes using commingled continuous E-glass rovings and Polypropylene (PP) filaments. The consolidated composite cylinders are characterized by high mechanical properties, with values comparable with the theoretical ones predicted by the micromechanical analysis.

  16. Dispersion engineering in nonlinear soft glass photonic crystal fibers infiltrated with liquids.

    PubMed

    Pniewski, Jacek; Stefaniuk, Tomasz; Van, Hieu Le; Long, Van Cao; Van, Lanh Chu; Kasztelanic, Rafał; Stępniewski, Grzegorz; Ramaniuk, Aleksandr; Trippenbach, Marek; Buczyński, Ryszard

    2016-07-01

    We present a numerical study of the dispersion characteristic modification of nonlinear photonic crystal fibers infiltrated with liquids. A photonic crystal fiber based on the soft glass PBG-08, infiltrated with 17 different organic solvents, is proposed. The glass has a light transmission window in the visible-mid-IR range of 0.4-5 μm and has a higher refractive index than fused silica, which provides high contrast between the fiber structure and the liquids. A fiber with air holes is designed and then developed in the stack-and-draw process. Analyzing SEM images of the real fiber, we calculate numerically the refractive index, effective mode area, and dispersion of the fundamental mode for the case when the air holes are filled with liquids. The influence of the liquids on the fiber properties is discussed. Numerical simulations of supercontinuum generation for the fiber with air holes only and infiltrated with toluene are presented. PMID:27409187

  17. Fiber glass prevents cracking of polyurethane foam insulation on cryogenic vessels

    NASA Technical Reports Server (NTRS)

    Forge, D. A.

    1968-01-01

    Fiber glass material, placed between polyurethane foam insulation and the outer surfaces of cryogenic vessels, retains its resilience at cryogenic temperatures and provides an expansion layer between the metal surfaces and the polyurethane foam, preventing cracking of the latter.

  18. Isothermal and hygrothermal agings of hybrid glass fiber/carbon fiber composite

    NASA Astrophysics Data System (ADS)

    Barjasteh, Ehsan

    New applications of fiber-reinforced polymer composites (FRPCs) are arising in non-traditional sectors of industry, such as civil infrastructure, automotive, and power distribution. For example, composites are being used in place of steel to support high-voltage overhead conductors. In this application, conductive strands of aluminum are wrapped around a solid composite rod comprised of unidirectional carbon and glass fibers in an epoxy matrix, which is commercially called ACCC conductor. Composite-core conductors such as these are expected to eventually replace conventional steel-reinforced conductors because of the reduced sag at high temperatures, lower weight, higher ampacity, and reduced line losses. Despite the considerable advantages in mechanical performance, long-term durability of composite conductors is a major concern, as overhead conductors are expected to retain properties (with minimal maintenance) over a service life that spans multiple decades. These concerns stem from the uncertain effects of long-term environmental exposure, which includes temperature, moisture, radiation, and aggressive chemicals, all of which can be exacerbated by cyclic loads. In general, the mechanical and physical properties of polymer composites are adversely affected by such environmental factors. Consequently, the ability to forecast changes in material properties as a function of environmental exposure, particularly bulk mechanical properties, which are affected by the integrity of fiber-matrix interfaces, is required to design for extended service lives. Polymer composites are susceptible to oxidative degradation at high temperatures approaching but not quite reaching the glass transition temperature ( Tg). Although the fibers are stable at such temperatures, the matrix and especially the fiber-matrix interface can undergo degradation that affects the physical and mechanical properties of the structure over time. Therefore, as a first step, the thermal aging of an

  19. The Effect of Exposed Glass Fibers and Particles of Bioactive Glass on the Surface Wettability of Composite Implants

    PubMed Central

    Abdulmajeed, Aous A.; Lassila, Lippo V.; Vallittu, Pekka K.; Närhi, Timo O.

    2011-01-01

    Measurement of the wettability of a material is a predictive index of cytocompatibility. This study was designed to evaluate the effect of exposed E-glass fibers and bioactive glass (BAG) particles on the surface wettability behavior of composite implants. Two different groups were investigated: (a) fiber reinforced composites (FRCs) with different fiber orientations and (b) polymer composites with different wt. % of BAG particles. Photopolymerized and heat postpolymerized composite substrates were made for both groups. The surface wettability, topography, and roughness were analyzed. Equilibrium contact angles were measured using the sessile drop method. Three liquids were used as a probe for surface free energy (SFE) calculations. SFE values were calculated from contact angles obtained on smooth surfaces. The surface with transverse distribution of fibers showed higher (P < 0.001) polar (γP) and total SFE (γTOT) components (16.9 and 51.04 mJ/m2, resp.) than the surface with in-plane distribution of fibers (13.77 and 48.27 mJ/m2, resp.). The increase in BAG particle wt. % increased the polar (γP) value, while the dispersive (γD) value decreased. Postpolymerization by heat treatment improved the SFE components on all the surfaces investigated (P < 0.001). Composites containing E-glass fibers and BAG particles are hydrophilic materials that show good wettability characteristics. PMID:22253628

  20. Three-Year Follow Up of Customized Glass Fiber Esthetic Posts

    PubMed Central

    da Costa, Rogério Goulart; de Morais, Eduardo Christiano Caregnatto; Leão, Moira Pedroso; Bindo, Márcio José Fraxino; Campos, Edson Alves; Correr, Gisele Maria

    2011-01-01

    Customized glass fiber posts that is well adjusted into the root canal and have mechanical properties similar to those of dentin may be a suitable treatment for severely compromised endodontically treated teeth. This article reports a 3-year follow up of severely damaged endodontically treated teeth restored with unidirectional fiber glass customized post and core system instead of a conventional fiber post. The fabrication of this glass fiber customized post is a simple technique, providing an increased volume of fibers into the root canal, and an adequate polymerization of the post-core system. Over a three-year period, the treatments demonstrated good clinical and radiographic characteristics, with no fracture or loss of the post and/or crown. This technique can be considered effective, less invasive, and suitable for restore endodontically treated teeth. PMID:21228960

  1. Method of producing a ceramic fiber-reinforced glass-ceramic matrix composite

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P. (Inventor)

    1994-01-01

    A fiber-reinforced composite composed of a BaO-Al2O3-2SiO2 (BAS) glass ceramic matrix is reinforced with CVD silicon carbide continuous fibers. A slurry of BAS glass powders is prepared and celsian seeds are added during ball melting. The slurry is cast into tapes which are cut to the proper size. Continuous CVD-SiC fibers are formed into mats of the desired size. The matrix tapes and the fiber mats are alternately stacked in the proper orientation. This tape-mat stack is warm pressed to produce a 'green' composite. The 'green' composite is then heated to an elevated temperature to burn out organic constituents. The remaining interim material is then hot pressed to form a silicon carbide fiber-reinforced celsian (BAS) glass-ceramic matrix composite which may be machined to size.

  2. Mechanical behavior of glass fiber polyester hybrid composite filled with natural fillers

    NASA Astrophysics Data System (ADS)

    Gupta, G.; Gupta, A.; Dhanola, A.; Raturi, A.

    2016-09-01

    Now-a-days, the natural fibers and fillers from renewable natural resources offer the potential to act as a reinforcing material for polymer composite material alternative to the use of synthetic fiber like as; glass, carbon and other man-made fibers. Among various natural fibers and fillers like banana, wheat straw, rice husk, wood powder, sisal, jute, hemp etc. are the most widely used natural fibers and fillers due to its advantages like easy availability, low density, low production cost and reasonable physical and mechanical properties This research work presents the effect of natural fillers loading with 5%, 10% and 15% on mechanical behavior of polyester based hybrid composites. The result of test depicted that hybrid composite has far better properties than single fibre glass reinforced composite under impact and flexural loads. However it is found that the hybrid composite have better strength as compared to single glass fibre composites.

  3. High-Strength / High Alkaline Resistant Fe-Phosphate Glass Fibers as Concrete Reinforcement

    SciTech Connect

    Mariano Velez

    2008-03-31

    Calcium-iron-phosphate glasses were developed whose chemical durabilities in alkaline solutions (pH 13) were comparable or superior to those of commercial alkaline-resistant (AR) silica-based glasses. However, the tensile strength of Ca-Fe-phosphate fibers, after being exposed to alkaline environments, including wet Portland cement pastes, is lower than that of current AR silicate fibers. Another series of Ca-Fe-phosphate glasses were developed with excellent chemical durability in strong acidic solutions (H2SO4, HF), indicating potential applications where silica-based fibers degrade very quickly, including E-glass. The new Ca-Fe-phosphate glasses can be melted and processed 300 to 500°C lower than silica-based glasses. This offers the possibility of manufacturing glass fibers with lower energy costs by 40-60% and the potential to reduce manufacturing waste and lower gas emissions. It was found that Ca-Fe-phosphate melts can be continuously pulled into fibers depending on the slope of the viscosity-temperature curve and with viscosity ~100 poise, using multi-hole Pt/Rh bushings.

  4. The recycling of comminuted glass-fiber-reinforced resin from electronic waste.

    PubMed

    Duan, Huabo; Jia, Weifeng; Li, Jinhui

    2010-05-01

    The reuse of comminuted glass-fiber-reinforced resin with various granularities gathered from printed circuit manufacturing residues was investigated. As fillers, these residues were converted into polymeric composite board by an extrusion and injection process using polypropylene as a bonding agent. The mechanical properties of the reproduced composite board were examined by considering the effects of mass fraction and glass-fiber distribution. Interfacial-layer micrograph analysis of the composite material fracture surface was used to study the fiber reinforcement mechanism. Results showed that using comminuted glass-fiber-reinforced resin as a filler material greatly enhanced the performance properties of the composite board. Although the length and diameter of filler varied, these variations had no appreciable effect on the mechanical properties of the processed board. Maximum values of 48.30 MPa for flexural strength, 31.34 MPa for tensile strength, and 31.34 J/m for impact strength were achieved from a composite board containing mass fractions of 30, 10, and 20% glass-fiber-reinforced resin waste, respectively. It was found that the maximum amount of recyclate that could be added to a composite board was 30% of weight. Beyond these percentages, the materials blend became unmanageable and the mixture less amenable to impregnation with fiber. Presented studies indicated that comminuted glass-fiber-reinforced resin waste-filled polypropylene composites are promising candidates for structural applications where high stiffness and fracture resistance are required.

  5. The microstructure of erbium-ytterbium co-doped oxyfluoride glass-ceramic optical fibers

    NASA Astrophysics Data System (ADS)

    Augustyn, Elżbieta; Żelechower, Michał; Stróż, Danuta; Chrapoński, Jacek

    2012-04-01

    Oxyfluoride transparent glass-ceramics combine some features of glasses (easier shaping or lower than single crystals cost of fabrication) and some advantages of rare-earth doped single crystals (narrow absorption/emission lines and longer lifetimes of luminescent levels). Since the material seems to be promising candidate for efficient fiber amplifiers, the manufacturing as well as structural and optical examination of the oxyfluoride glass-ceramic fibers doped with rare-earth ions seems to be a serious challenge. In the first stage oxyfluoride glasses of the following compositions 48SiO2-11Al2O3-7Na2CO3-10CaO-10PbO-11PbF2-3ErF3 and 48SiO2-11Al2O3-7Na2CO3-10CaO-10PbO-10PbF2-3YbF3-1ErF3 (in molar%) were fabricated from high purity commercial chemicals (Sigma-Aldrich). The fabricated glass preforms were drawn into glass fibers using the mini-tower. Finally, the transparent Er3+ doped and Er3+/Yb3+ co-doped oxyfluoride glass-ceramic fibers were obtained by controlled heat treatment of glass fibers. The preceding differential thermal analysis (DTA) studies allowed estimating both the fiber drawing temperature and the controlled crystallization temperature of glass fibers. X-ray diffraction examination (XRD) at each stage of the glass-ceramic fibers fabrication confirmed the undesirable crystallization of preforms and glass fibers has been avoided. The fibers shown their mixed amorphous-crystalline microstructure with nano-crystals of size even below 10 nm distributed in the glassy host. The crystal structure of the grown nano-crystals has been determined by XRD and confirmed by electron diffraction (SAED). Results obtained by both techniques seem to be compatible: Er3FO10Si3 (monoclinic; ICSD 92512), Pb5Al3F19 (triclinic; ICSD 91325) and Er4F2O11Si3 (triclinic; ICSD 51510) against to initially expected PbF2 crystals.

  6. Properties of indirect composites reinforced with monomer-impregnated glass fiber.

    PubMed

    Tanoue, Naomi; Sawase, Takashi; Matsumura, Hideo; McCabe, John F

    2012-07-01

    Sufficient flexural strength is required for long-term clinical use of fixed partial dentures made with fiber-reinforced composite. The flexural strengths of indirect composite materials reinforced with a monomer-preimpregnated glass fiber material were determined to evaluate the compatibility of the composites to glass fiber material. Four types (microhybrid, nanohybrid, microfilled, and minifilled) of indirect composites and a unidirectional long glass fiber material were selected for investigation. The composites were placed on a fiber plate and polymerized in accordance with the respective manufacturer's instructions. Rectangular bar fiber-composite specimens were machined and the flexural strength was calculated. The flexural strength of each indirect composite was also measured. The microfilled composite with the lowest filler content (70 wt%) exhibited the highest increase ratio using the fiber, although its strength without fiber reinforcement was the lowest (62.1 MPa). The fiber-microhybrid specimen demonstrated the highest mean strength (355.9 MPa), although the filler content of the microhybrid composite was comparatively low (73 wt%). The type of composite material should be considered for the selection of an optimal fiber-composite combination. PMID:21932008

  7. Effect of winding layer and speed on kenaf/glass fiber hybrid reinforced acrylonitrile butadiene styrene (ABS) composites

    NASA Astrophysics Data System (ADS)

    Khoni, Norizzahthul Ainaa Abdul; Sharifah Shahnaz S., B.; Ghazali, Che Mohd Ruzaidi

    2016-07-01

    The usage of natural fiber is becoming significant in composite industries due to their good performance. Single and continuous natural fibers have relatively high mechanical properties; especially their young modulus can be as high as glass fibers. Filament winding is a method to produce technically aligned composites which have high fibers content. The properties of filament winding can be tailored to meet the end product requirements. This research studied the compression properties of kenaf/glass fibers hybrid reinforced composites. Kenaf/glass fibers hybrid composite samples were fabricated by filament winding technique and their properties were compared with the properties of neat kenaf fiber and glass fibers composites. The kenaf/glass fiber hybrid composites exhibited higher strength compared to the neat glass fibers composites. Composites of helical pattern, which produced at low winding speed showed better compression resistance than hoop pattern winding, which produced at high winding speed. As predicted, kenaf composite showed highest water absorption; followed by kenaf/glass fiber hybrid composites while neat glass fiber has lowest water absorption capability.

  8. Fluorescent protein senses and reports mechanical damage in glass-fiber-reinforced polymer composites.

    PubMed

    Makyła, Katarzyna; Müller, Christoph; Lörcher, Samuel; Winkler, Thomas; Nussbaumer, Martin G; Eder, Michaela; Bruns, Nico

    2013-05-21

    Yellow fluorescent protein (YFP) is used as a mechanoresponsive layer at the fiber/resin interface in glass-fiber-reinforced composites. The protein loses its fluorescence when subjected to mechanical stress. Within the material, it reports interfacial shear debonding and barely visible impact damage by a transition from a fluorescent to a non-fluorescent state. PMID:23423911

  9. In vivo and in vitro studies of borate based glass micro-fibers for dermal repairing.

    PubMed

    Zhou, Jie; Wang, Hui; Zhao, Shichang; Zhou, Nai; Li, Le; Huang, Wenhai; Wang, Deping; Zhang, Changqing

    2016-03-01

    Full-thickness skin defects represent urgent clinical problem nowadays. Wound dressing materials are hotly needed to induce dermal reconstruction or to treat serious skin defects. In this study, the borate bioactive glass (BG) micro-fibers were fabricated and compared with the traditional material 45S5 Bioglass(®) (SiG) micro-fibers. The morphology, biodegradation and bioactivity of BG and SiG micro-fibers were investigated in vitro. The wound size reduction and angiogenic effects of BG and SiG micro-fibers were evaluated by the rat full-thickness skin defect model and Microfil technique in vivo. Results indicated that the BG micro-fibers showed thinner fiber diameter (1 μm) and better bioactivity than the SiG micro-fibers did. The ionic extracts of BG and SiG micro-fibers were not toxic to human umbilical vein endothelial cells (HUVECs). In vivo, the BG micro-fiber wound dressings obviously enhanced the formation of blood vessel, and resulted in a much faster wound size reduction than the SiG micro-fibers, or than the control groups, after 9 days application. The good skin defect reconstruction ability of BG micro-fibers contributed to the B element in the composition, which results in the better bioactivity and angiogenesis. As shown above, the novel bioactive borate glass micro-fibers are expected to provide a promising therapeutic alternative for dermal reconstruction or skin defect repair.

  10. PNNL/Euratom glass fiber optic, spent fuel neutron profile measurement system

    SciTech Connect

    SM Bowyer; JE Smart

    2000-03-03

    The glass fiber optic spent fuel neutron profile measurement system is designed to measure the neutron profile of a Castor with high reproducibility and to distinguish spent fuel Castor contents from vitrified waste Castor contents. The basic principle of the detector is that the glass fibers detect thermal neutrons. The glass is loaded with lithium enriched in Li-6, which has a high thermal neutron cross-section. A neutron is captured by the Li-6 and a He-4 and H-3 are created. Because the glass also contains Cerium in a 3{sup +} ionization state, the excitation caused by the movement of the He-4 and H-3 results in the emission of light from the cerium atoms. This light then travels to the ends of the fiber where it is detected by photon sensitive devices (e.g., photo-multiplier tubes).

  11. Energy Saving Method of Manufacturing Ceramic Products from Fiber Glass Waste

    SciTech Connect

    Michael J. Haun

    2005-07-15

    The U.S. fiber glass industry disposes of more than 260,000 tons of industrial fiber glass waste in landfills annually. New technology is needed to reprocess this industrial waste into useful products. A low-cost energy-saving method of manufacturing ceramic tile from fiber glass waste was developed. The technology is based on sintering fiber glass waste at 700-900 degrees C to produce products which traditionally require firing temperatures of >1200 degrees C, or glass-melting temperatures >1500 degrees C. The process also eliminates other energy intensive processing steps, including mining and transportation of raw materials, spray-drying to produce granulated powder, drying pressed tile, and glazing. The technology completely transforms fiber glass waste into a dense ceramic product, so that all future environmental problems in the handling and disposal of the fibers is eliminated. The processing steps were developed and optimized to produce glossy and matte surface finishes for wall and floor tile applications. High-quality prototype tile samples were processed for demonstration and tile standards testing. A Market Assessment confirmed the market potential for tile products produced by the technology. Manufacturing equipment trials were successfully conducted for each step of the process. An industrial demonstration plant was designed, including equipment and operating cost analysis. A fiber glass manufacturer was selected as an industrial partner to commercialize the technology. A technology development and licensing agreement was completed with the industrial partner. Haun labs will continue working to transfer the technology and assist the industrial partner with commercialization beyond the DOE project.

  12. Pulmonary deposition and clearance of glass fiber in rat lungs after long-term inhalation.

    PubMed Central

    Tanaka, I; Oyabu, T; Ishimatsu, S; Hori, H; Higashi, T; Yamato, H

    1994-01-01

    In this study Wistar male rats were exposed to glass fiber obtained by the disintegration of a binderless glass fiber filter, for 6 hr/day, 5 days/week for 12 months. The mass median aerodynamic diameter (MMAD) of the fiber, determined with an Andersen sampler, was 2.6 microns. The count median diameter and length of the fibers measured by scanning electron microscopy (SEM) were 0.51 and 5.5 microns, respectively. The daily average exposure fiber concentration was 2.2 +/- 0.6 mg/m3. Some rats were sacrificed 24 hr after removal from the exposure chamber following the 12 months' exposure. Others were sacrificed 12 months after the end of exposure. The wet organ weights were recorded at the time of death and the silicon content of the lungs was determined by absorption spectrophotometry. After 12 months' exposure, the amount of glass fiber retained in the rat lungs was 1.49 mg, and after 12 months' clearance it was 0.61 mg. The biological half-life in a single exponential model was to be 8.7 months, much longer than the predicted value of 1.5 months obtained in a previous experiment in which rats were exposed for 4 weeks to the same glass fiber. PMID:7882935

  13. Flexural Strength Comparison of Silorane- and Methacrylate-Based Composites with Pre-impregnated Glass Fiber

    PubMed Central

    Doozandeh, Maryam; Alavi, Ali Asghar; Karimizadeh, Zahra

    2016-01-01

    Statement of the Problem Sufficient adhesion between silorane/methacrylate-based composites and methacrylate impregnated glass fiber increases the benefits of fibers and enhances the mechanical and clinical performance of both composites. Purpose The aim of this study was to evaluate the compatibility of silorane and methacrylate-based composites with pre-impregnated glass fiber by using flexural strength (FS) test. Materials and Method A total of 60 bar specimens were prepared in a split mold (25×2×2 mm) in 6 groups (n=10). In groups 1 and 4 (control), silorane-based (Filtek P90) and nanohybrid (Filtek Z350) composites were placed into the mold and photopolymerized with a high-intensity curing unit. In groups 2 and 5, pre-impregnated glass fiber was first placed into the mold and after two minutes of curing, the mold was filled with respective composites. Prior to filling the mold in groups 3 and 6, an intermediate adhesive layer was applied to the glass fiber. The specimens were stored in distilled water for 24 hours and then their flexural strength was measured by 3 point bending test, using universal testing machine at the crosshead speed of 1 mm/min. Two-way ANOVA and post-hoc test were used for analyzing the data (p< 0.05). Results A significant difference was observed between the groups (p< 0.05). The highest FS was registered for combination of Z350 composite, impregnated glass fiber, and application of intermediate adhesive layer .The lowest FS was obtained in Filtek P90 alone. Cohesive failure in composite was the predominant failure in all groups, except group 5 in which adhesive failure between the composite and fiber was exclusively observed. Conclusion Significant improvement in FS was achieved for both composites with glass fiber. Additional application of intermediate adhesive layer before composite build up seems to increase FS. Nanohybrid composite showed higher FS than silorane-based composite. PMID:27284555

  14. Proof-testing and probabilistic lifetime estimation of glass fibers for sensor applications.

    PubMed

    Komachiya, M; Minamitani, R; Fumino, T; Sakaguchi, T; Watanabe, S

    1999-05-01

    The mechanical reliability of sensing glass fiber is one of the important problems in the practical use of fiber-optic sensors. To ensure long-term reliability on a mass-production level, a method of proof-testing is applied to a sensing glass fiber that will be subjected to mechanical deformation in its service situation. We propose to employ a higher strain level (screening level) in the proof-testing with a fiber-recoating technique that can suppress excessive damage during the testing. We consider a standard lifetime of 15 years of automotive applications and ensure a practical level of failure probability by a model calculation by using the strength data of a prototype fiber with the method of fracture-mechanics theory. PMID:18319853

  15. Single-mode hollow-core photonic crystal fiber made from soft glass.

    PubMed

    Jiang, X; Euser, T G; Abdolvand, A; Babic, F; Tani, F; Joly, N Y; Travers, J C; Russell, P St J

    2011-08-01

    We demonstrate the first soft-glass hollow core photonic crystal fiber. The fiber is made from a high-index lead-silicate glass (Schott SF6, refractive index 1.82 at 500 nm). Fabricated by the stack-and-draw technique, the fiber incorporates a 7-cell hollow core embedded in a highly uniform 6-layer cladding structure that resembles a kagomé-like lattice. Effective single mode guidance of light is observed from 750 to 1050 nm in a large mode area (core diameter ~30 µm) with a low loss of 0.74 dB/m. The underlying guidance mechanism of the fiber is investigated using finite element modeling. The fiber is promising for applications requiring single mode guidance in a large mode area, such as particle guidance, fluid and gas filled devices.

  16. Single-mode hollow-core photonic crystal fiber made from soft glass

    NASA Astrophysics Data System (ADS)

    Jiang, X.; Euser, T. G.; Abdolvand, A.; Babic, F.; Tani, F.; Joly, N. Y.; Travers, J. C.; St. J. Russell, P.

    2011-08-01

    We demonstrate the first soft-glass hollow core photonic crystal fiber. The fiber is made from a high-index lead-silicate glass (Schott SF6, refractive index 1.82 at 500 nm). Fabricated by the stack-and-draw technique, the fiber incorporates a 7-cell hollow core embedded in a highly uniform 6-layer cladding structure that resembles a kagomé-like lattice. Effective single mode guidance of light is observed from 750 to 1050 nm in a large mode area (core diameter ~30 μm) with a low loss of 0.74 dB/m. The underlying guidance mechanism of the fiber is investigated using finite element modeling. The fiber is promising for applications requiring single mode guidance in a large mode area, such as particle guidance, fluid and gas filled devices.

  17. Proof-testing and probabilistic lifetime estimation of glass fibers for sensor applications.

    PubMed

    Komachiya, M; Minamitani, R; Fumino, T; Sakaguchi, T; Watanabe, S

    1999-05-01

    The mechanical reliability of sensing glass fiber is one of the important problems in the practical use of fiber-optic sensors. To ensure long-term reliability on a mass-production level, a method of proof-testing is applied to a sensing glass fiber that will be subjected to mechanical deformation in its service situation. We propose to employ a higher strain level (screening level) in the proof-testing with a fiber-recoating technique that can suppress excessive damage during the testing. We consider a standard lifetime of 15 years of automotive applications and ensure a practical level of failure probability by a model calculation by using the strength data of a prototype fiber with the method of fracture-mechanics theory.

  18. Environmental effects on the hybrid glass fiber/carbon fiber composites

    NASA Astrophysics Data System (ADS)

    Tsai, Yun-I.

    2009-12-01

    Fiber reinforced polymer composites (FRPCs) have been widely used to replace conventional metals due to the high specific strength, fatigue resistance, and light weight. In the power distribution industry, an advanced composites rod has been developed to replace conventional steel cable as the load-bearing core of overhead conductors. Such conductors, called aluminum conductor composite core (ACCC) significantly increases the transmitting efficiency of existing power grid system without extensive rebuilding expenses, while meeting future demand for electricity. In general, the service life of such overhead conductors is required to be at least 30 years. Therefore, the long-term endurance of the composite core in various environments must be well-understood. Accelerated aging by hygrothermal exposure was conducted to determine the effect of moisture on the glass fiber (GF)/carbon fiber (CF) hybrid composites. The influence of water immersion and humid air exposure on mechanical properties is investigated. Results indicated that immersion in water is the most severe environment for such hybrid GF/CF composites, and results in greater saturation and degradation of properties. When immersed directly in water, the hybrid GF/CF composites exhibit a moisture uptake behavior that is more complex than composite materials reinforced with only one type of fiber. The unusual diffusion behavior is attributed to a higher packing density of fibers at the annular GF/CF interface, which acts as a temporary moisture barrier. Moisture uptake leads to the mechanical and thermal degradation of such hybrid GF/CF composites. Findings presented here indicate that the degradation is a function of exposure temperature, time, and moisture uptake level. Results also indicate that such hybrid GF/CF composites recover short beam shear (SBS) strength and glass transition temperature (Tg) values comparable to pre-aged samples after removal of the absorbed moisture. In the hygrothermal environment

  19. Tapered TeX glass optical fibers for remote IR spectroscopic analysis

    NASA Astrophysics Data System (ADS)

    Le Foulgoc, Karine; Le Neindre, Lydia; Zhang, Xhang H.; Lucas, Jacques

    1996-12-01

    Infrared TeX fibers operating in a wide wavelength region have various potential uses in the short distance area such as laser power delivery, remote temperature monitoring and chemical analysis. TeX glass fibers with a minimum attenuation of 0.5 dB/m in the 7 - 10 micrometer range have been obtained. A plastic coating protects these fibers from external environment and improves their mechanical properties. Remote spectroscopy using mono-index fiber is one of the most promising applications. This new technology allows the identification and in situ analysis of many substances such as oils and fertilizers, which have their fingerprint in the 2 - 13 micrometer domain. The detection efficiency using evanescent wave absorption has been studied as a function of the fiber's diameter. It is found that the sensitivity increases very rapidly when the fibers' diameter decreases. The possibility of detecting very low concentrations has been tested by using TeX tapered fibers.

  20. Ply Thickness Fiber Glass on Windmill Drive Salt Water Pump

    NASA Astrophysics Data System (ADS)

    Sifa, Agus; Badruzzaman; Suwandi, Dedi

    2016-04-01

    Factors management of salt-making processes need to be considered selection of the location and the season is very important to support the efforts of salting. Windmills owned by the farmers are still using wood materials are made each year it is not effectively done and the shape of windmills made not in accordance with the requirements without considering the wind speed and the pumping speed control influenced by the weight and size of windmill, it affects the productivity of salt. to optimize the function of windmills on pumping salt water by change the material blade on the wheel by using a material composite, composite or fiberglass are used for blades on windmills made of a material a mixture of Epoxy-Resin and Matrix E-Glass. The mechanical characteristics of the power of his blade one of determining the materials used and the thickness of the blade, which needed a strong and lightweight. The calculation result thick fiberglass with a composition of 60% fiber and 40% epoxy, at a wind speedof area salt fields 9 m/s, the drag force that occurs at 11,56 kg, then the calculation result by 0,19 mm thick with a layer of 10, the total thickness of 1,9 mm, with a density of 1760 kg/m3, mechanical character of elongated elastic modulus of 46200 MPa, modulus of transverse elasticity of 10309,6 MPa, shear modulus of 3719 MPa and Poisson ratio of 0,31, then the calculation using the finite element ABAQUS obtained critical point at the confluence of the blade to the value of Von Mises tension was happening 1,158e9 MPa maximum and minimum 2,123e5 MPa, for a maximum value of displacement occurred condition at the tip of the blade. The performance test results windmills at a wind speed of 5,5 m/s wind power shows that occur 402,42 watts and power turbines produced 44,21 watt, and TSR 0,095 and the value Cp of 0,1, test results windmill in salt fields in the beginning rotation windmill lighter, able to move above wind speed of 5.5 m/s.

  1. Strongly nonlinear optical glass fibers from noncentrosymmetric phase-change chalcogenide materials.

    PubMed

    Chung, In; Jang, Joon I; Malliakas, Christos D; Ketterson, John B; Kanatzidis, Mercouri G

    2010-01-13

    We report that the one-dimensional polar selenophosphate compounds APSe(6) (A = K, Rb), which show crystal-glass phase-change behavior, exhibit strong second harmonic generation (SHG) response in both crystal and glassy forms. The crystalline materials are type-I phase-matchable with SHG coefficients chi((2)) of 151.3 and 149.4 pm V(-1) for K(+) and Rb(+) salts, respectively, which is the highest among phase-matchable nonlinear optical (NLO) materials with band gaps over 1.0 eV. The glass of APSe(6) exhibits comparable SHG intensities to the top infrared NLO material AgGaSe(2) without any poling treatments. APSe(6) exhibit excellent mid-IR transparency. We demonstrate that starting from noncentrosymmetric phase-change materials such as APSe(6) (A = K, Rb), we can obtain optical glass fibers with strong, intrinsic, and temporally stable second-order nonlinear optical (NLO) response. The as-prepared glass fibers exhibit SHG and difference frequency generation (DFG) responses over a wide range of wavelengths. Raman spectroscopy and pair distribution function (PDF) analyses provide further understanding of the local structure in amorphous state of KPSe(6) bulk glass and glass fiber. We propose that this approach can be widely applied to prepare permanent NLO glass from materials that undergo a phase-change process.

  2. Strongly Nonlinear Optical Glass Fibers from Noncentrosymmetric Phase-Change Chalcogenide Materials

    SciTech Connect

    Chung, In; Jang, Joon I.; Malliakas, Christos D.; Ketterson, John B.; Kanatzidis, Mercouri G.

    2010-08-27

    We report that the one-dimensional polar selenophosphate compounds APSe{sub 6} (A = K, Rb), which show crystal-glass phase-change behavior, exhibit strong second harmonic generation (SHG) response in both crystal and glassy forms. The crystalline materials are type-I phase-matchable with SHG coefficients {chi}{sup (2)} of 151.3 and 149.4 pm V{sup -1} for K{sup +} and Rb{sup +} salts, respectively, which is the highest among phase-matchable nonlinear optical (NLO) materials with band gaps over 1.0 eV. The glass of APSe{sub 6} exhibits comparable SHG intensities to the top infrared NLO material AgGaSe{sub 2} without any poling treatments. APSe{sub 6} exhibit excellent mid-IR transparency. We demonstrate that starting from noncentrosymmetric phase-change materials such as APSe{sub 6} (A = K, Rb), we can obtain optical glass fibers with strong, intrinsic, and temporally stable second-order nonlinear optical (NLO) response. The as-prepared glass fibers exhibit SHG and difference frequency generation (DFG) responses over a wide range of wavelengths. Raman spectroscopy and pair distribution function (PDF) analyses provide further understanding of the local structure in amorphous state of KPSe{sub 6} bulk glass and glass fiber. We propose that this approach can be widely applied to prepare permanent NLO glass from materials that undergo a phase-change process.

  3. Preparation, mechanical, and in vitro properties of glass fiber-reinforced polycarbonate composites for orthodontic application.

    PubMed

    Tanimoto, Yasuhiro; Inami, Toshihiro; Yamaguchi, Masaru; Nishiyama, Norihiro; Kasai, Kazutaka

    2015-05-01

    Generally, orthodontic treatment uses metallic wires made from stainless steel, cobalt-chromium-nickel alloy, β-titanium alloy, and nickel-titanium (Ni-Ti) alloy. However, these wires are not esthetically pleasing and may induce allergic or toxic reactions. To correct these issues, in the present study we developed glass-fiber-reinforced plastic (GFRP) orthodontic wires made from polycarbonate and E-glass fiber by using pultrusion. After fabricating these GFRP round wires with a diameter of 0.45 mm (0.018 inch), we examined their mechanical and in vitro properties. To investigate how the glass-fiber diameter affected their physical properties, we prepared GFRP wires of varying diameters (7 and 13 µm). Both the GFRP with 13-µm fibers (GFRP-13) and GFRP with 7 µm fibers (GFRP-7) were more transparent than the metallic orthodontic wires. Flexural strengths of GFRP-13 and GFRP-7 were 690.3 ± 99.2 and 938.1 ± 95.0 MPa, respectively; flexural moduli of GFRP-13 and GFRP-7 were 25.4 ± 4.9 and 34.7 ± 7.7 GPa, respectively. These flexural properties of the GFRP wires were nearly equivalent to those of available Ni-Ti wires. GFRP-7 had better flexural properties than GFRP-13, indicating that the flexural properties of GFRP increase with decreasing fiber diameter. Using thermocycling, we found no significant change in the flexural properties of the GFRPs after 600 or 1,200 cycles. Using a cytotoxicity detection kit, we found that the glass fiber and polycarbonate components comprising the GFRP were not cytotoxic within the limitations of this study. We expect this metal-free GFRP wire composed of polycarbonate and glass fiber to be useful as an esthetically pleasing alternative to current metallic orthodontic wire.

  4. Simulation of Light Propagation within Glass Fiber Filled Thermoplastics for Laser Transmission Welding

    NASA Astrophysics Data System (ADS)

    Hohmann, Martin; Devrient, Martin; Klämpfl, Florian; Roth, Stephan; Schmidt, Michael

    Laser transmission welding is a well-known joining technology for thermoplastics. Because of the needs of lightweight, cost effective and green production nowadays injection molded parts usually have to be welded. These parts are made out of semi-crystalline thermoplastics which are filled to a high amount with glass fibers. This leads to higher absorption and more scattering within the upper joining partner and hasa negative influence onto the welding process. Here a ray tracing model capable of considering every single glass fiber is introduced. Hence spatially not equally distributed glass fibers can be taken into account. Therefore the model is able to calculate in detail the welding laser intensity distribution after transmission through the upper joining partner. Data gained by numerical simulation is compared to data obtained by laser radiation scattering experiments. Thus observed deviation is quantified and discussed.

  5. Mid-infrared surface plasmon polariton chemical sensing on fiber-coupled ITO coated glass

    NASA Astrophysics Data System (ADS)

    Martínez, Javier; Ródenas, Airán; Aguiló, Magdalena; Fernandez, Toney; Solis, Javier; Díaz, Francesc

    2016-06-01

    A novel fiber-coupled ITO coated glass slide sensor for performing surface plasmon polariton chemical monitoring in the 3.5 um mid-IR range is reported. Efficient mid-IR fiber coupling is achieved with 3D laser written waveguides, and the coupling of glass waveguide modes to ITO SPPs is driven by the varying phase matching conditions of different aqueous analytes across the anomalous dispersion range determined by their molecular fingerprints. By means of using both a mid-IR fiber supercontinuum source and a diode laser the excitation of SPPs is demonstrated. The efficient optical monitoring of mid-IR SPPs in smart glass could have a broad range of applications in biological and chemical sensing.

  6. On the study of crack-initiation fracture toughness of fiber glass asphalt shingles

    SciTech Connect

    Shiao, M.L.

    1999-07-01

    The fracture behavior of fiber glass asphalt shingles was examined by measuring their J-integral fracture toughness at crack initiation. The corresponding fracture mechanisms were also studied by in situ fracture observation and by scanning electron microscopy. The applicability of using J-integral fracture toughness to characterize asphalt shingles was discussed and its relationships to other mechanical properties was established. The results indicated that the fracture toughness at crack initiation can be accurately measured for fiber glass shingles and the values may be used to characterize their cracking resistance. Fracture toughness measured from various shingle samples was found to correlate to the shingle's tensile toughness and to its tear strength. Preliminary results on fracture mechanisms suggested that failure in the asphalt coatings by micro-cavitation may be the controlling event leading to crack advance. The importance of the glass fiber mat on a shingle's resistance to fracture was also discussed.

  7. Analysis of the mechanical and thermal properties of jute and glass fiber as reinforcement epoxy hybrid composites.

    PubMed

    Braga, R A; Magalhaes, P A A

    2015-11-01

    This work describes the study to investigate and compare the mechanical and thermal properties of raw jute and glass fiber reinforced epoxy hybrid composites. To improve the mechanical properties, jute fiber was hybridized with glass fiber. Epoxy resin, jute and glass fibers were laminated in three weight ratios (69/31/0, 68/25/7 and 64/18/19) respectively to form composites. The tensile, flexural, impact, density, thermal and water absorption tests were carried out using hybrid composite samples. This study shows that the addition of jute fiber and glass fiber in epoxy, increases the density, the impact energy, the tensile strength and the flexural strength, but decreases the loss mass in function of temperature and the water absorption. Morphological analysis was carried out to observe fracture behavior and fiber pull-out of the samples using scanning electron microscope.

  8. Analysis of the mechanical and thermal properties of jute and glass fiber as reinforcement epoxy hybrid composites.

    PubMed

    Braga, R A; Magalhaes, P A A

    2015-11-01

    This work describes the study to investigate and compare the mechanical and thermal properties of raw jute and glass fiber reinforced epoxy hybrid composites. To improve the mechanical properties, jute fiber was hybridized with glass fiber. Epoxy resin, jute and glass fibers were laminated in three weight ratios (69/31/0, 68/25/7 and 64/18/19) respectively to form composites. The tensile, flexural, impact, density, thermal and water absorption tests were carried out using hybrid composite samples. This study shows that the addition of jute fiber and glass fiber in epoxy, increases the density, the impact energy, the tensile strength and the flexural strength, but decreases the loss mass in function of temperature and the water absorption. Morphological analysis was carried out to observe fracture behavior and fiber pull-out of the samples using scanning electron microscope. PMID:26249589

  9. Push-out bond strength of fiber posts to root dentin using glass ionomer and resin modified glass ionomer cements

    PubMed Central

    PEREIRA, Jefferson Ricardo; da ROSA, Ricardo Abreu; SÓ, Marcus Vinícius Reis; AFONSO, Daniele; KUGA, Milton Carlos; HONÓRIO, Heitor Marques; do VALLE, Accácio Lins; VIDOTTI, Hugo Alberto

    2014-01-01

    Objective The purpose of this study was to assess the push-out bond strength of glass fiber posts to root dentin after cementation with glass ionomer (GICs) and resin-modified glass ionomer cements (RMGICs). Material and Methods Fifty human maxillary canines were transversally sectioned at 15 mm from the apex. Canals were prepared with a step back technique until the application of a #55 K-file and filled. Post spaces were prepared and specimens were divided into five groups according to the cement used for post cementation: Luting & Lining Cement; Fuji II LC Improved; RelyX Luting; Ketac Cem; and Ionoseal. After cementation of the glass fiber posts, all roots were stored at 100% humidity until testing. For push-out test, 1-mm thick slices were produced. The push-out test was performed in a universal testing machine at a crosshead speed of 0.5 mm/minute and the values (MPa) were analyzed by Kolmogorov-Smirnov and Levene's tests and by two-way ANOVA and Tukey's post hoc test at a significance level of 5%. Results Fiber posts cemented using Luting & Lining Cement, Fuji II LC Improved, and Ketac Cem presented the highest bond strength to root dentin, followed by RelyX Luting. Ionoseal presented the lowest bond strength values (P>0.05). The post level did not influence the bond strength of fiber posts to root dentin (P=0.148). The major cause of failure was cohesive at the cement for all GICs and RMGICs. Conclusions Except for Ionoseal, all cements provided satisfactory bond strength values. PMID:25004052

  10. Mechanical properties of glass fiber-reinforced endodontic posts.

    PubMed

    Cheleux, Nicolas; Sharrock, Patrick J

    2009-10-01

    Five types of posts from three different manufacturers (RTD, France, Carbotech, France and Ivoclar-Vivadent, Liechenstein) were subjected to three-point bending tests in order to obtain fatigue results, flexural strength and modulus. Transverse and longitudinal polished sections were examined by scanning electron microscopy and evaluated by computer-assisted image analysis. Physical parameters, including volume % of fibers, their dispersion index and coordination number, were calculated and correlated with mechanical properties. The weaker posts showed more fiber dispersion, higher resin contents, larger numbers of visible defects and reduced fatigue resistance. The flexural strength was inversely correlated with fiber diameter and the flexural modulus was weakly related to coordination number, volume % of fibers and dispersion index. The interfacial adhesion between the silica fibers and the resin matrix was observed to be of paramount importance.

  11. Silver iodide phosphate glass microsphere resonator integrated on an optical fiber taper.

    PubMed

    Milenko, Karolina; Konidakis, Ioannis; Pissadakis, Stavros

    2016-05-15

    In this Letter, we demonstrate the fabrication and characterization of a robust and functional whispering gallery mode (WGM) resonating system based on a silver iodide phosphate glass microsphere melted on an optical fiber taper. The fabrication process is presented, together with spectral characterization of the device. The effect of the thermal annealing of the soft glass resonator on the whispering gallery modes' excitation and Q-factor is shown and discussed. PMID:27176958

  12. Adhesion strategy and early bond strengths of glass-fiber posts luted into root canals.

    PubMed

    Faria-e-Silva, André Luis; Mendonça, Adriano Augusto Melo; Garcez, Rosa Maria Viana de Bragança; Oliveira, Aline da Silva de; Moreira, Andressa Goicochea; Moraes, Rafael Ratto de

    2012-01-01

    This study investigated the effect of coinitiator solutions and self-adhesive resin cement on the early retention of glass-fiber posts. Cylindrical glass-fiber posts were luted into 40 incisor roots with different adhesion strategies (n = 10): SB2, Single Bond 2 + conventional resin cement (RelyX ARC); AP, Scotchbond Multipurpose Plus (SBMP) activator + primer + ARC; APC, SBMP activator + primer + catalyst + ARC; and UNI, self-adhesive cement (RelyX Unicem). Pull-out bond strength results at 10 min after cementation showed APC > UNI > SB2 = AP (P < 0.05). The adhesion strategy significantly affected early bonding to root canals.

  13. Method of producing a silicon carbide fiber reinforced strontium aluminosilicate glass-ceramic matrix composite

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P. (Inventor)

    1995-01-01

    A SrO-Al2O3-2SrO2 (SAS) glass ceramic matrix is reinforced with CVD SiC continuous fibers. This material is prepared by casting a slurry of SAS glass powder into tapes. Mats of continuous CVD-SiC fibers are alternately stacked with the matrix tapes. This tape-mat stack is warm-pressed to produce a 'green' composite. Organic constituents are burned out of the 'green' composite, and the remaining interim material is hot pressed.

  14. Silicon carbide fiber reinforced strontium aluminosilicate glass-ceramic matrix composite

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam (Inventor)

    1992-01-01

    A SrO-Al2O3 - 2SrO2 (SAS) glass ceramic matrix is reinforced with CVD SiC continuous fibers. This material is prepared by casting a slurry of SAS glass powder into tapes. Mats of continuous CVD-SiC fibers are alternately stacked with the matrix tapes. This tape-mat stack is warm-pressed to produce a 'green' composite. Organic constituents are burned out of the 'green' composite, and the remaining interim material is hot pressed.

  15. Structural considerations in design of lightweight glass-fiber composite pressure vessels

    NASA Technical Reports Server (NTRS)

    Faddoul, J. R.

    1973-01-01

    The development of structurally efficient, metal-lined, glass-fiber composite pressure vessels. Both the current state-of-the-art and current problems are discussed along with fracture mechanics considerations for the metal liner. The design concepts used for metal-lined, glass-fiber, composite pressure vessels are described and the structural characteristics of the composite designs are compared with each other and with homogeneous metal pressure vessels. Specific design techniques and available design data are identified. Results of a current program to evaluate flaw growth and fracture characteristics of the metal liners are reviewed and the impact of these results on composite pressure vessel designs is discussed.

  16. Two-color mid-infrared thermometer with a hollow glass optical fiber

    SciTech Connect

    Small, W. IV; Celliers, P.M.; Da Silva, L.B.; Matthews, D.L.; Soltz, B.A.

    1998-10-01

    We have developed a low-temperature optical-fiber-based two-color infrared thermometer. A single 700-{mu}m-bore hollow glass optical fiber collects and transmits radiation that is then modulated and split into two paths by a reflective optical chopper. Two different thermoelectrically cooled mid-infrared HgCdZnTe photoconductors monitor the chopped signals that are recovered with lock-in amplification. With the two previously obtained blackbody calibration equations, a computer algorithm calculates the true temperature and emissivity of a target in real time, taking into account reflection of the ambient radiation field from the target surface. The small numerical aperture of the hollow glass fiber and the fast response of the detectors, together with the two-color principle, permit high spatial and temporal resolution while allowing the user to dynamically alter the fiber-to-target distance. {copyright} 1998 Optical Society of America

  17. Two-color mid-infrared thermometer with a hollow glass optical fiber.

    PubMed

    Small, W; Celliers, P M; Da Silva, L B; Matthews, D L; Soltz, B A

    1998-10-01

    We have developed a low-temperature optical-fiber-based two-color infrared thermometer. A single 700-mum-bore hollow glass optical fiber collects and transmits radiation that is then modulated and split into two paths by a reflective optical chopper. Two different thermoelectrically cooled mid-infrared HgCdZnTe photoconductors monitor the chopped signals that are recovered with lock-in amplification. With the two previously obtained blackbody calibration equations, a computer algorithm calculates the true temperature and emissivity of a target in real time, taking into account reflection of the ambient radiation field from the target surface. The small numerical aperture of the hollow glass fiber and the fast response of the detectors, together with the two-color principle, permit high spatial and temporal resolution while allowing the user to dynamically alter the fiber-to-target distance.

  18. Chalcogenide glass fibers: Optical window tailoring and suitability for bio-chemical sensing

    NASA Astrophysics Data System (ADS)

    Lucas, Pierre; Coleman, Garrett J.; Jiang, Shibin; Luo, Tao; Yang, Zhiyong

    2015-09-01

    Glassy materials based on chalcogen elements are becoming increasingly prominent in the development of advanced infrared sensors. In particular, infrared fibers constitute a desirable sensing platform due to their high sensitivity and versatile remote collection capabilities for in-situ detection. Tailoring the transparency window of an optical material to the vibrational signature of a target molecule is important for the design of infrared sensor, and particularly for fiber evanescent wave spectroscopy. Here we review the basic principles and recent developments in the fabrication of chalcogenide glass infrared fibers for application as bio-chemical sensors. We emphasize the challenges in designing materials that combine good rheological properties with chemical stability and sufficiently wide optical windows for bio-chemical sensing. The limitation in optical transparency due to higher order overtones of the amorphous network vibrations is established for this family of glasses. It is shown that glasses with wide optical window suffer from higher order overtone absorptions. Compositional engineering with heavy elements such as iodine is shown to widen the optical window but at the cost of lower chemical stability. The optical attenuations of various families of chalcogenide glass fibers are presented and weighed for their applications as chemical sensors. It is then shown that long-wave infrared fibers can be designed to optimize the collection of selective signal from bio-molecules such as cells and tissues. Issues of toxicity and mechanical resistance in the context of bio-sensing are also discussed.

  19. Excitation of single-mode glass fiber by partially coherent sources

    NASA Astrophysics Data System (ADS)

    Hillerich, Bernd

    Coherent light sources for single mode glass fibers on distances up to 10 km luminescence diodes are shown to be more appropriate than semiconductor laser diodes. Mathematical models are given for the computation of coherence function of partially coherent sources like luminescence diodes. The coupling efficiency between radiation source and monomode fibers with or without optical coupling is studied. Comparison of results between numerical simulation and measured coupling efficiency is concordant.

  20. Numerical study on mixing performance of glass fiber dispersion in a twin-screw extruder with backward-mixing elements

    NASA Astrophysics Data System (ADS)

    Hirata, Kunihiro; Ishida, Hiroshi; Hiragori, Motohiro; Nakayama, Yasuya; Kajiwara, Toshihisa

    2015-05-01

    In the kneading of glass-fiber-reinforced plastics by twin-screw extrusion, the use of a backward-mixing screw (BMS) element for melt mixing has been found to be effective in dispersing glass-fiber bundles. In this study, we use the computational fluid dynamics (CFD) to study the mechanism of dispersion by a BMS element for glass fiber bundles. The result of CFD for a BMS and a forward kneading disk (FKD) reveals that the melt mixing by a BMS is highly effective to act the required stress on overall resin. In addition, there is a good correlation between the incidence of undispersed glass-fiber bundles measured experimentally and the minimum value of distribution of the time-integrated stress calculated numerically. On the basis of the above results, we propose a method to predict the operating conditions in which the incident probability of undispersed glass-fiber bundles and thermal degradation are controlled.

  1. Growth and differentiation of osteoblastic cells on 13-93 bioactive glass fibers and scaffolds.

    PubMed

    Brown, Roger F; Day, Delbert E; Day, Thomas E; Jung, Steve; Rahaman, Mohamed N; Fu, Qiang

    2008-03-01

    This in vitro study was conducted to evaluate the ability of two types of constructs of bioactive, silica-based 13-93 glass fibers to support the growth and differentiation of MC3T3-E1 osteoblastic cells. The two types of constructs tested included single-layer 13-93 glass fiber rafts and three-dimensional porous scaffolds formed from sintered 13-93 fibers. Scanning electron micrographs showed a closely adhering, well-spread morphology of MC3T3-E1 cells seeded on both types of constructs. The scanning electron microscopy images also showed a continuous increase in cell densities during a 6 day incubation on 13-93 glass fiber rafts and scaffolds. Quantitative fluorescence measurements of DNA also revealed a linear increase in cell density during a 6 day incubation on both types of 13-93 constructs. Examination of scaffolds incubated in MTT containing medium showed the presence of metabolically active viable cells within the interior of the scaffold. The addition of ascorbic acid to MC3T3-E1 cells cultured on the 13-93 glass fibers triggered a threefold increase in alkaline phosphatase, a key indicator of osteoblast differentiation. The sintered scaffolds were found to have open, interconnected pores favorable for tissue ingrowth with a compressive strength similar to cancellous bone. Collectively, the results indicate that 13-93 glass fiber scaffolds are a favorable substrate for the growth and differentiation of osteoblasts and a promising material for bone tissue engineering and repair of bone defects.

  2. Influence of the curing cycles on the fatigue performance of unidirectional glass fiber reinforced epoxy composites

    NASA Astrophysics Data System (ADS)

    Hüther, Jonas; Brøndsted, Povl

    2016-07-01

    During the manufacturing process of fiber reinforced polymers the curing reaction of the resin results in shrinkage of the resin and introduces internal stresses in the composites. When curing at higher temperatures in order to shorten up the processing time, higher curing stresses and thermal stresses are built up and frozen, as residual stresses occur. In the present work, a glass fiber reinforced epoxy composite laminate with an unidirectional architecture based on non-crimp fabrics with backing fibers is investigated. Three different curing cycles (time-temperature cycles) are used, leading to different levels of internal stresses. The mechanical properties, static strength and fatigue life time, are measured in three different directions of the material, i.e. the fiber direction, 0°, the 30° off axis direction, and the 90° direction transverse to the fiber direction. It is experimentally demonstrated that the resulting residual stresses barely influences the quasi-static mechanical properties of reinforced glass-fiber composites. It is found that the fatigue performance in the 0° direction is significantly influenced by the internal stresses, whereas the fatigue performance in the off axes directions so is not significantly influenced of these stresses. This is related to the observations that the damage mechanisms in the off axes directions are mainly related to shear failure in the matrix and in the interface between fiber and matrix and different from the damage mechanisms in the fiber direction, where the damage initiates in the transverse backing fibers and is directly related to fiber fractures in the load-carrying axial fiber bundles.

  3. The deposition of boron nitride and carbon films on silica glass fibers

    SciTech Connect

    Smith, W.L.; Michalske, T.A.; Rye, R.R.

    1993-11-01

    A chemical vapor deposition technique is used to produce amorphous boron nitride and carbon thin films on high strength silica glass fibers. In this method, the fiber is drawn under ultra high vacuum conditions and low pressure process gases, in the presence of a hot tungsten filament, are used to grow films at low substrate temperatures. Films deposited with this technique do not degrade the intrinsic pristine strength of the silica fibers under dry conditions and, when stressed in chemically aggressive environments, act as effective barrier coatings.

  4. Chronic inhalation study of fiber glass and amosite asbestos in hamsters: twelve-month preliminary results.

    PubMed Central

    Hesterberg, T W; Axten, C; McConnell, E E; Oberdörster, G; Everitt, J; Miiller, W C; Chevalier, J; Chase, G R; Thevenaz, P

    1997-01-01

    The effects of chronic inhalation of glass fibers and amosite asbestos are currently under study in hamsters. The study includes 18 months of inhalation exposure followed by lifetime recovery. Syrian golden hamsters are exposed, nose only, for 6 hr/day, 5 day/week to size-selected test fibers: MMVF10a (Schuller 901 insulation glass); MMVF33 (Schuller 475 durable glass); amosite asbestos (three doses); or to filtered air (controls). Here we report interim results on airborne fiber characterization, lung fiber burden, and pathology (preliminary) through 12 months. Aerosolized test fibers averaged 15 to 20 microns in length and 0.5 to 1 micron in diameter. Target aerosol concentrations of World Health Organization (WHO) fibers (longer than 5 microns) were 250 fibers/cc for MMVF10a and MMVF33, and 25, 125, or 250 fibers/cc for amosite. WHO fiber lung burdens showed time-dependent and (for amosite) dose-dependent increases. After a 12-month exposure, lung burdens of fibers longer than 20 microns were greatest with amosite high and mid doses, similar for low-dose amosite and MMVF33, and smaller for MMVF10a. Biological responses of animals exposed for 12 months to MMVF10a were limited to nonspecific pulmonary inflammation. However, exposures to MMVF33 and each of three doses of amosite were associated with lung fibrosis and possible mesotheliomas (1 with MMVF33 and 2, 3, and 1 with amosite low, mid, and high doses, respectively). Pulmonary and pleural changes associated with amosite were qualitatively and quantitatively more severe than those associated with MMVF33. As of the 12-month time point, this study demonstrates that two different fiber glass compositions with similar fiber dimensions but different durabilities can have distinctly different effects on the hamster lung and pleura after inhalation exposure. (Preliminary tumor data through 18 months of exposure and 6 weeks of postexposure recovery became available as this manuscript went to press: No tumors were

  5. Scalable air cathode microbial fuel cells using glass fiber separators, plastic mesh supporters, and graphite fiber brush anodes.

    PubMed

    Zhang, Xiaoyuan; Cheng, Shaoan; Liang, Peng; Huang, Xia; Logan, Bruce E

    2011-01-01

    The combined use of brush anodes and glass fiber (GF1) separators, and plastic mesh supporters were used here for the first time to create a scalable microbial fuel cell architecture. Separators prevented short circuiting of closely-spaced electrodes, and cathode supporters were used to avoid water gaps between the separator and cathode that can reduce power production. The maximum power density with a separator and supporter and a single cathode was 75 ± 1 W/m(3). Removing the separator decreased power by 8%. Adding a second cathode increased power to 154 ± 1 W/m(3). Current was increased by connecting two MFCs connected in parallel. These results show that brush anodes, combined with a glass fiber separator and a plastic mesh supporter, produce a useful MFC architecture that is inherently scalable due to good insulation between the electrodes and a compact architecture. PMID:20566288

  6. Scalable air cathode microbial fuel cells using glass fiber separators, plastic mesh supporters, and graphite fiber brush anodes.

    PubMed

    Zhang, Xiaoyuan; Cheng, Shaoan; Liang, Peng; Huang, Xia; Logan, Bruce E

    2011-01-01

    The combined use of brush anodes and glass fiber (GF1) separators, and plastic mesh supporters were used here for the first time to create a scalable microbial fuel cell architecture. Separators prevented short circuiting of closely-spaced electrodes, and cathode supporters were used to avoid water gaps between the separator and cathode that can reduce power production. The maximum power density with a separator and supporter and a single cathode was 75 ± 1 W/m(3). Removing the separator decreased power by 8%. Adding a second cathode increased power to 154 ± 1 W/m(3). Current was increased by connecting two MFCs connected in parallel. These results show that brush anodes, combined with a glass fiber separator and a plastic mesh supporter, produce a useful MFC architecture that is inherently scalable due to good insulation between the electrodes and a compact architecture.

  7. Effect of fabric structure and polymer matrix on flexural strength, interlaminar shear stress, and energy dissipation of glass fiber-reinforced polymer composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report the effect of glass fiber structure and the epoxy polymer system on the flexural strength, interlaminar shear stress (ILSS), and energy absorption properties of glass fiber-reinforced polymer (GFRP) composites. Four different GFRP composites were fabricated from two glass fiber textiles of...

  8. Effects of particle size and velocity on burial depth of airborne particles in glass fiber filters

    SciTech Connect

    Higby, D.P.

    1984-11-01

    Air sampling for particulate radioactive material involves collecting airborne particles on a filter and then determining the amount of radioactivity collected per unit volume of air drawn through the filter. The amount of radioactivity collected is frequently determined by directly measuring the radiation emitted from the particles collected on the filter. Counting losses caused by the particle becoming buried in the filter matrix may cause concentrations of airborne particulate radioactive materials to be underestimated by as much as 50%. Furthermore, the dose calculation for inhaled radionuclides will also be affected. The present study was designed to evaluate the extent to which particle size and sampling velocity influence burial depth in glass-fiber filters. Aerosols of high-fired /sup 239/PuO/sub 2/ were collected at various sampling velocities on glass-fiber filters. The fraction of alpha counts lost due to burial was determined as the ratio of activity detected by direct alpha count to the quantity determined by photon spectrometry. The results show that burial of airborne particles collected on glass-fiber filters appears to be a weak function of sampling velocity and particle size. Counting losses ranged from 0 to 25%. A correction that assumes losses of 10 to 15% would ensure that the concentration of airborne alpha-emitting radionuclides would not be underestimated when glass-fiber filters are used. 32 references, 21 figures, 11 tables.

  9. Synchronous Cultures of Bacillus subtilis Obtained by Filtration with Glass Fiber Filters

    PubMed Central

    Sargent, Michael G.

    1973-01-01

    A simple method of potentially wide applicability for obtaining synchronous cultures of Bacillus subtilis based on size selection is described. Using glass fiber filters, a population (about 1 to 2% of the parent population) can be obtained substantially enriched for small cells which grow synchronously. A method for rapidly concentrating dilute suspensions of cells is described. PMID:4200855

  10. Glass Solder Approach for Robust, Low-Loss, Fiber-to-Waveguide Coupling

    NASA Technical Reports Server (NTRS)

    McNeil, Shirley; Battle, Philip; Hawthorne, Todd; Lower, John; Wiley, Robert; Clark, Brett

    2012-01-01

    The key advantages of this approach include the fact that the index of interface glass (such as Pb glass n = 1.66) greatly reduces Fresnel losses at the fiber-to-waveguide interface, resulting in lower optical losses. A contiguous structure cannot be misaligned and readily lends itself for use on aircraft or space operation. The epoxy-free, fiber-to-waveguide interface provides an optically pure, sealed interface for low-loss, highpower coupling. Proof of concept of this approach has included successful attachment of the low-melting-temperature glass to the x-y plane of the crystal, successful attachment of the low-meltingtemperature glass to the end face of a standard SMF (single-mode fiber), and successful attachment of a wetted lowmelting- temperature glass SMF to the end face of a KTP crystal. There are many photonic components on the market whose performance and robustness could benefit from this coupling approach once fully developed. It can be used in a variety of fibercoupled waveguide-based components, such as frequency conversion modules, and amplitude and phase modulators. A robust, epoxy-free, contiguous optical interface lends itself to components that require low-loss, high-optical-power handling capability, and good performance in adverse environments such as flight or space operation.

  11. Development of potassium ion conducting hollow glass fibers. [potassium sulfur battery

    NASA Technical Reports Server (NTRS)

    Tsang, F. Y.

    1974-01-01

    Potassium ion conducting glasses, chemically resistant to potassium, potassium sulfide and sulfur, were made and their possible utility as the membrane material for a potassium/sulfur battery was evaluated. At least one satisfactory candidate was found. It possesses an electrical resistance which makes it usable as a membrane in the form of a fine hollow fiber. It's chemical and electrochemical resistances are excellent. The other aspects of the possible potassium sulfur battery utilizing such fine hollow fibers, including the header (or tube sheet) and a cathode current collector were studied. Several cathode materials were found to be satisfactory. None of the tube sheet materials studied possessed all the desired properties. Multi-fiber cells had very limited life-time due to physical failure of fibers at the fiber/tube sheet junctions.

  12. Properties of glass/carbon fiber reinforced epoxy hybrid polymer composites

    NASA Astrophysics Data System (ADS)

    Patel, R. H.; Sevkani, V. R.; Patel, B. R.; Patel, V. B.

    2016-05-01

    Composite Materials are well known for their tailor-made properties. For the fabrication of composites different types of reinforcements are used for different applications. Sometimes for a particular application, one type of reinforcement may not fulfill the requirements. Therefore, more than one type of reinforcements may be used. Thus, the idea of hybrid composites arises. Hybrid composites are made by joining two or more different reinforcements with suitable matrix system. It helps to improve the properties of composite materials. In the present work glass/carbon fiber reinforcement have been used with a matrix triglycidyl ether of tris(m-hydroxy phenyl) phosphate epoxy resin using amine curing agent. Different physical and mechanical properties of the glass, carbon and glass/carbon fiber reinforced polymeric systems have been found out.

  13. Positive paste with lead-coated glass fibers

    NASA Technical Reports Server (NTRS)

    Rippel, Wally E. (Inventor); Edwards, Dean B. (Inventor)

    1989-01-01

    A reliable positive plate for deep cycle lead-acid batteries is provided by dispersing about 2 percent by volume of fine, short, lead-coated reinforcement fibers such as fiberglass in the positive active paste before being applied to the grid of a battery plate and cured. The fibers improve the structural integrity of the plate and also provide electrical paths in a discharged plate. This results in greater utilization of the lead dioxide active material by preventing charged portions of the plate from becoming electrically isolated.

  14. Separation of Water from Ultralow Sulfur Diesel Using Novel Polymer Nanofiber-Coated Glass Fiber Media.

    PubMed

    Rajgarhia, Stuti S; Jana, Sadhan C; Chase, George G

    2016-08-24

    Polymer nanofibers with interpenetrating network (IPN) morphology are used in this work for the development of composite, hydrophobic filter media in conjunction with glass fibers for removal of water droplets from ultralow sulfur diesel (ULSD). The nanofibers are produced from hydrophobic polyvinyl acetate (PVAc) and hydrophilic polyvinylpyrrolidone (PVP) by spinning the polymer solutions using gas jet fiber (GJF) method. The nanofibers coat the individual glass fibers due to polar-polar interactions during the spinning process and render the filter media highly hydrophobic with a water contact angle approaching 150°. The efficiency of the resultant filter media is evaluated in terms of separation of water droplets of average size 20 μm from the suspensions in ULSD.

  15. Separation of Water from Ultralow Sulfur Diesel Using Novel Polymer Nanofiber-Coated Glass Fiber Media.

    PubMed

    Rajgarhia, Stuti S; Jana, Sadhan C; Chase, George G

    2016-08-24

    Polymer nanofibers with interpenetrating network (IPN) morphology are used in this work for the development of composite, hydrophobic filter media in conjunction with glass fibers for removal of water droplets from ultralow sulfur diesel (ULSD). The nanofibers are produced from hydrophobic polyvinyl acetate (PVAc) and hydrophilic polyvinylpyrrolidone (PVP) by spinning the polymer solutions using gas jet fiber (GJF) method. The nanofibers coat the individual glass fibers due to polar-polar interactions during the spinning process and render the filter media highly hydrophobic with a water contact angle approaching 150°. The efficiency of the resultant filter media is evaluated in terms of separation of water droplets of average size 20 μm from the suspensions in ULSD. PMID:27486993

  16. Processing and damage recovery of intrinsic self-healing glass fiber reinforced composites

    NASA Astrophysics Data System (ADS)

    Sordo, Federica; Michaud, Véronique

    2016-08-01

    Glass fiber reinforced composites with a self-healing, supramolecular hybrid network matrix were produced using a modified vacuum assisted resin infusion moulding process adapted to high temperature processing. The quality and fiber volume fraction (50%) of the obtained materials were assessed through microscopy and matrix burn-off methods. The thermo-mechanical properties were quantified by means of dynamic mechanical analysis, revealing very high damping properties compared to traditional epoxy-based glass fiber reinforced composites. Self-healing properties were assessed by three-point bending tests. A high recovery of the flexural properties, around 72% for the elastic modulus and 65% of the maximum flexural stress, was achieved after a resting period of 24 h at room temperature. Recovery after low velocity impact events was also visually observed. Applications for this intrinsic and autonomic self-healing highly reinforced composite material point towards semi-structural applications where high damping and/or integrity recovery after impact are required.

  17. Interphase formation and environmental degradation in glass fiber/vinyl ester composites

    NASA Astrophysics Data System (ADS)

    Gorowara, Rajeev Lochan

    2002-09-01

    Interphase formation mechanisms are identified, modeled, and correlated with degradation in glass fiber/thermoset polymer composites. This work focused on the effects of glass-fiber-surface coatings (sizings) in free-radical polymerizing vinyl ester/styrene resin. Prior research focused on silane coupling agents, which comprise only 10% of typical commercial sizing formulations. Well-defined models of commercial multi-component glass fiber sizings were formulated and applied to E-glass fibers in a manner consistent with commercial production. Sized fiber were chemically analyzed before and after extraction with acetone, a solubility model for the resin. Solution FTIR, HPLC-MALLS and fiber XPS determined quantity and quality of physically- and chemically-adsorbed layers. In these systems, thermodynamic equilibrium dominates interphase formation and structure, not a diffusion-gradient mechanism. Interphase environmental degradation (durability) was characterized by Interlaminar Shear Strength (ILSS) strength retention after hygrothermal exposure at 80°C, in unidirectional multi-fiber composites. Durability decreased with increasing amount of sizing inert relative to the matrix. Some sizing effects became less distinguished as the matrix degraded. Single fiber-microdroplet testing measuring interfacial shear strength showed similar results. Nonreactive species in the interphase would reduce the final interphase network crosslink density and reduce the durability of the interphase. Species partitioning between the bulk and interphase are described using a multi-component model for polymer chemical potential with a complex non-linear solution. A critical aspect considered is the elastic response of the swollen bound phase. It was found that predicted interphase concentrations were very sensitive to the crosslink density of the bound sizing layer, Mc, which describes the sizing structure. Other physical properties are calculated from the interphase species concentration

  18. Process for Converting Waste Glass Fiber into Value Added Products, Final Report

    SciTech Connect

    Hemmings, Raymond T.

    2005-12-31

    Nature of the Event: Technology demonstration. The project successfully met all of its technical objectives. Albacem has signed an exclusive licensing agreement with Vitro Minerals Inc., a specialty minerals company, to commercialize the Albacem technology (website: www.vitrominerals.com). Location: The basic research for the project was conducted in Peoria, Illinois, and Atlanta, Georgia, with third-party laboratory verification carried out in Ontario, Canada. Pilot-scale trials (multi-ton) were conducted at a facility in South Carolina. Full-scale manufacturing facilities have been designed and are scheduled for construction by Vitro Minerals during 2006 at a location in the Georgia, North Carolina, and South Carolina tri-state area. The Technology: This technology consists of a process to eliminate solid wastes generated at glass fiber manufacturing facilities by converting them to value-added materials (VCAS Pozzolans) suitable for use in cement and concrete applications. This technology will help divert up to 250,000 tpy of discarded glass fiber manufacturing wastes into beneficial use applications in the concrete construction industry. This technology can also be used for processing glass fiber waste materials reclaimed from monofills at manufacturing facilities. The addition of take-back materials and reclamation from landfills can help supply over 500,000 tpy of glass fiber waste for processing into value added products. In the Albacem process, waste glass fiber is ground to a fine powder that effectively functions as a reactive pozzolanic admixture for use in portland ce¬ment-based building materials and products, such as concrete, mortars, terrazzo, tile, and grouts. Because the waste fiber from the glass manufacturing industry is vitreous, clean, and low in iron and alkalis, the resulting pozzolan is white in color and highly consistent in chemical composition. This white pozzolan, termed VCAS Pozzolan (for Vitreous Calcium-Alumino-Silicate). is

  19. Low-temperature evaporative glass scoring using a single-mode ytterbium fiber laser

    NASA Astrophysics Data System (ADS)

    Tu, J. F.; Riley, P. E. B.

    2013-06-01

    Glass cutting is increasingly important in industry to cut glass into various sizes for high definition televisions, cell phones, laptops, and tablet computers. A conventional mechanical cutter is usually used to score the glass before a bending force is applied to separate the glass along the scoring mark. This paper presents a laser glass scoring technique aimed at replacing the mechanical cutter to reduce cracks. This scoring technique, denoted as the Low-temperature Evaporative Glass Scoring process (LEGS), is different because laser energy is not directly absorbed by the glass. To achieve the proposed laser scoring, a laser beam is focused through the glass onto a metal substrate. The metal substrate absorbs the laser energy to generate a metal vapor to etch the glass, forming a scoring mark. The feasibility of this glass scoring technique is demonstrated using a continuous-wave fiber laser, at a low power of 60 W, and a 7075-T6 Aluminum alloy plate as the metal substrate. When the laser beam scans across the substrate, the laser energy creates a quasi-static aluminum molten pool, covered by an aluminum vapor at a temperature about 3000 K. At an optimal setting of 51 μm gap distance, 60 W laser power, and 6 mm/s scoring speed, a uniform scoring mark of 37 μm width and 120 μm depth was successfully generated on a piece of soda-lime glass without visible micro-cracks. The paper also discussed the uncertainties and their remedies involved in the LEGS process. To facilitate the process design, a model for predicting the aluminum vapor temperature was developed. This model accounted for the laser focus, reflection, absorption and transmission, laser energy distribution, and the aluminum melting and vaporization processes. Finally, this model was validated by comparing the actual melt depth of the aluminum substrate with the one predicted by the model.

  20. Magnesium coated phosphate glass fibers for unidirectional reinforcement of polycaprolactone composites.

    PubMed

    Liu, Xiaoling; Grant, David M; Palmer, Graham; Parsons, Andrew J; Rudd, Chris D; Ahmed, Ifty

    2015-10-01

    Bioresorbable composites have shown much potential for bone repair applications, as they have the ability to degrade completely over time and their degradation and mechanical properties can be tailored to suit the end application. In this study, phosphate glass fiber (from the system 45% P2 O5-16% CaO-24% MgO-11% Na2 O-4% Fe2 O3 (given in mol%)) were used to reinforce polycaprolactone (PCL) with approximately 20% fiber volume fraction. The glass fiber surfaces were coated with magnesium (Mg) through magnetron sputtering to improve the fiber-matrix interfacial properties. The Mg coating provided a rough fiber surface (roughness (Ra) of about 44nm). Both noncoated and Mg-coated fiber-reinforced composites were assessed. The water uptake and mass loss properties for the composites were assessed in phosphate-buffered saline (PBS) at 37°C for up to 28 days, and ion release profiles were also investigated in both water and PBS media. Inhibition of media influx was observed for the Mg-coated composites. The composite mechanical properties were characterized on the basis of both tensile and flexural tests and their retention in PBS media at 37°C was also investigated. A higher retention of the mechanical properties was observed for the Mg-coated composites over the 28 days degradation period.

  1. Thermo-tunable hybrid photonic crystal fiber based on solution-processed chalcogenide glass nanolayers

    NASA Astrophysics Data System (ADS)

    Markos, Christos

    2016-08-01

    The possibility to combine silica photonic crystal fiber (PCF) as low-loss platform with advanced functional materials, offers an enormous range of choices for the development of fiber-based tunable devices. Here, we report a tunable hybrid silica PCF with integrated As2S3 glass nanolayers inside the air-capillaries of the fiber based on a solution-processed glass approach. The deposited high-index layers revealed antiresonant transmission windows from ~500 nm up to ~1300 nm. We experimentally demonstrate for the first time the possibility to thermally-tune the revealed antiresonances by taking advantage the high thermo-optic coefficient of the solution-processed nanolayers. Two different hybrid fiber structures, with core diameter 10 and 5 μm, were developed and characterized using a supercontinuum source. The maximum sensitivity was measured to be as high as 3.6 nm/°C at 1300 nm. The proposed fiber device could potentially constitute an efficient route towards realization of monolithic tunable fiber filters or sensing elements.

  2. Thermo-tunable hybrid photonic crystal fiber based on solution-processed chalcogenide glass nanolayers.

    PubMed

    Markos, Christos

    2016-01-01

    The possibility to combine silica photonic crystal fiber (PCF) as low-loss platform with advanced functional materials, offers an enormous range of choices for the development of fiber-based tunable devices. Here, we report a tunable hybrid silica PCF with integrated As2S3 glass nanolayers inside the air-capillaries of the fiber based on a solution-processed glass approach. The deposited high-index layers revealed antiresonant transmission windows from ~500 nm up to ~1300 nm. We experimentally demonstrate for the first time the possibility to thermally-tune the revealed antiresonances by taking advantage the high thermo-optic coefficient of the solution-processed nanolayers. Two different hybrid fiber structures, with core diameter 10 and 5 μm, were developed and characterized using a supercontinuum source. The maximum sensitivity was measured to be as high as 3.6 nm/°C at 1300 nm. The proposed fiber device could potentially constitute an efficient route towards realization of monolithic tunable fiber filters or sensing elements. PMID:27538726

  3. Thermo-tunable hybrid photonic crystal fiber based on solution-processed chalcogenide glass nanolayers

    PubMed Central

    Markos, Christos

    2016-01-01

    The possibility to combine silica photonic crystal fiber (PCF) as low-loss platform with advanced functional materials, offers an enormous range of choices for the development of fiber-based tunable devices. Here, we report a tunable hybrid silica PCF with integrated As2S3 glass nanolayers inside the air-capillaries of the fiber based on a solution-processed glass approach. The deposited high-index layers revealed antiresonant transmission windows from ~500 nm up to ~1300 nm. We experimentally demonstrate for the first time the possibility to thermally-tune the revealed antiresonances by taking advantage the high thermo-optic coefficient of the solution-processed nanolayers. Two different hybrid fiber structures, with core diameter 10 and 5 μm, were developed and characterized using a supercontinuum source. The maximum sensitivity was measured to be as high as 3.6 nm/°C at 1300 nm. The proposed fiber device could potentially constitute an efficient route towards realization of monolithic tunable fiber filters or sensing elements. PMID:27538726

  4. Optical and spectroscopic characterization of Er3+-Yb3+co-doped tellurite glasses and fibers

    NASA Astrophysics Data System (ADS)

    Narro-García, R.; Desirena, H.; Chillcce, E. F.; Barbosa, L. C.; Rodriguez, E.; De la Rosa, E.

    2014-04-01

    Optical and spectroscopic properties of Er3+-Yb3+ co-doped TeO2-WO3-Nb2O5-Na2O-Al2O3 glasses and fibers were investigated. Emission spectra and fluorescence lifetimes of 4I13/2 level of Er3+ion as a function of rare earth concentration and fiber length were measured in glasses. Results show that the self-absorption effect broadens the spectral bandwidth of 4I13/2→4I15/2 transition and lengthens the lifetime significantly from 3.5 to 4.6 ms. Fibers were fabricated by the rod-in-tube technique using a Heathway drawing tower. The emission power of these Er3+-Yb3+ co-doped Step Index Tellurite Fibers (SITFs; lengths varying from 2 to 60 cm) were generated by a 980 nm diode laser pump and then the emission power spectra were acquired with an OSA. The maximum emission power spectra, within the 1530-1560 nm region, were observed for fiber lengths ranging from 3 to 6 cm. The highest bandwidth obtained was 108 nm for 8 cm fiber length around 1.53 µm.

  5. Er/Yb co-doped oxy-fluoride glass-ceramics core/polymer cladding optical fibers

    NASA Astrophysics Data System (ADS)

    Czerska, E.; Świderska, M.

    2014-11-01

    Erbium/ytterbium co-doped glasses can be applied as NIR laser sources (1.55 μm) or optical amplifiers in this range. About hundred meters of Er/Yb co-doped oxy-fluoride glass-ceramics fibers have been drawn from a glass preform followed by controlled annealing. Processing temperatures (drawing and annealing) were selected upon thermal analysis results (DTA/DSC plots). Glass-ceramic structure was confirmed by the XRD measurements. Obtained fibers show good optical properties. As a cladding material polymer material (acrylic resin) is considered due to its low deposition temperature and suitable value of refractive index.

  6. Infrared Optical Properties of β-Spodumene Solid Solution Glass-Ceramic for Fiber-Optic Devices

    NASA Astrophysics Data System (ADS)

    Sakamoto, Akihiko; Yamamoto, Shigeru

    2006-09-01

    The IR optical properties of an opaque β-spodumene solid solution (s.s.) glass-ceramic for fiber-optic devices were studied in relation to its refractive indices in both crystalline and glass phases. We investigated the refractive indices of both phases on the basis of IR transmittance change due to the structural relaxation of the glass phase. The refractive indices of this β-spodumene s.s. glass-ceramic at a wavelength of 1550 nm in the crystalline and glass phases were first determined to be 1.530 and 1.495, respectively. It was found from the refractive index data that the optical scattering intensity of this glass-ceramic approximately follows the Rayleigh-Gans model. We also demonstrated that the inner diameter of an opaque glass-ceramic capillary used in optical fiber connectors can be optically measured with a sub-micrometer accuracy using an IR laser.

  7. In vitro study of improved wound-healing effect of bioactive borate-based glass nano-/micro-fibers.

    PubMed

    Yang, Qingbo; Chen, Sisi; Shi, Honglan; Xiao, Hai; Ma, Yinfa

    2015-10-01

    Because of the promising wound-healing capability, bioactive glasses have been considered as one of the next generation hard- and soft-tissue regeneration materials. The lack of understanding of the substantial mechanisms, however, indicates the need for further study on cell-glass interactions to better interpret the rehabilitation capability. In the present work, three bioactive glass nano-/micro-fibers, silicate-based 45S5, borate-based 13-93B3 and 1605 (additionally doped with copper oxide and zinc oxide), were firstly compared for their in vitro soaking/conversion rate. The results of elemental monitoring and electron microscopic characterization demonstrated that quicker ion releasing and glass conversion occurred in borate-based fibers than that of silicate-based one. This result was also reflected by the formation speed of hydroxyapatite (HA). This process was further correlated with original boron content and surrounding rheological condition. We showed that an optimal fiber pre-soaking time (or an ideal dynamic flow rate) should exist to stimulate the best cell proliferation and migration ability. Moreover, 13-93B3 and 1605 fibers showed different glass conversion and biocompatibility properties as well, indicating that trace amount variation in composition can also influence fiber's bioactivity. In sum, our in vitro rheological module closely simulated in vivo niche environment and proved a potentially improved wound-healing effect by borate-based glass fibers, and the results shall cast light on future improvement in bioactive glass fabrication.

  8. In vitro study of improved wound-healing effect of bioactive borate-based glass nano-/micro-fibers.

    PubMed

    Yang, Qingbo; Chen, Sisi; Shi, Honglan; Xiao, Hai; Ma, Yinfa

    2015-10-01

    Because of the promising wound-healing capability, bioactive glasses have been considered as one of the next generation hard- and soft-tissue regeneration materials. The lack of understanding of the substantial mechanisms, however, indicates the need for further study on cell-glass interactions to better interpret the rehabilitation capability. In the present work, three bioactive glass nano-/micro-fibers, silicate-based 45S5, borate-based 13-93B3 and 1605 (additionally doped with copper oxide and zinc oxide), were firstly compared for their in vitro soaking/conversion rate. The results of elemental monitoring and electron microscopic characterization demonstrated that quicker ion releasing and glass conversion occurred in borate-based fibers than that of silicate-based one. This result was also reflected by the formation speed of hydroxyapatite (HA). This process was further correlated with original boron content and surrounding rheological condition. We showed that an optimal fiber pre-soaking time (or an ideal dynamic flow rate) should exist to stimulate the best cell proliferation and migration ability. Moreover, 13-93B3 and 1605 fibers showed different glass conversion and biocompatibility properties as well, indicating that trace amount variation in composition can also influence fiber's bioactivity. In sum, our in vitro rheological module closely simulated in vivo niche environment and proved a potentially improved wound-healing effect by borate-based glass fibers, and the results shall cast light on future improvement in bioactive glass fabrication. PMID:26117744

  9. CO2-laser-assisted processing of glass fiber-reinforced thermoplastic composites

    NASA Astrophysics Data System (ADS)

    Brecher, Christian; Emonts, Michael; Schares, Richard Ludwig; Stimpfl, Joffrey

    2013-02-01

    To fully exploit the potential of fiber-reinforced thermoplastic composites (FRTC) and to achieve a broad industrial application, automated manufacturing systems are crucial. Investigations at Fraunhofer IPT have proven that the use of laser system technology in processing FRTC allows to achieve high throughput, quality, flexibility, reproducibility and out-of-autoclave processing simultaneously. As 90% of the FRP in Europe1 are glass fiber-reinforced a high impact can be achieved by introducing laser-assisted processing with all its benefits to glass fiber-reinforced thermoplastics (GFRTC). Fraunhofer IPT has developed the diode laser-assisted tape placement (laying and winding) to process carbon fiber-reinforced thermoplastic composites (CFRTC) for years. However, this technology cannot be transferred unchanged to process milky transparent GFRTC prepregs (preimpregnated fibers). Due to the short wavelength (approx. 980 nm) and therefore high transmission less than 20% of the diode laser energy is absorbed as heat into non-colored GFRTC prepregs. Hence, the use of a different wave length, e.g. CO2-laser (10.6 μm) with more than 90% laser absorption, is required to allow the full potential of laser-assisted processing of GFRTC. Also the absorption of CO2-laser radiation at the surface compared to volume absorption of diode laser radiation is beneficial for the interlaminar joining of GFRTC. Fraunhofer IPT is currently developing and investigating the CO2-laser-assisted tape placement including new system, beam guiding, process and monitoring technology to enable a resource and energy efficient mass production of GFRP composites, e.g. pipes, tanks, masts. The successful processing of non-colored glass fiber-reinforced Polypropylene (PP) and Polyphenylene Sulfide (PPS) has already been proven.

  10. Ferrule and use thereof for cooling a melt spun hollow glass fiber as it emerges from a spinnerette

    DOEpatents

    Brown, William E.

    1977-01-01

    An improvement in the process of melt spinning thin walled, hollow fibers from relatively low melting glasses results if cooling of the emerging fiber is accomplished by use of a thin layer of gas to transfer heat from the fiber to a ferrule which fits closely to the spinnerette face and the individual fiber. The ferrule incorporates or is in contact with a heat sink and is slotted or segmented so that it may be brought into position around the moving fiber. Thinner walled, more uniform fibers may be spun when this method of cooling is employed.

  11. Mechanisms of optical losses in Bi:SiO2 glass fibers.

    PubMed

    Zlenko, Alexander S; Mashinsky, Valery M; Iskhakova, Ludmila D; Semjonov, Sergey L; Koltashev, Vasiliy V; Karatun, Nikita M; Dianov, Evgeny M

    2012-10-01

    The mechanisms of optical losses in bismuth-doped silica glass (Bi:SiO(2)) and fibers were studied. It was found that in the fibers of this composition the up-conversion processes occur even at bismuth concentrations lower than 0.02 at.%. Bi:SiO(2) core holey fiber drawn under oxidizing conditions was investigated. The absorption spectrum of this fiber has no bands of the bismuth infrared active center. Annealing of this fiber under reducing conditions leads to the formation of the IR absorption bands of the bismuth active center (BAC) and to the simultaneous growth of background losses. Under the realized annealing conditions (argon atmosphere, T(max) = 1100°C, duration 30 min) the BAC concentration reaches its maximum and begins to decrease in the process of excessive Bi reduction, while the background losses only increase. It was shown that the cause of these background losses is the absorption of light by nanoparticles of metallic bismuth formed in bismuth-doped glasses as a result of reduction of a part of the bismuth ions to Bi(0) and their following aggregation. The growth of background losses occurs owing to the increase of the concentration and the size of the metallic bismuth nanoparticles.

  12. Tailoring Interfacial Properties by Controlling Carbon Nanotube Coating Thickness on Glass Fibers Using Electrophoretic Deposition.

    PubMed

    Tamrakar, Sandeep; An, Qi; Thostenson, Erik T; Rider, Andrew N; Haque, Bazle Z Gama; Gillespie, John W

    2016-01-20

    The electrophoretic deposition (EPD) method was used to deposit polyethylenimine (PEI) functionalized multiwall carbon nanotube (CNT) films onto the surface of individual S-2 glass fibers. By varying the processing parameters of EPD following Hamaker's equation, the thickness of the CNT film was controlled over a wide range from 200 nm to 2 μm. The films exhibited low electrical resistance, providing evidence of coating uniformity and consolidation. The effect of the CNT coating on fiber matrix interfacial properties was investigated through microdroplet experiments. Changes in interfacial properties due to application of CNT coatings onto the fiber surface with and without a CNT-modified matrix were studied. A glass fiber with a 2 μm thick CNT coating and the unmodified epoxy matrix showed the highest increase (58%) in interfacial shear strength (IFSS) compared to the baseline. The increase in the IFSS was proportional to CNT film thickness. Failure analysis of the microdroplet specimens indicated higher IFSS was related to fracture morphologies with higher levels of surface roughness. EPD enables the thickness of the CNT coating to be adjusted, facilitating control of fiber/matrix interfacial resistivity. The electrical sensitivity provides the opportunity to fabricate a new class of sizing with tailored interfacial properties and the ability to detect damage initiation.

  13. Tailoring Interfacial Properties by Controlling Carbon Nanotube Coating Thickness on Glass Fibers Using Electrophoretic Deposition.

    PubMed

    Tamrakar, Sandeep; An, Qi; Thostenson, Erik T; Rider, Andrew N; Haque, Bazle Z Gama; Gillespie, John W

    2016-01-20

    The electrophoretic deposition (EPD) method was used to deposit polyethylenimine (PEI) functionalized multiwall carbon nanotube (CNT) films onto the surface of individual S-2 glass fibers. By varying the processing parameters of EPD following Hamaker's equation, the thickness of the CNT film was controlled over a wide range from 200 nm to 2 μm. The films exhibited low electrical resistance, providing evidence of coating uniformity and consolidation. The effect of the CNT coating on fiber matrix interfacial properties was investigated through microdroplet experiments. Changes in interfacial properties due to application of CNT coatings onto the fiber surface with and without a CNT-modified matrix were studied. A glass fiber with a 2 μm thick CNT coating and the unmodified epoxy matrix showed the highest increase (58%) in interfacial shear strength (IFSS) compared to the baseline. The increase in the IFSS was proportional to CNT film thickness. Failure analysis of the microdroplet specimens indicated higher IFSS was related to fracture morphologies with higher levels of surface roughness. EPD enables the thickness of the CNT coating to be adjusted, facilitating control of fiber/matrix interfacial resistivity. The electrical sensitivity provides the opportunity to fabricate a new class of sizing with tailored interfacial properties and the ability to detect damage initiation. PMID:26699906

  14. Complete energy transfer due to rare-earth phase segregation in optical fiber preform glasses

    NASA Astrophysics Data System (ADS)

    Lahoz, F.; Pérez-Rodríguez, C.; Halder, A.; Das, S.; Paul, M. C.; Pal, M.; Bhadra, S. K.; Vasconcelos, H. C.

    2011-10-01

    An Yb3+ to Tm3+ energy-transfer quantum yield close to one has been found in phase-separated yttrium-alumina silicate optical fiber preform glasses. Optical absorption, luminescence, lifetime measurements, and rare-earth concentration dependence have been performed to investigate the feasibility of efficient blue upconversion fiber lasers through convenient Yb3+ sensitation. Luminescence decay measurements have demonstrated the co-existence of two phases. One of the phases is characterized by an yttrium-rich composition. Most of the RE ions partition into the yttrium-rich phase and produce the intense upconversion emission.

  15. Application of a Fiber Optic Distributed Strain Sensor System to Woven E-Glass Composite

    NASA Technical Reports Server (NTRS)

    Anastasi, Robert F.; Lopatin, Craig

    2001-01-01

    A distributed strain sensing system utilizing a series of identically written Bragg gratings along an optical fiber is examined for potential application to Composite Armored Vehicle health monitoring. A vacuum assisted resin transfer molding process was used to fabricate a woven fabric E-glass/composite panel with an embedded fiber optic strain sensor. Test samples machined from the panel were mechanically tested in 4-point bending. Experimental results are presented that show the mechanical strain from foil strain gages comparing well to optical strain from the embedded sensors. Also, it was found that the distributed strain along the sample length was consistent with the loading configuration.

  16. Enhanced green upconversion luminescence in Yb3+/Tb3+-codoped silica fiber based on glass phase-separated method

    NASA Astrophysics Data System (ADS)

    Chu, Yingbo; Yang, Yu; Liao, Lei; Wang, Yibo; Zhao, Nan; Wang, Zhao; Liu, Changbo; Peng, Jinggang; Li, Haiqin; Dai, Nengli; Li, Jinyan; Yang, Luyun

    2015-09-01

    We reported on an Yb3+/Tb3+-codoped silica fiber with a large fiber core prepared from nanoporous silica glass based on glass phase-separated method. The measured refractive index profile indicated an excellent homogeneity of the doped active fiber core. Intense green upconversion emission from Tb3+ centered at 543 nm was obtained in the Yb3+/Tb3+-codoped silica fiber under 976-nm excitation. It is suggested that the green upconversion emission is dominated by a two-photon absorption process. It is found that the Al3+ ions as a modifier can facilitate the energy transfer from Yb3+ to Tb3+ in the porous glass fiber. The energy transfer efficiency from Yb3+ to Tb3+ was calculated.

  17. Facile synthesis 3D flexible core-shell graphene/glass fiber via chemical vapor deposition

    PubMed Central

    2014-01-01

    Direct deposition of graphene layers on the flexible glass fiber surface to form the three-dimensional (3D) core-shell structures is offered using a two-heating reactor chemical vapor deposition system. The two-heating reactor is utilized to offer sufficient, well-proportioned floating C atoms and provide a facile way for low-temperature deposition. Graphene layers, which are controlled by changing the growth time, can be grown on the surface of wire-type glass fiber with the diameter from 30 nm to 120 um. The core-shell graphene/glass fiber deposition mechanism is proposed, suggesting that the 3D graphene films can be deposited on any proper wire-type substrates. These results open a facile way for direct and high-efficiency deposition of the transfer-free graphene layers on the low-temperature dielectric wire-type substrates. PACS 81.05.U-; 81.07.-b; 81.15.Gh PMID:25170331

  18. Mid-infrared surface plasmon polariton chemical sensing on fiber-coupled ITO coated glass.

    PubMed

    Martínez, Javier; Ródenas, Airán; Aguiló, Magdalena; Fernandez, Toney; Solis, Javier; Díaz, Francesc

    2016-06-01

    A novel fiber-coupled indium tin oxide (ITO) coated glass slide sensor for performing surface plasmon polariton chemical monitoring in the ∼3.5  μm mid-infrared (IR) range is reported. Efficient mid-IR fiber coupling is achieved with 3D laser written waveguides, and the coupling of glass waveguide modes to ITO surface plasmon polaritons (SPPs) is driven by the varying phase matching conditions of different aqueous analytes across the anomalous dispersion range determined by their molecular fingerprints. By means of using both a mid-IR fiber supercontinuum source and a diode laser, the excitation of SPPs is demonstrated. The sensor sensitivity is tested by discriminating CH from OH features of ethanol in water solutions, demonstrating an instrumental ethanol limit of detection of 0.02% in a wide concentration range of at least 0%-50%. The efficient optical monitoring of mid-IR SPPs in smart glass could have a broad range of applications in biological and chemical sensing.

  19. Skin problems among fiber-glass reinforced plastics factory workers in Japan.

    PubMed

    Minamoto, Keiko; Nagano, Megumi; Inaoka, Tsukasa; Kitano, Takao; Ushijima, Kayo; Fukuda, Yoshiharu; Futatsuka, Makoto

    2002-01-01

    Two surveys, one in winter the other in summer time, examined the skin problems of the entire manual workers (N=148) from 11 small-to-medium sized fiber-glass reinforced plastics (FRP) factories located in Kyushu, Japan. The workers were exposed to unsaturated polyester resin, including styrene and auxiliary agents such as cobalt naphthenate, hardeners such as methyl ethyl ketone peroxides, glass fiber and dust including shortened glass fiber and plastic particles. Eighty-seven workers (58.8%) reported having skin problems (mainly itching or dermatitis) since they started to work in FRP manufacturing and 25 workers had consulted a physician because of their skin problems; one worker was forced to take sick leave because of his severe dermatitis. History of allergic diseases and shorter occupational period (duration of employment) in a FRP factory were associated with greater probability of having a history of work-related skin symptoms. Workers in factories where dust-generating and lamination sites were located in different buildings were significantly less likely to have a history of skin problems than those in factories where the two sites were located in the same building. Of the 67 workers examined in both seasons closed to double the prevalence of dermatitis was found in summer (23.3%) than winter (13.4%). PMID:11926514

  20. Development of New Generation of Thermally-Enhanced Fiber Glass Insulation

    SciTech Connect

    Kosny, Jan; Yarbrough, David W; Childs, Phillip W; Miller, William A; Atchley, Jerald Allen; Shrestha, Som S

    2010-03-01

    This report presents experimental and numerical results from thermal performance studies. The purpose of this Cooperative Research and Development Agreement (CRADA) between UT-Battelle, LLC and John s Manville was to design a basic concept of a new generation of thermally-enhanced fiber glass insulation. Different types of Phase Change Materials (PCMs) have been tested as dynamic components in buildings during the last 4 decades. Most historical studies have found that PCMs enhance building energy performance. Some PCM-enhanced building materials, like PCM-gypsum boards or PCM-impregnated concretes have already found their limited applications in different countries. Today, continued improvements in building envelope technologies suggest that throughout Southern and Central U.S. climates, residences may soon be routinely constructed with PCM in order to maximize insulation effectiveness and maintain low heating and cooling loads. The proposed thermally-enhanced fiber glass insulation will maximize this integration by utilizing a highly-efficient building envelope with high-R thermal insulation, active thermal mass and superior air-tightness. Improved thermal resistance will come from modifications in infrared internal characteristics of the fiber glass insulation. Thermal mass effect can be provided by proprietary thermally-active microencapsulated phase change material (PCM). Work carried out at the Oak Ridge National Laboratory (ORNL) on the CRADA is described in this report.

  1. Mid-infrared surface plasmon polariton chemical sensing on fiber-coupled ITO coated glass.

    PubMed

    Martínez, Javier; Ródenas, Airán; Aguiló, Magdalena; Fernandez, Toney; Solis, Javier; Díaz, Francesc

    2016-06-01

    A novel fiber-coupled indium tin oxide (ITO) coated glass slide sensor for performing surface plasmon polariton chemical monitoring in the ∼3.5  μm mid-infrared (IR) range is reported. Efficient mid-IR fiber coupling is achieved with 3D laser written waveguides, and the coupling of glass waveguide modes to ITO surface plasmon polaritons (SPPs) is driven by the varying phase matching conditions of different aqueous analytes across the anomalous dispersion range determined by their molecular fingerprints. By means of using both a mid-IR fiber supercontinuum source and a diode laser, the excitation of SPPs is demonstrated. The sensor sensitivity is tested by discriminating CH from OH features of ethanol in water solutions, demonstrating an instrumental ethanol limit of detection of 0.02% in a wide concentration range of at least 0%-50%. The efficient optical monitoring of mid-IR SPPs in smart glass could have a broad range of applications in biological and chemical sensing. PMID:27244397

  2. Ce(3+)/Yb(3+)/Er(3+) triply doped bismuth borosilicate glass: a potential fiber material for broadband near-infrared fiber amplifiers.

    PubMed

    Chu, Yushi; Ren, Jing; Zhang, Jianzhong; Peng, Gangding; Yang, Jun; Wang, Pengfei; Yuan, Libo

    2016-01-01

    Erbium doped bismuth borosilicate (BBS) glasses, possessing the broadest 1.55 μm near infrared (NIR) emission band among oxide glasses, stand out as excellent fiber material for optical fiber amplifiers. In this work, we demonstrate that both broadened and enhanced NIR emission of Er(3+) can be obtained by sensibly combining the effects such as mixed glass former effect, phonon-assisted energy transfer (PAET) and de-excitation effect induced by codopant. Specially, by codoping CeO2 in a controlled manner, it leads to not only much improved optical quality of the glasses, enhanced NIR emission, but also significantly suppressed energy transfer up-conversion (ETU) luminescence which is detrimental to the NIR emission. Cerium incorporated in the glasses exists overwhelmingly as the trivalent oxidation state Ce(3+) and its effects on the luminescence properties of Er(3+) are discussed. Judd-Ofelt analysis is used to evaluate gain amplification of the glasses. The result indicates that Ce(3+)/Yb(3+)/Er(3+) triply doped BBS glasses are promising candidate for erbium doped fiber amplifiers. The strategy described here can be readily extended to other rare-earth ions (REs) to improve the performance of REs doped fiber lasers and amplifiers. PMID:27646191

  3. Ce(3+)/Yb(3+)/Er(3+) triply doped bismuth borosilicate glass: a potential fiber material for broadband near-infrared fiber amplifiers.

    PubMed

    Chu, Yushi; Ren, Jing; Zhang, Jianzhong; Peng, Gangding; Yang, Jun; Wang, Pengfei; Yuan, Libo

    2016-09-20

    Erbium doped bismuth borosilicate (BBS) glasses, possessing the broadest 1.55 μm near infrared (NIR) emission band among oxide glasses, stand out as excellent fiber material for optical fiber amplifiers. In this work, we demonstrate that both broadened and enhanced NIR emission of Er(3+) can be obtained by sensibly combining the effects such as mixed glass former effect, phonon-assisted energy transfer (PAET) and de-excitation effect induced by codopant. Specially, by codoping CeO2 in a controlled manner, it leads to not only much improved optical quality of the glasses, enhanced NIR emission, but also significantly suppressed energy transfer up-conversion (ETU) luminescence which is detrimental to the NIR emission. Cerium incorporated in the glasses exists overwhelmingly as the trivalent oxidation state Ce(3+) and its effects on the luminescence properties of Er(3+) are discussed. Judd-Ofelt analysis is used to evaluate gain amplification of the glasses. The result indicates that Ce(3+)/Yb(3+)/Er(3+) triply doped BBS glasses are promising candidate for erbium doped fiber amplifiers. The strategy described here can be readily extended to other rare-earth ions (REs) to improve the performance of REs doped fiber lasers and amplifiers.

  4. Ce3+/Yb3+/Er3+ triply doped bismuth borosilicate glass: a potential fiber material for broadband near-infrared fiber amplifiers

    PubMed Central

    Chu, Yushi; Ren, Jing; Zhang, Jianzhong; Peng, Gangding; Yang, Jun; Wang, Pengfei; Yuan, Libo

    2016-01-01

    Erbium doped bismuth borosilicate (BBS) glasses, possessing the broadest 1.55 μm near infrared (NIR) emission band among oxide glasses, stand out as excellent fiber material for optical fiber amplifiers. In this work, we demonstrate that both broadened and enhanced NIR emission of Er3+ can be obtained by sensibly combining the effects such as mixed glass former effect, phonon-assisted energy transfer (PAET) and de-excitation effect induced by codopant. Specially, by codoping CeO2 in a controlled manner, it leads to not only much improved optical quality of the glasses, enhanced NIR emission, but also significantly suppressed energy transfer up-conversion (ETU) luminescence which is detrimental to the NIR emission. Cerium incorporated in the glasses exists overwhelmingly as the trivalent oxidation state Ce3+ and its effects on the luminescence properties of Er3+ are discussed. Judd-Ofelt analysis is used to evaluate gain amplification of the glasses. The result indicates that Ce3+/Yb3+/Er3+ triply doped BBS glasses are promising candidate for erbium doped fiber amplifiers. The strategy described here can be readily extended to other rare-earth ions (REs) to improve the performance of REs doped fiber lasers and amplifiers. PMID:27646191

  5. Interfacial analysis of fiber-reinforced bioactive glass dental root implants.

    PubMed

    Schepers, E; Ducheyne, P; De Clercq, M

    1989-07-01

    Bioactive glass can form an effective bond with bone. Essential for this connection are the interfacial reactions which lead to the development of a Si-rich film covered by a CaP-rich film. The presence of these layers can be demonstrated clearly by EDX analysis of fiber-reinforced bioactive glass and bulk bioactive glass implants installed for 4 and 16 months in the partial edentulous jaws of beagle dogs. EDX analysis reveals three types of microchemical interface. The first type develops when the implant is bonded to bone. Here, a smooth transition of the CaP profile can be observed between bioactive glass and the bone, thus providing for a compositional gradient between the implant and the surrounding tissues. The second type is seen when the implant surface is surrounded by fibrous tissue. This causes a discontinuity in the CaP profile. The third type is characterized by a gradual decrease in the Ca and P concentrations across the interface, caused by the presence of Ca and P in the fibrous tissue near the implant surface. This suggests that the interface is dynamic in time and transforms to a functionally better optimized interface. EDX analysis does not reveal any metal fiber ion contamination of the outer glass rim of the implant. When stainless-steel or wrought Co-Cr alloy is exposed to the surrounding fluids, the interfacial osteogenesis is disturbed, possibly by a synergistic effect of glass ions and metal ions. Exposure of titanium does not interfere with this osteogenesis. The bone bonding can also be influenced by surgical trauma. However, with precise implantation techniques, an enhancement of bone growth by osteoconductivity can be measured. PMID:2738085

  6. Laser-diode pumped glass-clad Ti:sapphire crystal fiber laser.

    PubMed

    Wang, Shih-Chang; Hsu, Chun-Yang; Yang, Tzu-Te; Jheng, Dong-Yo; Yang, Teng-I; Ho, Tuan-Shu; Huang, Sheng-Lung

    2016-07-15

    Efficient glass-clad crystal fiber (CF) lasers were demonstrated using a Ti:sapphire crystalline core as the gain medium. With a core diameter of 18 μm, the laser diode (LD) pump source can be effectively coupled and guided throughout the crystal fiber for a low threshold and high slope efficiency laser operation. The advantage of high heat dissipation efficiency of the fiber structure can be derived from the low core temperature rising measurement (i.e., 17 K/W) with passive cooling. At an output transmittance of 23%, the lowest absorbed threshold of 118.2 mW and highest slope efficiency of 29.6% were achieved, with linear laser polarization.

  7. Laser-diode pumped glass-clad Ti:sapphire crystal fiber laser.

    PubMed

    Wang, Shih-Chang; Hsu, Chun-Yang; Yang, Tzu-Te; Jheng, Dong-Yo; Yang, Teng-I; Ho, Tuan-Shu; Huang, Sheng-Lung

    2016-07-15

    Efficient glass-clad crystal fiber (CF) lasers were demonstrated using a Ti:sapphire crystalline core as the gain medium. With a core diameter of 18 μm, the laser diode (LD) pump source can be effectively coupled and guided throughout the crystal fiber for a low threshold and high slope efficiency laser operation. The advantage of high heat dissipation efficiency of the fiber structure can be derived from the low core temperature rising measurement (i.e., 17 K/W) with passive cooling. At an output transmittance of 23%, the lowest absorbed threshold of 118.2 mW and highest slope efficiency of 29.6% were achieved, with linear laser polarization. PMID:27420499

  8. Te-As-Se glass microstructured optical fiber for the middle infrared

    SciTech Connect

    Desevedavy, Frederic; Renversez, Gilles; Troles, Johann; Brilland, Laurent; Houizot, Patrick; Coulombier, Quentin; Smektala, Frederic; Traynor, Nicholas; Adam, Jean-Luc

    2009-07-01

    We present the first fabrication, to the best of our knowledge, of chalcogenide microstructured optical fibers in Te-As-Se glass, their optical characterization, and numerical simulations in the middle infrared. In a first fiber, numerical simulations exhibit a single-mode behavior at 3.39 and 9.3 {mu}m, in good agreement with experimental near-field captures at 9.3 {mu}m. The second fiber is not monomode between 3.39 and 9.3 {mu}m, but the fundamental losses are 9 dB/m at 3.39 {mu}m and 6 dB/m at 9.3 {mu}m. The experimental mode field diameters are compared to the theoretical ones with a good accordance.

  9. Nanostructuring an erbium local environment inside sol-gel silica glasses: toward efficient erbium optical fiber lasers

    NASA Astrophysics Data System (ADS)

    Savelii, Inna; El Hamzaoui, Hicham; Bigot, Laurent; Bouwmans, Géraud; Fsaifes, Ihsan; Capoen, Bruno; Bouazaoui, Mohamed

    2016-02-01

    To extend the use of erbium- (Er-)/aluminum- (Al-) codoped optical fibers in hostile environments, the reduction of the Al amount has been identified as a serious way to harden them against harsh radiation. In this work, sol-gel monolithic Er3+-doped and Er3+/Al3+-codoped silica glasses were prepared from nanoporous silica xerogels soaked in a solution containing an Er salt together or not with an Al salt. After sintering, these glasses were used as the core material of microstructured optical fibers made by the stack-and-draw method. The influence of Al incorporation on the optical properties of Er3+-doped silica glasses and fibers is investigated. This approach enabled the preparation of silica glasses containing dispersed Er3+ ions with low Al content. The obtained fibers have been tested in an all-fibered cavity laser architecture. The Er3+/Al3+-codoped fiber laser presents a maximum efficiency of 27% at 1530 nm. We show that without Al doping, the laser exhibits lower performances that depend on Er content inside the doped fiber core. The effect of Er pair-induced quenching also has been investigated through nonsaturable absorption experiments, which clearly indicate that the fraction of Er ion pairs is significantly reduced in the Al-codoped fiber.

  10. Highly Tm(3+) doped germanate glass and its single mode fiber for 2.0 μm laser.

    PubMed

    Wen, Xin; Tang, Guowu; Yang, Qi; Chen, Xiaodong; Qian, Qi; Zhang, Qinyuan; Yang, Zhongmin

    2016-01-01

    Highly Tm(3+) doped optical fibers are urgently desirable for 2.0 μm compact single-frequency fiber laser and high-repetition-rate mode-locked fiber laser. Here, we systematically investigated the optical parameters, energy transfer processes and thermal properties of Tm(3+) doped barium gallo-germanate (BGG) glasses. Highly Tm(3+) doped BGG glass single mode (SM) fibers were fabricated by the rod-in-tube technique. The Tm(3+) doping concentration reaches 7.6 × 10(20) ions/cm(3), being the reported highest level in Tm(3+) doped BGG SM fibers. Using ultra short (1.6 cm) as-drawn highly Tm(3+) doped BGG SM fiber, a single-frequency fiber laser at 1.95 μm has been demonstrated with a maximum output power of 35 mW when in-band pumped by a home-made 1568 nm fiber laser. Additionally, a multilongitudinal-mode fiber laser at 1.95 μm has also been achieved in a 10 cm long as-drawn active fiber, yielding a maximum laser output power of 165 mW and a slope efficiency of 17%. The results confirm that the as-drawn highly Tm(3+) doped BGG SM fibers are promising in applications that require high gain and high power from a short piece of active optical fiber. PMID:26828920

  11. Highly Tm3+ doped germanate glass and its single mode fiber for 2.0 μm laser

    NASA Astrophysics Data System (ADS)

    Wen, Xin; Tang, Guowu; Yang, Qi; Chen, Xiaodong; Qian, Qi; Zhang, Qinyuan; Yang, Zhongmin

    2016-02-01

    Highly Tm3+ doped optical fibers are urgently desirable for 2.0 μm compact single-frequency fiber laser and high-repetition-rate mode-locked fiber laser. Here, we systematically investigated the optical parameters, energy transfer processes and thermal properties of Tm3+ doped barium gallo-germanate (BGG) glasses. Highly Tm3+ doped BGG glass single mode (SM) fibers were fabricated by the rod-in-tube technique. The Tm3+ doping concentration reaches 7.6 × 1020 ions/cm3, being the reported highest level in Tm3+ doped BGG SM fibers. Using ultra short (1.6 cm) as-drawn highly Tm3+ doped BGG SM fiber, a single-frequency fiber laser at 1.95 μm has been demonstrated with a maximum output power of 35 mW when in-band pumped by a home-made 1568 nm fiber laser. Additionally, a multilongitudinal-mode fiber laser at 1.95 μm has also been achieved in a 10 cm long as-drawn active fiber, yielding a maximum laser output power of 165 mW and a slope efficiency of 17%. The results confirm that the as-drawn highly Tm3+ doped BGG SM fibers are promising in applications that require high gain and high power from a short piece of active optical fiber.

  12. Highly Tm3+ doped germanate glass and its single mode fiber for 2.0 μm laser

    PubMed Central

    Wen, Xin; Tang, Guowu; Yang, Qi; Chen, Xiaodong; Qian, Qi; Zhang, Qinyuan; Yang, Zhongmin

    2016-01-01

    Highly Tm3+ doped optical fibers are urgently desirable for 2.0 μm compact single-frequency fiber laser and high-repetition-rate mode-locked fiber laser. Here, we systematically investigated the optical parameters, energy transfer processes and thermal properties of Tm3+ doped barium gallo-germanate (BGG) glasses. Highly Tm3+ doped BGG glass single mode (SM) fibers were fabricated by the rod-in-tube technique. The Tm3+ doping concentration reaches 7.6 × 1020 ions/cm3, being the reported highest level in Tm3+ doped BGG SM fibers. Using ultra short (1.6 cm) as-drawn highly Tm3+ doped BGG SM fiber, a single-frequency fiber laser at 1.95 μm has been demonstrated with a maximum output power of 35 mW when in-band pumped by a home-made 1568 nm fiber laser. Additionally, a multilongitudinal-mode fiber laser at 1.95 μm has also been achieved in a 10 cm long as-drawn active fiber, yielding a maximum laser output power of 165 mW and a slope efficiency of 17%. The results confirm that the as-drawn highly Tm3+ doped BGG SM fibers are promising in applications that require high gain and high power from a short piece of active optical fiber. PMID:26828920

  13. A glass fiber-reinforced composite - bioactive glass cranioplasty implant: A case study of an early development stage implant removed due to a late infection.

    PubMed

    Posti, Jussi P; Piitulainen, Jaakko M; Hupa, Leena; Fagerlund, Susanne; Frantzén, Janek; Aitasalo, Kalle M J; Vuorinen, Ville; Serlo, Willy; Syrjänen, Stina; Vallittu, Pekka K

    2015-03-01

    This case study describes the properties of an early development stage bioactive glass containing fiber-reinforced composite calvarial implant with histology that has been in function for two years and three months. The patient is a 33-year old woman with a history of substance abuse, who sustained a severe traumatic brain injury later unsuccessfully treated with an autologous bone flap and a custom-made porous polyethylene implant. She was thereafter treated with developmental stage glass fiber-reinforced composite - bioactive glass implant. After two years and three months, the implant was removed due to an implant site infection. The implant was analyzed histologically, mechanically, and in terms of chemistry and dissolution of bioactive glass. Mechanical integrity of the load bearing fiber-reinforced composite part of the implant was not affected by the in vivo period. Bioactive glass particles demonstrated surface layers of hydroxyapatite like mineral and dissolution, and related increase of pH was considerably less after two and three months period than that for fresh bioactive glass. There was a difference in the histology of the tissues inside the implant areas near to the margin of the implant that absorbed blood during implant installation surgery, showed fibrous tissue with blood vessels, osteoblasts, collagenous fibers with osteoid formation, and tiny clusters of more mature hard tissue. In the center of the implant, where there was less absorbed blood, only fibrous tissue was observed. This finding is in line with the combined positron emission tomography - computed tomography examination with (18F)-fluoride marker, which demonstrated activity of the mineralizing bone by osteoblasts especially at the area near to the margin of the implant 10 months after implantation. Based on these promising reactions found in the bioactive glass containing fiber-reinforced composite implant that has been implanted for two years and three months, calvarial

  14. A glass fiber-reinforced composite - bioactive glass cranioplasty implant: A case study of an early development stage implant removed due to a late infection.

    PubMed

    Posti, Jussi P; Piitulainen, Jaakko M; Hupa, Leena; Fagerlund, Susanne; Frantzén, Janek; Aitasalo, Kalle M J; Vuorinen, Ville; Serlo, Willy; Syrjänen, Stina; Vallittu, Pekka K

    2015-03-01

    This case study describes the properties of an early development stage bioactive glass containing fiber-reinforced composite calvarial implant with histology that has been in function for two years and three months. The patient is a 33-year old woman with a history of substance abuse, who sustained a severe traumatic brain injury later unsuccessfully treated with an autologous bone flap and a custom-made porous polyethylene implant. She was thereafter treated with developmental stage glass fiber-reinforced composite - bioactive glass implant. After two years and three months, the implant was removed due to an implant site infection. The implant was analyzed histologically, mechanically, and in terms of chemistry and dissolution of bioactive glass. Mechanical integrity of the load bearing fiber-reinforced composite part of the implant was not affected by the in vivo period. Bioactive glass particles demonstrated surface layers of hydroxyapatite like mineral and dissolution, and related increase of pH was considerably less after two and three months period than that for fresh bioactive glass. There was a difference in the histology of the tissues inside the implant areas near to the margin of the implant that absorbed blood during implant installation surgery, showed fibrous tissue with blood vessels, osteoblasts, collagenous fibers with osteoid formation, and tiny clusters of more mature hard tissue. In the center of the implant, where there was less absorbed blood, only fibrous tissue was observed. This finding is in line with the combined positron emission tomography - computed tomography examination with (18F)-fluoride marker, which demonstrated activity of the mineralizing bone by osteoblasts especially at the area near to the margin of the implant 10 months after implantation. Based on these promising reactions found in the bioactive glass containing fiber-reinforced composite implant that has been implanted for two years and three months, calvarial

  15. Fracture Resistance of Endodontically-treated Maxillary Premolars Restored with Composite Resin along with Glass Fiber Insertion in Different Positions

    PubMed Central

    Jafari Navimipour, Elmira; Ebrahimi Chaharom, Mohammad Esmaeel; Alizadeh Oskoee, Parnian; Mohammadi, Narmin; Bahari, Mahmoud; Firouzmandi, Maryam

    2012-01-01

    Background and aims The aim was to evaluate the effect of three methods of fiber insertion on fracture resistance of root-filled maxillary premolars in vitro. Materials and methods Sixty extracted human maxillary premolars received endodontic treatment followed by preparation of mesioocclusodistal (MOD) cavities, with gingival cavosurface margin 1.5 mm coronal to the cementoenamel junction (CEJ). Subsequently, the samples were randomly divided into four groups: no-fiber group; occlusal fiber group (fiber was placed in the occlusal third); circumferential fiber group (fiber was placed circumferentially in the cervical third); and dual-fiber group (occlusal and circumferential fibers). Subsequent to restoring with composite resin and thermocycling, a compressive force was applied until fracture. Data was analyzed using one-way ANOVA and Tukey test at significance levels of P < 0.05 and P < 0.02, respectively. Results Fiber placement significantly increased fracture resistance. Fracture resistance in the dual-fiber group was significantly higher than that in the circumferential fiber group (P < 0.007); however, there were no significant differences between the dual-fiber and occlusal fiber groups (P = 0.706). The highest favorable fracture rate was observed in the circumferential fiber group (60%). Conclusion Composite resin restoration along with glass fiber in the occlusal and gingival thirds can be an acceptable treatment option for restoring root-filled upper premolars. PMID:23277858

  16. Chemical behavior of aluminum and phosphorus during dissolution of glass fibers in physiological saline solutions.

    PubMed Central

    Baillif, P; Touray, J C

    1994-01-01

    The dissolution of textile glass fibers of four different compositions has been investigated at 37 degrees C. In these glasses, which are isolation type, the P2O5 contents scatter between 0 and 2 wt% and Al2O3 from 0.12 to 3.4 wt%. Both static (30-mg fibers; 250-ml solution) and dynamic (50-mg fibers; 40 ml/day flow rate) conditions with or without bubbling of a gas mixture (95:5, N2-CO2) have been used. Two physiological solutions, one proposed by Kanapilly and the other by Scholtze, were used. After each run (1, 3, 7, 14, and sometimes 30, 62 days) the solutions were analyzed for B and Si by inductively coupled plasma (ICP), the weight losses were determined, and the residual solid were observed by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Static runs give a better agreement between measured and calculated weight losses from solution analyses than dynamic experiments. SEM examinations indicate diameter reduction and formation of a hydrated Si-rich layer. Sometimes hollow tubes, suggesting the detachment of these layers, are observed. XPS and energy dispersive X-ray (EDX) analysis indicate the formation of a veneer of calcium phosphate for the most rapidly dissolving glass. In other cases an Al increase is observed at the solid solution interface. Whatever experimental conditions are used, the relative dissolution rates of the four glasses are identical. The kinetics may be modeled with variable dissolution rates from initial high values to final low ones. The latter reflect the very low solubility of the residual product. Images Figure 2. a Figure 2. b Figure 7. a Figure 7. b PMID:7882961

  17. Color stability of laboratory glass-fiber-reinforced plastics for esthetic orthodontic wires

    PubMed Central

    Inami, Toshihiro; Minami, Naomi; Yamaguchi, Masaru; Kasai, Kazutaka

    2015-01-01

    Objective In our previous study, glass-fiber-reinforced plastics (GFRPs) made from polycarbonate and glass fibers were prepared for esthetic orthodontic wires using pultrusion. These laboratory GFRP wires are more transparent than the commercially available nickel-titanium wire; however, an investigation of the color stability of GFRP during orthodontic treatment is needed. Accordingly, in the present study, the color stability of GFRP was assessed using colorimetry. Methods Preparation of GFRP esthetic round wires (diameter: 0.45 mm [0.018 inch]) using pultrusion was described previously. Here, to investigate how the diameter of fiber reinforcement affects color stability, GFRPs were prepared by incorporating either 13-µm (GFRP-13) or 7-µm glass (GFRP-7) fibers. The color changes of GFRPs after 24 h, and following 1, 2, and 4 weeks of coffee immersion at 37℃, were measured by colorimetry. We evaluated the color stability of GFRPs by two evaluating units: the color difference (ΔE*) and National Bureau of Standards (NBS). Results After immersion, both GFRPs showed almost no visible color change. According to the colorimetry measurements, the ΔE* values of GFRP-13 and GFRP-7 were 0.73-1.16, and 0.62-1.10, respectively. In accordance with NBS units, both GFRPs showed "slight" color changes. As a result, there were no significant differences in the ΔE* values or NBS units for GFRP-13 or GFRP-7. Moreover, for both GFRPs, no significant differences were observed in any of the immersion periods. Conclusions Our findings suggest that the GFRPs will maintain high color stability during orthodontic treatment, and are an attractive prospect as esthetic orthodontic wires. PMID:26023541

  18. Integrated optical-fiber capillary electrophoresis microchips with novel spin-on-glass surface modification.

    PubMed

    Lin, Che-Hsin; Lee, Gwo-Bin; Fu, Lung-Ming; Chen, Shu-Hui

    2004-07-30

    This paper presents a novel micro-capillary electrophoresis (CE) chip with embedded optical fibers for the on-line detection of DNA samples. The optical fibers are pre-etched and then inserted directly into fiber channels incorporated within low-cost soda-lime glass substrates. The embedded optical fibers are precisely aligned with the microfluidic channels such that the induced fluorescence signals from labeled bio-samples can be detected. This arrangement avoids the requirement for delicate optical alignment procedures and equipment. Surface modification of the CE channels is accomplished by means of a simple and reliable organic-based spin-on-glass (SOG) method. The zeta potential distribution and the corresponding electroosmotic mobility of the fluid are simulated numerically for the modified and non-modified channel surfaces, and then both sets of results are verified experimentally. The present results indicate that the value of the zeta potential for a surface with an SOG coating is 19.3 times smaller than that of an untreated surface. A phiX-174 DNA marker fluid is used to evaluate the injection and separation performance of the developed micro-CE device. Furthermore, the long-term stability of the SOG-coated surface is also investigated. The experimental data reveal that the microchip device is capable of providing highly efficient separations of bio-molecules, and that the SOG layer retains its low zeta potential characteristics for at least 45 days. The present results confirm the effectiveness of the proposed micro-CE chip in performing the on-line detection of DNA samples, and indicate that the SOG process represents a simple and reliable solution for the surface modification of glass-based microchannels. PMID:15142580

  19. High modulus rare earth and beryllium containing silicate glass compositions. [for glass reinforcing fibers

    NASA Technical Reports Server (NTRS)

    Bacon, J. F. (Inventor)

    1976-01-01

    Glass compositions having a Young's modulus of at least 16 million psi and a specific modulus of at least 110 million inches consisting essentially of approximately, by weight, 20 to 43% SiO2, 8 to 21% Al2O3, 4 to 10% BeO, 27 to 58% of at least one oxide selected from a first group consisting of Y2O3, La2O3, Nd2O3, Ce2O3, Ce2O3, and the mixed rare earth oxides, and 3 to 12% of at least one oxide selected from a second group consisting of MgO, ZrO2, ZnO and CaO are described. The molar ratio of BeO to the total content of the first group oxides is from 1.0 to 3.0.

  20. Stress generated by customized glass fiber posts and other types by photoelastic analysis.

    PubMed

    Bosso, Kátia; Gonini Júnior, Alcides; Guiraldo, Ricardo Danil; Berger, Sandrine Bittencourt; Lopes, Murilo Baena

    2015-01-01

    Endodontic posts are necessary to provide adequate retention and support when no sufficient remaining structure is available to retain the core. There are different materials and techniques to construct post-and-core, but there is no consensus about which one promotes better stress distribution on the remaining tooth structure. This study aimed to quantify and evaluate the distribution of stress in the root produced by customized glass fiber posts compared to different endodontic posts. Twenty-five simulated roots from photoelastic resin were made and divided into 5 groups: CPC, cast post-and-core; SP, screw post; CF, carbon fiber post; GF, glass fiber post; and CGF, customized glass fiber post. After cementing CPC and SP posts with zinc phosphate cement, and CF, GF and CGF posts with resin cement, resin cores were made for groups 2-5. Specimens were evaluated with vertical or 45° oblique loading. To analyze the fringes, the root was divided into 6 parts: palatal cervical, palatal middle, palatal apical, vestibular cervical, vestibular middle, and vestibular apical. The formed fringes were photographed and quantified. Data were recorded and subjected to two-way ANOVA and Tukey's test (5%). SP (1.95±0.60) showed higher stress (p<0.05) compared to the others (CPC-0.52±0.74; CF-0.50±0.75, GF-0.23±0.48 and CGF-0.45±0.83). All posts showed high stress in apical third (CPC-1.40±0.65; SP-2.30±0.44, CF-1.80±0.45, GF-1.20±0.45, CGF-1.70±1.03) Low stress was found in cervical third (CPC-0.20±0.45; CF-0.00±0.00, GF-0.00±0.00, CGF-0.00±0.00), except by SP (1.90±0.65), which showed statistical difference (p<0.05). Customized post showed high stress concentration at the root and conventional glass fiber posts showed more favorable biomechanical behavior.

  1. Flexural Properties of E Glass and TR50S Carbon Fiber Reinforced Epoxy Hybrid Composites

    NASA Astrophysics Data System (ADS)

    Dong, Chensong; Sudarisman; Davies, Ian J.

    2013-01-01

    A study on the flexural properties of E glass and TR50S carbon fiber reinforced hybrid composites is presented in this paper. Specimens were made by the hand lay-up process in an intra-ply configuration with varying degrees of glass fibers added to the surface of a carbon laminate. These specimens were then tested in the three-point bend configuration in accordance with ASTM D790-07 at three span-to-depth ratios: 16, 32, and 64. The failure modes were examined under an optical microscope. The flexural behavior was also simulated by finite element analysis, and the flexural modulus, flexural strength, and strain to failure were calculated. It is shown that although span-to-depth ratio shows an influence on the stress-strain relationship, it has no effect on the failure mode. The majority of specimens failed by either in-plane or out-of-plane local buckling followed by kinking and splitting at the compressive GFRP side and matrix cracking combined with fiber breakage at the CFRP tensile face. It is shown that positive hybrid effects exist for the flexural strengths of most of the hybrid configurations. The hybrid effect is noted to be more obvious when the hybrid ratio is small, which may be attributed to the relative position of the GFRP layer(s) with respect to the neutral plane. In contrast to this, flexural modulus seems to obey the rule of mixtures equation.

  2. Improvement of fatigue life and prevention of internal crack initiation of chopped carbon fiber reinforced plastics modified with micro glass fibers

    NASA Astrophysics Data System (ADS)

    Fujitani, Ryohei; Okubo, Kazuya; Fujii, Toru

    2016-04-01

    The purpose of this study is to improve fatigue properties of chopped carbon fiber reinforced plastics fabricated by SMC (Sheet Molding Compound) method and to clarify the mechanism for improvement. To enhance the properties, micro glass fibers with 500nm in diameter were added directly into vinyl ester resin with 0.3wt% contents. The chopped carbon fiber reinforced plastics were fabricated and cured at room temperature for 1hour under 1MPa and then at 60degree-C for 3hours. After curing, the fabricated plate was cut into the dimension of specimen. Tensile and bending strength and fatigue life of chopped carbon fiber reinforced plastics were investigated by tensile and three point bending test and cyclic tension-tension test, respectively. The behavior of strain concentration around the tips of carbon fiber were discussed with model specimen on the observations with DIC (Digital Image Correlation) method and polarizing microscope under tensile loading, in which one chopped carbon fiber was embedded into the matrix. In conclusion, when toughened vinyl ester resin modified with micro glass fibers was used as matrix, tensile and bending strength and fatigue life of chopped carbon fiber reinforced plastics were increased 56.6%, 49.8% and 14 to 23 times compared with those of unmodified specimens. It should be explained that static and dynamic properties of chopped carbon fiber reinforced plastics were improved by that crack initiation and propagation were prevented according to the prevention of the locally increasing of strain around the tip of carbon fiber, when vinyl ester resin modified with micro glass fibers was used as matrix.

  3. Yb-doped silica-based laser fibers: correlation of photodarkening kinetics and related optical properties with the glass composition

    NASA Astrophysics Data System (ADS)

    Kirchhof, J.; Unger, S.; Jetschke, S.; Schwuchow, A.; Leich, M.; Reichel, V.

    2009-02-01

    In the last years, photodarkening in ytterbium doped silica based laser fibers turned out to be a critical factor for high power laser action. Several investigations have been carried out in order to characterize the time dependent increase of the fiber loss and to understand and model the complex optical phenomenon. Despite of progress in this field, there is still a lack of data concerning the detailed influence of fiber composition and preparation process parameters as well as concerning the role of atomic defects in the core glass. Here we report on investigations about the photodarkening in dependence on the glass composition of the fiber laser core. By MCVD, fibers with different codopants (additional to the active ytterbium doping) have been prepared in a well-defined manner, regarding process parameters and glass composition, and comprehensively characterized. In addition to the photodarkening measurements, further optical properties have been measured on the fibers and fiber performs, which are related to the photodarkening effect: intensity and spectral behaviour of the Yb3+ absorption and emission in the NIR, cooperative visible fluorescence, UV absorption and UV excited visible emission. The concentration of codopants which are commonly used for active and passive lightguide fibers (aluminium, germanium, phosphorus) was systematically varied and correlated with the optical properties.

  4. Microstructure and mechanical behavior of metallic glass fiber-reinforced Al alloy matrix composites.

    PubMed

    Wang, Z; Georgarakis, K; Nakayama, K S; Li, Y; Tsarkov, A A; Xie, G; Dudina, D; Louzguine-Luzgin, D V; Yavari, A R

    2016-01-01

    Metallic glass-reinforced metal matrix composites are an emerging class of composite materials. The metallic nature and the high mechanical strength of the reinforcing phase offers unique possibilities for improving the engineering performance of composites. Understanding the structure at the amorphous/crystalline interfaces and the deformation behavior of these composites is of vital importance for their further development and potential application. In the present work, Zr-based metallic glass fibers have been introduced in Al7075 alloy (Al-Zn-Mg-Cu) matrices using spark plasma sintering (SPS) producing composites with low porosity. The addition of metallic glass reinforcements in the Al-based matrix significantly improves the mechanical behavior of the composites in compression. High-resolution TEM observations at the interface reveal the formation of a thin interdiffusion layer able to provide good bonding between the reinforcing phase and the Al-based matrix. The deformation behavior of the composites was studied, indicating that local plastic deformation occurred in the matrix near the glassy reinforcements followed by the initiation and propagation of cracks mainly through the matrix. The reinforcing phase is seen to inhibit the plastic deformation and retard the crack propagation. The findings offer new insights into the mechanical behavior of metal matrix composites reinforced with metallic glasses. PMID:27067824

  5. Microstructure and mechanical behavior of metallic glass fiber-reinforced Al alloy matrix composites.

    PubMed

    Wang, Z; Georgarakis, K; Nakayama, K S; Li, Y; Tsarkov, A A; Xie, G; Dudina, D; Louzguine-Luzgin, D V; Yavari, A R

    2016-01-01

    Metallic glass-reinforced metal matrix composites are an emerging class of composite materials. The metallic nature and the high mechanical strength of the reinforcing phase offers unique possibilities for improving the engineering performance of composites. Understanding the structure at the amorphous/crystalline interfaces and the deformation behavior of these composites is of vital importance for their further development and potential application. In the present work, Zr-based metallic glass fibers have been introduced in Al7075 alloy (Al-Zn-Mg-Cu) matrices using spark plasma sintering (SPS) producing composites with low porosity. The addition of metallic glass reinforcements in the Al-based matrix significantly improves the mechanical behavior of the composites in compression. High-resolution TEM observations at the interface reveal the formation of a thin interdiffusion layer able to provide good bonding between the reinforcing phase and the Al-based matrix. The deformation behavior of the composites was studied, indicating that local plastic deformation occurred in the matrix near the glassy reinforcements followed by the initiation and propagation of cracks mainly through the matrix. The reinforcing phase is seen to inhibit the plastic deformation and retard the crack propagation. The findings offer new insights into the mechanical behavior of metal matrix composites reinforced with metallic glasses.

  6. Microstructure and mechanical behavior of metallic glass fiber-reinforced Al alloy matrix composites

    PubMed Central

    Wang, Z.; Georgarakis, K.; Nakayama, K. S.; Li, Y.; Tsarkov, A. A.; Xie, G.; Dudina, D.; Louzguine-Luzgin, D. V.; Yavari, A. R.

    2016-01-01

    Metallic glass-reinforced metal matrix composites are an emerging class of composite materials. The metallic nature and the high mechanical strength of the reinforcing phase offers unique possibilities for improving the engineering performance of composites. Understanding the structure at the amorphous/crystalline interfaces and the deformation behavior of these composites is of vital importance for their further development and potential application. In the present work, Zr-based metallic glass fibers have been introduced in Al7075 alloy (Al-Zn-Mg-Cu) matrices using spark plasma sintering (SPS) producing composites with low porosity. The addition of metallic glass reinforcements in the Al-based matrix significantly improves the mechanical behavior of the composites in compression. High-resolution TEM observations at the interface reveal the formation of a thin interdiffusion layer able to provide good bonding between the reinforcing phase and the Al-based matrix. The deformation behavior of the composites was studied, indicating that local plastic deformation occurred in the matrix near the glassy reinforcements followed by the initiation and propagation of cracks mainly through the matrix. The reinforcing phase is seen to inhibit the plastic deformation and retard the crack propagation. The findings offer new insights into the mechanical behavior of metal matrix composites reinforced with metallic glasses. PMID:27067824

  7. Microstructure and mechanical behavior of metallic glass fiber-reinforced Al alloy matrix composites

    NASA Astrophysics Data System (ADS)

    Wang, Z.; Georgarakis, K.; Nakayama, K. S.; Li, Y.; Tsarkov, A. A.; Xie, G.; Dudina, D.; Louzguine-Luzgin, D. V.; Yavari, A. R.

    2016-04-01

    Metallic glass-reinforced metal matrix composites are an emerging class of composite materials. The metallic nature and the high mechanical strength of the reinforcing phase offers unique possibilities for improving the engineering performance of composites. Understanding the structure at the amorphous/crystalline interfaces and the deformation behavior of these composites is of vital importance for their further development and potential application. In the present work, Zr-based metallic glass fibers have been introduced in Al7075 alloy (Al-Zn-Mg-Cu) matrices using spark plasma sintering (SPS) producing composites with low porosity. The addition of metallic glass reinforcements in the Al-based matrix significantly improves the mechanical behavior of the composites in compression. High-resolution TEM observations at the interface reveal the formation of a thin interdiffusion layer able to provide good bonding between the reinforcing phase and the Al-based matrix. The deformation behavior of the composites was studied, indicating that local plastic deformation occurred in the matrix near the glassy reinforcements followed by the initiation and propagation of cracks mainly through the matrix. The reinforcing phase is seen to inhibit the plastic deformation and retard the crack propagation. The findings offer new insights into the mechanical behavior of metal matrix composites reinforced with metallic glasses.

  8. Crosslinked glass fiber affinity membrane chromatography and its application to fibronectin separation.

    PubMed

    Guo, Wei; Ruckenstein, Eli

    2003-09-25

    Macroporous glass membranes were prepared from glass fiber filters via chemical crosslinking and modification, and used for the membrane affinity chromatography of fibronectin from human blood plasma. The filters were first treated with a piranha solution (a concentrated solution of H2SO4 + H2O2 in water), and then crosslinked with bifunctional organosilanes and modified to introduce amino or aniline moieties. Ligand immobilizations via diazotization and glutaraldehyde pathways were carried out and compared. Characterization of the membranes was performed using bovine serum albumin and trypsin as test ligands. By using a cartridge containing gelatin immobilized affinity membranes followed by another cartridge containing heparin immobilized membranes, fibronectin from human blood plasma could be separated.

  9. Glass fibers and vapor phase components of cigarette smoke as cofactors in experimental respiratory tract carcinogenesis

    SciTech Connect

    Feron, V.J.; Kuper, C.F.; Spit, B.J.; Reuzel, P.G.; Woutersen, R.A.

    1985-01-01

    Syrian golden hamsters were given intratracheal instillations of glass fibers with or without BP suspended in saline, once a fortnight for 52 weeks; the experiment was terminated at week 85. No tumors of the respiratory tract were observed in hamsters treated with glass fibers alone. There was no indication that glass fibers enhanced the development of respiratory tract tumors induced by BP. In another study Syrian golden hamsters were exposed to fresh air or to a mixture of 4 major vapor phase components of cigarette smoke, viz. isoprene (800----700 ppm), methyl chloride (1000----900 ppm), methyl nitrite (200----190 ppm) and acetaldehyde (1400----1200 ppm) for a period of at most 23 months. Some of the animals were also given repeated intratracheal instillations of BP or norharman in saline. Laryngeal tumors were found in 7/31 male and 6/32 female hamsters exposed only to the vapor mixture, whereas no laryngeal tumors occurred in controls. The tumor response of the larynx most probably has to be ascribed entirely to the action of acetaldehyde. Simultaneous treatment with norharman or BP did not affect the tumor response of the larynx. Acetaldehyde may occur in the vapor phase of cigarette smoke at levels up to 2000 ppm. Chronic inhalation exposure of rats to acetaldehyde at levels of 0 (controls), 750, 1500 or 3000----1000 ppm resulted in a high incidence of nasal carcinomas, both squamous cell carcinomas of the respiratory epithelium and adenocarcinomas of the olfactory epithelium. It was discussed that acetaldehyde may significantly contribute to the induction of bronchogenic cancer by cigarette smoke in man.

  10. Abrasive Wear Performance of Aluminium Modified Epoxy-Glass Fiber Composites

    NASA Astrophysics Data System (ADS)

    Kamble, Vikram G.; Mishra, Punyapriya; Al Dabbas, Hassan A.; Panda, H. S.; Fernandez, Johnathan Bruce

    2015-07-01

    For a long time, Aluminum filled epoxies molds have been used in rapid tooling process. These molds are very economical when applied in manufacturing of low volume of plastic parts. To improve the thermal conductivity of the material, the metallic filler material is added to it and the glass fiber improves the wear resistance of the material. These two important parameters establish the life of composites. The present work reports on abrasive wear behavior of Aluminum modified epoxy and glass fiber composite with 5 wt.% and 10 wt.% of aluminum particles. Through pin on disc wear testing machine, we studied the wear behaviors of composites, and all these samples were fabricated by using hand layup process. Epoxy resin was used as matrix material which was reinforced with Glass fiber and Aluminum as filler. The composite with 5 wt.% and 10 wt.% of Al was cast with dimensions 100 × 100 × 6 mm. The specimens were machined to a size of 6 × 6 × 4 mm for abrasive testing. Abrasive tests were carried out for different grit paper sizes, i.e., 150, 320, 600 at different sliding distance, i.e., 20, 40, 60 m at different loads of 5, 10 and 15 N and at constant speed. The weight loss due to wear was calculated along with coefficient of friction. Hardness was found using Rockwell hardness machine. The SEM morphology of the worn out surface wear was analyzed to understand the wear mechanism. Results showed that the addition of Aluminum particles was beneficial for low abrasive conditions.

  11. Preparation and characterization of PVDF-glass fiber composite membrane reinforced by interfacial UV-grafting copolymerization.

    PubMed

    Luo, Nan; Xu, Rongle; Yang, Min; Yuan, Xing; Zhong, Hui; Fan, Yaobo

    2015-12-01

    A novel inorganic-organic composite membrane, namely poly(vinylidene fluoride) PVDF-glass fiber (PGF) composite membrane, was prepared and reinforced by interfacial ultraviolet (UV)-grafting copolymerization to improve the interfacial bonding strength between the membrane layer and the glass fiber. The interfacial polymerization between inorganic-organic interfaces is a chemical cross-linking reaction that depends on the functionalized glass fiber with silane coupling (KH570) as the initiator and the polymer solution with acrylamide monomer (AM) as the grafting block. The Fourier transform infrared spectrometer-attenuated total reflectance (FTIR-ATR) spectra and the energy dispersive X-ray (EDX) pictures of the interface between the glass fiber and polymer matrix confirmed that the AM was grafted to the surface of the glass fiber fabric and that the grafting polymer was successfully embedded in the membrane matrix. The formation mechanisms, permeation, and anti-fouling performance of the PGF composite membrane were measured with different amounts of AM in the doping solutions. The results showed that the grafting composite membrane improved the interfacial bonding strength and permeability, and the peeling strength was improved by 32.6% for PGF composite membranes with an AM concentration at 2wt.%.

  12. AN HYBRID GLASS/HEMP FIBERS SOLUTION FRP PIPES: TECHNICAL AND ECONOMIC ADVANTAGES OF HAND LAY UP VS LIGHT RTM

    SciTech Connect

    Cicala, G.; Cristaldi, G.; Recca, G.; Ziegmann, G.; ElSabbagh, A.; Dickert, M.

    2008-08-28

    The aim of the present research was to investigate the replacement of glass fibers with hemp fibers for applications in the piping industry. The choice of hemp fibers was mainly related to the needs, expressed by some companies operating in this sector, for cost reduction without adversely reducing the performances of the pipes. Two processing techniques, namely hand lay up and light RTM, were evaluated. The pipe selected for the study was a curved fitting (90 deg.) flanged at both ends. The fitting must withstand an internal pressure of 10 bar and the presence of acid aqueous solutions. The original lay-up used to build the pipe is a sequence of C-glass, glass mats and glass fabric. Commercial epoxy vinyl ester resin was used as thermoset matrix.Hemp fibers mats were selected as potential substitute of glass fibers mats because of their low cost and ready availability from different commercial sources. The data obtained from the mechanical characterization were used to define a favorable design of the pipe using hemp mats as internal layer. The proposed design for the fittings allowed for a cost reduction of about 24% and a weight saving of about 23% without any drawback in terms of the final performances.The light RTM techniques was developed on purpose for the manufacturing of the curved pipe. The comparison between hand lay up and light RTM evidenced a substantial cost reduction when light RTM was used.

  13. An Hybrid Glass/hemp Fibers Solution Frp Pipes: Technical and Economic Advantages of Hand Lay up VS Light Rtm

    NASA Astrophysics Data System (ADS)

    Cicala, G.; Cristaldi, G.; Recca, G.; Ziegmann, G.; ElSabbagh, A.; Dickert, M.

    2008-08-01

    The aim of the present research was to investigate the replacement of glass fibers with hemp fibers for applications in the piping industry. The choice of hemp fibers was mainly related to the needs, expressed by some companies operating in this sector, for cost reduction without adversely reducing the performances of the pipes. Two processing techniques, namely hand lay up and light RTM, were evaluated. The pipe selected for the study was a curved fitting (90°) flanged at both ends. The fitting must withstand an internal pressure of 10 bar and the presence of acid aqueous solutions. The original lay-up used to build the pipe is a sequence of C-glass, glass mats and glass fabric. Commercial epoxy vinyl ester resin was used as thermoset matrix. Hemp fibers mats were selected as potential substitute of glass fibers mats because of their low cost and ready availability from different commercial sources. The data obtained from the mechanical characterization were used to define a favorable design of the pipe using hemp mats as internal layer. The proposed design for the fittings allowed for a cost reduction of about 24% and a weight saving of about 23% without any drawback in terms of the final performances. The light RTM techniques was developed on purpose for the manufacturing of the curved pipe. The comparison between hand lay up and light RTM evidenced a substantial cost reduction when light RTM was used.

  14. Risk factors for failure of glass fiber-reinforced composite post restorations: a prospective observational clinical study.

    PubMed

    Naumann, Michael; Blankenstein, Felix; Kiessling, Saskia; Dietrich, Thomas

    2005-12-01

    Glass fiber-reinforced endodontic posts are considered to have favorable mechanical properties for the reconstruction of endodontically treated teeth. The aim of the present investigation was to evaluate the survival of two tapered and one parallel-sided glass fiber-reinforced endodontic post systems in teeth with different stages of hard tissue loss and to identify risk factors for restoration failure. One-hundred and forty-nine glass fiber-reinforced endodontic posts in 122 patients were followed-up for 5-56 months [mean +/- standard deviation (SD): 39 +/- 11 months]. Glass fiber-reinforced endodontic posts were adhesively luted and the core was built with a composite resin. Cox proportional hazards models were used to evaluate the association of clinical variables and failure rate. Higher failure rates were found for restorations of anterior teeth compared with posterior teeth [Hazard-Ratios (HR): 3.1; 95% confidence interval (CI): 1.3-7.4], for restorations in teeth with no proximal contacts compared with at least one proximal contact (HR: 3.0; 95% CI: 1.0-9.0), and for teeth restored with single crowns compared with fixed bridges (HR: 4.3; 95% CI: 1.1-16.2). Tooth type, type of final restoration and the presence of adjacent teeth were found to be significant predictors of failure rates in endodontically treated teeth restored with glass fiber-reinforced endodontic posts. PMID:16324143

  15. Determination of mechanical properties of some glass fiber reinforced plastics suitable to Wind Turbine Blade construction

    NASA Astrophysics Data System (ADS)

    Steigmann, R.; Savin, A.; Goanta, V.; Barsanescu, P. D.; Leitoiu, B.; Iftimie, N.; Stanciu, M. D.; Curtu, I.

    2016-08-01

    The control of wind turbine's components is very rigorous, while the tower and gearbox have more possibility for revision and repairing, the rotor blades, once they are deteriorated, the defects can rapidly propagate, producing failure, and the damages can affect large regions around the wind turbine. This paper presents the test results, performed on glass fiber reinforced plastics (GFRP) suitable to construction of wind turbine blades (WTB). The Young modulus, shear modulus, Poisson's ratio, ultimate stress have been determined using tensile and shear tests. Using Dynamical Mechanical Analysis (DMA), the activation energy for transitions that appear in polyester matrix as well as the complex elastic modulus can be determined, function of temperature.

  16. Esthetic and biologic mode of reattaching incisor fracture fragment utilizing glass fiber post

    PubMed Central

    Manju, M.; Shanthraj, Srinivas L.; Savitha, K. C.; Sethi, Ntasha

    2015-01-01

    Trauma to the anterior teeth affects the esthetic and psychological well-being of the patient. Advancement in the adhesive dentistry has facilitated the restoration of the coronal tooth fractures by minimally invasive procedures when the original tooth fragment is available. Reattachment of fractured fragment offers immediate treatment with improved preponderant aesthetics and restoration of function. Here, we describe a case of complicated fracture of the maxillary left immature permanent central incisor, which was treated endodontically followed by esthetic reattachment of the fractured fragment using the glass fiber post. Functional demands and esthetic considerations of the patient were fully met with this biologic mode of fragment reattachment. PMID:26283849

  17. Recommended Minimum Test Requirements and Test Methods for Assessing Durability of Random-Glass-Fiber Composites

    SciTech Connect

    Battiste, R.L.; Corum, J.M.; Ren, W.; Ruggles, M.B.

    1999-06-01

    This report provides recommended minimum test requirements are suggested test methods for establishing the durability properties and characteristics of candidate random-glass-fiber polymeric composites for automotive structural applications. The recommendations and suggestions are based on experience and results developed at Oak Ridge National Laboratory (ORNL) under a US Department of Energy Advanced Automotive Materials project entitled ''Durability of Lightweight Composite Structures,'' which is closely coordinated with the Automotive Composites Consortium. The report is intended as an aid to suppliers offering new structural composites for automotive applications and to testing organizations that are called on to characterize the composites.

  18. A glass fiber sheet-based electroosmotic lateral flow immunoassay for point-of-care testing.

    PubMed

    Oyama, Yuriko; Osaki, Toshihisa; Kamiya, Koki; Kawano, Ryuji; Honjoh, Tsutomu; Shibata, Haruki; Ide, Toru; Takeuchi, Shoji

    2012-12-21

    We have developed a quantitative immunoassay chip targeting point-of-care testing. To implement a lateral flow immunoassay, a glass fiber sheet was chosen as the material for the microfluidic channel in which the negative charge on the fiber surfaces efficiently generates the electroosmotic flow (EOF). The EOF, in turn, allows controllable bound/free separation of antigen/antibody interactions on the chip and enables precise determination of the antigen concentration. In addition, the defined size of the porous matrix was suitable for the filtration of undesired large particles. We confirmed the linear relationship between the concentration of analyte and the resulting fluorescence intensity from the immunoassay of two model analytes, C-reactive protein (CRP) and insulin, demonstrating that analyte concentration was quantitatively determined within the developed chip in 20 min. The limits of detection were 8.5 ng mL(-1) and 17 ng mL(-1) for CRP and insulin, respectively. PMID:23114383

  19. Temperature effect during humid ageing on interfaces of glass and carbon fibers reinforced epoxy composites.

    PubMed

    Ray, B C

    2006-06-01

    Weight change behavior of fiber-reinforced polymer composites in humid and thermal environments appears to be a complex phenomena. The state of fiber/matrix interface is believed to influence the nature of diffusion modes. A significant weakening often appears at the interface during the hygrothermal ageing. It effects the moisture uptake kinetics and also the reduction of mechanical properties. The importance of temperature at the time of conditioning plays an important role in environmental degradation of such composite materials. An attempt has been made here to evaluate the deleterious effect of temperature on shear strength of carbon/epoxy and glass/epoxy composites during hygrothermal conditionings. Mechanical tests were conducted at room temperature to assess the effectiveness of the relaxation process in the nullification of environmentally-induced damage in the composites.

  20. Visible to infrared photoluminescence from gold nanoparticles embedded in germano-silicate glass fiber.

    PubMed

    Lin, Aoxiang; Son, Dong Hoon; Ahn, Il Ho; Song, G Hugh; Han, Won-Taek

    2007-05-14

    Germano-silicate glass fiber containing gold nanoparticles was developed by modified chemical vapor deposition and solution doping processes. Pumping with 488 nm Argon ion laser, we firstly report on the visible to infrared photoluminescence of the gold nanoparticles embedded in the core of the germano-silicate fibers. The surface plasmon resonance absorption peak at 498.4 nm and the visible to infrared photoluminescence over the range of 600 nm approximately 1560 nm were found and explained according to the interband and intraband electronic transitions of Au atoms. The averaged quantum efficiencies of the photoluminescence at 833 nm and 1536 nm were estimated to be 5.75 x 10(-8) and 2.01 x 10(-9), respectively.

  1. 30  W fluoride glass all-fiber laser at 2.94  μm.

    PubMed

    Fortin, Vincent; Bernier, Martin; Bah, Souleymane T; Vallée, Réal

    2015-06-15

    We report the demonstration of a 2938 nm erbium-doped fluoride glass fiber laser delivering a record output power of 30.5 W in continuous wave operation. The passively cooled all-fiber laser cavity based on intracore fiber Bragg gratings has an overall laser efficiency of 16% as a function of the launched pump power at 980 nm and a single-mode output beam quality of M2<1.2. This power scaling demonstration of a fiber laser operating near the vibrational resonance of water is likely to have a significant impact on several biomedical applications. PMID:26076286

  2. The nature of the structural gradient in epoxy curing at a glass fiber/epoxy matrix interface using FTIR imaging.

    PubMed

    González-Benito, J

    2003-11-15

    The curing process of an epoxide system was studied at the interface formed between a silane-coated glass fiber and an epoxy matrix. The gradient in the structure of the epoxy resin as a result of the cure process at the fiber/matrix interfacial region was monitored by FTIR imaging. For comparison, the epoxy curing at the interface formed between the epoxy resin and (a) an uncoated glass fiber and (b) a polyorganosiloxane (obtained from the silane used for the glass-fiber coating) were also monitored. Chemically specific images of the OH and the H-N-H groups near the interface region were obtained. These images suggest that there is a chemical gradient in the structure of the matrix from the fiber surface to the polymer bulk due to different conversions. The basis of the different kinetics of the curing reactions is a result of amino group inactivation at the interface. This deactivation translates into an off-stoichiometry of the reaction mixture, which is a function of the distance from the surface of the glass fiber.

  3. On-Line Sensor Systems for Monitoring the Cure of Coatings on Glass Optical Fibers and Assemblies

    SciTech Connect

    J.F. McClelland; R.W. Jones

    2003-10-01

    Glass fiber technology, which enables light transmission and communication over great distances, was developed in the U.S. and has evolved into a major industry in this country. Continuous innovation is required to maintain the leadership position that the U.S. enjoys in glass optical fiber technology. This project addressed a key quality assurance aspect of glass optical fiber and cable assembly production-namely, assuring full cure of the polymer coating that protects the fiber from physical damage and moisture degradation. Properly cured coatings are imperative for the cable-assembly industry because they provide protection from the environment and assure both mechanical strength and long-term performance of the cable assembly, The industry loses approximately 5% of its production due to under-cured fiber. This loss amounts to roughly $70,000,000 per year. The standard procedure in the industry is to spot check cables after production because no on-line method has been available to continuously monitor cure during either the glass-fiber drawing process, which operates at high speeds of roughly 1 kilometer per minute, or the cable-assembly process. Many kilometers of out-of-specification material can therefore be produced before tests catch the flaw. This project strove to eliminate this delay.

  4. Investigation of Fiber Waviness in a Thick Glass Composite Beam Using THz NDE

    NASA Technical Reports Server (NTRS)

    Anastasi, Robert F.

    2008-01-01

    Fiber waviness in laminated composite material is introduced during manufacture because of uneven curing, resin shrinkage, or ply buckling caused by bending the composite lay-up into its final shape prior to curing. The resulting waviness has a detrimental effect on mechanical properties, therefore this condition is important to detect and characterize. Ultrasonic characterization methods are difficult to interpret because elastic wave propagation is highly dependent on ply orientation and material stresses. By comparison, the pulsed terahertz response of the composite is shown to provide clear indications of the fiber waviness. Pulsed Terahertz NDE is an electromagnetic inspection method that operates in the frequency range between 300 GHz and 3 THz. Its propagation is influenced by refractive index variations and interfaces. This work applies pulsed Terahertz NDE to the inspection of a thick composite beam with fiber waviness. The sample is a laminated glass composite material approximately 15mm thick with a 90-degree bend. Terahertz response from the planar section, away from the bend, is indicative of a homogeneous material with no major reflections from internal plies, while the multiple reflections at the bend area correspond to the fiber waviness. Results of these measurements are presented for the planar and bend areas.

  5. Phagosomal pH and glass fiber dissolution in cultured nasal epithelial cells and alveolar macrophages: a preliminary study.

    PubMed Central

    Johnson, N F

    1994-01-01

    The dissolution rate of glass fibers has been shown to be pH sensitive using in vitro lung fluid simulant models. The current study investigated whether there is a difference in phagosomal pH (ppH) between rat alveolar macrophages (AM) and rat nasal epithelial cells (RNEC) and whether such a difference would influence the dissolution of glass fibers. The ppH was measured in cultured AM and RNEC using flow cytometric, fluorescence-emission rationing techniques with fluorescein-labeled, amorphous silica particles. Glass fiber dissolution was determined in AM and RNEC cultured for 3 weeks with fast dissolving glass fibers (GF-A) or slow dissolving ones (GF-B). The mean diameters of GF-A were 2.7 microns and of GF-B, 2.6 microns, the average length of both fibers was approximately 22 to 25 microns. Dissolution was monitored by measuring the length and diameter of intracellular fibers and estimating the volume, assuming a cylindrical morphology. The ppH of AM was 5.2 to 5.8, and the ppH of RNEC was 7.0 to 7.5. The GF-A dissolved more slowly in RNEC than in AM, and no dissolution was evident in either cell type with GF-B. The volume loss with GF-A after a 3-week culture with AM was 66% compared to 45% for cultured RNEC. These results are different from those obtained using in vitro lung fluid-simulant models where dissolution is faster at higher pH. This difference suggests that dissolution rates of glass fibers in AM should not be applied to the dissolution of fibers in epithelial cells. Images Figure 1. a Figure 1. b Figure 2. a Figure 2. b Figure 3. a Figure 3. b PMID:7882965

  6. Enhanced upconversion emission in crystallization-controllable glass-ceramic fiber containing Yb(3+)-Er(3+) codoped CaF2 nanocrystals.

    PubMed

    Peng, Wencai; Fang, Zaijin; Ma, Zhijun; Qiu, Jianrong

    2016-10-01

    Functional nanocrystal-containing materials have been a hot topic in recent years. However, few researches have focused on functional nanocrystals contained in optical glass fibers. In this research, transparent CaF2 glass-ceramic was prepared by a melt-quenching method. Greatly enhanced upconversion luminescence was observed after heat treatment. By applying a novel method called melt-in-tube, precursor fiber free of crystals was fabricated at the drawing temperature where the clad was softened while the core was melted. Glass-ceramic fiber with fiber core containing Yb(3+)-Er(3+) codoped CaF2 nanocrystals was obtained after heat treatment at a relatively low temperature. Electron probe micro-analyzer measurement shows no obvious element diffusion between the core and clad. Greatly enhanced upconversion emission was detected in the glass-ceramic fiber excited by a 980 nm laser, suggesting the developed glass-ceramic fiber is a promising material for upconversion laser. PMID:27576586

  7. Enhanced upconversion emission in crystallization-controllable glass-ceramic fiber containing Yb3+-Er3+ codoped CaF2 nanocrystals

    NASA Astrophysics Data System (ADS)

    Peng, Wencai; Fang, Zaijin; Ma, Zhijun; Qiu, Jianrong

    2016-10-01

    Functional nanocrystal-containing materials have been a hot topic in recent years. However, few researches have focused on functional nanocrystals contained in optical glass fibers. In this research, transparent CaF2 glass-ceramic was prepared by a melt-quenching method. Greatly enhanced upconversion luminescence was observed after heat treatment. By applying a novel method called melt-in-tube, precursor fiber free of crystals was fabricated at the drawing temperature where the clad was softened while the core was melted. Glass-ceramic fiber with fiber core containing Yb3+-Er3+ codoped CaF2 nanocrystals was obtained after heat treatment at a relatively low temperature. Electron probe micro-analyzer measurement shows no obvious element diffusion between the core and clad. Greatly enhanced upconversion emission was detected in the glass-ceramic fiber excited by a 980 nm laser, suggesting the developed glass-ceramic fiber is a promising material for upconversion laser.

  8. Enhanced upconversion emission in crystallization-controllable glass-ceramic fiber containing Yb(3+)-Er(3+) codoped CaF2 nanocrystals.

    PubMed

    Peng, Wencai; Fang, Zaijin; Ma, Zhijun; Qiu, Jianrong

    2016-10-01

    Functional nanocrystal-containing materials have been a hot topic in recent years. However, few researches have focused on functional nanocrystals contained in optical glass fibers. In this research, transparent CaF2 glass-ceramic was prepared by a melt-quenching method. Greatly enhanced upconversion luminescence was observed after heat treatment. By applying a novel method called melt-in-tube, precursor fiber free of crystals was fabricated at the drawing temperature where the clad was softened while the core was melted. Glass-ceramic fiber with fiber core containing Yb(3+)-Er(3+) codoped CaF2 nanocrystals was obtained after heat treatment at a relatively low temperature. Electron probe micro-analyzer measurement shows no obvious element diffusion between the core and clad. Greatly enhanced upconversion emission was detected in the glass-ceramic fiber excited by a 980 nm laser, suggesting the developed glass-ceramic fiber is a promising material for upconversion laser.

  9. The kinetics of crystallization of molten binary and ternary oxide systems and their application to the origination of high modulus glass fibers

    NASA Technical Reports Server (NTRS)

    Bacon, J. F.

    1971-01-01

    Emphasis on the consideration of glass formation on a kinetic process made it possible to think of glass compositions different from those normally employed in the manufacture of glass fibers. Approximately 450 new glass compositions were prepared and three dozen of these compositions have values for Young's modulus measured on bulk specimens greater than nineteen million pounds per square inch. Of the new glasses about a hundred could be drawn into fibers by mechanical methods at high speeds. The fiber which has a Young's modulus measured on the fiber of 18.6 million pounds per square inch and has been prepared in quantity as a monofilament (to date more than 150 million lineal feet of 0.2 to 0.4 mil fiber have been produced). This fiber has also been successfully incorporated both in epoxy and polyimide matrices. The epoxy resin composite has shown a modulus forty percent better than that achievable using the most common grade of competitive glass fiber, and twenty percent better than that obtainable with the best available grade of competitive glass fiber. Other glass fibers of even higher modulus have been developed.

  10. Experimental investigation on the mechanical properties of glass fiber reinforced nylon

    NASA Astrophysics Data System (ADS)

    Nuruzzaman, D. M.; Iqbal, A. K. M. Asif; Oumer, A. N.; Ismail, N. M.; Basri, S.

    2016-02-01

    In this study, the influence of different weight percentages of glass fiber (GF) reinforcement on the mechanical properties of nylon (PA6) composite is investigated. Test specimens of pure nylon, 95% nylon + 5% GF, 90% nylon + 10% GF, 85% nylon + 15% GF and 80% nylon + 20% GF are prepared using an injection molding machine. In the experiments, tensile tests and impact tests are carried out. The obtained results reveal that mechanical properties of the nylon composites are significantly influenced by the weight percentage of glass fiber. From the tensile test results, it is observed that pure nylon has the lowest elastic modulus and yield strength whereas 80% nylon + 20% GF composite shows the highest elastic modulus and yield strength. Moreover, pure nylon shows the lowest tensile strength while 80% nylon + 20% GF shows significantly improved tensile strength. Results show that elongation at break is remarkably high for pure nylon whereas it is very low for 80% nylon + 20% GF. Izod impact test results reveal that, 85% nylon + 15% GF composite has the highest impact strength or toughness whereas 95% nylon + 5% GF composite shows the lowest impact strength. Furthermore, 80% nylon + 20% GF composite shows somewhat less impact strength or toughness than 85% nylon + 15% GF composite.

  11. Two-color mid-infrared thermometer using a hollow glass optical fiber

    SciTech Connect

    Small, W., IV.; Celliers, P.M.; Da Silva, L.D.; Matthews, D.L.

    1997-06-30

    A non-invasive two-color infrared thermometer has been developed for low-temperature biomedical applications. Mid-infrared radiation from the target is collected via a single 700 {mu}m-bore hollow glass optical fiber, simultaneously split into two paths and modulated by a gold-coated reflective optical chopper, and focused onto two thermoelectrically-cooled HgCdZnTe photoconductors (bandpasses of 2- 6 {mu}m and 2-12 {mu}m, respectively) by gold-coated spherical mirrors. The small numerical aperture of the hollow glass fiber provides high spatial resolution (is less than 1 mm), and the hollow bore eliminates reflective losses. The modulated detector signals are recovered using lock-in amplification, permitting measurement of small low-temperature signal buried in the background. A computer algorithm calculates the true temperature and emissivity of the target in real time based on a previous blackbody (emissivity equal to 1) calibration, taking into account reflection of the ambient radiation field from the target surface.

  12. An update on glass fiber dental restorative composites: a systematic review.

    PubMed

    Khan, Abdul Samad; Azam, Maria Tahir; Khan, Maria; Mian, Salman Aziz; Ur Rehman, Ihtesham

    2015-02-01

    Dentistry is a much developed field in the last few decades. New techniques have changed the conventional treatment methods as applications of new dental materials give better outcomes. The current century has suddenly forced on dentistry, a new paradigm regarding expected standards for state-of-the-art patient care. Within the field of restorative dentistry, the incredible advances in dental materials research have led to the current availability of esthetic adhesive restorations. The chemistry and structure of the resins and the nature of the glass fiber reinforced systems in dental composites are reviewed in relation to their influence and properties including mechanical, physical, thermal, biocompatibility, technique sensitivity, mode and rate of failure of restorations on clinical application. It is clear that a deeper understanding of the structure of the polymeric matrix and resin-based dental composite is required. As a result of ongoing research in the area of glass fiber reinforced composites and with the development and advancement of these composites, the future prospects of resin-based composite are encouraging.

  13. Comparison of Two Techniques for Evaluation of Coronal Leakage Along of a Glass Fiber Post

    PubMed Central

    Sadighpour, L.; Rezaei, S.; Geramipanah, F.; Mohammadi, M.; Choubchian, S.

    2010-01-01

    Objective: Contradictory results have been reported over microleakage studies of restorative materials and methods. Despite the number of publications on leakage there are few evidences comparing the different microleakage evaluation methods. The purpose of the present study was to compare the clearing technique and longitudinal sectioning in the evaluation of dye penetration along a glass fiber post. Materials and Methods: Fifteen single-rooted human teeth were endontically prepared and obturated with gutta percha points and a resin based sealer (AH26). A glass fiber post (Glassix) was cemented into each post space with a dual polymerizing resin cement (Varilink II) and the composite core (Tetric Ceram) was fabricated. Specimens were immersed in Indian ink solution for 72 hours after completion of 1500 cycles of thermal cycling. Then demineralized, cleared and evaluated for the deepest length of dye penetration using a stereomicroscope. Specimens were then cut longitudinally and the length of penetration was measured again by the same instrument. The mean difference of the penetrated length was analyzed by two methods using the paired t test and an analysis of correlation (α = 0.05). Results: No significant difference was found in the mean microleakage measured by the two methods (P= 0.07). Significant correlation was found between them (P=0.0001, r= 0.9) Conclusion: The clearing technique and longitudinal sectioning showed the same results in microleakage of Glassix post and composite core within the limitation of the present study. PMID:21998786

  14. Evaluation of glass fiber Hepa filters as a function of media velocity

    SciTech Connect

    Alderman, S.L.; Parsons, M.S.; Hogancamp, K.U.; Waggoner, C.A.

    2007-07-01

    Section FC of the ASME AG-1 Code addresses glass fiber HEPA filters and restricts the media velocity to a maximum of 5 ft./min. Advances in filter media technology allow glass fiber HEPA filters to function at significantly higher velocities and still achieve HEPA performance. Ultrafine particles (< 100 nm) are removed by a diffusive capture mechanism. The removal efficiency of these particles is reduced at higher media velocities due to shorter residence times within the media matrix. Therefore, it is unlikely that higher media velocities for HEPA filters will be allowed without data to demonstrate the effect of media velocity on removal of particles in the smaller size classes. Additional questions remain regarding particle loading and filter lifetimes at higher media velocities. In order to address these issues, nuclear grade AG-1 HEPA filters obtained from two manufacturers have been evaluated at media velocities ranging from 4 to 8.8 ft./min. KCl was utilized as aerosol challenge material and data regarding filter lifetimes, loading characteristics, changes in filtering efficiency and the most penetrating particle size are presented. Results of this testing will be provided to the ASME AG-1 FC Committee for consideration in future versions of the HEPA standard and will be useful for the development of air filtration systems in a nuclear environment. (authors)

  15. Thermal performance of glass fiber reinforced intumescent fire retardant coating for structural applications

    NASA Astrophysics Data System (ADS)

    Ahmad, Faiz; Ullah, Sami; Aziz, Hammad; Omar, Nor Sharifah

    2015-07-01

    The results of influence of glass fiber addition into the basic intumescent coating formulation towards the enhancement of its thermal insulation properties are presented. The intumescent coatings were formulated from expandable graphite, ammonium polyphosphate, melamine, boric acid, bisphenol A epoxy resin BE-188, polyamide amine H-2310 hardener and fiberglass (FG) of length 3.0 mm. Eight intumescent formulations were developed and the samples were tested for their fire performance by burning them at 450°C, 650°C and 850°C in the furnace for two hours. The effects of each fire test at different temperatures; low and high temperature were evaluated. Scanning Electron Microscope, X-Ray Diffraction technique and Thermo Gravimetric Analysis were conducted on the samples to study the morphology, the chemical components of char and the residual weight of the coatings. The formulation, FG08 containing 7.0 wt% glass fiber provided better results with enhanced thermal insulation properties of the coatings.

  16. Thermal performance of glass fiber reinforced intumescent fire retardant coating for structural applications

    SciTech Connect

    Ahmad, Faiz Ullah, Sami; Aziz, Hammad Omar, Nor Sharifah

    2015-07-22

    The results of influence of glass fiber addition into the basic intumescent coating formulation towards the enhancement of its thermal insulation properties are presented. The intumescent coatings were formulated from expandable graphite, ammonium polyphosphate, melamine, boric acid, bisphenol A epoxy resin BE-188, polyamide amine H-2310 hardener and fiberglass (FG) of length 3.0 mm. Eight intumescent formulations were developed and the samples were tested for their fire performance by burning them at 450°C, 650°C and 850°C in the furnace for two hours. The effects of each fire test at different temperatures; low and high temperature were evaluated. Scanning Electron Microscope, X-Ray Diffraction technique and Thermo Gravimetric Analysis were conducted on the samples to study the morphology, the chemical components of char and the residual weight of the coatings. The formulation, FG08 containing 7.0 wt% glass fiber provided better results with enhanced thermal insulation properties of the coatings.

  17. Research on Tribological Behavior of PEEK and Glass Fiber Reinforced PEEK Composite

    NASA Astrophysics Data System (ADS)

    Li, E. Z.; Guo, W. L.; Wang, H. D.; Xu, B. S.; Liu, X. T.

    The tribological behaviors of pure polyetheretherketone (PEEK) and PEEK composites reinforced by 30wt% short glass fibers (GF) were comparatively evaluated on a ball-on-disc configuration at room temperature. The effects of applied load and sliding time on the friction coefficient and wear loss of the GF/PEEK were examined. The mechanical property, morphology and thermal performance of the composite were studied. The results indicated that the friction coefficient and wear loss of the composite increased gradually and tended to be a stable state as the increase of applied load and sliding time. The GF/PEEK has an excellent wear resistance, compared with PEEK. The SEM and EDS indicated that the short glass-fibers were extruded from the composite rather than pulverized into the composite. Compared with that of pure PEEK, the thermal decomposition temperature of GF/PEEK composite had an increase of 75 °C. The tensile strength and flexural strength of the composite were increased by 64% and 66%, respectively.

  18. Grating-assisted glass waveguide devices and fiber-optic parametric amplifiers for optical communication systems

    NASA Astrophysics Data System (ADS)

    Kim, Jaeyoun

    The theory, design, and implementation of several photonics devices for the generation, amplification, and processing of optical signals in optical communication systems are described. A cascaded fiber-optic parametric amplifier based on a quasi-phase matching technique is implemented. This cascaded implementation is the first explicit application of quasi-phase matching techniques to a fiber-optic parametric amplifier and results in a 12 dB gain enhancement using a 3-stage structure. For the generation and the wavelength-sensitive processing of optical signals, distributed Bragg reflector (DBR) waveguide devices are fabricated in un-doped and Er/Yb co-doped glass substrates using Ag+ and K+ ion-exchange, respectively. Wavelength-selective operation is realized by implementing the DBRs using a high refractive index overlay technique. This technique allows DBR fabrication on substrates with hard-to-etch surfaces and can produce very short, high efficiency reflectors by utilizing the enhanced interactions between the waveguide and the high index overlay DBR. The development of methods for overlay/waveguide design, thin-film characterization, and optimum thickness deposition are reported. Using this technique, an Er/Yb co-doped glass waveguide DBR laser with a 30 mW lasing threshold and a 8.5% slope efficiency is demonstrated. An optical add-drop multiplexer with a 24 dB transmission dip and a 0.5 nm wide 3 dB bandwidth is also designed and fabricated based on the same technique.

  19. Polypropylene/glass fiber hierarchical composites incorporating inorganic fullerene-like nanoparticles for advanced technological applications.

    PubMed

    Díez-Pascual, Ana M; Naffakh, Mohammed

    2013-10-01

    Novel isotactic polypropylene (iPP)/glass fiber (GF) laminates reinforced with inorganic fullerene-like tungsten disulfide (IF-WS2) nanoparticles as environmentally friendly fillers have been successfully fabricated by simple melt-blending and fiber impregnation in a hot-press without the addition of any compatibilizer. The influence of IF-WS2 concentration on the morphology, viscosity. and thermal and mechanical behavior of the hierarchical composites has been investigated. Results revealed an unprecedented 62 °C increase in the degradation temperature of iPP/GF upon addition of only 4.0 wt % IF-WS2. The coexistence of both micro- and nanoscale fillers resulted in synergistic effects on enhancing the stiffness, strength, crystallinity, thermal stability, glass transition (Tg) and heat distortion temperature (HDT) of the matrix. The approach used in this work is an efficient, versatile, scalable and economic strategy to improve the mechanical and thermal behavior of GF-reinforced thermoplastics with a view to extend their use in advanced technological applications. This new type of composite materials shows great potential to improve the efficiency and sustainability of many forms of transport. PMID:24015820

  20. The Laser Accessory Market

    NASA Astrophysics Data System (ADS)

    Desai, Ashvin

    1988-09-01

    Wandering through the exhibit hall yesterday, I noticed that if you look at the laser companies and if you look at the accessory companies, there are pretty much the same number of accessory booths as well as the laser companies. There was one difference. Laser company booths are all sexy looking, very flashy, big booths. Whereas if you look at the accessories booths, they were small, not so prominent.

  1. Athermal distributed Brillouin sensors utilizing all-glass optical fibers fabricated from rare earth garnets: LuAG

    NASA Astrophysics Data System (ADS)

    Dragic, P. D.; Pamato, M. G.; Iordache, V.; Bass, J. D.; Kucera, C. J.; Jones, M.; Hawkins, T. W.; Ballato, J.

    2016-01-01

    An all-glass optical fiber derived from single-crystal LuAG is investigated for its potential use in athermal Brillouin distributed strain sensors. Such sensor systems are comprised of fiber whose Brillouin frequency shift is independent of temperature, but not independent of strain. Bulk Brillouin spectroscopy measurements on the precursor LuAG crystal are performed to gain insight into the crystal-to-glass transition. Results suggest that both the mass density and acoustic velocity are reduced relative to the crystal phase, in common with the other rare earth aluminosilicates. Advantages of the LuAG derived fiber over other rare earth garnet-derived fibers for the sensing application are a stronger strain response and larger Brilloun gain with narrower Brillouin spectral width.

  2. Infrared imaging spectrometry by the use of bundled chalcogenide glass fibers and a PtSi CCD camera

    NASA Astrophysics Data System (ADS)

    Saito, Mitsunori; Kikuchi, Katsuhiro; Tanaka, Chinari; Sone, Hiroshi; Morimoto, Shozo; Yamashita, Toshiharu T.; Nishii, Junji

    1999-10-01

    A coherent fiber bundle for infrared image transmission was prepared by arranging 8400 chalcogenide (AsS) glass fibers. The fiber bundle, 1 m in length, is transmissive in the infrared spectral region of 1 - 6 micrometer. A remote spectroscopic imaging system was constructed with the fiber bundle and an infrared PtSi CCD camera. The system was used for the real-time observation (frame time: 1/60 s) of gas distribution. Infrared light from a SiC heater was delivered to a gas cell through a chalcogenide fiber, and transmitted light was observed through the fiber bundle. A band-pass filter was used for the selection of gas species. A He-Ne laser of 3.4 micrometer wavelength was also used for the observation of hydrocarbon gases. Gases bursting from a nozzle were observed successfully by a remote imaging system.

  3. Advantages of reusable accessories.

    PubMed

    Wolfsen, H C

    2000-04-01

    Despite scant evidence supporting the use of disposable accessories, these devices have been widely disseminated. Manufacturers and governmental regulators, the most devout proponents of one-time use accessories, have framed the issue in economic terms-parsimonious practitioners reusing disposable accessories at the risk of cross-contamination, mechanical failure and product liability. This simplistic view represents revisionist history and ignores the long tradition of reusing these devices. This article reviews the numerous studies that support the safe and cost effective reuse of disposable and reusable accessories.

  4. Reinforcement of Dental Methacrylate with Glass Fiber after Heated Silane Application

    PubMed Central

    Fonseca, Rodrigo Borges; de Paula, Marcella Silva; Favarão, Isabella Negro; Kasuya, Amanda Vessoni Barbosa; de Almeida, Letícia Nunes; Mendes, Gustavo Adolfo Martins; Carlo, Hugo Lemes

    2014-01-01

    This study evaluated the influence of silane heat treatment and glass fiber fabrication type, industrially treated (I) or pure (P), on flexural and compressive strength of methacrylate resin bars (BISGMA/TEGDMA, 50/50%). Six groups (n = 10) were created: I-sil: I/silanated; P-sil: P-silanated; I-sil/heat: I/silanated heated to 100°; P-sil/heat: P/silanated heated to 100°; (I: I/not silanated; and P: P/not silanated. Specimens were prepared for flexural strength (10 × 2 × 1 mm) and for compressive strength 9.5 × 5.5 × 3 mm) and tested at 0.5 mm/min. Statistical analysis demonstrated the following for flexural strength (P < 0.05): I-sil: 155.89 ± 45.27BC; P-sil: 155.89 ± 45.27BC; I-sil/heat: 130.20 ± 22.11C; P-sil/heat: 169.86 ± 50.29AB; I: 131.87 ± 15.86C. For compressive strength, the following are demonstrated: I-sil: 1367.25 ± 188.77ab; P-sil: 867.61 ± 102.76d; I-sil/heat: 1162.98 ± 222.07c; P-sil/heat: 1499.35 ± 339.06a; and I: 1245.78 ± 211.16bc. Due to the impossibility of incorporating the stipulated amount of fiber, P group was excluded. Glass fiber treatment with heated silane enhanced flexural and compressive strength of a reinforced dental methacrylate. PMID:24967361

  5. Bioactive Glass Fiber Reinforced Starch-Polycaprolactone Composite for Bone Applications

    NASA Astrophysics Data System (ADS)

    Jukola, H.; Nikkola, L.; Gomes, M. E.; Chiellini, F.; Tukiainen, M.; Kellomäki, M.; Chiellini, E.; Reis, R. L.; Ashammakhi, N.

    2008-02-01

    For bone regeneration and repair, combinations of different materials are often needed. Biodegradable polymers are often combined with osteoconductive materials, such as bioactive glass (BaG), which can also improve the mechanical properties of the composite. The aim of this study was to develop and characterize BaG fiber-reinforced starch-poly-ɛ-caprolactone (SPCL) composite. Sheets of SPCL (30/70 wt%) were produced using single-screw extrusion. They were then cut and compression molded in layers with BaG fibers to form composite structures of different combinations. Thermal, mechanical, and degradation properties of the composites were studied. The actual amount of BaG in the composites was determined using combustion tests. A strong endothermic peak indicating melting at about 56 °C was observed by differential scanning calorimetry (DSC) analysis. Thermal gravimetry analysis (TGA) showed that thermal decomposition of SPCL started at 325 °C with the decomposition of starch and continued at 400 °C with the degradation of polycaprolactone (PCL). Initial mechanical properties of the reinforced composites were at least 50% better than the properties of the non-reinforced composites. However, the mechanical properties of the composites after two weeks of hydrolysis were comparable to those of the non-reinforced samples. During the six weeks' hydrolysis the mass of the composites had decreased only by about 5%. The amount of glass in the composites remained the same for the six-week period of hydrolysis. In conclusion, it is possible to enhance the initial mechanical properties of SPCL by reinforcing it with BaG fibers. However, the mechanical properties of the composites are only sufficient for use as filler material and they need to be further improved to allow long-lasting bone applications.

  6. Bioactive Glass Fiber Reinforced Starch-Polycaprolactone Composite for Bone Applications

    SciTech Connect

    Jukola, H.; Nikkola, L.; Tukiainen, M.; Kellomaeki, M.; Ashammakhi, N.; Gomes, M. E.; Reis, R. L.; Chiellini, F.; Chiellini, E.

    2008-02-15

    For bone regeneration and repair, combinations of different materials are often needed. Biodegradable polymers are often combined with osteoconductive materials, such as bioactive glass (BaG), which can also improve the mechanical properties of the composite. The aim of this study was to develop and characterize BaG fiber-reinforced starch-poly-{epsilon}-caprolactone (SPCL) composite. Sheets of SPCL (30/70 wt%) were produced using single-screw extrusion. They were then cut and compression molded in layers with BaG fibers to form composite structures of different combinations. Thermal, mechanical, and degradation properties of the composites were studied. The actual amount of BaG in the composites was determined using combustion tests. A strong endothermic peak indicating melting at about 56 deg. C was observed by differential scanning calorimetry (DSC) analysis. Thermal gravimetry analysis (TGA) showed that thermal decomposition of SPCL started at 325 deg. C with the decomposition of starch and continued at 400 deg. C with the degradation of polycaprolactone (PCL). Initial mechanical properties of the reinforced composites were at least 50% better than the properties of the non-reinforced composites. However, the mechanical properties of the composites after two weeks of hydrolysis were comparable to those of the non-reinforced samples. During the six weeks' hydrolysis the mass of the composites had decreased only by about 5%. The amount of glass in the composites remained the same for the six-week period of hydrolysis. In conclusion, it is possible to enhance the initial mechanical properties of SPCL by reinforcing it with BaG fibers. However, the mechanical properties of the composites are only sufficient for use as filler material and they need to be further improved to allow long-lasting bone applications.

  7. Model for second-harmonic generation in glass optical fibers based on asymmetric photoelectron emission from defect sites.

    PubMed

    Anderson, D Z; Mizrahi, V; Sipe, J E

    1991-06-01

    We present a self-consistent calculation of anomalous second-harmonic generation in glass optical fibers. Quantum interference between multiphoton absorption processes leads to asymmetric photoelectric emission from defects, creating a spatially periodic space-charge electric field. The second harmonic is found to grow exponentially along the fiber, then saturate to a maximum value proportional to the square of the fundamental intensity. The predicted conversion efficiency is in reasonable agreement with experiments.

  8. Er 3+ - Yb 3+ co-doped phosphate glass optical fiber for application at 1.54 microns

    NASA Astrophysics Data System (ADS)

    Lafond, Christophe; Osouf, Jocelyne; Laperle, Pierre; Soucy, Jean-Luc; Desrosiers, Cynthia; Morency, Steeve; Croteau, André; Parent, André

    2006-09-01

    We present current work developed at INO on phosphate glass optical fiber for laser and amplifier applications at 1.54 microns. Core and cladding glasses were fabricated by a multi-components melting process which gave an uniform refractive index core profile. Rod-in-tube method under Argon atmosphere was used to fabricate optical fibers. The effect of nitrogen atmosphere on hydroxyl groups OH - during glass melting was studied. The absorption coefficient calculated at 3.42 μm was found to be lower than 0.5 cm -1 which corresponds to less than 70 ppm OH -. Absorption and emission cross sections were calculated at 1534 nm. Fabrication process allowed us to decrease background losses of core Er 3+ - Yb 3+ co-doped fiber between 0.02 and 0.04 dB/cm. Laser power was measured at 1563 nm and a 26% slope efficiency was achieved with a 22 cm-long single-clad fiber co-doped with 1.1 wt% in Er 3+ and 11.1 wt% in Yb 3+. For the same fiber, an internal gain was found to be 20 dB at 1536 nm for a 5-cm-long fiber.

  9. Determination of local debonding stress and investigation of its effect on mechanical properties of glass short fiber reinforced polycarbonate composites

    NASA Astrophysics Data System (ADS)

    Zhao, Wenjie; Kim, Hyung-ick; Suhr, Jonghwan

    2012-04-01

    Thermoplastic polymers are often reinforced by adding short fibers to improve mechanical properties including Young's modulus and tensile strength of the polymers. In many engineering applications, energy absorbing characteristics in such particulate polymers is known to be a very important property to be considered in composite designs, and meanwhile debonding at the interface between fiber and matrix in the composites may affect the energy absorption properties. Here, the focus of this study is to employ a semi-empirical approach to determine the debonding stress and investigate the effect of the debonding stress on energy absorbing properties of short glass fiber reinforced polycarbonate composites. Glass short fiber reinforced polycarbonate composites are fabricated via a solution mixing technique. Tensile testing and acoustic emission measurement are simultaneously performed for the polycarbonate composites. The test results including toughness are compared for the composites over neat polycarbonate. Also the local debonding stress in the vicinity of each glass fiber in composites is estimated by combining modeling and experiments. A finite element model is developed to determine local debonding stress at the interface between the fiber and matrix. The local debonding stress appears to considerably affect the toughness of the composites.

  10. Superhydrophilic and underwater superoleophobic poly(sulfobetaine methacrylate)-grafted glass fiber filters for oil-water separation.

    PubMed

    Liu, Qingsheng; Patel, Ankit A; Liu, Lingyun

    2014-06-25

    Oil-water separation is a major problem in industries such as oil production and wastewater treatment, where millions of gallons of oil-contaminated water are produced. Zwitterionic poly(sulfobetaine methacrylate) (pSBMA) is a superhydrophilic polymer due to its strong interaction with water via electrostatic interactions. By coating surfaces of filter media with such a superhydrophilic polymer, it is expected that one can effectively separate oil and water. In this work, pSBMA was grafted onto glass fiber surfaces using surface-initiated atom transfer radical polymerization (SI-ATRP). The in-air water contact angle of the pSBMA-treated glass was 8-15°, as compared to 31° for the control untreated glass, whereas the underwater-oil contact angle of the pSBMA-grafted glass was 162-169°, as compared to 142° for the control pristine glass, suggesting that the pSBMA-grafted glass slides are superhydrophilic and underwater superoleophobic. Such superhydrophilicity and underwater superoleophobicity were realized by modifying surface chemistry only, with no need to create rough surfaces. The pSBMA-grafted glass fiber filters demonstrated exceptional results at separating oil from water without even allowing miniscule amounts of visible oil to permeate through. PMID:24865451

  11. Superhydrophilic and underwater superoleophobic poly(sulfobetaine methacrylate)-grafted glass fiber filters for oil-water separation.

    PubMed

    Liu, Qingsheng; Patel, Ankit A; Liu, Lingyun

    2014-06-25

    Oil-water separation is a major problem in industries such as oil production and wastewater treatment, where millions of gallons of oil-contaminated water are produced. Zwitterionic poly(sulfobetaine methacrylate) (pSBMA) is a superhydrophilic polymer due to its strong interaction with water via electrostatic interactions. By coating surfaces of filter media with such a superhydrophilic polymer, it is expected that one can effectively separate oil and water. In this work, pSBMA was grafted onto glass fiber surfaces using surface-initiated atom transfer radical polymerization (SI-ATRP). The in-air water contact angle of the pSBMA-treated glass was 8-15°, as compared to 31° for the control untreated glass, whereas the underwater-oil contact angle of the pSBMA-grafted glass was 162-169°, as compared to 142° for the control pristine glass, suggesting that the pSBMA-grafted glass slides are superhydrophilic and underwater superoleophobic. Such superhydrophilicity and underwater superoleophobicity were realized by modifying surface chemistry only, with no need to create rough surfaces. The pSBMA-grafted glass fiber filters demonstrated exceptional results at separating oil from water without even allowing miniscule amounts of visible oil to permeate through.

  12. Formation mechanism of a silane-PVA/PVAc complex film on a glass fiber surface.

    PubMed

    Repovsky, Daniel; Jane, Eduard; Palszegi, Tibor; Slobodnik, Marek; Velic, Dusan

    2013-10-21

    Mechanical properties of glass fiber reinforced composite materials are affected by fiber sizing. A complex film formation, based on a silane film and PVA/PVAc (polyvinyl alcohol/polyvinyl acetate) microspheres on a glass fiber surface is determined at 1) the nanoscale by using atomic force microscopy (AFM), and 2) the macroscale by using the zeta potential. Silane groups strongly bind through the Si-O-Si bond to the glass surface, which provides the attachment mechanism as a coupling agent. The silane groups form islands, a homogeneous film, as well as empty sites. The average roughness of the silanized surface is 6.5 nm, whereas it is only 0.6 nm for the non-silanized surface. The silane film vertically penetrates in a honeycomb fashion from the glass surface through the deposited PVA/PVAc microspheres to form a hexagonal close pack structure. The silane film not only penetrates, but also deforms the PVA/PVAc microspheres from the spherical shape in a dispersion to a ellipsoidal shape on the surface with average dimensions of 300/600 nm. The surface area value Sa represents an area of PVA/PVAc microspheres that are not affected by the silane penetration. The areas are found to be 0.2, 0.08, and 0.03 μm(2) if the ellipsoid sizes are 320/570, 300/610, and 270/620 nm for silane concentrations of 0, 3.8, and 7.2 μg mL(-1), respectively. The silane film also moves PVA/PVAc microspheres in the process of complex film formation, from the low silane concentration areas to the complex film area providing enough silane groups to stabilize the structure. The values for the residual silane honeycomb structure heights (Ha ) are 6.5, 7, and 12 nm for silane concentrations of 3.8, 7.2, and 14.3 μg mL(-1), respectively. The pH-dependent zeta-potential results suggest a specific role of the silane groups with effects on the glass fiber surface and also on the PVA/PVAc microspheres. The non-silanized glass fiber surface and the silane film have similar zeta potentials ranging

  13. Cytotoxicity, oxidative stress and genotoxicity induced by glass fibers on human alveolar epithelial cell line A549.

    PubMed

    Rapisarda, Venerando; Loreto, Carla; Ledda, Caterina; Musumeci, Giuseppe; Bracci, Massimo; Santarelli, Lory; Renis, Marcella; Ferrante, Margherita; Cardile, Venera

    2015-04-01

    Man-made vitreous fibers have been widely used as insulation material as asbestos substitutes; however their morphology and composition raises concerns. In 1988 the International Agency for Research on Cancer classified fiberglass, rock wool, slag wool, and ceramic fibers as Group 2B, i.e. possibly carcinogenic to humans. In 2002 it reassigned fiberglass, rock and slag wool, and continuous glass filaments to Group 3, not classifiable as carcinogenic to humans. The aim of this study was to verify the cytotoxic and genotoxic effects and oxidative stress production induced by in vitro exposure of human alveolar epithelial cells A549 to glass fibers with a predominant diameter <3 μm (97%) and length >5 μm (93%). A549 cells were incubated with 5, 50, or 100 μg/ml (2.1, 21, and 42 μg/cm(2), respectively) of glass fibers for 72 h. Cytotoxicity and DNA damage were tested by the MTT and the Comet assay, respectively. Oxidative stress was determined by measuring inducible nitric oxide synthase (iNOS) expression by Western blotting, production of nitric oxide (NO) with Griess reagent, and concentration of reactive oxygen species by fluorescent quantitative analysis with 2',7'-dichlorofluorescein-diacetate (DCFH-DA). The results showed that glass fiber exposure significantly reduced cell viability and increased DNA damage and oxidative stress production in a concentration-dependent manner, demonstrating that glass fibers exert cytotoxic and genotoxic effects related to increased oxidative stress on the human alveolar cell line A549.

  14. Effect of Glass Fiber Incorporation on Flexural Properties of Experimental Composites

    PubMed Central

    Fonseca, Rodrigo Borges; Marques, Aline Silva; Bernades, Karina de Oliveira; Carlo, Hugo Lemes; Naves, Lucas Zago

    2014-01-01

    This study evaluated the effect of fiber addiction in flexural properties of 30 wt% silica filled BisGMA resin (FR) or unfilled Bis-GMA (UR). Ten groups were created (N = 10) varying the resin (FR or UR) and quantity of glass fibers (wt%: 0, 10, 15, 20, and 30). Samples (10 × 2 × 1 mm) were submitted to flexural strength test following SEM examination. Data were analyzed by two-way ANOVA, Tukey, and Student t-test (α = 0.05). Results for flexural strength (MPa) were FR-groups: 0% (442.7 ± 140.6)C, 10% (772.8 ± 446.3)ABC, 15% (854.7 ± 297.3)AB, 20% (863.4 ± 418.0)A, 30% (459.5 ± 140.5)BC; UR-groups: 0% (187.7 ± 120.3)B, 10% (795.4 ± 688.1)B, 15% (1999.9 ± 1258.6)A, 20% (1911.5 ± 596.8)A, and 30% (2090.6 ± 656.7)A, and for flexural modulus (GPa) FR-groups: 0% (2065.63 ± 882.15)B, 10% (4479.06 ± 3019.82)AB, 15% (5694.89 ± 2790.3)A, 20% (6042.11 ± 3392.13)A, and 30% (2495.67 ± 1345.86)B; UR-groups: 0% (1090.08 ± 708.81)C, 10% (7032.13 ± 7864.53)BC, 15% (19331.57 ± 16759.12)AB, 20% (15726.03 ± 8035.09)AB, and 30% (29364.37 ± 13928.96)A. Fiber addiction in BisGMA resin increases flexural properties, and the interaction between resin and fibers seems better in the absence of inorganic fillers increasing flexural properties. PMID:25136595

  15. The effect of pressure changes during simulated diving on the pull out strength of glass fiber posts

    PubMed Central

    Gulve, Meenal Nitin; Gulve, Nitin Dilip

    2013-01-01

    Background: Scuba diving is one of the fastest growing sports in the world. The objective of this study was to evaluate the effect of pressure variations to which divers are exposed on the pull out strength of glass fiber post luted with different cements. Materials and Methods: In this in vitro study, 120 extracted, single-rooted lower premolars were endodontically treated. They were randomly divided into six groups and restored using the glass fiber post (Ivoclar Vivadent AG) and the following luting agents: Zinc phosphate, conventional glass ionomer, resin reinforced glass ionomer, resin cement with etch-and-rinse adhesive, resin cement with self-etching adhesive, and self-adhesive resin cement. Each group was randomly divided into two equal subgroups, one as a control, and the other to be used experimentally. After 7 days of storage, experimental groups were pressure cycled. The force required to dislodge each post was recorded in Newton (N) on Universal testing machine (Star Testing System) at a crosshead speed of 1 mm/min. Data were statistically analyzed using the ANOVA and Student's t-test (P < 0.001). Results: The pull out strength of posts cemented with zinc phosphate and conventional glass ionomer in pressure cycle group was significantly less than their control group. Although, no significant difference was found between pressure cycle and control group using resin reinforced glass ionomer cement and resin cements. Conclusion: Dentist should consider using resin reinforced glass ionomer or resin cement, for the cementation of glass fiber post, for the patients such as divers, who are likely to be exposed to pressure cycling. PMID:24379861

  16. Low loss, wide transparency, robust tellurite glass fibers for mid-IR (2 - 5 μm) applications

    NASA Astrophysics Data System (ADS)

    Rhonehouse, Dan L.; Zong, Jie; Nguyen, Dan; Thapa, Rajesh; Wiersma, Kort; Smith, Chris; Chavez-Pirson, Arturo

    2013-10-01

    Mid Infrared (MIR) fiber optics has gained a great deal of interest over the past several decades. Applications range from passive transport to fiber lasers and nonlinear applications. These fibers have found use in a wide array of fields such as sensing, military countermeasures, scientific instrumentation, medical instrumentation, and in research laboratories. As with all fiber development there is a continual urge to seek better performance characteristics including transparency over a wide wavelength range, corrosion resistance, high power handling and low loss. We report on development of tellurite glass fibers displaying exceptionally high performance for various applications including wide band, low loss passive transport for mid IR, high efficiency, wide wavelength range and high power supercontinuum generation from visible to MIR wavelengths >4.5um, and active doping in fibers for use in laser cooling. High performance in each of these areas of interest has been brought about by development of a stable glass formulation and advanced processing techniques to remove impurities ions, entrapped hydroxyl, and scatter centers which allow fibers to be made with exceptionally low losses ~0.2dB/m.

  17. Chemical Vapor Deposited SiC (SCS-0) Fiber-Reinforced Strontium Aluminosilicate Glass-Ceramic Composites

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P.

    1997-01-01

    Unidirectional SrO Al2O3 2SiO2 glass-ceramic matrix composites reinforced with uncoated Chemical Vapor Deposited (CVD) SiC (SCS-0) fibers have been fabricated by hot-pressing under appropriate conditions using the glass-ceramic approach. Almost fully dense composites having a fiber volume fraction of 0.24 have been obtained. Monoclinic celsian, SrAl2Si2O8, was the only crystalline phase observed in the matrix by x-ray diffraction. No chemical reaction was observed between the fiber and the matrix after high temperature processing. In three-point flexure, the composite exhibited a first matrix cracking stress of approx. 231 +/- 20 MPa and an ultimate strength of 265 +/- 17 MPa. Examination of fracture surfaces revealed limited short length fiber pull-out. From fiber push-out, the fiber/matrix interfacial debonding and frictional strengths were evaluated to be approx. 17.5 +/- 2.7 MPa and 11.3 +/- 1.6 MPa, respectively. Some fibers were strongly bonded to the matrix and could not be pushed out. The micromechanical models were not useful in predicting values of the first matrix cracking stress as well as the ultimate strength of the composites.

  18. Strength of anisotropic wood and synthetic materials. [plywood, laminated wood plastics, glass fiber reinforced plastics, polymeric film, and natural wood

    NASA Technical Reports Server (NTRS)

    Ashkenazi, Y. K.

    1981-01-01

    The possibility of using general formulas for determining the strength of different anisotropic materials is considered, and theoretical formulas are applied and confirmed by results of tests on various nonmetallic materials. Data are cited on the strength of wood, plywood, laminated wood plastics, fiber glass-reinforced plastics and directed polymer films.

  19. Light-weight sandwich panel honeycomb core with hybrid carbon-glass fiber composite skin for electric vehicle application

    NASA Astrophysics Data System (ADS)

    Cahyono, Sukmaji Indro; Widodo, Angit; Anwar, Miftahul; Diharjo, Kuncoro; Triyono, Teguh; Hapid, A.; Kaleg, S.

    2016-03-01

    The carbon fiber reinforced plastic (CFRP) composite is relative high cost material in current manufacturing process of electric vehicle body structure. Sandwich panels consisting polypropylene (PP) honeycomb core with hybrid carbon-glass fiber composite skin were investigated. The aim of present paper was evaluate the flexural properties and bending rigidity of various volume fraction carbon-glass fiber composite skins with the honeycomb core. The flexural properties and cost of panels were compared to the reported values of solid hybrid Carbon/Glass FRP used for the frame body structure of electric vehicle. The finite element model of represented sandwich panel was established to characterize the flexural properties of material using homogenization technique. Finally, simplified model was employed to crashworthiness analysis for engine hood of the body electric vehicle structure. The good cost-electiveness of honeycomb core with hybrid carbon-glass fiber skin has the potential to be used as a light-weight alternative material in body electric vehicle fabricated.

  20. Novel Application of Glass Fibers Recovered From Waste Printed Circuit Boards as Sound and Thermal Insulation Material

    NASA Astrophysics Data System (ADS)

    Sun, Zhixing; Shen, Zhigang; Ma, Shulin; Zhang, Xiaojing

    2013-10-01

    The aim of this study is to investigate the feasibility of using glass fibers, a recycled material from waste printed circuit boards (WPCB), as sound absorption and thermal insulation material. Glass fibers were obtained through a fluidized-bed recycling process. Acoustic properties of the recovered glass fibers (RGF) were measured and compared with some commercial sound absorbing materials, such as expanded perlite (EP), expanded vermiculite (EV), and commercial glass fiber. Results show that RGF have good sound absorption ability over the whole tested frequency range (100-6400 Hz). The average sound absorption coefficient of RGF is 0.86, which is prior to those of EP (0.81) and EV (0.73). Noise reduction coefficient analysis indicates that the absorption ability of RGF can meet the requirement of II rating for sound absorbing material according to national standard. The thermal insulation results show that RGF has a fair low thermal conductivity (0.046 W/m K), which is comparable to those of some insulation materials (i.e., EV, EP, and rock wool). Besides, an empirical dependence of thermal conductivity on material temperature was determined for RGF. All the results showed that the reuse of RGF for sound and thermal insulation material provided a promising way for recycling WPCB and obtaining high beneficial products.

  1. Micromechanics of ambient temperature cyclic fatigue loading in a composite of CAS glass ceramic reinforced with Nicalon fibers

    SciTech Connect

    Rousseau, C.Q.; Davidson, D.L.; Campbell, J.B. )

    1994-04-01

    The behavior of a Nicalon fiber reinforced glass ceramic composite cyclicly loaded has been evaluated at ambient temperature using high-resolution micromechanical test methods. On this basis, the events leading to fracture have been found to be similar to those accompanying fracture in unidirectional tension tests. Matrix strains were determined locally at the point of matrix fracture. Crack opening displacements (CODs) were measured as a function of loading cycles, and fiber strains were determined, in some cases. It is concluded that debonding of fibers begins at the point of matrix cracking and rapidly increases. Most of the cyclic lifetime of the material is spent with fibers debonded over large distances (fractions of a millimeter); these fibers are pulled out of the matrix on each loading cycle. Final debond length, as determined by fractography, is a function of the number of cycles to fracture, and of the applied stress level. 23 refs.

  2. Application of glass-fiber reinforced plastic (GRP) mud-mats for Daria-A platform

    SciTech Connect

    Bertorelli, D.; Spessa, A.

    1994-12-31

    A review of the experience gained with glass-fiber reinforced plastic (GRP) mud-mat materials used for the Garibaldi-C jacket, in the Adriatic sea, has shown that this solution can result in substantial cost savings. Therefore, Agip has investigated a further use of GRP mud-mats for the Daria-A platform as a means of reducing the lifting weight of the jacket and, moreover, to negate the requirement for additional buoyancy tanks during the free flotation and upending phases. Two possible solutions, the ``pultrusion`` and the ``lamination`` techniques, have been investigated to fabricate sandwich panels for the mud-mats. In this paper these two technologies are discussed with respect to their application to the construction and they are compared on a performance and cost basis.

  3. Non-destructive evaluation of delamination growth in glass fiber composites using optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Liu, Ping; Groves, Roger M.; Benedictus, Rinze

    2014-03-01

    Based on low coherence interferometry, a robust optical coherence tomography (OCT) system has been built. The system was used to monitor the growth of a delamination between the middle layers of a glass fiber composite under a static loading. Firstly specimens of the material used for the spar webs in wind turbines were prepared with an interlaminar crack from free edges. Then they were statically loaded by a customized tensile test stage to extend the delamination length and simultaneously scanned by the OCT system. To process the acquired data, an optimized signal processing algorithm was developed. The cross-sectional images clearly show the microstructure and the crack within the specimen. The 3D crack profiles show the application of OCT to determine the evolution of the crack structure inside the composite material during the propagation of the delamination, for the first time to the best of our knowledge.

  4. PNNL/Euratom glass fiber-optic, spent-fuel profile measurement system

    SciTech Connect

    Bowyer, S.M.; Smart, J.E.; Hansen, R.R.

    1999-07-01

    Discussions between Euratom and Pacific Northwest National Laboratory (PNNL) revealed a need for a neutron detection system that could measure the neutron profile down the entire length of a CASTOR in one measurement. The CASTORS (dry storage casks for spent fuel and vitrified wastes) are {approximately}6 m high and 2 x 2 m square in cross section. Neutron profiles of the CASTORS are desirable for both content identification and verification. Profile measurements have traditionally been done with {sup 3}He-based detectors {approximately}1 m high that scan the length of a CASTOR as they are lifted by a crane. Geometric reproducibility errors plague this type of measurement; hence, the ability to simultaneously measure the neutron profile over the entire length of the CASTOR became highly desirable. Use of the PNNL-developed neutron-sensitive glass fibers in the construction of a 6-m-high detector was proposed, and design and construction of the detector began.

  5. Supercontinuum generation in ZBLAN glass photonic crystal fiber with six nanobore cores.

    PubMed

    Jiang, Xin; Joly, Nicolas Y; Finger, Martin A; Babic, Fehim; Pang, Meng; Sopalla, Rafal; Frosz, Michael H; Poulain, Samuel; Poulain, Marcel; Cardin, Vincent; Travers, John C; St J Russell, Philip

    2016-09-15

    Photonic crystal fibers (PCFs) made from ZBLAN glass are of great interest for generating broadband supercontinua extending into the ultraviolet and mid-infrared regions. Precise sub-micrometer structuring makes it possible to adjust the modal dispersion over a wide range, making the generation of new frequencies more efficient. Here we report a novel ZBLAN PCF with six cores, each containing a central nanobore of a diameter ∼330  nm. Each nanobore core supports several guided modes, and the presence of the nanobore significantly modifies the dispersion, strongly influencing the dynamics and the extent of supercontinuum generation. Spectral broadening is observed when a single core is pumped in the fundamental and first higher order core modes with 200 fs long pulses at a wavelength of 1042 nm. Frequency-resolved optical gating is used to characterize the output pulses when pumping in the lowest order mode. The results are verified by numerical simulations. PMID:27628368

  6. Glass fiber-reinforced composite resin as a space maintainer: a clinical study.

    PubMed

    Subramaniam, P; Babu, Gkl; Sunny, R

    2008-01-01

    The aim of this study is to evaluate the use of glass fiber-reinforced composite resin (GFRCR) as a space maintainer and to compare it with a conventional band-and-loop space maintainer. A total of 30 children (23 boys and 7 girls) aged 6-8 years were selected for the study. Each of these children required maintenance of space due to premature loss of primary first molars in at least two quadrants. In one quadrant, a GFRCR space maintainer was applied and in the other quadrant a band-and-loop space maintainer was cemented. Patients were recalled at regular intervals over 12 months and retention of both the types of space maintainers was evaluated. The retention of the GFRCR space maintainer was found to be superior to that of the band-and-loop space maintainer, but this difference was not statistically significant.

  7. Efficient adsorption of waterborne short-lived radon decay products by glass fiber filters.

    PubMed

    von Philipsborn, H

    1997-02-01

    Glass fiber filters of a certain brand were found to be very efficient (retention > 95%) for adsorption of short-lived radon decay products during filtration of water. Carrier-free samples are obtained in a convenient geometry for efficient gross beta counting. Adsorption of "hot atoms" is not disturbed by the presence of "cold" lead ions. Approximate radioactive equilibrium between radon and its short-lived decay products may or may not exist in water at the source, but does exist after 3 h in PET bottles. These bottles are shown to be gas-tight for radon. Calibration of activity concentration in Bq L(-1) (radon gas concentration approximately equilibrium equivalent radon concentration) was performed by several standard procedures. Limit of detection is 2 Bq L(-1) within 10 min (total time) or 10 Bq L(-1) within 5 min for a net signal of 5 times standard deviation.

  8. Two-color infrared thermometer for low-temperature measurement using a hollow glass optical fiber

    SciTech Connect

    Small, W.

    1997-02-28

    In the thermometer, radiation from a target is collected via a single 700 {mu}m-bore hollow glass optical fiber coated with a metallic/dielectric layer on the inner surface, simultaneously split into two paths and modulated by a Au-coated reflective chopper, and focused onto two thermoelectrically cooled mid-infrared HgCdZnTe photoconductors by 128.8 mm-radius Au-coated spherical mirrors. The photoconductors have spectral bandpasses of 2-6 {mu}m and 2.12 {mu}m, respectively. The modulated detector signals are recovered using lock- in amplification. The two signals are calibrated using a blackbody (emissivity=1) of known temperature, and exponential fits are applied to the two resulting voltage vs temperature curves. Using the two calibration equations, a computer algorithm calculates the temperature and emissivity of a target in real time, taking into account reflection of the background radiation field from the target surface.

  9. Glass-fiber reinforced composite in management of avulsed central incisor: a case report.

    PubMed

    Aydin, M Yalçin; Kargül, Betül

    2004-01-01

    Reimplantation failure of avulsed anterior tooth in an adolescent patient requires removal of the failed tooth and consideration of restorative options. These options may include a removable partial denture, conventional 3-unit fixed partial denture, implant, or a resin-bonded appliance with a metal substructure (Maryland bridge). The glass-fiber reinforced composite material (everSTICK, StickTech Ltd, Turku, Finland) offers a restorative solution that is conservative and esthetic when compared to other restorations. Advantages include reduction of cost compared to conventional bridges, saving of time, elimination of second visit, ease of application, absence of metal allergy, ease of cleaning, and naturalness of feel. Its limitations include occlusal factors, and the presence of unsuitable abutment teeth. Another traditional contraindication is the presence of diastemas, which may limit the potential esthetic gains. This case of an 11-year-old girl, addresses the indications, preparation guidelines, and restorative procedures for an everSTICK bridge. PMID:15272660

  10. Modeling the flexural fatigue behavior of glass-fiber-reinforced thermoplastic matrices

    NASA Astrophysics Data System (ADS)

    D'Amore, Alberto; Grassia, Luigi; Verde, Pasquale

    2013-02-01

    A two-parameter model explicitly accounting for the cyclic as well as the mean stress was proposed and tested on the basis of static and fatigue data obtained in four-point bending on a random continuous glass-fiber-reinforced polypropylene. The model is based on residual strength degradation and captures the effect of stress ratio (i.e. the ratio between the minimal and the maximal stress). The experimental data were in excellent agreement with the theoretical predictions, indicating that a fatigue characterization can be achieved with a minimum of experimental tests. Further, the reasonable agreement between the static strength data and the theoretical predictions highlighted the potential and reliability of the model in view of its statistical implementation

  11. The development of a potassium-sulfide glass fiber cell and studies on impurities in alkali metal-sulfur cells

    NASA Technical Reports Server (NTRS)

    Tsang, F. Y.

    1977-01-01

    Potassium sulfur rechargeable cells, having as the electrolyte the thin walls of hollow glass fibers made from permeable glass, were developed. The cells had short lives, probably due to the construction materials and impurities in the potassium. The effect of the impurities in the analogous NA-S system was studied. Calcium, potassium, and NaOH/oxide impurities caused increased resistance or corrosion of the glass fibers. For long lived cell operation, the Na must contain less than 1 ppm Ca and less than a few ppm of hydroxide/oxide. Up to 150 ppm K can be tolerated. After purification of the Na anolyte, cell lifetimes in excess of 1000 deep charge-discharge cycles or over 8 months on continuous cycling at 10-30 percent depth of discharge were obtained.

  12. Dissolution of glass wool, rock wool and alkaline earth silicate wool: morphological and chemical changes in fibers.

    PubMed

    Campopiano, Antonella; Cannizzaro, Annapaola; Angelosanto, Federica; Astolfi, Maria Luisa; Ramires, Deborah; Olori, Angelo; Canepari, Silvia; Iavicoli, Sergio

    2014-10-01

    The behavior of alkaline earth silicate (AES) wool and of other biosoluble wools in saline solution simulating physiological fluids was compared with that of a traditional wool belonging to synthetic vitreous fibers. Morphological and size changes of fibers were studied by scanning electron microscopy (SEM). The elements extracted from fibers were analyzed by inductively coupled plasma atomic emission spectrometry. SEM analysis showed a larger reduction of length-weighted geometric mean fiber diameter at 4.5 pH than at 7.4 pH. At the 7.4 pH, AES wool showed a higher dissolution rate and a dissolution time less than a few days. Their dissolution was highly non-congruent with rapid leaching of calcium. Unlike rock wool, glass wool dissolved more rapidly at physiological pH than at acid pH. Dissolution of AES and biosoluble rock wool is accompanied by a noticeable change in morphology while by no change for glass wool. Biosoluble rock wool developed a leached surface with porous honeycomb structure. SEM analysis showed the dissolution for glass wool is mainly due to breakage transverse of fiber at pH 7.4. AES dissolution constant (Kdis) was the highest at pH 7.4, while at pH 4.5 only biosoluble rockwool 1 showed a higher Kdis.

  13. Continuous carbon and glass fiber reinforced polypropylene: Optimization of the compression molding process

    SciTech Connect

    Denault, J.; Guillemenet, J.

    1996-12-31

    The objective of this work was to optimize the processing conditions of polypropylene/carbon, PP/C, and polypropylene/glass, PP/G, composites. Investigation of the effects of molding parameters such as molding temperature and residence time and cooling rate on the tensile performance of PP/C and PP/G was undertaken. It is well known that the mechanical performance of composite based on thermoplastic matrix such as polypropylene is closely related to crystalline morphology which is dependent on the thermal history. Since the compression molding process involves kinetic behavior of systems undergoing phase transformations under non-isothermal conditions, the crystallization behavior of PP matrix in the presence of carbon and glass fibers was investigated under non-isothermal conditions. The effects of processing temperature, residence time and cooling rate on the crystallization temperature, degree of crystallinity, crystallization rate and kinetics of crystallization were analyzed. The tensile behavior of the {+-}45{degrees} laminate of PP/C and PP/G and their interfacial properties were evaluated as a function of molding parameters. The variation in the tensile strength of the {+-}45{degrees} laminates as a function of molding temperature was found to show three distinct regions: the tensile strength first increases with molding temperature, attains a plateau region, and finally decreases at high molding temperature. DSC analysis done in order to simulate phase transformation under non-isothermal conditions also revealed similar behavior suggesting a close relationship between mechanical performance and matrix properties.

  14. Ultra-bandwidth polarization splitter based on soft glass dual-core photonic crystal fiber

    NASA Astrophysics Data System (ADS)

    Fan, Zhenkai; Li, Shu-Guang; Li, Jianshe; Wei, Zhiyi; Tian, Wenlong

    2015-08-01

    A novel ultra-bandwidth polarization splitter based on soft glass dual-core photonic crystal fiber (DC-PCF) is designed in this paper, which is analyzed through the finite element method (FEM). The coupling characteristics of the designed DC-PCF can be enhanced by a high refractive index As2S3 core. Numerical results show the ultra-bandwidths of the x- and y-polarization modes can reach to 86 nm and 60 nm as the extinction ratios better than -20 dB and -30 dB at the vicinity of the wavelength of 1.31 μm. The length of the designed soft glass DC-PCF is 52.29 mm and the extinction ratios of the x- and y-polarization modes are -85.57 dB and -56.81 dB at the wavelength of 1.31 μm, respectively. In addition, the designed splitter has a tolerance of ±10 nm in its all structure parameters, which make the design not sensitive to the perturbation during the fabrication process.

  15. Processing of a fiber-reinforced transparent glass matrix composite and study of micromechanics of load transfer from matrix to fiber using micro-fluorescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Banerjee, Debangshu

    The brittleness of monolithic ceramic materials can be overcome by reinforcing them with high strength, high modulus ceramic fibers. These ceramic matrix composites exhibit improved strength, toughness, and work of fracture. Successful design of a ceramic matrix composite (CMC) depends on two factors: proper choice of fiber, matrix, and interface material, and understanding the mechanics of fracture. The conventional techniques for measuring stress and strain at a local level in CMCs are based on indirect experiments and analytical models. In recent years a couple of optical techniques have been explored for non- contact and direct evaluation of the stress and strain in materials, such as laser Raman spectroscopy and fluorescence spectroscopy. In order to employ spectroscopy to study stress in a composite, a transparent matrix was needed. In this study a SiC fiber reinforced transparent glass matrix composite was developed. A tape casting, binder burnout, and sintering route was adopted to achieve the optimum transparency with proper fiber alignment and interfacial properties. Sapphire fibers were used to act as probe to generate fluorescence signals for measuring stress. A fugitive carbon coating was developed to act as a weak interface for the sapphire fiber, which otherwise, forms a strong bond with the matrix. A fixture was designed to apply stress on the composite specimen, in situ, under the microscope of the spectrometer. Using fluorescence spectroscopy, the micromechanics of load transfer from matrix to fibers were studied. Studies were conducted on both strongly and weakly bonded fibers, as well as on single fiber, and multi fiber situations. Residual stresses arising from thermal expansion mismatch have been mapped along the fiber length with resolution in microns. Residual axial stress was found to follow a shear lag profile along the fiber length. A finite residual axial stress was detected at the fiber ends. Correction of the measured stress for sample

  16. Micromechanical modeling of short glass-fiber reinforced thermoplastics-Isotropic damage of pseudograins

    SciTech Connect

    Kammoun, S.; Brassart, L.; Doghri, I.; Delannay, L.; Robert, G.

    2011-05-04

    A micromechanical damage modeling approach is presented to predict the overall elasto-plastic behavior and damage evolution in short fiber reinforced composite materials. The practical use of the approach is for injection molded thermoplastic parts reinforced with short glass fibers. The modeling is proceeded as follows. The representative volume element is decomposed into a set of pseudograins, the damage of which affects progressively the overall stiffness and strength up to total failure. Each pseudograin is a two-phase composite with aligned inclusions having same aspect ratio. A two-step mean-field homogenization procedure is adopted. In the first step, the pseudograins are homogenized individually according to the Mori-Tanaka scheme. The second step consists in a self-consistent homogenization of homogenized pseudograins. An isotropic damage model is applied at the pseudograin level. The model is implemented as a UMAT in the finite element code ABAQUS. Model is shown to reproduce the strength and the anisotropy (Lankford coefficient) during uniaxial tensile tests on samples cut under different directions relative to the injection flow direction.

  17. Effect of temperature on the dynamic characteristics of the glass-carbon fiber hybrid composites

    NASA Astrophysics Data System (ADS)

    Hidayat, Yon Afif; Susilo, Didik Djoko; Raharjo, Wijang W.

    2016-03-01

    This study aimed to investigate the effect of temperature on the dynamic characteristics of hybrid composites. Hybrid composites consisting of unsaturated polyester resin and glass fiber reinforced with carbon fiber. The volume fraction used in this study was 0.4. The hybrid composite was made using hand lay-up technique. The dynamic characteristics were obtained through vibration testing. The testing was conducted according to ASTM E756. The variables studied were composite without heating, heating at 100 °C, 200 °C and 280 °C. The experiments were done in three mounting configurations, i.e. upright, downward and horizontal configurations. The natural frequency and damping ratio was determined using half-power bandwidth method. The results showed that heating of composite structure affects the natural frequency and damping ratio of the hybrid composite. Heating until 100 °C will increase the natural frequency of the hybrid composite and decrease the damping ratio, but heating at the temperature above 100 °C will decrease the natural frequency and will damage the hybrid composite structure. The composite mounting configurations do not give significant effect to natural frequency and damping ratio of the hybrid composites.

  18. Chemical and physical degradation of glass fiber reinforced cross-linked polyester immersed in hot water

    SciTech Connect

    Hamada, H.; Maekawa, Z.I.; Ikuta, N.; Kiyosumi, K.; Tanimoto, T.; Morii, T.

    1994-12-31

    This study deals with chemical and physical degradation behavior of randomly oriented E-glass fiber continuous strand mat reinforced cross-linked polyester immersed in hot water at 80 and 95 C. The specimens were immersed in hot water for 3, 10, 30, 100, 300, 1000, 3000 and 4000h. Weight change measurement, three-point bending and infrared measurement were performed for the specimens after the immersion. Changes of the weight gain indicated the Fickian diffusion at early immersion time, and after that, it indicated the non-Fickian diffusion with a gradual progress of debonding between fiber and matrix. This degradation of the interface caused a remarkable increase of the weight loss, which was never observed in neat resin. The bending modulus decreased with increase of the weight gain at early immersion time, however, it kept constant at longer immersion time both at 80 C and at 95 C. The constant modulus level at 80C was higher than that at 95 C. At longer immersion time at 80 C, the modulus decreased again to the same level at 95C. The results of infrared measurement suggested the difference of degradation mechanism between early immersion time and longer immersion time. At early immersion time, the resin changed physically by swelling and extraction of polymer with water penetration. Such differences of degradation affected the reduction of modulus. Moreover, the effect of the debonding at the interface on the modulus was discussed by the finite element analysis by introducing the damage mechanics.

  19. Multichannel transition emissions of Dy{sup 3+} in fiber-adaptive germanium tellurite glasses

    SciTech Connect

    Li, Y. H.; Chen, B. J.; Lin, H.; Pun, E. Y. B.

    2013-03-28

    Multichannel transition visible and near-infrared (NIR) fluorescences have been captured in Dy{sup 3+}-doped fiber-adaptive Na{sub 2}O-ZnO-PbO-GeO{sub 2}-TeO{sub 2} glasses. The maximum stimulated emission cross-sections {sigma}{sub em-max} were derived to be 0.33 Multiplication-Sign 10{sup -21}, 3.66 Multiplication-Sign 10{sup -21}, and 0.67 Multiplication-Sign 10{sup -21} cm{sup 2} for conventional visible emissions assigned to {sup 4}F{sub 9/2}{yields}{sup 6}H{sub J} (J = 15/2, 13/2, and 11/2) transitions, respectively. Infrequent multi-peak NIR emissions were recorded in the spectral range of 900-1500 nm, among which the values of {sigma}{sub em-max} were solved to be 1.05 Multiplication-Sign 10{sup -22} and 1.56 Multiplication-Sign 10{sup -22} cm{sup 2} for {approx}1.02 and {approx}1.18 {mu}m emission bands. Internal quantum efficiency for the {sup 4}F{sub 9/2} level and external quantum yield for visible emissions of Dy{sup 3+} were determined to be 88.44% and 12.38%, severally. Effective multichannel radiative emissions reveal a potential in developing fiber-lighting sources, tunable lasers, and NIR optical amplifiers.

  20. Thermal expansion coefficients of a 30% glass fiber filled PEEK pyrotechnic charge holder

    SciTech Connect

    Donnelly, M.W.; Walters, R.R.; Miller, G.D.

    1985-01-01

    Pyrotechnic actuators use hollow cylindrical ceramic or plastic charge holders to electrically isolate the pyrotechnic charge from the actuator case. In a newly developed actuator, 30% glass fiber filled polyetheretherketone (PEEK) was selected as the charge holder material both for its strength and its forming properties. Because the actuators are exposed to significant temperature variations during storage and flight, a determination of the coefficient of thermal expansion, ..cap alpha.., of the charge holders was required to assure success in this, the first electroexplosive device application of PEEK. Of special interest in this project were the questions of whether ..cap alpha.. depends on the direction (with respect to flow in the mold) or on injection pressure. From the test results, the conclusions are: (1) ..cap alpha.. does depend on direction. Its value in the thickness direction is approximately twice that in either the height or circumferential direction. This is probably because the wall thickness, 0.015'', is less than the average fiber length, 0.100'', and the PEEK is, therefore, not acting as a composite in the t direction. (2) Varying the injection pressure over the range of this study has no detectable effect on ..cap alpha... This charge holder is molded into an Inconel actuator case with ..cap alpha.. = 11.4 ..mu..m/m.C. This relatively close match of ..cap alpha..'s between adjacent materials has resulted in no dimensional problems during manufacturing and environmental testing. 1 fig., 1 tab.

  1. Irradiation conditions for fiber laser bonding of HAp-glass ceramics with bovine cortical bone.

    PubMed

    Tadano, Shigeru; Yamada, Satoshi; Kanaoka, Masaru

    2014-01-01

    Orthopedic implants are widely used to repair bones and to replace articulating joint surfaces. It is important to develop an instantaneous technique for the direct bonding of bone and implant materials. The aim of this study was to develop a technique for the laser bonding of bone with an implant material like ceramics. Ceramic specimens (10 mm diameter and 1 mm thickness) were sintered with hydroxyapatite and MgO-Al2O3-SiO2 glass powders mixed in 40:60 wt% proportions. A small hole was bored at the center of a ceramic specimen. The ceramic specimen was positioned onto a bovine bone specimen and a 5 mm diameter area of the ceramic specimen was irradiated using a fiber laser beam (1070-1080 nm wavelength). As a result, the bone and the ceramic specimens bonded strongly under the irradiation conditions of a 400 W laser power and a 1.0 s exposure time. The maximum shear strength was 5.3 ± 2.3 N. A bonding substance that penetrated deeply into the bone specimen was generated around the hole in the ceramic specimen. On using the fiber laser, the ceramic specimen instantaneously bonded to the bone specimen. Further, the irradiation conditions required for the bonding were investigated.

  2. Effects of Fiber Content on Mechanical Properties of CVD SiC Fiber-Reinforced Strontium Aluminosilicate Glass-Ceramic Composites

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P.

    1996-01-01

    Unidirectional CVD SiC(f)(SCS-6) fiber-reinforced strontium aluminosilicate (SAS) glass-ceramic matrix composites containing various volume fractions, approximately 16 to 40 volume %, of fibers were fabricated by hot pressing at 1400 C for 2 h under 27.6 MPa. Monoclinic celsian, SrAl2Si2O8, was the only crystalline phase formed, with complete absence of the undesired hexacelsian phase, in the matrix. Room temperature mechanical properties were measured in 3-point flexure. The matrix microcracking stress and the ultimate strength increased with increase in fiber volume fraction, reached maximum values for V(sub f) approximately equal to 0.35, and degraded at higher fiber loadings. This degradation in mechanical properties is related to the change in failure mode, from tensile at lower V(sub f) to interlaminar shear at higher fiber contents. The extent of fiber loading did not have noticeable effect on either fiber-matrix debonding stress, or frictional sliding stress at the interface. The applicability of micromechanical models in predicting the mechanical properties of the composites was also examined. The currently available theoretical models do not appear to be useful in predicting the values of the first matrix cracking stress, and the ultimate strength of the SCS-6/SAS composites.

  3. Preventing photodarkening in ytterbium-doped high power fiber lasers; correlation to the UV-transparency of the core glass.

    PubMed

    Engholm, M; Norin, L

    2008-01-21

    Photodarkening experiments are performed on ytterbium-doped silicate glass samples. A strong charge-transfer (CT) absorption band near 230nm in aluminosilicate glass is found to be correlated to the mechanism of induced color center formation. Excitation into the CT-absorption band generates similar color centers as observed in ytterbium-doped fiber lasers under 915nm high power diode pumping. The position of the CT-absorption band is compositional dependent and is shifted to shorter wavelengths in ytterbium doped phosphosilicate glass. Very low levels of photodarkening is observed for the ytterbium doped phosphosilicate glass composition under 915nm high power diode pumping. Possible excitation routes to reach the CT-absorption band under 915nm pumping are discussed.

  4. 3D FEA of cemented glass fiber and cast posts with various dental cements in a maxillary central incisor.

    PubMed

    Madfa, Ahmed A; Al-Hamzi, Mohsen A; Al-Sanabani, Fadhel A; Al-Qudaimi, Nasr H; Yue, Xiao-Guang

    2015-01-01

    This study aimed to analyse and compare the stability of two dental posts cemented with four different luting agents by examining their shear stress transfer through the FEM. Eight three-dimensional finite element models of a maxillary central incisor restored with glass fiber and Ni-Cr alloy cast dental posts. Each dental post was luted with zinc phosphate, Panavia resin, super bond C&B resin and glass ionomer materials. Finite element models were constructed and oblique loading of 100 N was applied. The distribution of shear stress was investigated at posts and cement/dentine interfaces using ABAQUS/CAE software. The peak shear stress for glass fiber post models minimized approximately three to four times of those for Ni-Cr alloy cast post models. There was negligible difference in peak of shear stress when various cements were compared, irrespective of post materials. The shear stress had same trend for all cement materials. This study found that the glass fiber dental post reduced the shear stress concentration at interfacial of post and cement/dentine compared to Ni-Cr alloy cast dental post.

  5. 3D FEA of cemented glass fiber and cast posts with various dental cements in a maxillary central incisor.

    PubMed

    Madfa, Ahmed A; Al-Hamzi, Mohsen A; Al-Sanabani, Fadhel A; Al-Qudaimi, Nasr H; Yue, Xiao-Guang

    2015-01-01

    This study aimed to analyse and compare the stability of two dental posts cemented with four different luting agents by examining their shear stress transfer through the FEM. Eight three-dimensional finite element models of a maxillary central incisor restored with glass fiber and Ni-Cr alloy cast dental posts. Each dental post was luted with zinc phosphate, Panavia resin, super bond C&B resin and glass ionomer materials. Finite element models were constructed and oblique loading of 100 N was applied. The distribution of shear stress was investigated at posts and cement/dentine interfaces using ABAQUS/CAE software. The peak shear stress for glass fiber post models minimized approximately three to four times of those for Ni-Cr alloy cast post models. There was negligible difference in peak of shear stress when various cements were compared, irrespective of post materials. The shear stress had same trend for all cement materials. This study found that the glass fiber dental post reduced the shear stress concentration at interfacial of post and cement/dentine compared to Ni-Cr alloy cast dental post. PMID:26543733

  6. Measurement of thermal conductivity of PbTe nanocrystal coated glass fibers by the 3ω method.

    PubMed

    Finefrock, Scott W; Wang, Yan; Ferguson, John B; Ward, James V; Fang, Haiyu; Pfluger, Jonathan E; Dudis, Douglas S; Ruan, Xiulin; Wu, Yue

    2013-11-13

    Fiber-based thermoelectric materials can conform to curved surfaces to form energy harvesting devices for waste heat recovery. Here we investigate the thermal conductivity in the axial direction of glass fibers coated with lead telluride (PbTe) nanocrystals using the self-heated 3ω method particularly at low frequency. While prior 3ω measurements on wire-like structures have only been demonstrated for high thermal conductivity materials, the present work demonstrates the suitability of the 3ω method for PbTe nanocrystal coated glass fibers where the low thermal conductivity and high aspect ratio result in a significant thermal radiation effect. We simulate the experiment using a finite-difference method that corrects the thermal radiation effect and extract the thermal conductivity of glass fibers coated by PbTe nanocrystals. The simulation method for radiation correction is shown to be generally much more accurate than analytical methods. We explore the effect of nanocrystal volume fraction on thermal conductivity and obtain results in the range of 0.50-0.93 W/mK near room temperature.

  7. Epoxy/Glass Fiber Laminated Composites Integrated with Amino Functionalized ZrO2 for Advanced Structural Applications.

    PubMed

    Halder, Sudipta; Ahemad, Soyeb; Das, Subhankar; Wang, Jialai

    2016-01-27

    This work demonstrates the successful silanization of ZrO2 nanoparticles (ZN) and their incorporation in glass fiber/epoxy composites. Microscopic investigation under transmission electron microscope elucidates antiaggregation and size enhancement of silanized ZrO2 nanoparticles (SZNs). FTIR spectroscopy has been used to demonstrate the chemical nature of the SZNs prepared. EDX results reveal the presence of Si onto SZNs. Incorporation of SZNs shows a strong influence on tensile and flexural properties of hybrid multiscale glass fiber composite (SZGFRP) compared to that of the neat epoxy glass fiber composite (GFRP). A significant variation of tensile strength, stiffness, and toughness of ∼27%, 62%, and 110% is observed with respect to GFRP. Strength and modulus under bending are also enhanced to ∼22% and ∼38%, respectively. Failure mechanisms obtained from macroscopic and microscopic investigation demonstrate reduced interfacial delamination for SZGFRP. Additionally, increased roughness of the fiber surface in SZGFRP laminates produces better interfacial bonding arising from SZN incorporation in laminates. This symptomatic behavior exposes the espousal of organically modified ZrO2 to enhance the interfacial bonding for their use in next generation hybrid laminates. PMID:26714570

  8. Toward a mid-infrared femtosecond laser system with suspended-core tungstate-tellurite glass fibers.

    PubMed

    Anashkina, E A; Andrianov, A V; Dorofeev, V V; Kim, A V

    2016-06-10

    A simple design of a fiber laser system for generating high-quality pulses with a duration of order 100 fs with ultrabroad wavelength tunability in the 2-5 μm range is discussed. This design incorporates conventional fs near-IR lasers and specially developed tungstate-tellurite fibers with two zero-dispersion wavelengths (ZDW) and relies on nonlinear wavelength conversion via either soliton self-frequency shift (SSFS) or red-shifted dispersive wave (DW) generation. The fiber parameters needed for such optical conversion have been scanned numerically and showed a possibility of SSFS beyond 4 μm and of DW generation beyond 5 μm. We have also studied and prepared tungstate-tellurite glasses and preforms that are highly stable against crystallization, exhibit extremely low level of hydroxyl groups absorption, and from which the suspended-core two-ZDW fibers can be manufactured. PMID:27409007

  9. Glass fiber dissolution in simulated lung fluid and measures needed to improve consistency and correspondence to in vivo dissolution.

    PubMed Central

    Mattson, S M

    1994-01-01

    The dissolution of a range of glass fibers including commercial glass and mineral wools has been studied using a modification of Gamble's solution in a flow system at pH 7.4 and 37 degrees C. Dissolution has been followed by weight loss, effluent analysis, and morphology change of fibers and bulk glass. Flow per glass surface area can strongly affect both dissolution rate and morphology due to the effect of the dissolution process on the fluid. Effluent pH is shown to be a guide for choice of optimum flow/area conditions. These conditions provide measurable concentrations of dissolved glass in the effluent while maintaining their concentrations below the point at which they significantly affect the dissolution process. SiO2 and Al2O3 vary widely in the extent to which they are involved in the leaching process, which removes alkalis, alkaline earths, and B2O3. This makes analysis of a single component in the effluent unsuitable as a means of comparing the dissolution rates of a wide range of compositions. PMID:7882963

  10. Enhanced osteoprogenitor elongated collagen fiber matrix formation by bioactive glass ionic silicon dependent on Sp7 (osterix) transcription.

    PubMed

    Varanasi, Venu G; Odatsu, Tetsurou; Bishop, Timothy; Chang, Joyce; Owyoung, Jeremy; Loomer, Peter M

    2016-10-01

    Bioactive glasses release ions, those enhance osteoblast collagen matrix synthesis and osteogenic marker expression during bone healing. Collagen matrix density and osteogenic marker expression depend on osteogenic transcription factors, (e.g., Osterix (OSX)). We hypothesize that enhanced expression and formation of collagen by Si(4+) depends on enhanced expression of OSX transcription. Experimental bioactive glass (6P53-b) and commercial Bioglass(TM) (45S5) were dissolved in basal medium to make glass conditioned medium (GCM). ICP-MS analysis was used to measure bioactive glass ion release rates. MC3T3-E1 cells were cultured for 20 days, and gene expression and extracellular matrix collagen formation was analyzed. In a separate study, siRNA was used to determine the effect of OSX knockdown on impacting the effect of Si(4+) on osteogenic markers and matrix collagen formation. Each bioactive glass exhibited similar ion release rates for all ions, except Mg(2+) released by 6P53-b. Gene expression results showed that GCM markedly enhanced many osteogenic markers, and 45S5 GCM showed higher levels of expression and collagen matrix fiber bundle density than 6P53-b GCM. Upon knockdown of OSX transcription, collagen type 5, alkaline phosphatase, and matrix density were not enhanced as compared to wild type cells. This study illustrates that the enhancement of elongated collagen fiber matrix formation by Si(±) depends on OSX transcription. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2604-2615, 2016.

  11. Thermo-mechanical characterization of siliconized E-glass fiber/hematite particles reinforced epoxy resin hybrid composite

    NASA Astrophysics Data System (ADS)

    V. R., Arun prakash; Rajadurai, A.

    2016-10-01

    In this present work hybrid polymer (epoxy) matrix composite has been strengthened with surface modified E-glass fiber and iron(III) oxide particles with varying size. The particle sizes of 200 nm and <100 nm has been prepared by high energy ball milling and sol-gel methods respectively. To enhance better dispersion of particles and improve adhesion of fibers and fillers with epoxy matrix surface modification process has been done on both fiber and filler by an amino functional silane 3-Aminopropyltrimethoxysilane (APTMS). Crystalline and functional groups of siliconized iron(III) oxide particles were characterized by XRD and FTIR spectroscopy analysis. Fixed quantity of surface treated 15 vol% E-glass fiber was laid along with 0.5 and 1.0 vol% of iron(III) oxide particles into the matrix to fabricate hybrid composites. The composites were cured by an aliphatic hardener Triethylenetetramine (TETA). Effectiveness of surface modified particles and fibers addition into the resin matrix were revealed by mechanical testing like tensile testing, flexural testing, impact testing, inter laminar shear strength and hardness. Thermal behavior of composites was evaluated by TGA, DSC and thermal conductivity (Lee's disc). The scanning electron microscopy was employed to found shape and size of iron(III) oxide particles adhesion quality of fiber with epoxy matrix. Good dispersion of fillers in matrix was achieved with surface modifier APTMS. Tensile, flexural, impact and inter laminar shear strength of composites was improved by reinforcing surface modified fiber and filler. Thermal stability of epoxy resin was improved when surface modified fiber was reinforced along with hard hematite particles. Thermal conductivity of epoxy increased with increase of hematite content in epoxy matrix.

  12. Effect of Zn addition on non-resonant third-order optical nonlinearity of the Cu-doped germano-silicate optical glass fiber.

    PubMed

    Ju, Seongmin; Watekar, Pramod R; Jeong, Seongmook; Kim, Youngwoong; Han, Won-Taek

    2012-01-01

    Cu/Zn-codoped germano-silicate optical glass fiber was manufactured by using the modified chemical vapor deposition (MCVD) process and solution doping process. To investigate the reduction effect of Zn addition on Cu metal formation in the core of the Cu/Zn-codoped germano-silicate optical glass fiber, the optical absorption property and the non-resonant third-order optical nonlinearity were measured. Absorption peaks at 435 nm and 469 nm in the Cu/Zn-codoped germano-silicate optical glass fiber were contributed to Cu metal particles and ZnO semiconductor particles, respectively. The effective non-resonant optical nonlinearity, gamma, of the Cu/Zn-codoped germano-silicate optical glass fiber was measured to be 1.5097 W(-1) x km(-1) by using the continuous-wave self-phase modulation method. The gamma of the Cu/Zn-codoped germano-silicate optical glass fiber was about four times larger than that of the reference germano-silicate optical glass fiber without any dopants. The increase of the effective non-resonant optical nonlinearity, gamma, of the Cu/Zn-codoped germano-silicate optical glass fiber, can be attributed to the enhanced nonlinear polarization due to incorporated ZnO semiconductor particles and Cu metal ions in the glass network. The Cu/Zn-codoped germano-silicate optical glass fiber showed high nonlinearity and low transmission loss at the optical communication wavelength, which makes it suitable for high-speed-high-capacity optical communication systems.

  13. Thermal stress modification in regenerated fiber Bragg grating via manipulation of glass transition temperature based on CO₂-laser annealing.

    PubMed

    Lai, Man-Hong; Lim, Kok-Sing; Gunawardena, Dinusha S; Yang, Hang-Zhou; Chong, Wu-Yi; Ahmad, Harith

    2015-03-01

    In this work, we have demonstrated thermal stress relaxation in regenerated fiber Bragg gratings (RFBGs) by using direct CO₂-laser annealing technique. After the isothermal annealing and slow cooling process, the Bragg wavelength of the RFBG has been red-shifted. This modification is reversible by re-annealing and rapid cooling. It is repeatable with different cooling process in the subsequent annealing treatments. This phenomenon can be attributed to the thermal stress modification in the fiber core by means of manipulation of glass transition temperature with different cooling rates. This finding in this investigation is important for accurate temperature measurement of RFBG in dynamic environment. PMID:25723423

  14. The effect of glass and polyethylene fiber reinforcement on flexural strength of provisional restorative resins: an in vitro study.

    PubMed

    Natarajan, Parthasarathy; Thulasingam, C

    2013-12-01

    The aim is to evaluate and compare the flexural strength of different provisional restorative materials reinforced with glass and polyethylene fibers. A total of 90 samples were prepared and divided into three groups based on the type of fiber reinforcement, unidirectional S-glass (Splint-It) and ultra-molecular weight polyethylene (Ribbond). Unreinforced samples served as control group. Again each group was subdivided into three subgroups based on type of provisional restorative resins, heats cure polymethyl methacrylate, self-cure poly methyl methacrylate and self-cure bis-acryl composite. Samples were loaded in a universal testing machine until fracture occurs. The mean flexural strengths (MPa) were subjected to the one-way ANOVA, followed by the Tukey-HSD test at a significance level of 0.001. The result shows all the fiber reinforced samples possessed greater strength than the control samples. In control samples, the heat cure poly methyl methacrylate resin (72.74 ± 2.28 MPa) had the greatest flexural strength, followed by self-cure bis-acryl composite (67.05 ± 2.35 MPa) and self-cure poly methyl methacrylate resin (52.88 ± 1.90 MPa). In both heat and self-cure poly methyl methacrylate resin, the polyethylene fiber reinforcement (96.00 ± 2.63 MPa, 86.17 ± 1.92 MPa) provides the greatest strength than glass fiber reinforcement (92.68 ± 1.58 MPa, 76.40 ± 2.11 MPa). In self-cure bis-acryl composite, the glass fiber (105.95 ± 3.07 MPa) shows better reinforcement than polyethylene fiber (99.41 ± 1.74 MPa).The fibers reinforcement increases the flexural strength of provisional restorative resins.

  15. Large-mode-area single-mode-output Neodymium-doped silicate glass all-solid photonic crystal fiber.

    PubMed

    Li, Wentao; Chen, Danping; Qinling, Zhou; Hu, Lili

    2015-07-24

    We have demonstrated a 45 μm core diameter Neodymium-doped all-solid silicate glass photonic crystal fiber laser with a single mode laser output. The structure parameters and modes information of the fiber are both demonstrated by theoretical calculations using Finite Difference Time Domain (FDTD) method and experimental measurements. Maximum 0.8 W output power limited by launched pump power has been generated in 1064 nm with laser beam quality factor M(2) 1.18.

  16. Large-mode-area single-mode-output Neodymium-doped silicate glass all-solid photonic crystal fiber

    PubMed Central

    Li, Wentao; Chen, Danping; Qinling, Zhou; Hu, Lili

    2015-01-01

    We have demonstrated a 45 μm core diameter Neodymium-doped all-solid silicate glass photonic crystal fiber laser with a single mode laser output. The structure parameters and modes information of the fiber are both demonstrated by theoretical calculations using Finite Difference Time Domain (FDTD) method and experimental measurements. Maximum 0.8 W output power limited by launched pump power has been generated in 1064 nm with laser beam quality factor M2 1.18. PMID:26205850

  17. Rehabilitation of advanced periodontal problems by using a combination of a glass fiber-reinforced composite resin bridge and splint.

    PubMed

    Kumbuloglu, Ovul; Aksoy, Gokhan; User, Atilla

    2008-02-01

    Rehabilitation of masticatory ability in patients with reduced periodontal tissue support is a multiple challenge in dentistry. It has been shown that tooth mobility is reduced by a splint in place. Splints may be constructed of various materials. Development of fiber-reinforced composite materials offers a new and conservative approach for tooth replacement and stabilization. This case report describes the rehabilitation and 2-year follow-up of a patient with advanced periodontal problems by using a glass fiber-reinforced composite resin material. PMID:18389738

  18. Clinical evaluation of carbon fiber reinforced carbon endodontic post, glass fiber reinforced post with cast post and core: A one year comparative clinical study

    PubMed Central

    Preethi, GA; Kala, M

    2008-01-01

    Aim: Restoring endodontically treated teeth is one of the major treatments provided by the dental practitioner. Selection and proper use of restorative materials continues to be a source of frustration for many clinicians. There is controversy surrounding the most suitable choice of restorative material and the placement method that will result in the highest probability of successful treatment. This clinical study compares two different varieties of fiber posts and one cast post and core in terms of mobility of crown margin under finger pressure, recurrent caries detected at the crown margin, fracture of the restoration, fracture of the root and periapical and periodontal pathology requiring crown removal over the period of 12months as evaluated by clinical and radiographical examination. Materials and Methods: 30 root canal treated, single rooted maxillary anterior teeth of 25 patients in the age range of 18–60 years where a post retained crown was indicated were selected for the study between January 2007 and August 2007; and prepared in a standard clinical manner. It was divided into 3 groups of 10 teeth in each group. After post space preparation, the Carbon fiber and Glass fiber reinforced posts were cemented with Scotch bond multipurpose plus bonding agent and RelyX adhesive resin cement in the first and second groups respectively. The Cast post and cores were cemented with Zinc Phosphate cement in the third group. Following post- cementation, the preparation was further refined and a rubber base impression was taken for metal-ceramic crowns which was cemented with Zinc Phosphate cement. A baseline periapical radiograph was taken once each crown was cemented. All patients were evaluated after one week (baseline), 3 months, 6 months and one year for following characteristics mobility of crown margin under finger pressure, recurrent caries detected at the crown margin, fracture of the restoration, fracture of the root and periapical and periodontal pathology

  19. Role of mast cells in wound healing process after glass - fiber composite implant in rats

    PubMed Central

    Rodella, L F; Rezzani, Rita; Buffoli, Barbara; Bonomini, Francesca; Tengattini, Sandra; Laffranchi, Laura; Paganelli, C; Sapelli, P L; Bianchi, Rossella

    2006-01-01

    Glass-fiber composites are frequently used in dentistry. In order to evaluate their biocompatibility we tested, in an experimental model “in vivo”, their tissue response pointing our attention on presence of mast cells (MCs) and fibrotic process. Sprague Dawley rats were used for the experimental design. The fibers were introduced in a subcutaneous pocket along the middle dorsal line between the two scapulas for 7, 14 or 21 days. At the end of the treatments the skins were excised and then processed for Toluidine Blue, to determine the presence of MCs, and Picrosirius Red staining, to evaluate the presence of fibrotic tissue. Our preliminary results showed and increase of both MC number and deposition of collagen type I, which characterized the fibrotic tissue. So, subsequent aims of our study were to evaluate the role played by MCs in tissue fibrosis and to give a possible explanation regarding the mechanisms that were responsible of biological response observed, through the analyses of some proteins, such as metalloproteinase-2 (MMP-2), its inhibitor (TIMP-2) and transforming growth factor-β (TGF-β). Our data confirmed the involvement of TGF-β, released by MCs, in the disruption of the equilibrium between MMP-2 and TIMP-2 that were implicated in the enhancement of fibrosis. In summary, this study demonstrate that this type of materials induced an inflammatory response at the site of implant and help to clarify what type of mechanism and which proteins are involved in this biological response. Nevertheless, more extensive investigations are in progress to better evaluate the inflammatory process. PMID:17125597

  20. Flexible nanocrystal-coated glass fibers for high-performance thermoelectric energy harvesting.

    PubMed

    Liang, Daxin; Yang, Haoran; Finefrock, Scott W; Wu, Yue

    2012-04-11

    Recent efforts on the development of nanostructured thermoelectric materials from nanowires (Boukai, A. I.; et al. Nature 2008, 451, (7175), 168-171; Hochbaum, A. I.; et al. Nature 2008, 451, (7175), 163-167) and nanocrystals (Kim, W.; et al. Phys. Rev. Lett. 2006, 96, (4), 045901; Poudel, B.; et al. Science 2008, 320, (5876), 634-638; Scheele, M.; et al. Adv. Funct. Mater. 2009, 19, (21), 3476-3483; Wang, R. Y.; et al. Nano Lett. 2008, 8, (8), 2283-2288) show the comparable or superior performance to the bulk crystals possessing the same chemical compositions because of the dramatically reduced thermal conductivity due to phonon scattering at nanoscale surface and interface. Up to date, the majority of the thermoelectric devices made from these inorganic nanostructures are fabricated into rigid configuration. The explorations of truly flexible composite-based flexible thermoelectric devices (See, K. C.; et al. Nano Lett. 2010, 10, (11), 4664-4667) have thus far achieved much less progress, which in principle could significantly benefit the conversion of waste heat into electricity or the solid-state cooling by applying the devices to any kind of objects with any kind of shapes. Here we report an example using a scalable solution-phase deposition method to coat thermoelectric nanocrystals onto the surface of flexible glass fibers. Our investigation of the thermoelectric properties yields high performance comparable to the state of the art from the bulk crystals and proof-of-concept demonstration also suggests the potential of wrapping the thermoelectric fibers on the industrial pipes to improve the energy efficiency.

  1. Evaluation of a glass-fiber-reinforced, bonded, inlay-supported fixed partial denture--4-year results.

    PubMed

    Jain, Poonam; Cobb, Deborah

    2002-09-01

    Glass-fiber-reinforced composite resin systems may be used as conservative alternatives to conventional fixed partial dentures (FPDs) for the replacement of a single missing tooth. This article describes a clinical technique and 4-year evaluation of an inlay bonded FPD. The patient presented with a missing maxillary right second premolar. A high-caries risk and moderate-to-advanced attachment loss around the abutment teeth, which were clinically stable, were noted. The patient had a strong desire to maintain his remaining dentition. Advantages of supragingival margins and minimal tooth structure removal made the bonded inlay bridge a viable alternative to a conventional FPD for this compromised restorative situation. The clinical performance of this glass-fiber-reinforced resin inlay FPD at the 4-year follow-up is provided. The restoration has served satisfactorily for more than 4 years and holds promise as a conservative, esthetic alternative to the conventional FPD in certain clinical cases.

  2. Effect of part thickness, glass fiber and crystallinity on light scattering during laser transmission welding of thermoplastics

    NASA Astrophysics Data System (ADS)

    Xu, Xin Feng; Parkinson, Alexander; Bates, Philip J.; Zak, Gene

    2015-12-01

    It is important to understand how laser energy scatters within the transparent component in order to predict and optimize the laser transmission welding process. This paper examines the influence of part thickness, glass fiber and crystallinity levels on the distribution of laser light after transmission through amorphous polycarbonate (PC) and semi-crystalline polymers such as polyamide 6 (PA6), polypropylene (PP), and polyethylene (PE). An experimental technique based on laser-scanned lines of progressively increasing power was used to assess the transmitted energy distribution. This distribution was characterized using a two-parameter model that captures scattered and un-scattered components of the laser beam. The results clearly show how the scattering is increased by increasing the numbers of interactions between laser light and phase boundaries either by increasing the particle concentration (i.e., glass fiber level and crystallinity) or increasing part thickness.

  3. Coupled thermal/structural analyses of laser powered glass sealing methods for fiber optic and flat panel display applications

    SciTech Connect

    Chambers, R.S.; Gianoulakis, S.E.

    1996-12-31

    Glasses are used extensively by the electronics industry for packaging and in components. Because glasses have such low fracture toughness, glass components must maintain low tensile stresses to avoid cracking and ensure product stability. Modeling is a key tool for developing designs with low tensile stresses. Thermoelastic analyses are ideal for modeling slow, oven controlled processes where the temperature varies uniformly. Many processing environments, however, involve rapid heating and cooling cycles that produce nonhomogeneous temperature fields causing the volume and stresses in the glass to relax at different rates. This structural relaxation is an important nonlinear material behavior that gives rise to a point-to-point variability in effective properties of the material. To accurately model such stresses, a thermal analysis must be coupled to a structural analysis that employs a viscoelastic model of glass. Laser sealing of glasses is an example of a process where thermal history is an important factor in determining the residual stress state. Recent needs to consider laser sealing methods for fiber optic connectors and flat panel displays have spurred the development of coupled, three-dimensional thermal and structural finite element codes. Analyses of the temperatures and stresses generated in a flat panel display during a laser sealing operation are presented, an the idiosyncrasies and importance of modeling coupled thermal/structural phenomena are discussed.

  4. Time-Dependent Deformation Modelling for a Chopped-Glass Fiber Composite for Automotive Durability Design Criteria

    SciTech Connect

    Ren, W

    2001-08-24

    Time-dependent deformation behavior of a polymeric composite with chopped-glass-fiber reinforcement was investigated for automotive applications, The material under stress was exposed to representative automobile service environments. Results show that environment has substantial effects on time-dependent deformation behavior of the material. The data were analyzed and experimentally-based models developed for the time-dependent deformation behavior as a basis for automotive structural durability design criteria.

  5. Investigation on Stress-Rupture Behavior of a Chopped-Glass-Fiber Composite for Automotive Durability Design Criteria

    SciTech Connect

    Ren, W

    2001-08-24

    Practical and inexpensive testing methods were developed to investigate stress-rupture properties of a polymeric composite with chopped glass fiber reinforcement for automotive applications. The material was tested in representative automotive environments to generate experimental data. The results indicate that environments have substantial effects on the stress-rupture behavior. The data were analyzed and developed into stress-rupture design criteria to address one of the durability aspects of the material for automotive structural applications.

  6. Water sorption and solubility of glass fiber-reinforced denture polymethyl methacrylate resin.

    PubMed

    Miettinen, V M; Vallittu, P K; Docent, D T

    1997-05-01

    Polymethyl methacrylate (PMMA) absorbs water slowly over a period of time, primarily because of the polar properties of the resin molecules. The aim of this study was to determine the water sorption and solubility of heat-cured and chemical-cured glass fiber (GF) PMMA composite used in dentures. The test specimens (n = 5) were fabricated from experimental, unidirectional, continuous GF reinforcement; the GF concentration of the test specimens was approximately 11% by weight. Water sorption and solubility were tested in accordance with International Standards Organization specification No. 1567. The results revealed that the type of acrylate had more of an effect on water sorption than did the presence of GF reinforcement in the test specimen (p = 0.001 and p = 0.049, respectively). In the GF-reinforced test specimens the type of PMMA also affected the water sorption values (p = 0.006). GF reinforcement affected the solubility values of the test specimen (p = 0.002), but the type of acrylate had no effect on solubility (p = 0.585). The results of this study suggest that the water sorption and solubility of unreinforced PMMA and PMMA reinforced with GF are in accordance with International Standards Organization specification No. 1567.

  7. Research on the mechanical properties of a glass fiber reinforced polymer-steel combined truss structure.

    PubMed

    Liu, Pengfei; Zhao, Qilin; Li, Fei; Liu, Jinchun; Chen, Haosen

    2014-01-01

    An assembled plane truss structure used for vehicle loading is designed and manufactured. In the truss, the glass fiber reinforced polymer (GFRP) tube and the steel joint are connected by a new technology featuring a pretightened tooth connection. The detailed description for the rod and node design is introduced in this paper, and a typical truss panel is fabricated. Under natural conditions, the short-term load test and long-term mechanical performance test for one year are performed to analyze its performance and conduct a comparative analysis for a reasonable FEM model. The study shows that the design and fabrication for the node of an assembled truss panel are convenient, safe, and reliable; because of the creep control design of the rods, not only does the short-term structural stiffness meet the design requirement but also the long-term creep deformation tends towards stability. In addition, no significant change is found in the elastic modules, so this structure can be applied in actual engineering. Although the safety factor for the strength of the composite rods is very large, it has a lightweight advantage over the steel truss for the low density of GFRP. In the FEM model, simplifying the node as a hinge connection relatively conforms to the actual status. PMID:25247203

  8. Preparation and radar absorptive properties of BaFe12O19 -coated glass fiber

    NASA Astrophysics Data System (ADS)

    Jia, F.; Xu, M.; Bao, H. Q.; Cui, K.; Zhang, F.

    2016-07-01

    Traditional passive jamming materials such as chaff and foil showed some limitations in use because they can only reflect the electromagnetic wave. Therefore, to develop a kind of absorptive passive jamming material to make up for deficiencies of traditional passive jamming materials and improve the jamming efficiency is of great significance. In this paper, the BaFe12O19-coated glass fiber, used as a kind of radar absorptive chaff, was prepared by sol-gel dip-coating method. The effects of heat treatment temperature, heat treatment time and coating times on film quality, tensile strength and attenuation efficiency of the samples were discussed. The study shows that an increase of the heat treatment temperature and an extension of the heat treatment time is conducive to the growth of barium ferrite grain, while they would introduce the loss of chaff strength at the same time. In addition, multi-coating process can improve the film quality and attenuation efficiency of the sample. Data show that the 10 times coated samples have a best reflectivity of (15GHz, -6.65dB) and the bandwidth of reflectivity lower than -5dB is11.8 GHz. According to the test results, the prepared material has certain attenuation efficiency in the range of 2GHz-18GHz, having a high practical value.

  9. Behavior of Fiber Glass Bolts, Rock Bolts and Cable Bolts in Shear

    NASA Astrophysics Data System (ADS)

    Li, Xuwei; Aziz, Naj; Mirzaghorbanali, Ali; Nemcik, Jan

    2016-07-01

    This paper experimentally compares the shear behavior of fiber glass (FG) bolt, rock bolt (steel rebar bolt) and cable bolt for the bolt contribution to bolted concrete surface shear strength, and bolt failure mode. Two double shear apparatuses of different size were used for the study. The tensile strength, the shear strength and the deformation modulus of bolt control the shear behavior of a sheared bolted joint. Since the strength and deformation modulus of FG bolt, rock bolt and cable bolt obtained from uniaxial tensile tests are different, their shear behavior in reinforcing joints is accordingly different. Test results showed that the shear stiffness of FG bolted joints decreased gradually from the beginning to end, while the shear stiffness of joints reinforced by rock bolt and cable bolt decreased bi-linearly, which is clearly consistent with their tensile deformation modulus. The bolted joint shear stiffness was highly influenced by bolt pretension in the high stiffness stage for both rock bolt and cable bolt, but not in the low stiffness stage. The rock bolt contribution to joint shear strength standardised by the bolt tensile strength was the largest, followed by cable bolts, then FG bolts. Both the rock bolts and cable bolts tended to fail in tension, while FG bolts in shear due to their low shear strength and constant deformation modulus.

  10. Why is alsynite fiber glass sheet attractive to stable flies? Optical and behavioural studies.

    PubMed

    Zacks, D N; Loew, E R

    1989-01-01

    The fiber glass material Alsynite (Sequentia Corporation) is known to be an effective visual attractant to stable flies, Stomoxys calcitrans. The basis for this attractiveness is not certain, but is found to correlate with high near-UV reflectivity. While examining the transmission properties of Alsynite, it was found that the ratio of short- to long-wavelength photons shifts from 0.17 to 0.77, depending on the angle of the Alsynite relative to the source and the detector. This shift occurs suddenly at an angle of 15 degrees from the normal. To the human eye this shift results in an iridescent blue halo appearing around a light source and at the boundaries of illuminated objects. The phototactic response of stable flies to the 15 degrees off-axis spectral condition, as measured behaviourally, is greater than or equal to their phototactic response to a tungsten source more than 20 times the spectrally corrected intensity. This demonstrates a real preference for the off-axis photon ratio and may in part explain why Alsynite is attractive to stable flies in field situations. PMID:2776864

  11. Cheap glass fiber mats as a matrix of gel polymer electrolytes for lithium ion batteries

    PubMed Central

    Zhu, Yusong; Wang, Faxing; Liu, Lili; Xiao, Shiyin; Yang, Yaqiong; Wu, Yuping

    2013-01-01

    Lithium ion batteries (LIBs) are going to play more important roles in electric vehicles and smart grids. The safety of the current LIBs of large capacity has been remaining a challenge due to the existence of large amounts of organic liquid electrolytes. Gel polymer electrolytes (GPEs) have been tried to replace the organic electrolyte to improve their safety. However, the application of GPEs is handicapped by their poor mechanical strength and high cost. Here, we report an economic gel-type composite membrane with high safety and good mechanical strength based on glass fiber mats, which are separator for lead-acid batteries. The gelled membrane exhibits high ionic conductivity (1.13 mS cm−1), high Li+ ion transference number (0.56) and wide electrochemical window. Its electrochemical performance is evaluated by LiFePO4 cathode with good cycling. The results show this gel-type composite membrane has great attraction to the large-capacity LIBs requiring high safety with low cost. PMID:24216756

  12. Evaluation of Different Post Lengths’ Effect on Fracture Resistance of a Glass Fiber Post System

    PubMed Central

    Adanir, Necdet; Belli, Sema

    2008-01-01

    Objectives The purpose of this in vitro study was to evaluate the influence of different post lengths upon root fracture resistance. Methods 78 maxillary central teeth with similar dimensions were mounted in acrylic blocks with artificial silicone periodontal ligaments. Combinations of post lengths of 6 mm (shorter than 1/1 clinical crown length), 9 mm (1/1 clinical crown length), and 12 mm (longer than 1/1 clinical crown length) made up 6 different groups consisting of 13 teeth each. The glass fiber posts (Snowpost) were cemented with Super-Bond C&B and Panavia F luting cement. Composite-resin cores were made with Clearfil PhotoCore. The specimens were tested in a universal test machine. The testing machine applied controlled loads to the core, 2 mm from its incisal edge, on the palatal side at an angle 135 degrees to the long axis of the root. The testing machine was set at a crosshead speed of 5mm per minute. All samples were loaded until failure. Results There was no statistically significant difference between cements (P>.05). Posts shorter than clinical crown length, demonstrated root fracture under significantly lower loading forces (P<.05). Conclusion Usage of posts shorter than clinical crowns should be avoided to eliminate clinical failure. PMID:19212505

  13. Effects of Internal Bleaching on the Adhesion of Glass-Fiber Posts

    PubMed Central

    de Oliveira Moreira, Paulo E.; Pamplona, Lucianne S.; Nascimento, Gláucia C. R.; Esteves, Renata A.; Pessoa, Oscar F.; Silva, Cecy M.

    2015-01-01

    Objective: We evaluated the effects of internal bleaching on the adhesion of glass-fiber posts (GFPs) luted with different resin cements. Methods: Forty extracted human single-root teeth were endodontically treated and divided into four groups (n=10): G1- conventional resin cement (CRC); G2- self-adhesive resin cement (SARC); G3- bleaching + CRC; and G4- bleaching + SARC. Specimens were sectioned transversally into three slices to perform the push-out test at the coronal, middle and apical regions of the root canals. Data were analyzed using analysis of variance and Tukey's test (p<0.05). Results: The push-out bond strength of GFPs luted with SARC after bleaching (G4) was significantly lower than that of the other groups (p<0.001). We found no statistically significant differences in push-out bond strength among the other groups. Significance: Internal bleaching reduced the adhesion of GFPs luted with SARC. The adhesion of GFPs luted with CRC was not decreased after bleaching. PMID:26962369

  14. Research on the Mechanical Properties of a Glass Fiber Reinforced Polymer-Steel Combined Truss Structure

    PubMed Central

    Liu, Pengfei; Zhao, Qilin; Li, Fei; Liu, Jinchun; Chen, Haosen

    2014-01-01

    An assembled plane truss structure used for vehicle loading is designed and manufactured. In the truss, the glass fiber reinforced polymer (GFRP) tube and the steel joint are connected by a new technology featuring a pretightened tooth connection. The detailed description for the rod and node design is introduced in this paper, and a typical truss panel is fabricated. Under natural conditions, the short-term load test and long-term mechanical performance test for one year are performed to analyze its performance and conduct a comparative analysis for a reasonable FEM model. The study shows that the design and fabrication for the node of an assembled truss panel are convenient, safe, and reliable; because of the creep control design of the rods, not only does the short-term structural stiffness meet the design requirement but also the long-term creep deformation tends towards stability. In addition, no significant change is found in the elastic modules, so this structure can be applied in actual engineering. Although the safety factor for the strength of the composite rods is very large, it has a lightweight advantage over the steel truss for the low density of GFRP. In the FEM model, simplifying the node as a hinge connection relatively conforms to the actual status. PMID:25247203

  15. Tribological and Mechanical Behaviors of Polyamide 6/Glass Fiber Composite Filled with Various Solid Lubricants

    PubMed Central

    Li, Duxin; Xie, Ying; Li, Wenjuan; You, Yilan; Deng, Xin

    2013-01-01

    The effects of polytetrafluoroethylene (PTFE), graphite, ultrahigh molecular weight polyethylene (UHMWPE), and their compounds on mechanical and tribological properties of glass-fiber-reinforced polyamide 6 (PA6/GF) were studied. The polymeric materials were blended using twin-screw extruder and subsequently injection molded for test samples. Mechanical properties were investigated in terms of hardness, tensile strength, and impact strength. Friction and wear experiments were run under ambient conditions at a rotating speed of 200 rpm and load of 100 N. The morphologies of the worn surfaces were also observed with scanning electron microscope. The results showed that graphite could increase the tensile strength of PA6/GF-15 composite, but the material became soft. Graphite/UHMWPE complex solid lubricants were effective in increasing the already high impact strength of PA6/GF-15 composite. 5% PTFE gave the maximum reduction in the coefficient of friction. However, PTFE/UHMWPE complex solid lubricants were the best choice for improving both friction and wear behaviors due to the lower friction coefficient and mass wear rate. Moreover, the worn surface of PA6 composites revealed that adhesive wear, abrasive wear, and fatigue wear occurred in this study. PMID:23766687

  16. Research on the mechanical properties of a glass fiber reinforced polymer-steel combined truss structure.

    PubMed

    Liu, Pengfei; Zhao, Qilin; Li, Fei; Liu, Jinchun; Chen, Haosen

    2014-01-01

    An assembled plane truss structure used for vehicle loading is designed and manufactured. In the truss, the glass fiber reinforced polymer (GFRP) tube and the steel joint are connected by a new technology featuring a pretightened tooth connection. The detailed description for the rod and node design is introduced in this paper, and a typical truss panel is fabricated. Under natural conditions, the short-term load test and long-term mechanical performance test for one year are performed to analyze its performance and conduct a comparative analysis for a reasonable FEM model. The study shows that the design and fabrication for the node of an assembled truss panel are convenient, safe, and reliable; because of the creep control design of the rods, not only does the short-term structural stiffness meet the design requirement but also the long-term creep deformation tends towards stability. In addition, no significant change is found in the elastic modules, so this structure can be applied in actual engineering. Although the safety factor for the strength of the composite rods is very large, it has a lightweight advantage over the steel truss for the low density of GFRP. In the FEM model, simplifying the node as a hinge connection relatively conforms to the actual status.

  17. Tribological and mechanical behaviors of polyamide 6/glass fiber composite filled with various solid lubricants.

    PubMed

    Li, Duxin; Xie, Ying; Li, Wenjuan; You, Yilan; Deng, Xin

    2013-01-01

    The effects of polytetrafluoroethylene (PTFE), graphite, ultrahigh molecular weight polyethylene (UHMWPE), and their compounds on mechanical and tribological properties of glass-fiber-reinforced polyamide 6 (PA6/GF) were studied. The polymeric materials were blended using twin-screw extruder and subsequently injection molded for test samples. Mechanical properties were investigated in terms of hardness, tensile strength, and impact strength. Friction and wear experiments were run under ambient conditions at a rotating speed of 200 rpm and load of 100 N. The morphologies of the worn surfaces were also observed with scanning electron microscope. The results showed that graphite could increase the tensile strength of PA6/GF-15 composite, but the material became soft. Graphite/UHMWPE complex solid lubricants were effective in increasing the already high impact strength of PA6/GF-15 composite. 5% PTFE gave the maximum reduction in the coefficient of friction. However, PTFE/UHMWPE complex solid lubricants were the best choice for improving both friction and wear behaviors due to the lower friction coefficient and mass wear rate. Moreover, the worn surface of PA6 composites revealed that adhesive wear, abrasive wear, and fatigue wear occurred in this study. PMID:23766687

  18. Ten year environmental test of glass fiber/epoxy pressure vessels

    NASA Technical Reports Server (NTRS)

    Faddoul, J. R.

    1985-01-01

    By the beginning of the 1970's composite pressure vessels had received a significant amount of development effort, and applications were beginning to be investigated. One of the first applications grew out of NASA Johnson Space Center efforts to develop a superior emergency breathing system for firemen. While the new breathing system provided improved wearer comfort and an improved mask and regulator, the primary feature was low weight which was achieved by using a glass fiber reinforced aluminum pressure vessel. Part of the development effort was to evaluate the long term performance of the pressure vessel and as a consequence, some 30 bottles for a test program were procured. These bottles were then provided to NASA Lewis Research Center where they were maintained in an outdoor environment in a pressurized condition for a period of up to 10 yr. During this period, bottles were periodically subjected to cyclic and burst testing. There was no protective coating applied to the fiberglass/epoxy composite, and significant loss in strength did occur as a result of the environment. Similar bottles stored indoors showed little, if any, degradation. This report contains a description of the pressure vessels, a discussion of the test program, data for each bottle, and appropriate plots, comparisons, and conclusions.

  19. Preparation and characterization of glass fibers - polymers (epoxy) bars (GFRP) reinforced concrete for structural applications

    NASA Astrophysics Data System (ADS)

    Alkjk, Saeed; Jabra, Rafee; Alkhater, Salem

    2016-06-01

    The paper presents some of the results from a large experimental program undertaken at the Department of Civil Engineering of Damascus University. The project aims to study the ability to reinforce and strengthen the concrete by bars from Epoxy polymer reinforced with glass fibers (GFRP) and compared with reinforce concrete by steel bars in terms of mechanical properties. Five diameters of GFRP bars, and steel bars (4mm, 6mm, 8mm, 10mm, 12mm) tested on tensile strength tests. The test shown that GFRP bars need tensile strength more than steel bars. The concrete beams measuring (15cm wide × 15cm deep × and 70cm long) reinforced by GFRP with 0.5 vol.% ratio, then the concrete beams reinforced by steel with 0.89 vol.% ratio. The concrete beams tested on deflection test. The test shown that beams which reinforced by GFRP has higher deflection resistance, than beams which reinforced by steel. Which give more advantage to reinforced concrete by GFRP.

  20. Tribological and mechanical behaviors of polyamide 6/glass fiber composite filled with various solid lubricants.

    PubMed

    Li, Duxin; Xie, Ying; Li, Wenjuan; You, Yilan; Deng, Xin

    2013-01-01

    The effects of polytetrafluoroethylene (PTFE), graphite, ultrahigh molecular weight polyethylene (UHMWPE), and their compounds on mechanical and tribological properties of glass-fiber-reinforced polyamide 6 (PA6/GF) were studied. The polymeric materials were blended using twin-screw extruder and subsequently injection molded for test samples. Mechanical properties were investigated in terms of hardness, tensile strength, and impact strength. Friction and wear experiments were run under ambient conditions at a rotating speed of 200 rpm and load of 100 N. The morphologies of the worn surfaces were also observed with scanning electron microscope. The results showed that graphite could increase the tensile strength of PA6/GF-15 composite, but the material became soft. Graphite/UHMWPE complex solid lubricants were effective in increasing the already high impact strength of PA6/GF-15 composite. 5% PTFE gave the maximum reduction in the coefficient of friction. However, PTFE/UHMWPE complex solid lubricants were the best choice for improving both friction and wear behaviors due to the lower friction coefficient and mass wear rate. Moreover, the worn surface of PA6 composites revealed that adhesive wear, abrasive wear, and fatigue wear occurred in this study.

  1. Preparation and characterization of fibrous chitosan-glued phosphate glass fiber scaffolds for bone regeneration.

    PubMed

    Zheng, Kai; Wu, Zhaoying; Wei, Jie; Rűssel, Christian; Liang, Wen; Boccaccini, Aldo R

    2015-08-01

    Phosphate glass fibers (PGF) have emerged as promising building blocks for constructing bone scaffolds. In this study, fibrous scaffolds (PGFS) were fabricated using a facile binding method at room temperature. PGFS exhibited an extracellular matrix-like morphology and were composed of PGF as matrix and chitosan as the natural binding glue. They showed an interconnected porous structure with a porosity of ~87% and pore size of 100-500 µm. PGFS exhibited the typical compressive stress-strain behaviour of highly porous, low-density, open-cell scaffolds. Their yield stress and modulus were ~0.38 and ~2.84 MPa, respectively, with the strength being higher than the lower bound of the compressive strength of cancellous bone. PGFS were degradable and the weight loss was about 25% after immersion in stimulated body fluid (SBF) for 28 days. In addition, the yield stress and the modulus decreased with increasing immersion time in SBF. Apatite formation could be detected on the surface of PGFS within 7 days of immersion in SBF. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay indicated that PGFS were non-cytotoxic against bone marrow stromal cells (bMSCs) after culture for up to 72 h. These results suggest that PGFS could be promising scaffolds for bone regeneration applications. PMID:26271217

  2. Influence of Copper Layer Content in the Elastic and Damping Behavior of Glass-Fiber/Epoxy-Resin Composites

    NASA Astrophysics Data System (ADS)

    Carneiro, V. H.; Capela, P.; Teixeira, J. C.; Teixeira, S.; Cerqueira, F.; Macedo, F.; Ribas, L.; Soares, D.

    2016-06-01

    The impact in the elastic behavior and internal friction, caused by the introduction of Copper layers in Glass-Fiber/Epoxy Resin composites and temperature effects, were studied and evaluated recurring to Dynamic Mechanical Analysis. It is shown that the introduction of Copper layers increases the storage modulus of the composites and delays their glass transition temperature, however, it allows a faster transformation. Additionally, it is concluded that the introduction of Copper layers elevates the internal friction during the glass transition phase by the inversion of the deformation mechanism due to thermal expansion and increase in the Poisson's ratio of the epoxy resin to a value near 0.5 where its deformation is approximately isochoric. This increase in damping capacity is relevant in application with cyclic fatigue and mechanical vibration.

  3. Accessory oral cavity

    PubMed Central

    Gnaneswaran, Manica Ramamoorthy; Varadarajan, Usha; Srinivasan, Ramesh; Kamatchi, Sangeetha

    2012-01-01

    This is a rare case report of a patient around 11 years with the complaint of extra mouth who reported to the hospital for removal of that extra mouth. On examination there was accessory oral cavity with small upper and lower lips, seven teeth and saliva was drooling out. Under general anesthesia crevicular incision from 32 to 43 was put and labial gingiva with alveolar mucosa was reflected completely and bone exposed to lower border of mandible. There were seven teeth resembling lower permanent anterior teeth in the accessory mouth, which was excised with the accessory lips. 41 extracted and osteotomy carried out extending the incision from the extracted site and osteotomy carried out. Dermoid cyst both below and above the mylohyoid muscle and rudimentary tongue found and excised and the specimen sent for histopathological examination. The wound was closed and uneventful healing noted to the satisfaction of the patient. This is a rare and interesting case which has been documented. PMID:23833508

  4. SEM-EDS analysis of glass fibers corroded in physiological solutions by dynamic tests with variable flow rates.

    PubMed Central

    Lehuédé, P; de Meringo, A

    1994-01-01

    The dissolution of mineral fibers has been studied in simulated physiological fluids using a dynamic testing procedure. Fibers of different chemical composition and obtained by different processes with a mean diameter of about 1 micron, have been characterized with respect to their solubility under various test conditions of flow-rate. The surfaces were analyzed using scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and X-ray diffraction techniques. SEM examinations show the formation of various corrosion patterns: porous, gel-like outer layers; precipitation zones and even, in some cases, no modification of the surface aspect. EDS analyses performed on the fibers, on the fiber surface layers, or on the deposits show three types of chemical composition: areas enriched in Al, in Ca and P, or in Al, Ca, and P. These surface compositions can be found for the same type of fiber tested, depending on the flow rate of the solution. Surface changes depend strongly on the initial composition of the glass and on the test conditions, particularly the flow rate. It is of particular interest to characterize the remaining surfaces (if any) obtained at the end of the in vitro test run and to compare them with surface analysis of the recovered fibers from the in vivo tests to assess the validity of the in vitro tests. Images Figure 1. A Figure 1. A Figure 1. B Figure 1. B PMID:7882960

  5. Large temperature sensitivity of fiber-optic extrinsic Fabry-Perot interferometer based on polymer-filled glass capillary

    NASA Astrophysics Data System (ADS)

    Zhang, Guilin; Yang, Minghong; Wang, Min

    2013-12-01

    A novel and low cost fiber-optic extrinsic Fabry-Perot interferometer (EFPI) is proposed. The EFPI is fabricated at the fiber tip by inserting a single mode fiber (SMF) into a partially polymer-filled glass capillary to form an air micro-cavity, which can be precisely controlled with a three-dimensional translation stage. The optimal EFPI has a loss less than 10 dB and a fringe visibility more than 30 dB. Application of the EFPI for temperature measurement is experimentally demonstrated. Due to the high thermal expansion coefficient (TEC) of the polymer, the sensor exhibits a good linear response and large temperature sensitivity of ˜5.2 nm/°C, which is almost three orders larger than that of the current F-P temperature sensors. Therefore, it may be applied to the surrounding temperature sensing.

  6. The influence of glass fibers on elongational viscosity studied by means of optical coherence tomography and X-ray computed tomography

    SciTech Connect

    Aigner, M. Köpplmayr, T. E-mail: Christian.lang@jku.at; Lang, C. E-mail: Christian.lang@jku.at; Burzic, I. E-mail: juergen.miethlinger@jku.at; Miethlinger, J. E-mail: juergen.miethlinger@jku.at; Salaberger, D.; Buchsbaum, A. Leitner, M.; Heise, B.; Schausberger, S. E. Stifter, D.

    2014-05-15

    We report on the flow characteristics of glass-fiber-reinforced polymers in elongational rheometry. Unlike polymers with geometrically isotropic fillers, glass-fiber-reinforced polymers exhibit flow behavior and rheology that depend heavily on the orientation, the length distribution and the content of the fibers. One of the primary objectives of this study was to determine the effect of fiber orientation, concentration and distribution on the entrance pressure drop by means of optical coherence tomography (OCT), full-field optical coherence microscopy (FF-OCM), and X-ray computed tomography (X-CT). Both pressure drop and melt flow were analyzed using a special elongation die (Thermo Scientific X-Die [3]) for inline measurements. Samples with a variety of fiber volume fractions, fiber lengths and processing temperatures were measured.

  7. Influence of screw holes and gamma sterilization on properties of phosphate glass fiber-reinforced composite bone plates.

    PubMed

    Han, Na; Ahmed, Ifty; Parsons, Andrew J; Harper, Lee; Scotchford, Colin A; Scammell, Brigitte E; Rudd, Chris D

    2013-05-01

    Polymers prepared from polylactic acid (PLA) have found a multitude of uses as medical devices. For a material that degrades, the main advantage is that an implant would not necessitate a second surgical event for removal. In this study, fibers produced from a quaternary phosphate-based glass (PBG) in the system 50P2O5-40CaO-5Na2O-5Fe2O3 were used to reinforce PLA polymer. The purpose of this study was to assess the effect of screw holes in a range of PBG-reinforced PLA composites with varying fiber layup and volume fraction. The flexural properties obtained showed that the strength and modulus values increased with increasing fiber volume fraction; from 96 MPa to 320 MPa for strength and between 4 GPa and 24 GPa for modulus. Furthermore, utilizing a larger number of thinner unidirectional (UD) fiber prepreg layers provided a significant increase in mechanical properties, which was attributed to enhanced wet out and thus better fiber dispersion during production. The effect of gamma sterilization via flexural tests showed no statistically significant difference between the sterilized and nonsterilized samples, with the exception of the modulus values for samples with screw holes. Degradation profiles revealed that samples with screw holes degraded faster than those without screw holes due to an increased surface area for the plates with screw holes in PBS up to 30 days. Scanning electron microscope (SEM) analysis revealed fiber pullout before and after degradation. Compared with various fiber impregnation samples, with 25% volume fraction, 8 thinner unidirectional prepreg stacked samples had the shortest fiber pull-out lengths in comparison to the other samples investigated. PMID:22207606

  8. Accessory fissures of the lung

    SciTech Connect

    Godwin, D.; Tarver, R.D.

    1985-01-01

    Accessory fissures of the lung are commonly observed in lung specimens, but are often unappreciated or misinterpreted in radiographs and computer tomographic (CT) scans. They usually occur at the boundaries between bronchopulmonary segments. Most common are the inferior accessory fissure, which demarcates the medial basal segment; the superior accessory fissure, which demarcates the superior segment; and the left minor fissure, which demarcates the lingula. This essay will illustrate the findings of the common accessory fissures both on plain radiographs and on CT scans.

  9. Influence of instrumentation techniques and irrigating solutions on bond strength of glass fiber posts to root dentin.

    PubMed

    Marques, Eduardo Fernandes; Bueno, Carlos Eduardo da Silveira; Veloso, Heloisa Helena Pinho; Almeida, Gustavo; Pinheiro, Sergio Luiz

    2014-01-01

    This study sought to evaluate how instrumentation techniques and irrigating solutions affected the bond strength of glass fiber posts. For this study, 80 human maxillary central incisors were selected. Endodontic access was obtained, root canal length was measured, and the coronal third was prepared using Gates-Glidden drills. The specimens were embedded in acrylic resin and randomly assigned to 8 groups (n = 10): manual instrumentation only (Group 1), rotary instrumentation only (Group 2), irrigation with 2.5% sodium hypochlorite (NaOCl) (Group 3), irrigation with 2% chlorhexidine (CHX) (Group 4), manual instrumentation and irrigation with 2.5% NaOCl (Group 5), manual instrumentation and irrigation with 2% CHX (Group 6), rotary instrumentation and irrigation with 2.5% NaOCl (Group 7), and rotary instrumentation and irrigation with 2% CHX (Group 8). Specimens in Groups 5-8 also received a 1 minute final rinse with ethylenediaminetetraacetic acid. Canals were filled and the specimens stored for 30 days in distilled water. The restoration material was removed down to the apical 4 mm of the root canal. The glass fiber posts were luted with resin cement and stored for 24 hours at 37°C. Specimens were subjected to a tensile strength test at a constant speed of 1.0 mm/minute and a load of 2,000 kgf. The results were analyzed by analysis of variance and Tukey's test. Irrigation with 2.5% NaOCl reduced the bond strength of fiber posts significantly (P < 0.01), while CHX showed no effect (P > 0.05). It was concluded that irrigation with 2.5% NaOCl has a negative effect on micromechanical retention of glass fiber posts, whether manual or rotary instrumentation is used.

  10. Bilateral accessory thoracodorsal artery.

    PubMed

    Natsis, Konstantinos; Totlis, Trifon; Tsikaras, Prokopios; Skandalakis, Panagiotis

    2006-09-01

    The subscapular artery arises from the third part of the axillary artery and gives off the circumflex scapular and the thoracodorsal arteries. Although anatomical variations of the axillary artery are very common, the existence of a unilateral accessory thoracodorsal artery has been described in the literature only once. There are no reports of bilateral accessory thoracodorsal artery, in the literature. In the present study, a bilateral accessory thoracodorsal artery, originating on either side of the third part of the axillary artery, is described in a 68-year-old female cadaver. All the other branches of the axillary artery had a typical origin, course, distribution and termination. This extremely rare anatomical variation apart from the anatomical importance also has clinical significance for surgeons in this area. Especially, during the dissection or mobilization of the latissimus dorsi that is partly used for coverage problems in many regions of the body and also in dynamic cardiomyoplasty, any iatrogenic injury of this accessory artery may result in ischemia and functional loss of the graft.

  11. Accessory parotid gland tumors

    PubMed Central

    Ramachar, Sreevathsa M.; Huliyappa, Harsha A.

    2012-01-01

    Tumors of accessory parotid gland are considered in the differential diagnosis of a mid cheek mass. Parotidectomy is the procedure of choice. All pathological types of parotid main gland tumors occur in the accessory parotid gland also. Presenting as a mid cheek or infrazygomatic mass, the tumors of this accessory parotid gland are notorious for recurrences, if adequate margins are not achieved. We describe two such cases of such a tumor. 40-year-old male with a slowly progressive mid cheek mass was operated by a mid cheek incision. Histopathology of the tumor was pleomorphic adenoma. Facial nerve paresis recovered complelety in 6 months. A 52-year-old female with progressive mid cheek mass who underwent parotidectomy and neck dissection by a modified Blair's incision was diagnosed with extranodal marginal zone lymphoma with focal transformation to a diffuse large B-cell lymphoma. Chemotherapy with CHOP regime was initiated. There was no recurrence at 6 months of follow-up. Lymphoma of accessory parotid gland is a very rare tumor. Standard parotidectomy incision is advocated to prevent damage to facial nerve branches. PMID:23483721

  12. Intense visible upconversion and energy transfer in Ho3+/Yb3+ codoped tellurite glasses for potential fiber laser

    NASA Astrophysics Data System (ADS)

    Peng, Shengxi; Wu, Libo; Wang, Bo; Yang, Fengjing; Qi, Yawei; Zhou, Yaxun

    2015-03-01

    New Ho3+/Yb3+ codoped tellurite glasses (TeO2-Bi2O3-ZnO-Na2O) prepared by melt-quenching technique were investigated to realize visible-band upconversion emissions applied for compact fiber lasers. The absorption spectra, upconversion emission spectra, differential scanning calorimetry (DSC) curves, X-ray diffraction (XRD) and Raman spectra were measured to characterize the spectroscopic properties of Ho3+, thermal stability and structural nature of glass hosts. Under the excitation of 980 nm laser diode (LD), the intense green (∼543 nm) and red (∼657 nm) upconversion emissions corresponding to 5F4(5S2) → 5I8 and 5F5 → 5I8 transitions of Ho3+ respectively are simultaneously observed. The power dependence study of upconversion intensities on excited pump power revealed that the Ho3+ population at 5F4(5S2) and 5F5 levels was originated from two-photon absorption process based on the energy transfer from Yb3+ to Ho3+. The energy transfer mechanism from Yb3+ to Ho3+ was investigated and relevant micro-parameters (energy transfer coefficient and critical radius) and phonon contribution ratio were presented. With the increase of Yb3+ doped concentration, both the green and red upconversion intensities enhanced greatly, meanwhile the thermal stability of glass hosts, characterized by the three characteristic temperatures, also got a slight improvement. Furthermore, the glass structure was briefly analyzed with the calculated Judd-Ofelt intensity parameters, the measured Raman spectra and XRD curves. The present results indicate that the new synthesized Ho3+/Yb3+ codoped tellurite glass with intense green and red upconversion emissions is a promising medium applied for the visible-band fiber lasers.

  13. Enhanced osteoprogenitor elongated collagen fiber matrix formation by bioactive glass ionic silicon dependent on Sp7 (osterix) transcription.

    PubMed

    Varanasi, Venu G; Odatsu, Tetsurou; Bishop, Timothy; Chang, Joyce; Owyoung, Jeremy; Loomer, Peter M

    2016-10-01

    Bioactive glasses release ions, those enhance osteoblast collagen matrix synthesis and osteogenic marker expression during bone healing. Collagen matrix density and osteogenic marker expression depend on osteogenic transcription factors, (e.g., Osterix (OSX)). We hypothesize that enhanced expression and formation of collagen by Si(4+) depends on enhanced expression of OSX transcription. Experimental bioactive glass (6P53-b) and commercial Bioglass(TM) (45S5) were dissolved in basal medium to make glass conditioned medium (GCM). ICP-MS analysis was used to measure bioactive glass ion release rates. MC3T3-E1 cells were cultured for 20 days, and gene expression and extracellular matrix collagen formation was analyzed. In a separate study, siRNA was used to determine the effect of OSX knockdown on impacting the effect of Si(4+) on osteogenic markers and matrix collagen formation. Each bioactive glass exhibited similar ion release rates for all ions, except Mg(2+) released by 6P53-b. Gene expression results showed that GCM markedly enhanced many osteogenic markers, and 45S5 GCM showed higher levels of expression and collagen matrix fiber bundle density than 6P53-b GCM. Upon knockdown of OSX transcription, collagen type 5, alkaline phosphatase, and matrix density were not enhanced as compared to wild type cells. This study illustrates that the enhancement of elongated collagen fiber matrix formation by Si(±) depends on OSX transcription. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2604-2615, 2016. PMID:27279631

  14. A Comparative Evaluation of Effect of Different Chemical Solvents on the Shear Bond Strength of Glass Fiber reinforced Post to Core Material

    PubMed Central

    Samadi, Firoza; Jaiswal, JN; Saha, Sonali

    2014-01-01

    ABSTRACT% Aim: To compare the effect of different chemical solvents on glass fiber reinforced posts and to study the effect of these solvents on the shear bond strength of glass fiber reinforced post to core material. Materials and methods: This study was conducted to evaluate the effect of three chemical solvents, i.e. silane coupling agent, 6% H2O2 and 37% phosphoric acid on the shear bond strength of glass fiber post to a composite resin restorative material. The changes in post surface characteristics after different treatments were also observed, using scanning electron microscopy (SEM) and shear bond strength was analyzed using universal testing machine (UTM). Results: Surface treatment with hydrogen peroxide had greatest impact on the post surface followed by 37% phosphoric acid and silane. On evaluation of the shear bond strength, 6% H2O2 exhibited the maximum shear bond strength followed in descending order by 37% phosphoric acid and silane respectively. Conclusion: The surface treatment of glass fiber post enhances the adhesion between the post and composite resin which is used as core material. Failure of a fiber post and composite resin core often occurs at the junction between the two materials. This failure process requires better characterization. How to cite this article: Sharma A, Samadi F, Jaiswal JN, Saha S. A Comparative Evaluation of Effect of Different Chemical Solvents on the Shear Bond Strength of Glass Fiber Reinforced Post to Core Material. Int J Clin Pediatr Dent 2014;7(3):192-196. PMID:25709300

  15. [Occurrence and structure of accessory adrenal glands in Wistar rats].

    PubMed

    Schwabedal, P E; Partenheimer, U

    1983-01-01

    In complete series of histological sections through the entire abdomen of one normal Wistar-rat, one untreated and two bilaterally adrenalectomized, spontaneously hypertensive Wistar-rats accessory suprarenal glands were found in each case. The detailed findings in the various groups of animals investigated were as follows: (1) In the normal animal 10 accessory suprarenal glands were present. They consisted of tiny aggregates of cortical cells and were surrounded by a thin layer of collageneous fibers. The diameters of the accessory suprarenal complexes were in the order of 0.3 mm. (2) In the untreated, spontaneously hypertensive rat three accessory suprarenal glands were found. However, in contrast to what was seen in the normal rat, these complexes were larger and had diameters of up to 1 mm. Some of these accessory suprarenal glands consisted almost exclusively of small, chromophobe cells, whereas in others a rim of such cells was seen to surround a central core of larger and more acidophile cortical cells. There were few and collapsed capillaries. (3) In the bilaterally adrenalectomized, spontaneously hypertensive rats three, respectively four, accessory suprarenal glands were found. They were situated in the retroperitoneum and partly within the adipose capsule of the kidney but never in the place of the exstirpated main suprarenal glands. In one case an accessory gland was found within the fibrous capsule of the kidney and seen to compress the renal parenchyma. In the bilaterally adrenalectomized animals the average diameters of the accessory glands were larger than in the other groups reaching values of up to 5 mm. At least in both animals one of the accessory glands had a diameter comparable to that of the normal suprarenal gland of an untreated animal. The capillaries were dilated and their number was increased in comparison to what was seen in the other groups. In certain regions the cortical tissue of the accessory glands had an appearance resembling

  16. Atomically smooth hybrid crystalline-core glass-clad fibers for low-loss broadband wave guiding.

    PubMed

    Lai, Chien-Chih; Lo, Chia-Yao; Nguyen, Duc Huy; Huang, Jian-Zhi; Tsai, Wan-Shao; Ma, Yuan-Ron

    2016-09-01

    We demonstrate direct evidence for the first realization of atomically smooth sapphire crystalline fiber cores with a surface variation of only ~1.9 Å. The hybrid glass-clad crystalline cores were grown by a laser-based fiber drawing technique. Because of the improvement in crystal fiber quality, we were able, for the first time, to comprehensively and quantitatively elucidate the correlation between fiber nanostructure and optical loss. We also experimentally demonstrated that high-temperature treatment has a significant impact on defect relaxation and promotes excellent crystallinity, and hence enables low-loss optical wave guiding. The experimentally measured propagation losses in the order of 0.01-0.1 dB/cm are the lowest ever reported among conventional Ti:sapphire channel waveguides and ultrafast-laser-inscribed waveguides, and agree well with the theory. Through experiments and numerical calculation, we have demonstrated that low threshold and high efficiency of Ti:sapphire crystal fiber lasers are possible with the atomic-level roughness, low-loss propagation, and high crystallinity of the Ti:sapphire crystalline core. PMID:27607618

  17. Ge-Sb-Se glass fiber-optics for in-vivo mid-infrared optical biopsy

    NASA Astrophysics Data System (ADS)

    Parnell, H.; Butterworth, J. H.; Sakr, H.; Tang, Z.; Furniss, D.; Benson, T. M.; Scotchford, C.; Seddon, A. B.

    2016-03-01

    In the UK, it is now recognised that 1 in 2 people born after 1960 will develop some form of cancer during their lifetime. Diagnosing patients whilst in the early stages drastically improves their chances of survival but up until now the gold standard for cancer detection is via a lengthy excision biopsy procedure, which relies on the skill of a histopathologist. Evidently, the need for a faster solution is paramount. The mid-infrared (MIR) spectral region covers the wavelengths 3-25 μm and characteristic vibrational spectra unique to each molecular type. Subtle changes in the specific spectral response within this region are indicative of changes within the cells relative to normal cells, signifying the presence or absence of a disease. Our goal is to carry out disease diagnosis in vivo. Reaching these wavelengths has previously presented difficulties as conventional MIR blackbody light sources are weak and optical fibers for transmitting MIR light to/from tissue in vivo can be limited by strong material absorption such as silica glass >2.4 μm and tellurite, and heavy metal fluoride, >4.75 μm. However, chalcogenide glasses have been shown to transmit MIR light out to 25 μm. This paper reports on a glass composition in the Ge-Sb-Se system and its suitability as an optical fiber for the transmission of MIR to and from tissue samples, enabling in vivo mapping for an immediate diagnostic response- a technique termed `optical biopsy'.

  18. Bone plate composed of a ternary nano-hydroxyapatite/polyamide 66/glass fiber composite: biomechanical properties and biocompatibility

    PubMed Central

    Qiao, Bo; Li, Jidong; Zhu, Qingmao; Guo, Shuquan; Qi, Xiaotong; Li, Weichao; Wu, Jun; Liu, Yang; Jiang, Dianming

    2014-01-01

    An ideal bone plate for internal fixation of bone fractures should have good biomechanical properties and biocompatibility. In this study, we prepared a new nondegradable bone plate composed of a ternary nano-hydroxyapatite/polyamide 66/glass fiber (n-HA/PA66/GF) composite. A breakage area on the n-HA/PA66/GF plate surface was characterized by scanning electron microscopy. Its mechanical properties were investigated using bone-plate constructs and biocompatibility was evaluated in vitro using bone marrow-derived mesenchymal stem cells. The results confirmed that adhesion between the n-HA/PA66 matrix and the glass fibers was strong, with only a few fibers pulled out at the site of breakage. Fractures fixed by the n-HA/PA66/GF plate showed lower stiffness and had satisfactory strength compared with rigid fixation using a titanium plate. Moreover, the results with regard to mesenchymal stem cell morphology, MTT assay, Alizarin Red S staining, enzyme-linked immunosorbent assay, and reverse transcription polymerase chain reaction for alkaline phosphatase and osteocalcin showed that the n-HA/PA66/GF composite was suitable for attachment and proliferation of mesenchymal stem cells, and did not have a negative influence on matrix mineralization or osteogenic differentiation of mesenchymal stem cells. These observations indicate that the n-HA/PA66/GF plate has good biomechanical properties and biocompatibility, and may be considered a new option for internal fixation in orthopedic surgery. PMID:24669191

  19. Microscopic study of surface degradation of glass fiber-reinforced polymer rods embedded in concrete castings subjected to environmental conditioning

    SciTech Connect

    Bank, L.C.; Puterman, M.

    1997-12-31

    The surface degradation of glass fiber-reinforced polymer (GFRP) pultruded rods when embedded in concrete castings and subjected to environmental conditioning is discussed in this paper. Investigation of the degradation of the GFRP rods were performed using optical microscopy and scanning electron microscopy (SEM). Unidirectionally reinforced pultruded rods (6.3- and 12.7-mm diameters) containing E-glass fibers in polyester and vinylester matrices were conditioned at standard laboratory conditions (21 C, 65% relative humidity) or submerged in aqueous solutions (tap water) at 80 C for durations of 14 and 84 days. Observations of the surfaces and cross-sections of the rods by optical microscopy and SEM revealed a variety of degradation phenomena. Embedded hygrothermally conditioned rods were found to have developed surface blisters of different sizes and depths. SEM studies of the surface revealed degradation of the polymer matrix material and exposure and degradation of the fibers close to the surface of the rods. The rods with the vinylester resin matrix showed less extensive degradation than those with the polyester resin matrix; however, the degradation characteristics of the two types of rods appear to be similar.

  20. Fracture resistance of tooth restored with four glass fiber post systems of varying surface geometries-An in vitro study

    PubMed Central

    Solomon-Sathish, Emmanuel; Venkatalakshmi-Aparna, Potluri; Balagopal, Sunderasan

    2016-01-01

    Background The purpose of this study was to relate the fracture resistance of endodontically treated teeth in relation to post geometry. Material and Methods Forty single rooted mandibular premolars were instrumented by step - back technique and obturated by lateral condensation. Forty teeth were randomly divided into four groups: Reforpost glass fiber X-ray®, RelyX®, Exacto conical® and Parapost Fiber Lux®. The post spaces were prepared using respective drills and luted. The core build up was done and metal crowns were luted. Fracture resistance was determined in universal testing machine. The statistical analysis was done using one way ANOVA and post hoc Tukey Kramer test. Results The teeth restored with Reforpost showed highest fracture resistance followed by Parapost and Exacto conical. The teeth restored with RelyX showed least fracture resistance. The teeth restored with Parapost had less unfavourable fracture followed by exacto conical. Conclusions Parallel design had less number of catastrophic failure and had better fracture resistance. Key words:Fracture resistance, glass fiber post, post geometry, stress. PMID:26855705

  1. Bone plate composed of a ternary nano-hydroxyapatite/polyamide 66/glass fiber composite: biomechanical properties and biocompatibility.

    PubMed

    Qiao, Bo; Li, Jidong; Zhu, Qingmao; Guo, Shuquan; Qi, Xiaotong; Li, Weichao; Wu, Jun; Liu, Yang; Jiang, Dianming

    2014-01-01

    An ideal bone plate for internal fixation of bone fractures should have good biomechanical properties and biocompatibility. In this study, we prepared a new nondegradable bone plate composed of a ternary nano-hydroxyapatite/polyamide 66/glass fiber (n-HA/PA66/GF) composite. A breakage area on the n-HA/PA66/GF plate surface was characterized by scanning electron microscopy. Its mechanical properties were investigated using bone-plate constructs and biocompatibility was evaluated in vitro using bone marrow-derived mesenchymal stem cells. The results confirmed that adhesion between the n-HA/PA66 matrix and the glass fibers was strong, with only a few fibers pulled out at the site of breakage. Fractures fixed by the n-HA/PA66/GF plate showed lower stiffness and had satisfactory strength compared with rigid fixation using a titanium plate. Moreover, the results with regard to mesenchymal stem cell morphology, MTT assay, Alizarin Red S staining, enzyme-linked immunosorbent assay, and reverse transcription polymerase chain reaction for alkaline phosphatase and osteocalcin showed that the n-HA/PA66/GF composite was suitable for attachment and proliferation of mesenchymal stem cells, and did not have a negative influence on matrix mineralization or osteogenic differentiation of mesenchymal stem cells. These observations indicate that the n-HA/PA66/GF plate has good biomechanical properties and biocompatibility, and may be considered a new option for internal fixation in orthopedic surgery. PMID:24669191

  2. Effect of Reinforcement Using Stainless Steel Mesh, Glass Fibers, and Polyethylene on the Impact Strength of Heat Cure Denture Base Resin - An In Vitro Study

    PubMed Central

    Murthy, H B Mallikarjuna; Shaik, Sharaz; Sachdeva, Harleen; Khare, Sumit; Haralur, Satheesh B; Roopa, K T

    2015-01-01

    Background: The impact strength of denture base resin is of great concern and many approaches have been made to strengthen acrylic resin dentures. The objective of this study was to compare the impact strength of the denture base resin with and without reinforcement and to evaluate the impact strength of denture base resin when reinforced with stainless steel mesh, glass fiber, and polyethylene fibers in the woven form. Materials and Methods: The specimens (maxillary denture bases) were fabricated using a standard polyvinylsiloxane mold with conventional heat cured polymethyl methacrylate resin. The specimens were divided into four groups (n = 10). Group I specimens or control group were not reinforced. Group II specimens were reinforced with stainless steel mesh and Group III and Group IV specimens were reinforced with three percent by weight of glass fibers and polyethylene fibers in weave form respectively. All the specimens were immersed in water for 1-week before testing. The impact strength was measured with falling weight impact testing machine. One-way analysis of variance and Tukey’s post-hoc test were used for statistical analysis. Results: Highest impact strength values were exhibited by the specimens reinforced with polyethylene fibers followed by glass fibers, stainless steel mesh, and control group. Conclusions: Reinforcement of maxillary complete dentures showed a significant increase in impact strength when compared to unreinforced dentures. Polyethylene fibers exhibit better impact strength followed by glass fibers and stainless steel mesh. By using pre-impregnated glass and polyethylene fibers in woven form (prepregs) the impact strength of the denture bases can be increased effectively. PMID:26124604

  3. Pump absorption and temperature distribution in erbium-doped double-clad fluoride-glass fibers.

    PubMed

    Gorjan, Martin; Marincek, Marko; Copic, Martin

    2009-10-26

    We investigate diode pump absorption and temperature distribution in three erbium-doped double-clad fluoride fibers. Absorption is measured via fluorescence intensity and temperature distribution is measured with thermal imaging. Ray-tracing calculations of absorption and heat-equation modeling of temperature distribution are also conducted. We found excellent agreement between measurements and calculations for all fibers. Results indicate that erbium-doped fluoride fiber lasers have already reached maximum output powers allowed under natural convection cooling, with fiber end being the most critical. We propose cooling and fiber design optimizations that may allow an order-of-magnitude further power-scaling.

  4. Comparison of selected optical properties of oxyfluoride glass fibers doped with Er3+ and co-doped with Er3+ Yb3+

    NASA Astrophysics Data System (ADS)

    Augustyn, E.; Stremplewski, P.; Rozanski, M.; Koepke, C.; Dominiak-Dzik, G.; Kępińska, M.; Żelechower, M.

    2011-12-01

    The method of manufacturing and spectroscopic evaluation of the Er3+ ions doped and Er3+-Yb3+co-doped SiO2-Al2O3-Na2CO3-CaO-PbO-PbF2 oxyfluoride glass fibers is presented in the paper. Both optically active elements erbium and ytterbium were introduced into the batch in the form of fluorides. The X-ray diffraction (XRD) technique was applied at each stage of fibers manufacturing in order to control an amorphous structure of the preforms and fibers. Optical studies of glass preforms and fibers (reflection/transmission, absorption, emission, and excited state absorption (ESA)) were directed to examine their suitability as fiber amplifiers at 1.55 μm band.

  5. Glass-fiber-based neutron detectors for high- and low-flux environments

    NASA Astrophysics Data System (ADS)

    Bliss, Mary; Brodzinski, Ronald L.; Craig, Richard A.; Geelhood, Bruce D.; Knopf, Michael A.; Miley, Harry S.; Perkins, Richard W.; Reeder, Paul L.; Sunberg, Debra S.; Warner, Ray A.; Wogman, Ned A.

    1995-09-01

    Pacific Northwest Laboratory (PNL) has fabricated cerium-activated lithium silicate scintillating fibers via a hot-downdraw process. These fibers typically have a operational transmission length (e(superscript -1) length) of greater than 2 meters. This permits the fabrication of devices which were not possible to consider. Scintillating fibers permit conformable devices, large-area devices, and extremely small devices; in addition, as the thermal-neutron sensitive elements in a fast neutron detection system, scintillating fibers can be dispersed within moderator, improving neutron economy, over that possible with commercially available (superscript 3)He or BF(subscript 3) proportional counters. These fibers can be used for national-security applications, in medical applications, in the nuclear-power industry, and for personnel protection at experimental facilities. Data are presented for devices based on single fibers and devices made up of ribbons containing many fibers under high-and low-flux conditions.

  6. Fracture Strength of Endodontically Treated Teeth Restored with Casting Post and Core and Glass-Fiber with Composite Core

    PubMed Central

    Saatian, Sedigheh

    2006-01-01

    INTRODUCTION: Prefabricated metal and ceramic posts can be used with different kinds of core materials as an alternative to the conventional casting post and cores. It is unclear how these post and core systems can withstand different kind of forces in the mouth. The purpose of this study was to compare the fracture strength of endodontically treated, crowned maxillary incisors restored with casting post and cores and glass- fiber post with composite core and to evaluate their mode of fractures. MATERIALS AND METHODS: Thirty caries free, human maxillary central incisors with incisoapical length of 23 ± 1 mm were divided into two groups. After root canal treatment procedures and decronation of teeth 2mm above cementoenamel junction, Grope 1 was restored with glass- fiber posts and composite cores and group 2 received casting post and cores. Teeth were prepared with a circumferential shoulder including a 1-2 mm ferrule and 0.5 mm bevel; all posts were cemented with an adhesive resin and teeth were restored with complete coverage crowns. Loads were applied at an angle of 135 degrees using a universal testing machine. Compression force was applied until the specimens fractured. RESULTS: The median fracture strengths of groups 1 and 2 were 459 and 686 respectively (p<0.5). In group I, all fractures occurred in incisal third of roots. In groups II, 40% of fractures were in apical third and middle of roots. CONCLUSION: Within the limitation of this study, the results suggested that glass fiber with composite cores can be used as an alternative to cast posts and cores in anterior teeth when creating 2mm ferrule effect was possible in normal occlusion. Clinical trial is required to verify these in vitro results. PMID:24470803

  7. Influence of antimicrobial solutions in the decontamination and adhesion of glass-fiber posts to root canals

    PubMed Central

    HARAGUSHIKU, Gisele Aihara; BACK, Eduardo Donato Eing Engelke; TOMAZINHO, Paulo Henrique; BARATTO, Flares; FURUSE, Adilson Yoshio

    2015-01-01

    Objective This study evaluated the effect of root canal disinfectants on the elimination of bacteria from the root canals, as well as their effect on glass-fiber posts bond strength. Material and Methods Fifty-three endodontically treated root canals had post spaces of 11 mm in length prepared and contaminated with E. faecalis. For CFU/ml analysis, eight teeth were contaminated for 1 h or 30 days (n=4). Teeth were decontaminated with 5% NaOCl, 2% CHX, or distilled water. As control, no decontamination was conducted. After decontamination, sterile paper points were used to collect samples, and CFU/ml were counted. For push-out, three groups were evaluated (n=15): irrigation with 2.5% NaOCl, 2% CHX, or sterile distilled water. A bonding agent was applied to root canal dentin, and a glass-fiber post was cemented with a dual-cured cement. After 24 h, 1-mm-thick slices of the middle portion of root canals were obtained and submitted to the push-out evaluation. Three specimens of each group were evaluated in scanning electron microscopy (SEM). Data were analyzed with one-way ANOVA and Dunnett’s T3 test (α=0.05). Results The number of CFU/ml increased from 1 h to 30 days of contamination in control and sterile distilled water groups. Decontamination with NaOCl was effective only when teeth were contaminated for 1 h. CHX was effective at both contamination times. NaOCl did not influence the bond strength (p>0.05). Higher values were observed with CHX (p<0.05). SEM showed formation of resin tags in all groups. Conclusion CHX showed better results for the irrigation of contaminated root canals both in reducing the bacterial contamination and in improving the glass-fiber post bonding. PMID:26398518

  8. A glass-coated tungsten microelectrode enclosing optical fibers for optogenetic exploration in primate deep brain structures.

    PubMed

    Tamura, Keita; Ohashi, Yohei; Tsubota, Tadashi; Takeuchi, Daigo; Hirabayashi, Toshiyuki; Yaguchi, Masae; Matsuyama, Makoto; Sekine, Takeru; Miyashita, Yasushi

    2012-10-15

    The optogenetic approach to primate brain circuitry has unparalleled potential for uncovering genetically and temporally resolved neuronal mechanisms of higher brain functions. In order to optogenetically investigate the large and complex primate brain, an optical-/electrical probe, or "optrode", must be inserted deeply, which requires the optrode to be not only long and stiff, but also sharp and smooth to reduce possible tissue damage. This study presents a tungsten microelectrode-based optrode that encloses optical fibers within its insulation glass. Optical fibers and a tungsten wire were tightly bound to each other and integrally coated with a smooth, thin layer of glass. This design satisfied the structural requirements for use in deep brain structures. The performance of the optrode was then examined in the thalamus of the rat and macaque monkeys which were injected with lentiviral vectors carrying the channelrhodopsin-2-enhanced yellow fluorescent protein (ChR2-EYFP) transgene. With fluorescence measurements via the optical fiber, ChR2-EYFP expression was detected clearly in vivo, which was confirmed by histological analysis in the rat. With photostimulation and extracellular recording, photo-responsive single-unit activities were isolated in the monkeys. The depth distribution of these units and the peak of the EYFP fluorescence profile overlapped consistently with each other. Thus, by developing a new probe, optogenetic methodology was successfully applied to a primate subcortical structure. This smooth glass-coated optrode is a promising tool for chronic in vivo experiments with various research targets including deep brain structures in behaving monkeys. PMID:22971353

  9. Iatrogenic accessory nerve injury.

    PubMed Central

    London, J.; London, N. J.; Kay, S. P.

    1996-01-01

    Accessory nerve injury produces considerable disability. The nerve is most frequently damaged as a complication of radical neck dissection, cervical lymph node biopsy and other surgical procedures. The problem is frequently compounded by a failure to recognise the error immediately after surgery when surgical repair has the greatest chance of success. We present cases which outline the risk of accessory nerve injury, the spectrum of clinical presentations and the problems produced by a failure to recognise the deficit. Regional anatomy, consequences of nerve damage and management options are discussed. Diagnostic biopsy of neck nodes should not be undertaken as a primary investigation and, when indicated, surgery in this region should be performed by suitably trained staff under well-defined conditions. Awareness of iatrogenic injury and its consequences would avoid delays in diagnosis and treatment. Images Figure 2 PMID:8678450

  10. Incorporation of Deoxyribonucleic Acid Precursors by T4 Deoxyribonucleic Acid-Protein Complexes Retained on Glass Fiber Filters

    PubMed Central

    Miller, Robert C.; Kozinski, Andrzej W.

    1970-01-01

    Bacteriophage T4 deoxyribonucleic acid (DNA)-protein complexes were retained preferentially on glass fiber filters. DNA polymerase activity in the complex was detected through the incorporation of 3H-labeled DNA precursors. The primer-product DNA hybridized with both phage and Escherichia coli DNA. Density labeling experiments showed that about 30% of incorporated 3H-deoxyadenosine triphosphate was found in DNA which hybridized with phage DNA; this DNA was found to be covalently attached to the primer DNA. PMID:5497903

  11. Health monitoring of precast bridge deck panels reinforced with glass fiber reinforced polymer bars

    NASA Astrophysics Data System (ADS)

    Ries, James Mcdaniel

    The Beaver Creek Bridge on US highway 6 is the pilot project for Glass Fiber Reinforced Polymer (GFRP) bridge decks and posttensioned bridge decks in the state of Utah. The bridge was built in 2009, using accelerated bridge construction practices, including the use of precast prestressed girders, as well as precast decking. The westbound bridge decking was composed of 12 precast panels each measuring 41'-5" long, 6'-10" wide, and 9¼" thick, and weighing approximately 33 kips. At the time, these panels were the longest GFRP panels in the United States. The Utah Department of Transportation has decided to evaluate GFRP reinforcing bars as an alternative to steel rebar in this bridge deck. The hope is to increase the lifespan of bridge decks to match the service life of the entire bridge. Due to the nature of the GFRP bars, the panels were lifted at four points using straps instead of imbedded anchors. During the four-point lifting, the panels exhibited small deflections and strains; furthermore, no cracks larger than hairline cracks were found in the panels after lifting. The Beaver Creek Bridge deck is the first precast deck in the state of Utah to be posttensioned in the direction of traffic. Posttensioning bridge decks is expected to become the norm in the state of Utah. The posttensioning resulted in increased continuity between panels. In order to quantify the expected performance of the bridge during its service life, a truck load test was performed. The truck load test was comprised of a static and dynamic test. During the truck load test, the bridge experienced deflections in the panels which were 93% below design values. Girder deflections were also small. The use of GFRP bars has the potential to extend the life of bridge decks exposed to deicing salts from 45 years to 100 years, while only requiring an increased capital cost in the bridge of 8%. Furthermore, the use of GFRP bars in conjunction with accelerated building practices has the potential to

  12. Improvement of the mode II interface fracture toughness of glass fiber reinforced plastics/aluminum laminates through vapor grown carbon fiber interleaves

    NASA Astrophysics Data System (ADS)

    Ning, Huiming; Li, Yuan; Hu, Ning; Cao, Yanping; Yan, Cheng; Azuma, Takesi; Peng, Xianghe; Wu, Liangke; Li, Jinhua; Li, Leilei

    2014-06-01

    The effects of acid treatment, vapor grown carbon fiber (VGCF) interlayer and the angle, i.e., 0° and 90°, between the rolling stripes of an aluminum (Al) plate and the fiber direction of glass fiber reinforced plastics (GFRP) on the mode II interlaminar mechanical properties of GFRP/Al laminates were investigated. The experimental results of an end notched flexure test demonstrate that the acid treatment and the proper addition of VGCF can effectively improve the critical load and mode II fracture toughness of GFRP/Al laminates. The specimens with acid treatment and 10 g m-2 VGCF addition possess the highest mode II fracture toughness, i.e., 269% and 385% increases in the 0° and 90° specimens, respectively compared to those corresponding pristine ones. Due to the induced anisotropy by the rolling stripes on the aluminum plate, the 90° specimens possess 15.3%-73.6% higher mode II fracture toughness compared to the 0° specimens. The improvement mechanisms were explored by the observation of crack propagation path and fracture surface with optical, laser scanning and scanning electron microscopies. Moreover, finite element analyses were carried out based on the cohesive zone model to verify the experimental fracture toughness and to predict the interface shear strength between the aluminum plates and GFRP laminates.

  13. Linkage of oxygen deficiency defects and rare earth concentrations in silica glass optical fiber probed by ultraviolet absorption and laser excitation spectroscopy.

    PubMed

    Liu, Y-S; Galvin, T C; Hawkins, T; Ballato, J; Dong, L; Foy, P R; Dragic, P D; Eden, J G

    2012-06-18

    Ultraviolet absorption measurements and laser excitation spectroscopy in the vicinity of 248 nm provide compelling evidence for linkages between the oxygen deficiency center (ODC) and rare earth concentrations in Yb and Er-doped glass optical fibers. Investigations of YAG-derived and solution-doped glass fibers are described. For both Yb and Er-doped fibers, the dependence of Type II ODC absorption on the rare earth number density is approximately linear, but the magnitude of the effect is greater for Yb-doped fibers. Furthermore, laser excitation spectra demonstrate unambiguously the existence of an energy transfer mechanism coupling an ODC with Yb(3+). Photopumping glass fibers with a Ti:sapphire laser/optical parametric amplifier system, tunable over the 225-265 nm region, or with a KrF laser at 248.4 nm show: 1) emission features in the 200-1100 nm interval attributable only to the ODC (Type II) defect or Yb(3+), and 2) the excitation spectra for ODC (II) emission at ~280 nm and Yb(3+) fluorescence (λ ~1.03 μm) to be, within experimental uncertainty, identical. The latter demonstrates that, when irradiating Yb-doped silica fibers between ~240 and 255 nm, the ODC (II) defect is at least the primary precursor to Yb(3+) emission. Consistent with previous reports in the literature, the data show the ODC (II) absorption spectrum to have a peak wavelength and breadth of ~246 nm and ~19 nm (FWHM). Experiments also reveal that, in the absence of Yb, incorporating either Al(2)O(3) or Y(2)O(3) into glass fibers has a negligible impact on the ODC concentration. Not only do the data reported here demonstrate the relationship between the ODC (II) number density and the Yb doping concentration, but they also suggest that the appearance of ODC defects in the fiber is associated with the introduction of Yb and the process by which the fiber is formed.

  14. Er(3)/Yb(3)-codoped phosphate glass for short-length high-gain fiber lasers and amplifiers.

    PubMed

    Wang, Fengxiao; Song, Feng; An, Shuangxin; Wan, Wenshun; Guo, Hao; Liu, Shujing; Tian, Jianguo

    2015-02-10

    Er(3)/Yb(3)-codoped phosphate glass with compositions of (78.2-x)P(2)O(5)-14Al(2)O(3)-5Li(2)O-1K(2)O-1.8Yb(2)O(3)-xEr(2)O(3)(x=0.2,0.4,0.6) in mol. % were investigated. Judd-Ofelt (JO) intensity parameters have been calculated to predict radiative properties based on absorption spectra. The stimulated emission cross section (σ(e)) calculated according to McCumber theory was 1.50×10(-20)  cm(2), almost twice larger than values reported before. The effective line width (Δ(eff)), full width at half-maximum (FWHM) and the quality parameters for designing optical amplifier devices were listed in the table compared with other types of phosphate glass matrices. A theoretical model of a Er(3)/Yb(3)-codoped system based on rate and power propagation equations was put forward to investigate the potential advantages of the materials applied for short-length, high-gain fiber amplifiers. A simulated gain of 32.2 and 2.6  dB/cm per unit length was achieved in 12.5-cm-long fiber. PMID:25968040

  15. Photocatalytic oxidation of H2S in the gas phase over TiO2-coated glass fiber filter.

    PubMed

    Brancher, Marlon; Franco, Davide; de Melo Lisboa, Henrique

    2016-11-01

    To promote the photocatalytic oxidation (PCO) of hydrogen sulfide (H2S) in the gas phase, TiO2-coated glass fiber filters were packed in an annular photoreactor. Glass fibers coated with TiO2 thin films were characterized structurally and morphologically by field emission gun scanning electron microscopy (FEG-SEM), scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS) and X-ray diffractometry (XRD). Flow rate and H2S inlet concentration were evaluated to determine the performance of the reactor. Removal efficiencies up to 99% were achieved for flow rate of 25 L h(-1) (residence time of 121 s) and H2S inlet concentration from 12 to 14 ppmv. The long-term experiment presented H2S removal of 89% for 16 h. After 28 h of continuous use, H2S degradation was observed at 64%, which suggests that the photocatalyst was losing activity due to deactivation. Moreover, the kinetics of the PCO of H2S according to the Langmuir-Hinshelwood (L-H) approach along with the mass balance of a plug-flow reactor was modeled. The reaction constant (k) was calculated at approximately 10.5 μmol m(-3) s(-1) and the adsorption constant (K) of approximately 5263 m(-3) mol with linearity (R2) of 0.98.

  16. Disruption of the primary fouling sequence on fiber glass-reinforced plastic submerged in the marine environment.

    PubMed

    Caron, D A; Sieburth, J M

    1981-01-01

    Fiber glass-reinforced plastic immersed in an experimental estuarine mesocosm fouled at estimated rates of 0.5, 5.5, and 18.8 ng (wet weight) mm day over days 0 to 2, 2 to 6, and 6 to 14, respectively. Protists, dominated by diatoms, which developed between days 3 and 6 and covered 90% of the undisturbed surface in 2 weeks, were effectively removed by twice-weekly brushing of the surface to maintain an immature 3-day bacterial film which covered 12% or less of the surface and had a biomass 3 orders of magnitude smaller than surfaces with 2 weeks' unrestricted fouling. Direct brushing of the fiber glass-reinforced plastic tank walls of experimental estuarine mesocosms minimized the "wall effect" by keeping a surface that maintained a low biomass of a slowly accumulating bacterial film rather than a surface which supported the more rapid accumulation of protists which in turn may induce the settlement of invertebrates and macrophytes.

  17. Electroblotting of polypeptides onto glass fiber filters for direct sequence analysis after sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

    PubMed

    Bergman, T; Jörnvall, H

    1990-07-01

    The technique of electroblotting polypeptides onto Polybrene-treated glass fiber filter discs after protein detection with potassium chloride is evaluated further with different proteins in separate applications. The number of proteins analyzed with this method is now more than double that previously reported. Reproducible results in good yield are obtained. Average overall yield--including the electrophoretic step before blotting--is 26%, with maximal recoveries through all steps up to 60%. High sensitivity radiosequence analysis is also applicable. Recent modifications of the previously described procedure include use of Whatman glass fiber filters, removal of air in the Polybrene-impregnated filters by buffer penetration under reduced pressure, and use of widely different times for electrotransfer. Special advantages with this method are low extent of protein alpha-amino group destruction, direct use of the entire filter in the sequencer, and insensitivity to variations in electroblotting time. Gas-phase hydrolysis in situ of blotted proteins followed by amino acid analysis is known to give a low yield of polar amino acids, and often artifacts, but can still give an estimate of the amount of polypeptide immobilized on the filter. A wash with n-butyl chloride is now shown to reduce the Polybrene-associated artifacts, and an addition of sodium chloride to increase the recovery of polar amino acids. These two steps therefore appear interesting in schemes for compositional analyses of electroblotted proteins.

  18. Tensile properties and translaminar fracture toughness of glass fiber reinforced unsaturated polyester resin composites aged in distilled and salt water

    NASA Astrophysics Data System (ADS)

    Sugiman, Gozali, M. Hulaifi; Setyawan, Paryanto Dwi

    2016-03-01

    Glass fiber reinforced polymer has been widely used in chemical industry and transportation due to lightweight and cost effective manufacturing. However due to the ability to absorb water from the environment, the durability issue is of interest for up to days. This paper investigated the water uptake and the effect of absorbed water on the tensile properties and the translaminar fracture toughness of glass fiber reinforced unsaturated polyester composites (GFRP) aged in distilled and salt water up to 30 days at a temperature of 50°C. It has been shown that GFRP absorbed more water in distilled water than in salt water. In distilled water, the tensile strength of GFRP tends to decrease steeply at 7 days and then slightly recovered for further immersion time. In salt water, the tensile strength tends to decrease continually up to 30 days immersion. The translaminar fracture toughness of GFRP aged in both distilled and salt-water shows the similar behavior. The translaminar fracture toughness increases after 7 days immersion and then tends to decrease beyond that immersion time. In the existence of ionics content in salt water, it causes more detrimental effect on the mechanical properties of fiberglass/unsaturated polyester composites compared to that of distilled water.

  19. Thermal energy harvesting for large-scale applications using MWCNT-grafted glass fibers and polycarbonate-MWCNT nanocomposites

    SciTech Connect

    Tzounis, L.; Liebscher, M.; Stamm, M.; Mäder, E.; Pötschke, P.; Logothetidis, S.

    2015-02-17

    The thermoelectric properties of multi-wall carbon nanotube (MWCNT) -grafted glass fiber yarns (GF-CNT) and their epoxy model composites, as well as of polymer nanocomposites consisting of a polycarbonate (PC) matrix filled with differently functionalized MWCNTs have been examined. The GF-CNT hierarchical multi-scale structures were prepared by dip coating glass fiber yarns in a solution of carbonyl chloride modified MWCNTs; MWCNT-COCl (at a concentration of 0.5 mg/ml) under Ar atmosphere. The resulting GF-CNT exhibited high electrical conductivity (σ = 2.1×10{sup 3} S/m) due to the dense MWCNT deposited networks. The fiber surface morphology was investigated by scanning electron microscopy (SEM). The GF-CNT showed Seebeck coefficient (S); S = 16.8 μV/K, and power factor (P.F); P.F = 0.59 μW/mK−2. The high electrical conductivity of the GF-CNT is a key parameter for an optimum thermoelectric performance, since it can facilitate the flow of the thermally induced charge carriers upon being exposed to a temperature gradient. Polycarbonate/MWCNT nanocomposites were prepared by small-scale melt-mixing process using a microcompounder. Unfunctionalized, carboxyl (-COOH) and hydroxyl (-OH) modified MWCNTs were incorporated in PC at a constant amount of 2.5 wt.%, concentration above the electrical percolation threshold. The amount of MWCNTs was kept low to understand the fundamental aspects of their physical properties and their correlation to the composite morphology, as revealed by transmission electron microscopy (TEM). It was found that different functional groups can affect the thermoelectric performance and the conductivity of the nanocomposites. Namely, the highest Seebeck coefficient (S) was found for the composite containing carboxyl functionalized MWCNTs (11.3 μV/K), due to the highest oxygen content of MWCNTs proven by X-Ray Photoelectron spectroscopy (XPS). It is believed that MWCNT-grafted glass fibers as reinforcements in composite structural

  20. Recovery of phosphonate surface contaminants from glass using a simple vacuum extractor with a solid-phase microextraction fiber

    SciTech Connect

    Gary S. Groenewold; Jill R. Scott; Cathy Rae

    2011-07-01

    Recovery of chemical contaminants from fixed surfaces for analysis can be challenging particularly if it is not possible to acquire a solid sample. A simple device is described that collects semivolatile organic compounds from fixed surfaces by creating an enclosed volume over the surface, then generating a modest vacuum. A solid-phase microextraction fiber is then inserted into the evacuated volume where it functions to sorb volatilized organic contaminants. The device is based on a syringe modified with a seal that is used to create the vacuum, with a perforable plunger through which the SPME fiber is inserted. The vacuum speeds partitioning of the semivolatile compounds into the gas phase, and reduces the boundary layer around the SPME fiber, which enables a fraction of the volatilized organics to partition into the SPME fiber. After sample collection the SPME fiber is analyzed using conventional gas chromatography/mass spectrometry. The methodology has been used to collect organophosphorus compounds from glass surfaces, to provide a simple test for the functionality of the devices. Thirty minute sampling times (deltaTvac) resulted in fractional recovery efficiencies ranged from 10(-3) to > 10(-1), and in absolute terms collection of low nanograms was demonstrated. Fractional recovery values were correlated to the vapor pressure of the compounds being sampled. Fractional recovery increased with increasing deltaTvac, and displayed a roughly logarithmic profile indicating that an operational equilibrium is being approached. Fractional recovery decreased with increasing time between exposure and sampling, however recordable quantities of the phosphonates could be collected three weeks after exposure.

  1. The use of an experimental room for monitoring of airborne concentrations of microorganisms, glass fibers, and total particles

    SciTech Connect

    Buttner, M.P.; Stetzenbach, L.D.

    1996-12-31

    An experimental room was used as a microcosm for studies of airborne particles and microorganisms in indoor environments. The interior of the room measures 4 by 4 by 2.2 m high and has a hardwood floor and the walls and ceiling are sheetrocked and coated with interior latex paint. Exterior walls are 11.4-cm thick plywood panels consisting of two outer sections of plywood insulated with fiber glass batts. The ceiling is of similar construction with 17.1-cm thick panels. Attached to the room entrance is an anteroom equipped with a HEPA-filtered air shower to reduce mixing of air resulting from entering and exiting during experiments. The room is equipped with a computer-controlled heating, ventilation, and cooling system. Temperature, relative humidity, air flow, and room pressure can be continuously monitored by probes located in the room and air handling system components. Several research projects have been conducted using this room including monitoring the potential for airborne glass fibers released from rigid fibrous ductboard, comparisons of commercially available samplers for monitoring of airborne fungal spores, and a study on the efficacy of vacuum bags to minimize dispersal of particles, including fungal spores from fungal-contaminated carpet. During studies designed to monitor airborne fiberglass, air samples were taken in the room serviced by new rigid fibrous glass ductwork, and the results were compared to those obtained in the room with bare metal ductwork installed. Monitoring of airborne fungal spores using the Andersen six-stage sampler, the high flow Spiral Biotech sampler, the Biotest RCS Plus sampler, and the Burkard spore trap sampler was performed following the release of Penicillium spores into the room through the supply register. Dispersal of carpet-associated particles and fungal spores was measured after vacuuming using conventional cellulose vacuum bags in comparison to recently developed bags.

  2. An In Vitro Comparative Evaluation of Fracture Resistance of Custom Made, Metal, Glass Fiber Reinforced and Carbon Reinforced Posts in Endodontically Treated Teeth

    PubMed Central

    Sonkesriya, Subhash; Olekar, Santosh T; Saravanan, V; Somasunderam, P; Chauhan, Rashmi Singh; Chaurasia, Vishwajit Rampratap

    2015-01-01

    Background: Posts are used to enhance crown buildup in pulpless teeth with destructed crown portion. Different types of post are used in endodontically treated teeth. The aim of the present in vitro study was to evaluate fracture resistance of custom made, metal, glass fiber reinforced and carbon reinforced posts in endodontically treated teeth. Materials and Methods: An in vitro study was carried out on extracted 40 human maxillary central incisor teeth, which was divided into four groups with 10 samples in each group with custom made, metal post, glass fiber reinforced, and carbon reinforced posts. The samples were decoronated at cemento-enamel junction and endodontically treated. Post space was prepared and selected posts were cemented. The composite cores were prepared at the height of 5 mm and samples mounted on acrylic blocks. Later fracture resistance to the compressive force of samples was measured using Universal Testing Machine. Results: The maximum resistance to the compressive force was observed in carbon reinforced and glass fiber reinforced posts compared others which is statistically significant (P > 0.001) and least was seen in custom fabricated post. Conclusion: It is concluded that carbon reinforced fiber post and glass fiber posts showed good fracture resistance compared to custom made and metal posts. PMID:26028904

  3. Fiber

    MedlinePlus

    ... it can help with weight control. Fiber aids digestion and helps prevent constipation . It is sometimes used ... fiber attracts water and turns to gel during digestion. This slows digestion. Soluble fiber is found in ...

  4. The photosensitivity of ytterbium-doped optical fibers with aluminophosphosilicate glass cores

    NASA Astrophysics Data System (ADS)

    Rybaltovsky, A. A.; Butov, O. V.; Savel'ev, E. A.; Chamorovskii, Yu. K.

    2016-05-01

    The phenomenon of photoinduced refractive index change in active optical fibers with Al2O3/P2O5/Yb2O3/SiO2 core composition has been observed under the action of UV laser radiation with 193-nm wavelength. It is established that hydrogen treatment of active fibers plays a key role in ensuring a radical (about two orders of magnitude) increase in their photosensitivity. It is shown that intrafiber Bragg gratings with reflection coefficients above 99% can be formed, which are promising mirror reflectors for fiber laser cavities.

  5. ZnO-coated glass fibers for the analysis of trihalomethanes by headspace-solid phase microextraction-gas chromatography.

    PubMed

    Duarte, Adriana Pereira; de Campos, Elvio Antonio; Schneider, Ricardo; de Campos, Sílvia Denofre; Cottica, Solange Maria; Favreto, Wagner Alex Jahn

    2010-12-15

    Li(2)O-ZrO(2)-BaO-SiO(2) glass fibers were produced and their surfaces were coated with zinc oxide. The fibers' surface morphology was examined by scanning electron microscopy and the zinc oxide layer was characterized by mapping the K(α) and L(α) lines of zinc by energy dispersive X-ray spectroscopy. The results indicated that a homogeneous and porous layer of ZnO was formed on the fibers' surface. This layer was subjected to a simultaneous determination of trihalomethanes using headspace-solid phase microextraction-gas chromatography. The study was conducted after evaluating the ideal time of incubation (15 min), extraction (15 min) and desorption (10 min), as well as the effect of the addition of salt (15%, m/v) on the analytical response. A good linear dynamic range was observed individually for trihalomethanes aqueous solutions containing 20 μg L(-1) and 500 μg L(-1) of trichloromethane, 15 μg L(-1) and 250 μg L(-1) of dichlorobromomethane and dibromochloromethane and 10 μg L(-1) and 100 μg L(-1) of tribromomethane, with all the compounds showing correlation coefficients higher than 0.9900.

  6. Intermediate-temperature environmental effects on boron nitride-coated silicon carbide-fiber-reinforced glass-ceramic composites

    SciTech Connect

    Sun, E.Y.; Lin, H.T.; Brennan, J.J.

    1997-03-01

    The environmental effects on the mechanical properties of fiber-reinforced composites at intermediate temperatures were investigated by conducting flexural static-fatigue experiments in air at 600 and 950 C. The material that was studied was a silicon carbide/boron nitride (SiC/BN) dual-coated Nicalon-fiber-reinforced barium magnesium aluminosilicate glass-ceramic. Comparable time-dependent failure responses were found at 600 and 950 C when the maximum tensile stress applied in the bend bar was >60% of the room-temperature ultimate flexural strength of as-received materials. At both temperatures, the materials survived 500 h fatigue tests at lower stress levels. Among the samples that survived the 500 h fatigue tests, a 20% degradation in the room temperature flexural strength was measured in samples that were fatigued at 600 C. The growth rate of the Si-C-O fiber oxidation product at 600 C was not sufficient to seal the stress-induced cracks, so that the interior of the material was oxidized and resulted in a strength degradation and less fibrous fracture. In contrast, the interior of the material remained intact at 950 C because of crack sealing by rapid silicate formation, and strength/toughness of the composite was maintained. Also, at 600 C, BN oxidized via volatilization, because no borosilicate was formed.

  7. Rhabdovirus accessory genes.

    PubMed

    Walker, Peter J; Dietzgen, Ralf G; Joubert, D Albert; Blasdell, Kim R

    2011-12-01

    The Rhabdoviridae is one of the most ecologically diverse families of RNA viruses with members infecting a wide range of organisms including placental mammals, marsupials, birds, reptiles, fish, insects and plants. The availability of complete nucleotide sequences for an increasing number of rhabdoviruses has revealed that their ecological diversity is reflected in the diversity and complexity of their genomes. The five canonical rhabdovirus structural protein genes (N, P, M, G and L) that are shared by all rhabdoviruses are overprinted, overlapped and interspersed with a multitude of novel and diverse accessory genes. Although not essential for replication in cell culture, several of these genes have been shown to have roles associated with pathogenesis and apoptosis in animals, and cell-to-cell movement in plants. Others appear to be secreted or have the characteristics of membrane-anchored glycoproteins or viroporins. However, most encode proteins of unknown function that are unrelated to any other known proteins. Understanding the roles of these accessory genes and the strategies by which rhabdoviruses use them to engage, divert and re-direct cellular processes will not only present opportunities to develop new anti-viral therapies but may also reveal aspects of cellar function that have broader significance in biology, agriculture and medicine.

  8. Material Characterization of Glass, Carbon, and Hybrid-Fiber SCRIMP Panels

    SciTech Connect

    KURAISHI, AKIRA; TSAI, STEPHEN W.; WANG, JULIE

    2002-12-01

    The purpose of this study was to generate the material database for carbon and glass composite panels created by the SCRIMP process. The materials tested were glass/polyester composites, two types of carbon/polyester composites, and carbon and glass hybrid composites. The differences between the two types of carbon/polyester, which we call Type 1 and Type 2, are the ply thickness (.037 inch/ply and .048 inch/ply) and slightly different treatment of polyester resin. The tests that were performed for this study are four-point-bending tests, tension tests, panel warping tests, and beam bend-twist coupling tests. The material properties of interest were basic longitudinal and transverse stiffness and strength, residual stress due to curing, and the effect of bend-twist coupling. The bend-twist coupling is a feature that can be added to the composite laminate or structure, such that when it is bent, it will also twist.

  9. Hybrid carbon-glass fiber/toughened epoxy thick composites subject to drop-weight and ballistic impacts

    NASA Astrophysics Data System (ADS)

    Sevkat, Ercan

    The goals of this study are to investigate the low velocity and ballistic impact response of thick-section hybrid fiber composites at room temperature. Plain-woven S2-Glass and IM7 Graphite fabrics are chosen as fiber materials reinforcing the SC-79 epoxy. Four different types of composites consisting of alternating layers of glass and graphite woven fabric sheets are considered. Tensile tests are conducted using 98 KN (22 kip) MTS testing machine equipped with environmental chamber. Low-velocity impact tests are conducted using an Instron-Dynatup 8250 impact test machine equipped with an environmental chamber. Ballistic impact tests are performed using helium pressured high-speed gas-gun. Tensile tests results were used to define the material behavior of the hybrid and non-hybrid composites in Finite Element modeling. The low velocity and ballistic impact tests showed that hybrid composites performance was somewhere between non-hybrid woven composites. Using woven glass fabrics as outer skin improved the impact performance of woven graphite composite. However hybrid composites are prone to delamination especially between dissimilar layers. The ballistic limit velocity V50 hybrid composites were higher that of woven graphite composite and lower than that of woven glass composite. Both destructive cross-sectional micrographs and nondestructive ultrasonic techniques are used to evaluate the damage created by impact. The Finite Element code LS-DYNA is chosen to perform numerical simulations of low velocity and ballistic impact on thick-section hybrid composites. The damage progression in these composites shows anisotropic nonlinearity. The material model to describe this behavior is not available in LS-DYNA material library. Initially, linear orthotropic material with damage (Chan-Chan Model) is employed to simulate some of the experimental results. Then, user-defined material subroutine is incorporated into LS-DYNA to simulate the nonlinear behavior. The

  10. Dynamic mechanical analysis and high strain-rate energy absorption characteristics of vertically aligned carbon nanotube reinforced woven fiber-glass composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The dynamic mechanical behavior and energy absorption characteristics of nano-enhanced functionally graded composites, consisting of 3 layers of vertically aligned carbon nanotube (VACNT) forests grown on woven fiber-glass (FG) layer and embedded within 10 layers of woven FG, with polyester (PE) and...

  11. An Undergraduate Laboratory Experiment that Utilizes a Glass Fiber Filter Assay to Determine the Steroid Specificity and Equilibrium Binding Properties of Glucocorticoid Receptors.

    ERIC Educational Resources Information Center

    John, Nancy J.; Firestone, Gary L.

    1987-01-01

    Describes two complementary laboratory exercises that use the glass fiber assay to assess receptor specificity and hormone binding affinity in rat liver cytoplasmic extracts. Details the methods, materials and protocol of the experiments. Discusses the basic concepts illustrated and the feasibility of using the experiments at the undergraduate…

  12. Epitaxy and fiber texture of Pb films on mica and glass.

    NASA Technical Reports Server (NTRS)

    Wyatt, P. W.; Yelon, A.

    1972-01-01

    We report the production of (111) epitaxial Pb films on mica and (111) textured Pb films on mica and glass. Film structure is studied by reflection electron diffraction and by etching and optical microscopy. Thin (about 1000 A) epitaxial films are found to be doubly positioned. Reorientation during growth of thicker films leads to single positioning in areas several tenths of a millimeter across.

  13. Enhanced sensitivity of Raman spectroscopy for tritium gas analysis using a metal-lined hollow glass fiber

    SciTech Connect

    Rupp, S.; Schloesser, M.; Bornschein, B.; James, T.M.; Telle, H.H.

    2015-03-15

    The precise compositional analysis of tritium-containing gases is of high interest for tritium accountancy in future fusion power plants. Raman spectroscopy provides a fast and contact-free gas analysis procedure with high precision, thus being an advantageous tool for the named purpose. In this paper, it is shown that the sensitivity achieved with conventional Raman systems (in 90 degrees or forward/backward configurations) can be enhanced by at least one order of magnitude by using a metal-lined hollow glass fiber as the Raman cell. This leads to the ability of detecting low partial pressures of tritium within short measurement intervals (< 0.5 mbar in < 0.5 s) opening the way for real-time applications.

  14. The effect of electron beam irradiation on properties of virgin and glass fiber-reinforced polyamide 6

    NASA Astrophysics Data System (ADS)

    Porubská, Mária; Janigová, Ivica; Jomová, Klaudia; Chodák, Ivan

    2014-09-01

    Crosslinking of virgin polyamide 6 (PA-6) and PA-6 filled with 30 wt% glass fibers (GF) was investigated. The crosslinking was initiated by electron irradiation applying dose ranging from 50 to 500 kGy. The gel point was determined to be 200 kGy for both materials. The results obtained indicate that the GF presence may retard gel formation in the PA-matrix. The irradiation of unfilled PA-6 resulted in an increase in tensile strength at break and Young's moduli (a minimum 50% gel content is needed), tensile properties at yield were not affected by crosslinking. Thermal resistance, as measured by the heat deflection temperature and Vicat softening temperature, was affected only marginally. Considering these effects, electron beam irradiation is found to be more beneficial for the virgin PA than for the corresponding PA/GF composite.

  15. Generation of broadband mid-infrared supercontinuum radiation in cascaded soft-glass fibers

    NASA Astrophysics Data System (ADS)

    Kneis, C.; Robin, T.; Cadier, B.; Brilland, Laurent; Caillaud, Celine; Troles, Johann; Manek-Hönninger, I.; Eichhorn, M.; Kieleck, C.

    2016-03-01

    The generation of mid-infrared (mid-IR) radiation, ranging from 2 - 5 μm, is getting much attention in recent years thanks to many applications it can be used for, e.g. in free space optical communication, range finding, counter measures and remote chemical sensing systems. It also plays an increasing role in medicine, for instance in optical tissue ablation or optical coherence tomography, owing to the high water absorption in that wavelength range. In this research study, a ZrF4-BaF2-LaF3-AlF3-NaF (ZBLAN) fluoride fiber is pumped by a Q-switched mode-locked (QML) thulium (Tm3+)- doped double-clad silica fiber laser, emitting at around 2 μm, to generate mid-IR supercontinuum (SC). Further spectral broadening of this SC radiation is achieved by coupling it into a chalcogenide arsenide-selenide (AsSe) photonic crystal fiber (PCF). An output power of 24 W at 2 μm has been achieved in QML operation for the Tm3+-doped fiber laser. The SC output power from the ZBLAN fiber has been 7.8 W with a spectrum extending to approximately 4.1 μm. For further wavelength broadening experiments, a long-wave-pass filter with a 3 dB edge around 3.6 μm has been implemented between the ZBLAN and the AsSe fiber to cut out the residual pump light at 2 μm and the radiation between 2 μm and 3.5 μm. The pump power was approximately 120 mW with a spectrum from 3.5 μm to 3.9 μm. First proof of principal experiments has been performed with 20 mW of averaged output power and a spectrum extending to 4.9 μm. The coupling efficiency of the SC radiation from the ZBLAN fiber into the AsSe fiber has been around 30%.

  16. Influence of different cantilever extensions and glass or polyaramide reinforcement fibers on fracture strength of implant-supported temporary.

    PubMed

    Colán Guzmán, Paola; Freitas, Fernando Furtado Antunes de; Ferreira, Paulo Martins; Freitas, César Antunes de; Reis, Kátia Rodrigues

    2008-01-01

    In long-term oral rehabilitation treatments, resistance of provisional crowns is a very important factor, especially in cases of an extensive edentulous distal space. The aim of this laboratorial study was to evaluate an acrylic resin cantilever-type prosthesis regarding the flexural strength of its in-balance portion as a function of its extension variation and reinforcement by two types of fibers (glass and polyaramid), considering that literature is not conclusive on this subject. Each specimen was composed by 3 total crowns at its mesial portion, each one attached to an implant component (abutment), while the distal portion (cantilever) had two crowns. Each specimen was constructed by injecting acrylic resin into a two-part silicone matrix placed on a metallic base. In each specimen, the crowns were fabricated with either acrylic resin (control group) or acrylic resin reinforced by glass (Fibrante, Angelus) or polyaramide (Kevlar 49, Du Pont) fibers. Compression load was applied on the cantilever, in a point located 7, 14 or 21 mm from the distal surface of the nearest crown with abutment, to simulate different extensions. The specimen was fixed on the metallic base and the force was applied until fracture in a universal test machine. Each one of the 9 sub-groups was composed by 10 specimens. Flexural strength means (in kgf) for the distances of 7, 14 and 21 mm were, respectively, 28.07, 8.27 and 6.39 for control group, 31.89, 9.18 and 5.16 for Kevlar 49 and 30.90, 9.31 and 6.86 for Fibrante. Data analysis ANOVA showed statistically significant difference (p<0.05) only regarding cantilever extension. Tukey's test detected significantly higher flexural strength for the 7 mm-distance, followed by 14 and 21 mm. Fracture was complete only on specimens of non-reinforced groups.

  17. [Influence of retainer design on fixation strength of resin-bonded glass fiber reinforced composite fixed cantilever dentures].

    PubMed

    Petrikas, O A; Voroshilin, Iu G; Petrikas, I V

    2013-01-01

    Fiber-reinforced composite (FRC) fixed partial dentures (FPD) have become an accepted part of the restorative dentist's armamentarium. The aim of this study was to evaluate in vitro the influence of retainer design on the strength of two-unit cantilever resin-bonded glass FRC-FPDs. Four retainer designs were tested: a dual wing, a dual wing + horizontal groove, a dual wing + occlusal rest and a step-box. Of each design on 7 human mandibular molars, FRC-FPDs of a premolar size were produced. The FRC framework was made of resin Revolution (Kerr) impregnated glass fibers (GlasSpan, GlasSpan) and veneered with hybrid resin composite (Charisma, Kulzer). Revolution (Kerr) was used as resin luting cement. FRC-FPDs were loaded to failure in a universal testing machine. T (Student's)-test was used to evaluate the data. The four designs were analyzed with finite element analysis (FEA) to reveal the stress distribution within the tooth/restoration complex. Significantly lower fracture strengths were observed with inlay-retained FPDs (step-box: 172±11 N) compared to wing-retained FPDs (p<0.05) (a dual wing + horizontal groove 222±9 N). The highest fracture strengths were observed with dual wing + occlusal rest FPDs: 250±10 N compared to inlay-retained FPDs (p<0.001) and wing-retained FPDs (p<0.001). FEA showed more favorable stress distributions within the tooth/restoration complex for dual wing retainers+ occlusal rest FPDs. There was stress concentration around connectors and retainers near connectors. A dual-wing retainer with occlusal rest is the optimal design for replacement of a single premolar by means of a two-unit cantilever FRC-FPDs.

  18. Feasibility of Silver Doped TiO2/Glass Fiber Photocatalyst under Visible Irradiation as an Indoor Air Germicide

    PubMed Central

    Pham, Thanh-Dong; Lee, Byeong-Kyu

    2014-01-01

    This study investigated the feasibility of using Ag-TiO2 photocatalyst supported on glass fiber (Ag-TiO2/GF) prepared by a sol-gel method as an indoor air germicide. An experimental model was designed to investigate the bacterial disinfection efficiency of Staphylococcus (Staph), the most popular bacterium in hospitals in Korea, by the Ag-TiO2/GF photocatalyst. The silver content in Ag/TiO2 was altered from 1 to 10% to investigate the optimal ratio of Ag doped on TiO2/glass fiber (TiO2/GF) for photocatalytic disinfection of Staph. This study confirmed that Ag in Ag-TiO2/GF could work as an electron sink or donor to increase photocatalytic activity and promote the charge separation of electron-hole pairs generated from TiO2 after photon absorption. Ag also acts as an intermediate agent for the transfer of photo-generated electrons from the valence band of TiO2 to an acceptor (O2 gas) to promote photo-oxidation processes. The photocatalytic disinfection activity of Ag-TiO2/GF under visible light increased with the increase in silver content up to 7.5% and then slightly decreased with further increasing silver content. The highest disinfection efficiency and disinfection capacity of Staph using 7.5% Ag-TiO2/GF were 75.23% and 20 (CFU∙s−1∙cm−2) respectively. The medium level of humidity of 60% ± 5% showed better photocatalytic disinfection than the lower (40% ± 5%) or higher (80% ± 5%) levels. PMID:24658408

  19. [Influence of retainer design on fixation strength of resin-bonded glass fiber reinforced composite fixed cantilever dentures].

    PubMed

    Petrikas, O A; Voroshilin, Iu G; Petrikas, I V

    2013-01-01

    Fiber-reinforced composite (FRC) fixed partial dentures (FPD) have become an accepted part of the restorative dentist's armamentarium. The aim of this study was to evaluate in vitro the influence of retainer design on the strength of two-unit cantilever resin-bonded glass FRC-FPDs. Four retainer designs were tested: a dual wing, a dual wing + horizontal groove, a dual wing + occlusal rest and a step-box. Of each design on 7 human mandibular molars, FRC-FPDs of a premolar size were produced. The FRC framework was made of resin Revolution (Kerr) impregnated glass fibers (GlasSpan, GlasSpan) and veneered with hybrid resin composite (Charisma, Kulzer). Revolution (Kerr) was used as resin luting cement. FRC-FPDs were loaded to failure in a universal testing machine. T (Student's)-test was used to evaluate the data. The four designs were analyzed with finite element analysis (FEA) to reveal the stress distribution within the tooth/restoration complex. Significantly lower fracture strengths were observed with inlay-retained FPDs (step-box: 172±11 N) compared to wing-retained FPDs (p<0.05) (a dual wing + horizontal groove 222±9 N). The highest fracture strengths were observed with dual wing + occlusal rest FPDs: 250±10 N compared to inlay-retained FPDs (p<0.001) and wing-retained FPDs (p<0.001). FEA showed more favorable stress distributions within the tooth/restoration complex for dual wing retainers+ occlusal rest FPDs. There was stress concentration around connectors and retainers near connectors. A dual-wing retainer with occlusal rest is the optimal design for replacement of a single premolar by means of a two-unit cantilever FRC-FPDs. PMID:23715455

  20. Survival of Composite Resin Restorations of severely Decayed Primary Anterior Teeth retained by Glass Fiber Posts or Reversed-orientated Metal Posts

    PubMed Central

    Ranjkesh, Bahram; Lovschall, Henrik; Erfanparast, Leila; Jafarabadi, Mohammad A; Oskouei, Sina Ghertasi; Isidor, Flemming

    2016-01-01

    ABSTRACT Aim: The aim of this study was to compare the survival of composite resin restorations retained by glass fiber posts or reversed-orientated (upside-down) metal posts in severely decayed primary anterior teeth after 6, 12, and 18 months. Materials and methods: A total of forty-four 3- to 5-year-old children with bilateral severely decayed primary maxillary canines were included. Patients were treated under general anesthesia. After pulpectomy, an intracanal post was seated in the primary maxillary canine on each side: either a glass fiber post or a metallic post in reversed orientation and teeth restored with light-cured composite. Survival rate of each technique was evaluated at predetermined follow-ups and data were analyzed with McNemar’s test (α = 0.05). Results: The difference in survival of restorations retained by two types of posts was not statistically significant in clinical and radiographical evaluations after 6, 12, and 18 months. The survival rate of reversed-orientated metal and glass fiber posts after 18 months was 81.1 and 67.6% respectively (p = 0.14). Conclusion: Reversed-orientated metal post did not show lower clinical survival compared with glass fiber posts in 18-month follow-up. Hence, reversed-orientated metal post can be considered as a potential method to obtain retention for composite restorations in severely decayed primary anterior teeth. How to cite this article: Vafaei A, Ranjkesh B, L0vschall H, Erfanparast L, Jafarabadi MA, Oskouei SG, Isidor F. Survival of Composite Resin Restorations of severely Decayed Primary Anterior Teeth retained by Glass Fiber Posts or Reversed-orientated Metal Posts. Int J Clin Pediatr Dent 2016;9(2):109-113. PMID:27365929

  1. The effect of joint surface contours and glass fiber reinforcement on the transverse strength of repaired acrylic resin: An in vitro study

    PubMed Central

    Anasane, Nayana; Ahirrao, Yogesh; Chitnis, Deepa; Meshram, Suresh

    2013-01-01

    Background: Denture fracture is an unresolved problem in complete denture prosthodontics. However, the repaired denture often experiences a refracture at the repaired site due to poor transverse strength. Hence, this study was conducted to evaluate the effect of joint surface contours and glass fiber reinforcement on the transverse strength of repaired acrylic resins. Materials and Methods: A total of 135 specimens of heat polymerized polymethyl methacrylate resin of dimensions 64 × 10 × 2.5 mm were fabricated. Fifteen intact specimens served as the control and 120 test specimens were divided into four groups (30 specimens each), depending upon the joint surface contour (butt, bevel, rabbet and round), with two subgroups based on type of the repair. Half of the specimens were repaired with plain repair resin and the other half with glass fibers reinforced repair resin. Transverse strength of the specimens was determined using three-point bending test. The results were analyzed using one-way ANOVA and Tukey post-hoc test (α= 0.05). Results: Transverse strength values for all repaired groups were significantly lower than those for the control group (P < 0.001) (88.77 MPa), with exception of round surface design repaired with glass fiber reinforced repair resin (89.92 MPa) which was significantly superior to the other joint surface contours (P < 0.001). Glass fiber reinforced resin significantly improved the repaired denture base resins as compared to the plain repair resin (P < 0.001). Conclusion: Specimens repaired with glass fiber reinforced resin and round surface design exhibited highest transverse strength; hence, it can be advocated for repair of denture base resins. PMID:23946739

  2. Improved patterning of ITO coated with gold masking layer on glass substrate using nanosecond fiber laser and etching

    NASA Astrophysics Data System (ADS)

    Tan, Nguyen Ngoc; Hung, Duong Thanh; Anh, Vo Tran; BongChul, Kang; HyunChul, Kim

    2015-05-01

    In this paper, an indium-tin oxide (ITO) thin-film patterning method for higher pattern quality and productivity compared to the short-pulsed laser direct writing method is presented. We sputtered a thin ITO layer on a glass substrate, and then, plated a thin gold layer onto the ITO layer. The combined structure of the three layers (glass-ITO-gold) was patterned using laser-induced plasma generated by an ytterbium pulsed fiber laser (λ = 1064 nm). The results showed that the process parameters of 50 mm/s in scanning speed, 14 ns pulse duration, and a repetition rate of 7.5 kHz represented optimum conditions for the fabrication of ITO channels. Under these conditions, a channel 23.4 μm wide and 20 nm deep was obtained. However, built-up spikes (∼15 nm in height) resulted in a decrease in channel quality, and consequently, short circuit occurred at some patterned positions. These built-up spikes were completely removed by dipping the ITO layer into an etchant (18 wt.% HCl). A gold masking layer on the ITO surface was found to increase the channel surface quality without any decrease in ITO thickness. Moreover, the effects of repetition rate, scanning speed, and etching characteristics on surface quality were investigated.

  3. Fabrication and characterization of multimaterial chalcogenide glass fiber tapers with high numerical apertures.

    PubMed

    Sun, Ya'nan; Dai, Shixun; Zhang, Peiqing; Wang, Xunsi; Xu, Yinsheng; Liu, Zijun; Chen, Feifei; Wu, Yuehao; Zhang, Yuji; Wang, Rongping; Tao, Guangming

    2015-09-01

    This paper reports on the fabrication and characterization of multimaterial chalcogenide fiber tapers that have high numerical apertures (NAs). We first fabricated multimaterial As(2)Se(3)-As(2)S(3) chalcogenide fiber preforms via a modified one-step coextrusion process. The preforms were drawn into multi- and single-mode fibers with high NAs (≈1.45), whose core/cladding diameters were 103/207 and 11/246 μm, respectively. The outer diameter of the fiber was tapered from a few hundred microns to approximately two microns through a self-developed automatic tapering process. Simulation results showed that the zero-dispersion wavelengths (ZDWs) of the tapers were shorter than 2 μm, indicating that the tapers can be conveniently pumped by commercial short wavelength infrared lasers. We also experimentally demonstrated the supercontinuum generation (SCG) in a 15-cm-long multimaterial As(2)Se(3)-As(2)S(3) chalcogenide taper with 1.9 μm core diameter and the ZDW was shifted to 3.3 μm. When pumping the taper with 100 fs short pulses at 3.4 µm, a 20 dB spectral of the generated supercontinuum spans from 1.5 μm to longer than 4.8 μm. PMID:26368447

  4. Effect of irrigating solutions used for postspace treatment on the push-out bond strength of glass fiber posts

    PubMed Central

    Vangala, Amulya; Hegde, Vivek; Sathe, Sucheta; Dixit, Manisha; Jain, Paresh

    2016-01-01

    Aim: To evaluate the effect of different irrigating solutions on postspace treatments on the push-out bond strength of glass fiber posts. Materials and Methods: Thirty mandibular premolar roots were decoronated and endodontically treated. Postspaces were prepared and roots were divided into three groups: In group 1: 2.5% sodium hypochlorite irrigation (control), group 2: 17% ethylenediaminetetraacetic acid (EDTA) with hand activation, group 3: 17% EDTA irrigation with photon-induced photoacoustic streaming (PIPS) has been done to the postspaces. Scanning electron microscope (SEM) analysis has been made for two samples of each group. Fiber posts were then luted with resin cement. Each root was prepared for push-out test. Data have been statistically analyzed. Results: SEM results showed clean postwalls with both group 2 and group 3, whereas group 1 showed adhesion of resin cement to intraradicular dentine. When all groups were compared, the bond strength values are higher with group 2 followed by group 3. Conclusion: Within the limitations of the study, clean postwalls and the highest bond strength values were obtained from 17% EDTA with hand activation and 17% EDTA with PIPS. PMID:26957800

  5. Evaluation of Interfacial Tensile Strength in Glass Fiber/Epoxy Resin Interface using the Cruciform Specimen Method

    NASA Astrophysics Data System (ADS)

    Ogihara, Shinji; Sakamoto, Yoriaki; Koyanagi, Jun

    Glass/epoxy interfacial tensile strength is investigated by the cruciform specimen method. The conventional transverse tensile test for single fiber composite is one of methods for evaluating the interfacial tensile strength, but stress singularity at the specimen edge is a very complicated problem to be solved. A cruciform specimen which has large width only around fiber embedded in transverse direction can potentially prevent the stress singularity problem. The cruciform specimen geometry is first discussed by means of finite element analysis considering experimental conditions. Transverse tensile test is conducted and an interfacial debonding which initiates at the middle of specimen not at edge is observed using the cruciform specimens. The interfacial tensile strength can be obtained by the value of stress concentration factor at interface multiplied by specimen stress. The location which the debonding initiates from is discussed and the validity of the evaluation method in this study is verified when interfacial tensile strength is as high as or lower than interfacial shear strength.

  6. Accessories or necessities? Exploring consensus on usage of stoma accessories.

    PubMed

    Rudoni, Caroline; Dennis, Heather

    Usage and opinion of accessory products in stoma care vary enormously. The aim of this study was to identify what constitutes an accessory product and to find out whether there is any standardization regarding their recommendation. Views of both patients and stoma nurses were examined. Patients identify accessory products as being necessary both physically and psychologically in improving their quality of life. While stoma nurses identify that the psychological effects of having a stoma should never be underestimated, there is still concern regarding the cost of recommending these products and their clinical necessity. It would appear that clinical necessity is based on nurses' opinions and is not always evidence or research based. Since accessory products have been shown to be essential to many patients with a stoma, should stoma nurses be more empathetic when considering their recommendation?

  7. Sodium sulfate corrosion of silicon carbide fiber-reinforced lithium aluminosilicate glass-ceramic matrix composites. Master's thesis

    SciTech Connect

    Maldia, L.C.

    1993-12-01

    Sodium sulfate hot corrosion of a SiC fiber-reinforced lithium aluminosilicate (LAS) glass-ceramic matrix composite was studied using Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD). Changes in the microstructural chemical composition of the specimens were investigated. The samples provided by Naval Air Warfare Center (NAWC), Warminster, PA were grouped as follows: (1) as-received, (2) Na2SO4 salt-coated and heat-treated in oxygen, (3) noncoated and heat-treated in oxygen, (4) Na2SO4. Salt-coated and heat-treated in argon, and (5) noncoated and heat-treated in argon. Heat treatment was performed by NAWC for 100 hours at 900 deg C. Experimental data obtained indicated that the presence of Na2SO4 in an oxidative environment resulted in rapid corrosion of the matrix and SiC fibers and in the latter rings of SiO2 replaced what had previously been SiC. There was very limited degradation of the fibers and matrix exposed at the surface in the noncoated sample heat-treated in oxygen and in the salt-coated sample heat-treated in argon. A significant reduction in the amount of mullite in the matrices of all heat-treated samples was observed. Mullite dissolved into either the glassy phase or into the Beta-spodumene matrix. Lastly, the presence of distinct magnesium silicate crystalline phases in the salt-coated and heat-treated in oxygen sample implies that the MgO at the surface reacted with the SiO2 in the matrix.

  8. Evaluation of the Load-bearing Capacity of Fractured Incisal Edge of Maxillary Permanent Central Incisors restored with a Glass Fiber-reinforced Nanocomposite: An in vitro Study

    PubMed Central

    Srilatha, KT; Nandlal, B; Dhull, Kanika Singh

    2015-01-01

    ABSTRACT Objectives: The aim of this study was to evaluate and compare the load-bearing capacity of fractured incisal edge of maxillary permanent central incisors restored with a nanocomposite and a glass fiber-reinforced nanocomposite. Materials and methods: Thirty-six extracted sound maxillary central incisors randomly divided in three groups were used for the present study. Group I (control) contained untreated teeth. Samples in experimental groups II and III were prepared by cutting the incisal (one-third) part of the crown horizontally and subjected to enamel preparations and restored with a nanocomposite and a glass fiber-reinforced nanocomposite respectively. All restored teeth were stored in distilled water at room temperature for 24 hours. Fracture resistance was evaluated as peak load at failure (Newton) for samples tested in a cantilever-bending test using Hounsfield universal testing machine. Failure modes were microscopically examined. Results: Highest mean peak failure load (Newton) among experimental groups was observed in glass fiber-reinforced nano composite group (863.50 ± 76.12 N) followed by nanocomposite group (633.67 ± 40.14 N). One-way analysis of variance (ANOVA) revealed that the restoration technique significantly affected the load-bearing capacity (p < 0.001). Scheffe’s post-hoc comparison test (subset for α = 0.05) revealed that there was significant difference in the mean peak failure load values of nanocomposite and glass fiber-reinforced nanocomposite groups when considered together (p < 0.001). Experimental groups showed similar types of failure modes with majority occurring ascohesive and mixed type. Fifty-eight percent of the teeth in glass fiber-reinforced nanocomposite group fractured below the cementoenamel junction. Conclusion: By using fiber-reinforced composite substructure under conventional composites in the repair of fractured incisors, the load-bearing capacity of the restored incisal edge could be substantially

  9. 14 CFR 33.25 - Accessory attachments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Accessory attachments. 33.25 Section 33.25... STANDARDS: AIRCRAFT ENGINES Design and Construction; General § 33.25 Accessory attachments. The engine must operate properly with the accessory drive and mounting attachments loaded. Each engine accessory drive...

  10. Single gain peak from modulation instability in As2Se3 chalcogenide glass photonic crystal fiber

    NASA Astrophysics Data System (ADS)

    Wang, Helin; Yang, Aijun

    2016-09-01

    With the As2Se3 photonic crystal fiber (PCF), the effect of pump power and wavelength on modulation instability (MI) gain is studied in detail. Due to high Raman scattering effect and high nonlinearity of As2Se3 PCF, ultra-broadband MI gain is obtained when appropriate pump power and wavelength is chosen, and the optimal MI gain bandwidth reaches 2812 nm. More importantly, competing between Raman scattering and four-wave mixing results in a single gain peak observed in the anti-Stokes region of As2Se3 PCF when pump power is higher than about 3000 W, while there is no gain spectrum in the fiber Stokes region. The phenomenon is found for the first time, and the obtained single gain peak mainly results from Raman scattering effect.

  11. The luminescent properties of Er 3+-Yb 3+-doped fluorophosphate fiber glass preforms at high temperatures

    NASA Astrophysics Data System (ADS)

    Cruz Vicente, S. G.; Martínez Gámez, M. A.; Kir'yanov, A. V.; Kumar, G. A.

    2005-09-01

    Optical properties of fluorophosphate Er3+-Yb3+ fiber preforms with different concentrations of ErF3 and YbF3 are investigated in the temperature interval 25-300 °C. The temperature-dependent absorption spectra and luminescence at 1535 nm (under the λ = 970 nm excitation) spectra as well as the 4I13/2 → 4I15/2 luminescence decay times are used to compute the luminescence cross-section σe(λ). Our results show that in the range of the temperature investigated the quenching effect due to the temperature increase weakly affects the luminescence cross-section and decay time, which make these materials promising for fiber-optics applications.

  12. Investigation of upconversion luminescence in Yb3+/Tm3+/Ho3+ triply doped antimony-germanate glass and double-clad optical fiber

    NASA Astrophysics Data System (ADS)

    Zmojda, Jacek; Kochanowicz, Marcin; Miluski, Piotr; Righini, Giancarlo C.; Ferrari, Maurizio; Dorosz, Dominik

    2016-08-01

    The optical properties of novel antimony-germanate glass and optical fiber co-doped with Yb3+/Tm3+/Ho3+ ions were presented. White light luminescence in glass was observed as a result of energy transfer with upconversion between donor (Yb3+) and acceptors (Tm3+, Ho3+) ions under 976 nm excitation. The double-clad optical fiber with off-set core co-doped with Yb2O3/Tm2O3/Ho2O3 system was fabricated using a modified rod-in-tube technique. In glass co-doped with 0.5 mol%Yb2O3/0.1 mol%Tm2O3/0.2 mol%Ho2O3 the spectral distribution of three luminescence bands (478, 545 and 660 nm) corresponds to x = 0.35 and y = 0.32 CIE coordinates. In comparison to glass the optical fiber emission are located in the green region (CIE, x = 0.37, y = 0.49).

  13. Bonding Effectiveness of Two Adhesive Luting Cements to Glass Fiber Posts: Pull-Out Evaluation of Three Different Post Surface Conditioning Methods

    PubMed Central

    Calabrese, Marco

    2014-01-01

    The purpose of this study was to evaluate the bond strength at the post/resin-cement interface with 3 different surface treatments of glass fiber posts and with 2 different luting resin cements. Sixty glass fiber posts (RelyX Fiber Post) were randomly divided into 3 groups (n = 20) and were luted with a dual-polymerizing self-adhesive universal resin cement (RelyX Unicem) and with a dual-polymerizing resin cement (RelyX ARC). This was carried out in association with a dual-polymerizing adhesive (Scotchbond Multi-Purpose Plus) in simulated plexiglass root canals after receiving three different pretreatment procedures. A pull-out test was performed on each sample to measure bond strengths. Data were analyzed with two-way ANOVA. Two samples from each group were processed for SEM observations in order to investigate the morphologic aspect of the post/cement interface. Both resin cements demonstrated significant different bond strength values (P < 0.0001). The surface treatment result was also statistically significant (P = 0.0465). SEM examination showed a modification of the post surface after pretreatment with methyl methacrylate. The dual-polymerizing self-adhesive universal resin cement achieved higher MPa bond strength values. The use of methyl methacrylate as a surface treatment of glass fiber posts provided a significant increase in bond strengths between the posts and both luting materials. PMID:24987418

  14. Experimental Study of the Flexural and Compression Performance of an Innovative Pultruded Glass-Fiber-Reinforced Polymer-Wood Composite Profile.

    PubMed

    Qi, Yujun; Xiong, Wei; Liu, Weiqing; Fang, Hai; Lu, Weidong

    2015-01-01

    The plate of a pultruded fiber-reinforced polymer or fiber-reinforced plastic (FRP) profile produced via a pultrusion process is likely to undergo local buckling and cracking along the fiber direction under an external load. In this study, we constructed a pultruded glass-fiber-reinforced polymer-light wood composite (PGWC) profile to explore its mechanical performance. A rectangular cross-sectional PGWC profile was fabricated with a paulownia wood core, alkali-free glass fiber filaments, and unsaturated phthalate resin. Three-point bending and short column axial compression tests were conducted. Then, the stress calculation for the PGWC profile in the bending and axial compression tests was performed using the Timoshenko beam theory and the composite component analysis method to derive the flexural and axial compression rigidity of the profile during the elastic stress stage. The flexural capacity for this type of PGWC profile is 3.3-fold the sum of the flexural capacities of the wood core and the glass-fiber-reinforced polymer (GFRP) shell. The equivalent flexural rigidity is 1.5-fold the summed flexural rigidity of the wood core and GFRP shell. The maximum axial compressive bearing capacity for this type of PGWC profile can reach 1.79-fold the sum of those of the wood core and GFRP shell, and its elastic flexural rigidity is 1.2-fold the sum of their rigidities. These results indicate that in PGWC profiles, GFRP and wood materials have a positive combined effect. This study produced a pultruded composite material product with excellent mechanical performance for application in structures that require a large bearing capacity.

  15. Experimental Study of the Flexural and Compression Performance of an Innovative Pultruded Glass-Fiber-Reinforced Polymer-Wood Composite Profile.

    PubMed

    Qi, Yujun; Xiong, Wei; Liu, Weiqing; Fang, Hai; Lu, Weidong

    2015-01-01

    The plate of a pultruded fiber-reinforced polymer or fiber-reinforced plastic (FRP) profile produced via a pultrusion process is likely to undergo local buckling and cracking along the fiber direction under an external load. In this study, we constructed a pultruded glass-fiber-reinforced polymer-light wood composite (PGWC) profile to explore its mechanical performance. A rectangular cross-sectional PGWC profile was fabricated with a paulownia wood core, alkali-free glass fiber filaments, and unsaturated phthalate resin. Three-point bending and short column axial compression tests were conducted. Then, the stress calculation for the PGWC profile in the bending and axial compression tests was performed using the Timoshenko beam theory and the composite component analysis method to derive the flexural and axial compression rigidity of the profile during the elastic stress stage. The flexural capacity for this type of PGWC profile is 3.3-fold the sum of the flexural capacities of the wood core and the glass-fiber-reinforced polymer (GFRP) shell. The equivalent flexural rigidity is 1.5-fold the summed flexural rigidity of the wood core and GFRP shell. The maximum axial compressive bearing capacity for this type of PGWC profile can reach 1.79-fold the sum of those of the wood core and GFRP shell, and its elastic flexural rigidity is 1.2-fold the sum of their rigidities. These results indicate that in PGWC profiles, GFRP and wood materials have a positive combined effect. This study produced a pultruded composite material product with excellent mechanical performance for application in structures that require a large bearing capacity. PMID:26485431

  16. Experimental Study of the Flexural and Compression Performance of an Innovative Pultruded Glass-Fiber-Reinforced Polymer-Wood Composite Profile

    PubMed Central

    Qi, Yujun; Xiong, Wei; Liu, Weiqing; Fang, Hai; Lu, Weidong

    2015-01-01

    The plate of a pultruded fiber-reinforced polymer or fiber-reinforced plastic (FRP) profile produced via a pultrusion process is likely to undergo local buckling and cracking along the fiber direction under an external load. In this study, we constructed a pultruded glass-fiber-reinforced polymer-light wood composite (PGWC) profile to explore its mechanical performance. A rectangular cross-sectional PGWC profile was fabricated with a paulownia wood core, alkali-free glass fiber filaments, and unsaturated phthalate resin. Three-point bending and short column axial compression tests were conducted. Then, the stress calculation for the PGWC profile in the bending and axial compression tests was performed using the Timoshenko beam theory and the composite component analysis method to derive the flexural and axial compression rigidity of the profile during the elastic stress stage. The flexural capacity for this type of PGWC profile is 3.3-fold the sum of the flexural capacities of the wood core and the glass-fiber-reinforced polymer (GFRP) shell. The equivalent flexural rigidity is 1.5-fold the summed flexural rigidity of the wood core and GFRP shell. The maximum axial compressive bearing capacity for this type of PGWC profile can reach 1.79-fold the sum of those of the wood core and GFRP shell, and its elastic flexural rigidity is 1.2-fold the sum of their rigidities. These results indicate that in PGWC profiles, GFRP and wood materials have a positive combined effect. This study produced a pultruded composite material product with excellent mechanical performance for application in structures that require a large bearing capacity. PMID:26485431

  17. Characterization of nonlinear saturation and mode-locking potential of ionically-doped colored glass filter for short-pulse fiber lasers.

    PubMed

    Zhang, M; Kelleher, E J R; Popov, S V; Taylor, J R

    2013-05-20

    The nonlinear saturable absorption of an ionically-doped colored glass filter is measured directly using a Z-scan technique. For the first time, we demonstrate the potential of this material as a saturable asborber in fiber lasers. We achieve mode-locking of an ytterbium doped system. Mode-locking of cavities with all-positive and net-negative group velocity dispersion are demonstrated, achieving pulse durations of 60 ps and 4.1 ps, respectively. This inexpensive and optically robust material, with the potential for broadband operation, could surplant other saturable absorber devices in affordable mode-locked fiber lasers.

  18. The Effect of Temperature and Nanoclay on the Low Velocity and Ballistic Behavior of Woven Glass-Fiber Reinforced Composites

    NASA Astrophysics Data System (ADS)

    Patrin, Lauren

    The objective of this research was to study the effect of nanoclay and temperature on the behavior of woven glass-fabric reinforced epoxy composite under low velocity and ballistic impacts. The materials used in manufacturing the composite were S2 (6181) glass-fibers, epoxy resin (EPON 828), hardener (Epikure 3230), nanoclay and Heloxy 61 modifier. The nanoclay addition was 0%, 1%, 3% and 5% by weight, with respect to the resin. All specimens were manufactured at the City College facilities using vacuum infusion. Tensile tests were conducted to characterize the material and obtain the Young's modulus, ultimate stress, failure strain, Poisson's ratio, shear modulus and shear strength and their variation with nanoclay percentage and temperature. The tests were conducted at room temperature (21°C/70°F), -54°C (-65°F), -20°C (-4°F), 49°C (120°F) and 71°C (160°F). Next composite specimens with 0%, 1%, 3% and 5% nanoclay by weight, with respect to the resin, were subjected to low velocity impact at the previously specified temperatures to determine dynamic force, displacement and energy correlations. The extent of damage was studied using the ultrasound technique. Then ballistic tests were conducted on the nanoclay infused specimens at room temperature to obtain the ballistic limit (V50) and the damage behavior of the composite. The dynamic finite element analysis (FEA) software LS-DYNA was used to model and simulate the results of low velocity impact tests. Good agreement was obtained between experimental and numerical (FEA) results. Analytical analyses were undertaken to compare the results from the tensile experiments. The finite element analysis (FEA) allowed for further analytical comparison of the results. The FEA platform used was LS-DYNA due to its proficient dynamic and damage capabilities in composite materials. The FEA was used to model and simulate the low velocity impacts and compare the results to experiments.

  19. Modeling the Fatigue Behavior of Glass Fiber Reinforced Thermoplastic and Thermosetting Matrices

    NASA Astrophysics Data System (ADS)

    D'Amore, Alberto; Grassia, Luigi; Verde, Pasquale

    2012-07-01

    The flexural fatigue behavior of continuous and short glass reinforced composites was investigated under four-point bending loading. The effect of mean stress and stress amplitude was identified. It was found that the fatigue life decreased rapidly with the decreasing stress ratio (i.e. the ratio between the minimum and the maximum stress). Further, the specimen lifetime for any loading mode increased with : (a) decreasing load range and decreasing stress ratio and (b) decreasing mean load and increasing stress ratio. From the above observations a brand new two-parameter model based on strength degradation was developed accounting for both the mean load and the load range, in order to express analytically the strength variation during fatigue cycle evolution.

  20. Effect of embedded printed circuit board (PCB) sensors on the mechanical behavior of glass fiber-reinforced polymer (GFRP) structures

    NASA Astrophysics Data System (ADS)

    Javdanitehran, M.; Hoffmann, R.; Groh, J.; Vossiek, M.; Ziegmann, G.

    2016-06-01

    The embedding of dielectric chipless sensors for cure monitoring into fiber-reinforced thermosets allows for monitoring and controlling the curing process and consequently higher quality in production. The embedded sensors remain after the processing in the structure. This affects the integrity of the composite structure locally. In order to investigate these effects on the mechanical behavior of the glass fiber-reinforced polymer (GFRP), sensors made on special low loss substrates are integrated into laminates with different lay-ups and thicknesses using vacuum assisted resin transfer molding (VARTM) method. In a parametric study the size of the sensor is varied to observe its influence on the strength and the stiffness of the laminates according to its lay-up and thickness. The size and orientation of the resin rich areas near sensors as well as the distortion in load bearing area as the consequences of the introduction of the sensors are investigated in conjunction with the strength of the structure. An empirical model is proposed by the authors which involves the previously mentioned factors and is used as a rapid tool for the prediction of the changes in bending and tensile strength of simple structures with embedded sensors. The methodology for model’s calibration as well as the validation of the model against the experimental data of different laminates with distinct lay-ups and thicknesses are presented in this work. Mechanical tests under tensile and bending loading indicate that the reduction of the structure’s strength due to sensor integration can be attributed to the size and the orientation of rich resin zones and depends over and above on the size of distorted load bearing area. Depending on the sensor’s elastic modulus the stiffness of the structure may vary through the introduction of a sensor.

  1. Effects of Porosity on Ultrasonic Characteristic Parameters and Mechanical Properties of Glass Fiber Reinforced Composites

    NASA Astrophysics Data System (ADS)

    Ma, Wen; Liu, Fushun

    Voids are inevitable in the fabrication of fiber reinforced composites and have a detrimental impact on mechanical properties of composites. Different void contents were acquired by applying different vacuum bag pressures. Ultrasonic inspection and ablation density method were adopted to measure the ultrasonic characteristic parameters and average porosity, the characterization of voids' distribution, shape and size were carried out through metallographic analysis. Effects of void content on the tensile, flexural and interlaminar shear properties and the ultrasonic characteristic parameters were discussed. The results showed that, as vacuum bag pressure went from -50kPa to -98kPa, the voids content decreased from 4.36 to 0.34, the ultrasonic attenuation coefficient decreased, but the mechanical strengths all increased.

  2. The Use of Glass-fibers Ribbon and Composite for Prosthetic Restoration of Missing Primary Teeth-Laboratory and Clinical Research.

    PubMed

    Zilberman, Uri; Lasilla, Lippo

    2014-01-01

    Very few modalities can be used for restoring missing primary anterior teeth, although the impact of missing anterior teeth during early childhood can be harmful. In the permanent dentition the use of glass-fibers ribbon and composite materials are frequently used for restoring missing teeth with no or minimal preparation. The purpose of this study was to examine the possibility to use the glass-fibers ribbon (ever-Stick from GC Corporation, Japan) together with esthetic composite materials (G-aenial A1 from GC Corporation, Japan) for restoring anterior primary teeth and to determine the best methodology and bonding system to be used. The effect of etching time was analyzed using 20-80 sec on primary buccal enamel with SEM and the results showed that at least 60 second is necessary in order to remove the prismless layer and to affect the prismatic layer similar (as observed by SEM) to the 20 sec etching time on permanent enamel. Three bonding systems (SE Bond by Kurary, Japan, Scotchbond Universal by 3M/ESPE, Germany and G-aenial bond by GC Company, Japan) were compared for bonding the glass-fibers ribbon to the primary enamel and microtensile strength analyses were performed. Mean tensile strength ranged from 10.9 to 13 MPa with no statistically significant differences between all three systems. Based on the laboratory results it can be concluded that the glass-fibers ribbon together with the composite material can be used clinically to restore missing primary teeth for esthetic and functional reasons. Two clinical cases are presented that show favorable results.

  3. Theoretical and Experimental Thermal Performance Analysis of Building Shell Components Containing Blown Fiber Glass Insulation Enhanced with Phase Change Material (PCM)

    SciTech Connect

    Miller, William A; Kosny, Jan; Yarbrough, David W; Childs, Phillip W; Shrestha, Som S; Atchley, Jerald Allen; Bianchi, Marcus V; Smith, John B; Fellinger, Thomas; Kossecka, Elizabeth; Lee, Edwin S

    2010-01-01

    Different types of Phase Change Materials (PCMs) have been tested as dynamic components in buildings during the last 4 decades. Most historical studies have found that PCMs enhance building energy performance. Some PCM-enhanced building materials, like PCM-gypsum boards or PCM-impregnated concretes have already found their limited applications in different countries. Today, continued improvements in building envelope technologies suggest that throughout Southern and Central US climates, residences may soon be routinely constructed with PCM in order to maximize insulation effectiveness and maintain low heating and cooling loads. The proposed paper presents experimental and numerical results from thermal performance studies. These studies focus on blown fiber glass insulation modified with a novel spray-applied microencapsulated PCM. Experimental results are reported for both laboratory-scale and full-size building elements tested in the field. In order to confirm theoretical predictions, PCM enhanced fiber glass insulation was evaluated in a guarded hot box facility to demonstrate heat flow reductions when one side of a test wall is subjected to a temperature increase. The laboratory work showed reductions in heat flow of 30% due to the presence of approximately 20 wt % PCM in the insulation. Field testing of residential attics insulated with blown fiber glass and PCM was completed in Oak Ridge, Tennessee. Experimental work was followed by detailed whole building EnergyPlus simulations in order to generate energy performance data for different US climates. In addition, a series of numerical simulations and field experiments demonstrated a potential for application of a novel PCM fiber glass insulation as enabling technology to be utilized during the attic thermal renovations.

  4. Preparation and investigation of [GeSe4]100-xIx glasses as promising materials for infrared fiber sensors

    NASA Astrophysics Data System (ADS)

    Velmuzhov, A. P.; Sukhanov, M. V.; Shiryaev, V. S.; Plekhovich, A. D.; Kotereva, T. V.; Snopatin, G. E.; Gerasimenko, V. V.; Pushkin, A. A.

    2016-10-01

    The glasses of [GeSe4]100-xIx (x = 1, 3, 5, 8, 10) compositions are prepared; their thermal properties, transparency in the mid-IR range and stability against crystallization are investigated. The glass transition temperature (Tg) in this system decreases monotonically with increasing iodine content from the value of Tg = 176 °C at x = 1 to Tg = 129 °C at x = 10. It has been determined by X-ray diffraction method that the addition of iodine reduces the volume fraction of the crystalline phase in glasses after annealing at 350 °C. Using a single crucible technique, the rod of [GeSe4]95I5 glass was drawn into a single-index fiber of 300 μm diameter and 10 m length. The optical losses were 2-3 dB/m in the spectral range 2.5-8 μm; the minimum optical losses were 1.7 dB/m at a wavelength of 5.5 μm. The content of impurity hydrogen in the form of Se-H in the fiber was about 3.6 ppm(wt), impurity oxygen in the form of Ge-O is 1 ppm(wt). The possibility of use of such [GeSe4]95I5 glass single-index fiber for infrared analysis of liquids by example of crude oil and water solutions of acetone has been demonstrated.

  5. Effects of heat treating silane and different etching techniques on glass fiber post push-out bond strength.

    PubMed

    Samimi, P; Mortazavi, V; Salamat, F

    2014-01-01

    The aims of this study were to compare two pretreatment methods of a fiber post and to evaluate the effect of heat treatment to applied silane on the push-out bond strength for different levels of root. In this in vitro study, 40 glass fiber posts were divided into five groups (n=8) according to the kind of surface treatment applied. They were then inserted into extracted and endodontically treated human canines using a self-etch resin cement (Panavia F2.0, Kuraray, Japan). Group HF+S = hydrofluoric acid (HF) etching and silane (S) application; group HF+S+WP = HF etching and heat-treated silane application and warmed posts (WP); group H2O2+S = hydrogen peroxide etching and silane application; group H2O2+S+WP = hydrogen peroxide and heat-treated-silane application and warmed post; and group C, the control group, received no pretreatment. After completion of thermal cycling (1000 cycles, 5-55°C), all specimens were cut horizontally to obtain three sections. Each section was subjected to a push-out test, and the test results were analyzed using two-way analysis of variance, post-hoc Tukey honestly significant difference test, and a paired sample t-test (α=0.05). It was found that bond strength was not statistically influenced by the kind of etching material used (p=0.224), but was significantly affected by heat treatment of applied silane (p<0.001). The interaction between these two factors was not statistically significant (p=0.142). Group HF+S+WP showed the highest bond strength (12.56±1.73 MPa) (p<0.05). Scanning electron microscopy revealed the effect of the different treatments on the surface characteristics of posts. In the four pretreated groups, the bond strength decreased significantly from the coronal to the apical root canal sections (p≤0.05). The results of this study show that the use of heat-treated silane significantly enhances the push-out bond strength of the fiber posts to root. HF acid etching with heat-treated silane application led to the

  6. Comparative evaluation of fracture resistance of glass fiber reinforced, carbon, and quartz post in endodontically treated teeth: An in-vitro study

    PubMed Central

    Sharma, Shweta; Attokaran, George; Singh, Kunwar S.; Jerry, Jeethu J.; Ahmed, Naima; Mitra, Nirban

    2016-01-01

    Aim and Objectives: Use of posts improves the physical properties of endodontically-treated teeth. Different post types are developed such as metal, custom-made, carbon, and quartz. The present study was conducted to evaluate the fracture resistance of glass fiber-reinforced, carbon, and quartz post in endodontically-treated teeth. Materials and Methods: Forty extracted human maxillary incisor teeth were decoronated and endodontically treated and equally divided into 4 groups; control, glass fiber-reinforced, carbon, and quartz posts. No post was used in the control group. Post space was prepared and cemented with different posts and subjected to universal testing machine to check fracture resistance. The data were statistically analyzed using t-test and analysis of variance to compare the mean difference between groups (SPSS version 20, IBM). Results: Quartz type of endodontic post showed good fracture resistance compared to carbon and resin-reinforced post. Least resistance was observed in the control group without post. Conclusion: Quartz, carbon, and glass fiber-reinforced posts show good resistance to fracture, and hence can be used in endodontically-treated teeth to enhance their strength. PMID:27583227

  7. Tuning the mechanical properties of glass fiber-reinforced bismaleimide-triazine resin composites by constructing a flexible bridge at the interface

    NASA Astrophysics Data System (ADS)

    Zeng, Xiaoliang; Yu, Shuhui; Lai, Maobai; Sun, Rong; Wong, Ching-Ping

    2013-12-01

    We demonstrate a new method that can simultaneously improve the strength and toughness of the glass fiber-reinforced bismaleimide-triazine (BT) resin composites by using polyethylene glycol (PEG) to construct a flexible bridge at the interface. The mechanical properties, including the elongation, ultimate tensile stress, Young's modulus, toughness and dynamical mechanical properties were studied as a function of the length of PEG molecular chain. It was found that the PEG molecule acts as a bridge to link BT resin and glass fiber through covalent and non-covalent bondings, respectively, resulting in improved interfacial bonding. The incorporation of PEG produces an increase in elongation, ultimate tensile stress and toughness. The Young's modulus and Tg were slightly reduced when the length of the PEG molecular chain was high. The elongation of the PEG-modified glass fiber-reinforced composites containing 5 wt% PEG-8000 increased by 67.1%, the ultimate tensile stress by 17.9% and the toughness by 78.2% compared to the unmodified one. This approach provides an efficient way to develop substrate material with improved strength and toughness for integrated circuit packaging applications.

  8. Plasma vitrification and re-use of non-combustible fiber reinforced plastic, gill net and waste glass.

    PubMed

    Chu, J P; Chen, Y T; Mahalingam, T; Tzeng, C C; Cheng, T W

    2006-12-01

    Fiber reinforced plastic (FRP) composite material has widespread use in general tank, special chemical tank and body of yacht, etc. The purpose of this study is directed towards the volume reduction of non-combustible FRP by thermal plasma and recycling of vitrified slag with specific procedures. In this study, we have employed three main wastes such as, FRP, gill net and waste glass. The thermal molten process was applied to treat vitrified slag at high temperatures whereas in the post-heat treatment vitrified slags were mixed with specific additive and ground into powder form and then heat treated at high temperatures. With a two-stage heat treatment, the treated sample was generated into four crystalline phases, cristobalite, albite, anorthite and wollastonite. Fine and relatively high dense structures with desirable properties were obtained for samples treated by the two-stage heating treatment. Good physical and mechanical properties were achieved after heat treatment, and this study reveals that our results could be comparable with the commercial products. PMID:16839685

  9. Plasma vitrification and re-use of non-combustible fiber reinforced plastic, gill net and waste glass.

    PubMed

    Chu, J P; Chen, Y T; Mahalingam, T; Tzeng, C C; Cheng, T W

    2006-12-01

    Fiber reinforced plastic (FRP) composite material has widespread use in general tank, special chemical tank and body of yacht, etc. The purpose of this study is directed towards the volume reduction of non-combustible FRP by thermal plasma and recycling of vitrified slag with specific procedures. In this study, we have employed three main wastes such as, FRP, gill net and waste glass. The thermal molten process was applied to treat vitrified slag at high temperatures whereas in the post-heat treatment vitrified slags were mixed with specific additive and ground into powder form and then heat treated at high temperatures. With a two-stage heat treatment, the treated sample was generated into four crystalline phases, cristobalite, albite, anorthite and wollastonite. Fine and relatively high dense structures with desirable properties were obtained for samples treated by the two-stage heating treatment. Good physical and mechanical properties were achieved after heat treatment, and this study reveals that our results could be comparable with the commercial products.

  10. Bright-dark vector soliton solutions for a generalized coupled Hirota system in the optical glass fiber

    NASA Astrophysics Data System (ADS)

    Liu, Lei; Tian, Bo; Sun, Wen-Rong; Zhen, Hui-Ling; Shan, Wen-Rui

    2016-10-01

    Studied in this paper are the bright-dark vector soliton solutions for a generalized coupled Hirota system which describes the propagation for the high-intensity ultrashort pulses in the optical glass fiber. Beyond the existing bilinear forms, using an auxiliary function, we obtain the improved bilinear forms and bright-dark soliton solutions under two integrable constraints through the Hirota method and symbolic computation. With the help the analytic and graphic analysis, we study the soliton properties including the amplitudes, velocities and phase shifts, and show that the interactions for the bright-dark two solitons are elastic. For the bright-dark one soliton, parametric conditions that the dark component is "black" or "gray" are obtained. For the bright-dark two solitons, we find that the bright component is affected by the dark component background parameters during such an interaction, while the dark component is not affected by the bright component background parameters. Velocities for the bright-dark two solitons are inversely proportional to the higher-order effect parameter, but amplitudes and phase shifts are independent of it. Besides, the bound-state bright-dark two solitons are also presented.

  11. Effect of implant design and bioactive glass coating on biomechanical properties of fiber-reinforced composite implants.

    PubMed

    Ballo, Ahmed M; Akca, Eralp; Ozen, Tuncer; Moritz, Niko; Lassila, Lippo; Vallittu, Pekka; Närhi, Timo

    2014-08-01

    This study aimed to evaluate the influence of implant design and bioactive glass (BAG) coating on the response of bone to fiber-reinforced composite (FRC) implants. Three different FRC implant types were manufactured for the study: non-threaded implants with a BAG coating; threaded implants with a BAG coating; and threaded implants with a grit-blasted surface. Thirty-six implants (six implants for each group per time point) were installed in the tibiae of six pigs. After an implantation period of 4 and 12 wk, the implants were retrieved and prepared for micro-computed tomography (micro-CT), push-out testing, and scanning electron microscopy analysis. Micro-CT demonstrated that the screw-threads and implant structure remained undamaged during the installation. The threaded FRC/BAG implants had the highest bone volume after 12 wk of implantation. The push-out strengths of the threaded FRC/BAG implants after 4 and 12 wk (463°N and 676°N, respectively) were significantly higher than those of the threaded FRC implants (416°N and 549°N, respectively) and the nonthreaded FRC/BAG implants (219°N and 430°N, respectively). Statistically significant correlation was found between bone volume and push-out strength values. This study showed that osseointegrated FRC implants can withstand the static loading up to failure without fracture, and that the addition of BAG significantly improves the push-out strength of FRC implants.

  12. LIBS system with compact fiber spectrometer, head mounted spectra display and hand held eye-safe erbium glass laser gun

    NASA Astrophysics Data System (ADS)

    Myers, Michael J.; Myers, John D.; Sarracino, John T.; Hardy, Christopher R.; Guo, Baoping; Christian, Sean M.; Myers, Jeffrey A.; Roth, Franziska; Myers, Abbey G.

    2010-02-01

    LIBS (Laser Induced Breakdown Spectroscopy) systems are capable of real-time chemical analysis with little or no sample preparation. A Q-switched laser is configured such that laser induced plasma is produced on targeted material. Chemical element line spectra are created, collected and analyzed by a fiber spectrometer. Line spectra emission data is instantly viewed on a head mounted display. "Eye-safe" Class I erbium glass lasers provide for insitu LIBS applications without the need for eye-protection goggles. This is due to the fact that Megawatt peak power Q-switched lasers operating in the narrow spectral window between 1.5um and 1.6um are approximately 8000 times more "eye-safe" than other laser devices operating in the UV, visible and near infrared. In this work we construct and demonstrate a LIBS system that includes a hand held eye-safe laser gun. The laser gun is fitted with a micro-integrating sphere in-situ target interface and is designed to facilitate chemical analysis in remote locations. The laser power supply, battery pack, computer controller and spectrophotometer components are packaged into a utility belt. A head mounted display is employed for "hands free" viewing of the emitted line spectra. The system demonstrates that instant qualitative and semi-quantitative chemical analyses may be performed in remote locations utilizing lightweight commercially available system components ergonomically fitted to the operator.

  13. Experimental study on influence of dimples on lubrication performance of glass fiber-epoxy resin composite under natural seawater lubrication

    NASA Astrophysics Data System (ADS)

    Wu, Shaofeng; Gao, Dianrong; Liang, Yingna; Chen, Bo

    2016-08-01

    Bionic non-smooth surface is widely applied in metal and ceramics materials. In order to introduce this technology to high pressure seawater pump, the influence of bionic non-smooth surface on the engineering plastics used in pump should be investigated. The comparative tests are carried out with a ring-on-disc configuration under 800, 1000, 1200 and 1400 r/min in order to research the influence of the bionic non-smooth surface on glass fiber-epoxy resin composite(GF/EPR) under natural seawater lubrication. The disc surfaces are textured with five kinds of pits, which are semi-spherical, conical, cone-cylinder combined, cylindrical pits and through holes, respectively. A smooth surface is tested as reference. The results show that the lubrication performance of dimpled GF/EPR sample is much better than that of the smooth sample under all rotational speeds. The semi-spherical pits surface has more obvious friction reduction than the others, which shows that the least reduction is approximately 43.29% of smooth surface under 1200 r/min. However, the wear level is only marginally influenced by dimples. The surface morphology investigations disclose severe modifications caused by abrasive wear primarily. The results are helpful to vary friction properties of GF/EPR by non-smooth surface, or provide references to the design of non-smooth surfaces under certain condition.

  14. Evaluating quality of adhesive joints in glass-fiber plastic piping by using active thermal NDT

    NASA Astrophysics Data System (ADS)

    Grosso, M.; Marinho, C. A.; Nesteruk, D. A.; Rebello, J. M.; Soares, S. D.; Vavilov, V. P.

    2013-05-01

    GRP-type composites (Glass-fibre Reinforced Plastics) have been continuously employed in the oil industry in recent years, often on platforms, especially in pipes for water or oil under moderate temperatures. In this case, the pipes are usually connected through adhesive joints and, consequently, the detection of defects in these joints, as areas without adhesive or adhesive failure (disbonding), gains great importance. One-sided inspection on the joint surface (front side) is a challenging task because the material thickness easily exceeds 10 mm that is far beyond the limits of the capacity of thermography applied to GRP inspection, as confirmed by the experience. Detection limits have been evaluated both theoretically and experimentally as a function of outer wall thickness and defect lateral size. The 3D modeling was accomplished by using the ThermoCalc-6L software. The experimental unit consisted of a FLIR SC640 and NEC TH- 9100 IR imagers and some home-made heaters with the power from 1,5 to 30 kW. The results obtained by applying pulsed heating have demonstrated that the inspection efficiency is strongly dependent on the outer wall thickness with a value of about 8 mm being a detection limit.

  15. Automobile accessories: Assessment and improvement

    SciTech Connect

    Jackson, M.

    1995-11-01

    With mandates and regulatory policies to meet both the California Air Resources Board (CARB) and the Partnership for a New Generation of Vehicles (PNGV), designing vehicles of the future will become a difficult task. As we look into the use of electric and hybrid vehicles, reduction of the required power demand by influential automobile components is necessary in order to obtain performance and range goals. Among those automobile components are accessories. Accessories have a profound impact on the range and mileage of future vehicles with limited amounts of energy or without power generating capabilities such as conventional vehicles. Careful assessment of major power consuming accessories helps us focus on those that need improvement and contributes to attainment of mileage and range goals for electric and hybrid vehicles.

  16. Advantages of disposable endoscopic accessories.

    PubMed

    Petersen, B T

    2000-04-01

    Despite the prevailing emphasis on falling reimbursements and cost containment, the use of disposable endoscopic accessories has grown tremendously. They offer simplicity of use, certain sterility, and reduced labor costs in exchange for higher purchase costs per procedure and the burden of waste disposal. Disposable accessories provide greater variety, complexity, and utility. They carry a cost burden that may be acceptable when the devices are difficult to reprocess, when they incorporate features that justify the added cost, or when their unit cost approaches purchase plus reprocessing costs for reusable alternatives, such as for biopsy forceps. Units with small volumes may prefer the ease of disposable accessories independent of relative cost issues, while large high-volume units may need to evaluate cost data more carefully to maintain sustainable practices.

  17. Mechanical properties of resin glass fiber-reinforced abutment in comparison to titanium abutment

    PubMed Central

    Andreasi Bassi, Mirko; Bedini, Rossella; Pecci, Raffella; Ioppolo, Pietro; Lauritano, Dorina; Carinci, Francesco

    2015-01-01

    Purpose: So far, definitive implant abutments have been performed with high elastic modulus materials, which prevented any type of shock absorption of the chewing loads and as a consequence, the protection of the bone-fixture interface. This is particularly the case when the esthetic restorative material chosen is ceramic rather than composite resin. The adoption of an anisotropic abutment, characterized by an elastic deformability, could allow decreasing the impulse of chewing forces transmitted to the crestal bone. Materials and Methods: According to research protocol, the mechanical resistance to cyclical load was evaluated in a tooth-colored fiber-reinforced abutment (TCFRA) prototype and compared to that of a titanium abutment (TA), thus eight TCFRAs and eight TAs were adhesively cemented on as many titanium implants. The swinging that the two types of abutments showed during the application of sinusoidal load was also analyzed. Results: In the TA group, both fracture and deformation occurred in 12.5% of samples while debonding 62.5%. In the TCFRA group, only debonding was present in 37.5% of samples. In comparison to the TAs, the TCFRAs exhibited a greater swinging during the application of sinusoidal load. In the TA group, the extrusion prevailed, whereas in the TCFRA group, the intrusion was more frequent. Conclusion: The greater elasticity of TCFRA to the flexural load allows absorbing part of the transversal load applied on the fixture during the chewing function, thus reducing the stress on the bone-implant interface. PMID:26229266

  18. Mechanical resistance evaluation of a novel anatomical short glass fiber reinforced post in artificial endodontically treated premolar under rotational/lateral fracture fatigue testing.

    PubMed

    Wang, Hsuan-Wen; Chang, Yen-Hsiang; Lin, Chun-Li

    2016-01-01

    This study develops a novel anatomical short glass fiber reinforced (anatomical SGFR) post and evaluates the mechanical performance in artificial endodontically treated premolars. An anatomical SGFR fiber post with an oval shape and slot/notch designs was manufactured using an injection-molding machine. The three-point bending test and crown/core restorations using the anatomical SGFR and commercial cylindrical fiber posts under fatigue test were executed to understand the mechanical resistances. The results showed that static and dynamic rotational resistance were found significantly higher in the anatomical SGFR fiber post than in the commercial post. The endurance limitations at 1.2×10(6) cycles were 66.81 and 64.77 N for the anatomical SGFR and commercial fiber posts, respectively. The anatomical SGFR fiber post presented acceptable value of flexural strength and modulus, better fit adaption in the root canal resist torque more efficiency but was not a key issue in the lateral fracture resistance in an endodontically treated premolar. PMID:27041013

  19. Mechanical resistance evaluation of a novel anatomical short glass fiber reinforced post in artificial endodontically treated premolar under rotational/lateral fracture fatigue testing.

    PubMed

    Wang, Hsuan-Wen; Chang, Yen-Hsiang; Lin, Chun-Li

    2016-01-01

    This study develops a novel anatomical short glass fiber reinforced (anatomical SGFR) post and evaluates the mechanical performance in artificial endodontically treated premolars. An anatomical SGFR fiber post with an oval shape and slot/notch designs was manufactured using an injection-molding machine. The three-point bending test and crown/core restorations using the anatomical SGFR and commercial cylindrical fiber posts under fatigue test were executed to understand the mechanical resistances. The results showed that static and dynamic rotational resistance were found significantly higher in the anatomical SGFR fiber post than in the commercial post. The endurance limitations at 1.2×10(6) cycles were 66.81 and 64.77 N for the anatomical SGFR and commercial fiber posts, respectively. The anatomical SGFR fiber post presented acceptable value of flexural strength and modulus, better fit adaption in the root canal resist torque more efficiency but was not a key issue in the lateral fracture resistance in an endodontically treated premolar.

  20. Fracture mechanics applied to the analysis of the degradation of anti-corrosion glass/resin pipes as a function of the fiber/matrix interface quality

    SciTech Connect

    Krawczak, P.; Pabiot, J.

    1995-10-01

    The aim of this paper is to propose a characterization method of the damage of glass/epoxy pipes, based on mode 1 fracture mechanics, making it possible to separate the cracks initiation and cracks propagation mechanisms that exist in practice. In a first part, it is shown that this technique is highly sensitive (in factors 4 to 5) to the fiber/matrix interface quality, the latter being either modified by the use of different sizings or degraded by hydrothermal aging. In a second part, the application of this method to pipes under pressure shows that mode I fracture mechanics tests performed on unidirectionally fiber reinforced flat test pieces monoaxially loaded allow the explanation of the short term as well as long term behavior and damage of complex composite structures under biaxial loading, and this on the basis of the participation of the fiber/matrix interface to the observed phenomena.

  1. Fiber

    MedlinePlus

    ... broccoli, spinach, and artichokes legumes (split peas, soy, lentils, etc.) almonds Look for the fiber content of ... salsa, taco sauce, and cheese for dinner. Add lentils or whole-grain barley to your favorite soups. ...

  2. Constitutive modelling of creep in a long fiber random glass mat thermoplastic composite

    NASA Astrophysics Data System (ADS)

    Dasappa, Prasad

    The primary objective of this proposed research is to characterize and model the creep behaviour of Glass Mat Thermoplastic (GMT) composites under thermo-mechanical loads. In addition, tensile testing has been performed to study the variability in mechanical properties. The thermo-physical properties of the polypropylene matrix including crystallinity level, transitions and the variation of the stiffness with temperature have also been determined. In this work, the creep of a long fibre GMT composite has been investigated for a relatively wide range of stresses from 5 to 80 MPa and temperatures from 25 to 90°C. The higher limit for stress is approximately 90% of the nominal tensile strength of the material. A Design of Experiments (ANOVA) statistical method was applied to determine the effects of stress and temperature in the random mat material which is known for wild experimental scatter. Two sets of creep tests were conducted. First, preliminary short-term creep tests consisting of 30 minutes creep followed by recovery were carried out over a wide range of stresses and temperatures. These tests were carried out to determine the linear viscoelastic region of the material. From these tests, the material was found to be linear viscoelastic up-to 20 MPa at room temperature and considerable non-linearities were observed with both stress and temperature. Using Time-Temperature superposition (TTS) a long term master curve for creep compliance for up-to 185 years at room temperature has been obtained. Further, viscoplastic strains were developed in these tests indicating the need for a non-linear viscoelastic viscoplastic constitutive model. The second set of creep tests was performed to develop a general non-linear viscoelastic viscoplastic constitutive model. Long term creep-recovery tests consisting of 1 day creep followed by recovery has been conducted over the stress range between 20 and 70 MPa at four temperatures: 25°C, 40°C, 60°C and 80°C. Findley's model

  3. Effect of weight fraction of carbon black and number of plies of E-glass fiber to reflection loss of E-glass/ripoxy composite for radar absorbing structure (RAS)

    NASA Astrophysics Data System (ADS)

    Widyastuti, Ramadhan, Rizal; Ardhyananta, Hosta; Zainuri, Mochamad

    2013-09-01

    Nowadays, studies on investigating radar absorbing structure (RAS) using fiber reinforced polymeric (FRP) composite materials are becoming popular research field because the electromagnetic properties of FRP composites can be tailored effectively by just adding some electromagnetic powders, such as carbon black, ferrite, carbonyl iron, and etc., to the matrix of composites. The RAS works not only as a load bearing structure to hold the antenna system, but also has the important function of absorbing the in-band electromagnetic wave coming from the electromagnetic energy of tracking systems. In this study, E-glass fiber reinforced ripoxy resin composite was fabricated by blending the conductive carbon black (Ketjenblack EC300J) with the binder matrix of the composite material and maximizing the coefficient of absorption more than 90% (more than -10 dB) within the X-band frequency (8 - 12 GHz). It was measured by electrical conductivity (LCR meter) and vector network analyzer (VNA). Finally, the composite RAS with 0.02 weight fraction of carbon black and 4 plies of E-glass fiber showed thickness of 2.1 mm, electrical conductivity of 8.33 × 10-6 S/m, and maximum reflection loss of -27.123 dB, which can absorb more than 90% of incident EM wave throughout the entire X-band frequency range, has been developed.

  4. Energy dissipation and high-strain rate dynamic response of E-glass fiber composites with anchored carbon nanotubes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study explores the mechanical properties of an E-glass fabric composite reinforced with anchored multi-walled carbon nanotubes (CNTs). The CNTs were grown on the E-glass fabric using a floating catalyst chemical vapor deposition procedure. The E-glass fabric with attached CNTs was then incorpor...

  5. Intrahepatic accessory spleen: imaging features.

    PubMed

    Izzo, Luciano; Caputo, Maria; Galati, Gaspare

    2004-06-01

    The authors present a case report of a 60-year-old man with a hepatic unknown mass. For diagnosis, they used ECO, CT (with and without contrast), MR (with and without contrast) and an ultrasound-assisted percutaneous lesion biopsy. Thus the mass-lesion in the liver appeared to be an intrahepatic accessory spleen in a patient afflicted with chronic hepatitis.

  6. Teaching Techniques for Accessory Percussion

    ERIC Educational Resources Information Center

    Micallef, Ken

    2007-01-01

    Everyone is familiar with the main percussion instruments of the contemporary orchestra: bass drum, snare drum, suspended cymbal, vibraphone, and timpani. But as source material broadens, so do the demands placed on the percussion section. Accessory, or auxiliary percussion, can make the difference between a typical rendition of a well-known piece…

  7. Factors affecting on bond strength of glass fiber post cemented with different resin cements to root canal

    NASA Astrophysics Data System (ADS)

    Clavijo, V. R. G.; Bandéca, M. C.; Calixto, L. R.; Nadalin, M. R.; Saade, E. G.; Oliveira-Junior, O. B.; Andrade, M. F.

    2009-09-01

    Luting materials provides the retention of endodontic post. However, the failures of endodontic posts predominantly occurred are the losses of retention. Thus, the alternating use to remove the smear layer, open the dentine tubules, and/or etch the inter-tubular dentine can be provided by EDTA. This study was performed to evaluate effect of EDTA on bond strength of glass fiber post cemented with different resin cements to root canal. Fifty bovine incisors were selected and the crowns were removed to obtain a remaining 14-mm-height root. The roots were randomly distributed into five groups: GI: RelyX™ ARC/LED; GII: RelyX™ U100/LED; GIII EDTA/RelyX™ U100/LED; GIV: Multilink™; and GV: EDTA/Multlink™. After endodontic treatment, the post space was prepared with the drills designated for the quartz-coated-carbon-fiber post Aestheti-Post®. Before application of resin cements, root canals were irrigated with 17% EDTA (GIII and GV) during 1 min, rinsed with distilled water and dried using paper points. The light-cured materials were light-activated with UltraLume LED 5 (Ultradent, South Jordan, Utah) with power density of 1315 mW/cm2. Specimens were perpendicularly sectioned into approximately 1 mm thick sections and the stubs were performed on Universal Testing Machine. The analysis of variance (ANOVA) and Tukey’s post-hoc tests showed significant statistical different between RelyX™ ARC (GI) and RelyX™ U100 independent of the pre-treatment (GII to GIII) ( P < 0.05). The Multlink™ showed between RelyX™ ARC and RelyX™ U100 (GI to GIII; GII to GV) ( P < 0.05). The ANOVA showed significant statistical similar ( P > 0.05) to all resin cements between the Cervical to Apical regions (GI to GV). The use of 17% EDTA showed no difference significant between the resin cements evaluated (GII to GIII; GIV to GV). Within the limitations of the current study, it can be concluded that the use of EDTA did not provide efficiency on bond strength. The RelyX™ ARC

  8. The effect of shock wave impingement on thin, woven glass fiber reinforced, polymer composite plates

    NASA Astrophysics Data System (ADS)

    Jahnke, Douglas M.

    High-performance fiber-reinforced polymer (FRP) composites have been increasingly used in many applications over the last 30 years. Their high specific stiffness, specific strength, and energy absorption capacity have made them attractive as replacements for traditional materials. While the dynamic response of homogeneous or monolithic materials has been well documented, the response of FRP composites is still under investigation. Knowledge of the response of FRP composites under this type of loading is essential to evaluating its performance as a structural or protective material. While such information starts to be slowly available, the effects of dynamic thermomechanical extremes such as shock wave loading on the FRP composites is relatively unknown. The challenge then is to develop a consistent laboratory methodology that allows investigations of the interactions between a FRP composite and a shock wave and eventually testing of such materials for performance evaluations under shock loading. Measuring the deformation of test specimens caused by shock wave impingement of different intensities was basic to understanding the gross effects on the FRP composites. In early tests, displacement across the diameter of the test specimen was measured after the end of the test giving a static measurement of the permanent deformation. To allow meaningful comparisons between disparate materials subject to different shock wave intensities a method of weighting and normalizing the was developed. The complexity of setting up and running a shock wave test limited the number tests could be performed, so while the results aren't statically robust, the trends observed are useful in comparing or choosing among different materials. A Time-Resolved Catadioptric Stereo Digital Image Correlation (TRC-SDIC) technique was developed which provide a non-contact, full-field method of measuring deformation over the time span from the impingement of the shock wave including the maximum

  9. Multidisciplinary Design Optimization for Glass-Fiber Epoxy-Matrix Composite 5 MW Horizontal-Axis Wind-Turbine Blades

    NASA Astrophysics Data System (ADS)

    Grujicic, M.; Arakere, G.; Pandurangan, B.; Sellappan, V.; Vallejo, A.; Ozen, M.

    2010-11-01

    A multi-disciplinary design-optimization procedure has been introduced and used for the development of cost-effective glass-fiber reinforced epoxy-matrix composite 5 MW horizontal-axis wind-turbine (HAWT) blades. The turbine-blade cost-effectiveness has been defined using the cost of energy (CoE), i.e., a ratio of the three-blade HAWT rotor development/fabrication cost and the associated annual energy production. To assess the annual energy production as a function of the blade design and operating conditions, an aerodynamics-based computational analysis had to be employed. As far as the turbine blade cost is concerned, it is assessed for a given aerodynamic design by separately computing the blade mass and the associated blade-mass/size-dependent production cost. For each aerodynamic design analyzed, a structural finite element-based and a post-processing life-cycle assessment analyses were employed in order to determine a minimal blade mass which ensures that the functional requirements pertaining to the quasi-static strength of the blade, fatigue-controlled blade durability and blade stiffness are satisfied. To determine the turbine-blade production cost (for the currently prevailing fabrication process, the wet lay-up) available data regarding the industry manufacturing experience were combined with the attendant blade mass, surface area, and the duration of the assumed production run. The work clearly revealed the challenges associated with simultaneously satisfying the strength, durability and stiffness requirements while maintaining a high level of wind-energy capture efficiency and a lower production cost.

  10. Study on the impact of fiber length on the correlation of separation and orientation in flow molded glass fiber-reinforced plastic composites.

    PubMed

    Kim, Jin-Woo; Lee, Dong-Gi

    2014-10-01

    During the compression molding of fiber-reinforced plastic composites, there are two issues: one is separation of fiber and matrix because of the different flow state and fiber orientation. Due to separation and orientation, moldings become nonhomogeneous, and show anisotropy. Therefore, separation and orientation should be closely corresponded to molding condition and fiber structure. If fiber shows strong agglomeration, it increases the separation, but fiber orientation will be limited. That is, separation and orientation of fiber is closely related, and the relationship should be clearly defined. In this study, fiber content and length is varied for stacked laminates, and primary sheet is fabricated with thermal compression press. Primary sheet is heated and molded with 30-ton hydraulic press. Nonhomogeneity, one of indicators for separation, is measured from one-dimensional rectangular plate after compression. Orientation function is calculated using X-ray image on moldings and image scanner for processing imagery data. From the correlation between the separation and the orientation of fiber and matrix, the correlation coefficient is defined, and the impact of fiber length on the coefficient is evaluated.

  11. Role of multiwalled carbon nanotube in interlaminar shear strength of epoxy/glass fiber/multi walled carbon nanotube hybrid composites

    NASA Astrophysics Data System (ADS)

    Srinivasan Chandrasekaran, Vasan Churchill

    2011-12-01

    The motivation of this thesis is to investigate the role of multi-walled carbon nanotube (MWCNT) in enhancing the interlaminar shear strength (ILSS) of hybrid composites. The objective of this thesis is to understand the relationships between processing history, material variability, matrix properties, glass fiber/matrix interface properties and their correlations with interlaminar shear strength of hybrid composites. The interlaminar shear strength (ILSS) of hybrid composites made from glass fiber and multi-walled carbon nanotube (MWCNT) modified epoxy is compared with that for unmodified epoxy/glass fiber composites (control). By combining the techniques of high speed mechanical stirring and ultrasonic agitation, 0.5% MWCNT by weight were dispersed in epoxy to prepare a suspension. Composites were manufactured by both injection double vacuum-assisted resin transfer molding (IDVARTM) and the flow flooding chamber (FFC) methods. Compression shear tests (CST) were conducted on the manufactured samples to determine the ILSS. The effect of processing history and batch-to-batch variability of materials---glass fiber preform, resin and carbon nanotubes---on the ILSS of samples made by both techniques was investigated. Statistical comparison of the measured ILSS values for hybrid composites with the control specimens clearly show that hybrid composites made by the FFC process resulted in significant ILSS enhancement relative to the control and the IDVARTM specimens. After it was established that the FFC process improved the ILSS, the effect of functionalizing the nanotubes was explored. Multi walled carbon nanotubes (MWCNT) were oxidized by acid treatment and heated with triethylene tetra amine (TETA) to obtain amino functionalized MWCNTs (f-MWCNT). Hybrid composites with f-MWCNTs were manufactured using FFC technique and control samples were fabricated using the same E-Glass fiber mat and unmodified epoxy resin subjected to the same processing history. CST results show

  12. Effect of surface treatments on the flexural properties and adhesion of glass fiber-reinforced composite post to self-adhesive luting agent and radicular dentin.

    PubMed

    Elnaghy, Amr M; Elsaka, Shaymaa E

    2016-01-01

    This study evaluated the effect of different surface treatments on the flexural properties and adhesion of glass fiber post to self-adhesive luting agent and radicular dentin. Seventy-five single-rooted human teeth were prepared to receive a glass fiber post (Reblida). The posts were divided into five groups according to the surface treatment: Gr C (control; no treatment), Gr S (silanization for 60 s), Gr AP (airborne-particle abrasion), Gr HF (etching with 9 % hydrofluoric acid for 1 min), and Gr M10 (etching with CH2Cl2 for 10 min). Dual-cure self-adhesive luting agent (Rely X Unicem) was applied to each group for testing the adhesion using micropush-out test. Failure types were examined with stereomicroscope and surface morphology of the posts was characterized using a scanning electron microscopy (SEM). Flexural properties of posts were assessed using a three-point bending test. Data were analyzed using ANOVA and Tukey's HSD test. Statistical significance was set at the 0.05 probability level. Groups treated with M10 showed significantly higher bond strength than those obtained with other surface treatments (P < 0.05). In general, improvements in bond strength (MPa) were found in the following order: M10 > C > S > AP > HF. Most failure modes were adhesive type of failures between dentin and luting agent (48.2%). SEM analysis revealed that the fiber post surfaces were modified after surface treatments. The surface treatments did not compromise the flexural properties of fiber posts. Application of M10 to the fiber post surfaces enhanced the adhesion to self-adhesive luting agent and radicular dentin. PMID:25424595

  13. Investigation on broadband near-infrared emission in Yb3+/Ho3+ co-doped antimony-silicate glass and optical fiber

    NASA Astrophysics Data System (ADS)

    Dorosz, D.; Zmojda, J.; Kochanowicz, M.

    2013-10-01

    In the paper antimony-silicate glass and double-clad optical fiber co-doped with ytterbium and holmium ions were investigated. Absorption spectra in infrared (FT-IR) showed characteristic bands: 445, 605, 1037, 1168 cm-1 coming from the vibration of chemical bonds of SbO3 and SiO4, respectively. The combination of relatively low phonon energy with a capability for greater separation (avoiding clustering) of optically active centers in the fabricated glasses should allow an effective expansion of spontaneous emission band. The highest intensity of emission at the wavelength of λe = 1950 nm resulting from energy transfer between Yb3+ → Ho3+ ions was observed in the glass co-doped with 1 mol% Yb2O3:0.5 mol% Ho2O3. As a result of the optical pumping at the wavelength of 976 nm in the produced optical fiber, strong and narrow band of amplified spontaneous emission (ASE) around 2.1 μm, corresponds to the 5I7 → 5I8 transition, were obtained.

  14. Intratracheal fiber glass instillation in rats: IL8 and lymphocytes levels in bronchoalveolar lavage, correlation with the histopathological findings

    PubMed Central

    HANCU, BIANCA DOMOKOS; POP, MONICA

    2013-01-01

    Introduction Fiberglass (FG) is the largest category of man –made mineral fibers. Many types of FG are manufactured for specific uses building insulation, air handling, and sound absorption. Because of increasing use and potential for widespread human exposure, a chronic toxicity instillation study was conducted in Wistar rats, which were found to be sensitive to the induction of mesotheliomas with another MMVF. Aim The present study is focused on the effect of fiber glass on lung through intratracheal exposure, the analysis of bronchoalveolar lavage and measurement of IL 8 levels, lymphocytes number and histopathological finding after the exposure period. Material and method Four groups of 8 female Wistar rats were included in the study. The animals were divided into three groups of 8 each, exposed to different doses of FG and one control group. The first group (1–8) was exposed to 6 mg dose/0.2 ml saline 5 days/week for 10 weeks, the second (9–16) group was exposed to 10 mg/0.2 ml saline 5 days/week 10 weeks, the third group (17–24) was exposed to 12 mg FG/0.2 ml saline solution 5 days/week 10 weeks and the control group (25–32) was exposed to the same volume of saline. The fibers had been size selected to be rat respirable. At the end of the exposure period of 10 weeks the rats were killed one week after the last exposure. Following preparation of the lungs, they were lavaged with 2x5 ml saline without massage. The lavage fluid was collected in calibrated tubes and harvested volume was recorded. Supernatant was obtained after centrifugation at 1,500 r.p.m for 5 minutes and IL8 levels and lymphocytes number were measured. Results The IL8 levels were found to be dose related; the first group had values ranging from 10 to 19.8 pg/ml and the total lymphocytes number in the bronchoalveolar lavage fluid ranging from 1,500–1,900 and minimal/slight inflammatory lesions. The second group had the IL8 levels ranging between 60.4–80.4 pg/ml, lymphocytes number

  15. Mid-IR supercontinuum generation in ultra-low loss, dispersion-zero shifted tellurite glass fiber with extended coverage beyond 4.5 μm

    NASA Astrophysics Data System (ADS)

    Thapa, Rajesh; Rhonehouse, Dan; Nguyen, Dan; Wiersma, Kort; Smith, Chris; Zong, Jie; Chavez-Pirson, Arturo

    2013-10-01

    Mid-infrared sources are a key enabling technology for various applications such as remote chemical sensing, defense communications and countermeasures, and bio-photonic diagnostics and therapeutics. Conventional mid-IR sources include optical parametric amplifiers, quantum cascade lasers, synchrotron and free electron lasers. An all-fiber approach to generate a high power, single mode beam with extremely wide (1μm-5μm) and simultaneous wavelength coverage has significant advantages in terms of reliability (no moving parts or alignment), room temperature operation, size, weight, and power efficiency. Here, we report single mode, high power extended wavelength coverage (1μm to 5μm) supercontinuum generation using a tellurite-based dispersion managed nonlinear fiber and an all-fiber based short pulse (20 ps), single mode pump source. We have developed this mid IR supercontinuum source based on highly purified solid-core tellurite glass fibers that are waveguide engineered for dispersion-zero matching with Tm-doped pulsed fiber laser pumps. The conversion efficiency from 1922nm pump to mid IR (2μm-5μm) supercontinuum is greater than 30%, and approaching 60% for the full spectrum. We have achieved > 1.2W covering from 1μm to 5μm with 2W of pump. In particular, the wavelength region above 4μm has been difficult to cover with supercontinuum sources based on ZBLAN or chalcogenide fibers. In contrast to that, our nonlinear tellurite fibers have a wider transparency window free of unwanted absorption, and are highly suited for extending the long wavelength emission above 4μm. We achieve spectral power density at 4.1μm already exceeding 0.2mW/nm and with potential for higher by scaling of pump power.

  16. Noise suppression in curved glass shells using macro-fiber-composite actuators studied by the means of digital holography and acoustic measurements

    NASA Astrophysics Data System (ADS)

    Mokrý, P.; Psota, P.; Steiger, K.; Václavík, J.; Doleček, R.; Lédl, V.; Šulc, M.

    2015-02-01

    The paper presents methods and experimental results of the semi-active control of noise transmission in a curved glass shell with attached piezoelectric macro fiber composite (MFC) actuators. The semi-active noise control is achieved via active elasticity control of piezoelectric actuators by connecting them to an active electric shunt circuit that has a negative effective capacitance. Using this approach, it is possible to suppress the vibration of the glass shell in the normal direction with respect to its surface and to increase the acoustic transmission loss of the piezoelectric MFC-glass composite structure. The effect of the MFC actuators connected to the negative capacitance shunt circuit on the surface distribution of the normal vibration amplitude is studied using frequency-shifted digital holography (FSDH). The principle of the used FSDH method is described in the paper. The frequency dependence of the acoustic transmission loss through the piezoelectric MFC-glass composite structure is estimated using measurements of the specific acoustic impedance of the curved glass shell. The specific acoustic impedance is measured using two microphones and a laser Doppler vibrometer (LDV). The results from the LDV measurements are compared with the FSDH data. The results of the experiments show that using this approach, the acoustic transmission loss in a glass shell can be increased by 36 dB in the frequency range around 247 Hz and by 25 dB in the frequency range around 258 Hz. The experiments indicate that FSDH measurements provide an efficient tool that can be used for fast and accurate measurements of the acoustic transmission loss in large planar structures.

  17. Locally vascularized pelvic accessory spleen.

    PubMed

    Iorio, F; Frantellizzi, V; Drudi, Francesco M; Maghella, F; Liberatore, M

    2016-01-01

    Polysplenism and accessory spleen are congenital, usually asymptomatic anomalies. A rare case of polysplenism with ectopic spleen in pelvis of a 67-year-old, Caucasian female is reported here. A transvaginal ultrasound found a soft well-defined homogeneous and vascularized mass in the left pelvis. Patient underwent MRI evaluation and contrast-CT abdominal scan: images with parenchymal aspect, similar to spleen were obtained. Abdominal scintigraphy with 99mTc-albumin nanocolloid was performed and pelvic region was studied with planar scans and SPECT. The results showed the presence of an uptake area of the radiopharmaceutical in the pelvis, while the spleen was normally visualized. These findings confirmed the presence of an accessory spleen with an artery originated from the aorta and a vein that joined with the superior mesenteric vein. To our knowledge, in the literature, there is just only one case of a true ectopic, locally vascularized spleen in the pelvis.

  18. Wavelength tunable Q-switch laser in visible region with Pr3+-doped fluoride-glass fiber pumped by GaN diode laser

    NASA Astrophysics Data System (ADS)

    Kojou, Junichiro; Watanabe, Yojiro; Agrawal, Priyanka; Kamimura, Toshihiro; Kannari, Fumihiko

    2013-03-01

    We demonstrate pulse laser operation of a 4-cm-long Pr3+-doped fluoride-glass fiber laser pumped by InGaN laser diodes (444 nm) using an acousto-optic modulator. We obtained maximum laser peak power of 105.6 W (2.1 μJ/pulse) with a pulse width of 20 ns at an 8.3-kHz repetition rate for a 607-nm wavelength. Employing a prism tuning cavity, we obtained wavelength tunable Q-switch pulse laser oscillation in the visible region (488-491, 520-526, 601-624, 631-644 nm).

  19. BRIEF COMMUNICATIONS: Influence of γ irradiation on the temperature dependence of the optical losses in quartz glass-polymer fiber waveguides

    NASA Astrophysics Data System (ADS)

    Andreev, A. Ts; Borkina, G. Yu; Bubnov, M. M.; Voĭtsekhovskiĭ, V. V.; Dianov, Evgenii M.; Kotov, V. M.; Pryakhina, Tatiana A.

    1981-08-01

    A study was made of the influence of γ irradiation on the temperature dependences of the optical losses in quartz glass-polymer fiber waveguides. The working temperature range was extended by γ irradiation to subzero temperatures in the case of two types of waveguide: those with a cladding made of SIÉL commercial silicone rubber and those made by the Quartz-Silice firm. The results obtained were explained by changes in the structure of silicone rubber under the action of γ irradiation.

  20. Methods for an investigation of the effect of material components on the mechanical characteristics of glass-fiber-reinforced plastics

    NASA Technical Reports Server (NTRS)

    Willax, H. O.

    1980-01-01

    The materials used in the production of glass reinforced plastics are discussed. Specific emphasis is given to matrix polyester materials, the reinforcing glass materials, and aspects of specimen preparation. Various methods of investigation are described, giving attention to optical impregnation and wetting measurements and the gravimetric determination of the angle of contact. Deformation measurements and approaches utilizing a piezoelectric device are also considered.

  1. Optimum design for fixed partial dentures made of hybrid resin with glass fiber reinforcement by finite element analysis: effect of vertical reinforced thickness on fiber frame.

    PubMed

    Ootaki, Masayuki; Shin-Ya, Akikazu; Gomi, Harunori; Shin-Ya, Akiyoshi; Nakasone, Yuji

    2007-03-01

    By means of finite element analysis, the optimal thickness of fiber framework placed in a fiber-reinforced composite bridge replacing the mandibular first molar was obtained. Test results demonstrated that more than 30% maximum principal stress was reduced by reinforcing with fiber framework in a thickness of up to 0.6 mm for 1.5-mm occlusal clearance. Indeed, maximum principal stress generated in lower embrasure of connectors was reduced from 107 MPa to 70 MPa by maximizing reinforcement effect. PMID:17621946

  2. Accessory spleen hypertrophy mimicking colon cancer metastasis.

    PubMed

    Ates, I; Yazici, O; Yazilitas, D; Ozdemir, N; Zengin, N

    2016-09-01

    Accessory spleen is a congenital form of an ectopic splenic tissue. In this report, we present a case of a patient who was followed with the diagnosis of rectal and sigmoid colon cancer and an accessory spleen hypertrophy, which was thought to be colon cancer metastasis in the left hypochondriac region. After colectomy and splenectomy, accessory spleen that mimics cancer metastasis was diffrentially diagnosed using scintigraphy. PMID:27685531

  3. Accessory suprarenal gland: report of a case.

    PubMed

    Kirici, Y; Mas, M R; Saglamkaya, U; Oztas, E; Ozan, H

    2001-06-01

    The suprarenal glands are normally located at the superomedial aspect of the kidneys. Accessory cortical masses are seen in approximately half of the newborn but usually disappear later. Several cases with accessory cortical tissues located near the main suprarenal glands have been reported but their usual locations have been rarely described. Here we report a case with accessory cortical tissue located on the right in the retrocrural space with compression symptoms. Such a lesion may be confused with lymphadenopathy radiologically.

  4. Fabrication of solar light induced Fe-TiO{sub 2} immobilized on glass-fiber and application for phenol photocatalytic degradation

    SciTech Connect

    Lin, Shaohua; Zhang, Xiwang; Sun, Qinju; Zhou, Tingting; Lu, Jingjing

    2013-11-15

    Graphical abstract: - Highlights: • Fe-doped TiO{sub 2} immobilized on glass-fiber net were prepared by sol–gel method. • Fe inhibited the phase transition of TiO{sub 2} from anatase to rutile. • The optimal Fe doping dose was around 0.005 wt%. • The optimal calcination temperature was around 600 °C. - Abstract: Iron-doped anatase titanium dioxide catalysts coated on glass-fiber were successfully synthesized by a dip-coating sol–gel method. The prepared catalysts were characterized by scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis, X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy to understand the synthesis mechanism, and their photocatalytic activities were evaluated by photodegradation of phenol under simulated solar irradiation. EDX analysis confirmed the existence of iron in the immobilized catalysts. XRD suggested that the phase transition of the catalysts from anatase to rutile were restrained, and almost pure anatase TiO{sub 2} could retain even the calcination temperature reached 800 °C. The UV-Vis diffuse reflectance spectroscopy of the catalysts showed a red shift and increased photoabsorbance in the visible range for all the doped samples. Iron loading and calcination temperature have obvious influences on photocatalytic activity. In this study, the optimal doping dose and calcination temperature were around 0.005 wt% and 600 °C, respectively.

  5. Advanced Accessory Power Supply Topologies

    SciTech Connect

    Marlino, L.D.

    2010-06-15

    This Cooperative Research and Development Agreement (CRADA) began December 8, 2000 and ended September 30, 2009. The total funding provided by the Participant (General Motors Advanced Technology Vehicles [GM]) during the course of the CRADA totaled $1.2M enabling the Contractor (UT-Battelle, LLC [Oak Ridge National Laboratory, a.k.a. ORNL]) to contribute significantly to the joint project. The initial task was to work with GM on the feasibility of developing their conceptual approach of modifying major components of the existing traction inverter/drive to develop low cost, robust, accessory power. Two alternate methods for implementation were suggested by ORNL and both were proven successful through simulations and then extensive testing of prototypes designed and fabricated during the project. This validated the GM overall concept. Moreover, three joint U.S. patents were issued and subsequently licensed by GM. After successfully fulfilling the initial objective, the direction and duration of the CRADA was modified and GM provided funding for two additional tasks. The first new task was to provide the basic development for implementing a cascaded inverter technology into hybrid vehicles (including plug-in hybrid, fuel cell, and electric). The second new task was to continue the basic development for implementing inverter and converter topologies and new technology assessments for hybrid vehicle applications. Additionally, this task was to address the use of high temperature components in drive systems. Under this CRADA, ORNL conducted further research based on GM’s idea of using the motor magnetic core and windings to produce bidirectional accessory power supply that is nongalvanically coupled to the terminals of the high voltage dc-link battery of hybrid vehicles. In order not to interfere with the motor’s torque, ORNL suggested to use the zero-sequence, highfrequency harmonics carried by the main fundamental motor current for producing the accessory power

  6. Mechanical accessories for mobile teleoperators

    SciTech Connect

    Feldman, M.J.; Herndon, J.N.

    1985-01-01

    The choice of optimum mechanical accessories for mobile teleoperators involves matching the criteria for emergency response with the available technology. This paper presents a general background to teleoperations, a potpourri of the manipulator systems available, and an argument for force reflecting manipulation. The theme presented is that the accomplishment of humanlike endeavors in hostile environments will be most successful when man model capabilities are utilized. The application of recent electronic technology to manipulator development has made new tools available to be applied to emergency response activities. The development activities described are products of the Consolidated Fuel Reprocessing Program at the Oak Ridge National Laboratory. 13 refs., 7 figs.

  7. Characterization of cure kinetics and physical properties of a high performance, glass fiber-reinforced epoxy prepreg and a novel fluorine-modified, amine-cured commercial epoxy

    NASA Astrophysics Data System (ADS)

    Bilyeu, Bryan

    Kinetic equation parameters for the curing reaction of a commercial glass fiber reinforced high performance epoxy prepreg composed of the tetrafunctional epoxy tetraglycidyl 4,4-diaminodiphenyl methane (TGDDM), the tetrafunctional amine curing agent 4,4'-diaminodiphenylsulfone (DDS) and an ionic initiator/accelerator, are determined by various thermal analysis techniques and the results compared. The reaction is monitored by heat generated determined by differential scanning calorimetry (DSC) and by high speed DSC when the reaction rate is high. The changes in physical properties indicating increasing conversion are followed by shifts in glass transition temperature determined by DSC, temperature-modulated DSC (TMDSC), step scan DSC and high speed DSC, thermomechanical (TMA) and dynamic mechanical (DMA) analysis and thermally stimulated depolarization (TSD). Changes in viscosity, also indicative of degree of conversion, are monitored by DMA. Thermal stability as a function of degree of cure is monitored by thermogravimetric analysis (TGA). The parameters of the general kinetic equations, including activation energy and rate constant, are explained and used to compare results of various techniques. The utilities of the kinetic descriptions are demonstrated in the construction of a useful time-temperature-transformation (TTT) diagram and a continuous heating transformation (CHT) diagram for rapid determination of processing parameters in the processing of prepregs. Shrinkage due to both resin consolidation and fiber rearrangement is measured as the linear expansion of the piston on a quartz dilatometry cell using TMA. The shrinkage of prepregs was determined to depend on the curing temperature, pressure applied and the fiber orientation. Chemical modification of an epoxy was done by mixing a fluorinated aromatic amine (aniline) with a standard aliphatic amine as a curing agent for a commercial Diglycidylether of Bisphenol-A (DGEBA) epoxy. The resulting cured network

  8. Utilization of fiber optic Bragg grating sensors in concrete columns confined with glass-fiber-reinforced plastic (GFRP) laminate under uniaxial compression test

    NASA Astrophysics Data System (ADS)

    Chan, Peter K. C.; Lau, Alan K.; Jin, Wei; Zhou, Limin

    1999-01-01

    In this paper we report of experimental studies on strain monitoring by using fiber Bragg grating sensors in concrete structures. The strain variation of the specimen under different loading conditions were monitored by the Fiber- optic Bragg grating (FBG) sensors. The FBG sensors have been pre-installed in the structure by embedding either inside the concrete specimen or at the interface between the concrete and the composites. The strain reading from the fiber grating sensor compares favorably with that obtained from the conventional strain gauge in uni-axial compression testing. The test result generally indicated that the concrete structures can be strengthened significantly by wrapping with glassfiber composites. The sensor embedded at the notch tip provides a very good indication of the health condition of the strengthened structure, especially in high stress concentration area. The strain sensitivity by using FBG sensor is 67 (mu) (epsilon) .

  9. Revolution in airplane construction? Grob G110: The first modern fiber glass composition airplane shortly before its maiden flight

    NASA Technical Reports Server (NTRS)

    Dorpinghaus, R.

    1982-01-01

    A single engine two passenger airplane, constructed completely from fiber reinforced plastic materials is introduced. The cockpit, controls, wing profile, and landing gear are discussed. Development of the airframe is also presented.

  10. Progress in simulating semi-flexible glass fiber orientation in an injection molded end-gated plaque

    NASA Astrophysics Data System (ADS)

    Cieslinski, Mark J.; Meyer, Kevin J.; Baird, Donald G.

    2014-05-01

    The use of long fiber reinforced thermoplastics has gained increasing interest as a means to enhance a part's mechanical properties created through traditional melt processing techniques. Injection molding creates a complex microstructure to develop caused by flow field within the mold. Accurate predictions of fiber orientation can allow for mold design to be tailored to achieve a desired microstructure and mechanical properties. Simulations utilize the Bead-Rod orientation model adapted for concentrated suspensions to account for semi-flexible fibers by representing a fiber as two adjoined vectors that are free to rotate around the connecting point. This work uses orientation model parameters extracted from orientation data taken along the center plane at the transition between the gate and plaque. The entire mold cavity is simulated under non-isothermal conditions including the entry region to the plaque and the fountain flow behavior at the advancing front. Simulations of the semi-flexible model are compared to the Strain Reduction Factor (SRF) model developed for rigid fibers following the same simulation procedure. Predictions are compared to experimental data measured along and away from the plane of symmetry. Improvement in orientation predictions are obtained from the Bead-Rod model which greatly out performs the rigid fiber model away from the center plane.

  11. 14 CFR 27.1163 - Powerplant accessories.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... involved; (2) Use the provisions on the engine for mounting; and (3) Be sealed in such a way as to prevent contamination of the engine oil system and the accessory system. (b) Unless other means are provided, torque... drive system to prevent damage to these components from excessive accessory load. Powerplant...

  12. 14 CFR 27.1163 - Powerplant accessories.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... involved; (2) Use the provisions on the engine for mounting; and (3) Be sealed in such a way as to prevent contamination of the engine oil system and the accessory system. (b) Unless other means are provided, torque... drive system to prevent damage to these components from excessive accessory load. Powerplant...

  13. Three Accessories for a Rotating Platform.

    ERIC Educational Resources Information Center

    Riley, James A.; Fryer, Oscar G.

    1980-01-01

    Describes three accessories developed to be used in conjunction with the rotating platform or turntable. Three demonstrations using these accessories are included. These demonstrations are: (a) conservation of angular momentum; (b) gravity-defying goblets; and (c) direct measurement of centripetal force. (HM)

  14. 21 CFR 890.5925 - Traction accessory.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Traction accessory. 890.5925 Section 890.5925 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5925 Traction accessory....

  15. 21 CFR 890.5925 - Traction accessory.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Traction accessory. 890.5925 Section 890.5925 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5925 Traction accessory....

  16. 21 CFR 890.5925 - Traction accessory.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Traction accessory. 890.5925 Section 890.5925 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5925 Traction accessory....

  17. 21 CFR 890.5925 - Traction accessory.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Traction accessory. 890.5925 Section 890.5925 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5925 Traction accessory....

  18. 21 CFR 890.5925 - Traction accessory.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Traction accessory. 890.5925 Section 890.5925 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5925 Traction accessory....

  19. Fiber pulling apparatus modification

    NASA Technical Reports Server (NTRS)

    Smith, Guy A.; Workman, Gary L.

    1992-01-01

    A reduced gravity fiber pulling apparatus (FPA) was constructed in order to study the effects of gravity on glass fiber formation. The apparatus was specifically designed and built for use on NASA's KC-135 aircraft. Four flights have been completed to date during which E-glass fiber was successfully produced in simulated zero, high, and lunar gravity environments. In addition simulated lunar soil samples were tested for their fiber producing properties using the FPA.

  20. Carcinoma in accessory axillary breast.

    PubMed

    Khanna, Seema; Mishra, Shashi Prakash; Kumar, Satendra; Khanna, Ajay Kumar

    2015-08-10

    We present a rare case of carcinoma developing in an accessory breast. The patient presented with a progressive lump in her right axilla for 1 year. On examination, there was a well-developed nipple areola complex in the right axilla overlying a hard, fixed 5 × 3 cm lump. On investigation, core biopsy revealed poorly differentiated carcinoma of the breast. Mammography also revealed features of a malignant lesion with skin and muscle infiltration. Neoadjuvant chemotherapy was administered followed by modified radical mastectomy after three cycles. Immunohistochemistry study showed positive status of oestrogen and progesterone receptors, and negative HER-2 neu. Three more cycles of chemotherapy along with 50 Gy radiotherapy were given in an adjuvant setting followed by hormone therapy.

  1. Electrical resistance tomography with constrained sine wave solutions for impact damage identification in glass fiber/epoxy/carbon black laminate composites

    NASA Astrophysics Data System (ADS)

    Tallman, T. N.

    2016-04-01

    Electrical impedance tomography (EIT) has incredible potential for structural health monitoring (SHM) when applied to structures in which mechanical damage is coupled with changes in electrical conductivity. Practically, however, the potential of EIT for SHM is largely nullified by requiring both non-negligible computational resources and accurate initial conductivity estimates. By working in resistivity instead of conductivity and constraining the change in resistivity to be a series of two-dimensional sine waves, a novel resistivity-based EIT formulation is herein developed that significantly abates the computational requirements of EIT and is independent of initial estimates. This approach is explored analytically and then demonstrated experimentally by locating impact damage to a glass fiber/epoxy/carbon black laminate.

  2. INFLUENCE OF DIFFERENT CANTILEVER EXTENSIONS AND GLASS OR POLYARAMID REINFORCEMENT FIBERS ON FRACTURE STRENGTH OF IMPLANT-SUPPORTED TEMPORARY FIXED PROSTHESIS

    PubMed Central

    Colán Guzmán, Paola; de Freitas, Fernando Furtado Antunes; Ferreira, Paulo Martins; de Freitas, César Antunes; Reis, Kátia Rodrigues

    2008-01-01

    In long-term oral rehabilitation treatments, resistance of provisional crowns is a very important factor, especially in cases of an extensive edentulous distal space. The aim of this laboratorial study was to evaluate an acrylic resin cantilever-type prosthesis regarding the flexural strength of its in-balance portion as a function of its extension variation and reinforcement by two types of fibers (glass and polyaramid), considering that literature is not conclusive on this subject. Each specimen was composed by 3 total crowns at its mesial portion, each one attached to an implant component (abutment), while the distal portion (cantilever) had two crowns. Each specimen was constructed by injecting acrylic resin into a two-part silicone matrix placed on a metallic base. In each specimen, the crowns were fabricated with either acrylic resin (control group) or acrylic resin reinforced by glass (Fibrante, Angelus) or polyaramide (Kevlar 49, Du Pont) fibers. Compression load was applied on the cantilever, in a point located 7, 14 or 21 mm from the distal surface of the nearest crown with abutment, to simulate different extensions. The specimen was fixed on the metallic base and the force was applied until fracture in a universal test machine. Each one of the 9 sub-groups was composed by 10 specimens. Flexural strength means (in kgf) for the distances of 7, 14 and 21 mm were, respectively, 28.07, 8.27 and 6.39 for control group, 31.89, 9.18 and 5.16 for Kevlar 49 and 30.90, 9.31 and 6.86 for Fibrante. Data analysis ANOVA showed statistically significant difference (p<0.05) only regarding cantilever extension. Tukey's test detected significantly higher flexural strength for the 7 mm-distance, followed by 14 and 21 mm. Fracture was complete only on specimens of non-reinforced groups. PMID:19089201

  3. Epoxy/Glass and Polyimide (LaRC(TradeMark) PETI-8)/Carbon Fiber Metal Laminates Made by the VARTM Process

    NASA Technical Reports Server (NTRS)

    Cano, Roberto J.; Loos, Alfred C.; Jensen, Brian J.; Britton, Sean M.; Tuncol, Goker; Long, Kai

    2010-01-01

    Recent work at NASA Langley Research Center (LaRC) has concentrated on developing new polyimide resin systems for advanced aerospace applications that can be processed without the use of an autoclave. Polyimide composites are very attractive for applications that require a high strength to weight ratio and thermal stability. Vacuum assisted resin transfer molding (VARTM) has shown the potential to reduce the manufacturing cost of composite structures. Fiber metal laminates (FML) made via this process with aluminum, glass fabric, and epoxy resins have been previously fabricated at LaRC. In this work, the VARTM process has been refined for epoxy/glass FMLs and extended to the fabrication of FM Ls with titanium/carbon fabric layers and a polyimide system developed at NASA, LARC(TradeMark) PETI-8. Resin flow pathways were introduced into the titanium foils to aid the infiltration of the polyimide resin. Injection temperatures in the range of 250-280 C were required to achieve the necessary VARTM viscosities (<10 Poise). Laminate quality and initial mechanical properties will be presented.

  4. Influence of the Cement Film Thickness on the Push-Out Bond Strength of Glass Fiber Posts Cemented in Human Root Canals

    PubMed Central

    Prado, Natália Araújo Silva; Ferreira, Reinaldo de Souza; Maurício, Marcos Henrique de Pinho; Paciornik, Sidnei; de Miranda, Mauro Sayão

    2016-01-01

    The present study evaluated the influence of the cement film thickness on the push-out bond strength of glass fiber posts in the cervical, medium, and apical thirds of root canal spaces. Thirty roots were randomly divided into three groups, according to the fiber post system's drills: (G1) #2; (G2) #3; (G3) #4. The posts were cemented using a self-adhesive cement, and a small amount of powdered Rhodamine B was used as a stain. Images of both sides of each slice were obtained before and after the push-out test. To determine the cement thickness, a macro routine was developed using the software KS 400. The data were analyzed statistically using Kruskal-Wallis and Dunn's test. G2 (14.62 ± 5.15 MPa) showed statistically higher bond strength values than G1 (10.04 ± 5.13 MPa) and G3 (7.68 ± 6.14 MPa). All groups presented higher bond strength values in the apical third. The bur diameter significantly influenced the results of the shear bond strength for the push-out test. The slight increase in the cement thickness allowed an increase in the values of shear bond strength when compared to very thin or very thick cement films. PMID:27143971

  5. Ultra-miniature all-glass Fabry-Pérot pressure sensor manufactured at the tip of a multimode optical fiber

    NASA Astrophysics Data System (ADS)

    Pinet, Éric; Cibula, Edvard; Đonlagić, Denis

    2007-09-01

    The design and fabrication of an ultra-miniature all-glass pressure sensor with a diameter of 125 μm are presented. The sensor consists of a thin flexible silica membrane fused on a capillary tube section, which is assembled at the tip of a standard multimode fiber, thus forming a Fabry-Pérot air cavity whose length depends on applied pressure. Controlled polishing steps including on-line tuning of the diaphragm thickness during the manufacturing process achieve good repeatability and high sensitivity of the pressure sensor. The prototypes obtained with the described manufacturing method could easily have a sensitivity of ~2 nm/kPa (~0.3 nm/mmHg) with a record, so far, of ~5 nm/kPa (~0.7 nm/mmHg). The relatively simple fabrication technique using common and inexpensive equipments and materials combined with the fact that such sensitive sensors with multimode fiber could be interrogated with low-cost commercial interrogators (such as those using white-light interferometry) make this option very attractive for many applications involving pressure measurement. The sensor significant size reduction is valuable especially for the medical field, for applications such as minimally invasive patient health monitoring and diagnostics or small animals testing. Disposable sensors with ultra-miniature size will certainly open the way for new medical diagnostics and therapies.

  6. Evaluation of polyimide/glass fiber composites for construction of light weight pressure vessels for cryogenic propellants

    NASA Technical Reports Server (NTRS)

    Petker, I.; Segimoto, M.

    1973-01-01

    The application of polyimide resin as a matrix for glass filament-wound thin metal-lined pressure vessels was studied over a temperature range of (minus) 320 to 600 F. Keramid 601 polyimide was found to perform quite well over the entire range of temperature. Hoop stress values of 425 ksi were determined at 75 F which is equivalent to epoxy resin in similar structures. At -320 and 600 F, 125 and 80% of this strength was retained. Thermal ageing at 500 F for up to 50 hours was studied with severe reduction in strength, but there is evidence that this reduction could be improved. Another polyimide resin studied was P10PA which was found to have processing characteristics inappropriate for filament-winding. NOL ring tensile and shear data was determined from both resins with S-glass. Pressure vessel design, fabrication and test procedures are described in detail.

  7. 19 CFR 10.920 - Accessories, spare parts, or tools.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Accessories, spare parts, or tools. 10.920 Section... Promotion Agreement Rules of Origin § 10.920 Accessories, spare parts, or tools. (a) General. Accessories... accessories, spare parts, or tools will be treated as originating goods if the good is an originating...

  8. 19 CFR 10.456 - Accessories, spare parts or tools.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... good will be treated as a material used in the production of the good, if— (a) The accessories, spare... 19 Customs Duties 1 2014-04-01 2014-04-01 false Accessories, spare parts or tools. 10.456 Section... Trade Agreement Rules of Origin § 10.456 Accessories, spare parts or tools. Accessories, spare parts...

  9. 19 CFR 10.920 - Accessories, spare parts, or tools.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Accessories, spare parts, or tools. 10.920 Section... Promotion Agreement Rules of Origin § 10.920 Accessories, spare parts, or tools. (a) General. Accessories... accessories, spare parts, or tools will be treated as originating goods if the good is an originating...

  10. 19 CFR 10.456 - Accessories, spare parts or tools.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... good will be treated as a material used in the production of the good, if— (a) The accessories, spare... 19 Customs Duties 1 2011-04-01 2011-04-01 false Accessories, spare parts or tools. 10.456 Section... Trade Agreement Rules of Origin § 10.456 Accessories, spare parts or tools. Accessories, spare parts...

  11. 19 CFR 10.456 - Accessories, spare parts or tools.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... good will be treated as a material used in the production of the good, if— (a) The accessories, spare... 19 Customs Duties 1 2012-04-01 2012-04-01 false Accessories, spare parts or tools. 10.456 Section... Trade Agreement Rules of Origin § 10.456 Accessories, spare parts or tools. Accessories, spare parts...

  12. 19 CFR 10.456 - Accessories, spare parts or tools.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... good will be treated as a material used in the production of the good, if— (a) The accessories, spare... 19 Customs Duties 1 2013-04-01 2013-04-01 false Accessories, spare parts or tools. 10.456 Section... Trade Agreement Rules of Origin § 10.456 Accessories, spare parts or tools. Accessories, spare parts...

  13. 19 CFR 10.456 - Accessories, spare parts or tools.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... good will be treated as a material used in the production of the good, if— (a) The accessories, spare... 19 Customs Duties 1 2010-04-01 2010-04-01 false Accessories, spare parts or tools. 10.456 Section... Trade Agreement Rules of Origin § 10.456 Accessories, spare parts or tools. Accessories, spare parts...

  14. 19 CFR 10.920 - Accessories, spare parts, or tools.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Accessories, spare parts, or tools. 10.920 Section... Promotion Agreement Rules of Origin § 10.920 Accessories, spare parts, or tools. (a) General. Accessories... accessories, spare parts, or tools will be treated as originating goods if the good is an originating...

  15. 14 CFR 29.1163 - Powerplant accessories.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... continued rotation of an engine-driven cabin supercharger or any remote accessory driven by the engine will be a hazard if they malfunction, there must be means to prevent their hazardous rotation...

  16. 14 CFR 23.1163 - Powerplant accessories.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... in the event it malfunctions. (d) If the continued rotation of any accessory remotely driven by the engine is hazardous when malfunctioning occurs, a means to prevent rotation without interfering with...

  17. 14 CFR 29.1163 - Powerplant accessories.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... continued rotation of an engine-driven cabin supercharger or any remote accessory driven by the engine will be a hazard if they malfunction, there must be means to prevent their hazardous rotation...

  18. 14 CFR 23.1163 - Powerplant accessories.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... in the event it malfunctions. (d) If the continued rotation of any accessory remotely driven by the engine is hazardous when malfunctioning occurs, a means to prevent rotation without interfering with...

  19. 14 CFR 23.1163 - Powerplant accessories.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... in the event it malfunctions. (d) If the continued rotation of any accessory remotely driven by the engine is hazardous when malfunctioning occurs, a means to prevent rotation without interfering with...

  20. 14 CFR 23.1163 - Powerplant accessories.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... in the event it malfunctions. (d) If the continued rotation of any accessory remotely driven by the engine is hazardous when malfunctioning occurs, a means to prevent rotation without interfering with...

  1. 14 CFR 23.1163 - Powerplant accessories.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... in the event it malfunctions. (d) If the continued rotation of any accessory remotely driven by the engine is hazardous when malfunctioning occurs, a means to prevent rotation without interfering with...

  2. 14 CFR 29.1163 - Powerplant accessories.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... continued rotation of an engine-driven cabin supercharger or any remote accessory driven by the engine will be a hazard if they malfunction, there must be means to prevent their hazardous rotation...

  3. 46 CFR 169.671 - Accessories.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Electrical Electrical Installations Operating at Potentials of Less Than 50 Volts on Vessels of Less Than 100 Gross Tons § 169.671 Accessories. Each light, receptacle and switch exposed to the weather must...

  4. The Accessory Genome of Pseudomonas aeruginosa

    PubMed Central

    Kung, Vanderlene L.; Ozer, Egon A.; Hauser, Alan R.

    2010-01-01

    Summary: Pseudomonas aeruginosa strains exhibit significant variability in pathogenicity and ecological flexibility. Such interstrain differences reflect the dynamic nature of the P. aeruginosa genome, which is composed of a relatively invariable “core genome” and a highly variable “accessory genome.” Here we review the major classes of genetic elements comprising the P. aeruginosa accessory genome and highlight emerging themes in the acquisition and functional importance of these elements. Although the precise phenotypes endowed by the majority of the P. aeruginosa accessory genome have yet to be determined, rapid progress is being made, and a clearer understanding of the role of the P. aeruginosa accessory genome in ecology and infection is emerging. PMID:21119020

  5. Testing of containers made of glass-fiber reinforced plastic with the aid of acoustic emission analysis

    NASA Technical Reports Server (NTRS)

    Wolitz, K.; Brockmann, W.; Fischer, T.

    1979-01-01

    Acoustic emission analysis as a quasi-nondestructive test method makes it possible to differentiate clearly, in judging the total behavior of fiber-reinforced plastic composites, between critical failure modes (in the case of unidirectional composites fiber fractures) and non-critical failure modes (delamination processes or matrix fractures). A particular advantage is that, for varying pressure demands on the composites, the emitted acoustic pulses can be analyzed with regard to their amplitude distribution. In addition, definite indications as to how the damages occurred can be obtained from the time curves of the emitted acoustic pulses as well as from the particular frequency spectrum. Distinct analogies can be drawn between the various analytical methods with respect to whether the failure modes can be classified as critical or non-critical.

  6. The effect of different adhesive system applications on push-out bond strengths of glass fiber posts

    PubMed Central

    Deniz Arısu, Hacer; Üçtaşlı, Mine Betül; Okay, Tufan Can

    2013-01-01

    PURPOSE Over the past years, the adhesion of fiber posts luted with simplified adhesive systems has been a matter of great interest. The aim of this study was to assess the post retentive potential of a self-adhesive resin cement using different adhesive systems to compare the push-out bond strengths of fiber posts. MATERIALS AND METHODS The post spaces of 56 mandibular premolar roots were prepared and divided into 4 experimental groups and further divided into 2 subgroups according to testing time (n=7). The fiber posts (Rely X Fiber Post) were luted with a self-adhesive resin cement (RelyX Unicem) and one of the following adhesive systems: no adhesive, a total-etch adhesive resin (Single Bond), a two-step self-etch adhesive resin (Clearfil SE Bond) and a one-step self-etch adhesive resin (Clearfil S3 Bond). Each root was cut horizontally, and 1.5 mm thick six root segments were prepared. Push-out tests were performed after one week or three months (0.5 mm/min). Statistical analysis were performed with three-way ANOVA (α=.05). RESULTS Cervical root segments showed higher bond strength values than middle segments. Adhesive application increased the bond strength. For one week group, the total-etch adhesive resin Single Bond showed higher bond strength than the self-adhesive resin cement RelyX Unicem applied without adhesive resin at middle region. For 3 months group, the two-step self-etch adhesive resin Clearfil SE Bond showed the highest bond strength for both regions. Regarding the time considered, Clearfil SE Bond 3 months group showed higher bond strength values than one week group. CONCLUSION Using the adhesive resins in combination with the self-adhesive resin cement improves the bond strengths. The bond strength values of two-step self-etch adhesive resin Clearfil SE Bond improved as time passes. PMID:24049572

  7. Preparation of a biomimetic composite scaffold from gelatin/collagen and bioactive glass fibers for bone tissue engineering.

    PubMed

    Sharifi, Esmaeel; Azami, Mahmoud; Kajbafzadeh, Abdol-Mohammad; Moztarzadeh, Fatollah; Faridi-Majidi, Reza; Shamousi, Atefeh; Karimi, Roya; Ai, Jafar

    2016-02-01

    Bone tissue is a composite material made of organic and inorganic components. Bone tissue engineering requires scaffolds that mimic bone nature in chemical and mechanical properties. This study proposes a novel method for preparing composite scaffolds that uses sub-micron bioglass fibers as the organic phase and gelatin/collagen as the inorganic phase. The scaffolds were constructed by using freeze drying and electro spinning methods and their mechanical properties were enhanced by using genipin crosslinking agent. Electron microscopy micrographs showed that the structure of composite scaffolds were porous with pore diameters of approximately 70-200μm, this was again confirmed by mercury porosimetery. These pores are suitable for osteoblast growth. The diameters of the fibers were approximately 150-450nm. Structural analysis confirmed the formation of desirable phases of sub-micron bioglass fibers. Cellular biocompatibility tests illustrated that scaffolds containing copper ion in the bioglass structure had more cell growth and osteoblast attachment in comparison to copper-free scaffolds.

  8. Laparoscopic excision of infarcted accessory spleen.

    PubMed

    Yousef, Yasmin; Cameron, Brian H; Maizlin, Zeev V; Boutross-Tadross, Odette

    2010-04-01

    An accessory spleen is present in about 10-30% of the population and, usually, does not cause symptoms. We present a case report of an unusual presentation of accessory spleen infarction, with a literature review. A 12-year old male presented with acute left-upper quadrant pain that slowly resolved. An ultrasound and computed tomography scan showed a 3.5 x 2.5 x 2 cm solid mass abutting and displacing the splenic flexure of the colon, with surrounding inflammatory changes. This was interpreted as a colonic duplication cyst, and the boy was treated with antibiotics and underwent elective laparoscopic exploration. It was removed laparoscopically without complication and, on pathologic examination, proved to be consistent with an infarcted accessory spleen. Less than two dozen similar cases of accessory spleen infarction have been reported in the literature, most presenting with acute abdominal pain. Preoperative diagnoses included appendicitis, ovarian torsion, neoplasm, and, in our case, colonic duplication. The natural course of infarcted accessory spleen would be to atrophy, but, even with advanced imaging techniques, it may be impossible to diagnose infarcted accessory spleen with enough confidence to avoid surgery.

  9. Natural Fiber Composites: A Review

    SciTech Connect

    Westman, Matthew P.; Fifield, Leonard S.; Simmons, Kevin L.; Laddha, Sachin; Kafentzis, Tyler A.

    2010-03-07

    The need for renewable fiber reinforced composites has never been as prevalent as it currently is. Natural fibers offer both cost savings and a reduction in density when compared to glass fibers. Though the strength of natural fibers is not as great as glass, the specific properties are comparable. Currently natural fiber composites have two issues that need to be addressed: resin compatibility and water absorption. The following preliminary research has investigated the use of Kenaf, Hibiscus cannabinus, as a possible glass replacement in fiber reinforced composites.

  10. 21 CFR 878.4950 - Manual operating table and accessories and manual operating chair and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Manual operating table and accessories and manual operating chair and accessories. 878.4950 Section 878.4950 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY...

  11. 21 CFR 878.4960 - Operating tables and accessories and operating chairs and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Operating tables and accessories and operating chairs and accessories. 878.4960 Section 878.4960 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES...

  12. 21 CFR 878.4950 - Manual operating table and accessories and manual operating chair and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Manual operating table and accessories and manual operating chair and accessories. 878.4950 Section 878.4950 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY...

  13. 21 CFR 878.4960 - Operating tables and accessories and operating chairs and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Operating tables and accessories and operating chairs and accessories. 878.4960 Section 878.4960 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES...

  14. 21 CFR 878.4950 - Manual operating table and accessories and manual operating chair and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Manual operating table and accessories and manual operating chair and accessories. 878.4950 Section 878.4950 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY...

  15. 21 CFR 878.4960 - Operating tables and accessories and operating chairs and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Operating tables and accessories and operating chairs and accessories. 878.4960 Section 878.4960 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES...

  16. 21 CFR 878.4960 - Operating tables and accessories and operating chairs and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Operating tables and accessories and operating chairs and accessories. 878.4960 Section 878.4960 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES...

  17. 21 CFR 878.4950 - Manual operating table and accessories and manual operating chair and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Manual operating table and accessories and manual operating chair and accessories. 878.4950 Section 878.4950 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY...

  18. 21 CFR 878.4950 - Manual operating table and accessories and manual operating chair and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Manual operating table and accessories and manual operating chair and accessories. 878.4950 Section 878.4950 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY...

  19. 21 CFR 878.4960 - Operating tables and accessories and operating chairs and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Operating tables and accessories and operating chairs and accessories. 878.4960 Section 878.4960 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES...

  20. All-glass extrinsic Fabry-Perot interferometer thermo-optic coefficient sensor based on a capillary bridged two fiber ends.

    PubMed

    Cao, Zhitao; Jiang, Lan; Wang, Sumei; Wang, Mengmeng; Liu, Da; Wang, Peng; Zhang, Fei; Lu, Yongfeng

    2015-03-20

    An all-glass extrinsic Fabry-Perot interferometer (EFPI) is demonstrated for thermal-optic coefficient (TOC) of water, glycerol, and their mixture (volume ratio of 1:1). The compensation for the thermal expansion of Fabry-Perot (FP) cavity is realized by assembling a glass capillary and optical fibers through a CO2 laser welding. The thermal responses of EFPIs are tested in air at different cavity lengths of 578.6 μm, 911.7 μm, and 1520.3 μm, respectively. The corresponding refractive index errors induced by thermal expansion of FP cavity are negligible, which are demonstrated to be 4.33×10-6  RIU/°C, 4.13×10-6  RIU/°C, and 3.45×10-6  RIU/°C when temperature increases from 20.03°C to 60.78°C. The thermal-optic coefficients of water, glycerol, and their mixture are measured to be -1.5×10-4  RIU/°C, -2.3×10-4  RIU/°C, and -2.0×10-4  RIU/°C, respectively. Our study suggests a potential use of this sensor for TOC measurements of liquids with the advantages of low costs and robustness.