WorldWideScience

Sample records for vulcanization

  1. Vulcanized Vortex

    CERN Document Server

    Cho, Inyong

    2008-01-01

    We investigate vortex configurations with the "vulcanization" term introduced for renormalization of $\\phi_\\star^4$ theory in canonical $\\theta$-deformed noncommutativity. In the small-$\\theta$ limit, we perform numerical calculations and find that nontopological vortex solutions exist as well as Q-ball type solutions, but topological vortex solutions are not admitted.

  2. Vulcan god of fire

    CERN Document Server

    McLelland, Tim

    2012-01-01

    Vulcan: God of Fire is a historical account of Britain's nuclear deterrent force, the development of atomic/thermonuclear weapons and the bombers. It includes a description of the design, development and manufacture of the Vulcan, the flight testing programme and entry into RAF service. There is also a full account of the Vulcan's career, including its primary role as a nuclear bomber and as a key participant in the 1982 Falklands conflict. Further coverage includes the use of the Vulcan as a refuelling tanker and reconnaissance platform, and the recent project to restore a Vulcan to flyi

  3. The Vulcan kidney.

    Science.gov (United States)

    Waud, D R

    1999-02-01

    One can often gain new insights into a topic when approaching it from a new angle. The paradigm example involves the insights into histology that can be gained from studying pathology. For example, a rare cell type in the pituitary suddenly becomes very easy to recognize once a whole field of them can be seen in a tumour. Similarly, one can gain insights by looking at species other than our own. In this article, Doug Waud, using the kidney in Vulcans, takes this latter theme one step further to provide useful insights into renal physiology and pharmacology.

  4. Vulcanism and Radiocarbon Dates

    Science.gov (United States)

    Libby, L. M.; Libby, W. F.

    1972-10-01

    We consider whether the long term perturbation of radiocarbon dates, which is known to be approximately a sin function of period about 8000 years and amplitude of about 8% peak-to-peak, could have been caused in any major part by vulcanism. We conclude that this is not the case. On the contrary, present day volcanoes are a far less important source of inert CO{sub 2} (about 100 fold less) than is man's burning of fossil fuels which has caused the Suess dilution of about 2%. (auth)

  5. VULCANIZATION KINETICS OF SILICONE RUBBER

    Institute of Scientific and Technical Information of China (English)

    YUAN Qiang; LI Yufu; LI Guangliang

    1988-01-01

    Vulcanization rate of silicone rubber with the aid of organic peroxide or hydrosilylation agent was studied by using oscillation disk rheometer. It was found that the process of network formation would take place through one, two or three steps depending on the structure of the reactants. The effect of phenyl group, vinyl terminals on polysiloxane chain and the functionality of silylation agent was also studied.

  6. Development of rubber gloves by radiation vulcanization

    Science.gov (United States)

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

    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.

  7. First Results from the VULCAN Diffractometer at the SNS

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xun-Li [ORNL; Holden, T. M. [Northern Stress Technology; Stoica, Alexandru Dan [ORNL; An, Ke [ORNL; Skorpenske, Harley David [ORNL; Rennich, George Q [ORNL; Iverson, Erik B [ORNL; Jones, Amy Black [ORNL

    2010-01-01

    On Friday June 26, 2009, the neutron beam shutter for the VULCAN diffractometer at the SNS was opened for the first time. Initial measurements to characterize the instrument performance are reported. It is shown that the measurement results are by and large in agreement with design calculations. New research opportunities with VULCAN are discussed.

  8. Effect of vulcanization system and carbon black on mechanical and swelling properties of EPDM blends

    Directory of Open Access Journals (Sweden)

    Hesty Eka Mayasari

    2016-06-01

    Full Text Available EPDM (Ethylene propylene diene monomer is one of synthetic rubber that widely used in automotive. It must be vulcanized and added by other materials before used. The aim of this study is to investigate the effect of vulcanization system and the addition of carbon black (CB to the mechanical properties and swelling characteristic of EPDM. This research used three vulcanization system, conventional vulcanization (CV, efficient vulcanization (EV and semi-efficient vulcanization (SEV with the variation of carbon black 50, 60, 70 phr (per hundred resin. This research showed that EV system resulted faster vulcanization time and lower delta torque than SEV and CV systems. This system also performed the highest tensile strength, elongation, and tear strength, while SEV system resulted the highest hardness. Furthermore, the conventional vulcanization system resulted the lowest swelling index.

  9. Algorithmic Enhancements for the VULCAN Navier-Stokes Solver

    Science.gov (United States)

    Edwards, Jack R.

    2004-01-01

    Work performed over the last three years has resulted in the addition of several new algorithms to the VULCAN code, NASA's standard for Navier-Stokes calculations in high-speed aeropropulsion devices. This final report describes the new techniques in brief and presents sample results from their use.

  10. Review of laser diagnostics at the Vulcan laser facility

    Institute of Scientific and Technical Information of China (English)

    Ian Musgrave; Marco Galimberti; Alexis Boyle; Cristina Hernandez-Gomez; Andrew Kidd; Bryn Parry; Dave Pepler; Trevor Winstone; John Collier

    2015-01-01

    In this paper we review the provision of the laser diagnostics that are installed on the Vulcan laser facility. We will present strategies for dealing with the energy of high energy systems and with ways of handling the beam sizes of the lasers. We present data captured during typical experimental campaigns to demonstrate their reliability and variation in shot to shot values.

  11. Algorithmic Enhancements to the VULCAN Navier-Stokes Solver

    Science.gov (United States)

    Litton, D. K.; Edwards, J. R.; White, J. A.

    2003-01-01

    VULCAN (Viscous Upwind aLgorithm for Complex flow ANalysis) is a cell centered, finite volume code used to solve high speed flows related to hypersonic vehicles. Two algorithms are presented for expanding the range of applications of the current Navier-Stokes solver implemented in VULCAN. The first addition is a highly implicit approach that uses subiterations to enhance block to block connectivity between adjacent subdomains. The addition of this scheme allows more efficient solution of viscous flows on highly-stretched meshes. The second algorithm addresses the shortcomings associated with density-based schemes by the addition of a time-derivative preconditioning strategy. High speed, compressible flows are typically solved with density based schemes, which show a high level of degradation in accuracy and convergence at low Mach numbers (M less than or equal to 0.1). With the addition of preconditioning and associated modifications to the numerical discretization scheme, the eigenvalues will scale with the local velocity, and the above problems will be eliminated. With these additions, VULCAN now has improved convergence behavior for multi-block, highly-stretched meshes and also can solve the Navier-Stokes equations for very low Mach numbers.

  12. Radiation vulcanization of natural rubber latex (part 6). Improvement of aging propreties of latex lubber vulcanized with radiation

    Energy Technology Data Exchange (ETDEWEB)

    Makuuchi, Keizo; Tsushima, Kyogo

    1988-10-15

    Concerning the vulcanization of natural rubber latex with radiation by using acrylic ester as accelerator, causes for loss of anti-aging property by leaching and counter-measure against it were reported. For the experiment, 2-ethyl hexyl acrylate with carbon tetra-chloride as accelerator, 2% aqueous solution of ammonia or acetic acid as leaching water, were used. For the analysis of extracts, ultra-violet absorption and gas chromatography were applied. As the result of the experiment, it was recognized that anti-aging property was more decreased by more increased quantity of extracted protein which was naturally contained in the natural rubber latex and functioned as anti-aging material, and that by radiation vulcanization, non-rubber components were destroyed to result the increased quantity of extracts compared with that of non-vulcanized. Concerning the improvement of anti-aging property, experimental comparison of miscellaneous methods resulted that the addition of sodium di-n-buthyl di-thiocarbamate was most effective. 3 references, 3 figures, 5 tables.

  13. An open-source chemical kinetics network: VULCAN

    Science.gov (United States)

    Tsai, Shang-Min; Lyons, James; Heng, Kevin

    2015-12-01

    I will present VULCAN, an open-source 1D chemical kinetics code suited for the temperature and pressure range relevant to observable exoplanet atmospheres. The chemical network is based on a set of reduced rate coefficients for C-H-O systems. Most of the rate coefficients are based on the NIST online database, and validated by comparing withthermodynamic equilibrium codes (TEA, STANJAN). The difference between the experimental rates and those from the thermodynamical data is carefully examined and discussed. For the numerical method, a simple, quick, semi-implicit Euler integrator is adopted to solve the stiff chemical reactions, within an operator-splitting scheme for computational efficiency.Several test runs of VULCAN are shown in a hierarchical way: pure H, H+O, H+O+C, including controlled experiments performed with a simple analytical temperature-pressure profiles, so that different parameters, such as the stellar irradiation, atmospheric opacities and albedo can be individually explored to understand how these properties affect the temperaturestructure and hence the chemical abundances. I will also revisit the "transport-induced-quenching” effects, and discuss the limitation of this approximation and its impact on observations. Finally, I will discuss the effects of C/O ratio and compare with published work in the literature.VULCAN is written in Python and is part of the publicly-available set of community tools we call the Exoclimes Simulation Platform (ESP; www.exoclime.org). I am a Ph.D student of Kevin Heng at the University of Bern, Switzerland.

  14. Study on radiation vulcanization of natural rubber latex

    Institute of Scientific and Technical Information of China (English)

    ZhuNan-Kang; MakuuchiK; 等

    1997-01-01

    The effect of dose rate of 60Co γ-ray on radiation vulacnization of natural rubber latex is studied using Malysian latex with 0.002 mass fraction KOH and 0.05 mass fraction n-BA.Results show that,when radiation doses are 20 and 15kGy,only that the dose rates are greater than 0.49 and 1.6 kGY/h,respectively can make the tensile strength of latex film meet the related standard;besides,storage time of radiation vulcanization latex has no effect on physical properties of the film.

  15. 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.

  16. Progress in radiation vulcanization of natural rubber latex

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-03-01

    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)

  17. The use of vulcanic glasses in cellular concrete

    Directory of Open Access Journals (Sweden)

    Alvarez, J. L.

    1996-12-01

    Full Text Available This paper covers studies made using different mixes for cellular concrete variating silica sand, vulcanic glass and aluminium powder contents. Studies on compressive strenght, dry density and X-ray diffraction are performed on autoclave cured cellular concrete, concluding that best results are attained when vulcanic glass contents reaches 50% of silica sand. When percentage of aluminium powder is diminished from 0.11% to 0.09%, alight increase in density, with noticiable growth of comprensive strength are observed.

    Se hace un estudio con diferentes mezclas, teniendo como variables la arena sílice, el vidrio volcánico y el polvo de aluminio. Al hormigón celular, una vez curado en autoclave, se le hace un estudio de resistencia a la compresión, densidad en estado seco y difracción de rayos X, llegándose a la conclusión de que los mejores resultados se obtienen cuando se emplea el vidrio volcánico al 50% en sustitución de la arena sílice. Cuando se disminuye el porcentaje de polvo de aluminio de 0,11% a 0,09%, se presenta un ligero aumento en la densidad, con un notable crecimiento de la resistencia a la compresión.

  18. Progress in radiation vulcanization of natural rubber latex

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-03-01

    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)

  19. 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.

  20. Dynamically vulcanized biobased polylactide/natural rubber blend material with continuous cross-linked rubber phase.

    Science.gov (United States)

    Chen, Yukun; Yuan, Daosheng; Xu, Chuanhui

    2014-03-26

    We prepared a biobased material, dynamically vulcanized polylactide (PLA)/natural rubber (NR) blend in which the cross-linked NR phase owned a continuous network-like dispersion. This finding breaks the traditional concept of a sea-island morphology formed after dynamic vulcanization of the blends. The scan electron microscopy and dissolution/swell experiments provided the direct proof of the continuous cross-linked NR phase. This new biobased PLA/NR blend material with the novel structure is reported for the first time in the field of dynamic vulcanization and shows promise for development for various functional applications.

  1. 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.

  2. First in-situ lattice strains measurements under load at VULCAN

    Energy Technology Data Exchange (ETDEWEB)

    An, Ke [ORNL; Skorpenske, Harley David [ORNL; Stoica, Alexandru Dan [ORNL; Wang, Xun-Li [ORNL; Cakmak, Ercan [ORNL

    2011-01-01

    The engineering materials diffractometer, VULCAN, at the Spallation Neutron Source began commissioning on June 26, 2009. This instrument is designed for materials science and engineering studies. In situ lattice strain measurements of a model metallic material under monotonic tensile load have been performed on VULCAN. The tensile load was applied under two different strain rates, and neutron diffraction measurements were carried out in both high-intensity and high-resolution modes. These experiments demonstrated VULCAN's in situ study capability of deformation behaviors even during the early phases of commissioning.

  3. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

    Barroso-Bujans, F. [Instituto de Ciencia y Tecnologia de Polimeros, CSIC, Juan de la Cierva 3, 28006 Madrid (Spain)], E-mail: fbarroso@ictp.csic.es; Verdejo, R.; Lozano, A. [Instituto de Ciencia y Tecnologia de Polimeros, CSIC, Juan de la Cierva 3, 28006 Madrid (Spain); Fierro, J.L.G. [Instituto de Catalisis y Petroleoquimica, CSIC, Marie Curie 2, Cantoblanco, 28049 Madrid (Spain); Lopez-Manchado, M.A. [Instituto de Ciencia y Tecnologia de Polimeros, CSIC, Juan de la Cierva 3, 28006 Madrid (Spain)

    2008-10-15

    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.

  5. Accelerated aging and stabilization of radiation-vulcanized EPDM rubber

    Science.gov (United States)

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

    2000-03-01

    The effect of different antioxidants and their mixtures on the thermal aging and accelerated weathering of γ-radiation vulcanized EPDM rubber in presence of crosslinking coagent, was investigated. The compounds used were either a synergistic blend of phenolic and phosphite antioxidants, i.e. 1:4 Irganox 1076: Irgafos 168 or a blend of arylamine and quinoline type antioxidants, i.e. 1:1 IPPD: TMQ, at fixed concentration. Tinuvin 622 LD hindered amine light stabilized (HALS) was also used. The response was evaluated by the tensile strength and elongation at break for irradiated samples after thermal aging at 100°C for 28 days and accelerated weathering (Xenon test) up to 200 h.

  6. STUDIES ON SELF-VULCANIZING FLUOROELASTOMER/PHENOL HYDROXY SILICONE RUBBER BLENDS

    Institute of Scientific and Technical Information of China (English)

    Ya-ming Wang; Lan Liu; Yuan-fang Luo; De-min Jia

    2009-01-01

    Self-vulcanizing blends of phenol hydroxy silicone rubber (PHSR) and fluoroelastomer (FPM) were prepared. Vulcanized rubbers with lower glass transition temperature (Tg) were successfully obtained. The results of dynamic mechanical analysis (DMA) show that the vulcanized FPM/PHSR (10 phr) blend has only one Tg temperature, demonstrating the well compatibility between FPM and PHSR. The thermogravimetric analysis (TGA) demonstrates that the PHSR do little damage to the thermal stability of FPM. The vulcanization characteristics of the FPM/PHSR blends were analyzed by using oscillating disc rheometer (ODR). The results show that FPM/PHSR blends have smaller Smin values and longer scorch time than that of FPM with the same level of bisphenol AF curing agent. It means that FPM/PHSR blends have better processability and curing security. Better mechanical properties can be gained for FPM/PHSR blends at appropriate level of PHSR.

  7. VULCAN: an Open-Source, Validated Chemical Kinetics Python Code for Exoplanetary Atmospheres

    OpenAIRE

    2016-01-01

    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 ...

  8. NBR 的硫化体系优化%Optimizing of Vulcanization System of NBR

    Institute of Scientific and Technical Information of China (English)

    吴祥东; 王鹤; 李海; 赵树高

    2016-01-01

    The effect of sulfur content in sulfur vulcanization and dicumyl peroxide (DCP) content in peroxide vulcanization on curing characteristics ,curing dynamics of nitrile rubber (NBR) compound and physical and mechanical properties ,ageing‐resistant performance of NBR vulcanizate were investi‐gated .The results showed that with the increase of sulfur or DCP content ,the scorch time and vul‐canization time of NBR compound reduced ,but the vulcanization degree and the curing rate increased . The vulcanization process had two first order reactions in the sulfur vulcanization and only a first order reaction in the peroxide vulcanization .The curing reaction rate constant increased linearly with the in‐crease of DCP content .Compared with sulfur vulcanization ,the NBR vulcanizate had good compres‐sion resistance and aging resistance with peroxide vulcanization .%研究了硫黄硫化体系中硫黄变量以及过氧化物硫化体系中DCP变量对NBR硫化特性、硫化动力学及力学性能、耐老化性能的影响。结果表明,NBR混炼胶的焦烧时间、正硫化时间均随硫黄用量或过氧化物用量的增加而降低,硫化程度和硫化速率增加;硫黄硫化表现为两个一级反应,而过氧化物硫化为一个一级反应,并且硫化反应速率常数随DCP用量的增加而线性增大;与硫黄硫化体系相比,过氧化物硫化体系得到的NBR硫化胶具有较好的抗压变性能和耐老化性能。

  9. Micro-structural evolution of rubber/clay nanocomposites with vulcanization process

    Directory of Open Access Journals (Sweden)

    2011-09-01

    Full Text Available Brominated isobutyl-isoprene rubber/clay nanocomposite (BIIRCN and ethylene-propylene-diene-monomer rubber/clay nanocomposite (EPDMCN were prepared by melt blending. The micro-structural evolution of these two kinds of rubber/clay nanocomposites (RCNs with vulcanization process was investigated using wide-angle X-ray diffraction (WAXD and transmission electron microscope (TEM. The WAXD results revealed that the intercalated structure of organically modified clay (OMC changed throughout the whole curing process. The intercalated structure kept on changing beyond the vulcanization stage of T90. The interlayer space of intercalated silicate in uncured BIIRCN is larger than that in uncured EPDMCN. However, the intercalated structure for EPDMCN changed by a larger extent than that for BIIRCN during the vulcanization process, and the interlayer space of the intercalated structure is larger in the cured EPDMCN than that in the cured BIIRCN. It was found that the intercalant (i.e., octadecylamine, ODA for OMC could shorten the scorch time of the curing reaction, and increase the curing rate, which was attributed to the further intercalation during vulcanization. TEM results indicated that the spatial distribution of OMC is much better in BIIR (a polar rubber matrix than that in EPDM (a non-polar rubber matrix. The changes in spatial dispersion structure during vulcanization for EPDMCN and BIIRCN show different trends. In conclusion, the polarity of the rubber is the determining factor influencing the evolution of both the intercalated structure and the spatial dispersion of clay during vulcanization.

  10. 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.

  11. A Performance Comparison for Two Versions of the Vulcan Photometer

    Science.gov (United States)

    Borucki, W. J.; Caldwell, D. A.; Koch, D. G.; Jenkins, J. M.; Showen, R. L.

    2001-01-01

    Analysis of the images produced by the first version (V1) of the Vulcan photometer indicated that two major sources of noise were sky brightness and image motion. To reduce the effect of the sky brightness, a second version (V2) with a longer focal length and a larger format detector was developed and tested. The first version consisted of 15-centimeter (cm) focal length, F/1.5 Aerojet Delft reconnaissance lens, and a 2048 x 2048 format front-illuminated charged coupled device (CCD) with 9 microns micropixels (Mpixels). The second version used a 30-cm focal length, F/2.5 Kodak AeroEktar lens, and a 4096 x 4096 format CCD with 9 micro pixels. Both have a 49-square-degree field of view (FOV) but the area of the sky subtended by each pixel in the V2 version is one-fourth that of the V1 version. This modification substantially reduces the shot noise due to the sky background and allows fainter stars to be monitored for planetary transits. To remove the data gap and consequent signal-level change caused by flipping the photometer around the declination axis and to reduce image movement on the detector, several other modifications were incorporated. These include modifying the mount and stiffening the photometer and autoguider structures to reduce flexure. This paper compares the performance characteristics of each photometer and discusses tests to identify sources of systematic noise.

  12. adidas Vulcanized Slim 古铜情怀

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    由于Adidas Originals鞋款众多。有些鞋款也难免会出现滞销的情况。为了避免这种情况的扩大,设计团队推出了Vulcanized Slim。窄型鞋身的设计使得穿上以后显得脚型修长.鞋侧有着类型Zoom Tennis Classic设计的内嵌式镂空设计,并以此标识Adidas的三道杠,若隐若现地增加了低调而优雅的气质。最瞩目的是此款鞋除了雪白色之外,古铜色是主推的配色,这种雅致的色调,远处看仿佛闪烁着金粉色。用来搭配正装无疑会为整体搭配增色不少。

  13. Wettability of Nafion and Nafion/Vulcan carbon composite films.

    Science.gov (United States)

    Li, Xiaoan; Feng, Fangxia; Zhang, Ke; Ye, Siyu; Kwok, Daniel Y; Birss, Viola

    2012-04-24

    The wettability of the Pt/carbon/Nafion catalyst layer in proton exchange membrane fuel cells is critical to their performance and durability, especially the cathode, as water is needed for the transport of protons to the active sites and is also involved in deleterious Pt nanoparticle dissolution and carbon corrosion. Therefore, the focus of this work has been on the first-time use of the water droplet impacting method to determine the wettability of 100% Nafion films, as a benchmark, and then of Vulcan carbon (VC)/Nafion composite films, both deposited by spin-coating in the Pt-free state. Pure Nafion films, shown by SEM analysis to have a nanochanneled structure, are initially hydrophobic but become hydrophilic as the water droplet spreads, likely due to reorientation of the sulfonic acid groups toward water. The wettability of VC/Nafion composite films depends significantly on the VC/Nafion mass ratios, even though Nafion is believed to be preferentially oriented (sulfonate groups toward VC) in all cases. At low VC contents, a significant water droplet contact angle hysteresis is seen, similar to pure Nafion films, while at higher VC contents (>30%), the films become hydrophobic, also exhibiting superhydrophobicity, with surface roughness playing a significant role. At >80% VC, the surfaces become wettable again as there is insufficient Nafion loading present to fully cover the carbon surface, allowing the calculation of the Nafion:carbon ratio required for a full coverage of carbon by Nafion.

  14. 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.

  15. INFLUENCE OF THE VOLATILE FATTY ACID CONTENT TO RADIATION VULCANIZED NATURAL RUBBER LATEX (RVNRL

    Directory of Open Access Journals (Sweden)

    CHIRINOS, Hugo David

    2012-01-01

    Full Text Available Natural rubber latex is a dispersion of natural rubber particles in water. These particles are coated with aprotein layer which will stabilize the dispersion in water by forming an electric charge in the layer. Any differentcondition affecting this layer disturbs the stability of dispersion. Microorganism attack disturbs the protein layerand consequently the stability of the dispersion. By adding 1.2% by weight of NH3, the stability of the dispersioncan be improved. The fresh latex was irradiated by Co-60 with irradiation dose of 10, 20, 30, 40 and 100 kGy.The results showed a relationship between the volatile fatty acid content (VFA, product from microorganismattack on carbohydrate and the green strength or the physical properties of vulcanized film. Low VFA numbershowing a higher physical strength of the film either un-vulcanized or vulcanized. It appeared that the structurewas responsible in yielding a good physical property of the film.

  16. 变换工序硫化管线改造%Revamp of Vulcanization Pipeline in CO Shift Unit

    Institute of Scientific and Technical Information of China (English)

    李彦兴

    2013-01-01

    介绍合成氨装置变换催化剂选型、催化剂硫化工艺、硫化存在的问题及改造措施。%Describe the choice of CO shift catalyst , the catalyst vulcanization process , the vulcanization problems and the revamping measures .

  17. 78 FR 28836 - Vulcan/BN Geothermal Power Company; Supplemental Notice That Initial Market-Based Rate Filing...

    Science.gov (United States)

    2013-05-16

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Vulcan/BN Geothermal Power Company; Supplemental Notice That Initial Market... in the above-referenced proceeding of Vulcan/BN Geothermal Power Company's application for...

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

    Science.gov (United States)

    Tsai, Shang-Min; Lyons, James R.; Grosheintz, Luc; Rimmer, Paul B.; Kitzmann, Daniel; Heng, Kevin

    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 & 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.

  19. 【电竞之音】 ASUS ROG Vulcan ANC

    Institute of Scientific and Technical Information of China (English)

    鞠遵霖

    2012-01-01

    ASUS ROG Vulcan ANC编辑评价作为华硕ROG的首款专业电竞耳机,ROG Vulcan ANC的设计针对性强,对于电竞用户而言具有相当的实用价值,音质还有较大提升空间产品信息价格厂商电话网址1099元华硕电脑800-820-6655www.asus.com.cn在过去,有一群人钟意用粗糙的设备录制晦涩抽象的音乐,

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

    Science.gov (United States)

    1975-08-01

    53 percent for the unstressed and 66 percent for the stressed specimens. 4 A Z! - ~ - The attempt to improve the hydroltyic stability of vulcanized...vulcanized bonds show no loss in bond strength after two years otdoors at Rock Island * or after 14 days in the hydrolytic stability test in which...METAL Part b Weit COMPOUNDNG INGREDIENTS E57 MU__ N200 Nordel i04o0 ( EPDm ) 100 Stereon 700 (SBR) 100 Neoprene WD (CR) 100 Paracril AJ (NBR) 85 Paracril B

  1. Hydrophilicity Modification of Addition-cured Room Temperature Vulcanization Silicone Rubber

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Allyl terminated polyether was used to improve the hydrophilicity of addition-cured room temperature vulcanization silicone rubber. With the increasing of the polyether, both the hydrophilicity and water absorbed of the vulcanizates were increased. The mechanical properties were also improved by adding the polyether. The result showed that 1.5wt% of the polyether provided the silicone rubber with proper hydrophilicity.

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

    Directory of Open Access Journals (Sweden)

    Tipapon Khamdaeng

    2014-01-01

    Full Text Available 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 mechanical interaction of rubber constituents. In this study, tensile force and elongation were measured to analyze the rubber deformation. In order to describe the deformation behavior of the combined infrared and hot-air vulcanized rubber glove, the material properties, stress and stretch, were therefore presented. The stress-stretch relationships of the vulcanized rubber gloves were established based on previously well-known hyperelastic material model and their material parameters were determined using a parameter estimation technique. In conclusion, the stress-stretch relationships of the combined infrared and hot-air vulcanized rubber glove can be successfully established with our optimized material parameters; the magnitudes of rubber modulus (CR and locking stretch (λL were in a range of 0.041-0.079 MPa and 10.27-70.12, respectively. Furthermore, the resulting material parameters can be properly used to indicate the micro structural deformation.

  3. Inverse Vulcanization of Sulfur using Natural Dienes as Sustainable Materials for Lithium-Sulfur Batteries.

    Science.gov (United States)

    Gomez, Iñaki; Leonet, Olatz; Blazquez, J Alberto; Mecerreyes, David

    2016-12-20

    Lithium-sulfur batteries are among the most promising next-generation battery systems due to the high capacity of sulfur as cathodic material. Beyond its interesting intrinsic properties, sulfur possesses a very low conductivity and complex electrochemistry, which involves the high solubility of the lithium sulfides in the electrolyte. These two characteristics are at the core of a series of limitations of its performance as active cathode material, which leads to batteries with low cyclability. Recently, inverse vulcanized sulfur was shown to retain capacity far better than elemental sulfur, leading to batteries with excellent cyclability. Nevertheless, the diene co-monomers used so far in the inverse vulcanization process are man-made molecules. Herein, a tentative work on exploring inverse vulcanization using two naturally available monomers, diallyl sulfide and myrcene, is presented. The inverse vulcanization of sulfur was successfully completed, and the resulting polymers were characterized by FTIR, NMR spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. Afterwards these polymers were tested as cathodic materials in lithium-sulfur cells. The sulfur-natural dienes materials exhibited high capacity at different C rates and high lifetime over 200 cycles with very high capacity retention at a moderate C rate of C/5. Altogether, these materials made from inexpensive and abundant chemicals are an excellent option as sustainable materials for electrochemical energy storage.

  4. 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.

  5. Effect of Crystallinity of TPI on the Properties of SBR/TPI Blends vulcanized by Different Sulfur Vulcanization Systems%TPI结晶性对硫黄硫化SBR/TPI并用胶性能的影响

    Institute of Scientific and Technical Information of China (English)

    张志广; 车永兴; 杨晨燕; 杜爱华

    2011-01-01

    The effects of crystallinity of TPI on the properties of SBR/TPI vulcanizates vulcanized by conventional vulcanization (CV) system and semi-efficient vulcanization (SEV) system were investigated, respectively.The results showed that the crystallization melting enthalpy of SBR/TPI vulcanizates vulcanized by SEV system were slightly higher than those of the vulcanizates vulcanized by CV system.The tensile strength of original sample, frozen sample and pre-tension frozen sample vulcanized by SEV system were higher than those of the samples vulcanized by CV system.The modulus at 100 % and compression strength of pre-tension frozen sample vulcanized by SEV system were significantly greater than those of pre-tension frozen sample vulcanized by CV system when the content of TPI was more than 50 phr.The tanδ peak values of the vulcanizates vulcanized by SEV system were lower than those of the vulcanizates vulcanized by CV system.The differences of tanδ peak values of 2 kinds of vulcanizates gradually became small with the increase of TPI content.%分别研究了反式-1,4-聚异戊二烯(TPI)结晶性对普通硫黄硫化体系(CV)和半有效硫黄硫化体系(SEV)硫化的SBR/TPI硫化胶性能的影响.结果表明,SEV体系的硫化胶结晶熔融焓略高.与CV体系相比,SEV体系的硫化试样拉伸强度高.在同一压缩深度下,当TPI用量超过50份后,SEV体系的硫化胶压缩强度高于CV体系的硫化胶.同一并用比时,SEV体系的硫化胶tanδ峰值低于CV体系的硫化胶;随着TPI用量的增加,两种体系的硫化胶tanδ峰值之间的差异逐渐减小.

  6. Patent for Invention of Guilin Rubber Machinery Transla- tional Vulcanizer Awarded the Honorary Title of China Excel- lent Patent

    Institute of Scientific and Technical Information of China (English)

    Yang Wenguang; Li Li

    2011-01-01

    Recently, the results of the 13th China Patent Awards were publicized. The patent for invention of "translational vulcanizer" applied by Guilin Rubber Machinery Factory was appraised as China Excellent Patent.

  7. 传统与现代的融合——川崎 2003 Vulcan 1600经典款

    Institute of Scientific and Technical Information of China (English)

    陈方

    2003-01-01

    @@ 日本川崎公司是世界上著名的摩托车生产商,由川崎公司推出的 2003 Vulcan 1600 经典款(以下简称Vulcan1600)以其出色的质量、外观和性能赢得市场一致的好评,并成为川崎公司的旗舰产品.

  8. 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.

  9. 用价值诠释完美——2006 Kawasaki VULCAN 900 CLASSIC

    Institute of Scientific and Technical Information of China (English)

    Charles; Fveritt; Kinney; Jones(摄影); 别嘉(编译)

    2006-01-01

    在今年“戴托纳摩托周”期间,川崎向公众展示了他们推出的新款巡航车Vulcan 900 Classic。作为经典车系的最新传承,Vulcan 900 Classic具有非凡的价值体现。如今这个年代,价值并不是特别难以体现的东西,甚至那些惹人喜爱的宠物,都能明白什么是价值:如果能够讨得主人的欢心,就能得到想要的食物。简而言之,价值的核心定义就在于呈现所有的可爱之处,换来欣赏及肯定。

  10. 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 

  11. Methodology for construction of Vulcan model of the Saltby Volcanic Formation, DGSM Nottingham-Melton project

    OpenAIRE

    2005-01-01

    The object of constructing the Vulcan model was to create a quantitative 3-D visualisation of the concealed Saltby Volcanic Formation (SVF) (Carboniferous) within the area covered by the Nottingham and Melton Mobray 1:50 000 scale geological sheets (Nos. 126 and 142) which forms part of the current (2003) DGSM Nottingham-Melton Project. The model was not intended to be a structural geological representation; rather, a lithostratigraphic visualisation 'normalised' to an arbitrar...

  12. STUDY ON THE MISCIBILITY OF DYNAMICALLY VULCANIZED EPDM/PP BLEND BY POSITRON ANNIHILATION SPECTROSCOPY

    Institute of Scientific and Technical Information of China (English)

    Tao Jiang; Xue-liang Jiang; Shi-yuan Cheng; Yi-qun Dai; Shao-jie Wang; Bo Wang

    2000-01-01

    Positron annihilation spectroscopy (PAS) was utilized to investigate the relationship between the free-volume hole properties and miscibility of dynamically vulcanized EPDM/PP blend. The results showed that the noncrystalline region of PP and EPDM in the blend was partially miscible and the miscibility of the blend became worse when the weight percent of EPDM was <50%. This was also demonstrated by DMTA and mechanical properties of the blends with various compositions.

  13. 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.

  14. VULCAN: an Open-Source, Validated Chemical Kinetics Python Code for Exoplanetary Atmospheres

    CERN Document Server

    Tsai, Shang-Min; Grosheintz, Luc; Rimmer, Paul B; Kitzmann, Daniel; Heng, Kevin

    2016-01-01

    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 & Helling. It reproduces the models of HD 189733b and HD 209458b by Moses et al., which employ a network with nearly 1600 reactions. Further validation of VULCAN is made by examining 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 ap...

  15. 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)

  16. Vulcanization character of trans- 1,4- polyisoprene and mechanical properties of vulcanized TPI%反式聚异戊二烯的硫化特性及硫化胶的性能

    Institute of Scientific and Technical Information of China (English)

    马祖伟; 黄宝琛; 宋景社; 姚薇; 王名东

    2001-01-01

    Vulcanization character of trans- 1,4- polyisoprene(TPI) and effect of vulcanization degree on mechanical properties of vulcanized TPI were studied. The results showed that among three conventional kinds of accelerator (M,CZ and TT ), vulcanization curve of TPI with CZ as accelerator was ideal. Vulcanized TPI changes suddenly from hard material to soft elastic rubber when the sulfur content increased from 4 phr to 5 phr. The addition of carbon black could improve the tensile strength of the rubber obviously.%研究了反式-1,4-聚异戊二烯(TPI)的硫化特性及硫化程度对其力学性能的影响。结果表明:采用硫黄-促进剂CZ硫化体系时,TPI的硫化曲线较为理想;硫化使得TPI的力学性能在硫黄用量达到一定值时发生突变,由硬质材料转变为软质橡胶,即从硫化三阶段中的第二阶段过渡到第三阶段。

  17. Co-vulcanization of Rubber Blends%共混橡胶的共硫化研究

    Institute of Scientific and Technical Information of China (English)

    罗权煜; 郭建华

    2011-01-01

    The effect of several co-vulcanization systems on the properties of rubber blends was explored. CO/ECO,CSM/NBR,IIR/EPDM and IIR/CIIR blends were vulcanized by co-vulcanization a-gents, while PUR/CR, ACM/ECO, ACM/NBR, CR/CIIR and CR/SBR blends were vulcanized by compound curing systems. The effect of varieties and dosage of curing systems on the curing behavior and mechanical properties of several rubber blends were studied,which could provied studying scheme and theotetical guidance to the vulcanization of rubber blends.%探讨了多种共混橡胶的共硫化体系及其对共混橡胶性能的影响.其中采用共硫化剂硫化CO/ECO、CSM/NBR、IIR/EPDM、IIR/CIIR共混胶,采用复合硫化剂硫化PUR/CR、ACM/ECO、ACM/NBR、CR/CIIR、CR/SBR共混胶,研究了硫化体系品种和用量对几种共混胶的硫化特性和力学性能的影响,为共混橡胶的硫化提供研究方案和理论指导.

  18. Fully biobased and supertough polylactide-based thermoplastic vulcanizates fabricated by peroxide-induced dynamic vulcanization and interfacial compatibilization.

    Science.gov (United States)

    Liu, Guang-Chen; He, Yi-Song; Zeng, Jian-Bing; Li, Qiu-Tong; Wang, Yu-Zhong

    2014-11-10

    A fully biobased and supertough thermoplastic vulcanizate (TPV) consisting of polylactide (PLA) and a biobased vulcanized unsaturated aliphatic polyester elastomer (UPE) was fabricated via peroxide-induced dynamic vulcanization. Interfacial compatibilization between PLA and UPE took place during dynamic vulcanization, which was confirmed by gel measurement and NMR analysis. After vulcanization, the TPV exhibited a quasi cocontinuous morphology with vulcanized UPE compactly dispersed in PLA matrix, which was different from the pristine PLA/UPE blend, exhibiting typically phase-separated morphology with unvulcanized UPE droplets discretely dispersed in matrix. The TPV showed significantly improved tensile and impact toughness with values up to about 99.3 MJ/m(3) and 586.6 J/m, respectively, compared to those of 3.2 MJ/m(3) and 16.8 J/m for neat PLA, respectively. The toughening mechanisms under tensile and impact tests were investigated and deduced as massive shear yielding of the PLA matrix triggered by internal cavitation of VUPE. The fully biobased supertough PLA vulcanizate could serve as a promising alternative to traditional commodity plastics.

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

    Science.gov (United States)

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

    2014-06-01

    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. Synthesis, Characterization and Vulcanizing Properties of Rare Earth Complexes with 2-Mercaptobenthiazole

    Institute of Scientific and Technical Information of China (English)

    张启交; 韦凤仙; 章伟光; 黄庙由; 罗远芳

    2002-01-01

    Eight complexes of rare earth with 2-mercaptobenthiazole, RELCl2*RE(OH)3*xH2O (L=2-mercaptobenthiazole, RE= La~Gd, Y, except for Pm,x=0, 2~4), were synthesized in unhydrous ethanol and characterized by elemental analyses, IR spectra and thermal analyses. The results show that the ligand is coordinated to the RE ion through both the exocyclic sulfur and the thiazole nitrogen. The vulcanizing properties of the La complex as accelerator were studied in the traditional tire rubber, which indicate that the cross-linked rubber accelerated by the rare earth complex has good physical and dynamic mechanical properties by comparison.

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

    Science.gov (United States)

    1974-11-01

    subjected to the hydrolytic stability test or when exposed to the severe climatic conditions at Panama. EPDM and nitrile vulcanized bonded-specimens...butadiene acrylonitrile rubber bonded Sassembliesshowed a severe loes of 100 percent in bond strength; the EPDM bond.ed assemblies shcwed a 40 percent lose...02 ~ 4 -0 04 0: 00 V 4 o ~no 󈧄 0 80 EPDM Spgcimens aged up to 450°F are .shown .in Table 7. At 3000F, all - bonding agents provided good retention

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

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, J. [Departamento de Mecanica, Universidad Simon Bolivar, Caracas (Venezuela)]. E-mail: jjgonza@usb.ve; Albano, C. [Centro de Quimica, Laboratorio de Polimeros, Instituto Venezolano de Investigaciones Cientificas (IVIC), Caracas (Venezuela) and Universidad Central de Venezuela, Facultad de Ingenieria, Escuela de Ingenieria Quimica, Caracas (Venezuela)]. E-mail: calbano@ivic.ve; Candal, M.V. [Departamento de Mecanica, Universidad Simon Bolivar, Caracas (Venezuela); Ichazo, M.N. [Departamento de Mecanica, Universidad Simon Bolivar, Caracas (Venezuela); Hernandez, M. [Departamento de Mecanica, Universidad Simon Bolivar, Caracas (Venezuela)

    2005-07-01

    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.

  3. 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)

  4. Relationship among Vulcanization, Mechanical Properties and Morphology of Blends Containing Recycled EPDM

    Directory of Open Access Journals (Sweden)

    Aline Zanchet

    2017-09-01

    Full Text Available The production of consumption goods made of elastomer generates large amounts of vulcanized residues. The final proper environmental disposal of this material is a serious problem, which involves high costs and a possible waste of a material with high added value. The recycling of elastomers is a very important alternative since it is related directly to the protection of the environment, energy conservation, and sustainability. An option for companies that produce elastomeric residues is their incorporation in the formulations by producing polymeric blends. Thus, this work aims to prepare polymeric blends composed of ethylene-propylene diene monomer rubber (EPDM and raw EPDM/EPDM residue (EPDM-r in different concentrations, when the residue is ground at room temperature. The morphology of the residue, vulcanization characteristics, mechanical properties, and morphology of the blends were analyzed, showing promising results that point to the feasibility of using EPDM-r in the production of polymeric blends and as a possible solution to the problem of the final disposal of solid residues.

  5. 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.

  6. Study on Kinetics of Natural Rubber Vulcanization by S/La(DiPDP)3

    Institute of Scientific and Technical Information of China (English)

    Lin Xinhua; Liu Qingting; Chen Zhaohui; Wang Dizhen

    2007-01-01

    Kinetics of natural rubber (NR) vulcanization by lanthanum O, O'-diisopropyldithiophosphate [La(DiPDP)3] was studied. La(DiPDP)3 had remarkable accelerating effect on the vulcanization of NR. The rate constant k6 of the reaction that turned polysulphidic cross-links into the modified main chain was higher than that of desulfuration reaction of polysulfidic cross-links (k3). The activation energies (Ea2, Ea3, and Ea6) of the formation, desulfuration, and decomposition of polysulfidic cross-links were 87.57, 102.34, and 95.01 kJ·mol-1, respectively. Activation energy (Ea5) of the reaction that turned the cross-link precursors into the modified main chain was 82.67 kJ·mol-1. It could be concluded that the proportion of polysulphidic cross-links was higher than mono- and di- sulphidic cross-links during induction and curing periods, mono- and di- sulphidic cross-links increased as curing temperature rose. In the temperature range of 140~160 ℃, the amounts of polysulphidic cross-links were similar. However, over 160 ℃, mono- and di- sulphidic cross-links increased rapidly. Moreover, cross-link density of the vulcanizates was determined from the equilibrium-swelling data. A chemical probe detected the concentration of polysulphidic cross-links of vulcanizates. The change trend of the results predicated from equation corresponded to that of the experimental results.

  7. Origin and evolution of a new retained intron on the vulcan gene in Drosophila melanogaster subgroup species.

    Science.gov (United States)

    Zhan, Leilei; Meng, Qiaohong; Chen, Ran; Yue, Yuan; Jin, Yongfeng

    2014-10-01

    Although numerous intron gains have been discovered, the mechanisms of intron creation have proven to be elusive. Previous study revealed that the vulcan gene of Drosophila melanogaster contained four exons in its coding region. In the current study, a newly created intron (Intron L) was identified on exon 2 of vulcan in D. melanogaster by comparing expression sequence tags. The RT-PCR experiment revealed that Intron L was associated with intron retention, in which two alternative transcripts of the gene differ by the inclusion or removal of an intron. It was found that Intron L was created by intronization of exonic sequence, and its donor and acceptor splice sites were created by synonymous mutation, leading to the origin of a new vulcan protein that is 22 amino acids shorter than the previously reported vulcan protein. Moreover, to track the origin of Intron L, 36 orthologous genes of species of Drosophila were cloned or annotated, and phylogenetic analysis was carried out. It indicated that the common ancestor of D. melangaster subgroup species created Intron L about 15 million years ago.

  8. 拒绝干扰华硕ROG Vulcan ANC游戏耳机

    Institute of Scientific and Technical Information of China (English)

    刘东

    2011-01-01

    对于职业游戏玩家来说,都希望拥有一个能专注比赛的安静氛围。但事实上,想完全杜绝赛场的外部噪音不太可能。但对于这个问题,玩家其实有一个很好的选择,那就是我们今天体验这款华硕ROG Vulcan ANC游戏耳机,它的主动降噪技术能营造出更安静的比赛环境。

  9. 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.

  10. 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.

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

    Science.gov (United States)

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

    2001-12-01

    Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) have been used to study the oxidation of γ-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.

  12. Microbial scission of sulfide linkages in vulcanized natural rubber by a white rot basidiomycete, Ceriporiopsis subvermispora.

    Science.gov (United States)

    Sato, Shin; Honda, Yoichi; Kuwahara, Masaaki; Kishimoto, Hiroyuki; Yagi, Noriko; Muraoka, Kiyoshige; Watanabe, Takashi

    2004-01-01

    A white rot basidiomycete, Ceriporiopsis subvermispora, degraded vulcanized natural rubber (NR) sheets on a wood medium. The fungus decreased the total sulfur content of the rubber by 29% in 200 days, accompanied by the cleavage of sulfide bonds between polyisoprene chains. X-ray photoelectron spectroscopy (XPS) demonstrated that C. subvermispora reduced the frequency of S-C bonds by 69% with a concomitant formation of S-O bonds during the culture period. Dipolar decoupling/magic angle spinning (DD/MAS) solid state 13C NMR revealed that the fungus preferentially decomposed monosulfide bonds linked to a cis- and trans-1,4-isoprene backbone but the cleavage of polysulfide bonds was also observed. In contrast, no decrease in weight or devulcanization of rubber was observed in cultures of a white rot fungus, Dichomitus squalens. The oxidative cleavage of sulfide bonds by C. subvermispora demonstrates that ligninolytic basidiomycetes are potential microbes for the biological devulcanization of rubber products.

  13. Experimental study of temperature distribution in rubber material during microwave heating and vulcanization process

    Science.gov (United States)

    Chen, Hai-Long; Li, Tao; Liang, Yun; Sun, Bin; Li, Qing-Ling

    2017-03-01

    Microwave technology has been employed to heat sheet rubber, the optical fiber temperature online monitor and optical fiber temperature sensor have been employed to measure the temperature in sheet rubber. The temperature of sheet rubber increased with increase of heating time during microwave heating process in which the maximum of temperature was rubber was higher than the rate of temperature rising in marginal zone of sheet rubber, and the final temperature in central zone of sheet rubber was also higher than the final temperature in marginal zone of sheet rubber. In the microwave heating and vulcanization process of sheet rubber, the maximum of rate of temperature rising and the maximum of temperature belong to the central zone of sheet rubber, so the distribution of electric field was uneven in heating chamber, which led to the uneven temperature distribution of sheet rubber. The higher electric field intensity value converges on the central zone of sheet rubber.

  14. 烷基硫代磷酸锌硫化促进剂对天然橡胶老化性能影响研究%Effect of Dialhydithiophate Vulcanizing Accelerator on Aging of Vulcanized Natural Rubber in Hot Air

    Institute of Scientific and Technical Information of China (English)

    赵华松; 李建雄; 刘小波; 刘安华

    2011-01-01

    Natural rubber was vulcanized with the aid of zinc dialkydithiophosphates and other common vulcanizing accelerators and the resultant samples were aged in hot air. The mechanical properties of the samples were measured before and after aging and the anti-aging performance were compared. The experiment results indicated that the sample with zinc diisopropyldithiophate possessed excellent anti-aging performance.%研究了烷基硫代磷酸锌和其他常用硫化促进剂对天然橡胶硫化胶的老化性能的影响.实验表明二异丙基二硫代磷酸锌能赋予天然橡胶硫化胶优良的耐热空气老化性能.

  15. Development of Cu2O/Carbon Vulcan XC-72 as non-enzymatic sensor for glucose determination.

    Science.gov (United States)

    El Khatib, K M; Abdel Hameed, R M

    2011-04-15

    A novel and stable non-enzymatic glucose sensor was developed based on the chemical reduction of Cu(2)O nanoparticles on Carbon Vulcan XC-72 using NaBH(4) as the reducing agent via the impregnation method. Different molar ratios of NaBH(4) to the copper salt were employed during the reduction step. This was found to affect the morphology; composition and structure of the prepared samples as investigated by TEM, EDX and XRD analyses. Cyclic voltammetry and chronoamperometry were applied to examine the electrocatalytic activity of the different samples of Cu(2)O/Carbon Vulcan XC-72 towards glucose oxidation in alkaline medium. The 'x70' sample got the highest oxidation current density and the lowest oxidation potential. The performance of this sensor was evaluated showing a wide linear range up to 6mM with sensitivity of 629 μA cm(-2)mM(-1) and detection limit of 2.4 μM. Its good tolerance to ascorbic acid with long-term stability elects Cu(2)O/Carbon Vulcan XC-72 as a promising glucose sensor.

  16. 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.

  17. 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

  18. Experimental and theoretical analyses of pulverization and recycling of vulcanized rubber

    Science.gov (United States)

    Bilgili, Ecevit Atalay

    A two-stage process for recycling of vulcanized rubber was proposed. In the first stage, the vulcanized rubber was shredded into granulates, and then the granulates were pulverized into fine particles using a single screw extruder in the solid state shear extrusion (SSSE) process. In the second stage, the produced rubber powder was compression molded to produce new items. The major objective of this research is to understand the fundamental aspects of the pulverization and the compression molding of the rubber powder. Fine rubber particles were obtained using the SSSE process when the granulates were compressed sufficiently, and loss of strain energy due to viscoelastic stress relaxation was minimized by significant cooling in the pulverization zone. Agglomeration of rubber particles was found to be competing with the pulverization process. A sharp temperature gradient in the rubber was experimentally determined, which was qualitatively predicted by our heat transfer computer simulation. The rubber particles produced by the SSSE process and the unprocessed rubber granulates were analyzed using physical, thermal, and chemical characterization methods. The characterization study showed that the particles had irregular shapes with convoluted surfaces, and that the powder had a larger specific surface area compared with a cryogenically produced powder. The particles had lower crosslink density than the granulates indicating the breakage of sulfur crosslinks in the rubber, which makes the SSSE powder very suitable for many recycling applications. In the second stage, the produced powder within several size ranges was compression molded at various processing conditions. Rubber slabs with low-medium tensile strength were obtained without using any virgin rubber. It was found that the strength of the slabs is strongly dependent on the degree of particle bonding. Inhomogeneous shearing deformations of a homogeneous thermoelastic slab and a non-homogeneous rubber-like slab

  19. 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.

  20. 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.

  1. Experimental study of temperature distribution in rubber material during microwave heating and vulcanization process

    Science.gov (United States)

    Chen, Hai-Long; Li, Tao; Liang, Yun; Sun, Bin; Li, Qing-Ling

    2016-07-01

    Microwave technology has been employed to heat sheet rubber, the optical fiber temperature online monitor and optical fiber temperature sensor have been employed to measure the temperature in sheet rubber. The temperature of sheet rubber increased with increase of heating time during microwave heating process in which the maximum of temperature was curves of temperature-time presented nonlinearity. The rate of temperature rising in central zone of sheet rubber was higher than the rate of temperature rising in marginal zone of sheet rubber, and the final temperature in central zone of sheet rubber was also higher than the final temperature in marginal zone of sheet rubber. In the microwave heating and vulcanization process of sheet rubber, the maximum of rate of temperature rising and the maximum of temperature belong to the central zone of sheet rubber, so the distribution of electric field was uneven in heating chamber, which led to the uneven temperature distribution of sheet rubber. The higher electric field intensity value converges on the central zone of sheet rubber.

  2. Amperometric glucose sensor based on nickel nanoparticles/carbon Vulcan XC-72R.

    Science.gov (United States)

    Abdel Hameed, R M

    2013-09-15

    A stable non-enzymatic glucose sensor was constructed by chemical deposition of nickel nanoparticles on carbon Vulcan XC-72R using microwave irradiation technique. The mode and time of microwave irradiation during nickel salt reduction were varied. This was found to affect the morphology of formed Ni/C powder as evidenced by TEM analysis. Nickel nanoparticles aggregation becomes more serious at longer microwave irradiation times. The electrocatalytic activity of different Ni/C samples towards glucose oxidation was studied in KOH solution by employing cyclic voltammetry and chronoamperometry techniques. Ni/C sample, prepared by pulse mode with total operating time of 150s, showed the highest oxidation current density. An excellent sensitivity value of 1349.7μAmM(-1)cm(-2) with a detection limit of 0.232μM was gained by Ni/C sensor. It also exhibits good reproducibility and long-term stability, as well as high selectivity with insignificant interference from ascorbic acid.

  3. Hydrocarbon-Derived Carbonate Cements of Subsurface Origin in the Vulcan Sub-Basin, Timor Sea

    Directory of Open Access Journals (Sweden)

    Shou-Yeh Gong

    2010-01-01

    Full Text Available Localized carbonate cementation occurs in the Eocene Grebe Sandstone of the Vulcan Sub-basin, Timor Sea, Australia. The cements have been previously interpreted as originating from microbial methane oxidation and sulfate reduction in a shallow subsurface environment and were related to hydrocarbon leakage. Here we reassess these localized carbonate cements in the Grebe Sandstone, and reported new findings. Petrography shows that there are two facies of sands in the Grebe Sandstone: (1 cemented, mostly fine-grained sands; and (2 loose, often coarse-grained sands. In addition, two types of carbonate matrix occur in the Grebe Sandstone: (1 spars to microspars in calcareous, fine-grained sandstones; and (2 micritic to microsparry matrix associated with limestone grains. Stable carbon isotopic values reveal that only the cements associated with sandstones were probably hydrocarbon-derived, and the resultant mineral is mainly calcite. Petrographic attributes and Mn+2 and Co+2 compositions of these cements differ significantly from those of modern cold-seep carbonates at or near the sea floor. Moreover, the hydrocarbon-derived carbonate mineralization only occurs in the fine-grained sands, not in the coarse-grained sands. In other word, the cementation was not only dependent on hydrocarbon leakage but also on the lithofacies of the host rock. We propose that the extent of hydrocarbon-related cementation alone cannot be used to evaluate the trap integrity as has been previously suggested.

  4. Analysis of Toxicity of Ceramic Nanoparticles and Functional Nanocomposites Based on Vulcanized Natural Rubber

    Directory of Open Access Journals (Sweden)

    Bellucci Felipe Silva

    2015-01-01

    Full Text Available Nanocomposites are multiphase materials of which, at least one of the phases, has a dimension smaller than 100 nm. These materials have attracted technological and scientific interest due to their multifunctional characteristics and potential, which allow them to combine unique properties which are not found in traditional commercial materials, such as natural rubber alone. The objective of this work is to analyse the toxicity of nanoparticles and nanocomposites when applied to mammal cells in order to obtain bioactive agents, as well as to evaluate the potential to be applied in biological systems. Ferroelectric ceramic nanoparticles of KSr2Nb5O15 (KSN and paramagnetic ceramic nanoparticles Ni0.5Zn0.5Fe2O4 (NZF were prepared and utilized to produce functional and multifunctional nanocomposites based on vulcanized natural rubber (NR/KSN and NR/NZF with different nanoparticle concentrations. For both kinds of nanoparticles and both classes of nanocomposites, independently of the nanoparticle concentration, it is not possible to observe any reduction of the cellular viability until the incubation time is finished. In this way, these results point to the possibility of using these nanoparticles and nanocomposites, from the toxicity point of view, as bioactivity agents in biological systems based on mammalian cells.

  5. 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.

  6. 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.

  7. Computer simulation of thermal conductivity in vulcanized polyisoprene at variable strain and temperature

    Science.gov (United States)

    Engelmann, Sven; Meyer, Jan; Hentschke, Reinhard

    2017-08-01

    We study the thermal conductivity tensor in an atomistic model of vulcanized cis-1,4-polyisoprene (PI) rubber via molecular dynamics simulations. Our polymer force field is based on V. A. Harmandaris et al. [J. Chem. Phys. 116, 436 (2002), 10.1063/1.1416872], whereas the polymerization algorithm follows the description in J. Hager et al. [Macromolecules 48, 9039 (2015), 10.1021/acs.macromol.5b01864]. The polymer chains are chemically cross linked via sulfur bridges of adjustable cross-link density. A volume-conserving uniaxial strain of up to 200% is applied to the systems. The widely used GROMACS simulation package is adapted to allow using the Green-Kubo approach to calculate the thermal conductivity tensor components. Our analysis of the heat flux autocorrelation functions leads to the conclusion that the thermal conductivity in PI is governed by short-lived phonon modes at low wave numbers due to deformation of the monomers along the polymer backbone. Applying uniaxial strain causes increased orientation of monomers along the strain direction, which enhances the attendant thermal conductivity component. We find an exponential increase of the conductivity in stretch direction in terms of an attendant orientation order parameter. This is accompanied by a simultaneous decline of thermal conductivity in the orthogonal directions. Increase of the cross-link density only has a weak effect on thermal conductivity in the unstrained system, even at high cross-link density. In the strained system we do observed a rising thermal conductivity in the limit of high stress. This increase is attributed to enhanced coupling between chains rather than to their orientation.

  8. 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.

  9. 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.

  10. Hierarchical SnO2 Nanospheres: Bio-inspired Mineralization, Vulcanization, Oxidation Techniques, and the Application for NO Sensors

    Science.gov (United States)

    Wang, Lei; Chen, Yuejiao; Ma, Jianmin; Chen, Libao; Xu, Zhi; Wang, Taihong

    2013-12-01

    Controllable synthesis and surface engineering of nanomaterials are of strategic importance for tailoring their properties. Here, we demonstrate that the synthesis and surface adjustment of highly stable hierarchical of SnO2 nanospheres can be realized by biomineralization, vulcanization and oxidation techniques. Furthermore, we reveal that the highly stable hierarchical SnO2 nanospheres ensure a remarkable sensitivity towards NO gas with fast response and recovery due to their high crystallinity and special structure. Such technique acquiring highly stable hierarchical SnO2 nanospheres offers promising potential for future practical applications in monitoring the emission from waste incinerators and combustion process of fossil fuels.

  11. 不同硫化体系对环保型硬丁腈橡胶性能的影响%Effect of different vulcanization systems on properties of environment-friendly hard nitrile rubber

    Institute of Scientific and Technical Information of China (English)

    李冬红; 高卫光; 李彤霞; 潘广勤; 李晓强

    2012-01-01

    以松香酸皂与油酸皂组成的复合乳化体系制备的中试产品丁腈橡胶(NBR)为基胶,分别用硫黄体系和过氧化物体系进行硫化,研究了NBR混炼胶的硫化特性和硫化胶的物理机械性能、耐老化性能、耐油及耐寒性能,并与传统产品NBR 3604进行了比较.结果表明,采用硫黄体系时,NBR混炼胶的硫化程度较浅,硫化速率较慢;采用过氧化物体系时,NBR混炼胶的硫化程度较深,硫化速率较快,NBR胶料宜采用过氧化物硫化体系进行硫化;2种硫化体系下制得NBR硫化胶的物理机械性能与NBR3604硫化胶相差不大,过氧化物硫化体系制得NBR硫化胶的耐老化性能较好;与NBR 3604硫化胶相比,2种硫化体系下制得NBR硫化胶的耐寒性稍好,耐油性稍差.%The pilot product of nitrile rubber ( NBR) was synthesized with rosin soap and oleic acid soap as complex emulsifier system, and the product was vulcanized with sulfur and peroxide vulcanization systems respectively. The curing characteristics of NBR and mechanical properties, aging resistance, oil and cold resistances of NBR vulcani-zates were studied and compared with those of traditional NBR 3604, The results showed that the sulfur vulcanized NBR had lower degree of vulcanization and slower vulcanization rate, but the peroxide vulcanized NBR had higher degree of vulcanization and faster vulcanization rate, so that the NBR was fitter to be vulcanized with peroxide. There were no evident difference between NBR 3604 and NBR vulcanized with the two vulcanizer systems in mechanical properties, but the peroxide vulcanized NBR had better aging resistance, and the two vulcanizers vulcanized NBR had better cold resistance and poor oil resistance.

  12. New Synthesis of Pt-Ru Nanoparticles on Surface Modified Carbon Vulcane XC-72 as an Effective Catalyst for Direct Methanol Fuel Cell

    Institute of Scientific and Technical Information of China (English)

    Ahmad; Nozad; Golikand; Sajjad; Sadaghat; Sharehjini; Mohammad; Yari

    2007-01-01

    1 Results Pt-Ru nanoparticles are synthesised on the surface oxidized carbon Vulcane XC-72 as catalyst support by chemically anchoring Pt and Ru onto the surface of modified carbon vulcane XC-72 (by refluxing in 70% HNO3 at 120 ℃ for 12 h to introduce surface functional groups) .The nanoparticles of Pt and Ru are synthesized by reduction of H2PtCl6 and K4Ru(CN)6 with sodium borohydride in a 5.5 buffer solution of sodium citrate,the complexation of citrate with metal ions is beneficial to the formati...

  13. Platinium Nanoparticles Deposited on Oxygen-Containing Functional Groups at Carbon Vulcane XC-72 as a Cathode Catalyst for Direct Methanol Fuel Cell

    Institute of Scientific and Technical Information of China (English)

    Sajjad; Sadaghat; Sharehjini; Ahmad; Nozad; Golikand; Mohammad; Yari

    2007-01-01

    1 Results Surface oxidized carbon vulcane XC-72 as catalyst support, prepared by chemically anchoring Pt onto the surface modified carbon vulcane XC-72. The nanoparticles of Pt are synthesized by reduction of H2PtCl6 with sodium borohydride in a 5.5 buffer solution of sodium citrate, the complexation of citrate with metal ions is beneficial to the formation of nanoparticles. For comparison, an electrode is prepared by E-Tek Pt/C 20 Wt% with a typical Pt loading of 50 μg·cm-2, that shows higher specifi...

  14. Electrochemical characteristics and performance of platinum nanoparticles supported by Vulcan/polyaniline for oxygen reduction in PEMFC

    Energy Technology Data Exchange (ETDEWEB)

    Kakaei, K. [Faculty of Science, Department of Chemistry, University Of Maragheh, P.O. Box. 55181-83111, Maragheh (Iran, Islamic Republic of)

    2012-12-15

    We report a Pt/Vulcan carbon-polyaniline (VC-PANI) catalyst for the oxygen reduction reaction (ORR). This electrocatalyst was prepared from Pt nanoparticles supported by a VC-PANI composite substrate. Electrochemical performance was measured using potentiostat/galvanostats technique and a proton exchange membrane fuel cell (PEMFC) test station. The electrochemical properties of the electrodes were characterized using linear sweep voltammetry, AC impedance spectroscopy and chronoamperometry. Electrochemical characterization by hydrogen adsorption/desorption cyclic voltammetry and CO stripping voltammetry indicates that the electrochemical active surface areas of the Pt/VC-PANI are comparable to the commercial catalyst. The performance of the Pt/VC-PANI and Pt/C(E-TEK) + PANI electrocatalysts were found to be 1.82 and 1.33 times higher than of the Pt/C(E-TEK) electrode. The surface morphologies of the electrodes were characterized by using scanning electron microscopy (SEM). PANI has a fibrous structure and the improved performance was attributed to the PANI effect and synergistic effects between the carbon Vulcan and the PANI fiber. These results indicate that Pt/VC-PANI is a promising catalyst for the ORR in PEMFCs using an H{sub 2}/O{sub 2} feed. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. 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.

  16. 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.

  17. 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)

  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, Rui

    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 o

  19. Study on Vulcanization Performance of Dealcoholized RTV-1 Silicone Rubber%脱醇型RTV-1硅橡胶硫化性能的研究

    Institute of Scientific and Technical Information of China (English)

    成钢

    2013-01-01

    研究了硫化温度、相对湿度对脱醇型单组分室温硫化硅橡胶GD-414的硫化性能的影响.结果表明,随着硫化时间的延长,GD-414胶层的硫化深度加深,但硫化时间并不和硫化深度成正比;相同胶层厚度时,随着相对湿度的增大,硫化时间显著缩短;随着硫化温度的提高,表干时间和硫化时间同样缩短;提高湿度和温度可缩短GD-414的硫化时间.采用GD-414粘接和固封电子产品时,较佳的硫化温度是50 ~ 60℃,相对湿度为50% ~ 70%.硫化3天以后,硅橡胶的拉断伸长率、断裂强度已达到技术指标.%This paper studies the vulcanization performance of the dealcoholized RTV - 1 GD -414 silicone rubber. Results show that the depth of vulcanization of the rubber deepens with the extension of the vulcanization time, but the vulcanization time is not proportional to the depth. As the relative humidity increases, the curing time significantly shortened. When the vulcanizing temperature increased, the surface dry time and cure time both shortened. Increasing the humidity and temperature can increase the vulcanization rate of GD -414 and shorten its curing time. When GD -414 silicone rubber adhesive is used for sealing the electronic products, the preferred curing temperature is 50~60℃ at relative humidity of 50% to 70%. After vulcanization for 3days, the elongation at break and the breaking strength of silicone rubber meets the technical requirements.

  20. Synthesis and characterization of palladium and palladium-cobalt nanoparticles on Vulcan XC-72R for the oxygen reduction reaction.

    Science.gov (United States)

    Arroyo-Ramírez, Lisandra; Montano-Serrano, Rubenier; Luna-Pineda, Tatiana; Román, Félix R; Raptis, Raphael G; Cabrera, Carlos R

    2013-11-27

    A single-source approach was used to synthesize bimetallic nanoparticles on a high-surface-area carbon-support surface. The synthesis of palladium and palladium-cobalt nanoparticles on carbon black (Vulcan XC-72R) by chemical and thermal reduction using organometallic complexes as precursors is described. The electrocatalysts studied were Pd/C, Pd2Co/C, and PdCo2/C. The nanoparticles composition and morphology were characterized using inductively coupled plasma mass spectrophotometer (ICP-MS), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray fluorescence spectroscopy (EDS), X-ray diffraction (XRD), and transmission electron microscopy (TEM) techniques. Electrocatalytic activity towards the oxygen reduction reaction (ORR) and methanol tolerance in oxygen-saturated acid solution were determined. The bimetallic catalyst on carbon support synthetized by thermal reduction of the Pd2Co precursor has ORR electrocatalytic activity and a higher methanol tolerance than a Pt/C catalyst.

  1. The content determination of calcium, magnesium and ascorbic acid in sea buckthorn fruits at vulcan coal dump

    Directory of Open Access Journals (Sweden)

    Andreea BRASOVAN

    2009-11-01

    Full Text Available The study presents data on content determination of calcium, magnesium and ascorbic acid in sea buckthorn fruits collected from Vulcan coal dump. The dump was never covered with soil or fertilizers containing azoth, potassium and phosphorus. The sea buckthorn was planted directly on the sterile and it has an important function in stabilizing the acclivity and fixing the atmospheric azoth with the nodosities on the roots. So, the sea buckthorn becomes widespread plant in coal dumps because it helps to the soil formation. The results obtained after the determination of calcium, magnesium and ascorbic acid from the fruits of this plant were compared with the values already reported in various references, concluding that these differences are insignificant (3.7% for magnesium and 9.4% for calcium. Therefore, the sea buckthorn from the dump can be used in food industry, as well as in pharmaceutics and medicine.

  2. 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

  3. Vulcanization of lipidic organic matter in reactive-iron deficient environments: a possible enhancement for the storage of hydrogen-rich organic matter

    Energy Technology Data Exchange (ETDEWEB)

    Tribovillard, N.P.; Desprairies, A. (Paris-11 Univ., 91 - Orsay (France)); Lallier-Verges, E. (Orleans Univ., 45 (France)); Bertrand, P. (Bordeaux-1 Univ., 33 - Talence (France))

    1994-11-01

    Geochemists have highlighted an important mechanism for kerogen formation: the early, HS[sup -]/H[sub 2]S - induced, vulcanization which protects organic-sulfur compounds from bacterial degradation. We base our study on two formations in which organic-matter accumulation is thought to result principally from organic-walled-plankton productivity. When reactive iron was a limiting factor for Fe-sulfide formation, organic matter was enriched in sulfur, and TOC and HI values were higher. We suggest the lack of reactive iron could promote vulcanization of organic matter, helping its storage and keeping HI at high values. Bottom-water anoxia could promote this mechanism (positive feedback effect). (authors). 11 refs., 2 figs., 1 tab.

  4. Electrochemical characterization of adsorbed bilirubin oxidase on Vulcan XC 72R for the biocathode preparation in a glucose/O{sub 2} biofuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Habrioux, A.; Napporn, T.; Servat, K. [LACCO ' Equipe Electrocatalyse' UMR 6503 CNRS-Universite de Poitiers, 40 av. du Recteur Pineau 86022 Poitiers (France); Tingry, S. [Institut Europeen des Membranes, UMR 5635, Place Eugene Bataillon, CC 047, 34095 Montpellier, cedex 5 (France); Kokoh, K.B., E-mail: boniface.kokoh@univ-poitiers.f [LACCO ' Equipe Electrocatalyse' UMR 6503 CNRS-Universite de Poitiers, 40 av. du Recteur Pineau 86022 Poitiers (France)

    2010-11-01

    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{sub 70}Pt{sub 30} nanoparticles as anode catalyst permitted to reach a power density of 170 {mu}W cm{sup -2} at a cell voltage of 0.6 V, which is superior to what can be obtained with the concentric design.

  5. 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.

  6. Minimization of the impact of a broad bandwidth high-gain nonlinear preamplifier to the amplified spontaneous emission pedestal of the Vulcan petawatt laser facility.

    Science.gov (United States)

    Musgrave, I O; Hernandez-Gomez, C; Canny, D; Collier, J; Heathcote, R

    2007-10-01

    To generate petawatt pulses using the Vulcan Nd:glass laser requires a broad bandwidth high-gain preamplifier. The preamplifier used is an optical parametric amplifier that provides a total gain of 10(8) in three amplification stages. We report on a detailed investigation of the effect of the Vulcan optical parametric chirped pulse amplification (OPCPA) preamplifier on contrast caused by the amplified spontaneous emission (ASE) pedestal that extends up to 2 ns before the arrival of the main pulse. The contrast after compression is improved to 4x10(8) of the intensity of the main pulse using near-field apertures between the stages of the OPCPA preamplifier. Further reduction of the level of the ASE pedestal can be achieved at the cost of a reduction in amplified bandwidth by solely phosphate glass amplification after initial preamplification rather than a mixed glass amplification scheme.

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

    OpenAIRE

    2015-01-01

    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-ra...

  8. Development and Application of Radiation Pre-vulcanization Technology of Tire%轮胎辐射预硫化技术的发展与应用

    Institute of Scientific and Technical Information of China (English)

    韩秀东

    2015-01-01

    介绍轮胎辐射预硫化技术的发展与应用概况。辐射预硫化可以减小轮胎部件厚度,增强部件的尺寸稳定性、减小轮胎质量、缩短轮胎硫化时间、提高轮胎均匀性能和动平衡等性能,经济效益十分显著。辐射预硫化技术是提升我国轮胎行业技术水平和产品质量的有效举措。%This paper introduces the development and application of radiation technology in the pre-vulcanization of tires. By using radiation pre-vulcanized, the part thickness of tire components can be reduced, the dimensional stability is improved, tire weight is reduced, tire curing time could be shortened, and tire uniformity and balancing performance are improved. Application of radiation pre-vulcanization technology enhances economic beneifts and can boost China's tire industry technology level and tire quality.

  9. Intelligence Based Fusion Control Strategy for Complex Vulcanizing Process%复杂硫化过程的智能融合控制策略

    Institute of Scientific and Technical Information of China (English)

    裴玉玲

    2013-01-01

    针对硫化过程中因模糊性与不确定性导致的塑胶产品成形过程难以控制、产品质量稳定性差的问题,提出了一种智能融合控制策略.总结了复杂硫化过程中的控制难点,探讨了硫化过程的控制论特性,研究了对不确定性复杂过程的控制策略,讨论了控制模型,提出了智能融合控制策略,基于仿人智能构造了基本控制算法.仿真结果显示该策略的鲁棒性强与控制精度高.研究结果表明:智能融合控制策略对不确定性复杂硫化过程实施控制是可行与有效的.%The vulcanization of plastic & rubber products is a typical complex control process with uncertainty.Aimed at the puzzle that the shaping process of plastic & rubber products is difficult to control resulted from fuzzification and uncertainty,and poor in stability of product quality in the process of vulcanization,the paper proposed a sort of intelligence based control strategy based on human simulated intelligent controller.In the paper,it summed up the control puzzles in the process of complex vulcanization,explored the cybernetics characteristic of vulcanizing process,researched on the control strategy of complex process with uncertainty,proposed a sort of intelligence based control strategy,discussed control model,and constructed the control algorithm based on human simulated intelligence.It made the simulation experiment,and the curve of algorithm response demonstrated that it could be stronger in robustness,and higher in control precision compared with PID controller.The research result shows that it is feasible and effective to the proposed control strategy based on human simulated intelligence in actualizing control for complex vulcanizing process with uncertainty.

  10. Electroreduction of oxygen on Vulcan carbon supported Pd nanoparticles and Pd-M nanoalloys in acid and alkaline solutions

    Energy Technology Data Exchange (ETDEWEB)

    Alexeyeva, N. [Institute of Chemistry, University of Tartu, Ravila 14A, 50411 Tartu (Estonia); Sarapuu, A., E-mail: ave.sarapuu@ut.ee [Institute of Chemistry, University of Tartu, Ravila 14A, 50411 Tartu (Estonia); Tammeveski, K. [Institute of Chemistry, University of Tartu, Ravila 14A, 50411 Tartu (Estonia); Vidal-Iglesias, F.J.; Solla-Gullon, J.; Feliu, J.M. [Instituto de Electroquimica, Universidad de Alicante, Apartado 99, 03080 Alicante (Spain)

    2011-07-30

    Highlights: > Electroreduction of O{sub 2} on carbon-supported Pd, PdCo and PdFe nanoparticles is studied. > Pd-based catalysts were prepared by reduction in the presence of citrate and in microemulsion. > Four-electron reduction of O{sub 2} proceeds in both acid and alkaline media. > Specific activity of PdCo and PdFe nanocatalysts was similar to that of Pd nanoparticles. - Abstract: The kinetics of O{sub 2} reduction on novel electrocatalyst materials deposited on carbon substrates were studied using the rotating disk electrode (RDE) technique. Palladium nanoparticles and Pd-M (PdCo and PdFe) nanoalloys supported on Vulcan XC-72R were prepared using two different synthetic routes. The catalyst samples were examined by transmission electron microscopy (TEM) and the average size of metal nanoparticles was determined. Electrochemical measurements were performed in 0.5 M H{sub 2}SO{sub 4} and in 0.1 M NaOH solutions. The influence of different synthetic conditions on the values of specific activity and other kinetic parameters was investigated. These parameters were determined from the Tafel plots taking into account the real electroactive area for each electrode. Pd nanoparticles and Pd-M nanoalloys exhibit significantly high electrocatalytic activity for the four-electron reduction of oxygen to water.

  11. Inverse vulcanization of sulfur with divinylbenzene: Stable and easy processable cathode material for lithium-sulfur batteries

    Science.gov (United States)

    Gomez, Iñaki; Mecerreyes, David; Blazquez, J. Alberto; Leonet, Olatz; Ben Youcef, Hicham; Li, Chunmei; Gómez-Cámer, Juan Luis; Bondarchuk, Oleksandr; Rodriguez-Martinez, Lide

    2016-10-01

    Lithium-Sulfur (Li-S) battery technology is one of the promising candidates for next generation energy storage systems. Many studies have focused on the cathode materials to improve the cell performance. In this work we present a series of poly (S-DVB) copolymers synthesised by inverse vulcanization of sulfur with divinylbenzene (DVB). The poly (S-DVB) cathode shows excellent cycling performances at C/2 and C/4 current rates, respectively. It was demonstrated poly (S-DVB) copolymer containing 20% DVB did not influence the electrochemical performance of the sulfur material, compared to elemental sulfur as high specific capacities over ∼700 mAh g-1 at 500 cycles were achieved at C/4 current rate, comparable to conventional carbon-based S cathodes. However, the use of copolymer network is assumed to act firstly as sulfur reservoir and secondly as mechanical stabilizer, enhancing significantly the cycling lifetime. The Li-poly (S-DVB) cell demonstrated an extremely low degradation rate of 0.04% per cycle achieving over 1600 cycles at C/2 current rate.

  12. Evaluation of Effect of Various Nanofillers on Technological Properties of NBR/NR Blend Vulcanized Using BIAT-CBS System

    Directory of Open Access Journals (Sweden)

    Shaji P. Thomas

    2013-01-01

    Full Text Available Owing to processing ease and resistance to oils and chemicals, NBR is widely used in many industries. But since neat NBR has only poor tensile properties, it is better to use suitable blends of NR and NBR after incorporating appropriate nanoingredients before vulcanization. It is well established that nanoparticles can be easily dispersed in a more uniform pattern in polymer matrix, thereby enhancing the technological properties of the elastomer vulcanizate. Since there are no systematic comparative studies on technological properties of NBR/NR blend containing different nanoingredients, efforts have been made in this study to investigate cure and technological properties like tensile properties, tear resistance, compression set, hardness, abrasion loss and swelling value of NBR/NR (80/20 blend vulcanizates containing stearic acid-coated nano-zinc oxide (ZOS, nano-BIAT, nano-silicate-coated CaCO3, PEO-coated calcium silicate, and surface-modified carbon nanotubes (CNT. XRD and electron microscopy have been used for morphological analysis. The nano ingredients were effective in enhancing the technological properties of the vulcanizates. Among the nanofillers, modified CNT was found to impart superior properties to NBR/NR blend due to more intercalation.

  13. Electrospun Pd nanoparticles loaded on Vulcan carbon/ conductive polymeric ionic liquid nanofibers for selective and sensitive determination of tramadol.

    Science.gov (United States)

    Fathirad, Fariba; Mostafavi, Ali; Afzali, Daryoush

    2016-10-12

    In the present work a sensitive and selective electrochemical sensor was fabricated based on a glassy carbon electrode which has been modified with Pd nanoparticles loaded on Vulcan carbon/conductive polymeric ionic liquid composite nanofibers. The nanostructures were characterized by UV-Vis, FT-IR, FESEM, EDX and XRD techniques. The electrochemical study of the modified electrode, as well as its efficiency for the electrooxidation of tramadol was described in 0.1 M phosphate buffered solution (PBS) (pH 7.0) using cyclic voltammetry, linear sweep voltammetry, chronoamperometry and square wave voltammetry as diagnostic techniques. It has been found that application of the composite nanofibers result in a sensitivity enhancement and a considerable decrease in the anodic overpotential, leading to negative shifts about 200 mV in peak potential. The results exhibit a linear dynamic range from 0.05 μM to 200 μM and a detection limit of 0.015 μM for tramadol. Finally, the modified electrode was used for the determination of tramadol in pharmaceutical and biological samples.

  14. Direct electron transfer at a glucose oxidase-chitosan-modified Vulcan carbon paste electrode for electrochemical biosensing of glucose.

    Science.gov (United States)

    Mutyala, Sankararao; Mathiyarasu, Jayaraman

    2014-02-01

    This article describes the investigation of direct electron transfer (DET) between glucose oxidase (GOD) and the electrode materials in an enzyme-catalyzed reaction for the development of improved bioelectrocatalytic system. The GOD pedestal electrochemical reaction takes place by means of DET in a tailored Vulcan carbon paste electrode surfaces with GOD and chitosan (CS), allowing efficient electron transfer between the electrode and enzyme. The key understanding of the stability, biocatalytic activity, selectivity, and redox properties of these enzyme-based glucose biosensors is studied without using any reagents, and the properties are characterized using electrochemical techniques like cyclic voltammogram, amperometry, and electrochemical impedance spectroscopy. Furthermore, the interaction between the enzyme and the electrode surface is studied using ultraviolet-visible (UV-Vis) and Fourier transform infrared (FTIR) spectroscopy. The present glucose biosensor exhibited better linearity, limit of detection (LOD = 0.37 ± 0.02 mol/L) and a Michaelis-Menten constant of 0.40 ± 0.01 mol/L. The proposed enzyme electrode exhibited excellent sensitivity, selectivity, reproducibility, and stability. This provides a simple "reagent-less" approach and efficient platform for the direct electrochemistry of GOD and developing novel bioelectrocatalytic systems.

  15. SnO2-decorated multiwalled carbon nanotubes and Vulcan carbon through a sonochemical approach for supercapacitor applications.

    Science.gov (United States)

    Vinoth, Victor; Wu, Jerry J; Asiri, Abdullah M; Lana-Villarreal, Teresa; Bonete, Pedro; Anandan, Sambandam

    2016-03-01

    Multiwalled carbon nanotubes (MWCNTs) and Vulcan carbon (VC) decorated with SnO2 nanoparticles were synthesized using a facile and versatile sonochemical procedure. The as-prepared nanocomposites were characterized by means of transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier transform infra red spectroscopy. It was evidenced that SnO2 nanoparticles were uniformly distributed on both carbon surfaces, tightly decorating the MWCNTs and VC. The electrochemical performance of the nanocomposites was evaluated by cyclic voltammetry and galvanostatic charge/discharge cycling. The as-synthesized SnO2/MWCNTs nanocomposites show a higher capacity than the SnO2/VC nanocomposites. Concretely, the SnO2/MWCNTs electrodes exhibit a specific capacitance of 133.33 F g(-1), whereas SnO2/VC electrodes exhibit a specific capacitance of 112.14 F g(-1) measured at 0.5 mA cm(-2) in 1 M Na2SO4.

  16. 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.

  17. 橡胶硫化改性路用沥青紫外老化过程的研究%A Study on the UV Aging Process of Rubber Vulcanization Modified Road Asphalt

    Institute of Scientific and Technical Information of China (English)

    祁欣; 武光明; 尹亮

    2011-01-01

    In this paper, researchers study the change rules of the structure and properties of rubber vulcanization asphalt in the UV aging process. The changes of the properties of rubber vulcanization asphalt are analyzed under the condition of UV aging, with the extension and softening point as the assessing index. It is found that the changes of the extension and the softening point of rubber vulcanization asphalt is slower than the base asphalt and the changes of the sulfoxide absorption of rubber vulcanization asphalt is less than the base asphalt. The results show that the rubber vulcanization asphalt has the performance of anti-aging properties of UV.%研究了橡胶硫化沥青在紫外光老化过程中结构与性能的变化规律.以物理延展度、软化点为评价指标分析了橡胶硫化沥青在紫外线老化条件下性能的变化,发现其延展度、软化点速率慢于基质沥青,亚砜基吸收峰的变化小于基质沥青.研究结果表明,橡胶硫化沥青具有较强的抗紫外线老化的性能.

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

    Science.gov (United States)

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

    2016-06-01

    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.

  19. 硫化异丁烯在酯类合成油中的摩擦学特性*%Tribological Characteristics of Vulcanization Isobutylene Additives in Ester Oil

    Institute of Scientific and Technical Information of China (English)

    陈卓君; 冯龙龙; 徐嘉宁; 李宝良; 路瑶

    2013-01-01

      为探讨硫化异丁烯在新戊基多元醇酯和偏苯三酸酯中的摩擦学特性,在四球试验机上考察不同硫化异丁烯含量的新戊基多元醇酯和偏苯三酸酯基础油的最大无卡咬负荷、烧结负荷和磨斑直径,并用扫描电镜(SEM)观察钢球磨痕形貌,分析硫化异丁烯的润滑机制。结果表明:新戊基多元醇酯对硫化异丁烯添加剂的感受性、配伍性优于偏苯三酸酯;力优于新戊基多元醇酯。%  In order to study the tribological characteristics of vulcanization isobutylene additives in the neopentyl polyol ester (NPE)or the trimellitate (TMT),the maximum non-seizure load and weld point of NPE or TMT base oil with differ-ent content of vulcanization isobutylene(T321)and the wear scar diameter of steel ball were investigated by the four ball test machine. The appearance of abrasive scar on steel ball was observed with the electron microscope (SEM),and the lu-brication mechanism of vulcanization isobutylene was analyzed. The results show that the additive T321 in NPE shows ex-cellent sensitivity and compatibility than that in TMT. The boundary lubrication ability of T321 in NPE is better than that in TMT. The antiwear ability of T321 in TMT is better than that in NPE.

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

    Energy Technology Data Exchange (ETDEWEB)

    Barnard, H.S., E-mail: hbar@mit.edu [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA (United States); Hartwig, Z.S.; Olynyk, G.M.; Payne, J.E. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA (United States)

    2012-03-15

    The Vulcan conceptual design (R = 1.2 m, a = 0.3 m, B{sub 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{sup -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 {approx}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

  1. Nonvolatile write-once-read-many times memory devices based on the composites of poly(4-vinylphenol)/Vulcan XC-72.

    Science.gov (United States)

    Song, Sunghoon; Kim, Tae-Wook; Cho, Byungjin; Ji, Yongsung; Lee, Takhee

    2011-05-01

    We fabricated write-once-read-many times (WORM) type organic memory devices in 8 x 8 cross-bar structure. The active material for organic based WORM memory devices is mixture of both poly(4-vinyphenol) (PVP) and Vulcan XC-72s. From the electrical characteristics of the WORM memory devices, we observed two different resistance states, low resistance state and high resistance state, with six orders of ON/OFF ratio (I(ON)/I(OFF) - 10(6)). In addition, the WORM memory devices were maintained for longer than 50000 seconds without any serious degradation.

  2. THE IMPACT OF MINING ACTIVITIES ON THE WEST OF PETROŞANI DEPRESSION AND IDENTIFICATION OF AFFECTED GEOMORPHOLOGICAL RESOURCES. CASE STUDY: ANINOASA-VULCAN-LUPENI SECTOR

    Directory of Open Access Journals (Sweden)

    N. NIMARĂ

    2015-10-01

    Full Text Available The Impact of Mining Activities on the West of Petroşani Depression and Identification of Affected Geomorphological Resources. Case Study: Aninoasa- Vulcan-Lupeni Sector. The west region of Petroşani Depression, like the whole depression, suffered some changes in the geomorphologic environment as a result of coal mining activities. Following displacement processes of mass materials and relocation of it, changes in shape are brought to the original territory that contrast with the natural landscape. The human impact on the West of Petroşani Depression and hence to the analyzed sector is especially highlighted as it materializes into waste dumps and coal pits.

  3. 丙烯腈含量对NBR混炼胶硫化反应的影响%Effect of AN Content on Vulcanization Reaction of NBR Compounds

    Institute of Scientific and Technical Information of China (English)

    刘莉; 张保岗; 杨槐

    2012-01-01

    Effect of acrylonitrile(AN) content and carbon black on nitrile butadiene rubber(NBR)vulcanization reaction was studied by DSC in this paper.The results show that as AN content increases from 18.8% to 43.3%,the physical cross-linking increases by 20% and the chemical cross-linking is increased by 73%.The vulcanization of NBR compounds contains two stages: sulfur vulcanization and double bond crosslinking.When AN content increases,curing reaction temperature compound reduces,and heat release rate reduces at the first stage,while it increases at the second stage.After the addition of carbon black,the curing reaction is improved,chemical cross-linking density is increased and heat release of vulcanization reduces.With acrylonitrile content increasing,the initial curing temperature increases by 34 ℃ without carbon black,but only by 12 ℃ with carbon black.In addition,the content of acrylonitrile is lower,the influence of carbon black on curing reaction is larger.%采用差示扫描量热法(DSC)研究了丙烯腈(AN)含量和炭黑对丁腈橡胶(NBR)硫化反应的影响。研究表明,AN含量由18.8%(质量分数,下同)增加至43.3%,硫化胶的物理交联密度增加约20%,化学交联密度大大增加,增加约73%。NBR复合材料的硫化反应分两个阶段:第一阶段硫磺硫化反应,第二阶段硫键短化和双键交联反应。AN含量增加,两阶段分离明显,硫化温度降低,第一阶段放热量减小,第二阶段放热量增加。炭黑加入后,催化了硫化反应,提高了化学交联密度,降低了反应热,且起始硫化温度受丙烯腈含量的影响变小,由未加炭黑的34℃降低到12℃。此外,丙烯腈含量越低,硫化反应受炭黑的影响越大。

  4. Simulación del proceso de inyección a alta presión mediante los programas de elementos finitos ProCAST y Vulcan

    OpenAIRE

    García Ramos, Cristian

    2008-01-01

    En este proyecto se simula el proceso de inyección a alta presión de la pletina de una motocicleta, mediante los programas comerciales de elementos finitos ProCAST y Vulcan. El proceso simulado está formado por una máquina de inyección THT presses de la que destaca que es de cámara fría y de inyección vertical, hecho que hay que tener en cuenta a la hora de realizar la simulación con ambos programas. Para realizar la simulación con ambos programas y con la finalidad de ...

  5. PREPARATION OF HIGH-TEMPERATURE VULCANIZED SILICONE RUBBER OF EXCELLENT MECHANICAL AND OPTICAL PROPERTIES USING HYDROPHOBIC NANO SILICA SOL AS REINFORCEMENT

    Institute of Scientific and Technical Information of China (English)

    Qian Wang; Qin Zhang; Yu-hong Huang; Qiang Fu; Xian-jian Duan; Yue-ling Wang

    2008-01-01

    Hydrophobic nano silica sol (HNSS) was incorporated into polyvinylmethylsiloxane to prepare reinforced high-temperature vulcanized (HTV) silicone rubber. HTV silicone rubber filled with 40 phr HNSS showed excellent mechanical and optical properties: the tensile strength reached 11.7 MPa and the optical transmittance was higher than 90%. Possible reasons for reinforcement and transparency were discussed on the basis of the bound rubber percentage, total crosslink density, and SEM analysis. Our work suggests that HNSS is effective for reinforcement of HTV silicone rubber to endow excellent mechanical and optical properties.

  6. Vulcanizing machine suppress electrothermal device, cooling device and application development Jining III coal mine%电热式硫化机打压装置、冷却装置研制及应用

    Institute of Scientific and Technical Information of China (English)

    袁向科; 李双忠

    2012-01-01

    In that paper, by introducing the electric - type vulcanizing machine encountered in the vulcanizing joint suppression, cooling problems, de- velopment of a reliable and practical curing pressure from the cooling device to ensure the quality of vulcanized joints.%该文通过分绍电热式硫化机在接头硫化过程中遇到打压、冷却问题,研制一套可靠、实用的硫化打压、冷却装置来保证硫化接头质量。该装置在井下硫化接头中得到了应用,收到良好的效果。

  7. Effect of N, N'-4,4'-Diphenyimethane-Bismaleimide on Vulcanization and Mechanical Properties of Methyl-Vinyl Silicone Rubber/EPDM Blends%二苯甲烷双马来酰亚胺对硅橡胶/三元乙丙橡胶共混物硫化特性和力学性能的影响

    Institute of Scientific and Technical Information of China (English)

    李远; 李建雄; 游长江; 刘安华

    2013-01-01

    Diphenyl-methane bismaleimide (BMI)was added to methyl-vinyl silicone rubber (MVQ), ethylene-propylene-diene monomer rubber(EPDM)and their blends. The effects of BMI on the vulcanization and mechanical properties were studied. EPDM has the lower vulcanizing activity and its optimum vulcanizing time is two times longer than of MVQ. The co-vulcanization and compatibility between MVQ and EPDM are very poor. BMI can promote the vulcanization of EPDM and enhance the vulcanizing speed. Meanwhile, BMI depresses the vulcanizing speed of MVQ. Thereby, the vulcanizing speeds of MVQ and EPDM can approach closely as MBI content increases. In MVQ/ EPDM blend, BMI made parts of EPDM and MVQ to vulcanize simultaneously at about 140 ℃ and promoted the co-vulcanization in the blend, consequently. The compatibility between MVQ and EPDM is improved and the mechanical properties of the blend increase.%在硅橡胶(MVQ)和三元乙丙橡胶(EPDM)及其共混物中加入交联剂二苯甲烷双马来酰亚胺(BMI),研究了BMI对MVQ、EPDM及其共混物的硫化特性和力学性能的影响.EPDM的硫化活性低,正硫化时间是MVQ的3倍,共混物的共硫化性和相容性不佳.BMI能降低EPDM的活化温度,提高EPDM的硫化速度,同时减慢MVQ的硫化速度,从而使二者的硫化速度趋于接近.在MVQ/EPDM共混物中,BMI能使MVQ和EPDM在较低温度下同步反应,实现两组分的共硫化,改善MVQ与EPDM的相容性,提高了MVQ/EPDM共混物的力学性能.

  8. 硫化促进剂对氯丁橡胶性能的影响%Effect of Vulcanization Accelerator on Properties of Neoprene

    Institute of Scientific and Technical Information of China (English)

    金耀程; 韩雪; 李帅孝; 陈丽飞

    2016-01-01

    Influence of different vulcanization accelerator and curing temperature on neoprene vulcanization and mechanical behavior was investigated. The results indicate that: curing time and scorch time of CR at 180 ℃ are shorter than that at 170 ℃ in the most of curing system. The shortest curing time and better mechanical property can be obtained when ZnO(5),MgO(4) , NA-22(1), TMTD(0.5)and silica (40) treated with silane coupling agent KH550 are added.%讨论了不同硫化促进剂和硫化温度对氯丁橡胶硫化和力学性能的影响。结果表明:多数胶料在180℃硫化比在170℃硫化的正硫化时间短,焦烧时间也短。在加入 ZnO 5份、MgO 4份,NA-221份、TMTD 0.5份,KH550活化的白炭黑40份时,胶料获得最短的硫化时间,且该体系也能使胶料获得较好的力学性能。

  9. Effect of chemically modified Vulcan XC-72R on the performance of air-breathing cathode in a single-chamber microbial fuel cell.

    Science.gov (United States)

    Duteanu, N; Erable, B; Senthil Kumar, S M; Ghangrekar, M M; Scott, K

    2010-07-01

    The catalytic activity of modified carbon powder (Vulcan XC-72R) for oxygen reduction reaction (ORR) in an air-breathing cathode of a microbial fuel cell (MFC) has been investigated. Chemical modification was carried out by using various chemicals, namely 5% nitric acid, 0.2N phosphoric acid, 0.2N potassium hydroxide and 10% hydrogen peroxide. Electrochemical study was performed for ORR of these modified carbon materials in the buffer solution pH range of 6-7.5 in the anodic compartment. Although, these treatments influenced the surface properties of the carbon material, as evident from the SEM-EDX analysis, treatment with H(2)PO(4), KOH, and H(2)O(2) did not show significant activity during the electrochemical test. The HNO(3) treated Vulcan demonstrated significant ORR activity and when used in the single-chamber MFC cathode, current densities (1115mA/m(2), at 5.6mV) greater than those for a Pt-supported un-treated carbon cathode were achieved. However, the power density for the latter was higher. Such chemically modified carbon material can be a cheaper alternative for expensive platinum catalyst used in MFC cathode construction.

  10. 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.

  11. 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)

  12. 橡胶电缆连续硫化生产线水汽平衡系统设计探讨%Discussion on Design of Water-steam Balance System of Continue Vulcanization Rubber Line

    Institute of Scientific and Technical Information of China (English)

    孙竹; 宋海峰

    2014-01-01

    简述了橡胶电缆的硫化过程及半悬链式橡胶电缆硫化生产线硫化管道及冷却管道长度的选择,介绍了橡胶硫化包覆过程中水汽平衡系统的组成及工作原理,围绕蒸汽压力控制、冷却水外循环、内循环三个方面对水汽平衡系统进行了设计探讨。%This paper briefly describes the vulcanization process of rubber line and the length selection of the vulcanization and cool-ing tubes of the hanging chain vulcanization rubber line,introduces the configuration and operating prinoiple of water-steam balance system during the sheathing process of rubber vulcanization and discusses the design of this system from three aspects, such as steam pressure control,cooling water external and internal circulation.

  13. 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.)

  14. Design and FEA of Beam in New Modular Vulcanizer for Rubber Dam Bag in Two Directions%新型模块化两方向用无限坝袋硫化机大梁的设计及有限元分析

    Institute of Scientific and Technical Information of China (English)

    马娟娟; 贾瑞清; 王乾; 刘杰

    2011-01-01

    针对目前橡胶坝袋硫化机整体受力条件恶劣及硫化工艺过程复杂等问题,提出一种新型模块化两方向用无限坝袋硫化机,并对其关键部件即大梁进行有限元分析,得到大梁的优化设计.该新型坝袋硫化机可实现两个方向连续硫化,不需要接缝工艺,所需工时仅为目前所用接缝硫化工艺的1/5~1/10.%To overcome present problems such as vulcanizer working in poor condition for rubber dam bag and vulcanizing process being complcx,a ncw modular vulcanizer for continuous rubber dam bag in two directions was designed.and the FEA of its key part,the beam, was conducted to get the optimal design. The new vulcanizer could vulcanize rubber dam bag continuously in two directions without overlapping proccss,and the production time was only 1/5 ~ 1/10 of the present overlapping vulcanization process.

  15. Influence of Vulcanization Process on Compression and Rebound Performance of Non-asbestos Gaskets%无石棉密封垫片硫化工艺对及压缩回弹性能的影响

    Institute of Scientific and Technical Information of China (English)

    贾星宇; 刘美红; 焦健; 田硕; 冯洪飞

    2016-01-01

    采用均匀实验方案,研究硫磺和硫化促进剂 TMTD 用量、硫化温度、硫化时间、硫化压力5种硫化工艺参数对无石棉密封橡胶垫片压缩回弹性能的影响,采用多元线性回归方法研究压缩率和回弹率与各硫化工艺参数的关系,并提出回归模型。结果表明,硫化温度、硫化压力以及硫化时间对压缩率的影响较大,提高硫化温度、时间和压力均有利于压缩率的降低;硫磺用量对垫片压缩率有负面影响;硫化促进剂 TMTD 与硫化温度交互影响压缩率,增加促进剂的用量可降低硫化反应温度,而提高硫化温度可减少促进剂用量。利用建立的回归模型对不同硫化工艺下制备的垫片试样的性能进行预测,预测值与实测值较接近。%A homogeneous experimental design was used to study influence of vulcanization process of 5 independent variables as sulfur and vulcanization accelerant TMTD dosage,vulcanization temperature,time and pressure on compression and rebound performance of non-asbestos gaskets.By using of multiple linear regression method,the relationship between the compression rate and rebound with all process parameters was studied,and a regression model was set up.The results show that the vulcanization temperature,pressure and time have a great influence of on the compression rate.The increase of vulcanization temperature,pressure and time is favorable to decrease the compression rate,while the increase of sulfur content has a negative effect on the compression ratio.Accelerant TMTD dosage and temperature have an interactive influ-ence on the compression rate,and the increasing of TMTD can reduce vulcanization temperature,while the increasing of vulcanization temperature can reduce the TMTD dosage.The performance of the gasket samples prepared under different vulcanization process was predicted by the regression model, and the predicted values were quite close to the practical measured

  16. Impact of the Curing System on the Co-Vulcanizing Properties of CR/CM Blends%硫化体系对CR/CM橡胶共硫化特性的影响

    Institute of Scientific and Technical Information of China (English)

    刘世练; 苑宾; 李荣勋

    2015-01-01

    The properties of CR prepared by the primary vulcanization system of CM were investigated, and the comparison with a metal oxide was also studied. The results showed that, CR had significantly shorter scorch time and the higher vulcanization rate. NA-22/S, FSH and TCHC vulcanization system had obvious reversion phenomenon. The Vulcanizing processing of CR/CM blends vulcanized by NA-22 / S, PT75/903 or TCHC were not synchronous. Those with DCP/TAIC, FSH and TCY were better in synchronism. For individual CR, NA-22/S and TCHC system had higher tensile strength, and the physical properties of all the six kinds of vulcanized rubber were worse than metal oxide vulcanized one. NA-22/S and TCHC in blends had higher tensile strength(22.8 MPa), and metal oxides and TCY in blends had lower tensile strength. For NA-22/S, DCP/TAIC, PT75/903, FSH and TCHC, the mechanical properties of vulcanized blends were similar with those of individual CR, and showed good performance.%研究了氯化聚乙烯橡胶(CM)的主要硫化体系对氯丁橡胶(CR)的硫化特性的影响,并与金属氧化物(ZnO/MgO)的效果进行对比,发现CR的焦烧时间明显缩短,硫化速度显著提高,硫化体系NA-22(亚乙基硫脲)/S (硫磺)、FSH(三唑二巯基胺盐)和TCHC(复配型交联剂EataMix)都有明显的返原现象。NA-22/S、PT75(噻二唑衍生物类化合物EataVulc)/903(噻二唑衍生物类化合物EataAccel)和TCHC硫化的CR/CM出现明显的硫化不同步现象。DCP(过氧化二异丙苯)/TAIC、FSH和TCY(三巯基均三嗪)硫化的CR/CM,硫化同步性较好。对于纯CR,硫脲类和TCHC硫化胶料的拉伸强度较高,六种硫化体系的硫化胶物理性能都低于金属氧化物硫化胶。共混胶中NA-22/S和TCHC类拉伸强度较高(达22.8 MPa),金属氧化物和TCY拉伸强度较低。NA-22/S、DCP/TAIC、PT75/903、FSH和TCHC硫化的共混胶的力学性能与硫化CR相近,显示出较好的共混性能。

  17. Synthesis and vulcanization activity of N-butylxanthate-tetramethyl quaternary ammonium ionic liquids as vulcanization accelerator%正丁基黄原酸-四甲基季铵盐离子液体的合成及硫化促进性能研究∗

    Institute of Scientific and Technical Information of China (English)

    游兴均; 周元林; 曾燕飞

    2014-01-01

    通过以正丁醇、CS2、NaOH 为原料,以水作溶剂合成正丁基黄原酸钠盐。再将合成的正丁基黄原酸钠盐溶解在甲醇中,加入四甲基氯化铵在室温条件下搅拌反应得到正丁基黄原酸-四甲基季铵盐离子液体(ILS),产物结构通过质谱(MS),元素分析,核磁(1 H-NMR)确定。将所得到的产品作为硫化促进剂用于天然橡胶(NR),讨论了不同的 ILS 用量、不同的硫化温度和不同的硫化时间对天然橡胶制品的性能的影响,并与传统硫化促进剂 TMTD,CBS 作了对比实验,结果表明正丁基黄原酸-四甲基季铵盐离子液体对天然橡胶(NR)具有较好的低温、高效的硫化促进效果。%Using n-butyl alcohol,CS2 and NaOH as starting materials,and water as a solvent,sodium n-butyx-anthate was synthesized.The synthetic Sodium n-butyxanthate was dissolved in methanol,afterward,tetram-ethylammonium chloride in methanol was added.After completion of the reaction,the N-butylxanthate-tetram-ethyl quaternary ammonium ionic liquids (ILS)will be obtained.The structure of the product was confirmed by mass spectrometry (MS),elemental analysis and 1 H-NMR.The product was used as a vulcanization accelerator of natural rubber (NR),and compared with the traditional vulcanization accelerator TMTD,CBS.The results show that the n-butyxanthate-tetramethyl quaternary ammonium ionic liquids has excellent performance as vul-canization accelerator for NR,worth of further investigation.

  18. 国产原子吸收分光光度计测定硫化橡胶钴含量%Determination of Cobalt Content in Vulcanized Rubber by Domestic Atomic Absorption Spectrophotometer

    Institute of Scientific and Technical Information of China (English)

    王毅

    2014-01-01

    Since the adding of binder, vulcanized rubber always has cobalt. The conventional determination method of cobalt is the colorimetric method and the titration method. In this paper, application of domestic atomic absorption spectrophotometer TAS-990 in measuring cobalt in vulcanized rubber was explored;detail process of testing operation was described. The test results show that domestic TAS-990 atomic absorption spectrophotometer can be used for measuring cobalt content of vulcanized rubber;it is simple and easy to operate. Its test accuracy and sensitivity can be achieved to meet the requirements of chemical analysis test methods.%硫化橡胶中由于黏合剂的加入带入钴盐,传统的钴测定方法有比色法、滴定法等。探索使用国产原子吸收分光光度计 TAS-990进行测定,详细介绍了测试操作过程,通过试验验证结果可见,国产 TAS-990原子吸收分光光度计用于测定硫化橡胶中钴含量,操作方便简捷,测试准确度、灱敏度能够达到并满足化学分析试验方法要求。

  19. 動的再構成可能プロセッサVulcan2 とそのソフトウェア開発環境ISAcc に関する研究

    OpenAIRE

    2007-01-01

    特定用途向けプロセッサとは,アプリケーションに特化した命令を実行することによって,汎用プロセッサに対して高性能を実現するものである.本稿では,特定用途向けプロセッサの実現方式として,データパスに動的再構成可能ハードウェアを用いたプロセッサVulcan2 とそのソフトウェア開発環境ISAcc を提案する.また,実際にISAcc を用いてアプリケーションをVulcan2 シミュレータ上に実装した結果を解析し,Vulcan2 及びISAcc の評価を行った....

  20. The Temperature Control System for Plate Vulcanization Machine Based on the Fuzzy Adaptive PID Control%基于模糊自适应PID控制的平板硫化机温度控制系统

    Institute of Scientific and Technical Information of China (English)

    张才

    2013-01-01

    The control precision of the temperature Control System for Plate Vulcanization Machine is low, which can not reach the national standard. The paper proposed a new temperature Control System for Plate Vulcanization Machine with fuzzy tem?perature control system and PLC,the hardware and software design of the temperature Control System for Plate Vulcanization Machine is elaborated in detailed.%平板硫化机系统温度控制系统存在控制精度低,难以达到国家硫化标准等问题,提出了一种基于模糊自适应PID控制的平板硫化机温度控制系统,该系统以模糊自适应PID控制为理论基础,以PLC为控制平台,配以高性能的模块化外设,详细介绍了平板硫化机温度控制系统的硬件选型及软件设计.

  1. 碳化钨和Vulcan XC-72炭混合载Ir催化剂对氨氧化的电催化性能%Electrocatalytic Performance of Ir Catalyst Supported on Mixture of WC and Vulcan XC-72 Carbon for Ammonia Oxidation

    Institute of Scientific and Technical Information of China (English)

    郁明珠; 李林儒; 陆天虹; 陈赵扬; 马淳安; 杜江燕

    2013-01-01

    以碳化钨(WC)和Vulcan XC-72炭黑(XC)为载体制备了XC载Ir(Ir/XC)和WC/XC载Ir(Ir-WC/XC)催化剂,在用X射线能量色散谱、X射线衍射谱对催化剂表征的基础上,用电化学方法研究了2种载体Ir催化剂对氨氧化的电催化性能,发现氨在Ir-WC/XC催化剂电极上的氧化峰峰电流密度比在Ir/XC催化剂电极上大31.26%,而且电催化稳定性明显好于Ir/XC催化剂.

  2. 碳化钨和Vulcan XC-72炭黑载钯催化剂对甲酸氧化的电催化性能%Electrocatalytic Performance of Tungsten Carbide and Vulcan XC-72 Carbon Supported Pd Catalyst for Formic Acid Oxidation

    Institute of Scientific and Technical Information of China (English)

    沈娟章; 季芸; 陈赵杨; 马淳安; 陆天虹

    2012-01-01

    研究了碳化钨(WC)和Vulcan XC-72炭黑(XC)作混合载体的Pd/WC-XC催化剂对甲酸氧化的电催化性能.发现Pd/WC-XC催化剂对甲酸氧化的电催化性能优于Pd/XC催化剂.而且,Pd/WC-XC催化剂的电催化性能与WC和XC的质量比有关,当质量比为3:1时,催化剂对甲酸氧化的电催化活性最好,当质量比为2:1时,催化剂对甲酸氧化的电催化稳定性性最好.%This work investigated the elecrocatalytic performance of tungsten carbide(WC) and Vulcan XC-72 carbon (XC) supported Pd(Pd/WC-XC) catalysts for formic acid oxidation.It is found that the electrocatalytic performance of the Pd/WC-XC catalysts for formic acid oxidation is better than that of the Pd/XC catalyst.Furthermore,the electrocatalytic performance of the Pd/WC-XC catalyst is related to the mass ratio of WC and XC.When the mass ratio of WC and XC is 3:1,the electrocatalytic activity of the catalyst is best.When the mass ratio of WC and XC is 2:1,the electrocatalytic stability of the catalyst is best.

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

    Science.gov (United States)

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

    2016-06-01

    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.

  4. Effect of Betaine on Vulcanization Characteristics of NR Latex Film%甜菜碱对天然胶乳胶膜硫化特性的影响

    Institute of Scientific and Technical Information of China (English)

    罗文杰; 黎燕飞

    2014-01-01

    The effect of betaine on the vulcanization characteristics of NR latex iflm was studied with the use of an oscillating disc rheometer. The results showed thatMH,ML,t10 andt90 decreased with the addition of betaine. The parameters of curing kinetics were then calculated using Arrhenius equation. The curing reaction activation energy (Ea) of NR latex iflm with betaine was smaller than that of original NR latex iflm while the reaction rate constant (k) was higher. With the increase of betaine amount, the curing rate and crosslinking degree of the vulcanizates increased.%研究甜菜碱对天然胶乳胶膜硫化特性的影响,并通过Arrhenius方程对胶膜的硫化过程进行动力学分析。结果表明:添加甜菜碱,天然胶乳胶膜的MH和ML减小,t10和t90缩短;胶膜的硫化反应活化能减小,硫化反应速率常数增大,硫化速率提高,交联密度增大。

  5. Enhanced activity of Pd nanoparticles supported on Vulcan XC72R carbon pretreated via a modified Hummers method for formic acid electrooxidation

    Science.gov (United States)

    Cao, Jianyu; Song, Lingzheng; Tang, Jiali; Xu, Juan; Wang, Wenchang; Chen, Zhidong

    2013-06-01

    Vulcan XC72R carbons were pretreated using a modified Hummers method and adopted as the support of palladium nanoparticles for formic acid electrooxidation. XPS analysis was used to investigate the surface species of the pretreated XC72R (XC72R-O), indicating a significant increase in the content of surface carboxyl groups. The structural properties of Pd nanoparticles deposited on the XC72R-O (Pd/XC72R-O) were determined by X-ray diffraction (XRD) and transmission electron microscopy (TEM), and their electrochemical performance was evaluated by cyclic voltammetry (CV) and chronoamperometry. Pd nanoparticles in the Pd/XC72R-O display an average size of ~6.7 nm with narrow size distribution. Electrochemical studies for formic acid oxidation reveal that the Pd/XC72R-O presents much higher electrocatalytic activity than that of the Pd/XC72R and commercial Pd/C, which may be due to the formation of carboxyl groups enhanced the interaction between the Pd particles and the carbon support, facilitating the dispersion of Pd particles and the formation of preferred plane orientation available for electrocatalytic reaction.

  6. Preparation of Pt-Re/Vulcan carbon nanocomposites using a single-source molecular precursor and relative performance as a direct methanol fuel cell electrooxidation catalyst.

    Science.gov (United States)

    Anderson, Angela D; Deluga, Gregg A; Moore, Joshua T; Vergne, Matthew J; Hercules, David M; Kenik, Edward A; Lukehart, C M

    2004-09-01

    Pt-Re/Vulcan carbon powder nanocomposites have been prepared with total metal loadings of 18 wt.% and 40 wt.% using a new non-cluster (1:1)-PtRe bimetallic precursor as the source of metal. Pt-Re nanoparticles having an average diameter of ca. 6 nm and atomic stoichiometry near 1:1 are formed. TEM, on-particle HR-EDS, and powder XRD data are consistent with the formation of Pt-Re alloy nanoparticles having a hexagonal unit cell with cell constants of a = 2.77 A and c = 4.47 A. A nanocomposite prepared at higher total metal loading under more rigorous thermal treatment also contains Pt-Re alloy nanoparticles having a fcc unit cell structure (a = 3.95 A). The precise dependence of Pt-Re nanocrystal structure on the thermal history of the nanocomposite specimen has not been investigated in detail. While these Pt-Re/carbon nanocomposites are active as anode catalysts in operating direct methanol fuel cells, the measured performance is less than that of commercial Pt-Ru/carbon catalysts and has marginal practical importance.

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

    Science.gov (United States)

    Manzo-Robledo, A.; Costa, Natália J. S.; Philippot, K.; Rossi, Liane M.; Ramírez-Meneses, E.; Guerrero-Ortega, L. P. A.; Ezquerra-Quiroga, S.

    2015-12-01

    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, Pd90Ni10, Pd50Ni50, Pd10Ni90, and Ni) have been synthesized from organometallic precursors, namely tris(dibenzylideneacetone) dipalladium(0), Pd2(dba)3, and bis(1,5-cyclooctadiene)nickel(0), Ni(cod)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.

  8. Facile Enhancement in CO-Tolerance of a Polymer-Coated Pt Electrocatalyst Supported on Carbon Black: Comparison between Vulcan and Ketjenblack.

    Science.gov (United States)

    Yang, Zehui; Kim, ChaeRin; Hirata, Shinsuke; Fujigaya, Tsuyohiko; Nakashima, Naotoshi

    2015-07-29

    The CO poisoning and low durability of the anode platinum electrocatalyst in the direct methanol fuel cell (DMFC) are the two crucial obstacles of the wide commercialization of the DMFC. In this study, we synthesized two different electrocatalysts using VulcanXC-72R (VC) and Ketjenblack (KB) as the carbon supporting material for the methanol oxidation reaction (MOR) and long-term durability test, in which the carbon supporting materials were wrapped by poly[2,2'-(2,6-pyridine)-5,5'-bibenzimidazole] (PyPBI) before the platinum deposition and the fabricated electrocatalysts were coated by the poly(vinylphosphonic acid) (PVPA) via the base-acid reaction. We have found that the as-prepared KB/PyPBI/Pt/PVPA shows a higher durability (7% loss in ECSA) under the potential cycling from 1.0 to 1.5 V vs. RHE compared to that of the VC/PyPBI/Pt/PVPA, which showed a 20% loss in ECSA after 10 000 cycle-durability test. Meanwhile, the KB/PyPBI/Pt/PVPA shows a higher CO tolerance before and after the durability test compared to that of the VC/PyPBI/Pt/PVPA, especially under very high methanol concentration (4 M and 8 M), which is close to the practical application of the DMFC. The observed higher CO tolerance is due to the higher amount of the PVPA (14.6 wt %) in the KB/PyPBI/Pt/PVPA caused by the higher specific surface area of the KB (1232 m(2)/g) compared to the VC (235 m(2)/g).

  9. 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.

  10. 橡胶助剂Silane-M对丁苯橡胶/白炭黑复合材料硫化性能的影响%Effect of rubber additive Silane-M on vulcanization property of styrene butadiene rubber/silica composites

    Institute of Scientific and Technical Information of China (English)

    彭华龙; 刘岚; 罗远芳; 高宏; 贾德民

    2009-01-01

    用硫化仪考察了橡胶助剂3-苯并噻唑硫代-1-丙基-三乙氧基硅烷(Silane-M)对丁苯橡胶/白炭黑复合材料硫化性能的影响.结果表明,Silane-M可明显缩短丁苯橡胶/白炭黑复合材料的正硫化时间,但不影响其焦烧时间.Silane-M具有一定的促进作用,可以加快硫化速率.未添加和添加6份(质量)Silane-M的丁苯橡胶/白炭黑复合材料在135~160 ℃的硫化温度系数和硫化反应表观活化能均比较接近,2种复合材料的硫化性能对温度的依赖性基本一致.%The effect of rubber additive 3-benzothiazolthio-1-propyl-triethoxylsilane(Silane-M) on vulcanization behavior of styrene butadiene rubber(SBR)/silica composites was investigated with rubber curometer. The results showed that Silane-M shortered vulcanization time, but had no effect on scorching time. It could accelerate rubber vulcanization process. The vulcanization temperature coefficient and apparent vulcanization activation energy of silica filled rubber without and with 6 phr Silane-M at 135-160 ℃ were approximately equal. The temperature dependence of vulcanization behavior of two kinds of composites were basically consistent.

  11. HNBR/AO80共混阻尼橡胶的结构和性能%Structure and Properties of Vulcanized HNBR/AO80 Damping Rubbers

    Institute of Scientific and Technical Information of China (English)

    王爽; 张继华; 赵云峰

    2013-01-01

    在氢化丁腈橡胶(HNBR)中添加受阻酚AO80,制备HNBR/AO80共混橡胶,以改善HNBR的阻尼性能.采用DMA和FTIR等方法研究了HNBR/AO80共混硫化体系结构和性能之间的关系,并通过热处理的方法,研究了该体系的稳定性.结果表明:由于AO80的羟基与HNBR的腈基间强氢键作用,使HNBR/AO80硫化体系具有较好的阻尼性能.而热处理后,硫化体系中一些与橡胶分子有氢键作用的AO80,会不断自聚形成AO80的富相区、结晶、长大,形成大的结晶聚集体,导致共混体系的阻尼性能不稳定.%In order to improve the damping properties of hydrogenated nitrilebutadiene rubber (HNBR ) ,3,9-bis[ 1, 1-dimethyl-21 {β-(3-tertbutyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl ] -2,4,8,10-tetraoxaspi-ro [ 5, 5 ] -undecane (AO80) were added into it to prepare the vulcanized HNBR/AO80 rubbers. The relationship between the damping properties and micro-structure of this blending system was characterized by DMA & FTIR. Then the stability of this system was studied by thermal treatment at 8011. The results showed good damping property of this blending system, which was due to the effect of intermolecular hydrogen bonds between the hydroxyl groups of AO80 and the nitrile groups of HNBR. But the damping property of this curing system become unstable after thermal treated because of the self polymerization of AO80. With the increasing of thermal treated time, large number of AO80 formed rich phase,crystallized,grewed up,then formed large crystallise aggregates.

  12. 硫化工艺对轴箱弹簧硫化内压及性能的影响%The Effect of the Rubber-inner-vulcanizing-pressure on the Surface and Properties of the Rubber Products

    Institute of Scientific and Technical Information of China (English)

    程志; 吴卫东; 程海涛; 贺永红; 丁周清

    2014-01-01

    以轴箱弹簧产品为例,研究了填胶量及硫化温度对轴箱弹簧的硫化内压以及刚度等性能的影响。结果表明,随着填胶量的增加,硫化内压增大,橡胶的交联程度及致密度增大,产品刚度增大;随着硫化温度的升高,硫化内压先迅速增大后有所降低,对产品的刚度影响不明显。%T he effect of the rubber‐inner‐vulcanizing‐pressure on the surface and properties of the rubber products was studied by changing the weight of rubber and vulcanizing temperature .The re‐sults showed that machine pressure did not much affect the rubber‐inner‐vulcanizing‐pressure ;the rubber‐inner‐vulcanizing‐pressure was increased with the increase of rubber weight ,and the rubber‐in‐ner‐vulcanizing‐pressure had influence on the routine properties but the surface ;The rubber‐inner‐vul‐canizing‐pressure increased firstly and then decreased with the increase of vulcanizing temperature and the rubber‐inner‐vulcanizing‐pressure had influence on the surface but the routine properties .

  13. 基于C/S模式的轮胎胶囊硫化机远程监控系统设计%Remote monitoring system for tyre capsule vulcanizer based on C/S

    Institute of Scientific and Technical Information of China (English)

    苗岱江; 邢建国; 张华

    2009-01-01

    Tyre capsule vulcanizer remote monitoring system which based on C/S mode is developed by using the VC++6.0 as programming method in the Windows environment by the TCP/IP communication protocol. In this paper, client / server mode and the tyre capsule vulcanizing process are introduced, realization method of key technologies such as network communication and remote database are presented. The application indicated that the system is good at real time and works safely, and has widely used in the future.%在Windows环境下采用Visual C++ 6.0开发工具,遵循TCP/IP网络通信协议,开发了基于C/S模式的轮胎胶囊硫化机的远程监控系统.对客户端/服务器模式、胶囊硫化机的工作过程进行了介绍,对网络通信和远程数据库等关健技术给出了实现方法.运行结果表明,该系统具有良好的实时性和安全性,具有较强的实际应用价值.

  14. The Rise of the Vulcans

    CERN Document Server

    Charbonneau, David

    2008-01-01

    In this introductory review presented at the IAU Symposium 253 "Transiting Planets", I summarize the path from the initial 1995 radial-velocity discovery of hot Jupiters to the current rich panoply of investigations that are afforded when such objects are observed to transit their parent stars. Forty transiting exoplanets are now known, and the time for that population to double has dropped below one year. It is only for these objects that we have direct estimates of their masses and radii, and for which (at the current time) we can undertake direct studies of the chemistries and dynamics of their atmospheres. Informed by the successes of hot Jupiter studies, I outline a path for the spectroscopic study of certain habitable exoplanets that obviates the need for direct imaging.

  15. 硫化胶中炭黑品种的粒径分布鉴别方法%Determination of Carbon Black Type in Vulcanized Compound by Particle Size Distribution Analysis

    Institute of Scientific and Technical Information of China (English)

    张翠翠; 苍飞飞; 邹滔; 高原; 马姜; 邓平晔

    2015-01-01

    The relationship between particle size distribution and carbon black type was established and the test method to determine the carbon black type in vulcanized compound was obtained by particle size distribution analysis. The carbon black in the vulcanized compound was recovered by pyrolysis and its particle size distribution was measured by laser diffraction nano-particle size analyzer. The results showed that peak value and standard deviation of different type of carbon black were different and the peak value and standard deviation fluctuated within a small range for the same type of carbon black. Thus the unknown carbon black could be identiifed by measuring its particle size distribution. This identiifcation method was suitable for analysis of carbon black in the vulcanized compound iflled with only one type of carbon black and it could not be applied to blended carbon black and carbon black N774.%探索炭黑粒径分布与炭黑品种之间的关系,建立通过炭黑粒径分布鉴别炭黑品种的方法。通过热裂解法回收硫化胶中的炭黑,将回收的炭黑加入分散剂制成悬浊液,利用纳米激光粒度分布仪进行粒径分布测试。结果表明,不同品种炭黑粒径分布的峰值和标准偏差不同,同种炭黑粒径分布的峰值和标准偏差在一个较小的范围内波动,这是硫化胶中未知炭黑品种鉴别的依据。本方法适用于单一炭黑品种硫化胶分析,不适用于并用炭黑及炭黑N774硫化胶分析。

  16. 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)

  17. 乘用车/轻型载重车子午线轮胎氮气硫化工艺%Nitrogen Vulcanization Process for Passenger Car/Light Truck Radial Tire

    Institute of Scientific and Technical Information of China (English)

    白雅

    2013-01-01

    介绍乘用车/轻型载重车子午线轮胎氮气硫化工艺条件及工序。采取严格控制定型压力、增加胎侧板排气孔、及时更换老化胶囊、采用双工位后充气装置和加强设备管理等措施,解决氮气硫化轮胎出现的缺胶、重皮、胎里打褶和胀肚等外观缺陷。轮胎的氮气硫化工艺能耗低、硫化时间短、效率高,成品轮胎的外观合格率高,高速性能、耐久性能、动平衡性能和均匀性能好。%The nitrogen vulcanization process for passenger car radial tire and light truck radial tire was introduced. With strict control on the pressure, addition of extra side vent, timely replacement of capsule, application of duplex inflation devices and strengthening equipment management, the appearance defects of tire such as lack of rubber, repeat skin, corrugated inner surface or tire bulge could be reduced. The nitrogen vulcanization process had advantages in low energy consumption, short curing time and high efficiency. The pass rate of appearance quality of the finished tire was quite high, and the high-speed performance, endurance performance, dynamic unbalance performance and tire uniformity of the finished tire were excellent.

  18. 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.

  19. 填胶量对BR/SBR/NR发泡材料硫化发泡特性及相结构的影响%Effect of feeding volume on morphology, vulcanization and foaming characteristics of BR/SBR/NR foams

    Institute of Scientific and Technical Information of China (English)

    冯钠; 王旭; 常素芹

    2012-01-01

    The effects of the feeding volumes on the vulcanization and foaming characteristics of the blends of 1,4-cis polybutadiene rubbers(BR) , styrene-butadiene rubber(SBR) ,and natural rubber (NR) foams were investigated by foam force rheometer. The rubber foams were prepared by two-stage compression molding technique to precure degree 30% with the various feeding volumes,and observed and calculated to the morphology (including of the cell size, the thickness of cell wall and the number of cells per cubic centimeter) by SEM. The results showed that the range of feeding volume between 70% ~-120% appears the typical vulcanization process,and the range between 60% and 90% presents the typical foam process clearly. With the increasing of feeding volume between 60% and 90%,the cell size decreases obviously,the thickness of cell wall becomes thinner apparently,and the number of cells per cubic centimeter increases obviously. The feeding volume had little influence on the morphology between 100% and 120%.%采用无转子发泡流变仪系统研究了不同填胶量对顺丁橡胶(BR)/丁苯橡胶(SBR)/天然橡胶(NR)发泡体系的硫化及发泡特性的影响,并采用两步模压法制备了预交联度为30%不同填胶量的发泡材料,通过扫描电镜(SEM)观察并计算出填胶量对相结构(泡孔直径、泡孔壁厚度、单位体积内的泡孔数)的影响.结果表明,体积分数为70%~120%的填胶范围时可呈现典型的硫化历程;填胶体积分数为60%~80%时可清晰地呈现典型的发泡历程;填胶体积分数在70%~90%范围内,随着填胶量增加,泡孔直径显著减小,泡孔壁显著变薄,单位体积内的泡孔数显著增加;填料体积分数在100%~120%范围内对相结构的影响较小.

  20. 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.

  1. Preparation and Properties of Oil Resistant Room Temperature Vulcanized Silicone Rubber%耐油室温硫化硅橡胶的制备与性能研究

    Institute of Scientific and Technical Information of China (English)

    贾振梅; 陈双俊; 金宇; 张军

    2012-01-01

    制备耐油室温硫化(RTV)硅橡胶,并对其性能进行研究.耐油RTV硅橡胶优化制备条件为:端乙烯基硅油(粘度为1.5Pa·s)/支链型乙烯基硅油(粘度为4.8Pa·s)用量比100/20,含氢硅油(氢质量分数为0.01)/乙烯基摩尔比2,白炭黑/云母用量比15/15.采用该条件制备的RTV硅橡胶物理性能和耐油性能良好.%The oil resistant room temperature vulcanized(RTV) silicone rubber was prepared,and its properties were investigated. The optimized formulation was as follows: the blending ratio of vinyl-terminated polydimethylsiloxane with viscosity of 1. 5 Pa · s/vinyl-branched polydimethylsiloxane with viscosity of 4. 8 Pa · s 100/20, mole ratio of hydrogen-containing silicone oil (the mass fraction of hydrogen was 0. 01)/vinyl 2,and the blending ratio of silica/mica 15/15. The RTV silicone rubber ,prepared by optimized formulation had good physical properties and oil resistance.

  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. Influência do Sistema de Vulcanização nas Propriedades da Mistura NBR/EPDM The Influence of the Vulcanizing System on Curing, Mechanical and Ageing Properties of NBR/EPDM Blends

    Directory of Open Access Journals (Sweden)

    Marcia G. Oliveira

    2002-01-01

    Full Text Available A mistura NBR/EPDM apresenta diferentes velocidades de cura, o que resulta na vulcanização heterogênea das fases, isto é, a fase NBR encontra-se em grande parte reticulada enquanto que a fase EPDM encontra-se pouco reticulada ou não-reticulada em casos extremos, prejudicando as propriedades finais da mistura. Este trabalho avalia os efeitos de diferentes sistemas de vulcanização à base de enxofre no processo de cura, na dureza, na resistência à tração, ao rasgamento e ao envelhecimento da mistura NBR/EPDM. Foram estudados os sistemas S/MBTS, S/TMTD e S/MBTS/TMTD variando-se a quantidade de enxofre em 0,3 e 1,0 phr. O processo de cura é influenciado pelo tipo de acelerador (MBTS, TMTD e a combinação destes e pela quantidade de enxofre (0,3 e 1,0 phr presente nas formulações. Esta influência é percebida na resistência à pré-cura e na velocidade de cura da mistura NBR/EPDM. A reticulação da fase EPDM também varia com o sistema de vulcanização empregado e influi diretamente nas propriedades mecânicas e na resistência ao envelhecimento.NBR and EPDM differ in the number of double bonds and also in polarity, thus presenting different cure rates. Their blends frequently result in a maldistribution of crosslinks. In this work, sulfur-based systems varying in accelerator type and sulfur amount were investigated as vulcanizing systems for NBR/EPDM blends. The accelerator type and the sulfur concentration affected the curing characteristics of the blends. Some formulations were able to crosslink the EPDM phase to a larger extent and consequently displayed better mechanical and ageing properties.

  5. Effect of Vulcanization Reagent on the Properties of Fire Resistant Ceramic Silicone Rubber%硫化剂对陶瓷化耐火硅橡胶性能的影响

    Institute of Scientific and Technical Information of China (English)

    李承斌; 赵源; 岳学民; 王卫东

    2014-01-01

    研究了2,5-二甲基-2,5-二(叔丁基过氧基)己烷(俗称双二五)、2,4-二氯过氧化苯甲酰(俗称双二四)、过氧化二异丙苯(DCP)3种硫化剂对陶瓷化耐火硅橡胶力学性能和烧结性能的影响。结果表明,一次硫化和二次硫化后,使用DCP做硫化剂的硅橡胶的硬度都是最大,使用双二五做硫化剂的硅橡胶的拉断伸长率都是最高,采用双二四做硫化剂的硅橡胶拉伸强度都是最大;使用双二四做硫化剂的硅橡胶烧结硬度最高。综合来看,使用双二四作硫化剂时陶瓷化耐火硅橡胶的力学性能最好,其最佳用量为1.25份。%The effect of 3 vulcanization reagents on the mechanical properties and sintering performance of a fire resistant ceramic silicone rubber was studied. They were 2,5-dimethyl 2,5-di(tert-butylperoxy)hex-ane(DBPH),2,4-dichloro-benzoyl peroxide(DCBP)and dicumyl peroxide (DCP). Results show that after one-step curing and post curing,the hardness of the fire resistant ceramic silicone rubber is the maximum with DCP as the curing agent. The tensile elongation of the fire resistant ceramic silicone rubber is the highest with DBPH as the curing agent. The tensile strength of the silicone rubber is the maximum with DCBP as the curing agent. The sintering hardness of the rubber is the highest with DCBP as the curing agent. Taken all together, the mechanical properties of the fire resistant ceramic silicone rubber is the best with DCBP as the curing agent with 1. 25 parts.

  6. 硫化类型对 RTV-2氟硅密封胶性能的影响%Effects of Vulcanization Reagents on Properties of RTV-2 Fluorosilicone Sealants

    Institute of Scientific and Technical Information of China (English)

    郭琳琳; 肖雯静; 吕亚非; 齐士成

    2013-01-01

    以自制的端羟基氟硅共聚物为基础聚合物, ZnO为填料,二月桂酸二丁基锡为催化剂,分别采用正硅酸乙酯、甲基三丁酮肟基硅烷( D31)、甲基三乙酰氧基硅烷( D17)为交联剂,制得脱醇型、脱酮肟型和脱醋酸型双组分室温硫化( RTV-2)氟硅密封胶。探讨了硫化类型对氟硅密封胶表干时间、耐热空气老化性能、耐油性能、热失重性能以及动态热机械性能的影响。结果表明:脱酮肟型氟硅密封胶具有良好的综合性能:玻璃化转变温度为-114℃;热质量损失率为10%时的温度达到482.2℃;经200℃×24 h老化后,拉伸强度降低4%,拉断伸长率降低7%。%The dealcoholic , ketonic oxime and acetate RTV-2 fluorosilicone sealants were prepared by self-made hydroxyl-terminated fluorosilicone copolymer as the polymer matrix , ZnO as the filler , dibutyltin di-laurate as the catalyst , ethyl orthosilicate , trimethylbutylketoneoximesilane ( D31) and triacetoxylmethylsilane ( D17 ) as the crosslinking agents , respectively .The effect of the different vulcanization reagents on the tack free time, the thermal aging properties in air , oil resistance performance , thermogravimetric performance and dynamic thermomechanical properties of fluorosilicone sealants was discussed .Results showed that the ketonic oxime fluorosilicone sealant had better physical and thermal properties with a glass transition temperature of-114℃, a temperature of 10%weight loss at 482.2℃, and a decrease of tensile strength and elongation at break of 4%and 7%, respectively after aging for 24 hours at 200 ℃.

  7. 硫酸钙晶须在室温硫化硅橡胶中的应用%Application of Calcium Sulfate Whisker in Room Temperature Vulcanized Silicone Rubber Compounds

    Institute of Scientific and Technical Information of China (English)

    王锦成; 薛烨; 仓世娇; 杨科

    2011-01-01

    研究硫酸钙晶须制备方法和用量对室温硫化硫酸钙晶须/硅橡胶复合材料性能的影响.结果表明,当硫酸钙晶须用量为10份时,复合材料的物理性能总体提高显著.扫描电子显微镜分析结果显示,烟气脱硫法硫酸钙晶须杂质较多,在硅橡胶中分散不均匀;电石渣法硫酸钙晶须内部结构完整,在硅橡胶中分散均匀.随着硫酸钙晶须用量增大,硅橡胶的粘度增大.热重分析结果显示,与烟气脱硫法硫酸钙晶须相比,电石渣法硫酸钙晶须对复合材料热稳定性能的改善较明显.%The influence of preparation method and addition level of calcium sulfate whisker on theproperties of room temperature vulcanized silicone rubber/calcium sulfate whisker composite was investigated. The results showed that, as the addition level of calcium sulfate whisker was 10 phr,the physical properties of composite were improved significantly. The SEM analysis result showed that, the calcium sulfate whisker prepared by gas desulfurization method possessed more impurities,and was dispersed unevenly in silicone rubber;the calcium sulfate whisker prepared by carbide slag method had better integrated internal structure, and was dispersed uniformly in silicone rubber. As the addition level of calcium sulfate whisker increased,the viscosity of silicone rubber increased. The TG analysis result showed that,compared with gas desulfurization method,the calcium sulfate whisker prepared by carbide slag method provided the composite better thermal stability.

  8. Effect of DCP on Properties of Flame Retardant PE-HD/EPDM Prepared by Dynamic Vulcanizing%DCP对动态硫化阻燃PE-HD/EPDM性能的影响

    Institute of Scientific and Technical Information of China (English)

    李镇; 胡珊; 范龙

    2014-01-01

    将过氧化二异丙苯(DCP)添加到碱式碳酸镁阻燃高密度聚乙烯/三元乙丙橡胶(PE-HD/EPDM)体系中,采用动态硫化法制备了阻燃PE-HD/EPDM材料。利用热重-差示扫描量热法分析了阻燃PE-HD/EPDM的热稳定性,扫描电子显微镜观察了阻燃PE-HD/EPDM的微观形貌,研究了DCP含量对阻燃PE-HD/EPDM性能的影响。结果表明,DCP的质量分数为1.0%时,阻燃PE-HD/EPDM材料的拉伸强度为9.7 MPa,断裂伸长率为1.2%,缺口冲击强度为39.5 kJ/m2,极限氧指数为30.8%;加入DCP后,PE-HD/EPDM材料的吸热峰有所滞后、燃烧炭层更为致密。%The DCP was used to add into flame retardant high density polyethylene(PE-HD)/EPDM system with basic magnesium carbonate. The flame retardant system was prepared by dynamic vulcanization. The thermal stability of the system was studied by TG/DSC,the microstructure was studied by SEM and the influence of the DCP content on the properties of the systems was studied. The results show that when the mass fraction of DCP was 1.0%,the tensile strength,elongation at break,notched impact strength and limited oxygen index is 9.7 MPa,1.2%,39.5 kJ/m2 and 30.8%, respectively. When the DCP is added,the endothermic peak of PE-HD/EPDM system lagged behind and the carbon layer of combustion is denser.

  9. Vulcan: A deep-towed CSEM receiver

    Science.gov (United States)

    Constable, Steven; Kannberg, Peter K.; Weitemeyer, Karen

    2016-03-01

    We have developed a three-axis electric field receiver designed to be towed behind a marine electromagnetic transmitter for the purpose of mapping the electrical resistivity in the upper 1000 m of seafloor geology. By careful adjustment of buoyancy and the use of real-time monitoring of depth and altitude, we are able to deep-tow multiple receivers on arrays up to 1200 m long within 50 m of the seafloor, thereby obtaining good coupling to geology. The rigid body of the receiver is designed to reduce noise associated with lateral motion of flexible antennas during towing, and allows the measurement of the vertical electric field component, which modeling shows to be particularly sensitive to near-seafloor resistivity variations. The positions and orientations of the receivers are continuously measured, and realistic estimates of positioning errors can be used to build an error model for the data. During a test in the San Diego Trough, offshore California, inversions of the data were able to fit amplitude and phase of horizontal electric fields at three frequencies on three receivers to about 1% in amplitude and 1° in phase and vertical fields to about 5% in amplitude and 5° in phase. The geological target of the tests was a known cold seep and methane vent in 1000 m water depth, which inversions show to be associated with a 1 km wide resistor at a depth between 50 and 150 m below seafloor. Given the high resistivity (30 Ωm) and position within the gas hydrate stability field, we interpret this to be massive methane hydrate.

  10. 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...

  11. Vulcan's fury: Man against the volcano

    Science.gov (United States)

    Varekamp, Johan C.

    I read this book on an 11-hour flight back from a field trip in the Andes, where I got first-hand insight into how people live with a volcano that now and then explodes. Appropriate reading, I felt, especially as the fascination of the human world with volcanoes and eruptive disasters is indeed long standing. This book is a recent addition to a list of titles in this genre (e.g., the new book by Sigurdsson to be reviewed in Eos shortly). The scope of the book is summarized in the introductory sentence of the preface: “This book is about an unequal contest. It describes human reactions to volcanic eruptions.” This is the perspective of the book's descriptions of 16 large and not-so-large eruptions over the last two millennia.

  12. 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.

  13. Preparation of EPDM/TPX TPV through Dynamic Vulcanization%动态硫化 EPDM/TPX 共混型热塑性弹性体的制备

    Institute of Scientific and Technical Information of China (English)

    徐萌萌; 张鹏; 华欣倩; 崔杰; 宗成中

    2015-01-01

    研究了共混工艺和不同硫化体系对动态硫化三元乙丙橡胶(EPDM )/聚-4-甲基戊烯-1热塑性弹性体(T PX T PV )力学性能的影响,并探讨了不同硫化体系共混物的热氧老化性能和微观相态结构。结果表明,EPDM与T PX先混匀再加入硫化剂的共混物力学性能好于先在EPDM中加入硫化剂再混合的共混物力学性能。硫黄最佳用量为0.4份,硫载体最佳用量为1.5份。当硫化剂选用最佳用量时,共混物具有较好力学性能。硫黄硫化共混物和硫载体硫化共混物分别在100℃×72 h和180℃×72 h热氧老化条件下的力学性能均有所下降,但幅度不太明显,二者均表现出了较好的耐热氧老化性。DM A结果表明,EPDM 与 T PX有一定的相容性。%Effects of blend technology and different curing system on mechanical properties of dy‐namic vulcanized EPDM/T PX T PV w ere investigated .T he thermo‐oxidative aging properties and mi‐cro‐structure of the TPV cured with different curing systems were studied .The results showed that the mechanical properties of the TPV that EPDM and TPX were first uniformly blended then adding curing agent to it were better than those of the TPV that first adding curing agent to EPDM then blen‐ded with TPX .The optimum dosage of sulfur and sulfur donator was o .4 phr and 1 .5 phr ,respective‐ly .The TPV had good mechanical properties at the optimun dosage of curing agent .The mechanical properties of both the TPV cured with sulfur and the TPV cured with sulfur donator decreased at thermo‐oxidative aging condition of 100 ℃ × 72 h and 180 ℃ × 72 h ,respectively .The DMA results showed that both EPDM and TPX had some compatibility .

  14. Efeito do óleo de linhaça e do óleo de amendoim sobre a vulcanização da borracha natural (NR. parte II: modelo detalhado Effect of linseed oil and peanut oil upon natural rubber (NR vulcanization. part II: detailed model

    Directory of Open Access Journals (Sweden)

    Alexandre Bezerra

    2013-01-01

    Full Text Available O efeito da substituição total ou parcial do ácido esteárico por óleos vegetais de linhaça e amendoim foi investigado em composições de borracha natural (NR. Um sistema de vulcanização convencional foi escolhido e os estudos cinéticos foram conduzidos nas temperaturas de 160 ºC, 170 ºC e 180 ºC. O modelo cinético detalhado permitiu estudar os diferentes estágios da vulcanização e verificar que na etapa de formação do precursor de ligações cruzadas (A → B houve diferenças significativas entre o ácido esteárico e os óleos vegetais. Tal resultado foi devido à presença expressiva de ácidos graxos insaturados na composição química dos óleos de linhaça e de amendoim (principalmente, os ácidos oléico e linolênico, o que facilitou a ocorrência de reações laterais inesperadas e, consequentemente, diminuiu o rendimento final de ligações cruzadas nos vulcanizados.The effect of the total or partial replacement of stearic acid with vegetable oils of linseed and peanut has been investigated in natural rubber (NR compositions. A conventional vulcanization system has been chosen and kinetic studies have been done in the temperatures of 160 ºC, 170 ºC and 180 ºC. The detailed kinetic model has allowed studying the different stages of vulcanization and verifying that in the formation of the crosslink precursor (A → B there were significant differences between stearic acid and the vegetable oils. This result has been attributed to the high concentration of unsaturated fat acids in the chemical composition of the vegetable oils (mainly, oleic and linolenic acids, which allowed unexpected side reactions and, consequently, diminished the final yield of crosslinking in the vulcanizates.

  15. 低温硫化 NR/BR 并用胶的硫化特性及其力学性能研究%Study on the Vulcanization Characteristics and Mechanical Properties of Natural Rubber/Butadiene Rubber Cured at Low Temperature

    Institute of Scientific and Technical Information of China (English)

    吕明哲; 方蕾; 李普旺; 王永周; 杨春亮

    2014-01-01

    采用异丙基黄原酸钠SIP、N-乙基-N-苯基二硫代氨基甲酸PX的复合促进剂体系(用量分别为1.5phhr和0.5phhr)可使天然橡胶/顺丁橡胶并用胶(并用比为70∶30)在90℃~95℃内快速硫化,硫化特性符合缓冲胶工艺的要求,但其性能与HG/T 4124-2009《预硫化缓冲胶》存在一定的差距。%Isopropyl xanthate sodium ( SIP) and N-Ethyl-N-phenyldithiocarbamic Acid Zinc Salt ( PX) ,1.5 and 0.5phhr respectively ,are applied to make up complex accelerator system ,and cause the NR/BR blends ( with a blending ratio of 70∶30 ) fast curing at 90℃~95℃.The vulcanization characteristics meet requirements of the cushion gum processing , but its performances keep a certain distance from those described in the HG /T 4124 -2009“precured tread cushion gum”.

  16. Desenvolvimento de elastômeros termoplásticos vulcanizados (TPV a base de polipropileno com resíduo de pneu: I - Planejamento fatorial de experimentos Development of thermoplastic elastomers vulcanized (TPV with polypropylene waste tire: I - Factorial design experiments

    Directory of Open Access Journals (Sweden)

    Matheus M. Cossa

    2009-01-01

    Full Text Available O uso do pó de pneu em misturas com termoplásticos possibilita a formação de novos materiais. Nesse trabalho o uso do pó de pneu foi caracterizado pelo planejamento fatorial completo 2³, com ponto central, em misturas com polipropileno (PP, para desenvolvimento de novos elastômeros termoplásticos vulcanizados dinamicamente (TPVs, contendo material reciclado. Os fatores utilizados neste estudo foram, pó de pneu, peróxido de dicumila e bismaleimida (em três n��veis, sendo um deles, o ponto central. O planejamento foi construído para avaliar os efeitos dos fatores (principais e suas interações nas respostas de tração, alongamento e inchamento em óleo. Os resultados mostraram que o teor de pó de pneu é predominante para melhorar o desempenho das misturas. A resistência ao inchamento é aproximadamente 150% superior em algumas formulações.The use of waste tire in blends with thermoplastics enables the formation of new materials. In this paper the use of waste tire was characterized with a complete 2³ factorial design with central point, in blends with polypropylene (PP, in the development of new thermoplastic elastomers vulcanized dynamically (TPVs and containing recycled material. The factors used in this study were: waste tire, dicumylperoxide and bismaleimides in three levels, one being the central point. The factorial design was built to evaluate the effects of the factors (and their interaction in the responses of tensile, elongation and oil swelling. The results showed that the level of waste tire is predominant to improve the performance of TPV. The swelling resistance is approximately 150% higher in some formulations.

  17. Efeito de um novo acelerador de vulcanização nas propriedades reométricas de composições de borracha nitrílica com diferentes teores de AN Effect of a new accelerator of vulcanization in the rheometric properties of nitrile rubber compositions with different AN amounts

    Directory of Open Access Journals (Sweden)

    Iara T. D. de Oliveira

    2010-01-01

    Full Text Available O efeito do tipo de acelerador no processo de vulcanização de compostos de borracha nitrílica com dois teores de acrilonitrila foi investigado. Dois aceleradores comerciais, dissulfeto de 2,2'-dibenzotiazol (MBTS e bis (dimetilditiocarbamato de zinco (ZDMC, de grupos químicos diferentes, tiazol e ditiocarbamato, respectivamente, foram selecionados e comparados com o composto bis (4 metilfenilsulfonilditiocarbimato-zincato (II de tetrabutilamônio (ZNIBU. Os resultados mostram que o tipo de acelerador não só afeta as características de cura, como também tem grande influência nas propriedades físicas. Entre os aceleradores estudados, MBTS foi o menos adequado para a formulação utilizada. Surpreendentemente, verificou-se que o ZNIBU mostrou comportamento intermediário, sendo mais eficaz do que o MBTS e menos eficiente que o ZDMC, considerado um ultra-acelerador, em relação ao tempo ótimo de vulcanização.The effect of the type of accelerator on the vulcanization process of nitrile rubber compounds with two acrilonitrile amounts was investigated. Two commercial accelerators benzothiazole (MBTS and zinc dimethyldithiocarbamate (ZDMC, from different chemical groups, thiazole and dithiocarbamate, respectively, were selected and compared with the compound bis (4 methylphenylsulfonyldithiocarbimato-zincate (II of tetrabutylammoniun (ZNIBU. The results show that the type of accelerator not only affects the cure characteristics, but also has great influence on the physical properties. Among the accelerators studied, MBTS was found to be the least adequate for the formulation used as far as rheometric parameters are concerned. Surprisingly, it was found that ZNIBU showed an intermediate behavior, being more efficient than MBTS but not as much as ZDMC, considered an ultra accelerator, as for the optimum cure time.

  18. Propriedades reométricas e mecânicas e morfologia de compósitos desenvolvidos com resíduos elastoméricos vulcanizados Cure characteristics, mechanical properties and morphology of composites developed with addition of elastomeric vulcanized ground scraps

    Directory of Open Access Journals (Sweden)

    Aline Zanchet

    2007-03-01

    Full Text Available Uma alternativa para as empresas geradoras de resíduos elastoméricos é a incorporação dos mesmos em suas formulações. Esse trabalho tem como objetivo preparar compósitos a partir da incorporação de resíduos industriais de SBR (copolímero de butadieno-estireno e de EPDM (terpolímero de etileno-propileno-dieno, em formulação ASTM específica para cada tipo de elastômero. Foram avaliadas as propriedades reométricas, mecânicas e morfológicas dos compósitos desenvolvidos. A incorporação do resíduo permitiu a obtenção de produtos que vulcanizam em menores tempos quando comparados a composições sem resíduo. A quantidade de resíduo, para o melhor resultado de resistência à tração foi de 37 e de 196 phr para os compósitos com SBR e EPDM, respectivamente. As micrografias de MEV corroboraram os resultados mecânicos dessas composições, indicando melhor homogeneidade do resíduo na respectiva matriz elastomérica.One alternative for elastomeric scraps generation is its incorporation in conventional formulations in the industry itself. In this work, compositions with incorporation of SBR (styrene butadiene rubber and EPDM (ethylene propylene diene rubber industrial scraps, in specific ASTM formulation for each elastomer, were prepared. Rheometric characteristics, mechanical properties and the morphology of the compounds developed were evaluated. With the ground scraps incorporation the vulcanization time decreases, comparing with compounds without ground scraps. The amount of scraps for the best tensile strength properties was 37 and 196 phr for SBR and EPDM compositions, respectively. Micrographs corroborated the mechanical results, indicating the best homogeneity of the scraps in the elastomeric matrix for these compositions.

  19. 交联密度法研究硅烷偶联剂对室温硫化硅橡胶性能的影响%A cross-linking density method study of the effect of a silane coupling agent on the performance of room temperature vulcanized (RTV) silicone rubber

    Institute of Scientific and Technical Information of China (English)

    苏清福; 杨宇; 李刚; 杨小平

    2013-01-01

    The cross-linking density method was used to investigate the effects of a coupling agent on the mechanical properties and the high and low temperature performance of silica-enhanced hydroxyl-terminated phenylsiloxane rubber. Mechanical properties, SEM, cross-linking density, DSC, DMA, and TGA analysis all showed that the chemical cross-linking density ratio was the greatest when the mass fraction of γ-aminopropyltriethoxysilane ( KH550) was 6 parts per hundreds of hydroxyl-terminated phenylsiloxane rubber, which resulted in room temperature vulcanized silicone rubber with the highest tensile properties, as well as the optimum interface adhesion between silica and the silicone rubber. Meanwhile, the lower glass transition temperature, which resulted from the decrease in the physical cross-linking density ratio, indicated the improvement of the low temperature resistance of the silicone rubber. The increase in the chemical cross-linking density ratio showed that the heat resistance of RTV silicone rubber was improved.%采用交联密度法探讨了硅烷偶联剂对SiO2增强端羟基苯基硅橡胶的作用机理及高低温性能的影响.对室温硫化硅橡胶的力学性能、交联密度、热性能等进行了测试,测试结果表明:当γ-氨丙基三乙氧基硅烷(KH550)用量为6份时,室温硫化硅橡胶的化学交联密度比例最大,力学性能最优,SiO2与硅橡胶的界面性能最好;硅橡胶交联体系中物理交联比例的减小导致玻璃化转变温度降低,硅橡胶的耐低温性能改善;化学交联密度比例增加,硅橡胶的耐热性提高.

  20. Selective Deuterium Ion Acceleration Using the Vulcan PW Laser

    CERN Document Server

    Krygier, AG; 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, RR

    2015-01-01

    We report on the successful demonstration of selective acceleration of deuterium ions by target-normal sheath acceleration (TNSA) with a high-energy petawatt laser. TNSA typically produces a multi-species ion beam that originates from the intrinsic hydrocarbon and water vapor contaminants on the target surface. Using the method first developed by Morrison, et al., \\cite{Morrison:POP2012} an ion beam with $>$99$\\%$ deuterium ions and peak energy 28 MeV is produced with a 200 J, 700fs, $>10^{20} W/cm^{2}$ laser pulse by cryogenically freezing heavy water (D$_{2}$O) vapor onto the rear surface of the target prior to the shot. The estimated total yield of deuterium ions in an assumed 10$^{\\circ}$ half-angle cone was 3.0 $\\mu$C (1.9 $\\times 10^{13}$ ions) with 6.6$\\%$ laser-to-deuterium ion energy conversion efficiency.

  1. Study on Dynamic Vulcanized EPDM/PP Thermoplastic Elastomer

    Institute of Scientific and Technical Information of China (English)

    YANG ShiYuan

    2001-01-01

    @@ Based upon the THE,HAAK RHEOCORD 90 and Wx-ray observation,a study was made on the structure and property of ethylene-propylene-ethlidene norborene (EPDM)/polyprolene (PP) blending systems ,and the experimental results were fully explained. (1) The effect of Mooney viscosity (ML)of EPDM、 melt flow rate(MFR) of peroxide(DCP) and mixing steps on mechanical properties of EPDM/PP blends was studied. The results showed that the mechanical and process properties of EPDM?PP thermoplastic elastomers were better using EPDM with the ML of 60 and PP with MFR of 7.5g/10min as matrix,DCP with the content of 1.2 per cent with the help of twostep curing process at the temperature of 170-175 ℃.

  2. Study on Dynamic Vulcanized EPDM/PP Thermoplastic Elastomer

    Institute of Scientific and Technical Information of China (English)

    YANG; ShiYuan

    2001-01-01

    Based upon the THE,HAAK RHEOCORD 90 and Wx-ray observation,a study was made on the structure and property of ethylene-propylene-ethlidene norborene (EPDM)/polyprolene (PP) blending systems ,and the experimental results were fully explained.  (1) The effect of Mooney viscosity (ML)of EPDM、 melt flow rate(MFR) of peroxide(DCP) and mixing steps on mechanical properties of EPDM/PP blends was studied. The results showed that the mechanical and process properties of EPDM?PP thermoplastic elastomers were better using EPDM with the ML of 60 and PP with MFR of 7.5g/10min as matrix,DCP with the content of 1.2 per cent with the help of twostep curing process at the temperature of 170-175 ℃.……

  3. Selective deuterium ion acceleration using the Vulcan petawatt laser

    Energy Technology Data Exchange (ETDEWEB)

    Krygier, A. G. [Laboratoire pour l' Utilisation des Lasers Intenses, École Polytechnique, 91128 Palasiseau (France); Physics Department, The Ohio State University, Columbus, Ohio 43210 (United States); Morrison, J. T. [Propulsion Systems Directorate, Air Force Research Lab, Wright Patterson Air Force Base, Ohio 45433 (United States); Kar, S., E-mail: s.kar@qub.ac.uk; Ahmed, H.; Alejo, A.; Green, A.; Jung, D. [Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN (United Kingdom); Clarke, R.; Notley, M. [Central Laser Facility, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX (United Kingdom); Fuchs, J.; Vassura, L. [Laboratoire pour l' Utilisation des Lasers Intenses, École Polytechnique, 91128 Palasiseau (France); Kleinschmidt, A.; Roth, M. [Institut für Kernphysik, Technische Universität Darmstadt, Schloßgartenstrasse 9, D-64289 Darmstadt (Germany); Najmudin, Z.; Nakamura, H. [The John Adams Institute, Blackett Laboratory, Department of Physics, Imperial College, London SW7 2AZ (United Kingdom); Norreys, P. [Central Laser Facility, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX (United Kingdom); Department of Physics, University of Oxford, Oxford OX1 3PU (United Kingdom); Oliver, M. [Department of Physics, University of Oxford, Oxford OX1 3PU (United Kingdom); Zepf, M. [Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN (United Kingdom); Helmholtz Institute Jena, D-07743 Jena (Germany); Borghesi, M. [Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN (United Kingdom); Institute of Physics of the ASCR, ELI-Beamlines Project, Na Slovance 2, 18221 Prague (Czech Republic); Freeman, R. R. [Physics Department, The Ohio State University, Columbus, Ohio 43210 (United States)

    2015-05-15

    We report on the successful demonstration of selective acceleration of deuterium ions by target-normal sheath acceleration (TNSA) with a high-energy petawatt laser. TNSA typically produces a multi-species ion beam that originates from the intrinsic hydrocarbon and water vapor contaminants on the target surface. Using the method first developed by Morrison et al. [Phys. Plasmas 19, 030707 (2012)], an ion beam with >99% deuterium ions and peak energy 14 MeV/nucleon is produced with a 200 J, 700 fs, >10{sup 20}W/cm{sup 2} laser pulse by cryogenically freezing heavy water (D{sub 2}O) vapor onto the rear surface of the target prior to the shot. Within the range of our detectors (0°–8.5°), we find laser-to-deuterium-ion energy conversion efficiency of 4.3% above 0.7 MeV/nucleon while a conservative estimate of the total beam gives a conversion efficiency of 9.4%.

  4. Collembolan trait patterns with climate modifications along a European gradient: the VULCAN case study

    DEFF Research Database (Denmark)

    Bonfanti, Jonathan; Cortet, Jérôme; Hedde, Mickaël

    In a climate change context, soil ecosystem services can be threatened, notably through impacts on soil fauna. Collembola can be therefore used for bioindication of soil mesofauna functionality. Here we aim (i) to link distribution of the collembolan communities with their functional traits...

  5. Hybrid Large-Eddy/Reynolds-Averaged Simulation of a Supersonic Cavity Using VULCAN

    Science.gov (United States)

    Quinlan, Jesse; McDaniel, James; Baurle, Robert A.

    2013-01-01

    Simulations of a supersonic recessed-cavity flow are performed using a hybrid large-eddy/Reynolds-averaged simulation approach utilizing an inflow turbulence recycling procedure and hybridized inviscid flux scheme. Calorically perfect air enters a three-dimensional domain at a free stream Mach number of 2.92. Simulations are performed to assess grid sensitivity of the solution, efficacy of the turbulence recycling, and the effect of the shock sensor used with the hybridized inviscid flux scheme. Analysis of the turbulent boundary layer upstream of the rearward-facing step for each case indicates excellent agreement with theoretical predictions. Mean velocity and pressure results are compared to Reynolds-averaged simulations and experimental data for each case and indicate good agreement on the finest grid. Simulations are repeated on a coarsened grid, and results indicate strong grid density sensitivity. Simulations are performed with and without inflow turbulence recycling on the coarse grid to isolate the effect of the recycling procedure, which is demonstrably critical to capturing the relevant shear layer dynamics. Shock sensor formulations of Ducros and Larsson are found to predict mean flow statistics equally well.

  6. Vulcan Planets: Inside-Out Formation of the Innermost Super-Earths

    CERN Document Server

    Chatterjee, Sourav

    2014-01-01

    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; (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 ($M_p$) 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 $M_p$, $M_p$ versus orbital radius $r$, and planet-planet separations are consistent with observed systems. Here we investigate the IOPF prediction for how the masses, $M_{p,1}$, of the inne...

  7. 理念的实现——Vicem呈现46米Vulcan

    Institute of Scientific and Technical Information of China (English)

    李勇

    2014-01-01

    46米的Vulcan是Vicem公司该系列的首艘,同时也是Vicem公司最大的一艘游艇,在建造上也独具特色,由MulderDesign负责其外部设计,内部则由Art—Line设计。流畅的线条、与众不同的蓝色船体、极佳的操作性能和宽敞的起居空间等特征将Vulcan与一般游艇区别开来,使其成为土耳其游艇制造业的骄傲。

  8. Ninja Warriors and Vulcan Logic: Using the Cultural Literacy Portfolio as a Curriculum Script.

    Science.gov (United States)

    Salvio, Paula M.

    1994-01-01

    Discusses how a teacher and university researcher brought to their students their concerns that students' portfolios were not "academic" enough. Notes that the teacher and researcher recognized the potential of literacy portfolios for strengthening a child's capacity to narrate the events of her life with authority and to tie these events to the…

  9. X-ray laser measurements of direct drive imprint on vulcan

    Energy Technology Data Exchange (ETDEWEB)

    Kalantar, D.H.; Wolfrum, E.; Zhang, J. [and others

    1997-07-01

    High gain direct drive inertial confinement fusion requires very uniform irradiation of a hollow spherical shell with a layer of fusionable deuterium and tritium on its inner surface. The intensity of laser irradiation builds up in several nanoseconds from an initial `foot` at {approximately}10{sup 13} W/cm{sup 2} to more than 10{sup 15} W/cm{sup 2} during the main drive pulse. Laser ablation of the capsule surface produces a high pressure, accelerating the shell radially inward, and resulting in Rayleigh-Taylor (R-T) growth of surface perturbations originating from both the initial surface roughness of the capsule and from imprint of spatial non- uniformities in the laser drive intensity early in the laser pulse. The uniformity of illumination on a direct drive implosion capsule is determined on a large scale by the multi-beam irradiation geometry, and on a small scale by beam smoothing techniques. By using a large number of beams (such as the 60 beams of the Omega laser or 48 beam clusters for the NIF), large scale non-uniformities due to the overlap of the laser focal spots are adequately reduced. Random phase plates (RPPs) are introduced to smooth the individual beam focal spots. The spatial intensity variations of the individual beam speckle patterns may be smoothed by spectral dispersion (SD) with induced spatial incoherence (ISI) or by using partially coherent light. We performed experiments to study the imprint under conditions simulating the low intensity foot of the pulse on an ignition target, such as designed for the NIF. We used a 0.53 micrometer laser wavelength, and considered the imprint in thin Al foils due to both a broadband distribution of modes such as those in smoothed speckle patterns, and a single mode optical intensity variation. We characterized the laser imprint using a Ge x-ray laser and multilayer imaging optics, as described previously. In this paper we summarize and compare the multiple and single mode imprinting results. 9 refs., 7 figs.

  10. Vulcanism, mercury-sensitized photo-reactions and abiogenetic synthesis: a theoretical treatment.

    Science.gov (United States)

    Siegel, S M; Siegel, B Z

    1976-08-01

    Attention is called to the photodynamic and thermodynamic properties of Periodic Group IIb elements, most notably Hg, as they relate to ultra-violet sensitization in organic chemical reactions. The energy levels of 6(1) P1 and 6(3) P1 resonance states and the high vapor pressure ((greater than 10(-3) mm) of the metal at temperatures as low as 293 K bring Hg with the range of bond dissociation energies in most organic molecules and many inorganics. These capabilities considered together with recent evidence for Hg emission as a regular part of volcanic and geothermal processes provide the basis for our proposal that Hg-sensitized ultraviolet photo-reactions may have played a significant part in abiogenetic organic synthesis on the primative earth.

  11. Degradation of non-vulcanized natural rubber - renewable resource for fine chemicals used in polymer synthesis

    Directory of Open Access Journals (Sweden)

    Alexander Fainleib

    2013-01-01

    Full Text Available In the current scenario, there is growing interest in the products of degradation of rubber (natural and synthetic for specific applications in different industry sectors, whose benefits in replacing conventionally used products are mainly related to sustainability. Since the degradation products of rubber can be used in different areas, several research groups may have the interest aroused by these products, but are not familiar with the aspects related to the chemical behavior of rubber. This review aims to bring together the key information in the published literature on the degradation of natural rubber, emphasizing metatheses reactions, oxidative damage and splitting of the double bond, in order to serve as a reference source for researchers from different fields interested in obtaining such kind of products. The structures and properties as well as additional chemical transformations resulting in oligomers of isoprene, functionalised oligomers and polymers based on both are also described.

  12. Study on the reliability of the underground conveyor belt system installed at Vulcan Mine, the Jiu Valley Basin in Romania

    Directory of Open Access Journals (Sweden)

    Tomuș Ovidiu-Bogdan

    2017-01-01

    Full Text Available The paper deals with a comprehensive reliability analysis of the conveyor belts belonging to an underground coal mine in the Jiu Valley, Romania. As resulted from the mine management reports, the transportation system is responsible for many downtimes and is a real bottleneck in the constant and adequate production, and the suspicion is the weak state of belt conveyers, which are the spinal column of the extraction process. For this reason, a comprehensive reliability analysis has been decided, in order to deliver a maintenance-upgrading plan.

  13. Absorption, distribution, metabolism and excretion of N-cyclohexyl-2-benzothiazyl sulfenamide (CBS), a vulcanizing accelerator, in rats

    Energy Technology Data Exchange (ETDEWEB)

    Adachi, Tohru; Tanaka, Akira; Yamaha, Tsutomu (National Inst. of Hygienic Sciences, Tokyo (Japan))

    1989-05-01

    Absorption, distribution, metabolism and excretion were studied in rats following a single oral administration of N-cyclohexyl-2-benzothiazyl sulfenamide (CBS) at a dose of 250 mg/kg. About 65% and 24% of the dose were excreted into urine and feces, respectively, for 3 days after administration of labeled CBS (cyclohexyl-/sup 14/C). Biliary excretion amounted to about 5% of the dose for 3 days. While about 92% of the dose was recovered in urine and feces at a ratio of 1 : 1 within 3 days when /sup 14/C-2CBS was given. No specific organ-affinity was observed in distribution study. Cyclohexylamine and 2-mercaptobenzothiazole were identified as urinary metabolites. (author).

  14. Occupational exposure to rubber vulcanization products during repair of rubber conveyor belts in a brown coal mine

    Energy Technology Data Exchange (ETDEWEB)

    Gromiec, J.P.; Wesolowski, W.; Brzeznicki, S.; Wroblewska-Jakubowska, K.; Kucharska, M. [Nofer Institute of Occupational Medicine, Lodz (Poland)

    2002-12-01

    This study was carried out to identify chemical substances and measure their air concentrations in the repair shop of a brown coal mine in which damaged rubber conveyor belts were repaired. GC-MS and HPLC analysis of stationary air samples resulted in identification of aliphatic and aromatic hydrocarbons to C{sub 12}, PAHs, alcohols, phenols, ketones, heterocyclic nitrogen and sulfur compounds. Quantitative evaluation of occupational exposure included determination of organic compound vapours collected on charcoal (GC-MSD), polycyclic aromatic hydrocarbons (HPLC), N-nitrosoamines and other amines (GC-NPD) and DNPH derivatives of aldehydes (HPLC) in the breathing zone of workers representing all job titles. The concentrations of investigated compounds were very low. Carcinogenic substances: N-nitrosoamines, benzene, and PAHs were not present in workroom air in concentrations exceeding limits of detection of the analytical methods being applied; concentrations of methylisobutylketone, tetrachloroethylene, naphtha, aromatic hydrocarbons, phthalates and aldehydes were much lower than the respective occupational exposure limit values. The results indicate much lower exposure than that reported in the production of tyres and other fabricated rubber products.

  15. Quick vulcanization accelerator system for neoprene%氯丁橡胶用快速硫化体系

    Institute of Scientific and Technical Information of China (English)

    黄良平; 杨军

    2007-01-01

    该文研究了氯丁橡胶用快速硫化体系.结果表明,以4份氧化镁、5份氧化锌、1.5份TMU、0.5份TMTD、0.5份CZ为W型氯丁橡胶的硫化体系,可使胶料具备焦烧时间长、硫化速率快的特点,硫化胶的综合性能较好.

  16. Post-consumer tires back into new tires: de-vulcanization and re-utilization of passenger car tires

    NARCIS (Netherlands)

    Saiwari, Sitisaiyidah

    2013-01-01

    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

  17. Development of thermoplastic elastomers based on maleated ethylene propylene rubber (m-EPM and polypropylene (PP by dynamic vulcanization

    Directory of Open Access Journals (Sweden)

    2007-08-01

    Full Text Available Dicumyl peroxide (DCP-cured thermoplastic vulcanizates (TPVs based on blends of maleated ethylene propylene rubber (m-EPM and polypropylene (PP using maleated-PP as a compatibilizer have been developed. Physical properties of these TPVs change significantly with concentrations of DCP and rubber/plastic blend ratios. Important correlations were obtained from rheometer delta torque values with various physical properties of the TPVs like tension set and crosslink density etc. Wide angle X-ray diffraction study confirms that concentration of DCP has a strong influence on the crystallinity of PP, which might affect the final physical properties of TPVs. The recyclability and ageing characteristics of these TPVs are also found excellent.

  18. Upscaling of a Batch De-Vulcanization Process for Ground Car Tire Rubber to a Continuous Process in a Twin Screw Extruder

    Directory of Open Access Journals (Sweden)

    Sitisaiyidah Saiwari

    2016-08-01

    Full Text Available As a means to decrease the amount of waste tires and to re-use tire rubber for new tires, devulcanization of ground passenger car tires is a promising process. Being an established process for NR and EPDM, earlier work has shown that for ground passenger car tire rubber with a relatively high amount of SBR, a devulcanization process can be formulated, as well. This was proven for a laboratory-scale batch process in an internal mixer, using diphenyl disulfide as the devulcanization aid and powder-sized material. In this paper, the devulcanization process for passenger car tire rubber is upscaled from 15 g per batch and transformed into a continuous process in a co-rotating twin screw extruder with a capacity of 2 kg/h. As SBR is rather sensitive to devulcanization process conditions, such as thermal and mechanical energy input, the screw design was based on a low shear concept. A granulate with particle sizes from 1–3.5 mm was chosen for purity, as well as economic reasons. The devulcanization process conditions were fine-tuned in terms of: devulcanization conditions (time/temperature profile, concentration of devulcanization aid, extruder parameters (screw configuration, screw speed, fill factor and ancillary equipment (pre-treatment, extrudate handling. The influence of these parameters on the devulcanization efficiency and the quality of the final product will be discussed. The ratio of random to crosslink scission as determined by a Horikx plot was taken for the evaluation of the process and material. A best practice for continuous devulcanization will be given.

  19. 现场冷硫化陶瓷包胶在矿井中的应用%Site Cold Vulcanized Ceramic Rubber Coating Applied to Mine

    Institute of Scientific and Technical Information of China (English)

    苗继军; 刘波; 张学忠; 吴江; 赵利杰

    2013-01-01

    在煤矿井下恶劣的生产工况下带式输送机易发生胶带打滑等不良现象,为改善带式输送机的运行状况,防止胶带打滑现象的发生,文章介绍了一种新型的陶瓷包胶工艺及技术,该技术的应用可提高驱动滚筒与输送带之间的摩擦系数及驱动摩擦力从而达到了消除胶带机打滑的目的.%Under the serious production performances in underground mine, the belt conveyor would be easy to cause the belt slippage and other harmful phenomenon. In order to improve the operation performances of the belt conveyor, to prevent the belt slippage phenomenon occurred, the paper introduced a new ceramic rubber costing technique and technology. The application of the technology could improve the friction coefficient and driving friction force between the driving drum and belt and thus the slippage of the belt conveyor could be eliminated.

  20. Resource use: a summary of the assessments of geothermal resource use limitations of Bruneau KGRA, Castle Creek KGRA, Crane Creek KGRA, Mountain Home KGRA, Vulcan KGRA

    Energy Technology Data Exchange (ETDEWEB)

    Moore, B.; Savage, N.; Gladwell, J.S.; Warnick, C.C.

    1979-02-23

    A brief overview is given of the physical, socioeconomic, and heritage resources of each KGRA summarized from the draft reports submitted to EG and G by subcontractors for this project. Included under the subheading of Physical Environment are geology, topography, and ecology with brief mention of climate, hydrology, and soils. Under Socioeconomic and Heritage Resources are demographic and economic data, land use and ownership, and known prehistoric and historic features. The information gaps are listed.

  1. Experimental Validation of the Charlesby and Horikx Models Applied to De-vulcanization of Sulfur and Peroxide Vulcanizates of NR and EPDM

    NARCIS (Netherlands)

    Verbruggen, M.A.L.; Does, van der L.; Dierkes, W.K.; Noordermeer, J.W.M.

    2016-01-01

    The theoretical model developed by Charlesby to quantify the balance between cross-links creation of polymers and chain scission during radiation cross-linking and further modifications by Horikx to describe network breakdown from aging were merged to characterize the balance of both types of scissi

  2. VULCAN系统在我国露天矿中应用前景%Prospect of VULCAN System Application In China's Surface Mine

    Institute of Scientific and Technical Information of China (English)

    宋子岭; 白润才; 谢雨志

    2000-01-01

    VULCAN软件系统是由澳大利亚MAPTEK公司开发成功的.该系统功能强大、内容丰富,主要用于地表及地下三维数据的处理,包括地质工程、环境工程、地理地形、测量工程、采矿工程、水库工程、地震分析等方面的数据处理及工程设计.VULCAN有PC版、工作站版等版本,操作使用方便、适应性强、性能优越,适合在我国露天矿推广应用,与我国自行开发的有关软件配合使用可达到优势互补、相互借鉴、促进提高软件开发水平的效果.

  3. VULCAN software system and its application in yuanbaoshan open cast%VULCAN软件系统及其在元宝山露天矿的应用

    Institute of Scientific and Technical Information of China (English)

    宋子岭

    2002-01-01

    VULCAN软件系统功能强大,内容丰富,主要用于地表及地下三维数据的处理,形成三维立体模型,包括地质工程、环境工程、地理地形、测量工程、采矿工程、水库工程、地震分析等方面的数据处理及工程设计.应用该软件成功地建立了元宝山露天煤矿的矿床地质模型,进行地质储量管理,形成采场测量验收现状图,并编制各种开采生产计划.

  4. 挤塑机加热系统及硫化工艺节电改造项目%Extruder heating system and vulcanization process energy saving reform

    Institute of Scientific and Technical Information of China (English)

    葛平; 伏建华; 陈亮; 单卫星; 李广虎

    2010-01-01

    江苏江扬电缆有限公司原有挤塑机加热系统及硫化工艺系统存在能源浪费严重,系统效率不高等问题.采用挤塑机电磁加热节电器替代原有电热圈,以及采用智能化共挤连续硫化工艺,进行节电改造,有效提高节电率.详细介绍2项改造的节电原理,对节电效果进行技术经济分析.

  5. The Relationship Between Vulcan Faith and Zoroastrianism in the Eastern District of Henan Province——Shangqiu Vulcan Station as the Center%试论豫东地区的火神信仰与祆教之关系——以商丘火神台为中心

    Institute of Scientific and Technical Information of China (English)

    胡宁

    2012-01-01

    火神信仰是我国民间传统信仰的一种.它与袄教的关系学术界历来争议不断.在田野调查中发现,以商丘火神台为代表的豫东地区的火神信仰,与中古时期祆教在当地的文化遗存有关.豫东地区的火神信仰很有可能包含袄教信仰的某些元素,而这种可能一定程度上是二者涵化的结果.

  6. 78 FR 10560 - Proposed Modification and Revocation of Air Traffic Service Routes; Jackson, MS

    Science.gov (United States)

    2013-02-14

    ...; Magnolia, MS; Meridian, MS; Crimson, AL; Vulcan, AL; Talladega, AL; Atlanta, GA; Colliers, SC; Charleston... Bigbee 082 and Crimson, AL, 304 radials; to Crimson. V-417 From Meridian, MS, via Crimson, AL; Vulcan,...

  7. 78 FR 29613 - Modification and Revocation of Air Traffic Service Routes; Jackson, MS

    Science.gov (United States)

    2013-05-21

    ...; Meridian, MS; Crimson, AL; Vulcan, AL; Talladega, AL; Atlanta, GA; Colliers, SC; Charleston, SC. V-74 From... Crimson, AL, 304 radials; to Crimson. V-417 From Meridian, MS, via Crimson, AL; Vulcan, AL; Rome, GA;...

  8. 78 FR 27421 - Endangered and Threatened Wildlife and Plants; Receipt of Application for Incidental Take Permit...

    Science.gov (United States)

    2013-05-10

    ... availability of an incidental take permit (ITP) application and a Habitat Conservation Plan (HCP). Vulcan Materials Company, Florida Rock Divisions (dba Florida Rock Industries, Inc. a subsidiary of Vulcan... announce the availability of an ITP application and HCP. Vulcan Materials Company, Florida Rock...

  9. Impact of the vulcanization process on the structural characteristics and IgE recognition of two allergens, Hev b 2 and Hev b 6.02, extracted from latex surgical gloves.

    Science.gov (United States)

    Galicia, Christian; Mendoza-Hernández, Guillermo; Rodríguez-Romero, Adela

    2015-06-01

    Latex allergy is a health problem that mainly affects medical environments, causing anaphylactic shocks in extreme cases. Sensitization and reactions to this material is closely linked to the use of latex gloves. The objective of this study was to purify two of the major allergens from latex surgical gloves to study the biochemical and structural changes that could be generated during the product manufacture and to compare their IgE recognition with the non-processed allergens. Glycosylated allergen Hev b 2 (β-1,3-glucanase) and Hev b 6.02 (hevein) were purified from glove extracts using affinity (Concanavalin A) and reversed-phase chromatographies, respectively. ELISA experiments were performed with both proteins and sera from allergic patients to assess the IgE recognition, which was heterogeneous. Crystallographic methods were used to obtain the 3D structure of Hev b 6.02 from surgical gloves, which did not show evident modification when compared with the protein from the natural non-processed form. Despite having the same crystallographic structure, the IgE from some patients showed different recognition when the glove and the natural allergen were used in ELISA. Furthermore, using electrophoretic techniques, we identified three forms of Hev b 2: one corresponding to the complete polypeptide chain with posttranslational modifications, and two glycosylated fragments. The mixture of these three forms showed stronger recognition by IgE from latex-allergic patients than the pure non-processed allergen. In conclusion, IgE from subjects sensitized to latex products showed different recognition between the allergens obtained from a natural source and the processed material, even when the structure was maintained. This demonstrates the importance of using processed allergens in further investigations of diagnosis, prevalence, product allergenicity, and therapies.

  10. The Influence of Vulcanization Reagent on the Property of flame Retardant Silicone Rubber%硫化剂种类对阻燃硅橡胶性能的影响

    Institute of Scientific and Technical Information of China (English)

    王文志; 涂春潮; 钱黄海; 米志安; 苏正涛

    2008-01-01

    研究了双叔丁基过氧化异丙基苯(BIPB)、过氧化二异丙苯(DCP)、过氧化苯甲酰(BP)、2,4-二氯过氧化苯甲酰(DCBP)四种硫化剂对阻燃硅橡胶力学性能和阻燃性能的影响.结果表明:随硫化剂用量的增加,硅橡胶的扯断伸长率降低,硬度提高,拉伸强度和氧指数变化很小;二次硫化后,硅橡胶的硬度提高,扯断伸长率降低,采用BP的硅橡胶的拉伸强度降低,采用其它三种硫化剂的硅橡胶的拉伸强度则提高;阻燃性均提高;硫化剂种类对硅橡胶的耐热性没有明显影响.

  11. Characterization of the Peroxide Vulcanized Chlorinated Polyethylene/Nitrile Rubber Blends%氯化聚乙烯/丁腈橡胶共混胶的过氧化物硫化

    Institute of Scientific and Technical Information of China (English)

    高新文; 陈春花; 曹江勇; 辛振祥

    2009-01-01

    考察了氯化聚乙烯/丁腈橡胶(CM/NBR)共混胶的过氧化物硫化体系对其性能的影响.实验结果表明,当DCP和TAIC用量分别为2.5和3.5份时共混胶有最佳的力学性能.同时通过流化仪得到了CM和NBR有相近的硫化交联反应活化能和频率因子,进一步证明了DCP和TAIC的最佳用量为2.5和3.5份.

  12. Preparation and characterization of nano functionalized graphene/room temperature vulcanized silicone rubber composites%纳米功能化石墨烯/室温硫化硅橡胶复合材料的制备与表征

    Institute of Scientific and Technical Information of China (English)

    马文石; 邓帮君

    2011-01-01

    用KH-550对氧化石墨进行改性,再对其进行还原,获得功能化石墨烯(FG),未经干燥的FG经超声处理后可以稳定分散在质量比9∶1的丙酮/水混合液中;在高速搅拌和超声分散条件下,将FG分散液分散到室温硫化(RTV)硅橡胶中,固化后得到纳米FG(nano-FG)/RTV硅橡胶复合材料。采用FTIR、TEM、SEM、XRD和DSC分析了FG及复合材料的结构和形貌。结果表明:KH-550连接到石墨烯片层表面上,使其片层起皱、折叠,部分发生了剥离,层间距增大到3.46A°;FG经过超声处理后剥离成透明至半透明的片层%Graphite oxide was modified by KH-550,the modified graphite oxide was reduced to form functionalized graphene(FG) dispersing consistently in the acetone/water(mass ratio is 9∶1) solution by ultrasonic treatment before drying.The FG dispersion was intensively mixed for a certain time by ultrasonic treatment to disperse the nano-FG in α,ω-dihydroxy polydimethylsiloxane matrix and obtained an uniform and stable nano-FG/room temperature vulcanized(RTV) silicone rubber composite after curing.FTIR,TEM,SEM,XRD,and DSC analysis show that KH-550 bonds to the surface of FG sheet to make its layers wrinkled,folding and partially exfoliated,and broaden its layer spacing to 3.46.FG exfoliates into transparent or semi-transparent layers after ultrasonic treatment.The uniform and wrinkled cross-section morphology of nano-FG/RTV silicone rubber composite,which is different from that of pure silicone rubber,shows that there is no micro-phase separation between the two parts.Compared with the pure silicone rubber,the Tg,Tm and crystallinity of all the nano-FG/RTV silicone rubber composites are improved.Mechanical property tests show that nano-FG reinforces silicone rubber a lot.The tensile strength and the elongation at break of composite with 0.5wt% nano-FG are 0.43MPa and 265%,respectively.The tensile strength more than doubles and the elongation at break increases 52% compared with that of pure silicone rubber.

  13. Influence of the incorporation process of clay as filler on the properties of natural rubber and epoxidized natural vulcanized rubber; Influencia do processo de incorporacao de argila sobre as propriedades de vulcanizados de borracha natural e borracha natural epoxidada

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Andre L.S. da; Lutckmeier, Rafael; Azeredo, Luciane K. de; Jacobi, Marly A.M., E-mail: andredasilva@ufrgs.br [Universidade Federal do Rio Grande do Sul - UFRGS, Instituto de Quimica, Porto Alegre, RS (Brazil)

    2011-07-01

    Vulcanizates of natural rubber and epoxidized natural rubber, having clay as filler were prepared by different process. The degree of exfoliation of the clay was evaluated by X-ray analysis and mechanical properties were determined by stress-strain. The crosslink density was evaluated by swelling measurements. It could be observed that the use of epoxidized rubber improves significantly the mechanical properties of the vulcanizates. (author)

  14. Environmental MTT accelerator on the performance of vulcanized neoprene%环保促进剂MTT对硫化氯丁橡胶的性能影响研究

    Institute of Scientific and Technical Information of China (English)

    孟程龙; 程璞; 王亚南

    2015-01-01

    主要介绍了促进剂MTT代替NA-22在对氯丁橡胶中的应用,研究了该材料对氯丁橡胶硫化特性,常规及老化后的物理机械性能、压缩永久变形、电性能的影响.结果表明:促进剂MTT代替NA-22后,焦烧及正硫化时间均延长、除定伸应力、压缩变形下降外,其它物性及电性能得到提高.

  15. 硫化氯丁橡胶工艺优化及其在船舶管路支架中的应用%Processing optimization of vulcanized neoprene and its application in ship's pipe bracket

    Institute of Scientific and Technical Information of China (English)

    任晋宇; 吴建; 卢永全; 张伟; 吴枫

    2016-01-01

    研究了船舶管路支架用氯丁橡胶(CR)硫化配方组成及最佳硫化成型工艺参数,根据最佳配方组成及最佳成型工艺参数制作了管路支架样机,并对其性能进行了测试.结果表明,以牌号为DCR213的CR为基础胶,炭黑N 550为增强剂,增塑剂A/B为功能助剂,制得的硫化胶的拉伸强度为9 MPa,扯断伸长率为232%,在-20℃×24 h条件下无龟裂,硫化胶的力学性能和耐低温性能满足管路支架要求.分别采用注压硫化工艺和注射硫化工艺制作的φ32、φ65型船舶管路支架,前者的垂向静态刚度和动态刚度分别为282,763 kN/m,后者分别为1 856,2 889 kN/m;2种规格的管路支架的插入损失均不小于20 dB,振级落差均不小于30 dB,满足制品使用要求.

  16. Analysis of Catalyst Vulcanization of Coal Direct Liquefaction to Oil Hydrogenation Modification Combination%煤直接液化油加氢改质组合催化剂硫化过程分析

    Institute of Scientific and Technical Information of China (English)

    郭贵贵

    2013-01-01

    神华煤直接液化先期工程1.0Mt/a煤直接液化油加氢改质装置在首次工业应用中,采用了中国石化石油化工科学研究院开发的煤直接液化油加氢改质技术(RCHU),以及配套的RGC-1/RNC-2/RCC-1催化剂组合,该技术通过对煤直接液化轻馏分油进行加氢改质,以达到改善产品品质、提高柴油产品十六烷值。本文对煤直接液化油加氢改质装置,首次工业应用开工过程中的催化剂预硫化进行了总结,通过对比催化剂实际上硫量与理论上硫量、实际生成水量与理论生成水量,可知此次开工过程中催化剂的上硫率较高、硫化效果较好。%Shenhua coal direct liquefaction front engineering of the 1.0Mt/a coal direct liquefaction to oil hydrogenation modification unit in the first industrial application was using the coal direct liquefaction oil hydrogenation modified techonlogy (RCHU) and the supporting RGC-1/RNC-2/RCC-1 composition catalyst empoldered by Research Institute of the Petroleum Processing. The technology upgrades the coal direct liquefaction light distillate oil and improves product quality increasing the cetane number of diesel products. This article sum-marizes the catalyst pre-sulfuration process in first commercial application found that the rate of sulfur consumption on the catalyst finally is higher in the process and the sulfuration is successful by comparing sulfur consumed by the catalyst and generated water in fact and theory.

  17. 嵌入式计算机PC/104及其在轮胎硫化系统中的应用%Embedded Computer PC/104 And Its Application in Tyre Vulcanization System

    Institute of Scientific and Technical Information of China (English)

    陈剑; 刘君华; 史百舟; 赵向阳

    2001-01-01

    本文阐述了嵌入式计算机的优点,介绍了PC/104嵌入式计算机模块的结构特点和它在嵌入式系统的设计方法。以轮胎硫化系统为例,从硬件和软件两个方面讲述了PC/104模块在工业实际中的应用。

  18. Preparation and properties of EPDM / TPX dynamically vulcanized thermoplastic elastomer blends (TPV)%EPDM/TPX动态硫化共混型热塑性弹性体(TPV)的制备及性能

    Institute of Scientific and Technical Information of China (English)

    徐萌萌; 宗成中

    2015-01-01

    通过对不同橡塑比的EPDM/TPX进行动态硫化研究,发现当共混比60/40时,共混物的综合性能较好.在不同的温度下对橡塑比为60/40的共混物进行动态硫化,研究发现在230℃下动态硫化的效果较好.另外,对橡塑比为60/40的EPDM/TPX在不同转速下进行研究,结果表明当转速为70 r/min时,共混物的力学性能较好.

  19. DCP用量对动态硫化POE/PP热塑性弹性体性能的影响%Effect of DCP on Properties of Dynamically Vulcanized POE/PP Thermoplastic Elastomer

    Institute of Scientific and Technical Information of China (English)

    周琦; 王勇; 邱桂学

    2008-01-01

    研究了过氧化二异丙苯(DCP)用量对动态硫化乙烯-辛烯共聚物/聚丙烯(POE/PP)体系的物理性能以及PP结晶形态和POE相态结构的影响.结果表明:随DCP用量的增加,POE/PP体系的交联密度增大,而断裂伸长率、永久变形和拉伸强度下降.过量DCP的加入会导致PP降解,使体系的熔体流动速率随DCP用量的增加呈上升趋势.DSC分析表明,随着DCP用量的增加,POE/PP体系结晶度下降.微观分析得出,DCP对POE/PP体系相态结构影响显著,当DCP用量为1份时交联POE以较小的颗粒均匀分布于PP连续相中.

  20. 纳米Mg(OH)2对PVC泡沫塑料力学性能的影响%Effect of Nano-Magnesium Hydroxide on Tensile Properties of Vulcanized Slight Epispastic PVC

    Institute of Scientific and Technical Information of China (English)

    余建川; 刘东辉

    2005-01-01

    在一定的PVC泡沫塑料配方体系下,研究了阻燃材料纳米Mg(OH)2对PVC泡沫材料的主要力学性能的影响.结果表明,在25℃,纳米Mg(OH)2添加量在1.5 %以下,对拉伸强度、断裂伸长率两项指标基本没有影响;在105℃,纳米Mg(OH)2添加量在2.0 %以下,对热负荷下伸长率、冷却后永久伸长率两项指标基本没有影响.

  1. An Experimental Research of Nickel and Cobalt Recovery in Manganese Salt Production%锰盐生产中钴镍回收试验探索

    Institute of Scientific and Technical Information of China (English)

    甘昌远; 罗昌璃; 龙海平

    2013-01-01

    选用不同硫化剂对硫酸锰溶液进行硫化回收钴、镍的试验,通过对比不同硫化剂、不同硫化温度的实验结果,选择出了合适的硫化剂、硫化温度,用于回收锰浸出液中钴、镍金属,回收率达到了99.0%以上.%In conducting experiment of using different vulcanizers to vulcanize MnSO4 solution, the author compares the experiment results of different vulcanizers and different vulcanizing temperatures, and selects the suitable vulcanizer and vulcanizing temperature to recover nickel and cobalt in manganese leaching solution. The recovery rate is over 99.0%.

  2. EPDM Rubber Reclaim from Devulcanized EPDM

    NARCIS (Netherlands)

    Sutanto, P.; Picchioni, F.; Janssen, L.P.B.M.; Dijkhuis, K.A.J.; Dierkes, Wilma K.; Noordermeer, Jacobus W.M.

    2006-01-01

    Two types of ethylene-propylene-diene monomer (EPDM) rubbers, namely an efficient vulcanized (EV) and a semiefficient vulcanized (SEV), have been used to produce devulcanizates in a continuous setup. The devulcanizates are re-cured using the same recipes as for the virgin rubber. The influence of

  3. Influence of the Diene Monomer on Devulcanization of EPDM Rubber

    NARCIS (Netherlands)

    Verbruggen, M.A.L.; van der Does, L.; Noordermeer, Jacobus W.M.; van Duin, M.

    2008-01-01

    Ethylene–propylene–diene rubbers (EPDM) with 2-ethylidene-5-norbornene (ENB), dicyclopentadiene (DCPD), and 1,4-hexadiene (HD) as third monomers have been vulcanized with peroxide and with a conventional sulfur vulcanization recipe, and their devulcanization was subsequently investigated for

  4. EPDM rubber reclaim from devulcanized EPDM

    NARCIS (Netherlands)

    Sutanto, P.; Picchioni, F.; Janssen, L. P. B. M.; Dijkhuis, K. A. J.; Dierkes, W. K.; Noordermeer, J. W. M.

    2006-01-01

    Two types of ethylene-propylene-diene monomer (EPDM) rubbers, namely an efficient vulcanized (EV) and a serniefficient vulcanized (SEV), have been used to produce devulcanizates in a continuous setup. The devulcanizates are re-cured using the same recipes as for the virgin rubber. The influence of

  5. EST Table: FS888752 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available FS888752 E_FL_ftes_43E22_F_0 10/09/28 38 %/158 aa ref|NP_724426.2| vulcan, isoform ...D [Drosophila melanogaster] gb|AAM68355.2| vulcan, isoform D [Drosophila melanogaster] 10/09/12 38 %/158 aa

  6. EST Table: BY936095 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available BY936095 E_FL_prW-_08B23_F_0 10/09/28 43 %/130 aa ref|NP_724426.2| vulcan, isoform ...D [Drosophila melanogaster] gb|AAM68355.2| vulcan, isoform D [Drosophila melanogaster] 10/08/30 43 %/130 aa

  7. EST Table: AV398194 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available AV398194 NV021231 10/09/28 38 %/170 aa ref|NP_724426.2| vulcan, isoform D [Drosophi...la melanogaster] gb|AAM68355.2| vulcan, isoform D [Drosophila melanogaster] 10/08/28 38 %/170 aa FBpp0289730

  8. EST Table: FS884863 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available FS884863 E_FL_ftes_31G04_F_0 11/12/09 n.h 10/09/28 38 %/158 aa ref|NP_724426.2| vulcan..., isoform D [Drosophila melanogaster] gb|AAM68355.2| vulcan, isoform D [Drosophila melanogaster] 10/09/12

  9. EST Table: CK537262 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available CK537262 rswgb0_006427.y1 10/09/29 38 %/158 aa ref|NP_724426.2| vulcan, isoform D [...Drosophila melanogaster] gb|AAM68355.2| vulcan, isoform D [Drosophila melanogaster] 10/08/31 38 %/158 aa FBp

  10. EST Table: FS886995 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available FS886995 E_FL_ftes_37P08_F_0 10/09/28 42 %/133 aa ref|NP_724426.2| vulcan, isoform ...D [Drosophila melanogaster] gb|AAM68355.2| vulcan, isoform D [Drosophila melanogaster] 10/09/12 42 %/133 aa

  11. EST Table: FS730122 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available FS730122 E_FL_bmmt_17P19_F_0 10/09/28 43 %/123 aa ref|NP_724426.2| vulcan, isoform ...D [Drosophila melanogaster] gb|AAM68355.2| vulcan, isoform D [Drosophila melanogaster] 10/09/03 43 %/123 aa

  12. 40 CFR 82.5 - Apportionment of baseline production allowances for class I controlled substances.

    Science.gov (United States)

    2010-07-01

    ...,358 Vulcan Chemicals 21,931,987 (e) For Group V controlled substances: Methyl Chloroform Dow Chemical Company, USA 168,030,117 E.I. DuPont de Nemours & Co 2 PPG Industries, Inc 57,450,719 Vulcan Chemicals...

  13. EPDM rubber reclaim from devulcanized EPDM

    NARCIS (Netherlands)

    Sutanto, P.; Picchioni, F.; Janssen, L. P. B. M.; Dijkhuis, K. A. J.; Dierkes, W. K.; Noordermeer, J. W. M.

    2006-01-01

    Two types of ethylene-propylene-diene monomer (EPDM) rubbers, namely an efficient vulcanized (EV) and a serniefficient vulcanized (SEV), have been used to produce devulcanizates in a continuous setup. The devulcanizates are re-cured using the same recipes as for the virgin rubber. The influence of m

  14. Influence of the diene monomer on devulcanization of EPDM rubber

    NARCIS (Netherlands)

    Verbruggen, M.; Does, van der L.; Noordermeer, J.W.M.; Duin, van M.

    2008-01-01

    Ethylene–propylene–diene rubbers (EPDM) with 2-ethylidene-5-norbornene (ENB), dicyclopentadiene (DCPD), and 1,4-hexadiene (HD) as third monomers have been vulcanized with peroxide and with a conventional sulfur vulcanization recipe, and their devulcanization was subsequently investigated for recycli

  15. Pengaruh suhu vulkanisasi terhadap sifat tegangan putus, perpanjangan putus dan ketahanan sobek kompon sol karet

    Directory of Open Access Journals (Sweden)

    Prayitno Prayitno

    1995-12-01

    Full Text Available One of the processes steps for producing rubber sole is vulcanization process. This process is carried out by using pressed moulding methods in which rubber compound was heated and pressed in the mould of rubber sole at certain time and temperature. The aim of this research is to know the influence of the temperature used for vulcanization for the tensile strength, elongation and tearing strength properties of the rubber sole compound. Temperature vulcanization used for the research was varied at 1400C, 1500C, 1600C and 1700C. The results shows that vulcanization at 1400C, give the highest properties in tensile strength, elongation and tearing strength, those are : 113,70 kg/cm2; 326,60 % and 107,00 kg/cm2respectively. Increasing temperature vulcanization cause decreasing those physical properties.

  16. Avaliação do processo de cura da borracha nitrílica (NBR pela resina fenólica através do cálculo da constante de cura Evaluation of phenolic resin vulcanization of nitrile rubber (NBR through determination of the cure constant

    Directory of Open Access Journals (Sweden)

    Ana Maria Furtado

    2001-03-01

    Full Text Available O processo de cura envolve reações de múltiplos mecanismos e sua investigação pode ser feita por meio de várias técnicas. Este trabalho apresenta a comparação entre dois métodos que utilizam parâmetros reométricos para o cálculo da constante cinética de cura (k relacionada com a cura da borracha nitrílica com a resina fenólica, tendo o policloropreno e o óxido de zinco como sistema ativador. Foi utilizado o planejamento de experimentos fatorial completo (2³ + ponto central como base para a preparação das formulações e análise dos resultados. Os resultados obtidos identificaram a influência da temperatura, da quantidade de cada um dos componentes das formulações e da adequação dos métodos de avaliação para o processo de cura da borracha nitrílica pela resina fenólica.The cure process involves reactions with multiple mechanisms and its investigation can be followed by using different techniques. This work compares two methods in which rheometric parameters are used to calculate the cure rate constant (k, related to the cure of nitrile rubber with phenolic resin and having polychloroprene and zinc oxide as the activators. A complete factorial (2³ + central point experimental design was used as base to prepare the formulations and to analyse the results. The results obtained identified the influence of the temperature, the amount of each component in the formulation and the suitability of the evaluation methods for the cure process of nitrile rubber with phenolic resin.

  17. Non-isothermal crystallization kinetics of polyamide 12/acrylic rubber dynamic vulcanized thermoplastic elastomer%动态硫化尼龙12/丙烯酸酯橡胶热塑性弹性体的非等温结晶动力学

    Institute of Scientific and Technical Information of China (English)

    刘娜; 李超芹

    2016-01-01

    利用熔融共混动态硫化法制备了尼龙12/丙烯酸酯橡胶热塑性弹性体(PA 12/ACM TPV),采用差示扫描量热仪测试了PA 12/ACM TPV和PA 12在不同降温速率下的非等温结晶行为,并分别用Ozawa和Mo方程研究了材料的非等温结晶动力学.结果表明,不同降温速率下,PA 12/ACM TPV和PA 12的结晶峰均为单峰,前者的结晶速率大于后者;Mo方程可以很好地描述PA 12/ACM TPV和PA12的非等温结晶过程,而Ozawa方程则不适合;采用Mo方程分析,PA 12/ACM TPV中橡胶相ACM的存在提高了PA 12的结晶速率.

  18. Morphology Structure and Properties of Hydrogenated Acrylonitrile Butadiene Rubber/Ultra-Fine Full-Vulcanized Acrylonitrile Butadiene Rubber Powder Blends%氢化丁腈橡胶/超细全硫化粉末丁腈橡胶共混物的结构与性能研究

    Institute of Scientific and Technical Information of China (English)

    刘俊杰; 张立群; 刘力; 高富强; 肖大玲; 卢咏来

    2009-01-01

    采用熔融共混工艺制备了氢化丁腈橡胶(HNBR)/超细全硫化粉末丁腈橡胶(UFPNBR)共混物,研究了共混物相态结构、动态力学性能、力学性能及老化性能,并与HNBR/NBR共混物作了对比.透射电镜观察表明:在HNBR/UFPNBR体系中,HNBR容易形成连续相,UFPNBR为分散相;在HNBR/NBR体系中容易形成双连续相结构. DMA动态力学性能分析表明:2种共混物都只有一个tanδ峰,且相容性较好.HNBR/UFPNBR共混物在玻璃化转变区的tanδ峰值逐渐降低,而HNBR/NBR体系的tanδ峰值先减小后增大.加入适量的UFPNBR能降低HNBR/UFPNBR共混物的压缩永久变形;与常规共混胶相比,HNBR/UFPNBR具有低脆性温度和良好的耐老化性能,但力学性能略低.

  19. Porous carbon-coated graphite electrodes for energy production from salinity gradient using reverse electrodialysis

    Science.gov (United States)

    Lee, Su-Yoon; Jeong, Ye-Jin; Chae, So-Ryong; Yeon, Kyeong-Ho; Lee, Yunkyu; Kim, Chan-Soo; Jeong, Nam-Jo; Park, Jin-Soo

    2016-04-01

    Performance of graphite foil electrodes coated by porous carbon black (i.e., Vulcan) was investigated in comparison with metal electrodes for reverse electrodialysis (RED) application. The electrode slurry that was used for fabrication of the porous carbon-coated graphite foil is composed of 7.2 wt% of carbon black (Vulcan X-72), 0.8 wt% of a polymer binder (polyvinylidene fluoride, PVdF), and 92.0 wt% of a mixing solvent (dimethylacetamide, DMAc). Cyclic voltammograms of both the porous carbon (i.e., Vulcan)-coated graphite foil electrode and the graphite foil electrode without Vulcan showed good reversibility in the hexacyanoferrate(III) (i.e., Fe(CN)63-) and hexacyanoferrate(II) (i.e., Fe(CN)64-) redox couple and 1 M Na2SO4 at room temperature. However, anodic and cathodic current of the Vulcan-coated graphite foil electrode was much higher than those of the graphite foil electrode. Using a bench-scale RED stack, the current-voltage polarization curve of the Vulcan-coated graphite electrode was compared to that of metal electrodes such as iridium (Ir) and platinum (Pt). From the results, it was confirmed that resistance of four different electrodes increased with the following order: the Vulcan-coated graphite foilVulcan-coated graphite foil showed 5-10% higher power density than the metal mesh electrodes. From the polarization curve of the Vulcan-coated graphite foil electrode, it was found that total resistance decreased as thickness and geometric surface area of the electrode increased.

  20. Preparación y evaluación de electrocatalizadores de platino sobre diferentes soportes para celdas de combustible PEM

    OpenAIRE

    2016-01-01

    Se sintetizaron electrocatalizadores de Pt para celdas de combustible PEM sobre diferentes soportes: SC, modificado y sin modificar, y Vulcan XC72 para comparación. El material SC exhibió características que lo hacen un potencial sustituto del soporte Vulcan XC72. El estudio de estabilidad en las condiciones de operación de una celda de combustible PEM mostró que el electrocatalizador soportado sobre SC tiene una velocidad de degradación mayor al soportado sobre Vulcan XC72. Se requiere optim...

  1. A new air-Cherenkov array at the South Pole

    CERN Document Server

    Dickinson, J E; Hart, S P; Hill, G C; Hinton, J A; Lloyd-Evans, J; Potter, D; Pryke, C L; Rochester, K; Schwarz, R; Watson, A A

    2000-01-01

    VULCAN comprises a 9 element array of air-Cherenkov radiation detectors established at the South Pole. VULCAN operates in coincidence with the air-shower array SPASE-2 and the two Antarctic Muon And Neutrino Detector Arrays, AMANDA A and B, supplementing the data gathered by these instruments with a measurement of the lateral distribution of air-Cherenkov light from extensive air-showers. An overview of the aims and methods of the whole coincidence experiment (SPASE-2, VULCAN and AMANDA) can be found in an accompanying paper (Dickinson et al., Nucl. Instr. and Meth. A (1999), to be published).

  2. Ultra-short pulse reconstruction software in high power laser system

    Energy Technology Data Exchange (ETDEWEB)

    Galletti, M. [Physics Department of the University and INFN, Pisa (Italy); Galimberti, M. [Central Laser Facility, Rutherford Appleton Laboratory, Didcot (United Kingdom); Giulietti, D. [Physics Department of the University and INFN, Pisa (Italy)

    2015-07-15

    An ultra-short pulse reconstruction software, validated through a set of experimental measurements on the front-end of the Vulcan laser at the RAL Central Laser Facility is presented. The measurements were acquired in Target Area Petawatt of the Vulcan laser, both using a conventional autocorrelation technique and the GRENOUILLE technique in order to compare the results. The FWHM of the laser pulses considered came out to be comparable for the two techniques. In this experimental campaign for the first time a technique different from the autocorrelation one has been used for a PW class laser as Vulcan.

  3. 78 FR 41053 - Combined Notice of Filings #1

    Science.gov (United States)

    2013-07-09

    ... Mexico Electric Marketing, LLC, Tenaska Power Management, LLC, Tenaska Power Services, Co., Texas... Generation Company, Salton Sea Power L.L.C., Vulcan/BN Geothermal Power Company, Yuma Cogeneration...

  4. short communication microwave assisted oxidative coupling of thiols ...

    African Journals Online (AJOL)

    Preferred Customer

    minimal amount of solvent under microwave irradiation. ... [7-8] and also the industrial applications of disulfides in the vulcanization of rubbers and ..... Holbrook, D.L. Handbook of Petroleum Refining Processes, Meyers, R.A. (Ed.), McGraw.

  5. Influence of different curing systems on the physico-mechanical properties and stability of SBR and NR rubbers

    CERN Document Server

    Basfar, A A; Mofti, S

    2002-01-01

    The physical properties of radiation, sulfur and peroxide-cured styrene-butadiene rubber (SBR) and natural rubber (NR) were compared. The dependence of the mechanical properties of the radiation-vulcanized SBR and NR on the coagent concentration and radiation dose was studied. The effect of thermal aging on the mechanical properties of the different rubber formulations was discussed. The radiation-cured formulations of SBR have superior mechanical properties and thermal stability compared with those of the chemically vulcanized compounds. Whereas, the radiation-cured formulations of NR have similar mechanical properties but superior thermal stability (based on the % change in E after thermal aging), when compared with those of the sulfur-vulcanized compounds and slightly better than those of the peroxide-vulcanized compounds.

  6. Structural analysis of sulfur in natural rubber using X-ray absorption near-edge spectroscopy.

    Science.gov (United States)

    Pattanasiriwisawa, Wanwisa; Siritapetawee, Jaruwan; Patarapaiboolchai, Orasa; Klysubun, Wantana

    2008-09-01

    X-ray absorption near-edge spectroscopy (XANES) has been applied to natural rubber in order to study the local environment of sulfur atoms in sulfur crosslinking structures introduced in the vulcanization process. Different types of chemical accelerators in conventional, semi-efficient and efficient vulcanization systems were investigated. The experimental results show the good sensitivity and reproducibility of XANES to characterize the local geometry and electronic environment of the sulfur K-shell under various conditions of vulcanization and non-vulcanization of natural rubber. Several applications of XANES in this study demonstrate an alternative way of identifying sulfur crosslinks in treated natural rubber based on differences in their spectra and oxidation states.

  7. Mechanical and Thermal Properties of Polysiloxanes and NBR Blend Elastomer

    Institute of Scientific and Technical Information of China (English)

    WANG Yanbing; HUANG Zhixiong; ZHANG Lianmeng; MEI Qilin

    2006-01-01

    A series of elastomers, based on NBR, polysiloxanes (PS) were prepared and characterized by tensile tests, thermogravimetry (TG) and differential scanning calorimetry ( DSC ). Two kinds of vulcanizing agent, DMDBH ( 2 , 5- dimethyl- 2 , 5- di ( t- batyl perory ) hexane ) and DCP ( dicumylperoxide ) were used to investigate the irfluence of different vulcanizing agents on properties of PS/NBR. The addition of PS to NBR was found to improve the thermal stability and decrease the tensile strength of NBR. The tensile strength decreased considerably while the elongation at break increased obviously with the increase of PS content. The series using DMDBH as vulcanizing agent showed a higher tensile strength and elongation at break than the series using DCP as vulcanizing agent. Simultaneity the thermal stability increased with the increase of PS content.

  8. Dimensional regularization and renormalization of non-commutative QFT

    CERN Document Server

    Gurau, R

    2007-01-01

    Using the recently introduced parametric representation of non-commutative quantum field theory, we implement here the dimensional regularization and renormalization of the vulcanized $\\Phi^{\\star 4}_4$ model on the Moyal space.

  9. Enhanced Fuel Cell Catalyst Durability with Nitrogen Modified Carbon Supports

    Science.gov (United States)

    2013-02-12

    1000 mg of commercially available carbon powder (Cabot Vulcan XCR72R) was placed into the barrel and the chamber was evacuated to approximately 1 × 10−6...unmodified and N-modified Vulcan were obtained on a Philips CM200 TEM. X-ray Photoelectron Spectroscopy (XPS) analysis of the synthesized catalysts was done...durability cycles Pt-Ru/ Vulcan 73 3.3 × 10−5 24 51 10 Pt-Ru/N- Vulcan 55 2.9 × 10−5 17 60 40 Pt-Ru/C JM 5000 69 3.0 × 10−5 20 48 17 tials higher than 0.7 V

  10. Download this PDF file

    African Journals Online (AJOL)

    unemployed human capital, equitable distribution of income, the general ... parlours, grocery stores, _road side vulcanizer, mechanic workshops as ..... Masha, R.A. (1986), Self-[Reliance and Small Scale Enterprises: The Central banks Role”.

  11. Cure modification of natural rubber containing benzothiazole accelerators by some modified thiocarbamyl sulfenamides

    NARCIS (Netherlands)

    Datta, R.N.; Debnath, S.C.; Noordermeer, J.W.M.

    2003-01-01

    The effects of N-cyclopentamethylene thiocarbamyl-N-(cyclohexyl,thiocyclohexyl)sulfenamide (CPCTS) and N-oxydiethylene thiocarbamyl-N-(cyclohexyl,thiocyclohexyl)sulfenamide (ODCTS) as cure modifiers on the vulcanization of natural rubber (NR) containing benzothiazole accelerators were studied. CPCTS

  12. Chemistry of rubber processing and disposal.

    Science.gov (United States)

    Bebb, R L

    1976-10-01

    The major chemical changes during the processing of rubber occur with the breakdown in mastication and during vulcanization of the molded tire. There is little chemical change during the compounding, calendering, extrusion, and molding steps. Reclaiming is the process of converting scrap rubber into an unsaturated, processible product that can be vulcanized with sulfur. Pyrolysis of scrap rubber yields a complex mixture of liquids, gas, and residue in varying ratios dependent on the nature of the scrap and the conditions of pyrolysis.

  13. Cleaning Aged EPDM Rubber Roofing Membrane Material for Patching: Laboratory Investigations and Recommendations

    Science.gov (United States)

    1992-08-01

    membranes made from vulcanized cthylcne-propylenc-dienc terpolymer (EPDM) rubber as the waterproofing component of low-sloped roofing systems has...terpolymer). The use of vulcanized EPDM rubber for low-sloped roofing membranes has become common in the U.S. Current estimates indicate that more than 93...would provide a means for obtaining field data on this proposed tesi , which has not yet been investigated in the field. 45 5 SUMMARY, CONCLUSIONS, AND

  14. The Royal Navy and British Security Policy.

    Science.gov (United States)

    1983-12-01

    SCHOOL December 1983 Author Approved by: Tesis Avisor s" econd R e r Chafrman, Department of National Security Affairs -- and Policy Sciences " Dean of...8217s based on the 14 VULCAN , VICTOR and VALIANT bombers. Although cooperation with the American SAC was envisioned from the begining, the force did...British strategic nuclear deterrent. This responsibility was once the domain of the Royal Air Force and its VULCAN , VICTOR, and VALIANT bombers, but after

  15. Modeling of Nonlinear Combustion Instability in Solid Propellant Rocket Motors

    Science.gov (United States)

    1984-02-01

    results of two solutions that tesi the ability of the LW+H+ACM to trect such problems are discussed. In both cases, the initial Pressure distur$.;nce...piezoelectric transducers. Thermal shielding of the pressure transducers was accomplished using vulcanized rubber (RTV). Based on shock i,,be calibration tests...potted with vulcanized rubber (RTV) which is utilized to provide thermal shielding 24 45. 16.0 � AFT CLOSURE WI0.45 250. for the pressure transducers

  16. Demonstration/Validation of Hazardous Air Pollutant-Free Adhesive Replacement for Federal Specification MMM-A-121 on the Stryker Infantry Carrier Vehicle

    Science.gov (United States)

    2013-06-01

    for use on MMM-A-121 requisite substrates, such as vulcanized rubber (styrene-butadiene rubber, neoprene , and nitrile) bonded to unpolished steel, in...adhesive (baseline) is designed for bonding vulcanized synthetic rubber gaskets, matting, and similar items to steel. It will adhere to neoprene ...aggressive bonds are required. Clifton E-1293 meets the requirements of MMM-A-121 and contains 50%–60% HAPs (7, 8). 3M Scotch-Weld* 1357 neoprene

  17. PRELIMINARY RESULTS IN SYNCHROTRON X-RAY DIFFRACTION MEASUREMENTS OF RUBBER COMPOSITES STRUCTURE BEFORE AND AFTER EXPOSURE TO HYDROGEN

    Directory of Open Access Journals (Sweden)

    Francesca Cosmi

    2011-05-01

    Full Text Available In future years, fuel cells are expected to represent a promising technology as a source of heat and electricity in buildings and of electrical power for vehicles, since fossil fuels are exhausting and significantly degrade air quality. It is well known that, when exposed to a hydrogen environment, hydrogen embrittlerment may affect materials such as iron and steel. But these are not the only materials that are used for hydrogen equipment. In particular, the rubber materials used for O–rings that seal high pressure hydrogen gas equipment show problems of internal fracture, called blister fracture, when the gas is rapidly decompressed. As many different kinds of fillers can be used, in this work we started to investigate the influence of the type of filler on the rubber composites structure, by means of X-ray diffraction measurements performed at the Elettra synchrotron radiation facility in Trieste. In this preliminary study, three kinds of samples were analyzed before and after exposure to hydrogen: Sulphur vulcanized EPDM, Peroxide vulcanized EPDM and Sulphur vulcanized NBR. While Peroxide vulcanized samples did not show significant differences in the diffraction pattern, changes could be detected in the cristalline form of Sulfure vulcanized rubber.

  18. The evaluation of tetrabutylamonium bis(4-ethylphenylsulphonyldithiocarbimate)zincate(II) (ZNIBU) efficiency as a reclaiming agent for styrene-butadiene rubber (SBR); Avalicao da eficiencia do bis(4-metilfenilsulfonilditiocarbimato)zincato(II) de tetrabutilamonio (ZNIBU) como agente de regeneracao para borracha de butadieno-estireno (SBR)

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Pedro H.H.; Visconte, Leila L.Y.; Pacheco, Elen B.A.V., E-mail: pedro_hhm@ima.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Tavares, Eder C. [Universidade Federal de Itajuba (UNIFEI), Itajuba, MG (Brazil)

    2015-07-01

    In recent years, the production of rubber waste has been reported as a serious environmental problem. The chemical structure of rubbers (crosslinked, insoluble and infusible polymers) makes its reprocessing very difficult, unlike thermoplastics. The most common methods to treat rubber waste are of thermal, mechanical and chemical nature, wherein the chemical methods the purpose is to regenerate the rubber. Early studies with tetrabutylamonium bis(4-methylphenylsulphonyldithiocarbimate)zincate(II) (ZNIBU) point to its ability as an accelerator in the rubber curing process. In this work, this zinc complex was evaluated as a chemical regeneration agent. ZNIBU was synthesized and characterized by Nuclear Magnetic Resonance ({sup 13}C NMR) and Fourier Transform Infrared Spectroscopy (FTIR). The mixture of virgin SBR with vulcanization ingredients was performed in a two-roll mill, and the composition was then vulcanized and molded on a hydraulic press. The synthesized ZNIBU was then mixed with the vulcanized rubber and devulcanization was observed. Finally, the devulcanized elastomeric composition was revulcanized. The revulcanization of SBR regenerated with ZNIBU led to the formation of a rubber with maximum torque near the maximum torque of the virgin vulcanized rubber. After adjusting the optimal conditions of regeneration, mechanical tests will be carried out (tensile strength, tear strength and hardness) for the specimens of both vulcanized and revulcanized rubbers in order to compare their mechanical properties. (author)

  19. About the cure kinetics in natural rubber/styrene Butadiene rubber blends at 433 K

    Science.gov (United States)

    Mansilla, M. A.; Marzocca, A. J.

    2012-08-01

    Vulcanized blends of elastomers are employed in several goods mainly to improve physical properties and reduce costs. One of the most used blends of this kind is that composed by natural rubber (NR) and styrene butadiene rubber (SBR). The cure kinetic of these blends depends mainly on the compound formulation and the cure temperature and time. The preparation method of the blends can influence the mechanical properties of the vulcanized compounds. In this work the cure kinetic at 433 K of NR/SBR blends vulcanized with the system sulfur/TBBS (N-t-butyl-2-benzothiazole sulfenamide) is analyzed in samples prepared by mechanical mixing and solution blending. The two methods produce elastomer domains of NR and SBR, which present different microstructure due to the cure level attained during vulcanization. The cure kinetics is studied by means of rheometer tests and the model proposed by Kamal and Sourour. The analysis of the cure rate is presented and is related to the structure obtained during the vulcanization process.

  20. About the cure kinetics in natural rubber/styrene Butadiene rubber blends at 433 K

    Energy Technology Data Exchange (ETDEWEB)

    Mansilla, M.A., E-mail: mmansilla@df.uba.ar [Laboratorio de Polimeros y Materiales Compuestos, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon 1, C1428EGA Buenos Aires (Argentina); Marzocca, A.J. [Laboratorio de Polimeros y Materiales Compuestos, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon 1, C1428EGA Buenos Aires (Argentina)

    2012-08-15

    Vulcanized blends of elastomers are employed in several goods mainly to improve physical properties and reduce costs. One of the most used blends of this kind is that composed by natural rubber (NR) and styrene butadiene rubber (SBR). The cure kinetic of these blends depends mainly on the compound formulation and the cure temperature and time. The preparation method of the blends can influence the mechanical properties of the vulcanized compounds. In this work the cure kinetic at 433 K of NR/SBR blends vulcanized with the system sulfur/TBBS (N-t-butyl-2-benzothiazole sulfenamide) is analyzed in samples prepared by mechanical mixing and solution blending. The two methods produce elastomer domains of NR and SBR, which present different microstructure due to the cure level attained during vulcanization. The cure kinetics is studied by means of rheometer tests and the model proposed by Kamal and Sourour. The analysis of the cure rate is presented and is related to the structure obtained during the vulcanization process.

  1. Characterization of additives typically employed in EPDM formulations by using FT-IR of gaseous pyrolyzates

    Directory of Open Access Journals (Sweden)

    Natália Beck Sanches

    2014-06-01

    Full Text Available In this study, Fourier transform infrared spectroscopy (FT-IR was employed to investigate the gaseous pyrolysis products of ethylene - propylene - diene rubber (EPDM. The objective was to evaluate the potential of FT-IR analysis of gaseous pyrolyzates (PY-G/FT-IR for characterization of EPDM additives. Two EPDM formulations, containing additives typically employed in EPDM rubbers, were analyzed. Initially, gaseous pyrolysis products from paraffin oil, stearic acid, 2,2,4-trimethyl-1,2-dihydroquinoline, tetramethylthiuram monosulfide (TMTM, tetramethylthiuram disulfide (TMTD, and 2-mercaptobenzothiazole (MBT were characterized separately, and their main absorptions were identified. Subsequently, the gaseous pyrolysis products of raw, unvulcanized, and vulcanized EPDM formulations were analyzed. The similarities observed in the FT-IR spectra of unvulcanized and vulcanized EPDM show that the vulcanization process does not interfere with the pyrolysis products. The identification of the functional groups of the studied additives was possible in both unvulcanized and vulcanized EPDM samples, without solvent extraction. Results also demonstrate that the PY-G/FT-IR technique can identify additives containing sulfur in concentrations as low as 1.4 phr (1.26% in both unvulcanized and vulcanized EPDM. However, the method showed some limitation due to overlapping and to similarities of TMTM and TMTD PY-G/FT-IR spectra, which could not be distinguished from each other. The PY-G/FT-IR technique is a faster and cheaper alternative to the sophisticated techniques usually applied to detection of additives in rubbers.

  2. La planète Vulcain, une perspective américaine, traduction d'un article de William Shehan et Tony Misch

    Science.gov (United States)

    Lequeux, James

    2016-10-01

    After his discovery of Neptune in 1846, Le Verrier attempted to extend Newton's theory to the innermost planet, Mercury. He found a small unexplained discrepancy in its motion. Applying the same assumption as had succeeded to explain the motion of Uranus with Neptune, he proposed the existence of an intra-Mercurial planet, named Vulcan, which would have perturbed Mercury. This article describes the long searches for Vulcan in America. Vulcan was never found from either side of the Atlantic, as well as a possible ring of debris which could have played the same role. The anomalous precession of the perihelion of Mercury was finally explained by Einstein in1915 in terms of the General Theory of Relativity, and provided one of the first confirmations of the theory's correctness.

  3. Radiation processed ethylene vinyl acetate-multiple walled carbon nanotube nano-composites: Effect of MWNT addition on the gel content and crosslinking density

    Directory of Open Access Journals (Sweden)

    2009-08-01

    Full Text Available Different compositions of ethylene vinyl acetate (EVA/multiple walled carbon nanotube (MWNT nano-composites were prepared by melt mixing and subjected to different doses of gamma radiation. The efficiency of radiation vulcanization was analyzed by sol-gel analysis, Charlesby-Pinner parameter estimation and crosslinking density measurements. Gamma radiation induced crosslinking was found to increase with MWNT fraction in EVA-MWNT nano-composites (p0/q0 in the range: 1.15–0.98. These results ruled out the possibility of a significant neutralization of single ionization spurs by MWNT addition. The incorporation of MWNT also resulted in increased hardness and higher density of the nano-composite matrix. The efficiency of multifunctional acrylates as crosslinking aid in the radiation-induced vulcanization of EVA-MWNT nano-composites was also investigated. The results established lower efficiency of methacrylates than of acrylates in the radiation vulcanization process.

  4. Vulcan ~Redefisの一実施例とそれへのユーザ機能実装例の紹介~

    OpenAIRE

    2004-01-01

    ユーザ機能の実装に適したSoC プラットフォームRedefis の一実施例である,プロセッサVulcan について 紹介し,さらにVulcan 上へのアプリケーション実装例について紹介する.Vulcan は再構成可能なデータパスを持った プロセッサであり,アプリケーションに特化した命令を実行することで柔軟性と高性能化を両立させることができる.

  5. Recycling and processing of several typical crosslinked polymer scraps with enhanced mechanical properties based on solid-state mechanochemical milling

    Science.gov (United States)

    Lu, Canhui; Zhang, Xinxing; Zhang, Wei

    2015-05-01

    The partially devulcanization or de-crosslinking of ground tire rubber (GTR), post-vulcanized fluororubber scraps and crosslinked polyethylene from cable scraps through high-shear mechanochemical milling (HSMM) was conducted by a modified solid-state mechanochemical reactor. The results indicated that the HSMM treated crosslinked polymer scraps can be reprocessed as virgin rubbers or thermoplastics to produce materials with high performance. The foamed composites of low density polyethylene/GTR and the blend of post-vulcanized flurorubber (FKM) with polyacrylate rubber (ACM) with better processability and mechanical properties were obtained. The morphology observation showed that the dispersion and compatibility between de-crosslinked polymer scraps and matrix were enhanced. The results demonstrated that HSMM is a feasible alternative technology for recycling post-vulcanized or crosslinked polymer scraps.

  6. Recycling and processing of several typical crosslinked polymer scraps with enhanced mechanical properties based on solid-state mechanochemical milling

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Canhui; Zhang, Xinxing; Zhang, Wei [State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute, Sichuan University, Chengdu 610065 (China)

    2015-05-22

    The partially devulcanization or de-crosslinking of ground tire rubber (GTR), post-vulcanized fluororubber scraps and crosslinked polyethylene from cable scraps through high-shear mechanochemical milling (HSMM) was conducted by a modified solid-state mechanochemical reactor. The results indicated that the HSMM treated crosslinked polymer scraps can be reprocessed as virgin rubbers or thermoplastics to produce materials with high performance. The foamed composites of low density polyethylene/GTR and the blend of post-vulcanized flurorubber (FKM) with polyacrylate rubber (ACM) with better processability and mechanical properties were obtained. The morphology observation showed that the dispersion and compatibility between de-crosslinked polymer scraps and matrix were enhanced. The results demonstrated that HSMM is a feasible alternative technology for recycling post-vulcanized or crosslinked polymer scraps.

  7. The unique processing of rubber-insulated wires by radiation

    Science.gov (United States)

    Ishitani, Hayao; Saito, Eisuke; Sasaki, Yasushi

    Ethylene-propylene rubbers are able to be crosslinked (vulcanized) by high energy radiation. The radiation-induced crosslinking of ethylene-propylene copolymer or ethylene-propylene-diene terpolymer depends upon the ethylene/propylene ratio, the molecular weight of the polymer, the unsaturating degree of terpolymer and kinds of tercomponents. The mechanical properties of the crosslinked rubber were affected mainly by the E/P ratio and the molecular weight, and improved by blending of low density polyethylene or ethylene-vinylacetate copolymer. Aging of the rubber, due to kinds and contents of tercomponents, was mostly determined by addition of antioxidants to the compound. We developed EP rubber compounds for wire insulation crosslinked by electron beam radiation and applied to the insulation cores of the ship's cables, in the place of the wire vulcanized conventionally by the pressurized steam in the continuous vulcanizer. The rubber compounds are consisted of ethylene-propylene-diene terpolymer with high ethylene contents, ethylene-vinylacetate copolymer and antioxidants. The high-ethylene polymers are supplied in the shape of pellets, and antioxidants were added to the compounds by means of dry blending of concentrates in which antioxidants are mixed into pellets of ethylene copolymer. The EP rubbers were covered on the copper wire by the extruder, used to plastic material, and irradiated with the electron beam from an accelerator. These insulated cores manufactured on radiation processing had the excellent properties, particularly aging and electrical properties. Further, they are more simply colored. Therefore, they will be considered to be used to other applications. This method of manufacturing of the rubber-insulated wires made it possible to reduce both the material costs by simple compounding and the operating costs by radiation-induced crosslinking, to compare with the conventional compounding and vulcanizing process, in which the materials are

  8. Study on the Formula of Green Environmental Protection Radiator Coolant Hose for Automobile%绿色环保的汽车散热器冷却液胶管配方研究

    Institute of Scientific and Technical Information of China (English)

    柯宇旋

    2012-01-01

    The Author studied the application of sulfur donor vulcanization system and peroxide vulcanization system in automobile radiator coolant hose material,made the new formulation design from the economic and environmental protection angle,and tested the properties.The author through the analysis of experimental results,found out the best proportion of sulfur donor vulcanization system formula.By comparing the experimental results,in the same conditions,the sulfur donor vulcanization system of EPDM had greater tensile strength,elongation at break and tear strength.Moreover,the heat-resistant attributer of optimized sulfur donor vulcanization system was relatively close to the one of peroxide vulcanization system.The new formula was very practical.%笔者研究了硫磺给予体硫化体系与过氧化物硫化体系在汽车散热器冷却液胶管材料中的应用,从经济环保的角度进行了新的配方设计,并进行了性能测试。通过对实验结果分析,确定硫磺给予体硫化体系配方的最佳比例。通过对比实验,结果表明:同等条件下,EPDM的硫磺给予体硫化体系对比过氧化物硫化体系有较大的拉伸强度、拉断伸长率、撕裂强度。而且耐热性能方面优化硫磺给予体硫化体系也与过氧化物硫化体系比较接近。新配方实用性强。

  9. Proceedings of the Annual Conference of the Military Testing Association (27th) Held in San Diego, California on 21-25 October 1985. Volume 2

    Science.gov (United States)

    1985-10-25

    missiles; the other SHORAD weapons are the man-portable Redeye and Stinger missile systems, and the Vulcan vehicle-msunted gun system (FM 44-1, 1976). All...Chaparral / Vulcan . Washington, D.C. Headquarters, Departrnt of the Army (1984, Novenber 2). FM 44-4, Operations and training, Chaparral. Washington, D.C...c,tve Test Cevelonnpert The finalized tesi design specification is produced on-site via a word process;ng compLterized process, and is reviewed by

  10. Shopping For Danger: E-commerce techniques applied to collaboration in cyber security

    Energy Technology Data Exchange (ETDEWEB)

    Bruce, Joseph R.; Fink, Glenn A.

    2012-05-24

    Collaboration among cyber security analysts is essential to a successful protection strategy on the Internet today, but it is uncommonly practiced or encouraged in operating environments. Barriers to productive collaboration often include data sensitivity, time and effort to communicate, institutional policy, and protection of domain knowledge. We propose an ambient collaboration framework, Vulcan, designed to remove the barriers of time and effort and mitigate the others. Vulcan automated data collection, collaborative filtering, and asynchronous dissemination, eliminating the effort implied by explicit collaboration among peers. We instrumented two analytic applications and performed a mock analysis session to build a dataset and test the output of the system.

  11. JIS K 6262-1997硫化橡胶或热塑性橡胶永久变形试验方法

    Institute of Scientific and Technical Information of China (English)

    临风

    2003-01-01

    @@ 前言本标准参照了1991年第2次发布的ISO 815 Rubber,vulcanized or thermoplastic-Detemination of compression set at ambient,elevated or low temperatures以及1996年发布的ISO/DIS 2285 Rubber,vulcanized or thermoplastic- Determinatiion of tension set at normal and high temperatures国际标准,在不改变其技术内容的基础上,修订了日本工业标准.

  12. Physical properties of blended and vulcanizednitrile-butadiene rubber/chloroprene rubber%共混硫化丁腈橡胶-氯丁橡胶的物理性能

    Institute of Scientific and Technical Information of China (English)

    蒋利辉

    2014-01-01

    将丁腈橡胶(NBR)和氯丁橡胶(CR)按不同质量分数共混并硫化,研究了硫化橡胶在自然环境、热空气老化、热油老化等条件下的物理性能,并测定了硫化橡胶与镀铜钢丝的粘合性能.结果表明,随着 CR 质量分数的增大,混炼胶的焦烧时间逐渐缩短.经热空气老化后,NBR 的硬度增加幅度比 CR 的硬度增加幅度大,拉断强度降低幅度则比 CR 的小得多.此外,NBR 的耐油性能优于 CR.就物理性能以及与镀铜钢丝的粘合性能而言,单一 NBR 和单一 CR 优于共混 NBR/CR.%Nitrile-butadiene rubber (NBR)and chloroprene rubber (CR)were blended at differ-ent mass fractions and vulcanized,followed by aging at various conditions.The physical prop-erties of the vulcanized rubbers aged at ambient condition as well as in hot air and hot oil were determined,and their adhesion to Cu-coated steel wires was measured as well.Results indicate that,with the increase of the mass fraction of CR,the scorch time of the gross rubber tends to decline gradually.After being aged in hot air,the hardness of vulcanized NBR tends to rise more noticeably than that of vulcanized CR,while the tensile strength of the vulcanized NBR reduces at a much less extent than that of the vulcanized CR.Moreover,vulcanized NBR exhib-its better resistance against oil than vulcanized CR,while mono NBR and mono CR are advan-tageous over blended NBR/CR in terms of the physical properties and adhesion to Cu-coated steel wire.

  13. Eu(TTA)2(phen)(UAH)/SiR Fluorescence Materials Prepared by In-Situ Reaction Method

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Eu(TTA)2(phen)(UAH) (UAH=undecylenic acid)with fine fluorescent property and active group was synthesized. The measurement and characterization of complexes were also carried out. A series of composites based silicon rubber were prepared by blending silicon rubber and Eu(TTA)2(phen)(UAH) rare earth complex with active groups. Next, the effect of vulcanizing time on the property of materials was mainly studied. The results show that the dispersed particle size of rare earth complexes decreases gradually in the vulcanizing process.

  14. Effective Conveyor Belt Inspection for Improved Mining Productivity

    Energy Technology Data Exchange (ETDEWEB)

    David LaRose

    2006-07-01

    This document details progress on the project ''Effective Conveyor Belt Inspection for Improved Mining Productivity'' during the period from November 15, 2005 to May 14, 2006. Highlights include significant improvements in the accuracy and reliability of computer-vision based vulcanized splice detection, deployment of the vulcanized splice detection algorithms for daily use in two working mines, and successful demonstration of an early prototype of a Smart-Camera based system for on-site mechanical splice detection in coal mine installations.

  15. Chemistry of rubber processing and disposal.

    Science.gov (United States)

    Bebb, R L

    1976-01-01

    The major chemical changes during the processing of rubber occur with the breakdown in mastication and during vulcanization of the molded tire. There is little chemical change during the compounding, calendering, extrusion, and molding steps. Reclaiming is the process of converting scrap rubber into an unsaturated, processible product that can be vulcanized with sulfur. Pyrolysis of scrap rubber yields a complex mixture of liquids, gas, and residue in varying ratios dependent on the nature of the scrap and the conditions of pyrolysis. PMID:799964

  16. Strategic Resources and National Security: An Initial Assessment

    Science.gov (United States)

    1975-04-01

    Antimony oxides, sulfides, in metalware, ceramic enamels, special glass, pigments, infrared reflecting camouflage paints, vulcanizing agent, UV absorber...instrument lenses, mirrors, plate glass. Glass decolorizer, colorizer UV absorber in welder’s gog- gles, special sunglasses, optical filters, food...cylinders. Orange- red pigments for plastics, paints, enamels, inks, and rubber. Stainless steel additive. Pharmaceuticals such as niacin, cortisone

  17. Chinese IIR's Supply & Demand Situation and Development Prospect%Chinese IIR's Supply & Demand Situation and Development Prospect

    Institute of Scientific and Technical Information of China (English)

    Cui Xiaoming

    2011-01-01

    IIR is a kind of rubber polymerized by isobutylene and a little isoprene with such performances as good airtightness, heat resistance, aging resistance, acid-alkali resistance, ozone resis- tance, solvent resistance, electric insulation, shock absorption and low water absorption, which is widely applied on the inner tubes, tire bags, vulcanized bladders, air barriers, sidewalls,

  18. Survey and Assessment of Models or Decision Rules Determining Spare Parts Levels for Navy Electronics Equipments. Appendix A. Applicable Literature Source Material.

    Science.gov (United States)

    1979-09-07

    Dixon Repair Ships (Ocean Tailored, Industrial Mission) Atlantic Fleet AR 5 Vulcan AR 28 Grand Canyon Pacific Fleet AR 6 Ajax AR 7 Hector AR 8 Jason The...34* - . . . - ........... lisle -1’L ....- = .... 238 .... 17 34 31505 NSA 8,036 ... $ 498,502 APA 319 493,759 TOTAl " &,355 8991261 UNCLASSIFIED ATN8 9-28 .. NAVAL ESAGE

  19. Effects of moulding and environmental conditions on the mechanical and surface properties of injection moulded santoprene rubber

    DEFF Research Database (Denmark)

    Islam, Aminul; Ruby, Tobias M.; Jessen, Rikke L.

    the electronics inside from environmental hazards. The sealing ring is injection moulded in Santoprene-a thermoplastic vulcanizate consisting of Polypropelene and highly vulcanized EPDM rubber. The scope of the project was therefore to investigate the properties of Santoprene and make an immediate evaluation...

  20. Waverly Plantation: Ethnoarchaeology of a Tenant Farming Community,

    Science.gov (United States)

    1980-12-16

    until the mid-1930s (Randall 1971:103; 1979:9). °" D04 Reed stem pipes Short stemmed or reed stemmed pipes, differ From earlier " kaolin " clay pipes by...and solvents saking it sticky and plastic. 584 Vulcanization, a process involving adding sulphur and heating the rubber, forges crosslinks in the

  1. Ultra Small-angle X-ray Scattering Study of Flocculation in Silica-filled Rubber

    NARCIS (Netherlands)

    Mihara, S.; Datta, R.N.; Dierkes, W.K.; Noordermeer, J.W.M.; Amino, N.; Ishikawa, Y.; Nishitsuji, S.; Takenaka, M.

    2014-01-01

    The flocculation of silica during vulcanization is monitored using the ultra small-angle X-ray scattering technique for two different types of silica: a highly dispersible silica (HD) and a conventional silica (CV), mixed into a blend of S-SBR and BR rubbers. The cutoff length of the silica aggregat

  2. Lightweight Electric Power Cable.

    Science.gov (United States)

    1982-09-01

    8I~ .4 111 162 MICROCi Pi RL’ LUHION TESI CHARI "LIGHTWEIGHT ELECTRIC POWER CABLE" FINAL TECHNICAL REPORT SEPTEMBER 30, 1981 to SEPTEMBER 30, 1982... Vulcanized by heat to crosslink. TPE (Thermoplastic Elastomer) - Polymers having elastomeric proper- ties. Used as thermoplastics - melt formed by

  3. Practical Sensitivity Limits of Production Nondestructive Testing Methods in Aluminum and Steel

    Science.gov (United States)

    1975-01-01

    notches in the specimen blanks were replicated with a silicone flexible mold compound. This was a room temperature vulcanizing rubber, 630A, manufactured...supplied to the inspectors for each of the specimen designs, the tesi parts would have been identified as special (nonproduction) and would have been

  4. Study for Improving the Definition of the Army Objective Force Methodology, Phase II (IDOFOR II). Volume I. Executive Summary.

    Science.gov (United States)

    1981-10-01

    UNCLASSIFIED CAA-S-81-17-VOL-13 N MF__ 11111 32 11111 I.’ ’ 0 MICROCOPY RESOLUTION TESi CHART NATIONAL BURfAU OJf STANDARDS 1%3 A, • 1 - - H DISCLAIMER The...Support Agency USAREUR United States Army, Europe USMC United States Marine Corps VERT Venture Evaluation Review Technique VULCAN short-range, 20mm air

  5. Leadership Handbook for the Armor Officer. Volume 2. Headaches, Heartbeats, and Hamstrings: A Guide to Company Level Duties and Functions

    Science.gov (United States)

    1986-01-01

    rctcs 8h reaiztiotathe s ollwi. cors ththsbeucssu o tesi imlrcr mtne !-- ",/,,"-,. bolsters.’.-’ his.. confdene ad.ecouage.h. to.. adhere... Vulcan - Antiaircraft Weapon System w -With wa- Weather I WESS - Weapons Effect Signature Simulator WESTCC14 - US Army Western Command WETS - Weekend

  6. Laboratory Study of Deep-Based Structures in Support of DIABLO HAWK.

    Science.gov (United States)

    1978-02-01

    in two while removing it from testing machine. Peak pressures were P= 11.8 tesi = 81 MPa and PH = 8.4 ksi = 58 MPa. 79 _ _ _ _ _1 CN CL F- 0 C) 0U I...passing #L2 sieve and 61.37% retained on #16 sieve, saturated surface dry state); Source: Vulcan Materials Co., Calera, AL S. A. Ragan, Waterways

  7. Advanced Crash Survivable Flight Data Recorder And Accident Information Retrieval System (AIRS).

    Science.gov (United States)

    1981-08-01

    95 31 NARROW-BAND CONDUCTED EMISSIONS ON THE AIRS 24 VDC POWER RETURN (CE04 TESI ) ......................... 96 32 BROAD-BAND...three layers of vulcanized synthetic rubber containing an intumescent ceramic material and includes a wire mesh reinforcement between the outermost

  8. Product Improvement Program 1-84-09-7133 25 mm Metal PA 125 Container

    Science.gov (United States)

    1993-06-01

    house leaking test with a molded gasket design. The molded gasket, with a softness of 40 durometer, eliminated the vulcanized joint for improved...3 psig. The wide gasket design allows the container to be easily resealed. A sealing tesi conducted in April 1991 demonstrated this excellent

  9. High Pressure Hydraulic Distribution System

    Science.gov (United States)

    1991-05-20

    to 500 0 F. 5 cycles. 5000 F room temperature to 50001F; 45 ______________ Icycles The tesis planned for the distribution system demonstrator were...American Society for Testing and Materials ASTM D412 - Tension Testing of Vulcanized Rubber ASTM D571 - Testing Automotive Hydraulic Brake Hose Society of

  10. Prediction of Aerodynamic Loading

    Science.gov (United States)

    1977-02-01

    by overfueling an earlier Olympus engine, on the Vulcan flying test-bed. The scarcity of data and inadequate understanding at that time led to a...from wind tunnel tests and confirming flight tesIs , hAve indicated that airplanes. pauiti-ularly the highly maneuvering types, do have sioeslip

  11. Ocean Engineering Studies Compiled 1991. Volume 7. Acrylic Windows- Diverse Design Features and Types of Service

    Science.gov (United States)

    1991-01-01

    titanium hatches (Fig. 4) were inserted into the polar penetrations and scaled against leakage with room vulcanizing silicone rubber squirted into...higher than in the thick shell (0.31 versus 0.25 percent) (Table 5). Discussion Spherical Shell. The tesi results generated by the pressure cycling

  12. Methanol electro-oxidation on Pt-Ru-P/C and Pt-Ru-P/MWCNT in acidic medium

    CSIR Research Space (South Africa)

    Modibedi, M

    2009-06-01

    Full Text Available Pt-Ru-P was prepared by the chemical reduction method using sodium hypophoshite as a reducing agent on Vulcan XC 72 and multi-walled carbon nano-tubes (MWCNTs). Sodium citrate was added as the stabilizer during electro-catalyst preparation...

  13. 真空铸造

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Fabrication and Mechanical Properties of Cu-based Bulk Amorphous Alloys,Investigation of Al-Si compositions for thin film applications,Resins to be cheerful,Vacuum casting with room temperature vulcanizing rubber and aluminium moulds for rapid manufacturing of quality parts: a comparative study.

  14. TECHNOLOGICAL COMPLEX OF EQUIPMENT FOR REFINING AND CASTING OF STEEL AND ALLOYS IN THE FOUNDRY AND STEEL INDUSTRIES

    Directory of Open Access Journals (Sweden)

    V. I. Zolotukhin

    2013-01-01

    Full Text Available Vulcan TM is a small innovative company, specializing in the manufacture of steel and alloys casting systems and refractory accessories.Available for foundry and metallurgical industries, special technological equipment, designed and manufactured by LLC NPP “Vulkan-TM.”

  15. Existence of Asymptotic Expansions in Noncommutative Quantum Field Theories

    CERN Document Server

    Linhares, C A; Roditi, I

    2007-01-01

    Starting from the complete Mellin representation of Feynman amplitudes for noncommutative vulcanized scalar quantum field theory, introduced in a previous publication, we generalize to this theory the study of asymptotic behaviours under scaling of arbitrary subsets of external invariants of any Feynman amplitude. This is accomplished for both convergent and renormalized amplitudes.

  16. AcEST: BP912632 [AcEST

    Lifescience Database Archive (English)

    Full Text Available maxima PE=1 SV=2 88 2e-17 sp|P0A3D1|FER_THEVL Ferredoxin-1 OS=Thermosynechococcus vulcanus... 87 4e-17 sp|P...GYVLTCVAYPTSDCTIQTHQEEGL 98 >sp|P0A3D1|FER_THEVL Ferredoxin-1 OS=Thermosynechococcus vulcan

  17. AcEST: BP912293 [AcEST

    Lifescience Database Archive (English)

    Full Text Available oenolpyruvate carboxylase OS=Thermosynechococcus vulcanus Align length 55 Score (bit) 30.4 E-value 2.8 Repor... OS=Bartonella... 29 6.3 >sp|P0A3X6|CAPP_THEVL Phosphoenolpyruvate carboxylase OS=Thermosynechococcus vulcan

  18. COORDINATION CROSSLINKING OF NITRILE RUBBER FILLED WITH COPPER SULFATE PARTICLES

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    By incorporating copper sulfate (CuSO4) particles into acrylonitrile butadiene rubber (NBR) followed by heat pressing.a novel vulcanization method is developed in rubber through the formation of coordination crosslinking.This method totally differs from traditional covalent or non-covalent vulcanization approaches of rubber.No other vulcanizing agent or additional additive is involved in this process.By analyzing the results of DMA,XPS and FT-IR,it is found that the crosslinking of CuSO4 particles filled NBR was induced by in situ coordination between nitrogen atoms of nitrile groups (-CN) and copper ions (Cu2+) from CuSO4.SEM and EDX results revealed the generation of a core (CuSO4 solid particle) shell (adherent NBR) structure,which leads to a result that the crosslinked rubber has excellent mechanical properties.Moreover,poly (vinyl chloride)(PVC) and liquid acrylonitrile-butadiene rubber (LNBR) were used as mobilizer to improve the coordination crosslinking of CuSO4/NBR.The addition of PVC or LNBR could lead to higher crosslink density and better mechanical properties of coordination vulcanization.In addition,crystal water in CuSO4 played a positive role to coordination crosslinking of rubber because it decreased the metal point of CuSO4 and promoted the metal ionization.

  19. Microbial community changes in heathland soil communities along a geographical gradient: Interaction with climate change manipulations

    DEFF Research Database (Denmark)

    Sowerby, A.; Emmett, B.; Beier, C.;

    2005-01-01

    Climate change constitutes a serious threat for European heathlands as unlike other sources of damage, such as over-grazing, local remediation is not a possibility. Within the large pan-European projects, CLIMOOR and VULCAN, the effect of periodic drought and increased temperature were investigated...

  20. NCBI nr-aa BLAST: CBRC-TTRU-01-1184 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-TTRU-01-1184 ref|YP_003247073.1| polysaccharide biosynthesis protein [Methanocaldococcus vulcan...ius M7] gb|ACX72591.1| polysaccharide biosynthesis protein [Methanocaldococcus vulcanius M7] YP_003247073.1 0.079 22% ...

  1. Study on the curing properties of SBR/La-GDTC/SiO2 composites

    Institute of Scientific and Technical Information of China (English)

    YANG Shuyan; LIU Lan; JIA Zhixin; JIA Demin; LUO Yuanfang

    2011-01-01

    A lanthanum glutamic dithiocarbamate(La-GDTC) was synthesized. The vulcanization kinetic and crosslinking structure of styrene butadiene rubber (SBR)/La-GDTC/silica(SiO2) composites were studied via vulcanization kinetic simulation, swelling equilibrium and differential scanning calorimeter. Simulated curing parameters showed that the curing rate k2 of the SBR/La-GDTC/SiO2 composite was significantly higher than that of the SBR/La-GDTC composite. Also, swelling equilibrium test turned out that crosslinking density of SBR/LaGDTC/SiO2 composite evolved to higher level, compared to that of the SBR/La-GDTC composite. Ammonia modified swelling equilibrium interpreted both lanthanum ions and carboxyl groups could react with silanol groups of silica particles. Finally, vulcanization activation energies of SBR/La-GDTC/SiO2 composite were lower than that of SBR/La-GDTC composite, without respect to different approaches of the DSC measurement or Oscillated Disc Rheometer test. All the results showed that the lanthanum ions of La-GDTC could act as the metal ion catalyzer of sulfur vulcanization during the crosslinking process, which could be attributed to the unoccupied orbital of lanthanum ions.Therefore, a La-GDTC bridged structure between SBR and silica panicles for the SBR/La-GDTC/SiO2 composite was suggested according to the experimental results.

  2. The Moon that Wasn't

    DEFF Research Database (Denmark)

    Kragh, Helge

    than a mere curiosity in the annals of astronomy - Frederick II of Prussia was familiar with it, and so was Bonnet, Kant and Voltaire. The satellite of Venus belongs to the same category as other fictitious celestial bodies (such as the planet Vulcan), yet it had its own life and fascinating historical...

  3. Effect of Inflation Pressure Loss Rates on Tire Rolling Resistance,Vehicle Fuel Economy, and CO2 Emissions of Asia-Pacific and China

    Institute of Scientific and Technical Information of China (English)

    Dr.Walter H. Waddell

    2011-01-01

    INTRODUCTION Based on the low permeability to small-molecule diffusants as a result of efficient intermolecular packing, butyl rubber has contributed significantly to the improvement in the performance and safety of tires. Halogenated butyl rubbers provide higher vulcanization rates and improve the compatibility with unsatu-rated rubbers, enabling the production of tubeless tires.

  4. Preparation, characterisation and application of Pd/C nanocatalyst in passive alkaline direct ethanol fuel cells (ADEFC)

    CSIR Research Space (South Africa)

    Modibedi, RM

    2015-10-01

    Full Text Available This work describes the use of Pd nanocatalyst on Vulcan XC-72 (at a very low loading, 8 wt % Pd) in passive alkaline direct ethanol fuel cell (ADEFC). The average Pd particle size obtained with TEM was 3.5 ± 0.5 nm. The XRD results of the prepared...

  5. Report of the Defense Science Board Task Group on Independent Research and Development

    Science.gov (United States)

    1967-02-01

    Hispano Suiza 820 gun used in the Vehicle Rapid Fire Weapon System (VRFWS). Con· tract effort on these two fuzes to date totals $125,000. Although...potential production requirements for the Hispano Suiza fuze is approximately $40,000,000 over the next five to seven years and for the Vulcan fuze is

  6. Effective Conveyor Belt Inspection for Improved Mining Productivity

    Energy Technology Data Exchange (ETDEWEB)

    Chris Fromme

    2006-06-01

    This document details progress on the project entitled ''Effective Conveyor Belt Inspection for Improved Mining Productivity'' during the period from November 15, 2004 to May 14, 2004. Highlights include fabrication of an improved LED lightbar, fabrication of a line-scan sensor head for the Smart-Camera based prototype, and development of prototype vulcanized splice detection algorithms.

  7. Die Geognosie der Vulkane

    Directory of Open Access Journals (Sweden)

    Herbert Pieper

    2006-10-01

    Full Text Available Article in German, Abstract in English.The paper deals with Alexander von Humboldt’s researches into the “Geognosy” of volcanoes. In the long run these researches led him to changing his views from the "neptunistic" doctrine of Abraham Gottlob Werner to the concept of "vulcanism".

  8. Synthesis of N-Alkylperfluorooctanesulfonamides and Its Derivatives

    Institute of Scientific and Technical Information of China (English)

    LI Yan; CHEN Zhi-Qi; ZHOU Ye-Bing; CHEN Zu-Xing; LIU Zhao-Jie

    2003-01-01

    @@ N-Alkylperfluorooctanesulfonamide compounds are special fine chemicals, and have been applied in many fields, such as vulcanizing agents for fluoro rubbers, smooth and friction reducing for coatings, fire extinguisher, anticorrosive agents for metals, water- and oil-repellents for leather, textiles and paper, photographic emulsion.[1

  9. Bonding Elastomers To Metal Substrates

    Science.gov (United States)

    Dickerson, George E.; Kelley, Henry L.

    1990-01-01

    Improved, economical method for bonding elastomers to metals prevents failures caused by debonding. In new technique, vulcanization and curing occur simultaneously in specially designed mold that acts as form for desired shape of elastomer and as container that positions and supports metal parts. Increases interface adhesion between metal, adhesive, and elastomer.

  10. Army Overseas Water Sustainability Study

    Science.gov (United States)

    2011-06-01

    throughout Europe are causing mounting concern because of their increasing frequency and the high level of monetary dam- age they incur. The most recent...the peninsula. Italy maintains the active volcanoes Etna, Vulcan, Stromboli, and Vesuvius . Land use in Italy consists of 31 percent arable land and 8

  11. Categories of Insight and Their Correlates: An Exploration of Relationships among Classic-Type Insight Problems, Rebus Puzzles, Remote Associates and Esoteric Analogies

    Science.gov (United States)

    Cunningham, J. Barton; MacGregor, James N.; Gibb, Jenny; Haar, Jarrod

    2009-01-01

    A central question in creativity concerns how insightful ideas emerge. Anecdotal examples of insightful scientific and technical discoveries include Goodyear's discovery of the vulcanization of rubber, and Mendeleev's realization that there may be gaps as he tried to arrange the elements into the Periodic Table. Although most people would regard…

  12. Microwave heating: Industrial applications. (Latest citations from the EI Compendex*plus database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-01

    The bibliography contains citations concerning industrial uses and design of microwave heating equipment. Citations discuss applications in food processing, industrial heating, vulcanization, textile finishing, metallurgical sintering, ceramic manufacturing, paper industries, and curing of polymers. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  13. ALREST High Fidelity Modeling Program Approach

    Science.gov (United States)

    2011-05-18

    Gases and Mixtures of Redlich - Kwong and Peng- Robinson Fluids Assumed pdf Model based on k- ε-g Model in NASA/LaRc Vulcan code Level Set model...Potential Attractiveness Of Liquid Hydrocarbon Engines For Boost Applications • Propensity Of Hydrocarbon Engines For Combustion Instability • Air

  14. A new inversion method to calculate emission inventories without a prior at mesoscale: Application to the anthropogenic CO2 emission from Houston, Texas

    Science.gov (United States)

    Brioude, J.; Petron, G.; Frost, G. J.; Ahmadov, R.; Angevine, W. M.; Hsie, E.-Y.; Kim, S.-W.; Lee, S.-H.; McKeen, S. A.; Trainer, M.; Fehsenfeld, F. C.; Holloway, J. S.; Peischl, J.; Ryerson, T. B.; Gurney, K. R.

    2012-03-01

    We developed a new inversion method to calculate an emission inventory for an anthropogenic pollutant without a prior emission estimate at mesoscale. This method employs slopes between mixing ratio enhancements of a given pollutant (CO2, for instance) with other co-emitted tracers in conjunction with the emission inventories of those tracers (CO, NOy, and SO2 are used in this example). The current application of this method employed in situ measurements onboard the NOAA WP-3 research aircraft during the 2006 Texas Air Quality Study (TexAQS 2006). We used 3 different transport models to estimate the uncertainties introduced by the transport models in the inversion. We demonstrated the validity of the new inversion method by calculating a 4 × 4 km2 emission inventory of anthropogenic CO2 in the Houston area in Texas, and comparing it to the 10 × 10 km2 Vulcan emission inventory for the same region. The calculated anthropogenic CO2 inventory for the Houston Ship Channel, home to numerous major industrial and port emission sources, showed excellent agreement with Vulcan. The daytime CO2 average flux from the Ship Channel is the largest urban CO2 flux reported in the literature. Compared to Vulcan, the daytime urban area CO2 emissions were higher by 37% ± 6%. Those differences can be explained by uncertainties in emission factors in Vulcan and by increased emissions from point sources and on-road emitters between 2002, the reference year in Vulcan, and 2006, the year that the TexAQS observations were made.

  15. High resolution fossil fuel combustion CO2 emission fluxes for the United States.

    Science.gov (United States)

    Gurney, Kevin R; Mendoza, Daniel L; Zhou, Yuyu; Fischer, Marc L; Miller, Chris C; Geethakumar, Sarath; de la Rue du Can, Stephane

    2009-07-15

    Quantification of fossil fuel CO2 emissions at fine space and time resolution is emerging as a critical need in carbon cycle and climate change research. As atmospheric CO2 measurements expand with the advent of a dedicated remote sensing platform and denser in situ measurements, the ability to close the carbon budget at spatial scales of approximately 100 km2 and daily time scales requires fossil fuel CO2 inventories at commensurate resolution. Additionally, the growing interest in U.S. climate change policy measures are best served by emissions that are tied to the driving processes in space and time. Here we introduce a high resolution data product (the "Vulcan" inventory: www.purdue.edu/eas/carbon/vulcan/) that has quantified fossil fuel CO2 emissions for the contiguous U.S. at spatial scales less than 100 km2 and temporal scales as small as hours. This data product completed for the year 2002, includes detail on combustion technology and 48 fuel types through all sectors of the U.S. economy. The Vulcan inventory is built from the decades of local/regional air pollution monitoring and complements these data with census, traffic, and digital road data sets. The Vulcan inventory shows excellent agreement with national-level Department of Energy inventories, despite the different approach taken by the DOE to quantify U.S. fossil fuel CO2 emissions. Comparison to the global 1degree x 1 degree fossil fuel CO2 inventory, used widely by the carbon cycle and climate change community prior to the construction of the Vulcan inventory, highlights the space/time biases inherent in the population-based approach.

  16. Physical and chemical aspects of long-term biodeterioration of some polymers and composites.

    Science.gov (United States)

    Lugauskas, A; Prosychevas, I; Levinskaite, L; Jaskelevicius, B

    2004-08-01

    A biodeterioration study was performed on synthetic polymeric materials including homogenous film made from poly(tetrafluorine ethylene), copolymer film made from tetrafluorine ethylene and perfluoromethyl vinyl ether, vulcanized rubber containing natural caoutchouc, and vulcanized rubber, the main component of which was synthetic butadiene nitrile caoutchouc. The materials were exposed for 12 years to the open air, in mycological containers, and in a cellar in maritime climate conditions: air humidity 72%-90% and seasonal average temperature of 17 degrees C in summer and -2.5 degrees C in winter. The studies of optical and electron microscopy revealed that microorganisms were able to develop not only on the surface of the materials but also to penetrate inside into deeper layers. The fungi that produced the most intensive deterioration in the fluorine polymers and vulcanized rubbers belonged to the Alternaria, Aspergillus, Aureobasidium, Cladosporium, Penicillium, Oidiodendron and Trichoderma genera. The fungi Aspergillus fumigatus, A. niger, Aureobasidium pullulans, and Trichoderma viride produced the most intensive deterioration in the fluorine films, whereas Alternaria tenuissima, Cladosporium herbarum, C. sphaerospermum, and fungi of the Oidiodendron genus were widespread on vulcanized rubbers. Fungi of the Aspergillus and Penicillium genera prevailed on both fluorine films and rubbers exposed in a cellar. Infrared spectroscopy indicated that the structures of poly(tetrafluorine ethylene) and the copolymer of tetrafluorine ethylene and perfluoromethyl vinyl ether did not change after the 12-year exposure; only insignificant changes in surface morphology were observed by optical microscopy. Vulcanized rubber made both from natural and from synthetic caoutchouc exposed for the same length of time showed rather evident changes in appearance and structure. X-ray graphical analysis revealed that new crystallization of the caoutchouc and a possible change in

  17. High resolution fossil fuel combustion CO2 emission fluxes for the United States

    Energy Technology Data Exchange (ETDEWEB)

    Gurney, Kevin R.; Mendoza, Daniel L.; Zhou, Yuyu; Fischer, Marc L.; Miller, Chris C.; Geethakumar, Sarath; de la Rue du Can, Stephane

    2009-03-19

    Quantification of fossil fuel CO{sub 2} emissions at fine space and time resolution is emerging as a critical need in carbon cycle and climate change research. As atmospheric CO{sub 2} measurements expand with the advent of a dedicated remote sensing platform and denser in situ measurements, the ability to close the carbon budget at spatial scales of {approx}100 km{sup 2} and daily time scales requires fossil fuel CO{sub 2} inventories at commensurate resolution. Additionally, the growing interest in U.S. climate change policy measures are best served by emissions that are tied to the driving processes in space and time. Here we introduce a high resolution data product (the 'Vulcan' inventory: www.purdue.edu/eas/carbon/vulcan/) that has quantified fossil fuel CO{sub 2} emissions for the contiguous U.S. at spatial scales less than 100 km{sup 2} and temporal scales as small as hours. This data product, completed for the year 2002, includes detail on combustion technology and 48 fuel types through all sectors of the U.S. economy. The Vulcan inventory is built from the decades of local/regional air pollution monitoring and complements these data with census, traffic, and digital road data sets. The Vulcan inventory shows excellent agreement with national-level Department of Energy inventories, despite the different approach taken by the DOE to quantify U.S. fossil fuel CO{sub 2} emissions. Comparison to the global 1{sup o} x 1{sup o} fossil fuel CO{sub 2} inventory, used widely by the carbon cycle and climate change community prior to the construction of the Vulcan inventory, highlights the space/time biases inherent in the population-based approach.

  18. Influence of Reaction-Induced Phase Decomposition to Dispersion of Samariam Acrylic Acid (Sm (AA)3 ) in Rubber and Shielding Property of Sm(AA) 3/NR Composites

    Institute of Scientific and Technical Information of China (English)

    Liu Li; He Lei; Zhang Wan; Yang Cheng; Liu Yandong; Jin Riguang; Zhang Liqun

    2004-01-01

    According to radiation protection theory, the radiation shielding properties of composites are closely related to dispersion condition of radiation absorbing materials in matrix. The more equably radiation-shielding materials dispersed in the matrix, the better the composites' shielding properties are. Rare earth ions have preferably absorbing ability for radiation due to their special electronic structures. From our early work, we know Sm(AA) 3 has good radiationabsorbing ability and excellent compatibility with polymer matrix. Furthermore, Sm (AA) 3 has double key structures which can in-situ react with polymer matrix in vulcanization process. This in-situ reaction can also help Sm(AA) 3 disperse better in the matrix. Based on these, we studied a new method to prepare Sm( AA)3/NR( nature rubber) composites( NR used as matrix), in which Sm(AA)3 dispersed very equably with tiny particle size. Both sulfur and peroxide exist in the system as crosslinking agent. The vulcanization process occurred at the temperature of 110℃ first and a certain degree crosslinking network formed in this stage, which we called pre-vulcanization process in this paper. In this stage sulfur was used as the crosslinking agent. Then continued the vulcanization process at higher temperature(170℃). The peroxide was used as crosslinking agent in this stage. According to reaction-induced phase decomposition mechanism, we studied the phase decomposition changing mode of Sm(AA) 3 in NR matrix of different crosslinking degrees. We also studied the influence of different degrees of pre-vulcanization to the dispersion condition of Sm (AA) 3 in NR matrix. The crystal-fusion status of both Sm(AA) 3 powder and Sm(AA) 3 in cured rubber were observed by DSC (Differential Scanning Calorimetry) and XRD (X-rays Diffraction). The dispersion condition of Sm(AA) 3 in cured rubber was observed by SEM (Scanning Electron Microscopy) and TEM (Transmission Electron Microscope).The studyresults show different

  19. Líquidos iônicos como plastificantes em blendas de borracha nitrílica/polianilina

    Directory of Open Access Journals (Sweden)

    Leandro Prudêncio

    2014-01-01

    Full Text Available Two imidazolium-based ionic liquids (C4MIMTf2N and C4MIMBF4 were used to verify their influence on polyaniline (PANI and nitrile rubber (NBR/PANI blend properties and the vulcanization process. High conductivity values were observed for PANI-C4MIMTf2N samples and no interference was found for the C4MIMBF4 samples. These materials were added to NBR by mechanical mixing. Based on the torque results, the presence of C4MIMBF4 does not protect the vulcanization reaction of NBR with PANI as performed by C4MIMTf2N. The highest conductivity value was obtained with 7 wt. % of PANI-DSBA-C4MIMTf2N (10-6 S/cm. This result is attributed to the more effective interaction of PANI and NBR phases promoted by the ionic liquid.

  20. Polypropylene/natural rubber thermoplastic vulcanizates by eco-friendly and sustainable electron induced reactive processing

    Science.gov (United States)

    Mondal, Manas; Gohs, Uwe; Wagenknecht, Udo; Heinrich, Gert

    2013-07-01

    TPVs are a special class of thermoplastic and elastomer blend where cross-linking of elastomeric phase takes place during melt mixing process known as dynamic vulcanization (DV). A 50/50 blend of natural rubber (NR) and polypropylene (PP) were dynamically vulcanized using Electron Induced Reactive Processing (EIReP) as a function of absorbed dose (150, 250, and 350 kGy) at fixed electron energy (1.5 MeV) and dose per rotation. Different methods like tensile test, DSC, melt rheology, and SEM have been employed to understand the structure-property relationship of the prepared samples. The results suggest that EIReP is a novel technique to offer handful of additional features without compromising the end user property.

  1. Electrochemical durability of heat-treated carbon nanospheres as catalyst supports for proton exchange membrane fuel cells.

    Science.gov (United States)

    Lv, Haifeng; Wu, Peng; Wan, Wei; Mu, Shichun

    2014-09-01

    Carbon nanospheres is wildly used to support noble metal nanocatalysts in proton exchange membrane (PEM) fuel cells, however they show a low resistance to electrochemical corrosion. In this study, the N-doped treatment of carbon nanospheres (Vulcan XC-72) is carried out in ammonia gas. The effect of heating treatment (up to 1000 degrees C) on resistances to electrochemical oxidation of the N-doped carbon nanospheres (HNC) is investigated. The resistance to electrochemical oxidation of carbon supports and stability of the catalysts are investigated with potentiostatic oxidation and accelerated durability test by simulating PEM fuel cell environment. The HNC exhibit a higher resistance to electrochemical oxidation than traditional Vulcan XC-72. The results show that the N-doped carbon nanospheres have a great potential application in PEM fuel cells.

  2. Adsorption behavior of perfluorinated sulfonic acid ionomer on highly graphitized carbon nanofibers and their thermal stabilities

    DEFF Research Database (Denmark)

    Andersen, Shuang Ma; Borghei, Maryam; Dhiman, Rajnish

    2014-01-01

    isotherm), the ionomer has varying affinities for CNFs (Keq. = between 5 and 22) as compared to Vulcan (Keq. = 18), depending on surface treatments. However, the interactions are most likely governed by different adsorption mechanisms depending on hydrophilicity / hydrophobicity of the adsorbent carbon......A systematic adsorption study of perfluorinated sulfonic acid Nafion® ionomer on ribbon type highly graphitized carbon nanofibers (CNFs) was carried out using 19 fluorine nuclear magnetic resonance spectroscopy. Based on the values obtained for the equilibrium constant (Keq., derived from Langmuir....... The ionomer is probably adsorbed via the polar sulfonic group on hydrophilic Vulcan, whereas, it is adsorbed primarily via hydrophobic -CF2- backbone on the highly hydrophobic pristine CNFs. Ionomer adsorption behavior is gradually altered from apolar to polar group adsorption for the acid modified CNFs...

  3. 东京

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    新零售店VULCANIZE LONDON的顶级体验Vulcanize London的经营理念是完全借鉴伦敦的高级购物街而来。超过30种的顶级英国品牌.包括Penhaligons、Liberty和Grenfel.以及其他同等品质的高级服饰品牌,在这个既现代又古典的优雅英伦情调的展示空间里汇聚在一起。每一个品牌的独特内涵和气质都被发挥得淋漓尽致.为日本消费者展现了真正倡导“终身价值”的英式理念。

  4. Preparation and Electrocatalytic Characteristics of PdW/C Catalyst for Ethanol Oxidation

    Directory of Open Access Journals (Sweden)

    Qi Liu

    2015-06-01

    Full Text Available A series of PdW alloy supported on Vulcan XC-72 Carbon (PdW/C with total 20 wt. % as electrocatalyst are prepared for ethanol oxidation by an ethylene glycol assisted method. Transmission electron microscopy (TEM characterization shows that PdW nanoparticles with an average size of 3.6 nm are well dispersed on the surface of Vulcan XC-72 Carbon. It is found that the catalytic activity and stability of the PdW/C catalysts are strongly dependent on Pd/W ratios, an optimal Pd/W composition at 1/1 ratio revealed the highest catalytic activity toward ethanol oxidation, which is much better than commercial Pd/C catalysts.

  5. High surface area graphite as alternative support for proton exchange membrane fuel cell catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira-Aparicio, P.; Folgado, M.A. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Avda. Complutense 22, E-28040 Madrid (Spain); Daza, L. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Avda. Complutense 22, E-28040 Madrid (Spain); Instituto de Catalisis y Petroleoquimica (CSIC), C/Marie Curie, 2 Campus de Cantoblanco, E-28049 Madrid (Spain)

    2009-07-01

    The suitability of a high surface area graphite (HSAG) as proton exchange membrane fuel cell (PEMFC) catalyst support has been evaluated and compared with that of the most popular carbon black: the Vulcan XC72. It has been observed that Pt is arranged on the graphite surface resulting in different structures which depend on the catalysts synthesis conditions. The influence that the metal particle size and the metal-support interaction exert on the catalysts degradation rate is analyzed. Temperature programmed oxidation (TPO) under oxygen containing streams has been shown to be a useful method to assess the resistance of PEMFC catalysts to carbon corrosion. The synthesized Pt/HSAG catalysts have been evaluated in single cell tests in the cathode catalytic layer. The obtained results show that HSAG can be a promising alternative to the traditionally used Vulcan XC72 carbon black when suitable catalysts synthesis conditions are used. (author)

  6. Preparation of Pt Ru/C + rare earths by the method of reduction by alcohol for the electro-oxidation of ethanol; Preparacao de eletrocatalisadores PtRu/C + terras raras pelo metodo da reducao por alcool para a eletro-oxidacao do etanol

    Energy Technology Data Exchange (ETDEWEB)

    Tusi, M.M.; Rodrigues, R.M.S.; Spinace, E.V.; Oliveira Neto, A., E-mail: aolivei@ipen.b, E-mail: espinace@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2010-07-01

    PtRu/C electrocatalyst was prepared in a single step, while that PtRu/85%C-15%Ce, PtRu/85%C-15%La, PtRu/85%C-15%Nd and PtRu/85%C-15%Er electrocatalyst were prepared in a two step. In the first step a Carbon Vulcan XC72 + rare earth supports were prepared. In the second step PtRu electrocatalyst were prepared by an alcohol-reduction process using ethylene glycol as solvent and reducing agent and supported on Vulcan XC72 + earth rare. The obtained electrocatalysts were characterized by EDAX, XRD and chronoamperometry. The electro-oxidation of ethanol was studied by chronoamperometry at room temperature. PtRu/85%C- 15%Ce electrocatalyst showed a significant increase of performance for ethanol oxidation compared to PtRu/C electrocatalyst. (author)

  7. Improvement of the service properties of elastomer compositions by introduction of carbon nanomaterials

    Science.gov (United States)

    Vishnevskii, K. V.; Shashok, Zh. S.; Prokopchuk, N. R.; Krauklis, A. V.; Zhdanok, S. A.

    2012-09-01

    The influence of a carbon nanomaterial obtained in a high-voltage discharge plasma on the endurance of elastomer compositions has been investigated for the first time. The results of these investigations agree with those obtained in determining the parameters of the vulcanization kinetics, conventional tensile strength, relative breaking elongation, and resistance to thermal aging and swelling in liquid hydrocarbon media of highly filled rubbers based on butadiene-nitrile caoutchoucs. To verify the assumed mechanism underlying the action of a carbon nanomaterial on elastomer compositions, the parameters of their vulcanizing network have been determined using the method of equilibrium swelling. It is shown that the introduction of a carbon nanomaterial into polar caoutchouc-based rubber allows one to substantially improve its service characteristics and endurance.

  8. Carbon-Supported Fe Catalysts for CO2 Electroreduction to High-Added Value Products: A DEMS Study: Effect of the Functionalization of the Support

    Directory of Open Access Journals (Sweden)

    S. Pérez-Rodríguez

    2011-01-01

    Full Text Available Vulcan XC-72R-supported Fe catalysts have been synthesised for the electroreduction of CO2 to high-added value products. Catalysts were obtained by the polyol method, using ethylene glycol as solvent and reducing agent. Prior to the metal deposition, Vulcan was subjected to different oxidation treatments in order to modify its surface chemistry and study its influence on the physicochemical and electrochemical properties of the catalysts, as well as on the product distribution. The oxidation treatments of the supports modify their textural properties, but do not affect significantly the physicochemical properties of catalysts. However, DEMS studies showed that the carbon support degradation, the distribution of products, and the catalytic activity toward the CO2 electroreduction reaction depend significantly on the surface chemistry of the carbon support.

  9. Radiation processing of liquid with low energy electron accelerator

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-02-01

    Radiation induced emulsion polymerization, radiation vulcanization of NR latex (RVNRL) and radiation degradation of natural polymers were selected and reviewed as the radiation processing of liquid. The characteristic of high dose rate emulsion polymerization is the occurrence of cationic polymerization. Thus, it can be used for the production of new materials that cannot be obtained by radical polymerization. A potential application will be production of polymer emulsion that can be used as water-borne UV/EB curing resins. The technology of RVNRL by {gamma}-ray has been commercialized. RVNRL with low energy electron accelerator is under development for further vulcanization cost reduction. Vessel type irradiator will be favorable for industrial application. Radiation degradation of polysaccharides is an emerging and promising area of radiation processing. However, strict cost comparison between liquid irradiation with low energy EB and state irradiation with {gamma}-ray should be carried out. (author)

  10. Effects of Prior Aging at 191 C on Creep Response of IM7/BMI 5250-4

    Science.gov (United States)

    2007-06-01

    as 1500 Mayans were using rubber in their everyday lives. In 1839, Charles Goodyear discovered vulcanization, the adding of sulfur to natural rubber... civil aircraft applications. (33:437) Boeing looks to recapture the lead on composite materials usage with its 787 model. The 787 will become the...sets pace for composite usage in large civil aircraft May 2005 http://www.compositesworld.com/hpc/issues/2005/May/865/3 37. Ruggles-Wrenn, M.B

  11. Mixed phase Pt-Ru catalyst for direct methanol fuel cell anode by flame aerosol synthesis

    DEFF Research Database (Denmark)

    Chakraborty, Debasish; Bischoff, H.; Chorkendorff, Ib

    2005-01-01

    A spray-flame aerosol catalyzation technique was studied for producing Pt-Ru anode electrodes for the direct methanol fuel cell. Catalysts were produced as aerosol nanoparticles in a spray-flame reactor and deposited directly as a thin layer on the gas diffusion layer. The as-prepared catalyst......Ru1/Vulcan carbon. The kinetics of methanol oxidation on the mixed phase catalyst was also explored by electrochemical impedance spectroscopy. (c) 2005 The Electrochemical Society....

  12. Isolation of Microorganisms Able To Metabolize Purified Natural Rubber

    OpenAIRE

    Heisey, R. M.; Papadatos, S

    1995-01-01

    Bacteria able to grow on purified natural rubber in the absence of other organic carbon sources were isolated from soil. Ten isolates reduced the weight of vulcanized rubber from latex gloves by >10% in 6 weeks. Scanning electron microscopy clearly revealed the ability of the microorganisms to colonize, penetrate, and dramatically alter the physical structure of the rubber. The rubber-metabolizing bacteria were identified on the basis of fatty acid profiles and cell wall characteristics. Seve...

  13. Pengaruh Penambahan Alkanolamida Terhadap Karakteristik Pematangan Dan Kekerasan Vulkanisat Karet Alam Berpengisi Kaolin

    OpenAIRE

    Sitorus, Indah Maulina Syafitri

    2014-01-01

    By using a semi-efficient sulphur accelerated vulcanization system, an investigation of the effect of alkanolamide on cure characteristics and hardness properties of kaolin-filled natural rubber compounds was carried out. Alkanolamide was synthesized from Refined Bleached Deodorized Palm Stearin (RBDPS) and diethanolamine. Alkanolamide was incorporated into the kaolin filled-natural rubber compound at 1.0; 3.0; 5.0 and 7.0 Parts per-Hundred Rubber (phr). It was found that alkanolamide gave...

  14. Antifungal Sealing Rings - A New Approach

    Science.gov (United States)

    1977-10-01

    standard conditions (19,20). The properties of the O-rings were determined on an Instron Model 1026 tensometer using a motorised specimen holder drive unit...dismantled for modi- fication or servicing, adhesive strength between rubber and substrate should 4 bý. weak- All these factor& were assessed as part of...Marine Coatings. Part II: Marine Biocidal Rubbers Containing Organotin Toxics. M.R.L. Report 496. 13. - . (1963). Vulcanized Polychloroprene Rubbers for

  15. Distribución de elementos traza en el registro de la Turbera de Roñanzas (Asturias, España)

    OpenAIRE

    Torres Pérez-Hidalgo, Trinidad José

    2009-01-01

    The Pb, Zn and Hg concentrations in the peat-bog samples of the Roñanzas record, that covers the last 8000 cal. BP, reveal a relationship with natural processes (climate, vulcanism) together with the atmospheric pollution linked to ancient minning, industrial activities, and agricultural development in northern Spain. There are metal enrichments along the peat profile probably related to the Roman Period, after 1700 AD and the Industrial Revolution and, in some cases, during the V...

  16. The Utilization of Advanced Composites in Military Aircraft Held in San Diego, California on 7-11 October 1991 (L’Emploi des Materiaux Composites de Pointe pour les Avions Militaires)

    Science.gov (United States)

    1992-04-01

    performed with: P = C.05 Tes!: Frequency x 2.5 Fz. rLL r Design Limit LA U S Fiq.l0 LOAD S1KIR[CIRM F’OR IATIGU[ TESI I.2-II COMPRESSION :1I:T:AL Bt,’C...Aerospace Series, Fluids for Assessment of Non-Metallic Materials. :3. ISO 1817 Rubber, Vulcanized -Effect of Liquids. 13-4 FLUID INTERACTIONS a7 0 6

  17. Methodology and Criteria for Accurately Determining Logistics Assistance Manpower Requirements.

    Science.gov (United States)

    1982-09-01

    L *3 2.2 11111L2 1.8IIN 5*IIII1 1.6ll MICROCOPY RESOLUTION TESI CHART NA YIAL KL0il !IN "I! ~ . A Bf LOGISTOC STUDIS OFFICE PROJECT NUMBER 028 1...one ARRCOM position is mostly used to support the VULCAN gun, and one TACOM position is in support of construction equipment. In each MSC the

  18. The Battalion Decision Aid: A Kernel Decision Support System

    Science.gov (United States)

    1989-06-01

    RECON PLT E Co 1/33 INF (ITV) 4.1 MORTOR PLY B Co 1140 AR (MI) 1-2 Seo SPLT 8 Co 258 ADA (STINGER) C Co 1/40 AR ftl) 1-2 Sea 8PLT A Co 266 ADA ( VULCAN ...number) / TESIS CRAINW: JOBN R. VALUSEK Lt Col USAFASaTA L NOSSOR Of 6Pm11Ioy RESEARC ABSTRACT: SEE REVERSE SIDE. 20 DISTRIBUTION /AVAILABILITY OF

  19. Advanced Bristle Seals for Gas Turbine Engines

    Science.gov (United States)

    1993-01-28

    test sequence I retained the .003 inch shim and added a positive seal between the shim stock and the housing using Room Temperature Vulcanizing (RTV...113.4 200 6 1.131 1.040 175.142 0.219 * STANDARD CUBIC FOOT PER MINUTE u FLOW(cfm) OF AIR 2 70F/14.7psil TABLE C-8. TESI SEQUENCE H DATA "H. STATIC

  20. Research of Air Cathodes for Aluminum Air Batteries

    Science.gov (United States)

    2006-05-31

    Catalysts used in the existing cathodes include: platinum, silver, manganese and cobalt . Ruthenium is known for its catalytic ability and has received much...manganese, silver, cobalt , platinum, and ruthenium. The carbons used were Black Pearls 2000, proprietary carbons, Vulcan XC-72R, and Vapor Grown...discharge, the dissolved aluminate ion produced in this reaction precipitates out as crystalline hydrargillite (aluminum hydroxide): In addition to

  1. Characteristics and utilization of thermoplastic elastomers (TPE)-an overview

    Energy Technology Data Exchange (ETDEWEB)

    Roestamsjah [R and D Center for Applied Chemistry, Indonesian Inst. of Sciences (Indonesia)

    1998-10-01

    The unique feature of thermoplastic elastomer, the combining of processing characteristics of thermoplastics with the physical properties of vulcanized rubber is reviewed. Highlights of TPE and its characteristics is aimed to generate interest in TPE, where SANS technique will be utilized for its characterization. The topics discussed include rubber elasticity, state of aggregation of polymers, microseparation in block copolymer system, application of TPE, and finally some notes in developing interest in TPE and SANS in Indonesia. (author)

  2. The Physical Modification of a Natural Rubber-Polypropylene Thermoplastic Elastomer Blend by Azobisformamide Blowing Agent

    OpenAIRE

    Safia Merabet; Farid Riahi; Abdelmalek Douibi

    2012-01-01

    The decomposition of azobisformamide (ABFA) blowing agent and its expansion in a soft grade of thermoplastic natural rubber composed of a 70/30 natural rubber (NR)/polypropylene (PP) was monitored using a Haake plasticorder. The aim of the study was to evaluate the effect of different concentrations of the blowing agent and to investigate its eventual interactions with a sulfur-based curing system that was used for the dynamic vulcanization. The plastograms allowed to detect variations in the...

  3. Effect of gamma irradiation on the properties of natural rubber/styrene butadiene rubber blends

    OpenAIRE

    A.B. Moustafa; Rania Mounir; A.A. El Miligy; Maysa A. Mohamed

    2016-01-01

    Blends of natural rubber (NR) with styrene butadiene rubber (SBR) with varying ratios have been prepared. Vulcanization of the prepared blends has been induced by irradiation of gamma rays with varying doses up to 250 kGy. Mechanical properties, namely tensile strength, tensile modulus at 100% elongation, elongation at break have been followed up as a function of irradiation dose as well as blend composition. Physical properties, namely gel fraction and swelling number have been followed up u...

  4. Pengaruh Temperatur Vulkanisasi Terhadap Kekuatan Tarik (Tensile Strength) Pada Packing Pintu Rebusan PT. Industri Karet Nusantara Medan

    OpenAIRE

    Ayutami, Rizki

    2012-01-01

    In this paper will discuss how is the influence of temperature vulcanization which in used at Rubber Articles Factory in PT. Rubbin Industry Nusantara Medan. The start with selection raw materials natural rubber and synthetic rubber in used until became rubber articles. The variety rubber which in used to produce rubber articles is rubber smoke sheet, there for variety synthetic rubber which used is SBR (Styrine Butadine Rubber). At the first process, main material rubber and chemical is mixe...

  5. Adhesion of nitrile rubber (NBR) to polyethylene terephthalate (PET) fabric. Part 1: PET surface modification by methylenediphenyl di-isocyanate (MDI)

    Energy Technology Data Exchange (ETDEWEB)

    Razavizadeh, Mahmoud; Jamshidi, Masoud, E-mail: mjamshidi@iust.ac.ir

    2016-01-01

    Graphical abstract: - Highlights: • Glutaric anhydride peroxide (GAP) was grafted on PET surface by UV irradiation method. Then MDI was attached to GAP on PET surface. • The fabric was vulcanized by nitrile rubber. • Peet test was performed after each stage of surface modification. • Curing temperature was increased and the tests were repeated. • Effect of MDI coating on PET without carboxylation was evaluated. Effect of vulcanizing temperature on this product was also studied. - Abstract: Fiber to rubber adhesion is an important subject in rubber composite industry. It is well known that surface physical, mechanical and chemical treatments are effective methods to improve interfacial bonding. Ultra violet (UV) light irradiation is an efficient method which is used to increase interfacial interactions. In this research UV assisted chemical modification of PET fabric was used to increase its bonding to nitrile rubber (NBR). NBR is perfect selection to produce fuel and oil resistant rubber parts but it has weak bonding to fabrics. For this purpose at first, the PET fabric was carboxylated under UV irradiation and then methylenediphenyl diisocyanate (MDI) was reacted and grafted to carboxylated PET. T-peel test was used to evaluate PET fabric to NBR bonding strength. Attenuated total reflectance-Fourier transform infrared spectroscopy (FTIR-AT) was used to assess surface modifications of the PET fabrics. The chemical composition of the PET surfaces before and after carboxylation and MDI grafting was investigated by X-ray photoelectron spectroscopy (XPS). It was found that at vulcanizing temperature of 150 °C, carboxylation in contrary to MDI grafting, improved considerably PET to NBR adhesion. Finally effect of curing temperature on PET to NBR bonding strength was determined. It was found that increasing vulcanizing temperature to 170 °C caused considerable improvement (about 134%) in bonding strength.

  6. Surface degradation of silicone rubber exposed to corona discharge

    OpenAIRE

    Zhu, Yong; Haji, Kenichi; Otsubo, Masahisa; Honda, Chikahisa

    2006-01-01

    This paper describes the surface degradation of unfilled high-temperature vulcanized silicone rubber (HTV-SR)###resulting from creeping corona discharges under atmospheric pressure. In this paper, HTV-SR specimens were exposed to corona###stress generated by a parallel needle-plate electrode system; furthermore, physicochemical analyses were conducted on the surface layer of SR before and after corona discharge treatment. The results showed that the plasma impingement from the corona discharg...

  7. Evaluation of Membrane Interlayers for Prevention of Crack Reflection in Thin Overlays.

    Science.gov (United States)

    1981-10-01

    25 per- cent granulated crumb rubber (100 percent vulcanized) with 75 percent asphalt. About 5 to 7 percent kerosene is normally added to this mix...resulting from case studies of pavement performance conducted by the U. S. Army Engineer Waterways Experiment Station as requested by the U. S. Army...Forces Command, Fort McPherson, Ga. The pur- pose of this study was to determine if a layer consisting of an asphalt- rubber membrane or a nonwoven fabric

  8. STEEL CORD WITH A COMPLETE PENETRATION OF COMPOUND INTO THE STRUCTURE

    Directory of Open Access Journals (Sweden)

    A. V. Vedeneev

    2011-01-01

    Full Text Available It is shown that one of the perspective types of metal cord for breaker layer of automobile tires are the constructions with maximal degree of rubber compound penetration at vulcanization. the constructions and technologies of metal cord productions with full rubber penetration (FrP already in the process of treatment into rubber-cord cloth are developed at RUP “BMZ”.

  9. Penelitian “rubber blend” antara karet alam rss dengan karet sintesis jsr 0061 untuk sol ringan sesuai sni 12-0778-1989

    Directory of Open Access Journals (Sweden)

    Penny Setyowati

    1997-12-01

    Full Text Available The objective of this research is to find composision of rubber blend of RSS and JSR 0061 and Carbon black for preparation light rubber sole compound and stabile on high process temperature that give the best fisical properties and the best sole product at moulding vulcanization trial. The best rubber compound to be reached at the compound formulation R III with composision of RSS 90 phr, JSR 0061 10 phr dan carbon black 40 phr.

  10. Thermal Stability and Flammability of Styrene-Butadiene Rubber-Based (SBR) Ceramifiable Composites

    OpenAIRE

    Rafał Anyszka; Dariusz M. Bieliński; Zbigniew Pędzich; Przemysław Rybiński; Mateusz Imiela; Mariusz Siciński; Magdalena Zarzecka-Napierała; Tomasz Gozdek; Paweł Rutkowski

    2016-01-01

    Ceramifiable styrene-butadiene (SBR)-based composites containing low-softening-point-temperature glassy frit promoting ceramification, precipitated silica, one of four thermally stable refractory fillers (halloysite, calcined kaolin, mica or wollastonite) and a sulfur-based curing system were prepared. Kinetics of vulcanization and basic mechanical properties were analyzed and added as Supplementary Materials. Combustibility of the composites was measured by means of cone calorimetry. Their t...

  11. 爱克发Vulcan橡皮布系列

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    一般应用 Vulcan 714 Plus 适用范围广泛,包括平张印刷机、轮转机、包装印刷机以至连续报表印刷机 容易使用 具有极低的网点扩印率及丰富的阶调,印刷质素

  12. Understanding Core-Collapse Supernovae

    CERN Document Server

    Burrows, A

    2004-01-01

    I summarize, in the form of an extended abstract, the ongoing efforts at the University of Arizona (and in collaboration) to understand core-collapse supernovae theoretically. Included are short discussions of 1D (SESAME) and 2D (VULCAN/2D) codes and results, as well as discussions of the possible role of rotation. Highlighted are recent developments in multi-dimensional radiation hydrodynamics and the essential physics of the neutrino-driven mechanism.

  13. An Experimental Investigation Studying the Influence of Dimples on a Film Cooled Turbine Blade Leading Edge

    Science.gov (United States)

    2009-03-01

    Room Temperature Vulcanizing (RTV) silicone sealant was used to attach the heat flux plate to the surface of the model while carefully aligning...was negligible. 4.2 RECOMMENDATIONS FOR FUTURE RESEARCH This scientific investigation was able to demonstrate that dimples placed upstream of a film...Education Limited. Harlow, England, 2001. 3. Han, J.-C. “Turbine Blade Cooling Studies at Texas A&M University: 1980-2004,” Journal of

  14. Military Training Lands Historic Context: Large Arms Ranges

    Science.gov (United States)

    2010-03-01

    to five 2.75-in. rocket motors for propulsion. The system became operational in 1972 and was used for training Vulcan , Chaparral, and Redeye gunners...superpowers. 2. Through the architectural or engineering design, they clearly reflect one of the Cold War themes: a. Basic Scientific Research (Laboratories...Historians Journal . Vol 52, No.1 http://en.wikipedia.org/wiki/Anti-aircraft_artillery U.S. Army Corps of Engineers. St. Louis District. 2006. Range

  15. Ionic Liquids Applied to Improve the Dispersion of Coagent Particles in an Elastomer

    OpenAIRE

    Magdalena Maciejewska; Marian Zaborski

    2013-01-01

    The aim of this work was to study the activity of several ionic liquids (alkylimidazolium salts) that are used to improve the dispersion of coagent particles in peroxide-cross-linked hydrogenated acrylonitrile butadiene elastomer (HNBR). Hydrotalcite grafted with monoallyl maleate was applied as a coagent for the HNBR vulcanization. In this paper, we discuss the effect of the ionic liquids (alkylimidazolium salts) with respect to their anion (bromide, chloride, tetrafluoroborate, and hexafluo...

  16. Computational Analysis of Geometric Effects on Strut Induced Mixing in a Scramjet Combustor

    Science.gov (United States)

    2009-03-01

    NASA also aided in the understanding of how VULCAN worked. Thanks to my advisor, Dr. Robert Greendyke, and the rest of the AFIT faculty for imparting...Magre, A. Bresson , F. Grisch, M. Orain, and M. Kodera, “Exper- imental study of strut injectors in a supersonic combustor using oh-plif,” AIAA Paper...OF RESPONSIBLE PERSON Dr. Robert Greendyke Associate Professor a. REPORT U b. ABSTRACT U c. THIS PAGE U 19b. TELEPHONE NUMBER (Include

  17. A qualitative ecosystem assessment for different shrublands in western Europe under impact of climate change

    DEFF Research Database (Denmark)

    Wessel, W.W.; Tietema, A.; Beier, C.

    2004-01-01

    of field manipulation experiments of the CLIMOOR and VULCAN projects. Goods and services of these shrublands mainly encompass biodiversity, various forms of recreation, conservation of culturally and historically important landscapes, groundwater as a drinking water source, and carbon sequestration...... vegetation. Similarly, warming increases and drought decreases the chances of nitrate pollution to the groundwater, which is often used as a drinking water source. Warming of the upland heathland in the UK increases its productivity, which might enable higher grazing densities leading to improved...

  18. Assessment of Acute Toxicity of Hexachloroethane in Laboratory Animals

    Science.gov (United States)

    1978-01-09

    camphoraceous odor, readily sublimes without meltinq and is solubl,: in alcohol. benzene, chloroform, ether and oil: insoluble in water. It is used as a solvent...in explosives, as ý camphor suostitute in celluloid, and as a rubber vulcanizing accelerator.’ It is used in veterinary practice as an anthelminthic...moderately toxic orally, produced reversible eye irritation and little or no skin irritation. Although it sublimes at room temperature

  19. Effect Of Operating Conditions On Scrap Tire Pyrolysis

    OpenAIRE

    Carla Fabiana Scatolim Rombaldo; Antonio Carlos Luz Lisbôa; Manoel Orlando Alvarez Méndez; Aparecido dos Reis Coutinho

    2008-01-01

    The ever growing focus on environmental issues has raised concerns about scrap tires, whose major component - vulcanized rubber - does not degrade easily. When burned, tires release toxic gases containing substantial amounts of sulfur and ammonia in addition to other pollutants. Dumped on empty city lots, tires are also a breeding ground for mosquitoes. Many proposals have been put forward to handle the disposal of scrap tires, but none of them have proved to offer a definitive solution. The ...

  20. Investigation of Spray-Applied Polyurethane Foam Roofing Systems-II

    Science.gov (United States)

    1990-09-01

    CA MARCOR BASE / PWO, Camp Pendleton, CA ELASTPORT INTI., INC / Jil Osborn, Mgr, Ventura , CA MARCORBASE / PWO, Camp Lejeune, NC ED)WARD) K NODA...Code 1121 (EA Silva ), Arlington, VA SAN DIEGO STATE UNIV /CE Dept (Noorany), San Diego, CA OCNR / Code 1234, Arlington, VA SCIENCE APPS INTL CORP...VAN ALLEN, B / Kingston, NY VENTURA COUNTY / Deputy PW Dir, Ventura , CA VENTURA COUNTY I PWA (Brownie), Ventura , CA VERNON KUEHN / Lakewood, CO VULCAN

  1. Innovative Application of Biopolymer Keratin as a Filler of Synthetic Acrylonitrile-Butadiene Rubber NBR

    OpenAIRE

    Mirosława Prochoń; Anita Przepiórkowska

    2013-01-01

    The current investigations show the influence of keratin, recovered from the tanning industry, on the thermal and mechanical properties of vulcanizates with synthetic rubber acrylonitrile-butadiene rubber NBR. The addition of waste protein to NBR vulcanizates influences the improvement of resistance at high temperatures and mechanical properties like tensile strength and hardness. The introduction of keratin to the mixes of rubber previously blended with zinc oxide (ZnO) before vulcanization ...

  2. Compréhension des mécanismes de modification de surface d’élastomères non réticulés consécutifs à une exposition plasma et ses conséquences sur le comportement adhésif

    OpenAIRE

    Henry, Alicia

    2015-01-01

    Plasma treatment has become a powerful candidate to modify surface properties without any change in bulk properties. It combines high chemical reactivity with low operational costs, in environmentally friendly processes. Plasma treatment has been intensively applied for surface modification of vulcanized rubbers. Almost no studies have been dedicated to plasma treatment of unvulcanized rubbers. The role of each additive during plasma exposure is poorly understood. It is also admitted that sur...

  3. Asphaltenes-based polymer nano-composites

    Science.gov (United States)

    Bowen, III, Daniel E

    2013-12-17

    Inventive composite materials are provided. The composite is preferably a nano-composite, and comprises an asphaltene, or a mixture of asphaltenes, blended with a polymer. The polymer can be any polymer in need of altered properties, including those selected from the group consisting of epoxies, acrylics, urethanes, silicones, cyanoacrylates, vulcanized rubber, phenol-formaldehyde, melamine-formaldehyde, urea-formaldehyde, imides, esters, cyanate esters, allyl resins.

  4. Natural rubber: leather composites

    OpenAIRE

    K. Ravichandran; N. Natchimuthu

    2005-01-01

    Leather is a fibrous protein consisting of collagen in a three dimensionally crosslinked network. Chrome tanning of leather improves the appearance of leather but at the same time emits both solid and liquid chrome leather wastes. Scrap rubber recycling using untreated and neutralized leather fibrous particles in natural rubber has been studied. Vulcanization, mechanical, morphological and swelling properties of the natural rubber - scrap rubber composites containing neutralized leather have ...

  5. Validation of the NCC Code for Staged Transverse Injection and Computations for a RBCC Combustor

    Science.gov (United States)

    Ajmani, Kumud; Liu, Nan-Suey

    2005-01-01

    The NCC code was validated for a case involving staged transverse injection into Mach 2 flow behind a rearward facing step. Comparisons with experimental data and with solutions from the FPVortex code was then used to perform computations to study fuel-air mixing for the combustor of a candidate rocket based combined cycle engine geometry. Comparisons with a one-dimensional analysis and a three-dimensional code (VULCAN) were performed to assess the qualitative and quantitative performance of the NCC solver.

  6. EFFECTS OF SOME PHENYLETHYNYLSILICON COMPOUNDS ON HEAT-CURABLE SILICONE RUBBER Ⅲ 1,1,3,3-TETRAMETHYL- 1,3-DIPHENYLETHYNYL-DISILOXANE

    Institute of Scientific and Technical Information of China (English)

    FENG Shengyu; YU Shuqi; LI Shijun; ZHANG Shengyou; CHEN Jianhua; DU Zuodong

    1995-01-01

    We have shown that some phenylethynylsilicon compounds are good cure crosslinkers of heat-curable silicone rubber(HCSR). In this paper the effects of 1,1,3,3-tetramethyl1,3-diphenylethynyldisiloxane (TMDPDS) as a crosslinker on HCSR were studied. The vulcanizates with fine mechanical properties could be obtained with suitable amounts of TMDPDS. Sol fractions, and crosslinking density of vulcanizates and vulcanization retardation effect of TMDPDS on hydrosilation curing silicone rubber were also discussed.

  7. Widget and Mobile Technologies a Forcing Function for Acquisition Change: Paradigm Shift Without Leaving Bodies Behind

    Science.gov (United States)

    2012-04-30

    the automation officer for the 32nd AADCOM in Darmstadt, Germany. He then served as a chaparral platoon leader, vulcan platoon leader, maintenance... California , San Diego, with a Bachelor of Science in electrical engineering. She has since served as an electronics engineer in the Information...and allow program offices to evaluate applications with the goal of selecting capabilities for Programs of Record. Introduction The Department of

  8. Military Cost-Benefit Analysis: Introducing Affordability in Vendor Selection Decisions

    Science.gov (United States)

    2011-04-30

    unlimited. Prepared for the Naval Postgraduate School, Monterey, California 93943 Disclaimer: The views represented in this report are those of... Chaparral Platoon Leader, Vulcan Platoon Leader, Maintenance Officer and Executive Officer in C Battery, 108th Brigade, Hahn Air Force Base, Germany...êÅÜW=`ob^qfkd=pvkbodv=clo=fkclojba=`e^kdb==== - 410 - = = Introduction This study focuses on the growing global challenge of affordability

  9. Mechanical Properties of Polymers Used for Anatomical Components in the Warrior Injury Assessment Manikin (WIAMan) Technology Demonstrator

    Science.gov (United States)

    2016-07-01

    speeds and therefore do not address vertical loading rates of interest to the military to simulate underbody blasts (UBBs) generated from mines or...XL-10216-E-1 Custom- compounded vulcanized elastomer 1.46 75 Shore A Compliant elements in spine and tibia FD-70 BJB Enterprises 2-part semi...1.41 81 Shore D Calcaneus cap The materials in Table 1 are arranged by their durometer category (Shore A or Shore D). The 6 polyurethanes are all

  10. Lem kompon karet untuk sepatu kulit yang dibuat dengan proses vulkanisasi

    Directory of Open Access Journals (Sweden)

    Herminiwati Herminiwati

    2008-12-01

    Full Text Available The purpose of this research was to find rubber compound adhesive formula for preparing leather shoes of direct vulcanizing process. Leather shoes manufactured by vulcanizing process need a suitable rubber compound adhesive for joining the leather uppers and unvulcanized rubber compound soles. The amount of tackifier in rubber compound adhesive influence the adhesive bonding strength. In preparing the adhesive formula, the effect of coumarone resin addition as tackifier were varies in the mount of 5 , 10 and 15 phr respectively. Rubber compound adhesive was produced by two roll mill machine, after that compound were dissolved in wash benzene with ratio 1 : 10. The prepared adhesive then was applied to manufacture leather shoes using vulcanization moulding at temperature 1700 C and 150 kg/cm2 pressure for 8 minutes. The best adhesive formula could be as the following : natural rubber 100 phr, calcium silicate 5 phr, coumarone resin 10 phr, zinc oxide 10 phr, stearic acid 2 phr, AOSP 2 phr, MBTS 0,8 phr; TMTD 0,2 phr and sulphur 2 phr. The best formula had the peeling strength of the outsole 65,25 kg, peeling strength of the insole 1553 g/cm, and could meet the requirements of JIS 5050, 1984 for Leather shoes. Viscosity of the formula was 2250 cp.

  11. TG/FT-IR characterization of additives typically employed in EPDM formulations

    Directory of Open Access Journals (Sweden)

    Natália Beck Sanches

    2015-06-01

    Full Text Available AbstractThermogravimetric analysis coupled to Fourier transform infrared spectroscopy (TG/FT-IR is a very popular technique for rubbers characterization. It involves analyses of the base polymer and additives. Ethylene–propylene–diene (EPDM rubbers are frequently investigated by TG/FT-IR; however, the focus has been the degradation temperature range of the polymer. In this study, unvulcanized and vulcanized EPDM rubber and its additives were investigated by TG/FT-IR, without solvent extraction, and in a wide temperature range. Initially, the additives were individually characterized. TG/FT-IR identified the characteristic groups of all the additives analyzed and distinguished them from each other. Afterwards, unvulcanized and vulcanized EPDM rubbers were investigated without prior extraction.TG/FT-IR detected absorptions due to the additives tetramethylthiuram monosulfide and 2-mercaptobenzothiazole. Both of these sulfur-containing additives were present in the EPDM formulation at concentrations of 0.7 phr (0.63 wt %. The TG/FT-IR technique had some limitations, because not all the additives in EPDM rubber were detected. Paraffin oil, stearic acid and 2,2,4-trimethyl-1,2-dihydroquinoline functional groups were not observed in either the unvulcanized or vulcanized EPDM. Nevertheless, in addition to the ability of this method to detect sulfur-containing groups, the lack of a pre-extraction reduces the time and effort required for additive analysis in rubbers.

  12. Avaliação de bis(4-metilfenilditiocarbimatozincato(II de tetrabutilamônio como acelerador em composições de borracha natural Evaluation of tetrabutyl ammonium bis(4-methylphenyldithiocarbimatozincate(II as accelerator in natural rubber (NR compounds

    Directory of Open Access Journals (Sweden)

    Roberta M. Mariano

    2008-01-01

    Full Text Available Neste trabalho a substância ZNIBU [bis(4-metilfenilditiocarbimatozincato(II de tetrabutilamônio] foi usada em formulações de borracha natural (NR e o seu efeito como acelerador de vulcanização foi investigado. As composições, vulcanizadas com a substância em questão, foram submetidas a testes mecânicos e os resultados comparados com os de outras composições vulcanizadas com os aceleradores comerciais CBS (N-ciclohexil-2-benzotiazol-2-sulfenamida, TMTD (dissulfeto de tetrametiltiuram e MBTS (dissulfeto de benzotiazol. Propriedades como dureza, resiliência e densidade foram avaliadas em presença ou não da carga negro de fumo.The acceleration potential of ZNIBU [tetrabutyl ammonium bis(4-methylphenyldithiocarbimatozincate(II] in the vulcanization process of natural rubber compounds was investigated. The vulcanized compounds were tested for hardness, resilience and density and compared with those vulcanized with commercial accelerators such as CBS (N-cyclohexyl-2-benzothiazolesulphenamide, TMTD (tetramethyl thiuram disulphide and MBTS (dibenzothiazole disulphide. The new accelerator tested was found to be too slow for a commercial application, but its properties were similar to those of other accelerators.

  13. Study on the structure-properties relationship of natural rubber/SiO2 composites modified by a novel multi-functional rubber agent

    Directory of Open Access Journals (Sweden)

    S. Y. Yang

    2014-06-01

    Full Text Available Vulcanization property and structure-properties relationship of natural rubber (NR/silica (SiO2 composites modified by a novel multi-functional rubber agent, N-phenyl- N'-(γ-triethoxysilane-propyl thiourea (STU, are investigated in detail. Results from the infrared spectroscopy (IR and X-ray photoelectron spectroscopy (XPS show that STU can graft to the surface of SiO2 under heating, resulting in a fine-dispersed structure in the rubber matrix without the connectivity of SiO2 particles as revealed by transmission electron microscopy (TEM. This modification effect reduces the block vulcanization effect of SiO2 for NR/SiO2/STU compounds under vulcanization process evidently. The 400% modulus and tensile strength of NR/SiO2/STU composites are much higher than that of NR/SiO2/TU composites, although the crystal index at the stretching ratio of 4 and crosslinking densities of NR/SiO2 composites are almost the same at the same dosage of SiO2. Consequently, a structure-property relationship of NR/SiO2/STU composites is proposed that the silane chain of STU can entangle with NR molecular chains to form an interfacial region, which is in accordance with the experimental observations quite well.

  14. Two-dimensional, Time-dependent, Multi-group, Multi-angle Radiation Hydrodynamics Test Simulation in the Core-Collapse Supernova Context

    CERN Document Server

    Livne, E; Walder, R; Lichtenstadt, I; Thompson, T A; Livne, Eli; Burrows, Adam; Walder, Rolf; Lichtenstadt, Itamar; Thompson, Todd A.

    2004-01-01

    We have developed a time-dependent, multi-energy-group, and multi-angle (S$_n$) Boltzmann transport scheme for radiation hydrodynamics simulations, in one and two spatial dimensions. The implicit transport is coupled to both 1D (spherically-symmetric) and 2D (axially-symmetric) versions of the explicit Newtonian hydrodynamics code VULCAN. The 2D variant, VULCAN/2D, can be operated in general structured or unstructured grids and though the code can address many problems in astrophysics it was constructed specifically to study the core-collapse supernova problem. Furthermore, VULCAN/2D can simulate the radiation/hydrodynamic evolution of differentially rotating bodies. We summarize the equations solved and methods incorporated into the algorithm and present results of a time-dependent 2D test calculation. A more complete description of the algorithm is postponed to another paper. We highlight a 2D test run that follows for 22 milliseconds the immediate post-bounce evolution of a collapsed core. We present the r...

  15. The investigation of influence of adhesion promoters on adhesion bond between vulcanisate and zinc coated steel cord in products based on mixtures of natural and 1,4-cis-polybutadiene rubber

    Directory of Open Access Journals (Sweden)

    Gojić Mirko T.

    2007-01-01

    Full Text Available The mixtures of elastomer compounds based on natural and 1,4-cispolybutadiene rubber of 80:20 ratio, were used for the investigation of adhesion promoters influence on adhesion of vulcanisate to steel cord. Ni-stearate and resorsynol-formaldehyde resin combined with hexamethylenetetramine in various mass ratios were included as adhesion promoters. Elastomer mixtures were prepared using a laboratory double mill, and the rheological and vulcanization characteristics were examined on a vulcameter provided with an oscillating disc, a higher temperature of 145 °C. The crosslinking of the mixture was carried out by press, at a temperature of 145 °C and specific pressure of 40 bar, in period of 45 minutes. A wide number of standardized methods for physical mechanical characterization of vulcanization prior and after accelerated aging were used. The adhesion of vulcanizate bond with zinc coated steel cord was determined according to the so called H-test, by measuring the pulling-out force of the cord from the vulcanized block, and the degree of coverage of cord with vulcanizate after separation. The results of examinations show significant dependence of physico-mechanical characteristics and adhesion forces on the type and amount of used adhesion promoters in experimental elastomer mixtures.

  16. Penelitian penggunaan paraffinic oil pertamina sebagai minyak pelunak kompon karet untuk sol sepatu kanvas

    Directory of Open Access Journals (Sweden)

    Sofyan Karani

    1992-12-01

    Full Text Available The objective of the research is to use parafinic oil, by product of Pertamina, as a softener in making rubber sole compound for canvas shoes. The formula of the compound applled two kinds of parafinic oil, namely paraffinic 60 and paraffinic 95 with variation 2-8 phr. The mastication and mixing processes used two roll mill machine and the compound was vulcanized at 150 0C, at the pressure 150 kg/cm2 and 10 minutes curing time. The comformityt of softener, paraffinic oil, is excellent and no oil exist to the surface of the vulcanized compound. The property of the vulcanized compound fulfilled all the quality requirements of SNI 0778-89-A and SNI 1844 – 90 – A for canvas shoe rubber sole, except abrassion for sport shoe (max. 1.00 mm3/kgm compared with the result of the tes, 1.36 – 2.32 mm3/kgm. Data analysed proves that the addition of paraffinic oil in rubber compound decreased tear strenght and tensile strenght. The properties of elongation at break, permanent set, hardness, abrassion, density and flexing not significant defferences between kinds, types and the treatment of paraffinic oil Pertamina as a softener in rubber compound.

  17. Penelitian penggunaan minarex pertamina sebagai minyak pelunak kompon karet untuk sol sepatu kanvas

    Directory of Open Access Journals (Sweden)

    Sofyan Karani

    1995-06-01

    Full Text Available The objective of the research is to use minarex, by product of Pertamina, as a softener in making rubber sole compound for canvas shoes. The formula of the compound applied four kinds of minarex, manely minarex A, B, C and D with variation 2 – 8 phr. The mastication and mixing processes used two roll mill machine and the compound was vulcanized at 150 oC, at the pressure 150 kg/cm2and 10 mnutes curing time. The comformityt of softener, minaret, is excellent and no oil exist to the surface of the vulcanized compound. The property of the vulcanized compound fulfilled all the quality requirements of SNI 0778-89- A and SNI 1844-90-A for canvas shoe rubber sole, except abrasion for sport shoe (max. 1.00 mm3/ kgm compared with the result of the test, 1.52 – 2.35 mm3/kgm. Data analysed proves the to kinds of minarex to influence all properties in rubber compounds. While treatment of minarex to inflience the properties of elongation at break, permanent set and hardness. The type of minarex to influince properties of the tear strength, abrasion and density to rubber compound.

  18. Pemanfaatan ter sebagai softener dalam pembuatan karet riklim

    Directory of Open Access Journals (Sweden)

    Arum Yuniari

    2006-07-01

    Full Text Available The aims of this research was to study the effect of Coal Tar as softener for reclaim rubber production from waste of rubber of tyre rethreading as input materials was scrap rubber. Coal Tar as softener was used with variation; 2,5; 5; 7,5; 10; 12,5 and 15% respectively from total scrap rubber. Reclaimed rubber was made at temperature 1200C for 1 hour in autoclave and than it was subsequently ground with two rolls mills. The characteristics of the reclaimed rubber was tested for the vulcanization and physical properties. The results showed that Coal Tar could be utilized as softener for reclaimed rubber. Reclaimed rubber production containing Coal Tar 15% would give good vulcanization and physical properties. The vulcanization 1062 seconds, maximum torque 39,08 kgf-cm, minimum torque 4,71 kgf-cm. Good physical properties : tensile strength 80,74 kg/cm2 elongation at break 444,62%, hardness 49 shore A, tear strength 40,39 kg/cm, density 1,15 g/cm3, abrasion resistance 1,87 mm3/kgm, and no crack detected on the flex cracking test of 150 kcs

  19. 不同品系橡胶树的组份及生胶性能研究%Study on Components and Raw Rubber Performance of Different Strains Rubber Tree

    Institute of Scientific and Technical Information of China (English)

    吴翠; 廖小雪; 廖双泉; 谭海生; 刘日; 廖新荣

    2011-01-01

    为了利于天然橡胶研发利用,利于橡胶制品选材,顺应可持续发展战略,提高天然橡胶制品经济效益,笔者研究了RRIM600、热研7-20-59、热研88-13、热研7-33-97、PR107和热研8-79这6个橡胶树品系的天然橡胶鲜胶乳性能、生胶性能和混炼胶的硫化特性以及硫化胶的物理机械性能.结果表明:不同品系天然胶乳的化学成分、生胶性能存在差异;热研8-79的干胶含量最高,杂质含量最高;热研7-20-59的灰分含量、丙酮溶物含量最高;热研8-79和热研7-33-97的硫化胶所需的正硫化时间最长,而热研88-13所需的正硫化时间最短;RRIM600物理机械性能最好.%In order to benefit at natural rubber for research, development and utilization, benefit at rubber products material, comply with the strategy of sustainable development route, improve natural rubber products economic benefits, performance of fresh nature rubber latex, properties of raw rubber, vulcanization characteristics of compounded rubber and the properties of physical and mechanical vulcanized rubber about Reyan RRIM600, Reyan 7-20-59, Reyan 88-13, Reyan 7-33-97, PR107 and Reyan 8-79 strains of 6 kinds of rubber tree were studied. The results showed that chemical ingredient of natural rubber latex, properties of raw rubber different of strain were diversity; dry rubber content and impurity content of Reyan 8-79 were highest; ashes content and acetone solute of Reyan 7-20-59 were highest; vulcanized rubber of Reyan 8-79 and Reyan 7-33-97 had a longest vulcanizing time, while Reyan 88-13 was shortest; physical and mechanical vulcanized rubber of Reyan RRIM600 were best.

  20. Microbial Load Analysis in Silicone Gel Breast Implants

    Directory of Open Access Journals (Sweden)

    GLAUCIA CRISTINA MELLO SANTOS

    2010-06-01

    Full Text Available Silicone breast implants consist of biomaterials widely used in breast reconstitution surgeries or in mammary augmentation for esthetic reasons. A preliminary stage of the implant production process is vulcanization, which consists of heating the implant to 165±5°C for approximately 9 hours. The aim of this work was to evaluate the bioburden of silicone breast implants prior to the vulcanization process and the decline in bioburden due to this process, and to confirm the sterility of the gel contained in the membrane. Breast implant production stages were evaluated by microbial counting in different steps, according to the USP 32 methodology. To evaluation of decrease in microbial load, spores strips were introduced inside the implant, and after vulcanization cycles the strips were removed from the implant. The strips were transferred to tubes containing TSB, followed by incubation for 7 days at 30-35°C. The results obtained showed that the level of microbial contamination of gel implants is relatively low, and that vulcanization allowed for the inactivation of up to 108 spores. This study led us to the conclusion that vulcanization leaded to sterility of the gel inside the product. Thus, the final sterilizing process contributed to an increase in the Sterility Assurance Level 1. Keywords: Silicone. Breast implant. Sterilization. Dry heat. Vulcanization. Bioburden. RESUMO Análise da Carga Microbiana de Implantes Mamários de Silicone Os implantes mamários de silicone constituem-se em biomateriais que têm sido amplamente utilizados em cirurgias para reconstituição da mama ou para o aumento do tamanho da mama por motivos estéticos. Uma etapa preliminar do processo produtivo do implante é a vulcanização, que consiste no aquecimento do implante a 165±5°C por aproximadamente 9 horas. O objetivo deste estudo foi avaliar a carga microbiana dos implantes mamários de silicone antes do processo de vulcanização, o decaimento

  1. Urban CO2 emissions metabolism: The Hestia Project

    Science.gov (United States)

    Gurney, K. R.; Razlivanov, I.; Zhou, Y.; Song, Y.

    2011-12-01

    A central expression of urban metabolism is the consumption of energy and the resulting environmental impact, particularly the emission of CO2 and other greenhouse gases. Quantification of energy and emissions has been performed for numerous cities but rarely has this been done in explicit space/time detail. Here, we present the Hestia Project, an effort aimed at building a high resolution (eg. building and road link-specific, hourly) fossil fuel CO2 emissions data product for the urban domain. A complete data product has been built for the city of Indianapolis and work is ongoing for the city of Los Angeles (Figure 1). The effort in Indianapolis is now part of a larger effort aimed at a convergent top-down/bottom-up assessment of greenhouse gas emissions, called INFLUX. Our urban-level quantification relies on a mixture of data and modeling structures. We start with the sector-specific Vulcan Project estimate at the mix of geocoded and county-wide levels. The Hestia aim is to distribute the Vulcan result in space and time. Two components take the majority of effort: buildings and onroad emissions. For the buildings, we utilize an energy building model which we constrain through lidar data, county assessor parcel data and GIS layers. For onroad emissions, we use a combination of traffic data and GIS road layers maintaining vehicle class information. Finally, all pointwise data in the Vulcan Project are transferred to our urban landscape and additional time distribution is performed. A key benefit of the approach taken in this study is the tracking and archiving of fuel and process-level detail (eg. combustion process, other pollutants), allowing for a more thorough understanding and analysis of energy throughputs in the urban environment. Next steps in this research from the metabolism perspective is to consider the carbon footprint of material goods and their lateral transfer in addition to the connection between electricity consumption and production.

  2. Preparation and application of nanocrystalline cellulose derived from sugarcane waste as filler modified alkanolamide on crosslink of natural rubber latex film

    Science.gov (United States)

    Harahap, Hamidah; Hayat, Nuim; Lubis, Marfuah

    2017-07-01

    Sugarcane waste is abundant sources of cellulose and it has potential to reutilize. Cellulose from sugarcane waste can be derived into nanocystalline cellulose (NCC) from crystalline region. The NCC as a filler has capability to reinforce natural rubber latex product. The crosslink in vulcanized natural rubber latex film influences several properties of product. In this work, we extracted NCC from sugarcane waste then added into natural rubber latex as filler modified alkanolamide (ALK) and also studied the crosslink of natural rubber latex films. NCC were produced from sugarcane waste by hydrolysis process with sulfuric acid 45%. The obtained NCC was characterized by using x-ray diffraction (XRD), transmission electron microscopy (TEM), and fourier transform infra red (FTIR). NCC was modified by alkanolamide and dispersed in water with filler concentration of 10%. Then the dispersion were added into latex system followed by pre-vulcanization at 70 °C. The films were prepared by coagulant dipping method and dried at 100 °C and 120 °C for 20 minutes. Characterization of NCC from sugarcane waste by using FTIR was done, it clearly showed the functional groups of cellulose. TEM showed the obtained NCC were rod-shaped with about 40-160 nm in diameter and several hundred nm in length, and XRD showed that the degree of crystalinity of NCC from sugarcane waste is 92.33%. The crosslink of natural rubber films were studied by measure the crosslink density for different filler loading by using swelling measurement with toluene solution. The result show that the crosslink density increased in line with amount of filler which added into the system, and also the crosslink density that obtained from vulcanization at 120 °C were higher than 100 °C.

  3. Elucidating the degradation mechanism of the cathode catalyst of PEFCs by a combination of electrochemical methods and X-ray fluorescence spectroscopy.

    Science.gov (United States)

    Monzó, J; van der Vliet, D F; Yanson, A; Rodriguez, P

    2016-08-10

    In this study, we report a methodology which enables the determination of the degradation mechanisms responsible for catalyst deterioration under different accelerated stress protocols (ASPs) by combining measurements of the electrochemical surface area (ECSA) and Pt content (by X-ray fluorescence). The validation of this method was assessed on high surface area unsupported Pt nanoparticles (Pt-NPs), Pt nanoparticles supported on TaC (Pt/TaC) and Pt nanoparticles supported on Vulcan carbon (Pt/Vulcan). In the load cycle protocol, the degradation of Pt-NPs and Pt/Vulcan follows associative processes (e.g. agglomeration) in the first 2000 cycles, however, in successive cycles the degradation goes through dissociative processes such as Pt dissolution, as is evident from a similar decay of ECSA and Pt content. In contrast, the degradation mechanism for Pt nanoparticles dispersed on TaC occurs continuously through the dissociative processes (e.g. Pt dissolution or particle detachment), with similar decay rates of both Pt content and ECSA. In the start-up/shut-down protocol, high surface area Pt-NPs follow associative processes (e.g. Ostwald ripening) in the first 4000 cycles, after which the degradation continues through dissociative processes. On the other hand, dissociative mechanisms always govern the degradation of Pt/TaC under start-up/shut-down protocol conditions. Finally, we report that Pt nanoparticles supported on TaC exhibit the highest catalytic activity and long term durability of the three nanoparticle systems tested. This makes Pt/TaC a potentially valuable catalyst system for application in polymer electrolyte fuel cell cathodes.

  4. Functionalized Materials From Elastomers to High Performance Thermoplastics

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, Laura Ann [Iowa State Univ., Ames, IA (United States)

    2003-01-01

    Synthesis and incorporation of functionalized materials continues to generate significant research interest in academia and in industry. If chosen correctly, a functional group when incorporated into a polymer can deliver enhanced properties, such as adhesion, water solubility, thermal stability, etc. The utility of these new materials has been demonstrated in drug-delivery systems, coatings, membranes and compatibilizers. Two approaches exist to functionalize a material. The desired moiety can be added to the monomer either before or after polymerization. The polymers used range from low glass transition temperature elastomers to high glass transition temperature, high performance materials. One industrial example of the first approach is the synthesis of Teflon(reg. sign). Poly(tetrafluoroethylene) (PTFE or Teflon(reg. sign)) is synthesized from tetrafluoroethylene, a functionalized monomer. The resulting material has significant property differences from the parent, poly(ethylene). Due to the fluorine in the polymer, PTFE has excellent solvent and heat resistance, a low surface energy and a low coefficient of friction. This allows the material to be used in high temperature applications where the surface needs to be nonabrasive and nonstick. This material has a wide spread use in the cooking industry because it allows for ease of cooking and cleaning as a nonstick coating on cookware. One of the best examples of the second approach, functionalization after polymerization, is the vulcanization process used to make tires. Natural rubber (from the Hevea brasiliensis) has a very low glass transition temperature, is very tacky and would not be useful to make tires without synthetic alteration. Goodyear's invention was the vulcanization of polyisoprene by crosslinking the material with sulfur to create a rubber that was tough enough to withstand the elements of weather and road conditions. Due to the development of polymerization techniques to make cis

  5. Functionalized Materials From Elastomers to High Performance Thermoplastics

    Energy Technology Data Exchange (ETDEWEB)

    Laura Ann Salazar

    2003-05-31

    Synthesis and incorporation of functionalized materials continues to generate significant research interest in academia and in industry. If chosen correctly, a functional group when incorporated into a polymer can deliver enhanced properties, such as adhesion, water solubility, thermal stability, etc. The utility of these new materials has been demonstrated in drug-delivery systems, coatings, membranes and compatibilizers. Two approaches exist to functionalize a material. The desired moiety can be added to the monomer either before or after polymerization. The polymers used range from low glass transition temperature elastomers to high glass transition temperature, high performance materials. One industrial example of the first approach is the synthesis of Teflon(reg. sign). Poly(tetrafluoroethylene) (PTFE or Teflon(reg. sign)) is synthesized from tetrafluoroethylene, a functionalized monomer. The resulting material has significant property differences from the parent, poly(ethylene). Due to the fluorine in the polymer, PTFE has excellent solvent and heat resistance, a low surface energy and a low coefficient of friction. This allows the material to be used in high temperature applications where the surface needs to be nonabrasive and nonstick. This material has a wide spread use in the cooking industry because it allows for ease of cooking and cleaning as a nonstick coating on cookware. One of the best examples of the second approach, functionalization after polymerization, is the vulcanization process used to make tires. Natural rubber (from the Hevea brasiliensis) has a very low glass transition temperature, is very tacky and would not be useful to make tires without synthetic alteration. Goodyear's invention was the vulcanization of polyisoprene by crosslinking the material with sulfur to create a rubber that was tough enough to withstand the elements of weather and road conditions. Due to the development of polymerization techniques to make cis

  6. Pt supported on carbon nanofibers as electrocatalyst for low temperature polymer electrolyte membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Alcaide, Francisco; Alvarez, Garbine; Miguel, Oscar [Dpto. de Energia, CIDETEC, Paseo Miramon, 196, 20009 Donostia/San Sebastian (Spain); Lazaro, Maria Jesus; Moliner, Rafael [Instituto de Carboquimica, CSIC, Miguel Luesma Castan 4, 50018 Zaragoza (Spain); Lopez-Cudero, Ana; Solla-Gullon, Jose; Herrero, Enrique; Aldaz, Antonio [Instituto de Electroquimica, Universidad de Alicante, Apdo. 99, E-03080 Alicante (Spain)

    2009-05-15

    Carbon nanofibers synthesized via the thermo catalytic decomposition of methane were investigated for the first time as an electrocatalyst support in PEMFC cathodes. Their textural and physical properties make them a highly efficient catalyst support for cathodic oxygen reduction in low temperature PEMFC. Tests performed in MEAs showed that Pt supported on carbon nanofibers exhibited an enhancement of ca. 94% in power density at 0.600 V, in comparison with a commercial catalyst supported on conventional carbon black, Pt/Vulcan XC-72R. (author)

  7. Physical chemistry research for engineering and applied sciences

    CERN Document Server

    Pearce, Eli M; Pethrick, Richard A; Zaikov, Gennady E

    2015-01-01

    PrefaceRegularity of Oxidation of Waste Fibrous and Film Materials of Polyethylene and Polypropylene: A Research Note; M. V. Bazunova, S. V. Kolesov, R. F. Tukhvatullin, E. I. Kulish, G. E. ZaikovA Research Note on Creation of ?arbon-Polymer Nanocomposites with Polyethylene as a Binder; Sergei V. Kolesov, Marina V. Bazunova, Elena I. Kulish, Denis R. Valiev, and Gennady E. ZaikovA Research Note on the Influence of Hybrid Antioxidants Ichphans on the Structure of Liposome Lipid Bilayer; E. Yu. Parshina, L. Ya. Gendel', and A. B. RubinDynamically Vulcanized Thermoelastoplastics Based on Butadien

  8. DYNAMIC RHEOLOGICAL BEHAVIOR OF POLYPROPYLENE FILLED WITH ULTRA-FINE POWDERED RUBBER PARTICLES

    Institute of Scientific and Technical Information of China (English)

    Qiang Zheng; Yan-xia Cao; Miao Du

    2004-01-01

    Dynamic rheological characteristics of polypropylene (PP) filled with ultra-fine full-vulcanized powdered rubber (UFPR) composed of styrene-butadiene copolymer were studied through dynamic rheological measurements on an Advanced Rheometric Expansion System (ARES). A specific viscoelastic phenomenon, i.e. "the second plateau", appeared at low frequencies, and exhibits a certain dependence on the amount of rubber particles and the dispersion state in the matrix. This phenomenon is attributed to the formation of aggregation structure of rubber particles. The analyses of Cole-Cole diagrams of the dynamic viscoelastic functions suggest that the heterogeneity of the composites is enhanced on increasing both particle content and temperature.

  9. Fisicoquímica de materiales para celdas de combustible PEM alimentadas con metanol

    OpenAIRE

    Franceschini, Esteban Andrés

    2012-01-01

    Las celdas de combustible de membrana de intercambio protónico (PEM) alimentadas con metanol directo (DMPEM) utilizan en la actualidad como catalizadores catódico y anódico, platino y aleaciones platino/rutenio, respectivamente. Los catalizadores comerciales utilizados, están compuestos por nanopartículas de estos metales soportadas sobre partículas de carbón Vulcan XC72®. Estos catalizadores soportados presentan un bajo aprovechamiento del platino debido a que, para obtener una alta área ele...

  10. Phenology, biomass and community composition changes in European shrublands submitted to experimental warming and drought

    OpenAIRE

    Prieto Calvo, Patricia

    2007-01-01

    Descripció del recurs: el 18-08-2008 A la part superior de la portada: CREAF. Unitat d'Ecologia Consultable des del TDX Títol obtingut de la portada digitalitzada Esta tesis se ha desarrollado como parte del proyecto VULCAN (Vulnerabibilty assessment of shrubland ecosystems under climatic changes), un proyecto de investigación llevado a cabo en seis ecosistemas de matorrales europeos (Gales-Reino Unido, Dinamarca, Holanda, Hungría, Cerdaña-Italia y Catalunya-España), distribuidos ...

  11. Evaluation of the geologic relations and seismotectonic stability of the Yucca Mountain area, Nevada Nuclear Waste Site Investigation (NNWSI); Final report, January 1, 1987--June 30, 1988: Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1988-10-01

    This report provides a summary of progress for the project ``Evaluation of the Geologic Relations and Seismotectonic Stability of the Yucca Mountain Area, Nevada Nuclear Waste Site Investigation (NNWSI)`` for the eighteen month period of January 1, 1987 to June 10, 1988. This final report was preceded by the final report for the initial six month period, July 1, 1986 to December 31, 1986 (submitted on January 25, 1987, and revised in June 1987.) Quaternary Tectonics, Geochemical, Mineral Deposits, Vulcanic Geology, Seismology, Tectonics, Neotectonics, Remote Sensing, Geotechnical Assessments, Geotechnical Rock Mass Assessments, Basinal Studies, and Strong Ground Motion.

  12. RubBer Contact Dermatitis in patients attended at Walter Cantídio Hospital, Federal University of Ceará, Brasil

    Directory of Open Access Journals (Sweden)

    DIÓGENES Maria José N.

    1998-01-01

    Full Text Available Nowadays 70% of the world's rubber supply is synthesized artificially. The process involved in its manufacture is vulcanization which requires many chemical substances for speeding the process, as antioxidants to prevent deterioration of rubber, or others. These substances may constitute important sensitizers and thus be responsible for dermatological diseases like contact dermatitis. The objective of this study is to search for the main sensitizers among these rubber chemicals in a population mostly composed by women of a tropical country and compare the results with the ones obtained from previous studies which tested populations mainly composed by men and on different climates.

  13. Oxygen Plasma Treatment of Rubber Surface by the Atmospheric Pressure Cold Plasma Torch

    DEFF Research Database (Denmark)

    Lee, Bong-ju; Kusano, Yukihiro; Kato, Nobuko

    1997-01-01

    A new application of the atmospheric cold plasma torch has been investigated. Namely, the surface treatment of an air-exposed vulcanized rubber compound. The effect of plasma treatment was evaluated by the bondability of the treated rubber compound with another rubber compound using a polyurethane...... adhesive. The adhesion property was improved by treatment of the rubber compound with plasma containing oxygen radicals. Physical and chemical changes of the rubber surface as a result of the plasma treatment were analyzed by field emission scanning electron microscopy (FE-SEM) and fourier transform...

  14. Curing characteristics of chlorosulphonated polyethylene and natural rubber blends

    OpenAIRE

    M. MARINOVIC-CINCOVIC; J. BUDINSKI SIMENDIC; Markovic, G.; Radovanovic, B.

    2005-01-01

    The dependence of the Mooney scorch time and cure index on the blend ratio of chlorosulphonated polyethylene/natural rubber (CSM/SMR 20 CV) and chlorosulphonated polyethylene/chlorinated natural rubber (CSM/Pergut S 40) blends were determined in the temperature range from 120 oC to 160 oC using a Monsanto Mooney viscometer. Semi-efficient vulcanization systems were used for the study. The morphology of the fracture surface of the crosslinked systems was determined by Scanning Electron Microsc...

  15. ROLE OF SYNTHETIC ANTIOXIDANTS ON THE AGING PROPERTY OF ELECTRON BEAM IRRADIATED NATURAL RUBBER

    Institute of Scientific and Technical Information of China (English)

    M. E. Haque; K. Makuuchi; F. Yoshii; H. Mitomo

    2005-01-01

    The aging property of radiation vulcanized natural rubber was studied using various kinds of antioxidants. Aging test was done at 100℃ for various lengths of time. It was found that some antioxidants are excellent in preventing the oxidative degradation of the irradiated rubber. DAH (2,5-di-tert-amylhydroquinone) + CBP (2,2'-dihydroxy-3,3'-di(-methylcyclohexyl)-5,5'-dimethyl diphenyl methane) + P16 (tris(2,4-di-tert-butylphenyl)phosphate) in a proportion of (1:0.5:0.5)was found to be the best combination to achieve 100% retention of tensile strength.

  16. Mechanochemical modification of natural rubber

    Science.gov (United States)

    Mikhaylov, I. A.; Sukhareva, K. V.; Andriasyan, Yu. O.; Popov, A. A.; Vorontsov, N. V.

    2016-11-01

    Thermomechanochemical changes of SVR 3L natural rubber after the treatment in the internal rubber mixer in the self-heating mode were studied. The effect of the molecular mass and content of the gel fraction of natural rubber is shown. Properties of rubber compounds and vulcanized rubber are presented. Taking into account modern requirements, a new alternative technology of obtaining halogenated elastomers based on the solid-phase (mechanochemical) halide modification is created. New halogen-containing natural rubber produced by this technology proves themselves in the conditions of rubber production. New fluorinated natural rubber produced by this technology proves themselves in the conditions of rubber production.

  17. Effect of different plasticizers on the properties of bio-based thermoplastic elastomer containing poly(lactic acid) and natural rubber

    OpenAIRE

    V. Tanrattanakul; P. Bunkaew

    2014-01-01

    Bio-based thermoplastic elastomers (TPE) containing natural rubber and poly(lactic acid) were prepared by melt blending in an internal mixer. The blend ratio was 60% of natural rubber and 40% of poly(lactic acid). Dynamic vulcanization of natural rubber was performed with the sulfur system. The 2 mm – thick sheet samples were prepared by compression molding. The objective of this study was to investigate the effect of plasticization of PLA on the mechanical and physical properties of the deri...

  18. Stabilizing platinum in phosphoric acid fuel cells

    Science.gov (United States)

    Remick, R. J.

    1981-10-01

    A carbon substrate for use in fabricating phosphoric acid fuel cell cathodes was modified by catalytic oxidation to stabilize the platinum catalyst by retarding the sintering of small platinum crystallites. Results of 100-hour operational tests confirmed that the rate of platinum surface area loss observed on catalytically oxidized supports was less than that observed with unmodified supports of the same starting material. Fuel cell electrodes fabricated from Vulcan XC-72R, which was modified by catalytic in a nitric oxide atmosphere, produced low platium sintering rates and high activity for the reduction of oxygen in the phosphoric acid environment.

  19. La stratégie britannique pour les grands équipements de recherche et le CCLRC

    CERN Multimedia

    2003-01-01

    "Le Royaume-Uni dispose d'un certain nombre de grands outils de recherche (par exemple le synchrotron SRS de Daresbury ou encore le laser de puissance Vulcan) et participe egalement a des installations internationales (comme le CERN, l'Agence Spatiale Europeenne et le "European Southern Observatory"). La diversite des projets et des systemes de financement fait que les projets sont geres de differentes facons: soit par des organisations internationales, soit directement par un des sept conseils de recherche britanniques, soit par un des instituts des conseils de recherche, soit par des universites ou d'autres designes par le conseil de recherche" (1 page).

  20. Neoprene.

    Science.gov (United States)

    Woo, Denise K; Militello, Giuseppe; James, William D

    2004-12-01

    Neoprene is a synthetic rubber with many common uses, including use in shoe insoles and adhesives, orthopedic braces, and gloves. Many cases of type IV hypersensitivity from neoprene contact have been reported. Thioureas, the most commonly used vulcanization accelerators in the manufacture of neoprene, are responsible for the majority of these cases. However, thioureas are not included in the TRUE Test whereas the North American Contact Dermatitis Group standard tray contains only mixed dialkyl thioureas. Since most data indicate that many cases will be missed when only mixed dialkyl thioureas are used for screening, a more complete thiourea panel should be used when neoprene hypersensitivity is suspected.

  1. Report on ’PCTE 󈨟, the First International Conference on PCTE’

    Science.gov (United States)

    1992-05-01

    29 4.3 PME: The Project Management Environment 30 4.4 A Broadcast Message Server on PCTE 31 4.5 The ENTREPRISE II environment 32 4.6 VULCAN/AD Analysis...AD/Cycle and IBM AIX/CASE. IBM AD/Cycle is used on an enterprise level for application areas like finance , insurance, transportation, public sector and...framework product. 4 i I I TNO rpowf Pa 32 4.5 The ENTREPRISE 11 environment Speaker: Dr Amury Logalt The ENTREPRISE II environment is an IPSE supporting

  2. Okoliš i automobil

    Directory of Open Access Journals (Sweden)

    Nada Štrumberger

    2012-10-01

    Full Text Available Constant increase of the number of automobiles causes demand for individual materials to get on the rise, thus giving an impulse to the development of recycling logistics. Used automobiles get disassembled and individual parts which can be used as raw materials or additives get recycled. Automobile tires can be reclaimed or vulcanized. In July 1978 the environmental-friendly "Blauer Engel" or "Blue Angel" symbol was first introduced for reclaimed tires. Later, emblems were introduced for other recycled automobile pans. The awarding of the emblem is being controlled and approved by authorized institutes, because the emblem rightfully designates traffic safety.

  3. SnO2 nanospheres supported Pd catalyst with enhanced performance for formic acid oxidation

    Science.gov (United States)

    Lu, Haiting; Fan, Yang; Huang, Ping; Xu, Dongli

    2012-10-01

    SnO2 nanospheres were employed as the support material for Pd catalyst. The as-prepared Pd/SnO2 catalyst exhibited remarkably improved electrocatalytic activity and stability towards formic acid oxidation, in comparison with that of the Vulcan XC-72 carbon black and the commercial SnO2 nanopowder supported Pd catalyst. The enhanced catalytic performance may arise from the unique structure and surface properties of the SnO2 nanospheres, which process extraordinary promotional effect on Pd catalyst.

  4. Highly dispersed Pd nanoparticles on chemically modified graphene with aminophenyl groups for formic acid oxidation

    Science.gov (United States)

    Yang, Su-Dong; Shen, Cheng-Min; Tong, Hao; He, Wei; Zhang, Xiao-Gang; Gao, Hong-Jun

    2011-11-01

    A novel electrode material based on chemically modified graphene (CMG) with aminophenyl groups is covalently functionalized by a nucleophilic ring-opening reaction between the epoxy groups of graphene oxide and the aminophenyl groups of p-phenylenediamine. Palladium nanoparticles with an average diameter of 4.2 nm are deposited on the CMG by a liquid-phase borohydride reduction. The electrocatalytic activity and stability of the Pd/CMG composite towards formic acid oxidation are found to be higher than those of reduced graphene oxide and commercial carbon materials such as Vulcan XC-72 supported Pd electrocatalysts.

  5. Interpretation of the New Version of ISO 21461%新版ISO 21461标准解读

    Institute of Scientific and Technical Information of China (English)

    洪颖; 艾峰; 李瑜; 何重辉; 曹丽华

    2013-01-01

    本文主要介绍了ISO 21461-2012《橡胶--硫化橡胶化合物中油的芳香性测定》标准的背景及适用范围,选取重点并结合检测实际对新版标准进行解读。%This paper mainly introduces the background and application scope of ISO 21461-2012 Rubber-Determination of the aromaticity of oil in vulcanized rubber compounds, and interpreted on the focus with the new standard.

  6. Electrochemical Activity of a La0.9Ca0.1Co1−xFexO3 Catalyst for a Zinc Air Battery Electrode

    OpenAIRE

    Seungwook Eom; Seyoung Ahn; Sanghwan Jeong

    2015-01-01

    The optimum composition of cathode catalyst has been studied for rechargeable zinc air battery application. La0.9Ca0.1Co1−xFexO3  (x=0–0.4) perovskite powders were prepared using the citrate method. The substitution ratio of Co2+ with Fe3+ cations was controlled in the range of 0–0.4. The optimum substitution ratio of Fe3+ cations was determined by electrochemical measurement of the air cathode composed of the catalyst, polytetrafluoroethylene (PTFE) binder, and Vulcan XC-72 carbon. The subst...

  7. Detection, Characterization and Classification of Biological Components in Aerosols by Time-Resolved Laser Pyrolysis Mass Spectrometry

    Science.gov (United States)

    1987-03-20

    samples were more than 2 cm from the center of a very open ion source. The laser pyrolysis spectra of the SBR sample (Figure 5a) and a SBR and natural...z) Figure 5. Laser pyrolysis mass spectra of vulcanized SBR (a) and SBR -NR (b) rubber compounds. Spectra consist primarily of fragment and molecular...4X .210󈨢 Ol~~L&42fjy DETECTION, CHARACTERIZATION AND CLASSIFICATION OF BIOLOGICAL COMPONENTS IN AEROSOLS BY TIME-RESOLVED LASER PYROLYSIS MASS

  8. Seeded QED cascades in counter propagating laser pulses

    CERN Document Server

    Grismayer, Thomas; Martins, Joana L; Fonseca, Ricardo; Silva, Luís O

    2015-01-01

    The growth rates of seeded QED cascades in counter propagating lasers are calculated with 2D/3D QED-PIC simulations. The dependence of the growth rate on laser polarisation and intensity are compared with analytical models that support simulations results. The models provide an insight regarding the qualitative trend of the cascade growth when the intensity of the laser field is varied. The results suggest that relativistic pair plasmas and efficient conversion from laser photons to gamma rays can be created with the typical intensities planned to operate on future ultra-intense laser facilities such as ELI or VULCAN.

  9. Riflessioni con Vincenzo Cabianca sulle Isole Eolie

    Directory of Open Access Journals (Sweden)

    Giorgio Costa

    2015-11-01

    Full Text Available With Vincenzo Cabianca, planner of Aeolian Islands landscape, we talk about scientific knowledge and landscape planning in small islands. In particular, when natural system is so strongly giving shape from the viewpoint of geophysics and vulcanology. During the discussion we carry out deep reflections upon significant of cultural heritage and insularity in this geographical contest, so unique like an insular Vulcan arc can be. Before partially lived in, then place of permanent and productive life, today archipelago’s landscape plan challenges the strong tourist pressure and business to protect his cultural scientific heritage, subject of specific international research. 

  10. 我与盖茨:从分歧到分手

    Institute of Scientific and Technical Information of China (English)

    保罗·艾伦

    2012-01-01

    保罗·艾伦,1953年出生于美国西雅图,与比尔·盖茨创立了微软公司,现任Vulcan Inc.的创始人和主席,是世界上最富有的人之一。他投资创建了西雅图摇滚博物馆和科幻博物馆,还在2003年捐资1亿美元建立了非营利的艾伦脑科学研究所。

  11. 美国以Vulcan项目推进CVC发动机技术发展

    Institute of Scientific and Technical Information of China (English)

    武卉; 李文杰

    2014-01-01

    美国Vulcan(火神)项目已经完成了第二阶段的研究工作,首先介绍了该项目各个阶段的研究目标以及定容燃烧(CVC)技术的研发进展,然后重点梳理了脉冲爆震发动机(PDE)和连续爆震发动机(CDE)等发动机技术的发展水平,最后给出了CVC发动机技术的应用前景.

  12. MANA杀虫剂Vulcan获美国环保署批准登记

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    马克西姆阿甘北美分公司(MANA)杀虫剂Vulcan TM(毒死蜱,chlorpyrifos)新剂型获美国环保署批准登记,用于玉米,大豆,小麦,梨果,葡萄,柑橘,蔬菜及其他作物。该产品使用专利技术,剂型先进,比可溶性剂型起效速度更快,气味轻,使用更方便。

  13. Neutrino signatures and the neutrino-driven wind in Binary Neutron Star Mergers

    CERN Document Server

    Dessart, Luc; Burrows, Adam; Rosswog, Stefan; Livne, Eli

    2008-01-01

    We present VULCAN/2D multi-group flux-limited-diffusion radiation hydrodynamics simulations of binary neutron star (BNS) mergers, using the Shen equation of state, covering ~100 ms, and starting from azimuthal-averaged 2D slices obtained from 3D SPH simulations of Rosswog & Price for 1.4 Msun (baryonic) neutron stars with no initial spins, co-rotating spins, and counter-rotating spins. Snapshots are post-processed at 10 ms intervals with a multi-angle neutrino-transport solver. We find polar-enhanced neutrino luminosities, dominated by $\\bar{\

  14. A summary of test operation of 300kt/a ammonia synthesis CO transform system%300kt/a合成氨CO变换系统试开车总结

    Institute of Scientific and Technical Information of China (English)

    董华林

    2012-01-01

    The flow path, catalytic agent loading, vulcanization and heavy -duty operation of 300kt/a ammonia synthesis CO transform system was introduced, while as the problems and treatment measures at process of test operation.%介绍了300kt/a合成氨CO变换系统的流程、催化剂的装填、硫化及高负荷运行等情况,试开车过程中出现的问题及采取的处理措施。

  15. Ecological Binding Material of First Generation

    Directory of Open Access Journals (Sweden)

    Vasková I.

    2014-06-01

    Full Text Available Bentonite is clay rock, which is created by decomposition of vulcanic glass. It is formed from mixture of clay minerals of smectite group, mainly montmorillonite, beidellite and nontronite. Its typical characteristics is, that when in contact with water, it intensively swells. First who used this term was W.C. Knight in 1887. The rock had been named after town Fort Benton in American state Montana. For its interesting technological properties and whiteness has wide technological use. Bentonite is selectively mined and according to its final use separately modified, which results in high quality product with specific parameters.

  16. Discusión de modelos para la corteza y manto superior en la zona Sur del área Centroibérica, basados en anomalías gravimétricas

    Directory of Open Access Journals (Sweden)

    Bergamín, J. F.

    1986-06-01

    Full Text Available With the porpuse of realize an interpretation in deep of the Campo de Calatrava vulcanism origin, it is done a gravimetric porfile, making various two-dimensional models of the Crust and Upper Mantle. Lately we discussed differents compatible posibilites with the existence of such volcanism.

    Con el fin de realizar una interpretación en profundidad del origen del vulcanismo de Campo de Calatrava, se efectúa un perfil gravimétrico, elaborándose varios modelos bidimensionales de Corteza y Manto superior. Posteriormente se discuten las distintas posibilidades compatibles con la existencia del citado vulcanismo.

  17. Study of Forebody Injection and Mixing with Application to Hypervelocity Airbreathing Propulsion

    Science.gov (United States)

    Axdahl, Erik; Kumar, Ajay; Wilhite, Alan

    2012-01-01

    The use of premixed, shock-induced combustion in the context of a hypervelocity, airbreathing vehicle requires effective injection and mixing of hydrogen fuel and air on the vehicle forebody. Three dimensional computational simulations of fuel injection and mixing from flush-wall and modified ramp and strut injectors are reported in this study. A well-established code, VULCAN, is used to conduct nonreacting, viscous, turbulent simulations on a flat plate at conditions relevant to a Mach 12 flight vehicle forebody. In comparing results of various fuel injection strategies, it is found that strut injection provides the greatest balance of performance between mixing efficiency and stream thrust potential.

  18. Transformer Specification Language: A System for Generating Analyzers and Its Applications

    Science.gov (United States)

    2011-01-01

    vector arithmetic—in its solver. Quoting A. Nori , “[[98] handles] the complexities of binaries via its front-end Vulcan and not via its property...Components and Objects, 2005. [49] N.E. Beckman, A.V. Nori , S.K. Rajamani, and R.J. Simmons. Proofs from tests. In Int. Symp. on Softw. Testing and...M.Y. Levin, and D. Molnar. Automated whitebox fuzz testing. In Network and Dist. Syst. Security, 2008. [96] P. Godefroid, A.V. Nori , S.K. Rajamani, and

  19. V-6电瓶增强剂改善电瓶性能的机理和使用方法

    Institute of Scientific and Technical Information of China (English)

    张健

    1987-01-01

    V-6 battery cell fortifier is a kind of new ene gy-saving chemical products. It can effeciently prevent or eliminate vulcanization of the electrode plates inside the battery cell,lower the temperature of the battery cell, shorten the time for charging, enlarge the output power, improve activity of active material, strengthen the reversible electricchemical reaction and enlarge the capatiance oft he battery cell as well. V-6 battery cell fortifier is quite portable and easy to use and can be applied to all lead-acid battery cells.

  20. Nano carbon supported platinum catalyst interaction behavior with perfluorosulfonic acid ionomer and their interface structures

    DEFF Research Database (Denmark)

    Andersen, Shuang Ma

    2016-01-01

    behavior of Nafion ionomer on platinized carbon nano fibers (CNFs), carbon nano tubes (CNTs) and amorphous carbon (Vulcan). The interaction is affected by the catalyst surface oxygen groups as well as porosity. Comparisons between the carbon supports and platinized equivalents are carried out. It reveals......, the ionomer may have an adsorption preference to the platinum nano particle rather than to the overall catalyst. This was verified by a close examination on the decomposition temperature of the carbon support and the ionomer. The electrochemical stability of the catalyst ionomer composite electrode suggests...

  1. 复合硫化剂对氟橡胶/硅橡胶共混物结构和性能的影响%Effect of Compound Curing Systems on Morphology and Properties of Fluororubber/Silicone Rubber Blends

    Institute of Scientific and Technical Information of China (English)

    郭建华; 曾幸荣; 罗权焜

    2011-01-01

    The fluororubber(FKM) and silicone rubber(MVQ) blends were vulcanized with dicumyl peroxide(DCP)/triallyl isocyanurate(TAIC),bisphenol AF/benzyltriphenylchlorophosphine(BPP)/DCP and N,N′-dicinnamal-1,6-hexamethylenediamine(DIAK No.3)/DCP compound curing system,respectively.Effect of the compound curing systems on curing behavior,mechanical properties,heat ageing properties,oil resistance and low temperature properties of FKM/MVQ blends was studied.FKM/MVQ blends were characterized by DMA,TG and SEM analysis.The results show that FKM/MVQ blends vulcanized with DCP/TAIC curing system have better over-all physical properties than those vulcanized with bisphenol AF/BPP/DCP and DIAK No.3/DCP curing systems.DMA results indicate that Tg of FKM and MVQ matrix in the blends cured with DCP/TAIC is highest.DCP/TAIC-cured blends show better thermal stability than those vulcanized with the other curing systems by TG analysis.There are well adhered at the interface in DCP/TAIC-cured blends by SEM photos.%分别采用过氧化二异丙苯(DCP)/三烯丙基异氰脲酸酯(TAIC)、双酚AF/苄基三苯基氯化磷(BPP)/DCP、3#硫化剂/DCP三种复合硫化剂硫化氟橡胶/硅橡胶共混物。研究了不同复合硫化剂对氟橡胶/硅橡胶共混物的硫化特性、力学性能、耐热老化性能、耐油性能和低温性能的影响,采用动态热机械分析(DMA)、热重分析(TG)和扫描电镜(SEM)方法对氟橡胶/硅橡胶共混物进行表征。结果表明,采用DCP/TAIC硫化的氟橡胶/硅橡胶共混物具有良好的综合物理力学性能。DMA分析表明,DCP/TAIC硫化的共混物中氟橡胶相和硅橡胶相的Tg最高,TG分析表明,DCP/TAIC硫化的共混物具有良好的热稳定性。SEM照片表明,DCP/TAIC硫化的共混物界面结合作用较强。

  2. Component Testing for Modular Pier Replacement at McMurdo Station, Antarctica: Inflatable Pontoons, Gelbo Flex and Full-Scale Cold Storage/Fold Tests

    Science.gov (United States)

    2014-08-01

    40 4 0 10,000 No leaks Welded -4 Vulcanized −40 4 0 10,000 No leaks ERDC/CRREL TR-14-14 8 The LMCS pontoon fabric (samples Pontoon-1 to 3...cracking or leaks in the fabric or fabric joint welds . Upon receiving the pontoon, we inflated it and determined that there were 5 leaks caused from prior...durability and strength of the pontoon fabric when tested at Antarctic temperatures by using a cold-modified Gelbo flex (ASTM F392) test. The

  3. Propiedades y procesado de la silicona liquida inyectada

    Directory of Open Access Journals (Sweden)

    David Juarez Varon

    2013-02-01

    Full Text Available Silicones are polymeric character materials formed by a chain of alternating silicon atoms and oxygen atoms, which constitute good elastomers because the main chain is very flexible.The biocompatibility of silicone is formulated completely with FDA Biocompatibility Guidelines (Food and Drug Administration.Its manufacturing is based on radical addition vulcanizing (HTV and thanks to their chemical structure are achieved special technical and aesthetic results difficult to obtain with traditional products.Injection molding of liquid silicone has several advantages in the manufacture of silicone, emphasizing the excellent speed and termination of the products, although it emphasizes the great difficulty in the design and machining of molds.

  4. Spatially- explicit Fossil Fuel Carbon Dioxide Inventories for Transportation in the U.S.

    Science.gov (United States)

    Hutchins, M.; Gurney, K. R.

    2016-12-01

    The transportation sector is the second largest source of Fossil Fuel CO2 (FFCO2) emissions, and is unique in that federal, state, and municipal levels of government are all able to enact transportation policy. However, since data related to transportation activities are reported by multiple different government agencies, the data are not always consistent. As a result, the methods and data used to inventory and account for transportation related FFCO2 emissions have important implications for both science and policy. Aggregate estimates of transportation related FFCO2 emissions can be spatially distributed using traffic data, such as the Highway Performance Monitoring System (HPMS) Average Annual Daily Traffic (AADT). There are currently two datasets that estimate the spatial distribution of transportation related FFCO2 in the United States- Vulcan 3.0 and the Database of Road Transportation Emissions (DARTE). Both datasets are at 1 km resolution, for the year 2011, and utilize HPMS AADT traffic data. However, Vulcan 3.0 and DARTE spatially distribute emissions using different methods and inputs, resulting in a number of differences. Vulcan 3.0 and DARTE estimate national transportation related FFCO2 emissions within 2.5% of each other, with more significant differences at the county and state level. The differences are most notable in urban versus rural regions, and for specific road classes. The origin of these differences are explored in depth to understand the implication of using specific data sources, such as the National Emissions Inventory and other aggregate transportation statistics from the Federal Highway Administration (FHWA). In addition to comparing Vulcan 3.0 and DARTE to each other, the results from both data sets are compared to independent traffic volume measurements acquired from the FHWA Continuous Count Station (CCS) network. The CCS records hourly traffic counts at fixed locations in space throughout the U.S. We calculate transportation

  5. Devulcanization of styrenebutadiene (SBR waste tire by controlled oxidation

    Directory of Open Access Journals (Sweden)

    Rios Rachel R.V.A.

    2006-01-01

    Full Text Available This work describes the devulcanization of vulcanized SBR (Styrene Butadiene Rubber based on controlled oxidation with nitric acid. IR, ¹H and 13C-NMR, CHN elemental analyses, TG, GPC and TPD-MS (Temperature Programmed Decomposition-Mass Spectrometry experiments suggest that nitric acid promotes two processes: (i devulcanization by oxidation of the sulfide crosslinks and (ii oxidation of the carbon framework leading to the formation of -COOH and -NO2 groups. Under aggressive conditions (HNO3, reflux the polymer chain is strongly oxidized and fragmented to a highly oxygenated low molecular weight fraction, which is soluble in water.

  6. Study of PtNi/C catalyst for direct ethanol fuel cell; Estudo do catalisador PtNi/C para celula a combustivel de etanol direto

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, L.P.R. de; Silva, E.L. da; Amico, S.C.; Malfatti, C.F., E-mail: eticiaprm@gmail.com [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil)

    2014-07-01

    In this work, PtNi binary catalyst and pure platin catalyst were synthesized by the impregnation-reduction method, using Vulcan XC72R as support, for direct ethanol fuel cells. The composition and structure of the catalysts were analyzed by X-ray diffraction, the electrochemical behavior was evaluated by cyclic voltammetry and morphology of the catalysts was studied by high-resolution transmission electron microscopy. The results showed that the addition of Ni to Pt led to the contraction of the crystal lattice, increased the catalytic activity compared to pure Pt and initiated the electrooxidation of ethanol at lower potential. (author)

  7. Importance of the support and the grade of Pt in the oxygen reduction reaction; Importancia del soporte y del grado del Pt en la reaccion de reduccion de oxigeno

    Energy Technology Data Exchange (ETDEWEB)

    Enriquez M, O.; Fernandez V, S.M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2004-07-01

    The technology of the fuel cells type Proton Exchange Membrane (PEM), needs to define clearly the influence of the different involved parameters, this is made in general using methods of electrochemical impedance, in which the involved reactions can be presupposed. Another form of making is identifying experimentally the influence of the different parameters. In this work the obtained results are reported with for the oxygen reduction reaction using as electro catalyst platinum analytical grade and fuel cell grade and like support graphite and vulcan. It was found that as much the support as the particle size modify the over potential for the oxygen reduction reaction (Orr). (Author)

  8. 加成型液体硅橡胶用含环氧基的有机硅增粘剂的制备、表征及性能%Preparation, Characterization & Property of Epoxy Modified Organosilicon Tackifier for Addition-type Liquid Silicone Rubber

    Institute of Scientific and Technical Information of China (English)

    凌钦才; 谢国庆; 郭文欣

    2012-01-01

    A tackifier with epoxy functional groups for the addition-type liquid silicone rubber was prepared, using tetramethylcyclotetrasiloxane and allyl glycidyl ether as the raw materials. The microstructure was characterized by Fourier transform infrared spectroscopy (FT - IR) and 1H Nuclear Magnetic Resonance ( H - NMR). The effect of the tackifier amount on the viscosity of the addition-type LSR, the hardness, dielectric constant, dielectric loss factor, insulation resistivity, electrical breakdown strength, and bonding property of vulcanized silicone rubber and reverse leakage current of encapsulation diode at high temperature was investigated. The results showed that the tackifier could significantly improve the bonding strength of the vulcanized silicone rubber, affect the insulation resistivity and electrical breakdown strength of the vulcanized silicone rubber, decrease the reverse leakage current of the encapsulation diode at high temperature, and have no effect on the viscosity of the addition-type liquid silicone rubber and the hardness, dielectric constant, dielectric loss factor of the vulcanized silicone rubber.%以烯丙基缩水甘油醚和四甲基环四硅氧烷为原料,制备加成型液体硅橡胶用含环氧基的有机硅增粘剂.用红外光谱和核磁共振氢谱对其结构进行了表征,考察了加入量对硅橡胶胶料黏度及硫化胶硬度、介电常数、介质损耗因数、绝缘电阻率、电气强度、粘接性能及封装二极管高温反向漏电流的影响.结果表明:增粘剂能提高硅橡胶的粘接强度;影响其绝缘电阻率和电气强度;降低封装二极管的高温反向漏电流;基本不影响硅橡胶胶料黏度及硫化橡胶的硬度、介电常数、介质损耗因数.

  9. Synthesis of sulfur-containing lubricant additives on the basis of fatty acid ethyl esters

    Directory of Open Access Journals (Sweden)

    Iurii S. Bodachivskyi

    2016-12-01

    Full Text Available The study reveals an energy-, resource- and eco-friendly method for preparation of sulfur-containing lubricant additives via interaction of fatty acid ethyl esters of rapeseed oil with elemental sulfur. The structure of synthesized compounds under various reactants ratio (5–50 wt.% of sulfur, duration (30–240 min and temperature of the process (160–215°С was investigated using various analytical techniques. According to the established data, aside from addition to double bonds, the side reaction of hydrogen substitution at α-methylene groups near these bonds occurs and induces the formation of conjugated systems and chromophoric sulfur-rich derivatives. Also, we found that increase of process duration evokes growth of polysulfane chains, in contrast to the raise of temperature, which leads to the formation of sulfur-containing heterocycles and hydrogen sulfide, as a result of elimination. Influence of accelerators on sulfurization of fatty acid ethyl esters was also examined. The most effective among them are mixtures of zinc dibutyldithiocarbamate with zinc oxide or stearic acid, which soften synthesis conditions and doubly decrease duration of the high-temperature stage. In addition, sulfur-containing compositions of ethyl esters and α-olefins, vulcanized esters by benzoyl peroxide, nonylphenols and zinc dinonylphenyldithiophosphate were designed. The study identified that lithium lubricant with sulfurized vulcanized esters provides improved tribological properties, in comparison with base lubricant or lubricant with the non-modified product.

  10. Impact Craters on Pluto and Charon Indicate a Deficit of Small Kuiper Belt Objects

    Science.gov (United States)

    Singer, Kelsi N.; McKinnon, William B.; Greenstreet, Sarah; Gladman, Brett; Parker, Alex Harrison; Robbins, Stuart J.; Schenk, Paul M.; Stern, S. Alan; Bray, Veronica; Spencer, John R.; Weaver, Harold A.; Beyer, Ross A.; Young, Leslie; Moore, Jeffrey M.; Olkin, Catherine B.; Ennico, Kimberly; Binzel, Richard; Grundy, William M.; New Horizons Geology Geophysics and Imaging Science Theme Team, The New Horizons MVIC and LORRI Teams

    2016-10-01

    The impact craters observed during the New Horizons flyby of the Pluto system currently provide the most extensive empirical constraints on the size-frequency distribution of smaller impactors in the Kuiper belt. These craters also help us understand the surface ages and geologic evolution of the Pluto system bodies. Pluto's terrains display a diversity of crater retention ages and terrain types, indicating ongoing geologic activity and a variety of resurfacing styles including both exogenic and endogenic processes. Charon's informally named Vulcan Planum did experience early resurfacing, but crater densities suggest this is also a relatively ancient surface. We will present and compare the craters mapped across all of the relevant New Horizons LOng Range Reconnaissance Imager (LORRI) and Multispectral Visible Imaging Camera (MVIC) datasets of Pluto and Charon. We observe a paucity of small craters on all terrains (there is a break to a shallower slope for craters below 10 km in diameter), despite adequate resolution to observe them. This lack of small craters cannot be explained by geological resurfacing alone. In particular, the main area of Charon's Vulcan Planum displays no obviously embayed or breached crater rims, and may be the best representation of a production population since the emplacement of the plain. The craters on Pluto and Charon are more consistent with Kuiper belt and solar system evolution models producing fewer small objects.This work was supported by NASA's New Horizons project.

  11. Development of multifunctional fluoroelastomers based on nanocomposites; Desenvolvimento de elastomeros fluorados multifuncionais baseados em nanocompositos

    Energy Technology Data Exchange (ETDEWEB)

    Zen, Heloisa Augusto

    2015-07-01

    The fluoropolymers are known for their great mechanical properties, high thermal stability and resistance to aggressive chemical environment, and because of those properties they are widely used in industries, such as automobile, petroleum, chemistry, manufacturing, among others. To improve the thermal properties and gases barrier of the polymeric matrix, the incorporation of nanoparticle is used, this process permits the polymer to maintain their own characteristics and acquire new properties of nanoparticle. Because of those properties, the structural and morphological modification of fluoropolymers are very hard to be obtained through traditional techniques, in order to surmount this difficulty, the ionizing radiation is a well-known and effective method to modify fluoropolymers structures. In this thesis a nanocomposite polymeric based on fluoroelastomer (FKM) was developed and incorporated with four different configurations of nanoparticles: clay Cloisite 15A, POSS 1159, POSS 1160 and POSS 1163. After the nanocomposites films were obtained, a radiation induced grafting process was carried out, followed by sulfonation in order to obtain a ionic exchanged membrane. The effect of nanoparticle incorporation and the ionizing radiation onto films were characterized by X-ray diffraction, thermal and mechanical analysis, scanning electron microscopy and swelling; and the membranes were evaluated by degree of grafting, ionic exchange capacity and swelling. After the films were characterized, the crosslinking effect was observed to be predominant for the nanocomposites irradiated before the vulcanization, whereas the degradation was the predominant effect in the nanocomposites irradiated after vulcanization. (author)

  12. Volcanic gas

    Science.gov (United States)

    McGee, Kenneth A.; Gerlach, Terrance M.

    1995-01-01

    In Roman mythology, Vulcan, the god of fire, was said to have made tools and weapons for the other gods in his workshop at Olympus. Throughout history, volcanoes have frequently been identified with Vulcan and other mythological figures. Scientists now know that the “smoke" from volcanoes, once attributed by poets to be from Vulcan’s forge, is actually volcanic gas naturally released from both active and many inactive volcanoes. The molten rock, or magma, that lies beneath volcanoes and fuels eruptions, contains abundant gases that are released to the surface before, during, and after eruptions. These gases range from relatively benign low-temperature steam to thick hot clouds of choking sulfurous fume jetting from the earth. Water vapor is typically the most abundant volcanic gas, followed by carbon dioxide and sulfur dioxide. Other volcanic gases are hydrogen sulfide, hydrochloric acid, hydrogen, carbon monoxide, hydrofluoric acid, and other trace gases and volatile metals. The concentrations of these gas species can vary considerably from one volcano to the next.

  13. Effect of radiation-induced modification in fluoroelastomer

    Energy Technology Data Exchange (ETDEWEB)

    Zen, Heloisa Augusto; Lugao, Ademar Benevolo, E-mail: helozen@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Polymers exposed to ionizing irradiation, even at low doses, often undergo structural changes accompanied by molecular crosslinking and chain scission (degradation) reactions. The general effect of the radiation on polymers is determined by the ratio of crosslinking to chain scission events. This ratio depends on parameters such as chemical structure, physical state, radicals stability and mobility, irradiation rate and irradiation atmosphere. The radiation process is a large used technique to promote modification in their structures to apply them in different areas and is well known for its merits and potential in modifying the chemical and the physical properties of polymeric materials without cause drastic changes in their inherent properties, depend on the dose irradiated. In this study was used fluoroelastomer with 70% - fluor that having excellent thermal, chemical and mechanical properties. Vulcanized and non-vulcanized samples of this material were submitted to gamma radiation under air atmosphere in order to observe the effect of atmosphere in the polymer matrix. The irradiated doses were 5, 10 and 20kGy, at room temperature. The characterization was made by scanning electron microscope (SEM), infrared spectroscopy using attenuate reflectance (ATR-IR) and X-ray diffraction. The results demonstrated which was expected, the degradation reactions were observed. (author)

  14. Synthesis, Characterization & Application of Phenyltriisopropenyloxysilane%苯基三异丙烯氧基硅烷的合成、表征及应用

    Institute of Scientific and Technical Information of China (English)

    李晓雷; 凌钦才; 谢国庆; 龚彦; 郭文欣

    2013-01-01

    Phenyltriisopropenyloxysilane was synthesized with cuprous chloride as catalyzer , triethylamine as deacid reagent , acetone and phenylrichlorosilane as raw materials .The product yield was 43%when the re-action temperature was 50°C.Its microstructure was analyzed and characterized by FTIR , 1 H NMR, 13 C NMR and MS .The prepared phenyltriisopropenyloxysilane was used as the across-linking agent to prepare deaceton-ized room temperature vulcanization ( RTV-1) silicone rubber and the vulcanized silicone rubber showed good dielectric and mechanical properties .%以丙酮与苯基三氯硅烷为原料、氯化亚铜为催化剂、三乙胺为缚酸剂、苯为溶剂,合成了苯基三异丙烯氧基硅烷。当反应温度为50°C时,产品收率在43%左右。通过红外、核磁共振氢谱和碳谱及裂解质谱对产物结构进行了表征;并将其作为交联剂,配成了脱丙酮型室温硫化硅橡胶,硫化后的硅橡胶具有较好的介电性能和机械性能。

  15. Spectroscopic investigation of nitrogen-functionalized carbon materials

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Kevin N. [Department of Metallurgical and Materials Engineering, Colorado School of Mines, 1500 Illinois Street Golden CO 80401 USA; Department of Mechanical Engineering, University of Michigan, Ann Arbor MI 48109 USA; Christensen, Steven T. [National Renewable Energy Laboratory, 15013 Denver West Pkwy Golden CO 80401 USA; Nordlund, Dennis [Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Rd Menlo Park CA 94023 USA; Dameron, Arrelaine A. [National Renewable Energy Laboratory, 15013 Denver West Pkwy Golden CO 80401 USA; Ngo, Chilan [Department of Chemistry and Geochemistry, Colorado School of Mines, 1012 14th Street Golden CO 80401 USA; Dinh, Huyen [National Renewable Energy Laboratory, 15013 Denver West Pkwy Golden CO 80401 USA; Gennett, Thomas [National Renewable Energy Laboratory, 15013 Denver West Pkwy Golden CO 80401 USA; O' Hayre, Ryan [Department of Metallurgical and Materials Engineering, Colorado School of Mines, 1500 Illinois Street Golden CO 80401 USA; Pylypenko, Svitlana [Department of Chemistry and Geochemistry, Colorado School of Mines, 1012 14th Street Golden CO 80401 USA

    2016-04-07

    Carbon materials are used in a diverse set of applications ranging from pharmaceuticals to catalysis. Nitrogen modification of carbon powders has shown to be an effective method for enhancing both surface and bulk properties of as-received material for a number of applications. Unfortunately, control of the nitrogen modification process is challenging and can limit the effectiveness and reproducibility of N-doped materials. Additionally, the assignment of functional groups to specific moieties on the surface of nitrogen-modified carbon materials is not straightforward. Herein, we complete an in-depth analysis of functional groups present at the surface of ion-implanted Vulcan and Graphitic Vulcan through the use of X-ray photoelectron spectroscopy (XPS) and near edge X-ray adsorption fine structure spectroscopy (NEXAFS). Our results show that regardless of the initial starting materials used, nitrogen ion implantation conditions can be tuned to increase the amount of nitrogen incorporation and to obtain both similar and reproducible final distributions of nitrogen functional groups. The development of a well-controlled/reproducible nitrogen implantation pathway opens the door for carbon supported catalyst architectures to have improved numbers of nucleation sites, decreased particle size, and enhanced catalyst-support interactions.

  16. Structure and Properties of FKM/ACM Blend%FKM/ACM并用胶的结构及性能研究

    Institute of Scientific and Technical Information of China (English)

    刘岚; 陈娟娟; 王亚明; 贾德民; 罗远芳

    2011-01-01

    对采用双酚AF/促进剂BPP硫化体系的氟橡胶(FKM)/丙烯酸酯橡胶(AcM)并用胶的各项性能进行研究.结果表明:以双酚AF/促进剂BPP为硫化体系,FKM和ACM可以实现共硫化,制得的FKM/ACM并用胶物理性能优良,耐热氧、耐紫外光和耐臭氧老化性能以及热稳定性较好,压缩永久变形性能优异}扫描电子显微镜显示FKM和ACM具有较好的相容性.%The properties of FKM/ACM blends prepared by bisphenol AF/BPP vulcanization system were investigated. The results showed that, FKM and ACM could be covulcanized under the bisphenol AF/BPP vulcanization system, and the physical properties, thermal oxidative aging property, ultraviolet aging property,ozone aging property, thermal stability and compression set of FKM/ACM blends were good. The scanning electron microscope analysis showed that FKM and ACM had good compatibility.

  17. Recycling Waste Natural Rubber Latex by Blending with Polystyrene - Characterization of Mechanical Properties

    Science.gov (United States)

    Boondamnoen, O.; Ohshima, M.; Azura, A. R.; Chuayjuljit, S.; Ariffin, A.

    Waste natural rubber latex was blended with polystyrene (WNRL/PS) for recycling. A mixture with a 50/50 ratio of rubber to PS was blended by an internal mixer (Haake) at 140 °C and 60 rpm. The PS became the matrix, and the WNRL was dispersed within the matrix. Dynamically vulcanized natural rubber/PS (NRv/PS) blends and natural rubber/PS (NR/PS) blends without vulcanization were also prepared in the same way for comparison. The tensile properties and morphologies of all blends were investigated. The crosslinking density was determined by using the Flory-Rehner equation. The experiments showed that the WNRL/PS blend exhibited a higher tensile strength, Young's modulus and crosslinking density, but a lower elongation at break, than the NRv/PS and NR/PS blends. SEM observations of the tensile fracture surface and TEM observations of the blend morphology indicated that the WNRL/PS blend needed a higher energy to break than the NRv/PS and NR/PS blends.

  18. Curing characteristics of chlorosulphonated polyethylene and natural rubber blends

    Directory of Open Access Journals (Sweden)

    M. MARINOVIC-CINCOVIC

    2005-05-01

    Full Text Available The dependence of the Mooney scorch time and cure index on the blend ratio of chlorosulphonated polyethylene/natural rubber (CSM/SMR 20 CV and chlorosulphonated polyethylene/chlorinated natural rubber (CSM/Pergut S 40 blends were determined in the temperature range from 120 oC to 160 oC using a Monsanto Mooney viscometer. Semi-efficient vulcanization systems were used for the study. The morphology of the fracture surface of the crosslinked systems was determined by Scanning Electron Microscopy (SEM. The results showed that the scorch time decreased with increasing SMR 20 CV and Pergut S 40 contents. This observation is attributed to the increasing solubility of sulfur, as the content of SMR 20 CV and Pergut S 40 in the composition increased. For temperatures greater than 140 oC, the dependence of the scorch time on blend ratios diminishes, as enough thermal energy is available to overcome the activation energy of vulcanization. The differing curing characteristics of the two blends is explained by the compatibility factor of the respective blend. Morphological analysis of the blends shows a very satisfactory agreement.

  19. Penelitian pemanfaatan lateks alam iradiasi pada pembuatan sepatu kanvas

    Directory of Open Access Journals (Sweden)

    Murwati Murwati

    1996-06-01

    Full Text Available The aim of the research is to applicate irradiation natural latex as cement material for sole and foxing of convas shoes. The process of shoe manufacturing is carried out using steam vulcanization system. Shoe production is tested their cemented strenght consisting of cemented strength testing of sole to canvas, and foxing testing to canvas. The result of cemented strength of canvas shoes Li compared with sulphuric vulcanization latex LA based on SNI -12-0172-1987, Canvas shoes for general purposes, proved that cemented strength of sole to canvas shoes Li = 10.660 N/6 mm is lower compared with canvas shoes LA. Cemented strenght of foxing to canvas shoes Li = 11.892 N/6 mm is higher compared with canvas LA. Cemented strength result to all testings of canvas shoes Li fulfills specification of SNI-12-0172-1987, Canvas shoes for general purposes, in addition irradiation natural latex can be used as cemented material in shoes manufacturing.

  20. Karakteristik karet ebonit yang dibuat dengan berbagai variasi rasio RSS I/Riklim dan jumlah belerang

    Directory of Open Access Journals (Sweden)

    Penny Setyowati

    2004-07-01

    Full Text Available The aim of the research was to study the influence of utilization of sulphur and reclaim rubber on the characteristics of ebonite rubber, and also to determine the optimum utilization of reclaim rubber and sulphur which yield good physical properties. Ebonite rubber was made by special natural rubber of RSS I (Ribbed Smoke Sheet I mixed with reclaimed rubber at ratio 80/20, 70/30 and 60/40 part hundred rubber/part hundred rubber (phr/phr and utilization of sulphur 30, 40, and 50 phr and also additives respectively. Mixing was done by using open mill, and vulcanization was conducted at early temperature 1200C for 2 hours, and it was continued by post curing at temperature 1500C for 2 hours. The physical properties such as tensile strength, elongation at break, D shore hardness, and izod impact of ebonite rubber vulcanized were determined. The result indicated that characteristics of ebonite rubber was significantly influenced by the amount of added sulphur and 40 phr reclaim rubber or at ratio of RSS I to reclaim rubber 60 to 40 phr/phr. However, the physical properties of ebonite rubber was able to meet the standard quality of group 2 regarding to Classification Hard Rubber issued by ASTM D 2135

  1. Harvest of table olives by mechanical harvesting equipment

    Directory of Open Access Journals (Sweden)

    Filippo Gambella

    2013-09-01

    Full Text Available In this work, we have evaluated the performance, of an electric comb equipped with five undulated fingers used for mechanized the harvesting of table olives. The first aim of the work was to test three different types of coating materials used for covering the fingers: Silicon (S, Vulcanized rubber (VR and Natural rubber (NR. The diameter of the coating materials tested were 7mm (D1, 14 mm (D2, 19 mm (D3 in order to evaluate the damage of different working conditions on the intact olives. During harvesting, silicon at 7mm and 14mm resulted in the largest percentage of undamaged the fruit (67% and 65%, natural rubber 63% and vulcanized rubber at the 54%. The second aim was to evaluate the combination, in terms of the best performance, of the machines used for mechanized harvesting of table olives. Several factors have been examined: undulating fingers variation thickness, different rotational speeds and different coating materials used to reduce the impact damage on olives. From the tests on olive tree we have determined that while plastic materials (S and (NR appear to have a positive role in harvest quality, the vibration transmitted to the operator’s hand is great from 6.48 m/s2 for S to 6.31 m/ s2 for NR and 2.92 m/s2 for VR, respect to the materials used.

  2. Synergistic effects in the processes of crosslinking of elastomers

    Science.gov (United States)

    Głuszewski, Wojciech; Zagórski, Zbigniew P.; Rajkiewicz, Maria

    2014-01-01

    Radiation crosslinking of elastomers is an example of the modification of polymers by ionizing radiation. In practice, often parallel both traditional crosslinking (with peroxide) and radiation treatment is applied (Bik et al., 2003, 2004). Elastomers can be irradiated both before and/or after vulcanization products. The aim of this study was to investigate the system of the mixed radiation/peroxide and peroxide/radiation crosslinking of selected elastomers (Engage 8200, HNBR). In particular, attention was directed to the influence of the protective effects of aromatic additives in elastomers (peroxides, thermal- and light stabilizers) on the phenomenon of crosslinking and postradiation oxidation. Aromatic peroxides may undergo modifications during the preirradiation, which affect the subsequent processes of vulcanization. In this way the method of gas chromatography (GC) was applied for determination of hydrogen and oxidation effects, never described before for Engage 8200. Using that approach, radiation efficiency of hydrogen evolution and oxygen absorption efficiency of the polymers has been identified. To describe the phenomena of postradiation oxidation of elastomers, the method of Diffuse Reflection Spectrophotometry (DRS) was also applied.

  3. Effect of the Purple carbon black on the properties of NR/BR blend

    Science.gov (United States)

    Yanfang, Zhao; Dan, Liu; Shengbo, Lin; Binjian; Yinmei, Zhao; Shuangquan, Liao

    2014-08-01

    Purple black is light colored mineral filler mining in recent years in Hainan. The effect of the dosage of the purple carbon black and purple carbon black modificated by Si69 on the vulcanization characteristics, mechanical properties, thermal stability, the damping performance of NR/BR blend rubber were studied, and the blending adhesive tensile sections were analyzed by SEM. Research showed that, with the increasing dosage of the purple carbon black, vulcanization characteristics of NR/BR blend had a little change. Adding the purple carbon black into blending had a reinforcing effect. when the dosage of the purple carbon black was 20, the mechanical properties of blending adhesive was good; Coupling agent Si69 had a modification effect on the purple carbon black. With increasing dosage of Si69, performance of the rubber was improved initially and then decreased; when the mass fraction of Si69 was 8% of the dosage of the purple carbon black, rubber performance was optimal. Purple carbon black had no obvious effect on thermal stability of the rubber, but it improved the damping rubber temperature and damping factor.

  4. Study of rheological behavior and miscibility of epoxidized natural rubber modified neoprene

    Science.gov (United States)

    Chiu, Hsien-Tang; Tsai, Peir-An; Cheng, Tzu-Chi

    2006-02-01

    The Mooney viscosity, curing rates, vulcanization behavior, and the relationship between molecular motion of epoxidized natural rubber (ENR) and neoprene (CR) blends at different blending ratios have been studied. The experimental results of ENR/CR blends show that the Mooney viscosity decreased gradually. Plasticization was most pronounced at an ENR/CR ratio of 75/25 and is thus the easiest to process. Owing to the ring opening of the epoxy group of ENR, the rate of crosslink formation is much faster than that of CR at higher temperature. The vulcanized rate increased with increasing ENR content. The results indicated that 175 °C and 5 min were the optimum processing conditions for ENR/CR blends. The DMA spectra showed a single damping peak for the ENR/CR blends, which suggests that ENR and CR are miscible. As seen in the Arrhenius plot of frequency against T g, the activation energy increased with increasing ENR contents. This suggests the existence of interpenetration of these two rubber molecular networks.

  5. Ionic Liquids Applied to Improve the Dispersion of Coagent Particles in an Elastomer

    Directory of Open Access Journals (Sweden)

    Magdalena Maciejewska

    2013-01-01

    Full Text Available The aim of this work was to study the activity of several ionic liquids (alkylimidazolium salts that are used to improve the dispersion of coagent particles in peroxide-cross-linked hydrogenated acrylonitrile butadiene elastomer (HNBR. Hydrotalcite grafted with monoallyl maleate was applied as a coagent for the HNBR vulcanization. In this paper, we discuss the effect of the ionic liquids (alkylimidazolium salts with respect to their anion (bromide, chloride, tetrafluoroborate, and hexafluorophosphate and the length of alkyl chain in the cation (allyl-, ethyl-, butyl-, hexyl-, and octyl- on the vulcanization kinetics of rubber compounds. The influence of ionic liquids on the cross-link density, the mechanical properties of the vulcanizates, and their resistance to weather ageing were also studied. Alkylimidazolium salts seem to improve the dispersion of the coagent particles and to be active in the cross-linking of HNBR with peroxide. The type of ionic liquid considerably influences the activity of the coagent particles toward the HNBR. The application of ionic liquids increases the cross-link density of the vulcanizates and improves their resistance to weather aging.

  6. Swelling behaviour in n-pentane and mechanical properties of epoxidized natural rubber with different epoxide content

    Science.gov (United States)

    Kinasih, N. A.; Fathurrohman, M. I.; Winarto, D. A.

    2017-07-01

    Epoxidized natural rubber (ENR) with different level of epoxidation (i.e. 10, 20, 30, 40 and 50 mol% indicated as ENR ENR10, ENR20, ENR30, ENR40 and ENR50, respectively) were prepared. They were then vulcanized by using efficient system vulcanization. The effect of epoxide content on curing characteristic, swelling and mechanical properties in N-pentane was investigated. The Attenuated Resonance Fourier Transform Infrared (ATR-FTIR) and H-Nuclear Magnetic Resonance (H-NMR) were used to determine the epoxidation level. Glass transition (Tg) of ENR samples was determined by using Direct Scanning Calorimetry (DSC). The result revealed that the resistance of ENR in N-pentane increased with increasing epoxidation level, which indicated by decreasing equilibrium mol uptake and diffusion coefficient. The compression set of ENR and aging resistance increased with increasing epoxide content, except ENR50 was due to ENR 50 have two Tg value. However, the value of hardness and tensile strength were not effected by epoxidation level.

  7. 動的再構成可能プロセッサVulcanの評価

    OpenAIRE

    2006-01-01

    特定用途向けプロセッサとは,アプリケーションに特化した命令を実行することによって,汎用プロセッ サに対して高性能を実現するものである.本稿では,特定用途向けプロセッサの実現方式として,データパスに動的 再構成可能ハードウェアを用いたプロセッサVulcan を提案する.また,実際にアプリケーションを実装した結果を, 汎用プロセッサで同様のアプリケーションを実行した結果と比較し,Vulcan の評価を行った....

  8. A Two-Dimensional MagnetoHydrodynamics Scheme for General Unstructured Grids

    CERN Document Server

    Livne, E; Burrows, A; Meakin, C A; Livne, Eli; Dessart, Luc; Burrows, Adam; Meakin, Casey A.

    2007-01-01

    We report a new finite-difference scheme for two-dimensional magnetohydrodynamics (MHD) simulations, with and without rotation, in unstructured grids with quadrilateral cells. The new scheme is implemented within the code VULCAN/2D, which already includes radiation-hydrodynamics in various approximations and can be used with arbitrarily moving meshes (ALE). The MHD scheme, which consists of cell-centered magnetic field variables, preserves the nodal finite difference representation of $div(\\bB)$ by construction, and therefore any initially divergence-free field remains divergence-free through the simulation. In this paper, we describe the new scheme in detail and present comparisons of VULCAN/2D results with those of the code ZEUS/2D for several one-dimensional and two-dimensional test problems. The code now enables two-dimensional simulations of the collapse and explosion of the rotating, magnetic cores of massive stars. Moreover, it can be used to simulate the very wide variety of astrophysical problems for...

  9. Raman Spectroscopy and Electrochemical Investigations of Pt Electrocatalyst Supported on Carbon Prepared through Plasma Pyrolysis of Natural Gas

    Directory of Open Access Journals (Sweden)

    Tereza Cristina Santos Evangelista

    2015-01-01

    Full Text Available Physicochemical and electrochemical characterisations of Pt-based electrocatalysts supported on carbon (Vulcan carbon, C1, and carbon produced by plasma pyrolysis of natural gas, C2 toward ethanol electrooxidation were investigated. The Pt20/C180 and Pt20/C280 electrocatalysts were prepared by thermal decomposition of polymeric precursors at 350°C. The electrochemical and physicochemical characterisations of the electrocatalysts were performed by means of X-ray diffraction (XRD, transmission electron microscope (TEM, Raman scattering, cyclic voltammetry, and chronoamperometry tests. The XRD results show that the Pt-based electrocatalysts present platinum metallic which is face-centered cubic structure. The results indicate that the Pt20/C180 electrocatalyst has a smaller particle size (10.1–6.9 nm compared with the Pt20/C280 electrocatalyst; however, the Pt20/C280 particle sizes are similar (12.8–10.4 nm and almost independent of the reflection planes, which suggests that the Pt crystallites grow with a radial shape. Raman results reveal that both Vulcan carbon and plasma carbon are graphite-like materials consisting mostly of sp2 carbon. Cyclic voltammetry and chronoamperometry data obtained in this study indicate that the deposition of Pt on plasma carbon increases its electrocatalytic activity toward ethanol oxidation reaction.

  10. Exfoliated sodium-montmorillonite in nitrile butadiene rubber nanocomposites with good properties

    Institute of Scientific and Technical Information of China (English)

    WANG QingGuo; ZHANG XiaoHong; QIAO JinLiang

    2009-01-01

    We prepared and utilized a novel ultrafine fully-vulcanized powder nitrile butadiene rubber (UFPNBR)/ sodium montmorillonite (Na-MMT) nanocompound powder, in which nanoscale UFPNBR particles and nanoscale platelets of Na-MMT were isolated and stuck each other. When the UFPNBR/Na-MMT nano-compoud powder was mixed with crude nitrile butadiene rubber (NBR), UFPNBR particles could be easily dispersed in NBR matrix because of good compatibility, and nanoscale Na-MMT was also dis-persed well in NBR matrix due to the carrier aidance of UFPNBR particle, thus the NBR/UFPNBPJNa-MMT ternary nanocomposites adapting to industry was fabricated. X-ray diffraction test and scanning electron microscopy (SEM) observation indicated that nanoscale Na-MMT was dispersed well in NBR matrix. Compared with NBR/Na-MMT binary composites, NBR/UFPNBR/Na-MMT ternary nanocompo-sites have shorter vulcanization time and higher flame retardancy due to the exfoliated Na-MMT in NBR matrix.

  11. A Two-dimensional Magnetohydrodynamics Scheme for General Unstructured Grids

    Science.gov (United States)

    Livne, Eli; Dessart, Luc; Burrows, Adam; Meakin, Casey A.

    2007-05-01

    We report a new finite-difference scheme for two-dimensional magnetohydrodynamics (MHD) simulations, with and without rotation, in unstructured grids with quadrilateral cells. The new scheme is implemented within the code VULCAN/2D, which already includes radiation hydrodynamics in various approximations and can be used with arbitrarily moving meshes (ALEs). The MHD scheme, which consists of cell-centered magnetic field variables, preserves the nodal finite difference representation of divB by construction, and therefore any initially divergence-free field remains divergence-free through the simulation. In this paper, we describe the new scheme in detail and present comparisons of VULCAN/2D results with those of the code ZEUS/2D for several one-dimensional and two-dimensional test problems. The code now enables two-dimensional simulations of the collapse and explosion of the rotating, magnetic cores of massive stars. Moreover, it can be used to simulate the very wide variety of astrophysical problems for which multidimensional radiation magnetohydrodynamics (RMHD) is relevant.

  12. Comparative degradation study of carbon supported proton exchange membrane fuel cell electrocatalysts - The influence of the platinum to carbon ratio on the degradation rate

    Science.gov (United States)

    Speder, Jozsef; Zana, Alessandro; Spanos, Ioannis; Kirkensgaard, Jacob J. K.; Mortensen, Kell; Hanzlik, Marianne; Arenz, Matthias

    2014-09-01

    A colloidal synthesis approach is used to prepare supported proton exchange membrane fuel cell (PEMFC) catalysts with various Pt loadings - from low to extremely high ones. The catalyst samples are used to continue our investigation of the role of the Pt:C ratio in the degradation processes. The influence of the platinum loading on the electrochemical surface area (ECSA) loss is evaluated in a systematic electrochemical study by using two commercially available carbon blacks, namely Vulcan XC72R and Ketjenblack EC-300J. Accelerated degradation tests simulating load cycle and start-up/shutdown conditions are carried out in accordance with the Fuel Cell Commercialization Conference of Japan (FCCJ) recommendations. Under conditions simulating the load cycle of PEM fuel cells no unambiguous correlation between the ECSA loss and the Pt:C ratio is found. By contrast, under conditions simulating the repetitive start-up/shutdown processes of PEMFCs the ECSA loss first increases with increasing Pt loading. However, it decreases again for very high loadings. Furthermore, the Vulcan samples exhibited higher ECSA losses than the Ketjenblack samples, indicating the important role of the physical and chemical properties of pristine carbon supports in the carbon degradation mechanism.

  13. Digital Modeling Phenomenon Of Surface Ground Movement

    Directory of Open Access Journals (Sweden)

    Ioan Voina

    2016-11-01

    Full Text Available With the development of specialized software applications it was possible to approach and resolve complex problems concerning automating and process optimization for which are being used field data. Computerized representation of the shape and dimensions of the Earth requires a detailed mathematical modeling, known as "digital terrain model". The paper aims to present the digital terrain model of Vulcan mining, Hunedoara County, Romania. Modeling consists of a set of mathematical equations that define in detail the surface of Earth and has an approximate surface rigorously and mathematical, that calculated the land area. Therefore, the digital terrain model means a digital representation of the earth's surface through a mathematical model that approximates the land surface modeling, which can be used in various civil and industrial applications in. To achieve the digital terrain model of data recorded using linear and nonlinear interpolation method based on point survey which highlights the natural surface studied. Given the complexity of this work it is absolutely necessary to know in detail of all topographic elements of work area, without the actions to be undertaken to project and manipulate would not be possible. To achieve digital terrain model, within a specialized software were set appropriate parameters required to achieve this case study. After performing all steps we obtained digital terrain model of Vulcan Mine. Digital terrain model is the complex product, which has characteristics that are equivalent to the specialists that use satellite images and information stored in a digital model, this is easier to use.

  14. Degradation of sulfide linkages between isoprenes by lipid peroxidation catalyzed by manganese peroxidase.

    Science.gov (United States)

    Sato, Shin; Ohashi, Yasunori; Kojima, Masaaki; Watanabe, Takahito; Honda, Yoichi; Watanabe, Takashi

    2009-10-01

    Scission of sulfide linkages in vulcanized rubber has been a major concern since the early 20th century, because devulcanization is a key process for recycling waste rubber products as polymer materials that pose low environmental risks. We herein demonstrate that lipid peroxidation (LPO) of linoleic acid by manganese peroxidase (MnP), a proposed lignin-degradation system in the early stage of selective white rot fungi, cleaves sulfide bond in a model rubber compound, di(2-methylpent-2-enyl) sulfide, to 2,4-dimethylthiophene and 2-methyl-2-pentenal. The major intermediate of the LPO process, 2,4-decadienal was directly oxidized by MnP to cleave the sulfur-carbon bond. We propose that electrophilic radicals from 2,4-decadienal abstract one electron from a sulfur atom of the model compound to produce the sulfur radical cation intermediate, which in turn reacts with molecular oxygen to cleave the sulfur-carbon bond. The discovery of free radical-mediated scission of sulfide bond coupled with Mn oxidation provides a novel strategy for recycling vulcanized rubber wastes.

  15. Investigation of reinforcement of the modified carbon black from wasted tires by nuclear magnetic resonance

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jie; YANG Yong-rong; REN Xiao-hong; STAPF Siegfried

    2006-01-01

    Pyrolysis has the potential of transforming waste into recyclable products. Pyrolytic carbon black (PCB) is one of the most important products from the pyrolysis of used tires. Techniques for surface modifications of PCB have been developed. One of the most significant applications for modified PCB is to reinforce the rubber matrix to obtain high added values. The transverse relaxation and the chain dynamics of vulcanized rubber networks with PCB and modified PCB were studied and compared with those of the commercial carbon blacks using selective 1H transverse relaxation (T2) experiments and dipolar correlation effect (DCE) experiments on the stimulated echo. Demineralization and coupling agent modification not only intensified the interactions between the modified PCB and the neighboring polyisoprene chains, but also increased the chemical cross-link density of the vulcanized rubber with modified PCB. The mechanical testing of the rubbers with different kinds of carbon blacks showed that the maximum strain of the rubber with modified PCB was improved greatly. The mechanical testing results confirmed the conclusion obtained by nuclear magnetic resonance (NMR). PCB modified by the demineralization and NDZ-105 titanate coupling agent could be used to replace the commercial semi-reinforcing carbon black.

  16. Supported PtRu on mesoporous carbons for direct methanol fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Arbizzani, Catia; Beninati, Sabina; Soavi, Francesca; Varzi, Alberto; Mastragostino, Marina [University of Bologna, Department of Metal Science, Electrochemistry and Chemical Techniques, via San Donato 15, 40127 Bologna (Italy)

    2008-12-01

    We prepared and characterized several cryogel mesoporous carbons of different pore size distribution and report the catalytic activity of PtRu supported on mesoporous carbons of pore size >15 nm in passive and in active direct methanol fuel cells (DMFCs). At room temperature (RT), the specific maximum power of the passive DMFCs with mesoporous carbon/PtRu systems as anode was in the range 3-5 W g{sup -1}. Passive DMFC assembly and RT tests limit the performance of the electrocatalytic systems and the anodes were thus tested in active DMFCs at 30, 60 and 80 C. Their responses were also compared to those of commercial Vulcan carbon/PtRu. At 80 C, the specific maximum power of the active DMFC with C656/PtRu was 37 W g{sup -1} and the required amount of Pt per kW estimated at 0.4 V cell voltage was 31 g kW{sup -1}, a value less than half that of Vulcan carbon/PtRu. (author)

  17. A composite of hollow carbon nanospheres and sulfur-rich polymers for lithium-sulfur batteries

    Science.gov (United States)

    Zeng, Shao-Zhong; Yao, Yuechao; Zeng, Xierong; He, Qianjun; Zheng, Xianfeng; Chen, Shuangshuang; Tu, Wenxuan; Zou, Jizhao

    2017-07-01

    Lithium-sulfur batteries are the most promising candidates for future high-energy applications because of the unparalleled capacity of sulfur (1675 mAh g-1). However, lithium-sulfur batteries have limited cycle life and rate capability due to the dissolution of polysulfides and the extremely low electronic conductivity of sulfur. To solve these issues, various porous carbons including hollow carbon nanospheres (HCNs) have been used for improving the conductivity. However, these methods still suffer from polysulfides dissolution/loss owing to their weak physical adsorption to polysulfides. Herein, we introduced a covalent grafting route to composite the HCNs and the vulcanized trithiocyanuric acid (TTCA). The composite exhibits a high loading of the vulcanized TTCA by the HCNs with high surface area and large pore volume, and covalent bonds to sulfur, effectively depressing the dissolution of polysulfides. The first discharge capacity of the composite reaches 1430 mAh g-1 at 0.1 C and 1227 mAh g-1 at 0.2 C.

  18. Preparation, characterization and evaluation of electrocatalysts supported on functionalized carbon black for polymer exchange membrane fuel cell applications; Preparacao, caracterizacao e avaliacao de eletrocatalisadores suportados em carbono funcionalizado para aplicacao em celulas a combustivel tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Carmo, Marcelo do

    2008-12-18

    The fuel cell technology associated with the growing exigency of low environmental impact energy became prosperous in the world energy scenery. The fuel cell is basically a device that converts directly the chemical energy of a fuel into electrical and thermal energy with a continuous operation by the constant feed of a fuel. Especially, the carbon black Vulcan XC72 is usually employed as an electro catalyst support, and some factors as an accessible and high surface area in order to get maximum particles dispersion, pore size, adequate pore distribution and the presence of functional groups in the carbon black surface are considered fundamental characteristics for an innovative materials development. However, the Vulcan XC72 still reveals insufficient conditions for these purposes. This study consists in the preparation and in the physical chemical characterization of functionalized carbon black by hydrogen peroxide and by polymeric chains with proton conduction properties, and its posterior utilization as electro catalyst support for PEMFC and DMFC application. After the carbon functionalization, an improvement in the carbon black dispersion in water media was observed, a beneficial effect for electro catalyst preparation. It was also observed, that the functional groups and the polymeric chains worked as stabilizers in the particle growing, producing much more homogeneous electrocatalysts, exhibiting smaller average particle size. Especially, in the case of polymeric chains functionalization, a decrease in the ohmic drop was observed for this system, attributed to an improvement in the proton transference. (author)

  19. Cathode catalysts for primary phosphoric acid fuel cells

    Science.gov (United States)

    1981-01-01

    Alkylation or carbon Vulcan XC-72, the support carbon, was shown to provide the most stable bond type for linking cobalt dehydrodibenzo tetraazannulene (CoTAA) to the surface of the carbon; this result is based on data obtained by cyclic voltammetry, pulse voltammetry and by release of 14C from bonded CoTAA. Half-cell tests at 100 C in 85% phosphoric acid showed that CoTAA bonded to the surface of carbon (Vulcan XC-72) via an alkylation procedure is a more active catalyst than is platinum based on a factor of two improvement in Tafel slope; dimeric CoTAA had catalytic activity equal to platinum. Half-cell tests also showed that bonded CoTAA catalysts do not suffer a loss in potential when air is used as a fuel rather than oxygen. Commercially available polytetrafluroethylene (PTFE) was shown to be unstable in the fuel cell environment with degradation occurring in 2000 hours or less. The PTFE was stressed at 200 C in concentrated phosphoric acid as well as electrochemically stressed in 150 C concentrated phosphoric acid; the surface chemistry of PTFE was observed to change significantly. Radiolabeled PTFE was prepared and used to verify that such chemical changes also occur in the primary fuel cell environment.

  20. High performance hybrid supercapacitors by using para-Benzoquinone ionic liquid redox electrolyte

    Science.gov (United States)

    Navalpotro, Paula; Palma, Jesús; Anderson, Marc; Marcilla, Rebeca

    2016-02-01

    A solution of 0.4M para-Benzoquinone (p-BQ) in the ionic liquid N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide (PYR14TFSI) was used as a redox electrolyte in hybrid supercapacitors. Two carbons with very different textural properties, Pica carbon and Vulcan carbon, were used as electrode material. Electrochemical performance of these energy storage systems was investigated by cyclic voltammetry (CV) and galvanostatic charge-discharge (CD). Unlike SCs with pure IL electrolyte, new battery-like features appeared in the CV curves and CD profiles. This electrochemical performance, associated with the faradaic contribution of the redox electrolyte, results in a significant improvement of the electrochemical performance of the hybrid system. For Vulcan carbon with low specific surface area (SBET = 240 m2 g-1), specific capacitance (Cs) and specific real energy (Ereal) values as high as 70 Fg-1 and 10.3 WhKg-1 were obtained at 5 mAcm-2 with hybrid SC operating at 3 V. This represents an increment of 300% in Cs and Ereal with respect to the SC based on pure PYR14TFSI. For high surface area carbon such as Pica (SBET = 2410 m2g-1), the addition of the redox quinone molecule resulted in a moderate enhancement reaching values of 156 Fg-1 and 30 WhKg-1 under the same experimental conditions (36% and 10% increment, respectively).

  1. Nanostructure and Formation Mechanism of PtWO3/C Nanocatalyst by Ethylene Glycol Method

    Institute of Scientific and Technical Information of China (English)

    WU Feng; LIU Yanhong; WU Chuan

    2011-01-01

    Pt-WO3 nanoparticles uniformly dispersed on Vulcan XC-72R carbon black were prepared by an ethylene glycol method. The morphology, composition, nanosturcture, electrochemical characteristics and electrocatalytic activity were characterized, and the formation mechanism was investigated. The average particle size was 2.3 nm, the same as that of Pt/C catalyst. The W/Pt atomic ratio was 1/20, much lower than the design of 1/3. The deposition of WO3·xH2O nanoparticles on Vulcan XC-72R carbon black was found to be very difficult by TEM. From XPS and XRD, the Pt nanoparticles were formed in the colloidal solution of Na2WO4,the EG insoluble Na2WO4 resulted in the decreased relative crystallinity and increased crystalline lattice constant compared with those of Pt/C catalyst and, subsequently, the higher specific electrocatalytic activity as determined by CV. The Pt-mass and Pt-electrochemically-active-specific-surface-area based anodic peak current densities for ethanol oxidation were 422.2 mA·mg-1Pt and 0.43 mA·cm-2Pt, 1.2 and 1.1 times higher than those of Pt/C catalyst, respectively.

  2. Sifat fisika dan analisis gugus fungsi karet seal o-ring dari bahan termoplastik elastomer nitrile butadiene rubber (NBR dan polyvinyl chloride (PVC

    Directory of Open Access Journals (Sweden)

    Arum Yuniari

    2013-06-01

    Full Text Available The purpose of this research was to determine the physical properties and functional groups on O-ring rubber seals made of thermoplastic elastomers blend NBR and PVC. Composition of the NBR / PVC were successively varied : 90/10; 85/15; 80/20; 75/25; 70/30 and 65/35 phr. Mixing process between NBR/PVC with additive used a two roll mill within a temperature of 60º - 80 ºC, the vulcanization process used a hydraulic press at a temperature of 170 oC and pressure of 150 kg/cm2. The physical properties were evaluated including tensile strength, elongation at break, hardness, before and after aging, hardness after immersion in isooctane and swelling while analysis of functional groups was also carried out by method of Fourier Transform Infrared Spectrophotometer (FTIR. The result of the best vulcanized was characterized by tensile strength 188.93 kg/cm2, the change of tensile strength after aging 2.50%, elongation at break of 400%, the change of elongation at break after aging was 12.5%, hardness 75 shore A, the change of hardness after aging 0%, the change of hardness after immersion in isooctane 1.3%, swelling 0.8% and functional group of vulcanisate was indicated by new peak (OH at wave band of 3468 cm-1. Those formula met the requirements of the technical specifications of ASTM D 2000 seal O-ring.

  3. Pembuatan sol karet lembaran untuk sandal

    Directory of Open Access Journals (Sweden)

    Herminiwati Herminiwati

    1999-12-01

    Full Text Available The purpose of the research was to find best formulation for rubber sole sheeting for sandal. The formulation of the compounds were made by variation ratio of natural rubber and sintetic rubber SBR as follow : 100/0, 75/25, 50/50, 25/75 and 0/100, where as the variation ratio of carbon black N330 and aluminium silicate filler 100/0, 60/40 and 20/80 respectively. Compounding process was carried out on two roll mill. The rubber compounds were vulcanized at temperature 150oC and pressure of 150 kg/cm2 with curing time as indicated by curometer. Vulcanized rubber were tested based on SNI. 06-0899-1989 : Rubber sheeting for sole. The best formulation was consist of natural rubber 75 phr, sintetic rubber SBR 25 phr, stearic acid 3 phr, zinc oxide 5 phr, Minarex B oil 5 phr, car bon black 100 phr, MBTS 1 phr, PBN 1 phr and sulfur 2 phr. The physical properties of the best compound were : tensile strength 185,42 kg/cm2, elongation at break 276,64%, tear resistance 158,90 kg/cm2, hardness 74 shore A, density 1,21 g/cm3, Grasselli abrasion resistance 0,326 mm3/kgm, permanent set 7,78% and no crack on the flex cracking test. The best compound could meet the requirements of SNI. 06-0899-1989.

  4. INVESTIGATION INTO MORPHOLOGY, MICROSTRUCTURE AND PROPERTIES OF SBR/EPDM/ORGANO MONTMORILLONITE NANOCOMPOSITES

    Institute of Scientific and Technical Information of China (English)

    Massud Durandish; Abdolmajid Alipour

    2013-01-01

    Rubber compounds based on styrene-butadiene rubber/ethylene propylene diene monomer blends of different compositions (60/40,70/30,80/20,90/10,100/0) reinforced with 1 wt%,3 wt%,5 wt% and 7 wt% organoclay (Cloisite 20A)were prepared on a two roll mill via a vulcanization process and characterized by several techniques.Results of X-ray diffraction showed expansion of the inter-gallery distance,and transmission electron microscopy (TEM) micrographs confirmed that the prepared nanocomposite samples have intercalated and partially exfoliated structures.Cure characteristics showed that,organoclay not only accelerates the vulcanization reaction,but also gives rise to a marked increase of the torque,indicating crosslink density of the prepared compounds increases at the presence of organoclay.Mechanical properties of samples received markedly increase by clay loading due to the good interaction established between nanoclay particles and polymer matrix as it was evidenced by SEM photomicrographs.At the same time,rheological properties showed that addition of nanoclay could improve storage modulus as well as complex viscosity of SBR/EPDM samples.The results of ozone test revealed that the ozone resistance of samples significantly increases as nanoclay or EPDM content increases.

  5. Effect of neodymium stearate on cure and mechanical properties of epoxidized natural rubber

    Institute of Scientific and Technical Information of China (English)

    LUO Yongyue; YANG Changjin; WANG Yueqiong; HE Canzhong; ZHONG Jieping; LIAO Shuangquan; PENG Zheng; LIU Xingxun

    2012-01-01

    The effect of neodymium stearate (NdSt) on cure and mechanical properties of expoxidized natural rubber with 25 mol.% epoxidation (ENR25) was studied in the concentration range of 0 to 2 phr,and the relationship between structure and mechanical properties of ENR25 vulcanizates was also discussed.Neodymium sterate was synthesized by saponification of stearic acid with newly formed rare earth hydroxide in water medium,and the structure of NdSt was investigated by Fourier transform infrared spectroscopy (FTIR).Crosslinking density of vulcanized natural rubber was studied by equilibrium swelling method.The results indicated that the interaction force between carboxylic ion of NdSt prepared in the lab and Nd ion was mainly ionic bond through FTIR analysis.NdSt could accelerate the vulcanization of ENR25 and influence the network structure of ENR25 vulcanizates.The incorporation of 1 phr NdSt for ENR25 vulcanizates showed the optimal aging resistance.

  6. Investigating the Inverse Faraday Effect with an intense short pulse laser

    Science.gov (United States)

    Najmudin, Zulfikar; Tatarakis, Michealis; Krushelnick, Karl; Clark, Eugene; Santala, Marko; Dangor, Bucker; Clarke, Robert; Neely, David; Faure, Jerome; Malka, Victor

    2000-10-01

    A circularly polarised laser beam traversing through a plasma can generate an azimuthal electron current, due to their combined quiver motion. This will generate a solenoidal magnetic field in the plasma colinear with the laser propagation. This phenomena is known as the Inverse Faraday Effect (IFE), and can result in sizeable magnetic field strength for an ultra-intense laser pulses traversing through sufficiently dense plasmas. We present here measurements of the IFE field generated by the ultra-intense Vulcan:CPA laser travelling through underdense plasmas. The Vulcan:CPA laser can be focused to greater than 5 × 10^18 Wcm-2, and can generate IFE magnetic fields in excess of 2 MG. We present here the variation of the field with intensity and density, as well as measurements of its temporal and spatial behaviour. Noticeably the field is only observed for the time duration of the driver pulse, and decreases in spatial extent with increasing strength of magnetic field.

  7. A systematic framework for computer-aided design of engineering rubber formulations

    Science.gov (United States)

    Ghosh, Prasenjeet

    This thesis considers the design of engineering rubber formulations, whose unique properties of elasticity and resilience enable diverse applications. Engineering rubber formulations are a complex mixture of different materials called curatives that includes elastomers, fillers, crosslinking agents, accelerators, activators, retarders, anti-oxidants and processing aids, where the amount of curatives must be adjusted for each application. The characterization of the final properties of the rubber in application is complex and depends on the chemical interplay between the different curatives in formulation via vulcanization chemistry. The details of the processing conditions and the thermal, deformational, and chemical environment encountered in application also have a pronounced effect on the performance of the rubber. Consequently, for much of the history of rubber as an engineering material, its recipe formulations have been developed largely by trial-and-error, rather than by a fundamental understanding. A computer-aided, systematic and automated framework for the design of such materials is proposed in this thesis. The framework requires the solution to two sub-problems: (a) the forward problem, which involves prediction of the desired properties when the formulation is known and (b) the inverse problem that requires identification of the appropriate formulation, given the desired target properties. As part of the forward model, the chemistry of accelerated sulfur vulcanization is reviewed that permits integration of the knowledge of the past five decades in the literature to answer some old questions, reconcile some of the contradicting mechanisms and present a holistic description of the governing chemistry. Based on this mechanistic chemistry, a fundamental kinetic model is derived using population balance equations. The model quantitatively describes, for the first time, the different aspects of vulcanization chemistry. Subsequently, a novel three

  8. 汽车用橡胶减震材料新型环保配方研究%Study on the Formula of new Environmental Protection Rubber Damping Material for Automobile

    Institute of Scientific and Technical Information of China (English)

    柯宇旋

    2012-01-01

    笔者研究了氯丁橡胶、三元乙丙橡胶共混胶:防老剂4020、防老剂RD、防老剂NBC,硫化促进剂TATD在橡胶减震材料中的应用,从经济环保的角度进行了新的配方设计,并进行了性能(邵尔A型硬度、拉伸强度、扯断伸长率、老化系数和耐久性)测试。通过对实验结果分析,确定氯丁橡胶、三元乙丙橡胶共混胶的在橡胶减震材料配方的壤佳比例及防老刑4020、防老荆RD、防老剂NBC的优化配伍比例。通过对比实验.结果表明:问等条件下,生产相同的橡胶减震材料产晶,使用硫化促进剂TATD的制品综合性能要优于使用硫化促进剂TMTD的制品.且用量少。%The author studied the application of chloroprene rubber, ethylene propylene diene monomer (EPDM) rubber blends, antioxidant 4020, antioxidant RD, antioxidant NBC and vulcanization accelerator TATD in the rubber damping material product, made the new formulation design from the economic and environmental protection angle, and tested properties (Shore A hardness, tensile strength, elongation at break, aging coeffcient and durability). The author through the analysis of experimental results, found out the best proportion of chloroprene rubber and EPDM rubber in the rubber damping material formula. The author also found out the optimized compatibility proportion of antioxidant 4020, anti0xidant RD and antioxidant NBC in the formula. By comparing the experimental results, the properties use vulcanization accelerator TATD were better than which use vulcanization accelerator TMTD in the same conditions producing rubber damping material. Also the used quantity was less.

  9. VARIATION OF PHYSICO-CHEMICAL PROPERTIES OF RADIATION CROSSLINKED RUBBER WITH STORAGE TIME

    Institute of Scientific and Technical Information of China (English)

    N.C. Dafader; M.E. Haque; F. Akhtar

    2005-01-01

    The effect of storage on physico-chemical properties of non-irradiated natural rubber and radiation vulcanized natural rubber (RVNR) were evaluated. The rubber films were stored under two different conditions, namely in open air and sealed polyethylene bags. The antioxidant, tris(nonylated phenyl) phosphite (TNPP) was used for preventing degradation of RVNR films. Gel content, cross-link density, tensile strength at break and 500% elongation of rubber films were measured.The results show that the retention (%) of tensile properties of rubber films with TNPP is higher than that of rubber films without antioxidants. The rubber films stored in polyethylene bags also show better retention of tensile properties than those of rubber films stored in open air.

  10. Evaluating laser-driven Bremsstrahlung radiation sources for imaging and analysis of nuclear waste packages.

    Science.gov (United States)

    Jones, Christopher P; Brenner, Ceri M; Stitt, Camilla A; Armstrong, Chris; Rusby, Dean R; Mirfayzi, Seyed R; Wilson, Lucy A; Alejo, Aarón; Ahmed, Hamad; Allott, Ric; Butler, Nicholas M H; Clarke, Robert J; Haddock, David; Hernandez-Gomez, Cristina; Higginson, Adam; Murphy, Christopher; Notley, Margaret; Paraskevoulakos, Charilaos; Jowsey, John; McKenna, Paul; Neely, David; Kar, Satya; Scott, Thomas B

    2016-11-15

    A small scale sample nuclear waste package, consisting of a 28mm diameter uranium penny encased in grout, was imaged by absorption contrast radiography using a single pulse exposure from an X-ray source driven by a high-power laser. The Vulcan laser was used to deliver a focused pulse of photons to a tantalum foil, in order to generate a bright burst of highly penetrating X-rays (with energy >500keV), with a source size of waste materials. This feasibility study successfully demonstrated non-destructive radiography of encapsulated, high density, nuclear material. With recent developments of high-power laser systems, to 10Hz operation, a laser-driven multi-modal beamline for waste monitoring applications is envisioned.

  11. Development of Soft Tactile Sensor for Prostatic Palpation Diagnosis: Sensor Structure Design and Analysis

    Directory of Open Access Journals (Sweden)

    Zhongwei Jiang

    2000-01-01

    Full Text Available This paper is concerned with the development of a palpation probe for assessment of prostatic cancer and hypertrophy. The sensor is constructed by layering two polivinylidene fluoride (PVDF films into soft material layers such as vulcanized rubber and sponge rubber sheets. Since the contact condition between the sensor and soft objects influences the sensor output significantly, the improvement of its sensitivity is investigated by design of an attachment covered over the sensor surface. In this report, the theoretical model of the sensor and the design of the attachment are presented and the attachment is validated for soft substances due to experimental investigation. Finally, a compact probe developed for clinical testing is presented and the data obtained from the patients are treated by the wavelet transform for de-noising. Some representative clinical data show that the sensor could be a useful tool for group medical checkup on prostatic cancer and hypertrophy.

  12. Novel route to synthesize Pt-Ws2 nanoparticles for electrochemical applications

    Energy Technology Data Exchange (ETDEWEB)

    Gochi-Ponce, Y. [Inst. Tecnologico de Oaxaca, Oaxaca (Mexico). Dept. of Mechanical Engineering; Research Center on Advanced Materials, Chihuahua, (Mexico). Dept. of Chemical Materials; Morales, D.; Arriaga, L.G. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, Queretaro (Mexico); Chinas-Castillo, F. [Inst. Tecnologico de Oaxaca, Oaxaca (Mexico). Dept. of Mechanical Engineering; Alonso-Nunez, G. [Research Center on Advanced Materials, Chihuahua, (Mexico). Dept. of Chemical Materials; Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, Queretaro (Mexico)

    2008-07-01

    This paper reported on a new and easier way to prepare platinum (Pt)-WS2 nanostructures supported on Vulcan carbon and multi-walled carbon nanotubes (MWCNTs). The chemical synthesis included heat treatment. The study focused on the influence of exfoliated sulphide on Pt that modifies the catalytic properties and enhances the activity of pure Pt. The resulting material was characterized by X-ray Diffraction, Scanning Electron Microscopy and High-Resolution Transmission Electron Microscopy. The material was compared to commercial Pt/C. Synthesized Pt-WS2 nanoparticles exhibited high dispersion on both supporting carbon materials. The study showed that the amount of platinum can be optimized to be lower when diluted or coordinated in the chalcogenic environment. This represents a good alternative to tailor new materials based essentially on non-noble metals for electrochemical applications. It was concluded that the WS2 modified Pt nanoparticles are a promising material for electrochemical applications. 7 refs., 4 figs.

  13. Microporous layer based on SiC for high temperature proton exchange membrane fuel cells

    Science.gov (United States)

    Lobato, Justo; Zamora, Héctor; Cañizares, Pablo; Plaza, Jorge; Rodrigo, Manuel Andrés

    2015-08-01

    This work reports the evaluation of Silicon Carbide (SiC) for its application in microporous layers (MPL) of HT-PEMFC electrodes and compares results with those obtained using conventional MPL based on Vulcan XC72. Influence of the support load on the MPL prepared with SiC was evaluated, and the MPL were characterized by XRD, Hg porosimetry and cyclic voltammetries. In addition, a short lifetest was carried out to evaluate performance in accelerated stress conditions. Results demonstrate that SiC is a promising alternative to carbonaceous materials because of its higher electrochemical and thermal stability and the positive effect on mass transfer associated to its different pore size distribution. Ohmic resistance is the most significant challenge to be overcome in further studies.

  14. [Magician nature and human magician: on a fundamental analogy of alchemy].

    Science.gov (United States)

    Schott, Heinz

    2010-01-01

    This contribution discusses Paracelsism-influenced early-modern alchemy. There are notably two forms of analogy, each hierarchically arranged: a vertically ordered analogy ("as above, thus below") in which Nature is situated as mediator between God and man, and a horizontally ordered analogy ("as without, thus within") in which Nature's magic is regarded as a model for man, particularly expressed in the metaphor of "Vulcan" (smith) and doctor (e.g., Nature as inner healer). In alchemy the conventional "healing power of Nature" is pin-pointed: The doctor (as alchemist, magician) must unravel Nature's secrets and emulate her magic to perfect her work -particularly medicine production. Diagrams and historical depictions illustrate this.

  15. The Symbolic Wealth produced by the Rock Movement in the 80’s

    Directory of Open Access Journals (Sweden)

    GUSTAVO DOS SANTOS PRADO

    2012-01-01

    Full Text Available Music, as a source of research, originating from the vulcanization of theoretical and methodological postulates of Cultural History, places in the academic setting, a series of possibilities, challenges and risks, originating from its largely subjective character. In particular, such a source requires an interdisciplinary dialogue to provide a fruitful process of historicity. Aiming to contribute to this debate, the article in question makes use of semiotics as a mechanism for such a dialogue in an attempt to discuss the symbols created by the Rock movement in the eighties, taking into account the lyrics and melody. It is expected that the proposal causes concerns, resolutions and irresolutions, fundamental to the scientific development.

  16. 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.

  17. Reologi, sifat aging, termal, dan swelling dari campuran EPDM/NR dengan bahan pengisi carbon black N220

    Directory of Open Access Journals (Sweden)

    Arum Yuniari

    2016-06-01

    Full Text Available The blends of EPDM and NR are immiscible in nature and incompatible. Introducing maleic anhydride as a compatibilizer into the blends was expected to produce compatible blends with balanced mechanical properties. The purpose of this research was to determine the effect of EPDM/NR ratio on the rheological, aging, thermal and swelling properties of the blends. The variation of EPDM/NR ratio were 100/0, 80/20, 70/30, 60/40, 50/50, and 40/60 phr. The blends were mixed using two roll mill. The results showed that the addition of NR affects the maximum torque, scorch time, and optimum vulcanization time. In the blends, EPDM plays an important role in improving aging, swelling, thermal properties.

  18. Hot electron generation and transport using Kα emission

    Science.gov (United States)

    Akli, K. U.; Stephens, R. B.; Key, M. H.; Bartal, T.; Beg, F. N.; Chawla, S.; Chen, C. D.; Fedosejevs, R.; Freeman, R. R.; Friesen, H.; Giraldez, E.; Green, J. S.; Hey, D. S.; Higginson, D. P.; Hund, J.; Jarrott, L. C.; Kemp, G. E.; King, J. A.; Kryger, A.; Lancaster, K.; LePape, S.; Link, A.; Ma, T.; Mackinnon, A. J.; MacPhee, A. G.; McLean, H. S.; Murphy, C.; Norreys, P. A.; Ovchinnikov, V.; Patel, P. K.; Ping, Y.; Sawada, H.; Schumacher, D.; Theobald, W.; Tsui, Y. Y.; Van Woerkom, L. D.; Wei, M. S.; Westover, B.; Yabuuchi, T.

    2010-08-01

    We have conducted experiments on both the Vulcan and Titan laser facilities to study hot electron generation and transport in the context of fast ignition. Cu wires attached to Al cones were used to investigate the effect on coupling efficiency of plasma surround and the pre-formed plasma inside the cone. We found that with thin cones 15% of laser energy is coupled to the 40μm diameter wire emulating a 40μm fast ignition spot. Thick cone walls, simulating plasma in fast ignition, reduce coupling by x4. An increase of pre-pulse level inside the cone by a factor of 50 reduces coupling by a factor of 3.

  19. Technical inventions that enabled artificial infant feeding.

    Science.gov (United States)

    Obladen, Michael

    2014-01-01

    Artificial feeding of infants, called hand-feeding, was unsafe well into the 19th century. This paper aims to identify technical innovations which made artificial feeding less dangerous. In rapid succession from 1844 to 1886, the vulcanization of rubber, production of rubber teats, cooling machines for large-scale ice production, techniques for milk pasteurization, evaporation and condensation, and packing in closed tins were invented or initiated. Remarkably, most of these inventions preceded the discovery of pathogenic bacteria. The producers of proprietary infant formula made immediate use of these innovations, whereas in the private household artificial feeding remained highly dangerous - mostly because of ignorance about bacteria and hygiene, and partly because the equipment for safe storage, transport, preparation and application of baby food was lacking.

  20. Poly (ricinoleic acid) based novel thermosetting elastomer.

    Science.gov (United States)

    Ebata, Hiroki; Yasuda, Mayumi; Toshima, Kazunobu; Matsumura, Shuichi

    2008-01-01

    A novel bio-based thermosetting elastomer was prepared by the lipase-catalyzed polymerization of methyl ricinoleate with subsequent vulcanization. Some mechanical properties of the cured carbon black-filled polyricinoleate compounds were evaluated as a thermosetting elastomer. It was found that the carbon black-filled polyricinoleate compounds were readily cured by sulfur curatives to produce a thermosetting elastomer that formed a rubber-like sheet with a smooth and non-sticky surface. The curing behaviors and mechanical properties were dependent on both the molecular weight of the polyricinoleate and the amount of the sulfur curatives. Cured compounds consisting of polyricinoleate with a molecular weight of 100,800 showed good mechanical properties, such as a hardness of 48 A based on the durometer A measurements, a tensile strength at break of 6.91 MPa and an elongation at break of 350%.

  1. Visual evoked potentials in rubber factory workers.

    Science.gov (United States)

    Tandon, O P; Kumar, V

    1997-01-01

    Pattern reversal visual evoked potentials (pVEP) were studied in 39 male rubber factory workers in the age range of 18-55 years and 20 control subjects (aged 18-46 years) not exposed to the rubber factory environment. Results revealed that 20 (51%) rubber factory workers had abnormal latencies of wave P1 (dominant component of pVEP) as per accepted criteria of 99% tolerance limit set for the control group (i.e. any value above mean +3 SD of control was considered abnormal). The section-wise per cent distribution of abnormalities was vulcanization (83%), tubing (75%), calendering (60%), loading (38%) and mixing (14%). This study provides electrophysiological evidence that rubber factory environments affect the conduction processes in optical pathways from their origin in the retina to striate cortex. However, this study has its limitations in not identifying the specific chemical(s) causing these changes in VEP.

  2. TECHNOLOGY ASSESSMENT OF TIRE MOULD CLEANING SYSTEMS AND QUALITY FINISHING

    Directory of Open Access Journals (Sweden)

    Cristiano Fragassa

    2016-09-01

    Full Text Available A modern tire merges up to 300 different chemical elements, both organic and inorganic, natural and synthetic. During manufacturing, various processes are present such as mixing, calendering and extrusion, forming dozens of individual parts. Then, moulding and vulcanization inside special moulds provides the tire its final shape. Since the surface quality of moulds strongly affects the quality of tire, mould cleaning is a fundamental aspect of the whole tire production and cleaning techniques are in continuous development. This investigation proposes a global technology assessment of tire mould cleaning systems including uncommon solutions as multi-axis robots for cleaning on board by laser or dry ice, or ultrasonic cleaning which use cavitation. A specific attention is also focused on the industry adoption of spring-vents in moulds and how they are influencing the development the quality of final products.

  3. Infrared Spectroscopic Study on Structural Change and Interfacial Interaction in Rubber Composites Filled with Silica-Kaolin Hybrid Fillers

    Science.gov (United States)

    Chen, Y.; Guan, J.; Hu, H.; Gao, H.; Zhang, L.

    2016-07-01

    A series of natural rubber/styrene butadiene rubber/polybutadiene rubber composites was prepared with nanometer silica and micron kaolin by a dry modification process, mechanical compounding, and mold vulcanization. Fourier transform infrared spectroscopy and a scanning electron microscope were used to investigate the structural changes and interfacial interactions in composites. The results showed that the "seesaw" structure was formed particularly with the incorporation of silica particles in the preparation process, which would be beneficial to the dispersibility of fillers in the rubber matrix. The kaolinite platelets were generally arranged in directional alignment. Kaolinite with smaller particle size and low-defect structure was more stable in preparation, but kaolinite with larger particle size and high defect structure tended to change the crystal structure. The composite prepared in this research exhibited excellent mechanical and thermal properties.

  4. Exotic dense-matter states pumped by a relativistic laser plasma in the radiation-dominated regime.

    Science.gov (United States)

    Colgan, J; Abdallah, J; Faenov, A Ya; Pikuz, S A; Wagenaars, E; Booth, N; Culfa, O; Dance, R J; Evans, R G; Gray, R J; Kaempfer, T; Lancaster, K L; McKenna, P; Rossall, A L; Skobelev, I Yu; Schulze, K S; Uschmann, I; Zhidkov, A G; Woolsey, N C

    2013-03-22

    In high-spectral resolution experiments with the petawatt Vulcan laser, strong x-ray radiation of KK hollow atoms (atoms without n = 1 electrons) from thin Al foils was observed at pulse intensities of 3 × 10(20) W/cm(2). The observations of spectra from these exotic states of matter are supported by detailed kinetics calculations, and are consistent with a picture in which an intense polychromatic x-ray field, formed from Thomson scattering and bremsstrahlung in the electrostatic fields at the target surface, drives the KK hollow atom production. We estimate that this x-ray field has an intensity of >5 × 10(18) W/cm(2) and is in the 3 keV range.

  5. Penelitian pengaruh naphthenic oil dan HAF black terhadap sifat pampat tetap pada kompon lis kaca mobil

    Directory of Open Access Journals (Sweden)

    A Buchori

    1996-06-01

    Full Text Available The objective of the research is to know the influence of naphthenic oil and HAF black properties of the compression set by constant load and constant deflection rubber strip compound. Rubber strip compound is made from natural rubber (RSS and synthetic rubber (SBR 1502 with the addition of ingredient such as softener, activator, filler, anti oxidant, accelerator and vulcanizing agent. It should be carried out using base formula by varrying naphtenic oil 3; 5 and 7 parts and carbon black 45; 50 and 55 parts for 9 compounds, then it should be tested their physical properties, compression set by constant load and constant deflection. The test is actually able to fullfill the specification of SII 1999-86 “Lis karet kaca kendaraan bermotor”. The result of the test statistically prove that naphthenicc oil and HAF black influence the physical properties.

  6. The Properties of Sulfur Rubber Concrete (SRC)

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The mix designs and specimen preparation for the dry process and wet process of sulfur rubber concrete (SRC) were investigated.The compressive strength, corrosion-resistance and toughness were studied and discussed.The results show that SRC is corrosion-resistanct.Although the compressive strength of SRC decreases with increasing rubber content, the toughness increases instead.Adding micro-filler will improve the compressive strength of SRC. There is a threshold value for the sulfur content, at which the compressive strength and the work ability of SRC reach an optimum balanc e.The bond between rubber particles and surrounding sulfur is strong due to the vulcanization process that generates cross-links through S-C bonds.

  7. Electrocatalytic oxygen evolution reaction at a FeNi composite on a carbon nanofiber matrix in alkaline media

    Institute of Scientific and Technical Information of China (English)

    Xianghua An; Dongyoon Shin; Joey D. Ocon; Jae Kwang Lee; Young-il Son; Jaeyoung Lee

    2014-01-01

    Non-noble metals such as Fe and Ni have comparable electrocatalytic activity and stability to that of Ir and Ru in an oxygen evolution reaction (OER). In this study, we synthesized carbon nanofibers with embedded FeNi composites (FeNi-CNFs) as OER electrocatalysts by a facile route comprising electrospinning and the pyrolysis of a mixture of metal precursors and a polymer solution. FeNi-CNFs demonstrated catalytic activity and stability that were better than that of 20 wt%Ir on Vulcan carbon black in oxidizing water to produce oxygen in an alkaline media. Physicochemical and electrochemical characterization revealed that Fe and Ni had synergistic roles that enhanced OER activity by the uniform formation and widening of pores in the carbon structure, while the CNF matrix also contributed to the increased stability of the catalyst.

  8. Penelitian pengaruh variasi bahan pelunak naphtenic oil terhadap sifat fisis tegangan putus dan perpanjangan putus kompon karet untuk alas sapi

    Directory of Open Access Journals (Sweden)

    Luciawati Sunarjo

    1996-12-01

    Full Text Available The aim of this research is to know influence of plasticizer naphtenic oil to the physical properties of tensile strength and elongation at break of rubber compound for cowmats. It makes from Rubber Smoke Sheet (RSS and Styrene Butadiene Rubber 1502 (SBR as raw material with addition ingredients are Calcium Carbonate, FEF black, Stearic Acid, Zinc Oxide, Plasticizer Naphtenic Oil, Paraffine Wax, TMT, CBS, AOSP and Sulphur as Vulcanizing agent. Rubber compound for cowmats, formed to slab by hydraulic press at 1500C and 150 Kg/cm2. Than tested tensile strength and elongation at break. The result of this research indicated that platicizer naphtenic oil (x and tensile strength have regression equation as Y1 = 24.168 – 0.634 X (r = 0.87, while naphtenic oil and elongation at break have regression equation as Y2 = 236.32 + 21 X (r = 0.88.

  9. Productive response of Gerbera cultivar on pot with closed system; Prima esperienza di coltivazione di gerbera in vaso con sistema a ciclo chiuso

    Energy Technology Data Exchange (ETDEWEB)

    Martignon, G. [ENEL DSR, Centro Ricerche Ambiente e Materiali, Milan (Italy); Venezia, A.; Quattrini, E. [MIRAAF, Istituto Sperimentale per l`Orticultura (Italy) Sezione di Montanaso Lombardo

    1996-01-01

    The aim of the trial, carried out in the experimental station at Tavazzano, was to evaluate the productive response of four cultivar of gerbera (Maria, Vulcan, Adriana, Belair) grown on peat+perlite 1:1 v/v in pot, and sub irrigated through an intermittent flow of nutrient solution. A closed soil less culture system was utilized. The trail, started in april 1994, is still in progress. From june 1994 till july 1995 the cultivar Maria gave the best commercial yield. The average number of commercial cut flowers per plant was higher than that obtained in a previous trial growing gerbera on inert substrates with a semi-closed system; while it was not so far from those obtained on the same inert substrates but with an open system, considering the utilization in the previous trial of different cultivars of gerbera, and that harvesting time was longer.

  10. Palladium-based electrocatalysts for PEM applications

    Energy Technology Data Exchange (ETDEWEB)

    Grigoriev S; Lyutikova E; Fateev V [Hydrogen Energy and Plasma Technology Institute of Russian Research Center ' Kurchatov Institute' 1, Kurchatov sq., 123182 Moscow (Russian Federation); Martemianov S [Laboratoire d Etudes Thermiques, UMR CNRS no 6608, ESIP, Universite de Poitiers 40, avenue du Recteur Pineau, 86022 Poitiers Cedex (France); Lebouin C; Millet P [Institut de Chimie Moleculaire et des Materiaux d' Orsay, UMR CNRS no 8182, Universite Paris-sud XI 15, rue Georges Clemenceau, 91405 Orsay Cedex (France); Lebouin C [Laboratoire d Electrochimie et de Physicochimie des Materiaux et des Interfaces, CNRS-INPG-UJF 1130 rue de la Piscine, 38402 Saint Martin d Heres, (France)

    2006-07-01

    The goal of present study is development and investigation of nano-structured Pd-based electrocatalysts for hydrogen oxidation and proton reduction in proton exchange membrane (PEM) fuel cells and electrolyzers. Electro-active metallic structures were obtained by chemical reduction of precursor salts (including on Vulcan XC-72 carbon carrier) using ethylene glycol with addition of formaldehyde or using borohydride. Alternatively, Pd nano-clusters have been obtained from chemical reduction of precursor salts in per-fluorinated polymer Nafion membrane. Using the synthesized Pd-based catalyst membrane-electrode assemblies (MEAs) have been prepared and successfully tested in single fuel and electrolysis cells. Comparison of MEAs performances based on Pt, PtPd- and Pd-based electrocatalysts were provided. The present study demonstrates the principal possibility of partial or total replacement of the Pt by the Pd on the hydrogen electrode of PEM systems. (authors)

  11. Leaching of zinc compound from rubber stoppers into the contents of automatic atropine injectors.

    Science.gov (United States)

    Ellin, R I; Kaminskis, A; Zvirblis, P; Sultan, W E; Shutz, M B; Matthews, R

    1985-07-01

    This report describes how a material within the cartridge of an automatic injector contaminated its contents. On prolonged storage, a formulation that contained atropine produced lethality in mice. The toxic material originated from zinc compounds that were present in the rubber stopper and plunger of the container and that subsequently leached into the formulation. The contents of cartridges that contained greater than or equal to 0.75 mg/mL of solubilized zinc were lethal to at least 20% of the mice tested; those that contained 0.42 mg/mL showed no lethality. The problem resulted from the physicochemical properties of the rubber, not the concentration of zinc used in the vulcanization process.

  12. Surface Modification of Fillers and Curatives by Plasma Polymerization for Enhanced Performance of Single Rubbers and Dissimilar Rubber/Rubber Blends

    Science.gov (United States)

    Noordermeer, J. W. M.; Datta, R. N.; Dierkes, W. K.; Guo, R.; Mathew, T.; Talma, A. G.; Tiwari, M.; van Ooij, W.

    Plasma polymerization is a technique for modifying the surface characteristics of fillers and curatives for rubber from essentially polar to nonpolar. Acetylene, thiophene, and pyrrole are employed to modify silica and carbon black reinforcing fillers. Silica is easy to modify because its surface contains siloxane and silanol species. On carbon black, only a limited amount of plasma deposition takes place, due to its nonreactive nature. Oxidized gas blacks, with larger oxygen functionality, and particularly carbon black left over from fullerene production, show substantial plasma deposition. Also, carbon/silica dual-phase fillers react well because the silica content is reactive. Elemental sulfur, the well-known vulcanization agent for rubbers, can also be modified reasonably well.

  13. Effect of gamma irradiation on the properties of natural rubber/styrene butadiene rubber blends

    Directory of Open Access Journals (Sweden)

    A.B. Moustafa

    2016-09-01

    Full Text Available Blends of natural rubber (NR with styrene butadiene rubber (SBR with varying ratios have been prepared. Vulcanization of the prepared blends has been induced by irradiation of gamma rays with varying doses up to 250 kGy. Mechanical properties, namely tensile strength, tensile modulus at 100% elongation, elongation at break have been followed up as a function of irradiation dose as well as blend composition. Physical properties, namely gel fraction and swelling number have been followed up using benzene as a solvent. Thermal measurements namely thermogravimetric analysis were carried out. The results indicated that the addition of NR has improved the properties of NR / SBR blends. Also NR/SBR blend is thermally stable than NR alone.

  14. On the Damping Properties of Modified Ground Rubber Tires

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Large amounts of used rubber tires are discarded annually. A long time is neededfor them to degrade naturally. This poses two major problems: environmental pollutionand wastage of valuable rubber. On the other hand, with the harm of vibration and noisewidely recognized, desires to control them intensify. As an important means of vibrationcontrol, viscoelastic damping technology has advanced greatly. The need for cheap andhigh quality viscoelastic damping materials increases rapidly. This paper made a trial touse ground rubber tire (GRT) recovered from old tires to make damping materials. TheGRT is treated specially first. Then it was pressed into slabs and vulcanized. Finally, theproduct was cut into test samples. An Oberst beam was used to determine the loss factor βand storage modulus E. Results show that the damping materials exhibit good damping ability.

  15. Modified graphite filled natural rubber composites with good thermal conductivity

    Institute of Scientific and Technical Information of China (English)

    Junping Song; Lianxiang Ma; Yan He; Haiquan Yan; Zan Wu; Wei Li

    2015-01-01

    The rubber composites with good thermal conductivity contribute to heat dissipation of tires. Graphite filled natural rubber composites were developed in this study to provide good thermal conductivity. Graphite was coated with polyacrylate polymerized by monomers including methyl methacrylate, n-butyl acrylate and acrylic acid. The ratios between a filler and acrylate polymerization emulsion and those between monomers were varied. Eight types of surface modification formulas were experimentally investigated. Modification formula can affect coating results and composite properties greatly. The best coating type was achieved by a ratio of 1:1 between methyl methacrylate and n-butyl acrylate. The coating of graphite was thermal y stable in a running tire. Filled with modified graphite, the tire thermal conductivity reached up to 0.517–0.569 W·m-1·K-1. In addition, the mechanical performance was improved with increased crosslink density, extended scorch time and short vulcanization time.

  16. Electro-oxidation of methanol at the different carbon materials supported Pt nano-particles

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yu.; Zhang, Guojie; Zhou, Yiming; Tang, Yawen; Lu, Tianhong [The Laboratory of Electrochemistry, College of Chemistry and Material Science, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046 (China); Ma, Juan [Institute of Electrochemical Power Sources, Soochow University, Suzhou 215006 (China)

    2010-10-15

    Single-wall carbon nano-tubes (SWNTs), multi-wall carbon nano-tubes (MWNTs) and Vulcan XC-72 carbon (XC-72) are used as supporting carbon materials to prepare Pt/XC-72, Pt/SWNTs and Pt/MWNTs catalysts in tetrahydrofuran/water/ethanol mixture solution. Transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS) measurements demonstrate that the type of supporting carbon material affects significantly the morphology and the electronic structure of supported Pt nano-particles (NPs). Electrochemical measurements indicate that the Pt/SWNTs catalyst exhibited the highest current density, the lowest onset oxidation potential and the best stability for methanol electro-oxidation among the three samples, indicating SWNTs are an ideal anode catalyst supporting material for the practical application of direct methanol fuel cells. (author)

  17. Nanostructured polypyrrole/carbon composite as Pt catalyst support for fuel cell applications

    Science.gov (United States)

    Zhao, Hongbin; Li, Lei; Yang, Jun; Zhang, Yongming

    A novel catalyst support was synthesized by in situ chemical oxidative polymerization of pyrrole on Vulcan XC-72 carbon in naphthalene sulfonic acid (NSA) solution containing ammonium persulfate as oxidant at room temperature. Pt nanoparticles with 3-4 nm size were deposited on the prepared polypyrrole-carbon composites by chemical reduction method. Scanning electron microscopy and transmission electron microscopy measurements showed that Pt particles were homogeneously dispersed in polypyrrole-carbon composites. The Pt nanoparticles-dispersed catalyst composites were used as anodes of fuel cells for hydrogen and methanol oxidation. Cyclic voltammetry measurements of hydrogen and methanol oxidation showed that Pt nanoparticles deposited on polypyrrole-carbon with NSA as dopant exhibit better catalytic activity than those on plain carbon. This result might be due to the higher electrochemically available surface areas, electronic conductivity and easier charge-transfer at polymer/carbon particle interfaces allowing a high dispersion and utilization of deposited Pt nanoparticles.

  18. Estudio impacto ambiental y restauración de una actividad extractiva a cielo abierto

    OpenAIRE

    Guzmán Álvarez, Arnaldo Andrés

    2016-01-01

    En el presente proyecto realizaremos una restauración de la ampliación de una cantera, la cual fue realizada por una estudiante de la Escuela Politécnica Superior de Ingeniería de Manresa (EPSEM), El proyecto se realiza a través del software vulcan® el cual nos dará los resultados más óptimos, El espacio se restaura según las ley 12/1989 de restauración de espacios afectados por la minería. Con diversas funciones que tiene el software podremos obtener datos importantes de la restauración los ...

  19. Cyclophosphazene based conductive polymer-carbon nanotube composite as novel supporting material for methanol fuel cell applications.

    Science.gov (United States)

    Prasanna, Dakshinamoorthy; Selvaraj, Vaithilingam

    2016-06-15

    This present study reports the development of novel catalyst support of amine terminated cyclophosphazene/cyclophosphazene/hexafluoroisopropylidenedianiline-carbon nanotube (ATCP/CP/HFPA-CNT) composite. The ATCP/CP/HFPA-CNT composite has been used as a catalyst support for platinum (Pt) and platinum-gold (Pt-Au) nanoparticles towards electrooxidation of methanol in alkaline medium. The obtained anode materials were characterized by X-ray diffraction, transmission electron microscope and energy dispersive X-ray analysis. Electrocatalytic performances of Pt/ATCP/CP/HFPA-CNT and Pt-Au/ATCP/CP/HFPA-CNT catalysts were investigated by cyclic voltammetry, CO stripping and chronoamperometric techniques. The electrooxidation of methanol and CO stripping results conclude that the metal nanocatalyst embedded with ATCP/CP/HFPA-CNT composite shows significantly higher anodic oxidation current, more CO tolerance and lower onset potential when compared to that of the Pt/CNT and Pt/C (Vulcan carbon) catalysts.

  20. An Efficient and Practical Procedure for Synthesis of Diacetals

    Institute of Scientific and Technical Information of China (English)

    JIN Tong-Shou; YANG Mi-Na; FENG Guo-Liang; LI Tong-Shuang

    2003-01-01

    @@ Pentaerythritol diacetals are useful in many fields. They can be applied as plasticizers and vulcanizers of various polymeric materials, as raw materials for production of valuable resins and lacquers, as physiologically active substances and as defoamers for washing solution containing anionic surfactants. [ 1 ~ 4] Synthsis of diacetals from 2,2bis(hydroxymethyl)-1, 3-propanediol with aldehydes and ketones in refluxing toluene using ZrO2/S2O2- 8 solid superacid as catalyst in 85% ~ 99% yields has been described. The catalysts are easily regenerated by washing with ethanol followed by drying at 120 ℃ for 4 h and could be reused 5 times for the synthesis pentaerythritol diacetal 3e without significant loss of activity. This method possesses the advantages of the operational simplicity, short reaction time, use of inexpensive materials, non-corrosion, non-polluting, high yields and reusable catalysts.