WorldWideScience

Sample records for vulcanized fibers

  1. Radiation vulcanization in Argentina

    International Nuclear Information System (INIS)

    Ferenaz, Guillermo W.; Smolko, Eduardo E.

    1999-01-01

    The possibilities of using in Argentina the radiation process to vulcanize natural latex are analyzed. Experimental studies to define the irradiation conditions have been carried out and the preliminary elaboration of an irradiation device that includes the chemical reactor has been started. (author)

  2. The Vulcan pulse generating system

    International Nuclear Information System (INIS)

    Danson, C.N.; Edwards, C.B.; Wyatt, R.W.W.

    1985-01-01

    During the past two years several changes have been made to the front end system on the VULCAN pulse generating system. These changes give greater flexibility and a wider choice of operating conditions. This note gives an updated description of the system capabilities, and gives users of the facility an idea of the various pulse combinations that are available. (author)

  3. The Vulcan Advanced Hybrid Manufacturing System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Made In Space is developing the The Vulcan Advanced Hybrid Manufacturing System (VULCAN) to address NASA's requirement to produce high-strength, high-precision...

  4. Development of rubber gloves by radiation vulcanization

    International Nuclear Information System (INIS)

    Makuuchi, K.; Yoshii, F.; Ishigaki, I.; Mogi, M.; Saito, T.

    1990-01-01

    The processes of radiation vulcanization and production of protective rubber gloves for radioactive contamination are described. A newly developed sensitizing system consisting of 5 phr 2-ethylhexyl acrylate and 1 phr carbon tetrachloride was used to vulcanize natural rubber latex at 12 kGy. Transparent and soft gloves were obtained from the radiation vulcanized latex by a coagulant dipping process. The mechanical properties of the gloves meet Japanese Industrial Standard specification for protective gloves. Combustion analysis of the gloves revealed that the amount of evolved sulfur dioxide and remaining ashes are less than those from commercially available rubber gloves. A trial usage of the gloves at a nuclear power plant showed that the gloves were easy to use for delicate work without undergoing fatigue. (author)

  5. Thermo-chemical de-vulcanization of suphur-vulcanized SBR assisted by de-vulcanization aids and oxidation stabilizers

    NARCIS (Netherlands)

    Saiwari, Sitisaiyidah; Dierkes, Wilma K.; Noordermeer, Jacobus W.M.

    2013-01-01

    Ground tire rubber (GTR) from whole passenger car tires is composed of several types of rubbers and fillers, making de-vulcanization of this material rather complicated. The most critical component in this material is SBR, as it tends to degrade and recombine during the commonly used reclaiming

  6. Production of medical supplies from elastomers vulcanized with ionizing radiation

    International Nuclear Information System (INIS)

    Guedes, Selma M.L.; Collantes, Hugo David Chirinos; Kodama, Yasko

    1996-01-01

    The silicon was vulcanized by gamma rays in the absence of organic peroxides. The natural rubber latex was vulcanized by gamma rays and electron beams in the absence and presence of sensitizer. The surgical gloves fabricated with latex containing nB-A vulcanized by gamma rays can be commercialized. Another expected applications are the development of the catheter and the material utilized in the radiotherapy treatment. (author)

  7. Vulcanization Kinetics of Natural Rubber Based On Free Sulfur Determination

    Directory of Open Access Journals (Sweden)

    Abu Hasan

    2013-05-01

    Full Text Available The determination of free sulfur in the rubber vulcanizates provided significant representation of vulcanization reaction. In this research, the effects of vulcanization temperature, the mixing method of carbon black into rubber, the ingredients mixing sequence and the type of carbon black were studied on masticated and milled natural rubber in which the reaction was observed by un-reacted sulfur determination. The results showed that higher vulcanization temperature provided faster vulcanization reaction and greater reaction rate constant. Similarly, the mixing sequence of ingredient and carbon black into rubber influenced the rate of vulcanization reaction. The subsequent ingredients mixing sequence, in this case, resulted in higher vulcanization rate compared to that of the simultaneous one. However, the mixing method of carbon black into rubber brought small effect on the rate of vulcanization reaction. The type of carbon black applied was observed to influence the reaction rate of vulcanization. Smaller particle sizes of carbon black gave larger reaction rate constant. In this case, the type of carbon black N 330 gave faster vulcanization rate than that of N 660.

  8. Radiation vulcanization of natural rubber latex

    International Nuclear Information System (INIS)

    Wan Manshol bin Wan Zin; Norjanah binti Mohid

    1994-01-01

    This paper describes the experimental techniques and the results of radiation vulcanization of natural rubber latex carried out on several high ammonia latices available in the country. The efficiency of various sensitisers and stabilisers used were evaluated in terms of the gamma radiation dose required to produce the maximum tensile strengths. The extent of crosslinking of RVNRL sample films were estimated by equilibrium swelling ratio measurements. The stability of pre-irradiated and post-irradiated samples were monitored using viscosity measurements as the parameter

  9. Thermal stability of radiation vulcanized EPDM rubber

    International Nuclear Information System (INIS)

    Abdel-Aziz, M.M.

    2005-01-01

    Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) have been used to study the thermal stability of gamma- ray vulcanized ethylene-propylene diene rubber (EPDM) stabilized with various types of antioxidants. The antioxidants used were penta erythrityl tetrakis(3,5- di-tert-butyl(-4-hydroxyphenyl)propionate (Irganox 1010), Irganox 1035, Irganox 1520 D, as primary antioxidants; Irganox B 561 and Irganox B 900, as synergistic blends; hindered amine light stabilizer (HALS), i.e. Tinuvin 622 LD; N-isopropyl-N-phenyl-p-phenylene diamine (IPPD) and Trimethyl quinoline (TMQ) and their mixtures. The measurements were carried out under atmospheric conditions. The effect of antioxidant type, selected concentration and mechanism of reaction were determined

  10. Radiation vulcanization of Philippine natural rubber latex

    International Nuclear Information System (INIS)

    Dela Rosa, A.M.; Abad, L.V.; Sta.Ana-Relleve, L.P.; Tranquilan-Aranilla, C.O.; Pascual, C.L.

    1996-01-01

    The response of Philippine natural rubber latex to irradiation vulcanization and the stability of the irradiated natural rubber latex (INRL) upon storage and aging were investigated. Commercially available high ammonia (HA) concentrated latices obtained from various rubber plantations in Mindanao island were treated with 5 phr of n-butyl acrylate (nBA), and gamma-irradiated at the PNRI 60 Co irradiation facility at a dose rate of 2.57 kGy/hr. Unirradiated cast latex films gave different green strengths which varied from 2-11 MPa. Cast films from INRL exhibited maximum tensile strengths were obtained from cast films with low Mg and high nitrogen contents. Thermal analysis using thermogravimetry (TG) revealed one major decomposition product at 374 o -377 o C. Its rate of decomposition decreased to a minimum at 15 kGy, then increased as radiation dose was increased. This trend correlated well with the tensile strength measurements. The stability of the INRL upon storage and aging is an essential parameter to the rubbe latex industry. For storage studies, INRL was stored for various periods of time. It was found that the pH and total solids content of the stored INRL did not change significantly after 12 months of storage; the MST values remained at above 1000 seconds, and the viscosity decreased with time. The cast films exhibited a decline in tensile strength, modulus 300% , and crosslinking density upon storage. While there were observed changes in the physical properties of the INRL during the storage period, the data indicate that these properties were within values acceptable to the latex industry. Tests on the aging properties of INRL films were undertaken. It was shown that among the chemical antioxidants presently used by the latex industry, TNPP demonstrated the highest antioxidant property, followed by Antage DAHQ and Vulcanox BKF. Our data indicate that the natural rubber latex produced and processed in the Philippines is suited for radiation vulcanization

  11. Industrial application of electron beams for grafting and vulcanization

    Energy Technology Data Exchange (ETDEWEB)

    Makuuchi, Keizo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1994-12-31

    The topics discussed are radiation graft polymerization; industrial application of radiation grafting - ion exchange membrane for a battery separator, ammonia adsorbent, non-flammable PE (polyethylene) foam; R and D on radiation grafting, radiation vulcanization of natural rubber.

  12. Radiation vulcanization of natural rubber latex sensitized with commercial gases

    Energy Technology Data Exchange (ETDEWEB)

    Chirinos, H.; Lugao, A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    2002-07-01

    The industrial activities using natural rubber latex are fully compatible with rural areas in Amazon and other places in Brazil, as well as in other tropical countries. However the classical sulfur vulcanization presents many occupational problems for the workers in rural areas. Radiation vulcanization of natural rubber latex is a much more friendly process as sulfur compounds are not needed for crosslinking, although chemicals as acrylate monomers, particularly multifunctional acrylates are still used as sensitizers for radiation processes. Two commercial gases, acetylene and butadiene, were selected as sensitizers for the radiation vulcanization of natural rubber latex instead of acrylates. These gases accelerate the crosslinking rates of the cure process and lower the radiation dose required to achieve vulcanization of natural rubber latex and improve the mechanical properties to reduce the tackiness of rubber goods. (author)

  13. Radiation vulcanization of natural rubber latex sensitized with commercial gases

    International Nuclear Information System (INIS)

    Chirinos, H.; Lugao, A.

    2002-01-01

    The industrial activities using natural rubber latex are fully compatible with rural areas in Amazon and other places in Brazil, as well as in other tropical countries. However the classical sulfur vulcanization presents many occupational problems for the workers in rural areas. Radiation vulcanization of natural rubber latex is a much more friendly process as sulfur compounds are not needed for crosslinking, although chemicals as acrylate monomers, particularly multifunctional acrylates are still used as sensitizers for radiation processes. Two commercial gases, acetylene and butadiene, were selected as sensitizers for the radiation vulcanization of natural rubber latex instead of acrylates. These gases accelerate the crosslinking rates of the cure process and lower the radiation dose required to achieve vulcanization of natural rubber latex and improve the mechanical properties to reduce the tackiness of rubber goods. (author)

  14. Industrial application of electron beams for grafting and vulcanization

    International Nuclear Information System (INIS)

    Keizo Makuuchi

    1994-01-01

    The topics discussed are radiation graft polymerization; industrial application of radiation grafting - ion exchange membrane for a battery separator, ammonia adsorbent, non-flammable PE (polyethylene) foam; R and D on radiation grafting, radiation vulcanization of natural rubber

  15. Radiation vulcanization of Philippine natural rubber latex

    International Nuclear Information System (INIS)

    Dela Rosa, Alumanda M.; Abad, Lucille V.; Sta, Lorna P.; Ana-Relleve; Tranquilan-Aranilla, Charito O.; Pascual, Cristina L.

    1996-01-01

    The response of Philippine natural rubber latex to radiation vulcanization and the stability of the irradiated natural rubber latex (INRL) upon storage and aging were investigated. Commercially available high ammonia (HA) concentrated lattices obtained from various rubber plantations in Mindanao Island were treated with 5 phr of n-butyl acrylate (nBA), and gamma-irradiated at the PNRI sup 60 Co irradiation facility at dose rate of 2.57 KGy/hr. Unirradiated cast latex films gave different green strength which varied from 2 - 11 MPa. Cast films from INRL exhibited maximum tensile strengths of 25 - 32 MPa at a radiation dose of 15 kGy. Higher tensile strengths were obtained from cast films with low Mg and high nitrogen contents. Thermal analysis using thermogravimetry (TG) revealed one major decomposition product at 374 degree C - 377 degree C. Its rate of decomposition decreased to a minimum at 15 kGy, then increased as radiation dose increased. This trend correlated well with the tensile strength measurements. The stability of the INRL upon storage and aging is an essential parameter to the rubber latex industry. For storage studies, INRL was stored for various periods of time. It was found that the pH and total solids content of the stored INRL did not change significantly after 12 months of storage; the MST values remained at above 100 seconds, and the viscosity decreased with time. The cast films exhibited a decline in tensile strength, modulus 300% and crosslinking density upon storage. While there were observed changes in the physical properties of the IRNL during the storage period, the data indicate that these properties were within values acceptable to the latex industry. Tests on the aging properties of INRL film were undertaken. It was shown that among the chemical antioxidants presently used by the latex industry. TNPP demonstrated the highest antioxidant property, followed by Antage DAHQ and Vulcanox BKF. Our data indicate that the natural rubber latex

  16. Pilot scale experiments on radiation vulcanization of NR latex

    Science.gov (United States)

    Ridwan, M.

    The potential of irradiated latex as raw material of commercial use is under testing on pilot plant scale in Indonesia which has 225 kCi Co-60 irradiation facility and can irradiate 1000 tonnes of centrifuged latex per annum. The facility was jointly designed by BATAN of Indonesia and JAERI of Japan and was jointly financed by UNDP/IAEA, Government of Japan and Government of Indonesia under UNDP/IAEA Regional Cooperative Agreement Project on Industrial Application of Isotopes and Radiation Technology. The facility is a water pool type and can accomodate 400 kCi Co-60. The Co-60 rack has two shapes, plate and cylindrical shapes. The plate shape source is used for natural rubber latex irradiation and the cylindrical one is used for other irradiation services. The vulcanization system consists of three major components : emulsification unit ( height : 650 mm, diameter 500 mm ), mixing unit ( height : 1900mm, diameter 1200 mm ) and vulcanization reactor ( height : 1800 mm, diameter 1300 mm ). The first two components are located outside shielded room while the third one-in irradiation room. The radiation vulcanization process is a much simpler energy saving process comparedto the conventional thermal process which has two vulcanization steps before and after dipping. The physical and mechanical properties of irradiated NR Latex are comparable to those of sulfur vulcanized, and depend on many factors such as irradiation dose, sensitizer content, dry rubber content and storage time.

  17. Continuous vulcanization of extruded profile by microwave process

    International Nuclear Information System (INIS)

    Lim Hun Soo

    1994-01-01

    Continuous vulcanization is being increasingly used today in the manufacture of extrusion profiles. This is particularly so with the microwave/hot air continuous vulcanization process. Although this process is now quite widely used in Europe and to a lesser extent in USA, it is still not used in Malaysia. To improve the technological capability of the rubber-based industry in extrusion product, the RRIM has acquired a microwave/hot air tunnel continuous vulcanization equipment to enable development work in this area to be carried out with the aim of upgrading the rubber industry towards this more automated manufacturing process. This is particularly pertinent in view of the anticipated labour shortage, and, increasing labour and energy cost. This paper outlines the basic principles of operation of the microwave/hot air tunnel continuous vulcanization process and describes some aspects of compounding involving natural and synthetic rubbers for use in the process. As temperature increase is one of the major factors influencing the vulcanization of profile in this process, study was therefore concentrated on the heat generation aspect in the microwave tunnel

  18. Pilot scale experiments on radiation vulcanization of NR latex

    International Nuclear Information System (INIS)

    Ridwan, M.

    1985-01-01

    The potential of irradiated latex as raw material of commercial use is under testing on pilot plant scale in Indonesia which has 225 kCi Co-60 irradiation facility and can irradiate 1000 tonnes of centrifuged latex per annum. The facility was jointly designed by BATAN of Indonesia and JAERI of Japan and was jointly financed by UNDP/IAEA, Government of Japan and Government of Indonesia under UNDP/IAEA Regional Cooperative Agreement Project on Industrial Application of Isotopes and Radiation Technology. The facility is a water pool type and can accommodate 400 kCi Co-60. The Co-60 rack has two shapes, plate and cylindrical shapes. The plate shape source is used for natural rubber latex irradiation and the cylindrical one is used for other irradiation services. The vulcanization system consists of three major components: emulsification unit, mixing unit and vulcanization reactor. The first two components are located outside shielded room while the third one in irradiation room. The radiation vulcanization process is a much simpler energy saving process compared to the conventional thermal process which has two vulcanization steps before and after dipping. The physical and mechanical properties of irradiated NR latex are comparable to those of sulfur vulcanized. (author)

  19. Radiation vulcanization of ethylene-propylene rubber with polyfunctional monomers

    Energy Technology Data Exchange (ETDEWEB)

    Jinhua, Wang; Yoshii, Fumio; Makuuchi, Keizo

    2001-01-01

    This paper reports on the sensitizing efficiency of several polyfunctional monomers to radiation vulcanization of ethylene-propylene rubber. And the results show that triethyleneglycol dimethacrylate (TEGDMA) gave the best results. TEGDMA not only lowers the vulcanization dose (D{sub v}), but also increases the tensile strength greatly. The content of TEGDMA does not affect the D{sub v} of TEGDMA-EPM, but affects the tensile strength at the D{sub v}. At best content (0.04 mol/100 g EPM), the tensile strength is increased from 6.0 to 12 MPa, and the elongation is 790% at the D{sub v}. (author)

  20. Influence of zinc oxide during different stages of sulfur vulcanization. Elucidated by model compound studies

    NARCIS (Netherlands)

    Heideman, G.; Datta, Rabin; Noordermeer, Jacobus W.M.; van Baarle, B.

    2005-01-01

    The addition of zinc oxide (ZnO) as an activator for the sulfur vulcanization of rubbers enhances the vulcanization efficiency and vulcanizate properties and reduces the vulcanization time. The first part of this article deals with the reduction and optimization of the amount of ZnO. Two different

  1. Effect of vulcanization temperature and humidity on the properties of RTV silicone rubber

    Science.gov (United States)

    Wu, Xutao; Li, Xiuguang; Hao, Lu; Wen, Xishan; Lan, Lei; Yuan, Xiaoqing; Zhang, Qingping

    2017-06-01

    In order to study the difference in performance of room temperature vulcanized (RTV) silicone rubber in vulcanization environment with different temperature and humidity, static contact angle method, FTIR and TG is utilized to depict the properties of hydrophobicity, transfer of hydrophobicity, functional groups and thermal stability of RTV silicone rubber. It is found that different vulcanization conditions have effects on the characteristics of RTV silicone rubber, which shows that the hydrophobicity of RTV silicone rubber changes little with the vulcanization temperature but a slight increase with the vulcanization humidity. Temperature and humidity have obvious effects on the hydrophobicity transfer ability of RTV silicone rubber, which is better when vulcanization temperature is 5°C or vulcanization humidity is 95%. From the Fourier transform infrared spectroscopy, it can be concluded that humidity and temperature of vulcanization conditions have great effect on the functional groups of silicone rubber, and vulcanization conditions also have effect on thermal stability of RTV silicone rubber. When vulcanization temperature is 5°C or vulcanization humidity is 15% or 95%, the thermal stability of silicone rubber becomes worse.

  2. Toxicological evaluation of natural rubber latex film vulcanized with ionizing radiation

    International Nuclear Information System (INIS)

    Campos, Vania E.; Higa, Olga Z.; Guedes, Selma M.L.; Hanada, Seico

    1999-01-01

    The industrial vulcanization of natural rubber latex (NRL) is made worldwide by conventional process using sulphur, but it can be made by an alternative process using ionizing radiation. The main advantages of this process are related to absence of toxic effect promoted by chemical substances added to the NRL on the conventional process. In this research was tested the toxicological properties of the films vulcanized by the alternative process in relation to that vulcanized by the conventional process. The toxicity was evaluated by in vitro cytotoxicity assay and in vivo systemic toxicity assay. The results showed that vulcanized films by gamma ray are less cytotoxic. The systemic toxicity assay showed that only the vulcanized film using sulphur induced allaying and motor in coordination on the animals for a short period of time. these results evidence the less cytotoxic properties of vulcanized films by gamma ray in relation to that vulcanized by conventional process using sulphur. (author)

  3. Extractable protein content of radiation vulcanized natural rubber latex films

    International Nuclear Information System (INIS)

    Ma'zam Md Said; Wan Manshol Wan Zin

    1996-01-01

    The effects of processing conditions on extractable protein content of coagulant dipped radiation vulcanized natural rubber latex films have been investigated. Drying of wet-gel of radiation vulcanized latex films even at a relatively low temperature of 70 degree C resulted in increases of extractable protein content of the films. The extractable protein content is dependent upon both the temperature and time of drying of wet-gel deposit. Wet-gel leaching of film alone is not adequate to reduce the extractable protein content of films to low levels. Combination of wet-gel leaching, post-leaching, a dip in corn starch slurry, followed by drying at a low temperature of 70 degree C reduces the extractable protein content of films to very low levels

  4. Proceedings of the international symposium on radiation vulcanization of natural rubber latex

    International Nuclear Information System (INIS)

    Machi, Sueo

    1990-01-01

    The First International Symposium on Radiation Vulcanization of Natural Rubber Latex (RVNRL) was held from 26 to 28 July 1989 at Tokyo and Takasaki. In these proceedings, thirty six papers presented at the Symposium are compiled. Main topics are commercial application of RVNRL, characterization of NR latex and vulcanization, properties of radiation vulcanized NR latex, development of sensitizers, mechanism of RVNRL, RVNRL with electron beams, and new Co-60 irradiator for RVNRL. Absence of nitrosamines and low cytotoxicity of radiation vulcanized NR latex are recognized as the remarkable advantages of RVNRL. The radiation vulcanization process for the production of protective rubber gloves for radioactive contamination was presented as the first commercial success in RVNRL. It was reported that various kinds of rubber articles for medical uses have being developed in West Germany. A sensitizer system consisting of n-butyl acrylate and t-butyl hydroperoxide was found to reduce the vulcanization dose to 8 kGy. (author)

  5. Radiation vulcanization of natural rubber latex (NRL) using low energy electron beam accelerator

    International Nuclear Information System (INIS)

    Feroza Akhtar; Keizo Makuuchi; Fumio Yoshii

    1996-01-01

    The electron beam induced vulcanization of natural rubber latex has been studied using low energy Electron Beam (EB) accelerators of 300, 250 and 175 keV ne latex was irradiated in a special type stainless steel reaction reactor with a stirrer at the bottom of the reactor. From the results it was found that 300 and 250 keV accelerators could effectively vulcanize NRL. But accelerator of 175 keV is too low energy to vulcanize the latex. At the same time a drum type irradiator where thin layer of NRL was irradiated by accelerator, was used for vulcanization of NRL. This type of irradiator also showed good physical properties of vulcanized latex. The effects of beam current and stirrer speed on vulcanization were studied

  6. Fiber

    Science.gov (United States)

    ... meals instead of white rice. Add beans (kidney, black, navy, and pinto) to rice dishes for even more fiber. Spice up salads with berries and almonds, chickpeas, cooked artichokes, and beans (kidney, black, navy, or pinto). Use whole-grain (corn or ...

  7. Application of radiation vulcanized natural rubber latex in Indonesia

    International Nuclear Information System (INIS)

    Soebianto, Y.S.; Wiwik Sofiarti; Razzak, M.T.

    1996-01-01

    The center has carried out R and D of Radiation Vulcanization Natural Rubber Latex (RVNRL) technology and introduced it to the industries since the inauguration and operation of the latex pilot plant in 1983. After years of experiences and the environmental consideration, n-butylacrylate (n-BA) has replaced CCI, as the sensitizer. Until now the introduction program shows that radiation vulcanized latex is more suitable for home industries than large industries. The obstacle of the program is the marketing of the dipped products. In spite of these problems, the introduction of this technology to the people in some undeveloped area of Java has supported the national program to improve their living standard. The problems of nitrosamine and protein allergic have turn up RVNRL to be the substitute of sulfur vulcanized latex in the future. The cooperation with a national condom manufacturer (PT Mitra Banjaran) has applied RVNRL for condom production in the large scale. Soft condoms with less probability of pinhole are obtained, but the technical problem is stickiness after pilling. Supply to a baby teat and a rubber thread manufacturer offers great advantages by not using any chemicals. In spite of the advantages, the problem of latex viscosity for dipping and the low modulus of elasticity of the threads arise. Through those input CAIR-BATAN is conducting the research and development in improving the crosslinking among the rubber particles that are supposed to be the reason of the stickiness and low modulus of elasticity. This effort is expected to be able to broaden the application of RVNRL, and it will be achieved only by the involvement of rubber chemist, rubber technologist, and radiation chemist

  8. Radiation vulcanization of natural rubber latex with low energy accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Haque, Emdadul; Makuuchi, Keizo; Ikeda, Kenichi; Yoshii, Fumio; Kume Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Mitomo, Hiroshi [Gunma Univ., Faculty of Engineering, Department of Biological and Chemical Engineering, Kiryu, Gunma (Japan)

    2001-03-01

    The radiation vulcanization of natural rubber latex (RVNRL) with the recently installed electron beam (EB) pilot plant at Takasaki Radiation Chemistry Research Establishment, Takasaki, Japan has been discussed. The accelerating voltage and beam current of the plant are 250 kV and 10 mA respectively. The plant has a reaction vessel with the capacity of 18 liters latex to irradiate at a time. In order to obtain a suitable setting of experimental for RVNRL under EB of the plant the parameters such as irradiation time, defoamer concentration, volume of latex, beam current etc. are being optimized by varying the individual parameter at a constant set of the other variables. (author)

  9. ESR investigation of NR and IR rubber vulcanized with different cross-link agents

    Directory of Open Access Journals (Sweden)

    P. Posadas

    2016-01-01

    Full Text Available This study evaluates the formation of radical species in natural rubber (NR and poly-isoprene rubber (IR during the vulcanization process and the uniaxial deformation of the formed networks by means of Electron Spin Resonance (ESR. Vulcanization of NR and IR always shows a radical pathway, where the different vulcanization systems dictate the concentration of radical species in the course of this complex process. The greatest concentration of radicals were detected during the vulcanization with sulfur/accelerator based on efficient systems (EV, followed by conventional (CV and sulfur donor systems, whereas azide and organic peroxide agents showed smaller concentration of radicals. Independently of the vulcanization system, certain amount of radicals was detected on the vulcanized samples after the end of the vulcanization process. Comparison between different matrices demonstrates that NR always shows higher concentration of radicals than IR in the vulcanization process as well as during uniaxial deformation, fact that could be associated to the presence of nonrubber components in NR.

  10. Development of an efficient process for radiation vulcanization of natural rubber latex using hydroperoxide with sensitizer

    International Nuclear Information System (INIS)

    Siri-upathum, C.; Sonsuk, M.

    1996-01-01

    An attempt was made to reduce irradiation dose for radiation vulcanization of natural rubber latex. A promising method was to partially crosslink the latex by radiation vulcanization using n-butyl acrylate (n-BA) as sensitizer and t-butyl hydroperoxide (BHPO) as a co-sensitizer followed by redox vulcanization using residual BHPO as an oxidant and either fructose or tetra ethylene penta mine as reducing agents. It was found that the irradiation dose was reduced to 4 kGy with 5 phr n-BA as sensitizer and 0.1 phr BHPO as co-sensitizer. Successive crosslinking to full vulcanization was done by redox vulcanization using either 4 phr fructose at 60 degree C for 3 hours of 0.4 phr tetra-ethylene penta mine at room temperature for 1 hour. The rubber films obtained had tensile strength of about 25 MPa, modulus 300% of 0.9 MPa and crosslink density of about 1.5 x 10 19 crosslink/cm 3 . It was noted that the rubber film from the co-vulcanization was the average value of the values obtained by radiation vulcanization and redox vulcanization

  11. Pathway for high-quality reclaim by thermal treatment of sulfur-vulcanized SBR

    NARCIS (Netherlands)

    Saiwari, Sitisaiyidah; Dierkes, Wilma K.; Noordermeer, Jacobus W.M.

    2011-01-01

    De-vulcanization of SBR (Styrene Butadiene Rubber) is a challenge, as the broken polymer chains tend to re-arrange. This influences the properties of the reclaimed and re-vulcanized rubber, and reduces the quality of the recycled material. Within this study, the breakdown of sulfur-cured SBR in a

  12. Progress in radiation vulcanization of natural rubber latex

    International Nuclear Information System (INIS)

    Makuuchi, Keizo

    2000-01-01

    Vulcanization dose defined as the radiation dose at which cross-linked natural rubber in latex has the maximum tensile strength can be reduced by adding carbon tetrachloride as a reaction accelerator. The radiation vulcanization of natural rubber latex was selected as one of regional projects of IAEA in 1989 and a pilot plant was built in Jakarta. The products from it were evaluated during 1983-1985, followed by IAEA decision to support the continued R and D study at Takasaki, JAERI. Various factors to improve the properties of the products have been studied. Several advantages of the process over conventional method, such as absence of N-nitrosoamines, low cytotoxicity, decomposability in the environment, transparency and softness, were confirmed. The technology has been transferred toward commercial application in Thailand, and pilot plants being set up in Indonesia, India, Malaysia and Thailand. Moreover, the process was found to be effective in reducing protein remaining in natural rubber latex products and the initial investment and irradiation cost was found to be greatly reduced by employing low energy electron accelerator. This paper reviews such progress. (S. Ohno)

  13. Cost evaluation of radiation vulcanization of natural rubber latex

    International Nuclear Information System (INIS)

    Makuuchi, K.

    2003-01-01

    Cost of radiation vulcanized NR latex was evaluated. The plant would be built in an existing dipping factory in an industrial area in a Southeast Asian country. One thousands dry tons of NR latex are vulcanized with a low energy electron accelerator. The electron accelerator is a self-shielding low energy type. The maximum accelerating voltage is 300 kV and the output power is 10 kW. The total construction cost of the plant is $400,000 including electron accelerator and other equipments. Costs of raw materials and utilities are $1.165 and $0.023 per one kg of product, respectively. The fixed costs of the plant consist of labor costs, labor overhead, maintenance, plant overhead, depreciation, and bank interest. It is $0.190/kg of product. The company overhead for operation including company management, R and D and insurance is $0.044/kg of product. Thus, the total production cost is estimated to be $1.422/kg of product. (author)

  14. Vulcan Hot Springs known geothermal resource area: an environmental analysis

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, S.G.; Russell, B.F. (eds.)

    1979-09-01

    The Vulcan Hot Springs known geothermal resource area (KGRA) is one of the more remote KGRAs in Idaho. The chemistry of Vulcan Hot Springs indicates a subsurface resource temperature of 147/sup 0/C, which may be high enough for power generation. An analysis of the limited data available on climate, meteorology, and air quality indicates few geothermal development concerns in these areas. The KGRA is located on the edge of the Idaho Batholith on a north-trending lineament which may be a factor in the presence of the hot springs. An occasional earthquake of magnitude 7 or greater may be expected in the region. Subsidence or elevation as a result of geothermal development in the KGRA do not appear to be of concern. Fragile granitic soils on steep slopes in the KGRA are unstable and may restrict development. The South fork of the Salmon River, the primary stream in the region, is an important salmon spawning grounds. Stolle Meadows, on the edge of the KGRA, is used as a wintering and calving area for elk, and access to the area is limited during this period. Socioeconomic and demographic surveys indicate that facilities and services will probably not be significantly impacted by development. Known heritage resources in the KGRA include two sites and the potential for additional cultural sites is significant.

  15. Toxicological evaluation of natural rubber films from vulcanized latex by the conventional process and the alternative process with ionizing radiation

    International Nuclear Information System (INIS)

    Campos, Vania Elisabeth

    1997-01-01

    The industrial vulcanization of natural rubber latex (NRL) is made all over the world by conventional process using sulphur and heat but it can be made by an alternative process using ionizing radiation. In this research the NRL was tested by 13 physical, chemical and mechanical assays which showed its good quality. It was done a preliminary study of the toxicological properties of 4 natural rubber films obtained by casting process of NRL: one non vulcanized, other vulcanized by the conventional process and two vulcanized by the alternative process. In the alternative process the films were obtained by irradiation of NRL by gamma rays from the 60 Co source at 250 kGy in the absence of sensitizer and irradiated NRL at 12 kGy in the presence of 4ph r of n-butyl acrylate / 0.2 phr of KOH. These vulcanization doses were determined from broken tensile strength. In the conventional process, sulphur vulcanized NRL was made using a classical composition. Another film was made with non vulcanized NRL. The preliminary evaluation of the toxicological properties was made from in vitro cytotoxicity and in vivo systemic toxicity assays. The LBN films vulcanized by the alternative process have less cytotoxicity than the NRL film vulcanized by the conventional process. The sensitized vulcanized films by gamma rays and non vulcanized films showed similar cytotoxicity while the vulcanized films without sensitizer showed a slight lower cytotoxicity. The non vulcanized NRL film and the NRL films vulcanized by the alternative process did not show toxic effects int he 72 hours period of the systemic toxicity assay. However the NRL film vulcanized with sulphur induced effects like allaying and motor in coordination on the animals treated with an oil extract at the fourth hour and recovering after that. The alternative process promoted lower toxic effects than conventional process because there was no toxic substances present. (author)

  16. Mechanism of n-butyl acrylate sensitization action in radiation vulcanization of natural rubber latex

    International Nuclear Information System (INIS)

    Sabharwal, S.; Chaudhari, C.V.; Bhardwaj, Y.K.; Majali, A.B.; Das, T.N.

    1996-01-01

    In order to understand the role of n-butyl acrylate (nBA) in radiation vulcanization of natural rubber latex, pulse radiolysis technique has been utilized to study the reactions of the transient species produced by reaction of OH . , e- aq and H . atoms with nBA in aqueous solutions. The results show that transients produced by reaction of e- aq with nBA alone are capable of propagating the polymerization reaction and enhance the vulcanization process. These results have been further confirmed by studying the effect of electron scavengers on the vulcanization behaviour of natural rubber latex in presence of nBA. (author). 3 refs., 3 figs

  17. The Effect of Novel Binary Accelerator System on Properties of Vulcanized Natural Rubber

    Directory of Open Access Journals (Sweden)

    Moez Kamoun

    2009-01-01

    Full Text Available The mechanical properties, curing characteristics, and swelling behaviour of vulcanized natural rubber with a novel binary accelerator system are investigated. Results indicate that the mechanical properties were improved. Crosslinking density of vulcanized natural rubber was measured by equilibrium swelling method. As a result, the new binary accelerator was found to be able to improve both cure rate and crosslinking density. Using the numerical analysis of test interaction between binary accelerator and operational modelling of vulcanization-factors experiments, it can be concluded that the interaction (Cystine, N-cyclohexyl-2-benzothiazyl sulfenamide was significant and the optimum value of binary accelerator was suggested, respectively, at levels 0 and +1.

  18. The mechanical properties of radiation-vulcanized NR/BR blending system

    Energy Technology Data Exchange (ETDEWEB)

    Yan Aoshuang E-mail: yanas@public3.bta.net.cn; Guo Zhengtao; Li Li; Zhai Ying; Zhou Peng

    2002-03-01

    The effect of radiation dose on the mechanical properties of NR/BR blending system is reported in this paper. A comparison was made between sulphur vulcanization and radiation vulcanization for an optimal nature rubber (NR)/ butyl rubber (BR) blending ratio (60/40) at dose range from 10 to 150 kGy. The result shows that the mechanical properties, especially, tensile strength, elongation at break, and tear strength have been improved significantly by radiation-vulcanization. This finding was also proved by thermal aging experiment on a selected NR/BR blend at 70 deg. C for up to 168 h.

  19. Radiation vulcanization of natural rubber latex using 250 keV electron beam machine

    Energy Technology Data Exchange (ETDEWEB)

    Chirinos, H.; Yoshii, F.; Makuuchi, K.; Lugao, A. E-mail: ablugao@net.ipen.br

    2003-08-01

    The sensitized radiation vulcanization of natural rubber latex has been carried out with 250 keV electrons. Latex was irradiated over a range of the beam current from 5 to 20 mA in the presence of sensitizers like the n-butyl acrylate (n-BA). The vulcanization dose decreases with increasing beam current condition. The rate of vulcanization (R{sub vul}) depends on the beam current (I) as given by the equation R{sub vul}=kI{sup 0.6}.

  20. Sulfonation of vulcanized ethylene-propylene-diene terpolymer membranes

    International Nuclear Information System (INIS)

    Barroso-Bujans, F.; Verdejo, R.; Lozano, A.; Fierro, J.L.G.; Lopez-Manchado, M.A.

    2008-01-01

    In the present work, sulfonation of previously vulcanized ethylene propylene diene terpolymer (EPDM) membranes was developed in a swelling solvent with acetyl sulfate. This procedure avoids the need to pre-dissolve the raw polymer. The reaction conditions were optimized in terms of solvent type, reaction time, acetyl sulfate concentration and film thickness to obtain the maximum degree of sulfonation of the polymer. The sulfonation procedure presented in this study yields a degree of sulfonation comparable to the chlorosulfonic acid procedure. Sulfonic acid groups were detected by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy, and quantified by titrations. Proton conductivity and water uptake were measured by means of impedance spectroscopy and swelling measurements, respectively, and were correlated with the degree of sulfonation. Tensile strength and Young's modulus of sulfonated EPDM increased with the degree of sulfonation, while elongation at break remained constant. Thermal stability of the sulfonated EPDM was studied by simultaneous thermogravimetry-mass spectroscopy

  1. Extractable protein of radiation vulcanized natural rubber latex

    International Nuclear Information System (INIS)

    Soebianto, Y.S.; Upul, R.M.; Makuuchi, K.; Yoshii, F.; Kume, T.

    2000-01-01

    A new method to reduce the protein level in the latex products by irradiation is reported. Water soluble protein (WSP) solution (10%) was added into radiation vulcanized NR latex (RVNRL) as much as 3 phr in three different processes: added to RVNRL, added to re-centrifuged RVNRL, and added to RVNRL followed by centrifugation. The protein content was determined by enhanced BCA method, and identified by SDS-PAGE analysis. Addition of WSP followed by centrifugation reduces EP up to the minimum protein detection, and shortens the leaching time to 20-30 min. SDS-PAGE analysis confirms the reduction of soluble protein in the serum phase, and disappearance of protein bands in the rubber extract. Protein-WSP interaction produces water soluble complex, and removed by centrifugation. The molecular weight of WSP dictates the efficiency of protein removal. (author)

  2. Extractable protein of radiation vulcanized natural rubber latex

    Energy Technology Data Exchange (ETDEWEB)

    Soebianto, Y.S. [Center for Research and Development of Isotopes and Radiation Technology, BATAN, Jakarta (Indonesia); Upul, R.M. [Rubber Research Institute of Sri Lanka, Ratmalana (Sri Lanka); Makuuchi, K.; Yoshii, F.; Kume, T. [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2000-03-01

    A new method to reduce the protein level in the latex products by irradiation is reported. Water soluble protein (WSP) solution (10%) was added into radiation vulcanized NR latex (RVNRL) as much as 3 phr in three different processes: added to RVNRL, added to re-centrifuged RVNRL, and added to RVNRL followed by centrifugation. The protein content was determined by enhanced BCA method, and identified by SDS-PAGE analysis. Addition of WSP followed by centrifugation reduces EP up to the minimum protein detection, and shortens the leaching time to 20-30 min. SDS-PAGE analysis confirms the reduction of soluble protein in the serum phase, and disappearance of protein bands in the rubber extract. Protein-WSP interaction produces water soluble complex, and removed by centrifugation. The molecular weight of WSP dictates the efficiency of protein removal. (author)

  3. Multifunctional Peroxidegas Alternative Crosslink Agents for Dynamically Vulcanized Expoxidized Natural Rubber/Polypropylene Blends

    NARCIS (Netherlands)

    Thitithammawong, A.; Thitithammawong, A.; Sahakaro, Kannika; Noordermeer, Jacobus W.M.

    2009-01-01

    Commonly used dicumyl peroxide (DCP) in combination with coagent, triallyl cyanurate (TAC), as a crosslinking agent is well acceptable for dynamically vulcanized rubber phase of thermoplastic vulcanizates (TPVs). However, it generally produces volatile decomposition products, which cause a typical

  4. A novel thermoplastic elastomer based on dynamically vulcanized polypropylene/acrylic rubber blends

    Directory of Open Access Journals (Sweden)

    2008-08-01

    Full Text Available Thermoplastic elastomer based on polypropylene (PP and acrylic rubber (ACM was investigated, with special attention on the compatibilization and dynamic vulcanization. ACM component contains chlorine and carboxyl groups along the backbone, which act as center for the curing and reactive compatibilization. The last event was carried out by adding a combination of maleic anhydride-modified PP (PP-g-MA and triethylene tetramine (TETA, which act as interfacial agents between PP and ACM phases. The effectiveness of the compatibilization was suggested from mixing torque and viscosity, determined from rheological measurements. Outstanding mechanical performance, especially elongation at break, and better tensile set (lower values were obtained with the compatibilization. The dynamic vulcanization also resulted in good mechanical properties for compatibilized blends, but the performance was inferior to that observed for non vulcanized blends. The effect of the compatibilization and/or dynamic vulcanization on the dynamic mechanical, thermal, morphological and stress relaxation properties was investigated.

  5. Vulcanization of rubber mixtures by simultaneous electron beam and microwave irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Martin, D. E-mail: martin@ifin.nipne.ro; Ighigeanu, D.; Mateescu, E.; Craciun, G.; Ighigeanu, A

    2002-08-01

    The comparative results obtained by applying separate electron beam (EB) irradiation and simultaneous EB and microwave (MW) irradiation to vulcanization of rubber mixtures based on natural rubber and polybutadiene rubber with carbon black are presented. In the absence of MW, EB irradiation doses of 200-250 kGy are required in order to obtain a higher vulcanization degree. The irradiation doses as well as irradiation times were markedly diminished, from 2 to 6 times, by simultaneous EB and MW irradiation.

  6. Comparative studies on sulfur, peroxide, and radiation vulcanization of EFDM rubber

    International Nuclear Information System (INIS)

    Abdel-Aziz, M.M.; Basfar, A.A.; Mofti, S.

    2000-01-01

    The temperature and concentration dependence of the vulcanization characteristics and mechanical properties of epdm rubber containing various concentrations of peroxide compounds was studied. The peroxides used are Luperox Di, Luperox 500-40 Ke, peroximon Dc Sc and peroximon Dc 40 Ke. The optimum cure parameters for the different types of peroxides indicated that Luperox Di, relatively, Give the best properties among the studied peroxides. The mechanical properties of EPDM containing different concentrations of Luperox Di and vulcanized at different temperatures were compared with those of either radiation or sulfur-cured EPDM. The modulus stress and tensile strength of the Luperox Di-cured EPDM were found to increase with either increasing the temperature of vulcanization and/ or concentration of the peroxide. Moreover, the tensile strength values are much higher than those of the sulfur-cured samples, except for those with low concentration of peroxide and vulcanized at relatively low temperature. A comparable result to those of the chemically vulcanized samples was attained by the radiation- vulcanized samples containing 1 phr of crosslinking agent and irradiated to 150 KGy

  7. Electron linear accelerator system for natural rubber vulcanization

    Science.gov (United States)

    Rimjaem, S.; Kongmon, E.; Rhodes, M. W.; Saisut, J.; Thongbai, C.

    2017-09-01

    Development of an electron accelerator system, beam diagnostic instruments, an irradiation apparatus and electron beam processing methodology for natural rubber vulcanization is underway at the Plasma and Beam Physics Research Facility, Chiang Mai University, Thailand. The project is carried out with the aims to improve the qualities of natural rubber products. The system consists of a DC thermionic electron gun, 5-cell standing-wave radio-frequency (RF) linear accelerator (linac) with side-coupling cavities and an electron beam irradiation apparatus. This system is used to produce electron beams with an adjustable energy between 0.5 and 4 MeV and a pulse current of 10-100 mA at a pulse repetition rate of 20-400 Hz. An average absorbed dose between 160 and 640 Gy is expected to be archived for 4 MeV electron beam when the accelerator is operated at 400 Hz. The research activities focus firstly on assembling of the accelerator system, study on accelerator properties and electron beam dynamic simulations. The resonant frequency of the RF linac in π/2 operating mode is 2996.82 MHz for the operating temperature of 35 °C. The beam dynamic simulations were conducted by using the code ASTRA. Simulation results suggest that electron beams with an average energy of 4.002 MeV can be obtained when the linac accelerating gradient is 41.7 MV/m. The rms transverse beam size and normalized rms transverse emittance at the linac exit are 0.91 mm and 10.48 π mm·mrad, respectively. This information can then be used as the input data for Monte Carlo simulations to estimate the electron beam penetration depth and dose distribution in the natural rubber latex. The study results from this research will be used to define optimal conditions for natural rubber vulcanization with different electron beam energies and doses. This is very useful for development of future practical industrial accelerator units.

  8. Extractable proteins from field radiation vulcanized natural rubber latex

    Energy Technology Data Exchange (ETDEWEB)

    Parra, Duclerc F. [Chemical and Environmental Centre, Nuclear Energy Research Institute, Av. Lineu Prestes, 2242-CEP Sao Paulo (Brazil)]. E-mail: dfparra@ipen.br; Pinto Martins, Carlos Felipe [Chemical and Environmental Centre, Nuclear Energy Research Institute, Av. Lineu Prestes, 2242-CEP Sao Paulo (Brazil); Collantes, Hugo D.C. [Chemical and Environmental Centre, Nuclear Energy Research Institute, Av. Lineu Prestes, 2242-CEP Sao Paulo (Brazil); Lugao, Ademar B. [Chemical and Environmental Centre, Nuclear Energy Research Institute, Av. Lineu Prestes, 2242-CEP Sao Paulo (Brazil)

    2005-07-01

    The type I allergy associated with the use of natural rubber latex (NRL) products is caused by the NRL proteins leached by the sweat or other body fluids. Makuuchi's group proposed for the first time the proteins removal by the addition of water-soluble polymers (WSP) on radiation vulcanization of natural rubber latex (RVNRL) that is a promising process under development in many countries. In this study, Brazilian field natural rubber was irradiated with a {sup 60}Co gamma source to reduce the content of WSP in the final product. WSP was used as additive to improve the extraction of protein. After irradiation the RVNRL was centrifuged to extract the WSP and proteins. The analytical methodology for protein content was based on the modified Lowry method according to ASTM D5712. Protein determination was carried out in serum of latex and in the extracts of the gloves. The concentration of extractable water-soluble proteins in serum of irradiated field NRL (NRL1), not irradiated one (NRL2); of twice centrifuged sample with polymer additive NRL (NRL3) and of the glove manufactured (NRLG) are compared with commercial glove (CG). The irradiation process increases the extractable water-soluble proteins, EP, as reported in the literature. In this study the use of polymeric additive on the bi-centrifugation process to remove protein was successful and the EP of the glove obtained in NRL3 was at around 40% of the commercial glove.

  9. Extractable protein of radiation vulcanized natural rubber latex

    International Nuclear Information System (INIS)

    Soebianto, Y.S.; Ratnayake, U.M.; Makuuchi, Keizo; Yoshii, Fumio; Kume, Tamikazu

    2000-01-01

    Protein remained in the latex products are reported to cause serious allergy. A new method to reduce the protein level in the latex products by irradiation is reported. Water soluble protein (WSP) solution (10%) was added into radiation vulcanized NR latex (RVNRL) in three different processes. The amount of WSP was 3 phr. It was only added to RVNRL (standard), added to re-centrifuged RVNRL (pre-centrifugation), and added to RVNRL followed by centrifugation (post-centrifugation). The protein content was determined by enhanced BCA method, and identified by SDS-PAGE. Extractable protein (EP) from the rubber has been reduced up to the minimum protein detection by combining WSP addition and centrifugation. Short leaching time (20-30 min.) can be achieved after the combine treatment, and SDS-PAGE confirms the reduction of soluble protein in the serum phase, and disappearance of protein bands in the rubber extract. Protein-WSP interaction produces water soluble complex, and removed by centrifugation. The efficiency of protein removal by WSP depends on its molecular weight of WSP which relates to its water solubility. (author)

  10. Mechanical Properties of Dynamically Vulcanized Thermoplastic Polyurethane (TPU/Polybutadiene Rubber (BR Blends

    Directory of Open Access Journals (Sweden)

    Ji-Hoo Kim

    2017-01-01

    Full Text Available To obtain thermoplastic polyurethane (TPU with low hardness, dynamically vulcanized TPU/polybutadiene rubber(BR(70/30 blends were prepared. The effect of dicumyl peroxide (DCP content and stabilizers on the tensile strength and elongation at break of the dynamically vulcanized blends was examined. The tensile strength and elongation at break of the dynamically vulcanized blends decrease with increasing content of DCP. The addition of optimal content of stabilizer leads to the improvement of tensile strength and elongation at break of the blends. Also, the effect of sulfur cure systems and accelerators on the tensile strength and elongation of the blends was investigated. The tensile strength and elongation at break of all the dynamically vulcanized TPU/BR (70/30 blends using 1-step processing are not higher than those of simple TPU/BR (70/30 blends. However, the tensile strength and elongation of the dynamically vulcanized blends prepared at 8 min (mixing time using 2-step processing are higher than those of the simple blends.

  11. Effects of radio sensitizers in the vulcanization of natural rubber latex induced by gamma radiation

    International Nuclear Information System (INIS)

    Souza, A. de; Canavel, V.; Araujo, S.C. de; Guedes, S.M.L.

    1992-01-01

    The effect of C Cl 4 and n-butyl acrylate as a sensitizer for radiation vulcanization of 60% DRC natural rubber latex with gamma rays, was studied relating tensile strength of vulcanized latex. The vulcanization dose is 200 kGy for natural rubber latex and it decreases to 40 kGy and to 9 kGy in the presence of C Cl 4 / potassium laureate and n-butyl acrylate / t-butyl hydroperoxide, respectively. The H 2 O 2 as a co-sensitizer does not change the efficiency of the combination of these sensitizers. The IV spectra show the formation of C=O after the irradiation as consequence of oxidation reactions. (author)

  12. On The compatibility and dynamic vulcanization of Pom/Nbr blends

    International Nuclear Information System (INIS)

    Mortezaee, M.; Naveed Family, M.H.; Mehrabzadeh, M.

    2001-01-01

    Polymer blends based on polyacetal butadiene rubber were prepared by melt blending technique. The mixing parameters such ad temperature, time and speed of mixing were varied to obtain a wide range of properties. The mixing parameters were optimized by evaluating the mechanical properties of the blend over a wide range of mixing conditions. The morphology of the blend indicated a two-phase structure. This study describes an attempt to improve the tensile strength of Pom/Nbr blends by means of compatibility and dynamic vulcanization. A commercial compatibility, maleic anhydride (Ma), has been used to control the phase morphology of the blend system. Dicumyl peroxide is used to dynamically vulcanize the Nbr elastomer in the blend. The tensile strength of the compatibility systems showed improvement. Dynamic vulcanization raises elastic recovery and tensile modulus of the blends, but the elongation at break decreases

  13. Radiation vulcanization of natural rubber latex using irradiation n-butyl acrylate aqueous emulsion as sensitizer

    International Nuclear Information System (INIS)

    Vo Van Thien; Nguyen Quoc Hien; Keizo Makuuchi; Fumio Yoshii

    2000-01-01

    Natural rubber latex was vulcanized by gamma radiation with n-butyl acrylate aqueous emulsion irradiated at dose of 1.5 kGy as sensitizer. The total solid content of latex increases on the irradiation dose. The viscosity of latex on the standing time was investigated and became stable after one month of storage. The gel content of latex films increasing with irradiation dose and attained more than 94% at dose of 10 kGy. Tensile strength of films reached the values of 31MPa; 30 Mpa and 25 Mpa at vulcanization doses of 20 kGy, 15 kGy and 8 kGy for the concentrations of sensitizer 7 phr, 9 phr and 13 phr respectively. Elongation at break decreases as increasing dose. Tear strength of rubber films was from 30-40 N/mm. The tackiness of latex films decreases and smell of vulcanized latex is almost negligible. (author)

  14. VULCAN: An Open-source, Validated Chemical Kinetics Python Code for Exoplanetary Atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Shang-Min; Grosheintz, Luc; Kitzmann, Daniel; Heng, Kevin [University of Bern, Center for Space and Habitability, Sidlerstrasse 5, CH-3012, Bern (Switzerland); Lyons, James R. [Arizona State University, School of Earth and Space Exploration, Bateman Physical Sciences, Tempe, AZ 85287-1404 (United States); Rimmer, Paul B., E-mail: shang-min.tsai@space.unibe.ch, E-mail: kevin.heng@csh.unibe.ch, E-mail: jimlyons@asu.edu [University of St. Andrews, School of Physics and Astronomy, St. Andrews, KY16 9SS (United Kingdom)

    2017-02-01

    We present an open-source and validated chemical kinetics code for studying hot exoplanetary atmospheres, which we name VULCAN. It is constructed for gaseous chemistry from 500 to 2500 K, using a reduced C–H–O chemical network with about 300 reactions. It uses eddy diffusion to mimic atmospheric dynamics and excludes photochemistry. We have provided a full description of the rate coefficients and thermodynamic data used. We validate VULCAN by reproducing chemical equilibrium and by comparing its output versus the disequilibrium-chemistry calculations of Moses et al. and Rimmer and Helling. It reproduces the models of HD 189733b and HD 209458b by Moses et al., which employ a network with nearly 1600 reactions. We also use VULCAN to examine the theoretical trends produced when the temperature–pressure profile and carbon-to-oxygen ratio are varied. Assisted by a sensitivity test designed to identify the key reactions responsible for producing a specific molecule, we revisit the quenching approximation and find that it is accurate for methane but breaks down for acetylene, because the disequilibrium abundance of acetylene is not directly determined by transport-induced quenching, but is rather indirectly controlled by the disequilibrium abundance of methane. Therefore we suggest that the quenching approximation should be used with caution and must always be checked against a chemical kinetics calculation. A one-dimensional model atmosphere with 100 layers, computed using VULCAN, typically takes several minutes to complete. VULCAN is part of the Exoclimes Simulation Platform (ESP; exoclime.net) and publicly available at https://github.com/exoclime/VULCAN.

  15. Environmental Exposure and Accelerated Testing of Rubber-to-Metal Vulcanized Bonded Assemblies

    Science.gov (United States)

    1974-11-01

    btadiene/acrylonitrile ( NBR ) rubber -to-metat -. canized bonded assemblies at the two exposure sites are shown in Table 5. After exposure for one year...AD-A0-17 368 EN~VIRONMENTAL EXPOSURE AND ACCELERATED TESTING OF RUBBER -TO-METAL VULCANIZED BONDED ASSEMBLIES John A. WilliamsI Rock Island Arseital...COMMERCE 325116 1AD R-TR-75-013 ENViRONMENTAL EXPOSURE AND ACCELERATED TESTING OF RUBBER -TO-METAL VULCANIZED BONDED ASSEMBLIES by __ John A. Williams

  16. The influence of radiolytic sensitizers in natural rubber latex vulcanization induced by ionizing radiation

    International Nuclear Information System (INIS)

    Guedes, S.M.L.; Souza, A. de

    1991-01-01

    This work made on radiation vulcanization of natural rubber latex process by gamma rays from 60 Co source and electron beam of 1.5 MeV, 25 m A by Dynamitron, instead of classic process using sulfur. The experiment was carried out to study the influence of sensitizers (C Cl 4 and n-butyl acrylate) and was reported the vulcanization dose for each sensitizers, related to maximum tensile strength. The results show the possibility to introduce the volatile sensitizer (n-butyl acrylate) instead of C Cl 4 (toxic) in industry applications. (author)

  17. Surgical gloves fabrication using natural rubber latex vulcanized with gamma radiation

    International Nuclear Information System (INIS)

    Collantes, Hugo David Chirinos.

    1995-01-01

    Surgical gloves were manufactured by immersion coagulant method from vulcanized natural rubber latex by gamma rays at dose of 10 kGy in the air, at room temperature, using the following sensitizer vulcanization An-B 3 phr/KOH 0.2 phr. The influence of the parameter in the thickness of the surgical gloves manufacture, studied through fractional factorial designs technic, can be resumed by empirical linear correlation: y = 0.213 + 0.025 [Ca Cl 2 ] + 0.019 t. (author). 49 refs., 13 figs., 31 tabs

  18. Radiation Vulcanization of Natural Rubber Latex (RVNRL): A Potential Material for Nuclear Power Plant Gloves

    International Nuclear Information System (INIS)

    Pairu Ibrahim; Wan Manshol Wan Zain; Keong, C.C.; Mohd Noorwadi Mat Lazim

    2011-01-01

    Radiation vulcanization of natural rubber latex has great potential for the production of nuclear power plant gloves due to its low ash and mineral content. And this is in-line with the role played by Malaysian Nuclear Agency as Technical Supporting Organization for Nuclear Power Program. This paper discussed the evaluation done to determine ash content in RVNRL and SVNRL films. Both samples were prepared using casting technique and the properties were compared. Films prepared from raw latex without any vulcanizing agent were regarded as a control. (author)

  19. Analysis of Aqueous Extractable Protein in Radiation Pre vulcanized Natural Rubber Latex (RVNRL) And Sulphur Pre vulcanized Natural Rubber Latex (SVNRL)

    International Nuclear Information System (INIS)

    Sofian Ibrahim; Mohd Noor Wadi Mat Lazim; Syuhada Ramli; Keong, C.C.; Khairul Hisyam Mohd Yusof; Muhammad Saiful Omar; Najib Mohd Zakey; Hafizuddin Maseri; Noor Hasni Mohd Ali

    2015-01-01

    The use of radiation do not only produces Radiation Pre vulcanized Natural Rubber Latex (RVNRL) that can be used for the production of nitrosamines free products, moreover, RVNRL also able to exclude type IV allergy that caused by high protein content in the products. Leaching water from production of finger coat from RVNRL and Sulphur Pre vulcanized Natural rubber Latex (SVNRL) has been collected. Extractable protein content from water samples measured according to the test protocol ASTM D5712-2010. Water from leaching process of finger coat made from RVNRL showed a higher protein content than SVNRL. This explains why RVNRL based products contain very low protein content and thus reduce the risk of Type IV allergy. (author)

  20. Biodegradability and aging study of rubber films obtained by gamma radiation vulcanization processes of latex

    International Nuclear Information System (INIS)

    Martins, Carlos Felipe Pinto

    2005-01-01

    The natural rubber latex (NRL) is industrially crosslinked by the conventional process of vulcanization, which uses sulphur and heat. Otherwise, the network can also be done by the alternative process with ionizing radiation. In this work the crosslinking of NRL was studied by the comparison of the conventional vulcanization system and the ionizing radiation process of 60 C source. The products obtained, the irradiated latex, the irradiated latex with approximately 1% of soy lecithin and the sulphur vulcanized latex were tested by accelerated aging with ultraviolet (UV) and outdoor aging with compostage, tensile strength at break, swelling and gel fraction, fungi micro biota, scanning electron microscopy (SEM), infrared spectroscopy (FTIR) and thermogravimetry and differential scanning calorimetry analysis (TG and DSC). The results showed that the aging with microorganisms have a great influence in the physical properties of the samples. The thermal stability order observed showed that the sulphur vulcanized latex is more resistant, what is probably associated to a network more stable under the aging conditions. On the other hand, the irradiated latex showed intense biodegradation aspects, particularly with the presence of the soy lecithin. (author)

  1. Effect of phenol formaldehyde resin as vulcanizing agent on flow behavior of HDPE/PB blend

    Directory of Open Access Journals (Sweden)

    Moayad N. Khalaf

    2014-07-01

    Full Text Available Thermoplastic elastomer (TPE based on High density polyethylene (HDPE/polybutadiene (HDPE/PB = 70/30 parts blends containing 1, 3, 5, 7 and 10 wt.% of dimethylol phenolic resin as a vulcanizing agent in the presence of SnCl2 as catalyst was prepared. The dimethylol phenolic resin was prepared in our laboratory. The blends were compounded in mixer-60 attached to a Haake rheochord meter-90. The rheological properties were measured at temperatures 140, 160, 180 and 200 °C. The linearity of the flow curve appeared for 5% of the vulcanizing agent. The shear stress and shear viscosity have increased upon increasing the shear rate over a range of loading levels of vulcanizing agent of 1%, 3%, 5%, 7% and 10%. This may be attributed to the increased vulcanization between polyethylene and the rubber blend. The flow behavior index of the system shows a pseudo plastic nature behavior (since n < 1. The consistency index (K increased with the increase in the phenol formaldehyde resin content and the temperature. Hence, the increase in the value of the consistency index (K of the polymer melts refers to more viscous materials prepared. The activation energy for the TPE blends fluctuated indicating that there is phase separation; where each polymer behaved separately. This study showed that HDPE/PB blends are characterized with good rheological properties, which can be recommended to be processed with the injection molding technique.

  2. Preparation of the vulcan XC-72R-supported Pt nanoparticles for the hydrogen evolution reaction in PEM water electrolysers

    International Nuclear Information System (INIS)

    Nguyen, Huy Du; Nguyen, T Thuy Luyen; Nguyen, Khac Manh; Ha, Thuc Huy; Nguyen, Quoc Hien

    2015-01-01

    Pt nanoparticles on vulcan XC-72R support (Pt/vulcan XC-72R) were prepared by the impregnation–reduction method. The Pt content, the morphological properties and the electrochemical catalysis of the Pt/vulcan XC 72R materials have been investigated by ICP-OES analysis, FESEM, TEM, and cyclic voltammetry. These materials were then used as catalyst for hydrogen evolution reaction at the cathode of proton exchange membrane (PEM) water electrolysers. The best catalyst was Pt/vulcan XC-72R prepared by the impregnation–reduction method which is conducted in two reducing steps with the reductants of sodium borohydride and ethylene glycol, respectively. The current density of PEM water electrolysers reached 1.0 A cm"−"2 when applying a voltage of 2.0 V at 25 °C. (paper)

  3. The Effect of Gamma Irradiation on the Mechanical Properties of vulcanized Natural Rubber and Natural Rubber-Polyethylene Blends

    International Nuclear Information System (INIS)

    Sudradjat Iskandar

    2008-01-01

    To enhance the quality of vulcanized natural rubber and natural rubber-polyethylene blends, gamma irradiation has been done. The compound of natural rubber and natural rubber-polyethylene blends made by using roll mill machine. The mixed materials were antioxidant, anti ozon, plasticizer and vulcanisator. The natural rubber and natural rubber-polyethylene blends compound were vulcanizer and made a slab (film of sample) using hot and could press machine. The slabs produced were then gamma irradiated at irradiation dose of 75, 150 and 300 kGy. Before and after irradiation, the slab were characterized using strograph R1 machine. The results showed that the modulus 300 and hardness of vulcanized natural rubber and natural rubber-polyethylene blends were increasing; the tensile strength and tear strength were increasing to maximum level then decreasing with gamma irradiation, while the elongation at break was decreasing. The maximum tensile strength of vulcanized natural rubber and natural rubber-polyethylene blends were found at irradiation dose of 75 kGy. At the irradiation dose of 75 kGy, the tensile strength of vulcanized natural rubber increased from 17.6 MN/m 2 to 21.2 MN/m 2 , while the tensile strength of vulcanized natural rubber-polyethylene blends increased slightly from 18.7 MN/m 2 to 19.4 MN/m 2 . (author)

  4. Crosslinked bicontinuous biobased PLA/NR blends via dynamic vulcanization using different curing systems.

    Science.gov (United States)

    Yuan, Daosheng; Chen, Kunling; Xu, Chuanhui; Chen, Zhonghua; Chen, Yukun

    2014-11-26

    In this study, blends of entirely biosourced polymers, namely polylactide (PLA) and natural rubber (NR), were prepared through dynamic vulcanization using dicumyl peroxide (DCP), sulphur (S) and phenolic resin (2402) as curing agents, respectively. The crosslinked NR phase was found to be a continuous structure in all the prepared blends. The molecular weight changes of PLA were studied by gel permeation chromatography. Interfacial compatibilization between PLA and NR was investigated using Fourier transform infrared spectroscopy and scanning electron microscopy. The thermal properties of blends were evaluated by differential scanning calorimetry and thermogravimetric analysis instrument. It was found that the molecular weight of PLA and interfacial compatibilizaion between PLA and NR showed a significant influence on the mechanical and thermal properties of blends. The PLA/NR blend (60/40 w/w) by DCP-induced dynamic vulcanization owned the finest mechanical properties and thermal stability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Aspectos históricos da vulcanização Historical aspects of vulcanization

    Directory of Open Access Journals (Sweden)

    Helson M. da Costa

    2003-06-01

    Full Text Available As borrachas, para serem convertidas em materiais úteis do ponto de vista de aplicações, precisam ser misturadas a alguns ingredientes, os quais vão lhes dar as características desejadas para, então, serem vulcanizadas. Neste artigo, os aspectos históricos da vulcanização são abordados bem como a evolução dos aditivos essenciais à maioria das formulações.Rubbers, to be turned into useful materials from the commercial applications point of view, need the addition of a few other ingredients which, upon vulcanization, will impart the desired characteristics to the material. In this paper, historical aspects of vulcanization are revised as well as the evolution of the additives used in most of the formulations.

  6. MATERIAL PARAMETER OF RUBBER GLOVE VULCANIZED USING COMBINED INFRARED AND HOT-AIR HEATING

    OpenAIRE

    Tipapon Khamdaeng; Numpon Panyoyai; Thanasit Wongsiriamnuay

    2014-01-01

    Vulcanization is an important chemical-thermal process in production of rubber products resulting in change of material properties, increased elasticity and strength. In general, Young’s modulus is used as an indicator of elastic deformation at loading configuration. However, rubber is not truly elastic and a single parameter is insufficient to describe the whole deformation contributed by microstructure of rubber network. Therefore, we present the material parameters concerning the mec...

  7. Elastomeric Nanocomposite Based on Exfoliated Graphene Oxide and Its Characteristics without Vulcanization

    OpenAIRE

    Nasser Abdullah Habib; Buong Woei Chieng; Norkhairunnisa Mazlan; Umer Rashid; Robiah Yunus; Suraya Abdul Rashid

    2017-01-01

    Rubber nanocomposites have emerged as one of the advanced materials in recent years. The aim of this work was to homogeneously disperse graphene oxide (GO) sheets into Nitrile Butadiene Rubber (NBR) and investigate the characteristics of GO/NBR nanocomposite without vulcanization. A suitable solvent was found to dissolve dry NBR while GO was exfoliated completely in an aqueous base solution using sonication. GO was dispersed into NBR at different loadings by solution mixing to produce unvulca...

  8. Vulcanization Kinetics and Mechanical Properties of Ethylene Propylene Diene Monomer Thermal Insulation

    Directory of Open Access Journals (Sweden)

    Mohamad Irfan Fathurrohman

    2015-07-01

    Full Text Available The vulcanization kinetics of Ethylene-propylene diene monomer (EPDM rubber thermal insulation was studied by using rheometer under isothermal condition at different temperatures. The rheometry analysis was used to determining the cure kinetic parameters and predicting the cure time of EPDM thermal insulation. The experimental results revealed that the curing curves of EPDM thermal insulation were marching and the optimum curing time decreased with increasing the temperature. The kinetic parameters were determined from the autocatalytic model showed close fitting with the experimental results, indicating suitability of autocatalytic model in characterizing the cure kinetics. The activation energy was determined from the autocatalytic model is 46.3661 kJ mol-1. The cure time were predicted from autocatalytic model and the obtained kinetic parameter by using the relationship among degree of conversion, cure temperature, and cure time. The predictions of cure time provide information for the actual curing characteristic of EPDM thermal insulation. The mechanical properties of EPDM thermal insulation with different vulcanization temperatures showed the same hardness, tensile strength and modulus at 300%, except at temperature 70 °C, while the elongation at breaking point decreased with increasing temperature of vulcanization. © 2015 BCREC UNDIP. All rights reservedReceived: 8th April 2014; Revised: 7th January 2015; Accepted: 16th January 2015How to Cite: Fathurrohman, M.I., Maspanger, D.R., Sutrisno, S. (2015. Vulcanization Kinetics and Mechanical Properties of Ethylene Propylene Diene Monomer Thermal Insulation. Bulletin of Chemi-cal Reaction Engineering & Catalysis, 10 (2, 104-110. (doi:10.9767/bcrec.10.2.6682.104-110Permalink/DOI: http://dx.doi.org/10.9767/bcrec.10.2.6682.104-110 

  9. New infrared transmitting material via inverse vulcanization of elemental sulfur to prepare high refractive index polymers.

    Science.gov (United States)

    Griebel, Jared J; Namnabat, Soha; Kim, Eui Tae; Himmelhuber, Roland; Moronta, Dominic H; Chung, Woo Jin; Simmonds, Adam G; Kim, Kyung-Jo; van der Laan, John; Nguyen, Ngoc A; Dereniak, Eustace L; Mackay, Michael E; Char, Kookheon; Glass, Richard S; Norwood, Robert A; Pyun, Jeffrey

    2014-05-21

    Polymers for IR imaging: The preparation of high refractive index polymers (n = 1.75 to 1.86) via the inverse vulcanization of elemental sulfur is reported. High quality imaging in the near (1.5 μm) and mid-IR (3-5 μm) regions using high refractive index polymeric lenses from these sulfur materials was demonstrated. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Study on preparation of new antioxidants for radiation vulcanized natural rubber latex product. Antioxidant from keratin

    International Nuclear Information System (INIS)

    Nguyen Quoc Hien; Nguyen Van Toan; Vo Tan Thien; Le Hai

    2000-01-01

    The thermo-oxidative aging resistance of radiation vulcanization of natural rubber latex (RVNRL) products should be adequately by using suitable antioxidants or new kind of effective antioxidant. This work presents the results of preparation of natural antioxidant from hair keratin. Characteristics and effectiveness of resultant antioxidant are also presented. The results obtained indicates that antioxidant made from hair keratin is safe and effective for rubber products from RVNRL. (author)

  11. Test trial radiation vulcanization of natural rubber latex in Jakarta Indonesia

    International Nuclear Information System (INIS)

    Devendra, R.; Kulatunge, S.S.; Chandralal, H.N.K.K.; Kalyani, N.M.V.; Seneviratne, J.; Wellage, S.

    1994-01-01

    Radiation vulcanization of natural rubber latex (RVNRL) can be used to make large quantities of specially stabilized latex. It is possible to obtain RVNRL films of tensile strength over 25 MPa. The films could be either coagulant dipped or cast. It is very important to determine the correct radiation dose which gives the maximum tensile strength. Cross linking density or prevulcanized relax modulus (PRM) at 100% is a reliable property to control the prevulcanization

  12. Vulcanization characteristics and dynamic mechanical behavior of natural rubber reinforced with silane modified silica.

    Science.gov (United States)

    Chonkaew, Wunpen; Minghvanish, Withawat; Kungliean, Ulchulee; Rochanawipart, Nutthaya; Brostow, Witold

    2011-03-01

    Two silane coupling agents were used for hydrolysis-condensation reaction modification of nanosilica surfaces. The surface characteristics were analyzed using Fourier transform infrared spectroscopy (FTIR). The vulcanization kinetics of natural rubber (NR) + silica composites was studied and compared to behavior of the neat NR using differential scanning calorimetry (DSC) in the dynamic scan mode. Dynamic mechanical analysis (DMA) was performed to evaluate the effects of the surface modification. Activation energy E(a) values for the reaction are obtained. The presence of silica, modified or otherwise, inhibits the vulcanization reaction of NR. The neat silica containing system has the lowest cure rate index and the highest activation energy for the vulcanization reaction. The coupling agent with longer chains causes more swelling and moves the glass transition temperature T(g) downwards. Below the glass transition region, silica causes a lowering of the dynamic storage modulus G', a result of hindering the cure reaction. Above the glass transition, silica-again modified or otherwise-provides the expected reinforcement effect.

  13. Vulcanization of polybutadiene latex induced by 60Co γ-rays irradiation

    International Nuclear Information System (INIS)

    Liu Yuguang; Huang Yudong; Hou Jing; Gao Deyu; Zhang Xuequan

    2007-01-01

    Fully vulcanized polybutadiene rubber particles (FVBR) were prepared by polybutadiene latex (PBL) vulcanization induced by 60 Co γ-rays irradiation, and the effect of absorbed dose on crosslinking behavior was studied. Mean diameter, diameter distribution and morphology of the particles in the PBL irradiated at different doses as well as in the FVBR were characterized by laser particle analyzer and AFM. The crosslinking effect on the mechanical properties of the films, by casting from PBL at different doses correspondingly, was evaluated by mechanical and dynamic mechanical analysis (DMA) respectively. The results showed that the diameter and swelling property decreased with absorbed dose, while crosslink density and gel fraction increased. Moreover, the decrease of the tensile strength and elongation at break, the increase of the hardness in shore A and young's modulus (E), and the increase of storage modulus (E') and narrowing of loss tangent peak (Tan 8) were all accounted for the increment of crosslinking. The Charlesby-Pinner equation fits well with the PBL vulcanization in the range of absorbed doses from 0 to 200kGy. (authors)

  14. Antioxidant and sensitizer effect on the stability of natural rubber latex vulcanized by gamma rays

    International Nuclear Information System (INIS)

    Canavel, V.

    1993-01-01

    The natural rubber latex was vulcanized by gamma rays and electrons beam, in the presence and absence of sensitizer at room temperature. The sensitizers were the following; n-butyl acrylate (n-BA) / t-butyl hydroperoxide (t-B H) / KOH, C Cl 4 / potassium laurate and n-BA / KOH. The studied antioxidants, Irganox 1520, Vulcanox SP and Vulcanox BKF, were added to the latex after irradiation. Among the studied antioxidants in function of tensile strength (TS) after the aging of rubber plates, the Irganox was the best efficient on the gamma vulcanization in the presence of n-BA/t-B H/KOH, because only 0,20 p hr is enough to obtain the greatest increase of TS, that was 34%, 12 MPa to 16 MPa. The formulating method of latex with the sensitizer constituted the 3,0 p hr of n-BA/ 0,1 p hr of t-B H and 0,2 p hr of KOH, was evaluated respecting the TS of rubber plates. The electrons beam vulcanization produces the greatest reversible perturbance in the colloidal stability of latex after irradiation caused by radiolytic species absorption that promotes the increase of particle size. The antioxidant also contributes to reversible destabilization of gamma irradiated latex, because it is also adsorbed by particles surface. The relation between the latex viscosity and the TS of respective rubber plates is reverse, showing the latex stability affects the quality of rubber goods. (author)

  15. Radiation vulcanization of natural rubber latex with low energy accelerator-II

    Energy Technology Data Exchange (ETDEWEB)

    Haque, Md. Emdadul; Makuuchi, Keizo; Ikeda, Kenichi; Yoshii, Fumio; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Mitomo, Hiroshi [Gunma Univ., Faculty of Engineering, Dept. of Biological and Chemical Engineering, Kiryu, Gunma (Japan)

    2002-03-01

    The natural rubber latex (NRL) was radiation vulcanized under a low energy electron accelerator. Accelerating voltage and maximum beam current of this accelerator are 250 kV and 10 mA respectively. Irradiation was carried out in a reaction vessel with constant stirring. The capacity of the vessel is 18 liters. Radiation vulcanization accelerators (RVA) were normal butyl acrylate (n-BA) and nonane-diol-diacrylate (NDDA). NDDA has no bad smell like that of n-BA. 20 minutes irradiation time is enough to vulcanize 14 liters of latex when 5 phr RVA (both types) are used. Maximum of {approx}30 MPa tensile strength was obtained with 5 phr NDD-A. However the remained NDDA is difficult to remove due to high molecular weight. Water-extractable proteins content was determined in dipped films for various leaching conditions without and with additive (polyvinyl alcohol, PVA). Water extractable proteins content is reduced to {<=} 41 by adding 5 phr PVA and leaching for 8 hours. The tackiness of the dipped films is reduced to 0.1 from 9 gf by mixing 6 phr PVA with the irradiated latex. Hand gloves (surgical and examination) were successfully produced from the irradiated latex. (author)

  16. Production of medical supplies from elastomers vulcanized with ionizing radiation; Obtencao de artefatos medicos a partir de elastomeros vulcanizados com radiacao ionizante

    Energy Technology Data Exchange (ETDEWEB)

    Guedes, Selma M.L.; Collantes, Hugo David Chirinos; Kodama, Yasko [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    1996-07-01

    The silicon was vulcanized by gamma rays in the absence of organic peroxides. The natural rubber latex was vulcanized by gamma rays and electron beams in the absence and presence of sensitizer. The surgical gloves fabricated with latex containing nB-A vulcanized by gamma rays can be commercialized. Another expected applications are the development of the catheter and the material utilized in the radiotherapy treatment. (author)

  17. Efficiency of 1,9- Nonane-diol-diacrylate as a radiation vulcanization accelerator for natural rubber latex

    International Nuclear Information System (INIS)

    Haque, M.E.

    2003-09-01

    The efficiency of 1,9- Nonane-diol-diacrylate (NDDA) as a radiation vulcanization accelerator (RVA) for natural rubber latex (NRL) was investigated. Both gamma rays and electron beam (EB) were used for vulcanizing NRL with NDDA. The radiation dose of gamma rays, concentration of NDDA required to vulcanize the latex were optimized. 20 kGy radiation dose of gamma rays and 5 phr concentration of NDDA were found optimum to get maximum tensile and related properties. NRL was vulcanized under EB to find out the optimum condition of irradiation with this RVA. The defoamer concentrations, length of irradiation time under EB, concentration of RVA were optimizer by changing various parameters of the EB machine with a constant set of the others. 0.2 phr defoamer concentration, 30 minutes irradiation time and 5 phr concentration of NDDA were found optimum for irradiation of NRL under the EB machine. Effect of low current and optimum volume of latex charged in the reaction vessel suitable for vulcanization at a time were found out. (author)

  18. RESEARCH ON THE HOMOGENEITY OF TEMPERATURES IN JOINT'S AREA BY VULCANIZING THE CONVEYOR BELTS

    Directory of Open Access Journals (Sweden)

    Dan DOBROTA

    2016-05-01

    Full Text Available The researches presented in this paper have followed the analysis of the heat transfer mode during joining through vulcanization of the conveyor belts and also the homogeneity of the temperatures in the joint area. The researches were made under laboratory conditions taking into account the process of joining of two conveyor belts of the type ST 2000 with an installation of the type DSLQ. Temperature measurement was conducted using an EX42570 pyrometer in four distinct points corresponding to each end of the two conveyor belts on the both sides of the band, namely the active and inactive side.

  19. Study of rheological, viscoelastic and vulcanization behavior of sponge EPDM/NR blended nano- composites

    International Nuclear Information System (INIS)

    Bashir, M Arshad; Shahid, M; Ahmed, Riaz; Yahya, A G

    2014-01-01

    In this research paper the effect of blending ratio of natural rubber (NR) with Ethylene Propylene Diene Monomer (EPDM) were investigated. Different samples of EPDM/NR ratio were prepared to study the variation of NR in EPDM on rheology, curing characteristics, tangent δ, and viscosity variation during vulcanization of sponge nano composites.The main aim of present research is to develop elastomeric based sponge composites with the blending ratio of base elastomers along with the carbon nano particles for high energy absorbing and damping applications. The curing characteristics, rheology and viscoelastic nature of the composite is remarkably influenced with the progressive blending ratio of the base elastomeric matrix

  20. Study of rheological, viscoelastic and vulcanization behavior of sponge EPDM/NR blended nano-composites

    International Nuclear Information System (INIS)

    Bashir, M. A.; Shahid, M.; Ahmed, R.; Yahya, A. G.

    2013-01-01

    In this research paper the effect of blending ratio of natural rubber (NR) with Ethylene Propylene Diene Monomer (EPDM) were investigated. Different samples of EPDM/NR ratio were prepared to study the variation of NR in EPDM on rheology, curing characteristics, tangent d, and viscosity variation during vulcanization of sponge nano composites. The main aim of present research is to develop elastomeric based sponge composites with the blending ratio of base elastomers along with the carbon nano particles for high energy absorbing and damping applications. The curing characteristics, rheology and viscoelastic nature of the composite is remarkably influenced with the progressive blending ratio of the base elastomeric matrix. (author)

  1. Effect of Antioxidants on Radiation Vulcanization Natural Rubber Latex (RVNRL) Film

    International Nuclear Information System (INIS)

    Syuhada Ramli; Sofian Ibrahim; Muhammad Saiful Omar

    2015-01-01

    This paper presents the results on the effects of different antioxidants used in Radiation Vulcanization Natural Rubber Latex (RVNRL)) films between 0 to 10 weeks monitoring. Antioxidants used for the RVNRL formulation were Aquanox LP, Irganox and Wingstay L. Color difference evaluation by using Chroma Meter CR-400 found that RVNRL film with Irganox was the most stained yellowish after 8 weeks monitoring. Tensile strength for RVNRL with Aquanox found achieved the optimum strength between 25.4 to 27.13 mPa. The scanner electron microscopic (SEM) indicated more Aquanox molecules to penetrate and interact with the rubber molecule, thus becoming more effective inhibitor against its oxidative ageing. (author)

  2. Improvement of Some Physical Properties of Loaded Nitrile Rubber Vulcanized by Ionizing Radiation

    International Nuclear Information System (INIS)

    Abdel-Aziz, M.M.; Basfar, A.A.; Mofti, S.

    2000-01-01

    The effect of four-selected polyfunctional compounds namely, tri methylacrylic ester, trimethylol propane trimethacrylate, zinc diacrylate and modified pentaerthritol triacrylate, as crosslinking agents, on the mechanical properties of radiation vulcanized nitrile rubber was studied. The effect of incorporation of either HAF-carbon black or fumed silica, as filler and reinforcing agents, on its mechanical properties was also studied. The co agent namely, tri methylacrylic ester, was found to produce a set of optimum mechanical properties, i.e. moderate crosslink density, good tensile strength and elasticity at low irradiation doses, i.e.40 kGy

  3. Surface modification of argon/oxygen plasma treated vulcanized ethylene propylene diene polymethylene surfaces for improved adhesion with natural rubber

    International Nuclear Information System (INIS)

    Basak, Ganesh C.; Bandyopadhyay, Abhijit; Neogi, Sudarsan; Bhowmick, Anil K.

    2011-01-01

    Vulcanized ethylene propylene diene polymethylene (EPDM) rubber surface was treated in a radio frequency capacitatively coupled low pressure argon/oxygen plasma to improve adhesion with compounded natural rubber (NR) during co-vulcanization. The plasma modified surfaces were analyzed by means of contact angle measurement, surface energy, attenuated total reflection-infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray sulfur mapping and atomic force microscopy. Several experimental variables such as plasma power, length of exposure time and composition of the argon-oxygen gas mixture were considered. It was delineated that plasma treatment changed both surface composition and roughness, and consequently increased peel strength. The change in surface composition was mainly ascribed to the formation of C-O and -C=O functional groups on the vulcanized surfaces. A maximum of 98% improvement in peel strength was observed after plasma treatment.

  4. Surface modification of argon/oxygen plasma treated vulcanized ethylene propylene diene polymethylene surfaces for improved adhesion with natural rubber

    Energy Technology Data Exchange (ETDEWEB)

    Basak, Ganesh C. [Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302 (India); Bandyopadhyay, Abhijit [Department of Polymer Science and Technology, University of Calcutta, Calcutta 700 009 (India); Neogi, Sudarsan [Department of Chemical Engineering, Indian Institute of Technology, Kharagpur 721302 (India); Bhowmick, Anil K., E-mail: anilkb@rtc.iitkgp.ernet.in [Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302 (India)

    2011-01-15

    Vulcanized ethylene propylene diene polymethylene (EPDM) rubber surface was treated in a radio frequency capacitatively coupled low pressure argon/oxygen plasma to improve adhesion with compounded natural rubber (NR) during co-vulcanization. The plasma modified surfaces were analyzed by means of contact angle measurement, surface energy, attenuated total reflection-infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray sulfur mapping and atomic force microscopy. Several experimental variables such as plasma power, length of exposure time and composition of the argon-oxygen gas mixture were considered. It was delineated that plasma treatment changed both surface composition and roughness, and consequently increased peel strength. The change in surface composition was mainly ascribed to the formation of C-O and -C=O functional groups on the vulcanized surfaces. A maximum of 98% improvement in peel strength was observed after plasma treatment.

  5. Aspects of Degradability and Aging of Natural Rubber Latex Films Obtained by Induced Ionizing Radiation Processes of Latex Vulcanization

    International Nuclear Information System (INIS)

    Parra, D. F.

    2006-01-01

    This study refers to the degradability of NRLF, natural rubber latex films, obtained by ionizing radiation. Three types of NRLF were prepared: irradiated latex, irradiated latex with about 1% of soy lecithin and sulfur-vulcanized latex, by cold vulcanization process. The films were buried in vases of two different kinds of soil: common soil and common soil with earthworm humus. Fast aging tests in laboratory with exposition to ultraviolet rays were done in irradiated latex films and irradiated latex films with soy lecithin. The results obtained after ten months of tests with buried films agree with the results of the fast aging tests, showing singularities of each type of soil and each kind of latex process. It also shows how weather inclemency can induce the films degradation process. The sulfur-vulcanized films were weakly degraded when buried. The films with lecithin and buried in vase with only common soil showed the biggest mass loss, but the films with lecithin buried in vases with common earthworm humus and soil increased their weigh and dimensions due to fungi formation. The irradiated latex films are more degradable then the sulfur-vulcanized films. The irradiated latex film, unlike the sulfur vulcanized film, showed high fungi colonization when buried. We conclude that the irradiated latex films are more easily biodegradable than the sulfur vulcanized latex films. The biodegradability increases with the addition of small amounts of soy lecithin (∼1%). The mechanical resistance of the buried films decreased related to the non-buried ones, proving that the outdoor aging in soil and the presence of fungi in the films can modify the mechanical properties of the irradiated latex owing to the biodegradation

  6. Research and application of fuzzy subtractive clustering model on tensile strength of radiation vulcanization for nitrile-butadiene rubber

    International Nuclear Information System (INIS)

    Zuo Duwen; Wang Hong; Zhu Nankang

    2010-01-01

    By use of fuzzy subtractive clustering model, the relationship between tensile strength of radiation vulcanization of NBRL (Nitrile-butadiene rubber latex) and irradiation parameters have been investigated. The correlation coefficient was calculated to be 0.8222 in the comparison of experimental data to the predicted data. It was obvious that fuzzy model identification method is not only high precision with small computation, but also easy to be used. It can directly supply the evolution of tensile strength of NBR by fuzzy modeling method in radiation vulcanization process for nitrile-butadiene rubber. (authors)

  7. Zinc chelates as new activators for sulphur vulcanization of acrylonitrile-butadiene elastomer

    Directory of Open Access Journals (Sweden)

    2009-04-01

    Full Text Available The goal of this work was to apply several zinc chelates as activators for sulphur vulcanization of acrylonitrilebutadiene elastomer (NBR, in order to find alternatives for the conventionally used zinc oxide. In this article, we discuss the effects of different zinc complexes on the cure characteristics, crosslinks distribution in the elastomer network and mechanical properties of acrylonitrile-butadiene rubber. Zinc chelates seem to be good substitutes for zinc oxide as activators for sulphur vulcanization of NBR rubber, without detrimental effects on the crosslinking process and physical properties of the obtained vulcanizates. Moreover, application of zinc complexes allows to reduce the amount of zinc ions in rubber compounds by 40% compared to conventionally crosslinked vulcanizates with zinc oxide. It is a very important ecological goal since zinc oxide is classified as toxic to aquatic species and its amount in rubber products must be reduced below 2.5% at least. From a technological point of view it is a very important challenge.

  8. Evaluation of electron beam irradiation under heating process on vulcanized EPDM

    International Nuclear Information System (INIS)

    Gabriel, Leandro; Cardoso, Jessica R.; Moura, Eduardo; Geraldo, Aurea B.C.

    2015-01-01

    The Global consumption of rubber is estimated around 30.5 million tons in 2015, when it is expected an increase of 4.3% of this volume in the coming of years. This demand is mainly attributed to the production of elastomeric accessories for the automotive sector. However, the generation of this type of waste also reaches major proportions at the end of its useful life, when it is necessary to dispose the environmental liability. Rubber reprocessing is an alternative where it can be used as filler in other polymer matrices or in other types of materials. The devulcanization process is another alternative and it includes the study of methods that allow economic viability and waste reduction. Therefore, this study aims to recycle vulcanized EPDM rubber with the use of ionizing radiation. In this work we are using the electron beam irradiation process with simultaneous heating at absorbed doses from 150 kGy to 800 kGy, under high dose rate of 22.3 kGy/s on vulcanized EPDM powder and on samples about 4 mm thick. Their characterization, before and after the irradiation process, have been realized by thermal analysis and their changes have been discussed. (author)

  9. Characterization of blends of PP and SBS vulcanized with gamma irradiation

    International Nuclear Information System (INIS)

    Gonzalez, J.; Albano, C.; Candal, M.V.; Ichazo, M.N.; Hernandez, M.

    2005-01-01

    The present work has the objective of analyzing blends of PP with 30 wt% SBS vulcanized with gamma irradiation. In order to do so, SBS was irradiated at 10, 25 and 50 kGy with gamma rays. Results indicate that the gel fraction increases with irradiation dose, varying from 0.3% to 13.0% for the doses employed. Concerning tensile properties, it can be seen that the incorporation of SBS non-irradiated or irradiated decreases Young's modulus, while increasing elongation at break. Respect to thermal studies, it was detected that SBS decreases melting enthalpy of blends, fact that implies a decrease on crystallinity degree, being this effect more noticeable when SBS is irradiated at doses higher than 10 kGy. On the other hand, melting temperature diminishes slightly when adding SBS to PP, but does not show significant variations when SBS is irradiated. PPs MFI decreased with the addition of SBS, being the effect more notorious with irradiation dose. Finally, it can be concluded that SBS can be vulcanized by gamma irradiation, and that the crosslinking degree increases with irradiation dose

  10. Properties of Vulcanized Polyisoprene Rubber Composites Filled with Opalized White Tuff and Precipitated Silica

    Directory of Open Access Journals (Sweden)

    Suzana Samaržija-Jovanović

    2014-01-01

    Full Text Available Opalized white tuff (OWT with 40 μm average particle size and 39.3 m2/g specific surface area has been introduced into polyisoprene rubber (NR. Their reinforcing effects were evaluated by comparisons with those from precipitated silica (PSi. The cure characteristic, apparent activation energy of cross-link (Eac and reversion (Ear, and mechanical properties of a variety of composites based on these rubbers were studied. This was done using vulcanization techniques, mechanical testing, and scanning electron microscopy (SEM. The results showed that OWT can greatly improve the vulcanizing process by shortening the time of optimum cure (tc90 and the scorch time (ts2 of cross-linked rubber composites, which improves production efficiency and operational security. The rubber composites filled with 50 phr of OWT were found to have good mechanical and elastomeric properties. The tensile strengths of the NR/OWT composites are close to those of NR/PSi composites, but the tear strength and modulus are not as good as the corresponding properties of those containing precipitated silica. Morphology results revealed that the OWT is poorly dispersed in the rubber matrix. According to that, the lower interactions between OWT and polyisoprene rubber macromolecules are obtained, but similar mechanical properties of NR/OWT (100/50 rubber composites compared with NR/PSi (100/50 rubber composites are resulted.

  11. Evaluation of electron beam irradiation under heating process on vulcanized EPDM

    Energy Technology Data Exchange (ETDEWEB)

    Gabriel, Leandro; Cardoso, Jessica R.; Moura, Eduardo; Geraldo, Aurea B.C., E-mail: lgabriell@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    The Global consumption of rubber is estimated around 30.5 million tons in 2015, when it is expected an increase of 4.3% of this volume in the coming of years. This demand is mainly attributed to the production of elastomeric accessories for the automotive sector. However, the generation of this type of waste also reaches major proportions at the end of its useful life, when it is necessary to dispose the environmental liability. Rubber reprocessing is an alternative where it can be used as filler in other polymer matrices or in other types of materials. The devulcanization process is another alternative and it includes the study of methods that allow economic viability and waste reduction. Therefore, this study aims to recycle vulcanized EPDM rubber with the use of ionizing radiation. In this work we are using the electron beam irradiation process with simultaneous heating at absorbed doses from 150 kGy to 800 kGy, under high dose rate of 22.3 kGy/s on vulcanized EPDM powder and on samples about 4 mm thick. Their characterization, before and after the irradiation process, have been realized by thermal analysis and their changes have been discussed. (author)

  12. Vulcan: A steady-state tokamak for reactor-relevant plasma–material interaction science

    International Nuclear Information System (INIS)

    Olynyk, G.M.; Hartwig, Z.S.; Whyte, D.G.; Barnard, H.S.; Bonoli, P.T.; Bromberg, L.; Garrett, M.L.; Haakonsen, C.B.; Mumgaard, R.T.; Podpaly, Y.A.

    2012-01-01

    Highlights: ► A new scaling for obtaining reactor similarity in the divertor of scaled tokamaks. ► Conceptual design for a tokamak (“Vulcan”) to implement this new scaling. ► Demountable superconducting coils and compact neutron shielding. ► Helium-cooled high-temperature vacuum vessel and first wall. ► High-field-side lower hybrid current drive for non-inductive operation. - Abstract: An economically viable magnetic-confinement fusion reactor will require steady-state operation and high areal power density for sufficient energy output, and elevated wall/blanket temperatures for efficient energy conversion. These three requirements frame, and couple to, the challenge of plasma–material interaction (PMI) for fusion energy sciences. Present and planned tokamaks are not designed to simultaneously meet these criteria. A new and expanded set of dimensionless figures of merit for PMI have been developed. The key feature of the scaling is that the power flux across the last closed flux surface P/S ≃ 1 MW m −2 is to be held constant, while scaling the core volume-averaged density weakly with major radius, n ∼ R −2/7 . While complete similarity is not possible, this new “P/S” or “PMI” scaling provides similarity for the most critical reactor PMI issues, compatible with sufficient current drive efficiency for non-inductive steady-state core scenarios. A conceptual design is developed for Vulcan, a compact steady-state deuterium main-ion tokamak which implements the P/S scaling rules. A zero-dimensional core analysis is used to determine R = 1.2 m, with a conventional reactor aspect ratio R/a = 4.0, as the minimum feasible size for Vulcan. Scoping studies of innovative fusion technologies to support the Vulcan PMI mission were carried out for three critical areas: a high-temperature, helium-cooled vacuum vessel and divertor design; a demountable superconducting toroidal field magnet system; and a steady-state lower hybrid current drive system

  13. Surface modification of halloysite nanotubes by vulcanization accelerator and properties of styrene-butadiene rubber nanocomposites with modified halloysite nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Bangchao; Jia, Zhixin, E-mail: zxjia@scut.edu.cn; Hu, Dechao; Luo, Yuanfang; Guo, Baochun; Jia, Demin

    2016-03-15

    Graphical abstract: - Highlights: • Vulcanization accelerant was used to modify halloysite nanotubes (HNTs). • The modified HNTs reduced the activation energy of vulcanization. • Strong filler–rubber interaction was achieved in rubber/modified HNTs composites. • The modified HNTs exhibited excellent reinforcement effect on rubber. - Abstract: Vulcanization accelerant N-cyclohexyl-2-benzothiazole sulfenamide (CZ) was used as a surface modifier and chemically grafted on the surface of halloysite nanotubes (HNTs) to obtain CZ-functionalized HNTs (HNTs-s-CZ). It was found that HNTs-s-CZ could be homogeneously dispersed into styrene-butadiene rubber (SBR). The grafted CZ molecules, exactly located at the filler-rubber interface, reduced the activation energy of vulcanization of SBR/HNTs-s-CZ compounds. Besides, the density of chain segments introduced by the interfacial phase of SBR/HNTs-s-CZ nanocomposites was higher than the other nanocomposites with silane-modified HNTs (m-HNTs) or pristine HNTs, manifesting an indication of enhanced filler-rubber interfacial interaction in SBR/HNTs-s-CZ nanocomposites. Consequently, SBR/HNTs-s-CZ nanocomposites showed excellent mechanical properties. The tensile strength could be enhanced by as much as 38.6% and 102.5% compared to those of SBR/m-HNTs and SBR/HNTs nanocomposites, respectively, though containing equivalent accelerant component. The value of this work lies in the fact that apparent properties improvement of elastomer composites has been achieved by the incorporation of vulcanization accelerant-functionalized HNTs, which may be fruitful for the rational design of filler surface treatment and offer new scientific and technological opportunities for the preparation of high performance elastomer composites.

  14. Surface modification of halloysite nanotubes by vulcanization accelerator and properties of styrene-butadiene rubber nanocomposites with modified halloysite nanotubes

    International Nuclear Information System (INIS)

    Zhong, Bangchao; Jia, Zhixin; Hu, Dechao; Luo, Yuanfang; Guo, Baochun; Jia, Demin

    2016-01-01

    Graphical abstract: - Highlights: • Vulcanization accelerant was used to modify halloysite nanotubes (HNTs). • The modified HNTs reduced the activation energy of vulcanization. • Strong filler–rubber interaction was achieved in rubber/modified HNTs composites. • The modified HNTs exhibited excellent reinforcement effect on rubber. - Abstract: Vulcanization accelerant N-cyclohexyl-2-benzothiazole sulfenamide (CZ) was used as a surface modifier and chemically grafted on the surface of halloysite nanotubes (HNTs) to obtain CZ-functionalized HNTs (HNTs-s-CZ). It was found that HNTs-s-CZ could be homogeneously dispersed into styrene-butadiene rubber (SBR). The grafted CZ molecules, exactly located at the filler-rubber interface, reduced the activation energy of vulcanization of SBR/HNTs-s-CZ compounds. Besides, the density of chain segments introduced by the interfacial phase of SBR/HNTs-s-CZ nanocomposites was higher than the other nanocomposites with silane-modified HNTs (m-HNTs) or pristine HNTs, manifesting an indication of enhanced filler-rubber interfacial interaction in SBR/HNTs-s-CZ nanocomposites. Consequently, SBR/HNTs-s-CZ nanocomposites showed excellent mechanical properties. The tensile strength could be enhanced by as much as 38.6% and 102.5% compared to those of SBR/m-HNTs and SBR/HNTs nanocomposites, respectively, though containing equivalent accelerant component. The value of this work lies in the fact that apparent properties improvement of elastomer composites has been achieved by the incorporation of vulcanization accelerant-functionalized HNTs, which may be fruitful for the rational design of filler surface treatment and offer new scientific and technological opportunities for the preparation of high performance elastomer composites.

  15. Study on influence of irradiation vulcanization to silicon rubber autohesive tape's properties

    International Nuclear Information System (INIS)

    Chen Chun; Tang Jian; Wu Ling; Han Yingchun; Zhou Hong; Mo Yan; Fu Haijun

    2006-01-01

    After using 60 Co γ-ray to irradiate vulcanization silicon rubber autohesive tape, the effect of absorbed dose to the autohesive tape's tensile strength, elongation at break, autohesion and breakdown voltage strength and dose rate's effect to the autohesive tape's properties were studied. The results indicate that autohesive tape's tensile strength increases and the elongation at break decreases with the increasing dose. Under the dose of 25 kGy, the tape's autohesion increases with the increasing dose. When the dose is up to 25 kGy, the tape's autohesion achieves to the maximum, and then decreases with the increasing dose. Absorbed dose has no effect to the tape's breakdown voltage strength, and the dose rate has no effect to the autohesive tape's properties. (authors)

  16. An Automated DAKOTA and VULCAN-CFD Framework with Application to Supersonic Facility Nozzle Flowpath Optimization

    Science.gov (United States)

    Axdahl, Erik L.

    2015-01-01

    Removing human interaction from design processes by using automation may lead to gains in both productivity and design precision. This memorandum describes efforts to incorporate high fidelity numerical analysis tools into an automated framework and applying that framework to applications of practical interest. The purpose of this effort was to integrate VULCAN-CFD into an automated, DAKOTA-enabled framework with a proof-of-concept application being the optimization of supersonic test facility nozzles. It was shown that the optimization framework could be deployed on a high performance computing cluster with the flow of information handled effectively to guide the optimization process. Furthermore, the application of the framework to supersonic test facility nozzle flowpath design and optimization was demonstrated using multiple optimization algorithms.

  17. Modification of the properties of NBR/EPDM blends vulcanized by gamma irradiation

    International Nuclear Information System (INIS)

    Abou Zeid, M.M.; Shaltout, N.A.; Mohamed, M.A.; El Miligy, A.A.

    2001-01-01

    Blends of nitrile-butadiene rubber, NBR with ethylene propylene diene monomer EPDM rubber with varying contents have been prepared. Unloaded or loaded blends with 40 phr of HAF carbon black have been vulcanized by using gamma irradiation. Mechanical properties, namely tensile strength, tensile modulus and elongation at break have been followed up as a function of irradiation dose as well as blend component compositions. Moreover, the susceptibility of prepared composites towards organic solvents and car oils has been followed up in terms of swelling number and soluble fraction measurements. The organic solvents used are toluene and dimethyl-formamide and oil are car lubricating and brake oils. The results indicated improvements in mechanical properties of blend composites with irradiation dose and increased content NBR in the blend. Also, susceptibility to fluids decreased appreciably with irradiation dose but with different extents for different fluids

  18. n-BA/KOH/t-BHP behaviour in the natural rubber latex vulcanization by gamma rays

    International Nuclear Information System (INIS)

    Souza, A. de.

    1994-01-01

    Natural rubber latex was vulcanized in the absence and in the presence of sensitizer (S), with gamma ray from 60 Co source, panoramic type, at the dose rate range of 1,20-1,33 kGy/h. The components of used S were n-butyl acrylate (n-BA), the KOH as stabilizer and t-butyl hydroperoxide (t-BHP) as co-S. The purpose of this work was to study the efficiency and the behaviour of each component of S in the irradiated latex crosslinking by tensile strength (T b ), volume fraction and permanent set. In the absence of S occur straight crosslinking between macromolecular adjacent radicals. IN the presence of S, the n-BA participates in the crosslinking through acrylic bridges between macromolecules. (author)

  19. The effect of proteins on the aging properties of radiation vulcanized natural rubber latex

    International Nuclear Information System (INIS)

    Abad, L.V.

    1993-01-01

    The effect of natural rubber latex (NRL) proteins on the aging properties of NRL films was investigated. SDS-PAGE electrophoresis of the rubber proteins in NRL (Sri-Lanka) indicated a total of 18 proteins. A sharp decrease in tensile strength was observed after aging when NRL films were leached in 1% NH 4 OH. However, when these films were soaked in ethanol prior to leaching, the aging properties approximated those of the unleashed samples. Electrophoretic analysis of the proteins present in the NH 3 extracts of leached RVNRL films showed a high concentration of the protein herein. This protein was not found in the NH 3 extracts of ethanol soaked films. NRL proteins were shown to decelerate the aging process of Radiation Vulcanized Natural Rubber Latex (RVNRL) films. Among the proteins, herein exhibited good anti-aging properties. The hydrolyzates from NR proteins also enhanced considerably the aging properties of RVNRL. (auth.). 8 refs.; 40 figs.; 30 tabs

  20. Evaluation of some antioxidants in radiation vulcanized ethylene-propylene diene (EPDM) rubber

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Aziz, M.M.; Basfar, A.A. E-mail: abasfar@kacst.edu.sa

    2001-12-01

    Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) have been used to study the oxidation of {gamma}-ray vulcanized ethylene-propylene diene rubber (EPDM) stabilized with various types of antioxidants. The antioxidants used were pentaerythrityl tetrakis(3,5-di-tert-butyl(-4-hydroxyphenyl))propionate (Irganox 1010), Irganox 1035, Irganox 1520D, as primary antioxidants; Irganox B561 and Irganox B900, as synergistic blends; hindered amine light stabilizer (HALS), i.e. Tinuvin 622 LD; N-isopropyl-N-phenyl-p-phenylene diamine (IPPD) and trimethyl quinoline (TMQ) and their mixtures. The measurements were carried out under atmospheric conditions. The effects of antioxidant type and its selected concentration were determined and mechanism of reaction proposed.

  1. The Effect of Paraffin Wax to Properties of Radiation Vulcanization Natural Rubber Latex (RVNRL)

    International Nuclear Information System (INIS)

    Mohd Noorwadi Mat Lazim; Sofian Ibrahim; Muhammad Saiful Omar

    2015-01-01

    Dipping factories often encounter a serious problem with high tackiness of the finish products during storage. The tackiness effect can be lead to rejection of products. This tackiness effect of natural (NR) rubber film originates in the free rubber chain ends at the surface of the film. The tackiness is not depends on the degree of crosslinking (vulcanization), since radiation itself unable to reduce the tackiness effect. The RVNRL requires addition of additive or anti-tack agent into formulation to reduce tackiness effect. In this experiment, paraffin wax manufactured by Emulco Sdn Bhd under the trade name Aquawax 48 was added into RVNRL formulation as anti-tack and the effect of paraffin wax to physical and mechanical properties of RVNRL was study. (author)

  2. Selective Deuteron Acceleration and Neutron Production on the Vulcan PW Laser

    Science.gov (United States)

    Krygier, A. G.; Morrison, J. T.; Freeman, R. R.; Ahmed, H.; Green, J. A.; Alejo, A.; Kar, S.; Vassura, L.

    2014-10-01

    Fast neutron sources are important for a variety of applications including radiography and the detection of sensitive materials. Here we report on the results of an experiment using the Vulcan PW laser at Rutherford Appleton Laboratory to produce a nearly pure deuterium ion beam via Target Normal Sheath Acceleration. The typical contaminants are suppressed by freezing a μ m's thick layer of heavy water vapor (D2 O) onto a cryogenic target during the shot sequence. Neutrons were generated by colliding the accelerated deuterons were into secondary targets made of deuterated plastic in the pitcher-catcher arrangement. Absolute yields for deuterium ions and neutrons are reported. This work is supported by DOE Contract DE-FC02-04ER54789.

  3. Neutron Production from In-situ Heavy Ice Coated Targets at Vulcan

    Science.gov (United States)

    Morrison, John; Krygier, A. G.; Kar, S.; Ahmed, H.; Alejo, A.; Clarke, R.; Fuchs, J.; Green, A.; Jung, D.; Kleinschmidt, A.; Najmudin, Z.; Nakamura, H.; Norreys, P.; Notley, M.; Oliver, M.; Roth, M.; Vassura, L.; Zepf, M.; Borghesi, M.; Freeman, R. R.

    2015-05-01

    Laser based neutron production experiments have been performed utilizing ultra-high intensity laser accelerated ions impinging upon a secondary target. The neutron yield from such experiments may be improved if the accelerated ions were primarily deuterons taking advantage of the d-d cross section. Recent experiments have demonstrated that selective deuteron acceleration from in-situ heavy ice coating of targets can produce ion spectra where deuterons comprise > 99 % of the measured ions. Results will be presented from integrated neutron production experiments from heavy ice targets coated in-situ recently performed on the Vulcan laser at Rutherford Appleton Laboratory. We are grateful for the Staff at RAL and acknowledge funding from the US DoE. AFOSR, European Social Fund, and the Czech Republic.

  4. The role of proteins on the thermal oxidative aging of radiation vulcanized natural rubber latex

    International Nuclear Information System (INIS)

    Abad, L.V.; Rosa, A. de la; Keizo Makuuchi; Fumio Yoshii

    1996-01-01

    The effect of Hevea latex proteins on the aging properties of radiation vulcanized natural rubber latex (RVNRL) was investigated. Unpurified RVNRL films exhibited better aging properties than the purified RVNRL films. A sharp decrease in tensile strength was observed after aging when RVNRL films were leached in 1% NH sub 4 OH. However, when these films were soaked in ethanol prior to leaching, the aging properties approximated those of the unleached samples. Kjeldahl and FT-IR analyses of the leached and unleached RVNRL films indicated a higher protein content for both the unleached and ethanol-soaked films than for leached films. Electrophoretic analysis of the proteins present in the NH, extracts of leached RVNRL films showed a high concentration of hevein. This protein was not found in the ATH, extracts of ethanol soaked films. Hevein was shown to improve the aging properties of RVNRL

  5. Syntheses, spectroscopic characterization, crystal structure and natural rubber vulcanization activity of new disulfides derived from sulfonyldithiocarbimates

    Science.gov (United States)

    Alves, Leandro de Carvalho; Rubinger, Mayura Marques Magalhães; Tavares, Eder do Couto; Janczak, Jan; Pacheco, Elen Beatriz Acordi Vasques; Visconte, Leila Lea Yuan; Oliveira, Marcelo Ribeiro Leite

    2013-09-01

    The compounds (Bu4N)2[(4-RC6H4SO2NCS2)2] [Bu4N = tetrabutylammonium cation; R = H (1), F (2), Cl (3) and Br (4)] and (Ph4P)2[(4-RC6H4SO2NCS2)2]ṡH2O [Ph4P = tetraphenylphosphonium cation and R = I (5)] were synthesized by the reaction of the potassium dithiocarbimates (4-RC6H4SO2NCS2K2ṡ2H2O) with I2 and Bu4NBr or Ph4PCl. The IR data were consistent with the formation of the dithiocarbimatodisulfides anions. The NMR spectra showed the expected signals for the cations and anions in a 2:1 proportion. The structures of compounds 1-5 were determined by the single crystal X-ray diffraction. The compounds 2, 3 and 4 are isostructural and crystallise in the centrosymmetric space group C2/c of the monoclinic system. Compound 1 crystallises in the monoclinic system in the space group of P21/n and the compound 5 crystallises in the centrosymmetric space group P-1 of the triclinic system. The complex anions of compounds 2, 3 and 4 exhibit similar conformations having twofold symmetry, while in 1 and 5 the anions exhibit C1 symmetry. The activity of the new compounds in the vulcanization of the natural rubber was evaluated and compared to the commercial accelerators ZDMC, TBBS and TMTD. These studies confirm that the sulfonyldithiocarbimato disulfides anions are new vulcanization accelerators, being slower than the commercial accelerators, but producing a greater degree of crosslinking, and scorch time values compatible with good processing safety for industrial applications. The mechanical properties, stress and tear resistances were determined and compared to those obtained with the commercial accelerators.

  6. ODC-Free Solvent Implementation Issues for Vulcanized Rubber and Bond Systems

    Science.gov (United States)

    Hodgson, James R.; McCool, Alex (Technical Monitor)

    2001-01-01

    Thiokol Propulsion has worked extensively to replace 1,1,1-trichloroethane (TCA) with ozone depleting chemicals (ODC)-free solvents for use in the manufacture of the Reusable Solid Rocket Motor (RSRM) for the Space Shuttle Program. As Thiokol has transitioned from sub-scale to full-scale testing and implementation of these new solvents, issues have been discovered which have required special attention. The original intent of Thiokol's solvent replacement strategy was to replace TCA with a single drop-in solvent for all equivalent applications. We have learned that a single candidate does not exist for replacing TCA. Solvent incompatibility with process materials has caused us to seek for niche solvents and/or processing changes that provide an ODC-free solution for special applications. This paper addresses some of the solvent incompatibilities, which have lead to processes changes and possible niche solvent usage. These incompatibilities were discovered during full-scale testing of ODC-free solvents and relate to vulcanized rubber and bond systems in the RSRM. Specifically, the following items are presented: (1) Cure effects of d-limonene based solvents on Silica Filled Ethylene Propylene Diene Monomer (SF-EPDM) rubber. During full-scale test operations, Thiokol discovered that d-limonene (terpene) based solvents inhibit the cure of EPDM rubber. Subsequent testing showed the same issue with Nitrile Butadiene Rubber (NBR). Also discussed are efforts to minimize uncured rubber exposure to solvents; and (2) Cured bond system sensitivity to ODC-free solvents. During full scale testing it was discovered that a natural rubber to steel vulcanized bond could degrade after prolonged exposure to ODC-free solvents. Follow on testing showed that low vapor pressure and residence time seemed to be most likely cause for failure.

  7. GURU v2.0: An interactive Graphical User interface to fit rheometer curves in Han’s model for rubber vulcanization

    OpenAIRE

    Milani, G.; Milani, F.

    2016-01-01

    A GUI software (GURU) for experimental data fitting of rheometer curves in Natural Rubber (NR) vulcanized with sulphur at different curing temperatures is presented. Experimental data are automatically loaded in GURU from an Excel spreadsheet coming from the output of the experimental machine (moving die rheometer). To fit the experimental data, the general reaction scheme proposed by Han and co-workers for NR vulcanized with sulphur is considered. From the simplified kinetic scheme adopted, ...

  8. THE NUMERICAL ALGORITHM FOR CALCULATING TEMPERATURE FIELDS OF THE PNEUMATIC TIRES DURING VULCANIZATION

    Directory of Open Access Journals (Sweden)

    S. G. Tikhomirov

    2015-01-01

    Full Text Available In the article discussed the mathematical formulation and numerical algorithm for solving the problem of calculating the temperature field in the process vulcanizing of the product, whose the thermal characteristics are depended on the temperature. As a mathematical model considered the system of differential equations of heat conduction, taking into account the change in the coefficients of thermal conductivity and heat density in multilayer product of the temperature. The system of equations is solved for a given initial distribution of temperature and for a given (time-dependent temperatures on the border of the product to the press-mold and to the diaphragm. On the border of the contacts of adjacent layers are given the condition of continuity of temperature and heat flux. Change of the thermal conductivity from the time is approximated by linear functions. The activation energy of the vulcanization process is determined on the basis of experimental data obtained in the control test samples using a reometer. Considering the function representing the corresponding integrals of the thermal conductivity, the original system of differential equations is transformed to an equivalent system of differential equations convenient for constructing numerical algorithms for solving the problem. The resulting system of partial differential equations derived using the method of finite-difference approximation is replaced by a system of algebraic equations. Solution of the system of algebraic equations is carried out under the scheme explicit difference approximation. In the article calculated the temperature field for the tire at given initial and boundary conditions. Stability and accuracy of the numerical algorithm for solving the problem is demonstrated by the calculations performed with different sampling step along the time and space coordinates. Assessment of the degree of completion of the process is carried out by calculated equivalent time for

  9. VULCAN PLANETS: INSIDE-OUT FORMATION OF THE INNERMOST SUPER-EARTHS

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Sourav [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States); Tan, Jonathan C., E-mail: sourav.chatterjee@northwestern.edu, E-mail: jt@astro.ufl.edu [Departments of Astronomy and Physics, University of Florida, Gainesville, FL 32611 (United States)

    2015-01-10

    The compact multi-transiting systems discovered by Kepler challenge traditional planet formation theories. These fall into two broad classes: (1) formation further out followed by migration and (2) formation in situ from a disk of gas and planetesimals. In the former, an abundance of resonant chains is expected, which the Kepler data do not support. In the latter, required disk mass surface densities may be too high. A recently proposed mechanism hypothesizes that planets form in situ at the pressure trap associated with the dead-zone inner boundary (DZIB) where radially drifting ''pebbles'' accumulate. This scenario predicts planet masses (M{sub p} ) are set by the gap-opening process that then leads to DZIB retreat, followed by sequential, inside-out planet formation (IOPF). For typical disk accretion rates, IOPF predictions for M{sub p} , M{sub p} versus orbital radius r, and planet-planet separations are consistent with observed systems. Here we investigate the IOPF prediction for how the masses, M{sub p,} {sub 1}, of the innermost (''Vulcan'') planets vary with r. We show that for fiducial parameters, M {sub p,} {sub 1} ≅ 5.0(r/0.1 AU) M {sub ⊕}, independent of the disk's accretion rate at time of planet formation. Then, using Monte Carlo sampling of a population of these innermost planets, we test this predicted scaling against observed planet properties, allowing for intrinsic dispersions in planetary densities and Kepler's observational biases. These effects lead to a slightly shallower relation M{sub p,} {sub 1}∝r {sup 0.9} {sup ±} {sup 0.2}, which is consistent with M{sub p,} 1∝r {sup 0.7} {sup ±} {sup 0.2} of the observed Vulcans. The normalization of the relation constrains the gap-opening process, favoring relatively low viscosities in the inner dead zone.

  10. Effect of heterogeneous distribution of crosslink density on physical properties of radiation vulcanized NR (Natural Rubber) latex film

    International Nuclear Information System (INIS)

    Keizo Makuuchi; Fumio Yoshii; Miura, H.; Murakami, K.

    1996-01-01

    Thus a study has been carried out to investigate the effect of particle to particle variation in crosslink density on physical properties of radiation vulcanized NR latex film. NR latex was irradiated in small bottle by γ rays without vulcanization accelerator to provide latex rubber particles having homogeneous distribution of crosslink density. The doses were 30, 50, 100, 250, 300, 400, 500 and 600 kGy. Weight swelling ratio, gel fraction, tensile strength and elongation at break of the latex film from the mixed latex were measured. The vulcanization dose of this latex was 250 kGy. Then the two different latexes were mixed in a such way to adjust the average dose of 250 kGy to prepare a latex consisting of rubber particles having heterogeneous distribution of crosslink density. Tensile strength of the latex film was depressed by mixing. The reduction increased with increasing the decrease of gel fraction by mixing. However the reduction was not serious when the dose difference of two latexes was less than 200 kGy

  11. Degradation of blending vulcanized natural rubber and nitril rubber (NR/NBR) by dimethyl ether through variation of elastomer ratio

    Science.gov (United States)

    Saputra, A. H.; Juneva, S.; Sari, T. I.; Cifriadi, A.

    2018-04-01

    Dimethyl ether can cause degradation of the rubber material seal in some applications. In order to use of natural rubber in industry, research about a blending of natural rubber (NR) and nitrile rubber (NBR) to produce rubber to meet the standard seal material application were conducted. This study will observe the degradation mechanisms that occur in the blending natural rubber and nitrile rubber (NR/NBR) by dimethyl ether. Nitrile rubber types used in this study is medium quality nitrile rubber with 33% of acrylonitrile content (NBR33). The observed parameters are percent change in mass, mechanical properties and surface morphology. This study is limited to see the effect of variation vulcanized blending ratio (NR/NBR33) against to swelling. The increase of nitrile rubber (NBR33) ratio of blending rubber vulcanized can reduce the tensile strength and elongation. The best elastomer variation was obtained after comparing with the standard feasibility material of seal is rubber vulcanized blending (NR/NBR33) with ratio 40:60 NR: NBR.

  12. Fiber webs

    Science.gov (United States)

    Roger M. Rowell; James S. Han; Von L. Byrd

    2005-01-01

    Wood fibers can be used to produce a wide variety of low-density three-dimensional webs, mats, and fiber-molded products. Short wood fibers blended with long fibers can be formed into flexible fiber mats, which can be made by physical entanglement, nonwoven needling, or thermoplastic fiber melt matrix technologies. The most common types of flexible mats are carded, air...

  13. Preparation and evaluation of some investigated natural and acrylonitrile rubber vulcanizations for physiotherapeutic purposes

    International Nuclear Information System (INIS)

    Helaly, F.M; El-Sawy, S.M.

    2005-01-01

    A trial was made to design and prepare rubber article that can be used to reactivate, strengthen and reinforce the hand muscles and fingers which had suffered from trouble movement.The investigated rubber article was prepared from natural and acrylonitrile rubber formulations. These formulations were processed in the form of compounds which contain significant quantities of fillers as Hisil, CaCO 3 and TiO 2 .The rheological characteristics and physicochemical properties of the vulcanizations were determined according to standard tests. It was found that it is possible to prepare the designated rubber article for the desired purpose. The test results show that the prepared rubber article has a good chemical resistant against acid, alkali, and salt. Also it possesses high resistance to deterioration and deformation. The prepared article has an ability to retain its elastic property after the action of compressive forces at 70 degree C for 24 hours.This was conformed with applied commercial hand exercise therapeutic article

  14. In situ reactive compatibilization of natural rubber/acrylic-bentonite composites via peroxide-induced vulcanization

    International Nuclear Information System (INIS)

    Fu, Lihua; Lei, Zhiwen; Xu, Chuanhui; Chen, Yukun

    2016-01-01

    To achieve good interfacial interaction between fillers and rubber matrix is always a hot topic in rubber reinforcing industry. In this paper, acid activated bentonite (Bt) was alkalified to be alkaline calcium-bentonite (ACBt), then acrylic acid (AA) was employed to modify ACBt to obtain acrylic-bentonite (ABt). The results of Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) illustrated that acrylate groups were chemically boned onto the surface of Bt and the layer spacing of Bt was increased. During peroxide-induced vulcanization, in situ compatibilization of ABt was realized via the reaction between the unsaturated bonds of acrylate groups on the surface of Bt and the natural rubber (NR) chains. This resulted in an enhanced cross-linked network which contributed to the improved mechanical properties of NR/ABt composites. - Highlights: • Acrylate groups were chemically boned onto the surface of bentonite. • In situ compatibilization was realized via the reaction of acrylate group and NR. • ABt particles participated in forming the NR crosslink network. • A potential reinforcing material options for “white” rubber products.

  15. In situ reactive compatibilization of natural rubber/acrylic-bentonite composites via peroxide-induced vulcanization

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Lihua; Lei, Zhiwen [Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004 (China); Xu, Chuanhui, E-mail: xuhuiyee@gxu.edu.cn [Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004 (China); Chen, Yukun, E-mail: cyk@scut.edu.cn [The Key Laboratory of Polymer Processing Engineering, Ministry of Education, China(South China University of Technology), Guangzhou, 510640 (China)

    2016-02-15

    To achieve good interfacial interaction between fillers and rubber matrix is always a hot topic in rubber reinforcing industry. In this paper, acid activated bentonite (Bt) was alkalified to be alkaline calcium-bentonite (ACBt), then acrylic acid (AA) was employed to modify ACBt to obtain acrylic-bentonite (ABt). The results of Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) illustrated that acrylate groups were chemically boned onto the surface of Bt and the layer spacing of Bt was increased. During peroxide-induced vulcanization, in situ compatibilization of ABt was realized via the reaction between the unsaturated bonds of acrylate groups on the surface of Bt and the natural rubber (NR) chains. This resulted in an enhanced cross-linked network which contributed to the improved mechanical properties of NR/ABt composites. - Highlights: • Acrylate groups were chemically boned onto the surface of bentonite. • In situ compatibilization was realized via the reaction of acrylate group and NR. • ABt particles participated in forming the NR crosslink network. • A potential reinforcing material options for “white” rubber products.

  16. Effect of Ingredient Loading on Surface Migration Kinetics of Additives in Vulcanized Natural Rubber Compounds

    Directory of Open Access Journals (Sweden)

    Bryan B. Pajarito

    2014-12-01

    Full Text Available Surface migration kinetics of chemical additives in vulcanized natural rubber compounds were studied as function of ingredient loading. Rubber sheets were compounded according to a 212-8 fractional factorial design of experiment, where ingredients were treated as factors varied at two levels of loading. Amount of migrated additives in surface of rubber sheets was monitored through time at ambient conditions. The maximum amount and estimated rate of additive migration were determined from weight loss kinetic curves. Attenuated total reflection–Fourier transform infrared (ATR-FTIR spectroscopy and optical microscopy were used to characterize the chemical structure and surface morphology of sheet specimens during additive migration. ANOVA results showed that increased loading of reclaimed rubber, CaCO3, and paraffin wax signif icantly decreased the maximum amount of additive migration; by contrast, increased loading of used oil, asphalt, and mercaptobenzothiazole disulphide (MBTS increased the maximum amount. Increased loading of sulfur, diphenylguanidine (DPG, and paraffin wax significantly decreased the additive migration rate; increased loading of used oil, asphalt, and stearic acid elicited an opposite effect. Comparison of ATRFTIR spectra of migrated and cleaned rubber surfaces showed signif icant variation in intensity of specif ic absorbance bands that are also present in infrared spectra of migrating chemicals. Paraffin wax, used oil, stearic acid, MBTS, asphalt, and zinc stearate were identified to bloom and bleed in the rubber sheets. Optical micrographs of migrated rubber surfaces revealed formation of white precipitates due to blooming and of semi-transparent wet patches due to bleeding.

  17. Mechanical and Electrical Properties of Sulfur-Containing Polymeric Materials Prepared via Inverse Vulcanization

    Directory of Open Access Journals (Sweden)

    Sergej Diez

    2017-02-01

    Full Text Available Recently, new methods have been developed for the utilization of elemental sulfur as a feedstock for novel polymeric materials. One promising method is the inverse vulcanization, which is used to prepare polymeric structures derived from sulfur and divinyl comonomers. However, the mechanical and electrical properties of the products are virtually unexplored. Hence, in the present study, we synthesized a 200 g scale of amorphous, hydrophobic as well as translucent, hyperbranched polymeric sulfur networks that provide a high thermal resistance (>220 °C. The polymeric material properties of these sulfur copolymers can be controlled significantly by varying the monomers as well as the feed content. The investigated comonomers are divinylbenzene (DVB and 1,3-diisopropenylbenzene (DIB. Plastomers with low elastic content and high shape retention containing 12.5%–30% DVB as well as low viscose waxy plastomers with a high flow behavior containing a high DVB content of 30%–35% were obtained. Copolymers with 15%–30% DIB act, on the one hand, as thermoplastics and, on the other hand, as vitreous thermosets with a DIB of 30%–35%. Results of the thermogravimetric analysis (TGA, the dynamic scanning calorimetry (DSC and mechanical characterization, such as stress–strain experiments and dynamic mechanical thermal analysis, are discussed with the outcome that they support the assumption of a polymeric cross-linked network structure in the form of hyper-branched polymers.

  18. Elastomeric Nanocomposite Based on Exfoliated Graphene Oxide and Its Characteristics without Vulcanization

    Directory of Open Access Journals (Sweden)

    Nasser Abdullah Habib

    2017-01-01

    Full Text Available Rubber nanocomposites have emerged as one of the advanced materials in recent years. The aim of this work was to homogeneously disperse graphene oxide (GO sheets into Nitrile Butadiene Rubber (NBR and investigate the characteristics of GO/NBR nanocomposite without vulcanization. A suitable solvent was found to dissolve dry NBR while GO was exfoliated completely in an aqueous base solution using sonication. GO was dispersed into NBR at different loadings by solution mixing to produce unvulcanized GO/NBR nanocomposites. Scanning Electron Microscopy (SEM, Fourier-Transform Infrared Spectroscopy (FTIR, and X-Ray Diffraction (XRD were used to characterize the samples. Furthermore, mechanical and electrical properties of unvulcanized GO/NBR nanocomposites were carried out to determine the influence of GO on the NBR properties. The results showed that the modulus of GO/NBR nanocomposite at 1 wt% of GO was enhanced by about 238% compared with unfilled NBR. These results provide insight into the properties of unvulcanized GO/NBR nanocomposite for application as coatings or adhesives.

  19. Thermal stabilities of various rubber vulcanization cured by sulfur, peroxide and gamma radiation

    International Nuclear Information System (INIS)

    Basfar, A.A.; Shamshad Ahmed; Abdel Aziz, M.M.

    1999-01-01

    Sulfur and peroxide-cured rubber vulcanizates of NR and EPDM were obtained by blending the elastomers with fillers, antioxidants and appropriate accelerators, followed by vulcanization at 150 - 160 degree C. Blends of the same elastomers with appropriate co-agents and additives were also cured by gamma radiation at 150 and 200 kGy. A comparison of the thermal stabilities of these vulcanizates prepared by different curing techniques has been made by thermogravimetric analysis (TGA), assessed on the basis of comparison of DTG peak maxima, temperature for loss of 50% mass and actual thermal curves. The comparison reveals that the sulfur-cured vulcanizates are less thermally stable than their peroxide-cured counterparts. This may be attributed to the presence of a stronger C-C bond in case of peroxide-cured vulcanizates compared to weaker C-S sub x-C bond in case of sulfur-cured vulcanizates. However, compared to peroxide-cured vulcanizates, radiation-cured formulations demonstrated much improved thermal stability. This may originate from the existence of more uniformly distributed crosslinks and the enhanced rate of crosslink formation in the radiation process as compared to peroxide curing. In all the formulations whether sulfur, peroxide or radiation-cured, the natural rubber vulcanizates were found to be thermally much inferior to the synthetic contender, EPDM. Influence of variation of the amount of co-agent and other additives on the thermal stabilities of formulations of radiation cured NR and EPDM vulcanizates was also investigated

  20. Effect of Rubber Nanoparticle Agglomeration on Properties of Thermoplastic Vulcanizates during Dynamic Vulcanization

    Directory of Open Access Journals (Sweden)

    Hanguang Wu

    2016-04-01

    Full Text Available We previously reported that the dispersed rubber microparticles in ethylene-propylene-diene monomer (EPDM/polypropylene (PP thermoplastic vulcanizates (TPVs are actually agglomerates of rubber nanoparticles. In this study, based on this new understanding of the microstructure of TPV, we further revealed the microstructure-properties relationship of EPDM/PP TPV during dynamic vulcanization, especially the effect of the size of rubber nanoparticle agglomerates (dn, the thicknesses of PP ligaments (IDpoly and the rubber network on the properties of EPDM/PP TPV. We were able to simultaneously obtain a high tensile strength, elongation at break, elastic modulus, and elasticity for the EPDM/PP TPV by the achievement of a smaller dn, a thinner IDpoly and a denser rubber network. Interestingly, the effect of dn and IDpoly on the elastic modulus of EPDM/PP TPV composed of rubber nanoparticle agglomerates is different from that of EPDM/PP TPVs composed of rubber microparticles reported previously. The deformation behavior of the TPVs during stretching was studied to understand the mechanism for the achievement of good mechanical properties. Interestingly, the rubber nanoparticle agglomerates are oriented along the tensile direction during stretching. The TPV samples with smaller and more numerous rubber nanoparticle agglomerates can slow down the development of voids and cracks more effectively, thus leading to increase in tensile strength and elongation at break of the EPDM/PP TPV.

  1. Computer models of dipole magnets of a series 'VULCAN' for the ALICE experiment

    International Nuclear Information System (INIS)

    Vodop'yanov, A.S.; Shishov, Yu.A.; Yuldasheva, M.B.; Yuldashev, O.I.

    1998-01-01

    The paper is devoted to a construction of computer models for three magnets of the 'VULCAN' series in the framework of a differential approach for two scalar potentials. The distinctive property of these magnets is that they are 'warm' and their coils are of conic saddle shape. The algorithm of creating a computer model for the coils is suggested. The coil field is computed by Biot-Savart law and a part of the integrals is calculated with the help of analytical formulas. To compute three-dimensional magnetic fields by the finite element method with a local accuracy control, two new algorithms are suggested. The former is based on a comparison of the fields computed by means of linear and quadratic shape functions. The latter is based on a comparison of the field computed with the help of linear shape functions and a local classical solution. The distributions of the local accuracy control characteristics within a working part of the third magnet and the other results of the computations are presented

  2. Photorefractive Fibers

    National Research Council Canada - National Science Library

    Kuzyk, Mark G

    2003-01-01

    ... scope of the project. In addition to our work in optical limiting fibers, spillover results included making fiber-based light-sources, writing holograms in fibers, and developing the theory of the limits of the nonlinear...

  3. Electrochemical behavior of nanostructured MnO2/C (Vulcan® composite in aqueous electrolyte LiNO3

    Directory of Open Access Journals (Sweden)

    Vujković Milica

    2011-01-01

    Full Text Available The electrolytic solutions of contemporary Li-ion batteries are made exclusively with the organic solvents since anodic materials of these batteries have potentials with greater negativity than the potential of the water reduction, thus the organic electrolytes can withstand the voltages of 3-5 V that are characteristic for these batteries. Ever since it was discovered that some materials can electrochemically intercalate and deintercalate Li+ ions in aqueous solutions, numerous studies have been conducted with the aim of extending operational time of the aqueous Li-ion batteries. Manganese oxide has been studied as the electrode material in rechargeable lithium-ion batteries with organic electrolytes. In this paper its electrochemical behavior as an anode material in aqueous electrolyte solutions was examined. MnO2 as a component of nanodispersed MnO2/C (Vulcan® composite was successfully synthesized hydrothermally. Electrochemical properties of this material were investigated in aqueous saturated LiNO3 solution by both cyclic voltammetry and galvanostatic charging/discharging (LiMn2O4 as cathode material techniques. The obtained composite shows a relatively good initial discharge capacity of 96.5 mAh/g which, after 50th charging/discharging cycles, drops to the value of 57mAh/g. MnO2/C (Vulcan® composite, in combination with LiMn2O4 as a cathode material, shows better discharge capacity compared to other anodic materials used in aqueous Li-ion batteries according to certain studies that have been conducted. Its good reversibility and cyclability, and the fact that hydrothermal method is simple and effective, makes MnO2/C(Vulcan® composite a promising anodic material for aqueous Li-ion batteries.

  4. Highly toughened polypropylene/ethylene–propylene-diene monomer/zinc dimethacrylate ternary blends prepared via peroxide-induced dynamic vulcanization

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yukun, E-mail: cyk@scut.edu.cn [The Key Laboratory of Polymer Processing Engineering, Ministry of Education, South China University of Technology, Guangzhou 510640 (China); School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640 (China); Xu, Chuanhui [College of Material Science and Engineering, South China University of Technology, Guangzhou 510640 (China); Cao, Liming [The Key Laboratory of Polymer Processing Engineering, Ministry of Education, South China University of Technology, Guangzhou 510640 (China); School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640 (China); Cao, Xiaodong [College of Material Science and Engineering, South China University of Technology, Guangzhou 510640 (China)

    2013-02-15

    Polypropylene (PP)/ethylene–propylene-diene monomer (EPDM)/zinc dimethacrylate (ZDMA) blends with remarkable toughness and extensibility were successfully prepared via peroxide dynamical vulcanization. A unique structure with the EPDM particles surrounded by a transition zone containing numerous polymerized ZDMA (PZDMA) nano-particles was observed for the first time by using transmission electron microscopy (TEM) examination, which contributed to the dramatically increase of Izod impact strength. Dynamic mechanical analysis (DMA) confirmed that the possible PZDMA graft products resulted from peroxide dynamical vulcanization improved the compatibility between EPDM and PP phases. The specific morphology of the PP/EPDM/ZDMA blends indicated that ZDMA can lead to size reduction and good distribution uniformity of the crosslinked rubber particles and the increase of adhesion between PP matrix and EPDM phases during deformation. The synergic effect of the increase in the effective volume of the EPDM phase, the improved compatibility and adhesion between EPDM and PP phases and the deformation of those fine rubber particles is believed to result in the remarkable high toughness and extensibility of the PP/EPDM/ZDMA blends. Particularly for the PP/EPDM ratio of 70/30, the PP/EPDM/ZDMA (70/30/9, w/w/w) ternary blends with the Izod impact strength nearly 2 times higher than PP/EPDM (70/30, w/w) binary blends and 15–20 times higher than PP are achieved; besides, the elongation at break of PP/EPDM/ZDMA ternary blends is 4–5 times higher than that of PP/EPDM binary blends. - Highlights: ► ZDMA largely toughen peroxide dynamically vulcanized PP/EPDM blend. ► PZDMA graft products improved the compatibility and adhesion between EPDM and PP. ► Size reduction and good distribution uniformity of crosslinked rubber particles.

  5. Highly toughened polypropylene/ethylene–propylene-diene monomer/zinc dimethacrylate ternary blends prepared via peroxide-induced dynamic vulcanization

    International Nuclear Information System (INIS)

    Chen, Yukun; Xu, Chuanhui; Cao, Liming; Cao, Xiaodong

    2013-01-01

    Polypropylene (PP)/ethylene–propylene-diene monomer (EPDM)/zinc dimethacrylate (ZDMA) blends with remarkable toughness and extensibility were successfully prepared via peroxide dynamical vulcanization. A unique structure with the EPDM particles surrounded by a transition zone containing numerous polymerized ZDMA (PZDMA) nano-particles was observed for the first time by using transmission electron microscopy (TEM) examination, which contributed to the dramatically increase of Izod impact strength. Dynamic mechanical analysis (DMA) confirmed that the possible PZDMA graft products resulted from peroxide dynamical vulcanization improved the compatibility between EPDM and PP phases. The specific morphology of the PP/EPDM/ZDMA blends indicated that ZDMA can lead to size reduction and good distribution uniformity of the crosslinked rubber particles and the increase of adhesion between PP matrix and EPDM phases during deformation. The synergic effect of the increase in the effective volume of the EPDM phase, the improved compatibility and adhesion between EPDM and PP phases and the deformation of those fine rubber particles is believed to result in the remarkable high toughness and extensibility of the PP/EPDM/ZDMA blends. Particularly for the PP/EPDM ratio of 70/30, the PP/EPDM/ZDMA (70/30/9, w/w/w) ternary blends with the Izod impact strength nearly 2 times higher than PP/EPDM (70/30, w/w) binary blends and 15–20 times higher than PP are achieved; besides, the elongation at break of PP/EPDM/ZDMA ternary blends is 4–5 times higher than that of PP/EPDM binary blends. - Highlights: ► ZDMA largely toughen peroxide dynamically vulcanized PP/EPDM blend. ► PZDMA graft products improved the compatibility and adhesion between EPDM and PP. ► Size reduction and good distribution uniformity of crosslinked rubber particles

  6. Gamma irradiation degradation/modification of 5-ethylidene 2-norbornene (ENB)-based ethylene propylene diene rubber (EPDM) depending on ENB content of EPDM and type/content of peroxides used in vulcanization

    Energy Technology Data Exchange (ETDEWEB)

    Ozdemir, Tonguc [Department of Polymer Science and Technology, Middle East Technical University, 06531 Ankara (Turkey)], E-mail: tonguc.ozdemir@tr.net

    2008-06-15

    In this study, the radiation degradation/modification of the vulcanized EPDM and the effects of dose rate, peroxide type/content in vulcanization system and ENB content of EPDM were studied to investigate the change in the extend of the modification/degradation of the mechanical properties of vulcanized EPDM via gamma irradiation. In addition, thermal, dynamic mechanical, ATR-FTIR, TGA, TGA-FTIR tests were carried out to understand the change of properties of vulcanized EPDM via irradiation. Samples were irradiated with two different dose rates of 1280 and 64.6 Gy/h. Total dose of irradiation was up to 184 kGy. The FTIR spectral analysis showed structural changes of EPDM via irradiation. It was observed that the dose rate changed the mechanical properties with different extends. The change of ENB content of EPDM and peroxide type and content in vulcanization system affect extend of the modification/degradation of the EPDM's properties.

  7. News from Front (of the Solar System): the problem with Mercury, the Vulcan hypothesis, and General Relativity's first astronomical triumph

    Science.gov (United States)

    Sheehan, William

    2016-01-01

    The discovery of the outer planet Neptune in 1846, based on the calculated position published by Urbain Jean Joseph Le Verrier, has been hailed as the "zenith of Newtonian mechanics." An attempt by Le Verrier to further extend the dominion of Newton's gravitational theory to the innermost known planet of the Solar System, Mercury, seemingly came to grief with the discovery of a small unexplained discrepancy in the precession of the perihelion of Mercury, whose value was later calculated as 43".0 per century. Le Verrier proposed that it could be explained on the basis of Newtonian theory by assuming the existence of an intra-mercurial planet ("Vulcan") or ring of debris. Efforts to confirm this hypothesis, culminating in high drama on the plains of the western United States at the great North American solar eclipse of July 1878, proved futile; by 1908, W. W. Campbell and C.D. Perrine of Lick Observatory, who had carried out exhaustive photographic searches at three eclipses (1901, 1905, and 1908) could declare that Vulcan did not exist. The theoretical problem it was invoked to explain remained until November 1915, when Albert Einstein used the recently discovered generally covariant gravitational equations to put the problem to rest. "Perihelion motions explained quantitatively … you will be astonished," he wrote to his friend Michael Besso.

  8. Effective closed form mathematical approach to determine kinetic constants of NR vulcanized with sulphur and accelerators at different concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Milani, Gabriele, E-mail: milani@stru.polimi.it, E-mail: gabriele.milani@polimi.it [Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan (Italy); Hanel, Thomas; Donetti, Raffaella [Pirelli Tyre, Via Alberto e Piero Pirelli 25, 20126 Milan (Italy); Milani, Federico [CHEMCO Consultant, Via J.F. Kennedy 2, 45030 Occhiobello (Italy)

    2015-03-10

    The basic reaction scheme due to Han and co-workers for NR vulcanized with sulphur is adopted and modified taking into account the single contributions of the different accelerators, focusing in particular on some experimental data ad hoc obtained at Pirelli’s laboratories, where NR was vulcanized at different temperatures (from 150 to 180 °C) and concentrations of sulphur, using TBBS and DPG in the mixture as co-agents. Typically, the chain reactions are initiated by the formation of macro-compounds that are responsible of the formation of the unmatured crosslinked polymer. This first reaction depends on the reciprocal concentrations of all components and their chemical nature. In presence of two accelerators, it was considered that the reactions between each single accelerator and the NR raw material occur in parallel, making the reasonable assumption that there are no mutual reactions between the two accelerators. From the kinetic scheme adopted, a closed form solution was found for the crosslink density, with the only limitation that the induction period is excluded from computations. Even kinetic constants are evaluated in closed form, avoiding a numerically demanding least-squares best fitting on rheometer experimental data. Two series of experiments available, relying into rheometer curves at different temperatures and different concentrations of sulphur and accelerator, are utilized to evaluate the fitting capabilities of the mathematical model. Very good agreement between numerical output and experimental data is experienced in all cases analysed.

  9. Radiation processed polychloroprene-co-ethylene-propene diene terpolymer blends: Effect of radiation vulcanization on solvent transport kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Dubey, K.A. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Room No. S-1, HIRUP Building, Trombay, Mumbai 400 085 (India); Bhardwaj, Y.K. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Room No. S-1, HIRUP Building, Trombay, Mumbai 400 085 (India)], E-mail: ykbhard@barc.gov.in; Chaudhari, C.V.; Kumar, Virendra; Goel, N.K.; Sabharwal, S. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Room No. S-1, HIRUP Building, Trombay, Mumbai 400 085 (India)

    2009-03-15

    Blends of polychloroprene rubber (PCR) and ethylene propylene diene terpolymer rubber (EPDM) of different compositions were made and exposed to different gamma radiation doses. The radiation sensitivity and radiation vulcanization efficiency of blends was estimated by gel-content analysis, Charlesby-Pinner parameter determination and crosslinking density measurements. Gamma radiation induced crosslinking was most efficient for EPDM (p{sub 0}/q{sub 0} {approx} 0.08), whereas it was the lowest for blends containing 40% PCR (p{sub 0}/q{sub 0} {approx} 0.34). The vulcanized blends were characterized for solvent diffusion characteristics by following the swelling dynamics. Blends with higher PCR content showed anomalous swelling. The sorption and permeability of the solvent were not strictly in accordance with each other and the extent of variation in two parameters was found to be a function of blend composition. The {delta}G values for solvent diffusion were in the range -2.97 to -9.58 kJ/mol and indicated thermodynamically favorable sorption for all blends. These results were corroborated by dynamic swelling, experimental as well as simulated profiles and have been explained on the basis of correlation between crosslinking density, diffusion kinetics, thermodynamic parameters and polymer-polymer interaction parameter.

  10. Oscillator and system development on the VULCAN glass laser system for the plasma beat-wave program

    International Nuclear Information System (INIS)

    Danson, C.N.

    1990-03-01

    This thesis describes the oscillator and system development on the VULCAN glass laser undertaken in support of the RAL Plasma Beat-wave experiments. This program seeks to evaluate advanced particle acceleration schemes for a new generation of machines for fundamental research in high energy physics. The experiments required two synchronised high power laser pulses of slightly different wavelength. These pulses were generated using two different laser media; Nd:YAG and Nd:YLF operating at 1.064 and 1.053 microns respectively. The first oscillator system developed operated with both lasing media housed in the same laser cavity. Problems with the stability of the optical output required the development of a second system which housed the two lasing media in separate cavities. The second aspect of the development work, described in this thesis, was the reconfiguration of the VULCAN glass laser system to amplify the two laser pulses to power levels of 0.5 TW per pulse. The first scheduled experiment required the two pulses to be propagated co-linearly. To amplify the pulses to the high output powers required two amplifying media to be used which preferentially amplify the two lasing wavelengths. For the later experiments the two laser pulses were amplified in separate amplifier chains which required the design of an efficient beam combiner. (author)

  11. Design of Self-Healing Supramolecular Rubbers by Introducing Ionic Cross-Links into Natural Rubber via a Controlled Vulcanization.

    Science.gov (United States)

    Xu, Chuanhui; Cao, Liming; Lin, Baofeng; Liang, Xingquan; Chen, Yukun

    2016-07-13

    Introducing ionic associations is one of the most effective approaches to realize a self-healing behavior for rubbers. However, most of commercial rubbers are nonpolar rubbers without now available functional groups to be converted into ionic groups. In this paper, our strategy was based on a controlled peroxide-induced vulcanization to generate massive ionic cross-links via polymerization of zinc dimethacrylate (ZDMA) in natural rubber (NR) and exploited it as a potential self-healable material. We controlled vulcanization process to retard the formation of covalent cross-link network, and successfully generated a reversible supramolecular network mainly constructed by ionic cross-links. Without the restriction of covalent cross-linkings, the NR chains in ionic supramolecular network had good flexibility and mobility. The nature that the ionic cross-links was easily reconstructed and rearranged facilitating the self-healing behavior, thereby enabling a fully cut sample to rejoin and retain to its original properties after a suitable self-healing process at ambient temperature. This study thus demonstrates a feasible approach to impart an ionic association induced self-healing function to commercial rubbers without ionic functional groups.

  12. GURU v2.0: An interactive Graphical User interface to fit rheometer curves in Han's model for rubber vulcanization

    Science.gov (United States)

    Milani, G.; Milani, F.

    A GUI software (GURU) for experimental data fitting of rheometer curves in Natural Rubber (NR) vulcanized with sulphur at different curing temperatures is presented. Experimental data are automatically loaded in GURU from an Excel spreadsheet coming from the output of the experimental machine (moving die rheometer). To fit the experimental data, the general reaction scheme proposed by Han and co-workers for NR vulcanized with sulphur is considered. From the simplified kinetic scheme adopted, a closed form solution can be found for the crosslink density, with the only limitation that the induction period is excluded from computations. Three kinetic constants must be determined in such a way to minimize the absolute error between normalized experimental data and numerical prediction. Usually, this result is achieved by means of standard least-squares data fitting. On the contrary, GURU works interactively by means of a Graphical User Interface (GUI) to minimize the error and allows an interactive calibration of the kinetic constants by means of sliders. A simple mouse click on the sliders allows the assignment of a value for each kinetic constant and a visual comparison between numerical and experimental curves. Users will thus find optimal values of the constants by means of a classic trial and error strategy. An experimental case of technical relevance is shown as benchmark.

  13. Fiber dielectrophoresis

    International Nuclear Information System (INIS)

    Lipowicz, P.J.; Yeh, H.C.

    1988-01-01

    Dielectrophoresis is the motion of uncharged particles in nonuniform electric fields. We find that the theoretical dielectrophoretic velocity of a conducting fiber in an insulating medium is proportional to the square of the fiber length, and is virtually independent of fiber diameter. This prediction has been verified experimentally. The results point to the development of a fiber length classifier based on dielectrophoresis. (author)

  14. Vulcan - A low-resolution spectrophotometer for measuring the integrated colors of galaxies

    International Nuclear Information System (INIS)

    Rakos, K.D.; Weiss, W.W.; Mueller, S.; Pressberger, R.; Wachtler, P.

    1990-01-01

    Recent advances in fiber optics, holographic gratings, and blue CCD sensitivity have been combined to develop a low-resolution spectrophotometer. Combining the principles of aperture photometry and spectroscopy, this device is designed specifically to measure the light from galaxies with low contrast to the sky brightness (i.e., low surface brightness galaxies). The instrument consists of two large apertures (up to several arcmin) with fast-field lens for imaging the entrance pupil onto a fiber-optics cable. The circular configuration for the input end of the fiber cable is modified to a rectangular slit at the output end. The output is then imaged onto a concave holographic grating producing a spectrum from 3200 A to 7600 A with a resolution of 140 A. The main purpose of this instrument is to obtain narrow-band optical colors for low surface brightness galaxies, which can then be applied to the study of stellar populations in these galaxies. 11 refs

  15. Fiber Amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten

    2017-01-01

    The chapter provides a discussion of optical fiber amplifiers and through three sections provides a detailed treatment of three types of optical fiber amplifiers, erbium doped fiber amplifiers (EDFA), Raman amplifiers, and parametric amplifiers. Each section comprises the fundamentals including...... the basic physics and relevant in-depth theoretical modeling, amplifiers characteristics and performance data as a function of specific operation parameters. Typical applications in fiber optic communication systems and the improvement achievable through the use of fiber amplifiers are illustrated....

  16. Toxicological evaluation of natural rubber films from vulcanized latex by the conventional process and the alternative process with ionizing radiation; Avaliacao toxicologica de filmes de borracha natural obtidos do latex vulcanizado pelo processo convencional e pelo processo alternativo com radiacao ionizante

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Vania Elisabeth

    1997-07-01

    The industrial vulcanization of natural rubber latex (NRL) is made all over the world by conventional process using sulphur and heat but it can be made by an alternative process using ionizing radiation. In this research the NRL was tested by 13 physical, chemical and mechanical assays which showed its good quality. It was done a preliminary study of the toxicological properties of 4 natural rubber films obtained by casting process of NRL: one non vulcanized, other vulcanized by the conventional process and two vulcanized by the alternative process. In the alternative process the films were obtained by irradiation of NRL by gamma rays from the {sup 60} Co source at 250 kGy in the absence of sensitizer and irradiated NRL at 12 kGy in the presence of 4ph r of n-butyl acrylate / 0.2 phr of KOH. These vulcanization doses were determined from broken tensile strength. In the conventional process, sulphur vulcanized NRL was made using a classical composition. Another film was made with non vulcanized NRL. The preliminary evaluation of the toxicological properties was made from in vitro cytotoxicity and in vivo systemic toxicity assays. The LBN films vulcanized by the alternative process have less cytotoxicity than the NRL film vulcanized by the conventional process. The sensitized vulcanized films by gamma rays and non vulcanized films showed similar cytotoxicity while the vulcanized films without sensitizer showed a slight lower cytotoxicity. The non vulcanized NRL film and the NRL films vulcanized by the alternative process did not show toxic effects in the 72 hours period of the systemic toxicity assay. However the NRL film vulcanized with sulphur induced effects like allaying and motor in coordination on the animals treated with an oil extract at the fourth hour and recovering after that. The alternative process promoted lower toxic effects than conventional process because there was no toxic substances present. (author)

  17. The Influence of Fiber Length and Concentration on the Physical Properties of Wheat Husk Fibers Rubber Composites

    Directory of Open Access Journals (Sweden)

    Maged S. Sobhy

    2010-01-01

    Full Text Available Ethylene-propylene-diene terpolymer (EPDM/wheat husk fibers (WHFs composites were prepared using a laboratory size two-roll mill. Cure characteristics and some physical properties such as swelling, mechanical, and thermal properties of the vulcanizates were studied. The adhesion status between the WHF and rubber matrix is lacked in general, but it started to reinforce the matrix at higher WHF contents where a higher restriction to molecular motion of the macromolecules with uniformed stress distribution of the fibers is produced. From the TGA analysis, a thermally stable property is exhibited, which in turn partially enhanced the reinforcement of the WHF-EPDM composites due to the natural adhesion during vulcanization.

  18. Improved properties of dissimilar rubber-rubber blends using plasma polymer encapsulated curatives : a novel surface modification method to improve co-vulcanization

    NARCIS (Netherlands)

    Guo, R.

    2009-01-01

    In industrial applications, different rubber types are often blended to fine-tune or optimize the property portfolio required for successful performance of articles. Considering the complexity of a rubber blend compound, wherein numerous additives are involved, vulcanization or cure mismatch often

  19. Effects of composition and processing conditions on morphology and properties of thermoplastic elastomer blends of SEBS-PP-Oil and dynamically vulcanized EPDM-PP-Oil

    NARCIS (Netherlands)

    Sengupta, P.; Noordermeer, Jacobus W.M.

    2004-01-01

    This work presents a comparative study of the morphology and structure-related properties of thermoplastic elastomer blends based on SEBS-PP-oil and dynamically vulcanized EPDM-PP-oil prepared under identical conditions. Compositions of each blend type with three different SEBS-PP and EPDM-PP ratios

  20. Radiation pre-vulcanization effect on properties of the truck tyre's transition layer and the truck tyre

    International Nuclear Information System (INIS)

    Yang Mingcheng; Zhu Jun; Li Kunhao; Guo Dongquan; Zhang Hongna; Zhang Benshang; Li Zhaopeng

    2013-01-01

    In this paper, the natural rubber is chosen as the main constituents for the transition layer of all-steel load radial tyre, which is pre-vulcanized by 500-keV E-beam irradiation of up to 60 kGy. The results show that the green strength of transitional layer increases with the dose, reaching four times as much as the control (without irradiation) at 60 kGy. The final mechanical properties do not differ significantly from those of the control except that the aging and fatigue performance increased. However, thickness of the natural rubber transitional layer for an average single tyre can be reduced by 1 mm (or 1.5 kg) without obvious adverse effect on tyre performance. (authors)

  1. The VULCAN Project: Toward a better understanding of the vulnerability of soil organic matter to climate change in permafrost ecosystems

    Science.gov (United States)

    Plaza, C.; Schuur, E.; Maestre, F. T.

    2015-12-01

    Despite much recent research, high uncertainty persists concerning the extent to which global warming influences the rate of permafrost soil organic matter loss and how this affects the functioning of permafrost ecosystems and the net transfer of C to the atmosphere. This uncertainty continues, at least in part, because the processes that protect soil organic matter from decomposition and stabilize fresh plant-derived organic materials entering the soil are largely unknown. The objective of the VULCAN (VULnerability of soil organic CArboN to climate change in permafrost and dryland ecosystems) project is to gain a deeper insight into these processes, especially at the molecular level, and to explore potential implications in terms of permafrost ecosystem functioning and feedback to climate change. We will capitalize on a globally unique ecosystem warming experiment in Alaska, the C in Permafrost Experimental Heating Research (CiPEHR) project, which is monitoring soil temperature and moisture, thaw depth, water table depth, plant productivity, phenology, and nutrient status, and soil CO2 and CH4 fluxes. Soil samples have been collected from the CiPEHR experiment from strategic depths, depending on thaw depth, and allow us to examine effects related to freeze/thaw, waterlogging, and organic matter relocation along the soil profile. We will use physical fractionation methods to separate soil organic matter pools characterized by different preservation mechanisms of aggregation and mineral interaction. We will determine organic C and total N content, transformation rates, turnovers, ages, and structural composition of soil organic matter fractions by elemental analysis, stable and radioactive isotope techniques, and nuclear magnetic resonance tools. Acknowledgements: This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 654132. Web site: http://vulcan.comule.com

  2. A novel coating strategy towards improving interfacial adhesion strength of Cu–Sn alloy coated steel with vulcanized rubber

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Atanu [Tata Steel, Jamshedpur 831001 (India); Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Kharagpur 721302 (India); Dutta, Monojit [Tata Steel, Jamshedpur 831001 (India); Bysakh, Sandip [Central Glass and Ceramic Research Institute, Kolkata 700032 (India); Bhowmick, Anil K. [Rubber Technology Center, Indian Institute of Technology, Kharagpur 721302 (India); Laha, Tapas, E-mail: laha@metal.iitkgp.ernet.in [Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Kharagpur 721302 (India)

    2014-09-15

    Highlights: • We propose a double layer Cu–Sn alloy coating strategy on steel to improve adhesion. • Uniform coating with adequate penetration inside micro-roughness was observed. • XPS and GDOES study revealed improved substrate surface coverage by coating. • TEM investigation confirmed compact, uniform and micro-porosity free interface. • Peel test with vulcanized rubber confirmed improved adhesion with cohesive fracture. - Abstract: A comparative assessment in terms of uniformity, coating coverage and coating deposition mechanism has been carried out for two different types of Cu–Sn coatings on steel substrate with varying Sn composition (2–6.5 wt%) deposited via immersion technique, viz. (i) single layer Cu–Sn coating and (ii) double layer coating consisting of a thin Cu strike layer followed by a Cu–Sn layer. Coating morphology, surface coverage, coating-substrate interface, and coating composition at surface and along the depth were studied using laser confocal microscope (OLS), scanning electron microscope (SEM) coupled with energy dispersive spectroscope (EDS), glow discharge optical emission spectroscopy (GDOES), X-ray photoelectron spectroscopy (XPS) and cross-sectional transmission electron microscopy (TEM). Quantitative depth profiling using GDOES and surface compositional analysis via XPS suggested improvement in surface coverage in the case of double layer coatings. SEM-EDS and TEM analysis confirmed that the coating deposition was more uniform with sufficient coating penetration inside the deep roughness troughs resulting in compact and micro-porosity free interface for this type of coatings. Better adhesion strength with less variation in peel force and cohesive mode of fracture within the rubber was observed for the double layer coated samples during the peel test carried out on coated steel samples vulcanized with rubber. On the other hand, the single layer coated samples showed large variation in peel force with adhesive

  3. A novel coating strategy towards improving interfacial adhesion strength of Cu–Sn alloy coated steel with vulcanized rubber

    International Nuclear Information System (INIS)

    Banerjee, Atanu; Dutta, Monojit; Bysakh, Sandip; Bhowmick, Anil K.; Laha, Tapas

    2014-01-01

    Highlights: • We propose a double layer Cu–Sn alloy coating strategy on steel to improve adhesion. • Uniform coating with adequate penetration inside micro-roughness was observed. • XPS and GDOES study revealed improved substrate surface coverage by coating. • TEM investigation confirmed compact, uniform and micro-porosity free interface. • Peel test with vulcanized rubber confirmed improved adhesion with cohesive fracture. - Abstract: A comparative assessment in terms of uniformity, coating coverage and coating deposition mechanism has been carried out for two different types of Cu–Sn coatings on steel substrate with varying Sn composition (2–6.5 wt%) deposited via immersion technique, viz. (i) single layer Cu–Sn coating and (ii) double layer coating consisting of a thin Cu strike layer followed by a Cu–Sn layer. Coating morphology, surface coverage, coating-substrate interface, and coating composition at surface and along the depth were studied using laser confocal microscope (OLS), scanning electron microscope (SEM) coupled with energy dispersive spectroscope (EDS), glow discharge optical emission spectroscopy (GDOES), X-ray photoelectron spectroscopy (XPS) and cross-sectional transmission electron microscopy (TEM). Quantitative depth profiling using GDOES and surface compositional analysis via XPS suggested improvement in surface coverage in the case of double layer coatings. SEM-EDS and TEM analysis confirmed that the coating deposition was more uniform with sufficient coating penetration inside the deep roughness troughs resulting in compact and micro-porosity free interface for this type of coatings. Better adhesion strength with less variation in peel force and cohesive mode of fracture within the rubber was observed for the double layer coated samples during the peel test carried out on coated steel samples vulcanized with rubber. On the other hand, the single layer coated samples showed large variation in peel force with adhesive

  4. Influence of the Synthesis Method for Pt Catalysts Supported on Highly Mesoporous Carbon Xerogel and Vulcan Carbon Black on the Electro-Oxidation of Methanol

    Directory of Open Access Journals (Sweden)

    Cinthia Alegre

    2015-03-01

    Full Text Available Platinum catalysts supported on carbon xerogel and carbon black (Vulcan were synthesized with the aim of investigating the influence of the characteristics of the support on the electrochemical performance of the catalysts. Three synthesis methods were compared: an impregnation method with two different reducing agents, sodium borohydride and formic acid, and a microemulsion method, in order to study the effect of the synthesis method on the physico-chemical properties of the catalysts. X-ray diffraction and transmission electron microscopy were applied. Cyclic voltammetry and chronoamperometry were used for studying carbon monoxide and methanol oxidation. Catalysts supported on carbon xerogel presented higher catalytic activities towards CO and CH3OH oxidation than catalysts supported on Vulcan. The higher mesoporosity of carbon xerogel was responsible for the favored diffusion of reagents towards catalytic centers.

  5. Electrochemical characterization of adsorbed bilirubin oxidase on Vulcan XC 72R for the biocathode preparation in a glucose/O2 biofuel cell

    International Nuclear Information System (INIS)

    Habrioux, A.; Napporn, T.; Servat, K.; Tingry, S.; Kokoh, K.B.

    2010-01-01

    A new biocathode was built and tested. It consisted of bilirubin oxidase adsorbed on Vulcan XC 72 R and immobilized into a Nafion matrix. The possibility of direct electron transfer between bilirubin oxidase and Vulcan XC 72 R was also demonstrated. The kinetics on biocathode were enhanced by including 2,2'-azinobis-3-ethylbenzothiazoline-5-sulfonic acid in the catalytic film. A first order reaction rate was observed for oxygen concentrations lower than 22%. A complete kinetic investigation of the system was shown. A biofuel cell test performed with this biocathode and Au 70 Pt 30 nanoparticles as anode catalyst permitted to reach a power density of 170 μW cm -2 at a cell voltage of 0.6 V, which is superior to what can be obtained with the concentric design.

  6. Effectiveness of the custom-mold room temperature vulcanizing silicone toe separator on hallux valgus: A prospective, randomized single-blinded controlled trial.

    Science.gov (United States)

    Chadchavalpanichaya, Navaporn; Prakotmongkol, Voraluck; Polhan, Nattapong; Rayothee, Pitchaya; Seng-Iad, Sirirat

    2018-04-01

    Silicone toe separator is considered as a conservative treatment for hallux valgus. The prefabricated toe separator does not fit all. However, effectiveness in prescription of the custom-mold toe separator is still unknown. To investigate the effect of using a custom-mold room temperature vulcanizing silicone toe separator to decrease hallux valgus angle and hallux pain. The compliances, complications, and satisfactions of toe separator were also explored. A prospective, randomized single-blinded controlled trial. A total of 90 patients with a moderate degree of hallux valgus were enrolled in a study at the Foot Clinic, Siriraj Hospital, Thailand. Patients were randomized into two groups; the study group was prescribed a custom-mold room temperature vulcanizing silicone toe separator for 6 h per night for 12 months. Patients in both groups received proper foot care and shoes and were permitted to continue drug treatment. In total, 40 patients in the study group and 39 patients in the control group completed the study. The hallux valgus angle was obtained through radiographic measurement. At month 12, both groups had significant differences in mean hallux valgus angle with a decrease of 3.3° ± 2.4° for the study group and increase of 1.9° ± 1.9° for the control group. There were statistically significant differences of hallux valgus angle between the two groups ( p Hallux pain was decreased in the study group. A custom-mold room temperature vulcanizing silicone toe separator can decrease hallux valgus angle and pain with no serious complications. Clinical relevance The custom-mold room temperature vulcanizing silicone toe separator for treatment of hallux valgus reduces deformity and hallux pain.

  7. Reactor similarity for plasma–material interactions in scaled-down tokamaks as the basis for the Vulcan conceptual design

    International Nuclear Information System (INIS)

    Whyte, D.G.; Olynyk, G.M.; Barnard, H.S.; Bonoli, P.T.; Bromberg, L.; Garrett, M.L.; Haakonsen, C.B.; Hartwig, Z.S.; Mumgaard, R.T.; Podpaly, Y.A.

    2012-01-01

    Highlights: ► Discussion of similarity scalings for reduced-size tokamaks. ► Proposal of a new set of scaling laws for divertor similarity. ► Discussion of how the new scaling provides fidelity to a reactor. ► The new scaling is used as the basis for the Vulcan conceptual design. - Abstract: Dimensionless parameter scaling techniques are a powerful tool in the study of complex physical systems, especially in tokamak fusion experiments where the cost of full-size devices is high. It is proposed that dimensionless similarity be used to study in a small-scale device the coupled issues of the scrape-off layer (SOL) plasma, plasma–material interactions (PMI), and the plasma-facing material (PFM) response expected in a tokamak fusion reactor. Complete similarity is not possible in a reduced-size device. In addition, “hard” technological limits on the achievable magnetic field and peak heat flux, as well as the necessity to produce non-inductive scenarios, must be taken into account. A practical approach is advocated, in which the most important dimensionless parameters are matched to a reactor in the reduced-size device, while relaxing those parameters which are far from a threshold in behavior. “Hard” technological limits are avoided, so that the reduced-size device is technologically feasible. A criticism on these grounds is offered of the “P/R” model, in which the ratio of power crossing the last closed flux surface (LCFS), P, to the device major radius, R, is held constant. A new set of scaling rules, referred to as the “P/S” scaling (where S is the LCFS area) or the “PMI” scaling, is proposed: (i) non-inductive, steady-state operation; (ii) P is scaled with R 2 so that LCFS areal power flux P/S is constant; (iii) magnetic field B constant; (iv) geometry (elongation, safety factor q * , etc.) constant; (v) volume-averaged core density scaled as n≈n ¯ e ∼R −2/7 ; and (vi) ambient wall material temperature T W,0 constant. It is

  8. Effects of carbon blacks with various structures on vulcanization and reinforcement of filled ethylene-propylene-diene rubber

    Directory of Open Access Journals (Sweden)

    2008-10-01

    Full Text Available The effects of carbon blacks on vulcanization and mechanical properties of filled ethylene-propylene-diene rubber (EPDM are investigated, by comparing with five types of rubber-grade carbon blacks. Curing kinetics is studied by rheometer and the results indicate that the curing characteristics are influenced by combination of surface area of carbon black and sulphur content on the filler surface, because the former one enhances the physical cross-linking and the latter one introduces the additional chemical cross-linking. Both the degree of cross-linking and cure rate increase with increasing surface area and sulphur content, whereas the optimum cure time and scorch time decrease. The reinforcing nature of the carbon black is assessed from mechanical measurements. It is suggested that the surface area of carbon blacks strongly affects the physical properties of EPDM/carbon black composites. Conductive carbon black (N472 can be used as desirable reinforcing filler due to the higher degree of cross-linking of EPDM with N472 than other EPDM/carbon black composites. The morphology and distribution of particles are studied by using scanning electron microscope. The sound reinforcing ability of N472 is also supported by scanning electron microscope due to the notable dispersibility of N472 within EPDM matrix. N472 ensures the EPDM/N472 composite the most conductive sample among the five composites.

  9. Production Of Hollow Toy Product From Radiation Pre vulcanized Natural Rubber Latex (RVNRL) By Using Casting And Moulding Technique

    International Nuclear Information System (INIS)

    Mohd Noorwadi Mat Lazim; Sofian Ibrahim; Muhammad Saiful Omar

    2013-01-01

    Hollow toy products are very synonym to the child from the age of months since it able to stimulating each of their sense such as sight, hearing, taste, touch and smell. Most of hollow toy products are made from natural rubber latex by using moulding and casting technique. The moulding and casting technique is a manufacturing process by pored liquid latex into a mould, which contain cavity of the desired shape. The mould made from plaster of Paris able to absorbs water from latex meanwhile the presence of calcium ions from plaster of Paris will tend to diffuse into latex thus promote formation of deposit on surface of cavity mould. To improve the quality and safety of hollow toy product made from latex, Radiation Pre vulcanized Natural Rubber Latex (RVNRL) has been identified to be used because it can fulfill the standard requirement for latex and also due to its special abilities such as lower modulus (soft latex products), nitrosamines free, low in nitrosatables, free from chemical accelerators induced allergies and better biodegradability. This paper identify the problem appears from the process of making hollow toy products from RVNRL by using moulding and casting technique. (author)

  10. To minimized power outage by the application of 'RTV' (room temperature vulcanizing) silicon on high voltage porcelain insulators in Pakistan

    International Nuclear Information System (INIS)

    Hafiz Tehzeeb ul Hassan

    2003-01-01

    In Pakistan power network comprises of 500KV, 220KV, 132KV, 66KV and 33KV transmission lines and 11KV power distribution systems. Number of insulators are used in connected units in the shape of strings with transmission line as per insulation requirements with proper design according to the various kinds of pollution stresses. The transmission lines are passing from or near polluted areas and very dusty plains of Punjab and Sindh provinces. Practices are being used in these transmission lines for removal of accumulated contamination of insulators by periodic cleaning twice a year or de-energized transmission lines. Even then discontinuation of supply takes place in the polluted areas in foggy weather. Special technique of using water repellent (Room Temperature Vulcanizing) silicone coating/paint has been introduced on high voltage disc Insulators to minimize the outage in power net work in Pakistan. Especially in high pollution areas near chemical factories and near brick kilns etc comparison study of coated and uncoated disc Insulators have been carried out by ESDD (Equal Salt Deposit Density) measurement in salt fog chamber. (author)

  11. Two Fiber Optical Fiber Thermometry

    Science.gov (United States)

    Jones, Mathew R.; Farmer, Jeffery T.; Breeding, Shawn P.

    2000-01-01

    An optical fiber thermometer consists of an optical fiber whose sensing tip is given a metallic coating. The sensing tip of the fiber is essentially an isothermal cavity, so the emission from this cavity will be approximately equal to the emission from a blackbody. Temperature readings are obtained by measuring the spectral radiative heat flux at the end of the fiber at two wavelengths. The ratio of these measurements and Planck's Law are used to infer the temperature at the sensing tip. Optical fiber thermometers have high accuracy, excellent long-term stability and are immune to electromagnetic interference. In addition, they can be operated for extended periods without requiring re-calibration. For these reasons. it is desirable to use optical fiber thermometers in environments such as the International Space Station. However, it has recently been shown that temperature readings are corrupted by emission from the fiber when extended portions of the probe are exposed to elevated temperatures. This paper will describe several ways in which the reading from a second fiber can be used to correct the corrupted temperature measurements. The accuracy and sensitivity to measurement uncertainty will be presented for each method.

  12. Combined experimental and numerical kinetic characterization of NR vulcanized with sulphur, N terbutyl, 2 benzothiazylsulphenamide and N,N diphenyl guanidine

    Energy Technology Data Exchange (ETDEWEB)

    Milani, G., E-mail: gabriele.milani@polimi.it [Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan (Italy); Hanel, T.; Donetti, R. [Pirelli Tyre, Via Alberto e Piero Pirelli 25, 20126 Milan (Italy); Milani, F. [Chem. Co, Via J.F.Kennedy 2, 45030 Occhiobello (Italy)

    2016-06-08

    The paper presents the final results of a comprehensive experimental and numerical analysis aimed at deeply investigating the behavior of Natural Rubber (NR) vulcanized with sulphur in presence of different accelerators during standard rheometer tests. NR in presence of sulphur and two different accelerators (DPG and TBBS) in various concentrations is investigated, changing the curing temperature in the range 150-180°C and obtaining rheometer curves with a step of 10°C. Sulphur-TBBS concentrations considered are 1-1, 1-3, 3-3 and 3-1, with DPG at 1-4 phr respectively. A total of 48 experimental rheometer curves is so obtained. To fit experimental data, the general reaction scheme proposed by Han and co-workers for vulcanized sulphur NR is re-adapted and suitably modified taking into account the single contributions of the different accelerators. Chain reactions initiated by the formation of macro-compounds responsible for the formation of the unmatured crosslinked polymer are accounted for. In presence of two accelerators, reactions are assumed to proceed in parallel, making the practically effective hypothesis that there is no interaction between the two accelerators. From the simplified kinetic scheme adopted, a closed form solution is found for the crosslink density, with the only limitation that the induction period is excluded from computations. For each experimented case on the same blend, reaction kinetic constants provided by the model are utilized to deduce their trend in the Arrhenius space, also outside the temperature range inspected. Rather close linearity is found in the majority of the cases. A comparative analysis is carefully conducted among the constants at the different concentrations of S, TBBS and DPG investigated, allowing a prediction of curing behavior at any vulcanization temperature and with concentrations not experimentally tested, without the need of addition costly experimentation.

  13. Combined experimental and numerical kinetic characterization of NR vulcanized with sulphur, N terbutyl, 2 benzothiazylsulphenamide and N,N diphenyl guanidine

    International Nuclear Information System (INIS)

    Milani, G.; Hanel, T.; Donetti, R.; Milani, F.

    2016-01-01

    The paper presents the final results of a comprehensive experimental and numerical analysis aimed at deeply investigating the behavior of Natural Rubber (NR) vulcanized with sulphur in presence of different accelerators during standard rheometer tests. NR in presence of sulphur and two different accelerators (DPG and TBBS) in various concentrations is investigated, changing the curing temperature in the range 150-180°C and obtaining rheometer curves with a step of 10°C. Sulphur-TBBS concentrations considered are 1-1, 1-3, 3-3 and 3-1, with DPG at 1-4 phr respectively. A total of 48 experimental rheometer curves is so obtained. To fit experimental data, the general reaction scheme proposed by Han and co-workers for vulcanized sulphur NR is re-adapted and suitably modified taking into account the single contributions of the different accelerators. Chain reactions initiated by the formation of macro-compounds responsible for the formation of the unmatured crosslinked polymer are accounted for. In presence of two accelerators, reactions are assumed to proceed in parallel, making the practically effective hypothesis that there is no interaction between the two accelerators. From the simplified kinetic scheme adopted, a closed form solution is found for the crosslink density, with the only limitation that the induction period is excluded from computations. For each experimented case on the same blend, reaction kinetic constants provided by the model are utilized to deduce their trend in the Arrhenius space, also outside the temperature range inspected. Rather close linearity is found in the majority of the cases. A comparative analysis is carefully conducted among the constants at the different concentrations of S, TBBS and DPG investigated, allowing a prediction of curing behavior at any vulcanization temperature and with concentrations not experimentally tested, without the need of addition costly experimentation.

  14. Studied on Virgin Coconut Oil (VCO) and Olive Oil (OO) as an Alternative for Stabilizer of Radiation Vulcanized Natural Rubber Latex (RVNRL) Preparation

    International Nuclear Information System (INIS)

    Syuhada Ramli; Sofian Ibrahim; Mohd Noorwadi Mat Lazim

    2016-01-01

    This paper presents the effects of virgin coconut oil (VCO) and olive oil (OO) as an alternative stabilizer in the radiation vulcanized natural rubber latex (RVNRL). Potassium laurite (KL) as a stabilizer considered as a control of RVNRL sample were compared to mixed ratio 1:1 KL: VCO and 1:1 KL: OO stabilizer formulation. Total solid content (TSC) and tensile strength (TS) results showed no significant different between the formulations. Mechanical stability time (MST) indicates higher stability of RVNRL with addition of VCO. The fatty acid composition in VCO indicate VCO was acting well as stabilizer for latex stabilizer formulation. (author)

  15. Assessing the feasibility of a high-temperature, helium-cooled vacuum vessel and first wall for the Vulcan tokamak conceptual design

    International Nuclear Information System (INIS)

    Barnard, H.S.; Hartwig, Z.S.; Olynyk, G.M.; Payne, J.E.

    2012-01-01

    The Vulcan conceptual design (R = 1.2 m, a = 0.3 m, B 0 = 7 T), a compact, steady-state tokamak for plasma–material interaction (PMI) science, must incorporate a vacuum vessel capable of operating at 1000 K in order to replicate the temperature-dependent physical chemistry that will govern PMI in a reactor. In addition, the Vulcan divertor must be capable of handling steady-state heat fluxes up to 10 MW m −2 so that integrated materials testing can be performed under reactor-relevant conditions. A conceptual design scoping study has been performed to assess the challenges involved in achieving such a configuration. The Vulcan vacuum system comprises an inner, primary vacuum vessel that is thermally and mechanically isolated from the outer, secondary vacuum vessel by a 10 cm vacuum gap. The thermal isolation minimizes heat conduction between the high-temperature helium-cooled primary vessel and the water-cooled secondary vessel. The mechanical isolation allows for thermal expansion and enables vertical removal of the primary vessel for maintenance or replacement. Access to the primary vessel for diagnostics, lower hybrid waveguides, and helium coolant is achieved through ∼1 m long intra-vessel pipes to minimize temperature gradients and is shown to be commensurate with the available port space in Vulcan. The isolated primary vacuum vessel is shown to be mechanically feasible and robust to plasma disruptions with analytic calculations and finite element analyses. Heat removal in the first wall and divertor, coupled with the ability to perform in situ maintenance and replacement of divertor components for scientific purposes, is achieved by combining existing helium-cooled techniques with innovative mechanical attachments of plasma facing components, either in plate-type helium-cooled modules or independently bolted, helium-jet impingement-cooled tiles. The vacuum vessel and first wall design enables a wide range of potential PFC materials and configurations to

  16. Low-fiber diet

    Science.gov (United States)

    ... residue; Low-fiber diet; Fiber restricted diet; Crohn disease - low fiber diet; Ulcerative colitis - low fiber diet; ... them if they do not contain seeds or pulp: Yellow squash (without seeds) Spinach Pumpkin Eggplant Potatoes, ...

  17. Photovoltaic fibers

    Science.gov (United States)

    Gaudiana, Russell; Eckert, Robert; Cardone, John; Ryan, James; Montello, Alan

    2006-08-01

    It was realized early in the history of Konarka that the ability to produce fibers that generate power from solar energy could be applied to a wide variety of applications where fabrics are utilized currently. These applications include personal items such as jackets, shirts and hats, to architectural uses such as awnings, tents, large covers for cars, trucks and even doomed stadiums, to indoor furnishings such as window blinds, shades and drapes. They may also be used as small fabric patches or fiber bundles for powering or recharging batteries in small sensors. Power generating fabrics for clothing is of particular interest to the military where they would be used in uniforms and body armor where portable power is vital to field operations. In strong sunlight these power generating fabrics could be used as a primary source of energy, or they can be used in either direct sunlight or low light conditions to recharge batteries. Early in 2002, Konarka performed a series of proof-of-concept experiments to demonstrate the feasibility of building a photovoltaic cell using dye-sensitized titania and electrolyte on a metal wire core. The approach taken was based on the sequential coating processes used in making fiber optics, namely, a fiber core, e.g., a metal wire serving as the primary electrode, is passed through a series of vertically aligned coating cups. Each of the cups contains a coating fluid that has a specific function in the photocell. A second wire, used as the counter electrode, is brought into the process prior to entering the final coating cup. The latter contains a photopolymerizable, transparent cladding which hardens when passed through a UV chamber. Upon exiting the UV chamber, the finished PV fiber is spooled. Two hundred of foot lengths of PV fiber have been made using this process. When the fiber is exposed to visible radiation, it generates electrical power. The best efficiency exhibited by these fibers is 6% with an average value in the 4

  18. Radiation Vulcanization of Polymeric Blends Based on Ethylene Propylene Diene Monomer Rubber/ Waste Materials in Presence of Different Additives

    International Nuclear Information System (INIS)

    MOHAMED, R.M.

    2015-01-01

    In this investigation, the mechanical blending technique was applied for preparation of elastomeric blend of ethylene propylene diene monomer rubber (EPDM)and nitrile butadiene rubber (NBR) having a fixed ratio of (50/50) by weight. The prepared blend of EPDM/NBR (50/50) was used as a rubber matrix to be loaded with waste materials, namely rice husk (RH) as a natural waste filler and then with ground tire rubber (GTR) as an artificial one. The degree of loading varied from 5 p hr to 20 p hr. Ionizing radiation, namely ,gamma rays were applied for inducing vulcanization of prepared and loaded rubber blends, in the range from 5 kGy to 250 kGy. Different properties of prepared composites were followed up as a function of degree of loading with the waste material and dose of irradiation. The mechanical properties, namely tensile strength and elongation at break percent of the composites slightly decreased as the filler loading increased over the whole range of irradiation .Tensile modulus and hardness, on the other hand, showed an opposite trend, i.e. the increased. Other properties, namely physical, thermal and morphological confirmed the mechanical ones. Obtained results were affiliated with lack of interface adhesion between the waste materials and the rubber matrix elastomers. The lack of interface adhesion was improved by filling the composite with a limited content, up to 7 p hr, of the compatibilizer, namely, maleic anhydride (MAH). Measurements of different properties was carried out for composite loaded with 10 p hr of waste material. It has been found that the tensile properties were significantly improved with addition of the compatibilizing agent Further and significant improvement was attained in properties of prepared later composite by its loading with 40 p hr of either HAF- carbon black or Hisil as reinforcing fillers that participates in chemical as well as physical bonding. Similarly and lastly 8 p hr of N, N- methylene di acrylamide (MDA) were loaded

  19. A study of using polythiol compounds and 2-ethyl-hexyl-acrylate with carbon tetrachloride as sensitizers for radiation vulcanization of natural rubber latex

    International Nuclear Information System (INIS)

    Polsuksiri, C.

    1989-01-01

    Experiments on using 3 different compounds of polythiol and an acrylate as sensitizer for radiation vulcanization were conducted. It was found that 1,4 butane diol propane tris-3-mercapto propionate showed the tendency to be a good sensitizer. The tensile strength of the rubber film prepared from the irradiated latex was found to be 14 MPa at sensitizer concentration of 1 phr and radiation dose of 45 kGy. As for 2-ethyl hexyl acrylate (2EHA), the maximum tensile strength of rubber film was found to be 23 MPa at concentration of 3 phr and radiation dose of 35 kGy. The mixture of 2 EHA and CCl 4 at various ratio was also used as sensitizer. The optimum ratio was found to be 5:1 at concentration of 6 phr and radiation dose of 15 kGy. The maximum tensile strength was as high as 25 MPa. The study also revealed that the radiation vulcanized latex with crosslink density of about 18x10 18 C.L./cm 3 would give the rubber film of highest tensile strength

  20. GURU v2.0: An interactive Graphical User interface to fit rheometer curves in Han’s model for rubber vulcanization

    Directory of Open Access Journals (Sweden)

    G. Milani

    2016-01-01

    Full Text Available A GUI software (GURU for experimental data fitting of rheometer curves in Natural Rubber (NR vulcanized with sulphur at different curing temperatures is presented. Experimental data are automatically loaded in GURU from an Excel spreadsheet coming from the output of the experimental machine (moving die rheometer. To fit the experimental data, the general reaction scheme proposed by Han and co-workers for NR vulcanized with sulphur is considered. From the simplified kinetic scheme adopted, a closed form solution can be found for the crosslink density, with the only limitation that the induction period is excluded from computations. Three kinetic constants must be determined in such a way to minimize the absolute error between normalized experimental data and numerical prediction. Usually, this result is achieved by means of standard least-squares data fitting. On the contrary, GURU works interactively by means of a Graphical User Interface (GUI to minimize the error and allows an interactive calibration of the kinetic constants by means of sliders. A simple mouse click on the sliders allows the assignment of a value for each kinetic constant and a visual comparison between numerical and experimental curves. Users will thus find optimal values of the constants by means of a classic trial and error strategy. An experimental case of technical relevance is shown as benchmark.

  1. The Effect of Minarex B Oil and Gamma Irradiation on the Mechanical Properties of Vulcanized Natural Rubber-LDPE Mixture for Shoe Sole

    International Nuclear Information System (INIS)

    Sudradjat Iskandar; Isni Marliyanti

    2004-01-01

    To obtain the optimum concentration of minarex B oil and gamma irradiation dose on natural rubber compound for shoe sole, study on the effect of minarex B oil and gamma radiation on the mechanical properties of vulcanized natural rubber-LDPE mixture has been done. Natural rubber was masticated and mixed with additive and filler using two-roll machine, at 120 o C of forward roll and 100 o C of backward roll, with rotation speed of 18 rpm. The additives added with irganox 1076, paraffin wax, stearic acid, and minarex B oil, while fillers used were polyethylene (LDPE) and calcium carbonate. Minarex B oil mixed was vary such as 5, 10 and 20 phr (part per hundred of rubber). The amount of filler and other additives mixed was not varied. The natural rubber film was obtained by pressing the mixture using hot and cold press machine at 135 o C and room temperature for about 3 minutes. The film then irradiated with gamma rays from cobalt-60 source, at the doses of 150, 300, and 500 kGy. The results show that the mechanical properties of natural rubber vulcanized decreases by increasing minarex B oil, and increases by increasing of irradiation dose. The concentration optimum of minarex B oil in the natural rubber compound for shoe sole and irradiation dose about 5 phr and 300 kGy were agree with SII 0944-84. (author)

  2. Radiation vulcanization of rubbers

    Energy Technology Data Exchange (ETDEWEB)

    Makuuchi, Keizo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2002-02-01

    An abstract of the radiation process of polymer materials and the polymer reaction by radiation is explained. Main radiation is 250 keV to 10 MeV of electron rays in the industry. Radiation cross-linked rubber has less the tensile strength than that by sulfur and organic peroxide crosslinking. The main origins of low tensile strength are caused by cut of backbone chain and ozone depend on radiation. Acceleration of crosslinking and short time of radiation are necessary to improve these defects. To accelerate crosslinking, we used crosslinking accelerators, for example, three poly-functional monomers (PFM). The maximum tensile strength of styrene-butadiene rubber (SBR) not added crosslinking accelerators showed 3 MPa at 110 kGy, but SBR added A-TMMT (tetramethylolmethane tetraacrylate) showed 5.5 MPa at 110 kGy. Radiation crosslinking of many kinds of rubber: isoprene (IR), SBR, CR, nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), butyl rubber (IIR), chlorinated butyl rubber (CIIR), EPM and TPE are explained. (S.Y.)

  3. Radiation vulcanization of rubbers

    International Nuclear Information System (INIS)

    Makuuchi, Keizo

    2002-01-01

    An abstract of the radiation process of polymer materials and the polymer reaction by radiation is explained. Main radiation is 250 keV to 10 MeV of electron rays in the industry. Radiation cross-linked rubber has less the tensile strength than that by sulfur and organic peroxide crosslinking. The main origins of low tensile strength are caused by cut of backbone chain and ozone depend on radiation. Acceleration of crosslinking and short time of radiation are necessary to improve these defects. To accelerate crosslinking, we used crosslinking accelerators, for example, three poly-functional monomers (PFM). The maximum tensile strength of styrene-butadiene rubber (SBR) not added crosslinking accelerators showed 3 MPa at 110 kGy, but SBR added A-TMMT (tetramethylolmethane tetraacrylate) showed 5.5 MPa at 110 kGy. Radiation crosslinking of many kinds of rubber: isoprene (IR), SBR, CR, nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), butyl rubber (IIR), chlorinated butyl rubber (CIIR), EPM and TPE are explained. (S.Y.)

  4. Vulcanization of Rubber

    Indian Academy of Sciences (India)

    Temperature 140 -180°C. Sulfur. 2-3 parts per. 100 parts of rubber (phr). Accelerator 0.5-1.0 phr. ZnO ... out an experiment, he spilt a mixture of rubber and sulfur with other ingredients on a hot .... both carbon-sulfur and sulfur-nitrogen bonds -.

  5. Application Specific Optical Fibers

    OpenAIRE

    Pal, Bishnu P.

    2010-01-01

    In this chapter we have attempted to provide a unified summary description of the most important propagation characteristics of an optical fiber followed by discussion on several variety of special fibers for realizing fiber amplifiers, dispersion compensating fibers, microstructured optical fibers, and so on. Even though huge progress has been made on development of optical fibers for telecom application, a need for developing special fibers, not necessarily for telecom alone, has arisen. Th...

  6. Biodegradability and aging study of rubber films obtained by gamma radiation vulcanization processes of latex; Estudo da biodegradabilidade e envelhecimento de filmes de borracha obtidos por processos de vulcanizacao do latex por radiacao induzida de fonte gama

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Carlos Felipe Pinto

    2005-07-01

    The natural rubber latex (NRL) is industrially crosslinked by the conventional process of vulcanization, which uses sulphur and heat. Otherwise, the network can also be done by the alternative process with ionizing radiation. In this work the crosslinking of NRL was studied by the comparison of the conventional vulcanization system and the ionizing radiation process of {sup 60}C source. The products obtained, the irradiated latex, the irradiated latex with approximately 1% of soy lecithin and the sulphur vulcanized latex were tested by accelerated aging with ultraviolet (UV) and outdoor aging with compostage, tensile strength at break, swelling and gel fraction, fungi micro biota, scanning electron microscopy (SEM), infrared spectroscopy (FTIR) and thermogravimetry and differential scanning calorimetry analysis (TG and DSC). The results showed that the aging with microorganisms have a great influence in the physical properties of the samples. The thermal stability order observed showed that the sulphur vulcanized latex is more resistant, what is probably associated to a network more stable under the aging conditions. On the other hand, the irradiated latex showed intense biodegradation aspects, particularly with the presence of the soy lecithin. (author)

  7. Radiation pre-vulcanization of transitional layer of all-steel load meridian tyre and performance tests of the tyre products

    International Nuclear Information System (INIS)

    Zhang Benshang; Zhu Chengshen; Ying Shizhou; Liu Kebo; Li Zhaopeng; Li Kunhao; Zhang Hongna; Zhao Meihong; Yang Mingcheng

    2012-01-01

    In this article, natural rubber is chosen as transitional layer of all-steel load meridian tyre, which is pre-vulcanized by 500 keV E-beam irradiation of up to 60 kGy. The results show that the Green strength of transitional layer increases with the dose, reaching four times at 60 kGy as much as the control (without irradiation). The viscosity of transitional layer increases rapidly below about 29 kGy, but changes little at higher doses. The final mechanical properties do not differ significantly from those of the control. However, thickness of the natural rubber transitional layer for an average single tire can be reduced by 1 mm (or 1.5 kg), without obvious adverse effect on the tyre performance. (authors)

  8. Mineralogical and structural transformations related to alterations in hydrothermal and climatological conditions of basic vulcanic rocks from northern Parana (Ribeirao Preto region, SP, Brazil)

    International Nuclear Information System (INIS)

    Goncalves, N.M.M.

    1987-01-01

    Detailed studies of the basic vulcanic rocks of northern Parana basin (Region of Ribeirao Preto, SP) reveled that these rocks were affected by pre-meteoric activity (hydrothermal alteration) before being exposed to the supergene system of alteration linked to the lithosphere/atmosphere interface. Mineralogical and structural transformation are studied. The appearance of sequential crystalline-chemical paragenesis in zones suggest that the hydrothermal activity occurred during two successives processes of alteration: the expulsion of the water from the rock during the later stages of magma cooling and the continous process of dissolution of the rock wall and the ionic diffusion involving the rock sistem of structural voids. The hydro-thermal action was followed by weathering action developing a thin 'front' of superficial alteration. This alteration system, can lead to the formation of three major levels of alteration horizons and superficial accumulations: alterites, glebular and suil surface materials. (C.D.G.) [pt

  9. Nanosílice como carga en la RTV SR usada para cubrir aisladores; Nanosilica as filler in the Room temperature vulcanized silicone rubber used to coat insulators

    Directory of Open Access Journals (Sweden)

    Ignat Pérez Almirall

    2014-04-01

    Full Text Available En el presente trabajo se realiza un estudio sobre la influencia que tiene agregar como carga nanosílice a la goma de silicona vulcanizada a temperatura ambiente (RTV SR, por sus siglas en inglés que es empleada para cubrir aisladores de vidrio o de porcelana. Con este objetivo se observó la dispersión de la nanosílice en la RTV SR por medio de microscopía electrónica de barrido (MEV, por sus siglas en inglés, se midió la permitividad de la RTV SR con y sin nanosílice para varias frecuencias y se evaluó la influencia que tiene la nanosílice en la resistencia a la erosión. Además fueron medidas las corrientes de fuga durante ensayos de niebla salina a aisladores de vidrio pintados con estos recubrimientos, analizando también la pérdida de hidrofobicidad que ocurre durante el ensayo y su recuperación una vez finalizado el mismo.  The present research work carries out a study on the influence of nanosilica on room temperature vulcanized silicone rubber (RTV SR used to coat insulators. Considering this objective, the dispersion of nanosilica was observed by means of scanning electron microscopy (MEV, the permittivity of the room temperature vulcanized silicone rubber was measured with and without nanosilica for different frequencies and the influence of nanosilica in erosion resistance. Leakage currents were also measured during salt spray tests to glass insulators covered with these coatings; the loss of hidrophobicity during the test was also measured and its recovery was analyzed the test was finished.

  10. Nanosílice como carga en la RTV SR usada para cubrir aisladores/ Nanosilica as filler in the Room temperature vulcanized silicone rubber used to coat insulators

    Directory of Open Access Journals (Sweden)

    Ignat Pérez Almirall

    2012-02-01

    Full Text Available En el presente trabajo se realiza un estudio sobre la influencia que tiene agregar como carga nanosílice a la goma de silicona vulcanizada a temperatura ambiente (RTV SR, por sus siglas en inglés que es empleada para cubrir aisladores de vidrio o de porcelana. Con este objetivo se observó la dispersión de la nanosílice en la RTV SR por medio de microscopía electrónica de barrido (MEV, por sus siglas en inglés, se midió la permitividad de la RTV SR con y sin nanosílice para varias frecuencias y se evaluó la influencia que tiene la nanosílice en la resistencia a la erosión. Además fueron medidas las corrientes de fuga durante ensayos de niebla salina a aisladores de vidrio pintados con estos recubrimientos, analizando también la pérdida de hidrofobicidad que ocurre durante el ensayo y su recuperación una vez finalizado el mismo.The present research work carries out a study on the influence of nanosilica on room temperature vulcanized silicone rubber (RTV SR used to coat insulators. Considering this objective, the dispersion of nanosilica was observed by means of scanning electron microscopy (MEV, the permittivity of the room temperature vulcanized silicone rubber was measured with and without nanosilica for different frequencies and the influence of nanosilica in erosion resistance. Leakage currents were also measured during salt spray tests to glass insulators covered with these coatings; the loss of hidrophobicity during the test was also measured and its recovery was analyzed the test was finished.

  11. Mechanical and Morphological Properties of Waste Short Nylon Fibers and Nanoclay Reinforced NR/SBR Rubber Nanocomposites

    Directory of Open Access Journals (Sweden)

    Mohammad Andideh

    2013-02-01

    Full Text Available Natural rubber and styrene butadiene rubber (NR/SBR reinforced with short nylon fibers along with nanoclay (Cloisite 15A hybrid composites were prepared in an internal and a two roll-mill mixer by a three-step mixingprocess. The effects of fiber content at a constant loading of 3 wt% nanoclay were studied on the microstructure, mechanical and morphological properties of the prepared nanocomposites. The adhesion between the fiber and the rubber was enhanced by the addition of a dry bonding system consisting of resorcinol, hexamethylene tetramine and hydrated silica (HRH. The curing characteristics of the composites were determined and subsequently vulcanized at 150°C using a hot press. It was observed that the cure time and swelling index of the composites decreased while maximum torque, and cure rate increased with increasing of short fiber and nanoclay contents. Thestructure and fracture surface morphology of the nanocomposites were characterized using X-ray diffraction, scanning electron microscopy. X-ray diffraction results of nanocomposites indicated that the interlayer distance of silicate layers increased. The mechanical properties (tensile, tear strength, elongation-at-break and hardness ofnanocomposites containing virgin and waste fibers in the longitudinal direction are compared.

  12. Fibered F-Algebra

    OpenAIRE

    Kleyn, Aleks

    2007-01-01

    The concept of F-algebra and its representation can be extended to an arbitrary bundle. We define operations of fibered F-algebra in fiber. The paper presents the representation theory of of fibered F-algebra as well as a comparison of representation of F-algebra and of representation of fibered F-algebra.

  13. Photonic crystal fibers

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper; Hansen, K P; Nielsen, M D

    2003-01-01

    Photonic crystal fibers having a complex microstructure in the transverse plane constitute a new and promising class of optical fibers. Such fibers can either guide light through total internal reflection or the photonic bandgap effect, In this paper, we review the different types and applications...... of photonic crystal fibers with particular emphasis on recent advances in the field....

  14. Photonic crystal fibers -

    DEFF Research Database (Denmark)

    Libori, Stig E. Barkou

    2002-01-01

    . Such micro-structured fibers are the ones most often trated in literature concerning micro-structured fibers. These micro-structured fibers offer a whole range of novel wave guiding characteristics, including the possibility of fibers that guide only one mode irrespective of the frequency of light...

  15. Fiber optic connector

    Science.gov (United States)

    Rajic, Slobodan; Muhs, Jeffrey D.

    1996-01-01

    A fiber optic connector and method for connecting composite materials within which optical fibers are imbedded. The fiber optic connector includes a capillary tube for receiving optical fibers at opposing ends. The method involves inserting a first optical fiber into the capillary tube and imbedding the unit in the end of a softened composite material. The capillary tube is injected with a coupling medium which subsequently solidifies. The composite material is machined to a desired configuration. An external optical fiber is then inserted into the capillary tube after fluidizing the coupling medium, whereby the optical fibers are coupled.

  16. Thermal-kinetic study of natural rubber latex films vulcanized by using gamma radiation; Estudo termo-cinetico de filmes de latex de borracha natural de Hevea brasiliensis vulcanizada por radiacao gama

    Energy Technology Data Exchange (ETDEWEB)

    Leal, Ana Paula Pinho Rodrigues; Barros, Glaucione Gomes de [Brasilia Univ., DF (Brazil). Inst. de Quimica; Guedes, Selma M.L. [Instituto de Pesquisa em Energia Nuclear, Sao Paulo, SP (Brazil)

    1999-07-01

    Vulcanization of natural rubber latex by ionization radiation produces the crosslink in disperse latex particles. Advantages over conventional process of vulcanization are: the absence of carcinogenic nitrosamines, low cytotoxicity and better degradation at room conditions, due to mainly to the absence of sulfur, zinc oxide and dithiocarbamates. Thermogravimetric analysis (TG) is the measurement of the weight change of a material as a function of temperature and time. TG data different heat speed provide an alternative model of the kinetics of degradation of polymeric materials. The kinetic studies of this material showed a single degradation process at least for 76,5% of mass loss. The activation energy was 49 Kcal/mol. For higher mass loss (85%) the degradation was characterized by associate mechanism. (author)

  17. Nonlinear Photonic Crystal Fibers

    DEFF Research Database (Denmark)

    Hansen, Kim Per

    2004-01-01

    Despite the general recession in the global economy and the collapse of the optical telecommunication market, research within specialty fibers is thriving. This is, more than anything else, due to the technology transition from standard all-glass fibers to photonic crystal fibers, which, instead....... The freedom to design the dispersion profile of the fibers is much larger and it is possible to create fibers, which support only a single spatial mode, regardless of wavelength. In comparison, the standard dispersion-shifted fibers are limited by a much lower index-contrast between the core and the cladding...... in 1996, and are today on their way to become the dominating technology within the specialty fiber field. Whether they will replace the standard fiber in the more traditional areas like telecommunication transmission, is not yet clear, but the nonlinear photonic crystal fibers are here to stay....

  18. Optical Fiber Fusion Splicing

    CERN Document Server

    Yablon, Andrew D

    2005-01-01

    This book is an up-to-date treatment of optical fiber fusion splicing incorporating all the recent innovations in the field. It provides a toolbox of general strategies and specific techniques that the reader can apply when optimizing fusion splices between novel fibers. It specifically addresses considerations important for fusion splicing of contemporary specialty fibers including dispersion compensating fiber, erbium-doped gain fiber, polarization maintaining fiber, and microstructured fiber. Finally, it discusses the future of optical fiber fusion splicing including silica and non-silica based optical fibers as well as the trend toward increasing automation. Whilst serving as a self-contained reference work, abundant citations from the technical literature will enable readers to readily locate primary sources.

  19. Experiment-Based Sensitivity Analysis of Scaled Carbon-Fiber-Reinforced Elastomeric Isolators in Bonded Applications

    Directory of Open Access Journals (Sweden)

    Farshad Hedayati Dezfuli

    2016-01-01

    Full Text Available Fiber-reinforced elastomeric isolators (FREIs are a new type of elastomeric base isolation systems. Producing FREIs in the form of long laminated pads and cutting them to the required size significantly reduces the time and cost of the manufacturing process. Due to the lack of adequate information on the performance of FREIs in bonded applications, the goal of this study is to assess the performance sensitivity of 1/4-scale carbon-FREIs based on the experimental tests. The scaled carbon-FREIs are manufactured using a fast cold-vulcanization process. The effect of several factors including the vertical pressure, the lateral cyclic rate, the number of rubber layers, and the thickness of carbon fiber-reinforced layers are explored on the cyclic behavior of rubber bearings. Results show that the effect of vertical pressure on the lateral response of base isolators is negligible. However, decreasing the cyclic loading rate increases the lateral flexibility and the damping capacity. Additionally, carbon fiber-reinforced layers can be considered as a minor source of energy dissipation.

  20. Amplitude-modulated fiber-ring laser

    DEFF Research Database (Denmark)

    Caputo, J. G.; Clausen, Carl A. Balslev; Sørensen, Mads Peter

    2000-01-01

    Soliton pulses generated by a fiber-ring laser are investigated by numerical simulation and perturbation methods. The mathematical modeling is based on the nonlinear Schrödinger equation with perturbative terms. We show that active mode locking with an amplitude modulator leads to a self......-starting of stable solitonic pulses from small random noise, provided the modulation depth is small. The perturbative analysis leads to a nonlinear coupled return map for the amplitude, phase, and position of the soliton pulses circulating in the fiber-ring laser. We established the validity of this approach...

  1. Impacts of Different Functional Groups on the Kinetic Rates of α-Amine Ketoximesilanes Hydrolysis in the Preparation of Room Temperature Vulcanized Silicone Rubber.

    Science.gov (United States)

    Xu, Huihui; Liu, Zihou; Liu, Qingyang; Bei, Yiling; Zhu, Qingzeng

    2018-05-13

    α-Amine ketoximesilanes are proven to be effective crosslinkers in the preparation of ketone-oxime one-component room temperature vulcanized (RTV) silicone rubber without the use of toxic metal catalyst. This work aimed to investigate the hydrolysis kinetic of α-amine ketoximesilanes, which is vitally important for the preparation of RTV silicone rubber. Five kinds of α-amine ketoximesilanes, namely α-(N,N-diethyl)aminomethyltri(methylethylketoxime)silane (DEMOS), α-(N,N-di-n-butyl)aminomethyltri(methylethylketoxime)silane (DBMOS), α-(N-n-butyl)aminomethyltri(methylethylketoxime)silane (n-BMOS), α-(N-cyclohexyl)aminomethyltri(methylethylketoxime)silane (CMOS) and α-(β-aminomethyl)aminomethyltri(methylethylketoxime)silane (AEMOS), were successfully obtained and confirmed using Fourier transform infrared spectrometer (FT-IR) and hydrogen-1 nuclear magnetic resonance ( ¹H NMR). Kinetics of hydrolysis reactions were measured by FT-IR and conductivity. Our results illustrated that the kinetic constant rates ranged from 12.2 × 10 −4 s −1 to 7.6 × 10 −4 s −1 , with the decreasing order of DEMOS > n-BMOS > DBMOS > CMOS > AEMOS at the given temperature and humidity. Better performances of thermal stability could be achieved when using the α-amine ketoximesilanes as crosslinkers in the preparation of RTV silicon rubber than that of RTV silicone rubber with the use of methyltri(methylethylketoxime)silane (MOS) as a crosslinker and organic tin as a catalyst.

  2. NR sulphur vulcanization: Interaction study between TBBS and DPG by means of a combined experimental rheometer and meta-model best fitting strategy

    Energy Technology Data Exchange (ETDEWEB)

    Milani, G., E-mail: gabriele.milani@polimi.it [Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan (Italy); Hanel, T.; Donetti, R. [Pirelli Tyre, Via Alberto e Piero Pirelli 25, 20126 Milan (Italy); Milani, F. [Chem. Co, Via J.F. Kennedy 2, 45030 Occhiobello (Italy)

    2016-06-08

    The paper is aimed at studying the possible interaction between two different accelerators (DPG and TBBS) in the chemical kinetic of Natural Rubber (NR) vulcanized with sulphur. The same blend with several DPG and TBBS concentrations is deeply analyzed from an experimental point of view, varying the curing temperature in the range 150-180°C and obtaining rheometer curves with a step of 10°C. In order to study any possible interaction between the two accelerators –and eventually evaluating its engineering relevance-rheometer data are normalized by means of the well known Sun and Isayev normalization approach and two output parameters are assumed as meaningful to have an insight into the possible interaction, namely time at maximum torque and reversion percentage. Two different numerical meta-models, which belong to the family of the so-called response surfaces RS are compared. The first is linear against TBBS and DPG and therefore well reproduces no interaction between the accelerators, whereas the latter is a non-linear RS with bilinear term. Both RS are deduced from standard best fitting of experimental data available. It is found that, generally, there is a sort of interaction between TBBS and DPG, but that the error introduced making use of a linear model (no interaction) is generally lower than 10%, i.e. fully acceptable from an engineering standpoint.

  3. Ceramic fiber reinforced filter

    Science.gov (United States)

    Stinton, David P.; McLaughlin, Jerry C.; Lowden, Richard A.

    1991-01-01

    A filter for removing particulate matter from high temperature flowing fluids, and in particular gases, that is reinforced with ceramic fibers. The filter has a ceramic base fiber material in the form of a fabric, felt, paper of the like, with the refractory fibers thereof coated with a thin layer of a protective and bonding refractory applied by chemical vapor deposition techniques. This coating causes each fiber to be physically joined to adjoining fibers so as to prevent movement of the fibers during use and to increase the strength and toughness of the composite filter. Further, the coating can be selected to minimize any reactions between the constituents of the fluids and the fibers. A description is given of the formation of a composite filter using a felt preform of commercial silicon carbide fibers together with the coating of these fibers with pure silicon carbide. Filter efficiency approaching 100% has been demonstrated with these filters. The fiber base material is alternately made from aluminosilicate fibers, zirconia fibers and alumina fibers. Coating with Al.sub.2 O.sub.3 is also described. Advanced configurations for the composite filter are suggested.

  4. Steel fiber reinforced concrete

    International Nuclear Information System (INIS)

    Baloch, S.U.

    2005-01-01

    Steel-Fiber Reinforced Concrete is constructed by adding short fibers of small cross-sectional size .to the fresh concrete. These fibers reinforce the concrete in all directions, as they are randomly oriented. The improved mechanical properties of concrete include ductility, impact-resistance, compressive, tensile and flexural strength and abrasion-resistance. These uniqlte properties of the fiber- reinforcement can be exploited to great advantage in concrete structural members containing both conventional bar-reinforcement and steel fibers. The improvements in mechanical properties of cementitious materials resulting from steel-fiber reinforcement depend on the type, geometry, volume fraction and material-properties of fibers, the matrix mix proportions and the fiber-matrix interfacial bond characteristics. Effects of steel fibers on the mechanical properties of concrete have been investigated in this paper through a comprehensive testing-programme, by varying the fiber volume fraction and the aspect-ratio (Lid) of fibers. Significant improvements are observed in compressive, tensile, flexural strength and impact-resistance of concrete, accompanied by marked improvement in ductility. optimum fiber-volume fraction and aspect-ratio of steel fibers is identified. Test results are analyzed in details and relevant conclusions drawn. The research is finally concluded with future research needs. (author)

  5. Fiber optics in adverse environments

    International Nuclear Information System (INIS)

    Lyous, P.B.

    1982-01-01

    Radiation effects in optical fibers are considered, taking into account recent progress in the investigation of radiation resistant optical fibers, radiation damage in optical fibers, radiation-induced transient absorption in optical fibers, X-ray-induced transient attenuation at low temperatures in polymer clad silica (PCS) fibers, optical fiber composition and radiation hardness, the response of irradiated optical waveguides at low temperatures, and the effect of ionizing radiation on fiber-optic waveguides. Other topics explored are related to environmental effects on components of fiber optic systems, and radiation detection systems using optical fibers. Fiber optic systems in adverse environments are also discussed, giving attention to the survivability of Army fiber optics systems, space application of fiber optics systems, fiber optic wavelength multiplexing for civil aviation applications, a new fiber optic data bus topology, fiber optics for aircraft engine/inlet control, and application of fiber optics in high voltage substations

  6. Fiber Optics Technology.

    Science.gov (United States)

    Burns, William E.

    1986-01-01

    Discusses various applications of fiber optics technology: information systems, industrial robots, medicine, television, transportation, and training. Types of jobs that will be available with fiber optics training (such as electricians and telephone cable installers and splicers) are examined. (CT)

  7. Fiber Optics Instrumentation Development

    Science.gov (United States)

    Chan, Patrick Hon Man; Parker, Allen R., Jr.; Richards, W. Lance

    2010-01-01

    This is a general presentation of fiber optics instrumentation development work being conducted at NASA Dryden for the past 10 years and recent achievements in the field of fiber optics strain sensors.

  8. Shaped fiber composites

    Science.gov (United States)

    Kinnan, Mark K.; Roach, Dennis P.

    2017-12-05

    A composite article is disclosed that has non-circular fibers embedded in a polymer matrix. The composite article has improved damage tolerance, toughness, bending, and impact resistance compared to composites having traditional round fibers.

  9. Advances in Fiber Lasers

    National Research Council Canada - National Science Library

    Morse, T

    1999-01-01

    Most of the time of this contract has been devoted toward improvements in optical fiber lasers and toward gathering experience to improve our program in high power, cladding pumped optical fiber lasers...

  10. Hierarchically Structured Electrospun Fibers

    Science.gov (United States)

    2013-01-07

    in the natural lotus and silver ragwort leaves. Figure 4. Examples of electrospun bio-mimics of natural hierarchical structures. (A) Lotus leaf...B) pillared poly(methyl methacrylate) (PMMA) electrospun fiber mimic; (C) silver ragwort leaf; (D) electrospun fiber mimic made from nylon 6 and...domains containing the protein in the surrounding EVA fibers [115]. A wide variety of core-shell fibers have been generated, including PCL/ gelatin

  11. Superlattice Microstructured Optical Fiber

    Science.gov (United States)

    Tse, Ming-Leung Vincent; Liu, Zhengyong; Cho, Lok-Hin; Lu, Chao; Wai, Ping-Kong Alex; Tam, Hwa-Yaw

    2014-01-01

    A generic three-stage stack-and-draw method is demonstrated for the fabrication of complex-microstructured optical fibers. We report the fabrication and characterization of a silica superlattice microstructured fiber with more than 800 rhomboidally arranged air-holes. A polarization-maintaining fiber with a birefringence of 8.5 × 10−4 is demonstrated. The birefringent property of the fiber is found to be highly insensitive to external environmental effects, such as pressure. PMID:28788693

  12. High-fiber foods

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000193.htm High-fiber foods To use the sharing features on this page, ... Read food labels carefully to see how much fiber they have. Choose foods that have higher amounts of fiber, such as ...

  13. Resonant filtered fiber amplifiers

    DEFF Research Database (Denmark)

    Alkeskjold, Thomas Tanggaard; Laurila, Marko; Olausson, Christina Bjarnal Thulin

    2013-01-01

    In this paper we present our recent result on utilizing resonant/bandgap fiber designs to achieve high performance ytterbium doped fiber amplifers for achieving diffraction limited beam quality in large mode area fibers, robust bending performance and gain shaping for long wavelength operation...

  14. Fiber Singular Optics

    OpenAIRE

    A. V. Volyar

    2002-01-01

    The present review is devoted to the optical vortex behavior both in free space and optical fibers. The processes of the vortex transformations in perturbed optical fibers are analyzed on the base of the operator of the spin – orbit interaction in order to forecast the possible ways of manufacturing the vortex preserving fibers and their applications in supersensitive optical devices.

  15. Superconducting tin core fiber

    International Nuclear Information System (INIS)

    Homa, Daniel; Liang, Yongxuan; Hill, Cary; Kaur, Gurbinder; Pickrell, Gary

    2015-01-01

    In this study, we demonstrated superconductivity in a fiber with a tin core and fused silica cladding. The fibers were fabricated via a modified melt-draw technique and maintained core diameters ranging from 50-300 microns and overall diameters of 125-800 microns. Superconductivity of this fiber design was validated via the traditional four-probe test method in a bath of liquid helium at temperatures on the order of 3.8 K. The synthesis route and fiber design are perquisites to ongoing research dedicated all-fiber optoelectronics and the relationships between superconductivity and the material structures, as well as corresponding fabrication techniques. (orig.)

  16. Airclad fiber laser technology

    DEFF Research Database (Denmark)

    Hansen, Kim P.; Olausson, Christina Bjarnal Thulin; Broeng, Jes

    2011-01-01

    High-power fiber lasers and amplifiers have gained tremendous momentum in the last 5 years. Many of the traditional manufacturers of gas and solid-state lasers are now pursuing the fiber-based systems, which are displacing the conventional technology in many areas. High-power fiber laser systems...... require reliable fibers with large cores, stable mode quality, and good power handling capabilities-requirements that are all met by the airclad fiber technology. In the present paper we go through many of the building blocks needed to build high-power systems and we show an example of a complete airclad...... laser system. We present the latest advancements within airclad fiber technology including a new 100 m single-mode polarization-maintaining rod-type fiber capable of amplifying to megawatt power levels. Furthermore, we describe the novel airclad-based pump combiners and their use in a completely...

  17. Airclad fiber laser technology

    DEFF Research Database (Denmark)

    Hansen, Kim P.; Olausson, Christina Bjarnal Thulin; Broeng, Jes

    2008-01-01

    High-power fiber lasers and amplifiers have gained tremendous momentum in the last five years, and many of the traditional manufactures of gas and solid-state lasers are pursuing the attractive fiber-based systems, which are now displacing the old technology in many areas. High-power fiber laser...... systems require specially designed fibers with large cores and good power handling capabilities - requirements that are all met by the airclad fiber technology. In the present paper we go through many of the building blocks needed to build high-power systems and we show an example of a complete airclad...... laser system. We present the latest advancements within airclad fiber technology including a new 70 μm single-mode polarization-maintaining rod-type fiber capable of amplifying to MW power levels. Furthermore we describe the novel airclad based pump combiners and their use in a completely monolithic 350...

  18. Electro-oxidation of methanol in alkaline conditions using Pd–Ni nanoparticles prepared from organometallic precursors and supported on carbon vulcan

    Energy Technology Data Exchange (ETDEWEB)

    Manzo-Robledo, A., E-mail: amanzor@ipn.mx [UPALM, Laboratorio de Electroquímica y Corrosión, Escuela Superior de Ingeniería Química e Industrias Extractivas-IPN (Mexico); Costa, Natália J. S. [Universidade de São Paulo, Instituto de Química (Brazil); Philippot, K. [CNRS, LCC, Laboratoire de Chimie de Coordination (France); Rossi, Liane M. [Universidade de São Paulo, Instituto de Química (Brazil); Ramírez-Meneses, E. [Universidad Iberoamericana, Departamento de Ingeniería y Ciencias Químicas (Mexico); Guerrero-Ortega, L. P. A. [UPALM, Laboratorio de Electroquímica y Corrosión, Escuela Superior de Ingeniería Química e Industrias Extractivas-IPN (Mexico); Ezquerra-Quiroga, S. [Universidad Iberoamericana, Departamento de Ingeniería y Ciencias Químicas (Mexico)

    2015-12-15

    Oxidation of low-molecular weight alcohols as energy sources using metal nanoparticles has attracted considerable interest for use as a power source in portable electronic devices. In this work, a series of mono- and bimetallic nanoparticles based on palladium and nickel (Pd, Pd{sub 90}Ni{sub 10}, Pd{sub 50}Ni{sub 50}, Pd{sub 10}Ni{sub 90}, and Ni) have been synthesized from organometallic precursors, namely tris(dibenzylideneacetone) dipalladium(0), Pd{sub 2}(dba){sub 3}, and bis(1,5-cyclooctadiene)nickel(0), Ni(cod){sub 2}. Well-defined metal particles in the nanometric scale from 4.2 to 6.3 nm were observed by transmission electron microscopy. The as-prepared nanoparticles were mixed with a carbon Vulcan matrix (10 % wt. of the catalyst in turn) for investigation as electrocatalysts in methanol oxidation reaction (MOR) in alkaline conditions. The i–E profiles from cyclic voltammetry for the monometallic systems indicated a redox process attributed only to palladium or nickel, as expected. With the bimetallic nanomaterials, the redox process and the i–E characteristics are functions of the amount of nickel associated to palladium. From a fundamental point of view, it has been established that the OH ions’ interfacial interaction and the MOR kinetics are affected by the presence of nickel (decreasing the faradic current) as supported by the current versus potential profiles obtained as a function of methanol concentration and with temperature variation.

  19. Hierarchically Structured Electrospun Fibers

    Directory of Open Access Journals (Sweden)

    Nicole E. Zander

    2013-01-01

    Full Text Available Traditional electrospun nanofibers have a myriad of applications ranging from scaffolds for tissue engineering to components of biosensors and energy harvesting devices. The generally smooth one-dimensional structure of the fibers has stood as a limitation to several interesting novel applications. Control of fiber diameter, porosity and collector geometry will be briefly discussed, as will more traditional methods for controlling fiber morphology and fiber mat architecture. The remainder of the review will focus on new techniques to prepare hierarchically structured fibers. Fibers with hierarchical primary structures—including helical, buckled, and beads-on-a-string fibers, as well as fibers with secondary structures, such as nanopores, nanopillars, nanorods, and internally structured fibers and their applications—will be discussed. These new materials with helical/buckled morphology are expected to possess unique optical and mechanical properties with possible applications for negative refractive index materials, highly stretchable/high-tensile-strength materials, and components in microelectromechanical devices. Core-shell type fibers enable a much wider variety of materials to be electrospun and are expected to be widely applied in the sensing, drug delivery/controlled release fields, and in the encapsulation of live cells for biological applications. Materials with a hierarchical secondary structure are expected to provide new superhydrophobic and self-cleaning materials.

  20. Cinética de vulcanização de composições de borracha natural com incorporação de cinza de casca de arroz Vulcanization kinetics of natural rubber filled with rice husk ash

    Directory of Open Access Journals (Sweden)

    Helson M. da Costa

    2003-06-01

    Full Text Available Cinza da casca de arroz foi incorporada em borracha natural (NR utilizando-se um misturador de cilindros. O sistema de vulcanização convencional (CV foi escolhido e os estudos sobre a cura das composições foram conduzidos em um Curômetro TI-100. As curvas de torque foram obtidas em 150, 160, 170 e 180 °C. A velocidade global e a energia de ativação aparente para o processo de vulcanização foram calculadas para cada composição, assumindo que a vulcanização segue uma cinética de primeira ordem. Para fins de comparação, duas cargas comerciais, sílica precipitada (Zeosil-175 e negro de fumo (N762, foram também usadas. Foi observado que a adição da cinza da casca de arroz às composições de NR, em comparação às outras cargas utilizadas, aumentou a velocidade de reticulação e diminuiu a energia de ativação aparente de modo mais marcante.Rice husk ash was incorporated into natural rubber (NR using a laboratory size two-roll mill. A conventional vulcanization system (CV was chosen and cure studies were carried out on a TI-100 Curometer. The torque curves were obtained at 150, 160, 170, and 180 °C. The overall rate and the apparent activation energy for the vulcanization process were calculated for each compound assuming that vulcanization follows first-order kinetics. For the purpose of comparison, two commercial fillers, precipitated silica (Zeosil-175 and carbon black (N762, were also used. In comparison to the other fillers used, the addition of rice husk ash to NR compounds increased the crosslinking rate and lowered the apparent activation energy in a more marked way.

  1. Hevea brasiliensis natural rubber latex film vulcanization by gamma radiation containing n-butyl acrylate: properties and morphology; Filme de latex de borracha natural de Hevea brasiliensis vulcanizado por radiacao gama contendo acrilato de n-butila: propriedades e morfologia

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Ana Paula Pinho; Barros, Glaucione Gomes de [Brasilia Univ., DF (Brazil). Dept. de Quimica; Guedes, Selma M.L. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    1997-07-01

    Radiation vulcanization of natural rubber latex (RVNRL) in the presence of n-butyl acrylate (n-Ba) as sensitizer was carried out. The RVNRL films were investigated with respect to their thermal properties and morphology. The films presented two T{sub g} values obtained by DSC which were identified as due to linear and crosslinked domains. The thermal stability of the material was similar to that of linear material rubber. The morphology showed smooth regular surface characteristic of homogeneous phase domains. (author)

  2. Efeito de um resíduo do processo de galvanoplastia sobre a vulcanização da borracha natural (NR Effect from the waste from the electroplating process on the natural rubber (NR vulcanization

    Directory of Open Access Journals (Sweden)

    Alex C. S. Santos

    2009-01-01

    Full Text Available Um resíduo gerado no processo de galvanoplastia (RG, rico em metais, foi incorporado em composições de borracha natural (NR em substituição parcial ou total ao ativador comum do processo de vulcanização, o óxido de zinco (ZnO. As diferentes misturas foram preparadas em um misturador de calandras e, após a reometria, foram vulcanizadas a 150 °C. As propriedades mecânicas de resistência à tração e rasgo foram determinadas, além do teor de gel. Além disso, o efeito do resíduo RG sobre a cinética de vulcanização foi analisado através do modelo de Coran, usando-se as temperaturas de 150, 160 e 170 °C. Os resultados mostraram que RG desenvolve algum efeito catalítico sobre a vulcanização de NR, embora exista uma considerável perda na resistência à tração quando o teor de RG excede o do ZnO nas composições. Quanto ao rasgo, a propriedade é mantida em um patamar satisfatório enquanto teores menores de RG são utilizados.A waste generated in the electroplating process (RG, rich in metals, was incorporated in natural rubber (NR compositions, as a partial or complete replacement of zinc oxide (ZnO, which is a typical activator of the vulcanization process. Different mixtures were prepared in a two-roll mixer, which were vulcanized at 150 ºC after the rheometry measurements. Mechanical properties such as tensile and tear strength were evaluated, as well as the gel content. In addition, the effect of RG waste upon the vulcanization kinetics was analyzed with the Coran model using temperatures at 150, 160 and 170 ºC. The results showed that RG develops some catalytic effect upon NR vulcanization, but there is a poor mechanical performance when RG loading is higher than that of ZnO in the compositions. For the tear strength, the property is maintained at a reasonable level if a small RG loading is utilized.

  3. Fiber optics in SHIVA

    International Nuclear Information System (INIS)

    Severyn, J.; Parker, J.

    1978-01-01

    SHIVA is a twenty arm laser which is controlled with a network of fifty computers, interconnected with digital fiber optic links. Three different fiber optic systems employed on the Shiva laser will be described. Two of the systems are for digital communications, one at 9600 baud and the other at 1 megabaud. The third system uses fiber optics to distribute diagnostic triggers with subnanosecond jitter

  4. Continuous Fiber Ceramic Composites

    Energy Technology Data Exchange (ETDEWEB)

    Fareed, Ali [Honeywell Advanced Composites Inc. (HACI), Newark, DE (United States); Craig, Phillip A. [Honeywell Advanced Composites Inc. (HACI), Newark, DE (United States)

    2002-09-01

    Fiber-reinforced ceramic composites demonstrate the high-temperature stability of ceramics--with an increased fracture toughness resulting from the fiber reinforcement of the composite. The material optimization performed under the continuous fiber ceramic composites (CFCC) included a series of systematic optimizations. The overall goals were to define the processing window, to increase the robustinous of the process, to increase process yield while reducing costs, and to define the complexity of parts that could be fabricated.

  5. Agave Americana Leaf Fibers

    Directory of Open Access Journals (Sweden)

    Ashish Hulle

    2015-02-01

    Full Text Available The growing environmental problems, the problem of waste disposal and the depletion of non-renewable resources have stimulated the use of green materials compatible with the environment to reduce environmental impacts. Therefore, there is a need to design products by using natural resources. Natural fibers seem to be a good alternative since they are abundantly available and there are a number of possibilities to use all the components of a fiber-yielding crop; one such fiber-yielding plant is Agave Americana. The leaves of this plant yield fibers and all the parts of this plant can be utilized in many applications. The “zero-waste” utilization of the plant would enable its production and processing to be translated into a viable and sustainable industry. Agave Americana fibers are characterized by low density, high tenacity and high moisture absorbency in comparison with other leaf fibers. These fibers are long and biodegradable. Therefore, we can look this fiber as a sustainable resource for manufacturing and technical applications. Detailed discussion is carried out on extraction, characterization and applications of Agave Americana fiber in this paper.

  6. USDA Flax fiber utilization research

    Science.gov (United States)

    The United States is pursuing natural fibers as sustainable, environmentally friendly sources for a variety of industrial applications. Flax (Linum usitatissimum L.) fiber offers many possibilities towards this goal. Research on flax fiber production, processing, and standards development is urgen...

  7. Ultrafine PBI fibers and yarns

    Science.gov (United States)

    Leal, J. R.; Tan, M.

    1979-01-01

    Gentle precisely controlled process is used to draw polybenzimidazole (PBI) fibers to denier as low as 0.17 per fiber. Yarns of lightweight fibers could be useful in applications where lightweight textiles must withstand high temperatures, corrosion, or radiation.

  8. Applications of nonlinear fiber optics

    CERN Document Server

    Agrawal, Govind

    2008-01-01

    * The only book describing applications of nonlinear fiber optics * Two new chapters on the latest developments: highly nonlinear fibers and quantum applications* Coverage of biomedical applications* Problems provided at the end of each chapterThe development of new highly nonlinear fibers - referred to as microstructured fibers, holey fibers and photonic crystal fibers - is the next generation technology for all-optical signal processing and biomedical applications. This new edition has been thoroughly updated to incorporate these key technology developments.The bo

  9. Multimode optical fiber

    Science.gov (United States)

    Bigot-Astruc, Marianne; Molin, Denis; Sillard, Pierre

    2014-11-04

    A depressed graded-index multimode optical fiber includes a central core, an inner depressed cladding, a depressed trench, an outer depressed cladding, and an outer cladding. The central core has an alpha-index profile. The depressed claddings limit the impact of leaky modes on optical-fiber performance characteristics (e.g., bandwidth, core size, and/or numerical aperture).

  10. Fiber Lasers V

    DEFF Research Database (Denmark)

    Hansen, Kim P.; Olausson, Christina Bjarnal Thulin; Broeng, Jes

    2008-01-01

    laser system. We present the latest advancements within airclad fiber technology including a new 70 μm single-mode polarization-maintaining rod-type fiber capable of amplifying to MW power levels. Furthermore we describe the novel airclad based pump combiners and their use in a completely monolithic 350...

  11. Fiber Sensor Technology Today

    Science.gov (United States)

    Hotate, Kazuo

    2006-08-01

    Fiber sensor technologies are overviewed. Since the early 1970s, this field has been developed, on the basis of the same devices and photonic principles as fiber communication technologies. Besides simple configurations, in which the fiber acts only as a data transmission line, sophisticated configurations have also been developed, in which the fiber is used as a device to realize unique sensing mechanisms. The fiber optic gyroscope (FOG) is a good example, and has been developed as an absolute rotation sensor used, for example, for navigation and/or attitude control applications. Compared with traditional spinning-mass gyroscopes, the FOG has advantages, such as a short warming-up time, a light weight, and easy handling. A Japanese satellite, which was launched in August 2005 with a mission to observe the aurora, is controlled with a FOG. The FOG has also been used in consumer applications, such as the camera stabilizer, radio-controlled (RC) helicopter navigation, and the control of humanoid robots. Recently, distributed and multiplexed sensing schemes, in particular, have been studied and developed, in which a long fiber acts like a “nerve” for feeling the strain and/or the temperature distribution along the fiber. Performances of artificial nerve systems have markedly improved within the last couple of years, in spatial resolution and measurement speed. By embedding the “fiber-optic nerve system” in aircraft wings, bridges and tall buildings, these materials and structures can sense damage to prevent disasters.

  12. Ways to Boost Fiber

    Science.gov (United States)

    ... can help to lower cholesterol. Third, it helps prevent constipation and diverticulosis. And fourth, adequate fiber from food ... is similar to a new sponge; it needs water to plump up pass smoothly. If you ... or constipation. Before you reach for the fiber supplements, consider ...

  13. Quartz fiber calorimeter

    International Nuclear Information System (INIS)

    Akchurin, N.; Doulas, S.; Ganel, O.; Gershtein, Y.; Gavrilov, V.; Kolosov, V.; Kuleshov, S.; Litvinsev, D.; Merlo, J.-P.; Onel, Y.; Osborne, D.; Rosowsky, A.; Stolin, V.; Sulak, L.; Sullivan, J.; Ulyanov, A.; Wigmans, R.; Winn, D.

    1996-01-01

    A calorimeter with optical quartz fibers embedded into an absorber matrix was proposed for the small angle region of the CMS detector at LHC (CERN). This type of calorimeter is expected to be radiation hard and to produce extremely fast signal. Some results from beam tests of the quartz fiber calorimeter prototype are presented. (orig.)

  14. High-density multicore fibers

    DEFF Research Database (Denmark)

    Takenaga, K.; Matsuo, S.; Saitoh, K.

    2016-01-01

    High-density single-mode multicore fibers were designed and fabricated. A heterogeneous 30-core fiber realized a low crosstalk of −55 dB. A quasi-single-mode homogeneous 31-core fiber attained the highest core count as a single-mode multicore fiber.......High-density single-mode multicore fibers were designed and fabricated. A heterogeneous 30-core fiber realized a low crosstalk of −55 dB. A quasi-single-mode homogeneous 31-core fiber attained the highest core count as a single-mode multicore fiber....

  15. Green insulation: hemp fibers

    Energy Technology Data Exchange (ETDEWEB)

    Anon,

    2011-09-15

    Indian hemp (Cannabis indica) is known for its psychotropic values and it is banned in most countries. However, industrial hemp (Cannabis sativa) is known for its tough fibers. Several manufactures in Europe including, small niche players, have been marketing hemp insulation products for several years. Hemp is a low environmental impact material. Neither herbicide nor pesticide is used during the growth of hemp. The fibers are extracted in a waste-free and chemical-free mechanical process. Hemp can consume CO2 during its growth. In addition, hemp fiber can be disposed of harmlessly by composting or incineration at the end of its life. Hemp fibers are processed and treated only minimally to resist rot and fungal activity. There is little health risk when producing and installing the insulation, thanks to the absence of toxic additive. Its thermal resistance is comparable to mineral wool. But the development and marketing of hemp fibers may be restricted in North America.

  16. Raman fiber lasers

    CERN Document Server

    2017-01-01

    This book serves as a comprehensive, up-to-date reference about this cutting-edge laser technology and its many new and interesting developments. Various aspects and trends of Raman fiber lasers are described in detail by experts in their fields. Raman fiber lasers have progressed quickly in the past decade, and have emerged as a versatile laser technology for generating high power light sources covering a spectral range from visible to mid-infrared. The technology is already being applied in the fields of telecommunication, astronomy, cold atom physics, laser spectroscopy, environmental sensing, and laser medicine. This book covers various topics relating to Raman fiber laser research, including power scaling, cladding and diode pumping, cascade Raman shifting, single frequency operation and power amplification, mid-infrared laser generation, specialty optical fibers, and random distributed feedback Raman fiber lasers. The book will appeal to scientists, students, and technicians seeking to understand the re...

  17. Birefringent hollow core fibers

    DEFF Research Database (Denmark)

    Roberts, John

    2007-01-01

    Hollow core photonic crystal fiber (HC-PCF), fabricated according to a nominally non-birefringent design, shows a degree of un-controlled birefringence or polarization mode dispersion far in excess of conventional non polarization maintaining fibers. This can degrade the output pulse in many...... applications, and places emphasis on the development of polarization maintaining (PM) HC-PCF. The polarization cross-coupling characteristics of PM HC-PCF are very different from those of conventional PM fibers. The former fibers have the advantage of suffering far less from stress-field fluctuations...... and an increased overlap between the polarization modes at the glass interfaces. The interplay between these effects leads to a wavelength for optimum polarization maintenance, lambda(PM), which is detuned from the wavelength of highest birefringence. By a suitable fiber design involving antiresonance of the core...

  18. Fiber optic hydrophone

    Science.gov (United States)

    Kuzmenko, Paul J.; Davis, Donald T.

    1994-01-01

    A miniature fiber optic hydrophone based on the principles of a Fabry-Perot interferometer. The hydrophone, in one embodiment, includes a body having a shaped flexible bladder at one end which defines a volume containing air or suitable gas, and including a membrane disposed adjacent a vent. An optic fiber extends into the body with one end terminating in spaced relation to the membrane. Acoustic waves in the water that impinge on the bladder cause the pressure of the volume therein to vary causing the membrane to deflect and modulate the reflectivity of the Fabry-Perot cavity formed by the membrane surface and the cleaved end of the optical fiber disposed adjacent to the membrane. When the light is transmitted down the optical fiber, the reflected signal is amplitude modulated by the incident acoustic wave. Another embodiment utilizes a fluid filled volume within which the fiber optic extends.

  19. Efficient de-vulcanization of sulfur-vulcanized SBR

    NARCIS (Netherlands)

    Saiwari, Sitisaiyidah; Dierkes, Wilma K.; Noordermeer, Jacques W.M.

    Enabling recycling loops for used passenger car tires is a challenge and an opportunity: The challenge lies in the presence of SBR as the main elastomer in this type of tires, which makes this material difficult to reclaim due to the tendency of the elastomer chain fragments to re-combine. The

  20. Method for the preparation of carbon fiber from polyolefin fiber precursor, and carbon fibers made thereby

    Science.gov (United States)

    Naskar, Amit Kumar; Hunt, Marcus Andrew; Saito, Tomonori

    2015-08-04

    Methods for the preparation of carbon fiber from polyolefin fiber precursor, wherein the polyolefin fiber precursor is partially sulfonated and then carbonized to produce carbon fiber. Methods for producing hollow carbon fibers, wherein the hollow core is circular- or complex-shaped, are also described. Methods for producing carbon fibers possessing a circular- or complex-shaped outer surface, which may be solid or hollow, are also described.

  1. Fiber Pulling Apparatus

    Science.gov (United States)

    Workman, Gary L.; Smith, Guy A.; OBrien, Sue; Adcock, Leonard

    1998-01-01

    The fiber optics industry has grown into a multi-billion marketplace that will continue to grow into the 21st century. Optical fiber communications is currently dominated by silica glass technology. Successful efforts to improve upon the low loss transmission characteristics of silica fibers have propelled the technology into the forefront of the communications industry. However, reaching the theoretical transmission capability of silica fiber through improved processing has still left a few application areas in which other fiber systems can provide an influential role due to specific characteristics of high theoretical transmission in the 2 - 3 micron wavelength region. One of the other major materials used for optical fibers is the systems based upon Heavy Metal Fluoride Glass (HMFG). Commercial interest is driven primarily by the potential for low loss repeaterless infrared fibers. An example of the major communications marketplace which would benefit from the long distance repeaterless capability of infrared fibers is the submarine cables which link the continents. When considering commercial interests, optical fiber systems provide a healthy industrial position which continues to expand. Major investments in the systems used for optical fiber communications have continued to increase each year and are predicted to continue well into the next century. Estimates of 8.5% compounded annually are predicted through 1999 for the North American market and 1 1 % worldwide. The growth for the optical fiber cable itself is expected to continue between 44 and 50 per cent of the optical fiber communications budget through 1999. The total budget in 1999 world-wide is expected to be in the neighborhood of $9 billion. Another survey predicts that long haul telecommunications represents 15% of a world-wide fiber optics market in 1998. The actual amount allotted to cable was not specified. However, another market research had predicted that the cable costs alone represents more

  2. Fiber Optic Microphone

    Science.gov (United States)

    Cho, Y. C.; George, Thomas; Norvig, Peter (Technical Monitor)

    1999-01-01

    Research into advanced pressure sensors using fiber-optic technology is aimed at developing compact size microphones. Fiber optic sensors are inherently immune to electromagnetic noise, and are very sensitive, light weight, and highly flexible. In FY 98, NASA researchers successfully designed and assembled a prototype fiber-optic microphone. The sensing technique employed was fiber optic Fabry-Perot interferometry. The sensing head is composed of an optical fiber terminated in a miniature ferrule with a thin, silicon-microfabricated diaphragm mounted on it. The optical fiber is a single mode fiber with a core diameter of 8 micron, with the cleaved end positioned 50 micron from the diaphragm surface. The diaphragm is made up of a 0.2 micron thick silicon nitride membrane whose inner surface is metallized with layers of 30 nm titanium, 30 nm platinum, and 0.2 micron gold for efficient reflection. The active sensing area is approximately 1.5 mm in diameter. The measured differential pressure tolerance of this diaphragm is more than 1 bar, yielding a dynamic range of more than 100 dB.

  3. Optical fiber spectrophotometer

    International Nuclear Information System (INIS)

    Zhuang Weixin; Tian Guocheng; Ye Guoan; Zhou Zhihong; Cheng Weiwei; Huang Lifeng; Liu Suying; Tang Yanji; Hu Jingxin; Zhao Yonggang

    1998-12-01

    A method called 'Two Arm's Photo out and Electricity Send-back' is introduced. UV-365 UV/VIS/NIR spectrophotometer has been reequipped by this way with 5 meters long optical fiber. Another method called 'One Arm's Photo out and Photo Send-back' is also introduced. λ 19 UV/VIS/NIR spectrophotometer has been reequipped by this way with 10 meters long optical fiber. Optical fiber spectrophotometer can work as its main set. So it is particularly applicable to radio activity work

  4. Chemistry Research of Optical Fibers.

    Science.gov (United States)

    1982-09-27

    BROADENING IN OPTICAL FIBERS Herbert B. Rosenstock* Naval Research Laboratory Washington, DC 20375 ABSTRACT A light pulse transmitted through a fiber...Marcatili, Marcuse , and Personick, "Dispersion Properties of Fibers" (Ch. 4 in "Optical Fiber Telecommunications," S. E. Miller and A. C. Chynoweth, eds

  5. Robust fiber clustering of cerebral fiber bundles in white matter

    Science.gov (United States)

    Yao, Xufeng; Wang, Yongxiong; Zhuang, Songlin

    2014-11-01

    Diffusion tensor imaging fiber tracking (DTI-FT) has been widely accepted in the diagnosis and treatment of brain diseases. During the rendering pipeline of specific fiber tracts, the image noise and low resolution of DTI would lead to false propagations. In this paper, we propose a robust fiber clustering (FC) approach to diminish false fibers from one fiber tract. Our algorithm consists of three steps. Firstly, the optimized fiber assignment continuous tracking (FACT) is implemented to reconstruct one fiber tract; and then each curved fiber in the fiber tract is mapped to a point by kernel principal component analysis (KPCA); finally, the point clouds of fiber tract are clustered by hierarchical clustering which could distinguish false fibers from true fibers in one tract. In our experiment, the corticospinal tract (CST) in one case of human data in vivo was used to validate our method. Our method showed reliable capability in decreasing the false fibers in one tract. In conclusion, our method could effectively optimize the visualization of fiber bundles and would help a lot in the field of fiber evaluation.

  6. Fiber optics standard dictionary

    CERN Document Server

    Weik, Martin H

    1997-01-01

    Fiber Optics Vocabulary Development In 1979, the National Communications System published Technical InfonnationBulle­ tin TB 79-1, Vocabulary for Fiber Optics and Lightwave Communications, written by this author. Based on a draft prepared by this author, the National Communications System published Federal Standard FED-STD-1037, Glossary of Telecommunications Terms, in 1980 with no fiber optics tenns. In 1981, the first edition of this dictionary was published under the title Fiber Optics and Lightwave Communications Standard Dictionary. In 1982, the then National Bureau of Standards, now the National Institute of Standards and Technology, published NBS Handbook 140, Optical Waveguide Communications Glossary, which was also published by the General Services Admin­ istration as PB82-166257 under the same title. Also in 1982, Dynamic Systems, Inc. , Fiberoptic Sensor Technology Handbook, co-authored and edited by published the this author, with an extensive Fiberoptic Sensors Glossary. In 1989, the handbook w...

  7. Fiber Optics: No Illusion.

    Science.gov (United States)

    American School and University, 1983

    1983-01-01

    A campus computer center at Hofstra University (New York) that holds 70 terminals for student use was first a gymnasium, then a language laboratory. Strands of fiber optics are used for the necessary wiring. (MLF)

  8. Fiber optic gas sensor

    Science.gov (United States)

    Chen, Peng (Inventor); Buric, Michael P. (Inventor); Swinehart, Philip R. (Inventor); Maklad, Mokhtar S. (Inventor)

    2010-01-01

    A gas sensor includes an in-fiber resonant wavelength device provided in a fiber core at a first location. The fiber propagates a sensing light and a power light. A layer of a material is attached to the fiber at the first location. The material is able to absorb the gas at a temperature dependent gas absorption rate. The power light is used to heat the material and increases the gas absorption rate, thereby increasing sensor performance, especially at low temperatures. Further, a method is described of flash heating the gas sensor to absorb more of the gas, allowing the sensor to cool, thereby locking in the gas content of the sensor material, and taking the difference between the starting and ending resonant wavelengths as an indication of the concentration of the gas in the ambient atmosphere.

  9. Photonic Crystal Fibers

    National Research Council Canada - National Science Library

    Kristiansen, Rene E

    2005-01-01

    This report results from a contract tasking Crystal Fibre A/S as follows: Crystal Fibre will conduct research and development of large mode area, dual clad multi-core Yb-doped photonic crystal fiber...

  10. Fiber Laser Array

    National Research Council Canada - National Science Library

    Simpson, Thomas

    2002-01-01

    ...., field-dependent, loss within the coupled laser array. During this program, Jaycor focused on the construction and use of an experimental apparatus that can be used to investigate the coherent combination of an array of fiber lasers...

  11. Robust Fiber Coatings

    National Research Council Canada - National Science Library

    Goettler, Richard

    2002-01-01

    The highly desired ceramic matrix composite is the one in which the high strength and strain-to-failure is achieved through judicious selection of a fiber coating that can survive the high-temperature...

  12. Fiber Optic Bragg Gratings

    National Research Council Canada - National Science Library

    Battiato, James

    1998-01-01

    Coupled mode theory was used to model reflection fiber gratings. The effects of experimental parameters on grating characteristics were modeled for both uniform and non-uniform grating profiles using this approach...

  13. Cerenkov fiber sampling calorimeters

    International Nuclear Information System (INIS)

    Arrington, K.; Kefford, D.; Kennedy, J.; Pisani, R.; Sanzeni, C.; Segall, K.; Wall, D.; Winn, D.R.; Carey, R.; Dye, S.; Miller, J.; Sulak, L.; Worstell, W.; Efremenko, Y.; Kamyshkov, Y.; Savin, A.; Shmakov, K.; Tarkovsky, E.

    1994-01-01

    Clear optical fibers were used as a Cerenkov sampling media in Pb (electromagnetic) and Cu (hadron) absorbers in spaghetti calorimeters, for high rate and high radiation dose experiments, such as the forward region of high energy colliders. The fiber axes were aligned close to the direction of the incident particles (1 degree--7 degree). The 7 λ deep hadron tower contained 2.8% by volume 1.5 mm diameter core clear plastic fibers. The 27 radiation length deep electromagnetic towers had packing fractions of 6.8% and 7.2% of 1 mm diameter core quartz fibers as the active Cerenkov sampling medium. The energy resolution on electrons and pions, energy response, pulse shapes and angular studies are presented

  14. Fiber optics welder

    Science.gov (United States)

    Higgins, R.W.; Robichaud, R.E.

    A system is described for welding fiber optic waveguides together. The ends of the two fibers to be joined together are accurately, collinearly aligned in a vertical orientation and subjected to a controlled, diffuse arc to effect welding and thermal conditioning. A front-surfaced mirror mounted at a 45/sup 0/ angle to the optical axis of a stereomicroscope mounted for viewing the junction of the ends provides two orthogonal views of the interface during the alignment operation.

  15. FIBER OPTIC LIGHTING SYSTEMS

    Directory of Open Access Journals (Sweden)

    Munir BATUR

    2013-01-01

    Full Text Available Recently there have been many important and valuable developments in the communication industry. The huge increase in the sound, data and visual communications has caused a parallel increase in the demand for systems with wider capacity, higher speed and higher quality. Communication systems that use light to transfer data are immensely increased. There have recently many systems in which glass or plastic fiber cables were developed for light wave to be transmitted from a source to a target place. Fiber optic systems, are nowadays widely used in energy transmission control systems, medicine, industry and lighting. The basics of the system is, movement of light from one point to another point in fiber cable with reflections. Fiber optic lighting systems are quite secure than other lighting systems and have flexibility for realizing many different designs. This situation makes fiber optics an alternative for other lighting systems. Fiber optic lighting systems usage is increasing day-by-day in our life. In this article, these systems are discussed in detail.

  16. Electrospun amplified fiber optics.

    Science.gov (United States)

    Morello, Giovanni; Camposeo, Andrea; Moffa, Maria; Pisignano, Dario

    2015-03-11

    All-optical signal processing is the focus of much research aiming to obtain effective alternatives to existing data transmission platforms. Amplification of light in fiber optics, such as in Erbium-doped fiber amplifiers, is especially important for efficient signal transmission. However, the complex fabrication methods involving high-temperature processes performed in a highly pure environment slow the fabrication process and make amplified components expensive with respect to an ideal, high-throughput, room temperature production. Here, we report on near-infrared polymer fiber amplifiers working over a band of ∼20 nm. The fibers are cheap, spun with a process entirely carried out at room temperature, and shown to have amplified spontaneous emission with good gain coefficients and low levels of optical losses (a few cm(-1)). The amplification process is favored by high fiber quality and low self-absorption. The found performance metrics appear to be suitable for short-distance operations, and the large variety of commercially available doping dyes might allow for effective multiwavelength operations by electrospun amplified fiber optics.

  17. Continuous Natural Fiber Reinforced Thermoplastic Composites by Fiber Surface Modification

    Directory of Open Access Journals (Sweden)

    Patcharat Wongsriraksa

    2013-01-01

    Full Text Available Continuous natural fiber reinforced thermoplastic materials are expected to replace inorganic fiber reinforced thermosetting materials. However, in the process of fabricating the composite, it is difficult to impregnate the thermoplastic resin into reinforcement fiber because of the high melt viscosity. Therefore, intermediate material, which allows high impregnation during molding, has been investigated for fabricating continuous fiber reinforced thermoplastic composite by aligning resin fiber alongside reinforcing fiber with braiding technique. This intermediate material has been called “microbraid yarn (MBY.” Moreover, it is well known that the interfacial properties between natural fiber and resin are low; therefore, surface treatment on continuous natural fiber was performed by using polyurethane (PU and flexible epoxy (FLEX to improve the interfacial properties. The effect of surface treatment on the mechanical properties of continuous natural fiber reinforced thermoplastic composites was examined. From these results, it was suggested that surface treatment by PU with low content could produce composites with better mechanical properties.

  18. Thulium fiber laser lithotripsy using a muzzle brake fiber tip

    Science.gov (United States)

    Hutchens, Thomas C.; Gonzalez, David A.; Irby, Pierce B.; Fried, Nathaniel M.

    2017-02-01

    The Thulium fiber laser (TFL) is being explored as an alternative to Holmium:YAG laser for lithotripsy. TFL beam profile allows coupling of higher power into smaller fibers than multimode Holmium laser beam, without proximal fiber tip degradation. A smaller fiber provides more space in ureteroscope working channel for increased saline irrigation and allows maximum ureteroscope flexion. However, distal fiber tip burnback increases as fiber diameter decreases. Previous studies utilizing hollow steel sheaths around recessed distal fiber tips reduced fiber burnback, but increased retropulsion. In this study, a "fiber muzzle brake" was tested for reducing fiber burnback and stone retropulsion. TFL lithotripsy studies were performed at 1908 nm, 35 mJ, 500 μs, and 300 Hz using a 100-μm-core fiber. The optimal stainless steel muzzle brake tip tested consisted of a 1-cm-long, 560-μm-OD, 360-μm-ID tube with 275-μm thru hole located 250-μm from the distal end. The fiber tip was recessed a distance of 500 μm. Stone phantom retropulsion, fiber tip burnback, and calcium oxalate stone ablation studies were performed, ex vivo. Small stones with a mass of 40 +/- 4 mg and 4-mm-diameter were ablated over a 1.5-mm sieve in 25 +/- 4 s (n=10), without distal fiber tip burnback. Reduction in stone phantom retropulsion distance by 50% and 85% was observed when using muzzle brake tips versus 100-μm-core bare fibers and hollow steel tip fibers. The muzzle brake fiber tip provided efficient stone ablation, reduced stone retropulsion, and minimal fiber degradation during TFL lithotripsy.

  19. Evaluation of the modified nanoclay effect on the vulcanization of SBR through rheometric curve and DSC;Avaliacao do efeito de nanoargila modificada na vulcanizacao de SBR atraves da curva reometrica e DSC

    Energy Technology Data Exchange (ETDEWEB)

    Forte, Maria Madalena C.; Brito, Karin J.S., E-mail: mmcforte@ufrgs.b [Universidade Federal do Rio Grande do Sul (PPGEM/UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia Mecanica; Gheller Junior, Jordao [SENAI, Sao Leopoldo, RS (Brazil). Centro Tecnologico de Polimeros

    2009-07-01

    Rubber nanocomposites with nanoclays organically modified by quaternary ammonium salts may have the curing features modified significantly, since the salts may act on the rubber cure system. The aim of this work is to evaluate the influences of an organically modified montmorillonite (OMMT) on the curing reaction of an SBR (styrene butadiene rubber) with sulfur. The SBR/OMMT nanocomposites were prepared by co-coagulating SBR latex and Cloisite{sup R} 20A aqueous suspension at different nanoclay concentrations. The OMMT effect on the sulfur curing reaction was evaluated by the rheometric curve using a rheometer type RPA (Rubber Process Analyzer) and the heat of vulcanization (DELTAH{sub v}) using Differential Scanning Calorimetry (DSC). The evaluation of the clay nanolayers dispersion in the SBR matrix was accomplished by x-ray diffraction (XRD) analysis. (author)

  20. Cellulosic Fibers: Effect of Processing on Fiber Bundle Strength

    DEFF Research Database (Denmark)

    Thygesen, Anders; Madsen, Bo; Thomsen, Anne Belinda

    2011-01-01

    A range of differently processed cellulosic fibers from flax and hemp plants were investigated to study the relation between processing of cellulosic fibers and fiber bundle strength. The studied processing methods are applied for yarn production and include retting, scutching, carding, and cotto......A range of differently processed cellulosic fibers from flax and hemp plants were investigated to study the relation between processing of cellulosic fibers and fiber bundle strength. The studied processing methods are applied for yarn production and include retting, scutching, carding...

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

    Science.gov (United States)

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

    2015-01-01

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

  2. The Dependence of Signal-To-Noise Ratio (S/N) Between Star Brightness and Background on the Filter Used in Images Taken by the Vulcan Photometric Planet Search Camera

    Science.gov (United States)

    Mena-Werth, Jose

    1998-01-01

    The Vulcan Photometric Planet Search is the ground-based counterpart of Kepler Mission Proposal. The Kepler Proposal calls for the launch of telescope to look intently at a small patch of sky for four year. The mission is designed to look for extra-solar planets that transit sun-like stars. The Kepler Mission should be able to detect Earth-size planets. This goal requires an instrument and software capable of detecting photometric changes of several parts per hundred thousand in the flux of a star. The goal also requires the continuous monitoring of about a hundred thousand stars. The Kepler Mission is a NASA Discovery Class proposal similar in cost to the Lunar Prospector. The Vulcan Search is also a NASA project but based at Lick Observatory. A small wide-field telescope monitors various star fields successively during the year. Dozens of images, each containing tens of thousands of stars, are taken any night that weather permits. The images are then monitored for photometric changes of the order of one part in a thousand. These changes would reveal the transit of an inner-orbit Jupiter-size planet similar to those discovered recently in spectroscopic searches. In order to achieve a one part in one thousand photometric precision even the choice of a filter used in taking an exposure can be critical. The ultimate purpose of an filter is to increase the signal-to-noise ratio (S/N) of one's observation. Ideally, filters reduce the sky glow cause by street lights and, thereby, make the star images more distinct. The higher the S/N, the higher is the chance to observe a transit signal that indicates the presence of a new planet. It is, therefore, important to select the filter that maximizes the S/N.

  3. Optical fiber stripper positioning apparatus

    Science.gov (United States)

    Fyfe, Richard W.; Sanchez, Jr., Amadeo

    1990-01-01

    An optical fiber positioning apparatus for an optical fiber stripping device is disclosed which is capable of providing precise axial alignment between an optical fiber to be stripped of its outer jacket and the cutting blades of a stripping device. The apparatus includes a first bore having a width approximately equal to the diameter of an unstripped optical fiber and a counter bore axially aligned with the first bore and dimensioned to precisely receive a portion of the stripping device in axial alignment with notched cutting blades within the stripping device to thereby axially align the notched cutting blades of the stripping device with the axis of the optical fiber to permit the notched cutting blades to sever the jacket on the optical fiber without damaging the cladding on the optical fiber. In a preferred embodiment, the apparatus further includes a fiber stop which permits determination of the length of jacket to be removed from the optical fiber.

  4. A predictive model for the stiffness and damping properties of fiber-reinforced bearings. (Draft)

    International Nuclear Information System (INIS)

    Kelly, J.M.

    1998-01-01

    Seismic isolation technology in the United States today is applied almost entirely to large, expensive buildings housing sensitive internal equipment. Examples are computer centers, chip fabrication factories, emergency operation centers, and hospitals. The isolators used in these applications are large, expensive, and heavy. An individual isolator can weight around 1 ton and often more. To extend this valuable earthquake-resistant strategy to housing and commercial buildings, it is necessary to reduce the cost and weight of the isolators. The primary weight in an isolator is in the reinforcing steel plates used to provide the vertical stiffness of the rubber-steel composite element. A typical rubber isolator has two large end-plates [around 1 in. (25 mm) thick] and 20 thin reinforcing plates [around 3 mm (1/8 in.) thick). The high cost of producing the isolators results from the labor involved in preparing the steel plates and laying-up the rubber sheets and steel plates for vulcanization bonding in a mold. The steel plates have to be cut, sandblasted, acid cleaned, and coated with bonding compound. Next, the compounded rubber sheets with the interleaved steel plates are put into a mold and heated under pressure for several hours to complete the manufacturing process. The purpose of this research is to suggest that both the weight and the cost of isolators can be reduced by eliminating the steel reinforcing plates and replacing them with a fiber reinforcement

  5. Natural Fiber Composites: A Review

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Enhanced radiation resistant fiber optics

    International Nuclear Information System (INIS)

    Lyons, P.B.; Looney, L.D.

    1993-01-01

    A process for producing an optical fiber having enhanced radiation resistance is provided, the process including maintaining an optical fiber within a hydrogen-containing atmosphere for sufficient time to yield a hydrogen-permeated optical fiber having an elevated internal hydrogen concentration, and irradiating the hydrogen-permeated optical fiber at a time while the optical fiber has an elevated internal hydrogen concentration with a source of ionizing radiation. The radiation source is typically a cobalt-60 source and the fiber is pre-irradiated with a dose level up to about 1000 kilorads of radiation. 4 figures

  7. Fiber-optic technology review

    International Nuclear Information System (INIS)

    Lyons, P.B.

    1980-01-01

    A history of fiber technology is presented. The advantages of fiber optics are discussed (bandwidth, cost, weight and size, nonmetallic construction and isolation). Some aspects of the disadvantages of fiber systems briefly discussed are fiber and cable availability, fiber components, radiation effects, receivers and transmitters, and material dispersion. Particular emphasis over the next several years will involve development of fibers and systems optimized for use at wavelengths near 1.3 μm and development of wavelengths multiplexers for simultaneous system operation at several wavelengths

  8. Enhanced radiation resistant fiber optics

    Science.gov (United States)

    Lyons, P.B.; Looney, L.D.

    1993-11-30

    A process for producing an optical fiber having enhanced radiation resistance is provided, the process including maintaining an optical fiber within a hydrogen-containing atmosphere for sufficient time to yield a hydrogen-permeated optical fiber having an elevated internal hydrogen concentration, and irradiating the hydrogen-permeated optical fiber at a time while the optical fiber has an elevated internal hydrogen concentration with a source of ionizing radiation. The radiation source is typically a cobalt-60 source and the fiber is pre-irradiated with a dose level up to about 1000 kilorads of radiation. 4 figures.

  9. Anisotropic elliptic optical fibers

    Science.gov (United States)

    Kang, Soon Ahm

    1991-05-01

    The exact characteristic equation for an anisotropic elliptic optical fiber is obtained for odd and even hybrid modes in terms of infinite determinants utilizing Mathieu and modified Mathieu functions. A simplified characteristic equation is obtained by applying the weakly guiding approximation such that the difference in the refractive indices of the core and the cladding is small. The simplified characteristic equation is used to compute the normalized guide wavelength for an elliptical fiber. When the anisotropic parameter is equal to unity, the results are compared with the previous research and they are in close agreement. For a fixed value normalized cross-section area or major axis, the normalized guide wavelength lambda/lambda(sub 0) for an anisotropic elliptic fiber is small for the larger value of anisotropy. This condition indicates that more energy is carried inside of the fiber. However, the geometry and anisotropy of the fiber have a smaller effect when the normalized cross-section area is very small or very large.

  10. Hybrid Fiber Layup and Fiber-Reinforced Polymeric Composites Produced Therefrom

    Science.gov (United States)

    Barnell, Thomas J. (Inventor); Garrigan, Sean P. (Inventor); Rauscher, Michael D. (Inventor); Dietsch, Benjamin A. (Inventor); Cupp, Gary N. (Inventor)

    2018-01-01

    Embodiments of a hybrid fiber layup used to form a fiber-reinforced polymeric composite, and a fiber-reinforced polymeric composite produced therefrom are disclosed. The hybrid fiber layup comprises one or more dry fiber strips and one or more prepreg fiber strips arranged side by side within each layer, wherein the prepreg fiber strips comprise fiber material impregnated with polymer resin and the dry fiber strips comprise fiber material without impregnated polymer resin.

  11. Graphene fiber: a new trend in carbon fibers

    OpenAIRE

    Zhen Xu; Chao Gao

    2015-01-01

    New fibers with increased strength and rich functionalities have been untiringly pursued by materials researchers. In recent years, graphene fiber has arisen as a new carbonaceous fiber with high expectations in terms of mechanical and functional performance. In this review, we elucidated the concept of sprouted graphene fibers, including strategies for their fabrication and their basic structural attributes. We examine the rapid advances in the promotion of mechanical/functional properties o...

  12. Optical fiber switch

    Science.gov (United States)

    Early, James W.; Lester, Charles S.

    2002-01-01

    Optical fiber switches operated by electrical activation of at least one laser light modulator through which laser light is directed into at least one polarizer are used for the sequential transport of laser light from a single laser into a plurality of optical fibers. In one embodiment of the invention, laser light from a single excitation laser is sequentially transported to a plurality of optical fibers which in turn transport the laser light to separate individual remotely located laser fuel ignitors. The invention can be operated electro-optically with no need for any mechanical or moving parts, or, alternatively, can be operated electro-mechanically. The invention can be used to switch either pulsed or continuous wave laser light.

  13. Fiber Optic Calorimetry

    International Nuclear Information System (INIS)

    Rudy, C.; Bayliss, S.; Bracken, D.; Bush, J.; Davis, P.

    1997-01-01

    A twin-bridge calorimeter using optical fiber as the sensor element was constructed and tested. This system demonstrates the principle and capability of using optical fibers for heat-flow measurements of special nuclear material. This calorimeter uses piezoelectric-generated phase-carrier modulation with subsequent electronic signal processes to allow phase shifts as small as 1 microradian (microrad) to be measured. The sensing element consists of 21-m lengths of single-mode optical fiber wrapped around sample and reference chambers. The sensitivity of the calorimeter was determined to be 74 radians (rad) of phase shift per milliwatt of thermal power. One milliwatt of thermal power is equivalent to 400 mg of plutonium (6% 240 Pu). The system noise base was about 0.2 rad, equivalent to about 1 mg of plutonium

  14. Femtosecond Fiber Lasers

    Science.gov (United States)

    Bock, Katherine J.

    This thesis focuses on research I have done on ytterbium-doped femtosecond fiber lasers. These lasers operate in the near infrared region, lasing at 1030 nm. This wavelength is particularly important in biomedical applications, which includes but is not limited to confocal microscopy and ablation for surgical incisions. Furthermore, fiber lasers are advantageous compared to solid state lasers in terms of their cost, form factor, and ease of use. Solid state lasers still dominate the market due to their comparatively high energy pulses. High energy pulse generation in fiber lasers is hindered by either optical wave breaking or by multipulsing. One of the main challenges for fiber lasers is to overcome these limitations to achieve high energy pulses. The motivation for the work done in this thesis is increasing the output pulse peak power and energy. The main idea of the work is that decreasing the nonlinearity that acts on the pulse inside the cavity will prevent optical wave breaking, and thus will generate higher energy pulses. By increasing the output energy, ytterbium-doped femtosecond fiber lasers can be competitive with solid state lasers which are used commonly in research. Although fiber lasers tend to lack the wavelength tuning ability of solid state lasers, many biomedical applications take advantage of the 1030 microm central wavelength of ytterbium-doped fiber lasers, so the major limiting factor of fiber lasers in this field is simply the output power. By increasing the output energy without resorting to external amplification, the cavity is optimized and cost can remain low and economical. During verification of the main idea, the cavity was examined for possible back-reflections and for components with narrow spectral bandwidths which may have contributed to the presence of multipulsing. Distinct cases of multipulsing, bound pulse and harmonic mode-locking, were observed and recorded as they may be of more interest in the future. The third

  15. Higher Order Mode Fibers

    DEFF Research Database (Denmark)

    Israelsen, Stine Møller

    This PhD thesis considers higher order modes (HOMs) in optical fibers. That includes their excitation and characteristics. Within the last decades, HOMs have been applied both for space multiplexing in optical communications, group velocity dispersion management and sensing among others......-radial polarization as opposed to the linear polarization of the LP0X modes. The effect is investigated numerically in a double cladding fiber with an outer aircladding using a full vectorial modesolver. Experimentally, the bowtie modes are excited using a long period grating and their free space characteristics...... and polarization state are investigated. For this fiber, the onset of the bowtie effect is shown numerically to be LP011. The characteristics usually associated with Bessel-likes modes such as long diffraction free length and selfhealing are shown to be conserved despite the lack of azimuthal symmetry...

  16. Fiber optic calorimetry

    International Nuclear Information System (INIS)

    Rudy, C.R.; Bayliss, S.C.; Bracken, D.S.; Bush, I.J.; Davis, P.G.

    1998-01-01

    A twin-bridge calorimeter using optical fiber as the sensor element was constructed and tested. This system demonstrates the principle and capability of using optical fibers for heat-flow measurements of special nuclear material. This calorimeter uses piezoelectric-generated phase-carrier modulation with subsequent electronic signal processing to allow phase shifts as small as 1 microrad to be measured. The sensing element consists of 21-m lengths of single-mode optical fiber wrapped around sample and reference chambers. The sensitivity of the calorimeter was determined to be 74 rad of phase shift per mW of thermal power. One milliwatt of thermal power is equivalent to 400 mg of plutonium (6% 240 Pu). The system noise base was about 0.2 rad, equivalent to about 1 mg of plutonium

  17. Fiber optic calorimetry

    International Nuclear Information System (INIS)

    Rudy, C.; Bayliss, S.; Bracken, D.; Bush, J.; Davis, P.

    1998-01-01

    A twin-bridge calorimeter using optical fiber as the sensor element was constructed and tested. This system demonstrates the principle and capability of using fiber for heat-flow measurements of special nuclear material. This calorimeter uses piezoelectric-generated phase-carrier modulation with subsequent electronic signal processing to allow phase shifts as small as 1 microradian (μrad) to be measured. The sensing element consists of 21-m lengths of single-mode optical fiber wrapped around sample and reference chambers. The sensitivity of the calorimeter was determined to be 74 radians (rad) of phase shift per milliwatt of thermal power. One milliwatt of thermal power is equivalent to 400 mg of plutonium (6% 240 Pu). The system noise base was about 0.2 rad, equivalent to about 1 mg of plutonium

  18. Multibeam fiber laser cutting

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove; Hansen, Klaus Schütt; Nielsen, Jakob Skov

    2009-01-01

    The appearance of the high power high brilliance fiber laser has opened for new possibilities in laser materials processing. In laser cutting this laser has demonstrated high cutting performance compared to the dominating Cutting laser, the CO2 laser. However, quality problems in fiber......-laser cutting have until now limited its application to metal cutting. In this paper the first results of proof-of-principle Studies applying a new approach (patent pending) for laser cutting with high brightness and short wavelength lasers will be presented. In the approach, multibeam patterns are applied...... to control the melt flow out of the cut kerf resulting in improved cut quality in metal cutting. The beam patterns in this study are created by splitting up beams from two single mode fiber lasers and combining these beams into a pattern in the cut kerf. The results are obtained with a total of 550 W...

  19. Monolithic Yb-fiber femtosecond laser using photonic crystal fiber

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Lægsgaard, Jesper; Turchinovich, Dmitry

    2008-01-01

    We demonstrate, both experimentally and theoretically, an environmentally stable monolithic all-PM modelocked femtosecond Yb-fiber laser, with laser output pulse compressed in a spliced-on low-loss hollow-core photonic crystal fiber. Our laser provides direct fiber-end delivery of 4 nJ pulses...

  20. K3-fibered Calabi-Yau threefolds II, singular fibers

    OpenAIRE

    Hunt, Bruce

    1999-01-01

    In part I of this paper we constructed certain fibered Calabi-Yaus by a quotient construction in the context of weighted hypersurfaces. In this paper look at the case of K3 fibrations more closely and study the singular fibers which occur. This differs from previous work since the fibrations we discuss have constant modulus, and the singular fibers have torsion monodromy.

  1. Single fiber pullout from hybrid fiber reinforced concrete

    NARCIS (Netherlands)

    Markovich, I.; Van Mier, J.G.M.; Walraven, J.C.

    2001-01-01

    Hybrid fiber reinforcement can be very efficient for improving the tensile response of the composite. In such materials, fibers of different geometries can act as bridging mechanisms over cracks of different widths. The fiber bridging efficiency depends on the interface properties, which makes

  2. Fluoride glass fiber optics

    CERN Document Server

    Aggarwal, Ishwar D

    1991-01-01

    Fluoride Glass Fiber Optics reviews the fundamental aspects of fluoride glasses. This book is divided into nine chapters. Chapter 1 discusses the wide range of fluoride glasses with an emphasis on fluorozirconate-based compositions. The structure of simple fluoride systems, such as BaF2 binary glass is elaborated in Chapter 2. The third chapter covers the intrinsic transparency of fluoride glasses from the UV to the IR, with particular emphasis on the multiphonon edge and electronic edge. The next three chapters are devoted to ultra-low loss optical fibers, reviewing methods for purifying and

  3. Nonlinear fiber optics

    CERN Document Server

    Agrawal, Govind

    2012-01-01

    Since the 4e appeared, a fast evolution of the field has occurred. The 5e of this classic work provides an up-to-date account of the nonlinear phenomena occurring inside optical fibers, the basis of all our telecommunications infastructure as well as being used in the medical field. Reflecting the big developments in research, this new edition includes major new content: slow light effects, which offers a reduction in noise and power consumption and more ordered network traffic-stimulated Brillouin scattering; vectorial treatment of highly nonlinear fibers; and a brand new chapter o

  4. Silicon photonics for multicore fiber communication

    DEFF Research Database (Denmark)

    Ding, Yunhong; Kamchevska, Valerija; Dalgaard, Kjeld

    2016-01-01

    We review our recent work on silicon photonics for multicore fiber communication, including multicore fiber fan-in/fan-out, multicore fiber switches towards reconfigurable optical add/drop multiplexers. We also present multicore fiber based quantum communication using silicon devices.......We review our recent work on silicon photonics for multicore fiber communication, including multicore fiber fan-in/fan-out, multicore fiber switches towards reconfigurable optical add/drop multiplexers. We also present multicore fiber based quantum communication using silicon devices....

  5. Fiber-optic seismic sensor

    International Nuclear Information System (INIS)

    Finch, G. W.; Udd, E.

    1985-01-01

    A vibration sensor is constructed by providing two preferably matched coils of fiber-optic material. When the sensor experiences vibration, a differential pressure is exerted on the two fiber coils. The differential pressure results in a variation in the relative optical path lengths between the two fibers so that light beams transmitted through the two fibers are differently delayed, the phase difference therebetween being a detectable indication of the vibration applied to the sensor

  6. Tunable femtosecond Cherenkov fiber laser

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Svane, Ask Sebastian; Lægsgaard, Jesper

    2014-01-01

    We demonstrate electrically-tunable femtosecond Cherenkov fiber laser output at the visible range. Using an all-fiber, self-starting femtosecond Yb-doped fiber laser as the pump source and nonlinear photonic crystal fiber link as the wave-conversion medium, ultrafast, milliwatt-level, tunable...... and spectral isolated Cherenkov radiation at visible wavelengths are reported. Such a femtosecond Cherenkov laser source is promising for practical biophotonics applications....

  7. In-fiber integrated Michelson interferometer.

    Science.gov (United States)

    Yuan, Libo; Yang, Jun; Liu, Zhihai; Sun, Jiaxing

    2006-09-15

    A novel fiber-optic in-fiber integrated Michelson interferometer has been proposed and demonstrated. It consists of a segment of two-core fiber with a mirrored fiber end. The sensing characteristics based on the two-core fiber bending, corresponding to the shift of the phase of the two-core in-fiber integrated Michelson interferometer, are investigated.

  8. Transient attenuation in optical fibers

    International Nuclear Information System (INIS)

    Hopkins, A.A.; Kelly, R.E.; Looney, L.D.; Lyons, P.B.

    1984-01-01

    Low and high energy pulsed electron beams were used to generate radiation-induced transient attenuation in high-OH, Suprasil core, PCS fibers, demonstrating the energy dependence of the radiation damage and recovery mechanisms. A radiation resistant low-OH fiber was studied and its performance contrasted to that of high-OH materials. Several fibers with differing core compositions were also studied

  9. Fiber Optics and Library Technology.

    Science.gov (United States)

    Koenig, Michael

    1984-01-01

    This article examines fiber optic technology, explains some of the key terminology, and speculates about the way fiber optics will change our world. Applications of fiber optics to library systems in three major areas--linkage of a number of mainframe computers, local area networks, and main trunk communications--are highlighted. (EJS)

  10. Water-core Fresnel fiber

    NARCIS (Netherlands)

    Martelli, C.; Canning, J.; Lyytikainen, K.; Groothoff, N.

    2005-01-01

    A water core photonic crystal Fresnel fiber exploiting a hole distribution on zone plates of a cylindrical waveguide was developed and characterized. This fiber has similar guiding properties as the pristine air-hole guiding fiber although a large loss edge ~900nm is observed indicating that the

  11. Optical fibers for FTTH application

    Science.gov (United States)

    Guzowski, Bartlomiej; Tosik, Grzegorz; Lisik, Zbigniew; Bedyk, Michal; Kubiak, Andrzej

    2013-07-01

    In this paper the specifics of FTTH (Fiber To The Home) networks in terms of requirements for optical fibers has been presented. Optical fiber samples used in FTTH applications acquired from the worldwide leading manufacturers were subjected to small diameter mandrel wraps tests. The detailed procedures of performed tests and the measurement results has been presented.

  12. Photonic-crystal fibers gyroscope

    Directory of Open Access Journals (Sweden)

    Ali Muse Haider

    2015-01-01

    Full Text Available In this paper we proposed to use of a photonic crystal fiber with an inner hollow defect. The use of such fibers is not affected by a material medium on the propagation of optical radiation. Photonic crystal fibers present special properties and capabilities that lead to an outstanding potential for sensing applications

  13. Thermal properties of Fiber ropes

    DEFF Research Database (Denmark)

    Bossolini, Elena; Nielsen, Ole Wennerberg; Oland, Espen

    There is a trend within the oil and gas market to shift from steel wire ropes to fiber ropes for lifting, hoisting and mooring applications. The cost of fiber ropes is about 2-3 times that of steel wire ropes, but the natural buoyancy of fiber ropes reduces the overall weight resulting in smaller...

  14. Shedding Light on Fiber Optics.

    Science.gov (United States)

    Bunch, Robert M.

    1994-01-01

    Explains the principles of fiber optics as a medium for light-wave communication. Current uses of fiber systems on college campuses include voice, video, and local area network applications. A group of seven school districts in Minnesota are linked via fiber-optic cables. Other uses are discussed. (MLF)

  15. Fabrication of Optical Fiber Devices

    Science.gov (United States)

    Andres, Miguel V.

    In this paper we present the main research activities of the Laboratorio de Fibras Opticas del Instituto de Ciencia de los Materiales de la Universidad de Valencia. We show some of the main results obtained for devices based on tapered fibers, fiber Bragg gratings, acousto-optic effects and photonic crystal fibers.

  16. Microstructured Fibers: Design and Applications

    DEFF Research Database (Denmark)

    Bjarklev, Anders Overgaard; Broeng, Jes

    2006-01-01

    Holey fibers, in which airholes are introduced in the cladding region and extended in the axial direction of the fiber, have been known since the early days of silica waveguide research. Early work demonstrated the first low-loss fibers, which featured very small silica cores held in air by thin...

  17. Illustrative white matter fiber bundles

    NARCIS (Netherlands)

    Otten, R.J.G.; Vilanova, A.; Wetering, van de H.M.M.

    2010-01-01

    Diffusion Tensor Imaging (DTI) has made feasible the visualization of the fibrous structure of the brain whitematter. In the last decades, several fiber-tracking methods have been developed to reconstruct the fiber tracts fromDTI data. Usually these fiber tracts are shown individually based on some

  18. Bluebonnet Fiber Collages

    Science.gov (United States)

    Sterling, Joan

    2009-01-01

    This article presents a lesson that uses stitching and applique techniques to create a fiber collage in which every child is successful with high-quality work. This lesson was inspired by Tomie dePaola's "The Legend of the Bluebonnet." The back cover had a lovely illustration of the bluebonnet flower the author thought would translate easily to a…

  19. The dentate mossy fibers

    DEFF Research Database (Denmark)

    Blaabjerg, Morten; Zimmer, Jens

    2007-01-01

    Hippocampal mossy fibers are the axons of the dentate granule cells and project to hippocampal CA3 pyramidal cells and mossy cells of the dentate hilus (CA4) as well as a number of interneurons in the two areas. Besides their role in hippocampal function, studies of which are still evolving...

  20. Optical Fiber Protection

    Science.gov (United States)

    1999-01-01

    F&S Inc. developed and commercialized fiber optic and microelectromechanical systems- (MEMS) based instrumentation for harsh environments encountered in the aerospace industry. The NASA SBIR programs have provided F&S the funds and the technology to develop ruggedized coatings and coating techniques that are applied during the optical fiber draw process. The F&S optical fiber fabrication facility and developed coating methods enable F&S to manufacture specialty optical fiber with custom designed refractive index profiles and protective or active coatings. F&S has demonstrated sputtered coatings using metals and ceramics and combinations of each, and has also developed techniques to apply thin coatings of specialized polyimides formulated at NASA Langley Research Center. With these capabilities, F&S has produced cost-effective, reliable instrumentation and sensors capable of withstanding temperatures up to 800? C and continues building commercial sales with corporate partners and private funding. More recently, F&S has adapted the same sensing platforms to provide the rapid detection and identification of chemical and biological agents

  1. Optical Fiber Spectroscopy

    Science.gov (United States)

    Buoncristiani, A. M.

    1999-01-01

    This is the final report of work done on NASA Grant NAG-1-443. The work covers the period from July 1, 1992 to December 1, 1998. During this period several distinct but related research studies and work tasks were undertaken. These different subjects are enumerated below with a description of the work done on each of them. The focus of the research was the development of optical fibers for use as distributed temperature and stress sensors. The initial concept was to utilize the utilize the temperature and stress dependence of emission from rare earth and transition metal ions substitutionally doped into crystalline or glass fibers. During the course of investigating this it became clear that fiber Bragg gratings provided a alternative for making the desired measurements and there was a shift of research focus on to include the photo-refractive properties of germano-silicate glasses used for most gratings and to the possibility of developing fiber laser sources for an integrated optical sensor in the research effort. During the course of this work several students from Christopher Newport University and other universities participated in this effort. Their names are listed below. Their participation was an important part of their education.

  2. Fiber and Your Child

    Science.gov (United States)

    ... meals instead of white rice. Add beans (kidney, black, navy, and pinto) to rice dishes for even more fiber. Spice up salads with berries and almonds, chickpeas, artichoke hearts, and beans (kidney, black, navy, or pinto). Use whole-grain (corn or ...

  3. Polymer-Derived Ceramic Fibers

    Science.gov (United States)

    Ichikawa, Hiroshi

    2016-07-01

    SiC-based ceramic fibers are derived from polycarbosilane or polymetallocarbosilane precursors and are classified into three groups according to their chemical composition, oxygen content, and C/Si atomic ratio. The first-generation fibers are Si-C-O (Nicalon) fibers and Si-Ti-C-O (Tyranno Lox M) fibers. Both fibers contain more than 10-wt% oxygen owing to oxidation during curing and lead to degradation in strength at temperatures exceeding 1,300°C. The maximum use temperature is 1,100°C. The second-generation fibers are SiC (Hi-Nicalon) fibers and Si-Zr-C-O (Tyranno ZMI) fibers. The oxygen content of these fibers is reduced to less than 1 wt% by electron beam irradiation curing in He. The thermal stability of these fibers is improved (they are stable up to 1,500°C), but their creep resistance is limited to a maximum of 1,150°C because their C/Si atomic ratio results in excess carbon. The third-generation fibers are stoichiometric SiC fibers, i.e., Hi-Nicalon Type S (hereafter Type S), Tyranno SA, and Sylramic™ fibers. They exhibit improved thermal stability and creep resistance up to 1,400°C. Stoichiometric SiC fibers meet many of the requirements for the use of ceramic matrix composites for high-temperature structural application. SiBN3C fibers derived from polyborosilazane also show promise for structural applications, remain in the amorphous state up to 1,800°C, and have good high-temperature creep resistance.

  4. Improved Optical Fiber Chemical Sensors

    Science.gov (United States)

    Egalon, Claudio O.; Rogowski, Robert S.

    1994-01-01

    Calculations, based on exact theory of optical fiber, have shown how to increase optical efficiency sensitivity of active-core, step-index-profile optical-fiber fluorosensor. Calculations result of efforts to improve efficiency of optical-fiber chemical sensor of previous concept described in "Making Optical-Fiber Chemical Sensors More Sensitive" (LAR-14525). Optical fiber chemical detector of enhanced sensitivity made in several configurations. Portion of fluorescence or chemiluminescence generated in core, and launched directly into bound electromagnetic modes that propagate along core to photodetector.

  5. Solid fiber Z-pinches

    International Nuclear Information System (INIS)

    Lindemuth, I.R.

    1989-01-01

    One- and two-dimensional magnetohydrodynamic computations have been performed to study the behavior of solid deuterium fiber Z-pinch experiments performed at Los Alamos and the Naval Research Laboratory. The computations use a tabulated atomic data base and ''cold-start'' initial conditions. The computations predict that the solid fiber persists longer in existing experiments than previously expected and that the discharge actually consists of a relatively low-density, hot plasma which has been ablated from the fiber. The computations exhibit m = 0 behavior in the hot, exterior plasma prior to complete ablation of the solid fiber. The m = 0 behavior enhances the fiber ablation rate. 10 refs., 5 figs

  6. Introduction to optical fiber sensors

    International Nuclear Information System (INIS)

    Moukdad, S.

    1991-01-01

    Optical fiber sensors have many advantages over other types of sensors, for example: Low weight, immunity from EMI, electrical isolation, chemical passivity, and high sensitivity. In this seminar, a brief explanation of the optical fiber sensors, their use, and their advantages will be given. After, a description of the main optical fiber sensor components will be presented. Principles of some kinds of optical fiber sensors will be presented, and the principle of the fiber-optic rotation sensor and its realization will be discussed in some details, as well as its main applications. (author). 5 refs, 8 figs, 2 tabs

  7. Bonding Properties of Basalt Fiber and Strength Reduction According to Fiber Orientation

    OpenAIRE

    Choi, Jeong-Il; Lee, Bang

    2015-01-01

    The basalt fiber is a promising reinforcing fiber because it has a relatively higher tensile strength and a density similar to that of a concrete matrix as well as no corrosion possibility. This study investigated experimentally the bonding properties of basalt fiber with cementitious material as well as the effect of fiber orientation on the tensile strength of basalt fiber for evaluating basalt fiber?s suitability as a reinforcing fiber. Single fiber pullout tests were performed and then th...

  8. Fiber optics: A brief introduction

    International Nuclear Information System (INIS)

    Gruchalla, M.E.

    1989-01-01

    A basic introduction into the principles of fiber optics is presented. A review of both the underlying physical principles and the individual elements of typical fiber-optic systems are presented. The optical phenomenon of total internal reflection is reviewed. The basic construction of the optical fiber is presented. Both step-index and graded-index fiber designs are reviewed. Multimode and single-mode fiber constructions are considered and typical performance parameters given. Typical optical-fiber bandwidth and loss characteristics are compared to various common coaxial cables, waveguides, and air transmission. The constructions of optical-fiber cables are reviewed. Both loose-tube and tightly-buffered designs are considered. Several optical connection approaches are presented. Photographs of several representative optical connectors are included. Light Emitting Diode and Laser Diode emitters for fiber-optic applications are reviewed, and some advantages and shortcomings of each are considered. The phenomenon of modal noise is briefly explained. Both PIN and Avalanche photodetectors are reviewed and their performance parameters compared. Methods of data transmission over optical fiber are introduced. Principles of Wavelength, Frequency, and Time Division Multiplexing are briefly presented. The technology of fiber-optic sensors is briefly reviewed with basic principles introduced. The performance of a fiber-optic strain sensor is included as a practical example. 7 refs., 10 figs

  9. All-Fiber Raman Probe

    DEFF Research Database (Denmark)

    Brunetti, Anna Chiara

    by means of fiber components. Assuming the possibility to use a fiber laser with a fundamental radiation at 1064nm, in-fiber efficient second harmonic generation is achieved by optically poling the core of the waveguide delivering the excitation light to the sample. In this way, Raman spectroscopy...... in the visible range can be performed. The simultaneous delivery of the excitation light and collection of the Raman signal from the sample are achieved by means of a doubleclad fiber, whose core and inner cladding act as \\independent" transmission channels. A double-clad fiber coupler allows for the recovery...... of the collected Raman scattering from the inner-cladding region of the double-clad fiber, thus replacing the bulk dichroic component normally used to demultiplex the pump and Raman signal. A tunable Rayleigh-rejection filter based on a liquid filled-photonic bandgap fiber is also demonstrated in this work...

  10. Blendas PVC/NBR por processamento reativo I: desenvolvimento do processo de vulcanização Dinâmica in situ PVC/NBR blends by reactive processing I: in situ dynamic vulcanization process

    Directory of Open Access Journals (Sweden)

    Fábio R. Passador

    2007-06-01

    Full Text Available Vulcanização dinâmica é o processo de vulcanização de um elastômero durante a mistura no estado fundido com um termoplástico, que resulta em uma classe de materiais denominada termoplásticos vulcanizados. Neste trabalho, um novo tipo de termoplástico vulcanizado foi obtido por vulcanização dinâmica in situ da blenda PVC/NBR, utilizando-se um sistema de cura a base de enxofre (S e combinação dos aceleradores 2,2-ditiomercaptobenzotiazol (MBTS e dissulfeto de tetrametiltiuram (TMTD. As blendas PVC/NBR (90/10, 80/20 e 70/30% em massa foram processadas em um reômetro de torque Haake (Rheomix 600 a 160 °C com rotação de 60 rpm. As blendas obtidas por processamento reativo foram caracterizadas por calorimetria diferencial de varredura (DSC para determinação do grau de cura. Observou-se aumento no grau de cura das blendas com o tempo de mistura sendo o sistema de cura considerado eficiente.Dynamic vulcanization is a process of vulcanization of an elastomer during melt mixing with a thermoplastic wich results in material called thermoplastic vulcanizates or TPVs. In this study, a new kind of TPV was obtained by in situ dynamic curing of poly(vinyl chloride (PVC/nitrile rubber (NBR blends. The crosslinking of PVC/NBR blends was accomplished using sulphur (S/tetramethylthiuram disulphide (TMTD and mercaptobenzthiazyl disulphide (MBTS curative system during the reactive processing. The blends of PVC/NBR at the ratio of 90/10; 80/20 and 70/30 wt. (% were melt mixed using a Haake Rheomix 600 at 160 °C and rotor speed of 60 rpm. The curing behavior of NBR was investigated by a Monsanto Rheometer and the degree of cure was calculated using differential scanning calorimetry (DSC for different mixing times. It was observed that the degree of cure increases with the mixing time and the crosslinking system used in this work was considered efficient.

  11. Chemically modified carbon fibers and their applications

    International Nuclear Information System (INIS)

    Ermolenko, I.N.; Lyubliner, I.P.; Gulko, N.V.

    1990-01-01

    This book gives a comprehensive review about chemically modified carbon fibers (e.g. by incorporation of other elements) and is structured as follows: 1. Types of carbon fibers, 2. Structure of carbon fibers, 3. Properties of carbon fibers, 4. The cellulose carbonization process, 5. Formation of element-carbon fiber materials, 6. Surface modification of carbon fibers, and 7. Applications of carbon fibers (e.g. adsorbents, catalysts, constituents of composites). (MM)

  12. Multispot fiber laser welding

    DEFF Research Database (Denmark)

    Schutt Hansen, Klaus

    This dissertation presents work and results achieved in the field of multi beam fiber laser welding. The project has had a practical approach, in which simulations and modelling have been kept at a minimum. Different methods to produce spot patterns with high power single mode fiber lasers have...... been examined and evaluated. It is found that both diamond turned DOE’s in zinc sulphide and multilevel etched DOE’s (Diffractive Optical Elements) in fused silica have a good performance. Welding with multiple beams in a butt joint configuration has been tested. Results are presented, showing it has...... been possible to control the welding width in incremental steps by adding more beams in a row. The laser power was used to independently control the keyhole and consequently the depth of fusion. An example of inline repair of a laser weld in butt joint configuration was examined. Zinc powder was placed...

  13. Fiber optic fluid detector

    Science.gov (United States)

    Angel, S.M.

    1987-02-27

    Particular gases or liquids are detected with a fiber optic element having a cladding or coating of a material which absorbs the fluid or fluids and which exhibits a change of an optical property, such as index of refraction, light transmissiveness or fluoresence emission, for example, in response to absorption of the fluid. The fluid is sensed by directing light into the fiber optic element and detecting changes in the light, such as exit angle changes for example, that result from the changed optical property of the coating material. The fluid detector may be used for such purposes as sensing toxic or explosive gases in the atmosphere, measuring ground water contamination or monitoring fluid flows in industrial processes, among other uses. 10 figs.

  14. Fiber optic fluid detector

    Science.gov (United States)

    Angel, S. Michael

    1989-01-01

    Particular gases or liquids are detected with a fiber optic element (11, 11a to 11j) having a cladding or coating of a material (23, 23a to 23j) which absorbs the fluid or fluids and which exhibits a change of an optical property, such as index of refraction, light transmissiveness or fluoresence emission, for example, in response to absorption of the fluid. The fluid is sensed by directing light into the fiber optic element and detecting changes in the light, such as exit angle changes for example, that result from the changed optical property of the coating material. The fluid detector (24, 24a to 24j) may be used for such purposes as sensing toxic or explosive gases in the atmosphere, measuring ground water contamination or monitoring fluid flows in industrial processes, among other uses.

  15. Optical fiber communications

    CERN Document Server

    Keiser, Gerd

    2008-01-01

    The fourth edition of this popular text and reference book presents the fundamental principles for understanding and applying optical fiber technology to sophisticated modern telecommunication systems. Optical-fiber-based telecommunication networks have become a major information-transmission-system, with high capacity links encircling the globe in both terrestrial and undersea installations. Numerous passive and active optical devices within these links perform complex transmission and networking functions in the optical domain, such as signal amplification, restoration, routing, and switching. Along with the need to understand the functions of these devices comes the necessity to measure both component and network performance, and to model and stimulate the complex behavior of reliable high-capacity networks.

  16. Stable fiber interferometer

    International Nuclear Information System (INIS)

    Izmajlov, G.N.; Nikolaev, F.A.; Ozolin, V.V.; Grigor'yants, V.V.; Chamorovskij, Yu.K.

    1989-01-01

    The problem of construction the long-base Michelson interferometer for gravitational wave detection is discussed. Possible sources of noise and instability are considered. It is shown that evacuation of fiber interferometer, the winding of its arms on the glass ceramic bases, stabilization of radiation source frequency and seismic isolation of the base allow one to reduce its instability to the level, typical of mirror interferometer with the comparable optical base. 10 refs.; 2 figs

  17. Deriving muscle fiber diameter from recorded single fiber potential.

    Science.gov (United States)

    Zalewska, Ewa

    2017-12-01

    The aim of the study was to estimate muscle fiber diameters through analysis of single muscle fiber potentials (SFPs) recorded in the frontalis muscle of a healthy subject. Our previously developed analytical and graphic method to derive fiber diameter from the analysis of the negative peak duration and the amplitude of SFP, was applied to a sample of ten SFPs recorded in vivo. Muscle fiber diameters derived from the simulation method for the sample of frontalis muscle SFPs are consistent with anatomical data for this muscle. The results confirm the utility of proposed simulation method. Outlying data could be considered as the result of a contribution of other fibers to the potential recorded using an SFEMG electrode. Our graphic tool provides a rapid estimation of muscle fiber diameter. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  18. Carbon fiber reinforced asphalt concrete

    International Nuclear Information System (INIS)

    Jahromi, Saeed G.

    2008-01-01

    Fibers are often used in the manufacture of other materials. For many years, they have been utilized extensively in numerous applications in civil engineering. Fiber-reinforcement refers to incorporating materials with desired properties within some other materials lacking those properties. Use of fibers is not a new phenomenon, as the technique of fiber-reinforced bitumen began early as 1950. In all industrialized countries today, nearly all concretes used in construction are reinforced. A multitude of fibers and fiber materials are being introduced in the market regularly. The present paper presents characteristics and properties of carbon fiber-reinforced asphalt mixtures, which improve the performance of pavements. To evaluate the effect of fiber contents on bituminous mixtures, laboratory investigations were carried out on the samples with and without fibers. During the course of this study, various tests were undertaken, applying Marshall Test indirect tensile test, creep test and resistance to fatigue cracking by using repeated load indirect tensile test. Carbon fiber exhibited consistency in results and as such it was observed that the addition of fiber does affect the properties of bituminous mixtures, i.e. an increase in its stability and decrease in the flow value as well as an increase in voids in the mix. Results indicate that fibers have the potential to resist structural distress in pavement, in the wake of growing traffic loads and thus improve fatigue by increasing resistance to cracks or permanent deformation. On the whole, the results show that the addition of carbon fiber will improve some of the mechanical properties like fatigue and deformation in the flexible pavement. (author)

  19. Monolithic femtosecond Yb-fiber laser with photonic crystal fibers

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Lægsgaard, Jesper; Turchinovich, Dmitry

    We demonstrate a monolithic stable SESAM-modelocked self-starting Yb-fiber laser. A novel PM all-solid photonic bandgap fiber is used for intra-cavity of dispersion management. The ex-cavity final pulse compression is performed in a spliced-on PM hollow-core photonic crystal fiber. The laser...... directly delivers 9 nJ pulses of 275 fs duration with pulse repetition of 26.7MHz....

  20. Homogenization of long fiber reinforced composites including fiber bending effects

    DEFF Research Database (Denmark)

    Poulios, Konstantinos; Niordson, Christian Frithiof

    2016-01-01

    This paper presents a homogenization method, which accounts for intrinsic size effects related to the fiber diameter in long fiber reinforced composite materials with two independent constitutive models for the matrix and fiber materials. A new choice of internal kinematic variables allows...... of the reinforcing fibers is captured by higher order strain terms, resulting in an accurate representation of the micro-mechanical behavior of the composite. Numerical examples show that the accuracy of the proposed model is very close to a non-homogenized finite-element model with an explicit discretization...

  1. Raman fiber distributed feedback lasers.

    Science.gov (United States)

    Westbrook, Paul S; Abedin, Kazi S; Nicholson, Jeffrey W; Kremp, Tristan; Porque, Jerome

    2011-08-01

    We demonstrate fiber distributed feedback (DFB) lasers using Raman gain in two germanosilicate fibers. Our DFB cavities were 124 mm uniform fiber Bragg gratings with a π phase shift offset from the grating center. Our pump was at 1480 nm and the DFB lasers operated on a single longitudinal mode near 1584 nm. In a commercial Raman gain fiber, the maximum output power, linewidth, and threshold were 150 mW, 7.5 MHz, and 39 W, respectively. In a commercial highly nonlinear fiber, these figures improved to 350 mW, 4 MHz, and 4.3 W, respectively. In both lasers, more than 75% of pump power was transmitted, allowing for the possibility of substantial amplification in subsequent Raman gain fiber. © 2011 Optical Society of America

  2. Radio-vulcanization of natural rubber in the latex phase. Study of an experimental 1 tonne per hour production; Radio-vulcanisation du caoutchouc naturel en phase latex. Etude d'une production experimentale de 1 tonne par heure

    Energy Technology Data Exchange (ETDEWEB)

    Leveque, P; Puig, J R; Roudeix, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1968-07-01

    After briefly reviewing the main research carried out on the radio-vulcanization of latex and elastomers, a description is given of 4 types of cell which have been used successively with a view to industrial irradiation. They have made it possible to acquire the information necessary for resolving the main problem arising during irradiation - the formation of coagulum. The first two cell are designed for irradiation by a horizontal beam ('Dynamitron'), the two others use a vertical beam ('Circe'). The study of the properties of the rubber obtained shows it to compare favorably with 'Revultex'. In the appendix are given some characteristics of natural latex and information about its processing. (authors) [French] Apres un rappel des principales etudes sur la radio-vulcanisation du latex et des elastomeres, on decrit les quatre types de cellules successivement essayes en vue de l'irradiation industrielle. Ils ont permis d'acquerir les informations necessaires a la resolution du probleme principal pose par l'irradiation, la formation de coagulum au cours de celle,-ci. Les deux premiers sont concus pour l'irradiation par un faisceau horizontal ('Dynamitron'), les derniers par un faisceau vertical ('Circe'). L'etude des proprietes du caoutchouc obtenu montre qu'il se compare favorablement au 'Revultex'. Un apercu est donne en annexe des caracteristiques du latex naturel et de sa mise en oeuvre. (auteurs)

  3. Venus y Vulcano de Juan Espinal: precisiones sobre su iconografía y medio artístico (Venus and Vulcan by Juan Espinal: details on the iconography and artistic medium

    Directory of Open Access Journals (Sweden)

    Álvaro Cabezas García

    2016-04-01

    Full Text Available Resumen: En las siguientes páginas se ofrece una nueva lectura iconográfica del lienzo de Juan Espinal conservado en el Museo de Bellas Artes de Sevilla Venus y Vulcano. Los indicios apuntan a que esta pintura estaría representando el momento en el que el dios herrero entrega a su esposa las armas que ella le ha solicitado para su hijo Eneas en los momentos en los que el héroe, después de llegar al Lacio, se dispone a fundar una nueva civilización. Además de esto, se precisan determinados aspectos sobre las circunstancias y la cronología de su realización artística.Abstract: The following pages provides a new iconographic reading of an lienzo preserved in the Museo de Bellas Artes of Seville: Venus and Vulcan of Juan Espinal. Signs point to that in this painting would be represented the time in which the divino blacksmith delivers his wife the weapons that she has asked for her son Aeneas in the moments in which the hero, after arriving at Lazio, is available to found a new civilization. It also addresses certain aspects about the circumstances and chronology of his artistic preparation.

  4. Flexible optical fiber sensor based on polyurethane

    DEFF Research Database (Denmark)

    Kaysir, Md Rejvi; Stefani, Alessio; Lwin, Richard

    Polyurethane (PU) based hollow core fibers are investigated as optical sensors. The flexibility of PU fibers makes it suitable for sensing mechanical perturbations. We fabricated a PU fiber using the fiber drawing method, characterized the fiber and experimentally demonstrated a simple way...... to measure deformation, in the form of applied pressure....

  5. A fiber-optic polarimetric demonstration kit

    International Nuclear Information System (INIS)

    Eftimov, T; Dimitrova, T L; Ivanov, G

    2012-01-01

    A simple and multifunctional fiber-optic polarimetric kit on the basis of highly birefringent single-mode fibers is presented. The fiber-optic polarimetric kit allows us to perform the following laboratory exercises: (i) fiber excitation and the measurement of numerical aperture, (ii) polarization preservation and (iii) obtain polarization-sensitive fiberized interferometers.

  6. Dynamic drainage of froth with wood fibers

    Science.gov (United States)

    J.Y. Zhu; Freya Tan

    2005-01-01

    Understanding froth drainage with fibers (or simply called fiber drainage in froth) is important for improving fiber yield in the flotation deinking operation. In this study, the data of water and fiber mass in foams collected at different froth heights were used to reconstruct the time dependent and spatially resolved froth density and fiber volumetric concentration...

  7. Fiber optic sensor and method for making

    Science.gov (United States)

    Vartuli, James Scott; Bousman, Kenneth Sherwood; Deng, Kung-Li; McEvoy, Kevin Paul; Xia, Hua

    2010-05-18

    A fiber optic sensor including a fiber having a modified surface integral with the fiber wherein the modified surface includes an open pore network with optical agents dispersed within the open pores of the open pore network. Methods for preparing the fiber optic sensor are also provided. The fiber optic sensors can withstand high temperatures and harsh environments.

  8. Electrochromic fiber-shaped supercapacitors.

    Science.gov (United States)

    Chen, Xuli; Lin, Huijuan; Deng, Jue; Zhang, Ye; Sun, Xuemei; Chen, Peining; Fang, Xin; Zhang, Zhitao; Guan, Guozhen; Peng, Huisheng

    2014-12-23

    An electrochromic fiber-shaped super-capacitor is developed by winding aligned carbon nanotube/polyaniline composite sheets on an elastic fiber. The fiber-shaped supercapacitors demonstrate rapid and reversible chromatic transitions under different working states, which can be directly observed by the naked eye. They are also stretchable and flexible, and are woven into textiles to display designed signals in addition to storing energy. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. System for testing optical fibers

    Science.gov (United States)

    Golob, John E. [Olathe, KS; Looney, Larry D. [Los Alamos, NM; Lyons, Peter B. [Los Alamos, NM; Nelson, Melvin A. [Santa Barbara, CA; Davies, Terence J. [Santa Barbara, CA

    1980-07-15

    A system for measuring a combination of optical transmission properties of fiber optic waveguides. A polarized light pulse probe is injected into one end of the optical fiber. Reflections from discontinuities within the fiber are unpolarized whereas reflections of the probe pulse incident to its injection remain polarized. The polarized reflections are prevented from reaching a light detector whereas reflections from the discontinuities reaches the detector.

  10. Fiber-Optic Sensor Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Constructs and evaluates fiber-optic sensors for a variety of measurands. These measurands include acoustic, pressure, magnetic, and electric field as well...

  11. Development of scintillating fiber tracker

    International Nuclear Information System (INIS)

    Ishikawa, Shuzo; Kawai, Toshihide; Kozaki, Tetsuo

    1995-01-01

    In order to use thin scintillating fiber (diameter 500 micron) as a particle tracking detector, we have developed a method to construct precise multi-layer scintillating fiber sheets. We have also developed dedicated machines for this purpose. This paper presents the details of the method and the machines. Using these machines, we have produced fiber sheets for CERN WA95/CHORUS, which intend to detect a neutrino oscillation in the νμ-ντ channel using Hybrid Emulsion Set-up. Fiber Trackers are used as a vertex detector which support the neutrino event location in the nuclear emulsion target. (author)

  12. Fiber Tracking Cylinder Nesting

    International Nuclear Information System (INIS)

    Stredde, H.

    1999-01-01

    The fiber tracker consists of 8 concentric carbon fiber cylinders of varying diameters, from 399mm to 1032.2mm and two different lengths. 1.66 and 2.52 meters. Each completed cylinder is covered over the entire o.d. with scintillating fiber ribbons with a connector on each ribbon. These ribbons are axial (parallel to the beam line) at one end and stereo (at 3 deg. to the beam line) at the other. The ribbon connectors have dowel pins which are used to match with the connectors on the wave guide ribbons. These dowel pins are also used during the nesting operation, locating and positioning measurements. The nesting operation is the insertion of one cylinder into another, aligning them with one another and fastening them together into a homogeneous assembly. For ease of assembly. the nesting operation is accomplished working from largest diameter to smallest. Although the completed assembly of all 8 cylinders glued and bolted together is very stiff. individual cylinders are relatively flexible. Therefore. during this operation, No.8 must be supported in a manner which maintains its integrity and yet allows the insertion of No.7. This is accomplished by essentially building a set of dummy end plates which replicate a No.9 cylinder. These end plates are mounted on a wheeled cart that becomes the nesting cart. Provisions for a protective cover fastened to these rings has been made and will be incorporated in finished product. These covers can be easily removed for access to No.8 and/or the connection of No.8 to No.9. Another wheeled cart, transfer cart, is used to push a completed cylinder into the cylinder(s) already mounted in the nesting cart.

  13. Fiber sample presentation system for spectrophotometer cotton fiber color measurements

    Science.gov (United States)

    The Uster® High Volume Instrument (HVI) is used to class U.S. cotton for fiber color, yielding the industry accepted, cotton-specific color parameters Rd and +b. The HVI examines a 9 square inch fiber sample, and it is also used to test large AMS standard cotton “biscuits” or rectangles. Much inte...

  14. Random fiber laser based on artificially controlled backscattering fibers.

    Science.gov (United States)

    Wang, Xiaoliang; Chen, Daru; Li, Haitao; She, Lijuan; Wu, Qiong

    2018-01-10

    The random fiber laser (RFL), which is a milestone in laser physics and nonlinear optics, has attracted considerable attention recently. Most previously reported RFLs are based on distributed feedback of Rayleigh scattering amplified through the stimulated Raman-Brillouin scattering effect in single-mode fibers, which require long-distance (tens of kilometers) single-mode fibers and high threshold, up to watt level, due to the extremely small Rayleigh scattering coefficient of the fiber. We proposed and demonstrated a half-open-cavity RFL based on a segment of an artificially controlled backscattering single-mode fiber with a length of 210 m, 310 m, or 390 m. A fiber Bragg grating with a central wavelength of 1530 nm and a segment of artificially controlled backscattering single-mode fiber fabricated by using a femtosecond laser form the half-open cavity. The proposed RFL achieves thresholds of 25 mW, 30 mW, and 30 mW, respectively. Random lasing at a wavelength of 1530 nm and extinction ratio of 50 dB is achieved when a segment of 5 m erbium-doped fiber is pumped by a 980 nm laser diode in the RFL. A novel RFL with many short cavities has been achieved with low threshold.

  15. Carbon Fiber Biocompatibility for Implants

    Directory of Open Access Journals (Sweden)

    Richard Petersen

    2016-01-01

    Full Text Available Carbon fibers have multiple potential advantages in developing high-strength biomaterials with a density close to bone for better stress transfer and electrical properties that enhance tissue formation. As a breakthrough example in biomaterials, a 1.5 mm diameter bisphenol-epoxy/carbon-fiber-reinforced composite rod was compared for two weeks in a rat tibia model with a similar 1.5 mm diameter titanium-6-4 alloy screw manufactured to retain bone implants. Results showed that carbon-fiber-reinforced composite stimulated osseointegration inside the tibia bone marrow measured as percent bone area (PBA to a great extent when compared to the titanium-6-4 alloy at statistically significant levels. PBA increased significantly with the carbon-fiber composite over the titanium-6-4 alloy for distances from the implant surfaces of 0.1 mm at 77.7% vs. 19.3% (p < 10−8 and 0.8 mm at 41.6% vs. 19.5% (p < 10−4, respectively. The review focuses on carbon fiber properties that increased PBA for enhanced implant osseointegration. Carbon fibers acting as polymer coated electrically conducting micro-biocircuits appear to provide a biocompatible semi-antioxidant property to remove damaging electron free radicals from the surrounding implant surface. Further, carbon fibers by removing excess electrons produced from the cellular mitochondrial electron transport chain during periods of hypoxia perhaps stimulate bone cell recruitment by free-radical chemotactic influences. In addition, well-studied bioorganic cell actin carbon fiber growth would appear to interface in close contact with the carbon-fiber-reinforced composite implant. Resulting subsequent actin carbon fiber/implant carbon fiber contacts then could help in discharging the electron biological overloads through electrochemical gradients to lower negative charges and lower concentration.

  16. Polymer optical fiber bragg grating sensors

    DEFF Research Database (Denmark)

    Stefani, Alessio; Yuan, Scott Wu; Andresen, Søren

    2010-01-01

    Fiber-optical accelerometers based on polymer optical fiber Bragg gratings are reported. We have written fiber Bragg gratings for 1550 nm and 850 nm operations, characterized their temperature and strain response, and tested their performance in a prototype accelerometer....

  17. Extraction and characterization of Retama monosperma fibers

    African Journals Online (AJOL)

    XPERT

    monosperma leaves and their mechanical, physical and chemical characteristics. The fibers .... The hook was removed gently, and the behavior of the fiber was observed ..... fibers reinforced cement mortar slabs: a comparative study. Cement.

  18. Actively doped solid core Photonic Bandgap Fiber

    DEFF Research Database (Denmark)

    Broeng, Jes; Olausson, Christina Bjarnal Thulin; Lyngsøe, Jens Kristian

    2010-01-01

    Solid photonic bandgap fibers offer distributed spectral filtering with extraordinary high suppression. This opens new possibilities of artificially tailoring the gain spectrum of fibers. We present record-performance of such fibers and outline their future applications....

  19. Fiber breakage phenomena in long fiber reinforced plastic preparation

    International Nuclear Information System (INIS)

    Huang, Chao-Tsai; Tseng, Huan-Chang; Chang, Rong-Yeu; Vlcek, Jiri

    2015-01-01

    Due to the high demand of smart green, the lightweight technologies have become the driving force for the development of automotives and other industries in recent years. Among those technologies, using short and long fiber-reinforced plastics (FRP) to replace some metal components can reduce the weight of an automotive significantly. However, the microstructures of fibers inside plastic matrix are too complicated to manage and control during the injection molding through the screw, the runner, the gate, and then into the cavity. This study focuses on the fiber breakage phenomena during the screw plastification. Results show that fiber breakage is strongly dependent on screw design and operation. When the screw geometry changes, the fiber breakage could be larger even with lower compression ratio. (paper)

  20. High-birefringent photonic crystal fiber

    DEFF Research Database (Denmark)

    Libori, Stig E. Barkou; Broeng, Jes; Knudsen, Erik

    2001-01-01

    A highly birefringent photonic crystal fiber design is analysed. Birefringence up to 10-3 is found. Random fluctuations in the cladding design are analysed, and the fiber is found to be a feasible polarization maintaining fiber.......A highly birefringent photonic crystal fiber design is analysed. Birefringence up to 10-3 is found. Random fluctuations in the cladding design are analysed, and the fiber is found to be a feasible polarization maintaining fiber....

  1. Quantitive DNA Fiber Mapping

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Chun-Mei; Wang, Mei; Greulich-Bode, Karin M.; Weier, Jingly F.; Weier, Heinz-Ulli G.

    2008-01-28

    Several hybridization-based methods used to delineate single copy or repeated DNA sequences in larger genomic intervals take advantage of the increased resolution and sensitivity of free chromatin, i.e., chromatin released from interphase cell nuclei. Quantitative DNA fiber mapping (QDFM) differs from the majority of these methods in that it applies FISH to purified, clonal DNA molecules which have been bound with at least one end to a solid substrate. The DNA molecules are then stretched by the action of a receding meniscus at the water-air interface resulting in DNA molecules stretched homogeneously to about 2.3 kb/{micro}m. When non-isotopically, multicolor-labeled probes are hybridized to these stretched DNA fibers, their respective binding sites are visualized in the fluorescence microscope, their relative distance can be measured and converted into kilobase pairs (kb). The QDFM technique has found useful applications ranging from the detection and delineation of deletions or overlap between linked clones to the construction of high-resolution physical maps to studies of stalled DNA replication and transcription.

  2. Optical fiber powered pressure sensor

    International Nuclear Information System (INIS)

    Schweizer, P.; Neveux, L.; Ostrowsky, D.B.

    1987-01-01

    In the system described, a pressure sensor and its associated electronics are optically powered by a 20 mw laser and a photovoltaic cell via an optical fiber. The sensor is periodically interrogated and sends the measures obtained back to the central unit using an LED and a second fiber. The results obtained as well as the expected evolution will be described

  3. Microstructured hollow fibers for ultrafiltration

    NARCIS (Netherlands)

    Culfaz, Pmar Zeynep; Culfaz, P.Z.; Rolevink, Hendrikus H.M.; van Rijn, C.J.M.; Lammertink, Rob G.H.; Wessling, Matthias

    2010-01-01

    Hollow fiber ultrafiltration membranes with a corrugated outer microstructure were prepared from a PES/PVP blend. The effect of spinning parameters such as air gap, take-up speed, polymer dope viscosity and coagulation value on the microstructure and membrane characteristics was investigated. Fibers

  4. Fiber optic-based biosensor

    Science.gov (United States)

    Ligler, Frances S.

    1991-01-01

    The NRL fiber optic biosensor is a device which measures the formation of a fluorescent complex at the surface of an optical fiber. Antibodies and DNA binding proteins provide the mechanism for recognizing an analyze and immobilizing a fluorescent complex on the fiber surface. The fiber optic biosensor is fast, sensitive, and permits analysis of hazardous materials remote from the instrumentation. The fiber optic biosensor is described in terms of the device configuration, chemistry for protein immobilization, and assay development. A lab version is being used for assay development and performance characterization while a portable device is under development. Antibodies coated on the fiber are stable for up to two years of storage prior to use. The fiber optic biosensor was used to measure concentration of toxins in the parts per billion (ng/ml) range in under a minute. Immunoassays for small molecules and whole bacteria are under development. Assays using DNA probes as the detection element can also be used with the fiber optic sensor, which is currently being developed to detect biological warfare agents, explosives, pathogens, and toxic materials which pollute the environment.

  5. Handbook of fiber optics theory and applications

    CERN Document Server

    Yeh, Chai

    2013-01-01

    Dr. Yeh supplies a firm theoretical foundation in such topics as propagation of light through fibers, fiber fabrication, loss mechanisms, and dispersion properties. He then expands from this into such practical areas as fiber splicing, measuring loss in fibers, fiber-based communications networks, remote fiber sensors, and integrated optics. Whether involved in fiber optics research, design, or practical implementation of systems, this handbook will be extremely useful.Key Features* Here is a comprehensive, ""one-stop"" reference with state-of-the-art information on fiber optics Included is da

  6. Radiation damage in optical fibers

    International Nuclear Information System (INIS)

    Lyons, P.B.; Looney, L.D.; Ogle, J.W.

    1983-01-01

    Optical fibers provide important advantages over coaxial cables for many data transmission applications. Some of these applications require that the fibers transmit data during a radiation pulse. Other applications utilize the fiber as a radiation-to-light transducer. In either case, radiation-induced luminescence and absorption must be understood. Most studies of radiation effects in fibers have emphasized time scales of interest in telecommunication systems, from the msec to hour range. Few studies have concentrated on response at times below 1 + s. At Los Alamos, both laboratory electron accelerators and nuclear tests have been used as radiation sources to probe this early time region. The use of a fiber (or any optical medium) as a Cerenkov radiation-to-light transducer is discussed. Since the radiation induces attenuation in the medium, the light output is not proportional to the radiation input. The nonlinearity introduced by this attenuation is calculated

  7. Photometric device using optical fibers

    International Nuclear Information System (INIS)

    Boisde, Gilbert; Perez, J.-J.

    1981-02-01

    Remote measurements in radioactive environment are now possible with optical fibers. Measurement instruments developed by CEA are constitued of: - an optical probe (5 mm to 1 meter optical path length), - a photometric measurement device, - optical fiber links. 'TELEPHOT' is a photometric device for industrial installations. It is uses interferentiel filters for 2 to 5 simultaneous wave lengths. 'CRUDMETER' measures the muddiness of water. It can be equipped with a high sensitivity cell of 50 cm optical path length tested up to 250 bars. Coupling a double beam spectrophotometer to a remote optical probe, up to 1 meter optical path length, is carried out by means of an optical device using optical fibers links, eventually several hundred meter long. For these equipments special step index large core fibers, 1 to 1.5 mm in diameter, have been developed as well connectors. For industrial control and research these instruments offer new prospect thanks to optical fibers use [fr

  8. Benefits of glass fibers in solar fiber optic lighting systems.

    Science.gov (United States)

    Volotinen, Tarja T; Lingfors, David H S

    2013-09-20

    The transmission properties and coupling of solar light have been studied for glass core multimode fibers in order to verify their benefits for a solar fiber optic lighting system. The light transportation distance can be extended from 20 m with plastic fibers to over 100 m with the kind of glass fibers studied here. A high luminous flux, full visible spectrum, as well as an outstanding color rendering index (98) and correlated color temperature similar to the direct sun light outside have been obtained. Thus the outstanding quality of solar light transmitted through these fibers would improve the visibility of all kinds of objects compared to fluorescent and other artificial lighting. Annual relative lighting energy savings of 36% in Uppsala, Sweden, and 76% in Dubai were estimated in an office environment. The absolute savings can be doubled by using glass optical fibers, and are estimated to be in the order of 550 kWh/year in Sweden and 1160 kWh/year in Dubai for one system of only 0.159 m(2) total light collecting area. The savings are dependent on the fiber length, the daily usage time of the interior, the type of artificial lighting substituted, the system light output flux, and the available time of sunny weather at the geographic location.

  9. Green Fiber Bottle

    DEFF Research Database (Denmark)

    Didone, Mattia; Tosello, Guido

    has to have an inner coating barrier. The most reliable solution proposed is to coat the inner walls with silicon dioxide, which is not biodegradable but rather environmentally inert. To enhance the environmental footprint and sustainability of the bottle, and to be competitive with the existing...... technologies, the manufacturing technology for the production of the bottle has to offer the possibility of significant energy savings. Molded pulp products are made from wood fibers dispersed in water, and then they are formed, drained and dried. A relatively large quantity of resources (i.e. energy and time......) is consumed during the drying process. It is in this process stage that an innovative way of drying the products can be exploited by using the concept of impulse drying. Impulse drying is an advance drying technique in which water is removed from a wet paper pulp by the combination of mechanical pressure...

  10. Formerly utilized MED/AEC sites remedial action program. Radiological survey of Universal Cyclopes, Inc., Titusville, Plant (formerly Vulcan Crucible Steel Company, Aliquippa, Pennsylvania, May 2-8, 1978)

    International Nuclear Information System (INIS)

    Wynveen, R.A.; Smith, W.H.; Mundis, R.L.; Mayes, C.B.

    1982-05-01

    A radiological survey was conducted at the Universal Cyclops, Inc. Titusville Plant (formerly Vulcan Crucible Steel Company), in Aliquippa, Pennsylvania, to determine the location and quantities of any radioactive materials remaining on the site as a result of MED/AEC activities in the late 1940s. This facility was used for rolling uranium billets during the MED/AEC era. The survey included measurements of alpha and beta-gamma contamination, both fixed and removable; beta-gamma exposure readings at contact and at 1 m (3 ft) above the floor or ground level; and measurements of the concentrations of radon daughters in air and concentrations of 137 Cs, the 232 Th decay chain, the 226 Ra decay chain, and uranium in the soil on the site. Fourteen spots of contamination exceeded the allowable limits for natural uranium. Under current use conditions, the potential for radiation exposure of occupants of the building from these sources of contamination is remote. Concentrations of radon daughters were below the 0.01 WL limit. Calculated radon concentrations based on the radon-daughter determinations ranged from 0.11 to 0.27 pCi/l. The concentration guide for 222 Rn in uncontrolled areas is 3 pCi/l. Analysis of soil samples from the site indicated elevated concentrations of uranium (15.1 +- 0.7 to 109.0 +- 5.5 pCi/g) at one sampling location near the building. There currently are no regulatory limits for uranium concentration in soil, but, a proposed guide value is pCi/g. After evaluation of results of the survey, it was concluded that although some areas of the Universal Cyclops facility are contaminated, these areas do not pose a significant risk to the present occupants of the building. Nonetheless, in a few cases the contamination does exceed accepted guidelines. Remedial measures are indicated to bring the contaminated areas within the guidelines

  11. Carbon Fiber from Biomass

    Energy Technology Data Exchange (ETDEWEB)

    Milbrandt, Anelia [Clean Energy Manufacturing Analysis Center, Godlen, CO (United States); Booth, Samuel [Clean Energy Manufacturing Analysis Center, Godlen, CO (United States)

    2016-09-01

    Carbon fiber (CF), known also as graphite fiber, is a lightweight, strong, and flexible material used in both structural (load-bearing) and non-structural applications (e.g., thermal insulation). The high cost of precursors (the starting material used to make CF, which comes predominately from fossil sources) and manufacturing have kept CF a niche market with applications limited mostly to high-performance structural materials (e.g., aerospace). Alternative precursors to reduce CF cost and dependence on fossil sources have been investigated over the years, including biomass-derived precursors such as rayon, lignin, glycerol, and lignocellulosic sugars. The purpose of this study is to provide a comprehensive overview of CF precursors from biomass and their market potential. We examine the potential CF production from these precursors, the state of technology and applications, and the production cost (when data are available). We discuss their advantages and limitations. We also discuss the physical properties of biomass-based CF, and we compare them to those of polyacrylonitrile (PAN)-based CF. We also discuss manufacturing and end-product considerations for bio-based CF, as well as considerations for plant siting and biomass feedstock logistics, feedstock competition, and risk mitigation strategies. The main contribution of this study is that it provides detailed technical and market information about each bio-based CF precursor in one document while other studies focus on one precursor at a time or a particular topic (e.g., processing). Thus, this publication allows for a comprehensive view of the CF potential from all biomass sources and serves as a reference for both novice and experienced professionals interested in CF production from alternative sources.

  12. Fabrication of elastomeric silk fibers.

    Science.gov (United States)

    Bradner, Sarah A; Partlow, Benjamin P; Cebe, Peggy; Omenetto, Fiorenzo G; Kaplan, David L

    2017-09-01

    Methods to generate fibers from hydrogels, with control over mechanical properties, fiber diameter, and crystallinity, while retaining cytocompatibility and degradability, would expand options for biomaterials. Here, we exploited features of silk fibroin protein for the formation of tunable silk hydrogel fibers. The biological, chemical, and morphological features inherent to silk were combined with elastomeric properties gained through enzymatic crosslinking of the protein. Postprocessing via methanol and autoclaving provided tunable control of fiber features. Mechanical, optical, and chemical analyses demonstrated control of fiber properties by exploiting the physical cross-links, and generating double network hydrogels consisting of chemical and physical cross-links. Structure and chemical analyses revealed crystallinity from 30 to 50%, modulus from 0.5 to 4 MPa, and ultimate strength 1-5 MPa depending on the processing method. Fabrication and postprocessing combined provided fibers with extensibility from 100 to 400% ultimate strain. Fibers strained to 100% exhibited fourth order birefringence, revealing macroscopic orientation driven by chain mobility. The physical cross-links were influenced in part by the drying rate of fabricated materials, where bound water, packing density, and microstructural homogeneity influenced cross-linking efficiency. The ability to generate robust and versatile hydrogel microfibers is desirable for bottom-up assembly of biological tissues and for broader biomaterial applications. © 2017 Wiley Periodicals, Inc.

  13. New all-fiber velocimeter

    International Nuclear Information System (INIS)

    Weng Jidong; Tan Hua; Hu Shaolou; Ma Yun; Wan Xiang

    2005-01-01

    A new all-fiber velocity interferometer system for any reflector (AFVISAR) was developed. It was conceived and realized with the purpose of using it as the basic measuring element of a complete system for multiple point velocity measurements. Its main features are that it works at 532 nm and partly adopts the multimode optical fiber. The velocimeter consists of only fibers or fiber coupled components and has no optic elements such as optic lenses or reflectors. It is therefore very compact and easy to operate. Unlike the conventional AFVISAR, which uses single-mode optic fiber components, the laser beam in this new interferometer system arrives at and reflects from the target surface through a multimode optical fiber component, and then enters and interferes in a [3x3] single-mode fiber coupler. Its working principle is elaborated on in this article. Preliminary experiments using a split Hopkins pressure bar (SHPB) device show that the new interferometer can successfully measure the velocity profiles of the metal specimen along the axial or radial direction. Further experiments on a one-stage gas gun are under consideration

  14. Dimensional stability of natural fibers

    Energy Technology Data Exchange (ETDEWEB)

    Driscoll, Mark S. [Ultraviolet Light/Electron Beam (UV/EB) Technology Center, State University of New York College of Environmental Science and Forestry (SUNY-ESF), 1 Forestry Drive, Syracuse, NY 13210 (United States); Smith, Jennifer L.; Woods, Sean; Tiss, Kenneth J. [Ultraviolet Light/Electron Beam (UV/EB) Technology Center, State University of New York College of Environmental Science and Forestry (SUNY-ESF), 1 Forestry Drive, Syracuse, NY 13210 and Sustainable Construction Management and Engineering, SUNY-ESF (United States); Larsen, L. Scott [New York State Energy Research and Development Authority (NYSERDA), 17 Columbia Circle, Albany, NY 12203 (United States)

    2013-04-19

    One of the main problems associated with the use of natural fibers as reinforcing agents in composites is their uptake of moisture. Many natural fibers are lignocellulosic, which causes them to swell and shrink as the amount of available moisture changes. Swelling and shrinking can cause composites to prematurely fail. This paper presents the results of a preliminary study that considers the use of two different low molecular weight monomers, hydroxyethyl methacrylate (HEMA) and hydroxyethyl acrylate (HEA), polymerized by electron beam ionizing radiation, to dimensionally stabilize natural fibers. Eight different treatments consisting of varying amounts of monomer, encapsulating agent, and cross-linkers, were evaluated for their ability to dimensionally stabilize sisal fiber. Results indicate that both polymerized HEA and HEMA can reduce the swelling of sisal fiber. The effectiveness of HEA and HEMA can be further enhanced with the use of a cross-linker (SR 454). The use of hydroxylated monomers to dimensionally stabilize natural fibers may play an important role in reducing delamination and improving fiber-resin adhesion in composites.

  15. Dimensional stability of natural fibers

    International Nuclear Information System (INIS)

    Driscoll, Mark S.; Smith, Jennifer L.; Woods, Sean; Tiss, Kenneth J.; Larsen, L. Scott

    2013-01-01

    One of the main problems associated with the use of natural fibers as reinforcing agents in composites is their uptake of moisture. Many natural fibers are lignocellulosic, which causes them to swell and shrink as the amount of available moisture changes. Swelling and shrinking can cause composites to prematurely fail. This paper presents the results of a preliminary study that considers the use of two different low molecular weight monomers, hydroxyethyl methacrylate (HEMA) and hydroxyethyl acrylate (HEA), polymerized by electron beam ionizing radiation, to dimensionally stabilize natural fibers. Eight different treatments consisting of varying amounts of monomer, encapsulating agent, and cross-linkers, were evaluated for their ability to dimensionally stabilize sisal fiber. Results indicate that both polymerized HEA and HEMA can reduce the swelling of sisal fiber. The effectiveness of HEA and HEMA can be further enhanced with the use of a cross-linker (SR 454). The use of hydroxylated monomers to dimensionally stabilize natural fibers may play an important role in reducing delamination and improving fiber-resin adhesion in composites.

  16. Optical Fiber Sensors Based on Fiber Ring Laser Demodulation Technology.

    Science.gov (United States)

    Xie, Wen-Ge; Zhang, Ya-Nan; Wang, Peng-Zhao; Wang, Jian-Zhang

    2018-02-08

    A review for optical fiber sensors based on fiber ring laser (FRL) demodulation technology is presented. The review focuses on the principles, main structures, and the sensing performances of different kinds of optical fiber sensors based on FRLs. First of all, the theory background of the sensors has been discussed. Secondly, four different types of sensors are described and compared, which includes Mach-Zehnder interferometer (MZI) typed sensors, Fabry-Perot interferometer (FPI) typed sensors, Sagnac typed sensors, and fiber Bragg grating (FBG) typed sensors. Typical studies and main properties of each type of sensors are presented. Thirdly, a comparison of different types of sensors are made. Finally, the existing problems and future research directions are pointed out and analyzed.

  17. Multiplexed displacement fiber sensor using thin core fiber exciter.

    Science.gov (United States)

    Chen, Zhen; Hefferman, Gerald; Wei, Tao

    2015-06-01

    This letter reports a multiplexed optical displacement sensor using a thin core fiber (TCF) exciter. The TCF exciter is followed by a stripped single mode optical fiber. A small section of buffer is used as the movable component along the single mode fiber. Ultra-weak cladding mode reflection (< - 75 dB) was employed to probe the refractive index discontinuity between the air and buffer coating boundary. The position change of the movable buffer segment results in a delay change of the cladding mode reflection. Thus, it is a measure of the displacement of the buffer segment with respect to the glass fiber. The insertion loss of one sensor was measured to be less than 3 dB. A linear relationship was evaluated between the measurement position and absolute position of the moving actuator. Multiplexed capability was demonstrated and no cross talk was found between the sensors.

  18. SBIR-Long fluoride fiber

    Science.gov (United States)

    Jaeger, Raymond E.; Vacha, Lubos J.

    1987-08-01

    This report summarizes results obtained under a program aimed at developing new techniques for fabricating long lengths of heavy metal fluoride glass (HMFG) optical fiber. A new method for overcladding conventional HMFG preforms with a low melting oxide glass was developed, and improvements in the rotational casting method were made to increase preform length. The resulting composite glass canes consist of a fluoride glass overcoat layer to enhance strength and chemical durability. To show feasibility, prototype optical fiber preforms up to 1.6 cm in diameter with lengths of 22 cm were fabricated. These were drawn into optical fibers with lengths up to 900 meters.

  19. All-fiber polarization switch

    Science.gov (United States)

    Knape, Harald; Margulis, Walter

    2007-03-01

    We report an all-fiber polarization switch made out of silica-based microstructured fiber suitable for Q-switching all-fiber lasers. Nanosecond high-voltage pulses are used to heat and expand an internal electrode to cause λ/2-polarization rotation in less than 10 ns for 1.5 μm light. The 10 cm long component has an experimentally measured optical insertion loss of 0.2 dB and a 0-10 kHz repetition frequency capacity and has been durability tested for more than 109 pulses.

  20. Use of optical fibers in spectrophotometry

    Science.gov (United States)

    Ramsey, Lawrence W.

    1988-01-01

    The use of single or small numbers of fiber optic fibers in astronomical spectroscopy with the goal of greater spectrophotometric and radial velocity accuracy is discussed. The properties of multimode step index fibers which are most important for this application are outlined, as are laboratory tests of currently available fibers.

  1. Optical fiber communication — An overview

    Indian Academy of Sciences (India)

    Fabrication of single mode fibers is very difficult and so the fiber is .... of waveguide dispersion depends on the fiber design like core radius, since the .... production reducing the water content in the fiber to below 10 parts per billion. 5. ..... Connectors of the same type must be compatible from one manufacturer to another. 3.

  2. Optical Fiber Thermometer Based on Fiber Bragg Gratings

    Science.gov (United States)

    Rosli, Ekbal Bin; Mohd. Noor, Uzer

    2018-03-01

    Fiber Bragg grating has generated much interest in use as sensors to measure strain, temperature, and other physical parameters. It also the most common component used to develop this sensor with the advantages of simple, intrinsic sensing elements, electrically passive operation, EMI immunity, high sensitivity, compact size and potentially low cost [6]. This paper reports the design of an optical fiber thermometer based on fiber Bragg gratings. The system was developed for detecting temperature and strain by monitoring the shift of Bragg wavelength. The shifting of Bragg wavelength is used to indicate the temperature and strain due to the change in the surrounding temperature and strain. When the temperature and strain reach the exact wavelength level of the system, the temperature and strain value will display on the Arduino liquid crystal display (LCD). The optical fiber will provide the broadband light source and after passing the FBG the Bragg wavelength into the optical spectrum analyzer (OSA). The system is based on FBG as a physical quantity sensor. The temperatures measured is taken from the water bath and that of the strain is provided by amount of slotted mass used. The outcome of this project is to characterize the Bragg wavelength shifting from the fiber Bragg grating output. As the conclusion, this project provides an efficient optical fiber thermometer in measuring temperature and strain in order to replace the use of conventional electrical instruments.

  3. Enhancing Optical Communications with Brand New Fibers

    DEFF Research Database (Denmark)

    Morioka, Toshio; Awaji, Yoshinari; Ryf, Roland

    2012-01-01

    Optical fibers have often been considered to offer effectively infinite capacity to support the rapid traffic growth essential to our information society. However, as demand has grown and technology has developed, we have begun to realize that there is a fundamental limit to fiber capacity of ~ 100...... Tb/s per fiber for systems based on conventional single-core single-mode optical fiber as the transmission medium. This limit arises from the interplay of a number of factors including the Shannon limit, optical fiber nonlinearities, the fiber fuse effect, as well as optical amplifier bandwidth...... new fibers for space-division multiplexing and mode-division multiplexing....

  4. The Use of Ionizing Radiation in the Vulcanization of Silicon Rubber; Utilisation des radiations ionisantes pour la vulcanisation du caoutchouc au silicone; Ispol'zovanie ioniziruyushchikh izluchenij dlya vulkanizatsii silikonovogo kauchuka; Empleo de las radiaciones ionizantes en la vulcanizacion del caucho de siliconas

    Energy Technology Data Exchange (ETDEWEB)

    Kuzminsky, A S; Nikitina, T S; Oksentevich, L A [Rubber Research Institute, Moscow, Union of Soviet Socialist Republics (Russian Federation)

    1960-07-15

    Main purpose of the work - a detailed study of the properties of materials obtained by irradiating mixtures of polydimethylsiloxan e rubber and various fillers (special silicic acid, titanium dioxide, flue dust, chimney soot and lamp black). The irradiation was done with a powerful X-ray unit and a Co{sup 60} gamma-ray source of 20,000 gr. radium equivalent. The relative speed of formation of the space lattice of the vulcanized material was evaluated (by the size of the equilibrium constant and the maximum degree of swelling in benzene). Changes in tensile strength and specific elongation during the irradiation process were studied. The optimum vulcanization regime was chosen and the basic physico-mechanical characteristics of the vulcanized materials were defined. Changes in the properties of the irradiated vulcanized material during hot aging at temperatures of 150{sup o}, 200{sup o} and 250{sup o} were studied. Irradiation in vulcanization removes the necessity for carrying out the process at high temperatures and for keeping the product under controlled temperature conditions for long periods after vulcanization. This new method of vulcanizing allows the use of carbon black as a filler. The use of ionizing radiation makes it possible to simplify the technique of vulcanizing silicon rubber and to improve the properties of the vulcanized material. (author) [French] L'etude porte avant tout sur les proprietes des matieres qu'on obtient apres avoir expose a des radiations du caoutchouc au polydimethyl-siloxane melange a des produits d'addition differents (acide silicique special, bioxyde de titane, noir de fumee en poudre impalpable obtenu au four et a la lampe). L'exposition aux radiations s'effectuait dans une installation puissante de rayons X et avec une source de rayonnement gamma en {sup 60}Co avec une activite de 20 000 g. eq. ra. Les auteurs ont evalue la vitesse relative de formation du reseau spatial des vulcanisants (selon la grandeur du module d

  5. Ethanol extraction of phytosterols from corn fiber

    Science.gov (United States)

    Abbas, Charles; Beery, Kyle E.; Binder, Thomas P.; Rammelsberg, Anne M.

    2010-11-16

    The present invention provides a process for extracting sterols from a high solids, thermochemically hydrolyzed corn fiber using ethanol as the extractant. The process includes obtaining a corn fiber slurry having a moisture content from about 20 weight percent to about 50 weight percent solids (high solids content), thermochemically processing the corn fiber slurry having high solids content of 20 to 50% to produce a hydrolyzed corn fiber slurry, dewatering the hydrolyzed corn fiber slurry to achieve a residual corn fiber having a moisture content from about 30 to 80 weight percent solids, washing the residual corn fiber, dewatering the washed, hydrolyzed corn fiber slurry to achieve a residual corn fiber having a moisture content from about 30 to 80 weight percent solids, and extracting the residual corn fiber with ethanol and separating at least one sterol.

  6. Direct writing of fiber optic components in photonic crystal fibers and other specialty fibers

    Science.gov (United States)

    Fernandes, Luis Andre; Sezerman, Omur; Best, Garland; Ng, Mi Li; Kane, Saidou

    2016-04-01

    Femtosecond direct laser writing has recently shown great potential for the fabrication of complex integrated devices in the cladding of optical fibers. Such devices have the advantage of requiring no bulk optical components and no breaks in the fiber path, thus reducing the need for complicated alignment, eliminating contamination, and increasing stability. This technology has already found applications using combinations of Bragg gratings, interferometers, and couplers for the fabrication of optical filters, sensors, and power monitors. The femtosecond laser writing method produces a local modification of refractive index through non-linear absorption of the ultrafast laser pulses inside the dielectric material of both the core and cladding of the fiber. However, fiber geometries that incorporate air or hollow structures, such as photonic crystal fibers (PCFs), still present a challenge since the index modification regions created by the writing process cannot be generated in the hollow regions of the fiber. In this work, the femtosecond laser method is used together with a pre-modification method that consists of partially collapsing the hollow holes using an electrical arc discharge. The partial collapse of the photonic band gap structure provides a path for femtosecond laser written waveguides to couple light from the core to the edge of the fiber for in-line power monitoring. This novel approach is expected to have applications in other specialty fibers such as suspended core fibers and can open the way for the integration of complex devices and facilitate miniaturization of optical circuits to take advantage of the particular characteristics of the PCFs.

  7. Carbon Fiber Technology Facility (CFTF)

    Data.gov (United States)

    Federal Laboratory Consortium — Functionally within the MDF, ORNL operates DOE’s unique Carbon Fiber Technology Facility (CFTF)—a 42,000 ft2 innovative technology facility and works with leading...

  8. Nanomechanics of electrospun phospholipid fiber

    Energy Technology Data Exchange (ETDEWEB)

    Mendes, Ana C., E-mail: anac@food.dtu.dk, E-mail: ioach@food.dtu.dk; Chronakis, Ioannis S., E-mail: anac@food.dtu.dk, E-mail: ioach@food.dtu.dk [Technical University of Denmark, DTU-Food, Søltofts Plads B227, DK-2800, Kgs. Lyngby (Denmark); Nikogeorgos, Nikolaos; Lee, Seunghwan [Department of Mechanical Engineering, Technical University of Denmark, DK-2800 Kgs. Lyngby (Denmark)

    2015-06-01

    Electrospun asolectin phospholipid fibers were prepared using isooctane as a solvent and had an average diameter of 6.1 ± 2.7 μm. Their mechanical properties were evaluated by nanoindentation using Atomic Force Microscopy, and their elastic modulus was found to be approximately 17.2 ± 1 MPa. At a cycle of piezo expansion-retraction (loading-unloading) of a silicon tip on a fiber, relatively high adhesion was observed during unloading. It is proposed that this was primarily due to molecular rearrangements at the utmost layers of the fiber caused by the indentation of the hydrophilic tip. The phospholipid fibers were shown to be stable in ambient conditions, preserving the modulus of elasticity up to 24 h.

  9. Nanomechanics of electrospun phospholipid fiber

    DEFF Research Database (Denmark)

    Mendes, Ana Carina Loureiro; Nikogeorgos, Nikolaos; Lee, Seunghwan

    2015-01-01

    Electrospun asolectin phospholipid fibers were prepared using isooctane as a solvent and had an average diameter of 6.1 +/- 2.7 mu m. Their mechanical properties were evaluated by nanoindentation using Atomic Force Microscopy, and their elastic modulus was found to be approximately 17.2 +/- 1MPa....... At a cycle of piezo expansion-retraction (loading-unloading) of a silicon tip on a fiber, relatively high adhesion was observed during unloading. It is proposed that this was primarily due to molecular rearrangements at the utmost layers of the fiber caused by the indentation of the hydrophilic tip....... The phospholipid fibers were shown to be stable in ambient conditions, preserving the modulus of elasticity up to 24 h. (c) 2015 AIP Publishing LLC....

  10. Fiber Optics: A Bright Future.

    Science.gov (United States)

    Rice, James, Jr.

    1980-01-01

    Presents an overview of the impact of fiber optics on telecommunications and its application to information processing and library services, including information retrieval, news services, remote transmission of library services, and library networking. (RAA)

  11. Application of Fiber Optic Instrumentation

    Science.gov (United States)

    Richards, William Lance; Parker, Allen R., Jr.; Ko, William L.; Piazza, Anthony; Chan, Patrick

    2012-01-01

    Fiber optic sensing technology has emerged in recent years offering tremendous advantages over conventional aircraft instrumentation systems. The advantages of fiber optic sensors over their conventional counterparts are well established; they are lighter, smaller, and can provide enormous numbers of measurements at a fraction of the total sensor weight. After a brief overview of conventional and fiber-optic sensing technology, this paper presents an overview of the research that has been conducted at NASA Dryden Flight Research Center in recent years to advance this promising new technology. Research and development areas include system and algorithm development, sensor characterization and attachment, and real-time experimentally-derived parameter monitoring for ground- and flight-based applications. The vision of fiber optic smart structure technology is presented and its potential benefits to aerospace vehicles throughout the lifecycle, from preliminary design to final retirement, are presented.

  12. High performance polyethylene nanocomposite fibers

    Directory of Open Access Journals (Sweden)

    A. Dorigato

    2012-12-01

    Full Text Available A high density polyethylene (HDPE matrix was melt compounded with 2 vol% of dimethyldichlorosilane treated fumed silica nanoparticles. Nanocomposite fibers were prepared by melt spinning through a co-rotating twin screw extruder and drawing at 125°C in air. Thermo-mechanical and morphological properties of the resulting fibers were then investigated. The introduction of nanosilica improved the drawability of the fibers, allowing the achievement of higher draw ratios with respect to the neat matrix. The elastic modulus and creep stability of the fibers were remarkably improved upon nanofiller addition, with a retention of the pristine tensile properties at break. Transmission electronic microscope (TEM images evidenced that the original morphology of the silica aggregates was disrupted by the applied drawing.

  13. All-optical fiber compressor

    International Nuclear Information System (INIS)

    Ivanov, Luben M.

    2015-01-01

    A simple all-optical fiber compressor, based on an idea of dispersion management using a fiber of positive dispersion in the first part and of negative dispersion in the second one at the working wavelength, is investigated. The method allows a combination of the advantages of the classic fiber-grating and of the multisoliton compression. It is possible to improve substantially the quality of the compressed pulse compared to the multisoliton compression. The compression factor could be increased up to 2-2.5 times when the fraction of the input pulse energy appearing within the compressed pulse enhances more than 2 times. Thus, the peak power of the compressed pulse is able to increase about 5 times and the quality of the obtained pulses should be comparable with those obtained by the fiber-grating compressor

  14. Influence of forming conditions on fiber tilt

    Science.gov (United States)

    David W. Vahey; John M. Considine; Michael A. and MacGregor

    2013-01-01

    Fiber tilt describes the projection of fiber length in the thickness direction of paper. The projection is described by the tilt angle of fibers with respect to the plane of the sheet. A simple model for fiber tilt is based on jet-to-wire velocity differential in combination with cross-flows on the wire. The tilt angle of a fiber is found to vary as the sine of its in-...

  15. Engineering modes in optical fibers with metamaterial

    DEFF Research Database (Denmark)

    Yan, Min; Mortensen, Asger; Qiu, Min

    2009-01-01

    In this paper, we report a preliminary theoretical study on optical fibers with fine material inclusions whose geometrical inhomogeneity is almost indistinguishable by the operating wavelength.We refer to such fibers as metamaterial optical fibers, which can conceptually be considered...... as an extension from the previously much publicized microstructured optical fibers. Metamaterials can have optical properties not obtainable in naturally existing materials, including artificial anisotropy as well as graded material properties. Therefore, incorporation of metamaterial in optical fiber designs can...

  16. Fundamentals of plastic optical fibers

    CERN Document Server

    Koike, Yasuhiro

    2014-01-01

    Polymer photonics is an interdisciplinary field which demands excellence both in optics (photonics) and materials science (polymer). However, theses disciplines have developed independently, and therefore the demand for a comprehensive work featuring the fundamentals of photonic polymers is greater than ever.This volume focuses on Polymer Optical Fiber and their applications. The first part of the book introduces typical optical fibers according to their classifications of material, propagating mode, and structure. Optical properties, the high bandwidth POF and transmission loss are discussed,

  17. Fiber Arts and Generative Justice

    Directory of Open Access Journals (Sweden)

    Sarah Kuhn

    2016-12-01

    Full Text Available The fiber arts, because they are practiced in different forms around the globe, have the potential to teach us much about generative justice that unites labor, ecological, and expressive values. The ecological mutualism documented in Navajo corrals supports traditional weaving, dyeing, food, and medicinal practices in a sustainable and generative cycle that survives despite disruption and exploitation. The network of fiber craftspeople, retailers, ranchers, teachers, spinners, and dyers and their organizations supports the social mutualism of fiber communities. Fiber arts practices can benefit individuals, communities, the environment, and public health, among other things. Conscious fiber activism and critical making can also be used to explicitly draw attention to problems such as overconsumption, waste, industrial “fast fashion,” labor exploitation, environmental degradation, toxic risks, intolerance, and the devaluing of women and their work. Fiber arts have the potential to support environmental and social mutualism and catalyze a new aesthetic of long-term attachment to meaningful objects and communities, reinforcing the creation and conservation of expressive, ecological, and labor value. 

  18. Advanced specialty fiber designs for high power fiber lasers

    Science.gov (United States)

    Gu, Guancheng

    The output power of fiber lasers has increased rapidly over the last decade. There are two major limiting factors, namely nonlinear effects and transverse mode instability, prohibiting the power scaling capability of fiber lasers. The nonlinear effects, originating from high optical intensity, primarily limit the peak power scaling. The mode instability, on the other hand, arises from quantum-defect driven heating, causing undesired mode coupling once the power exceeds the threshold and degradation of beam quality. The mode instability has now become the bottleneck for average output power scaling of fiber lasers. Mode area scaling is the most effective way to mitigate nonlinear effects. However, the use of large mode area may increase the tendency to support multiple modes in the core, resulting in lower mode instability threshold. Therefore, it is critical to maintain single mode operation in a large mode area fiber. Sufficient higher order mode suppression can lead to effective single-transverse-mode propagation. In this dissertation, we explore the feasibility of using specialty fiber to construct high power fiber lasers with robust single-mode output. The first type of fiber discussed is the resonantly-enhanced leakage channel fiber. Coherent reflection at the fiber outer boundary can lead to additional confinement especially for highly leaky HOM, leading to lower HOM losses than what are predicted by conventional finite element mothod mode solver considering infinite cladding. In this work, we conducted careful measurements of HOM losses in two leakage channel fibers (LCF) with circular and rounded hexagonal boundary shapes respectively. Impact on HOM losses from coiling, fiber boundary shapes and coating indexes were studied in comparison to simulations. This work demonstrates the limit of the simulation method commonly used in the large-mode-area fiber designs and the need for an improved approach. More importantly, this work also demonstrates that a

  19. Optical fiber inspection system

    Science.gov (United States)

    Moore, Francis W.

    1987-01-01

    A remote optical inspection system including an inspection head. The inspection head has a passageway through which pellets or other objects are passed. A window is provided along the passageway through which light is beamed against the objects being inspected. A plurality of lens assemblies are arranged about the window so that reflected light can be gathered and transferred to a plurality of coherent optical fiber light guides. The light guides transfer the light images to a television or other image transducer which converts the optical images into a representative electronic signal. The electronic signal can then be displayed on a signal viewer such as a television monitor for inspection by a person. A staging means can be used to support the objects for viewing through the window. Routing means can be used to direct inspected objects into appropriate exit passages for accepted or rejected objects. The inspected objects are advantageously fed in a singular manner to the staging means and routing means. The inspection system is advantageously used in an enclosure when toxic or hazardous materials are being inspected.

  20. Photonic bandgap fiber lasers and multicore fiber lasers for next generation high power lasers

    DEFF Research Database (Denmark)

    Shirakawa, A.; Chen, M.; Suzuki, Y.

    2014-01-01

    Photonic bandgap fiber lasers are realizing new laser spectra and nonlinearity mitigation that a conventional fiber laser cannot. Multicore fiber lasers are a promising tool for power scaling by coherent beam combination. © 2014 OSA....

  1. Hybrid Effect Evaluation of Steel Fiber and Carbon Fiber on the Performance of the Fiber Reinforced Concrete.

    Science.gov (United States)

    Song, Weimin; Yin, Jian

    2016-08-18

    Fiber reinforcement is an important method to enhance the performance of concrete. In this study, the compressive test and impact test were conducted, and then the hybrid effect between steel fiber (SF) and carbon fiber (CF) was evaluated by employing the hybrid effect index. Compressive toughness and impact toughness of steel fiber reinforced concrete (SFRC), carbon fiber reinforced concrete (CFRC) and hybrid fiber reinforced concrete (HFRC) were explored at steel fiber volume fraction 0.5%, 1%, 1.5% and carbon fiber 0.1%, 0.2%, 0.3%. Results showed that the addition of steel fiber and carbon fiber can increase the compressive strength. SF, CF and the hybridization between them could increase the compressive toughness significantly. The impact test results showed that as the volume of fiber increased, the impact number of the first visible crack and the ultimate failure also increased. The improvement of toughness mainly lay in improving the crack resistance after the first crack. Based on the test results, the positive hybrid effect of steel fiber and carbon fiber existed in hybrid fiber reinforced concrete. The relationship between the compressive toughness and impact toughness was also explored.

  2. Fiber optic muzzle brake tip for reducing fiber burnback and stone retropulsion during thulium fiber laser lithotripsy

    Science.gov (United States)

    Hutchens, Thomas C.; Gonzalez, David A.; Irby, Pierce B.; Fried, Nathaniel M.

    2017-01-01

    The experimental thulium fiber laser (TFL) is being explored as an alternative to the current clinical gold standard Holmium:YAG laser for lithotripsy. The near single-mode TFL beam allows coupling of higher power into smaller optical fibers than the multimode Holmium laser beam profile, without proximal fiber tip degradation. A smaller fiber is desirable because it provides more space in the ureteroscope working channel for increased saline irrigation rates and allows maximum ureteroscope deflection. However, distal fiber tip burnback increases as fiber diameter decreases. Previous studies utilizing hollow steel sheaths around recessed distal fiber tips reduced fiber burnback but increased stone retropulsion. A "fiber muzzle brake" was tested for reducing both fiber burnback and stone retropulsion by manipulating vapor bubble expansion. TFL lithotripsy studies were performed at 1908 nm, 35 mJ, 500 μs, and 300 Hz using a 100-μm-core fiber. The optimal stainless steel muzzle brake tip tested consisted of a 1-cm-long, 560-μm-outer-diameter, 360-μm-inner-diameter tube with a 275-μm-diameter through hole located 250 μm from the distal end. The fiber tip was recessed a distance of 500 μm. Stone phantom retropulsion, fiber tip burnback, and calcium oxalate stone ablation studies were performed ex vivo. Small stones with a mass of 40±4 mg and 4-mm-diameter were ablated over a 1.5-mm sieve in 25±4 s (n=10) without visible distal fiber tip burnback. Reduction in stone phantom retropulsion distance by 50% and 85% was observed when using muzzle brake tips versus 100-μm-core bare fibers and hollow steel tip fibers, respectively. The muzzle brake fiber tip simultaneously provided efficient stone ablation, reduced stone retropulsion, and minimal fiber degradation during TFL lithotripsy.

  3. Method for the preparation of carbon fiber from polyolefin fiber precursor

    Energy Technology Data Exchange (ETDEWEB)

    Naskar, Amit Kumar; Hunt, Marcus Andrew; Saito, Tomonori

    2017-11-28

    Methods for the preparation of carbon fiber from polyolefin fiber precursor, wherein the polyolefin fiber precursor is partially sulfonated and then carbonized to produce carbon fiber. Methods for producing hollow carbon fibers, wherein the hollow core is circular- or complex-shaped, are also described. Methods for producing carbon fibers possessing a circular- or complex-shaped outer surface, which may be solid or hollow, are also described.

  4. Advanced ultrafast fiber laser sources enabled by fiber nonlinearities

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wei

    2017-05-15

    Development of high power/energy ultrafast fiber lasers for scientific research and industrial applications is one of the most exciting fields in ultrafast optics. This thesis demonstrated new means to improve two essential properties - which are indispensable for novel applications such as high-harmonic generation (HHG) and multiphoton microscopy (MPM) - of an ultrafast fiber laser system: energy scaling capability and wavelength tunability. High photon-flux extreme ultraviolet sources enabled by HHG desire high power (>100 W), high repetition-rate (>1 MHz) ultrafast driving laser sources. We have constructed from scratch a high-power Yb-fiber laser system using the well-known chirped-pulse amplification (CPA) technique. Such a CPA system capable of producing ∝200-W average power consists of a monolithic Yb-fiber oscillator, an all-fiber stretcher, a pre-amplifier chain, a main amplifier constructed from rode-type large pitch fiber, and a diffraction-grating based compressor. To increase the HHG efficiency, ultrafast pulses with duration <60 fs are highly desired. We proposed and demonstrated a novel amplification technique, named as pre-chirp managed amplification (PCMA). We successfully constructed an Yb-fiber based PCMA system that outputs 75-MHz spectrally broadened pulses with >130-W average power. The amplified pulses are compressed to 60-fs pulses with 100-W average power, constituting a suitable HHG driving source. MPM is a powerful biomedical imaging tool, featuring larger penetration depth while providing the capability of optical sectioning. Although femtosecond solid-state lasers have been widely accepted as the standard option as MPM driving sources, fiber-based sources have received growing research efforts due to their superior performance. In the second part of this thesis, we both theoretically and experimentally demonstrated a new method of producing wavelength widely tunable femtosecond pulses for driving MPM. We employed self-phase modulation

  5. Brillouin lasing in single-mode tapered optical fiber with inscribed fiber Bragg grating array

    Directory of Open Access Journals (Sweden)

    S.M. Popov

    2018-06-01

    Full Text Available A tapered optical fiber has been manufactured with an array of fiber Bragg gratings (FBG inscribed during the drawing process. The total fiber peak reflectivity is 5% and the reflection bandwidth is ∼3.5 nm. A coherent frequency domain reflectometry has been applied for precise profiling of the fiber core diameter and grating reflectivity both distributed along the whole fiber length. These measurements are in a good agreement with the specific features of Brillouin lasing achieved in the semi-open fiber cavity configuration. Keywords: Tapered optical fibers, Fiber Bragg gratings, Random lasers

  6. Bonding Properties of Basalt Fiber and Strength Reduction According to Fiber Orientation.

    Science.gov (United States)

    Choi, Jeong-Il; Lee, Bang Yeon

    2015-09-30

    The basalt fiber is a promising reinforcing fiber because it has a relatively higher tensile strength and a density similar to that of a concrete matrix as well as no corrosion possibility. This study investigated experimentally the bonding properties of basalt fiber with cementitious material as well as the effect of fiber orientation on the tensile strength of basalt fiber for evaluating basalt fiber's suitability as a reinforcing fiber. Single fiber pullout tests were performed and then the tensile strength of fiber was measured according to fiber orientation. The test results showed that basalt fiber has a strong chemical bond with the cementitious matrix, 1.88 times higher than that of polyvinyl alcohol fibers with it. However, other properties of basalt fiber such as slip-hardening coefficient and strength reduction coefficient were worse than PVA and polyethylene fibers in terms of fiber bridging capacity. Theoretical fiber-bridging curves showed that the basalt fiber reinforcing system has a higher cracking strength than the PVA fiber reinforcing system, but the reinforcing system showed softening behavior after cracking.

  7. Toward a compact fibered squeezing parametric source.

    Science.gov (United States)

    Brieussel, Alexandre; Ott, Konstantin; Joos, Maxime; Treps, Nicolas; Fabre, Claude

    2018-03-15

    In this work, we investigate three different compact fibered systems generating vacuum squeezing that involve optical cavities limited by the end surface of a fiber and by a curved mirror and containing a thin parametric crystal. These systems have the advantage to couple squeezed states directly to a fiber, allowing the user to benefit from the flexibility of fibers in the use of squeezing. Three types of fibers are investigated: standard single-mode fibers, photonic-crystal large-mode-area single-mode fibers, and short multimode fibers taped to a single-mode fiber. The observed squeezing is modest (-0.56  dB, -0.9  dB, -1  dB), but these experiments open the way for miniaturized squeezing devices that could be a very interesting advantage in scaling up quantum systems for quantum processing, opening new perspectives in the domain of integrated quantum optics.

  8. Fiber optic fire detection technology

    International Nuclear Information System (INIS)

    Hering, D.W.

    1990-01-01

    Electrostatic application of paint was, and still is, the most technically feasible method of reducing VOC (volatile organic compounds) emissions, while reducing the cost to apply the coatings. Prior to the use of electrostatics, only two sides of the traditional fire triangle were normally present in the booth, fuel (solvent), and oxygen (air). Now the third leg (the ignition source) was present at virtually all times during the production operation in the form of the electrostatic charge and the resulting energy in the system. The introduction of fiber optics into the field of fire detection was for specific application to the electrostatic painting industry, but specifically, robots used in the application of electrostatic painting in the automotive industry. The use of fiber optics in this hazard provided detection for locations that have been previously prohibited or inaccessible with the traditional fire detection systems. The fiber optic technology that has been adapted to the field of fire detection operates on the principle of transmission of photons through a light guide (optic fiber). When the light guide is subjected to heat, the cladding on the light guide melts away from the core and allows the light (photons) to escape. The controller, which contains the emitter and receiver is set-up to distinguish between partial loss of light and a total loss of light. Glass optical fibers carrying light offer distinct advantages over wires or coaxial cables carrying electricity as a transmission media. The uses of fiber optic detection will be expanded in the near future into such areas as aircraft, cable trays and long conveyor runs because fiber optics can carry more information and deliver it with greater clarity over longer distances with total immunity to all kinds of electrical interference

  9. Fiber-Optic Vibration Sensor Based on Multimode Fiber

    Directory of Open Access Journals (Sweden)

    I. Lujo

    2008-06-01

    Full Text Available The purpose of this paper is to present a fiberoptic vibration sensor based on the monitoring of the mode distribution in a multimode optical fiber. Detection of vibrations and their parameters is possible through observation of the output speckle pattern from the multimode optical fiber. A working experimental model has been built in which all used components are widely available and cheap: a CCD camera (a simple web-cam, a multimode laser in visible range as a light source, a length of multimode optical fiber, and a computer for signal processing. Measurements have shown good agreement with the actual frequency of vibrations, and promising results were achieved with the amplitude measurements although they require some adaptation of the experimental model. Proposed sensor is cheap and lightweight and therefore presents an interesting alternative for monitoring large smart structures.

  10. Preliminary characterization of glass fiber sizing

    DEFF Research Database (Denmark)

    Petersen, Helga Nørgaard; Kusano, Yukihiro; Brøndsted, Povl

    2013-01-01

    Glass fiber surfaces are treated with sizing during manufacturing. Sizing consists of several components, including a film former and a silane coupling agent that is important for adhesion between glass fibers and a matrix. Although the sizing highly affects the composite interface and thus...... the strength of the composites, little is known about the structure and chemistry of the sizing. A part of sizing was extracted by soxhlet extraction. The fibers were subsequently burned and some fibers were merely burned for analysis of glass fiber and sizing. The results showed that the analyzed fibers had...

  11. Generation of non-overlapping fiber architecture

    DEFF Research Database (Denmark)

    Chapelle, Lucie; Lévesque, M.; Brøndsted, Povl

    2015-01-01

    and polymer networks. The model takes into account the complex geometry of the fiber arrangement in which a fiber can be modeled with a certain degree of bending while keeping a main fiber orientation. The model is built in two steps. First, fibers are generated as a chain of overlapping spheres or as a chain......: a repulsion force to suppress the overlap between two fibers and a bending and stretching force to ensure that the fiber structure is kept unchanged. The model can be used as the geometrical basis for further finite-element modelling....

  12. Carbon nanotube fiber spun from wetted ribbon

    Science.gov (United States)

    Zhu, Yuntian T; Arendt, Paul; Zhang, Xiefei; Li, Qingwen; Fu, Lei; Zheng, Lianxi

    2014-04-29

    A fiber of carbon nanotubes was prepared by a wet-spinning method involving drawing carbon nanotubes away from a substantially aligned, supported array of carbon nanotubes to form a ribbon, wetting the ribbon with a liquid, and spinning a fiber from the wetted ribbon. The liquid can be a polymer solution and after forming the fiber, the polymer can be cured. The resulting fiber has a higher tensile strength and higher conductivity compared to dry-spun fibers and to wet-spun fibers prepared by other methods.

  13. Simulation of Compressive Failure in Fiber Composites

    DEFF Research Database (Denmark)

    Veluri, Badrinath; Jensen, Henrik Myhre

    Kinkband formation is a non-linear phenomenon involving interacting effects of non-linear material behavior of the matrix materials and fiber buckling including fiber misalignment in fiber composites under compressive loading. Taking into account the non-linearties of the constituents a constitut......Kinkband formation is a non-linear phenomenon involving interacting effects of non-linear material behavior of the matrix materials and fiber buckling including fiber misalignment in fiber composites under compressive loading. Taking into account the non-linearties of the constituents...

  14. Photonic Crystal Fibers for Sensing Applications

    Directory of Open Access Journals (Sweden)

    Ana M. R. Pinto

    2012-01-01

    Full Text Available Photonic crystal fibers are a kind of fiber optics that present a diversity of new and improved features beyond what conventional optical fibers can offer. Due to their unique geometric structure, photonic crystal fibers present special properties and capabilities that lead to an outstanding potential for sensing applications. A review of photonic crystal fiber sensors is presented. Two different groups of sensors are detailed separately: physical and biochemical sensors, based on the sensor measured parameter. Several sensors have been reported until the date, and more are expected to be developed due to the remarkable characteristics such fibers can offer.

  15. Fiber optic evanescent wave biosensor

    Science.gov (United States)

    Duveneck, Gert L.; Ehrat, Markus; Widmer, H. M.

    1991-09-01

    The role of modern analytical chemistry is not restricted to quality control and environmental surveillance, but has been extended to process control using on-line analytical techniques. Besides industrial applications, highly specific, ultra-sensitive biochemical analysis becomes increasingly important as a diagnostic tool, both in central clinical laboratories and in the doctor's office. Fiber optic sensor technology can fulfill many of the requirements for both types of applications. As an example, the experimental arrangement of a fiber optic sensor for biochemical affinity assays is presented. The evanescent electromagnetic field, associated with a light ray guided in an optical fiber, is used for the excitation of luminescence labels attached to the biomolecules in solution to be analyzed. Due to the small penetration depth of the evanescent field into the medium, the generation of luminescence is restricted to the close proximity of the fiber, where, e.g., the luminescent analyte molecules combine with their affinity partners, which are immobilized on the fiber. Both cw- and pulsed light excitation can be used in evanescent wave sensor technology, enabling the on-line observation of an affinity assay on a macroscopic time scale (seconds and minutes), as well as on a microscopic, molecular time scale (nanoseconds or microseconds).

  16. Advanced ultrafast fiber laser sources enabled by fiber nonlinearities

    International Nuclear Information System (INIS)

    Liu, Wei

    2017-05-01

    Development of high power/energy ultrafast fiber lasers for scientific research and industrial applications is one of the most exciting fields in ultrafast optics. This thesis demonstrated new means to improve two essential properties - which are indispensable for novel applications such as high-harmonic generation (HHG) and multiphoton microscopy (MPM) - of an ultrafast fiber laser system: energy scaling capability and wavelength tunability. High photon-flux extreme ultraviolet sources enabled by HHG desire high power (>100 W), high repetition-rate (>1 MHz) ultrafast driving laser sources. We have constructed from scratch a high-power Yb-fiber laser system using the well-known chirped-pulse amplification (CPA) technique. Such a CPA system capable of producing ∝200-W average power consists of a monolithic Yb-fiber oscillator, an all-fiber stretcher, a pre-amplifier chain, a main amplifier constructed from rode-type large pitch fiber, and a diffraction-grating based compressor. To increase the HHG efficiency, ultrafast pulses with duration 130-W average power. The amplified pulses are compressed to 60-fs pulses with 100-W average power, constituting a suitable HHG driving source. MPM is a powerful biomedical imaging tool, featuring larger penetration depth while providing the capability of optical sectioning. Although femtosecond solid-state lasers have been widely accepted as the standard option as MPM driving sources, fiber-based sources have received growing research efforts due to their superior performance. In the second part of this thesis, we both theoretically and experimentally demonstrated a new method of producing wavelength widely tunable femtosecond pulses for driving MPM. We employed self-phase modulation to broaden a narrowband spectrum followed by bandpass filters to select the rightmost/leftmost spectral lobes. Widely tunable in 820-1225 nm, the resulting sources generated nearly transform-limited, ∝100 fs pulses. Using short fibers with large

  17. Modal noise impact in radio over fiber multimode fiber links.

    Science.gov (United States)

    Gasulla, I; Capmany, J

    2008-01-07

    A novel analysis is given on the statistics of modal noise for a graded-index multimode fiber (MMF) link excited by an analog intensity modulated laser diode. We present the speckle contrast as a function of the power spectrum of the modulated source and the transfer function of the MMF which behaves as an imperfect transversal microwave photonic filter. The theoretical results confirm that the modal noise is directly connected with the coherence properties of the optical source and show that the performance of high-frequency Radio Over Fiber (ROF) transmission through MMF links for short and middle reach distances is not substantially degraded by modal noise.

  18. Bonding Properties of Basalt Fiber and Strength Reduction According to Fiber Orientation

    Directory of Open Access Journals (Sweden)

    Jeong-Il Choi

    2015-09-01

    Full Text Available The basalt fiber is a promising reinforcing fiber because it has a relatively higher tensile strength and a density similar to that of a concrete matrix as well as no corrosion possibility. This study investigated experimentally the bonding properties of basalt fiber with cementitious material as well as the effect of fiber orientation on the tensile strength of basalt fiber for evaluating basalt fiber’s suitability as a reinforcing fiber. Single fiber pullout tests were performed and then the tensile strength of fiber was measured according to fiber orientation. The test results showed that basalt fiber has a strong chemical bond with the cementitious matrix, 1.88 times higher than that of polyvinyl alcohol fibers with it. However, other properties of basalt fiber such as slip-hardening coefficient and strength reduction coefficient were worse than PVA and polyethylene fibers in terms of fiber bridging capacity. Theoretical fiber-bridging curves showed that the basalt fiber reinforcing system has a higher cracking strength than the PVA fiber reinforcing system, but the reinforcing system showed softening behavior after cracking.

  19. Hybrid photonic-crystal fiber

    DEFF Research Database (Denmark)

    Markos, Christos; Travers, John C.; Abdolvand, Amir

    2017-01-01

    This article offers an extensive survey of results obtained using hybrid photonic-crystal fibers (PCFs) which constitute one of the most active research fields in contemporary fiber optics. The ability to integrate novel and functional materials in solid- and hollow-core PCFs through various...... is reviewed from scientific and technological perspectives, focusing on how different fluids, solids, and gases can significantly extend the functionality of PCFs. The first part of this review discusses the efforts to develop tunable linear and nonlinear fiber-optic devices using PCFs infiltrated...... with various liquids, glasses, semiconductors, and metals. The second part concentrates on recent and state-of-the-art advances in the field of gas-filled hollow-core PCFs. Extreme ultrafast gas-based nonlinear optics toward light generation in the extreme wavelength regions of vacuum ultraviolet, pulse...

  20. A helical scintillating fiber hodoscope

    CERN Document Server

    Altmeier, M; Bisplinghoff, J; Bissel, T; Bollmann, R; Busch, M; Büsser, K; Colberg, T; Demiroers, L; Diehl, O; Dohrmann, F; Engelhardt, H P; Eversheim, P D; Felden, O; Gebel, R; Glende, M; Greiff, J; Gross, A; Gross-Hardt, R; Hinterberger, F; Jahn, R; Jeske, M; Jonas, E; Krause, H; Lahr, U; Langkau, R; Lindemann, T; Lindlein, J; Maier, R; Maschuw, R; Mayer-Kuckuck, T; Meinerzhagen, A; Naehle, O; Pfuff, M; Prasuhn, D; Rohdjess, H; Rosendaal, D; Von Rossen, P; Sanz, B; Schirm, N; Schulz-Rojahn, M; Schwarz, V; Scobel, W; Thomas, S; Trelle, H J; Weise, E; Wellinghausen, A; Wiedmann, W; Woller, K; Ziegler, R

    1999-01-01

    A novel scintillating fiber hodoscope in helically cylindric geometry has been developed for detection of low multiplicity events of fast protons and other light charged particles in the internal target experiment EDDA at the Cooler Synchrotron COSY. The hodoscope consists of 640 scintillating fibers (2.5 mm diameter), arranged in four layers surrounding the COSY beam pipe. The fibers are helically wound in opposing directions and read out individually using 16-channel photomultipliers connected to a modified commercial encoding system. The detector covers an angular range of 9 deg. <= THETA<=72 deg. and 0 deg. <=phi (cursive,open) Greek<=360 deg. in the lab frame. The detector length is 590 mm, the inner diameter 161 mm. Geometry and granularity of the hodoscope afford a position resolution of about 1.3 mm. The detector design took into consideration a maximum of reliability and a minimum of maintenance. An LED array may be used for monitoring purposes. (author)

  1. Diffraction by disordered polycrystalline fibers

    International Nuclear Information System (INIS)

    Stroud, W.J.; Millane, R.P.

    1995-01-01

    X-ray diffraction patterns from some polycrystalline fibers show that the constituent microcrystallites are disordered. The relationship between the crystal structure and the diffracted intensities is then quite complicated and depends on the precise kind and degree of disorder present. The effects of disorder on diffracted intensities must be included in structure determinations using diffraction data from such specimens. Theory and algorithms are developed here that allow the full diffraction pattern to be calculated for a disordered polycrystalline fiber made up of helical molecules. The model accommodates various kinds of disorder and includes the effects of finite crystallite size and cylindrical averaging of the diffracted intensities from a fiber. Simulations using these methods show how different kinds, or components, of disorder produce particular diffraction effects. General properties of disordered arrays of helical molecules and their effects on diffraction patterns are described. Implications for structure determination are discussed. (orig.)

  2. Optical Fiber Grating based Sensors

    DEFF Research Database (Denmark)

    Michelsen, Susanne

    2003-01-01

    In this thesis differenct optical fiber gratings are used for sensor purposes. If a fiber with a core concentricity error (CCE) is used, a directional dependent bend sensor can be produced. The CCE direction can be determined by means of diffraction. This makes it possible to produce long......-period gratings in a fiber with a CCE direction parallel or perpendicular to the writing direction. The maximal bending sensitivity is independent on the writing direction, but the detailed bending response is different in the two cases. A temperature and strain sensor, based on a long-period grating and two...... sampled gratings, was produced and investigated. It is based on the different temperature and strain response of these gratings. Both a transfer matrix method and an overlap calculation is performed to explain the sensor response. Another type of sensor is based on tuning and modulation of a laser...

  3. Fiber tests on a radiotelescope.

    Science.gov (United States)

    Connes, P.; Reynaud, F.

    In order to demonstrate use of fibers in a future radio-dish-mounted interferometric array or optical telescopes, two 100-m SM fibers were installed on the Nançay radiotelescope, used in a serendipitous mode. They formed the two arms of a Mach-Zehnder interferometer, illuminated by a 6328 Å laser. Thermal and interferometric servo-control were simultaneously applied. Even under severe conditions, path difference was maintained stable to within a few Å.This is considerably better than needed for any ground-based application, and still more than adequate for a roughly-similar proposed space-borne device. Some more fiber problems remain to be solved.

  4. Optical fiber meta-tips

    Science.gov (United States)

    Principe, Maria; Micco, Alberto; Crescitelli, Alessio; Castaldi, Giuseppe; Consales, Marco; Esposito, Emanuela; La Ferrara, Vera; Galdi, Vincenzo; Cusano, Andrea

    2016-04-01

    We report on the first example of a "meta-tip" configuration that integrates a metasurface on the tip of an optical fiber. Our proposed design is based on an inverted-Babinet plasmonic metasurface obtained by patterning (via focused ion beam) a thin gold film deposited on the tip of an optical fiber, so as to realize an array of rectangular aperture nanoantennas with spatially modulated sizes. By properly tuning the resonances of the aperture nanoantennas, abrupt variations can be impressed in the field wavefront and polarization. We fabricated and characterized several proof-of-principle prototypes operating an near-infrared wavelengths, and implementing the beam-steering (with various angles) of the cross-polarized component, as well as the excitation of surface waves. Our results pave the way to the integration of the exceptional field-manipulation capabilities enabled by metasurfaces with the versatility and ubiquity of fiber-optics technological platforms.

  5. Comparison of fiber lasers based on distributed side-coupled cladding-pumped fibers and double-cladding fibers.

    Science.gov (United States)

    Huang, Zhihe; Cao, Jianqiu; Guo, Shaofeng; Chen, Jinbao; Xu, Xiaojun

    2014-04-01

    We compare both analytically and numerically the distributed side-coupled cladding-pumped (DSCCP) fiber lasers and double cladding fiber (DCF) lasers. We show that, through optimization of the coupling and absorbing coefficients, the optical-to-optical efficiency of DSCCP fiber lasers can be made as high as that of DCF lasers. At the same time, DSCCP fiber lasers are better than the DCF lasers in terms of thermal management.

  6. Study on Mechanical Properties of Hybrid Fiber Reinforced Concrete

    Science.gov (United States)

    He, Dongqing; Wu, Min; Jie, Pengyu

    2017-12-01

    Several common high elastic modulus fibers (steel fibers, basalt fibers, polyvinyl alcohol fibers) and low elastic modulus fibers (polypropylene fiber) are incorporated into the concrete, and its cube compressive strength, splitting tensile strength and flexural strength are studied. The test result and analysis demonstrate that single fiber and hybrid fiber will improve the integrity of the concrete at failure. The mechanical properties of hybrid steel fiber-polypropylene fiber reinforced concrete are excellent, and the cube compressive strength, splitting tensile strength and flexural strength respectively increase than plain concrete by 6.4%, 3.7%, 11.4%. Doped single basalt fiber or polypropylene fiber and basalt fibers hybrid has little effect on the mechanical properties of concrete. Polyvinyl alcohol fiber and polypropylene fiber hybrid exhibit ‘negative confounding effect’ on concrete, its splitting tensile and flexural strength respectively are reduced by 17.8% and 12.9% than the single-doped polyvinyl alcohol fiber concrete.

  7. Fiber optics principles and practices

    CERN Document Server

    Al-Azzawi, Abdul

    2007-01-01

    Since the invention of the laser, our fascination with the photon has led to one of the most dynamic and rapidly growing fields of technology. New advances in fiber optic devices, components, and materials make it more important than ever to stay current. Comprising chapters drawn from the author's highly anticipated book Photonics: Principles and Practices, Fiber Optics: Principles and Practices offers a detailed and focused treatment for anyone in need of authoritative information on this critical area underlying photonics.Using a consistent approach, the author leads you step-by-step throug

  8. Hollow fiber liquid supported membranes

    International Nuclear Information System (INIS)

    Violante, V.

    1987-01-01

    The hollow fiber system are well known and developed in the scientific literature because of their applicability in the process separation units. The authors approach to a mathematical model for a particular hollow fiber system, usin liquid membranes. The model has been developed in order to obtain a suitable tool for a sensitivy analysis and for a scaling-up. This kind of investigation is very usefull from an engineering point of view, to get a spread range of information to build up a pilot plant from the laboratory scale

  9. Ring mirror fiber laser gyroscope

    Science.gov (United States)

    Shalaby, Mohamed Y.; Khalil, Kamal; Afifi, Abdelrahman E.; Khalil, Diaa

    2017-02-01

    In this work we present a new architecture for a laser gyroscope based on the use of a Sagnac fiber loop mirror. The proposed system has the unique property that its scale factor can be increased by increasing the gain of the optical amplifier used in the system as demonstrated experimentally using standard single mode fiber and explained physically by the system operation. The proposed gyroscope system is also capable of identifying the direction of rotation. This new structure opens the door for a new category of low cost optical gyroscopes.

  10. Electrically controlled liquid crystal fiber

    Science.gov (United States)

    Corella-Madueño, A.; Reyes, J. Adrián

    2006-08-01

    We consider a cylindrical fiber whose core is a liquid crystal (LC) subject to the action of a low frequency field applied parallel to the axis of the cylinder and having initially the escaped configuration. We find the distorted textures of the nematic inside the cylinder by assuming arbitrary anchoring boundary conditions. In the optical limit we calculate the ray trajectories followed by a low intensity beam along the fiber parametrized by a low frequency electric field. Finally, we calculate exactly the spatial dependence of the transverse magnetic modes distribution in the guide, on the electric field, by using a numerical scheme. We summarize our paper and discuss our results.

  11. Coupling to photonic crystal fibers

    DEFF Research Database (Denmark)

    Hougaard, Kristian G.; Bjarklev, Anders Overgaard; Knudsen, Erik

    2002-01-01

    In this work we have analyzed the correspondence between the fundamental mode of PCFs and Gaussian modes as a function of frequency, pitch, and air hole size. Such analysis provides insight into design space regions of PCFs, where low-loss coupling to standard fibers may be obtained.......In this work we have analyzed the correspondence between the fundamental mode of PCFs and Gaussian modes as a function of frequency, pitch, and air hole size. Such analysis provides insight into design space regions of PCFs, where low-loss coupling to standard fibers may be obtained....

  12. Polarization-preserving holey fibers

    DEFF Research Database (Denmark)

    Broeng, Jes; Mogilevtsev, Dmitri; Libori, Stig E. Barkou

    2001-01-01

    In this work we suggest and discuss a microstructure of air capillaries with elliptical cross-section in a tread of glass that gives opportunity for Creation of polarization-preserving fiber with very small beat length between the fundamental modes of different polarization......In this work we suggest and discuss a microstructure of air capillaries with elliptical cross-section in a tread of glass that gives opportunity for Creation of polarization-preserving fiber with very small beat length between the fundamental modes of different polarization...

  13. Mechanochromic Fibers with Structural Color.

    Science.gov (United States)

    Li, Houpu; Sun, Xuemei; Peng, Huisheng

    2015-12-21

    Responsive photonic crystals have been widely developed to realize tunable structural colors by manipulating the flow of light. Among them, mechanochromic photonic crystals attract increasing attention due to the easy operation, high safety and broad applications. Recently, mechanochromic photonic crystal fibers were proposed to satisfy the booming wearable smart textile market. In this Concept, the fundamental mechanism, fabrication, and recent progress on mechanochromic photonic crystals, especially in fiber shape, are summarized to represent a new direction in sensing and displaying. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Lab-on-fiber technology

    CERN Document Server

    Cusano, Andrea; Crescitelli, Alessio; Ricciardi, Armando

    2014-01-01

    This book focuses on a research field that is rapidly emerging as one of the most promising ones for the global optics and photonics community: the "lab-on-fiber" technology. Inspired by the well-established 'lab on-a-chip' concept, this new technology essentially envisages novel and highly functionalized devices completely integrated into a single optical fiber for both communication and sensing applications.Based on the R&D experience of some of the world's leading authorities in the fields of optics, photonics, nanotechnology, and material science, this book provides a broad and accurate de

  15. Photonics and Fiber Optics Processor Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The Photonics and Fiber Optics Processor Lab develops, tests and evaluates high speed fiber optic network components as well as network protocols. In addition, this...

  16. Compression Behavior of High Performance Polymeric Fibers

    National Research Council Canada - National Science Library

    Kumar, Satish

    2003-01-01

    Hydrogen bonding has proven to be effective in improving the compressive strength of rigid-rod polymeric fibers without resulting in a decrease in tensile strength while covalent crosslinking results in brittle fibers...

  17. Fiber MOPA for Ascends, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — CO2 sensing using absorption bands near 1570nm is very attractive by taking advantage of the mature fiber-amplifier technology derived from fiber-optic telecom...

  18. TENSILE RESPONSES OF TREATED CISSUS POPULNEA FIBERS

    African Journals Online (AJOL)

    HOD

    2 DEPARTMENT OF CHEMICAL ENGINEERING, NNAMDI AZIKIWE ... (RSM) with central composite design. ... synthetic fibers for industrial applications partly ..... Cellulosic Fibers Using Eco-Friendly Compounds .... 1078 – 1097, 2017.

  19. Oriented collagen fibers direct tumor cell intravasation

    KAUST Repository

    Han, Weijing; Chen, Shaohua; Yuan, Wei; Fan, Qihui; Tian, Jianxiang; Wang, Xiaochen; Chen, Longqing; Zhang, Xixiang; Wei, Weili; Liu, Ruchuan; Qu, Junle; Jiao, Yang; Austin, Robert H.; Liu, Liyu

    2016-01-01

    that the local fiber alignment enhanced cell-ECM interactions. Specifically, metastatic MDA-MB-231 breast cancer cells followed the local fiber alignment direction during the intravasation into rigid Matrigel (∼10 mg/mL protein concentration).

  20. Dynamics of long ring Raman fiber laser

    Science.gov (United States)

    Sukhanov, Sergey V.; Melnikov, Leonid A.; Mazhirina, Yulia A.

    2016-04-01

    The numerical model for dynamics of long fiber ring Raman laser is proposed. The model is based on the transport equations and Courant-Isaacson-Rees numerical method. Different regimes of a long ring fiber Raman laser are investigated.

  1. Fiber Optic Augmented Reality System (FOARS)

    Data.gov (United States)

    National Aeronautics and Space Administration — Innovation: Fiber Optics Augmented Reality System. This system in form of a mobile app interacts real time with the actual FOSS(Fiber Optics Sensing System) data and...

  2. Fiber MOPA for Ascends, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — CO2 sensing using absorption bands near 1570nm is very attractive by taking advantage of the mature fiber-amplifier technology derived from fiber-optic telecom...

  3. IMPROVED SPECTROPHOTOMETER FIBER SAMPLING SYSTEM FOR COTTON FIBER COLOR MEASUREMENTS

    Science.gov (United States)

    Cotton in the U.S. is classified for color using the Uster® High Volume Instrument (HVI), and the parameters Rd and +b are used to designate color grades for cotton fiber. However, Rd and +b are cotton-specific color parameters, and the need existed to demonstrate the relationships of Rd and +b to...

  4. Fiber facet gratings for high power fiber lasers

    Science.gov (United States)

    Vanek, Martin; Vanis, Jan; Baravets, Yauhen; Todorov, Filip; Ctyroky, Jiri; Honzatko, Pavel

    2017-12-01

    We numerically investigated the properties of diffraction gratings designated for fabrication on the facet of an optical fiber. The gratings are intended to be used in high-power fiber lasers as mirrors either with a low or high reflectivity. The modal reflectance of low reflectivity polarizing grating has a value close to 3% for TE mode while it is significantly suppressed for TM mode. Such a grating can be fabricated on laser output fiber facet. The polarizing grating with high modal reflectance is designed as a leaky-mode resonant diffraction grating. The grating can be etched in a thin layer of high index dielectric which is sputtered on fiber facet. We used refractive index of Ta2O5 for such a layer. We found that modal reflectance can be close to 0.95 for TE polarization and polarization extinction ratio achieves 18 dB. Rigorous coupled wave analysis was used for fast optimization of grating parameters while aperiodic rigorous coupled wave analysis, Fourier modal method and finite difference time domain method were compared and used to compute modal reflectance of designed gratings.

  5. Identifying Practical Solutions to Meet America’s Fiber Needs: Proceedings from the Food & Fiber Summit

    Directory of Open Access Journals (Sweden)

    Amy R. Mobley

    2014-07-01

    Full Text Available Fiber continues to be singled out as a nutrient of public health concern. Adequate intakes of fiber are associated with reduced risk for cardiovascular disease, cancer, diabetes, certain gastrointestinal disorders and obesity. Despite ongoing efforts to promote adequate fiber through increased vegetable, fruit and whole-grain intakes, average fiber consumption has remained flat at approximately half of the recommended daily amounts. Research indicates that consumers report increasingly attempting to add fiber-containing foods, but there is confusion around fiber in whole grains. The persistent and alarmingly low intakes of fiber prompted the “Food & Fiber Summit,” which assembled nutrition researchers, educators and communicators to explore fiber’s role in public health, current fiber consumption trends and consumer awareness data with the objective of generating opportunities and solutions to help close the fiber gap. The summit outcomes highlight the need to address consumer confusion and improve the understanding of sources of fiber, to recognize the benefits of various types of fibers and to influence future dietary guidance to provide prominence and clarity around meeting daily fiber recommendations through a variety of foods and fiber types. Potential opportunities to increase fiber intake were identified, with emphasis on meal occasions and food categories that offer practical solutions for closing the fiber gap.

  6. Identifying Practical Solutions to Meet America’s Fiber Needs: Proceedings from the Food & Fiber Summit

    Science.gov (United States)

    Mobley, Amy R.; Jones, Julie Miller; Rodriguez, Judith; Slavin, Joanne; Zelman, Kathleen M.

    2014-01-01

    Fiber continues to be singled out as a nutrient of public health concern. Adequate intakes of fiber are associated with reduced risk for cardiovascular disease, cancer, diabetes, certain gastrointestinal disorders and obesity. Despite ongoing efforts to promote adequate fiber through increased vegetable, fruit and whole-grain intakes, average fiber consumption has remained flat at approximately half of the recommended daily amounts. Research indicates that consumers report increasingly attempting to add fiber-containing foods, but there is confusion around fiber in whole grains. The persistent and alarmingly low intakes of fiber prompted the “Food & Fiber Summit,” which assembled nutrition researchers, educators and communicators to explore fiber’s role in public health, current fiber consumption trends and consumer awareness data with the objective of generating opportunities and solutions to help close the fiber gap. The summit outcomes highlight the need to address consumer confusion and improve the understanding of sources of fiber, to recognize the benefits of various types of fibers and to influence future dietary guidance to provide prominence and clarity around meeting daily fiber recommendations through a variety of foods and fiber types. Potential opportunities to increase fiber intake were identified, with emphasis on meal occasions and food categories that offer practical solutions for closing the fiber gap. PMID:25006857

  7. Applications of fiber optics in physical protection

    International Nuclear Information System (INIS)

    Buckle, T.H.

    1994-03-01

    The purpose of this NUREG is to provide technical information useful for the development of fiber-optic communications and intrusion detection subsystems relevant to physical protection. There are major sections on fiber-optic technology and applications. Other topics include fiber-optic system components and systems engineering. This document also contains a glossary, a list of standards and specifications, and a list of fiber-optic equipment vendors

  8. Textile composites based on natural fibers

    CSIR Research Space (South Africa)

    Li, Yan

    2009-04-01

    Full Text Available . The two kinds of fiber surface treatment methods were permanganate treatment and silane treatment. Vinyl ester was used as the matrix. The permeability values of sisal textile before and after fiber surface treatments are listed in Table 3. Comparisons... and more liquid resin flow through inter-bundles. Figure 4. Intra-bundle and inter-bundle flows As reported, permanganate, as an oxidant, can etch sisal fiber surface [20]. Scanning electronic micrograph of a permanganate treated sisal fiber...

  9. Pulsed laser damage to optical fibers

    International Nuclear Information System (INIS)

    Allison, S.W.; Gillies, G.T.; Magnuson, D.W.; Pagano, T.S.

    1985-01-01

    This paper describes some observations of pulsed laser damage to optical fibers with emphasis on a damage mode characterized as a linear fracture along the outer core of a fiber. Damage threshold data are presented which illustrate the effects of the focusing lens, end-surface preparation, and type of fiber. An explanation based on fiber-beam misalignment is given and is illustrated by a simple experiment and ray trace

  10. STUDY JARINGAN FIBER-OPTIK dan SONET

    OpenAIRE

    Syarif, Syafruddin; Katu, Umar; Suyuti, Saidah

    2006-01-01

    Optical Fiber communication system is a communication system using fiber optic as a transmission media. This communication system is able to transmit information in high capacity and high fidelity. Fiber optic consist of cylinder glass, the inside part of the cylinder is called core surrounded a cladding. The outside part of this cylinder made by elastic plastic called coating. ?? Based on the bias index and the waves mode in light propagation, optic fiber can be elassified into...

  11. Adsorption characteristics of activated carbon hollow fibers

    Directory of Open Access Journals (Sweden)

    B. V. Kaludjerović

    2009-01-01

    Full Text Available Carbon hollow fibers were prepared with regenerated cellulose or polysulfone hollow fibers by chemical activation using sodium phosphate dibasic followed by the carbonization process. The activation process increases the adsorption properties of fibers which is more prominent for active carbone fibers obtained from the cellulose precursor. Chemical activation with sodium phosphate dibasic produces an active carbon material with both mesopores and micropores.

  12. Multi-core fiber undersea transmission systems

    DEFF Research Database (Denmark)

    Nooruzzaman, Md; Morioka, Toshio

    2017-01-01

    Various potential architectures of branching units for multi-core fiber undersea transmission systems are presented. It is also investigated how different architectures of branching unit influence the number of fibers and those of inline components.......Various potential architectures of branching units for multi-core fiber undersea transmission systems are presented. It is also investigated how different architectures of branching unit influence the number of fibers and those of inline components....

  13. High pressure fiber optic sensor system

    Science.gov (United States)

    Guida, Renato; Xia, Hua; Lee, Boon K; Dekate, Sachin N

    2013-11-26

    The present application provides a fiber optic sensor system. The fiber optic sensor system may include a small diameter bellows, a large diameter bellows, and a fiber optic pressure sensor attached to the small diameter bellows. Contraction of the large diameter bellows under an applied pressure may cause the small diameter bellows to expand such that the fiber optic pressure sensor may measure the applied pressure.

  14. Catching Attention in Fiber Optics Class

    OpenAIRE

    Kezerashvili, R. Ya.; Leng, L.

    2004-01-01

    Following a brief review on the history and the current development of fiber optics, the significance of teaching fiber optics for science and non-science major college students is addressed. Several experimental demonstrations designed to aid the teaching and learning process in fiber optics lectures are presented. Sample laboratory projects are also proposed to help the students to understand the physical principles of fiber optics.

  15. Using Vulcan to Recreate Planetary Cores

    CERN Document Server

    Collins, G W; Benedetti, L R; Benuzzi-Mounaix, A; Cauble, R; Celliers, P M; Danson, C; Da Silva, L B; Gessner, H; Henry, E; Hicks, D G; Huser, G; Jeanloz, R; Koening, M; Lee, K M; Mackinnon, A J; Moon, S J; Neely, D; Notley, M; Pasley, J; Willi, O

    2001-01-01

    An accurate equation of state (EOS) for planetary constituents at extreme conditions is the key to any credible model of planets or low mass stars. However, experimental validation has been carried out on at high pressure (>few Mbar), and then only on the principal Hugoniot. For planetary and stellar interiors, compression occurs from gravitational force so that material states follow a line of isentropic compression (ignoring phase separation) to ultra-high densities. An example of the predicted states for water along the isentrope for Neptune is shown in a figure. The cutaway figure on the left is from Hubbard, and the phase diagram on the right is from Cavazzoni et al. Clearly these states lie at quite a bit lower temperature and higher density than single shock Hugoniot states but they are at higher temperature than can be achieved with accurate diamond anvil experiments. At extreme densities, material states are predicted to have quite unearthly properties such as high temperature superconductivity and l...

  16. Photonic crystal fiber technology for compact fiber-delivered high-power ultrafast fiber lasers

    Science.gov (United States)

    Triches, Marco; Michieletto, Mattia; Johansen, Mette M.; Jakobsen, Christian; Olesen, Anders S.; Papior, Sidsel R.; Kristensen, Torben; Bondue, Magalie; Weirich, Johannes; Alkeskjold, Thomas T.

    2018-02-01

    Photonic crystal fiber (PCF) technology has radically impacted the scientific and industrial ultrafast laser market. Reducing platform dimensions are important to decrease cost and footprint while maintaining high optical efficiency. We present our recent work on short 85 μm core ROD-type fiber amplifiers that maintain single-mode performance and excellent beam quality. Robust long-term performance at 100 W average power and 250 kW peak power in 20 ps pulses at 1030 nm wavelength is presented, exceeding 500 h with stable performance in terms of both polarization and power. In addition, we present our recent results on hollow-core ultrafast fiber delivery maintaining high beam quality and polarization purity.

  17. Random fiber lasers based on artificially controlled backscattering fibers

    Science.gov (United States)

    Chen, Daru; Wang, Xiaoliang; She, Lijuan; Qiang, Zexuan; Yu, Zhangwei

    2017-10-01

    The random fiber laser (RFL) which is a milestone in laser physics and nonlinear optics, has attracted considerable attention recently. Most previous RFLs are based on distributed feedback of Rayleigh scattering amplified through stimulated Raman/Brillouin scattering effect in single mode fibers, which required long-distance (tens of kilometers) single mode fibers and high threshold up to watt-level due to the extremely small Rayleigh scattering coefficient of the fiber. We proposed and demonstrated a half-open cavity RFL based on a segment of a artificially controlled backscattering SMF(ACB-SMF) with a length of 210m, 310m or 390m. A fiber Bragg grating with the central wavelength of 1530nm and a segment of ACB-SMF forms the half-open cavity. The proposed RFL achieves the threshold of 25mW, 30mW and 30mW, respectively. Random lasing at the wavelength of 1530nm and the extinction ratio of 50dB is achieved when a segment of 5m EDF is pumped by a 980nm LD in the RFL. Another half-open cavity RFL based on a segment of a artificially controlled backscattering EDF(ACBS-EDF) is also demonstrated without an ACB-SMF. The 3m ACB-EDF is fabricated by using the femtosecond laser with pulse energy of 0.34mJ which introduces about 50 reflectors in the EDF. Random lasing at the wavelength of 1530nm is achieved with the output power of 7.5mW and the efficiency of 1.88%. Two novel RFLs with much short cavities have been achieved with low threshold and high efficiency.

  18. High force measurement sensitivity with fiber Bragg gratings fabricated in uniform-waist fiber tapers

    International Nuclear Information System (INIS)

    Wieduwilt, Torsten; Brückner, Sven; Bartelt, Hartmut

    2011-01-01

    Fiber Bragg gratings inscribed in the waist of tapered photosensitive fibers offer specific attractive properties for sensing applications. A small-diameter fiber reduces structural influences for imbedded fiber sensing elements. In the case of application as a force-sensing element for tensile forces, sensitivity scales inversely with the fiber cross-sectional area. It is therefore possible to increase force sensitivity by several orders of magnitude compared to Bragg grating sensors in conventionally sized fibers. Special requirements for such Bragg grating arrangements are discussed and experimental measurements for different fiber taper diameters down to 4 µm are presented

  19. Dynamic Characterization of Polymer Optical Fibers

    DEFF Research Database (Denmark)

    Stefani, Alessio; Andresen, Søren; Yuan, Wu

    2012-01-01

    With the increasing interest in fiber sensors based on polymer optical fibers, it becomes fundamental to determine the real applicability and reliability of this type of sensor. The viscoelastic nature of polymers gives rise to questions about the mechanical behavior of the fibers. In particular...

  20. Blood glucose response to pea fiber

    DEFF Research Database (Denmark)

    Hamberg, O; Rumessen, J J; Gudmand-Høyer, E

    1989-01-01

    Two new fiber types, pea fiber (PF) and sugar beet fiber (BF), were compared with wheat bran (WB) to investigate the effect on postprandial blood glucose and serum insulin responses in normal subjects. The control meal consisted of 150 g ground beef mixed with 50 g glucose and 20 g lactulose. Onl...

  1. Study of fiber optic sugar sensor

    Indian Academy of Sciences (India)

    is connected. By varying the concentration of sugar solution, the output power is noted. ... and Lin [3] and Ghatak et al [4] have studied the use of optical fibers as sensing elements. ... at the interface, an evanescent wave propagates parallel to the interface. .... the ends of the fiber are fixed with fiber holders on either side.

  2. Career Directions--Fiber Optic Installer

    Science.gov (United States)

    Tech Directions, 2012

    2012-01-01

    Fiber-optic communication is a method of transmitting information from one place to another by sending pulses of light through an optical fiber that is roughly the diameter of a human hair. The light forms an electromagnetic carrier wave that is modulated to carry information. Each optical fiber is capable of carrying an enormous amount of…

  3. Low Cost Carbon Fiber From Renewable Resources

    International Nuclear Information System (INIS)

    Compere, A.L.

    2001-01-01

    The Department of Energy Partnership for a New Generation of Vehicles has shown that, by lowering overall weight, the use of carbon fiber composites could dramatically decrease domestic vehicle fuel consumption. For the automotive industry to benefit from carbon fiber technology, fiber production will need to be substantially increased and fiber price decreased to$7/kg. To achieve this cost objective, alternate precursors to pitch and polyacrylonitrile (PAN) are being investigated as possible carbon fiber feedstocks. Additionally, sufficient fiber to provide 10 to 100 kg for each of the 13 million cars and light trucks produced annually in the U.S. will require an increase of 5 to 50-fold in worldwide carbon fiber production. High-volume, renewable or recycled materials, including lignin, cellulosic fibers, routinely recycled petrochemical fibers, and blends of these components, appear attractive because the cost of these materials is inherently both low and insensitive to changes in petroleum price. Current studies have shown that a number of recycled and renewable polymers can be incorporated into melt-spun fibers attractive as carbon fiber feedstocks. Highly extrudable lignin blends have attractive yields and can be readily carbonized and graphitized. Examination of the physical structure and properties of carbonized and graphitized fibers indicates the feasibility of use in transportation composite applications

  4. Functional Nano fibers: Production and Applications

    International Nuclear Information System (INIS)

    Khatri, Z.; Kim, I.S.; Kim, S.H.

    2016-01-01

    Nano fibers are lighter material with higher surface area in comparison to polymeric film. The ease of producing functional nano fiber is another advantage over many nano materials. Functional nano fiber in particular has attained a greater interest in recent years. The applications of functional nano fibers are increasing in various technical fields such as water filter membranes, tissue engineering, biosensors, drug delivery systems, wound dressings, catalysis, antibacterial. This special issue is comprised of well-selective articles that discuss production of functional nano fibers their applications in different emerging fields. M. Zhang et al. have presented exciting work on drug delivery using nano fibers. They used collagen that was extracted from abandoned Rana chensinensis skin in northeastern China via an acid enzymatic extraction method. They demonstrated two different nano fiber-vancomycin (VCM) systems, that is, VCM blended nano fibers and core-shell nano fibers with VCM in the core, and both systems sustained control release for a period of 80 hours. Another work was presented by R. Takai et al. on blood purification using composite nano fibers. About 10% of the population worldwide is affected by chronic kidney disease (CKD). The authors developed nano fiber meshes zeolite-polymer composite nano fibers for efficient adsorption of creatinine, which is a simpler and more accessible method for hemodialysis (HD) patients.

  5. Overview of Fiber-Optical Sensors

    Science.gov (United States)

    Depaula, Ramon P.; Moore, Emery L.

    1987-01-01

    Design, development, and sensitivity of sensors using fiber optics reviewed. State-of-the-art and probable future developments of sensors using fiber optics described in report including references to work in field. Serves to update previously published surveys. Systems incorporating fiber-optic sensors used in medical diagnosis, navigation, robotics, sonar, power industry, and industrial controls.

  6. Cartan frames for heart wall fiber motion

    NARCIS (Netherlands)

    Samari, Babak; Aumentado-Armstrong, Tristan; Strijkers, Gustav J.; Froeling, Martijn; Siddiqi, Kaleem

    2017-01-01

    Current understanding of heart wall fiber geometry is based on ex vivo static data obtained through diffusion imaging or histology. Thus, little is known about the manner in which fibers rotate as the heart beats. Yet, the geometric organization of moving fibers in the heart wall is key to its

  7. Multifunctional Next Generation Carbon Nanotube Super Fibers

    National Research Council Canada - National Science Library

    Ait-Haddou, Hassan

    2005-01-01

    The goal of this program was to produce continuous strong CNT-based fibers. The production of continuous fibers was met and we have matched 2/3 of the strength of what has been previously reported with CNT-PAN fibers...

  8. Highly Stretchable, Strain Sensing Hydrogel Optical Fibers.

    Science.gov (United States)

    Guo, Jingjing; Liu, Xinyue; Jiang, Nan; Yetisen, Ali K; Yuk, Hyunwoo; Yang, Changxi; Khademhosseini, Ali; Zhao, Xuanhe; Yun, Seok-Hyun

    2016-12-01

    A core-clad fiber made of elastic, tough hydrogels is highly stretchable while guiding light. Fluorescent dyes are easily doped into the hydrogel fiber by diffusion. When stretched, the transmission spectrum of the fiber is altered, enabling the strain to be measured and also its location. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Radiation damage in commercial optical fibers

    International Nuclear Information System (INIS)

    Bertolotti, M.; Franceschini, F.A.; Serra, A.

    1978-01-01

    Experimental results obtained by exposure of commercial optical fibers to 60 Co γ-ray irradiation, are reported. The possibility of utilizing these fibers as far as a total dose of 6000 rad in the light spectrum is shown. It is also shown that it is possible to obtain total recovery of irradiated fibers by annealing at 500 0 C. (author)

  10. Experimental Study of Fiber Length and Orientation in Injection Molded Natural Fiber/Starch Acetate Composites

    DEFF Research Database (Denmark)

    Peltola, Heidi; Madsen, Bo; Joffe, Roberts

    2011-01-01

    Composite compounds based on triethyl citrate plasticized starch acetate and hemp and flax fibers were prepared by melt processing. Plasticizer contents from 20 to 35 wt% and fiber contents of 10 and 40 wt% were used. The compounded composites were injection molded to tensile test specimens...... was noticed. A reduction of fiber length along the increasing fiber content and the decreasing plasticizer content was also detected. This reduction originated from the increasing shear forces during compounding, which again depended on the increased viscosity of the material. Hemp fibers were shown to remain...... longer and fibrillate more than flax fibers, leading to higher aspect ratio. Thus, the reinforcement efficiency of hemp fibers by the processing was improved, in contrast with flax fibers. In addition, the analysis of fiber dispersion and orientation showed a good dispersion of fibers in the matrix...

  11. Influence of fiber upon the radiation degradation of fiber-reinforced plastics

    International Nuclear Information System (INIS)

    Udagawa, Akira

    1992-01-01

    Influences of fiber upon the radiation degradation of fiber-reinforced plastics were investigated by using 2 MeV electrons. Radiation resistances were evaluated from the three-point bending strength of the fiber laminates which used bisphenol A-type epoxy resin as a matrix. Carbon fiber laminates had higher radiation resistance values than the laminates made of glass fiber. Model laminates using polyethylene as a matrix were prepared in order to examine the differences between carbon fiber and glass fiber filler, the relation between gel fraction and absorbed dose was established. When the polyethylene was filled in the carbon fiber, forming the gel was strikingly delayed. This result suggests that radiation protective action existing in carbon fiber to matrix resin is the main cause of the higher radiation resistance of carbon fiber reinforced plastics. (author)

  12. Experimental research on continuous basalt fiber and basalt-fibers-reinforced polymers

    Science.gov (United States)

    Zhang, Xueyi; Zou, Guangping; Shen, Zhiqiang

    2008-11-01

    The interest for continuous basalt fibers and reinforced polymers has recently grown because of its low price and rich natural resource. Basalt fiber was one type of high performance inorganic fibers which were made from natural basalt by the method of melt extraction. This paper discusses basic mechanical properties of basalt fiber. The other work in this paper was to conduct tensile testing of continuous basalt fiber-reinforced polymer rod. Tensile strength and stress-strain curve were obtained in this testing. The strength of rod was fairly equal to rod of E-glass fibers and weaker than rod of carbon fibers. Surface of crack of rod was studied. An investigation of fracture mechanism between matrix and fiber was analyzed by SEM (Scanning electron microscopy) method. A poor adhesion between the matrix and fibers was also shown for composites analyzing SEM photos. The promising tensile properties of the presented basalt fibers composites have shown their great potential as alternative classical composites.

  13. Cylindrical Piezoelectric Fiber Composite Actuators

    Science.gov (United States)

    Allison, Sidney G.; Shams, Qamar A.; Fox, Robert L.

    2008-01-01

    The use of piezoelectric devices has become widespread since Pierre and Jacques Curie discovered the piezoelectric effect in 1880. Examples of current applications of piezoelectric devices include ultrasonic transducers, micro-positioning devices, buzzers, strain sensors, and clocks. The invention of such lightweight, relatively inexpensive piezoceramic-fiber-composite actuators as macro fiber composite (MFC) actuators has made it possible to obtain strains and displacements greater than those that could be generated by prior actuators based on monolithic piezoceramic sheet materials. MFC actuators are flat, flexible actuators designed for bonding to structures to apply or detect strains. Bonding multiple layers of MFC actuators together could increase force capability, but not strain or displacement capability. Cylindrical piezoelectric fiber composite (CPFC) actuators have been invented as alternatives to MFC actuators for applications in which greater forces and/or strains or displacements may be required. In essence, a CPFC actuator is an MFC or other piezoceramic fiber composite actuator fabricated in a cylindrical instead of its conventional flat shape. Cylindrical is used here in the general sense, encompassing shapes that can have circular, elliptical, rectangular or other cross-sectional shapes in the planes perpendicular to their longitudinal axes.

  14. Photobleaching effect in image fiber

    International Nuclear Information System (INIS)

    Hayashi, Shotaro; Wada, Yukio; Chigusa, Yoshiki; Fujiwara, Kunio; Hattori, Yasuji.

    1985-01-01

    The photobleaching effect in two types of image fibers is investigated using various light sources, light intensities, radiation dose rates and environmental temperatures. It is shown that the use of a xenon lamp, He-Cd laser or deuterium lamp can cause the photobleaching effect on the induced loss in an image fiber in the ultraviolet region. Of these light sources, a xenon lamp is found to have the greatest effect. This effectiveness appears to arise from the fact that this light source possesses a spectrum over the range from 0.3 to 0.36 μm. It is also revealed that when an image fiber is used for spectroscopic analysis under irradiation of gamma rays at a dose rate of 300 R/h, the available period of the fiber can be increase by 4 - 8 times with the aid of the photobleaching effect caused by a xenon lamp. In addition, the photobleaching effect is found to be dependent on temperature. It is inferred that this temperature dependence occur because electrons first excited to a level by the light energy tend to be further excited more easily at higher temperatures. (Nogami, K.)

  15. Fiber tracking for brain tumor

    International Nuclear Information System (INIS)

    Yamada, Kei; Nakamura, Hisao; Ito, Hirotoshi; Tanaka, Osamu; Kubota, Takao; Yuen, Sachiko; Kizu, Osamu; Nishimura, Tsunehiko

    2003-01-01

    The purpose of this study was to validate an innovative scanning method for patients diagnosed with brain tumors. Using a 1.5 Tesla whole body magnetic resonance (MR) imager, 23 patients with brain tumors were scanned. The recorded data points of the diffusion-tensor imaging (DTI) sequences were 128 x 37 with the parallel imaging technique. The parallel imaging technique was equivalent to a true resolution of 128 x 74. The scan parameters were repetition time (TR)=6000, echo time (TE)=88, 6 averaging with a b-value of 800 s/mm 2 . The total scan time for DTI was 4 minutes and 24 seconds. DTI scans and subsequent fiber tracking were successfully applied in all cases. All fiber tracts on the contralesional side were visualized in the expected locations. Fiber tracts on the lesional side had varying degrees of displacement, disruption, or a combination of displacement and disruption due to the tumor. Tract disruption resulted from direct tumor involvement, compression upon the tract, and vasogenic edema surrounding the tumor. This DTI method using a parallel imaging technique allows for clinically feasible fiber tracking that can be incorporated into a routine MR examination. (author)

  16. Harvesting to optimize fiber quality

    Science.gov (United States)

    Production conditions typical to the Texas High Plains region can produce cotton crops with high short fiber and nep content, both of which have a detrimental impact on ring spinning performance. Since Texas now produces over 50% of the U.S. cotton crop annually, it is critical that production and p...

  17. Hollow-Core Fiber Lamp

    Science.gov (United States)

    Yi, Lin (Inventor); Tjoelker, Robert L. (Inventor); Burt, Eric A. (Inventor); Huang, Shouhua (Inventor)

    2016-01-01

    Hollow-core capillary discharge lamps on the millimeter or sub-millimeter scale are provided. The hollow-core capillary discharge lamps achieve an increased light intensity ratio between 194 millimeters (useful) and 254 millimeters (useless) light than conventional lamps. The capillary discharge lamps may include a cone to increase light output. Hollow-core photonic crystal fiber (HCPCF) may also be used.

  18. Monolithic fiber optic sensor assembly

    Science.gov (United States)

    Sanders, Scott

    2015-02-10

    A remote sensor element for spectrographic measurements employs a monolithic assembly of one or two fiber optics to two optical elements separated by a supporting structure to allow the flow of gases or particulates therebetween. In a preferred embodiment, the sensor element components are fused ceramic to resist high temperatures and failure from large temperature changes.

  19. Fiber Optics: Deregulate and Deploy.

    Science.gov (United States)

    Suwinski, Jan H.

    1993-01-01

    Describes fiber optic technology, explains its use in education and commercial settings, and recommends regulations and legislation that will speed its use to create broadband information networks. Topics discussed include distance learning; interactive video; costs; and the roles of policy makers, lawmakers, public advocacy groups, and consumers.…

  20. Fiber optics physics and technology

    CERN Document Server

    Mitschke, Fedor

    2016-01-01

    This book tells you all you want to know about optical fibers: Their structure, their light-guiding mechanism, their material and manufacture, their use. It began with telephone, then came telefax and email. Today we use search engines, music downloads and internet videos, all of which require shuffling of bits and bytes by the zillions. The key to all this is the conduit: the line which is designed to carry massive amounts of data at breakneck speed. In their data carrying capacity optical fiber lines beat all other technologies (copper cable, microwave beacons, satellite links) hands down, at least in the long haul; wireless devices rely on fibers, too. Several effects tend to degrade the signal as it travels down the fiber: they are spelled out in detail. Nonlinear processes are given due consideration for a twofold reason: On the one hand they are fundamentally different from the more familiar processes in electrical cable. On the other hand, they form the basis of particularly interesting and innovative ...

  1. Review of natural fiber composites

    Science.gov (United States)

    Rohan, T.; Tushar, B.; T, Mahesha G.

    2018-02-01

    Development of new alternative materials to the existing traditional metals, alloys and synthetic materials is the new buzz in recent research activities at the academic and industrial level taking place all over the world. Earning carbon credits by minimizing the atmospheric pollution is getting an increase in attention by industries. One small step to conserve the atmosphere around us is to use natural resources in making fully bio degradable or partially bio degradable composite materials. Such prepared alternative materials can find applications in interior housing, automotive, marine, domestic, and other applications. Composites made by using appropriate natural fibers as reinforcements is a possibility that ensures such a reality as they can be well received in multiple disciplines of engineering. Results published from various research activities illustrates that natural fiber composites can successfully be adapted for non-structural, moderate load bearing indoor applications. Further, the few deficiencies in the natural fibers can be overcome by subjecting them to morphological changes by various physical or chemical treatment methods. The overall objective of this paper is to provide a comprehensive overview of the property profiles of Natural Fiber Composites.

  2. FIBER LASER CONSTRUCTION AND THEORY INCLUDING FIBER BRAGG GRATINGS Photonic Crystal Fibers (PCFs) and applications of gas filled PCFs

    Energy Technology Data Exchange (ETDEWEB)

    Sutton, Jacob O. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-08

    The principles used in fiber lasers have been around for a while but it is only within the past few years that fiber lasers have become commercially available and used in high power laser applications. This paper will focus on the basic design principles of fiber lasers, including fiber Bragg gratings, principles of operation, and forms of non-linear effects. It will describe the type and associated doping of the fiber used and difficult designs used to guide energy from the pump to the active medium. Topics covered include fiber laser design, fiber Bragg gratings, materials used, differences in quantum energy loss, thermo-optical effects, stimulated Raman scattering, Brillouin scattering, photonic crystal fibers and applications of gas filled Photonic Crystal Fibers (PCFs). Thanks to fiber lasers, the energy required to produce high power lasers has greatly dropped and as such we can now produce kW power using a standard 120V 15A circuit. High power laser applications are always requiring more power. The fiber laser can now deliver the greater power that these applications demand. Future applications requiring more power than can be combined using standard materials or configurations will need to be developed to overcome the high energy density and high non-linear optical scattering effects present during high power operations.

  3. In-fiber modal interferometer based on multimode and double cladding fiber segments for tunable fiber laser applications

    Science.gov (United States)

    Prieto-Cortés, P.; Álvarez-Tamayo, R. I.; Durán-Sánchez, M.; Castillo-Guzmán, A.; Salceda-Delgado, G.; Ibarra-Escamilla, B.; Kuzin, E. A.; Barcelata-Pinzón, A.; Selvas-Aguilar, R.

    2018-02-01

    We report an in-fiber structure based on the use of a multimode fiber segment and a double cladding fiber segment, and its application as spectral filter in an erbium-doped fiber laser for selection and tuning of the laser line wavelength. The output transmission of the proposed device exhibit spectrum modulation of the input signal with free spectral range of 21 nm and maximum visibility enhanced to more than 20 dB. The output spectrum of the in-fiber filter is wavelength displaced by bending application which allows a wavelength tuning of the generated laser line in a range of 12 nm. The use of the proposed in-fiber structure is demonstrated as a reliable, simple, and low-cost wavelength filter for tunable fiber lasers design and optical instrumentation applications.

  4. Stretching single fibrin fibers hampers their lysis.

    Science.gov (United States)

    Li, Wei; Lucioni, Tomas; Li, Rongzhong; Bonin, Keith; Cho, Samuel S; Guthold, Martin

    2017-09-15

    Blood clots, whose main structural component is a mesh of microscopic fibrin fibers, experience mechanical strain from blood flow, clot retraction and interactions with platelets and other cells. We developed a transparent, striated and highly stretchable substrate made from fugitive glue (a styrenic block copolymer) to investigate how mechanical strain affects lysis of single, suspended fibrin fibers. In this suspended fiber assay, lysis manifested itself by fiber elongation, thickening (disassembly), fraying and collapse. Stretching single fibrin fibers significantly hampered their lysis. This effect was seen in uncrosslinked and crosslinked fibers. Crosslinking (without stretching) also hampered single fiber lysis. Our data suggest that strain is a novel mechanosensitive factor that regulates blood clot dissolution (fibrinolysis) at the single fiber level. At the molecular level of single fibrin molecules, strain may distort, or hinder access to, plasmin cleavage sites and thereby hamper lysis. Fibrin fibers are the major structural component of a blood clot. We developed a highly stretchable substrate made from fugitive glue and a suspended fibrin fiber lysis assay to investigate the effect of stretching on single fibrin fibers lysis. The key findings from our experiments are: 1) Fibers thicken and elongate upon lysis; 2) stretching strongly reduces lysis; 3) this effect is more pronounced for uncrosslinked fibers; and 4) stretching fibers has a similar effect on reducing lysis as crosslinking fibers. At the molecular level, strain may distort plasmin cleavage sites, or restrict access to those sites. Our results suggest that strain may be a novel mechanobiological factor that regulates fibrinolysis. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  5. Orange fiber laser for ophthalmology

    Science.gov (United States)

    Adachi, M.; Kojima, K.; Hayashi, K.

    2007-02-01

    For the light source of photocoagulators for ophthalmology, orange laser is more suitable than green laser because of low scattering loss by the crystalline lens, and low absorption by xanthophylls in the retina. We developed two orange fiber lasers (580 nm and 590 nm) to investigate the effect depending on the difference in the range of orange. The 580nm laser is composed of a 1160 nm fiber laser and a Periodically Polled Lithium Niobate (PPLN) crystal for second harmonic generation. The 1160 nm fiber laser beam is focused into the MgO-doped PPLN crystal whose length is 30 mm with 3-pass configuration. Continuous-wave 1.3 W output power of 580 nm was obtained with 5.8 W input power of 1160nm for the first time. The conversion efficiency was 22%. The band width of the second harmonic was 0.006 nm (FWHM). The 590 nm laser is almost the same as 580 nm laser source. In this case we used a Raman shift fiber to generate 1180 nm, and the output power of 590 nm was 1.4 W. We developed an evaluation model of photocoagulator system using these two laser sources. A 700 mW coagulation output power was obtained with this orange fiber laser photocoagulator system. This is enough power for the eye surgery. We have the prospect of the maintenance-free, long-life system that is completely air-cooled. We are planning to evaluate this photocoagulator system in order to investigate the difference between the two wavelengths at the field test.

  6. Biosensing with optical fiber gratings

    Science.gov (United States)

    Chiavaioli, Francesco; Baldini, Francesco; Tombelli, Sara; Trono, Cosimo; Giannetti, Ambra

    2017-06-01

    Optical fiber gratings (OFGs), especially long-period gratings (LPGs) and etched or tilted fiber Bragg gratings (FBGs), are playing an increasing role in the chemical and biochemical sensing based on the measurement of a surface refractive index (RI) change through a label-free configuration. In these devices, the electric field evanescent wave at the fiber/surrounding medium interface changes its optical properties (i.e. intensity and wavelength) as a result of the RI variation due to the interaction between a biological recognition layer deposited over the fiber and the analyte under investigation. The use of OFG-based technology platforms takes the advantages of optical fiber peculiarities, which are hardly offered by the other sensing systems, such as compactness, lightness, high compatibility with optoelectronic devices (both sources and detectors), and multiplexing and remote measurement capability as the signal is spectrally modulated. During the last decade, the growing request in practical applications pushed the technology behind the OFG-based sensors over its limits by means of the deposition of thin film overlays, nanocoatings, and nanostructures, in general. Here, we review efforts toward utilizing these nanomaterials as coatings for high-performance and low-detection limit devices. Moreover, we review the recent development in OFG-based biosensing and identify some of the key challenges for practical applications. While high-performance metrics are starting to be achieved experimentally, there are still open questions pertaining to an effective and reliable detection of small molecules, possibly up to single molecule, sensing in vivo and multi-target detection using OFG-based technology platforms.

  7. Biosensing with optical fiber gratings

    Directory of Open Access Journals (Sweden)

    Chiavaioli Francesco

    2017-06-01

    Full Text Available Optical fiber gratings (OFGs, especially long-period gratings (LPGs and etched or tilted fiber Bragg gratings (FBGs, are playing an increasing role in the chemical and biochemical sensing based on the measurement of a surface refractive index (RI change through a label-free configuration. In these devices, the electric field evanescent wave at the fiber/surrounding medium interface changes its optical properties (i.e. intensity and wavelength as a result of the RI variation due to the interaction between a biological recognition layer deposited over the fiber and the analyte under investigation. The use of OFG-based technology platforms takes the advantages of optical fiber peculiarities, which are hardly offered by the other sensing systems, such as compactness, lightness, high compatibility with optoelectronic devices (both sources and detectors, and multiplexing and remote measurement capability as the signal is spectrally modulated. During the last decade, the growing request in practical applications pushed the technology behind the OFG-based sensors over its limits by means of the deposition of thin film overlays, nanocoatings, and nanostructures, in general. Here, we review efforts toward utilizing these nanomaterials as coatings for high-performance and low-detection limit devices. Moreover, we review the recent development in OFG-based biosensing and identify some of the key challenges for practical applications. While high-performance metrics are starting to be achieved experimentally, there are still open questions pertaining to an effective and reliable detection of small molecules, possibly up to single molecule, sensing in vivo and multi-target detection using OFG-based technology platforms.

  8. Avaliação do bis(4-metilfenilditiocarbimatozincato(II de tetrabutilamônio como acelerador no processo de vulcanização do elastômero polibutadieno Evaluation of [tetrabutyl ammonium bis(4-methylphenyldithiocarbimatezincate-2] as accelerator in vulcanization process of polybutadiene elastomer

    Directory of Open Access Journals (Sweden)

    Leonardo F. V. dos Santos

    2011-01-01

    Full Text Available O ZNIBU, acelerador de caráter lento foi avaliado neste trabalho em composições de polibutadieno. Este acelerador foi sintetizado com o objetivo de substituir, ou reduzir, o uso de alguns aceleradores comerciais muito utilizados em composições elastoméricas mas que, por serem formadores de nitrosaminas, podem ser prejudiciais à saúde. A fim de corrigir o caráter de acelerador lento do ZNIBU, este composto foi utilizado em conjunto com o acelerador comercial CBS (N-ciclohexil-2-benzotiazol-2-sulfenamida. Foi observado que pequenas quantidades dos dois aceleradores não são efetivas na aceleração da vulcanização nas composições do tipo goma pura. No entanto a presença de negro de fumo exerce um efeito positivo sobre a velocidade. As propriedades mecânicas estudadas mostram que o ZNIBU aumenta a resistência à tração da goma pura (35%, em comparação com a composição similar vulcanizada com CBS e, na presença do negro de fumo, este aumento é ainda mais expressivo (175%. Quanto à resistência ao rasgamento, a vulcanização com o ZNIBU forneceu o mais baixo valor da propriedade para a goma pura, enquanto que a composição com negro de fumo apresentou o mais alto valor.ZNIBU, a slow accelerator, was evaluated in polybutadiene compositions. This accelerator was synthesized intending to replace or reduce the use of some very used commercial accelerators in rubber compositions which, due to their nitrosamine-forming potential, can be harmful to health. In order to correct for the slow accelerating character ZNIBU was used in combination with the commercial accelerator CBS (N-cyclohexyl-2-benzothiazole-2-sulfenamide. It was observed that small amounts of the accelerators are not effective in the vulcanization accelerating process of gum type compositions. Nevertheless, the presence of carbon black exerts a positive effect on the reaction rate. The investigated mechanical properties show that ZNIBU improves stress strength of

  9. O efeito de EPDM modificado com grupos mercapto ou tioacetato na cinética de vulcanização de misturas NR/EPDM The effect of mercapto- and thioacetate-modified EPDM on the vulcanization kinetics of NR/EPDM blends

    Directory of Open Access Journals (Sweden)

    Alex S. Sirqueira

    2006-12-01

    Full Text Available A cinética de vulcanização de misturas envolvendo borracha natural (NR e copolímero de etileno-propileno-dieno (EPDM na proporção 70:30 % em peso foi estudada em função da compatibilização. Para esse estudo foram utilizados 2,5 phr de EPDM funcionalizado com grupos tioacetato (EPDMTA ou mercaptana (EPDMSH. O estudo foi realizado em reômetro de disco oscilatório (curômetro. Ambos os copolímeros funcionalizados atuaram como aceleradores do processo de vulcanização das misturas NR/EPDM (70:30 na presença de enxofre e CBS, sendo EPDMSH mais efetivo do que EPDMTA pelo modelo de Chough e Chang. Entretanto, ao utilizar o modelo de Coran, observou-se que EPDMTA e EP-DMSH atuam em distintas etapas da vulcanização: EPDMSH atua preferencialmente no início do processo de vulcanização enquanto que EPDMTA aumenta a velocidade da formação das reticulações propriamente ditas. Além disso, EPDMTA diminuiu consideravelmente a tendência à degradação de reticulações, indicada pela menor taxa de reversão.Vulcanization kinetics for natural rubber (NR/ ethylene-propylene-diene rubber (EPDM blends was studied as a function of the compatibilization, by using an oscillatory disk rheometer. For this study, 2.5 phr of thioacetate- (EPDMTA or mercapto-modified EPDM (EPDMSH were employed in blends vulcanized with sulfur/CBS curing system. Both functionalized copolymers increased the curing velocity of the blends, but the higher overall rate was achieved with EPDMSH-modified systems, using the Chough and Chang model. However, when using the Coran model, we observed that they act in distinct vulcanization steps: EPDMSH acts preferentially at the beginning of the curing process whereas EPDMTA increases the rate of the crosslink formation. In addition, EPDMTA decreased the tendency for crosslink decomposition, as indicated by the lower value of reversion degree.

  10. Fiber optic neutron imaging system: calibration

    International Nuclear Information System (INIS)

    Malone, R.M.; Gow, C.E.; Thayer, D.R.

    1981-01-01

    Two neutron imaging experiments using fiber optics have been performed at the Nevada Test Site. In each experiment, an array of scintillator fluor tubes is exposed to neutrons. Light is coupled out through radiation resistant PCS fibers (8-m long) into high-bandwidth, graded index fibers. For image reconstruction to be accurate, common timing differences and transmission variations between fiber optic channels are needed. The calibration system featured a scanning pulsed dye laser, a specially designed fiber optic star coupler, a tektronix 7912AD transient digitizer, and a DEC PDP 11/34 computing system

  11. Characterization of polymer concrete with natural fibers

    Science.gov (United States)

    Barbuta, M.; Serbanoiu, A. A.; Teodorescu, R.; Rosca, B.; Mitroi, R.; Bejan, G.

    2017-09-01

    In the study are presented the experimental results obtained for polymer concrete prepared with epoxy resin, aggregates, fly ash as filler and two types of fibers: wool and hemp. The influence of type and dosage of fibers were studied. The density and mechanical characteristics were determined: compressive strength, flexural strength and split tensile strength. For both types of fibers, with increasing the fiber dosage the density decreases. The studied dosages had not an important influence on mechanical strengths. The fibers improved especially the tensile strength and the compressive strength presented generally smaller values than the control mix.

  12. Optical Fiber Grating Hydrogen Sensors: A Review.

    Science.gov (United States)

    Dai, Jixiang; Zhu, Li; Wang, Gaopeng; Xiang, Feng; Qin, Yuhuan; Wang, Min; Yang, Minghong

    2017-03-12

    In terms of hydrogen sensing and detection, optical fiber hydrogen sensors have been a research issue due to their intrinsic safety and good anti-electromagnetic interference. Among these sensors, hydrogen sensors consisting of fiber grating coated with sensitive materials have attracted intensive research interests due to their good reliability and distributed measurements. This review paper mainly focuses on optical fiber hydrogen sensors associated with fiber gratings and various materials. Their configurations and sensing performances proposed by different groups worldwide are reviewed, compared and discussed in this paper. Meanwhile, the challenges for fiber grating hydrogen sensors are also addressed.

  13. Properties of textile grade ceramic fibers

    International Nuclear Information System (INIS)

    Pudnos, E.

    1992-01-01

    The availability of textile grade ceramic fibers has sparked great interest for applications in composite reinforcement and high temperature insulation. This paper summarizes the properties of various small diameter textile grade ceramic fibers currently available. Room temperature mechanical and electrical properties of the fibers are discussed for three cases: ambient conditions, after heat aging in argon, and after heat aging in wet air. Dow Corning (R) HPZ Ceramic Fiber, a silicon nitride type fiber, is shown to have improved retention of mechanical and electrical properties above 1200 C

  14. Aligned Layers of Silver Nano-Fibers

    Directory of Open Access Journals (Sweden)

    Andrii B. Golovin

    2012-02-01

    Full Text Available We describe a new dichroic polarizers made by ordering silver nano-fibers to aligned layers. The aligned layers consist of nano-fibers and self-assembled molecular aggregates of lyotropic liquid crystals. Unidirectional alignment of the layers is achieved by means of mechanical shearing. Aligned layers of silver nano-fibers are partially transparent to a linearly polarized electromagnetic radiation. The unidirectional alignment and density of the silver nano-fibers determine degree of polarization of transmitted light. The aligned layers of silver nano-fibers might be used in optics, microwave applications, and organic electronics.

  15. Properties of Fiber Reinforced Polymer Concrete

    Directory of Open Access Journals (Sweden)

    Marinela Bărbuţă

    2008-01-01

    Full Text Available Polymer concrete is a composite material realized with resin and aggregates. In the present study the epoxy resin was used for binding the aggregates. In the composition were introduced near the fly ash, used as filler, the cellulose fibers. The mechanical characteristics such as compressive strength, flexural strength and split tensile strength of polymer concrete with fibers were investigated. The fiber percentage was constant, the epoxy resin and the filler dosages were varied. The cellulose fiber had not improved the mechanical characteristics of the polymer concrete in comparison to that of polymer concrete without cellulose fibers.

  16. Nonlinear fiber optics formerly quantum electronics

    CERN Document Server

    Agrawal, Govind

    1995-01-01

    The field of nonlinear fiber optics has grown substantially since the First Edition of Nonlinear Fiber Optics, published in 1989. Like the First Edition, this Second Edition is a comprehensive, tutorial, and up-to-date account of nonlinear optical phenomena in fiber optics. It synthesizes widely scattered research material and presents it in an accessible manner for students and researchers already engaged in or wishing to enter the field of nonlinear fiber optics. Particular attention is paid to the importance of nonlinear effects in the design of optical fiber communication systems. This is

  17. Optical fibers and RF a natural combination

    CERN Document Server

    Romeiser, Malcolm

    2004-01-01

    The optical fiber industry has experienced a period of consolidation and reorganization and is now poised for a new surge in growth. To take advantage of that growth, and to respond to the demand to use fiber more efficiently, designers need a better understanding of fiber optics. Taking the approach that optical fibers are an extension of RF-based communications, the author explains basic optical concepts, applications, and systems; the nature and performance characteristics of optical fibers; and optical sources, connectors and splices. Subsequent chapters explore current applications of fib

  18. Natural fiber-reinforced polymer composites

    International Nuclear Information System (INIS)

    Taj, S.; Khan, S.; Munawar, M.A.

    2007-01-01

    Natural fibers have been used to reinforce materials for over 3,000 years. More recently they have been employed in combination with plastics. Many types of natural fi fibers have been investigated for use in plastics including Flax, hemp, jute, straw, wood fiber, rice husks, wheat, barley, oats, rye, cane (sugar and bamboo), grass reeds, kenaf, ramie, oil palm empty fruit bunch, sisal, coir, water hyacinth, pennywort, kapok, paper-mulberry, raphia, banana fiber, pineapple leaf fiber and papyrus. Natural fibers have the advantage that they are renewable resources and have marketing appeal. The Asian markets have been using natural fibers for many years e.g., jute is a common reinforcement in India. Natural fibers are increasingly used in automotive and packaging materials. Pakistan is an agricultural country and it is the main stay of Pakistan's economy. Thousands of tons of different crops are produced but most of their wastes do not have any useful utilization. Agricultural wastes include wheat husk, rice husk, and their straw, hemp fiber and shells of various dry fruits. These agricultural wastes can be used to prepare fiber reinforced polymer composites for commercial use. This report examines the different types of fibers available and the current status of research. Many references to the latest work on properties, processing and application have been cited in this review. (author)

  19. Interfacial Studies of Sized Carbon Fiber

    International Nuclear Information System (INIS)

    Shahrul, S. N.; Hartini, M. N.; Hilmi, E. A.; Nizam, A.

    2010-01-01

    This study was performed to investigate the influence of sizing treatment on carbon fiber in respect of interfacial adhesion in composite materials, Epolam registered 2025. Fortafil unsized carbon fiber was used to performed the experiment. The fiber was commercially surface treated and it was a polyacrylonitrile based carbon fiber with 3000 filament per strand. Epicure registered 3370 was used as basic sizing chemical and dissolved in two types of solvent, ethanol and acetone for the comparison purpose. The single pull out test has been used to determine the influence of sizing on carbon fiber. The morphology of carbon fiber was observed by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The apparent interfacial strength IFSS values determined by pull out test for the Epicure registered 3370/ethanol sized carbon fiber pointed to a good interfacial behaviour compared to the Epicure registered 3370/acetone sized carbon fiber. The Epicure registered 3370/ethanol sizing agent was found to be effective in promoting adhesion because of the chemical reactions between the sizing and Epolam registered 2025 during the curing process. From this work, it showed that sized carbon fiber using Epicure registered 3370 with addition of ethanol give higher mechanical properties of carbon fiber in terms of shear strength and also provided a good adhesion between fiber and matrix compared to the sizing chemical that contain acetone as a solvent.

  20. Thermal tuning On narrow linewidth fiber laser

    Science.gov (United States)

    Han, Peiqi; Liu, Tianshan; Gao, Xincun; Ren, Shiwei

    2010-10-01

    At present, people have been dedicated to high-speed and large-capacity optical fiber communication system. Studies have been shown that optical wavelength division multiplexing (WDM) technology is an effective means of communication to increase the channel capacity. Tunable lasers have very important applications in high-speed, largecapacity optical communications, and distributed sensing, it can provide narrow linewidth and tunable laser for highspeed optical communication. As the erbium-doped fiber amplifier has a large gain bandwidth, the erbium-doped fiber laser can be achieved lasing wavelength tunable by adding a tunable filter components, so tunable filter device is the key components in tunable fiber laser.At present, fiber laser wavelength is tuned by PZT, if thermal wavelength tuning is combined with PZT, a broader range of wavelength tuning is appearance . Erbium-doped fiber laser is used in the experiments,the main research is the physical characteristics of fiber grating temperature-dependent relationship and the fiber grating laser wavelength effects. It is found that the fiber laser wavelength changes continuously with temperature, tracking several temperature points observed the self-heterodyne spectrum and found that the changes in spectra of the 3dB bandwidth of less than 1kHz, and therefore the fiber laser with election-mode fiber Bragg grating shows excellent spectral properties and wavelength stability.

  1. Side-emitting fiber optic position sensor

    Science.gov (United States)

    Weiss, Jonathan D [Albuquerque, NM

    2008-02-12

    A side-emitting fiber optic position sensor and method of determining an unknown position of an object by using the sensor. In one embodiment, a concentrated beam of light source illuminates the side of a side-emitting fiber optic at an unknown axial position along the fiber's length. Some of this side-illuminated light is in-scattered into the fiber and captured. As the captured light is guided down the fiber, its intensity decreases due to loss from side-emission away from the fiber and from bulk absorption within the fiber. By measuring the intensity of light emitted from one (or both) ends of the fiber with a photodetector(s), the axial position of the light source is determined by comparing the photodetector's signal to a calibrated response curve, look-up table, or by using a mathematical model. Alternatively, the side-emitting fiber is illuminated at one end, while a photodetector measures the intensity of light emitted from the side of the fiber, at an unknown position. As the photodetector moves further away from the illuminated end, the detector's signal strength decreases due to loss from side-emission and/or bulk absorption. As before, the detector's signal is correlated to a unique position along the fiber.

  2. Optical fiber sensors for harsh environments

    Science.gov (United States)

    Xu, Juncheng; Wang, Anbo

    2007-02-06

    A diaphragm optic sensor comprises a ferrule including a bore having an optical fiber disposed therein and a diaphragm attached to the ferrule, the diaphragm being spaced apart from the ferrule to form a Fabry-Perot cavity. The cavity is formed by creating a pit in the ferrule or in the diaphragm. The components of the sensor are preferably welded together, preferably by laser welding. In some embodiments, the entire ferrule is bonded to the fiber along the entire length of the fiber within the ferrule; in other embodiments, only a portion of the ferrule is welded to the fiber. A partial vacuum is preferably formed in the pit. A small piece of optical fiber with a coefficient of thermal expansion chosen to compensate for mismatches between the main fiber and ferrule may be spliced to the end of the fiber.

  3. Mode conversion in hybrid optical fiber coupler

    Science.gov (United States)

    Stasiewicz, Karol A.; Marc, P.; Jaroszewicz, Leszek R.

    2012-04-01

    Designing of all in-line fiber optic systems with a supercontinuum light source gives some issues. The use of a standard single mode fiber (SMF) as an input do not secure single mode transmission in full wavelength range. In the paper, the experimental results of the tested hybrid fiber optic coupler were presented. It was manufactured by fusing a standard single mode fiber (SMF28) and a photonic crystal fiber (PCF). The fabrication process is based on the standard fused biconical taper technique. Two types of large mode area fibers (LMA8 and LAM10 NKT Photonics) with different air holes arrangements were used as the photonic crystal fiber. Spectral characteristics within the range of 800 nm - 1700 nm were presented. All process was optimized to obtain a mode conversion between SMF and PCF and to reach a single mode transmission in the PCF output of the coupler.

  4. Degradation Behavior of Thermal Stabilized Polyacrylonitrile Fibers

    Directory of Open Access Journals (Sweden)

    LEI Shuai

    2017-05-01

    Full Text Available In the temperature range of 300-800℃, 40%-50% of the mass lost during the processing of polyacrylonitrile based carbon fiber (PANCF. Understanding the degradation behavior will be valuable in understanding the formation mechanism of pseudo-graphite structure, and providing theoretic basis for producing high performance carbon fiber and increasing the carbonization yield. The simulation of the degradation progress was carried out on the thermogravimetric analyzer (TGA, the results show that there are two degradation steps for PAN fiber stabilized in air, and controlled by cyclization coefficient and oxygen content. The cyclization coefficient and oxygen content are effective to the density of carbon fiber by influencing the degradation behavior, which cause defects in the fiber. The higher cyclization coefficient leads to form less structural defects and higher density of the fiber; on the contrary, the higher oxygen content leads to form more structural defects and lower density of the fiber.

  5. Dietary fiber and blood pressure control.

    Science.gov (United States)

    Aleixandre, A; Miguel, M

    2016-04-01

    In the past few years, new strategies to control blood pressure levels are emerging by developing new bioactive components of foods. Fiber has been linked to the prevention of a number of cardiovascular diseases and disorders. β-Glucan, the main soluble fiber component in oat grains, was initially linked to a reduction in plasma cholesterol. Several studies have shown afterward that dietary fiber may also improve glycaemia, insulin resistance and weight loss. The effect of dietary fiber on arterial blood pressure has been the subject of far fewer studies than its effect on the above-mentioned variables, but research has already shown that fiber intake can decrease arterial blood pressure in hypertensive rats. Moreover, certain fibers can improve arterial blood pressure when administered to hypertensive and pre-hypertensive subjects. The present review summarizes all those studies which attempt to establish the antihypertensive effects of dietary fiber, as well as its effect on other cardiovascular risk factors.

  6. Fiber cavities with integrated mode matching optics.

    Science.gov (United States)

    Gulati, Gurpreet Kaur; Takahashi, Hiroki; Podoliak, Nina; Horak, Peter; Keller, Matthias

    2017-07-17

    In fiber based Fabry-Pérot Cavities (FFPCs), limited spatial mode matching between the cavity mode and input/output modes has been the main hindrance for many applications. We have demonstrated a versatile mode matching method for FFPCs. Our novel design employs an assembly of a graded-index and large core multimode fiber directly spliced to a single mode fiber. This all-fiber assembly transforms the propagating mode of the single mode fiber to match with the mode of a FFPC. As a result, we have measured a mode matching of 90% for a cavity length of ~400 μm. This is a significant improvement compared to conventional FFPCs coupled with just a single mode fiber, especially at long cavity lengths. Adjusting the parameters of the assembly, the fundamental cavity mode can be matched with the mode of almost any single mode fiber, making this approach highly versatile and integrable.

  7. Physicochemical characterization of purple banana fiber

    International Nuclear Information System (INIS)

    Goncalves, A.P.B.; Guimaraes, D.H.; Miranda, C.S.; Oliveira, J.C.; Cruz, A.M.F.; Luporini, S.; Jose, N.M.

    2014-01-01

    Due to the environmental appeal that has grown in recent years, researches involving the use of renewable sources raw materials reaffirm this need. The vegetable fibers has excelled as promising materials with possibilities in different applications. The objective of this work is the evaluation of the physicochemical properties of banana fiber. These fibers were extracted from the banana pseudostem of a species not yet reported in the literature, Musa velutina, known as purple banana. For this experiment were used in natura fibers and processed fibers with NaOH 5% which were characterized by TGA, DSC, DRX and FTIR analysis. In the thermal analysis, both tested fibers showed good thermal properties. In DRX analysis, the processed fibers showed higher crystallinity. The use of these materials implies adding value to an agricultural waste in addition to being a more ecologically correct proposal. (author)

  8. Simulation of Glass Fiber Forming Processes

    DEFF Research Database (Denmark)

    Von der Ohe, Renate

    Two glass fiber forming processes have been simulated using FEM, which are the drawing of continuous glass fibers for reinforcement purposes and the spinning of discontinuous glass fibers - stone wool for insulation. The aim of this work was to set up a numerical model for each process, and to use...... this model in finding relationships between the production conditions and the resulting fiber properties. For both processes, a free surface with large deformation and radiative and convective heat transfer must be taken into account. The continuous fiber drawing has been simulated successfully......, and parametric studies have been made. Several properties that characterize the process have been calculated, and the relationship between the fictive temperature and the cooling rate of the fibers has been found. The model for the discontinuous fiber spinning was brought to the limits of the commercial code...

  9. Prebiotics, Fermentable Dietary Fiber, and Health Claims.

    Science.gov (United States)

    Delcour, Jan A; Aman, Per; Courtin, Christophe M; Hamaker, Bruce R; Verbeke, Kristin

    2016-01-01

    Since the 1970s, the positive effects of dietary fiber on health have increasingly been recognized. The collective term "dietary fiber" groups structures that have different physiologic effects. Since 1995, some dietary fibers have been denoted as prebiotics, implying a beneficial physiologic effect related to increasing numbers or activity of the gastrointestinal microbiota. Given the complex composition of the microbiota, the demonstration of such beneficial effects is difficult. In contrast, an exploration of the metabolites of dietary fiber formed as a result of its fermentation in the colon offers better perspectives for providing mechanistic links between fiber intake and health benefits. Positive outcomes of such studies hold the promise that claims describing specific health benefits can be granted. This would help bridge the "fiber gap"-that is, the considerable difference between recommended and actual fiber intakes by the average consumer. © 2016 American Society for Nutrition.

  10. Liquid Crystal photonic Bandgap Fiber Devices

    DEFF Research Database (Denmark)

    Wei, Lei

    In this Ph.D. thesis, an experimental investigation of liquid crystal photonic bandgap (LCPBG) fiber devices and applications is presented. Photonic crystal fibers (PCFs) consist of a cladding microstructure with periodic index variations and a core defined by a defect of the structure. The prese......In this Ph.D. thesis, an experimental investigation of liquid crystal photonic bandgap (LCPBG) fiber devices and applications is presented. Photonic crystal fibers (PCFs) consist of a cladding microstructure with periodic index variations and a core defined by a defect of the structure...... of each LCPBG fiber. Finally, the applications for LCPBG fiber devices based on the on-chip platform design have been demonstrated in realizing microwave true-time delay and creating an electrically tunable fiber laser. Referatet mailes...

  11. Wetting morphologies on randomly oriented fibers.

    Science.gov (United States)

    Sauret, Alban; Boulogne, François; Soh, Beatrice; Dressaire, Emilie; Stone, Howard A

    2015-06-01

    We characterize the different morphologies adopted by a drop of liquid placed on two randomly oriented fibers, which is a first step toward understanding the wetting of fibrous networks. The present work reviews previous modeling for parallel and touching crossed fibers and extends it to an arbitrary orientation of the fibers characterized by the tilting angle and the minimum spacing distance. Depending on the volume of liquid, the spacing distance between fibers and the angle between the fibers, we highlight that the liquid can adopt three different equilibrium morphologies: 1) a column morphology in which the liquid spreads between the fibers, 2) a mixed morphology where a drop grows at one end of the column or 3) a single drop located at the node. We capture the different morphologies observed using an analytical model that predicts the equilibrium configuration of the liquid based on the geometry of the fibers and the volume of liquid.

  12. Fiber optic vibration sensor using bifurcated plastic optical fiber

    Science.gov (United States)

    Abdullah, M.; Bidin, N.; Yasin, M.

    2016-11-01

    An extrinsic fiber optic vibration sensor is demonstrated for a fiber optic displacement sensor based on a bundled multimode fiber to measure a vibration frequency ranging from 100 until 3000 Hz. The front slope has a sensitivity of 0.1938mV/mm and linearity of 99.7% within a measurement range between 0.15-3.00 mm. By placing the diaphragm of the concave load-speaker within the linear range from the probe, the frequency of the vibration can be measured with error percentage of less than 1.54%. The graph of input against output frequency for low, medium and high frequency range show very high linearity up to 99%. Slope for low, medium, and high frequency range are calculated as 1.0026, 0.9934, and 1.0007 respectively. Simplicity, long term stability, low power consumption, wide dynamic and frequency ranges, noise reduction, ruggedness, linearity and light weight make it promising alternative to other well-establish methods for vibration frequency measurement.

  13. Interaction between carbon fibers and polymer sizing: Influence of fiber surface chemistry and sizing reactivity

    Science.gov (United States)

    Moosburger-Will, Judith; Bauer, Matthias; Laukmanis, Eva; Horny, Robert; Wetjen, Denise; Manske, Tamara; Schmidt-Stein, Felix; Töpker, Jochen; Horn, Siegfried

    2018-05-01

    Different aspects of the interaction of carbon fibers and epoxy-based polymer sizings are investigated, e.g. the wetting behavior, the strength of adhesion between fiber and sizing, and the thermal stability of the sizing layer. The influence of carbon fiber surface chemistry and sizing reactivity is investigated using fibers of different degree of anodic oxidation and sizings with different number of reactive epoxy groups per molecule. Wetting of the carbon fibers by the sizing dispersion is found to be specified by both, the degree of fiber activation and the sizing reactivity. In contrast, adhesion strength between fibers and sizing is dominated by the surface chemistry of the carbon fibers. Here, the number of surface oxygen groups seems to be the limiting factor. We also find that the sizing and the additional functionalities induced by anodic oxidation are removed by thermal treatment at 600 °C, leaving the carbon fiber in its original state after carbonization.

  14. Numerical approach of the injection molding process of fiber-reinforced composite with considering fiber orientation

    Science.gov (United States)

    Nguyen Thi, T. B.; Yokoyama, A.; Ota, K.; Kodama, K.; Yamashita, K.; Isogai, Y.; Furuichi, K.; Nonomura, C.

    2014-05-01

    One of the most important challenges in the injection molding process of the short-glass fiber/thermoplastic composite parts is being able to predict the fiber orientation, since it controls the mechanical and the physical properties of the final parts. Folgar and Tucker included into the Jeffery equation a diffusive type of term, which introduces a phenomenological coefficient for modeling the randomizing effect of the mechanical interactions between the fibers, to predict the fiber orientation in concentrated suspensions. Their experiments indicated that this coefficient depends on the fiber volume fraction and aspect ratio. However, a definition of the fiber interaction coefficient, which is very necessary in the fiber orientation simulations, hasn't still been proven yet. Consequently, this study proposed a developed fiber interaction model that has been introduced a fiber dynamics simulation in order to obtain a global fiber interaction coefficient. This supposed that the coefficient is a sum function of the fiber concentration, aspect ratio, and angular velocity. The proposed model was incorporated into a computer aided engineering simulation package C-Mold. Short-glass fiber/polyamide-6 composites were produced in the injection molding with the fiber weight concentration of 30 wt.%, 50 wt.%, and 70 wt.%. The physical properties of these composites were examined, and their fiber orientation distributions were measured by micro-computed-tomography equipment μ-CT. The simulation results showed a good agreement with experiment results.

  15. Erbium Doped Fiber Optic Gravimeter

    International Nuclear Information System (INIS)

    Pérez-Sánchez, G G; Pérez-Torres, J R; Flores-Bravo, J A; Álvarez-Chávez, J A; Martínez-Piñón, F

    2017-01-01

    Gravimeters are devices that can be used in a wide range of applications, such as mining, seismology, geodesy, archeology, geophysics and many others. These devices have great sensibility, which makes them susceptible to external vibrations like electromagnetic waves. There are several technologies regarding gravimeters that are of use in industrial metrology. Optical fiber is immune to electromagnetic interference, and together with long period gratings can form high sensibility sensors of small size, offering advantages over other systems with different technologies. This paper shows the development of an optical fiber gravimeter doped with Erbium that was characterized optically for loads going from 1 to 10 kg in a bandwidth between 1590nm to 1960nm, displaying a weight linear response against power. Later on this paper, the experimental results show that the previous described behavior can be modeled as characteristic function of the sensor. (paper)

  16. Monolithic all-PM femtosecond Yb-doped fiber laser using photonic bandgap fibers

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Lægsgaard, Jesper; Turchinovich, Dmitry

    2009-01-01

    We present a monolithic Yb fiber laser, dispersion managed by an all-solid photonic bandgap fiber, and pulse compressed in a hollow-core photonic crystal fiber. The laser delivers 9 nJ, 275-fs long pulses at 1035 nm.......We present a monolithic Yb fiber laser, dispersion managed by an all-solid photonic bandgap fiber, and pulse compressed in a hollow-core photonic crystal fiber. The laser delivers 9 nJ, 275-fs long pulses at 1035 nm....

  17. Brillouin lasing in single-mode tapered optical fiber with inscribed fiber Bragg grating array

    Science.gov (United States)

    Popov, S. M.; Butov, O. V.; Chamorovskiy, Y. K.; Isaev, V. A.; Kolosovskiy, A. O.; Voloshin, V. V.; Vorob'ev, I. L.; Vyatkin, M. Yu.; Mégret, P.; Odnoblyudov, M.; Korobko, D. A.; Zolotovskii, I. O.; Fotiadi, A. A.

    2018-06-01

    A tapered optical fiber has been manufactured with an array of fiber Bragg gratings (FBG) inscribed during the drawing process. The total fiber peak reflectivity is 5% and the reflection bandwidth is ∼3.5 nm. A coherent frequency domain reflectometry has been applied for precise profiling of the fiber core diameter and grating reflectivity both distributed along the whole fiber length. These measurements are in a good agreement with the specific features of Brillouin lasing achieved in the semi-open fiber cavity configuration.

  18. Integrated fiber Michelson interferometer based on poled hollow twin-core fiber.

    Science.gov (United States)

    Liu, Zhihai; Bo, Fusen; Wang, Lei; Tian, Fengjun; Yuan, Libo

    2011-07-01

    We propose an integrated fiber Michelson interferometer based on a poled hollow twin-core fiber. The Michelson interferometer can be used as an electro-optic modulator by thermal poling one core of the twin-core fiber and introducing second-order nonlinearity in the fiber. The proposed fiber Michelson interferometer is experimentally demonstrated under driving voltages at the frequency range of 149 to 1000 Hz. The half-wave voltage of the poled fiber is 135 V, and the effective second-order nonlinear coefficient χ² is 1.23 pm/V.

  19. The KLOE fiber electromagnetic calorimeter

    International Nuclear Information System (INIS)

    Incagli, Marco

    1998-01-01

    The construction and equipment of the KLOE electromagnetic calorimeter has ended in March 1997. In parallel to the construction, all modules have been tested at the Cosmic Ray Test Stand (CRTS) facility, in Frascati National Laboratories (Rome). The construction technique, based on scintillating fibers alternated to very thin (0.5 mm) grooved lead planes, is described and the main results both from the CRTS and from a preliminary Test Beam with low energy electrons and muons are reported in this note

  20. Electrospun Fibers for Composites Applications

    Science.gov (United States)

    2014-02-01

    in traditional woven mat composites. Nanofibrous interlayers were used to increase the impact and shear performance of a prepregged carbon fiber...Nylon 66 Nanofibrilmat Interleaved Carbon/Epoxy Laminates . Polymer Composites 2011, 32, 1781–1789. 21 13. Chen, Q.; Zhang, L.; Rahman, A.; Zhou...Resistance in Laminated Composites With Electrospun Nano-Interlayers. Comp. Sci. Tech. 2008, 68, 673– 683. 15. Zhang, J.; Lin, T.; Wang, X. Electrospun

  1. Fiber and Prebiotics: Mechanisms and Health Benefits

    Science.gov (United States)

    Slavin, Joanne

    2013-01-01

    The health benefits of dietary fiber have long been appreciated. Higher intakes of dietary fiber are linked to less cardiovascular disease and fiber plays a role in gut health, with many effective laxatives actually isolated fiber sources. Higher intakes of fiber are linked to lower body weights. Only polysaccharides were included in dietary fiber originally, but more recent definitions have included oligosaccharides as dietary fiber, not based on their chemical measurement as dietary fiber by the accepted total dietary fiber (TDF) method, but on their physiological effects. Inulin, fructo-oligosaccharides, and other oligosaccharides are included as fiber in food labels in the US. Additionally, oligosaccharides are the best known “prebiotics”, “a selectively fermented ingredient that allows specific changes, both in the composition and/or activity in the gastrointestinal microflora that confers benefits upon host well-bring and health.” To date, all known and suspected prebiotics are carbohydrate compounds, primarily oligosaccharides, known to resist digestion in the human small intestine and reach the colon where they are fermented by the gut microflora. Studies have provided evidence that inulin and oligofructose (OF), lactulose, and resistant starch (RS) meet all aspects of the definition, including the stimulation of Bifidobacterium, a beneficial bacterial genus. Other isolated carbohydrates and carbohydrate-containing foods, including galactooligosaccharides (GOS), transgalactooligosaccharides (TOS), polydextrose, wheat dextrin, acacia gum, psyllium, banana, whole grain wheat, and whole grain corn also have prebiotic effects. PMID:23609775

  2. Radiation shielding fiber and its manufacturing method

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Koji; Ono, Hiroshi.

    1988-08-17

    Purpose: To manufacture radiation shielding fibers of excellent shielding effects. Method: Fibers containing more than 1 mmol/g of carboxyl groups are bonded with heavy metals, or they are impregnated with an aqueous solution containing water-soluble heavy metal salts dissolved therein. Fibers as the substrate may be any of forms such as short fibers, long fibers, fiber tows, webs, threads, knitting or woven products, non-woven fabrics, etc. It is however necessary that fibers contain more than 1 mmol/g, preferably, from 2 to 7 mmol/g of carboxylic groups. Since heavy metals having radiation shielding performance are bonded to the outer layer of the fibers and the inherent performance of the fibers per se is possessed, excellent radiation shielding performance can be obtained, as well as they can be applied with spinning, knitting or weaving, stitching, etc. thus can be used for secondary fiber products such as clothings, caps, masks, curtains, carpets, cloths, etc. for use in radiation shieldings. (Kamimura, M.).

  3. Optical fiber-applied radiation detection system

    International Nuclear Information System (INIS)

    Nishiura, Ryuichi; Uranaka, Yasuo; Izumi, Nobuyuki

    2001-01-01

    A technique to measure radiation by using plastic scintillation fibers doped radiation fluorescent (scintillator) to plastic optical fiber for a radiation sensor, was developed. The technique contains some superiority such as high flexibility due to using fibers, relatively easy large area due to detecting portion of whole of fibers, and no electromagnetic noise effect due to optical radiation detection and signal transmission. Measurable to wide range of and continuous radiation distribution along optical fiber cable at a testing portion using scintillation fiber and flight time method, the optical fiber-applied radiation sensing system can effectively monitor space radiation dose or apparatus operation condition monitoring. And, a portable type scintillation optical fiber body surface pollution monitor can measure pollution concentration of radioactive materials attached onto body surface by arranging scintillation fiber processed to a plate with small size and flexibility around a man to be tested. Here were described on outline and fundamental properties of various application products using these plastic scintillation fiber. (G.K.)

  4. Fiber and Prebiotics: Mechanisms and Health Benefits

    Directory of Open Access Journals (Sweden)

    Joanne Slavin

    2013-04-01

    Full Text Available The health benefits of dietary fiber have long been appreciated. Higher intakes of dietary fiber are linked to less cardiovascular disease and fiber plays a role in gut health, with many effective laxatives actually isolated fiber sources. Higher intakes of fiber are linked to lower body weights. Only polysaccharides were included in dietary fiber originally, but more recent definitions have included oligosaccharides as dietary fiber, not based on their chemical measurement as dietary fiber by the accepted total dietary fiber (TDF method, but on their physiological effects. Inulin, fructo-oligosaccharides, and other oligosaccharides are included as fiber in food labels in the US. Additionally, oligosaccharides are the best known “prebiotics”, “a selectively fermented ingredient that allows specific changes, both in the composition and/or activity in the gastrointestinal microflora that confers benefits upon host well-bring and health.” To date, all known and suspected prebiotics are carbohydrate compounds, primarily oligosaccharides, known to resist digestion in the human small intestine and reach the colon where they are fermented by the gut microflora. Studies have provided evidence that inulin and oligofructose (OF, lactulose, and resistant starch (RS meet all aspects of the definition, including the stimulation of Bifidobacterium, a beneficial bacterial genus. Other isolated carbohydrates and carbohydrate-containing foods, including galactooligosaccharides (GOS, transgalactooligosaccharides (TOS, polydextrose, wheat dextrin, acacia gum, psyllium, banana, whole grain wheat, and whole grain corn also have prebiotic effects.

  5. Supersymmetric Transformations in Optical Fibers

    Science.gov (United States)

    Macho, Andrés; Llorente, Roberto; García-Meca, Carlos

    2018-01-01

    Supersymmetry (SUSY) has recently emerged as a tool to design unique optical structures with degenerate spectra. Here, we study several fundamental aspects and variants of one-dimensional SUSY in axially symmetric optical media, including their basic spectral features and the conditions for degeneracy breaking. Surprisingly, we find that the SUSY degeneracy theorem is partially (totally) violated in optical systems connected by isospectral (broken) SUSY transformations due to a degradation of the paraxial approximation. In addition, we show that isospectral constructions provide a dimension-independent design control over the group delay in SUSY fibers. Moreover, we find that the studied unbroken and isospectral SUSY transformations allow us to generate refractive-index superpartners with an extremely large phase-matching bandwidth spanning the S +C +L optical bands. These singular features define a class of optical fibers with a number of potential applications. To illustrate this, we numerically demonstrate the possibility of building photonic lanterns supporting broadband heterogeneous supermodes with large effective area, a broadband all-fiber true-mode (de)multiplexer requiring no mode conversion, and different mode-filtering, mode-conversion, and pulse-shaping devices. Finally, we discuss the possibility of extrapolating our results to acoustics and quantum mechanics.

  6. Carbon nanotube fiber terahertz polarizer

    Energy Technology Data Exchange (ETDEWEB)

    Zubair, Ahmed [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Tsentalovich, Dmitri E.; Young, Colin C. [Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005 (United States); Heimbeck, Martin S. [Charles M. Bowden Laboratory, Aviation & Missile Research, Development, and Engineering Center (AMRDEC), Redstone Arsenal, Alabama 35898 (United States); Everitt, Henry O. [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Charles M. Bowden Laboratory, Aviation & Missile Research, Development, and Engineering Center (AMRDEC), Redstone Arsenal, Alabama 35898 (United States); Pasquali, Matteo [Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005 (United States); Department of Chemistry, Rice University, Houston, Texas 77005 (United States); Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005 (United States); Kono, Junichiro, E-mail: kono@rice.edu [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005 (United States); Department of Physics and Astronomy, Rice University, Houston, Texas 77005 (United States)

    2016-04-04

    Conventional, commercially available terahertz (THz) polarizers are made of uniformly and precisely spaced metallic wires. They are fragile and expensive, with performance characteristics highly reliant on wire diameters and spacings. Here, we report a simple and highly error-tolerant method for fabricating a freestanding THz polarizer with nearly ideal performance, reliant on the intrinsically one-dimensional character of conduction electrons in well-aligned carbon nanotubes (CNTs). The polarizer was constructed on a mechanical frame over which we manually wound acid-doped CNT fibers with ultrahigh electrical conductivity. We demonstrated that the polarizer has an extinction ratio of ∼−30 dB with a low insertion loss (<0.5 dB) throughout a frequency range of 0.2–1.1 THz. In addition, we used a THz ellipsometer to measure the Müller matrix of the CNT-fiber polarizer and found comparable attenuation to a commercial metallic wire-grid polarizer. Furthermore, based on the classical theory of light transmission through an array of metallic wires, we demonstrated the most striking difference between the CNT-fiber and metallic wire-grid polarizers: the latter fails to work in the zero-spacing limit, where it acts as a simple mirror, while the former continues to work as an excellent polarizer even in that limit due to the one-dimensional conductivity of individual CNTs.

  7. Fiber Optics Physics and Technology

    CERN Document Server

    Mitschke, Fedor

    2010-01-01

    Telephone, telefax, email and internet -- the key ingredient of the inner workings is the conduit: the line which is designed to carry massive amounts of data at breakneck speed. In their data-carrying capacity optical fiber lines beat other technologies (copper cable, microwave beacons, satellite links) hands down, at least in the long haul. This book tells you all you want to know about optical fibers: Their structure, their light-guiding mechanism, their material and manufacture, their use. Several effects tend to degrade the signal as it travels down the fiber: they are spelled out in detail. Nonlinear processes are given due consideration for a twofold reason: On the one hand they are fundamentally different from the more familiar processes in electrical cable. On the other hand, they form the basis of particularly interesting and innovative applications, provided they are understood well enough. A case in point is the use of so-called solitons, i.e. special pulses of light which have the wonderful prope...

  8. Hybrid photonic-crystal fiber

    Science.gov (United States)

    Markos, Christos; Travers, John C.; Abdolvand, Amir; Eggleton, Benjamin J.; Bang, Ole

    2017-10-01

    This article offers an extensive survey of results obtained using hybrid photonic-crystal fibers (PCFs) which constitute one of the most active research fields in contemporary fiber optics. The ability to integrate novel and functional materials in solid- and hollow-core PCFs through various postprocessing methods has enabled new directions toward understanding fundamental linear and nonlinear phenomena as well as novel application aspects, within the fields of optoelectronics, material and laser science, remote sensing, and spectroscopy. Here the recent progress in the field of hybrid PCFs is reviewed from scientific and technological perspectives, focusing on how different fluids, solids, and gases can significantly extend the functionality of PCFs. The first part of this review discusses the efforts to develop tunable linear and nonlinear fiber-optic devices using PCFs infiltrated with various liquids, glasses, semiconductors, and metals. The second part concentrates on recent and state-of-the-art advances in the field of gas-filled hollow-core PCFs. Extreme ultrafast gas-based nonlinear optics toward light generation in the extreme wavelength regions of vacuum ultraviolet, pulse propagation, and compression dynamics in both atomic and molecular gases, and novel soliton-plasma interactions are reviewed. A discussion of future prospects and directions is also included.

  9. Patterned functional carbon fibers from polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, Marcus A [ORNL; Saito, Tomonori [ORNL; Brown, Rebecca H [ORNL; Kumbhar, Amar S [University of North Carolina, Chapel Hill; Naskar, Amit K [ORNL

    2012-01-01

    Patterned, continuous carbon fibers with controlled surface geometry were produced from a novel melt-processible carbon precursor. This portends the use of a unique technique to produce such technologically innovative fibers in large volume for important applications. The novelties of this technique include ease of designing and fabricating fibers with customized surface contour, the ability to manipulate filament diameter from submicron scale to a couple of orders of magnitude larger scale, and the amenable porosity gradient across the carbon wall by diffusion controlled functionalization of precursor. The geometry of fiber cross-section was tailored by using bicomponent melt-spinning with shaped dies and controlling the melt-processing of the precursor polymer. Circular, trilobal, gear-shaped hollow fibers, and solid star-shaped carbon fibers of 0.5 - 20 um diameters, either in self-assembled bundle form, or non-bonded loose filament form, were produced by carbonizing functionalized-polyethylene fibers. Prior to carbonization, melt-spun fibers were converted to a char-forming mass by optimizing the sulfonation on polyethylene macromolecules. The fibers exhibited distinctly ordered carbon morphologies at the outside skin compared to the inner surface or fiber core. Such order in carbon microstructure can be further tuned by altering processing parameters. Partially sulfonated polyethylene-derived hollow carbon fibers exhibit 2-10 fold surface area (50-500 m2/g) compared to the solid fibers (10-25 m2/g) with pore sizes closer to the inside diameter of the filaments larger than the sizes on the outer layer. These specially functionalized carbon fibers hold promise for extraordinary performance improvements when used, for example, as composite reinforcements, catalyst support media, membranes for gas separation, CO2 sorbents, and active electrodes and current collectors for energy storage applications.

  10. Radiation resistivity of quartz core fiber, 3

    International Nuclear Information System (INIS)

    Gozen, Toshikazu; Suzuki, Toshiya; Hayashi, Tokuji; Tanaka, Hiroyuki; Okamoto, Shinichi.

    1985-01-01

    Radiation resistance characteristics were evaluated for a multi-mode quartz core fiber in low temperature region together with photobleaching effect depending on the incident light power and dependency on the wavelength of measuring rays. This report describes the results of the abovementioned items and the next step study of trial manufacturing of a pure-quartz single-mode fiber for the employment of longer wavelength rays and greater capacity in light transmission communication system. Quartz core fiber specimens were irradiated by 60 Co γ-ray source at -55 deg C to 80 deg C in a constant temperature bath and light transmission loss was determined under irradiation conditions. Low temperature characteristics were superior in an MRT (modified rod-in tube) pure quartz fiber prepared by the plasma method as compared to VAD quartz and Ge-GI fibers. The MRT fiber showed better quality than the Ge-GI fiber also in the photobleaching effect examination. As for the wavelength dependency, light transmission loss of the MRT fiber was less than that of the Ge-GI fiber. The MRT fiber also showed a superior quality in the wide range of irradiation temperatures. Based on the above-mentioned understandings, a pure-quartz single-mode fiber of both BF 3 -doped and F-doped cladding types were developed for longer wavelengths uses. The fibers could attain low light transmission loss of less than 1.0 dB/km at 1.30 μm of wavelength. At the standpoint of radiation resistivity, the BF 3 -doped fiber was found superior. (Takagi, S.)

  11. Status of fiber lasers study of on ytterbium doped fiber laser and laser spectroscopy of doped fibers

    International Nuclear Information System (INIS)

    Magne, S.

    1994-07-01

    This work shows all the advantages and drawbacks of the rare-earth-doped fiber lasers and fiber optical amplifiers, pointing out their potential use for instrumentation and optical fiber sensor technology. The theory of light propagation in optical fibers is presented in order to understand the manufacturing methods. A comparative study of preform surface and concentration analysis is performed. The gain behaviour is also thoroughly examined. A synthesis of all technological parameters of the fiber laser is then established and all technologies of the constituting integrated components are reviewed and compared. The experimental techniques mainly involve: site selective excitation tunability, cooperative luminescence, oxidation state changes induced by gamma irradiation, ytterbium-doped mono-mode continuous wave tunable three-level fiber laser. (TEC). 622 refs., 176 figs

  12. Influence of fiber type, fiber mat orientation, and process time on the properties of a wood fiber/polymer composite

    DEFF Research Database (Denmark)

    Plackett, David; Torgilsson, R.; Løgstrup Andersen, T.

    2002-01-01

    involved pre-compression, contact heating to the process temperature under vacuum and then rapid transfer to the press for consolidation and cooling. Composites were tested to determine response to water or water vapor, porosity, fiber volume fraction and tensile properties. The composites absorbed water......A rapid press consolidation technique was used to produce composites from two types of air-laid wood fiber mat, incorporating either mechanically refined or bleached chemi-thermomechanically refined Norway Spruce [Picea abies (L.) Karst] and a bicomponent polymer fiber. The manufacturing technique...... rapidly and showed changes in thickness with fluctuations in relative humidity. Porosity was higher in composites containing mechanically refined (MDF) fibers than in composites containing bleached chemi-thermomechanically refined (CTMP) fibers. Tensile test results suggessted that fiber wetting...

  13. Deposition of carbon nanotubes onto aramid fibers using as-received and chemically modified fibers

    International Nuclear Information System (INIS)

    Rodríguez-Uicab, O.; Avilés, F.; Gonzalez-Chi, P.I; Canché-Escamilla, G.; Duarte-Aranda, S.; Yazdani-Pedram, M.; Toro, P.; Gamboa, F.; Mazo, M.A.; Nistal, A.; Rubio, J.

    2016-01-01

    Highlights: • The surface of aramid fibers was functionalized by two acid treatments. • The treatment based on HNO_3/H_2SO_4 reduced the mechanical properties of the fibers. • CNTs were deposited on the aramid fibers, reaching electrical conductivity. • Homogeneous CNT distribution was achieved by using pristine fibers or chlorosulfonic acid. - Abstract: Multiwall carbon nanotubes (MWCNTs) oxidized by an acid treatment were deposited on the surface of as-received commercial aramid fibers containing a surface coating (“sizing”), and fibers modified by either a chlorosulfonic treatment or a mixture of nitric and sulfuric acids. The surface of the aramid fiber activated by the chemical treatments presents increasing density of CO, COOH and OH functional groups. However, these chemical treatments reduced the tensile mechanical properties of the fibers, especially when the nitric and sulfuric acid mixture was used. Characterization of the MWCNTs deposited on the fiber surface was conducted by scanning electron microscopy, Raman spectroscopy mapping and X-ray photoelectron spectroscopy. These characterizations showed higher areal concentration and more homogeneous distribution of MWCNTs over the aramid fibers for as-received fibers and for those modified with chlorosulfonic acid, suggesting the existence of interaction between the oxidized MWCNTs and the fiber coating. The electrical resistance of the MWCNT-modified aramid yarns comprising ∼1000 individual fibers was in the order of MΩ/cm, which renders multifunctional properties.

  14. Deposition of carbon nanotubes onto aramid fibers using as-received and chemically modified fibers

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez-Uicab, O. [Centro de Investigación Científica de Yucatán A.C., Unidad de Materiales, Calle 43 No.130, Col. Chuburna de Hidalgo, C.P. 97200 Mérida, Yucatán (Mexico); Avilés, F., E-mail: faviles@cicy.mx [Centro de Investigación Científica de Yucatán A.C., Unidad de Materiales, Calle 43 No.130, Col. Chuburna de Hidalgo, C.P. 97200 Mérida, Yucatán (Mexico); Gonzalez-Chi, P.I; Canché-Escamilla, G.; Duarte-Aranda, S. [Centro de Investigación Científica de Yucatán A.C., Unidad de Materiales, Calle 43 No.130, Col. Chuburna de Hidalgo, C.P. 97200 Mérida, Yucatán (Mexico); Yazdani-Pedram, M. [Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, S. Livingstone 1007, Independencia, Santiago (Chile); Toro, P. [Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Av. Beauchef 850, Santiago (Chile); Gamboa, F. [Centro de Investigacion y de Estudios Avanzados del IPN, Unidad Mérida, Depto. de Física Aplicada, Km. 6 Antigua Carretera a Progreso, 97310 Mérida, Yucatán (Mexico); Mazo, M.A.; Nistal, A.; Rubio, J. [Instituto de Cerámica y Vidrio (ICV-CSIC), Kelsen 5, 28049 Madrid (Spain)

    2016-11-01

    Highlights: • The surface of aramid fibers was functionalized by two acid treatments. • The treatment based on HNO{sub 3}/H{sub 2}SO{sub 4} reduced the mechanical properties of the fibers. • CNTs were deposited on the aramid fibers, reaching electrical conductivity. • Homogeneous CNT distribution was achieved by using pristine fibers or chlorosulfonic acid. - Abstract: Multiwall carbon nanotubes (MWCNTs) oxidized by an acid treatment were deposited on the surface of as-received commercial aramid fibers containing a surface coating (“sizing”), and fibers modified by either a chlorosulfonic treatment or a mixture of nitric and sulfuric acids. The surface of the aramid fiber activated by the chemical treatments presents increasing density of CO, COOH and OH functional groups. However, these chemical treatments reduced the tensile mechanical properties of the fibers, especially when the nitric and sulfuric acid mixture was used. Characterization of the MWCNTs deposited on the fiber surface was conducted by scanning electron microscopy, Raman spectroscopy mapping and X-ray photoelectron spectroscopy. These characterizations showed higher areal concentration and more homogeneous distribution of MWCNTs over the aramid fibers for as-received fibers and for those modified with chlorosulfonic acid, suggesting the existence of interaction between the oxidized MWCNTs and the fiber coating. The electrical resistance of the MWCNT-modified aramid yarns comprising ∼1000 individual fibers was in the order of MΩ/cm, which renders multifunctional properties.

  15. Manufacturing of Nanocomposite Carbon Fibers and Composite Cylinders

    Science.gov (United States)

    Tan, Seng; Zhou, Jian-guo

    2013-01-01

    Pitch-based nanocomposite carbon fibers were prepared with various percentages of carbon nanofibers (CNFs), and the fibers were used for manufacturing composite structures. Experimental results show that these nanocomposite carbon fibers exhibit improved structural and electrical conductivity properties as compared to unreinforced carbon fibers. Composite panels fabricated from these nanocomposite carbon fibers and an epoxy system also show the same properties transformed from the fibers. Single-fiber testing per ASTM C1557 standard indicates that the nanocomposite carbon fiber has a tensile modulus of 110% higher, and a tensile strength 17.7% times higher, than the conventional carbon fiber manufactured from pitch. Also, the electrical resistance of the carbon fiber carbonized at 900 C was reduced from 4.8 to 2.2 ohm/cm. The manufacturing of the nanocomposite carbon fiber was based on an extrusion, non-solvent process. The precursor fibers were then carbonized and graphitized. The resultant fibers are continuous.

  16. Preliminary characterization of glass fiber sizing

    Energy Technology Data Exchange (ETDEWEB)

    Noergaard Petersen, H.; Almdal, K. [Technical Univ. of Denmark. DTU Nanotech, Kgs. Lyngby (Denmark); Kusano, Y.; Broendsted, P. [Technical Univ. of Denmark. DTU Wind Energy, Risoe Campus, Roskilde (Denmark)

    2013-09-01

    Glass fiber surfaces are treated with sizing during manufacturing. Sizing consists of several components, including a film former and a silane coupling agent that is important for adhesion between glass fibers and a matrix. Although the sizing highly affects the composite interface and thus the strength of the composites, little is known about the structure and chemistry of the sizing. A part of sizing was extracted by soxhlet extraction. The fibers were subsequently burned and some fibers were merely burned for analysis of glass fiber and sizing. The results showed that the analyzed fibers had amounts of bonded and physisorbed sizing similar to what has been presented in literature. An estimated sizing thickness was found to be approximately 100 nm. It is indicated that an epoxy-resin containing film former and a polyethylene oxide lubricant are present, yet no silanes or other sizing components were identified in the extractant. (Author)

  17. Optical fiber head for providing lateral viewing

    Science.gov (United States)

    Everett, Matthew J.; Colston, Billy W.; James, Dale L.; Brown, Steve; Da Silva, Luiz

    2002-01-01

    The head of an optical fiber comprising the sensing probe of an optical heterodyne sensing device includes a planar surface that intersects the perpendicular to axial centerline of the fiber at a polishing angle .theta.. The planar surface is coated with a reflective material so that light traveling axially through the fiber is reflected transverse to the fiber's axial centerline, and is emitted laterally through the side of the fiber. Alternatively, the planar surface can be left uncoated. The polishing angle .theta. must be no greater than 39.degree. or must be at least 51.degree.. The emitted light is reflected from adjacent biological tissue, collected by the head, and then processed to provide real-time images of the tissue. The method for forming the planar surface includes shearing the end of the optical fiber and applying the reflective material before removing the buffer that circumscribes the cladding and the core.

  18. Optical fiber composition and radiation hardness

    International Nuclear Information System (INIS)

    Wall, J.A.; Loretz, T.J.

    1982-01-01

    Germanium phosphosilicate and germanium borosilicate fibers doped with cerium were fabricated and tested for their responses to steady-state Co-60 radiation at -55 C, +20 C and +125 C. A fiber with germanium, boron and phosphorous in the silicate core and doped with antimony in the core and clad was similarly tested. All of the fibers showed significant improvements in radiation hardness at 20 C compared to undoped fibers of the same base composition. At -55 C, however, all except the cerium doped germanium phosphosilicate were very radiation sensitive and also showed increases in the rate of induced loss at +125 C. The cerium doped germanium phosphosilicate fiber showed virtually no change in radiation sensitivity at the temperature extremes and could prove useful in applications requiring relatively short lengths of fiber

  19. Adhesion of cellulose fibers in paper.

    Science.gov (United States)

    Persson, Bo N J; Ganser, Christian; Schmied, Franz; Teichert, Christian; Schennach, Robert; Gilli, Eduard; Hirn, Ulrich

    2013-01-30

    The surface topography of paper fibers is studied using atomic force microscopy (AFM), and thus the surface roughness power spectrum is obtained. Using AFM we have performed indentation experiments and measured the effective elastic modulus and the penetration hardness as a function of humidity. The influence of water capillary adhesion on the fiber-fiber binding strength is studied. Cellulose fibers can absorb a significant amount of water, resulting in swelling and a strong reduction in the elastic modulus and the penetration hardness. This will lead to closer contact between the fibers during the drying process (the capillary bridges pull the fibers into closer contact without storing up a lot of elastic energy at the contacting interface). In order for the contact to remain good in the dry state, plastic flow must occur (in the wet state) so that the dry surface profiles conform to each other (forming a key-and-lock type of contact).

  20. Uncladded sensing fiber for refractive index measurement

    International Nuclear Information System (INIS)

    Bhardwaj, V.; Gangwar, R. K.; Pathak, A. K.; Singh, V. K.

    2016-01-01

    The formation of chemically etched optical fiber for use in refractive index sensor is addressed. This presented design of a refractive index (RI) sensor is based on recording the power loss exhibited by radiation propagating through an etched multimode fiber (MMF) immersed in the liquid under study. The decreasing diameters of fibers are found to be strongly dependent on the temperature and etchant composition. This experiment was performed for different unclad etched fibers for same sensing length and the RI changes from 1.33 RIU to 1.38 RIU. When the multimode fiber (MMF) is etched for 12 hours the sensitivity of the sensor is approximately 204.25dBm/RIU, which is larger than without etched fiber having sensitivity 127.2dBm/RIU.