WorldWideScience

Sample records for study rubber crystallization

  1. A non-affine micro-macro approach to strain-crystallizing rubber-like materials

    Science.gov (United States)

    Rastak, Reza; Linder, Christian

    2018-02-01

    Crystallization can occur in rubber materials at large strains due to a phenomenon called strain-induced crystallization. We propose a multi-scale polymer network model to capture this process in rubber-like materials. At the microscopic scale, we present a chain formulation by studying the thermodynamic behavior of a polymer chain and its crystallization mechanism inside a stretching polymer network. The chain model accounts for the thermodynamics of crystallization and presents a rate-dependent evolution law for crystallization based on the gradient of the free energy with respect to the crystallinity variables to ensures the dissipation is always non-negative. The multiscale framework allows the anisotropic crystallization of rubber which has been observed experimentally. Two different approaches for formulating the orientational distribution of crystallinity are studied. In the first approach, the algorithm tracks the crystallization at a finite number of orientations. In contrast, the continuous distribution describes the crystallization for all polymer chain orientations and describes its evolution with only a few distribution parameters. To connect the deformation of the micro with that of the macro scale, our model combines the recently developed maximal advance path constraint with the principal of minimum average free energy, resulting in a non-affine deformation model for polymer chains. Various aspects of the proposed model are validated by existing experimental results, including the stress response, crystallinity evolution during loading and unloading, crystallinity distribution, and the rotation of the principal crystallization direction. As a case study, we simulate the formation of crystalline regions around a pre-existing notch in a 3D rubber block and we compare the results with experimental data.

  2. Fundamental studies on dynamic wear behavior of SBR rubber compounds modified by SBR rubber powder

    OpenAIRE

    Euchler, Eric; Heinrich, Gert; Michael, Hannes; Gehde, Michael; Stocek, Radek; Kratina, Ondrej; Kipscholl, Reinhold; Bunzel, Jörg-Michael; Saal, Wolfgang

    2016-01-01

    The aim of this study is focused on the experimental investigation of dynamic wear behavior of carbon black filled rubber compounds comprising pristine styrene butadiene rubber (SBR) together with incorporated SBR ground rubber (rubber powder). We also analyzed and described quantitatively the service conditions of some dynamically loaded rubber products, which are liable to wear (e.g. conveyor belts, tires). Beside the well-known standard test method to characterize wear resistance at steady...

  3. Tear energy and strain-induced crystallization of natural rubber/styrene-butadiene rubber blend

    International Nuclear Information System (INIS)

    Noguchi, F; Akabori, K; Yamamoto, Y; Kawahara, S; Kawazura, T

    2009-01-01

    Strain-induced crystallization of natural rubber (NR), dispersed in styrene-butadiene rubber (SBR), was investigated in relation to dimensional feature of a dispersoid and crosslink density of NR by measuring tear energy (G) of crosslinked NR/SBR blends. The crosslinked NR/SBR blends in ratios of 1/9 and 3/7 by weight were prepared by mixing masticated NR and SBR with an internal mixer at a rotor speed of 30 rpm, followed by crosslinking with dicumyl peroxide on a hot press at 444 K for 60 min. The G, measured in wide-ranges of temperature and tear rate, was superposed into a master curve with a Williams-Landel-Ferry shift factor. The G of the NR/SBR(3/7) blend abruptly decreased to a level comparable to that of SBR at about melting temperature of NR crystals formed on straining. The temperature, at which the dramatic decrease in the G occurred, was associated with the dimensional feature of the NR dispersoid and the crosslink density.

  4. STUDY ON HEAT DYNAMIC LOADING OF RUBBER

    Directory of Open Access Journals (Sweden)

    T. I. Igumenova

    2015-01-01

    Full Text Available A number of studies on heat buildup in tire rubber surface scan method samples using a thermal imaging camera. Investigated the exothermic chemical reaction mechanical destruction rubber when loading designs permanent cyclic stretching with deformation of the working zone 50%. Percentage of deformation of the working zone was chosen on the basis of the actual data on the stretch-compression zone "Rusk" tires, which is the maximum level difference of deformation during run-in. Experiment plan provided for periodic relaxation samples of at least 72 hours for more accurate simulation of operation process of structural products. Created and processed data on temperature changes in samples for bar and line profile for rubber compounds with the introduction of nanomodifiers (fulleren technical carbon in comparison with the control sample without him. The data obtained reflect the nature of heat depending on the composition of the compound. Identified common patterns of thermal nature of physico-chemical process mechanical destruction rubbers. For rubber with nanomodifikatorom there has been an increase in the temperature interval reaction from a minimum to a maximum 2 degrees that is also linked to the rise in the average temperature of the reaction on the histogram also at 2-3 degrees of deformation under the same conditions and the level of cyclic loading. However, the temperature in the control sample that is associated with the beginning of the formation of hardened rubber structures, economies of Mallinz-Petrikeev, occurs with delay twice compared with modified Fullerenes. Measurement of physic-mechanical indicators selected in the course of testing of samples showed the beginning of formation of structure with increased strength of samples in the sample temperature zone that corresponds to the thermal effect of èndotermičeskomu recombination reactions of macromolecules.

  5. Rubber

    Science.gov (United States)

    Graves, D. F.

    The word "rubber" immediately brings to mind materials that are highly flexible and will snap back to their original shape after being stretched. In this chapter a variety of materials are discussed that possess this odd characteristics. There will also be a discussion on the mechanism of this "elastic retractive force." Originally, rubber meant the gum collected from a tree growing in Brazil. The term "rubber" was coined for this material by the English chemist Joseph Priestley, who noted that it was effective for removing pencil marks from paper. Today, in addition to Priestley's natural product, many synthetic materials are made that possess these characteristics and many other properties. The common features of these materials are that they are made up of long-chain molecules that are amorphous (not crystalline), and the chains are above their glass transition temperature at room temperature.

  6. A comparative investigation on strain induced crystallization for graphene and carbon nanotubes filled natural rubber composites

    Directory of Open Access Journals (Sweden)

    D. H. Fu

    2015-07-01

    Full Text Available Natural rubber containing graphene and carbon nanotubes (CNTs composites were prepared by ultrasonicallyassisted latex mixing. Natural rubber filled by both graphene and CNTs show significant enhanced tensile strength, while graphene exhibits a better reinforcing effect than CNTs. Strain-induced crystallization in natural rubber composites during stretching was determined by synchrotron wide-angle X-ray diffraction. With the addition of CNTs or graphene, the crystallization for natural rubber occurs at a lower strain compared to unfilled natural rubber, and the strain amplification effects were observed. The incorporation of graphene results in a faster strain-induced crystallization rate and a higher crystallinity compared to CNTs. The entanglement-bound rubber tube model was used to analyze the chain network structure and determine the network parameters of composites. The results show that the addition of graphene or CNTs has an influence on the molecular network structure and improves the contribution of entanglement to the conformational constraint, while graphene has a more marked effect than CNTs.

  7. Solubility Study of Curatives in Various Rubbers

    NARCIS (Netherlands)

    Guo, R.; Talma, Auke; Datta, Rabin; Dierkes, Wilma K.; Noordermeer, Jacobus W.M.

    2008-01-01

    The previous works on solubility of curatives in rubbers were mainly carried out in natural rubber. Not too much information available on dissimilar rubbers and this is important because most of the compounds today are blends of dissimilar rubbers. Although solubility can be expected to certain

  8. Performance Study of the Natural Rubber Composite with Clay Minerals

    International Nuclear Information System (INIS)

    Nyo Nyo Myint; Tin Tin Aye; Kyaw Myo Naing; Nyunt Wynn

    2008-03-01

    The preparation, characterization and some applications of natural rubber clay composite have been studied. This study investigated the possibility of natural rubber latex to replace some part of natural clays. In formulation of rubber clay composite from natural rubber latex and various clay minerals, three main steps were involved (i) preparation of latex cream (ii) prevulcanization of latex cream (iii) mixing vulcanized latex compound, with other ingredients. In each step, several parameters have been carefully investigated to optimize the performance of natural rubber clay composite production. The composite products were of better quality and can be considered to be more cost effective.

  9. Studies on the increased heat effect within the rubber tree rows of man-made rubber-tea community

    International Nuclear Information System (INIS)

    Ma Youxin

    1994-01-01

    Differences in the various components of thermal balance and the microclimatic factors within lower layers of rubber tree rows between a man-made rubber-tea community(RTC)and a pure rubber garden(PRG)in the coldest month were studied in Xishuangbanna,Yun-nan province

  10. Study on the properties of blend rubber prepared with grafted rubber and irradiated rubber by Gamma Rays

    International Nuclear Information System (INIS)

    Dafader, N. C.; Haque, M. E.; Islam, K. A.

    2004-05-01

    The blend rubbers were prepared by mixing γ-rays irradiated and monomer grafted rubbers. The monomers, methyl methacrylate (MMA) and styrene were used separately to prepare grafted rubber by exposure to radiation. The physico-chemical properties of the blend rubbers were evaluated. The tensile strength and elongation at break of the blend rubbers decrease whereas modulus at 500% elongation, swelling ratio and permanent set increase with the increased proportion of grafted rubber in the blend. The tear strength of the blend between irradiated and styrene grafted rubbers increases with the increased proportion of grafted rubber but that of the blend of irradiated and MMA grafted rubbers remains almost constant. The blend rubber could be used for special type of application like rubber thread, tube, catheter etc

  11. Mechanistic study of the rubber-brass adhesion interphase

    Science.gov (United States)

    Ashirgade, Akshay

    Brass-plated steel tire cords form an essential strengthening component of a radial automobile tire. Adhesion between rubber compound and brass-plated steel tire cord is crucial in governing the overall performance of tires. The rubber-brass interfacial adhesion is influenced by the chemical composition and thickness of the interfacial layer. It has been shown that the interfacial layer consists mainly of sulfides and oxides of copper and zinc. This thesis discusses the effect of changes in the chemical composition and the structure of the interfacial layers due to addition of adhesion promoter resins. Grazing incidence X-Ray Diffraction (GIXRD) experiments were run on sulfidized polished brass coupons previously bonded to six experimental rubber compounds. It was confirmed that heat and humidity conditions lead to physical and chemical changes of the rubber-steel tire cord interfacial layer, closely related to the degree of rubber-brass adhesion. Morphological transformation of the interfacial layer led to loss of adhesion after aging. The adhesion promoter resins inhibit unfavorable morphological changes in the interfacial layer thus stabilizing it during aging and prolonging failure. Tire cord adhesion tests illustrated that the one-component resins improved adhesion after aging using a rubber compound with lower cobalt loading. Based on the acquired diffraction profiles, these resins were also found to impede crystallization of the sulfide layer after aging leading to improved adhesion. Secondary Ion Mass Spectrometry (SIMS) depth profiles, SEM micrographs and AFM images strongly corroborated the findings from GIXRD. FTIR was utilized in a novel way to understand the degradation mechanism due to aging. A model for rubber and interfacial layer degradation is proposed to illustrate the effect of aging and the one-component resins. This interfacial analysis adds valuable new information to our understanding of the complex nature of the rubber-brass bonding

  12. Experimental Study and Dynamic Modeling of Metal Rubber Isolating Bearing

    International Nuclear Information System (INIS)

    Zhang, Ke; Zhou, Yanguo; Jiang, Jian

    2015-01-01

    In this paper, dynamic shear mechanical properties of a new metal rubber isolating bearing is tested and studied. The mixed damping model is provided for theoretical modeling of MR isolating bearing, the shear stiffness and damping characteristics of the MR bearing can be analyzed separately and easily discussed, and the mixed damping model is proved to be an rather effective approach. The test results indicate that loading frequency bears little impact over shear property of metal rubber isolating bearing, the total energy consumption of metal rubber isolating bearing increases with the increase in loading amplitude. With the increase in loading amplitude, the stiffness of the isolating bearing will reduce showing its “soft property”; and the type of damping force gradually changes to be close to dry friction. The features of “soft property” and dry friction energy consumption of metal rubber isolating bearing are very useful in practical engineering application. (paper)

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

    Science.gov (United States)

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

    2013-09-01

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

  14. A comparative study of natural rubber modified with ground tire rubber of truck

    OpenAIRE

    Binti Haridan, Ili Liyana

    2016-01-01

    The recycling of waste rubber has considerable significance in term of environmental protection and energy conservation. Considering that most of the relevant literature is concerned with tire recycling, the aim of this work was to develop and characterize the elastomeric samples of natural rubber (NR) composites filled with ground tire rubber of truck (GTR) devulcanized by microwave (DGTR). The tire rubber was ground under ambient conditions and subjected to microwave exposure for 3, 5 and ...

  15. Study of radiation induced structural changes in nitrile rubber

    International Nuclear Information System (INIS)

    Cardona, F.; Hill, D.J.T.; Pomery, P.J.; Whittaker, A.K.

    1996-01-01

    Full text: Copolymers of butadiene (BD) and acrylonitrile (AN) (NBR rubber), have become important commercial material. NBR rubbers are part of a larger classification of products often referred to as special-purpose rubbers. Oil resistance is the most important property of nitrile rubbers, and refer to the ability of the vulcanised product to retain its original physical properties such as modulus, tensile strength, abrasion resistance and dimensions, while in contact with oils and fuels. Despite these reported advantages very few studies have been conducted on the radiation yields and structural changes in nitrile rubbers during exposure to high energy radiation. In this study we are investigating the stability against gamma and UV radiation, to different doses in vacuum, of butadiene, acrylonitrile and NBR copolymers with different composition ratio BD/AN. The mechanism of radiation induced structural changes is being investigated using experimental techniques such as ESR, NMR (Solid-state), FT-IR, RAMAN and UV spectroscopy. Also is being investigated the effect of irradiation on the mechanical properties of stressed and unstressed samples by TGA, DSC, DMA, Instron and Creep Test measurements. So far the main effect have been a marked radiation-induced loss of unsaturation in the butadiene units, cis to trans isomerization and formation of crosslink structures (intermolecular and intramolecular). One of the main challenges in the studies of NBR polymers is to observe directly the crosslinks produces by the radiation induced chemical reactions. IR spectroscopy is unsuitable because of the low molar absorbity of the peaks related to intermolecular crosslinking and the overlapping of the peaks (1630-1670 cm-1) related to intramolecular crosslinking (cyclization), with conjugated and nonconjugated (-C=C-; -C=N-) double bonds. A. K. Whittaker has shown that crosslink structures in PBD can be detected and measured directly using solid-state 13 C NMR. This technique

  16. Study on heat under dynamic loading of rubber

    Directory of Open Access Journals (Sweden)

    T. I. Igumenova

    2016-01-01

    Full Text Available A number of studies on heat buildup in tire rubber surface scan method samples using a thermal imaging camera. Investigated the exothermic chemical reaction mechanical destruction rubber when loading designs permanent cyclic stretching with deformation of the working zone 50%. Percentage of deformation of the working zone was chosen on the basis of the actual data on the stretch-compression zone "Rusk" tires, which is the maximum level difference of deformation during run-in. Experiment plan provided for periodic relaxation samples of at least 72 hours for more accurate simulation of operation process of structural products. Created and processed data on temperature changes in samples for bar and line profile for rubber compounds with the introduction of nanomodificator (fullerene-containing technical carbon in comparison with the control sample without him. The data obtained reflect the nature of heat depending on the composition of the compound. Identified common patterns of thermal nature of physicochemical process mechanical destruction rubbers. For rubber with nanomodifikatorom there has been an increase in the temperature interval reaction from a minimum to a maximum 2 degrees that is also linked to the rise in the average temperature of the reaction on the histogram also at 2-3 degrees of deformation under the same conditions and the level of cyclic loading. However, the temperature in the control sample that is associated with the beginning of the formation of hardened rubber structures, economies of Mallinza-Petrikeeva, occurs with delay twice compared with modified Fullerenes. Measurement of physic-mechanical indicators selected in the course of testing of samples showed the beginning of formation of structure with increased strength of samples in the sample temperature zone that corresponds to the thermal effect of èndotermičeskomu recombination reactions of macromolecules.

  17. Positron annihilation studies on proton irradiated nitrile rubber

    International Nuclear Information System (INIS)

    Ravi Chandran, T.S.G.; Lobo, Blaise; Ranganath, M.R.; Gopal, S.; Sreeramalu, V.

    1996-01-01

    NBR (Nitrile Butadiene Rubber) was irradiated with 4 MeV proton beam from a variable energy cyclotron (VEC) at VEC Centre, Calcutta, to a flux of 10 16 ions/cm 2 , in a vacuum of 10 -9 Torr and was studied through positron lifetime measurements

  18. Band gaps in the low-frequency range based on the two-dimensional phononic crystal plates composed of rubber matrix with periodic steel stubs

    International Nuclear Information System (INIS)

    Yu, Kunpeng; Chen, Tianning; Wang, Xiaopeng

    2013-01-01

    In this paper, the numerical investigation of elastic wave propagation in two-dimensional phononic crystals composed of an array of steel stepped resonators on a thin rubber slab is presented. For the first time the rubber material is used as the matrix of the PCs. With the finite-element method, the dispersion relations of this novel PCs structure and some factors of the band structure are studied. Results show that, with the rubber material as matrix, the PC structures exhibit extremely low-frequency band gaps, in the frequency range of hundreds of Hz or even tens of Hz; the geometrical parameters and the material parameters can modulate the band gaps to different extents. Furthermore, to understand the low-frequency band gaps caused by this new structure, some resonance eigenmodes of the structure are calculated. Results show that the vibration of the unit cell of the structure can be seen as several mass–spring systems, in which the vibration of the steel stepped resonator decides the lower boundary of the first band gap and the vibration of the rubber that is not in contact with the resonator decides the upper boundary

  19. Feasibility study of a soil-based rubberized CLSM.

    Science.gov (United States)

    Wu, Jason Y; Tsai, Mufan

    2009-02-01

    The development of beneficial uses of recycled scrap tires is always in great demand around the world. The disposal of on-site surplus excavated soil and the production of standard engineering aggregates have also been facing increasing environmental and ecological challenges in congested islands, such as Taiwan. This paper presents an experimental study using recycled crumb rubber and native silty sand to produce a lightweight, soil-based, rubberized controlled low strength material (CLSM) for a bridge approach repair. To assess the technical feasibility of this material, the effects of weight ratios of cement-to-water (C/W) and water-to-solid (W/S), and of rubber content on the engineering properties for different mixtures were investigated. The presented test results include flowability, unit weight, strength, settlement potential, and bearing capacity. Based on the findings, we conclude that a soil-based rubberized CLSM with 40% sand by weight and an optimal design ratio of 0.7 for C/W and 0.35 for W/S can be used for the proposed bridge approach repair. Such a mixture has demonstrated acceptable flowability, strength, and bearing capacity. Its lower unit weight, negligible compressibility, and hydrocollapse potential also help ensure that detrimental settlement is unlikely to occur. The results illustrate a novel scheme of CLSM production, and suggest a beneficial alternative for the reduction of scrap tires as well as conservation of resources and environment.

  20. Studies on gamma irradiated rubber materials

    Science.gov (United States)

    Lungu, I. B.; Stelescu, M. D.; Cutrubinis, M.

    2018-01-01

    Due to the increase in use and production of polymer materials, there is a constant pressure of finding a solution to more environmental friendly composites. Beside the constant effort of recycling used materials, it seems more appropriate to manufacture and use biodegradable and renewable row materials. Natural polymers like starch, cellulose, lignin etc are ideal for preparing biodegradable composites. Some of the dynamic markets that use polymer materials are the food and pharmaceutical industries. Because of their desinfastation and sometimes sterility requirements, different treatment processes are applied, one of it being radiation treatment. The scope of this paper is to analyze the mechanical behaviour of rubber based materials irradiated with gamma rays at four medium doses, 30.1 kGy, 60.6 kGy, 91 kGy and 121.8 kGy. The objectives are the following: to identify the optimum radiation dose in order to obtain a good mechanical behaviour and to identify the mechanical behaviour of the material when adding different quantities of natural filler (20 phr, 60 phr and 100 phr).

  1. Study on mechanical properties of laminated rubber bearing with small shape factor

    International Nuclear Information System (INIS)

    Mazda, T.; Ootori, Y.; Yabana, S.; Hirata, K.; Ishida, K.

    1995-01-01

    Laminated rubber bearings with a small shape factor are regarded as one of the most promising isolation devices to reduce the vertical seismic load of a nuclear power plant. In this study, three types of natural rubber bearings with different aspect ratios (diameter/total thickness of rubber) and one high-damping rubber bearing are tested under varied loading conditions. Basic characteristics and ultimate characteristics of the bearings are made clear, and applicability of estimation formula and analysis method are verified

  2. Study on grafting of different types of acrylic monomers onto natural rubber by γ-rays

    International Nuclear Information System (INIS)

    Dafader, N.C.; Haque, M.E.; Akhtar, F.; Ahmad, M.U.

    2006-01-01

    A comparative study of various acrylic monomers for grafting onto natural rubber was done. The stability of natural rubber latex (NRL) against coagulum with monomer, mechanical properties of grafted rubbers and percent of grafting were investigated. The NRL with monomers, methylacrylate (MA), ethylacrylate (EA) and n-butylacrylate (n-BA), is unstable but it is stable with methyl methacrylate (MMA), n-butyl methacrylate (BMA) and cyclohexyl methacrylate (CHMA). The mechanical properties and degree of grafting attained a maximum at a total radiation dose of 4 kGy. The values of tensile properties of MMA and CHMA grafted rubbers are almost similar, and higher than those of BMA grafted rubbers. On the other hand, the degree of grafting for CHMA is higher than those of MMA and BMA grafted rubbers. The infrared (IR) spectra of monomer grafted natural rubber were also studied

  3. Study of the stability of the tragacanto rubber irradiated

    International Nuclear Information System (INIS)

    Rodriguez, M.; Romero, M.; Montes de Oca, N.

    2001-01-01

    Presently work was studied the processing by radiations of the tragacanto rubber powdered, with ends of achieving its sterilization. For the irradiation, the envelopes were placed in aluminum containers to reason of an envelope for container. The material underwent analysis of its viscosity and microbiological tests. They got ready solutions, according to the British pharmacopoeia, starting from the material irradiated with dose of D0-0, D1-5, D2-7.5, and D3-10 kGy. The smaller than the applied doses (5kGy) it produced a variation of 72% in the viscosity of the solutions, in comparison with the rubber without irradiating. They were carried out tests of sterility to the material irradiated with inferior dose of 5 kGy, being contaminated in all the cases

  4. Study of fuel properties of rubber seed oil based biodiesel

    International Nuclear Information System (INIS)

    Ahmad, Junaid; Yusup, Suzana; Bokhari, Awais; Kamil, Ruzaimah Nik Mohammad

    2014-01-01

    Graphical abstract: - Highlights: • This article presents the comparative studies of the fuel properties of rubber seed oil based biodiesel. • The design expert has been adopted for the optimization of the process variables. • The FTIR, cold flow properties and oxidation stability are the findings of present study. • All the fuel properties met the standards such as ASTM D6751 and EN 14214. • Present study reveals that rubber seed oil as a non-edible source potentially contributes for esters production. - Abstract: The scarcity of the fossil fuel, environmental pollution and food crisis are the world’s major issues in current era. Biodiesel is an alternative to diesel fuel, environment friendly and biodegradable and is produced from either edible or non-edible oils. In this study, a non-edible rubber seed oil (RSO) with high free fatty acid (FFA) content of 45% were used for the production of biodiesel. The process comprises of two steps. The first step is the acid esterification to reduce the FFA value and the second step is the base transesterification. The response surface methodology (RSM) was used for parametric optimization of the two stage processes i.e. acid esterification and base transesterification. The yield of biodiesel was analyzed using gas chromatography. The FTIR (Fourier Transform Infra-Red) spectrum was also determined to confirm the conversion of fatty acid to methyl esters. The fuel properties were analyzed according to the ASTM D6751 and EN14214 and were compared with the previous finding of researchers. All analyzed properties fulfilled the biodiesel standard criteria

  5. Study on cord/rubber interface at elevated temperatures by H-pull test method

    Science.gov (United States)

    Jamshidi, M.; Afshar, F.; Mohammadi, N.; Pourmahdian, S.

    2005-08-01

    Cords are used as reinforcing materials in rubber compounds. To increase cord/rubber interfacial adhesion, they are coated by an adhesive (usually based on resorcinol-formaldehyde-latex). These composites are used in many sectors such as tire and belt industries. Cord/rubber adhesion strength is an important aspect to determine the durability of system. Due to temperature increase during running tires, the adhesion energy becomes different from initial one. To study cord/rubber interface at elevated temperatures, H-adhesion test method was used. H-pull test is a simple method for adhesion evaluation at ambient temperature, so it is usually used for material quality control. In this research, cord/rubber systems were vulcanized at different temperatures and H-adhesion of samples were evaluated at elevated temperatures. Also cord/rubber interface was studied by ATR analyze to determine interfacial interactions kind.

  6. Study on determination of durability analysis process and fatigue damage parameter for rubber component

    International Nuclear Information System (INIS)

    Moon, Seong In; Cho, Il Je; Woo, Chang Su; Kim, Wan Doo

    2011-01-01

    Rubber components, which have been widely used in the automotive industry as anti-vibration components for many years, are subjected to fluctuating loads, often failing due to the nucleation and growth of defects or cracks. To prevent such failures, it is necessary to understand the fatigue failure mechanism for rubber materials and to evaluate the fatigue life for rubber components. The objective of this study is to develop a durability analysis process for vulcanized rubber components, that can predict fatigue life at the initial product design step. The determination method of nonlinear material constants for FE analysis was proposed. Also, to investigate the applicability of the commonly used damage parameters, fatigue tests and corresponding finite element analyses were carried out and normal and shear strain was proposed as the fatigue damage parameter for rubber components. Fatigue analysis for automotive rubber components was performed and the durability analysis process was reviewed

  7. Comparative studies on the mechanical properties of natural rubber and natural rubber filled with multi-walled carbon nanotubes

    Science.gov (United States)

    Ismail, R.; Ibrahim, A.; Rusop, M.; Adnan, A.

    2018-05-01

    The present article compares the mechanical properties of natural rubber (NR) and carbon nanotubes (CNTs) filled natural rubber composites. Four types of nanocomposite specimens are fabricated with different MWCNT loadings: 0 wt% (pure natural rubber), 1 wt%, 3 wt%, and 5 wt%. The specimens are tested for their mechanical properties. It is observed that the tensile strength, hardness and elongation break of CNTs filled rubber composites are remarkably higher than that of raw rubber indicating the inherent reinforcing potential of CNTs. Percentage of the elongation at break of rubber CNTs composites is lower than that of raw rubber.

  8. Study for the degumming pretreatment of rubber seed oil

    Science.gov (United States)

    Li, X. Y.; Chen, Y. B.; Zhang, X.; Souliyathai, D.; Yang, S. P.; Wang, Q.

    2017-11-01

    With the rapid development of the aviation industry, appearing of the aviation carbon tax and the increasingly serious environmental problems have forced the world to research the development of renewable bio-aviation fuel. Renewable biological aviation fuel contains phosphorus that could reduce the synthesis of noble metal catalysts such as Pd, Pt activity. In order to get low content of phosphorus in degummed oil of non-edible vegetable oil, in this paper, with rubber seed oil as raw material, making the experiment of single factor at the influence of temperature, stirring speed, adding amount of monoethanolamine (MEA) and water amount. The experimental results show that the added amount of MEA is 2.5% in the weight of oil, and temperature is 60°C, while the amount of added water is 2% in the weight of oil, reaction time is 40 min, and stirring speed is 200 r/min. Under these conditions, the phosphorus content of rubber seed oil can be reduced to below 3 mg/kg, degumming rate is 91.37%, and the degumming effects are obvious, which also provides some foundation for follow-up studies.

  9. A theoretical and experimental study on solubility of curatives in rubbers

    NARCIS (Netherlands)

    Guo, R.; Talma, Auke; Datta, Rabin; Dierkes, Wilma K.; Noordermeer, Jacobus W.M.

    2009-01-01

    The current study provides indications for improving the properties of dissimilar rubber blends. As solubility is a key factor for the distribution and a driving force for the migration of curatives in dissimilar rubber blends, it is of importance to have precise data of their solubilities. The

  10. Wave bandgap formation and its evolution in two-dimensional phononic crystals composed of rubber matrix with periodic steel quarter-cylinders

    Science.gov (United States)

    Li, Peng; Wang, Guan; Luo, Dong; Cao, Xiaoshan

    2018-02-01

    The band structure of a two-dimensional phononic crystal, which is composed of four homogenous steel quarter-cylinders immersed in rubber matrix, is investigated and compared with the traditional steel/rubber crystal by the finite element method (FEM). It is revealed that the frequency can then be tuned by changing the distance between adjacent quarter-cylinders. When the distance is relatively small, the integrality of scatterers makes the inner region inside them almost motionless, so that they can be viewed as a whole at high-frequencies. In the case of relatively larger distance, the interaction between each quarter-cylinder and rubber will introduce some new bandgaps at relatively low-frequencies. Lastly, the point defect states induced by the four quarter-cylinders are revealed. These results will be helpful in fabricating devices, such as vibration insulators and acoustic/elastic filters, whose band frequencies can be manipulated artificially.

  11. Preparation and study of new rubber to steel adhesive systems

    International Nuclear Information System (INIS)

    Labaj, I.; Ondrusova, D.; Dubec, A.; Pajtasova, M.; Kohutiar, M.

    2017-01-01

    The present paper deals with the preparation of new rubber to steel adhesive systems using the steel surface treatment by applying the adhesive coats based on Co (II) and Cu(II) salts. For demonstration of coats chemical composition EDX analysis was used. The topography and microstructure of prepared adhesive coats were investigated using Scanning Electron Microscopy. Finally the efficiency of adhesion between rubber blends and coated metal steel pieces was evaluated according to Test ASTM D429 Rubber to metal adhesion, method A. The adhesive strength resulting values of prepared steel samples with new adhesive coats were compared with samples covered with adhesive systems commonly used in industry. (authors)

  12. Study on the Secant Segmentation Algorithm of Rubber Tree

    Science.gov (United States)

    Li, Shute; Zhang, Jie; Zhang, Jian; Sun, Liang; Liu, Yongna

    2018-04-01

    Natural rubber is one of the most important materials in the national defense and industry, and the tapping panel dryness (TPD) of the rubber tree is one of the most serious diseases that affect the production of rubber. Although considerable progress has been made in the more than 100 years of research on the TPD, there are still many areas to be improved. At present, the method of artificial observation is widely used to identify TPD, but the diversity of rubber tree secant symptoms leads to the inaccurate judgement of the level of TPD. In this paper, image processing technology is used to separate the secant and latex, so that we can get rid of the interference factors, get the exact secant and latex binary image. By calculating the area ratio of the corresponding binary images, the grade of TPD can be classified accurately. and can also provide an objective basis for the accurate identification of the tapping panel dryness (TPD) level.

  13. Studies on Hydrogenation of Liquid Natural Rubber Using Diimide

    Directory of Open Access Journals (Sweden)

    Nur Hanis Adila Azhar

    2015-01-01

    Full Text Available Liquid natural rubber (LNR is a depolymerized natural rubber (NR which consists of shorter polymeric chains and lower molecular weight (Mw90% was achieved by manipulating the reaction parameters such as sources of diimide, TSH concentration, solvent, and reaction time. The optimum condition was 3 : 1 weight ratio of TSH/LNR in o-xylene at 130°C in 4-hour reaction period.

  14. A study on creep properties of laminated rubber bearings. Pt. 1. Creep properties and numerical simulations of thick rubber bearings

    International Nuclear Information System (INIS)

    Matsuda, Akihiro; Yabana, Shuichi

    2000-01-01

    In this report, to evaluate creep properties and effects of creep deformation on mechanical properties of thick rubber bearings for three-dimensional isolation system, we show results of compression creep test for rubber bearings of various rubber materials and shapes and development of numerical simulation method. Creep properties of thick rubber bearings were obtained from compression creep tests. The creep strain shows steady creep that have logarithmic relationships between strain and time and accelerated creep that have linear relationships. We make numerical model of a rubber material with nonlinear viscoelastic constitutional equations. Mechanical properties after creep loading test are simulated with enough accuracy. (author)

  15. A molecular study of gas solubility in nitrile rubber

    Science.gov (United States)

    Khawaja, Musab; Mostofi, Arash; Sutton, Adrian

    2015-03-01

    One of the most important uses of elastomers in the oil industry is for seals to encase and protect sensitive monitoring equipment from contamination by gases and liquids at the high pressures and temperatures in the well. Failure of such seals sometimes occurs on decompression when they are returned to the surface. The conditions in the well lead to gases being absorbed by Nitrile rubber (NBR) seals. NBR exhibits a strong permselectivity towards CO2 compared to other gases; something attributed experimentally to the enhanced solubility of CO2. In this study an explanation is sought at the molecular level for this phenomenon. A series of molecular mechanics calculations are performed to compute solubilities of different gases in NBR. The effect of acrylonitrile content on their solubilities is studied for the first time by simulation, and we discuss the important issue of convergence with respect to the sampling of different elastomer configurations. It is observed that the presence of cyano groups has a marked impact on the solubility of CO2 and an explanation is offered.

  16. From rubber tree homeland to rubber tree plantation: Jacques Huber and his studies on the culture of heveas in the East (1911-1912

    Directory of Open Access Journals (Sweden)

    Anna Raquel de Matos Castro

    2009-12-01

    Full Text Available The paper deals with the trip of the Swiss botanist Jacques Huber (1867-1914 to the main eastern rubber producing countries between 1911 and 1912. This trip was intended to develop studies on the cultivation of Hevea brasiliensis in that region. Huber was commissioned with the task by the State of Pará governor João Coelho, who wanted to find solutions to the downfall of the regional economy. The economy of Amazonia was primarily based on rubber extractivism and was seriously endangered due the market controlled by England from eastern plantations. Back to Brazil, Huber published a report with information about the society, economy and environment where the rubber trees were cultivated. The report compiles scientific observations and the topics that motivated the regional elites in that context. In addition to the brief analyses of the report, photographs took by Huber in the East of rubber trees plantations, tree tapping and local workers are published.

  17. Comparison study of crosslink density determination in cured rubber

    International Nuclear Information System (INIS)

    El-sabbagh, S.H.; Yehia, A.A.

    2005-01-01

    The crosslink density is an important property affecting the major characteristics of cured rubber. The crosslink density can be determined by different methods such as: 1. Dynamic mechanical method using the data of stress-strain relationship. 2. Mooney-Rivlin equation 3. Swelling in organic solvents measurements using Flory-Rehner equation. The crosslink density calculated by the previous methods were discussed and compared with each other for cured NR, SBR and NBR. The obtained data showed that the dynamic-mechanical method can be considered as a simple and reliable method for determination of crosslink density for cured rubbers

  18. Natural rubber: leather composites

    OpenAIRE

    Ravichandran,K.; Natchimuthu,N.

    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 ...

  19. Blends of natural rubber and polyurethane lattices studied by solid-state NMR

    International Nuclear Information System (INIS)

    Ricardo, Nagila M.P.S.; Franca, Francisco C.F. de; Price, Colin; Heatley, Frank

    2001-01-01

    Molecular mixing in films formed from a mixture of a polyurethane and natural rubber lattices has been studied using 1 H and 13 C solid-state NMR. The techniques employed include 1 H relaxation measurements, and 13 C cross-polarisation and direct excitation methods. The spectra of the blends were essentially a weighted superposition of the spectra of the individual components, indicating that the polyurethane and rubber remained phase-separated in large domains. (author)

  20. Experimental and modelling studies on the solvent assisted hydraulic pressing of dehulled rubber seeds

    NARCIS (Netherlands)

    Abduh, Muhammad Yusuf; Rasrendra, C. B.; Subroto, Erna; Manurung, Robert; Heeres, Hero J.

    2016-01-01

    A systematic study on the expression of rubber seed oil from dehulled rubber seeds in a hydraulic press was performed in the presence and absence of ethanol. The effect of seed moisture content (0–6 wt%, w.b.), temperature (35–105 °C), pressure (15–25 MPa) and ethanol to seed ratio (0–21%v/w) on the

  1. Performance of maleated castor oil based plasticizer on rubber: rheology and curing characteristic studies

    Science.gov (United States)

    Indrajati, I. N.; Dewi, I. R.

    2017-07-01

    The objective of this study was to evaluate the performance of maleated castor oil (MACO) as plasticizer on natural rubber (NR), ethylene propylene diene monomer (EPDM), and nitrile butadiene rubber (NBR). The parameter studied were involving rheological, curing and swelling properties. The MACOs were prepared by an esterification reaction between castor oil (CO) and maleic anhydride (MAH) with the help of xylene as water entrainer to improve water removal. Resulting oils then applied as a plasticizer in each of those rubbers within a fixed loading of 5 phr. Comparison has been made to evaluate the performance of MACO and conventional plasticizer (paraffinic oil for NR and EPDM, DOP for NBR) on each rubber. Rheology, curing characteristic and swelling of each rubber were studied. The results showed that rubber (NR/EPDM/NBR) plasticized with MACO had given similar flow characteristic to conventional plasticizers. MACO exhibited slow curing, confirmed by higher t90, but the scorch safety was of the same magnitude. MAH loading tended to decrease the flow properties and curing rate, while scorch time (ts2) was independent.

  2. Studies of properties of rubber wood with impregnation of polymer

    Indian Academy of Sciences (India)

    Impregnation of rubber wood has been carried out under different conditions by using styrene as grafting monomer and glycidyl methacrylate (GMA) as crosslinker. Properties such as dimensional stability, water absorption, hardness, tensile strength, flexural strength, etc of the impregnated wood have been checked and ...

  3. Case study of rutting performance of HMA modified with waste rubber powder

    Directory of Open Access Journals (Sweden)

    G.H. Shafabakhsh

    2014-01-01

    Full Text Available Low resistance against dynamic loads and short service life of pavement are the most significant problems in the conservation and maintenance of roads, to the extent that, annually enormous costs are spent in order to improve capabilities of road services in the country. Research shows that the use of some wastes such as waste rubber powder in asphalt mixtures not only increase its serves life but also cause to reduce production costs; furthermore, recycling the crumb rubber has also considerably environmental benefits environmental benefits such as reduced need for landfill, less atmospheric pollution from burning. In this paper, the effect of adding waste rubber powder on the rutting performance of asphalt mixtures has been studied. In order to compare the performance of rubberized asphalt mixtures and conventional asphalt, wheel track test has been used. The results of this study show that the use of rubber powder caused a significant decrease in the rate of rutting depth of rubber asphalt mixtures compared to control samples.

  4. New Insights into the Relationship Between Network Structure and Strain Induced Crystallization in Unvolcanized Natural Rubber by Synchrotron X-ray Diffraction

    International Nuclear Information System (INIS)

    Toki, S.; Hsiao, B.; Amnuaypornsri, S.; Sakdapipanich, J.

    2009-01-01

    The relationship between the network structure and strain-induced crystallization in un-vulcanized as well as vulcanized natural rubbers (NR) and synthetic poly-isoprene rubbers (IR) was investigated via synchrotron wide-angle X-ray diffraction (WAXD) technique. It was found that the presence of a naturally occurring network structure formed by natural components in un-vulcanized NR significantly facilitates strain-induced crystallization and enhances modulus and tensile strength. The stress-strain relation in vulcanized NR is due to the combined effect of chemical and naturally occurring networks. The weakness of naturally occurring network against stress and temperature suggests that vulcanized NR has additional relaxation mechanism due to naturally occurring network. The superior mechanical properties in NR compared with IR are mainly due to the existence of naturally occurring network structure.

  5. Sem-edx and ftir studies of chlorinated rubber coating

    International Nuclear Information System (INIS)

    Bano, H.; Khan, M.I.

    2013-01-01

    Summary: Anticorrosive performance of chlorinated rubber coating has been investigated by visual examination, Scanning electron microscopy (SEM)/Energy dispersive X-ray (EDX) analysis and Fourier transform infrared (FTIR) spectroscopy. After surface preparation, commercially available coating system based on chlorinated rubber (primer)/chlorinated rubber (topcoat) formulation was applied on mild steel test panels (10cm x 15cm sizes). Prepared coated panels were exposed at marine, industrial and urban test sites located in Karachi, Pakistan according to ISO 8565 norm. Accelerated testing was performed by using a salt spray chamber (ASTM B117 norm). Accelerated weathering methods are the methods in which the factors responsible for the degradation of coatings are artificially intensified in order to achieve the rapid degradation of coatings. Visual examination of blistering and rusting as well as SEM micrographs indicated a more severe degradation of the coating surface characteristics at natural exposure testing sites (particularly at marine test site) than for accelerated (salt spray) testing. EDX determination of the Oxygen/Carbon (O/C) ratios also indicated increased degradation at natural test sites compared to the accelerated (salt spray) testing. Photooxidation of the binder results in the formation of carbonyl compounds as revealed by FTIR spectroscopy which also indicated dehydrochlorination. (author)

  6. Studies for methods to improve thermostability of the functionalized butadiene styrene rubbers

    Directory of Open Access Journals (Sweden)

    A. L. Rumyantseva

    2018-01-01

    Full Text Available It is well known that the tire performance properties can deteriorate in the processes of production, processing, storage and operation. One of the reasons for that is a series of processes occurring in the polymer under the influence of different factors: thermal, mechanical or chemical. This problem is particularly relevant for functionalized polymers, as functional groups can interact with each other, causing side cross linking reactions that lead to a deterioration of consumer properties of the products. The main purpose of this work was to study influence of several key factors on the thermostability of functionalized rubbers in order to find a solution: different types of antioxidants, rubber polymerizate stripping conditions and rubber processing. In accordance with the problem, solutions were found and work was carried out in several directions: changing the pH of the medium in the rubber stripping and using antioxidants containing carbonyl groups located in ?-positions to methylene groups, namely Irganox 1520 and Irganox 1076. As an evaluation factor, thermal treatment was selected in two modes: at 100 °C for 48 hours and after extruder at 130 °C for 5 minutes + 100 °C for 48 hours. At the same time, the following parameters were determined: molecular weight characteristics and Mooney viscosity of the starting polymers and after thermal aging. During the experiments, it was found that the acidity of the medium in the water degasser does not affect the crosslinking of the functionalized rubber during storage. In addition, a study was made of the effect of the type of antioxidant and its quantity on the thermal stability of functionalized styrene butadiene rubbers, as well as the study of the effect of the content of the modifying agent on the thermal stability of the product. It has been found that the use, as antioxidants, of carbonyl compounds containing a methylene group at the ?-position, leads to inhibition of the cross

  7. Rubber industry

    Science.gov (United States)

    Staszak, Maciej

    2018-03-01

    Following chapter presents short introductory description of rubber and rubber industry. The main problem of rubber industry is the way of the usage of spent tires. Furthermore very important group of problems arise considering the metal and nonmetal additives which are significant component of the vulcanized rubber. The key attention is dedicated to typical ways of rubber usage in utilization and recovery of metals from spent rubber materials concentrating specifically on used tires processing. The method of recovery of rare metals from rubber tires was described. The rubber debris finds widest use in the field of waste metal solutions processing. The environmental pollution caused by metals poses serious threat to humans. Several applications of the use of waste rubber debris to remove metals from environmental waters were described. Moreover, the agriculture usage of waste tire rubber debris is described, presenting systems where the rubber material can be useful as a soil replacement.

  8. Raman study of ? crystals

    Science.gov (United States)

    Pimenta, M. A.; Oliveira, M. A. S.; Bourson, P.; Crettez, J. M.

    1997-09-01

    In this work we present a polarized Raman study of 0953-8984/9/37/020/img7 single crystals for several values of the concentration 0953-8984/9/37/020/img8 made using different scattering geometries. The Raman spectra, composed of broad bands, have been fitted in accordance with a symmetry analysis which allowed us to assign the vibrational modes, and determine their frequencies and damping constants. The results are compatible with an average hexagonal symmetry for the solid solutions with x in the range 0953-8984/9/37/020/img9. In each of the spectra we found two bands at about 590 and 0953-8984/9/37/020/img10, probably associated with the existence of 0953-8984/9/37/020/img11 structures in the solid solutions.

  9. A Study on the Rheological Properties of Recycled Rubber-Modified Asphalt Mixtures

    Directory of Open Access Journals (Sweden)

    Murat Karacasu

    2015-01-01

    Full Text Available Using waste rubber in asphalt mixes has become a common practice in road construction. This paper presents the results of a study on the rheological characteristics of rubber-modified asphalt (RMA concrete under static and dynamic loading conditions. A number of static and dynamic creep tests were conducted on RMA mix specimens with different rubber sizes and contents, and a series of resonant column tests were conducted to evaluate the shear modulus and damping values. To simulate the stress-strain response of traffic-induced loading, the measurements were taken for different confining pressures and strain levels. The results of the study indicated that rubber modification increases stiffness and damping ratio, making it a very attractive material for use in road construction. However the grain size of the rubber is very important. Although RMA may cost up to 100% more than regular asphalt, the advantages it brings, such as an increased service life of the road and proper waste utilization contributing to a more sustainable infrastructure, may justify the added cost.

  10. Study of the mechanism of radiation-chemical transformations in rubber-resinous materials

    International Nuclear Information System (INIS)

    Sharova, L.B.; Astakhova, L.G. Trufanova, N.D.; Persinen, A.A.; Vasil'ev, I.A.

    1993-01-01

    Materials based on butadiene-nitrile rubbers reinforced by phenol-formaldehyde resins presently find wide application as reliable heat-insulating coatings for various metallic constructions and are utilized under exposure to ionizing radiation. In this connection, when estimating the assured lifetime of heat-insulating coatings, it is necessary to take into account the character and degree of their radiation-chemical transformations. The aim of the present work was to study the radiation-chemical transformations of materials based on a composite of butadiene-nitrile rubber and phenol-formaldehyde resin. The investigations were carried out on model materials S-O, S-25, S-100, S-130, and S-150 based on the SKN-40M rubber with a varied content of SF-010A brand phenol-formaldehyde resin, the content of which in parts by weight per 100 parts by weight of rubber is indicated in the specifications of the materials. The possible directions of the radiation-chemical transformations in the rubber-resinous vulcanizates were studied by the method of disrupted total internal reflection (MDTIR) IR spectroscopy

  11. EBM Irradiation Modification of Palm Oil Biomass Filled Reclaimed Rubber-Mechanical Study

    International Nuclear Information System (INIS)

    Pairu Ibrahim; Ratnam, C.T.

    2016-01-01

    In this project, a study was done to evaluate the mechanical properties of reclaimed rubber filled with palm oil empty fruit bunch (EFB) as fillers. The purpose of filler is to help improve the properties of reclaim rubber and the addition of filler is fixed at 10 parts. Palm oil EFB was obtained from Malaysian Palm Oil Board (MPOB) and prepared at different size. Various samples were prepared with various sizes of filler blended with reclaim rubber using Haake Hot Mixer. The compounds were then compression-moulded at 120 degree Celsius using an electrically heated hydraulic press for their cure times. Dumbbell-shaped tensile and test specimens for hardness and impact test were punched out from the compression-moulded slabs along the mill grain direction. From the test result, it was found that the addition of fillers able to increase the mechanical properties of reclaim rubber and the smaller size of fillers added produced higher tensile properties. The study shows that the palm oil EFB suitable to be used as filler in reclaim rubber. (author)

  12. 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.

  13. Studies of chemical interactions between chlorosulphonated polyethylene and nit rile rubber

    Directory of Open Access Journals (Sweden)

    Marković Gordana

    2005-01-01

    Full Text Available Highly polar rubbers interact with each other through their active functional groups via condensation or substitution reactions at high temperature. Chlorosulphonated polyethylene (CSM rubber is a highly reactive rubber, the reactivity of with is due to the -SO2CI groups. When CSM reacts with nit rile rubber (NBR, a chemical reaction takes place between the two rubbers at high temperature. Fourier transform infrared (FTIR studies support that CSM/NBR (50/50 w/w isothermally induces a self cross-linking blend, when cross-linking takes place via the acrylonitrile groups of NBR and the SO2CI groups or the insitu generated allyl chloride moieties of CSM. There is a loss of some -CN groups during cross-linking. This may be due to an attack on the -CN groups by HCI (produced during the heating of CSM in the presence of inherent moisture in the polymers. Amid type of linkage is formed due to cross-linking.

  14. Erratum to: Study on Chloride Ion Penetration Resistance of Rubberized Concrete Under Steady State Condition

    Directory of Open Access Journals (Sweden)

    Md Noor Nurazuwa

    2016-01-01

    In this paper, the effect of crumb rubber, CR as fine aggregate in the concrete to enhance concrete durability against chloride ion diffusion was studied. Chloride ion diffusion in rubberized concrete was tested by migration test under steady state condition. Concrete specimen with water-to-cement ratio of 0.50 was prepared to study the CR effectiveness in comparison with lower water-to-cement ratio. In addition, 10% silica fume, SF was added to provide denser concrete and to understand its effectiveness against chloride ion diffusion. Results showed that chloride transport characteristics were improved by the increasing amount of CR in all mixed due to the fact that CR has the ability to repel water. Meanwhile, rubberized concrete with w/c = 0.35 gave better resistance against chloride ion penetration compared to w/c = 0.50. This was much improved with combination of CR and SF.

  15. 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.

  16. Study on design procedure of three-dimensional building base isolation system using thick rubber bearing

    International Nuclear Information System (INIS)

    Yabana, Shuichi; Matsuda, Akihiro

    2003-01-01

    In this study, design procedure on three-dimensional base isolation system is developed. Base isolation system proposed by CRIEPI uses thick rubber bearing and damper as isolation device. As for thick rubber bearings, design formula for evaluating vertical stiffness is proposed, and design conditions regarding size and vertical pressure are investigated. Figure-U type lead damper is proposed as three-dimensional damper and by loading tests its mechanical characteristics is evaluated. The concept of multi-layered interconnected rubber bearing, which is advantageous over large scale bearing in manufacturability, is proposed and its good performance is confirmed by the loading test. Through the response analyses, it is shown the rocking response of the proposed three-dimensional base isolation system is very small and not influential to the system, and the reduction of the vertical response is attained using the proposed isolation device. (author)

  17. Study of microcellular injection-molded polypropylene/waste ground rubber tire powder blend

    International Nuclear Information System (INIS)

    Xin, Zhen Xiang; Zhang, Zhen Xiu; Pal, Kaushik; Byeon, Jong Ung; Lee, Sung Hyo; Kim, Jin Kuk

    2010-01-01

    Microcellular polypropylene/waste ground rubber tire powder blend processing was performed on an injection-molding machine with a chemical foaming agent. The molded samples produced based on the design of experiments (DOE) matrices were subjected to tensile testing and scanning electron microscope (SEM) analyses. Molding conditions and waste ground rubber tire (WGRT) powder have been found to have profound effects on the cell structures and mechanical properties of polypropylene (PP) and waste ground rubber tire powder composite samples. The result shows that microcellular PP/WGRT blend samples exhibit smaller cell size and higher cell density compare with polypropylene resin. Among the molding parameters studied, chemical foaming agent weight percentage has the most significant effect on cell size, cell density, and tensile strength. The results also suggest that tensile strength of microcellular PP/WGRT composites is sensitive to weight reduction, and skin thickness.

  18. Respiratory tract disease from thermosetting resins. Study of an outbreak in rubber tire workers.

    Science.gov (United States)

    doPico, G A; Rankin, J; Chosy, L W; Reddan, W G; Barbee, R A; Gee, B; Dickie, H A

    1975-08-01

    An outbreak of upper and lower respiratory tract inflammatory disease and conjunctivitis among synthetic rubber tire workers occurred. The outbreak began after the introduction of a new thermosetting resin, containing resorcinol and a trimere of methylene aminoacetronitrile, into the rubber tire carcass stock formulation. Two hundred ten workers were affected. Characteristically, symptoms improved during periods of sick leave or vacation, recurring upon the workers' return to the plant. Chest radiograms disclosed pneumonic infiltrates in about one fourth of the cases. Pulmonary function studies detected abnormal airways dynamics as well as abnormal diffusing capacity in more than one third of the workers tested. Lung biopsy showed evidence of focal interstitial fibrosis and peribronchiolar and perivascular chronic inflammatory reaction. The illness was ascribed to volatile products released during the manufacture of synthetic rubber tires. The exact chemical nature of these products is unknown.

  19. A computational study of adhesion between rubber and metal sulfides at rubber–brass interface

    Energy Technology Data Exchange (ETDEWEB)

    Ling, Chian Ye; Hirvi, Janne T.; Suvanto, Mika; Bazhenov, Andrey S. [Department of Chemistry, University of Eastern Finland, P.O. Box 111, FI80101 Joensuu (Finland); Ajoviita, Tommi; Markkula, Katriina [R & D, Car Tyres, Nokian Tyres plc., P.O. Box 20, FI37101 Nokia (Finland); Pakkanen, Tapani A., E-mail: tapani.pakkanen@uef.fi [Department of Chemistry, University of Eastern Finland, P.O. Box 111, FI80101 Joensuu (Finland)

    2015-05-12

    Highlights: • An atomic level model for brass–rubber interactions has been presented. • The main adhesion force has been tracked to the rubber sulfur–brass zinc or brass copper interaction. • The model gives new understanding of the adhesion and can be used for further developments of the system. - Abstract: Computational study at level of density functional theory has been carried out in order to investigate the adhesion between rubber and brass plated steel cord, which has high importance in tire manufacturing. Adsorption of natural rubber based adsorbate models has been studied on zinc sulfide, ZnS(1 1 0), and copper sulfide, Cu{sub 2}S(1 1 1) and CuS(0 0 1), surfaces as the corresponding phases are formed in adhesive interlayer during rubber vulcanization. Saturated hydrocarbons exhibited weak interactions, whereas unsaturated hydrocarbons and sulfur-containing adsorbates interacted with the metal atoms of sulfide surfaces more strongly. Sulfur-containing adsorbates interacted with ZnS(1 1 0) surface stronger than unsaturated hydrocarbons, whereras both Cu{sub 2}S(1 1 1) and CuS(0 0 1) surfaces showed opposite adsorption preference as unsaturated hydrocarbons adsorbed stronger than sulfur-containing adsorbates. The different interaction strength order can play role in rubber–brass adhesion with different relative sulfide concentrations. Moreover, Cu{sub 2}S(1 1 1) surface exhibits higher adsorption energies than CuS(0 0 1) surface, possibly indicating dominant role of Cu{sub 2}S in the adhesion between rubber and brass.

  20. Fracture behavior of rubber powder modified rubber blends applied for conveying belt top covers

    OpenAIRE

    Euchler, Eric; Stocek, Radek; Gehde, Michael; Bunzel, Jörg-Michael; Saal, Wolfgang; Kipscholl, Reinhold

    2016-01-01

    The aim of this study is concentrated on the experimental investigation of wear resistance of rubber powder modified rubber blends. Styrene-Butadiene-Rubber (SBR) blends applied for conveying belt top covers have been modified by ground rubber (rubber powder) based on SBR. We theoretically described the rubber wear mechanism due to loading conditions occurring at conveyor belts in the field, to simulate wear behavior of top cover rubber materials. An own developed testing equipment based on g...

  1. Natural rubber: leather composites

    Directory of Open Access Journals (Sweden)

    K. Ravichandran

    2005-06-01

    Full Text Available 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 been discussed. Use of chrome leather particles has been found to improve the consumption of scrap rubber powder in natural rubber formulations. Polymer composites based on leather wastes as fillers are reported to be useful for many applications such as in construction materials, automobile interior moldings, heat and sound insulating boards, shoe soles, flooring materials and moldings with good anti-static properties, air permeability and good appearances.

  2. Kinetic Study on Catalytic Cracking of Rubber Seed (Hevea brasiliensis Oil to Liquid Fuels

    Directory of Open Access Journals (Sweden)

    Wara Dyah Pita Rengga

    2015-03-01

    Full Text Available Reaction kinetics of catalytic cracking of rubber seed oil to liquid fuels has been investigated. The reac-tion was performed with sulfuric acid as catalyst at temperatures of 350-450 oC and the ratio of oil-catalyst of 0-2 wt.% for 30-90 minutes. Kinetics was studied using the model of 6-lump parameters. The parameters were rubber seed oil, gasoline, kerosene, diesel, gas, and coke. Analysis of experimen-tal data using regression models to obtain reaction rate constants. Activation energies and pre-exponential factors were then calculated based on the Arrhenius equation. The simulation result illus-trated that the six-lump kinetic model can well predict the product yields of rubber seed oil catalytic cracking. The product has high selectivity for gasoline fraction as liquid fuel and the smallest amount of coke. The constant indicates that secondary reactions occurred in diesel products compared to gaso-line and kerosene. The predicted results indicate that catalytic cracking of rubber seed oil had better be conducted at 450 oC for 90 minutes using 0.5 wt.% catalyst. © 2015 BCREC UNDIP. All rights reservedReceived: 3rd December 2013; Revised: 5th December 2014; Accepted: 7th December 2014How to Cite: Rengga, W.D.P., Handayani, P.A., Kadarwati, S., Feinnudin, A.(2015. Kinetic Study on Catalytic Cracking of Rubber Seed (Hevea brasiliensis Oil  to Liquid Fuels. Bulletin of Chemical Reaction Engineering & Catalysis, 10 (1: 50-60. (doi:10.9767/bcrec.10.1.5852.50-60Permalink/DOI: http://dx.doi.org/10.9767/bcrec.10.1.5852.50-60

  3. Preliminary studies of the rubber from unserviceable tires irradiated by electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Clecia M.; Silva, Leonardo G. Andrade e, E-mail: blgasilva@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Nowadays there is a growth in the developing processes for modification of polymers with ionizing radiation (gamma rays, electron beam) for several industrial applications. An option is ionizing radiation process due to their capacity of inducing crosslinking and scission on a wide range of polymeric materials without initiators or chemicals products. This method has significant advantages on economical and ecological fields, when compared to chemical, thermal and mechanical process. The rubber recycling has been extensively discussed, mainly related to tire. There are reports with data about production and consumption of rubber and unserviceable tire. There is very few information about the destination of others rubber items, incineration and landfill are the main methods for elimination of unserviceable tire, however those methods are not environmentally friendly. It is necessary to study better and effective methods to recycle and to give value to rubber residue. This work is about the use of ionizing radiation for the recovery and/or reuse and processing rubber of unserviceable tire. The samples were irradiated with 200, 400 and 600 kGy radiation dose, 22.39 kGy/s dose rates, at room temperature and in the presence of air using an 1.5 MeV electron beam accelerator. The irradiated and non-irradiated samples were studied by thermogravimetry (TG). The analyses were performed from room temperature up to 600 deg C, heating rate of 10 deg C/min in the presence of nitrogen (N{sub 2}) and air. By this technique it was possible to observe the effects of the radiation dose on the weight loss. (author)

  4. Preliminary studies of the rubber from unserviceable tires irradiated by electron beam

    International Nuclear Information System (INIS)

    Souza, Clecia M.; Silva, Leonardo G. Andrade e

    2011-01-01

    Nowadays there is a growth in the developing processes for modification of polymers with ionizing radiation (gamma rays, electron beam) for several industrial applications. An option is ionizing radiation process due to their capacity of inducing crosslinking and scission on a wide range of polymeric materials without initiators or chemicals products. This method has significant advantages on economical and ecological fields, when compared to chemical, thermal and mechanical process. The rubber recycling has been extensively discussed, mainly related to tire. There are reports with data about production and consumption of rubber and unserviceable tire. There is very few information about the destination of others rubber items, incineration and landfill are the main methods for elimination of unserviceable tire, however those methods are not environmentally friendly. It is necessary to study better and effective methods to recycle and to give value to rubber residue. This work is about the use of ionizing radiation for the recovery and/or reuse and processing rubber of unserviceable tire. The samples were irradiated with 200, 400 and 600 kGy radiation dose, 22.39 kGy/s dose rates, at room temperature and in the presence of air using an 1.5 MeV electron beam accelerator. The irradiated and non-irradiated samples were studied by thermogravimetry (TG). The analyses were performed from room temperature up to 600 deg C, heating rate of 10 deg C/min in the presence of nitrogen (N 2 ) and air. By this technique it was possible to observe the effects of the radiation dose on the weight loss. (author)

  5. Exploration of Barriers in Achieving Proactive Environmental Strategies in a Natural Rubber Industry : A Case Study

    Directory of Open Access Journals (Sweden)

    Syarifa Arum Kusumastuti

    2016-05-01

    Full Text Available As the evolving of environmental issues over time, the development of environmental management approaches in industries began to shift to the prevention of pollution to reduce environmental impact. However, in practice, many obstacles encountered during the environmental management change to be more proactive. This study aims to explore the barriers of achieving the proactive environmental strategy in a rubber processing industry. Used a case study approach in a natural rubber processing factory, the data was collected through interviews with experts and sources as well as observation in the field. This study shows main barriers that faced by the company consist of financial issue, human resources, communities’ pressure, technological change and communication with environmental experts. The results of this study suggest conducting cooperation with research institutions or environmental experts especially for skills that cannot be controlled by the manager or employees in the company. 

  6. Rubber molds for investment casting

    International Nuclear Information System (INIS)

    Sibtain, S.N.

    2011-01-01

    The main objective of the project is to investigate different types of molding rubbers used for investment casting. The level of shape complexity which can be achieved by using these rubber molds is also studied. It was almost impossible to make complex shapes molds using metal molds, in that cases rubber molds are very important because they arc flexible and give accurate and precise part dimensions. Turbine blades are hi-tech components with air-foil geometries that have close dimensional tolerances. They are made of super-alloys and manufactured by investment casting. The final blade profile depends upon the dimensional accuracy in each of the processing steps. In the present work experimental study for the production of high quality low cost castings of turbine blades using rubber molds and injected wax patterns is presented. Natural Rubber molds and wax patterns from these molds were made. Different types of molding rubbers were studied including natural rubber, silicone rubber and liquid silicone rubber. It was found that by using rubber molds we can make most complex shape with very less finishing required. The shrinkage was 12% as compared to original master pattern. Rubber molds were made using laboratory hot press. Three layers of rubber above and below the master pattern. After that vulcanization was done by giving temperature and pressure. (author)

  7. Parametric Study for Devulcanization of Waste Tire Rubber Utilizing Deep Eutectic Solvent (DES

    Directory of Open Access Journals (Sweden)

    Walvekar Rashmi

    2018-01-01

    Full Text Available Waste rubber is a polymeric material containing 50% of rubber and is generally referred to as waste tyre rubber. The main purpose of this research is to study ultrasonic devulcanisation of waste rubber utilising deep eutectic solvent (DES of ZnCl2:Urea by improving process parameters such as sonication time, reaction temperature and rubber: DES mass ratio by effectively cleaving cross-link sulphur bonds. DES was created and prepared by mixing ZnCl2 with urea at 2:7 and 1:4 molar ratios respectively. Physicochemical properties of the prepared DES was measured using DSC, KFT and TGA analysis to find the freezing point, moisture content and degradation temperature, whereby their freezing point below 60°C, moisture content lower than 3.0 wt.% and 200°C degradation temperature average. Rubber to DES mass ratio was varied at 1:20, 1:30 and 1:40 and sonicated for 15 minutes inside ultrasonic water-bath. Samples were placed onto hot plate whereby heating temperature was varied at room temperature, 130°C, 150°C, and 180°C for 15 minutes. Samples were filtered, washed with distilled water and dried in oven for 24 hours. Once dried, samples were taken for analysis using TGA, EDX, FESEM, FTIR and Gel content. Under TGA analysis, most samples have an average degradation temperature of 200°C, hence justifying a successful devulcanisation. EDX analysis shows two occurrences during devulcanisation process which is bond reformation and cleavage. Furthermore, it is determined that heating temperature of 130°C is an important parameter as it is the optimum temperature for ZnCl2:Urea. Under FTIR analysis, it shows that disulphide bond, S-S is the only bond that is being broken while the rest still remains the same. Gel content analysis showed that samples have a lower soluble fraction after devulcanisation process. Finally, FESEM proves that at 130°C and 15 minutes is the optimum temperature and time which is illustrated by the smooth surface at that

  8. Study of tribological properties of natural rubber containing carbon nanotubes and carbon black as hybrid fillers

    Science.gov (United States)

    Harea, Evghenii; Stoček, Radek; Storozhuk, Liudmyla; Sementsov, Yurii; Kartel, Nikolai

    2018-04-01

    Dry friction and wear properties of natural rubber (NR), containing multi-walled carbon nanotubes (MWCNT) and carbon black (CB), were investigated. Natural rubber (NR)-based composites containing all common additives and curatives, and a fixed amount (30 phr—parts per 100 rubber by weight) of hybrid fillers (MWCNT x + CB30-x ) were prepared by simple mixing procedure and tested. The main goal was to study the behaviours of composites at different tribological testing conditions, such as friction speed and normal load. It was found that with an increase of concentration of MWCNT from x = 0 phr to x = 5 phr in studied composites, there was a decrease in the coefficient of friction (COF) with no significant change in wear in the framework of each used combination of testing parameters. Generally, higher friction speed at certain normal force led to the increase of COF of all the samples and wear reflected deliberate value fluctuation. Also, it was established that considerable growth of wear and unexpected reducing of friction coefficient ensued from increasing of applied load for every fixed sliding speed.

  9. Study of the reinforcement of rubber styrene-butadiene with mesoporous silices by solid-state nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Sierra, Ligia; Lopez, Betty; Pena, Bibiana; Rios, Juan Esteban; Castano, Nelson

    2001-01-01

    The knowledge about the interaction rubber/filler for the rubber reinforced with carbon black of silica is important to understand the physical properties, which determine the reinforcement. This paper presents a comparative study of the interactions between styrene butadiene rubber (SBR) and silica for a silica Ultrasil type and mesoporous silica MCM-41 type prepared by different procedures, based on solid state nuclear magnetic resonance: 1H MAS NMR; 13C MAS NMR, 13C CP/MAS, 29Si MAS and 29Si CP/MAS NMR. Mesoporous silica synthesized under certain specific conditions showed better interaction with the rubber than the ultrasil VN3 silica, commonly used as a reinforcement load. Mechanical tests for the SBR vulcanised with this silica indicate an important increase for values of elongation and tearing resistance, but an increase in the vulcanization time in it is compared with the SBR vulcanise with Ultrasil

  10. Study on Load-displacement Test of Rubber Pads of Coal Mine Roadway Constructed by Shield

    Science.gov (United States)

    Yang, Yue; Chen, Xiaoguo; Yang, Liyun

    2017-12-01

    Shield method construction of coal mine roadway is the future trend of the development of deep coal mining. The main shaft supporting is the segment. There is rubber pads between segment and segment. The performance of compression deformation of rubber pad is essential for the overall stability of lining. Through load test, displacement of the rubber pad under load, the thrust force law of the rubber pad deformation, and provide a theoretical basis for the stability analysis of coal mine tunnel shield construction.

  11. Rubber Reclamation

    Science.gov (United States)

    Williams, Kathryn R.

    2007-01-01

    The safety and health hazards related to recycling of used rubber, due to the scarcity and high price of virgin rubber are reported. Various threats like stagnant water pools trapped in tires leading to diseases and ignited tires, which become very difficult to extinguish and generating smoke that is extremely detrimental to the environment, have…

  12. Study on a Haptic Sensor Using MCF (Magnetic Compound Fluid) Electric Conductive Rubber

    Science.gov (United States)

    Zheng, Yaoyang; Shimada, Kunio

    To provide a new composite material having a high degree of sensitivity regarding both electrical conduction and temperature for the field of robotics or sensing, we have developed magnetic rubber that contains a network-like magnetic cluster. We compared the temperature response of MCF rubber with others rubbers made under various experimental conditions, allowing us to find an optimum condition for making MCF rubber. The temperature response was obtained by an experimental equation. We also compared the electric conductivity of MCF rubber with that of ordinary electric conductive rubber and found that its electric sensitivity was lower at a small deformation, but increased at larger deformations. Therefore, MCF rubber has proven itself effective as a switching sensor when a small deformation is applied.

  13. Rubber mixing process and its relationship with bound rubber and crosslink density

    Science.gov (United States)

    Hasan, A.; Rochmadi; Sulistyo, H.; Honggokusumo, S.

    2017-06-01

    This research studied the relationship between bound rubber and crosslink density based on rubber mixing process. Bound rubber was obtained after natural rubber was masticated and mixed with rubber chemicals and filler while crosslink density was collected after rubber compound was vulcanized. Four methods are used and each method refers to four ways of incorporating carbon black during mixing. The first method, after rubber was masticated for 5 minutes, the addition of rubber chemicals and filler was done simultaneously. Rubber was masticated for 1 minute and continued mixing of rubber chemicals and filler where mixing was different from first method. This was the second method. The third method was the same as the second method but the filler used N 660 while in the second method N 330. The last method is not the same as the first and second, the rubber is only masticated for 3 minutes and then mixed with filler and followed by rubber chemicals sequentially. The results showed that bound rubber and crosslink density were influenced by mixing and mastication process. Bound rubber dropped and crosslink density was relatively stable in the first three mixing methods for increasing carbon black at the beginning of the mixing process. Bound rubber and crosslink density stated opposite results in the fourth mixing method. The higher the bound rubber the lower the crosslink density. Without regard to mixing methods, there is a non-linear relationship between bound rubber formation and crosslink density determination

  14. Mixtures of rubber tyre and plastic wastes pyrolysis: A kinetic study

    International Nuclear Information System (INIS)

    Miranda, Miguel; Cabrita, I.; Pinto, Filomena; Gulyurtlu, I.

    2013-01-01

    The study performed aimed at analysing possible routes for pyrolysis reaction mechanisms of polymeric materials namely RT (rubber tyre) and plastic wastes (PE (polyethylene), PP (polypropylene) and PS (polystyrene)). Consequently, and seeking sustainable transformation of waste streams into valuable chemicals and renewable liquid fuels, mixture of 30% RT, 20% PE, 30% PP and 20% PS was subjected to pyrolysis. Different kinetic models were studied using experimental data. None of the mechanisms found in literature led to a numerical adjustment and different pathways were investigated. Kinetic studies were performed aiming to evaluate direct conversions into new solid, liquid and gaseous products and if parallel reactions and/or reversible elementary steps should be included. Experiments were performed in batch system at different temperatures and reaction times. Kinetic models were evaluated and reaction pathways were proposed. Models reasonably fit experimental data, allow explaining wastes thermal degradation. Kinetic parameters were estimated for all temperatures and dependence of Ea and pre-exponential factor on temperature was evaluated. The rate constant of some reactions exhibited nonlinear temperature dependence on the logarithmic form of Arrhenius law. This fact strongly suggests that temperature has a significant effect on reaction mechanism of pyrolysis of mixtures of rubber tyre and plastic wastes. - Highlights: • Kinetic study of rubber tyre (RT) and different plastic wastes (PE, PP and PS) was performed in batch reactor. • Definition of possible pathways taken into account for the formation of final products. • Kinetic parameters were estimated. • The effect of reaction temperature and reaction time on liquid composition was performed

  15. Disturbances in Body Ownership in Schizophrenia: Evidence from the Rubber Hand Illusion and Case Study of a Spontaneous Out-of-Body Experience

    OpenAIRE

    Thakkar, Katharine N.; Nichols, Heathman S.; McIntosh, Lindsey G.; Park, Sohee

    2011-01-01

    Background A weakened sense of self may contribute to psychotic experiences. Body ownership, one component of self-awareness, can be studied with the rubber hand illusion (RHI). Watching a rubber hand being stroked while one's unseen hand is stroked synchronously can lead to a sense of ownership over the rubber hand, a shift in perceived position of the real hand, and a limb-specific drop in stimulated hand temperature. We aimed to assess the RHI in schizophrenia using quantifiable measures: ...

  16. Study on grafting of monomer onto natural rubber latex by radiation technique

    International Nuclear Information System (INIS)

    Nguyen Tan Man; Le Hai; Tran Thi Tam; Le Huu Tu, Pham Thi Sam; Dao Minh Phuong; Ha Thuc Huy

    2004-01-01

    Radiation vulcanization of natural rubber latex has been extensively developed through programmers assisted by the IAEA and UNDP under RCA in Asia and Pacific Region. R-D has been done in most of the Member States with technical assistance from Japan's Takasaki Radiation Chemistry Establishment. Radiation vulcanized natural rubber latex (RVNRL) has many advantages over the conventional sulfur vulcanized latex, such as absence of nitrosamine and low cytotoxicity. Radiation crosslinking is a room temperature process, itself an important cost advantage, it is easily controlled and desired extend of crosslinking is easily achieved by controlling the dose (irradiation time). Disadvantages of RVNRL to be improved are poor physical properties of film such as low tensile strength and tear strength. The research groups of Japan, Thailand and Indonesia concentrated on the improvement of physical properties of RVNRL using radiation grafted PMMA as additive [2]. F. Sundardi and W. Sofiarti have reported that tensile strength and hardness increased by radiation grafting of styrene onto NR [5]. Ono et al have reported the grafting of MMA onto NR by gamma irradiation at a dose of 5 kGy for producing thermoplastic elastomers [4]. The objective of this project is to report the results of studies of radiation graft-copolymerization of methyl methacrylate (MMA) or styrene (St) onto natural rubber latex in order to improve their physico-mechanical properties and evaluation of grafted material using Small-Angle Neutron Scattering through FNCA Project. The grafting degree of MMA and St onto NR increased with the increase of irradiation dose and monomer concentration. The alteration of grafted products structure was determined by IR method. Tensile strength, Shore A hardness, 100% modulus of grafted products increased with the increase of monomer concentration and irradiation dose while elongation at break decreased. The grafted products were characterized by Transmission Electron

  17. Natural rubber/nitrile butadiene rubber/hindered phenol composites with high-damping properties

    Directory of Open Access Journals (Sweden)

    Xiuying Zhao

    2015-10-01

    Full Text Available New natural rubber (NR/nitrile butadiene rubber (NBR/hindered phenol (AO-80 composites with high-damping properties were prepared in this study. The morphological, structural, and mechanical properties were characterized by atomic force microscopy (AFM, polarized Fourier transform infrared spectrometer (FTIR, dynamic mechanical thermal analyzer (DMTA, and a tensile tester. Each composite consisted of two phases: the NR phase and the NBR/AO-80 phase. There was partial compatibility between the NR phase and the NBR/AO-80 phase, and the NR/NBR/AO-80 (50/50/20 composite exhibited a co-continuous morphology. Strain-induced crystallization occurred in the NR phase at strains higher than 200%, and strain-induced orientation appeared in the NBR/AO-80 phase with the increase of strain from 100% to 500%. The composites had a special stress–strain behavior and mechanical properties because of the simultaneous strain-induced orientation and strain-induced crystallization. In the working temperature range of a seismic isolation bearing, the composites (especially the NR/NBR/AO-80 (50/50/20 composite presented a high loss factor, high area of loss peak (TA, and high hysteresis energy. Therefore, the NR/NBR/AO-80 rubber composites are expected to have important application as a high-performance damping material for rubber bearing.

  18. Morphological Study on Room-Temperature-Cured PMMA-Grafted Natural Rubber-Toughened Epoxy/Layered Silicate Nanocomposite

    Directory of Open Access Journals (Sweden)

    N. Y. Yuhana

    2012-01-01

    Full Text Available A morphological study was conducted on ternary systems containing epoxy, PMMA-grafted natural rubber, and organic chemically modified montmorillonite (Cloisite 30B. Optical microscopy, transmission electron microscopy (TEM, scanning electron microscopy (SEM, energy dispersive X-ray (EDX, and wide-angle X-ray diffraction (WAXD analysis were used. The following four materials were prepared at room temperature: cured unmodified epoxy, cured toughened epoxy, cured unmodified epoxy/Cloisite 30B nanocomposites, and cured toughened epoxy/Cloisite 30B nanocomposites. Mixing process was performed by mechanical stirring. Poly(etheramine was used as the curing agent. The detailed TEM images revealed co-continuous and dispersed spherical rubber in the epoxy-rubber blend, suggesting a new proposed mechanism of phase separation. High-magnification TEM analysis showed good interactions between rubber and Cloisite 30B in the ternary system. Also, it was found that rubber particles could enhance the separation of silicates layers. Both XRD and TEM analyses confirmed that the intercalation of Cloisite 30B was achieved. No distinct exfoliated silicates were observed by TEM. Aggregates of layered silicates (tactoids were observed by SEM and EDX, in addition to TEM at low magnification. EDX analysis confirmed the presence of organic and inorganic elements in the binary and ternary epoxy systems containing Cloisite 30B.

  19. Study of new rubber to steel adhesive systems based on Co(II and Cu(II sulphides coats

    Directory of Open Access Journals (Sweden)

    Labaj Ivan

    2018-01-01

    Full Text Available The presented paper deals with the preparation of new rubber to steel adhesive systems using the steel surface treatment with deposition of adhesive coats based on Co(II and Cu(II sulphides. Efficiency of new prepared adhesive systems containing Co(II and Cu(II sulphides has been compared with the efficiency of double layer adhesive system commonly used in industry. The chemical composition of prepared adhesive systems was determined using the EDX analysis. Scanning Electron Microscopy (SEM was used for study of topography and microstructure of prepared rubber to steel adhesive systems (Co(II, Cu(II sulphide, double layer adhesive system. For determination of adhesion strength between rubber blends and metal pieces with various adhesive systems deposited on these pieces, the test according to ASTM D429 standard relating to Rubber to metal adhesion, method A was used. For all test samples, the same type of rubber blend and the same curing conditions have been used.

  20. A prospective study of outcome from rubber band ligation of piles.

    Science.gov (United States)

    Longman, R J; Thomson, W H F

    2006-02-01

    With the recent introduction of stapled anopexy it is timely to review the benefits of existing treatment options for piles. This study investigates the effectiveness and safety of rubber band ligation (RBL) of piles in the outpatient setting. Two hundred and fifty-two consecutive patients referred with piles in an 18-month period were studied prospectively. In those patients deemed suitable for banding of piles, data were collected on symptoms, proctoscopic appearance and degree of piles. Short and long-term outcome data were recorded for success of treatment and complications. Of 203 patients considered suitable and who attended for RBL, 176 kept their follow-up appointment. One hundred and forty-eight (84%) had been rendered symptom-free. A third of patients, however, had proctoscopic evidence of persistent piles, whilst in half of those patients with continuing symptoms the anal cushions appeared normal. Six (3%) patients had suffered a complication. Long-term follow-up by questionnaire found that 44% of respondents remained asymptomatic at a median of 46 months from banding. Six (5%) of 117 responders to the questionnaire had, though previously normal, suffered a postbanding impairment of continence. Most patients with piles of any degree can be safely managed by rubber band ligation, but return of symptoms in the long term affects more than half of patients treated.

  1. Buildup factor and mechanical properties of high-density cement mixed with crumb rubber and prompt gamma ray study

    Science.gov (United States)

    Aim-O, P.; Wongsawaeng, D.; Tancharakorn, S.; Sophon, M.

    2017-09-01

    High-density cement mixed with crumb rubber has been studied to be a gamma ray and neutron shielding material, especially for photonuclear reactions that may occur from accelerators where both types of radiation exist. The Buildup factors from gamma ray scattering, prompt and secondary gamma ray emissions from neutron capture and mechanical properties were evaluated. For buildup factor studies, two different geometries were used: narrow beam and broad beam. Prompt Gamma Neutron Activation Analysis (PGNAA) was carried out to determine the prompt and secondary gamma ray emissions. The compressive strength of samples was evaluated by using compression testing machine which was central point loading crushing test. The results revealed that addition of crumb rubber increased the buildup factor. Gamma ray spectra following PGNAA revealed no prompt or secondary gamma ray emission. Mechanical testing indicated that the compressive strength of the shielding material decreased with increasing volume percentage of crumb rubber.

  2. Crystal plasticity study of single crystal tungsten by indentation tests

    International Nuclear Information System (INIS)

    Yao, Weizhi

    2012-01-01

    Owing to its favorable material properties, tungsten (W) has been studied as a plasma-facing material in fusion reactors. Experiments on W heating in plasma sources and electron beam facilities have shown an intense micro-crack formation at the heated surface and sub-surface. The cracks go deep inside the irradiated sample, and often large distorted areas caused by local plastic deformation are present around the cracks. To interpret the crack-induced microscopic damage evolution process in W, one needs firstly to understand its plasticity on a single grain level, which is referred to as crystal plasticity. In this thesis, the crystal plasticity of single crystal tungsten (SCW) has been studied by spherical and Berkovich indentation tests and the finite element method with a crystal plasticity model. Appropriate values of the material parameters included in the crystal plasticity model are determined by fitting measured load-displacement curves and pile-up profiles with simulated counterparts for spherical indentation. The numerical simulations reveal excellent agreement with experiment. While the load-displacement curves and the deduced indentation hardness exhibit little sensitivity to the indented plane at small indentation depths, the orientation of slip directions within the crystals governs the development of deformation hillocks at the surface. It is found that several factors like friction, indentation depth, active slip systems, misoriented crystal orientation, misoriented sample surface and azimuthal orientation of the indenter can affect the indentation behavior of SCW. The Berkovich indentation test was also used to study the crystal plasticity of SCW after deuterium irradiation. The critical load (pop-in load) for triggering plastic deformation under the indenter is found to depend on the crystallographic orientation. The pop-in loads decrease dramatically after deuterium plasma irradiation for all three investigated crystallographic planes.

  3. Study of the Properties of Polyurethane-waste Rubber Granulate Composites

    Institute of Scientific and Technical Information of China (English)

    W.W.Sulkowski; M.Moczy′ski; A.Sulkowska; A.Danch; J.Borek; S.Mistarz

    2007-01-01

    1 Results The production of rubber is very high and rises every year. Among other things it is directly connected with the growth of car production. Therefore, the processing of waste rubber and its management must be treated as a global problem. Used rubber may replace conventional fuel and, owing to its low price, can improve the economic effectiveness of combustion. Energy recovery by combustion of car tyres allows for rapid management of rubber waste. However, it is well-known that all kinds of wast...

  4. Effect of Modified Natural Rubber on PVC-ENR Electrospun Membrane: Thermal and Morphological Studies

    International Nuclear Information System (INIS)

    Mahathir Mohamed; Dahlan Mohd; Ratnam, C.T.; Pairu Ibrahim

    2016-01-01

    Electrospun fibers membrane (EFM) based on modified epoxidized natural rubber (ENR) and polyvinyl chloride (PVC) was successfully prepared by electro spinning technique. Epoxidized natural rubber was firstly prepared in solution by using 5 L flask and exposed to high intensity UV lamp for degradation. The PVC/ ENR mixture solution concentration were about 16 wt% and blended for 5 hours for homogeneity. The PVC/ ENR mixture were electro spun to form fibers membrane. The sample of electro spun fibers membrane were cured by electron beam. The resulting membranes were characterized for thermal and morphological studies. Thermal decomposition behavior of EFM was analyzed by thermogravimetric analysis (TGA). Thermo gram from TGA showed two stages of degradation for all formulation (90:10, 80:20, 70:30 PVC/ ENR) from 240 to 265 degree Celsius and 400 to 410 degree Celsius, respectively. From the DSC thermo gram of PVC/ ENR electro spun fibers showed that the addition of ENR resulted in the shifting of glass transition temperature (Tg) towards lower temperatures. The morphology of electro spun fibers was examined using scanning electron microscopy and it showed a variety of fiber morphologies. (author)

  5. Batch study, equilibrium and kinetics of adsorption of naphthalene using waste tyre rubber granules

    Directory of Open Access Journals (Sweden)

    Felix A. Aisien

    2014-04-01

    Full Text Available The potential use of waste tyre rubber granules (WTRG for the batch adsorption of naphthalene from aqueous solutions was investigated. The effect of various operational variables such as contact time, initial naphthalene concentration, adsorbent dose, size of adsorbent particles, and temperature of solution on the adsorption capacity of WTRG was evaluated. The adsorption of naphthalene by WTRG was a fast kinetic process with an equilibrium contact time of 60 min. A low temperature (5°C, small adsorbent particle size (0.212 mm and higher adsorbent dosage favored the adsorption process. Results of isotherm studies revealed that adsorption of naphthalene was best described by the Langmuir isotherm equation (R2=0.997 while the kinetics of the process was best described by the Lagergren pseudofirst order kinetic equation (R2=0.998. This study has demonstrated the suitability of WTRG for the removal of naphthalene from aqueous solution.

  6. Studies on nitrile rubber degradation in zinc bromide completion fluid and its prevention by surface fluorination

    Science.gov (United States)

    Vega-Cantu, Yadira Itzel

    Poly(acrylonitrile-co-butadiene) or nitrile-butadiene rubber (NBR) is frequently used as an O-ring material in the oil extraction industry due to its excellent chemical properties and resistance to oil. However, degradation of NBR gaskets is known to occur during the well completion and oil extraction process where packers are exposed to completion fluids such as ZnBr2 brine. Under these conditions NBR exhibits accelerated chemical degradation resulting in embrittlement and cracking. Samples of NBR, poly(acrylonitrile) (PAN) and poly(butadiene) (PB) have been exposed to ZnBr2 based completion fluid, and analyzed by ATR and diffuse reflectance IR. Analysis shows the ZnBr2 based completion fluid promotes hydrolysis of the nitrile group to form amides and carboxylic groups. Analysis also shows that carbon-carbon double bonds in NBR are unaffected after short exposure to zinc bromide based completion fluid, but are quickly hydrolyzed in acidic bromide mixtures. Although fluoropolymers have excellent chemical resistance, their strength is less than nitrile rubber and replacing the usual gasket materials with fluoroelastomers is expensive. However, a fluoropolymer surface on a nitrile elastomer can provide the needed chemical resistance while retaining their strength. In this study, we have shown that this can be achieved by direct fluorination, a rather easy and inexpensive process. Samples of NBR O-rings have been fluorinated by exposure to F2 and F2/HF mixtures at various temperatures. Fluorination with F 2 produces the desired fluoropolymer layer; however, fluorination by F2/HF mixtures gave a smoother fluorinated layer at lower temperatures and shorter times. Fluorinated samples were exposed to ZnBr2 drilling fluid and solvents. Elemental analysis shows that the fluorinated layer eliminates ZnBr2 diffusion into the NBR polymeric matrix. It was also found that surface fluorination significantly retards the loss of mechanical properties such as elasticity, tensile

  7. Effect of nano-scaled styrene butadiene rubber based nucleating agent on the thermal, crystallization and physical properties of isotactic polypropylene

    Energy Technology Data Exchange (ETDEWEB)

    Petchwattana, Nawadon [Division of Polymer Materials Technology, Faculty of Agricultural Product Innovation and Technology, Srinakharinwirot University, Sukhumvit 23, Wattana, Bangkok 10110 (Thailand); Covavisaruch, Sirijutaratana, E-mail: sirijutaratana.c@chula.ac.th [Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Pathumwan, Bangkok 10330 (Thailand); Sripanya, Panjapong [Thai Oleochemicals Company Limited (A Subsidiary of PTT Global Chemical Public Company Limited), Mueang Rayong, Rayong 21150 (Thailand)

    2014-01-05

    Highlights: • The effect of a SBR based β-NA on the properties iPP was investigated. • The addition of β-NA led to higher population of nuclei and smaller spherulites. • β to α phase transformation was observed when re-extrusion process was applied. • Impact strength was increased when the β-NA was added from 0.10 to 0.20 wt%. -- Abstract: The influence of a specific nano-scaled styrene butadiene rubber based β-nucleating agent (β-NA) on the properties of isotactic polypropylene (iPP) was investigated in the current research. β-NA was applied at the concentration ranged from 0.05 to 0.50 wt%. Microscopic observation revealed that the neat iPP crystals grew very slowly; they ranged in size from 100 to 200 μm. The addition of β-NA led to higher population of nuclei and smaller spherulites than those found in neat iPP. The addition of only 0.05 wt% β-NA significantly decreased the sizes of the spherulites down to 5 μm; the crystal grew very rapidly, leading to extremely fine morphology. Analysis by X-ray diffraction (XRD) confirmed that iPP/β-NA constituted mainly of β-crystal structure. The transformation of β to α phase was observed upon re-extrusion, it was verified by the lowered fraction of the β-crystalline phase (K{sub β}) although the total degree of crystallinity remained unchanged. A significant improvement in the impact strength of the iPP/β-NA was observed when the β-NA was employed from 0.10 to 0.20 wt%, leading to the formation of tough β-crystals in the β-NA nucleated iPP. The color measurement implied that the iPP nucleated with β-NA was superior in terms of whiteness but it was less transparent, as was evident by the increased haze.

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  9. An exploration study to find important factors influencing on brand in rubber industry

    Directory of Open Access Journals (Sweden)

    Mehrnaz Moshkelati

    2013-08-01

    Full Text Available Building a distinguished brand often makes it possible to have sustainable growth in competitive market. It also helps us sell products with higher price; attract reliable customers for long term relationships. This paper presents an empirical investigation to find important factors influencing rubber industry. The proposed study designs a questionnaire in Likert scale consists of 20 questions, distributes it among 300 people and collects 265 filled ones. Cronbach alpha is calculated as 0.756. In addition, Kaiser-Meyer-Olkin Measure of Sampling Adequacy and Approx. Chi-Square are 0.75 and 1292.573, respectively. Based on the results of our survey, we have derived six factors including brand transparency, expected quality, brand promises, brand support and brand sustainability.

  10. The Study of Government’s Role for Welfaring Rubber Farmer in The Globalization Vortex

    Directory of Open Access Journals (Sweden)

    Pahrudin HM

    2017-12-01

    Full Text Available Rubber is a type of plant that has been cultivated by the people of Indonesia for long a time. Until now, farmers have become the largest party to cultivate rubber in Indonesia (85.10% and contribute greatly to the nation’s economy, but are still far from prosperous. Rubber products produced by farmers are priced cheap so that they incomes are very small and create income inequality. As an export commodity, rubber is highly dependent with overseas which determines the price. In this context, the government through the bureaucratic system serves to produce a series of innovative-solutive development program in order to keep the people from the negative impacts of globalization. This effort can be run by the government with adopting The New Public Service Paradigm as part of efforts to better public services for the people. It is implementation in the form of domestic rubber needs priorities, bringing the industry to the center of rubber, training of rubber farmers, and improvement of transportation infrastructures.

  11. Study of technological parameters influence on homogeneity of rubber mixings by means of radiotracer methods

    International Nuclear Information System (INIS)

    Koczorowska, E.

    1995-01-01

    The radiotracer methods have been worked out for analysis of physico-chemical phenomena. The analysis were carried out for rubber mixings in technological conditions and played a deciding role for quality of manufacturing assortment. The 35 S and 65 Zn have been used as radiotracers. Analysis of different technological parameters influence on behaviour of soluble and polymerized sulfur, zinc compounds as well as other components of the rubber mixing enables to formulate the conclusions important for rubber industry and technology from view point of quality of manufacturing products

  12. Study of the effect of ionizing radiation on the structure of natural rubber latex by positron annihilation technique

    International Nuclear Information System (INIS)

    Lopez Saldana, I.R.

    1993-01-01

    At the present research, were studied the changes in natural rubber latex structure, due to electron beam by a 3 MeV, 25 m A Dynamitron electron accelerator. The natural rubber latex was irradiated at 30, 40 and 50 kGy/s dose rate, over a total dose range from 150 to 250 kGy, for each dose rate used. From natural rubber latex irradiated films were prepared by casting with 0.7 mm. thickness. In the main part, the study was made by positron annihilation lifetime (PAL), this technique is unique in the determination of free-volume properties due to the fact that positronium atom (Ps) is found to be preferentially localized in the free-volume region of polymeric materials. The positron lifetime measurements were performing using a gamma-gamma coincidence system. These results were analyzed by PATFIT-88 program computer into three components, the long-lived component for orthopositronium (o-Ps) with parameters lifetime (τ 3 ) and formation intensity (I 3 ), were plotted and analyzed for each dose rate and total dose used. Besides with τ 3 were calculated the mean free-volume size based on the spherical model for the free-volume bubble, found that the free-volume decrease slightly with the total dose due to the crosslinking of natural rubber latex. Besides was studied the effect of dose rate on tensile strength, the tensile strength is increased with the total dose although there was not a clear effect due to the dose rate. Also the films were subjected to aging in order to determined the thermal stability of natural rubber latex irradiated, the results show that the films have good stability. Besides was used the infrared spectroscopy to determine the changes due to the crosslinking by variations in the characteristically absorption bands for cis 1,4-polyisoprene. (Author)

  13. A study of crumb rubber modified bitumen used in South Africa

    CSIR Research Space (South Africa)

    Mturi, GAJ

    2014-05-01

    Full Text Available In South Africa, an empirical characterisation of crumb rubber modified (CRM) bituminous binders has historically been the only means of predicting their performance in pavement layers, short of constructing pavement test sections. An improved...

  14. A Study for Shelf Life Evaluation of Rubber O-ring

    International Nuclear Information System (INIS)

    Jung, Sun Chul; Kim, Jong Seog

    2005-01-01

    Non-metallic materials stored in warehouses in nuclear power plants have shelf life. The shelf life means the maximum storage time allowable such that the install life of the material is not affected. Materials whose shelf lives expire are generally discarded. unless the shelf lives of these materials can be extended by reducing the install life. Examples of this case are rubber materials. Rubber materials are widely used for sealing of various machines. There are various life evaluation methods for rubber material. For example, the compression set is generally used for evaluation the aging condition of rubber materials used for sealing. A compression set value can be calculated according to the ASTM D395. We have tried the compression set test by using specimens with 6.99mm diameter O-ring even when ASTM D 395 recommends the use of bar specimen. Test results and comparison between O-ring and reference data of EPRI NP-6608 are presented below

  15. PROPERTIES TYRE TREAD RUBBERS DEPENDING ON PARTICULARITY OF RUBBER COMPOUND

    Directory of Open Access Journals (Sweden)

    Z. S. Shashok

    2014-01-01

    Full Text Available Summary. The results of studies of the elastomeric compositions based on natural rubber containing curatives different ratio "curing agent : vulcanization accelerator" listed in this article. Influence of the composition of the vulcanizing group on stress-strain and elastic- deformation properties of tire tread rubber was installed. It has been shown that a significant effect on thermo-oxidative aging of vulcanizates was the composition of the vulcanizing group. Results of studies resistance tread rubber to exposure to elevated temperatures were presented . Vulcanizates differing type and density by varying the cross-linking ratio of "curing agent : vulcanization accelerator" were obtained . Research results in the formation of rubber resistance and crack growth at different temperatures were presented. Revealed that the best education and resistance to tear propagation under normal conditions characterized by rubber ratio "curing agent : vulcanization accelerator" equal to 1.5:1. It has been established that a dynamic endurance study rubbers depends largely on the nature and concentration of the cross-linking cross-links and movable promote increase efficiency due to the grid and reduce the sulfidity rearrangement. During loading mode alternating deformations at elevated temperatures lability of polysulfide bonds negatively affects the performance of rubber, and the decisive role of providing strength and thermal cross-linking. It is shown that the performance of the spatial grid rubbers allow indirectly judge the dynamic vulcanizates endurance and predict performance rubbers at elevated temperatures under conditions of repeated cyclic deformation. Revealed that the vulcanizing system containing sulfur and vulcanization accelerator TBBS 1:2, promotes the formation of the optimal structure of vulcanized rubber , which provides the best resistance to repeated cyclic deformations in the operating temperatures of the tire.

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

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  17. Crystal study and econometric model

    Science.gov (United States)

    1975-01-01

    An econometric model was developed that can be used to predict demand and supply figures for crystals over a time horizon roughly concurrent with that of NASA's Space Shuttle Program - that is, 1975 through 1990. The model includes an equation to predict the impact on investment in the crystal-growing industry. Actually, two models are presented. The first is a theoretical model which follows rather strictly the standard theoretical economic concepts involved in supply and demand analysis, and a modified version of the model was developed which, though not quite as theoretically sound, was testable utilizing existing data sources.

  18. Metadynamics studies of crystal nucleation

    Science.gov (United States)

    Giberti, Federico; Salvalaglio, Matteo; Parrinello, Michele

    2015-01-01

    Crystallization processes are characterized by activated events and long timescales. These characteristics prevent standard molecular dynamics techniques from being efficiently used for the direct investigation of processes such as nucleation. This short review provides an overview on the use of metadynamics, a state-of-the-art enhanced sampling technique, for the simulation of phase transitions involving the production of a crystalline solid. In particular the principles of metadynamics are outlined, several order parameters are described that have been or could be used in conjunction with metadynamics to sample nucleation events and then an overview is given of recent metadynamics results in the field of crystal nucleation. PMID:25866662

  19. Metadynamics studies of crystal nucleation

    Directory of Open Access Journals (Sweden)

    Federico Giberti

    2015-03-01

    Full Text Available Crystallization processes are characterized by activated events and long timescales. These characteristics prevent standard molecular dynamics techniques from being efficiently used for the direct investigation of processes such as nucleation. This short review provides an overview on the use of metadynamics, a state-of-the-art enhanced sampling technique, for the simulation of phase transitions involving the production of a crystalline solid. In particular the principles of metadynamics are outlined, several order parameters are described that have been or could be used in conjunction with metadynamics to sample nucleation events and then an overview is given of recent metadynamics results in the field of crystal nucleation.

  20. LITERATURE SURVEY FOR FRACTIONAL CRYSTALLIZATION STUDY

    International Nuclear Information System (INIS)

    PERSON, J.C.

    2004-01-01

    The literature survey for the fractional crystallization study of material from tank 241-S-112 is completed, fulfilling the requirements of the Test Plan for Tank 241-S-112 Fractional Crystallization Study (Herting 2003). Crystallization involves the formation of one or more solid phases from a fluid phase or an amorphous solid phase. It is applied extensively in the chemical industry, both as a purification process and a separation process. The main advantage of crystallization over distillation is the production of substances with a very high purity, at a low level of energy consumption, and at relatively mild process conditions. Crystallization is one of the older operations in the chemical industry; therefore, practical experience can usually be used for the design and operation of industrial crystallizers. In addition, advances in the understanding of crystallization kinetics can be useful in the control, design, and scale-up of industrial crystallizers. Research work is currently underway; e.g., the CrysCODE (Crystallizer Control and Design) project, littu://www.aui.tudelft.nl/uroiect/Cn/scode/crvscode.htm, at the Delft University of Technology, with the goal of improving the performance and controllability of industrial crystallizers by means of better control and improved design methodologies. Recent developments in fluid dynamics and reactor technology (e.g., compartment approaches) have led to a better understanding of processes and scale-up phenomena. The ultimate aim of such research is to develop a knowledge-based design frame for optimization of industrial crystallization units. Development work is in progress on a rigorous design analysis model for the description of the crystallization process as a function of the reactor geometry, crystallization kinetics, and operating conditions. One modeling effort is aimed at improving the predictive crystallizer model by implementing a population balance equation that depends on two variables: the size and

  1. Robotically enhanced rubber hand illusion.

    Science.gov (United States)

    Arata, Jumpei; Hattori, Masashi; Ichikawa, Shohei; Sakaguchi, Masamichi

    2014-01-01

    The rubber hand illusion is a well-known multisensory illusion. In brief, watching a rubber hand being stroked by a paintbrush while one's own unseen hand is synchronously stroked causes the rubber hand to be attributed to one's own body and to "feel like it's my hand." The rubber hand illusion is thought to be triggered by the synchronized tactile stimulation of both the subject's hand and the fake hand. To extend the conventional rubber hand illusion, we introduce robotic technology in the form of a master-slave telemanipulator. The developed one degree-of-freedom master-slave system consists of an exoskeleton master equipped with an optical encoder that is worn on the subject's index finger and a motor-actuated index finger on the rubber hand, which allows the subject to perform unilateral telemanipulation. The moving rubber hand illusion has been studied by several researchers in the past with mechanically connected rigs between the subject's body and the fake limb. The robotic instruments let us investigate the moving rubber hand illusion with less constraints, thus behaving closer to the classic rubber hand illusion. In addition, the temporal delay between the body and the fake limb can be precisely manipulated. The experimental results revealed that the robotic instruments significantly enhance the rubber hand illusion. The time delay is significantly correlated with the effect of the multisensory illusion, and the effect significantly decreased at time delays over 100 ms. These findings can potentially contribute to the investigations of neural mechanisms in the field of neuroscience and of master-slave systems in the field of robotics.

  2. Rubber compounding and processing

    CSIR Research Space (South Africa)

    John, MJ

    2014-06-01

    Full Text Available This chapter presents an overview on the compounding and processing techniques of natural rubber compounds. The introductory portion deals with different types of rubbers and principles of rubber compounding. The primary and secondary fillers used...

  3. Use of rubber crumbs in cement concrete

    Science.gov (United States)

    Longvinenko, A. A.

    2018-03-01

    Rubber crumb obtained from worn out tires has been increasingly used over the last 15-20 years, especially in manufacture of asphalt and cement concrete mixtures. This review pays principal attention to application of the rubber crumb to cement concrete mixtures. Use of the rubber crumb in cement concrete is not as successful as in asphalt concrete mixtures, due to incompatibility problems linked to chemical composition and a significant difference in rigidity between the rubber crumb and concrete mixture aggregates. Different methods are proposed and studied to mitigate the adverse influence and increase the beneficial effects of the rubber crumb when added to cement concrete.

  4. In-depth proteome analysis of the rubber particle of Hevea brasiliensis (para rubber tree).

    Science.gov (United States)

    Dai, Longjun; Kang, Guijuan; Li, Yu; Nie, Zhiyi; Duan, Cuifang; Zeng, Rizhong

    2013-05-01

    The rubber particle is a special organelle in which natural rubber is synthesised and stored in the laticifers of Hevea brasiliensis. To better understand the biological functions of rubber particles and to identify the candidate rubber biosynthesis-related proteins, a comprehensive proteome analysis was performed on H. brasiliensis rubber particles using shotgun tandem mass spectrometry profiling approaches-resulting in a thorough report on the rubber particle proteins. A total of 186 rubber particle proteins were identified, with a range in relative molecular mass of 3.9-194.2 kDa and in isoelectric point values of 4.0-11.2. The rubber particle proteins were analysed for gene ontology and could be categorised into eight major groups according to their functions: including rubber biosynthesis, stress- or defence-related responses, protein processing and folding, signal transduction and cellular transport. In addition to well-known rubber biosynthesis-related proteins such as rubber elongation factor (REF), small rubber particle protein (SRPP) and cis-prenyl transferase (CPT), many proteins were firstly identified to be on the rubber particles, including cyclophilin, phospholipase D, cytochrome P450, small GTP-binding protein, clathrin, eukaryotic translation initiation factor, annexin, ABC transporter, translationally controlled tumour protein, ubiquitin-conjugating enzymes, and several homologues of REF, SRPP and CPT. A procedure of multiple reaction monitoring was established for further protein validation. This comprehensive proteome data of rubber particles would facilitate investigation into molecular mechanisms of biogenesis, self-homeostasis and rubber biosynthesis of the rubber particle, and might serve as valuable biomarkers in molecular breeding studies of H. brasiliensis and other alternative rubber-producing species.

  5. Cardiac supporting device using artificial rubber muscle: preliminary study to active dynamic cardiomyoplasty.

    Science.gov (United States)

    Saito, Yoshiaki; Suzuki, Yasuyuki; Goto, Takeshi; Daitoku, Kazuyuki; Minakawa, Masahito; Fukuda, Ikuo

    2015-12-01

    Dynamic cardiomyoplasty is a surgical treatment that utilizes the patient's skeletal muscle to support circulation. To overcome the limitations of autologous skeletal muscles in dynamic cardiomyoplasty, we studied the use of a wrapped-type cardiac supporting device using pneumatic muscles. Four straight rubber muscles (Fluidic Muscle, FESTO, Esslingen, Germany) were used and connected to pressure sensors, solenoid valves, a controller and an air compressor. The driving force was compressed air. A proportional-integral-derivative system was employed to control the device movement. An overflow-type mock circulation system was used to analyze the power and the controllability of this new device. The device worked powerfully with pumped flow against afterload of 88 mmHg, and the beating rate and contraction/dilatation time were properly controlled using simple software. Maximum pressure inside the ventricle and maximum output were 187 mmHg and 546.5 ml/min, respectively, in the setting of 50 beats per minute, a contraction/dilatation ratio of 1:2, a preload of 18 mmHg, and an afterload of 88 mmHg. By changing proportional gain, contraction speed could be modulated. This study showed the efficacy and feasibility of a pneumatic muscle for use in a cardiac supporting device.

  6. An Experimental Study of Briquetting Process of Torrefied Rubber Seed Kernel and Palm Oil Shell

    Directory of Open Access Journals (Sweden)

    M. Fadzli Hamid

    2016-01-01

    Full Text Available Torrefaction process of biomass material is essential in converting them into biofuel with improved calorific value and physical strength. However, the production of torrefied biomass is loose, powdery, and nonuniform. One method of upgrading this material to improve their handling and combustion properties is by densification into briquettes of higher density than the original bulk density of the material. The effects of critical parameters of briquetting process that includes the type of biomass material used for torrefaction and briquetting, densification temperature, and composition of binder for torrefied biomass are studied and characterized. Starch is used as a binder in the study. The results showed that the briquette of torrefied rubber seed kernel (RSK is better than torrefied palm oil shell (POS in both calorific value and compressive strength. The best quality of briquettes is yielded from torrefied RSK at the ambient temperature of briquetting process with the composition of 60% water and 5% binder. The maximum compressive load for the briquettes of torrefied RSK is 141 N and the calorific value is 16 MJ/kg. Based on the economic evaluation analysis, the return of investment (ROI for the mass production of both RSK and POS briquettes is estimated in 2-year period and the annual profit after payback was approximately 107,428.6 USD.

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

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  8. Morphological Study on Room-Temperature-Cured PMMA-Grafted Natural Rubber-Toughened Epoxy/Layered Silicate Nanocomposite

    OpenAIRE

    Yuhana, N. Y.; Ahmad, S.; Kamal, M. R.; Jana, S. C.; Bahri, A. R. Shamsul

    2012-01-01

    A morphological study was conducted on ternary systems containing epoxy, PMMA-grafted natural rubber, and organic chemically modified montmorillonite (Cloisite 30B). Optical microscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and wide-angle X-ray diffraction (WAXD) analysis were used. The following four materials were prepared at room temperature: cured unmodified epoxy, cured toughened epoxy, cured unmodified epoxy/Cloisite 3...

  9. Experimental study of laminated rubber bearings for earthquake isolation of buildings, 2

    International Nuclear Information System (INIS)

    Fujita, Takafumi; Fujita, Satoshi; Suzuki, Shigenobu; Yoshizawa, Toshikazu.

    1987-01-01

    Rubber bearings of 980 kN rated load were tested to investigate the characteristics of restoring forces of full scale bearings for earthquake isolation of buildings. These bearings comprising 27 natural rubber sheets of 6 mm thickness and 600 mm diameter bonded to steel plates were designed to provide a 100000 kg rated mass with a horizontal natural frequency of 0.51 Hz and a vertical one of 21 Hz and to accept a horizontal displacement larger than 300 mm. The static tests were carried out with satisfactory results. It was confirmed that the performance of the bearing met the specifications well. Furthermore, the vertical load distributions across the top plane of the bearing under various horizontal displacements were measured, and showed that they were always concentrated in the overlapping area of the top and bottom planes. This verified that the rubber bearing substantially supported the vertical load by the overlapping area. (author)

  10. Study on the Performance Diagram of Multi-Lead Core Rubber Bearing for NPPs

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hong-Pyo; Cho, Myung-Sug [KHNP CRI, Daejeon (Korea, Republic of); Jang, Kwang-Seok [UNISON e-Tech, Cheonan (Korea, Republic of)

    2016-10-15

    The application of lead rubber bearing (LRB) system is able to secure the large shear deformation and high axial load’s stability for nuclear power plants. Typically LRB is having a large shear displacement performance. But when the general LRB applied for nuclear power plants, it was increase the quantity of device and a spaced arrangement get narrow. In this paper, a manufacture full-scale specimen and evaluated the performance testing in variable axial load and shear displacement with the LRB in previous use for architecture. This LRB is applied to the improved rubber material and applied the multi-lead core. In this paper, it was evaluated the performance testing in variable axial load and shear displacement with the full-scale multi-lead rubber bearing for the application of nuclear power plants. From the test results, the design of bearing performed properly and appeared the excellent stability under the more than design value.

  11. STUDIES ON NATURAL WEATHERING OF RATTAN POWDER-FILLED NATURAL RUBBER COMPOSITES

    Directory of Open Access Journals (Sweden)

    Komethi Muniandy,

    2012-07-01

    Full Text Available This article investigates the effect of natural weathering on mechanical and morphological properties of rattan powder-filled natural rubber (NR composites as a function of filler loading and silane coupling agent. The rattan powder samples in the range of 0 to 30 phr were compounded with NR using a laboratory size two-roll mill. The natural weathering test was carried out for six months. The degradation of the samples was evaluated by performing a tensile test, a Fourier transform infrared spectroscopy (FTIR, and a scanning electron microscopy (SEM test. The results indicated that after natural weathering, an increase in stress at 100% elongation (M100 can be seen for samples without the silane coupling agent, whilst M100 was reduced for samples with silane coupling agent. A drastic reduction in tensile strength and elongation at break were observed for all samples due to the photo-oxidation process that occurred during the degradation of the samples. The extent of degradation on the samples’ surfaces and the presence of oxygenated products were confirmed by SEM and FTIR studies, respectively.

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

    International Nuclear Information System (INIS)

    Martins, Carlos Felipe Pinto

    2005-01-01

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

  13. Experimental and numerical studies on the sensitivity of carbon fibre/silicone rubber composite sensors

    International Nuclear Information System (INIS)

    Yang, Lili; Ge, Yong; Zhu, Qinghua; Zhang, Ce; Wang, Zongpeng; Liu, Penghuan

    2012-01-01

    Flexible conductive composite sensors are of great importance for applications in structural monitoring due to their low cost, high durability and excellent compatibility. In this work, carbon fibre/silicone rubber composites were prepared and their sensitivity near the percolation threshold was investigated experimentally and theoretically. Results show that carbon fibre/silicone rubber composites have great mechanical and sensitivity even under high strain conditions. Two models based on the tunnelling effect and general effective medium theory were found to understand the sensitivity of composites with lower and higher fractions of carbon fibre. Moreover, the reversibility of the sensing performance is improved with the increase of carbon fibre addition. (paper)

  14. Characterization Study of EPDM Rubber Vulcanized by Gamma Radiation in The Presence of Epoxidized Soybean Oil

    International Nuclear Information System (INIS)

    Radi, H.; Mousaa, I.M.

    2015-01-01

    Composites based on ethylene-propylene-diene rubber (EPDM) were prepared. EPDM loaded with 40 phr fumed silica in the presence of different concentrations of epoxidized soybean oil ranging between 4 and 8 phr. The composites were subjected to various gamma irradiation doses up to 200 kGy. The physical, mechanical and thermal properties of rubber composition as a function of irradiation dose were investigated. Gamma irradiation led to a significant improvement in the properties of the all compositions. Besides, an improvement in the mechanical properties was attained with the addition of 4 phr of epoxidized soybean oil.

  15. imide, crystal structure, thermal and dielectric studies

    Indian Academy of Sciences (India)

    methyl imidazolium methylidene bis(trifluoromethanesulfonyl)imide, crystal structure, thermal and dielectric studies. BOUMEDIENE HADDAD1,2,3,∗, TAQIYEDDINE MOUMENE2, DIDIER VILLEMIN1,. JEAN-FRANÇOIS LOHIER1 and EL-HABIB ...

  16. Study on recycling of waste rubbers as medium components for hydroponic culture of rose

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin-Kuk; Lee, Hyung-Gyu; Jeong, Byoung-Ryong; Hwang, Seung-Jae [Gyeongsang National Univ., Kumi(Korea)

    2000-06-30

    Recently, the efficient disposal of the waste rubber is necessary due to increasing amount of the waste rubbers. In this paper, method of recycling waste rubbers as components of medium for hydroponic rose culture was suggested. We investigated growth of rose, and macro- and micro-elements, pH and EC of the media amended with waste rubber. In the beginning of culture, stress symptoms such as thin brittle stem and incipient wilting were observed, but they disappeared in a few weeks. Concentration of Zn{sup 2+} in media at flowering increased in proportion to contents of waste tire in the media. pH of media at flowering were in the range of 5.70 to 6.35. Rose growth in all media, except in waste rock wool mixed with EPDM powder at 9:3 ratio, was normal and equivalent to the control in terms of stem length, number of stems harvested and fresh weight. (author). 10 refs., 5 tabs., 4 figs.

  17. A multi-site recycled tire crumb rubber characterization study: recruitment strategy and field sampling approach

    Science.gov (United States)

    Recently, concerns have been raised by the public about the safety of tire crumb rubber infill used in synthetic turf fields. In response, the 2016 Federal Research Action Plan on Recycled Tire Crumb Used on Playing Fields and Playgrounds (FRAP) was developed to examine key envir...

  18. Biofilm formation and design features of indwelling silicone rubber tracheoesophageal voice prostheses - An electron microscopical study

    NARCIS (Netherlands)

    Leunisse, C; van Weissenbruch, R; Busscher, HJ; van der Mei, HC; Dijk, F; Albers, FWJ

    2001-01-01

    After total laryngectomy, voice can be restored with a silicone rubber tracheoesophageal voice prosthesis. However, biofilm formation and subsequent deterioration of the silicone material of the prosthesis will limit device life by impairing valve function. To simulate the natural process of biofilm

  19. Study on Pollen Quality and Quantity as Protein Source of Honeybee Apis mellifera In Rubber Plantation Area (Hevea brasiliensis

    Directory of Open Access Journals (Sweden)

    Sri Minarti

    2009-08-01

    The conclusion of this research is during migratory beekeeping in the area of rubber plantation, bees get pollen low amounts of protein and amino acid levels below the requirement. Keywords : Pollen, Protein, Amino Acids, Honey Bee, Rubber

  20. Kinetic studies of co-pyrolysis of rubber seed shell with high density polyethylene

    International Nuclear Information System (INIS)

    Chin, Bridgid Lai Fui; Yusup, Suzana; Al Shoaibi, Ahmed; Kannan, Pravin; Srinivasakannan, Chandrasekar; Sulaiman, Shaharin Anwar

    2014-01-01

    Highlights: • Co-pyrolysis of biomass and plastic waste in thermogravimetric analyzer. • Investigation of thermal degradation behavior in different feedstocks. • Synergistic effect of the biomass and plastic waste mixture is investigated. • Kinetic parameters using one step integral method are determined. - Abstract: This paper investigates the thermal degradation behavior of rubber seed shell (RSS), high density polyethylene (HDPE), and the HDPE/RSS mixtures (0.2:0.8 weight ratio) using thermogravimetric analyzer under non-isothermal condition in argon atmosphere at flowrate of 100 ml min −1 . Cellulose, hemicellulose, and lignin are also analyzed in this study for comparison of pyrolysis behavior with RSS. The experiments were conducted at different heating rates of 10, 20, 30, and 50 K min −1 in the temperature range of 323–1173 K. The kinetic data is generated based on first order rate of reaction. It is observed that the thermal degradation behavior of the main components in biomass such as hemicellulose, cellulose, and lignin differs during pyrolysis process due to the structural differences that leads to distinctive pathways of degradation of feedstock. It is found that there are one, two, and three stages of decomposition occurring in HDPE, RSS, and HDPE/RSS mixtures respectively during the pyrolysis process. The remaining solid residue increases with an increase in heating rate regardless of the type of samples used. The activation energies (E A ) for RSS, HDPE, HDPE/RSS mixtures are 46.94–63.21, 242.13–278.14, and 49.14–83.11 kJ mol −1 respectively for the range of heating rate studied

  1. Synthesis, characterization and impedance spectroscopy study of magnetite/epoxidized natural rubber nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Tan, W.L. [Nanoscience Research Laboratory, School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang (Malaysia); Abu Bakar, M., E-mail: bmohamad@usm.my [Nanoscience Research Laboratory, School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang (Malaysia)

    2013-06-05

    Highlights: ► The Fe{sub 3}O{sub 4}/ENR nanocomposites have not been synthesized and reported. ► Nanocomposites were obtained via in situ synthesis of Fe{sub 3}O{sub 4} in the presence of ENR. ► The use of ENR enabled control of the size of Fe{sub 3}O{sub 4} particles to <20 nm. ► Conductivity of the nanocomposites increases with the increase in Fe{sub 3}O{sub 4} loading. ► The equivalent circuit for the nanocomposites is proposed and discussed. -- Abstract: The magnetite (Fe{sub 3}O{sub 4}) particles were synthesized in situ in the presence of epoxidized natural rubber (ENR) to produce the various Fe{sub 3}O{sub 4}/ENR nanocomposites. The X-ray diffraction (XRD) analysis confirmed the existence of Fe{sub 3}O{sub 4} particles in the composites. The FTIR and DSC studies suggested that no chemical interactions between the particles and the matrix. The SEM and X-mapping micrographs revealed that the Fe{sub 3}O{sub 4} particles were distributed within the ENR matrix. The ENR matrix exerts control on the Fe{sub 3}O{sub 4} particles with a size of <20 nm in the composites. The Fe{sub 3}O{sub 4} particles also affect the electrical properties of the composites. Impedance spectroscopy studies show that the electrical conductivity of the nanocomposites increases with the increase in Fe{sub 3}O{sub 4} loading in the composite. The equivalent circuit for the Fe{sub 3}O{sub 4}/ENR nanocomposites is proposed and discussed.

  2. The Cyclization of natural rubber

    International Nuclear Information System (INIS)

    Mirzataheri, M.

    2000-01-01

    The effect of solvent, temperature, time, weight percent of catalyst on the rate and mechanism of cyclization of natural rubber was studied in toluene and xylene solutions having tin tetra chloride catalyst (SnCl 4 ). Iodo metric titration show, with 8% SnCl 4 (based on polymer weight) cyclization occurs, leaving 27.4% of the total unsaturation. Infrared spectra of cyclized natural rubber show decreased absorption intensity at 840 and 780 cm -1 which are characteristic bands of the linear polymer and the appearance of absorption band at 890 cm -1 as cycles were formed. By using this chemical modification, natural rubber is transformed into a resinous thermoplastic, hard, non rubbery cyclized material with much less unsaturation than the original rubber, which could find commercial applications ad adhesives, printing inks, industrial and ship paints

  3. Small-angle neutron scattering technique in liquid crystal studies

    International Nuclear Information System (INIS)

    Shahidan Radiman

    2005-01-01

    The following topics discussed: general principles of SAS (Small-angle Neutron Scattering), liquid crystals, nanoparticle templating on liquid crystals, examples of SAS results, prospects of this studies

  4. Effect of Recycled Rubber Particles and Silica on Tensile and Tear Properties of Natural Rubber Composites

    Directory of Open Access Journals (Sweden)

    Velu CHANDRAN

    2016-05-01

    Full Text Available Application of scrap rubber and worn out tires in natural rubber compounds has been studied. The scrap rubber can, however, be recycled and compounded with natural rubber and thus can be generated as a rubber composite. In this work, recycled rubber particles (RRP were prepared using pulverization process. Then, RRP was blended with natural rubber and silica compounds, and it was synthesized by two- roll mill and hydraulic press at specified operating conditions. The samples ranging from 0 to 40 phr of RRP loaded with silica were used as constant filler. The mechanical properties and morphological analysis were carried out. The results showed that tensile strength and elongation at break gradually decreased with increasing RRP loading in natural rubber and silica compounds. Tensile modulus went down at 10 phr of RRP and then showed an increasing trend. Hardness increased up to 30 phr of RRP and tear strength increased up to 20 phr of RRP. A comparative study was also carried out with virgin natural rubber vulcanizates. The incorporation of RRP and silica up to 20 phr in natural rubber did not lower the performance of rubber articles. Morphological studies revealed that better filler dispersion, interfacial adhesion, and cross link density could increase the tensile and tear strengths.DOI: http://dx.doi.org/10.5755/j01.ms.22.2.7330

  5. Study of properties of chloroprene rubber devulcanizate by radiation in microwave

    Energy Technology Data Exchange (ETDEWEB)

    Scagliusi, Sandra R.; Araujo, Sumair G.; Landini, Liliane; Lugao, Ademar B., E-mail: scagliusi@usp.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    Among the vulcanized elastomers, the chloroprene rubber (DuPont Neoprene{sup R} - generic name) possesses a good performance, being one of the most used in the current days. However, this kind of polymer causes a serious environmental problem if it is not reprocessed or recycled. A worldwide method that has been used and that is an important tool in the rubber devulcanization is microwave irradiation at high temperature Elastomer waste may be devulcanized without depolymerization and allows a new vulcanization into a product having physical properties essentially equivalent to the original vulcanized. In this work, the chloroprene samples were irradiated in microwave generator equipment with 2,450 MHz (frequency) and 1,000 W to 3,000 W (power). The properties of samples (according to ASTM standards) were analyzed before and after irradiation. The degraded material after irradiation will be tested for re-use. (author)

  6. A study on the design method of the laminated rubber bearing for FBR

    International Nuclear Information System (INIS)

    Mazda, T.; Ishida, K.; Ikeuchi, K.; Yashiro, T.

    1994-01-01

    The Central Research Institute of Electric Power Industry (Japan) has been carrying out the Demonstration Test and Research Program of the Seismic Isolation System for the Fast Breeder Reactor (FBR) under contract with the Ministry of International Trade and Industry (FY1987--FY1993). In this research program, development of the seismic isolation element, reliability evaluation of the seismic isolation system, and examination of a design-based earthquake have been conducted in order to develop and propose design guidelines of seismic isolation system for FBR plant. The purpose of this paper is to describe the test results concerned with structural design of the laminated rubber bearing, and to explain the construction of the design method for the laminated rubber bearing, which is one of the most important factors in the design guidelines of the seismic isolation system

  7. Study of properties of chloroprene rubber devulcanizate by radiation in microwave

    International Nuclear Information System (INIS)

    Scagliusi, Sandra R.; Araujo, Sumair G.; Landini, Liliane; Lugao, Ademar B.

    2009-01-01

    Among the vulcanized elastomers, the chloroprene rubber (DuPont Neoprene R - generic name) possesses a good performance, being one of the most used in the current days. However, this kind of polymer causes a serious environmental problem if it is not reprocessed or recycled. A worldwide method that has been used and that is an important tool in the rubber devulcanization is microwave irradiation at high temperature Elastomer waste may be devulcanized without depolymerization and allows a new vulcanization into a product having physical properties essentially equivalent to the original vulcanized. In this work, the chloroprene samples were irradiated in microwave generator equipment with 2,450 MHz (frequency) and 1,000 W to 3,000 W (power). The properties of samples (according to ASTM standards) were analyzed before and after irradiation. The degraded material after irradiation will be tested for re-use. (author)

  8. A comparative study of ground tire rubber devulcanization using twin screw extruder and internal mixer

    Science.gov (United States)

    Ujianto, O.; Putri, D. B.; Jayatin; AWinarto, D.

    2017-07-01

    Devulcanization of ground tire rubber (GTR) was done using twin screw extruder (TSE) and internal mixer (IM). Processing parameters were varied to analyze its effect on gel content. Fourier Transform Infrared Spectroscopy (FTIR) analysis was performed as qualitative technique to confirm structural change. The devulcanized rubbers with the least gel content percentage produced in both TSE and IM were then used as filler in natural rubber (NR)/coconut coir (CC) composite preparation. Effects of gel content percentage on NR/CC composite tensile strength and elongation at break were analyzed. The results show that the gel content decreased by 41% for sample processed in TSE and 50% in IM compared to control sample. Overall, the devulcanization is influenced by high energy generated by thermal or thermo-mechanical process. FTIR spectra show chemically structural changes of GTR as C=C, CH2, CH3 with higher intensity for IM sample than its counterpart indicated devulcanization. The replacement of GTR to DGTR on NR/CC/GTR composites provided less network structures and resulted better tensile strength and elongation at break.

  9. Rubber glove wearing device

    International Nuclear Information System (INIS)

    Nozaki, Tatsuo; Takada, Kaoru.

    1994-01-01

    Rubber groves are attached each to an upper end of a glove putting vessel having an air-sucking hole on the bottom by enlarging an opening end of the rubber glove and turning back the inside to the outside. When the sucking device is operated, air in the glove putting device is sucked and the rubber glove is expanded by an atmospheric pressure. After expansion of the rubber glove to some extent, the sucking device is stopped, and presence or absence of failures of the rubber glove is confirmed by shrinkage of the rubber glove and by an indication value of a pressure gauge for detecting the pressure change in the vessel. Then, a hand is inserted to the expanded rubber glove, and a detaching switch in the vessel is pushed by a finger tip. A detaching piece at the upper end of the vessel is protruded outwardly to enlarge the turned-back portion of the rubber glove to easily release the rubber glove from the putting vessel, and the rubber glove is put on. This enables to wear the rubber glove and conduct failure test simultaneously. Further, a user can put on the rubber glove without touching the outside of the rubber glove. (I.N.)

  10. Radiation-induced deterioration of natural rubber and isoprene rubber vulcanizates

    International Nuclear Information System (INIS)

    Kohjiya, Shinzo; Matsumura, Yasushige; Yamashita, Shinzo; Matsuyama, Tomochika; Yamaoka, Hitoshi.

    1984-01-01

    Natural rubber (NR) and isoprene rubber (IR) were cured by sulfur and accelerator to give rubber vulcanizates. Both vulcanizates were subject to solvent extraction to purify them, followed by the γ-ray irradiation in air at room temperature. The deterioration by γ-ray (0-20 Mrad) was investigated by the changes of tensile properties, hardness, swelling, and ATR-IR spectra. The tensile strength decreased much by a few Mrad irradiation, which is elucidated due to the difficulty of stretch-induced crystallization of polyisoprene after the irradiation. Modulus at 50 % elongation, network-chain density, and hardness did not show significant variation with the γ-ray dose. These irradiation results suggest both degradation and crosslinking occur comparably in the rubber vulcanizates and the regularity of polyisoprene chains may be somewhat randomized to prevent them from crystallizing on stretching. (author)

  11. Body Schema Illusions: A Study of the Link between the Rubber Hand and Kinesthetic Mirror Illusions through Individual Differences

    Directory of Open Access Journals (Sweden)

    Morgane Metral

    2017-01-01

    Full Text Available Background. The well-known rubber hand paradigm induces an illusion by having participants feel the touch applied to a fake hand. In parallel, the kinesthetic mirror illusion elicits illusions of movement by moving the reflection of a participant’s arm. Experimental manipulation of sensory inputs leads to emergence of these multisensory illusions. There are strong conceptual similarities between these two illusions, suggesting that they rely on the same neurophysiological mechanisms, but this relationship has never been investigated. Studies indicate that participants differ in their sensitivity to these illusions, which provides a possibility for studying the relationship between these two illusions. Method. We tested 36 healthy participants to confirm that there exist reliable individual differences in sensitivity to the two illusions and that participants sensitive to one illusion are also sensitive to the other. Results. The results revealed that illusion sensitivity was very stable across trials and that individual differences in sensitivity to the kinesthetic mirror illusion were highly related to individual differences in sensitivity to the rubber hand illusion. Conclusions. Overall, these results support the idea that these two illusions may be both linked to a transitory modification of body schema, wherein the most sensitive people have the most malleable body schema.

  12. Body Schema Illusions: A Study of the Link between the Rubber Hand and Kinesthetic Mirror Illusions through Individual Differences.

    Science.gov (United States)

    Metral, Morgane; Gonthier, Corentin; Luyat, Marion; Guerraz, Michel

    2017-01-01

    The well-known rubber hand paradigm induces an illusion by having participants feel the touch applied to a fake hand. In parallel, the kinesthetic mirror illusion elicits illusions of movement by moving the reflection of a participant's arm. Experimental manipulation of sensory inputs leads to emergence of these multisensory illusions. There are strong conceptual similarities between these two illusions, suggesting that they rely on the same neurophysiological mechanisms, but this relationship has never been investigated. Studies indicate that participants differ in their sensitivity to these illusions, which provides a possibility for studying the relationship between these two illusions. We tested 36 healthy participants to confirm that there exist reliable individual differences in sensitivity to the two illusions and that participants sensitive to one illusion are also sensitive to the other. The results revealed that illusion sensitivity was very stable across trials and that individual differences in sensitivity to the kinesthetic mirror illusion were highly related to individual differences in sensitivity to the rubber hand illusion. Overall, these results support the idea that these two illusions may be both linked to a transitory modification of body schema, wherein the most sensitive people have the most malleable body schema.

  13. A study of RHIC crystal collimation

    International Nuclear Information System (INIS)

    Trbojevic, D.; Harrison, M.; Parker, B.; Thompson, P.; Stevens, A.; Biryukov, V.; Mokhov, N.; Drozhdin, A.

    1998-01-01

    The Relativistic Heavy Ion Collider (RHIC) will experience increasing longitudinal and transverse heavy ion emittances, mostly due to intra-beam scattering (IBS). The experiments in RHIC are expected to not only have reduced luminosities due to IBS but also background caused by beam halo. Primary betatron collimators will be used to remove the large amplitude particles. The efficiency of the primary collimator in RHIC strongly depends on the alignment of the jaws which needs to be within about ten micro-radians for the optimum conditions. As proposed by V. biryukov bent crystals could be used to improve the efficiency of an existing collimation system by installing them upstream of the collimator jaws. Bent crystals have been successfully used in SPS, Protvino and Fermilab for extraction of the beam particles channeled through them. This study examines possible improvements of the primary collimator system for heavy ions at RHIC by use of bent crystals. Bent crystals will reduce the collimator jaws alignment requirement and will increase collimator efficiency thereby reducing detector background

  14. Oxidation Degradation Study And Use Of Phenol And Amina Antioxidant Compounds In Natural Rubber Cyclical

    Directory of Open Access Journals (Sweden)

    Arofah Megasari Siregar

    2015-08-01

    Full Text Available The research was conducted research into the use of commercial antioxidants Irganox 1010 wingstay to inhibit the oxidative degradation of cyclic polymers of natural rubber and polypropylene nanocomposite with commercial montmorillonite PP MMT-Clay. Proces mixing nanocomposit PPMMT using commercial compatibiliser PP-g-MA PB3200 made in an internal mixer at a temperature of 180 C for 10 minutes and 65 rpm rotor speed. Hyndered phenol antioxidant effectiveness was analyzed using Fourier Transform Infra Red FTIR. Analysis of infrared is done by measuring the broad index absorption of the carbonyl group CO at a wavelength of 1700 cm-1 and a broad index uptake hydroxyl group at a wavelength of 3400 cm-1 before and after heated in an oven temperature of 125oC with variations in exposure time. The results indicate the use of antioxidant Irganox 1010 in nanocomposite PP MMT with a stabilizing factor of 5.5. Further commercial antioxidants will be used to restrain the rate of oxidation degradation of the natural rubber products cyclical CNR.

  15. Effective Remediation of Lead Ions from Aqueous Solution by Chemically Carbonized Rubber Wood Sawdust: Equilibrium, Kinetics, and Thermodynamic Study

    Directory of Open Access Journals (Sweden)

    Swarup Biswas

    2015-01-01

    Full Text Available Rubber wood sawdust was carbonized into charcoal by chemical treatment which was used for removal of lead ion from aqueous solution. The work involves batch experiments to investigate the pH effect, initial concentration of adsorbate, contact time, and adsorbent dose. Experimental data confirmed that the adsorption capacities increased with increasing inlet concentration and bed height and decreased with increasing flow rate. Adsorption results showed a maximum adsorption capacity of 37 mg/g at 308 K. Langmuir, Freundlich, and Temkin model adsorption isotherm models were applied to analyze the process where Temkin was found as a best fitted model for present study. Simultaneously kinetics of adsorption like pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were investigated. Thermodynamic parameters were used to analyze the adsorption experiment. Fourier transform infrared spectroscopy, scanning electron microscope, and energy dispersive X-ray spectroscopy confirmed the batch adsorption of lead ion onto chemically carbonized rubber wood sawdust.

  16. A molecular dynamics study on Young's modulus and tribology of carbon nanotube reinforced styrene-butadiene rubber.

    Science.gov (United States)

    Chawla, Raj; Sharma, Sumit

    2018-03-18

    Styrene-butadiene rubber is a copolymer widely used in making car tires and has excellent abrasion resistance. The Young's modulus and tribology of pure styrene butadiene rubber (SBR) polymer and carbon nanotube reinforced polymer composites have been investigated using molecular dynamics simulations. The mechanism of enhanced tribology properties using carbon nanotube has been studied and discussed. The obtained Young's modulus shows the enhancement in mechanical properties of SBR polymer when carbon nanotubes are used as reinforcement. The concentration, temperature and velocity profiles, radial distribution function, frictional stresses, and cohesive energy density are calculated and analyzed in detail. The Young's modulus of SBR matrix increases about 29.16% in the presence of the 5% CNT. The atom movement velocity and average cohesive energy density in the friction area of pure SBR matrix was found to be more than that of the CNT/SBR composite. Graphical abstract Initial and final conditions of (a) pure SBR matrix and (b) CNT/SBR matrix subjected toshear loading and frictional stresses of top Fe layers of both pure SBR and CNT/SBR composite.

  17. Rubber composites cured with sulphur and peroxide and ...

    Indian Academy of Sciences (India)

    Besides classical applications of rubber products in tyres, ... application of sulphur curing systems leads to the forming ..... mobile sulphidic cross-links which promote crystallization of NR. ... PhD Thesis (Kingston, Ontario: Queen's University).

  18. Preliminary study of rubber seed Hevea brasiliensis oil utilization for tilapia diet

    Directory of Open Access Journals (Sweden)

    Siti Komariyah

    2015-05-01

    Full Text Available ABSTRACT This research was conducted as a preliminary study on utilization of RBO for Nile tilapia (Oreochromis sp. diet by also evaluating its effect on growth the performance. This research used SULTANA strain at average initial body weights of 8.33±0.07 g/ind. Experimental design was set in completely randomized design. Each treatment was done in triplicates. The treatments were various additions of RBO to replace corn oil in the diet, which were 0%, 25%, 50%, 75%, and 100%. Feeding rate, feed efficiency, protein retention, fat retention, specific growth rate, glucose, cholesterol, triglycerides, HDL (high-density lipoprotein, and hematology were used as evaluating parameters. The results showed that the growth performance, blood chemistry and hematology of fish decreased as the increasing of RBO level in the diet. These are caused by feed intake decreased significantly, which were 583.5 g to 145.6 g of treatments 0% to 100% RBO. Blood glucose, haemoglobin and specific growth of fish in the treatment of 0–100% RBO were 48.7–22.2 mg/dL, 7.6–5.4%, and 3.5–0.8%, respectively. The lowest survival was observed in fish fed 100% RBO (66.7%. Fish growth performance of 0% RBO was the best, so RBO could not be utilized yet as a source of fatty acid or corn oil replacement in tilapia diet. Keywords: free radical, HCN, Oreochromis sp., rubber seed oil  ABSTRAK Penelitian ini dilakukan sebagai studi awal pemanfaatan minyak biji karet (MBK untuk pakan ikan nila dan mengevaluasi pengaruhnya terhadap pertumbuhan ikan nila. Ikan uji yang digunakan adalah ikan nila strain SULTANA dengan bobot awal rata-rata 8,33±0,07 g/ind. Penelitian didesain dalam rancangan acak lengkap (RAL dengan lima perlakuan dan tiga ulangan. Perlakuan yang diuji berbagai sumbangan MBK untuk mengganti minyak jagung dalam pakan, yaitu 0%, 25%, 50%, 75%, dan 100%. Selama pemeliharaan, beberapa parameter yang diukur adalah jumlah konsumsi pakan, efisiensi pakan, retensi

  19. The Effect of Rubber Mixing Process on The Curing Characteristics of Natural Rubber

    Directory of Open Access Journals (Sweden)

    Abu Hasan

    2013-04-01

    Full Text Available This research is aimed at studying the relationship between rubber mixing processes and curing characteristics of natural rubber. The curing characteristic analysis was carried out through a natural rubber formula having been masticated and mixed, followed by curing. As many as four mastication methods were finely applied; each respected four sequences of rubber mixing process. In the first method, rubber was masticated for 5 minutes and then rubber chemicals and carbon black N 330 were  simultaneously added. In the second and the third methods, rubber was masticated for 1 minute and then carbon blacks and rubber chemicals were also simultaneously added but using different type of fillers. In the fourth method, rubber was masticated for 3 minutes and then rubber chemicals and carbon black were subsequently added. The additions of rubber chemicals and carbon blacks to the masticated rubber were distinguished by the sequence and time allocated for each mixing process. The carbon blacks were added in two stages by which 10 phr was added first and the remaining 40 phr was added later along with oil. In another method, ratios of the carbon blacks addition (as done in the first  and the second stages were 20:30, 30:20, and 40:10. The examination results showed that rubber mixing process gave an impact on the changes of curing characteristics. They were much affected by the method of carbon black addition. The mixing temperature also had an effect on both curing time and curing rate in which the higher the mixing temperature, the lower the curing time and curing rate. Vulcanization temperature also affected the curing time and curing rate in which the higher the vulcanization temperature, the lower the curing time and the higher the curing rate. Lastly, particle size of carbon black also gave an impact on the curing time and curing rate in which the smaller the particle size, the lower the curing time and the higher the curing rate.

  20. UTILISATION OF RUBBER SEED OL IN THE

    African Journals Online (AJOL)

    Thermal degradation studies on polyvinyl chloride in the presence of rubber seed oil, epoxidized rubber seed oil and metal ... Epoxidation of RSO was carried out at 29°C using peractic acid ..... impurities such as pigments, Vitamins, sterols ...

  1. Studying Crystal Growth With the Peltier Effect

    Science.gov (United States)

    Larsen, David J., Jr.; Dressler, B.; Silberstein, R. P.; Poit, W. J.

    1986-01-01

    Peltier interface demarcation (PID) shown useful as aid in studying heat and mass transfer during growth of crystals from molten material. In PID, two dissimilar "metals" solid and liquid phases of same material. Current pulse passed through unidirectionally solidifying sample to create rapid Peltier thermal disturbance at liquid/solid interface. Disturbance, measured by thermocouple stationed along path of solidification at or near interface, provides information about position and shape of interface.

  2. First results from electron-photon damage equivalence studies on a generic ethylene-propylene rubber

    International Nuclear Information System (INIS)

    Buckalew, W.H.

    1986-04-01

    As part of a simulator adequacy assessment program, the relative effectiveness of electrons and photons to produce damage in a generic ethylene propylene rubber (EPR) has been investigated. The investigation was limited in extent in that a single EPR material, in three thickness, was exposed to Cobalt-60 photons and three electron beam energies. Basing material damage on changes in the EPR mechanical properties elongation and tensile strength, we observed that EPR damage was a smoothly varying function of absorbed energy and independent of irradiating particle type. EPR damage tracked equally well as a function of both incident particle energy and material front surface dose. Based on these preliminary data, we tentatively concluded that a correlation between particle, particle energy, and material damage (as measured by changes in material elongation and/or tensile strength) has been demonstrated. 14 figs

  3. Experimental study on behaviors of dielectric elastomer based on acrylonitrile butadiene rubber

    Science.gov (United States)

    An, Kuangjun; Chuc, Nguyen Huu; Kwon, Hyeok Yong; Phuc, Vuong Hong; Koo, Jachoon; Lee, Youngkwan; Nam, Jaedo; Choi, Hyouk Ryeol

    2010-04-01

    Previously, the dielectric elastomer based on Acrylonitrile Butadiene Rubber (NBR), called synthetic elastomer has been reported by our group. It has the advantages that its characteristics can be modified according to the requirements of performances, and thus, it is applicable to a wide variety of applications. In this paper, we address the effects of additives and vulcanization conditions on the overall performance of synthetic elastomer. In the present work, factors to have effects on the performances are extracted, e.g additives such as dioctyl phthalate (DOP), barium titanium dioxide (BaTiO3) and vulcanization conditions such as dicumyl peroxide (DCP), cross-linking times. Also, it is described how the performances can be optimized by using DOE (Design of Experiments) technique and experimental results are analyzed by ANOVA (Analysis of variance).

  4. Developments in rubber technology 2 synthetic rubbers

    CERN Document Server

    Lee, K

    1981-01-01

    This book is intended for those people who have a knowledge or understanding of rubber materials and processes but who wish to update their knowledge. It should be read in conjunction with Developments in Rubber Technology-l as that volume discussed developments in natural rubber and selected special purpose synthetic rubbers as well as additives. The authors have been selected for their expertise in each particular field and we, as editors, would like to express our appreciation to the individual authors and also to their companies. Such a book would be impossible to produce without such active cooperation as we have received. Volumes 1 and 2 of Developments in Rubber Technology cover rubbers which are processed and vulcanised in the traditional manner. It is appreciated that the omission of non-vulcanised rubber materials (the so­ called thermoplastic elastomers) will be unwelcome to many readers but it is intended, because of the size of the subject, to cover these materials in a subsequent volume. A.W. K...

  5. Guided mode studies of smectic liquid crystals

    International Nuclear Information System (INIS)

    Hodder, B.

    2000-03-01

    Recently there has been considerable interest in the use of ferroelectric liquid crystals in low power, fast switching display devices. At present the voltage switching process in surface stabilised ferroelectric liquid crystal (SSFLC) devices is not fully understood and a convenient theory for such cells has yet to be found. It is the primary aim of this work to characterise the optic tensor configuration (director profile) in thin cells (∼ 3.5 μm) containing ferroelectric liquid crystal (FLC) material. These results form a benchmark by which continuum theories may be tested. Polarised microscopy is, perhaps, the most common optical probe of liquid crystal cells. It should be appreciated that this technique is fundamentally limited, as the results are deduced from an integrated optical response of any given cell, and cannot be used to spatially resolve details of the director profile through the cell. The guided mode techniques used in this study are the primary non-integral probe and enable detailed spatial resolution of the director profile within liquid crystal cells. Analysis of guided mode data from cells containing homeotropically aligned FLC reveals the temperature dependence of the optical biaxiality and cone angle for a 40% chiral mixture of the commercially available FLC SCE8*. From these optical biaxiality measurements the temperature dependence of the biaxial order parameter C is determined. Guided mode studies of cells containing homogeneously aligned SCE8* (the conventional alignment for SSFLC devices) reveal the 0V equilibrium director profile from which a cone and chevron model is constructed. Subsequent studies of voltage induced elastic deformations of the director profile are presented and compared with a single elastic constant continuum theory which is shown to be inadequate. Optical guided mode techniques are not directly sensitive to the smectic layer configuration but X-ray scattering is. Here, for the first time, results are presented

  6. Structural characterization of rubber from jackfruit and euphorbia as a model of natural rubber.

    Science.gov (United States)

    Mekkriengkrai, Dararat; Ute, Koiichi; Swiezewska, Ewa; Chojnacki, Tadeusz; Tanaka, Yasuyuki; Sakdapipanich, Jitladda T

    2004-01-01

    A structural study of low molecular weight rubbers from Jackfruit (Artocarpus heterophyllus) and Painted spurge (Euphorbia heterophylla) was carried out as model compounds of natural rubber from Hevea brasiliensis. The rubber content of latex from Jackfruit was 0.4-0.7%, which is very low compared with that of 30-35% in the latex from Hevea tree. The rubber from Jackfruit latex was low molecular weight with narrow unimodal molecular weight distribution (MWD), whereas that obtained from E. heterophylla showed very broad MWD. The 1H and 13C NMR analyses showed that Jackfruit rubber consists of a dimethylallyl group and two trans-isoprene units connected to a long sequence of cis-isoprene units. The alpha-terminal group of Jackfruit rubber was presumed to be composed of a phosphate group based on the presence of 1H NMR signal at 4.08 ppm corresponding to the terminal =CH-CH2OP group.

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

    Science.gov (United States)

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

    2018-04-01

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

  8. Gamma-radiation induced cross-links in ethylene-propylene rubber studied by CP-MAS NMR

    International Nuclear Information System (INIS)

    Sohma, J.; Shiotani, M.; Murakami, S.

    1983-01-01

    A new technique of 13 C-NMR, the CP-MAS method, was applied to study a chemistry of cross-links induced by #betta#-irradiation of ethylene-propylene rubber. The chemical species of cross-linking points were specified with their relative concentrations by the analysis of the CP-MAS spectra obtained before and after the irradiation. It was found that the short branches were also formed by the irradiation. A comparison was made between the cross-links detected by the CP-MAS method and those obtained by the Charlesby-Pinner analysis of the gelation caused by the #betta#-irradiation. The conventional 13 C-NMR of the cross-linked and swollen EPR provided us an information on the sol parts of the sample but little information on the cross-links in the gel parts. (author)

  9. A comparative study between chemical and enzymatic transesterification of high free fatty acid contained rubber seed oil for biodiesel production

    Directory of Open Access Journals (Sweden)

    Jilse Sebastian

    2016-12-01

    Full Text Available The choice of a paramount method for biodiesel production has significance as the demand of alternative fuels like biodiesel is growing rapidly. In the present study, experimental results from chemical-catalysed as well as enzyme-catalysed methods were compared using common influencing parameters such as oil/alcohol molar ratio, catalyst concentration and reaction duration. Requirement of certain solvents to enhance the reaction rate was explained in the enzyme-catalysed transesterification reaction. Biodiesel conversion of more than 90% was attained for chemical-catalysed transesterification, whereas the conversion rate was 85% for enzyme-catalysed method. This gives the indication of further refinement in the enzyme-catalysed transesterification process. The influencing parameters and absolute results of the analysis give the impression of superiority of enzymatic transesterification method for biodiesel production from high free fatty acid-contained rubber seed oil.

  10. Temperature dependence of the elastocaloric effect in natural rubber

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Zhongjian, E-mail: zhongjian.xie521@gmail.com; Sebald, Gael; Guyomar, Daniel

    2017-07-12

    The temperature dependence of the elastocaloric (eC) effect in natural rubber (NR) has been studied. This material exhibits a large eC effect over a broad temperature range from 0 °C to 49 °C. The maximum adiabatic temperature change (ΔT) occurred at 10 °C and the behavior could be predicted by the temperature dependence of the strain-induced crystallization (SIC) and the temperature-induced crystallization (TIC). The eC performance of NR was then compared with that of shape memory alloys (SMAs). This study contributes to the SIC research of NR and also broadens the application of elastomers. - Highlights: • A large elastocaloric effect over a broad temperature range was found in natural rubber (NR). • The caloric performance of NR was compared with that of shape memory alloys. • The temperature dependence of the elastocaloric effect in NR can be prediced by the theory of strain-induced crystallization.

  11. Magnetic rubber inspection (MRI)

    International Nuclear Information System (INIS)

    Carro, L.

    1997-01-01

    Magnetic Rubber Inspection (MRI) was developed to inspect for small cracks and flaws encountered in high performance aircraft. A formula of very fine magnetic particles immersed in a room temperature curing rubber is catalysed and poured into dams (retainers) on the surface of the part to be inspected. Inducing a magnetic field then causes the particles to be drawn to discontinuities in the component under test. These indicating particles are held to the discontinuity by magnetic attraction, as the rubber cures. The solid rubber cast (Replica) is then removed and examined under a microscope for indicating lines of particle concentrations. 3 refs., 6 figs

  12. Simulation work of fatigue life prediction of rubber automotive components

    International Nuclear Information System (INIS)

    Samad, M S A; Ali, Aidy

    2010-01-01

    The usage of rubbers has always been so important, especially in automotive industries. Rubbers have a hyper elastic behaviour which is the ability to withstand very large strain without failure. The normal applications for rubbers are used for shock absorption, sound isolation and mounting. In this study, the predictions of fatigue life of an engine mount of rubber automotive components were presented. The finite element analysis was performed to predict the critical part and the strain output were incorporated into fatigue model for prediction. The predicted result shows agreement in term of failure location of rubber mount.

  13. Draft Tube Baffle (DTB) crystallizers: A study of stationary and dynamically behaving Crystal Size Distributions (CSD)

    Science.gov (United States)

    Deleer, B. G. M.

    1981-11-01

    Based on population balance, CSD behavior as a function of geometrical and operating variables was studied, using a crystallizer. A potash alum-water system, involving a separation technique which uses surface active agents and an apolar, organic liquid to separate potash alum crystals from mother liquid under the influence of gravity was used to check experimental findings against literature data. Results show action of annular settling spaces is strongly influenced by fluid velocities perpendicular to those directed upwards. The well-mixed volume decreases with increasing crystallizer size until a minimum effective volume is reached. As supersaturation is constant throughout the crystallizer volume under stationary operating conditions, the annular settling space behaves like a growth chamber for crystals in its volume. Swirl in the lower part of the annular volume introduces significant back mixing. Crystals within this space either grow and return to the well-mixed part, or withdraw from the annular volume permanently.

  14. Disturbances in body ownership in schizophrenia: evidence from the rubber hand illusion and case study of a spontaneous out-of-body experience.

    Directory of Open Access Journals (Sweden)

    Katharine N Thakkar

    Full Text Available A weakened sense of self may contribute to psychotic experiences. Body ownership, one component of self-awareness, can be studied with the rubber hand illusion (RHI. Watching a rubber hand being stroked while one's unseen hand is stroked synchronously can lead to a sense of ownership over the rubber hand, a shift in perceived position of the real hand, and a limb-specific drop in stimulated hand temperature. We aimed to assess the RHI in schizophrenia using quantifiable measures: proprioceptive drift and stimulation-dependent changes in hand temperature.The RHI was elicited in 24 schizophrenia patients and 21 matched controls by placing their unseen hand adjacent to a visible rubber hand and brushing real and rubber hands synchronously or asynchronously. Perceived finger location was measured before and after stimulation. Hand temperature was taken before and during stimulation. Subjective strength of the illusion was assessed by a questionnaire.Across groups, the RHI was stronger during synchronous stimulation, indicated by self-report and proprioceptive drift. Patients reported a stronger RHI than controls. Self-reported strength of RHI was associated with schizotypy in controls Proprioceptive drift was larger in patients, but only following synchronous stimulation. Further, we observed stimulation-dependent changes in skin temperature. During right hand stimulation, temperature dropped in the stimulated hand and rose in the unstimulated hand. Interestingly, induction of RHI led to an out-of-body experience in one patient, linking body disownership and psychotic experiences.The RHI is quantitatively and qualitatively stronger in schizophrenia. These findings suggest that patients have a more flexible body representation and weakened sense of self, and potentially indicate abnormalities in temporo-parietal networks implicated in body ownership. Further, results suggest that these body ownership disturbances might be at the heart of a subset of

  15. Disturbances in Body Ownership in Schizophrenia: Evidence from the Rubber Hand Illusion and Case Study of a Spontaneous Out-of-Body Experience

    Science.gov (United States)

    Thakkar, Katharine N.; Nichols, Heathman S.; McIntosh, Lindsey G.; Park, Sohee

    2011-01-01

    Background A weakened sense of self may contribute to psychotic experiences. Body ownership, one component of self-awareness, can be studied with the rubber hand illusion (RHI). Watching a rubber hand being stroked while one's unseen hand is stroked synchronously can lead to a sense of ownership over the rubber hand, a shift in perceived position of the real hand, and a limb-specific drop in stimulated hand temperature. We aimed to assess the RHI in schizophrenia using quantifiable measures: proprioceptive drift and stimulation-dependent changes in hand temperature. Methods The RHI was elicited in 24 schizophrenia patients and 21 matched controls by placing their unseen hand adjacent to a visible rubber hand and brushing real and rubber hands synchronously or asynchronously. Perceived finger location was measured before and after stimulation. Hand temperature was taken before and during stimulation. Subjective strength of the illusion was assessed by a questionnaire. Results Across groups, the RHI was stronger during synchronous stimulation, indicated by self-report and proprioceptive drift. Patients reported a stronger RHI than controls. Self-reported strength of RHI was associated with schizotypy in controls Proprioceptive drift was larger in patients, but only following synchronous stimulation. Further, we observed stimulation-dependent changes in skin temperature. During right hand stimulation, temperature dropped in the stimulated hand and rose in the unstimulated hand. Interestingly, induction of RHI led to an out-of-body experience in one patient, linking body disownership and psychotic experiences. Conclusions The RHI is quantitatively and qualitatively stronger in schizophrenia. These findings suggest that patients have a more flexible body representation and weakened sense of self, and potentially indicate abnormalities in temporo-parietal networks implicated in body ownership. Further, results suggest that these body ownership disturbances might be at

  16. Influence the Rubber Seed Type and Altitude on Characteristic of Seed, Oil and Biodiesel

    OpenAIRE

    Salni Salni; Poedji Loekitowati Hariani; Hanifa Marisa Hanifa

    2017-01-01

    This research studies the influence of the type of rubber seed that is superior and local, altitude plant in South Sumatra province to the characteristic of seed, oil and biodiesel (methyl ester). Rubber plants planted from local rubber seed by seeds seedlings and superior rubber seed by selected clones. In the study, rubber plants planted at a different altitude, namely in Banyuasin district (18 m above sea level), Prabumulih District (176 m above sea level) and Lahat District (627 m above s...

  17. Influence of the Rubber Seed Type and Altitude on Characteristic of Seed, Oil and Biodiesel

    OpenAIRE

    Salni, Salni; Hariani, Poedji Loekitowati; Hanifa, Hanifa Marisa

    2017-01-01

    This research studies the influence of the type of rubber seed that is superior and local, altitude plant in South Sumatra province to the characteristic of seed, oil and biodiesel (methyl ester). Rubber plants planted from local rubber seed by seeds seedlings and superior rubber seed by selected clones. In the study, rubber plants planted at a different altitude, namely in Banyuasin district (18 m above sea level), Prabumulih District (176 m above sea level) and Lahat District (627 m above s...

  18. Studies on growth, crystal structure and characterization of novel organic nicotinium trifluoroacetate single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Dhanaraj, P.V. [Centre for Crystal Growth, SSN College of Engineering, Kalavakkam 603 110 (India); Rajesh, N.P., E-mail: rajeshnp@hotmail.com [Centre for Crystal Growth, SSN College of Engineering, Kalavakkam 603 110 (India); Sundar, J. Kalyana; Natarajan, S. [Department of Physics, Madurai Kamaraj University, Madurai 625 021 (India); Vinitha, G. [Department of Physics, Crescent Engineering College, Chennai 600 048 (India)

    2011-09-15

    Highlights: {yields} Good quality crystals of nicotinium trifluoroacetate in monoclinic system were grown for first time. {yields} Nicotinium trifluoroacetate crystal exhibits third order nonlinear optical properties. {yields} The optical spectrum of nicotinium trifluoroacetate crystal reveals the wide transmission in the entire range with cutoff wavelength at 286 nm. {yields} Nicotinium trifluoroacetate is a low dielectric constant material. - Abstract: An organic material, nicotinium trifluoroacetate (NTF) was synthesized and single crystals in monoclinic system were grown from aqueous solution for the first time. Its solubility and metastable zone width were estimated. The crystal structure of NTF was analyzed to reveal the molecular arrangements and the formation of hydrogen bonds in the crystal. High-resolution X-ray diffraction rocking curve measurements were performed to analyze the structural perfection of the grown crystals. Functional groups in NTF were identified by Fourier transform infrared spectral analysis. Thermal behaviour and stability of NTF were studied by thermogravimetric and differential thermal analysis and differential scanning calorimetry. Mechanical and dielectric properties of NTF crystals were analyzed. Optical studies reveal that NTF crystals are transparent in the wavelength range 286-1100 nm. The third order nonlinear optical parameters of NTF were derived by the Z-scan technique.

  19. Cream concentrated latex for foam rubber products

    Science.gov (United States)

    Suksup, R.; Imkaew, C.; Smitthipong, W.

    2017-12-01

    Fresh natural latex (around 40% rubber and 60% water) can be transformed to concentrated natural latex (around 60% rubber and 40% water) in order to realise economical transportation and easier latex product’s preparation. The concentrated natural latex is an extremely valuable material. It can be applied for many types of products, for example, foam rubber as pillow and mattress, elastic band, etc. Industrially, the concentrated natural latex can be prepared by centrifugation which requires an enormous expensive machine. From the eco-friendly products point of view, most of rubber entrepreneurs in the world try to develop a green rubber product. So, the main objective of this study is to prepare the cream concentrated latex without any sophisticated machine. Thus, we work on a simple, cheap and green method that does not use any expensive machine but uses water-based chemical as sodium alginate to prepare the cream concentrated latex. The optimal amount of sodium alginate in the latex was studied. The main characteristics of the cream concentrated latex were tested by various technics, such as alkalinity, total solid content (TSC), dry rubber content (DRC), etc. We found that there are no significant differences of results between fresh natural latex and cream concentrated latex, except for the TSC and DRC. The TSC and DRC of cream latex are higher than those of fresh natural latex. Finally, we propose a model of natural rubber particle and sodium alginate to form the cream concentrated latex.

  20. Exposure to rubber fume and rubber process dust in the general rubber goods, tyre manufacturing and retread industries.

    Science.gov (United States)

    Dost, A A; Redman, D; Cox, G

    2000-08-01

    This study assesses the current patterns and levels of exposure to rubber fume and rubber process dust in the British rubber industry and compares and contrasts the data obtained from the general rubber goods (GRG), retread tire (RT) and new tire (NT) sectors. A total of 179 rubber companies were visited and data were obtained from 52 general rubber goods, 29 retread tire and 7 new tire manufacturers. The survey was conducted using a questionnaire and included a walk-through inspection of the workplace to assess the extent of use of control measures and the nature of work practices being employed. The most recent (predominantly 1995-97) exposure monitoring data for rubber fume and rubber process dust were obtained from these companies; no additional sampling was conducted for the purpose of this study. In addition to the assessment of exposure data, evaluation of occupational hygiene reports for the quality of information and advice was also carried out.A comparison of the median exposures for processes showed that the order of exposure to rubber fume (E, in mg m(-3)) is: E(moulding) (0.40) approximately E(extrusion) (0.33)>E(milling) (0.18) for GRG; E(press) (0. 32)>E(extrusion) (0.19)>E(autoclave) (0.10) for RT; and E(press) (0. 22) approximately E(all other) (0.22) for NT. The order of exposure to rubber fume between sectors was E(GRG) (0.40)>E(RT) (0.32)>E(NT) (0.22). Median exposures to rubber process dust in the GRG was E(weighing) (4.2)>E(mixing) (1.2) approximately E(milling) (0.8) approximately E(extrusion) (0.8) and no significant difference (P=0. 31) between GRG and NT sectors. The findings compare well with the study carried out in the Netherlands [Kromhout et al. (1994), Annals of Occupational Hygiene 38(1), 3-22], and it is suggested that the factors governing the significant differences noted between the three sectors relate principally to the production and task functions and also to the extent of controls employed. Evaluation of occupational

  1. Modeling liquid crystal polymeric devices

    Science.gov (United States)

    Gimenez Pinto, Vianney Karina

    The main focus of this work is the theoretical and numerical study of materials that combine liquid crystal and polymer. Liquid crystal elastomers are polymeric materials that exhibit both the ordered properties of the liquid crystals and the elastic properties of rubbers. Changing the order of the liquid crystal molecules within the polymer network can induce shape change. These materials are very valuable for applications such as actuators, sensors, artificial muscles, haptic displays, etc. In this work we apply finite element elastodynamics simulations to study the temperature induced shape deformation in nematic elastomers with complex director microstructure. In another topic, we propose a novel numerical method to model the director dynamics and microstructural evolution of three dimensional nematic and cholesteric liquid crystals. Numerical studies presented in this work are in agreement with experimental observations and provide insight into the design of application devices.

  2. Biodiversity in rubber agroforests

    NARCIS (Netherlands)

    Beukema, Hendrien

    2013-01-01

    Jungle rubber tuinen zijn extensieve rubber agroforests die qua structuur op secundaire bossen lijken, en waarin wilde soorten door de boer worden getolereerd. Met het verdwijnen van het laaglandregenwoud rijst de vraag of de begroeiing die ervoor in de plaats komt een aantal kenmerken en functies

  3. Vulcanization of Rubber

    Indian Academy of Sciences (India)

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

  4. Performance of self-compacting rubberized concrete

    Directory of Open Access Journals (Sweden)

    Hamza Bensaci

    2018-01-01

    Full Text Available Used tyre rubber wastes present a serious environmental problem of pollution and storage. The recycling of this waste in the industry of construction could be an appropriate solution to produce an eco-concrete and could contribute to the improvement of some of its properties. This paper aims to study the possibility of using tyre rubber waste as fine aggregate replacement in self-compacting concrete (SCC. Fines rubber particles of 0-2 mm of waste tyres were added SCC mixtures as a partial substitution of the total volume of sand at different percentages (5, 10, 15, 20 and 30%. The influence of fines rubber of used tyres on fresh and hardened properties of the SCC was investigated. The fresh properties of SCC were performed by using slump-flow, T50 flow time, L-box, V-funnel and segregation resistance tests. Characteristics of the hardened state were obtained by compressive strength and thermal conductivity. The experimental results showed that the inclusion of fines rubber in SCC decreases the workability, reduced its passing capacity and increases the possibility of blocking. A decrease in compressive strength is observed with the increase in rubber content. On the other hand, the incorporation of the rubber fines aggregates enhances in a remarkably way the thermal conductivity.

  5. Rubber friction: role of the flash temperature

    International Nuclear Information System (INIS)

    Persson, B N J

    2006-01-01

    When a rubber block is sliding on a hard rough substrate, the substrate asperities will exert time-dependent deformations of the rubber surface resulting in viscoelastic energy dissipation in the rubber, which gives a contribution to the sliding friction. Most surfaces of solids have roughness on many different length scales, and when calculating the friction force it is necessary to include the viscoelastic deformations on all length scales. The energy dissipation will result in local heating of the rubber. Since the viscoelastic properties of rubber-like materials are extremely strongly temperature dependent, it is necessary to include the local temperature increase in the analysis. At very low sliding velocity the temperature increase is negligible because of heat diffusion, but already for velocities of order 10 -2 m s -1 the local heating may be very important. Here I study the influence of the local heating on the rubber friction, and I show that in a typical case the temperature increase results in a decrease in rubber friction with increasing sliding velocity for v>0.01 m s -1 . This may result in stick-slip instabilities, and is of crucial importance in many practical applications, e.g. for tyre-road friction and in particular for ABS braking systems

  6. Zinc Leaching from Tire Crumb Rubber

    Science.gov (United States)

    Rhodes, E. P.; Ren, J.; Mays, D. C.

    2010-12-01

    Recent estimates indicate that more than 2 billion scrap tires are currently stockpiled in the United States and approximately 280 million more tires are added annually. Various engineering applications utilize recycled tires in the form of shredded tire crumb rubber. However, the use of tire crumb rubber may have negative environmental impacts, especially when the rubber comes into contact with water. A review of the literature indicates that leaching of zinc from tire crumb rubber is the most significant water quality concern associated with using this material. Zinc is generally used in tire manufacturing, representing approximately 1.3% of the final product by mass. This study will report results from the U.S. Environmental Protection Agency’s (EPA’s) Synthetic Precipitation Leaching Procedure, batch leaching tests, and column leaching tests performed to quantify the process by which zinc leaches from tire crumb rubber into water. Results are interpreted with a first-order kinetic attachment/detachment model, implemented with the U.S. Agricultural Research Service software HYDRUS-1D, in order to determine the circumstances when zinc leaching from tire crumb rubber would be expected to comply with the applicable discharge limits. One potential application for recycled tires is replacing sand with tire crumb rubber in granular media filters used for stormwater pollution control. For this to be a viable application, the total zinc in the stormwater discharge must be below the EPA’s benchmark value of 0.117 mg/L.

  7. Application of gamma irradiation for incorporation of rubber powder in the formulations of EPDM and natural rubber

    International Nuclear Information System (INIS)

    Kiyan, Ludmila Y.P.; Parra, Duclerc Fernandes; Lugao, Ademar Benevolo

    2013-01-01

    The objective of this work was to study the behavior of the recycling of rubber burrs in form of powder, of the rubber industry from EPDM rubber powder and natural rubber with SBR. The rubber powder was irradiated and reused in rubber artifacts formulations for classical vulcanization. The processed material was irradiated using a 60 Co source in doses of 50, 100, 150 and 200 kGy and a dose rate of 5 kGy s-1 at room temperature. The radiation created devulcanization active sites for subsequent integration of the material (rubber powder) in formulations of commercial use. The processes were compared and their products characterized by analytical methods of the physical properties such as strength and elongation. Satisfactory results were found, noting a major spin-off of EPDM chain demonstrated by increased elongation

  8. Fatigue life of automotive rubber jounce bumper

    International Nuclear Information System (INIS)

    Sidhu, R S; Ali, Aidy

    2010-01-01

    It is evident that most rubber components in the automotive industry are subjected to repetitive loading. Vigorous research is needed towards improving the safety and reliability of the components. The study was done on an automotive rubber jounce bumper with a rubber hardness of 60 IRHD. The test was conducted in displacement-controlled environment under compressive load. The existing models by Kim, Harbour, Woo and Li were adopted to predict the fatigue life. The experimental results show strong similarities with the predicted models.

  9. Piezoelectric ribbons printed onto rubber for flexible energy conversion.

    Science.gov (United States)

    Qi, Yi; Jafferis, Noah T; Lyons, Kenneth; Lee, Christine M; Ahmad, Habib; McAlpine, Michael C

    2010-02-10

    The development of a method for integrating highly efficient energy conversion materials onto stretchable, biocompatible rubbers could yield breakthroughs in implantable or wearable energy harvesting systems. Being electromechanically coupled, piezoelectric crystals represent a particularly interesting subset of smart materials that function as sensors/actuators, bioMEMS devices, and energy converters. Yet, the crystallization of these materials generally requires high temperatures for maximally efficient performance, rendering them incompatible with temperature-sensitive plastics and rubbers. Here, we overcome these limitations by presenting a scalable and parallel process for transferring crystalline piezoelectric nanothick ribbons of lead zirconate titanate from host substrates onto flexible rubbers over macroscopic areas. Fundamental characterization of the ribbons by piezo-force microscopy indicates that their electromechanical energy conversion metrics are among the highest reported on a flexible medium. The excellent performance of the piezo-ribbon assemblies coupled with stretchable, biocompatible rubber may enable a host of exciting avenues in fundamental research and novel applications.

  10. Strength of mortar containing rubber tire particle

    Science.gov (United States)

    Jusoh, M. A.; Abdullah, S. R.; Adnan, S. H.

    2018-04-01

    The main focus in this investigation is to determine the strength consist compressive and tensile strength of mortar containing rubber tire particle. In fact, from the previous study, the strength of mortar containing waste rubber tire in mortar has a slightly decreases compare to normal mortar. In this study, rubber tire particle was replacing on volume of fine aggregate with 6%. 9% and 12%. The sample were indicated M0 (0%), M6 (6%), M9 (9%) and M12 (12%). In this study, two different size of sample used with cube 100mm x 100mm x 100mm for compressive strength and 40mm x 40mm x 160mm for flexural strength. Morphology test was conducted by using Scanning electron microscopic (SEM) were done after testing compressive strength test. The concrete sample were cured for day 3, 7 and 28 before testing. Results compressive strength and flexural strength of rubber mortar shown improved compare to normal mortar.

  11. 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.)

  12. Multilayer graphene rubber nanocomposites

    Science.gov (United States)

    Schartel, Bernhard; Frasca, Daniele; Schulze, Dietmar; Wachtendorf, Volker; Krafft, Bernd; Morys, Michael; Böhning, Martin; Rybak, Thomas

    2016-05-01

    Multilayer Graphene (MLG), a nanoparticle with a specific surface of BET = 250 m2/g and thus made of only approximately 10 graphene sheets, is proposed as a nanofiller for rubbers. When homogenously dispersed, it works at low loadings enabling the replacement of carbon black (CB), increase in efficiency, or reduction in filler concentration. Actually the appropriate preparation yielded nanocomposites in which just 3 phr are sufficient to significantly improve the rheological, curing and mechanical properties of different rubbers, as shown for Chlorine-Isobutylene-Isoprene Rubber (CIIR), Nitrile-Butadiene Rubber (NBR), Natural Rubber (NR), and Styrene-Butadiene Rubber (SBR). A mere 3 phr of MLG tripled the Young's modulus of CIIR, an effect equivalent to 20 phr of carbon black. Similar equivalents are observed for MLG/CB mixtures. MLG reduces gas permeability, increases thermal and electrical conductivities, and retards fire behavior. The later shown by the reduction in heat release rate in the cone calorimeter. The higher the nanofiller concentration is (3 phr, 5 phr, and 10 phr was investigated), the greater the improvement in the properties of the nanocomposites. Moreover, the MLG nanocomposites improve stability of mechanical properties against weathering. An increase in UV-absorption as well as a pronounced radical scavenging are proposed and were proved experimentally. To sum up, MLG is interesting as a multifunctional nanofiller and seems to be quite ready for rubber development.

  13. Radiation vulcanization of rubbers

    International Nuclear Information System (INIS)

    Makuuchi, Keizo

    2002-01-01

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

  14. US rubber markets recover

    International Nuclear Information System (INIS)

    Wood, A.

    1993-01-01

    Synthetic rubber markets in North America bounced back in no uncertain terms last year, with demand climbing an impressive 9.5%, to 2.97 million m.t.; and, according to the International Institute of Synthetic Rubber Producers (IIS-RP; Houston) latest five-year forecast, producers can look forward to a 3.3% increase in demand during 1993. This growth rate outpaced out 1992 forecast and demonstrates the resilience of the synthetic rubber industry, says William E. Tessemer, managing director of IISRP. We expect demand in 1993 to surpass 1992 and level off at a 2%/year growth rate for synthetic rubber - 2.5% including thermoplastic elastomers [TPEs]-over the 1993-97 period. The improvement reflects signs of a recovery in North America, especially the pickup in the auto and tire industry. The two major tire rubbers - styrene butadiene and polybutadiene rubber - notched up double-digit gains, and other materials that have autos uses, such as nitrile rubber and many of the specialty elastomers, also advanced strongly

  15. Use of Several Thermal Analysis Techniques to Study the Cracking of a Nitrile Butadiene Rubber (NBR) Insulator on the Booster Separation Motor (BSM) of the Space Shuttle

    Science.gov (United States)

    Wingard, Charles D.

    1999-01-01

    Two different vendor rubber formulations have been used to produce the silica-filled NBR insulators for the BSM of each of the two Solid Rocket Boosters (SRBs) on the Space Shuttle. Each cured insulator is bonded to the BSM aluminum aft closure with an epoxy adhesive, and some of the curved areas in the rubber may have significant residual stresses. A number of recently bonded NBR insulators have shown fine surface cracks, and stressed insulator areas may be aging at a faster rate than unstressed areas, thus hastening the surface cracking. Thermal analysis data on both vendor insulators by Dynamic Mechanical Analysis (DMA) through a temperature/frequency sweep from 24 to 74 C have shown a higher flexural storage modulus and Arrhenius activation energy for the stressed area than for the unstressed area. Other thermal analysis techniques are being used to study the insulator surface vs. bulk interior for better understanding this anomaly.

  16. Tribological Properties of Silicone Rubber-Based Ceramizable Composites Destined for Wire Covers. Part I. Studies of Block-On-Ring Friction Contact

    Directory of Open Access Journals (Sweden)

    R. Anyszka

    2015-06-01

    Full Text Available Ceramizable composites of silicone rubber matrix become more and more popular materials destined for wire covers, what can enhance fire safety of building increasing operation time of important equipment or devices (eg fire sprinklers, elevators, alarms etc. Aim of the research was to examine tribological properties and wear of commercially available silicone rubber-based ceramizable composites against steel, in configuration – steel block on composite ring, under various load (5, 10, 15, 20, 25 and 30 N. Changes to friction force in time were monitored by a tribotester, whereas wear of the composite surfaces were determined using an optical microscope. Performed studies demonstrate, that tribological characteristics and wear of the composites depend significantly on the origin of material.

  17. Randomized Prospective Study of Endoscopic Rubber Band Ligation Compared With Bipolar Coagulation for Chronically Bleeding Internal Hemorrhoids

    Science.gov (United States)

    Jutabha, Rome; Jensen, Dennis M.; Chavalitdhamrong, Disaya

    2013-01-01

    OBJECTIVES: Our purpose was to compare the efficacy, complications, success rate, recurrence rate at 1 year, and crossovers of rubber band ligation (RBL) with those of bipolar electrocoagulation (BPEC) treatment for chronically bleeding internal hemorrhoids. METHODS: A total of 45 patients of mean age 51.5 years, who had rectal bleeding from grade II or III hemorrhoids and in whom intensive medical therapy failed, were randomized in a prospective study comparing RBL with BPEC. Treatment failure was predefined as continued bleeding, occurrence of a major complication, or failure to reduce the size of all internal hemorrhoidal segments to grade I in ≤ 3 treatments. Patients were followed up for 1 year. RESULTS: With similar patients, rectal bleeding and other symptoms were controlled with significantly fewer treatments of RBL than of BPEC (2.3±0.2 vs. 3.8±0.4, P 0.05), but significantly fewer failures and crossovers (8% vs. 38%). Symptomatic recurrence at 1 year was 10% RBL and 15% BPEC. CONCLUSIONS: For patients with chronically bleeding grade II or III internal hemorrhoids that are unresponsive to medical therapy, safety and complication rates of banding and BPEC were similar. The success rate was significantly higher with RBL than with BPEC. Symptom recurrence rates at 1 year were similar. PMID:19513028

  18. Contact allergy to rubber accelerators remains prevalent

    DEFF Research Database (Denmark)

    Schwensen, J F; Menné, T; Johansen, J D

    2016-01-01

    several clinical cases with allergic facial dermatitis to rubber. OBJECTIVES: To evaluate temporal trends of contact allergy to rubber accelerators from the European baseline series in a tertiary patch test clinic in Denmark, and examine associations with anatomical locations of dermatitis. METHODS: Patch...... test and clinical data collected in a Danish tertiary dermatology clinic in Gentofte, Herlev, Copenhagen between 1 January 2005 and 31 December 2014 were analysed. The following rubber accelerators or mixtures in petrolatum from the European baseline patch test series were included: thiuram mix 1.......0%, mercaptobenzothiazole 2.0% and mercapto mix 1.0%. RESULTS: The overall prevalence of contact allergy to rubber accelerators was 3.1% with no significant change during the study period (Ptrend = 0.667). Contact allergy to thiuram mix was the most prevalent and was significantly associated with occupational contact...

  19. Optical Studies on Sol-Gel Derived Lead Chloride Crystals

    OpenAIRE

    Rejeena, I; Lillibai, B; Nithyaja, B; Nampoori, P.N V; Radhakrishnan, P

    2013-01-01

    Optical characterization of lead chloride crystals prepared by sol-gel method is reported. The relevant sol-gel technique is used for the preparation of PbCl2 samples with five different types. In this paper, we report the absorption and fluorescence behaviour of pure, UV& IR irradiated and electric & magnetic field applied lead chloride crystal samples in solution phase at two different concentrations. Optical bandgap and emission studies of these crystals are also done.

  20. Fundamental Ice Crystal Accretion Physics Studies

    Science.gov (United States)

    Struk, Peter M.; Broeren, Andy P.; Tsao, Jen-Ching; Vargas, Mario; Wright, William B.; Currie, Tom; Knezevici, Danny; Fuleki, Dan

    2012-01-01

    Due to numerous engine power-loss events associated with high-altitude convective weather, ice accretion within an engine due to ice crystal ingestion is being investigated. The National Aeronautics and Space Administration (NASA) and the National Research Council (NRC) of Canada are starting to examine the physical mechanisms of ice accretion on surfaces exposed to ice-crystal and mixed-phase conditions. In November 2010, two weeks of testing occurred at the NRC Research Altitude Facility utilizing a single wedge-type airfoil designed to facilitate fundamental studies while retaining critical features of a compressor stator blade or guide vane. The airfoil was placed in the NRC cascade wind tunnel for both aerodynamic and icing tests. Aerodynamic testing showed excellent agreement compared with CFD data on the icing pressure surface and allowed calculation of heat transfer coefficients at various airfoil locations. Icing tests were performed at Mach numbers of 0.2 to 0.3, total pressures from 93 to 45 kPa, and total temperatures from 5 to 15 C. Ice and liquid water contents ranged up to 20 and 3 g/m3, respectively. The ice appeared well adhered to the surface in the lowest pressure tests (45 kPa) and, in a particular case, showed continuous leading-edge ice growth to a thickness greater than 15 mm in 3 min. Such widespread deposits were not observed in the highest pressure tests, where the accretions were limited to a small area around the leading edge. The suction surface was typically ice-free in the tests at high pressure, but not at low pressure. The icing behavior at high and low pressure appeared to be correlated with the wet-bulb temperature, which was estimated to be above 0 C in tests at 93 kPa and below 0 C in tests at lower pressure, the latter enhanced by more evaporative cooling of water. The authors believe that the large ice accretions observed in the low pressure tests would undoubtedly cause the aerodynamic performance of a compressor component

  1. Continuous Fixed-Bed Column Study and Adsorption Modeling: Removal of Lead Ion from Aqueous Solution by Charcoal Originated from Chemical Carbonization of Rubber Wood Sawdust

    Directory of Open Access Journals (Sweden)

    Swarup Biswas

    2015-01-01

    Full Text Available The efficiency of chemically carbonized rubber wood sawdust for the removal of lead ion from the aqueous stream was investigated by column process. Chemically carbonized rubber wood sawdust was prepared by treating the sawdust with H2SO4 and HNO3. Maximum removal of lead ion in column process was found as 38.56 mg/g. The effects of operating parameters such as flow rate, bed depth, concentration, and pH were studied in column mode. Experimental data confirmed that the adsorption capacity increased with the increasing inlet concentration and bed depth and decreased with increasing flow rate. Thomas, Yoon-Nelson, and Adams-Bohart models were used to analyze the column experimental data and the relationship between operating parameters. Chemically carbonized rubber wood sawdust was characterized by using Fourier transform infrared spectroscopy. Scanning electron microscope was also utilized for morphological analysis of the adsorbent. Furthermore X-ray fluorescence spectrum analysis and energy dispersive X-ray spectroscopy were also used for the confirmation of lead adsorption process.

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

    International Nuclear Information System (INIS)

    Polsuksiri, C.

    1989-01-01

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

  3. Process simulation and techno economic analysis of renewable diesel production via catalytic decarboxylation of rubber seed oil - A case study in Malaysia.

    Science.gov (United States)

    Cheah, Kin Wai; Yusup, Suzana; Gurdeep Singh, Haswin Kaur; Uemura, Yoshimitsu; Lam, Hon Loong

    2017-12-01

    This work describes the economic feasibility of hydroprocessed diesel fuel production via catalytic decarboxylation of rubber seed oil in Malaysia. A comprehensive techno-economic assessment is developed using Aspen HYSYS V8.0 software for process modelling and economic cost estimates. The profitability profile and minimum fuels selling price of this synthetic fuels production using rubber seed oil as biomass feedstock are assessed under a set of assumptions for what can be plausibly be achieved in 10-years framework. In this study, renewable diesel processing facility is modelled to be capable of processing 65,000 L of inedible oil per day and producing a total of 20 million litre of renewable diesel product per annual with assumed annual operational days of 347. With the forecasted renewable diesel retail price of 3.64 RM per kg, the pioneering renewable diesel project investment offers an assuring return of investment of 12.1% and net return as high as 1.35 million RM. Sensitivity analysis conducted showed that renewable diesel production cost is most sensitive to rubber seed oil price and hydrogen gas price, reflecting on the relative importance of feedstock prices in the overall profitability profile. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. crystal

    Science.gov (United States)

    Yu, Yi; Huang, Yisheng; Zhang, Lizhen; Lin, Zhoubin; Sun, Shijia; Wang, Guofu

    2014-07-01

    A Nd3+:Na2La4(WO4)7 crystal with dimensions of ϕ 17 × 30 mm3 was grown by the Czochralski method. The thermal expansion coefficients of Nd3+:Na2La4(WO4)7 crystal are 1.32 × 10-5 K-1 along c-axis and 1.23 × 10-5 K-1 along a-axis, respectively. The spectroscopic characteristics of Nd3+:Na2La4(WO4)7 crystal were investigated. The Judd-Ofelt theory was applied to calculate the spectral parameters. The absorption cross sections at 805 nm are 2.17 × 10-20 cm2 with a full width at half maximum (FWHM) of 15 nm for π-polarization, and 2.29 × 10-20 cm2 with a FWHM of 14 nm for σ-polarization. The emission cross sections are 3.19 × 10-20 cm2 for σ-polarization and 2.67 × 10-20 cm2 for π-polarization at 1,064 nm. The fluorescence quantum efficiency is 67 %. The quasi-cw laser of Nd3+:Na2La4(WO4)7 crystal was performed. The maximum output power is 80 mW. The slope efficiency is 7.12 %. The results suggest Nd3+:Na2La4(WO4)7 crystal as a promising laser crystal fit for laser diode pumping.

  5. Ultrastructural studies of synthetic apatite crystals.

    Science.gov (United States)

    Arends, J; Jongebloed, W L

    1979-03-01

    In this paper a survey is given of some ultrastructural properties of synthetic hydroxyapatite. The preparation method by which single crystals with a length in the range of 0.1-3.0mm and a defined purity and stoïchiometry can be produced is given. Two groups of materials are considered in detail: carbonate-rich (greater than 0.1% CO3) and low-carbonate hydroxyapatites. The experiments on carbonate-rich material, being the most interesting from a biological point of view, show that acids attack at an active site in the hexagonal basal-plane of the crystals. Later on the crystals dissolve in the center of the crystal parallel to the c-axis forming tube-like structures. The active site can be protected from dissolution if the crystals are pretreated by EHDP or MFP. A comparison with lattice defect theory shows that most likely dislocations of the "hollow-core" type are responsible for the preferential dissolution.

  6. Cytotoxicity Comparison of the Nanoparticles Deposited on Latex Rubber Bands between the Original and Stretched State

    Directory of Open Access Journals (Sweden)

    Jung-Hwan Lee

    2014-01-01

    Full Text Available Understanding the biocompatibility of nanoparticles in dental materials is essential for their safe usage in the oral cavity. In this study, we investigated whether nanoparticles deposited on orthodontic latex rubber bands are involved in the induction of cytotoxicity. A method of stretching to three times (“3L” the length of the latex rubber bands was employed to detach the particles using the original length (“L” for comparison. The cytotoxicity tests were performed on extracts with mouse fibroblasts (L929 and human gingival fibroblasts (HGFs. Fourier transform infrared spectroscopy, ion chromatography, elemental analysis, and inductively coupled plasma mass spectrometry (ICP-MS were performed to detect the harmful components in the extracts from rubber bands. There was a significant decrease in the cell viability in the “L” samples compared with the “3L” samples (P<0.05 in the L929 and HGF cells. This was due to the Ni single crystal nanoparticles (~50nm from the inner surface of “L” samples that were detached in the “3L” samples as well as the Zn ion (~9 ppm detected in the extract. This study revealed that the Ni nanoparticles, as well as Zn ions, were involved in the induction of cytotoxicity from the latex rubber bands.

  7. House of risk approach for assessing supply chain risk management strategies: A case study in Crumb Rubber Company Ltd

    Directory of Open Access Journals (Sweden)

    Immawan Taufiq

    2018-01-01

    Full Text Available Risk is an uncertain and can have both negative and positive impacts. If the risks have a negative impact then a company will incur losses. CRUMB RUBBER COMPANY LTD is one of crumb rubber company in West Kalimantan. The length of the supply chain contained in CRUMB RUBBER COMPANY LTD and the high dependence on suppliers leads to vulnerability. So the purpose of this research is to identify the risk and determine the priority of source of risk along with the priority of handling it on CRUMB RUBBER COMPANY LTD supply chain with House of Risk approach. House of risk approach consists of two phases. Phase 1 is used to determine the dominant risk agent and phase 2 determines the effective action to deal with the dominant risk agent. From the research results, there are 19 risk events and 29 risk agents identified. The result of house of risk in phase 1 is known that 13 of 28 risk agents are dominant risk agent. Then the priority handling strategy in house of risk in phase 2, in this phase obtained 18 priority risk handling strategies.

  8. Identifying, studying and making good use of macromolecular crystals

    Energy Technology Data Exchange (ETDEWEB)

    Calero, Guillermo [University of Pittsburgh Medical School, Pittsburgh, PA 15261 (United States); Cohen, Aina E. [SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025 (United States); Luft, Joseph R. [Hauptman–Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203 (United States); State University of New York at Buffalo, 700 Ellicott Street, Buffalo, NY 14203 (United States); Newman, Janet [CSIRO Collaborative Crystallisation Centre, 343 Royal Parade, Parkville, Victoria 3052 (Australia); Snell, Edward H., E-mail: esnell@hwi.buffalo.edu [Hauptman–Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203 (United States); State University of New York at Buffalo, 700 Ellicott Street, Buffalo, NY 14203 (United States); University of Pittsburgh Medical School, Pittsburgh, PA 15261 (United States)

    2014-07-25

    As technology advances, the crystal volume that can be used to collect useful X-ray diffraction data decreases. The technologies available to detect and study growing crystals beyond the optical resolution limit and methods to successfully place the crystal into the X-ray beam are discussed. Structural biology has contributed tremendous knowledge to the understanding of life on the molecular scale. The Protein Data Bank, a depository of this structural knowledge, currently contains over 100 000 protein structures, with the majority stemming from X-ray crystallography. As the name might suggest, crystallography requires crystals. As detectors become more sensitive and X-ray sources more intense, the notion of a crystal is gradually changing from one large enough to embellish expensive jewellery to objects that have external dimensions of the order of the wavelength of visible light. Identifying these crystals is a prerequisite to their study. This paper discusses developments in identifying these crystals during crystallization screening and distinguishing them from other potential outcomes. The practical aspects of ensuring that once a crystal is identified it can then be positioned in the X-ray beam for data collection are also addressed.

  9. Identifying, studying and making good use of macromolecular crystals

    International Nuclear Information System (INIS)

    Calero, Guillermo; Cohen, Aina E.; Luft, Joseph R.; Newman, Janet; Snell, Edward H.

    2014-01-01

    As technology advances, the crystal volume that can be used to collect useful X-ray diffraction data decreases. The technologies available to detect and study growing crystals beyond the optical resolution limit and methods to successfully place the crystal into the X-ray beam are discussed. Structural biology has contributed tremendous knowledge to the understanding of life on the molecular scale. The Protein Data Bank, a depository of this structural knowledge, currently contains over 100 000 protein structures, with the majority stemming from X-ray crystallography. As the name might suggest, crystallography requires crystals. As detectors become more sensitive and X-ray sources more intense, the notion of a crystal is gradually changing from one large enough to embellish expensive jewellery to objects that have external dimensions of the order of the wavelength of visible light. Identifying these crystals is a prerequisite to their study. This paper discusses developments in identifying these crystals during crystallization screening and distinguishing them from other potential outcomes. The practical aspects of ensuring that once a crystal is identified it can then be positioned in the X-ray beam for data collection are also addressed

  10. Biodiesel Production from Rubber Seed Oil via Esterification Process

    Directory of Open Access Journals (Sweden)

    W Widayat

    2012-07-01

    Full Text Available One promise source of alternative energy is biodiesel from rubber seed oil, because the raw materials available in plentiful quantities and can be renewed. In addition, the rubber seed is still lack of utilization, and Indonesia is one of the largest rubbers producing country in the world. The objective of this research is to studied on biodiesel production by esterification process. Parameters used in this study are the ratio of catalyst and temperature and its influence on the characteristics of the resulting biodiesel product. Characterization of rubber seed include acid content number analysis, saponification numbers, density, viscosity, iodine number, type of free fatty acids and triglyceride oils. The results of analysis showed that rubber seed oil content obtained is 50.5%. The results of the GCMS analysis showed that a free fatty acid level in rubber seed is very high. Conversion into bio-diesel oil is obtained by at most 59.91% and lowest 48.24%.

  11. Exposure to aged crumb rubber reduces survival time during a stress test in earthworms (Eisenia fetida).

    Science.gov (United States)

    Pochron, Sharon; Nikakis, Jacqueline; Illuzzi, Kyra; Baatz, Andrea; Demirciyan, Loriana; Dhillon, Amritjot; Gaylor, Thomas; Manganaro, Alexa; Maritato, Nicholas; Moawad, Michael; Singh, Rajwinder; Tucker, Clara; Vaughan, Daniel

    2018-04-01

    Solid waste management struggles with the sustainable disposal of used tires. One solution involves shredding used tires into crumb rubber and using the material as infill for artificial turf. However, crumb rubber contains hydrocarbons, organic compounds, and heavy metals, and it travels into the environment. Earthworms living in soil contaminated with virgin crumb rubber gained 14% less body weight than did earthworms living in uncontaminated soil, but the impact of aged crumb rubber on the earthworms is unknown. Since many athletic fields contain aged crumb rubber, we compared the body weight, survivorship, and longevity in heat and light stress for earthworms living in clean topsoil to those living in topsoil contaminated with aged crumb rubber. We also characterized levels of metals, nutrients, and micronutrients of both soil treatments and compared those to published values for soil contaminated with virgin crumb rubber. Consistent with earlier research, we found that contaminated soil did not inhibit microbial respiration rates. Aged crumb rubber, like new crumb rubber, had high levels of zinc. However, while exposure to aged crumb rubber did not reduce earthworm body weight as did exposure to new crumb rubber, exposure to aged crumb rubber reduced earthworm survival time during a stress test by a statistically significant 38 min (16.2%) relative to the survival time for worms that had lived in clean soil. Aged crumb rubber and new crumb rubber appear to pose similar toxic risks to earthworms. This study suggests an environmental cost associated with the current tire-recycling solution.

  12. Characterization of crumb rubber modified by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Faldini, Sonia B.; Terence, Mauro C.; Miranda, Leila F.; Munhoz, Antonio H.; Domingues, Leandro S.; Coghetto, Gregory, E-mail: sfaldini@yahoo.com.br, E-mail: mauroterence@yahoo.com.br [Universidade Presbiteriana Mackenzie (UPM), Sao Paulo, SP (Brazil). Escola de Engenharia. Engenharia de Materiais

    2013-07-01

    The use of crumb rubber from scrap tires has become a common practice in the construction of roads, leading to improved properties of the asphalt and decreasing the environmental pollution. In this study, crumb rubber was modified by gamma radiation to eventually incorporate it into the asphalt and verify potential improvements of their properties. The crumb rubber modified by gamma radiation in the dose 500 kGy and 1000kGy was characterized by thermal analysis, infrared spectroscopy and scanning electron microscopy. The dose of radiation used has no effect on degradation temperatures. It is observed that the IV spectra of untreated rubbers and rubbers irradiated have substantially the same profile. The results indicate that despite small morphological changes in the irradiated rubber, they do not influence its degradation temperature and composition. (author)

  13. Characterization of crumb rubber modified by gamma radiation

    International Nuclear Information System (INIS)

    Faldini, Sonia B.; Terence, Mauro C.; Miranda, Leila F.; Munhoz, Antonio H.; Domingues, Leandro S.; Coghetto, Gregory

    2013-01-01

    The use of crumb rubber from scrap tires has become a common practice in the construction of roads, leading to improved properties of the asphalt and decreasing the environmental pollution. In this study, crumb rubber was modified by gamma radiation to eventually incorporate it into the asphalt and verify potential improvements of their properties. The crumb rubber modified by gamma radiation in the dose 500 kGy and 1000kGy was characterized by thermal analysis, infrared spectroscopy and scanning electron microscopy. The dose of radiation used has no effect on degradation temperatures. It is observed that the IV spectra of untreated rubbers and rubbers irradiated have substantially the same profile. The results indicate that despite small morphological changes in the irradiated rubber, they do not influence its degradation temperature and composition. (author)

  14. The use of radiotracers in natural rubber research in Malaysia

    International Nuclear Information System (INIS)

    Lai, P.F.; Singh, M.M.

    1981-01-01

    Five main areas where radiotracers have been used in research on natural rubber are on studies on the uptake of plant nutrients by Hevea brasiliensis using 32 P, 86 Rb and 45 Ca as tracers; biosynthesis of Hevea rubber using 14 C or 3 H labelled intermediates; translocation and metabolism of 14 C. Ethephon in Hevea brasiliensis; use of radiotracers as analytical tools and adsorption of labelled fatty acid soaps on natural rubber lattices. These studies are discussed to show the powerful tool that radiotracers provide in agricultural, biochemical and chemical research on natural rubber. (author)

  15. Studying Microstructure in Molecular Crystals With Nanoindentation

    DEFF Research Database (Denmark)

    Mishra, Manish Kumar; Desiraju, Gautam R; Ramamurty, Upadrasta

    2014-01-01

    Intergrowth polymorphism refers to the existence of distinct structural domains within a single crystal of a compound. The phenomenon is exhibited by form II of the active pharmaceutical ingredient felodipine, and the associated microstructure is a significant feature of the compound's structural...

  16. Systematic hardness studies on lithium niobate crystals

    Indian Academy of Sciences (India)

    Unknown

    crystals with different growth origins, and a Fe-doped sample. The problem of load ... The true hardness of LiNbO3 is found to be 630 ± 30 kg/mm2. .... Experimental. Pure lithium ... the index of d strikes at this simple and meaningful defini-.

  17. Lattice mechanics of ionic crystals - unified study

    International Nuclear Information System (INIS)

    Sengupta, S.; Roy, D.; Basu, A.N.

    1979-01-01

    The up-to-date situation in the understanding of the mechanical properties of ionic solids is reviewed. These properties are determined by the Born-Oppenheimer (B-O) potential energy function. For ionic crystals this potential energy function can be written down with some precision. To keep the expression tractable, the dominant electron deformation, the dipolar deformation, is treated as an adiabatic variable and the energy then becomes a function of both the nuclear coordinates and the ionic dipole moments. All the well known models for ionic crystals are discussed in terms of the energy expression they imply. This makes the comparison straight forward and brings out the essential difference between the models clearly. Next various quantum mechanical treatments for ionic crystals are reviewed. An attempt is made to obtain the B-O potential energy expression using a Heitler-London approach. By comparing the various models one can arrive at some definitive conclusions about the degree of validity and the assumptions underlying these models. Finally a comprehensive review of the results of actual computation on various ionic crystals done by different authors is undertaken. The crucial quantitative results are examined and the success and shortcoming of each calculation are critically analysed. The guiding principle in this part is the unified approach. i.e. to see how far a model with a given set of parameters accounts for both the dynamic and static properties. The discussion is divided in three sections for crystals with sodium chloride, cesium chloride and zinc sulfide structures. Outstanding problems and difficulties in the present understanding are pointed out. (auth.)

  18. Probing α-relaxation with nuclear magnetic resonance echo decay and relaxation: a study on nitrile butadiene rubber.

    Science.gov (United States)

    Sturniolo, Simone; Pieruccini, Marco; Corti, Maurizio; Rigamonti, Attilio

    2013-01-01

    One dimensional (1)H NMR measurements have been performed to probe slow molecular motions in nitrile butadiene rubber (NBR) around its calorimetric glass transition temperature Tg. The purpose is to show how software aided data analysis can extract meaningful dynamical data from these measurements. Spin-lattice relaxation time, free induction decay (FID) and magic sandwich echo (MSE) measurements have been carried out at different values of the static field, as a function of temperature. It has been evidenced how the efficiency of the MSE signal in reconstructing the original FID exhibits a sudden minimum at a given temperature, with a slight dependence from the measuring frequency. Computer simulations performed with the software SPINEVOLUTION have shown that the minimum in the efficiency reconstruction of the MSE signal corresponds to the average motional frequency taking a value around the inter-proton coupling. The FID signals have been fitted with a truncated form of a newly derived exact correlation function for the transverse magnetization of a dipolar interacting spin pair, which allows one to avoid the restriction of the stationary and Gaussian approximations. A direct estimate of the conformational dynamics on approaching the Tg is obtained, and the results are in agreement with the analysis performed via the MSE reconstruction efficiency. The occurrence of a wide distribution of correlation frequencies for the chains motion, with a Vogel-Fulcher type temperature dependence, is addressed. A route for a fruitful study of the dynamics accompanying the glass transition by a variety of NMR measurements is thus proposed. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Chrome-tanned leather shavings as a filler of butadiene-acrylonitrile rubber.

    Science.gov (United States)

    Przepiórkowska, A; Chrońska, K; Zaborski, M

    2007-03-06

    The noxious wastes from the tanning industry such as chrome-tanned leather shavings were used as the only filler of rubber mixes containing carboxylated butadiene-acrylonitrile rubber (XNBR) or butadiene-acrylonitrile rubber (NBR), and a dispersing agent Limanol PEV (Schill & Seilacher). The best form addition of leather powder to the rubber mixes is mixed the waste protein with zinc oxide. The leather powder added to the rubber mixes improves the mechanical properties: tensile strength (T(s)), elongation at break (epsilon(b)) and increase the cross-linking density of carboxylated XNBR and NBR rubber mixes. Satisfactory results of these studies are presented in this work.

  20. Fabrication of shape memory natural rubber using palmitic acid

    Directory of Open Access Journals (Sweden)

    Jeff Sze-Hua Wee

    2017-10-01

    Full Text Available This paper investigates the practicability of fabricating a shape memory natural rubber with the use of palmitic acid as the swelling agent. Strips of natural rubber samples were swollen in molten palmitic acid at 75 °C. Equilibrium swelling of natural rubber with palmitic acid was found to occur at approximately 50 min of swelling time. Under cooling effect, the palmitic acid crystallized to form a percolated crystalline platelet network. These networks allow fabricated shape memory natural rubber (SMNR to deform and recover its shape at a temperature above the melting point of palmitic acid. Under controlled uniaxial stress, the natural rubber sample with 0 parts per hundred rubber (phr carbon black loading exhibits fixity and recovery of 80 ± 10%. Motivation of this research is primarily on practicability of palmitic acid to be used as a swelling agent for shape memory properties. Results show that palmitic acid is a relatively good swelling agent to induce shape memory properties into natural rubber.

  1. Modification of rubber surface by UV surface grafting

    International Nuclear Information System (INIS)

    Shanmugharaj, A.M.; Kim, Jin Kuk; Ryu, Sung Hun

    2006-01-01

    Rubber surface is subjected to ultraviolet radiation (UV) in the presence of allylamine and radiation sensitizer benzophenone (BP). Fourier transform infrared spectral studies reveal the presence of allylamine on the surface. The presence of irregular needle shapes on the surface as observed in scanning electron micrographs also confirms the polymerized allylamine on the surface. Allylamine coatings have been further confirmed from atomic force microscopy (AFM) analysis. Thermogravimetric analysis (TGA) reveals that allylamine coating on the rubber surface lowers the thermal degradation rate. The contact angle between the water and rubber surface decreases for the modified rubber surface confirming the surface modification due to UV surface grafting

  2. Geotechnical Properties of Rubber Tires and Sediments Mixtures

    Directory of Open Access Journals (Sweden)

    H. Sellaf

    2014-04-01

    Full Text Available An experimental work was undertaken to study the effect of rubber tires on the geotechnical properties of a dredged sediment, using a mixing ratio of large size. For comparison, two types of soil were studied (dredged sediment from Fergoug dam and Tizi Tuff from the north west of Algeria. Taking into account the high compressibility and the low water absorption of the rubber tires, grain size analysis, density, Atterberg limits analysis, chemical composition, direct shear tests, loading-unloading tests, modified Proctor and CBR tests are performed on the two soils and their mixtures with different scrap tire rubber (10, 20, 25 and 50%. The results show that liquid limits and plastic indexes decrease with the scrap tire rubber content and that the decrease is more significant for soil with high plasticity. Cohesion also decreases with scrap tire rubber content when the internal friction angle is vacillating. Compression and recompression indexes increase gradually with the scrap tire rubber content and the variation for compression index is more significant for the two soils. Compaction characteristics and CBR values decrease with scrap tire rubber content. The CBR values for W=3% are important compared to those with W=5% excepted for mixture with (75% tuff and 25% scrap tire rubber. The results show that the scrap tire rubber can be used as a reinforcement material for dredged soil, but with a content that should not highly affect the compressibility.

  3. Crumb Rubber Recycling in Enhancing Damping Properties of Concrete

    Science.gov (United States)

    Sugapriya, P.; Ramkrishnan, R.

    2018-02-01

    Damping plays a major role in the design of roadside structures that gets affected due to vibrations transmitted from moving traffic. In this study, fine aggregates were partially replaced with crumb rubber in concrete, at varying percentages of 5, 10, 15 and 20% by weight. Three different sets of concrete, mixed with crumb rubber were prepared using raw rubber, treated rubber and treated rubber with partial replacement of cement. Cement was partially replaced with Ultra-Fine Ground Granulated Blast furnace Slag (UFGGBS) for this study. Samples were cast, cured and tested for various properties on the 7th and 28th day. The damping ratio and frequency of the peak value from a number of waves in rubber incorporated beams were found out using a FFT Analyser along with its Strength, Damping and Sorptivity characteristics. SEM analysis was conducted to analyse the micro structural bonding between rubber and concrete. The mode shapes of pavement slabs were modelled and analysed using a FEM tool, ANSYS. From the results, the behaviour of the three sets of rubberized concrete were compared and analysed, and an optimum percentage for crumb rubber and UFGGBS was proposed to achieve best possible damping without compromising the strength properties.

  4. Production and performance of desulfurized rubber asphalt binder

    Directory of Open Access Journals (Sweden)

    Yanping Sheng

    2017-05-01

    Full Text Available Asphalt rubber binder typically exhibits disadvantages like segregation and high viscosity; however, this can be improved by the incorporation of desulfurized rubber powder. This study examined the swelling principle of desulfurized rubber asphalt (DRA. In addition, it evaluated the performance of DRA fabricated with various rubber powder contents under different shear conditions and development time. Superpave binders tests, including Brookfield viscosity, dynamic shear rheometer (DSR and bending beam rheometer (BBR tests, were applied on three control binders (i.e., neat, 20 mesh asphalt rubber binder, 40 mesh asphalt rubber binder and a DRA binder. Binder testing results indicated that rubber powder swelled into the base binder and resulted in enhanced stability. Optimum performance of the DRA binder was achieved by adding 20% (by weight of rubber powder into the base binder at shear rate, shear temperature, shear time and development time of 7000 r/min, 170 °C, 60 min and 45 min, respectively. Modified ranges of production conditions were also provided to widen the application of DRA in field construction. It appeared that DRA binder benefited from the recovered plasticity and viscosity of the rubber and consequently, exhibited superior performance over the neat and conventional asphalt rubber binders. Preliminary mixture evaluation was also conducted and the DRA binder was found to significantly improve the mixture resistance to permanent deformation and water damage. Overall, the DAR binder is encouraged to be used as a modified binder for flexible pavements. Keywords: Desulfurized rubber asphalt, Swelling model, Production process, Asphalt performance, Rubber asphalt

  5. Computational study on potassium picrate crystal

    Energy Technology Data Exchange (ETDEWEB)

    Ju, Xue-Hai; Lu, Ya-Lin; Ma, Xiu-Fang; Xiao, He-Ming [Department of Chemistry, Nanjing University of Science and Technology, Nanjing, 210094 (China)

    2006-08-15

    DFT calculation at the B3LYP level was performed on crystalline potassium picrate. The frontier bands are slightly fluctuant. The energy gap between the highest occupied crystal orbital (HOCO) and the lowest unoccupied crystal orbital (LUCO) is 0.121 a.u. (3.29 eV). The carbon atoms that are connected with the nitro groups make up the narrow lower energy bands, with small contributions from nitro oxygen and phenol oxygen. The higher energy bands consist of orbitals from the nitro groups and carbon atom. The potassium bears almost 1 a.u. positive charge. The potassium forms ionic bonding with the phenol oxygen and the nitro oxygen at the same time. The crystal lattice energy is predicted to be -574.40 kJ/mol at the B3LYP level determined with the effective core pseudopotential HAYWSC-31G basis set for potassium and 6-31G** basis set for other atoms. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  6. Biodiesel production methods of rubber seed oil: a review

    Science.gov (United States)

    Ulfah, M.; Mulyazmi; Burmawi; Praputri, E.; Sundari, E.; Firdaus

    2018-03-01

    The utilization of rubber seed as raw material of biodiesel production is seen highly potential in Indonesia. The availability of rubber seeds in Indonesia is estimated about 5 million tons per annum, which can yield rubber seed oil about 2 million tons per year. Due to the demand of edible oils as a food source is tremendous and the edible oil feedstock costs are far expensive to be used as fuel, production of biodiesel from non-edible oils such as rubber seed is an effective way to overcome all the associated problems with edible oils. Various methods for producing biodiesel from rubber seed oil have been reported. This paper introduces an optimum condition of biodiesel production methods from rubber seed oil. This article was written to be a reference in the selection of methods and the further development of biodiesel production from rubber seed oil. Biodiesel production methods for rubber seed oils has been developed by means of homogeneous catalysts, heterogeneous catalysts, supercritical method, ultrasound, in-situ and enzymatic processes. Production of biodiesel from rubber seed oil using clinker loaded sodium methoxide as catalyst is very interesting to be studied and developed further.

  7. Is Body Dysmorphic Disorder Associated with Abnormal Bodily Self-Awareness? A Study Using the Rubber Hand Illusion

    Science.gov (United States)

    Kaplan, Ryan A.; Enticott, Peter G.; Hohwy, Jakob; Castle, David J.; Rossell, Susan L.

    2014-01-01

    Evidence from past research suggests that behaviours and characteristics related to body dissatisfaction may be associated with greater instability of perceptual body image, possibly due to problems in the integration of body-related multisensory information. We investigated whether people with body dysmorphic disorder (BDD), a condition characterised by body image disturbances, demonstrated enhanced susceptibility to the rubber hand illusion (RHI), which arises as a result of multisensory integration processes when a rubber hand and the participant's hidden real hand are stimulated in synchrony. Overall, differences in RHI experience between the BDD group and healthy and schizophrenia control groups (n = 17 in each) were not significant. RHI strength, however, was positively associated with body dissatisfaction and related tendencies. For the healthy control group, proprioceptive drift towards the rubber hand was observed following synchronous but not asynchronous stimulation, a typical pattern when inducing the RHI. Similar drifts in proprioceptive awareness occurred for the BDD group irrespective of whether stimulation was synchronous or not. These results are discussed in terms of possible abnormalities in visual processing and multisensory integration among people with BDD. PMID:24925079

  8. Is body dysmorphic disorder associated with abnormal bodily self-awareness? A study using the rubber hand illusion.

    Directory of Open Access Journals (Sweden)

    Ryan A Kaplan

    Full Text Available Evidence from past research suggests that behaviours and characteristics related to body dissatisfaction may be associated with greater instability of perceptual body image, possibly due to problems in the integration of body-related multisensory information. We investigated whether people with body dysmorphic disorder (BDD, a condition characterised by body image disturbances, demonstrated enhanced susceptibility to the rubber hand illusion (RHI, which arises as a result of multisensory integration processes when a rubber hand and the participant's hidden real hand are stimulated in synchrony. Overall, differences in RHI experience between the BDD group and healthy and schizophrenia control groups (n = 17 in each were not significant. RHI strength, however, was positively associated with body dissatisfaction and related tendencies. For the healthy control group, proprioceptive drift towards the rubber hand was observed following synchronous but not asynchronous stimulation, a typical pattern when inducing the RHI. Similar drifts in proprioceptive awareness occurred for the BDD group irrespective of whether stimulation was synchronous or not. These results are discussed in terms of possible abnormalities in visual processing and multisensory integration among people with BDD.

  9. Is body dysmorphic disorder associated with abnormal bodily self-awareness? A study using the rubber hand illusion.

    Science.gov (United States)

    Kaplan, Ryan A; Enticott, Peter G; Hohwy, Jakob; Castle, David J; Rossell, Susan L

    2014-01-01

    Evidence from past research suggests that behaviours and characteristics related to body dissatisfaction may be associated with greater instability of perceptual body image, possibly due to problems in the integration of body-related multisensory information. We investigated whether people with body dysmorphic disorder (BDD), a condition characterised by body image disturbances, demonstrated enhanced susceptibility to the rubber hand illusion (RHI), which arises as a result of multisensory integration processes when a rubber hand and the participant's hidden real hand are stimulated in synchrony. Overall, differences in RHI experience between the BDD group and healthy and schizophrenia control groups (n = 17 in each) were not significant. RHI strength, however, was positively associated with body dissatisfaction and related tendencies. For the healthy control group, proprioceptive drift towards the rubber hand was observed following synchronous but not asynchronous stimulation, a typical pattern when inducing the RHI. Similar drifts in proprioceptive awareness occurred for the BDD group irrespective of whether stimulation was synchronous or not. These results are discussed in terms of possible abnormalities in visual processing and multisensory integration among people with BDD.

  10. Comparative Transcriptome Analysis of Latex Reveals Molecular Mechanisms Underlying Increased Rubber Yield in Hevea brasiliensis Self-Rooting Juvenile Clones

    OpenAIRE

    Li, Hui-Liang; Guo, Dong; Zhu, Jia-Hong; Wang, Ying; Chen, Xiong-Ting; Peng, Shi-Qing

    2016-01-01

    Rubber tree (Hevea brasiliensis) self-rooting juvenile clones (JCs) are promising planting materials for rubber production. In a comparative trial between self-rooting JCs and donor clones (DCs), self-rooting JCs exhibited better performance in rubber yield. To study the molecular mechanism associated with higher rubber yield in self-rooting JCs, we sequenced and comparatively analyzed the latex of rubber tree self-rooting JCs and DCs at the transcriptome level. Total raw reads of 34,632,012 ...

  11. A Phase Blending Study on Rubber Blends Based on the Solubility Preference of Curatives

    NARCIS (Netherlands)

    Guo, R.; Talma, Auke; Datta, Rabin; Dierkes, Wilma K.; Noordermeer, Jacobus W.M.

    2009-01-01

    Using previously obtained data on the solubilities of curatives in SBR, EPDM and in NBR, different mixing procedures were performed on 50/50 SBR/EPDM and NBR/EPDM blends. In contrast to a previous phase-mixing study, the curatives were added to separate phases before final blending, in an attempt to

  12. Occupational dermatitis. An epidemiological study in the rubber and cement industries

    Energy Technology Data Exchange (ETDEWEB)

    Varigos, G A; Dunt, D R

    1981-03-01

    An epidemiological study of occupational dermatitis in a tyre company and a cement company is reported. Ninety-seven percent of 999 tyre workers and 78% of 151 cement workers were screened by an occupational nurse and subsequently assessed by a specialist dermatologist. Prevalence rates of occupational contact dermatitis were 37 per 1000 and 68 per 1000 in the tyre and cement companies, respectively. Maintenance workers and tyre builders - particularly if they were Yugoslav and female - had high prevalence rates amongst tyre workers. Worker's compensation claim rates for the tyre company are similar to U.K. and U.S. rates for this industry. Prevalence rates of 37 per 1000 can be considered as a lower limit for this industry. The high prevalence rates in the cement company are noteworthy and require further study.

  13. Study on irradiation condition in radiation vulcanization of natural rubber latex

    International Nuclear Information System (INIS)

    Zhu Nankang; Wang Chunlei; Makuuchi, K.; Yoshii, F.

    1996-01-01

    The effect of gamma rays irradiation dose rates on RVNRL preparation was studied using Malaysian latex added with O.2 phr of KOH and 5 phr n-BA. The results showed, to ensure the tensile strength of the latex film meet the requirement, when applying vulcanisation doses, Dv of 20 kGy 20 and 15 kGy, irradiation dose rates should not be greater than 0. 49 kGy/hr and 1. 6 kGy/hr respectively. Its was found that within the storage time of 20 days there was no change in the physical properties of the latex films

  14. Study on Chloride Ion Penetration Resistance of Rubberized Concrete Under Steady State Condition

    Directory of Open Access Journals (Sweden)

    Md Noor Nurazuwa

    2016-01-01

    Full Text Available Foamed concrete is a controlled low density ranging from 400kg/m3 to 1800kg/m3, and hence suitable for the construction of buildings and infrastructures. The uniqueness of foamed concrete is does not use aggregates in order to retain low density. Foamed concrete contains only cement, sand, water and foam agent. Therefore, the consumption of cement is higher in producing a good quality and strength of foamed concrete. Without the present of aggregates, the compressive strength of foamed concrete can only achieve as high as 15MPa. Therefore, this study aims to introduce the pelletized coconut fibre aggregate to reduce the consumption of cement but able to enhance the compressive strength. In the experimental study, forty-five (45 cube samples of foamed concrete with density 1600kg/m3 were prepared with different volume fractions of pelletized coconut fibre aggregate. All cube samples were tested using the compression test to obtain compressive strength. The results showed that the compressive strength of foamed concrete containing 5%, 10%, 15% and 20% of pelletized coconut fibre aggregate are 9.6MPa, 11.4MPa, 14.6MPa and 13.4MPa respectively. It is in fact higher than the controlled foamed concrete that only achieves 9MPa. It is found that the pelletized coconut fibre aggregate indicates a good potential to enhance the compressive strength of foamed concrete.

  15. Mechanical and Physical Studies on Different Doses of Radiation Pre vulcanized Natural Rubber Latex (RVNRL)

    International Nuclear Information System (INIS)

    Syuhada Ramli; Sofian Ibrahim; Muhammad Saiful Omar; Mohd Noorwadi Mat Lazim; Khairul Hisyam Mohamed Yusof; Najib Mohammmad Zakey; Hafizuddin Maseri

    2014-01-01

    RVNRL mixture of 12 kGy (RVNRL12) and 25 kGy (RVNRL25) at different blending ratios were prepared by stirring the mixture using a magnetic stirrer RVNRL at a speed of 1-3 rpm overnight to get the dough consistency. RVNRL12 with RVNRL25 attendance at a ratio of 90:10, 80:20, 70:30, 60:40 and 50:50 investigated. The study of physical and mechanical properties of 12/ 25 blends RVNRL performed on film samples prepared by immersion method coagulant. RVNRL25 result of the addition of the mixture RVNRL12 showed an increase in tensile strength mixture ratio of 90:10 RVNRL12 / RVNRL25 and tensile strength are declining at a ratio higher RVNRL25 content. Increase the tensile strength was found to increase due to the impact of lower doses of dough RVNRL12 and RVNRL25. This shows that blending RVNRL lower doses help improve the physical properties of latex due to exposure dose exceeding the dose required RVNRL. (author)

  16. Studies and Proposals for an Automatic Crystal Control System

    CERN Document Server

    Drobychev, Gleb; Khruschinsky, A A; Korzhik, Mikhail; Missevitch, Oleg; Oriboni, André; Peigneux, Jean-Pierre; Schneegans, Marc

    1997-01-01

    This document presents the status of the studies for an Automatic Crystal Control System ( ACCOS) performed since autumn 1995 for the CMS collaboration. Evaluation of a startstop method for light yield, light uniformity and decay time measurements of PbWO4 crystals is presented, as well as the first results obtained with a compact double-beam spectrophotometer for transverse transmission. Various overall schemes are proposed for an integrated set-up including crystal dimension measurement. The initial financial evaluationperformed is also given.

  17. Designing Robust Process Analytical Technology (PAT) Systems for Crystallization Processes: A Potassium Dichromate Crystallization Case Study

    DEFF Research Database (Denmark)

    Abdul Samad, Noor Asma Fazli Bin; Sin, Gürkan

    2013-01-01

    The objective of this study is to test and validate a Process Analytical Technology (PAT) system design on a potassium dichromate crystallization process in the presence of input uncertainties using uncertainty and sensitivity analysis. To this end a systematic framework for managing uncertaintie...

  18. Microbial detoxification of waste rubber material by wood-rotting fungi.

    Science.gov (United States)

    Bredberg, Katarina; Andersson, B Erik; Landfors, Eva; Holst, Olle

    2002-07-01

    The extensive use of rubber products, mainly tires, and the difficulties to recycle those products, has resulted in world wide environmental problems. Microbial devulcanisation is a promising way to increase the recycling of rubber materials. One obstacle is that several microorganisms tested for devulcanisation are sensitive to rubber additives. A way to overcome this might be to detoxify the rubber material with fungi prior to the devulcanisation. In this study, 15 species of white-rot and brown-rot fungi have been screened with regard to their capacity to degrade an aromatic model compound in the presence of ground waste tire rubber. The most effective fungus, Resinicium bicolor, was used for detoxification of rubber material. Increase in growth of the desulfurising bacterium Thiobacillus ferrooxidans in presence of the rubber treated with Resinicium bicolor compared to untreated rubber demonstrated that detoxification with fungi is possible.

  19. Performance of carbon fiber reinforced rubber composite armour against shaped charge jet penetration

    OpenAIRE

    Yue Lian-yong; Li Wei; Zu Xu-dong; Huang Zheng-xiang; Gao Zhen-yu

    2016-01-01

    Natural rubber is reinforced with carbon fiber; the protective performances of the carbonfiber reinforced rubber composite armour to shaped charge jet have been studied based on the depth of penetration experiments. The craters on the witness blocks, the nature rubber based composite plates’ deformation and the Scanning Electron Microscopy for the hybrid fiber reinforced rubber plate also is analyzed. The results showed that the composite armour can affect the stability of the jet and made pa...

  20. Rubber Flooring Impact on Production and Herdlife of Dairy Cows

    Science.gov (United States)

    Use of rubber flooring in dairies has become popular because of perceived cow comfort. The overall objective of this longitudinal study was to evaluate production, reproduction, and retention of first and second lactations of cows assigned to either rubber (RUB) or concrete (CON) flooring at the fe...

  1. Differential responses of two rubber tree clones to chilling stress ...

    African Journals Online (AJOL)

    Chilling stress is one of the most important environmental factors that limit the growth, distribution and yield of rubber tree in China. The effects of chilling stress on the grated plants of two rubber trees clones, GT1 and Wenchang217, were studied by physiological methods in controlled light chamber in order to explore the ...

  2. GRAFT COPOLYMERIZATION OF OLYGOESTERACRYLATES WITH LIQUID RUBBER AND COPOLYMER’S CHARACTERISTICS

    Directory of Open Access Journals (Sweden)

    Y. A. Anisimov

    2015-02-01

    Full Text Available The kinetic of graft copolymerization of threeethyleneglicoldimethacrylate and di threeethyleneglicolftalatedimethacrylate with liquid buthadiene rubber have been studied as a function of the olygomers composition. The experimental constants of copolymerization rate and efficiency olygoesteracrylates graft to liquid rubber were determined. The ihfluence of olygoesteracrylates’ nature on the grafting efficiency to olygomer rubber is determined and the strength characteristics are found.

  3. Biorefinery methods for separation of protein and oil fractions from rubber seed kernel

    NARCIS (Netherlands)

    Widyarani, R.; Ratnaningsih, E.; Sanders, J.P.M.; Bruins, M.E.

    2014-01-01

    Biorefinery of rubber seeds can generate additional income for farmers, who already grow rubber trees for latex production. The aim of this study was to find the best method for protein and oil production from rubber seed kernel, with focus on protein recovery. Different pre-treatments and oil

  4. Application of gamma irradiation for incorporation of rubber powder in the formulations EPDM and NBR rubber

    International Nuclear Information System (INIS)

    Kiyan, Ludmila de Ysasa Pozzo

    2014-01-01

    The natural decomposition of rubber is a very slow process due to its three-dimensional network formed by vulcanized crosslinked structures becoming extremely difficult to reprocess this material. The present work aims to study the application of gamma irradiation as devulcanization process for material reuse/recycling. The interactions of elastomers with ionizing radiation of a gamma source were investigated and the changes in physicochemical properties of the materials were evaluated. Formulations of NBR (acrylonitrile - butadiene) and EPDM (ethylene - propylene - diene terpolymer) from the rubber industry were crosslinked by conventional sulfur-based mixing. Master - batch was processed with rubber powder (industrial waste) and virgin rubber. The raw material (master batch) was irradiated in 60 Co source at doses of 50, 100, 150 kGy and dose rate of 5 kGy h -1 at room temperature. The irradiated material was incorporated in classical sulfur-based formulations. The formulations were characterized by: infrared spectroscopy (FTIR), thermal analysis (TG and DTG), tensile strength, elongation at break, hardness, abrasion resistance, rheometry and swelling. The results showed a predominance of chain scission at a dose of 50 kGy for EPDM rubber. For nitrile predominance of chain scission was observed at a dose of 100 kGy. These results show the possibility of the use of gamma radiation for the reuse/recycling of EPDM and nitrile rubbers. (author)

  5. Growth, spectral and thermal studies of ibuprofen crystals

    Energy Technology Data Exchange (ETDEWEB)

    Ramukutty, S.; Ramachandran, E. [Department of Physics, Thiruvalluvar College, Papanasam (India)

    2012-01-15

    RS -Ibuprofen was crystallized for the first time in silica gel under suitable pH conditions by reduction of solubility method. The grown crystals were characterized by single crystal X-ray diffraction and density measurement. The functional groups present in the crystal were identified using Fourier transform infrared spectroscopy. Optical bandgap energy of ibuprofen was estimated as 3.19(3) eV from UV-Vis spectrum. Thermogravimetric analysis revealed that ibuprofen is thermally stable upto 102.9 C and the initial loss of mass was due to evaporation only. Morphological study showed that the growth is prominent along b-axis and the prominent face is {l_brace}100{r_brace}. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. Nylon-6/rubber blends: 6. Notched tensile impact testing of nylon-6(ethylene-propylene rubber) blends

    NARCIS (Netherlands)

    Dijkstra, Krijn; Dijkstra, K.; ter Laak, J.A.; ter Laak, J.; Gaymans, R.J.

    1994-01-01

    The deformation and fracture behaviour of nylon-6/EPR (ethylene-propylene rubber) blends is studied as a function of strain rate and rubber content. Therefore, tensile experiments are conducted on notched specimens over a broad range of draw speeds (including strain rates as encountered in normal

  7. Strength and microstructure characteristics of the recycled rubber tire-sand mixtures as lightweight backfill.

    Science.gov (United States)

    Zhang, Tao; Cai, Guojun; Duan, Weihong

    2018-02-01

    The disposal of scrap rubber tires has induced critical environmental issue worldwide due to the rapid increase in the number of vehicles. Recycled scrap tires as a construction material in civil engineering have significant environmental benefits from a waste management perspective. A systematic study that deals with strength and microstructure characteristics of the rubber-sand mixtures is initiated, and mechanical response of the mixtures is discussed in this investigation. Experiments were conducted to evaluate the effects of rubber fraction on the basic properties including mass density (ρ), stress-strain characteristics, shear strength, and unconfined compression strength (q u ) of the rubber-sand mixtures. Additionally, scanning electron microscopy (SEM) was carried out to reveal the microstructure characteristics of the mixtures with various rubber fractions. A discussion on the micromechanics of the mixtures also was conducted. This study demonstrates that the ρ, friction angle, and q u decrease linearly with an increase in rubber fraction, whereas shear strain at peak increases. The stress-strain characteristics of the rubber-sand mixtures shift from brittle to ductile as the rubber fraction increase. These changes are attributed to remarkably lower stiffness and higher compressibility of the rubber particle compared with those of the conventional mineral aggregates. With an increase in the rubber fraction, the mechanical response of rubber-sand mixtures exhibits two types: sand-like material and rubber-like material. Rubber particle possesses the capacity to prevent the contacted sand particles from sliding at lower rubber fraction, whereas it transmits the applied loadings as the rubber fraction increased. This outcome reinforces the practicability of using recycled rubber tire-sand mixtures as a lightweight backfill in subbase/base applications.

  8. Crystallization study of Sn additive Se–Te chalcogenide alloys

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Rahim, M.A.; Gaber, A.; Abu-Sehly, A.A.; Abdelazim, N.M., E-mail: nana841@hotmail.co.uk

    2013-08-20

    Highlights: • The aim of the work deals with studying the crystallization kinetics by using different method. • Values of various kinetic parameters were calculated. • The results indicate that the rate of crystallization is related to the thermal stability and glass forming ability. - Abstract: Results of differential thermal analysis (DTA) under non-isothermal conditions of glasses Se{sub 90−x}Te{sub 10}Sn{sub x} (x = 0, 2.5, 5 and 7 at.%) are reported and discussed. The glass transition temperature (T{sub g}), the onset crystallization temperature (T{sub c}) and the peak temperature of crystallization (T{sub p}) were found to be dependent on the compositions and the heating rate. Values of various kinetic parameters such as activation energy of glass transition (E{sub g}), activation energy of crystallization (E{sub c}), rate constant (K{sub p}), Hurby number (H{sub r}) and the order parameter (n) were determined. For the present systems, the results indicate that the rate of crystallization is related to thermal stability and glass forming ability (GFA). According to the Avrami exponent (n), the results show a one dimensional growth for the composition Se{sub 90}Te{sub 10} and a three dimensional growth for the three other compositions. The crystalline phases resulting from DTA and (SEM) have been identified using X-ray diffraction.

  9. Studies on physical properties and fractography of electron beam irradiated poly(vinyl chloride)/epoxidized natural rubber blend in the presence of trimethylolpropane triacrylate

    International Nuclear Information System (INIS)

    Chantara Thevy Ratnam; Khairul Zaman Mohd Dahlan; Nasir, M.; Baharin, A.

    2000-01-01

    The effect of irradiation on the 50/50 poly(vinyl chloride)/epoxidized natural rubber blend was studied in the presence of 3 phr trimethylolpropane triacrylate (TMPTA). The blend was irradiated by using a 3.0 MeV electron beam machine at doses ranging from 20 to 200 kGy in air and room temperature. The tensile properties, resilience and gel fractions of the blends were measured. Electron beam irradiation of the blend in the presence of the TMPTA were found to cause crosslinking which in effect caused an enhancement in modulus and gel fraction together with a concomitant decline in ultimate elongation. The irradiation has resulted in a less hysteretic poly(vinyl chloride)/epoxidized natural rubber blend, with increased rebound resilience. The tensile strength of the blend reached a maximum at 60 kGy followed by a slight decrease at higher doses, implying embrittlement due to the excessive crosslinking. The scanning electron micrographs of the fracture surfaces of the irradiated blends show evidence consistent with the above contention. (Author)

  10. Recycling of rubber tires in electric arc furnace steelmaking: simultaneous combustion of metallurgical coke and rubber tyres blends

    Energy Technology Data Exchange (ETDEWEB)

    Magdalena Zaharia; Veena Sahajwalla; Byong-Chul Kim; Rita Khanna; N. Saha-Chaudhury; Paul O' Kane; Jonathan Dicker; Catherine Skidmore; David Knights [University of New South Wales, Sydney, NSW (Australia). School of Materials Science and Engineering

    2009-05-15

    The present study investigates the effect of addition of waste rubber tires on the combustion behavior of its blends with coke for carbon injection in electric arc furnace steelmaking. Waste rubber tires were mixed in different proportions with metallurgical coke (MC) (10:90, 20:80, 30:70) for combustion and pyrolysis at 1473 K in a drop tube furnace (DTF) and thermogravimetric analyzer (TGA), respectively. Under experimental conditions most of the rubber blends indicated higher combustion efficiencies compared to those of the constituent coke. In the early stage of combustion the weight loss rate of the blends is much faster compared to that of the raw coke due to the higher volatile yield of rubber. The presence of rubber in the blends may have had an impact upon the structure during the release and combustion of their high volatile matter (VM) and hence increased char burnout. Measurements of micropore surface area and bulk density of the chars collected after combustion support the higher combustion efficiency of the blends in comparison to coke alone. The surface morphology of the 30% rubber blend revealed pores in the residual char that might be attributed to volatile evolution during high temperature reaction in oxygen atmosphere. Physical properties and VM appear to have a major effect upon the measured combustion efficiency of rubber blends. The study demonstrates that waste rubber tires can be successfully co-injected with metallurgical coke in electric arc furnace steelmaking process to provide additional energy from combustion. 44 refs., 11 figs., 2 tabs.

  11. New type of liquid rubber and compositions based on it.

    Science.gov (United States)

    Semikolenov, S V; Nartova, A V; Voronchikhin, V D; Dubkov, K A

    2014-11-01

    The new method for producing the functionalized polymers and oligomers containing carbonyl C=O groups is developed. The method is based on the noncatalytic oxidation of unsaturated rubbers by nitrous oxide (N2O) at 180-230 °С. The proposed method allows obtaining the new type of functionalized rubbers-liquid unsaturated polyketones with regulated molecular weight and concentration of C=O groups. The influence of the liquid polyketone addition on properties of rubber-based composites is investigated. The study indicates good prospects of using the liquid polyketones for the improvement of properties and operating characteristics of the various types of rubbers and the rubber-cord systems.

  12. Experimental Investigation of the Mechanical and Durability Properties of Crumb Rubber Concrete.

    Science.gov (United States)

    Liu, Hanbing; Wang, Xianqiang; Jiao, Yubo; Sha, Tao

    2016-03-07

    Recycling waste tire rubber by incorporating it into concrete has become the preferred solution to dispose of waste tires. In this study, the effect of the volume content of crumb rubber and pretreatment methods on the performances of concrete was evaluated. Firstly, the fine aggregate and mixture were partly replaced by crumb rubber to produce crumb rubber concrete. Secondly, the mechanical and durability properties of crumb rubber concrete with different replacement forms and volume contents had been investigated. Finally, the crumb rubber after pretreatment by six modifiers was introduced into the concrete mixture. Corresponding tests were conducted to verify the effectiveness of pretreatment methods as compared to the concrete containing untreated crumb rubber. It was observed that the mechanical strength of crumb rubber concrete was reduced, while durability was improved with the increasing of crumb rubber content. 20% replacement of fine aggregate and 5% replacement of the total mixture exhibited acceptable properties for practical applications. In addition, the results indicated that the modifiers had a positive impact on the mechanical and durability properties of crumb rubber concrete. It avoided the disadvantage of crumb rubber concrete having lower strength and provides a reference for the production of modified crumb rubber concrete.

  13. Experimental Investigation of the Mechanical and Durability Properties of Crumb Rubber Concrete

    Directory of Open Access Journals (Sweden)

    Hanbing Liu

    2016-03-01

    Full Text Available Recycling waste tire rubber by incorporating it into concrete has become the preferred solution to dispose of waste tires. In this study, the effect of the volume content of crumb rubber and pretreatment methods on the performances of concrete was evaluated. Firstly, the fine aggregate and mixture were partly replaced by crumb rubber to produce crumb rubber concrete. Secondly, the mechanical and durability properties of crumb rubber concrete with different replacement forms and volume contents had been investigated. Finally, the crumb rubber after pretreatment by six modifiers was introduced into the concrete mixture. Corresponding tests were conducted to verify the effectiveness of pretreatment methods as compared to the concrete containing untreated crumb rubber. It was observed that the mechanical strength of crumb rubber concrete was reduced, while durability was improved with the increasing of crumb rubber content. 20% replacement of fine aggregate and 5% replacement of the total mixture exhibited acceptable properties for practical applications. In addition, the results indicated that the modifiers had a positive impact on the mechanical and durability properties of crumb rubber concrete. It avoided the disadvantage of crumb rubber concrete having lower strength and provides a reference for the production of modified crumb rubber concrete.

  14. Mechanical properties of irradiated rubber-blends

    International Nuclear Information System (INIS)

    Nasr, G.M.; Madani, M.

    2005-01-01

    A study has been made on blend ratios of natural rubber (NR) and acrylonitrile butadiene rubber (NBR) that are loaded with general purpose furnace (GPE) carbon black and irradiated at different gamma radiation doses. It was fount that the mechanical properties of such blend are highly affected by γ- irradiation dose and the composition ratios of its constituents. The elongation at break for blends was found to increase slightly with increasing NBR loafing which is mainly due to the stiffness of blending matrix formation between NR and GPF carbon black particles. The hysteresis loss, extension ratio and shape factor have been calculated for the different un-irradiated and irradiated samples

  15. A study on new types of metallic photonic crystals

    International Nuclear Information System (INIS)

    Ahmed, M.I.

    2013-01-01

    In this thesis, I tried to synthesize a one dimension dielectric photonic crystal. I have succeeded in depositing single layers of zinc oxide and magnesium oxide on glass substrates. Each single layer was characterized by a scanning electron microscope, X-ray diffraction, A Mirue interferometer, and a spectrophotometer. The refractive indices, extinction coefficients, and absorption coefficients of each single layer were calculated from the measured transmittance, reflectance, and thickness data. Using the calculated parameters (refractive indices) and measured parameters (thicknesses) the transmission spectrum of the one dimension photonic crystal composed of zinc oxide and magnesium oxide was modelled. Using the transfer matrix method, a comparative study of the one dimension-dielectric and metallic photonic crystals was done. Effect of the refractive index difference, filling factor, number of periods, Plasmon frequency, damping coefficient, and incidence angle on the transmittance of the dielectric and metallic photonic crystal was carried out. A multilayered structure composed of Silver and Gallium Nitride was designed to transmit in the visible region, block UV frequencies, and reflect the IR and microwave frequencies. Using a combination of MaxwellGarnett Approximation and the transfer matrix method; the properties of a nanocomposite photonic crystal consisting of Cryolite and spherical nanoparticles of silver distributed in a dielectric matrix of titanium dioxide was studied. Effect of the nanoparticle concentration, lattice constant and incidence angle on the polaritonic and structure photonic band gap were studied.

  16. Single Crystal Synthesis and STM Studies of High Temperature Superconductors

    Science.gov (United States)

    Barrientos, Alfonso

    1997-01-01

    This is a final report for the work initiated in September of 1994 under the grant NAG8-1085 - NASA/OMU, on the fabrication of bulk and single crystal synthesis, specific heat measuring and STM studies of high temperature superconductors. Efforts were made to fabricate bulk and single crystals of mercury based superconducting material. A systematic thermal analysis on the precursors for the corresponding oxides and carbonates were carried out to synthesized bulk samples. Bulk material was used as seed in an attempt to grow single crystals by a two-step self flux process. On the other hand bulk samples were characterized by x-ray diffraction, electrical resistivity and magnetic susceptibility, We studied the specific heat behavior in the range from 80 to 300 K. Some preliminary attempts were made to study the atomic morphology of our samples. As part of our efforts we built an ac susceptibility apparatus for measuring the transition temperature of our sintered samples.

  17. PENINGKATAN PRODUKTIVITAS PROSES BUDIDAYA KARET ALAM DENGAN PENDEKATAN GREEN PRODUCTIVITY: STUDI KASUS DI PT. XYZ (The Increase of Natural Rubber Plantations Productivity with Green Productivity Approach: a Case Study at PT. XYZ

    Directory of Open Access Journals (Sweden)

    Marimin Marimin

    2014-02-01

    Full Text Available Indonesia is the second largest natural rubber producer in the world with 28% of the total world production in 2010. In line with the growth of the world’s automotive industry, the needs of natural rubber as a complementary synthetic rubber products will also increase. The main objective of this research was to find the best alternative strategy to increase the productivity of the natural rubber plantations through the green productivity (GP approach. The case study was conducted at PT. XYZ, a private company which runs the plantation and processing of natural rubber businesses. The material flow analysis was performed to identify the seven green wastes. The best alternative strategy was determined by using the  analytical Hierarchy Process (AHP model developed into several improvement scenarios. The measurement of  the alternative strategy performance was rated as the future Green Productivity Index (GPI and compared with the value of current GPI, which had been calculated in the PT. XYZ, as the case study. The results of this research was  able to provide the best productivity improvement strategy, the level of company’s productivity which has been achieved, and the productivity levels of the implementation of the strategy chosen. Keywords: aHP, green productivity,  green wastes, natural rubber, green productivity index, latex   ABSTRAK Indonesia merupakan negara kedua penghasil karet alam terbesar di dunia dengan produksi sebesar 28% dari total produksi dunia di tahun 2010. Sejalan dengan bertumbuhnya industri otomotif dunia, kebutuhan karet alam sebagai produk komplementer karet sintetik akan turut mengalami peningkatan. Tujuan utama penelitian ini adalah untuk merumuskan alternatif strategi terbaik pada peningkatan produktivitas proses budidaya karet alam melalui pendekatan konsep Green Productivity (GP. Studi kasus dilakukan di PT. XYZ, perusahaan swasta yang bergerak dibidang usaha perkebunan dan pengolahan karet alam. analisis

  18. Purification of a Multidrug Resistance Transporter for Crystallization Studies

    Directory of Open Access Journals (Sweden)

    Kamela O. Alegre

    2015-03-01

    Full Text Available Crystallization of integral membrane proteins is a challenging field and much effort has been invested in optimizing the overexpression and purification steps needed to obtain milligram amounts of pure, stable, monodisperse protein sample for crystallography studies. Our current work involves the structural and functional characterization of the Escherichia coli multidrug resistance transporter MdtM, a member of the major facilitator superfamily (MFS. Here we present a protocol for isolation of MdtM to increase yields of recombinant protein to the milligram quantities necessary for pursuit of structural studies using X-ray crystallography. Purification of MdtM was enhanced by introduction of an elongated His-tag, followed by identification and subsequent removal of chaperonin contamination. For crystallization trials of MdtM, detergent screening using size exclusion chromatography determined that decylmaltoside (DM was the shortest-chain detergent that maintained the protein in a stable, monodispersed state. Crystallization trials of MdtM performed using the hanging-drop diffusion method with commercially available crystallization screens yielded 3D protein crystals under several different conditions. We contend that the purification protocol described here may be employed for production of high-quality protein of other multidrug efflux members of the MFS, a ubiquitous, physiologically and clinically important class of membrane transporters.

  19. Protein crystal growth studies at the Center for Macromolecular Crystallography

    International Nuclear Information System (INIS)

    DeLucas, Lawrence J.; Long, Marianna M.; Moore, Karen M.; Harrington, Michael; McDonald, William T.; Smith, Craig D.; Bray, Terry; Lewis, Johanna; Crysel, William B.; Weise, Lance D.

    2000-01-01

    The Center for Macromolecular Crystallography (CMC) has been involved in fundamental studies of protein crystal growth (PCG) in microgravity and in our earth-based laboratories. A large group of co-investigators from academia and industry participated in these experiments by providing protein samples and by performing the x-ray crystallographic analysis. These studies have clearly demonstrated the usefulness of a microgravity environment for enhancing the quality and size of protein crystals. Review of the vapor diffusion (VDA) PCG results from nineteen space shuttle missions is given in this paper

  20. Study of the mechanisms of humidity-induced adhesion loss of chlorinated rubber on cleaned and rusted steel substrates

    International Nuclear Information System (INIS)

    Chico, B.; Feliu, S.

    1998-01-01

    The effect of time of exposure to the humidity on the behaviour of the system chlorinated rubber paint-steel substrate (cleaned or pre-rusted) is investigated from the interfacial chemistry and adhesion points of view. After one day of humidity exposure, the paint-rust free steel substrate system shows an increase of adhesion. A maximum adhesion value is obtained after 15 days of exposure. This behaviour is similar to that previously described for a pre-rusted steel substrate. After 30-60 days of exposure, the adhesion strength values show an important reduction and the locus of adhesion loss shifts from the paint inside to the interphase between the metallic substrate and the paint. (Author) 4 refs

  1. Study on wood vinegars for use as coagulating and antifungal agents on the production of natural rubber sheets

    Energy Technology Data Exchange (ETDEWEB)

    Baimark, Yodthong; Niamsa, Noi [Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Mahasarakham University, Mahasarakham 44150 (Thailand)

    2009-06-15

    Coagulating and antifungal properties of wood vinegars in the preparation process of Hevea brasiliensis natural rubber (NR) sheets were investigated and compared with those of formic and acetic acids. The wood vinegars produced from biomasses such as inner coconut shell, bamboo and Eucalyptus woods were evaluated. It was found that plasticity retention index, Mooney viscosity and mechanical properties of NR coagulated by wood vinegars were similar to those using acetic acid and better than using formic acid. The antifungal efficiency of coagulants determined from a fungi growth area on NR sheet surfaces was found in the following order: coconut shell wood vinegar > bamboo wood vinegar {approx} Eucalyptus wood vinegar > acetic acid {approx} formic acid. The antifungal efficiency of the wood vinegars was strongly depended upon their phenolic compound contents and confirmed through the inhibitory growth of the main fungi, Penicillium griseofulvum, on potato dextrose agar. (author)

  2. Studies on dual fuel operation of rubber seed oil and its bio-diesel with hydrogen as the inducted fuel

    Energy Technology Data Exchange (ETDEWEB)

    Edwin Geo, V.; Nagalingam, B. [Department of Mechanical Engineering, KCG College of Technology, Chennai, Tamil Nadu 600097 (India); Nagarajan, G. [Department of Mechanical Engineering, IC Engineering Division, Anna University, Chennai, Tamil Nadu 600025 (India)

    2008-11-15

    The main problems with the use of neat vegetable oils in diesel engines are higher smoke levels and lower thermal efficiency as compared to diesel. The problem can be tackled by inducting a gaseous fuel in the intake manifold along with air. In this investigation, hydrogen is used as the inducted fuel and rubber seed oil (RSO), rubber seed oil methyl ester (RSOME) and diesel are used as main fuels in a dual fuel engine. A single cylinder diesel engine with rated output of 4.4 kW at 1500 rpm was converted to operate in the dual fuel mode. Dual fuel operation of varying hydrogen quantity with RSO and RSOME results in higher brake thermal efficiency and significant reduction in smoke levels at high outputs. The maximum brake thermal efficiency is 28.12%, 29.26% and 31.62% with RSO, RSOME and diesel at hydrogen energy share of 8.39%, 8.73% and 10.1%, respectively. Smoke is reduced from 5.5 to 3.5 BSU with RSOME and for RSO it is from 6.1 to 3.8 BSU at the maximum efficiency point. The peak pressure and maximum rate of pressure rise increase with hydrogen induction. Heat release rate indicates an increase in the combustion rate with hydrogen induction. On the whole it is concluded that hydrogen can be inducted along with air in order to reduce smoke levels and improve thermal efficiency of RSO and its bio-diesel fuelled diesel engines. (author)

  3. QENS investigation of filled rubbers

    CERN Document Server

    Triolo, A; Desmedt, A; Pieper, J K; Lo Celso, F; Triolo, R; Negroni, F; Arrighi, V; Qian, H; Frick, B

    2002-01-01

    The polymer segmental dynamics is investigated in a series of silica-filled rubbers. The presence of inert fillers in polymers greatly affects the mechanical and physical performance of the final materials. For example, silica has been proposed as a reinforcing agent of elastomers in tire production. Results from quasielastic neutron scattering and Dynamic Mechanical Thermal Analysis (DMTA) measurements are presented on styrene-ran-butadiene rubber filled with silica. A clear indication is obtained of the existence of a bimodal dynamics, which can be rationalized in terms of the relaxation of bulk rubber and the much slower relaxation of the rubber adsorbed on the filler surface. (orig.)

  4. Effect of high-energy radiation on the rheological characteristics and structure of liquid rubbers

    International Nuclear Information System (INIS)

    Govorkov, A.T.; Zaitseva, V.I.; Muryshkin, D.L.; Safonov, Yu.N.

    1987-01-01

    The effect of high-energy radiation (γ-radiation and accelerated electrons) on liquid polybutadiene and polyisoprene rubbers (SKD, SKD-KTR, SKN) and butyl rubber (BR) was studied by IR and EPR spectroscopy, rheoviscosimetry, and chemical analysis. Newtonian flow was conserved in the rubbers under irradiation. The activation energy of viscous flow was unchanged, evidence of an increase in the contour length of the macromolecules without significant branching and cross-linking at the initial stages of the irradiation. A quantitative relationship was established between the rubber's dynamic viscosity and the absorbed dose, and features of the structure-formation mechanism in the liquid rubbers were determined

  5. Cooking time harmonization attempts for main rubbers in a truck tyre-III. Activation energy evaluation

    International Nuclear Information System (INIS)

    Kadima, T.H.

    2011-01-01

    The harmonization of optimum cooking time of rubbers containing in a tyre is became possible. This occurrence is the result of the knowledge about the respective function of each element containing in the rubber. Many kind of rubbers are been studied. The obtained results demonstrate the realization of the harmonization of optimum cooking time in different rubbers at some conditions by modifying either a kind of vulcanization accelerator or a quantity of vulcanization activator. So, accelerator or activator modifies need of energy during cooking. In this paper, we are estimated activation energy for all new rubbers obtained

  6. Pengaruh Penggunaan Nitril Butadiene Rubber Dan Pale Crepe Pada Pembuatan Sol Karet Untuk Sepatu Pengaman

    OpenAIRE

    Yuniari, Arum

    2010-01-01

    Rubber sole for safety shoes was different on physical specification with general sole, especially on abrasion resistance and oil resistance. The objective of the study was to determine the effect of nitril butadiene rubber and pale crepe on physical properties of vulcanized rubber sole for safety shoes. Rubber sole for safety shoes was produced by blending pale crepe and nitril butadiene rubber with ratio of : 50/50; 60/40; 70/30 and 80/20 phr, respectively. Carbon black as filler was also v...

  7. Pengaruh penggunaan nitril butadiene rubber dan pale crepe pada pembuatan sol karet untuk sepatu pengaman

    OpenAIRE

    Arum Yuniari

    2010-01-01

    Abstract Rubber sole for safety shoes was different on physical specification with general sole, especially on abrasion resistance and oil resistance. The objective of the study was to determine the effect of nitril butadiene rubber and pale crepe on physical properties of vulcanized rubber sole for safety shoes. Rubber sole for safety shoes was produced by blending pale crepe and nitril butadiene rubber with ratio of : 50/50; 60/40; 70/30 and 80/20 phr, respectively. Carbon black as fill...

  8. Shrink, twist, ripple and melt: Studies of frustrated liquid crystals

    Science.gov (United States)

    Fernsler, Jonathan G.

    Complex structures can arise out of a simple system with more than one competing influence on its behavior. The protypical example of this is the two-dimensional triangular lattice Ising model. The ferromagnetic model has two simple degenerate ground states of all spins up or down, but the antiferromagnetic model is a frustrated system. Its geometry does not allow satisfaction of the antiferro condition everywhere, which produces complex ordered structures with dimerization of the spins [1]. Without frustration, the complex structures and phase behavior are lost. All of the topics discussed in this thesis concern smectic liquid crystals. Liquid crystals are perhaps uniquely adept at manifesting frustrated phases. Their combination of periodicity in one or more dimensions allows ordered structures, yet their fluid nature in remaining dimensions allows creation of defects and extraordinarily complex structures in ways that a normal crystal could not tolerate. Liquid crystals contain a huge menagerie of frustrated phases and effects including the polarization modulated [2], vortex lattice [3], twist grain boundary [4], and blue [5] phases, as well as frustrated structures such as cholesteric or SmC* helix unwinding [6], defect lattices in thin films [7], and bend melted grain boundary defects [8], arising from boundary conditions and field effects. In this thesis, we study four liquid crystal systems that show unusual phase behavior or complex structures, deriving from the effects of frustration. Frustration, despite some human prejudices against the word, leaves nature all the more interesting and beautiful.

  9. PROPERTIES OF NR AND NR/ENR BASED RUBBER COMPOUNDS REINFORCED WITH CHOPPED AND SIZED CARBON FIBER

    Directory of Open Access Journals (Sweden)

    Bağdagül Karaağaç

    2016-12-01

    Full Text Available High elasticity, mechanical resistance and antivibration characteristics of natural rubber (NR are essential issue in the main area of vehicle tyres and high modulus demanding bearing applications. In this study, especially in bearing applications, where natural rubber modulus properties are limited, natural rubber has been reinforced with chopped and hydrocarbon sized carbon fiber to get improved tensile modulus. Besides, epoxidized natural rubber (ENR, which was produced by chemical modification of natural rubber, blended with NR and the compounds have been reinforced with epoxy sized carbon fiber. NR and NR/ENR based rubber compounds’ rheological, mechanical, and aging properties have been systematically investigated and evaluated.

  10. Reassessment of anoxic storage of ethnographic rubber

    DEFF Research Database (Denmark)

    Shashoua, Yvonne; Dyer, Joanne; Ward, Clare

    2011-01-01

    This paper revisits the 1991–1995 British Museum field trial on anoxic storage, where 23 registered ethnographic rubber objects were enclosed in oxygen barrier film Cryovac BDF200 with sachets of the oxygen absorbent Ageless Z. A unique opportunity for study was presented since most of the enclos...

  11. Valorisation of Proteins from Rubber Tree

    NARCIS (Netherlands)

    Widyarani,; Coulen, Stef C.W.; Sanders, Johan P.M.; Bruins, Marieke E.

    2017-01-01

    Purpose: The objective of this study was to identify the availability, possible applications, and economic potential of proteins that are present in different parts of the rubber tree. Proteins from non-food sources can be used in e.g. animal feed or biochemicals production with no or little

  12. Boundary lubrication of glass: rubber sliding contacts

    NARCIS (Netherlands)

    Heide, E. van der; Lossie, C.M.; Bommel, K.J.C. van; Reinders, S.A.F.; Lenting, H.B.M.

    2009-01-01

    Polymer brush coatings represent a promising class of coatings for friction control [1], especially in a humid environment [2]. A study on the feasibility of a specific class of polymer brush coatings [5] was done for a sliding system that involves ‘silicon skin L7350’: a silicon rubber used by FIFA

  13. Improving rubber concrete by waste organic sulfur compounds.

    Science.gov (United States)

    Chou, Liang-Hisng; Lin, Chun-Nan; Lu, Chun-Ku; Lee, Cheng-Haw; Lee, Maw-Tien

    2010-01-01

    In this study, the use of crumb tyres as additives to concrete was investigated. For some time, researchers have been studying the physical properties of concrete to determine why the inclusion of rubber particles causes the concrete to degrade. Several methods have been developed to improve the bonding between rubber particles and cement hydration products (C-S-H) with the hope of creating a product with an improvement in mechanical strength. In this study, the crumb tyres were treated with waste organic sulfur compounds from a petroleum refining factory in order to modify their surface properties. Organic sulfur compounds with amphiphilic properties can enhance the hydrophilic properties of the rubber and increase the intermolecular interaction forces between rubber and C-S-H. In the present study, a colloid probe of C-S-H was prepared to measure these intermolecular interaction forces by utilizing an atomic force microscope. Experimental results showed that rubber particles treated with waste organic sulfur compounds became more hydrophilic. In addition, the intermolecular interaction forces increased with the adsorption of waste organic sulfur compounds on the surface of the rubber particles. The compressive, tensile and flexural strengths of concrete samples that included rubber particles treated with organic sulfur compound also increased significantly.

  14. Optical Study of Liquid Crystal Doped with Multiwalled Carbon Nanotube

    Science.gov (United States)

    Gharde, Rita A.; Thakare, Sangeeta Y.

    2014-11-01

    Liquid crystalline materials have been useful for display devices i.e watches, calculators, automobile dashboards, televisions, multi media projectors etc. as well as in electro tunable lasers, optical fibers and lenses. Carbon nanotube is chosen as the main experimental factor in this study as it has been observed that Carbon Nano Tube influence the existing properties of liquid crystal host and with the doping of CNT can enhance1 the properties of LC. The combination of carbon nanotube (CNT) and liquid crystal (LC) materials show considerable interest in the scientific community due to unique physical properties of CNT in liquid crystal. Dispersion of CNTs in LCs can provide us a cheap, simple, versatile and effective means of controlling nanotube orientation on macroscopic scale with no restrictions on nanotube type. LCs have the long range orientational order rendering them to be anisotropic phases. If CNTs can be well dispersed in LC matrix, they will align with their long axes along the LC director to minimize distortions of the LC director field and the free energy. In this paper, we doped liquid crystal (Cholesteryl Nonanoate) by a small amount of multiwall carbon nanotube 0.05% and 0.1% wt. We found that by adding carbon nanotube to liquid crystals the melting point of the mixture is decreased but TNI is increased. It has been also observed that with incereas in concentration of carbon nanotube into liquid crystal shows conciderable effect on LC. The prepared samples were characterized using various techniques to study structural, thermal and optical properties i.e PMS, FPSS, UV-Vis spectroscopy, FT-IR measurements, and DTA.

  15. Experimental studies on radiation damages of CsI(Tl) crystals

    International Nuclear Information System (INIS)

    He Jingtang; Mao Yufang; Dong Xiaoli; Chen Duanbao; Li Zuhao

    1997-01-01

    The results of experimental studies on radiation damage of CsI(Tl) crystal were reported. There are radiation damage effects on CsI(Tl) crystal. Experimental studies on recovery of damaged CsI(Tl) crystals were made. It seems that after heating at 200 degree C for 4 hours, the damaged crystals could be recovered completely

  16. Synthesis and room temperature single crystal EPR studies of a ...

    Indian Academy of Sciences (India)

    Unknown

    Hamiltonian parameters calculated from single crystal rotations are: g ... studies on two nickel complexes with SalX ligands (X = NH, NCH3) have shown the ..... here the positive sign is required for a shell that is less than half-filled and the ...

  17. Rubber hand illusion under delayed visual feedback.

    Directory of Open Access Journals (Sweden)

    Sotaro Shimada

    Full Text Available BACKGROUND: Rubber hand illusion (RHI is a subject's illusion of the self-ownership of a rubber hand that was touched synchronously with their own hand. Although previous studies have confirmed that this illusion disappears when the rubber hand was touched asynchronously with the subject's hand, the minimum temporal discrepancy of these two events for attenuation of RHI has not been examined. METHODOLOGY/PRINCIPAL FINDINGS: In this study, various temporal discrepancies between visual and tactile stimulations were introduced by using a visual feedback delay experimental setup, and RHI effects in each temporal discrepancy condition were systematically tested. The results showed that subjects felt significantly greater RHI effects with temporal discrepancies of less than 300 ms compared with longer temporal discrepancies. The RHI effects on reaching performance (proprioceptive drift showed similar conditional differences. CONCLUSIONS/SIGNIFICANCE: Our results first demonstrated that a temporal discrepancy of less than 300 ms between visual stimulation of the rubber hand and tactile stimulation to the subject's own hand is preferable to induce strong sensation of RHI. We suggest that the time window of less than 300 ms is critical for multi-sensory integration processes constituting the self-body image.

  18. Nitrile rubber and carboxylated nitrile rubber resistance to soybean biodiesel

    Directory of Open Access Journals (Sweden)

    Felipe Nunes Linhares

    2018-03-01

    Full Text Available Abstract Biodiesel has been considered a suitable substitute for petroleum diesel, but their chemical composition differs greatly. For this reason, biodiesel interacts differently than petroleum diesel with various materials, including rubbers. Therefore, the resistance of some elastomers should be thoroughly evaluated, specifically those which are commonly used in automotive industry. Nitrile rubber (NBR is widely used to produce vehicular parts that are constantly in contact with fuels. This paper aimed to assess the resistance of carboxylated nitrile rubber (XNBR with 28% of acrylonitrile content to soybean biodiesel in comparison with non-carboxylated nitrile rubber samples, with high and medium acrylonitrile content (33 and 45%. NBR with medium acrylonitrile content showed little resistance to biodiesel. However, carboxylated nitrile rubber even with low acrylonitrile content had similar performance to NBR with high acrylonitrile content.

  19. The optimum content of rubber ash in concrete: flexural strength

    Science.gov (United States)

    Senin, M. S.; Shahidan, S.; Shamsuddin, S. M.; Ariffin, S. F. A.; Othman, N. H.; Rahman, R.; Khalid, F. S.; Nazri, F. M.

    2017-11-01

    Discarded scrap tyres have become one of the major environmental problems nowadays. Several studies have been carried out to reuse waste tires as an additive or sand replacement in concrete with appropriate percentages of tire rubber, called as rubberized concrete to solve this problem. The main objectives of this study are to investigate the flexural strength performance of concrete when adding the rubber ash and also to analyse the optimum content of rubber ash in concrete prisms. The performance total of 30 number of concrete prisms in size of 100mm x 100mm x 500 mm were investigated, by partially replacement of rubber ash with percentage of 0%, 3%, 5%, 7% and 9% from the volume of the sand. The flexural strength is increased when percentage of rubber ash is added 3% from control concrete prism, RA 0 for both concrete prism age, 7 days and 28 days with value 1.21% and 0.976% respectively. However, for RA 5, RA 7 and RA 9, the flexural strength was decreased compared to the control for both age, 7 days and 28 days. In conclusion, 3% is the optimum content of rubber ash in concrete prism for both concrete age

  20. Performance of carbon fiber reinforced rubber composite armour against shaped charge jet penetration

    Directory of Open Access Journals (Sweden)

    Yue Lian-yong

    2016-01-01

    Full Text Available Natural rubber is reinforced with carbon fiber; the protective performances of the carbonfiber reinforced rubber composite armour to shaped charge jet have been studied based on the depth of penetration experiments. The craters on the witness blocks, the nature rubber based composite plates’ deformation and the Scanning Electron Microscopy for the hybrid fiber reinforced rubber plate also is analyzed. The results showed that the composite armour can affect the stability of the jet and made part of the jet fracture. The carbon fiber reinforced rubber composite armour has good defence ablity especially when the nature rubber plate hybrid 15% volume percentage carbonfiber and the obliquity angle is 68°. The hybrid fiber reinforced rubber composite armour can be used as a new kind of light protective armour.

  1. Rubber friction on road surfaces: Experiment and theory for low sliding speeds

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, B.; Persson, B. N. J. [PGI, FZ Jülich, 52425 Jülich (Germany); Oh, Y. R.; Nam, S. K.; Jeon, S. H. [Hankook Tire Co. LTD., 112 Gajeongbuk-ro, Yuseong-gu, Daejeon 305-725 (Korea, Republic of)

    2015-05-21

    We study rubber friction for tire tread compounds on asphalt road surfaces. The road surface topographies are measured using a stylus instrument and atomic force microscopy, and the surface roughness power spectra are calculated. The rubber viscoelastic modulus mastercurves are obtained from dynamic mechanical analysis measurements and the large-strain effective modulus is obtained from strain sweep data. The rubber friction is measured at different temperatures and sliding velocities, and is compared to the calculated data obtained using the Persson contact mechanics theory. We conclude that in addition to the viscoelastic deformations of the rubber surface by the road asperities, there is an important contribution to the rubber friction from shear processes in the area of contact. The analysis shows that the latter contribution may arise from rubber molecules (or patches of rubber) undergoing bonding-stretching-debonding cycles as discussed in a classic paper by Schallamach.

  2. NMR studies of macroscopic and microscopic properties of liquid crystals

    International Nuclear Information System (INIS)

    Hughes, J.R.

    1998-03-01

    The work presented is concerned with studies of orientational order in liquid crystals and the behaviour of certain mesophases. The experimental technique used in common with all the work is deuterium NMR spectroscopy. Much of the work involves studies of the orientational order of deuteriated solute molecules dissolved in liquid crystal solvents. Chapter 1 gives an introduction to liquid crystals followed by a quantitative description of orientational order. Deuterium NMR in liquid crystals is described and an outline of the molecular field theory behind the orientational order of a rigid, biaxial solute in a uniaxial mesophase is given. In Chapter 2 a novel type of mesophase induction is studied using NMR, where a solute induces up to two extra phases in a discotic mesogen depending on its concentration. The purpose of this work is to try to gain an understanding into the mechanism of the phase induction involved. Chapter 3 is concerned primarily with the macroscopic behaviour of the nematic phase formed by a semi-rigid main-chain polymer in solution. Of particular interest is the study of the reorientation of the monodomain, once the director has been rotated with respect to the magnetic field of the NMR spectrometer. A mesogen which has been claimed to exhibit a biaxial nematic phase is studied in Chapter 4, in order to determine the symmetry of the phase using NMR. Finally, Chapter 5 deals with the differing behaviour of a liquid crystal monomer and its dimer dissolved in common nematic solvents in order to determine whether this agrees with molecular field theory. (author)

  3. Characterization of the natural rubber from new rubber tree clones of PB 300 series

    International Nuclear Information System (INIS)

    Silva, Maycon J.; Spinelli, Rafaela O.; Moreno, Rogerio M.B.; Mattoso, Luiz H.C.; Martins, Maria Alice; Scaloppi Junior, Erivaldo J.

    2015-01-01

    The natural rubber (NR) is present in more than 2500 species of plants, being the Hevea brasiliensis the most commercially exploited. It is a raw material of great importance to the Brazilian economy, but the country faces a production's deficit, having to import about 60% of its consumption. In this work , the latex obtained from rubber tree of new clones of PB series 300 (PB 311, PB 312, PB 314 , PB 326, PB 346 and PB 350 ) and RRIM 600 (control) were characterized by dry rubber content (DRC), total solids content, distribution of particle size, Zeta potential, thermogravimetry, differential scanning calorimetry, infrared in the spectroscopy (FTIR), nuclear magnetic resonance (NMR) and technological properties. The DRC values ranged from 33% to 40%, and total solids of 38% to 44%. All of the clones showed average particle diameter between 180.0 to 192.1 nm, excluding clones PB 326 and PB 346 with 150.0 nm and 157.9 nm, respectively. The NMR spectra and FTIR showed that the structure of the natural rubber from all clones studied is cis -1,4- polyisoprene. Natural rubber from the new clones showed good thermal stability up to 285 °C and glass transition temperature of -64 °C. (author)

  4. Qualification study of LiF flight crystals for the objective crystal spectrometer on the SPECTRUM-X-GAMMA satellite

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Rasmussen, I.; Schnopper, Herbert W.

    1992-01-01

    The Objective Crystal Spectrometer (OXS) on the SPECTRUM-X-GAMMA satellite will carry these types of natural crystals LiF(220), Ge(111) and RAP(001). They will be used to study, among others, the H- and the He-like emission from the cosmically important elements Fe, S, Ar and O. More than 300 Li...

  5. Caltrans use of scrap tires in asphalt rubber products: a comprehensive review

    Directory of Open Access Journals (Sweden)

    Haiping Zhou

    2014-02-01

    Full Text Available The California Department of Transportation (Caltrans has been using scrap tire rubber in asphalt pavements since the 1970s in chip seals and the 1980s in rubberized hot mix asphalt(RHMA. Both the wet (field blend and dry processes were used in early trials. Caltrans has also used rubber modified binders containing both crumb rubber modifier and polymer modifier that could be manufactured at a refinery facility, a terminal blend wet process. Since the beginning of this century, Caltrans increased the use of scrap tire rubber in paving projects and invested considerable resources in developing technically sound, cost effective, and environmentally friendly strategies for using scrap tire rubber in roadway applications. By the end of year 2010, approximately 31%of all hot mix asphalt (HMA placed by Caltrans was rubberized HMA, roughly 1.2 million tons. Caltrans efforts in using asphalt rubber products were also demonstrated in its research and technology development. These included the construction of two full-scale field experiments, five warranty projects, and an accelerated pavement study using a heavy vehicle simulator. Additionally, terminal blend asphalt rubber and rubberized warm mix asphalts began to be experimented on trial basis. This paper provides a comprehensive review of Caltrans experience over four decades with asphalt rubber products. Current practices and future outlook are also discussed.

  6. Radiation modification of silicone rubber with glycidylmethacrylate

    International Nuclear Information System (INIS)

    Segura, Tania; Burillo, Guillermina

    2013-01-01

    The grafting of glycidilmethacrylate(GMA) was grafted onto silicone rubber (SR) by using the γ-ray pre-irradiation grafting method under different conditions. The effect of reaction time, total dose, reaction temperature and monomer concentration on the graft yield was studied. It was found that the degree of grafting can be controlled by adjusting these parameters. The chemical structure of SR before and after grafting was characterized using FTIR-ATR and SEM–EDS. The analysis revealed that the surface of the SR was uniformly covered by GMA and the cross-section analysis indicated that the grafting occurred in the bulk. Thermogravimetric analysis (TGA) showed that the graft copolymer was more thermally stable than polyglycidylmethacrylate but less stable than SR, and the DSC confirmed that the GMA was grafting onto silicone rubber. - Highlights: • A graft copolymer with silicone rubber was synthesized by gamma pre-irradiation method. • SEM–EDS analysis showed that the surface and the bulk of the new copolymer were grafted. • The thermal properties of the silicone rubber used were modified with grafting. • The new copolymer could be used to immobilize nucleophilic biomolecules

  7. Lignocellulosic fiber reinforced rubber composites

    CSIR Research Space (South Africa)

    Jacob John, Maya

    2009-04-01

    Full Text Available Natural Rubber (NR) is a naturally occurring elastomeric polymer of isoprene (2-methyl-1,3-butadiene). It can be extracted from latex of only one kind of tree, the Hevea braziliensis. Hevea rubber is produced in many tropical regions of Southeast...

  8. Crack Velocities in Natural Rubber.

    Science.gov (United States)

    1982-05-01

    vulcanized natural rubber (3). The surprisingly low value for natural rubber was attributed to highly anisotropic elastic behavior at high strains...Dr. R.L. Rabie Hercules Incorporated WX-2, MS-952 Alleghany Ballistic Lab Los Alamos National Lab. P.O. Box 210 P.O. Box 1663 Washington, D.C. 21502

  9. Alternative sources of natural rubber

    NARCIS (Netherlands)

    Mooibroek, H.; Cornish, K.

    2000-01-01

    Rubber (cis-1,4-polyisoprene) is one of the most important polymers naturally produced by plants because it is a strategic raw material used in more than 40,000 products, including more than 400 medical devices. The sole commercial source, at present, is natural rubber harvested from the Brazilian

  10. Preparation of vinyl acetate grafted natural rubber by irradiation method

    Energy Technology Data Exchange (ETDEWEB)

    Porntrairat, A.; Pattamaprom, C. [Center of Excellence on Natural Rubber Technology, Department of Chemical Engineering, Faculty of Engineering, Thammasat University, Pathumthani 12120 (Thailand)

    2016-03-09

    Improvement in properties of natural rubber could be done by several methods. In this research, gamma radiation technique, which is simple, accurate, easy to control and clean, was applied to enhance the properties of natural rubber (NR) in latex state. The purpose of this research is to study the appropriate condition for preparing grafted natural rubber latex by using irradiation method. Vinyl acetate monomers (VAc) were grafted onto natural rubber latex (NR-g-PVAc) at 0-10 kGys by gamma radiation from Cobalt-60 source at room temperature. Physical properties of grafted natural rubber such as chloroform number, swelling ratio and gel content were measured. The VAc content of NR-g-PVAc was investigated by titration and visualized by FTIR spectroscopy. The FTIR spectra of NR-g-PVAc prepared at 0-10 kGys showed characteristic peaks of the vinyl acetate confirming that VAc could be grafted onto natural rubber molecular chains effectively under appropriate irradiation conditions. From the result, radiation grafting was found to be a useful technique for grafting of vinyl acetate onto natural rubber.

  11. Practical application of thermoreversibly Cross-linked rubber products

    Science.gov (United States)

    Polgar, L. M.; Picchioni, F.; de Ruiter, E.; van Duin, M.

    2017-07-01

    Currently, rubber products cannot simply be reprocessed after their product life, due to the irreversible cross-linking methods traditionally applied. The purpose of this work is to investigate how thermoreversible cross-linking of rubbers via Diels Alder chemistry can be used for the development of recyclable rubber products. Unfortunately, the applicability of the thermoreversible EPM-g-furan/BM system appears to be limited to room temperature applications, because of the rapid deterioration of the compression set at elevated temperatures compared to irreversibly cross-linked EPM. However, the use of EPM rubber modified with thiophene or cyclopentadiene moieties may extend the temperature application range and results in rubber products with acceptable properties. Finally, rubber products generally comprise fillers such as silica, carbon black or fibers. In this context, the reinforcing effect of short cut aramid fibers on the material properties of the newly developed thermoreversibly cross-linked EPM rubbers was also studied. The material properties of the resulting products were found to be comparable to those of a fiber reinforced, peroxide cured reference sample.

  12. Utilization of waste tire rubber in manufacture of oriented strandboard.

    Science.gov (United States)

    Ayrilmis, Nadir; Buyuksari, Umit; Avci, Erkan

    2009-09-01

    Some physical and mechanical properties of oriented strandboards (OSBs) containing waste tire rubber at various addition levels based on the oven-dry strand weight, using the same method as that used in the manufacture of OSB. Two resin types, phenol-formaldehyde (PF) and polyisocyanate, were used in the experiments. The manufacturing parameters were: a specific gravity of 0.65 and waste tire rubber content (10/90, 20/80 and 30/70 by wt.% of waste tire rubber/wood strand). Average internal bond values of PF-bonded OSB panels with rubber chips were between 17.6% and 48.5% lower than the average of the control samples while polyisocyanate bonded OSBs were 16.5-50.6%. However, water resistance and mechanical properties of OSBs made using polyisocyanate resin were found to comply with general-purpose OSB minimum property requirements of EN 300 Type 1 (1997) values for use in dry conditions at the lowest tire rubber loading level (10%) based on the oven-dry panel weight. The tire rubber improved water resistance of the OSB panel due to its almost hydrophobic property. Based on the findings obtained from this study, we concluded that waste tire rubber could be used for general-purpose OSB manufacturing up to 10% ratio based on the oven-dry panel weight.

  13. Study on reducing radiation dose in dental radiography for children, 1. The seltering effects of lead content rubber sheet and ready-made apron

    Energy Technology Data Exchange (ETDEWEB)

    Shikone, Mitsuru; Tsuchida, Atsushi; Tateno, Hidemi; Uchimura, Noboru; Higaki, Morio; Kanno, Masanori; Higashi, Tomomitsu

    1986-12-01

    X-ray examination is one of the effective diagnoses in dentistry. And it is difficult to conduct a precise dental examination without X-ray films, especially in pedodontics. However, radiography may be attended with many radiation injury, and we must perform the complete protection of patients when taking X-ray radiography for children, because their tissues are much more sensitive to radiation than those of adult. Children have some radiosensitive immature organs such as the thyroid gland, eyes (crystalline lens), gonad etc., accordingly, it is very important to protect them from exposure of X-rey. It has been suggested that the thyroid gland is the most sensitive to radiation among many organs. We, therefore, establish a protector for children's thyroid gland as soon as possible. In this study, the auther had designed X-ray protecting rubber sheet which had various lead contents, for finding an optimum condition of the protector. Additionally, the sheltering effects were compared among ready-made protectors. 1. It was satisfactory for complete sheltering of direct beam that the rubber sheet contained 0.375 mmPb, 0.5 mmPb, and 0.75 mmPb, at the tubevoltage of 65 kVp, 70 kVp and 80 kVp, respectively. 2. The radiolucency ratio of Hagoromo Apron containing 0.25 mmPb was 0 % at 65 kVp, and that of X-ray Shield containing 0.50 mmPb was 0 % at 65, 70 kVp and 80 kVp too. 3. Among the ready-made aprons, there was one which had less lead content than the indicated value.

  14. Premilinary studies for optimiziing a protocol for obtaining embryogenic calluses in two rubber (Hevea brasiliensis Mull. Arg clones from different geographical origins

    Directory of Open Access Journals (Sweden)

    Santiago Cadavid Ruiz

    2006-01-01

    Full Text Available The influence of growth regulators on obtaining friable rubber (Hevea brasiliensis Müll. Arg. calluses with no plant regeneration as investigated. Two clones having different geographical origin were used in all trails carried out in this study: FX 3864 (South-American and PB 254 (Asian. Young leaves and eight- to ten-week-old seed integument from both clones were used as explants in several experiments; they were initially cultured in MH medium (Carron, et ál., 1989, modified MH medium (Montoro, et ál., 1993, 2000 and modified MS medium (Carron, et at,. 1992, no positive response being obtained by days 25 or 50. However, other trials were carried out with the integument in modified MS medium (1962, 0.67 mg/L BAP and 0.66 mg/L 2-4 D being added as medium for initiating embryogenesis, the formation of white, friable calluses being observed by day 25 in the two selected clones. These calluses were sub-cultured in MS supplemented with 0.35 mg/L BAP and 0.2 mg/L 2-4 D as callogenesis expression medium, embryogenic expression being observed in both clones by day 50. Equally friable white calluses were obtained from young leaves in the two clones in MS medium supplemented with 1.0 mg/L BAP, 1.0 mg/L ANA but without IBA and kinetin by day 25. Calluses sub-cultured in the same medium supplemented with 0.5 mg/L BAP and 0.5 mg/L ANA began to show increased friability after 50 days. culture. This work is a partial report of a macro-project for optimising a protocol for rubber (Hevea brasiliensis  multiplication by somatic embryogenesis.

  15. Influence of Rock Properties on Wear of M and SR Grade Rubber with Varying Normal Load and Sliding Speed

    Directory of Open Access Journals (Sweden)

    Pal Samir Kumar

    2017-09-01

    Full Text Available Rubbers are interesting materials and are extensively used in many mining industries for material transportation. Wear of rubber is a very complex phenomenon to understand. The present study aims to explain the influence of rock properties on wear of M and SR grade rubber used in top cover of conveyor belts. Extensive laboratory experiments were conducted under four combinations of normal load and sliding speed. The wear of both the rubber types were analyzed based on the rock properties like shear strength, abrasivity index and fractal dimension. A fully instrumented testing set up was used to study the wear of rubber samples under different operating conditions. In general, wear was higher for M grade rubber compared to SR grade rubber. Increase in shear strength of rocks depicts decreasing trend for the wear of M and SR grade rubber at lower load conditions. Moreover, a higher load combination displays no definite trend in both the rubbers. The strong correlation between the wear of rubber and frictional power for all rubber-rock combinations has given rise to the parameter A, which reflects the relative compatibility between the rubber and rock. Increase of Cerchar’s Abrasivity Index of rocks shows gradual enhancement in wear for M grade rubber in all the load and speed combinations whereas, it fails in SR grade rubber due to its higher strength. The wear of rubber tends to decrease marginally with the surface roughness of rocks at highest normal load and sliding speed in M grade rubber. However, the wear of M and SR grade rubber is influenced by the surface roughness of rocks.

  16. Studying The Effect of Various Parameters on The Characteristics of The Dielectric and Metallic Photonic Crystals

    International Nuclear Information System (INIS)

    Ismail, M.; Badawy, Z.M.; Abdel-Rahman, E.

    2015-01-01

    Transmittance characteristics of two types of photonic crystals have been analysed using the transfer matrix method. The first one is the dielectric photonic crystal (DPC), and the second is the metallic photonic crystal (MPC). The effect of the most parameters on the transmission spectra of the dielectric and metallic photonic crystals has been studied

  17. Properties of tire rubber with zinc-containing technological additives

    Directory of Open Access Journals (Sweden)

    S. N. Kayushnikov

    2017-01-01

    Full Text Available In this paper, we studied the influence of zinc-containing technological additives on partial replacement of zinc oxide and stearic acid on deformation-strength and performance properties of tire elastomeric compositions based on polyisoprene rubber and combination of oil-filled butadiene-styrene and polybutadiene rubbers. It was revealed that partial replacement of zinc oxide and stearic acid with zinc-containing technological additives does not significantly affect the basic physico-mechanical properties of rubbers based on synthetic rubbers of general use. It was determined that the introduction of zinc-containing technological additives SCC2 in combination with zinc oxide in all the studied ratios and SCC3 in combination with zinc oxide in 4: 1 and 3: 1 ratios leads to increase (up to 10.4% of the resistance of these rubbers under the action of temperature-force fields, which is probably due to a more even distribution of polar components of curing system in non-polar elastomeric matrix, as well as the type of cross-links formed during vulcanization under the action of surface-active additives. It has been found that the introduction of zinc-containing additives into the elastomeric compositions based on SRMS-30 ARKM-15 + SRD in combination with zinc oxide leads to increase to 6.3% of wear resistance of rubbers, which may be due to a lower defectiveness of vulcanization structure of these rubbers, concentration of stress centers in the material. For rubbers based on SRI-3, preservation of bond strength of rubber with a textile cord at a sufficiently high level is shown.

  18. Application of mathematical planning in production of filled emulsion rubbers

    Science.gov (United States)

    Pugacheva, I. N.; Molokanova, L. V.; Popova, L. V.; Repin, P. S.

    2018-05-01

    The applicability of mathematical planning of experiment in the field of chemistry and chemical engineering, in particular in the industrial production of synthetic rubbers, is considered in the article. Possibility of using secondary material resources, which are waste products of light industry, in the production of elastomeric compositions is studied. The method of obtaining a powdered cellulose additive from wastes containing cellulose fiber is described. The best way of introducing the obtained additive into elastomeric compositions based on the emulsion rubber is established. Optimal conditions for obtaining filled emulsion rubber with the help of a powdered cellulose additive were established basing on the mathematical planning of experiment.

  19. Dielectric properties of perbunan rubber: γ-irradiation effects

    International Nuclear Information System (INIS)

    El-Nour, K.N.A.; Fouda, I.M.; Migahed, M.D.

    1987-01-01

    A systematic dielectric study over a frequency range extending from 200 Hz to 100 kHz and temperature ranging from 20 0 to 60 0 C has been carried out on perbunan rubber. The acrylonitrile content of the rubber samples was 28% and 38%. The effect of 15 MR γ-irradiation on the dielectric properties of both samples was studied and the results are interpreted. The study revealed that NBR-38 is better than NBR-28 for insulating purposes. (author)

  20. Permeation Behavior and Physical Properties of Natural Rubber Nanocomposites

    National Research Council Canada - National Science Library

    Zukas, Walter; Sennett, Michael; Welsh, Elizabeth; Rodriguez, Axel; Ziegler, David; Touchet, Paul

    2004-01-01

    .... A study was carried out to examine the effects of varying nanoparticle morphology and composition on the mechanical and barrier properties of polymer nanocomposites made with natural rubber (NR...

  1. Equilibrium Kinetics Studies and Crystallization Aboard the International Space Station (ISS) Using the Protein Crystallization Apparatus for Microgravity (PCAM)

    Science.gov (United States)

    Achari, Aniruddha; Roeber, Dana F.; Barnes, Cindy L.; Kundrot, Craig E.; Stinson, Thomas N. (Technical Monitor)

    2002-01-01

    Protein Crystallization Apparatus in Microgravity (PCAM) trays have been used in Shuttle missions to crystallize proteins in a microgravity environment. The crystallization experiments are 'sitting drops' similar to that in Cryschem trays, but the reservoir solution is soaked in a wick. From early 2001, crystallization experiments are conducted on the International Space Station using mission durations of months rather than two weeks on previous shuttle missions. Experiments were set up in April 2001 on Flight 6A to characterize the time crystallization experiments will take to reach equilibrium in a microgravity environment using salts, polyethylene glycols and an organic solvent as precipitants. The experiments were set up to gather data for a series of days of activation with different droplet volumes and precipitants. The experimental set up on ISS and results of this study will be presented. These results will help future users of PCAM to choose precipitants to optimize crystallization conditions for their target macromolecules for a particular mission with known mission duration. Changes in crystal morphology and size between the ground and space grown crystals of a protein and a protein -DNA complex flown on the same mission will also be presented.

  2. Optical studies of metallo-dielectric photonic crystals

    Science.gov (United States)

    Kamaev, Vladimir

    2007-12-01

    Metallo-dielectric photonic crystals (MDPCs) are characterized by a large difference between the dielectric constants of the constituents. Owing to their high DC conductivity a broad omnidirectional band gap is formed at low frequencies. At the same time there exist numerous propagating electromagnetic modes at frequencies above a cutoff. This gives a possibility of creating a "transparent" metal: a crystal transparent in the visible spectral range and simultaneously having high DC conductivity. Since the cutoff wavelength linearly scales with the crystal periodicity, in order to make an MDPC with propagating modes in the visible range the crystal periodicity has to be around a quarter micrometer. Fabrication of such a crystal is a challenging task. One of the feasible choices is natural or artificial opals, structures made of silica balls arranged into a close packed fcc lattice. The ball diameters could vary from 200 nm to several microns, allowing the desired optical features to be in the visible spectral range. In the present work we studied metal-infiltrated opals numerically, analytically, and experimentally (Chapters 1 and 4). Both theory and experiment revealed high reflectance of the samples at large wavelengths associated with the low frequency metallic band gap formation, and low reflectance at short wavelengths that has characteristic wiggles. Contrarily, the absorbance is low in the IR region and goes up towards the UV end, which is due to low group velocity of light and high metal absorption in the region. Numerical analysis of thin metal-infiltrated opals (˜3-5 layers) did show a transmission peak around the first reflectance minimum and cutoff frequency. In Chapter 5 we present transmission experiments on thin metal films perforated with periodic arrays of holes or deposited on an opal monolayer. Both types of 2D MDPCs exhibited anomalous transmission peaks associated with surface plasma excitations. It was shown that the phenomenon could be

  3. Buffing dust as a filler of carboxylated butadiene-acrylonitrile rubber and butadiene-acrylonitrile rubber.

    Science.gov (United States)

    Chronska, K; Przepiorkowska, A

    2008-03-01

    Buffing dust from chrome tanned leather is one of the difficult tannery wastes to manage. It is also hazardous to both human health and the environment. The scientific literature rarely reports studies on dust management, especially on its utilization as a filler for elastomers. In this connection we have made an attempt to use this leather waste as a filler for rubbers such as XNBR and NBR. The addition of the buffing dust to rubber mixes brought improvement in mechanical properties, and increase in resistance to thermal ageing as well as in electric conductivity and crosslink density of vulcalizates.

  4. Nano-reinforcement of tire rubbers: silica-technology for natural rubber : exploring the infuence of non-rubber constituents on the natural rubber-silica system

    NARCIS (Netherlands)

    Sarkawi, S.S.

    2013-01-01

    Natural rubber is a renewable resource material with outstanding properties which offers significant advantages over its counterparts, the fossil-resource synthetic rubbers. In fact, a natural rubber tree is an efficient carbon dioxide sequester. Since natural rubber is a natural product, it is

  5. Ultraviolet curing of epoxidised palm oil acrylate (Epola) and liquid epoxidised natural rubber acrylate (Lenra) on rubberwood substrates-a preliminary study

    International Nuclear Information System (INIS)

    Mohd Hilmi bin Mahmood; Dahlan bin Hj Mohd; Abdul Ghani bin Harun; Ahmad Shakri bin Mat Seman; Azizol bin Abdul Kadir

    1992-01-01

    Palm oil based and natural rubber based formulations were cured by ultraviolet (UV) radiation using rubberwood as a substrate. The appearance properties of the cured films were assessed and subjected to mechanical testing. Both formulations gave good finish films. Mechanical tests show that both films can resist abrasion, heat as well as chemical. Overall results show that natural rubber based formulation is superior than palm oil based

  6. Behavior of Rubber Materials under Exposure to High Electric Fields

    DEFF Research Database (Denmark)

    Candela Garolera, Anna; Holbøll, Joachim; Henriksen, M,

    2013-01-01

    The effect of high electrical stress on rubber materials is investigated by performing breakdown tests and tracking resistance tests on selected samples. The study is focused on the relationship between the dielectric strength and the thickness of the samples, as well as the influence of the inte......The effect of high electrical stress on rubber materials is investigated by performing breakdown tests and tracking resistance tests on selected samples. The study is focused on the relationship between the dielectric strength and the thickness of the samples, as well as the influence...... of the interfaces between different layers of material. Tracking resistance tests are also performed on the rubber material. The purpose is to provide a complete study of the applicability of the rubber material in thunderstorm environments....

  7. SUPPLY-CHAIN OF NATURAL RUBBER IN INDONESIA

    Directory of Open Access Journals (Sweden)

    Bustanul Arifin

    2011-08-01

    Full Text Available Normal 0 false false false MicrosoftInternetExplorer4 st1\\:*{behavior:url(#ieooui } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} The study examines the supply chain of natural rubber production in Indonesia and assessing the transmission of prices to rubber growers and provides recommendations for a suitable scheme that would help to ensure high production standards and a sustainable return for natural rubber production.  The frameworks to examine the performance of supply chain of rubber marketing rely mostly on the efficiency level of marketing system of natural rubbers, including the value chain principles in marketing margin, and revealed price transmission from consumers to growers. The results show that the roles of subdistrict middlemen are extremely crucial in moving up the slabs from the village level to urban areas, where trader-brokers are expecting the slabs to be forwarded directly to crumb-rubber factories.  Changes in world price, hence the profits being accumulated by traders and rubber factories, are not transmitted properly to rubber farmers and/or sharetappers. Information asymmetry, the access over price information, and immediate response of rubber growers to the change in world price could explain this non-cointegration in price data between growers and exporters.  In the near future, the policy reforms in supply chain of natural rubber marketing in Indonesia should carefully address these issues in a more comprehensive manner.  Finally, in order to contribute to the positive environmental and social benefits, the major challenge for natural rubber

  8. Mapping Deciduous Rubber Plantation Areas and Stand Ages with PALSAR and Landsat Images

    Directory of Open Access Journals (Sweden)

    Weili Kou

    2015-01-01

    Full Text Available Accurate and updated finer resolution maps of rubber plantations and stand ages are needed to understand and assess the impacts of rubber plantations on regional ecosystem processes. This study presented a simple method for mapping rubber plantation areas and their stand ages by integration of PALSAR 50-m mosaic images and multi-temporal Landsat TM/ETM+ images. The L-band PALSAR 50-m mosaic images were used to map forests (including both natural forests and rubber trees and non-forests. For those PALSAR-based forest pixels, we analyzed the multi-temporal Landsat TM/ETM+ images from 2000 to 2009. We first studied phenological signatures of deciduous rubber plantations (defoliation and foliation and natural forests through analysis of surface reflectance, Normal Difference Vegetation Index (NDVI, Enhanced Vegetation Index (EVI, and Land Surface Water Index (LSWI and generated a map of rubber plantations in 2009. We then analyzed phenological signatures of rubber plantations with different stand ages and generated a map, in 2009, of rubber plantation stand ages (≤5, 6–10, >10 years-old based on multi-temporal Landsat images. The resultant maps clearly illustrated how rubber plantations have expanded into the mountains in the study area over the years. The results in this study demonstrate the potential of integrating microwave (e.g., PALSAR and optical remote sensing in the characterization of rubber plantations and their expansion over time.

  9. Phase Morphology and Mechanical Properties of Cyclic Butylene Terephthalate Oligomer-Containing Rubbers: Effect of Mixing Temperature

    OpenAIRE

    Hal?sz, Istv?n Zolt?n; B?r?ny, Tam?s

    2016-01-01

    In this work, the effect of mixing temperature (Tmix) on the mechanical, rheological, and morphological properties of rubber/cyclic butylene terephthalate (CBT) oligomer compounds was studied. Apolar (styrene butadiene rubber, SBR) and polar (acrylonitrile butadiene rubber, NBR) rubbers were modified by CBT (20 phr) for reinforcement and viscosity reduction. The mechanical properties were determined in tensile, tear, and dynamical mechanical analysis (DMTA) tests. The CBT-caused viscosity cha...

  10. Causes of fragmented crystals in ignimbrites: a case study of the Cardones ignimbrite, Northern Chile

    Science.gov (United States)

    van Zalinge, M. E.; Cashman, K. V.; Sparks, R. S. J.

    2018-03-01

    Broken crystals have been documented in many large-volume caldera-forming ignimbrites and can help to understand the role of crystal fragmentation in both eruption and compaction processes, the latter generally overlooked in the literature. This study investigates the origin of fragmented crystals in the > 1260 km3, crystal-rich Cardones ignimbrites located in the Central Andes. Observations of fragmented crystals in non-welded pumice clasts indicate that primary fragmentation includes extensive crystal breakage and an associated ca. 5 vol% expansion of individual crystals while preserving their original shapes. These observations are consistent with the hypothesis that crystals fragment in a brittle response to rapid decompression associated with the eruption. Additionally, we observe that the extent of crystal fragmentation increases with increasing stratigraphic depth in the ignimbrite, recording secondary crystal fragmentation during welding and compaction. Secondary crystal fragmentation aids welding and compaction in two ways. First, enhanced crystal fragmentation at crystal-crystal contacts accommodates compaction along the principal axis of stress. Second, rotation and displacement of individual crystal fragments enhances lateral flow in the direction(s) of least principal stress. This process increases crystal aspect ratios and forms textures that resemble mantled porphyroclasts in shear zones, indicating lateral flow adds to processes of compaction and welding alongside bubble collapse. In the Cardones ignimbrite, secondary fragmentation commences at depths of 175-250 m (lithostatic pressures 4-6 MPa), and is modulated by both the overlying crystal load and the time spent above the glass transition temperature. Under these conditions, the existence of force-chains can produce stresses at crystal-crystal contacts of a few times the lithostatic pressure. We suggest that documenting crystal textures, in addition to conventional welding parameters, can

  11. In situ self-polymerization of unsaturated metal methacrylate and its dispersion mechanism in rubber-based composites

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Shipeng; Zhou, Yao; Yao, Lu [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Zhang, Liqun [State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Chan, Tung W. [Department of Materials Science and Engineering, Virginia Polytechnic Institute and State University, VA 24061 (United States); Liang, Yongri [Beijing National Laboratory for Molecular Sciences, Joint Laboratory of Polymer Science and Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Liu, Li, E-mail: LiuL@mail.buct.edu.cn [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029 (China)

    2013-11-10

    Highlights: • In situ self-polymerization of unsaturated metal methacrylate was investigated mainly by the thermal effect. • UMM with low melting point can self-polymerize to a large extent. • The fine dispersion phase is composed of poly(UMM) nanoparticles formed by in situ self-polymerization in the rubber matrix. • The UMM crystals in the presence of peroxide and rubber undergo the processes of melting, diffusion, polymerization, and phase separation in this order. - Abstract: Unsaturated metal methacrylate (UMM) as one kind of functional filler has played an important role in reinforcing rubber materials. The in situ self-polymerization of UMM in UMM/rubber composite leads to the uniform dispersion of poly(UMM) in the rubber matrix, while the crosslinking of rubber and grafting between UMM and rubber chains occur simultaneously, making it difficult to clarify the effect of the in situ polymerization on the dispersion of poly(UMM) in the rubber matrix. In this work, we investigated the dispersion mechanism of UMM without rubber matrix for the first time using differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. Three types of UMMs including zinc methacrylate (Zn(MA){sub 2}), sodium methacrylate (Na(MA)) and samarium methacrylate (Sm(MA){sub 3}) were chosen to investigate the in situ self-polymerization of UMM. Based on DSC results, we conclude that the crystals with low melting point tend to self-polymerize first and generate a large amount of heat in the presence of peroxide. The high heat of reaction can melt the crystals with high melting point, and more UMM molecules are dissolved in the rubber matrix, thus increasing the extent of the in situ polymerization. Hence, the UMM with low melting point can self-polymerize to a large extent. Our findings provide in-depth understanding of the dispersion mechanism of UMM in rubber.

  12. In situ self-polymerization of unsaturated metal methacrylate and its dispersion mechanism in rubber-based composites

    International Nuclear Information System (INIS)

    Wen, Shipeng; Zhou, Yao; Yao, Lu; Zhang, Liqun; Chan, Tung W.; Liang, Yongri; Liu, Li

    2013-01-01

    Highlights: • In situ self-polymerization of unsaturated metal methacrylate was investigated mainly by the thermal effect. • UMM with low melting point can self-polymerize to a large extent. • The fine dispersion phase is composed of poly(UMM) nanoparticles formed by in situ self-polymerization in the rubber matrix. • The UMM crystals in the presence of peroxide and rubber undergo the processes of melting, diffusion, polymerization, and phase separation in this order. - Abstract: Unsaturated metal methacrylate (UMM) as one kind of functional filler has played an important role in reinforcing rubber materials. The in situ self-polymerization of UMM in UMM/rubber composite leads to the uniform dispersion of poly(UMM) in the rubber matrix, while the crosslinking of rubber and grafting between UMM and rubber chains occur simultaneously, making it difficult to clarify the effect of the in situ polymerization on the dispersion of poly(UMM) in the rubber matrix. In this work, we investigated the dispersion mechanism of UMM without rubber matrix for the first time using differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. Three types of UMMs including zinc methacrylate (Zn(MA) 2 ), sodium methacrylate (Na(MA)) and samarium methacrylate (Sm(MA) 3 ) were chosen to investigate the in situ self-polymerization of UMM. Based on DSC results, we conclude that the crystals with low melting point tend to self-polymerize first and generate a large amount of heat in the presence of peroxide. The high heat of reaction can melt the crystals with high melting point, and more UMM molecules are dissolved in the rubber matrix, thus increasing the extent of the in situ polymerization. Hence, the UMM with low melting point can self-polymerize to a large extent. Our findings provide in-depth understanding of the dispersion mechanism of UMM in rubber

  13. Identification, Functional Study, and Promoter Analysis of HbMFT1, a Homolog of MFT from Rubber Tree (Hevea brasiliensis

    Directory of Open Access Journals (Sweden)

    Zhenghong Bi

    2016-03-01

    Full Text Available A homolog of MOTHER OF FT AND TFL1 (MFT was isolated from Hevea brasiliensis and its biological function was investigated. Protein multiple sequence alignment and phylogenetic analysis revealed that HbMFT1 conserved critical amino acid residues to distinguish MFT, FLOWERING LOCUS T (FT and TERMINAL FLOWER1 (TFL1-like proteins and showed a closer genetic relationship to the MFT-like group. The accumulation of HbMFT1 was generally detected in various tissues except pericarps, with the highest expression in embryos and relatively higher expression in roots and stems of seedlings, flowering inflorescences, and male and female flowers. HbMFT1 putative promoter analysis showed that tissue-specific, environmental change responsive and hormone-signaling responsive elements were generally present. HbMFT1 was strongly induced under a short-day condition at 28 °C, with the highest expression after the onset of a day. Overexpression of HbMFT1 inhibited seed germination, seedling growth, and flowering in transgenic Arabidopsis. The qRT-PCR further confirmed that APETALA1 (AP1 and FRUITFULL (FUL were drastically down-regulated in 35S::HbMFT1 plants. A histochemical β-glucuronidase (GUS assay showed that HbMFT1::GUS activity was mainly detected in stamens and mature seeds coinciding with its original expression and notably induced in rosette leaves and seedlings of transgenic Arabidopsis by exogenous abscisic acid (ABA due to the presence of ABA cis-elements in HbMFT1 promoter. These results suggested that HbMFT1 was mainly involved in maintenance of seed maturation and stamen development, but negatively controlled germination, growth and development of seedlings and flowering. In addition, the HbMFT1 promoter can be utilized in controlling transgene expression in stamens and seeds of rubber tree or other plant species.

  14. AFM studies on heavy ion irradiated YBCO single crystals

    International Nuclear Information System (INIS)

    Lakhani, Archana; Marhas, M.K.; Saravanan, P.; Ganesan, V.; Srinivasan, R.; Kanjilal, D.; Mehta, G.K.; Elizabeth, Suja; Bhat, H.L.

    2000-01-01

    Atomic Force Microscopy (AFM) is extensively used to characterise the surface morphology of high energy ion irradiated single crystals of high temperature superconductor - YBCO. Our earlier systematic studies on thin films of YBCO under high energy and heavy ion irradiation shows clear evidence of ion induced sputtering or erosion, even though the effect is more on the grain boundaries. These earlier results were supported by electrical resistance measurements. In order to understand more clearly, the nature of surface modification at these high energies, AFM studies were carried out on single crystals of YBCO. Single crystals were chosen in order to see the effect on crystallites alone without interference from grain boundaries. 200 MeV gold ions were used for investigation using the facilities available at Nuclear Science Centre, New Delhi. The type of ion and the range of energies were chosen to meet the threshold for electronically mediated defect production. The results are in conformity with our earlier studies and will be described in detail in the context of electronic energy loss mediated sputtering or erosion. (author)

  15. Possibility of using waste tire rubber and fly ash with Portland cement as construction materials.

    Science.gov (United States)

    Yilmaz, Arin; Degirmenci, Nurhayat

    2009-05-01

    The growing amount of waste rubber produced from used tires has resulted in an environmental problem. Recycling waste tires has been widely studied for the last 20 years in applications such as asphalt pavement, waterproofing systems and membrane liners. The aim of this study is to evaluate the feasibility of utilizing fly ash and rubber waste with Portland cement as a composite material for masonry applications. Class C fly ash and waste automobile tires in three different sizes were used with Portland cement. Compressive and flexural strength, dry unit weight and water absorption tests were performed on the composite specimens containing waste tire rubber. The compressive strength decreased by increasing the rubber content while increased by increasing the fly ash content for all curing periods. This trend is slightly influenced by particle size. For flexural strength, the specimens with waste tire rubber showed higher values than the control mix probably due to the effect of rubber fibers. The dry unit weight of all specimens decreased with increasing rubber content, which can be explained by the low specific gravity of rubber particles. Water absorption decreased slightly with the increase in rubber particles size. These composite materials containing 10% Portland cement, 70% and 60% fly ash and 20% and 30% tire rubber particles have sufficient strength for masonry applications.

  16. Neutron scattering studies of molecular conformations in liquid crystal polymers

    Science.gov (United States)

    Noirez, L.; Moussa, F.; Cotton, J. P.; Keller, P.; Pépy, G.

    1991-03-01

    A comblike liquid crystal polymer (LPC) is a polymer on which mesogenic molecules have been grafted. It exhibits a succession of liquid crystal phases. Usually the equilibrium conformation of an ordinary polymeric chain corresponds to a maximum entropy, i.e., to an isotropic spherical coil. How does the backbone of a LCP behave in the nematic and smectic field? Small-angle neutron scattering may answer this question. Such measurements are presented here on four different polymers as a function of temperature. An anisotropy of the backbone conformation is found in all these studied compounds, much more pronounced in the smectic phase than in the nematic phase: the backbone spreads more or less perpendicularly to its hanging cores. A comparison with existing theories and a discussion of these results is outlined.

  17. Study of alloy crystallization in systems undergoing peritectic transformations

    International Nuclear Information System (INIS)

    Psarev, V.I.; Kirij, V.G.; Kuznetsov, A.V.; Psareva, I.V.; Ivanov, A.L.

    1982-01-01

    Studies into Ge-Te, In-Te, Al-Mn, Sb-Zn, Sn-Au systems are carried out at melt cooling rates from 50 deg/h to 10 5 deg/h to establish regularities in stable and metastable crystallization of alloys undergoing peritectic transformations. Methods of metallographic, X-ray phase and X-ray diffraction analyses are used. Differentiation in types of peritectic transformations is made through their mechanisms under equilibrium and non-equilibrium crystallization conditions for various alloy systems. It is found out that ability to supercooling even at low or moderate cooling rates for Te-Ge and Te-In system melts can be one of the main indication of the possibility of amorphous alloy formation [ru

  18. Computational study of heat transport in compositionally disordered binary crystals

    International Nuclear Information System (INIS)

    Lyver, John W.; Blaisten-Barojas, Estela

    2006-01-01

    The thermal conductivity of compositionally disordered binary crystals with atoms interacting through Lennard-Jones potentials has been studied as a function of temperature. The two species in the crystal differ in mass, hard-core atomic diameter, well depth and relative concentration. The isobaric Monte Carlo was used to equilibrate the samples at near-zero pressure. The isoenergy molecular dynamics combined with the Green-Kubo approach was taken to calculate the heat current time-dependent autocorrelation function and determine the lattice thermal conductivity of the sample. The inverse temperature dependence of the lattice thermal conductivity was shown to fail at low temperatures when the atomic diameters of the two species differ. Instead, the thermal conductivity was nearly a constant across temperatures for species with different atomic diameters. Overall, it is shown that there is a dramatic decrease of the lattice thermal conductivity with increasing atomic radii ratio between species and a moderate decrease due to mass disorder

  19. NMR studies of liquid crystals and molecules dissolved in liquid crystal solvents

    Energy Technology Data Exchange (ETDEWEB)

    Drobny, Gary Peter [Univ. of California, Berkeley, CA (United States)

    1982-11-01

    This thesis describes several studies in which nuclear magnetic resonance (nmr) spectroscopy has been used to probe the structure, orientation and dynamics of liquid crystal mesogens and molecules dissolved in liquid crystalline phases. In addition, a modern high field nmr spectrometer is described which has been used to perform such nmr studies. Chapter 1 introduces the quantum mechanical formalisms used throughout this thesis and briefly reviews the fundamentals of nuclear spin physics and pulsed nmr spectroscopy. First the density operator is described and a specific form for the canonical ensemble is derived. Then Clebsch-Gordon coefficients, Wigner rotation matrices, and irreducible tensor operators are reviewed. An expression for the equilibrium (Curie) magnetization is obtained and the linear response of a spin system to a strong pulsed r.f. irradiation is described. Finally, the spin interaction Hamiltonians relevant to this work are reviewed together with their truncated forms. Chapter 2 is a deuterium magnetic resonance study of two 'nom' liquid crystals which possess several low temperature mesomorphic phases. Specifically, deuterium quadrupolar echo spectroscopy is used to determine the orientation of the liquid crystal molecules in smectic phases, the changes in molecular orientation and motion that occur at smectic-smectic phase transitions, and the order of the phase transitions. For both compounds, the phase sequence is determined to be isotropic, nematic, smectic A, smectic C, smectic BA, smectic BC, and crystalline. The structure of the smectic A phase is found to be consistent with the well-known model of a two dimensional liquid in which molecules are rapidly rotating about their long axes and oriented at right angles to the plane of the layers. Molecules in the smectic C phase are found to have their long axes tilted with respect to the layer normal, and the tilt angle is temperature dependent, increasing from

  20. The performance and risk of Kossan Rubber Industries Berhad

    OpenAIRE

    teoh, kun youn

    2017-01-01

    The purpose of the study is to investigate the overall performance of Kossan Rubber Industries Bhd with internal factors and external factors on profitability performance. The data obtained from annual report of Kossan Rubber Industries Bhd during the years 2011 to 2015. The financial ratio used to measure the overall performance and risk of the company. The measurement of current ratio, return on assets (ROA), and inventory turnover are used to determine the overall performance and the effic...

  1. Nitrile rubber and carboxylated nitrile rubber resistance to soybean biodiesel

    OpenAIRE

    Felipe Nunes Linhares; Cléverson Fernandes Senra Gabriel; Ana Maria Furtado de Sousa; Marcia Christina Amorim Moreira Leite; Cristina Russi Guimarães Furtado

    2018-01-01

    Abstract Biodiesel has been considered a suitable substitute for petroleum diesel, but their chemical composition differs greatly. For this reason, biodiesel interacts differently than petroleum diesel with various materials, including rubbers. Therefore, the resistance of some elastomers should be thoroughly evaluated, specifically those which are commonly used in automotive industry. Nitrile rubber (NBR) is widely used to produce vehicular parts that are constantly in contact with fuels. T...

  2. Mechanical properties of concrete containing a high volume of tire-rubber particles.

    Science.gov (United States)

    Khaloo, Ali R; Dehestani, M; Rahmatabadi, P

    2008-12-01

    Due to the increasingly serious environmental problems presented by waste tires, the feasibility of using elastic and flexible tire-rubber particles as aggregate in concrete is investigated in this study. Tire-rubber particles composed of tire chips, crumb rubber, and a combination of tire chips and crumb rubber, were used to replace mineral aggregates in concrete. These particles were used to replace 12.5%, 25%, 37.5%, and 50% of the total mineral aggregate's volume in concrete. Cylindrical shape concrete specimens 15 cm in diameter and 30 cm in height were fabricated and cured. The fresh rubberized concrete exhibited lower unit weight and acceptable workability compared to plain concrete. The results of a uniaxial compressive strain control test conducted on hardened concrete specimens indicate large reductions in the strength and tangential modulus of elasticity. A significant decrease in the brittle behavior of concrete with increasing rubber content is also demonstrated using nonlinearity indices. The maximum toughness index, indicating the post failure strength of concrete, occurs in concretes with 25% rubber content. Unlike plain concrete, the failure state in rubberized concrete occurs gently and uniformly, and does not cause any separation in the specimen. Crack width and its propagation velocity in rubberized concrete are lower than those of plain concrete. Ultrasonic analysis reveals large reductions in the ultrasonic modulus and high sound absorption for tire-rubber concrete.

  3. Crystal growth of uranium compounds and study of UGe2

    International Nuclear Information System (INIS)

    Taufour, V.

    2011-01-01

    In this thesis, the study on the superconducting ferromagnet UGe 2 is presented. Crystal growth of UGe 2 single crystals was realized in a tetra-arc furnace using the Czochralski technique. This technique was also used to obtain high quality single crystals of other uranium compounds, notably UCoGe and URu 2 Si 2 . The Curie temperature of UGe 2 (T(Curie) = 53 K) decreases with pressure and is suppressed at p c = 1.5 GPa. Before being suppressed, the ferromagnetic transition changes from second to first order at a tricritical point. Precise resistivity and Hall resistivity measurements under pressure and magnetic field revealed the position of the tricritical point as well as its evolution under magnetic field which draw a wing structure phase diagram. Despite the theoretical prediction that this diagram is general for a ferromagnet, here we present the first experimental observation. Other measurements focus on the superconductivity (T sc = 0.75 K) which coexists with ferromagnetism under pressure. The bulk nature of the superconductivity is investigated by AC calorimetry measurements under pressure. The attention is turned to the interesting phenomenon of field enhanced superconductivity. (author) [fr

  4. Time series analysis of the behavior of brazilian natural rubber

    Directory of Open Access Journals (Sweden)

    Antônio Donizette de Oliveira

    2009-03-01

    Full Text Available The natural rubber is a non-wood product obtained of the coagulation of some lattices of forest species, being Hevea brasiliensis the main one. Native from the Amazon Region, this species was already known by the Indians before the discovery of America. The natural rubber became a product globally valued due to its multiple applications in the economy, being its almost perfect substitute the synthetic rubber derived from the petroleum. Similarly to what happens with other countless products the forecast of future prices of the natural rubber has been object of many studies. The use of models of forecast of univariate timeseries stands out as the more accurate and useful to reduce the uncertainty in the economic decision making process. This studyanalyzed the historical series of prices of the Brazilian natural rubber (R$/kg, in the Jan/99 - Jun/2006 period, in order tocharacterize the rubber price behavior in the domestic market; estimated a model for the time series of monthly natural rubberprices; and foresaw the domestic prices of the natural rubber, in the Jul/2006 - Jun/2007 period, based on the estimated models.The studied models were the ones belonging to the ARIMA family. The main results were: the domestic market of the natural rubberis expanding due to the growth of the world economy; among the adjusted models, the ARIMA (1,1,1 model provided the bestadjustment of the time series of prices of the natural rubber (R$/kg; the prognosis accomplished for the series supplied statistically adequate fittings.

  5. Study of molecular movements in some organic crystals by NMR

    International Nuclear Information System (INIS)

    Alexandre, M.

    1971-01-01

    After a discussion on molecular crystals (generalities, movements within molecular solids, study of movements, complexes by charge transfer) and some specific ones (molecular complexes of trinitrobenzene or TNB), this research thesis reports the use of nuclear magnetic resonance (NMR) to study molecular movements: generalities on broadband NMR, spin relaxation and strong field network, observation of the absorption signal and measurement of the second moment. The last part reports and discusses experimental results obtained on TNB-naphthalene, on TNB-azulene, on TNB-benzothiophene, and on TNB-indole

  6. Tribology Aspect of Rubber Shock Absorbers Development

    Directory of Open Access Journals (Sweden)

    M. Banić

    2013-09-01

    Full Text Available Rubber is a very flexible material with many desirable properties Which enable its broad use in engineering practice. Rubber or rubber-metal springs are widely used as anti-vibration or anti-shock components in technical systems. Rubber-metal springs are usually realized as a bonded assembly, however especially in shock absorbers, it is possible to realize free contacts between rubber and metal parts. In previous research it authors was observed that friction between rubber and metal in such case have a significant influence on the damping characteristics of shock absorber. This paper analyzes the development process of rubber or rubber-metal shock absorbers realized free contacts between the constitutive parts, starting from the design, construction, testing and operation, with special emphasis on the development of rubber-metal springs for the buffing and draw gear of railway vehicles.

  7. Growth, structural, optical, thermal and mechanical studies on 4-Aminopyridinium monophthalate: A novel nonlinear optical crystal

    Science.gov (United States)

    Marudhu, G.; Krishnan, S.; Palanichamy, M.

    2016-03-01

    A novel nonlinear optical crystal of 4-Aminopyridinium monophthalate (4-APMP) was grown by slow evaporation technique using methanol as solvent. Single crystal X-ray diffraction analysis confirms that the grown crystal belongs to orthorhombic system. The presence of functional groups was qualitatively determined by FTIR analysis. The optical absorption studies reveal very low absorption in the entire visible region. The fluorescence emission spectrum shows the emission is in blue region. The thermal stability of the grown crystal is found to be around 197.2 °C. The SHG efficiency of the grown crystal is found to be 1.1 times than that of KDP crystals.

  8. Laboratory Evaluation of Ground Tire Rubber in Stone Mastic Asphalt

    Directory of Open Access Journals (Sweden)

    R. Muniandy

    2004-12-01

    Full Text Available Stone mastic asphalt (SMA is a gap-graded mix whereby stiffer asphalt cement is required to bind the stone matrix or arrangement of stones together. Although various asphalt additives are traditionally available, the use of rubber crumbs in SMA is still a new rresearch endeavor. Many countries around the world are facing serious problems on what to do with reject or discarded tires. In the present study, commercial truck tires, containing 70% natural rubber, were ground and pre-blended in 80-100 penetration asphalt for use in SMA mixtures. An assessment was made of the laboratory performance of rubberized SMA in terms of stability, resilent modulus, dynamic creep and tensile strength ratio. It was observed that the performance of SMA with ground tire rubber was for superior as compared to SMA mix with unmodified asphalt. Sulfur and Styrene Butadeline Rubber (SBR were used in rubberized SMA mixes as additives to test the sensitivity of SMA mixtures. As standard practice a 0.3% newly developed cellulose oil palm fiber was used in SMA to minimize the asphalt drain-down effects.

  9. Rheological Properties of Rubber Compounds with Finely Divided Carbon Additives

    Science.gov (United States)

    Shashok, Zh. S.; Prokopchuk, N. R.; Vishnevskii, K. V.; Krauklis, A. V.; Borisevich, K. O.; Borisevich, I. O.

    2018-01-01

    A study has been made of the influence of three different nanomaterials: of the starting material, and also of those functionalized by amine and oxygen-containing groups, on the properties of elastomer compositions based on rubbers for special purposes. As the elastomer matrix, use was made in one case of a rubber compound based on BNKS-18 butadiene-nitrile rubber and in the other, of a combination of two grades of butadiene-nitrile rubber (BNKS-18 + BNKS-28 in a 50:50 ratio), which differed by the amount of the bound nitrile of acrylic acid. To determine the degree of interaction between the additives and the elastomer matrix, the authors carried out multiple tests of the rubber compounds. The indices of plastoelastic properties of the rubber compounds and the qualitative characteristics of distribution of the filler (elastic modulus at small deformation amplitudes and the shear modulus under large deformation) and the difference in these indices (complex dynamic modulus) alike have been determined.

  10. Crystal structure, growth and nonlinear optical studies of isonicotinamide p-nitrophenol: A new organic crystal for optical limiting applications

    Science.gov (United States)

    Vijayalakshmi, A.; Vidyavathy, B.; Vinitha, G.

    2016-08-01

    Isonicotinamide p-nitrophenol (ICPNP), a new organic material, was synthesized using methanol solvent. Single crystals of ICPNP were grown using a slow evaporation solution growth technique. Crystal structure of ICPNP is elucidated by single crystal X-ray diffraction analysis. It belongs to monoclinic crystal system with space group of P21/c. It forms two dimensional networks by O-H…O, N-H…O and C-H…O hydrogen bonds. The molecular structure of ICPNP was further confirmed by Fourier transform infrared (FTIR) spectral analysis. The optical transmittance range and the lower cut-off wavelength (421 nm) with the optical band gap (2.90 eV) of the ICPNP crystal were determined by UV-vis-NIR spectral study. Thermal behavior of ICPNP was studied by thermo gravimetric and differential thermal analyses (TG/DTA). The relative dielectric permittivity was calculated for various temperature ranges. Laser damage threshold of ICPNP crystal was found to be 1.9 GW/cm2 using an Nd:YAG laser. A Z-scan technique was employed to measure the nonlinear absorption coefficient, nonlinear refractive index and nonlinear optical susceptibility. Optical limiting behavior of ICPNP was observed at 35 mW input power.

  11. Influence the Rubber Seed Type and Altitude on Characteristic of Seed, Oil and Biodiesel

    Directory of Open Access Journals (Sweden)

    Salni Salni

    2017-06-01

    Full Text Available This research studies the influence of the type of rubber seed that is superior and local, altitude plant in South Sumatra province to the characteristic of seed, oil and biodiesel (methyl ester. Rubber plants planted from local rubber seed by seeds seedlings and superior rubber seed by selected clones. In the study, rubber plants planted at a different altitude, namely in Banyuasin district (18 m above sea level, Prabumulih District (176 m above sea level and Lahat District (627 m above sea level. The results showed that the weight of the flour, the water content and ash content in the local rubber seeds larger than the superior rubber seed for all altitude, but oil content a large in the superior rubber seeds. The major of fatty acids in the rubber seed oil in all types and altitude are a linoleic acid with a different percentage except local rubber seed oil from Lahat district with the large percentage of octadecanoic acid. Free fatty acids in the oil from the superior seeds rubber of 13.897-15.494 % large than local rubber seed oil was found 9.786-10.399 % for all altitude. By esterification process using sulfuric acid catalyst, Free Fatty Acid (FFA can be reduced to ≤ 2 %. The methyl ester made from the transesterification process of rubber seed oil after esterification using methanol and sodium hydroxide as catalyst. Analysis of methyl esters includes cetane index, flash point, kinematic viscosity, carbon residue, density, moisture content, water and sediment content and distillation compared with SNI 7182 and ASTM 6751-02.  The result indicated that the quality of methyl ester from superior rubber seed oil in the Banyuasin and Prabumulih district better than another methyl ester. The types of rubber seed altitude affect the characteristics of the seed, oil and methyl ester  but the altitude are not significantly different. Keywords: rubber seed, type, altitude, oil, biodiesel Article History: Received March 21st 2017; Received in

  12. Silicone rubber band for laparoscopic tubal sterilization.

    Science.gov (United States)

    Ansari, A H; Sealey, R M; Gay, J W; Kang, I

    1977-12-01

    In 1974, Yoon and associates (Am J Obstet Gynecol 120:132, 1974) described a new approach in which laparoscopic tubal occlusion was accomplished by utilizing the silicone rubber band technique. Recognizing the great advantages of the new technique in eliminating potential thermal injury associated with electrocoagulation, the authors have utilized the Yoon silicone rubber band technique in these institutions over the past 20 months. Thus far the procedure has been performed in 304 patients without any major complications. In the hope of eliminating and/or reducing possible pregnancy-failure rates, in 110 cases. In addition to application of the silicone band, the tube within the band was transected with non-electrical Seigler biopsy forceps. This, we believe, should provide an interesting long-term comparative study.

  13. Raman technique application for rubber blends characterization

    Directory of Open Access Journals (Sweden)

    Smitthipong, W.

    2007-11-01

    Full Text Available Raman spectroscopy has been employed in a number of studies to examine the morphological changes in a variety of materials. It is a non-destructive analysis method and an equally useful method for the investigation of material structure. Recently, Raman spectroscopy has been developed to employ as an imaging instrumentation. Sample surface scanning in X- and Y-axis and sample depth (Z-axis can be carried out by modifying the focus of the laser beam from the Raman microscope. Therefore, three-dimensional images can be thus built by using special software. The surface and bulk properties of immiscible rubber blend were investigated by Raman spectroscopy. The results obtained by Raman spectroscopy were in good agreement with those of Scanning Electron Microscope (SEM. The combination of Raman spectrometry and SEM clearly elucidates the identification of phases between the dispersed phase and the matrix (continuous phase of the immiscible rubber blends.

  14. Pengaruh Kualitas Kehidupan Kerja, Kepuasan Kerja dan Komitmen Karyawan terhadap Kinerja Karyawan terhadap Kinerja Karyawan dan Prilaku Kewargaan sebagai Variabel Intervening (Studi pada PT. Perindustrian dan Perdagangan Crumb Rubber Pekanbaru)

    OpenAIRE

    Lumbantoruan, Erick Robson

    2015-01-01

    The purpose of this study was to examine the influence of Influence Quality of working life, job satisfaction and employee commitment to Performance aganizational Citizenship Behavior as an intervening variable in PT. Crumb Rubber Industry and Trade Pekanbaru in 2009 to 2013. Random sampling method is used to determine our samplengs. Of the 365 field employees, 108 employees were taken as samples. For the analysis of this data using network analysis / path analisisbe. T-test, F-test, and dete...

  15. Solid-state reaction kinetics and optical studies of cadmium doped magnesium hydrogen phosphate crystals

    Science.gov (United States)

    Verma, Madhu; Gupta, Rashmi; Singh, Harjinder; Bamzai, K. K.

    2018-04-01

    The growth of cadmium doped magnesium hydrogen phosphate was successfully carried out by using room temperature solution technique i.e., gel encapsulation technique. Grown crystals were confirmed by single crystal X-ray diffraction (XRD). The structure of the grown crystal belongs to orthorhombic crystal system and crystallizes in centrosymmetric space group. Kinetics of the decomposition of the grown crystals were studied by non-isothermal analysis. Thermo gravimetric / differential thermo analytical (TG/DTA) studies revealed that the grown crystal is stable upto 119 °C. The various steps involved in the thermal decomposition of the material have been analysed using Horowitz-Metzger, Coats-Redfern and Piloyan-Novikova equations for evaluating various kinetic parameters. The optical studies shows that the grown crystals possess wide transmittance in the visible region and significant optical band gap of 5.5ev with cut off wavelength of 260 nm.

  16. Components of Soil Respiration and its Monthly Dynamics in Rubber Plantation Ecosystems

    OpenAIRE

    Zhixiang Wu; Limin Guan; Bangqian Chen; Chuan Yang; Guoyu Lan; Guishui Xie; Zhaode Zhou

    2014-01-01

    Aim: Our objective was to quantify four components and study effect factors of soil respiration in rubber plantation ecosystems. Providing the basic data support for the establishment of the trade of rubber plantation ecosystem carbon source/sink. Methods: We used Li-6400 (IRGA, Li-COR) to quantitate four components of soil respiration in rubber plantation ecosystems at different ages. Soil respiration can be separated as four components: heterotrophic respiration (Rh), Respiration of roots (...

  17. Fabrication of Wood-Rubber Composites Using Rubber Compound as a Bonding Agent Instead of Adhesives

    Directory of Open Access Journals (Sweden)

    Dongwei Shao

    2016-06-01

    Full Text Available Differing from the hot-pressing method in the manufacturing of traditional wood-rubber composites (WRCs, this study was aimed at fabricating WRCs using rubber processing to improve water resistance and mechanical properties. Three steps were used to make WRCs, namely, fiber-rubber mixing, tabletting, and the vulcanization molding process. Ninety-six WRC panels were made with wood fiber contents of 0%–50% at rotor rotational speeds of 15–45 rpm and filled coefficients of 0.55–0.75. Four regression equations, i.e., the tensile strength (Ts, elongation at break (Eb, hardness (Ha and rebound resilience (Rr as functions of fiber contents, rotational speed and filled coefficient, were derived and a nonlinear programming model were developed to obtain the optimum composite properties. Although the Ts, Eb and Rr of the panels were reduced, Ha was considerably increased by 17%–58% because of the wood fiber addition. Scanning electron microscope images indicated that fibers were well embedded in rubber matrix. The 24 h water absorption was only 1%–3%, which was much lower than commercial wood-based composites.

  18. Fabrication of Wood-Rubber Composites Using Rubber Compound as a Bonding Agent Instead of Adhesives.

    Science.gov (United States)

    Shao, Dongwei; Xu, Min; Cai, Liping; Shi, Sheldon Q

    2016-06-14

    Differing from the hot-pressing method in the manufacturing of traditional wood-rubber composites (WRCs), this study was aimed at fabricating WRCs using rubber processing to improve water resistance and mechanical properties. Three steps were used to make WRCs, namely, fiber-rubber mixing, tabletting, and the vulcanization molding process. Ninety-six WRC panels were made with wood fiber contents of 0%-50% at rotor rotational speeds of 15-45 rpm and filled coefficients of 0.55-0.75. Four regression equations, i.e. , the tensile strength ( T s), elongation at break ( E b), hardness ( H a) and rebound resilience ( R r) as functions of fiber contents, rotational speed and filled coefficient, were derived and a nonlinear programming model were developed to obtain the optimum composite properties. Although the T s, E b and R r of the panels were reduced, H a was considerably increased by 17%-58% because of the wood fiber addition. Scanning electron microscope images indicated that fibers were well embedded in rubber matrix. The 24 h water absorption was only 1%-3%, which was much lower than commercial wood-based composites.

  19. Toughening of carbon fibre reinforced polymer composites with rubber nanoparticles for advanced industrial applications

    Directory of Open Access Journals (Sweden)

    N. G. Ozdemir

    2016-05-01

    Full Text Available This study investigates the effects of nano carboxylic acrylonitrile butadiene rubber (CNBR-NP and nano acrylonitrile butadiene rubber (NBR-NP on the interlaminar shear strength and fracture toughness of carbon fibre reinforced polymer composites (CFRP with dicyandiamide-cured epoxy matrix. The results show that nano-size dispersion of rubber significantly improved the Mode I delamination fracture toughness (GIC of the CFRP by 250% and its Mode II delamination fracture toughness (GIIC by 80% with the addition of 20 phr of CNBR-NP. For the NBR-NP system, the GIC and GIIC delamination fracture toughness of the CFRP were increased by 200 and 80% respectively with the addition of 20 phr (parts per hundred rubber of nano rubber to the matrix. Scanning electron microscopy (SEM images of the fracture surface revealed that the toughening was mainly achieved by debonding of the nano rubber, crack path deflection and fibre bridging.

  20. Application of gamma irradiation for incorporation of rubber powder in the formulations

    International Nuclear Information System (INIS)

    Kiyan, Ludmila Y.P.; Lugao, Ademar B.; Parra, Duclerc F.; Zaharescu, Traian

    2013-01-01

    The aim of this paper was to study the behavior of rubber recycle, in powder form of rubber industry. It was used EPDM rubber powder. The rubber powder was irradiated and used directly in classical formulations of rubber vulcanizate. The master-batch processed material was irradiated at doses of 50, 100 and 150kGy in 60 Co source at 5kGy s -1 rate, at room temperature. Gamma radiation created active sites devulcanization for further integration of the material (rubber powder) with facilities in formulations of commercial use. The processes were compared and their products were characterized by analytical methods of the physical properties such as tensile strength, elongation, hardness, rheology and abrasion tests. (author)

  1. HLW Glass Studies: Development of Crystal-Tolerant HLW Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Matyas, Josef; Huckleberry, Adam R.; Rodriguez, Carmen P.; Lang, Jesse B.; Owen, Antionette T.; Kruger, Albert A.

    2012-04-02

    In our study, a series of lab-scale crucible tests were performed on designed glasses of different compositions to further investigate and simulate the effect of Cr, Ni, Fe, Al, Li, and RuO2 on the accumulation rate of spinel crystals in the glass discharge riser of the HLW melter. The experimental data were used to expand the compositional region covered by an empirical model developed previously (Matyáš et al. 2010b), improving its predictive performance. We also investigated the mechanism for agglomeration of particles and impact of agglomerates on accumulation rate. In addition, the TL was measured as a function of temperature and composition.

  2. EPR studies of gamma-irradiated taurine single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Bulut, A. E-mail: abulut@samsun.omu.edu.tr; Karabulut, B.; Tapramaz, R.; Koeksal, F

    2000-04-01

    An EPR study of gamma-irradiated taurine [C{sub 2}H{sub 7}NO{sub 3}S] single crystal was carried out at room temperature. The EPR spectra were recorded in the three at mutually perpendicular planes. There are two magnetically distinct sites in monoclinic lattice. The principle values of g and hyperfine constants for both sites were calculated. The results have indicated the presence of {sup 32}SO{sup -}{sub 2} and {sup 33}SO{sup -}{sub 2} radicals. The hyperfine values of {sup 33}SO{sup -}{sub 2} radical were used to obtain O-S-O bond angle for both sites.

  3. EPR studies of gamma-irradiated taurine single crystals

    International Nuclear Information System (INIS)

    Bulut, A.; Karabulut, B.; Tapramaz, R.; Koeksal, F.

    2000-01-01

    An EPR study of gamma-irradiated taurine [C 2 H 7 NO 3 S] single crystal was carried out at room temperature. The EPR spectra were recorded in the three at mutually perpendicular planes. There are two magnetically distinct sites in monoclinic lattice. The principle values of g and hyperfine constants for both sites were calculated. The results have indicated the presence of 32 SO - 2 and 33 SO - 2 radicals. The hyperfine values of 33 SO - 2 radical were used to obtain O-S-O bond angle for both sites

  4. Crystallization study of a glass used for fission product storage

    International Nuclear Information System (INIS)

    Morlevat, J.-P.; Uny, Gisele; Jacquet-Francillon, Noel.

    1981-06-01

    The vitreous matrix used in France is a borosilicate glass of low melting point allowing introduction of volatil fission products and of good chemical stability. However, like any glass, if storage temperature is higher than transformation temperature a partial crystallization can occur. Before final storage, it is important to determine of leaching by water eventually occuring on the choosen site is modified by crystalline phases. The aim of this study is the determination of the leaching rate and the identification of crystalline phases formed during thermal treatment and evaluation of its volumic fraction [fr

  5. Single crystal NMR studies of high temperature superconductors

    International Nuclear Information System (INIS)

    Pennington, C.H.; Durand, D.J.; Zax, D.B.; Slichter, C.P.; Rice, J.P.; Bukowski, E.D.; Ginsberg, D.M.

    1989-01-01

    The authors report Cu NMR studies in the normal state of a single crystal of the T/sub c/ = 90 K superconductor YBa 2 Cu 3 O/sub 7/minus/δ/. The authors have measured the magnetic shift tensor, the electric field gradient tensor, the nuclear spin-lattice relaxation rate tensor, and the time dependence and functional form of the transverse decay. From these data they obtain information about the charge state and magnetic state of the Cu atoms, and the existence and size of the electronic exchange coupling between spins of adjacent Cu atoms. 18 refs., 3 figs., 2 tabs

  6. X-ray crystal spectroscopy of JET - a design study

    International Nuclear Information System (INIS)

    Bateman, J.E.; Hobby, M.G.; Peacock, N.J.

    1980-02-01

    This study describes the design and specification of a diagnostic system to measure the space- and time-resolved x-ray spectrum from JET discharges with high-resolution crystal spectrometers operating in the wavelength region 1 - 15A. The specification is given in terms of sensitivity, resolving power, detector, and data handling requirements, special attention being given to the problems encountered in interfacing the spectrometer arrays to the torus vacuum system and in their disposition to the machine. Shielding requirements during the active mode are evaluated and a staged diagnostic is proposed to accommodate D - T operation. (U.K.)

  7. TEM studies of the crystal growth of indanthrone pigments

    International Nuclear Information System (INIS)

    McHendry, P.

    1998-01-01

    The aim of this work was to study the crystal growth of indanthrone during the pigmentation process. The colouring properties of a pigment are dependant on the chemical and crystallographic structure of the pigment. However, other factors are known to affect these properties including particle size, particle size distribution and level of dispersion in the chosen application medium. The parameters which affect the growth of the pigment particles were investigated with the emphasis placed on the mechanism by which growth took place. The final form of the crystals after growth was also investigated in some detail. Various electron microscopy techniques were employed in the investigations in this thesis. High and low magnification imaging and diffraction were studied on the CTEM (conventional transmission electron microscope) whilst PEELS (parallel electron energy loss spectroscopy) and DPC (differential phase contrast) studies took place on the VG HB5 STEM (scanning transmission electron microscope). In addition to these studies, x-ray diffraction and surface area analysis techniques were employed. The low magnification CTEM work gave good information on the size, shape and size distribution of the pigment particles and enabled detailed analysis of the level of growth attained under varied reaction conditions. (author)

  8. Optical and dielectric studies of KH2PO4 crystal influenced by organic ligand of citric acid and l-valine: A single crystal growth and comparative study

    Directory of Open Access Journals (Sweden)

    Mohd Anis

    Full Text Available In the present study pure, citric acid (CA and l-valine (LV doped potassium dihydrogen phosphate (KDP crystals have been grown with the aim to investigate the nonlinear optical applications facilitated by UV–visible, third order nonlinear optical (TONLO and dielectric properties. The structural parameters of grown crystals have been confirmed by single crystal X-ray diffraction analysis. The enhancement in optical transparency of KDP crystal due to addition of CA and LV has been examined within 200–900 nm by means of UV–visible spectral analysis. In addition, the transmittance data have been used to evaluate the effect of dopants on reflectance, refractive index and extinction coefficient of grown crystals in the visible region. The Z-scan analysis has been performed at 632.8 nm to identify the nature of photoinduced nonlinear refraction and nonlinear absorption in doped KDP crystals. The influence of π-bonded ligand of dopant CA and LV on TONLO susceptibility (χ3, refractive index (n2 and absorption coefficient (β of KDP crystals has been evaluated to discuss laser assisted device applications. The decrease in dielectric constant and dielectric loss of KDP crystal due to addition of CA and LV has been explored using the temperature dependent dielectric studies. Keywords: Crystal growth, Nonlinear optical materials, UV–visible studies, Z-scan analysis, Dielectric studies

  9. FTIR spectra and mechanical strength analysis of some selected rubber derivatives

    Science.gov (United States)

    Gunasekaran, S.; Natarajan, R. K.; Kala, A.

    2007-10-01

    Rubber materials have wide range of commercial applications such as, infant diapers, famine hygiene products, drug delivery devices and incontinency products such as rubber tubes, tyres, etc. In the present work, studies on mechanical properties of some selected rubber materials viz., natural rubber (NR), styrene butadiene rubber (SBR), nitrile butadiene rubber (NBR) and ethylene propylene diene monomer (EPDM) have been carried out in three states viz., raw, vulcanized and reinforced. To enhance the quality of rubber elastomers, an attempt is made to prepare new elastomers called polyblends. In the present study an attempt is made to blend NR with NBR and with EPDM. We here report, a novel approach for the evaluation of various physico-mechanical properties such as mechanical strength, tensile strength, elongation and hardness. The method is simple, direct and fast and involves infrared spectral measurements for the evaluation of these properties. With the applications of modern infrared spectroscopy, the mechanical strength of these rubber materials have been analyzed by calculating the internal standards among the methyl and methylene group vibrational frequencies obtained from FTIR spectroscopy. Also the tensile strength measurements carried out by universal testing machine. The results pertaining physico-mechanical properties of the rubber derivatives undertaken in the present study obtained by IR-based method are in good agreement with data resulted from the standard methods.

  10. Radiation vulcanization of Philippine natural rubber latex

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  11. Studies on various properties of pure and Li-doped Barium Hydrogen Phosphate (BHP) single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Nallamuthu, D. [Department of Physics, Aditanar College of Arts and Science, Tiruchendur 628216, Tamil Nadu (India); Selvarajan, P., E-mail: pselvarajanphy@yahoo.co.i [Department of Physics, Aditanar College of Arts and Science, Tiruchendur 628216, Tamil Nadu (India); Freeda, T.H. [Physics Research Centre, S.T. Hindu College, Nagercoil 629002 (India)

    2010-12-15

    Single crystals of pure and Li-doped barium hydrogen phosphate (BHP) were grown by solution method with gel technique. Various properties of the harvested crystals were studied by carrying out single crystal and powder XRD, FTIR, TG/DTA, microhardness and dielectric studies. Atomic absorption study was carried out for Li-doped BHP crystal to check the presence of Li dopants. Unit cell dimensions and diffracting planes of the grown crystals have been identified from XRD studies. Functional groups of the title compounds have been identified from FTIR studies. Density of the grown crystals was calculated using the XRD data. Thermal stability of the samples was checked by TG/DTA studies. Mechanical and dielectric characterizations of the harvested pure and Li-doped BHP crystals reveal the mechanical strength and ferroelectric transition. The observed results are reported and discussed.

  12. Study of the possibility of growing germanium single crystals under low temperature gradients

    Science.gov (United States)

    Moskovskih, V. A.; Kasimkin, P. V.; Shlegel, V. N.; Vasiliev, Y. V.; Gridchin, V. A.; Podkopaev, O. I.; Zhdankov, V. N.

    2014-03-01

    The possibility of growing germanium single crystals under low temperature gradients in order to produce a dislocation-free material has been studied. Germanium crystals with a dislocation density of about 100-200 cm-2 have been grown in a system with a weight control of crystal growth at maximum axial gradients of about 1.5 K/cm.

  13. Radiation induced graft copolymerization of acrylonitrile on natural rubber

    International Nuclear Information System (INIS)

    Claramma, N.M.; Mathew, N.M.; Thomas, E.V.

    1989-01-01

    Acrylonitrile graft natural rubber was prepared by initiating the polymerization of acrylonitrile in natural rubber field latex using γ-rays. The reaction was carried out at different rubber-monomer concentrations and the properties of the modified rubbers were compared with those of natural rubber and nitrile rubber. (author)

  14. 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.

  15. Pushing the Limits: The Pattern and Dynamics of Rubber Monoculture Expansion in Xishuangbanna, SW China.

    Directory of Open Access Journals (Sweden)

    Huafang Chen

    Full Text Available The rapidly growing car industry in China has led to an equally rapid expansion of monoculture rubber in many regions of South East Asia. Xishuangbanna, the second largest rubber planting area in China, located in the Indo-Burma biodiversity hotspot, supplies about 37% of the domestic natural rubber production. There, high income possibilities from rubber drive a dramatic expansion of monoculture plantations which poses a threat to natural forests. For the first time we mapped rubber plantations in and outside protected areas and their net present value for the years 1988, 2002 (Landsat, 30 m resolution and 2010 (RapidEye, 5 m resolution. The purpose of our study was to better understand the pattern and dynamics of the expansion of rubber plantations in Xishuangbanna, as well as its economic prospects and conservation impacts. We found that 1 the area of rubber plantations was 4.5% of the total area of Xishuangbanna in 1988, 9.9% in 2002, and 22.2% in 2010; 2 rubber monoculture expanded to higher elevations and onto steeper slopes between 1988 and 2010; 3 the proportion of rubber plantations with medium economic potential dropped from 57% between 1988 and 2002 to 47% in 2010, while the proportion of plantations with lower economic potential had increased from 30% to 40%; and 4 nearly 10% of the total area of nature reserves within Xishuangbanna has been converted to rubber monoculture by 2010. On the basis of our findings, we conclude that the rapid expansion of rubber plantations into higher elevations, steeper terrain, and into nature reserves (where most of the remaining forests of Xishuangbanna are located poses a serious threat to biodiversity and environmental services while not producing the expected economic returns. Therefore, it is essential that local governments develop long-term land use strategies for balancing economic benefits with environmental sustainability, as well as for assisting farmers with the selection of land suitable

  16. Application of gamma irradiation for incorporation of rubber powder in the formulations of EPDM and natural rubber; Aplicacao da radiacao gama para incorporacao do po de borracha em formulacoes de borracha natural e EPDM

    Energy Technology Data Exchange (ETDEWEB)

    Kiyan, Ludmila Y.P.; Parra, Duclerc Fernandes; Lugao, Ademar Benevolo, E-mail: ludmilapozzo@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP/CQMA), Sao Paulo, SP (Brazil). Centro de Quimica e Meio Ambiente

    2013-07-01

    The objective of this work was to study the behavior of the recycling of rubber burrs in form of powder, of the rubber industry from EPDM rubber powder and natural rubber with SBR. The rubber powder was irradiated and reused in rubber artifacts formulations for classical vulcanization. The processed material was irradiated using a {sup 60}Co source in doses of 50, 100, 150 and 200 kGy and a dose rate of 5 kGy s-1 at room temperature. The radiation created devulcanization active sites for subsequent integration of the material (rubber powder) in formulations of commercial use. The processes were compared and their products characterized by analytical methods of the physical properties such as strength and elongation. Satisfactory results were found, noting a major spin-off of EPDM chain demonstrated by increased elongation.

  17. Influence of Rubber Powders on Foaming Behavior and Mechanical Properties of Foamed Polypropylene Composites

    Directory of Open Access Journals (Sweden)

    HE Yue

    2017-02-01

    Full Text Available Polypropylene/rubber powders composites with different kinds of rubber powders were foamed by injection molding machine equipped with volume-adjustable cavity. The effect of dispersity of rubber powders and crystallization behavior of composites on the foaming behavior and mechanical properties was investigated. The results show that the addition of rubber powders can improve the cell structure of foamed PP with fine and uniform cell distribution. And cell density and size of PP/PP-MAH/NBR foams are 7.64×106cell/cm3 and 29.78μm respectively, which are the best among these foams. Combining cell structures with mechanical properties, notch impact strength of PP/PP-MAH/CNBR composites increases approximately by 2.2 times while tensile strength is reduced just by 26% compared with those of the pure PP. This indicates that PP/PP-MAH/CNBR composites are ideal foamed materials.

  18. Natural rubber producing plants: An overview | Venkatachalam ...

    African Journals Online (AJOL)

    ... Hevea and also other natural rubber producing species for alternative source of latex production in the near future. Keywords: Alternative rubber sources, biotechnology, breeding, Hevea brasiliensis, Parthenium argentatum, Taraxacum koksaghyz, Ficus bengalensis, Lactuca serriola. African Journal of Biotechnology Vol.

  19. Advances in rubber/halloysite nanotubes nanocomposites.

    Science.gov (United States)

    Jia, Zhixin; Guo, Baochun; Jia, Demin

    2014-02-01

    The research advances in rubber/halloysite nanotubes (rubber/HNTs) nanocomposites are reviewed. HNTs are environmentally-friendly natural nanomaterials, which could be used to prepare the rubber-based nanocomposites with high performance and low cost. Unmodified HNTs could be adopted to prepare the rubber/HNTs composites with improved mechanical properties, however, the rubber/HNTs nanocomposites with fine morphology and excellent properties were chiefly prepared with various modifiers by in situ mixing method. A series of rubber/HNTs nanocomposites containing several rubbers (SBR, NR, xSBR, NBR, PU) and different modifiers (ENR, RH, Si69, SA, MAA, ILs) have been investigated. The results showed that all the rubber/HNTs nanocomposites achieved strong interfacial interaction via interfacial covalent bonds, hydrogen bonds or multiple interactions, realized significantly improved dispersion of HNTs at nanoscale and exhibited excellent mechanical performances and other properties.

  20. Rubber modification of asphalt binders and mixes

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, G.; Hesp, S.A.M. [Queen`s Univ., Kingston, ON (Canada). Dept. of Chemistry

    1995-12-31

    The physical properties of asphalt binders and concrete, modified with waste rubber tire, were examined. In an experiment designed to address the concern of waste disposal of scrap rubber, a control asphalt, devulcanized rubber modified asphalt and a crumb rubber modified asphalt were used to make asphalt concrete mixes. The three mixes were subjected to a thermal stress test to determine their low temperature fracture temperatures and strengths. Results were discussed in terms of the binder material used. At high service temperatures, the addition of 10% devulcanized rubber was found to have no beneficial effect, whereas the addition of 10% 80 mesh crumb rubber produced a modest improvement in performance. At low temperatures, the addition of devulcanized rubber produced increased resistance to cracking up to 90%. The addition of 10% 80 mesh crumb rubber increased fracture toughness by a factor of 3.3 times. 12 refs., 3 tabs.

  1. Butyl Rubber: Compound Development and Characterization

    National Research Council Canada - National Science Library

    Sloan, James

    2000-01-01

    ...), to develop the standard butyl rubber compound. The strategy of this work was to compound- and compression-mold high-quality, uniform butyl rubber experimental sheets and to evaluate their cure properties, mechanical properties...

  2. Electrospinning of PVC with natural rubber

    Science.gov (United States)

    Othman, Muhammad Hariz; Mohamed, Mahathir; Abdullah, Ibrahim

    2013-11-01

    Polyvinyl chloride (PVC) was mixed with natural rubbers which are liquid natural rubber (LNR), liquid epoxidised natural rubber (LENR) and liquid epoxidised natural rubber acrylate (LENRA) for a preparation of a fine non-woven fiber's mat. PVC and each natural rubbers(PVC:LENR, PVC:LNR and PVC:LENRA) were mixed based on ratio of 70:30. Electrospinning method was used to prepare the fiber. The results show that the spinnable concentration of PVC/ natural rubber/THF solution is 16 wt%. The morphology, diameter, structure and degradation temperature of electrospun fibers were investigated by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). SEM photos showed that the morphology and diameter of the fibers were mainly affected by the addition of natural rubber. TGA results suggested that PVC electrospun fiber has higher degradation temperature than those electrospun fibers that contain natural rubber.

  3. Electrospinning of PVC with natural rubber

    International Nuclear Information System (INIS)

    Othman, Muhammad Hariz; Abdullah, Ibrahim; Mohamed, Mahathir

    2013-01-01

    Polyvinyl chloride (PVC) was mixed with natural rubbers which are liquid natural rubber (LNR), liquid epoxidised natural rubber (LENR) and liquid epoxidised natural rubber acrylate (LENRA) for a preparation of a fine non-woven fiber’s mat. PVC and each natural rubbers(PVC:LENR, PVC:LNR and PVC:LENRA) were mixed based on ratio of 70:30. Electrospinning method was used to prepare the fiber. The results show that the spinnable concentration of PVC/ natural rubber/THF solution is 16 wt%. The morphology, diameter, structure and degradation temperature of electrospun fibers were investigated by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). SEM photos showed that the morphology and diameter of the fibers were mainly affected by the addition of natural rubber. TGA results suggested that PVC electrospun fiber has higher degradation temperature than those electrospun fibers that contain natural rubber

  4. Electrospinning of PVC with natural rubber

    Energy Technology Data Exchange (ETDEWEB)

    Othman, Muhammad Hariz; Abdullah, Ibrahim [Department of Chemistry, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Mohamed, Mahathir [Radiation Processing Technology Division (BTS), Malaysian Nuclear Agency, Bangi, 43000, Kajang (Malaysia)

    2013-11-27

    Polyvinyl chloride (PVC) was mixed with natural rubbers which are liquid natural rubber (LNR), liquid epoxidised natural rubber (LENR) and liquid epoxidised natural rubber acrylate (LENRA) for a preparation of a fine non-woven fiber’s mat. PVC and each natural rubbers(PVC:LENR, PVC:LNR and PVC:LENRA) were mixed based on ratio of 70:30. Electrospinning method was used to prepare the fiber. The results show that the spinnable concentration of PVC/ natural rubber/THF solution is 16 wt%. The morphology, diameter, structure and degradation temperature of electrospun fibers were investigated by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). SEM photos showed that the morphology and diameter of the fibers were mainly affected by the addition of natural rubber. TGA results suggested that PVC electrospun fiber has higher degradation temperature than those electrospun fibers that contain natural rubber.

  5. Growth and microtopographic study of CuInSe{sub 2} single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Chauhan, Sanjaysinh M.; Chaki, Sunil, E-mail: sunilchaki@yahoo.co.in; Deshpande, M. P. [Department of Physics, Sardar Patel University, Vallabh Vidyanagar, Gujarat - 388120 (India); Tailor, J. P. [Applied Physics Department, S.V.N.I.T., Surat, Gujarat - 395007 (India)

    2016-05-23

    The CuInSe{sub 2} single crystals were grown by chemical vapour transport (CVT) technique using iodine as transporting agent. The elemental composition of the as-grown CuInSe{sub 2} single crystals was determined by energy dispersive analysis of X-ray (EDAX). The unit cell crystal structure and lattice parameters were determined by X-ray diffraction (XRD) technique. The surface microtopographic study of the as-grown CuInSe{sub 2} single crystals surfaces were done to study the defects, growth mechanism, etc. of the CVT grown crystals.

  6. Improving the forming capability of laser dynamic forming by using rubber as a forming medium

    Science.gov (United States)

    Shen, Zongbao; Liu, Huixia; Wang, Xiao; Wang, Cuntang

    2016-04-01

    Laser dynamic forming (LDF) is a novel high velocity forming technique, which employs laser-generated shock wave to load the sample. The forming velocity induced by the high energy laser pulse may exceed the critical forming velocity, resulting in the occurrence of premature fracture. To avoid the above premature fracture, rubber is introduced in LDF as a forming medium to prolong the loading duration in this paper. Laser induced shock wave energy is transferred to the sample in different forming stages, so the forming velocity can be kept below the critical forming velocity when the initial laser energy is high for fracture. Bulge forming experiments with and without rubber were performed to study the effect of rubber on loading duration. The experimental results show that, the shock wave energy attenuates during the propagation through the rubber layer, the rubber can avoid the premature fracture. So the plastic deformation can continue, the forming capability of LDF is improved. Due to the severe plastic deformation under rubber compression, adiabatic shear bands (ASB) occur in LDF with rubber. The material softening in ASB leads to the irregular fracture, which is different from the premature fracture pattern (regular fracture) in LDF without rubber. To better understand this deformation behavior, Johnson-Cook model is used to simulate the dynamic response and the evolution of ASB of copper sample. The simulation results also indicate the rubber can prolong the loading duration.

  7. Study of montmorillonite nanoparticles and electron beam irradiation interaction of ethylene vinyl acetate (EVA)/de-vulcanized waste rubber thermoplastic composites

    Science.gov (United States)

    Bee, Soo-Tueen; Sin, Lee Tin; Hoe, Tie Teck; Ratnam, C. T.; Bee, Soo Ling; Rahmat, A. R.

    2018-05-01

    The purpose of this work was to investigate the effects of montmorillonite (MMT) loading level and electron beam irradiation on the physical-mechanical properties and thermal stability of ethylene vinyl acetate (EVA)- devulcanised waste rubber blends. The addition of MMT particles has significantly increased the d-spacing and interchain separation of deflection peak (0 0 2) of MMT particles. This indicates that MMT particles have effectively intercalated in polymer matrix of EVA-devulcanised waste rubber blends. Besides, the application of electron beam irradiation dosages <150 kGy could also significantly induce the effective intercalation effect of MMT particles in polymer matrix by introducing crosslinking networks. The increasing of electron beam irradiation dosages up to 250 kGy has gradually increased the gel content of all EVA-devulcanized rubber blends by inducing the formation of crosslinking networks in polymer matrix. Also, the tensile strength of all EVA-devulcanized waste rubber blends was gradually increased when irradiated up to 150 kGy. This is due to the occurrence of crosslinking networks by irradiation could significantly provide reinforcement effect to polymer matrix by effectively transferring the stress applied on polymer matrix throughout the whole polymer matrix.

  8. STUDI PENENTUAN JENIS OUTLET LIMBAH CAIR KARET REMAH UNTUK PERTUMBUHAN MIKROALGA DENGAN SISTEM OPEN PONDS [Study of determination the type of crumb rubber waste water outlet for the growth of microalgae with open ponds system

    OpenAIRE

    Tanto Pratondo Utomo; Otik Nawansih; Anggun KOmalasari

    2015-01-01

    Waste water of crumb rubber industry is originated from coagulation, milling and leaching stage contains organic material that is derived from serum and rubber particles which haven’t been coagulated yet. The materials are potential to pollute the water therefore the crumb rubber industry must be treated through the wastewater plant. However, the characteristics of waste water are predicted suitable for the cultivation of Nannochloropsis sp. media a biofuel feedstock, especially biodiesel tha...

  9. Devulcanization of Waste Tire Rubber Using Amine Based Solvents and Ultrasonic Energy

    Directory of Open Access Journals (Sweden)

    Walvekar Rashmi

    2018-01-01

    Full Text Available This research project focuses on an alternative pathway of devulcanizing waste tire rubber by using amine based chemicals. Waste tire rubbers are known to be as toxic, non-degradable material due to their vulcanized crosslink carbon structure, and disposing of such waste could impose hazardous impacts on the environment. The current rubber recycling methods that are practiced today are rather uneconomical, non-environmentally friendly, and also producing recycled rubber with low quality due to the alteration in the main polymeric chains of waste rubber. This project aims to answer the question of whether the usage of amine can produce high quality rubber, where the properties of recycled rubber is almost the same as new/virgin rubber. With known potential of amine, it is a challenge for the chemical to selectively cleave the sulfur bonds without affecting the main carbon backbone chain in the rubber structure and diminishing much of the rubber properties. To study this research, amine-treated rubber must undergo devulcanisation process by applying heat and sonication energy. Then, the properties of the amine-treated rubber were determined through a set of characterization tests and analysis which are: gel content test to determine the weight of rubber before and after devulcanization, the thermogravimetric analysis (TGA to determine the thermal degradation and stability of rubber, and Fourier Transform Infrared Spectroscopy (FTIR to determine any structural change of the rubber. In this research so far, the first two preliminary analysis tests have been performed. The gel content test has shown that tertiary amine samples possessed a lower gel content (% of (77 – 63 %, compared to primary amine samples (falls within the range of 80%, as well as the TGA test in which tertiary amine samples degrade faster than primary amine samples (suggesting a higher degree of rubber structure breakdown. For each type of amine, the concertation of amine did

  10. Study of memory effects in polymer dispersed liquid crystal films

    International Nuclear Information System (INIS)

    Han, Jinwoo

    2006-01-01

    In this work, we have studied the memory effects in polymer dispersed liquid crystal films. We found that optical responses, such as the memory effects, of the films depended strongly on the morphology. For example, memory effects were observed for films with polymer ball morphologies; however, only weak hysteresis effects were observed for films with droplet morphologies. In particular, a stronger memory effect was observed for films with more complicated polymer ball structures. Coincidentally, T TE , the temperature at which the memory state is thermally erased, was generally higher for the films exhibiting a stronger memory effect. In addition, studies of the temporal evolution of the films show that the memory effects become stronger after films have been kept on the shelf for a period of time. This change is likely to be associated with a modification of surface anchoring properties at the LC-polymer interface.

  11. Morphological studies of polymer dispersed liquid crystal materials

    International Nuclear Information System (INIS)

    Han, Jin-Woo

    2006-01-01

    In this work, we have studied the morphologies of polymer dispersed liquid crystals (PDLCs) based on E7/NOA61. Scanning electron microscope studies show that the PDLC morphology is strongly affected by the LC concentration and the cure temperature. A typical PDLC morphology with isolated LC droplets dispersed in a polymer matrix is only observed at low LC compositions and at low cure temperatures. Increasing either the LC composition or the cure temperature results in a polymer ball morphology, in which LCs exist in irregularly shaped voids in the polymer network structure. It is shown that the transition between these two morphologies can be qualitatively explained using a pseudo-binary phase diagram.

  12. Rubber friction and tire dynamics

    International Nuclear Information System (INIS)

    Persson, B N J

    2011-01-01

    We propose a simple rubber friction law, which can be used, for example, in models of tire (and vehicle) dynamics. The friction law is tested by comparing numerical results to the full rubber friction theory (Persson 2006 J. Phys.: Condens. Matter 18 7789). Good agreement is found between the two theories. We describe a two-dimensional (2D) tire model which combines the rubber friction model with a simple mass-spring description of the tire body. The tire model is very flexible and can be used to accurately calculate μ-slip curves (and the self-aligning torque) for braking and cornering or combined motion (e.g. braking during cornering). We present numerical results which illustrate the theory. Simulations of anti-blocking system (ABS) braking are performed using two simple control algorithms.

  13. Rubber friction and tire dynamics.

    Science.gov (United States)

    Persson, B N J

    2011-01-12

    We propose a simple rubber friction law, which can be used, for example, in models of tire (and vehicle) dynamics. The friction law is tested by comparing numerical results to the full rubber friction theory (Persson 2006 J. Phys.: Condens. Matter 18 7789). Good agreement is found between the two theories. We describe a two-dimensional (2D) tire model which combines the rubber friction model with a simple mass-spring description of the tire body. The tire model is very flexible and can be used to accurately calculate μ-slip curves (and the self-aligning torque) for braking and cornering or combined motion (e.g. braking during cornering). We present numerical results which illustrate the theory. Simulations of anti-blocking system (ABS) braking are performed using two simple control algorithms.

  14. 75 FR 38119 - Polychloroprene Rubber From Japan

    Science.gov (United States)

    2010-07-01

    ... Rubber From Japan AGENCY: United States International Trade Commission. ACTION: Institution of a five-year review concerning the antidumping duty finding on polychloroprene rubber from Japan. SUMMARY: The... on polychloroprene rubber from Japan would be likely to lead to continuation or recurrence of...

  15. Radiation vulcanization of Philippine natural rubber latex

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  16. Relação entre diferentes caracteres de plantas jovens de seringueira Correlations and regressions studies among juvenile rubber tree characters

    Directory of Open Access Journals (Sweden)

    César Lavorenti

    1990-01-01

    Full Text Available O presente trabalho foi realizado com o objetivo de determinar a existência e as magnitudes de correlações e regressões lineares simples em plântulas jovens de seringueira (Hevea spp., para melhor condução de seleção nos futuros trabalhos de melhoramento. Foram utilizadas médias de produção de borracha seca por plântulas por corte, através do teste Hamaker-Morris-Mann (P; circunferência do caule (CC; espessura de casca (EC; número de anéis (NA; diâmetro dos vasos (DV; densidade dos vasos laticíleros (D e distância média entre anéis de vasos consecutivos (DMEAVC em um viveiro de cruzamento com três anos e meio de idade. Os resultados mostraram, entre outros fatores, que as correlações lineares simples de P com CC, EC, NA, D, DV e DMEAVC foram, respectivamente, r =t 0,61, 0,34, 0,28, 0,29, 0,43 e -0,13. As correlações de CC com EC, NA, D, DV e DMEAVC foram: 0,65, 0,22, 0,37, 0,33 e 0,096 respectivamente. Estudos de regressão linear simples de P com CC, EC, NA, DV, D e DMEAVC sugerem que CC foi o caráter independente mais significativo, contribuindo com 36% da variação em P. Em relação ao vigor, a regressão de CC com os respectivos caracteres sugere que EC foi o único caráter que contribuiu significativamente para a variação de CC com 42%. As altas correlações observadas da produção com circunferência do caule e com espessura de casca evidenciam a possibilidade de obter genótipos jovens de boa capacidade produtiva e grande vigor, através de seleção precoce dessas variáveis.This study was undertaken aiming to determine the existence of linear correlations, based on simple regression studies for a better improvement of young rubber tree (Hevea spp. breeding and selection. The characters studied were: yield of dry rubber per tapping by Hamaker-Morris-Mann test tapping (P, mean gurth (CC, bark thickness (EC, number of latex vessel rings (NA, diameter of latex vesseis (DV, density of latex vesseis per 5mm

  17. Costs and return analysis in rubber latex production in Edo State ...

    African Journals Online (AJOL)

    The study examined the costs and return analysis in rubber latex production in Edo Sate, Nigeria. Multi-stage sampling method was adopted to select 96 smallholder rubber framers for the study. The first stage was a purposive sampling of two LGAs and then simple random sampling of 6 villages each from the two LGA.

  18. Crystallization of ornithine acetyltransferase from yeast by counter-diffusion and preliminary X-ray study

    Energy Technology Data Exchange (ETDEWEB)

    Maes, Dominique, E-mail: dominique.maes@vub.ac.be; Crabeel, Marjolaine [Laboratorium voor Ultrastructuur, Vrije Universiteit Brussel (VUB) and Vlaams Interuniversitair Instituut voor Biotechnologie (VIB), Pleinlaan 2, B-1050 Brussels (Belgium); Van de Weerdt, Cécile; Martial, Joseph [Laboratoire de Biologie Moléculaire et de Génie Génétique, Université de Liège, Allée de la Chimie 3, B-4000 Liège (Belgium); Peeters, Eveline; Charlier, Daniël [Erfelijkheidsleer en Microbiologie, Vrije Universiteit Brussel (VUB), Pleinlaan 2, B-1050 Brussels (Belgium); Decanniere, Klaas; Vanhee, Celine; Wyns, Lode; Zegers, Ingrid [Laboratorium voor Ultrastructuur, Vrije Universiteit Brussel (VUB) and Vlaams Interuniversitair Instituut voor Biotechnologie (VIB), Pleinlaan 2, B-1050 Brussels (Belgium)

    2006-12-01

    A study on the crystallization of ornithine acetyltransferase from yeast, catalysing the fifth step in microbial arginine synthesis, is presented. The use of the counter-diffusion technique removes the disorder present in one dimension in crystals grown by either batch or hanging-drop techniques. A study is presented on the crystallization of ornithine acetyltransferase from yeast, which catalyzes the fifth step in microbial arginine synthesis. The use of the counter-diffusion technique removes the disorder present in one dimension in crystals grown by either the batch or hanging-drop techniques. This makes the difference between useless crystals and crystals that allow successful determination of the structure of the protein. The crystals belong to space group P4, with unit-cell parameters a = b = 66.98, c = 427.09 Å, and a data set was collected to 2.76 Å.

  19. Synchrotron white beam topographic studies of gallium arsenide crystals

    International Nuclear Information System (INIS)

    Wierzchowski, W.; Wieteska, K.; Graeff, W.

    1997-01-01

    A series of samples cut out from different types of gallium arsenide crystals with low dislocation density were studied by means of white beam synchrotron topography. The investigation was performed with transmission and black-reflection projection methods and transmission section method. Some of topographs in transmission geometry provided a very high sensitivity suitable for revealing small precipitates. The transmission section images significantly differed depending on the wavelength and absorption. In some cases a distinct Pendelloesung fringes and fine details of dislocation and precipitates images were observed. It was possible to reproduce the character of these images by means of numerical simulation based on integration of Takagi-Taupin equations. Due to more convenient choice of radiation, synchrotron back-reflection projection topography provided much better visibility of dislocations than analogous realized with conventional X-ray sources. (author)

  20. Comprehensive studies on irradiated single-crystal diamond sensors

    Energy Technology Data Exchange (ETDEWEB)

    Stegler, Martin [DESY, Zeuthen (Germany)

    2015-07-01

    Single-crystal diamond sensors are used as part of the Beam and Radiation Instrumentation and Luminosity (BRIL) projects of the CMS experiment. Due to an upgrade of the Fast Beam Conditions Monitor (BCM1F) these diamond sensors are exchanged and the irradiated ones are now used for comprehensive studies. Current over voltage (IV), current over time (CT) and charge collection efficiency (CCE) measurements were performed for a better understanding of the radiation damage incurred during operation and to compensate in the future. The effect of illumination with various light sources on the charge collection efficiency was investigated and led to interesting results. Intensity and wavelength of the light were varied for deeper insight of polarization effects.

  1. Photoinduced surface voltage mapping study for large perovskite single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaojing; Liu, Yucheng; Gao, Fei; Yang, Zhou [Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education, Shaanxi Engineering Laboratory for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi' an 710062 (China); Liu, Shengzhong, E-mail: liusz@snnu.edu.cn [Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education, Shaanxi Engineering Laboratory for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi' an 710062 (China); Dalian Institute of Chemical Physics, iChEM, Dalian National Laboratory for Clean Energy, Chinese Academy of Sciences, Dalian 116023 (China)

    2016-05-02

    Using a series of illumination sources, including white light (tungsten-halogen lamp), 445-nm, 532-nm, 635-nm, and 730-nm lasers, the surface photovoltage (SPV) images were mapped for centimeter-sized CH{sub 3}NH{sub 3}PbX{sub 3} (X = Cl, Br, I) perovskite single crystals using Kelvin probe force microscopy. The significant SPV signals were observed to be wavelength-dependent. We attribute the appreciable SPV to the built-in electric field in the space charge region. This study shines light into the understanding of photoinduced charge generation and separation processes at nanoscale to help advance the development of perovskite solar cells, optoelectronics, laser, photodetector, and light-emitting diode (LED).

  2. Endurance test report of rubber sealing materials for the containment vessel

    International Nuclear Information System (INIS)

    Yamamoto, R.; Watanabe, K.; Hanashima, K.

    2015-01-01

    In the event of a nuclear power plant accident such as a core meltdown and a cooling system failure, the containment contains radioactive materials released from the reactor pressure vessel to reduce the activity of the radioactive materials and the effects of radiation in the vicinity of the plant. Since high sealing performance and high pressure resistance are required of the containment, a silicone or EPDM rubber gasket with high heat and radiation resistance is used for the sealing of the sealing boundary of the containment. In recent years, it has been shown that a large amount of steam is released into the containment in the case of a severe accident. Consequently, radiation resistance at high temperature as well as steam resistance is required of the rubber gasket placed at the sealing boundary. However, the steam resistance of silicone rubber is not necessarily as good as that of EPDM rubber. Therefore, it is necessary to evaluate the sealing characteristics of rubber gaskets in such a degrading environment in a severe accident. O. Kato et al. [1] conducted a study on the degradation status of rubber gaskets and their application limits at high temperature. However, few studies have evaluated rubber gaskets in high-temperature radiation and steam environments. In this study, we degraded silicone rubber and EPDM rubber used for the containment in the high-temperature radiation and steam environments expected to occur in a severe accident and evaluated the useful life of the rubber as a sealing material by estimating the change in its performance as a sealing material from the change in permanent compressive strain in the rubber. (author)

  3. A study on properties of PbWO4 crystal

    International Nuclear Information System (INIS)

    He Jingtang; Mao Yufang; Dong Xiaoli

    1997-01-01

    The experimental results on properties of the PbWO 4 crystal are reported, including the excitation and fluorescence spectra, absolute and relative light yield and decay times. It seems that the PbWO 4 crystal can be used in high energy physics experiments for detecting high energy shower particles

  4. EB-promoted recycling of waste tire rubber with polyolefins

    International Nuclear Information System (INIS)

    Mészáros, László; Bárány, Tamás; Czvikovszky, Tibor

    2012-01-01

    Despite the fact that more and more methods and solutions are used in the recycling of polymers, there are still some problems, especially in the recycling of cross-linked materials such as rubber. Usually the biggest problem is the lack of compatibility between the cross-linked rubber and the thermoplastic matrix. In this study we applied ground tire rubber (GTR) as recycled material. The GTR was embedded into polyethylene (PE) and polyethylene/ethylene-vinyl acetate copolymer (PE/EVA) matrices. In order to increase the compatibility of the components electron beam (EB) irradiation was applied. The results showed that the irradiation has a beneficial effect on the polymer–GTR interfacial connection. The EB treatment increased not only the tensile strength but also the elongation at break. The irradiation had also positive effect on the impact strength properties. - Highlights: ► In this study ground tire rubber was incorporated into polyethylene (LDPE) matrix. ► Compatibilizing effects of irradiation and ethylene-vinyl acetate were investigated. ► The samples were manufactured by twin-screw extrusion and injection molding. ► Both compatibilizing methods improved the rubber-like properties of the blends. ► This improvement was especially significant when they were applied together.

  5. Factors affecting Thai rubber farmer production and marketing in the western province of Kanchanaburi

    Directory of Open Access Journals (Sweden)

    Narisa Thongtrai

    2016-04-01

    Full Text Available This research aimed to study the factors affecting the production and marketing of rubber farmers in the western Thai province of Kanchanaburi. The sample group included 30 farmers involved in rubber production. From the questionnaire and statistical analysis by SPSS, 15 observed variables were determined to be factors affecting the production and marketing of rubber farmers. The conclusion from the researchers determined that 1 The area planted is not appropriate and is still expanding plantations without any control was found that the rubber plantations are expanding at high plains area flooding. 2 Farmers of rubber technology farmers are not valid and do not conform to the instructions of the Rubber Research Institute study found that the cause is the opportunity to access technology and lack of knowledge regarding the management, production, and marketing. 3 Use rubber tree tapping of the system to high frequency screaming systems correctly. Does not comply with the instructions of the Rubber Research Institute found that of rubber farmers and farmers opening tapped the tire rubber accelerator before opening a huge size tapped that affect productivity and the income of farmers depressed farmers. 4 Problems with the labor of producing rubber of the household. It was found that labor households in the production system are lower 5 Farmers of Thailand are not yet aware of the concept of livelihood along the sufficiency economy as should farmers be life according to the way of life that is not adjusted to prepare 6 Group integration it was found that is not yet strong.

  6. Monitoring rubber plantation expansion using Landsat data time series and a Shapelet-based approach

    Science.gov (United States)

    Ye, Su; Rogan, John; Sangermano, Florencia

    2018-02-01

    The expansion of tree plantations in tropical forests for commercial rubber cultivation threatens biodiversity which may affect ecosystem services, and hinders ecosystem productivity, causing net carbon emission. Numerous studies refer to the challenge of reliably distinguishing rubber plantations from natural forest, using satellite data, due to their similar spectral signatures, even when phenology is incorporated into an analysis. This study presents a novel approach for monitoring the establishment and expansion of rubber plantations in Seima Protection Forest (SPF), Cambodia (1995-2015), by detecting and analyzing the 'shapelet' structure in a Landsat-NDVI time series. This paper introduces a new classification procedure consisting of two steps: (1) an exhaustive-searching algorithm to detect shapelets that represent a period for relatively low NDVI values within an image time series; and (2) a t-test used to determine if NDVI values of detected shapelets are significantly different than their non-shapelet trend, thereby indicating the presence of rubber plantations. Using this approach, historical rubber plantation events were mapped over the twenty-year timespan. The shapelet algorithm produced two types of information: (1) year of rubber plantation establishment; and (2) pre-conversion land-cover type (i.e., agriculture, or natural forest). The overall accuracy of the rubber plantation map for the year of 2015 was 89%. The multi-temporal map products reveal that more than half of the rubber planting activity (57%) took place in 2010 and 2011, following the granting of numerous rubber concessions two years prior. Seventy-three percent of the rubber plantations were converted from natural forest and twenty-three percent were established on non-forest land-cover. The shapelet approach developed here can be used reliably to improve our understanding of the expansion of rubber production beyond Seima Protection Forest of Cambodia, and likely elsewhere in the

  7. single crystals

    Indian Academy of Sciences (India)

    2018-05-18

    May 18, 2018 ... Abstract. 4-Nitrobenzoic acid (4-NBA) single crystals were studied for their linear and nonlinear optical ... studies on the proper growth, linear and nonlinear optical ..... between the optic axes and optic sign of the biaxial crystal.

  8. Crystal growth, morphology, thermal and spectral studies of an organosulfur nonlinear optical bis(guanidinium) 5-sulfosalicylate (BG5SS) single crystals

    Science.gov (United States)

    Dhavamurthy, M.; Peramaiyan, G.; Babu, K. Syed Suresh; Mohan, R.

    2015-04-01

    Organosulfur nonlinear optical single crystals of orthorhombic bis(guanidinium) 5-sulfosalicylate (2CH6N3 +·C7H4O6S2-·H2O) with dimension 14 mm × 4 mm × 5 mm have been grown from methanol and water solvents in 1:1 ratio by the slow evaporation growth technique. The crystal structure and morphology of the crystals have been studied by single-crystal X-ray diffraction. FTIR spectroscopic studies were carried out to identify the functional groups and vibrational modes present in the grown crystals. The UV-Vis spectrum was studied to analyze the linear optical properties of the grown crystals. The thermal gravimetric analysis was conducted on the grown crystals, and the result revealed that the grown crystal is thermally stable up to 65 °C. The dielectric tensor components ɛ 11, ɛ 22 and ɛ 33 of BG5SS crystal were evaluated as a function of frequency at 40 °C. The surface laser damage threshold for the grown crystal was measured using Nd:YAG laser. Further, Vickers micro-hardness study was carried out to analyze the mechanical strength of the grown crystals for various loads.

  9. Evaluation of rubber composites as shielding materials against ionizing radiation

    International Nuclear Information System (INIS)

    Atia, M.K.

    2010-01-01

    Styrene-butadiene rubber/lead oxide composites were prepared as γ-radiation shields.The composites were prepared with different concentration of red lead oxide (Pb 3 O 4 ) .The assessment of the linear attenuation coefficient of the SBR/lead oxide composites for γ -rays from 137 Cs 137 γ-radiation point source was studied . The factors affecting the mechanical properties and shielding capacity of the composites were also studied. These factors include the lead oxide concentration, the type of monomers added and the irradiation dose. The styrene-butadiene rubber/lead oxide composites can attain up to about 43% of the shielding capacity of pure lead. The incorporation of high concentrations of lead oxide and the effect of accumulative irradiation doses up to 3000 kGy on the physico-mechanical properties of the composites were studied . These led to hardening of the SBR rubber/lead oxide composites.

  10. Magnetron reactively sputtered Ti-DLC coatings on HNBR rubber : The influence of substrate bias

    NARCIS (Netherlands)

    Bui, X.L.; Pei, Y.T.; Hosson, J.Th.M. De

    2008-01-01

    In this study, Ti-containing diamond-like carbon (Ti-DLC) coatings have been deposited on HNBR (hydrogenated nitrile butadiene) rubber and also on Si wafer as reference via unbalanced magnetroli reactive sputtering from a Ti target in C2H2/Ar plasma. The deposition rates of coatings on rubber and Si

  11. Damage and fatigue in cross-linked rubbers

    Science.gov (United States)

    Melnikov, Alexei

    Damage and fatigue of elastomers have not been fundamentally understood because of the complex nature of these materials. All currently existing models are completely phenomenological. Therefore two problems have been investigated in this research to address those fundamental issues. The first problem was creating an innovative concept with a mathematical modeling, which would be able to describe the damage using molecular characteristics of elastomers. The second problem is developing new approaches to study fatigue, and especially impact fatigue of elastomers. The following results have been obtained in this research. A theoretical model of damage has been developed which involves the basic molecular characteristics of cross-linked elastomers and takes into account the effects of viscoelasticity and stress-induced crystallization. This model was found very reliable and successful in description of numerous quasi-static simple extension experiments for monotonous and repeating loadings. It also roughly predicts in molecular terms the failure of elastomers with various degrees of cross-linking. Quasi-impact fatigue tests with different geometry of an indenter have also been performed. Some microscopic features of rubber damage have been investigated using optical microscopy and SEM. In particular, the accumulation of a completely de-vulcanized, liquid-like substance was observed under intense, multi-cycle impacts. All the findings discovered in quasi-impact experiments are consistent with the damage model predictions.

  12. Soft matter: rubber and networks

    Science.gov (United States)

    McKenna, Gregory B.

    2018-06-01

    Rubber networks are important and form the basis for materials with properties ranging from rubber tires to super absorbents and contact lenses. The development of the entropy ideas of rubber deformation thermodynamics provides a powerful framework from which to understand and to use these materials. In addition, swelling of the rubber in the presence of small molecule liquids or solvents leads to materials that are very soft and ‘gel’ like in nature. The review covers the thermodynamics of polymer networks and gels from the perspective of the thermodynamics and mechanics of the strain energy density function. Important relationships are presented and experimental results show that the continuum ideas contained in the phenomenological thermodynamics are valid, but that the molecular bases for some of them remain to be fully elucidated. This is particularly so in the case of the entropic gels or swollen networks. The review is concluded with some perspectives on other networks, ranging from entropic polymer networks such as thermoplastic elastomers to physical gels in which cross-link points are formed by glassy or crystalline domains. A discussion is provided for other physical gels in which the network forms a spinodal-like decomposition, both in thermoplastic polymers that form a glassy network upon phase separation and for colloidal gels that seem to have a similar behavior.

  13. Cryogenic Deflashing for Rubber Products

    Directory of Open Access Journals (Sweden)

    Abhilash M.

    2018-01-01

    Full Text Available Deflashing is the process of removal of excess flashes from the rubber products. Initially deflashing was a manual operation where dozen of workers, seated at small work stations would take each part and trim the excess rubber off with scissors, knives or by grinding. Still the same method is employed in most of the rubber industry. The drawbacks of this method are demand inconsistent and repeatable quality. Work done by hand is often inconsistent. There are commercially available cryogenic deflashing machine but they are too expensive hence cost effectiveness is also a prime factor. The objective of this paper is to develop a technique, to identify the media through which the flashes can be removed easily and effectively. Based on the test results obtained from testing of five different types of media, ABCUT Steel media gave best results. The testing of the ABCUT Steel media on rubber samples like O-rings, grommet tail door, bottom bush etc. shows good results.

  14. Crystal growth, characterization and theoretical studies of 4-aminopyridinium picrate

    Science.gov (United States)

    Aditya Prasad, A.; Muthu, K.; Rajasekar, M.; Meenatchi, V.; Meenakshisundaram, S. P.

    2015-01-01

    Single crystals of 4-aminopyridinium picrate (APP) were grown by slow evaporation of a mixed solvent system methanol-acetone (1:1, v/v) containing equimolar quantities of 4-aminopyridine and picric acid. Structure is elucidated by single crystal XRD analysis and the crystal belongs to monoclinic system with four molecules in the unit cell (space group P21/c) and the cell parameter values are, a = 8.513 Å (±0.015), b = 11.33 Å (±0.02), c = 14.33 Å (±0.03) and β = 104.15° (±0.019), V = 1340 A3 (±6) with refined R factors R1 = 0.0053 and wR2 = 0.0126. The electron density mapping is interpreted to find coordinates for each atom in the crystallized molecules. The various functional groups present in the molecule are confirmed by FT-IR analysis. UV-visible spectral analysis was used to determine the band gap energy of 4-aminopyridinium picrate. Powder X-ray diffraction pattern reveals the crystallinity of the as-grown crystal and it closely resembles the simulated XRD from the single crystal XRD analysis. Scanning electron microscopy reveals the surface morphology of the grown crystal. Optimized geometry is derived by Hartree-Fock theory calculations and the first-order molecular hyperpolarizability (β), theoretically calculated bond length, bond angles and excited state energy from theoretical UV-vis spectrum were estimated.

  15. EVALUATION OF TIRE RUBBER DISPOSAL IN CONCRETE FOR PAVEMENTS

    Directory of Open Access Journals (Sweden)

    Rosa Cristina Cecche Lintz

    2009-12-01

    Full Text Available The production of waste by the tire industry has been a growing problem, indicating the need for its reuse. More than thirty million tires are discharged per year in Brazil, where regulation for the environment states that for each four new tires, five unusable ones must be adequately disposed by manufacturers and importers. Paving consumes an extremely large quantity of materials, which can be the source of rational application of waste and rejected materials. Research shows that tire rubber can be added to asphalt, which increases its durability and improves pavement quality and safety conditions by absorbing the rubber elastic properties, and also be used for architectural applications, among others. This study deals with the addition of rubber fibers from tire crushing in concrete for roadway pavements in order to provide proper indication about the alternative material disposal through an evaluation of the mechanical behavior of the modified concrete. Different concrete mixes were produced, within which, part of fine aggregates were substituted by tire rubber and mechanical experiment tests were performed, which show that, due to great resistance losses, the disposal of this alternative material in concrete should be considered for light traffic pavements, with the addition of rubber ranging up to 10% in mass.

  16. Behaviour of Steel Fibre Reinforced Rubberized Continuous Deep Beams

    Science.gov (United States)

    Sandeep, MS; Nagarajan, Praveen; Shashikala, A. P.

    2018-03-01

    Transfer girders and pier caps, which are in fact deep beams, are critical structural elements present in high-rise buildings and bridges respectively. During an earthquake, failure of lifeline structures like bridges and critical structural members like transfer girders will result in severe catastrophes. Ductility is the key factor that influences the resistance of any structural member against seismic action. Structural members cast using materials having higher ductility will possess higher seismic resistance. Previous research shows that concrete having rubber particles (rubcrete) possess better ductility and low density in comparison to ordinary concrete. The main hindrance to the use of rubcrete is the reduction in compressive and tensile strength of concrete due to the presence of rubber. If these undesirable properties of rubcrete can be controlled, a new cementitious composite with better ductility, seismic performance and economy can be developed. A combination of rubber particles and steel fibre has the potential to reduce the undesirable effect of rubcrete. In this paper, the effect of rubber particles and steel fibre in the behaviour of two-span continuous deep beams is studied experimentally. Based on the results, optimum proportions of steel fibre and rubber particles for getting good ductile behaviour with less reduction in collapse load is found out.

  17. Evaluation of rubber seal products for gamma facilities

    International Nuclear Information System (INIS)

    Sobhy, M.S.; Shafy, M.A.; Shahin, F.

    2005-01-01

    Ageing behavior by employing the prolonged exposures of high-energy radiation such as gamma-rays on the physicomechanical properties of some rubber seal products are studied. The proposed binary-rubber blends, SBR/NBR, EPDM/NBR and EPDM/EPM. have overcome their problem of inhomogeneity and incompatibility between the two rubber phases. Such enhancements are acquired by either the replacement of part of NBR by SBR during mastication, or the incorporation of maleic anhydride. Results show that the EPDM/EPM rubber blend has possessed the radiation resistance property towards the deterioration due to higher gamma-irradiation dose. The SEM images have c early observed the role of the used antioxidant, where a thin film is usually produced, degraded; with the appearance of surface cracks, and repaired with further gamma-irradiation up to high doses. Such enhancement is necessary for the definition of the requirements to be put on rubber seal materials. Finally, these products ought to assure the quality control in production and evaluate their application suitability that may employ in the pneumatic system in gamma facility

  18. Surface improvement of EPDM rubber by plasma treatment

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, J H [LPP, Physics Department, ITA, CTA, Pca Mal Eduardo Gomes 50, 12228-900 Sao Jose dos Campos, S.P. (Brazil); Silva Sobrinho, A S da [LPP, Physics Department, ITA, CTA, Pca Mal Eduardo Gomes 50, 12228-900 Sao Jose dos Campos, S.P. (Brazil); Maciel, H S [LPP, Physics Department, ITA, CTA, Pca Mal Eduardo Gomes 50, 12228-900 Sao Jose dos Campos, S.P. (Brazil); Dutra, J C N [EBO, Chemistry Division, IAE, CTA, Pca Mal Eduardo Gomes 50, 12228-904 Sao Jose dos Campos, S.P. (Brazil); Massi, M [LPP, Physics Department, ITA, CTA, Pca Mal Eduardo Gomes 50, 12228-900 Sao Jose dos Campos, S.P. (Brazil); Mello, S A C [EBO, Chemistry Division, IAE, CTA, Pca Mal Eduardo Gomes 50, 12228-904 Sao Jose dos Campos, S.P. (Brazil); Schreiner, W H [Physics Department, UFPR, Centro Politecnico, 80060-000 Curitiba, P.R. (Brazil)

    2007-12-21

    The surface of ethylene-propylene-diene monomer (EPDM) rubber was treated in N{sub 2}/Ar and N{sub 2}/H{sub 2}/Ar RF plasmas in order to achieve similar or better adhesion properties than NBR (acrylonitrile-butadiene) rubber, nowadays used as thermal protection of rocket chambers. The surface properties were studied by contact angle measurements and by x-ray photoelectron spectroscopy (XPS). The treated surfaces of the EPDM samples show a significant reduction in the contact angle measurement, indicating an increase in the surface energy. XPS analyses show the incorporation of polar nitrogen- and oxygen-containing groups on the rubber surface. After plasma treatment the presence of oxygen is observed due to surface oxidation which occurs when the samples are exposed to the air. Atomic force microscopy and scanning electron microscopy analyses indicate a decrease in the EPDM rubber surface roughness, promoted by surface etching during the plasma treatment. Strength tests indicate improvement of about 30% and 110% in the adhesion strength for the plasma treated EPDM/polyurethane liner interface and for the EPDM/epoxy adhesive interface, respectively. The adhesion strength of the EPDM/liner is similar to that obtained for the NBR/liner, which indicates that EPDM rubber can safely be used as thermal protection of the solid propellant rocket chamber.

  19. Surface improvement of EPDM rubber by plasma treatment

    International Nuclear Information System (INIS)

    Moraes, J H; Silva Sobrinho, A S da; Maciel, H S; Dutra, J C N; Massi, M; Mello, S A C; Schreiner, W H

    2007-01-01

    The surface of ethylene-propylene-diene monomer (EPDM) rubber was treated in N 2 /Ar and N 2 /H 2 /Ar RF plasmas in order to achieve similar or better adhesion properties than NBR (acrylonitrile-butadiene) rubber, nowadays used as thermal protection of rocket chambers. The surface properties were studied by contact angle measurements and by x-ray photoelectron spectroscopy (XPS). The treated surfaces of the EPDM samples show a significant reduction in the contact angle measurement, indicating an increase in the surface energy. XPS analyses show the incorporation of polar nitrogen- and oxygen-containing groups on the rubber surface. After plasma treatment the presence of oxygen is observed due to surface oxidation which occurs when the samples are exposed to the air. Atomic force microscopy and scanning electron microscopy analyses indicate a decrease in the EPDM rubber surface roughness, promoted by surface etching during the plasma treatment. Strength tests indicate improvement of about 30% and 110% in the adhesion strength for the plasma treated EPDM/polyurethane liner interface and for the EPDM/epoxy adhesive interface, respectively. The adhesion strength of the EPDM/liner is similar to that obtained for the NBR/liner, which indicates that EPDM rubber can safely be used as thermal protection of the solid propellant rocket chamber

  20. Surface improvement of EPDM rubber by plasma treatment

    Science.gov (United States)

    Moraes, J. H.; da Silva Sobrinho, A. S.; Maciel, H. S.; Dutra, J. C. N.; Massi, M.; Mello, S. A. C.; Schreiner, W. H.

    2007-12-01

    The surface of ethylene-propylene-diene monomer (EPDM) rubber was treated in N2/Ar and N2/H2/Ar RF plasmas in order to achieve similar or better adhesion properties than NBR (acrylonitrile-butadiene) rubber, nowadays used as thermal protection of rocket chambers. The surface properties were studied by contact angle measurements and by x-ray photoelectron spectroscopy (XPS). The treated surfaces of the EPDM samples show a significant reduction in the contact angle measurement, indicating an increase in the surface energy. XPS analyses show the incorporation of polar nitrogen- and oxygen-containing groups on the rubber surface. After plasma treatment the presence of oxygen is observed due to surface oxidation which occurs when the samples are exposed to the air. Atomic force microscopy and scanning electron microscopy analyses indicate a decrease in the EPDM rubber surface roughness, promoted by surface etching during the plasma treatment. Strength tests indicate improvement of about 30% and 110% in the adhesion strength for the plasma treated EPDM/polyurethane liner interface and for the EPDM/epoxy adhesive interface, respectively. The adhesion strength of the EPDM/liner is similar to that obtained for the NBR/liner, which indicates that EPDM rubber can safely be used as thermal protection of the solid propellant rocket chamber.

  1. EVALUATION OF TIRE RUBBER DISPOSAL IN CONCRETE FOR PAVEMENTS

    Directory of Open Access Journals (Sweden)

    Rosa Cristina Cecche Lintz

    2009-01-01

    Full Text Available The production of waste by the tire industry has been a growing problem, indicating the need for its reuse. More than thirty million tires are discharged per year in Brazil, where regulation for the environment states that for each four new tires, five unusable ones must be adequately disposed by manufacturers and importers. Paving consumes an extremely large quantity of materials, which can be the source of rational application of waste and rejected materials. Research shows that tire rubber can be added to asphalt, which increases its durability and improves pavement quality and safety conditions by absorbing the rubber elastic properties, and also be used for architectural applications, among others. This study deals with the addition of rubber fibers from tire crushing in concrete for roadway pavements in order to provide proper indication about the alternative material disposal through an evaluation of the mechanical behavior of the modified concrete. Different concrete mixes were produced, within which, part of fine aggregates were substituted by tire rubber and mechanical experiment tests were performed, which show that, due to great resistance losses, the disposal of this alternative material in concrete should be considered for light traffic pavements, with the addition of rubber ranging up to 10% in mass.

  2. Taxonomic revision and phylogenetic analyses of rubber powdery mildew fungi.

    Science.gov (United States)

    Liyanage, K K; Khan, Sehroon; Brooks, Siraprapa; Mortimer, Peter E; Karunarathna, Samantha C; Xu, Jianchu; Hyde, Kevin D

    2017-04-01

    Powdery mildew is a fungal disease that infects a wide range of plants, including rubber trees, which results in a reduction of latex yields of up to 45%. The causal agent of powdery mildew of rubber was first described as Oidium heveae, but later morpho-molecular research suggested that in the past, O. heveae has been confused with Erysiphe quercicola. However, it is still under debate whether the causal agent should be classified as a species of the genus Erysiphe emend. or Golovinomyces and Podosphaera, respectively. Therefore, the aim of this study was to undertake the morpho-molecular characterization of powdery mildew species associated with rubber trees, thus resolving these taxonomic issues. Morphological observation under light and scanning electron microscopes (SEM) clearly identified two morphotypes of the rubber powdery mildew. With the support of morphological and phylogenetic data, one of the two morphotypes was identified as the asexual morph of E. quercicola, while the second morphotype is still insufficiently known and according to the morphological results obtained we assume that it might belong to the genus Golovinomyces. More collections and additional molecular data are required for final conclusions regarding the exact taxonomic position of the second morphotype of rubber powdery mildew and its relation to the name O. heveae. The haplotype analysis identified eight haplotype groups of E. quercicola indicating the high genetic diversity of the species. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Abu Hasan

    2013-05-01

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

  4. Alexithymia Modulates the Experience of the Rubber Hand Illusion

    Directory of Open Access Journals (Sweden)

    Delphine eGrynberg

    2015-06-01

    Full Text Available Alexithymia is associated with lower awareness of emotional and non-emotional internal bodily signals. However, evidence suggesting that alexithymia modulates body awareness at an external level is scarce. This study aimed to investigate whether alexithymia is associated with disrupted multisensory integration by using the rubber hand illusion task.Fifty healthy individuals completed the Toronto Alexithymia Scale and underwent the rubber hand illusion measure. In this measure, one watches a rubber hand being stroked synchronously or asynchronously with one’s own hand, which is hidden from view. Compared to the asynchronous stimulation, the synchronous stimulation results in the illusion that the rubber hand and the participant’s hand are closer together than they really are and that the rubber hand belongs to them. Results revealed that higher levels of alexithymia are associated with a lower ownership illusion. In conclusion, our findings demonstrate that high alexithymia scorers integrate two simultaneous sensory and proprioceptive events into a single experience (lower multisensory integration to a lesser extent than low alexithymia scorers. Higher susceptibility to the illusion in high alexithymia scorers may -indicate that alexithymia is associated with impaired multisensory integration and that this association results from an abnormal focus of one's own body.

  5. EB-promoted recycling of waste tire rubber with polyolefins

    International Nuclear Information System (INIS)

    Meszaros, L.; Barany, T.; Czvikovszky, T.

    2011-01-01

    Complete text of publication follows. One of the principal problems of common recycling of technical polymers is the thermodynamical incompatibility. The change of the Gibbs 'free energy' during the mixing - determined by the changes of enthalpy and entropy - should be directed towards the miscibility. In most of cases, even between closely related polymers, the compatibility is on low level which leads to phase separation and weak adhesion between the phases. Radiation treatment may help in this problem making the polymers more compatible by creating covalent bonds between the polymer phases. Such problem arises at the recycling of ground tire rubbers (GTR). The rubber properties of GTR could be utilized by mixing the GTR with thermoplastic olefins. With the aid of radiation treatment the rubber-like properties of these types of thermoplastic elastomers can be increased. In this study polyethylene (PE) (50-70 wt%) as thermoplastic olefin, 30 wt% of GTR and ethylene vinyl acetate (EVA) (0-20 wt%) as rubber-like compatibilizing material were used for preparation of a recycled rubber containing blend, processable by thermoplastic processes. The melt-mixing of the samples was made by extrusion and then the test specimens were injection molded. The injection molded samples were than treated by high energy electron beam. On the specimens tensile tests, hysteresis, falling weight impact tests, hardness measurements, and dynamic mechanical thermal analysis (DMA) were carried out. The results proved the benefit of the electron beam treatment.

  6. The study of thermal tunable coupling between a Superconducting photonic crystal waveguide and semi-circular photonic crystal

    Energy Technology Data Exchange (ETDEWEB)

    Oskooi, Somayeh; Barvestani, Jamal, E-mail: barvestani@tabrizu.ac.ir

    2016-08-15

    Highlights: • The light coupling between superconducting photonic crystal waveguide and a semi-circular photonic crystal has been studied. • We utilized the finite difference time domain and plane wave expansion methods in the calculations. • The effect of the size of the nearest neighbor rods of waveguide on the coupling efficiency has been investigated. • The coupling efficiencies are reported versus the temperature of the superconducting waveguide. - Abstract: Through the present study, we investigated the light coupling between superconducting photonic crystal waveguide and a semi-circular photonic crystal. By using the finite difference time domain method, we evaluated the coupling efficiency between the mentioned structures at the various temperatures for different waveguide sizes. Calculation demonstrated that the coupling efficiency strongly depended on the temperature of the superconductor. The peak value of the coupling efficiency was influenced by the size of the nearest neighbor rods of waveguide. The results have shown that it is possible to obtain high efficiency at the desired temperature with proper selection of physical parameters in far-infrared frequency region. This structure has great potential in the optical integration and other areas.

  7. Some Tribological Characterization of “EPDM” Rubber

    Directory of Open Access Journals (Sweden)

    A. Mukhopadhyay

    2014-06-01

    Full Text Available Ethylene Propylene Diene Monomer (EPDM rubber emerges as a dominant elastomer for major engineering applications. The major properties of EPDM are its outstanding heat, ozone and weather resistance ability. It has a good resistance to polar substances and steam condition too. In automobiles EPDM rubber has a common use as seals. This includes door seals, window seals, trunk seals and sometimes hood seals. Frequently these seals are the source of noise due to the movement of the door versus the car body. This is due to friction between the EPDM rubber parts and the mating surfaces. Thus, the contact iteration between the rubber sealing and the indenting object must be known to optimize the performance of rubber sealing. However, it is need less to mention that the behaviour of any viscoelastic material is very difficult to be predicted. In the present work various tribo-characteristics of EPDM rubber of different hardness have been evaluated utilizing the available laboratory test facilities in the Jadavpur University, Kolkata, India. Compression tests have been carried out using ‘Instron’ to determine the flow behaviour of EPDM rubber of different hardness both in dry as well as under different conditions of lubrication. The flow behaviour like load -vs.- elongation curves, true stress -vs.- elongation curves and true stress -vs.- true strain curves have been drawn from the experimental data. Abrasive wear behaviour has been evaluated using a two-body abrasion tester and the pattern abrasion has been appraised through SEM/EDAX study. Experimental results reveal that the hardness of EPDM rubber has significant effect on the flow behaviour and wear characteristics. The hardness, again, depends on the proportion of carbon black (CB content. Thus it can be stated that the flow behaviour can be governed by controlling the CB concentration in the EPDM rubber. Based on the experimental results conclusion has been drawn accordingly. Some of the

  8. Aging-Resistant Functionalized LDH⁻SAS/Nitrile-Butadiene Rubber Composites: Preparation and Study of Aging Kinetics/Anti-Aging Mechanism.

    Science.gov (United States)

    Li, Tianxiang; Shi, Zhengren; He, Xianru; Jiang, Ping; Lu, Xiaobin; Zhang, Rui; Wang, Xin

    2018-05-18

    With the aim of improving the anti-aging properties of nitrile-butadiene rubber (NBR), a functional organic filler, namely LDH⁻SAS, prepared by intercalating 4-amino-benzenesulfonic acid monosodium salt (SAS) into layered double hydroxides (LDHs) through anion exchange, was added to nitrile-butadiene rubber (NBR), giving the NBR/LDH⁻SAS composites. Successful preparation of LDH⁻SAS was confirmed by XRD, TGA and FTIR. LDH⁻SAS was well dispersed in the NBR matrix, owing to its strong interaction with the nitrile group of NBR. The obtained NBR/LDH⁻SAS composites exhibited excellent thermo-oxidative aging resistance as shown by TGA-DSC. Further investigation by ATR-FTIR indicated that SAS can capture the radical groups, even during the aging process, which largely accounts for the improved aging resistance.

  9. Aging-Resistant Functionalized LDH–SAS/Nitrile-Butadiene Rubber Composites: Preparation and Study of Aging Kinetics/Anti-Aging Mechanism

    Science.gov (United States)

    Li, Tianxiang; Shi, Zhengren; He, Xianru; Jiang, Ping; Lu, Xiaobin; Zhang, Rui

    2018-01-01

    With the aim of improving the anti-aging properties of nitrile-butadiene rubber (NBR), a functional organic filler, namely LDH–SAS, prepared by intercalating 4-amino-benzenesulfonic acid monosodium salt (SAS) into layered double hydroxides (LDHs) through anion exchange, was added to nitrile-butadiene rubber (NBR), giving the NBR/LDH–SAS composites. Successful preparation of LDH–SAS was confirmed by XRD, TGA and FTIR. LDH–SAS was well dispersed in the NBR matrix, owing to its strong interaction with the nitrile group of NBR. The obtained NBR/LDH–SAS composites exhibited excellent thermo-oxidative aging resistance as shown by TGA-DSC. Further investigation by ATR-FTIR indicated that SAS can capture the radical groups, even during the aging process, which largely accounts for the improved aging resistance. PMID:29783656

  10. Crystal defect studies using x-ray diffuse scattering

    International Nuclear Information System (INIS)

    Larson, B.C.

    1980-01-01

    Microscopic lattice defects such as point (single atom) defects, dislocation loops, and solute precipitates are characterized by local electronic density changes at the defect sites and by distortions of the lattice structure surrounding the defects. The effect of these interruptions of the crystal lattice on the scattering of x-rays is considered in this paper, and examples are presented of the use of the diffuse scattering to study the defects. X-ray studies of self-interstitials in electron irradiated aluminum and copper are discussed in terms of the identification of the interstitial configuration. Methods for detecting the onset of point defect aggregation into dislocation loops are considered and new techniques for the determination of separate size distributions for vacancy loops and interstitial loops are presented. Direct comparisons of dislocation loop measurements by x-rays with existing electron microscopy studies of dislocation loops indicate agreement for larger size loops, but x-ray measurements report higher concentrations in the smaller loop range. Methods for distinguishing between loops and three-dimensional precipitates are discussed and possibilities for detailed studies considered. A comparison of dislocation loop size distributions obtained from integral diffuse scattering measurements with those from TEM show a discrepancy in the smaller sizes similar to that described above

  11. Crystal defect studies using x-ray diffuse scattering

    Energy Technology Data Exchange (ETDEWEB)

    Larson, B.C.

    1980-01-01

    Microscopic lattice defects such as point (single atom) defects, dislocation loops, and solute precipitates are characterized by local electronic density changes at the defect sites and by distortions of the lattice structure surrounding the defects. The effect of these interruptions of the crystal lattice on the scattering of x-rays is considered in this paper, and examples are presented of the use of the diffuse scattering to study the defects. X-ray studies of self-interstitials in electron irradiated aluminum and copper are discussed in terms of the identification of the interstitial configuration. Methods for detecting the onset of point defect aggregation into dislocation loops are considered and new techniques for the determination of separate size distributions for vacancy loops and interstitial loops are presented. Direct comparisons of dislocation loop measurements by x-rays with existing electron microscopy studies of dislocation loops indicate agreement for larger size loops, but x-ray measurements report higher concentrations in the smaller loop range. Methods for distinguishing between loops and three-dimensional precipitates are discussed and possibilities for detailed studies considered. A comparison of dislocation loop size distributions obtained from integral diffuse scattering measurements with those from TEM show a discrepancy in the smaller sizes similar to that described above.

  12. Natural rubber/high density polyethylene/ground rubber composites vulcanized by gamma irradiation

    International Nuclear Information System (INIS)

    Shaltout, N.A.; Abou zeid, M.M.; Khalil, A.M.; El Miligy, A.A.

    2010-01-01

    Natural rubber (NR) was blended mechanically with 50 phr high density polyethylene (HDPE). the mechanical, physical and thermal properties of NR/HDPE blend and its composites with different contents of ground tire rubber (GTR) before and after exposure to gamma irradiation to various doses up to 250 kGy were studied. Also, the change in structure morphology of irradiated NR/HDPE blend as well as NR/HDPE/GTR composites was examined by scanning electron microscope (SEM). The results showed that the substitution of a part of virgin NR with GTR decreases the mechanical and physical properties but not to the extent of deterioration . However, it was found that the mechanical and physical properties were improved after gamma irradiation . Composite of NR/GTR/HDPE (75/25/50) showed good properties. Scanning electron microscope showed homogeneity between the irradiated composites ingredients.

  13. Functionalization of Liquid Natural Rubber via Oxidative Degradation of Natural Rubber

    Directory of Open Access Journals (Sweden)

    Suhawati Ibrahim

    2014-12-01

    Full Text Available Natural rubber (NR is a high molecular weight natural polymer and can be degraded to liquid natural rubber (LNR leaving certain functional groups at the end of chains. In this study, LNR samples prepared via oxidative degradation using H2O2 and NaNO2 as reagents were found to have different end groups depending on the pH of the reaction medium. In an acidic medium, LNR with hydroxyl terminal groups was formed as the degradation reaction was initiated by hydroxyl radicals produced from decomposition of peroxynitrite acid. In contrast, a redox reaction took place in an alkaline medium to yield LNR with carbonyl terminal groups. The mechanisms of reaction are discussed and proposed to explain the formation of different end groups when reaction carried out in acidic and alkaline media. Chain degradation in an acidic medium seems to be more effective than in an alkaline medium, and thus yields LNR with lower Mn.

  14. Electron microscopy study of Ni induced crystallization in amorphous Si thin films

    International Nuclear Information System (INIS)

    Radnóczi, G. Z.; Battistig, G.; Pécz, B.; Dodony, E.; Vouroutzis, N.; Stoemenos, J.; Frangis, N.; Kovács, A.

    2015-01-01

    The crystallization of amorphous silicon is studied by transmission electron microscopy. The effect of Ni on the crystallization is studied in a wide temperature range heating thinned samples in-situ inside the microscope. Two cases of limited Ni source and unlimited Ni source are studied and compared. NiSi 2 phase started to form at a temperature as low as 250°C in the limited Ni source case. In-situ observation gives a clear view on the crystallization of silicon through small NiSi 2 grain formation. The same phase is observed at the crystallization front in the unlimited Ni source case, where a second region is also observed with large grains of Ni 3 Si 2 . Low temperature experiments show, that long annealing of amorphous silicon at 410 °C already results in large crystallized Si regions due to the Ni induced crystallization

  15. Study on the production of kanvas shoes adhesive from natural rubber latex grafted with methyl methacrylate (NRL-g PMMA) copolymer

    International Nuclear Information System (INIS)

    Utama, Marga; Sudirman; Setyowati, Penny

    2002-01-01

    The optimation condition of radiation copolymerization of MMA into natural rubber latex at the doses of radiation : 5; 7.5 and 10 kGy with concentration of MMA 25; 50; 75; and 100 phr (Part Hundred Ratio of Rubber) expectially and optimazation condition of the adhesive process all the production of canvas shoes have been carried out. The properties of NRL-g-MMA and its rubber such as total solid contain, viscosity, pH, modulus, tensile, strenght, hardnes, elongation at break, and adhesive strenght for producting canvas shoes where evaluated. The at adhesive results show that NRL-g-MMA with the 75 phr of MMA and iradiation dose 5 kGy is adhesive will good stability during storage. The adhesive strenght of shoes its 16-18 N/6mm, more here than SNI 1-0172-1987 with the value 10N/6mm. Besic there is a tendency that adhesive strengt of product shoes at rome temperature (30-50 o C). stronger than at high temperature (100 o C)

  16. Rubber gloves biodegradation by a consortium, mixed culture and pure culture isolated from soil samples.

    Science.gov (United States)

    Nawong, Chairat; Umsakul, Kamontam; Sermwittayawong, Natthawan

    2018-02-03

    An increasing production of natural rubber (NR) products has led to major challenges in waste management. In this study, the degradation of rubber latex gloves in a mineral salt medium (MSM) using a bacterial consortium, a mixed culture of the selected bacteria and a pure culture were studied. The highest 18% weight loss of the rubber gloves were detected after incubated with the mixed culture. The increased viable cell counts over incubation time indicated that cells used rubber gloves as sole carbon source leading to the degradation of the polymer. The growth behavior of NR-degrading bacteria on the latex gloves surface was investigated using the scanning electron microscope (SEM). The occurrence of the aldehyde groups in the degradation products was observed by Fourier Transform Infrared Spectroscopy analysis. Rhodococcus pyridinivorans strain F5 gave the highest weight loss of rubber gloves among the isolated strain and posses latex clearing protein encoded by lcp gene. The mixed culture of the selected strains showed the potential in degrading rubber within 30 days and is considered to be used efficiently for rubber product degradation. This is the first report to demonstrate a strong ability to degrade rubber by Rhodococcus pyridinivorans. Copyright © 2018. Published by Elsevier Editora Ltda.

  17. Ground rubber: Sorption media for ground water containing benzene and O-xylene

    International Nuclear Information System (INIS)

    Kershaw, D.S.; Pamukcu, S.

    1997-01-01

    The purpose of the current study is to examine the ability of ground rubber to sorb benzene and O-xylene from water contained with aromatic hydrocarbons. The study consisted of running both batch and packed bed column tests to determine the sorption capacity, the required sorption equilibration time, and the flow through utilization efficiency of ground rubber under various contact times when exposed to water contaminated with various amounts of benzene or O-xylene. Initial batch test results indicate that ground rubber can attain equilibrium sorption capacities up to 1.3 or 8.2 mg of benzene or O-xylene, respectively, per gram of tire rubber at solution equilibrium concentrations of 10 mg/L. Packed bed column tests indicate that ground tire rubber has on the average a 40% utilization rate when a hydraulic residence time of 15 min is used. Possible future uses of round rubber as a sorption media could include, but are not limited to, the use of ground rubber as an aggregate in slurry cutoff walls that are in contact with petroleum products. Ground rubber could also be used as a sorption media in pump-and-treat methodologies or as a sorption media in in-situ reactive permeable barriers

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

    Science.gov (United States)

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

    2016-07-13

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

  19. Crystal structure and pair potentials: A molecular-dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Parrinello, M.; Rahman, A.

    1980-10-06

    With use of a Lagrangian which allows for the variation of the shape and size of the periodically repeating molecular-dynamics cell, it is shown that different pair potentials lead to different crystal structures.

  20. Properties of concrete containing scrap-tire rubber--an overview.

    Science.gov (United States)

    Siddique, Rafat; Naik, Tarun R

    2004-01-01

    Solid waste management is one of the major environmental concerns in the United States. Over 5 billion tons of non-hazardous solid waste materials are generated in USA each year. Of these, more than 270 million scrap-tires (approximately 3.6 million tons) are generated each year. In addition to this, about 300 million scrap-tires have been stockpiled. Several studies have been carried out to reuse scrap-tires in a variety of rubber and plastic products, incineration for production of electricity, or as fuel for cement kilns, as well as in asphalt concrete. Studies show that workable rubberized concrete mixtures can be made with scrap-tire rubber. This paper presents an overview of some of the research published regarding the use of scrap-tires in portland cement concrete. The benefits of using magnesium oxychloride cement as a binder for rubberized concrete mixtures are also presented. The paper details the likely uses of rubberized concrete.

  1. Study of nonlinear effects in photonic crystals doped with nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Mahi R [Department of Physics and Astronomy, University of Western Ontario, London, N6A 3K7 Ontario (Canada)

    2008-07-14

    A theory of nonlinear phenomena has been developed for a photonic crystal in the presence of a pump and a coupling laser field. The crystal is doped with an ensemble of four-level nanoparticle impurities. It is considered that the impurity particles are not only interacting with the photonic crystal but also with each other via dipole-dipole interaction. An expression for the susceptibility has been obtained using the density matrix method. The nonlinear effects due to the coupling and the pump fields have been included in the formulation. The absorption spectrum has been calculated in the presence of the strong coupling and pump fields for an isotropic photonic crystal made from dielectric spheres. The photonic crystal has a gap to midgap ratio of about 21%. It is predicted that the absorption spectrum in the photonic crystal can have zero, one, two or three absorptionless states by tuning one of the transition energies within the bands. This is an interesting phenomenon which can be used to make photonic switching devices. We have also calculated the absorption spectrum in the presence of the dipole-dipole interaction. It is found that a symmetric absorption spectrum changes to an asymmetric one due to this interaction. It is also found that there is a large enhancement in the absorption and the dispersion simultaneously for certain values of the detuning and concentration.

  2. Study of nonlinear effects in photonic crystals doped with nanoparticles

    International Nuclear Information System (INIS)

    Singh, Mahi R

    2008-01-01

    A theory of nonlinear phenomena has been developed for a photonic crystal in the presence of a pump and a coupling laser field. The crystal is doped with an ensemble of four-level nanoparticle impurities. It is considered that the impurity particles are not only interacting with the photonic crystal but also with each other via dipole-dipole interaction. An expression for the susceptibility has been obtained using the density matrix method. The nonlinear effects due to the coupling and the pump fields have been included in the formulation. The absorption spectrum has been calculated in the presence of the strong coupling and pump fields for an isotropic photonic crystal made from dielectric spheres. The photonic crystal has a gap to midgap ratio of about 21%. It is predicted that the absorption spectrum in the photonic crystal can have zero, one, two or three absorptionless states by tuning one of the transition energies within the bands. This is an interesting phenomenon which can be used to make photonic switching devices. We have also calculated the absorption spectrum in the presence of the dipole-dipole interaction. It is found that a symmetric absorption spectrum changes to an asymmetric one due to this interaction. It is also found that there is a large enhancement in the absorption and the dispersion simultaneously for certain values of the detuning and concentration

  3. Demotivating factors influencing rubber production workers

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Iravani

    2012-01-01

    Full Text Available Motivation is one of the most important factors influencing workers' productivity. An increase in workers' motivation could add more value to organizations' structure and influence the profitability, significantly. In this paper, we study different factors on demotivating workers using questionnaire consist of various questions. The questionnaire is distributed among some employees who work for rubber production units located in Esfahan, Iran. The results of this survey indicate that discrimination on annual job compensation, entrusting responsibilities and unpleasant relationship with family partner are some of the most important factors influencing employees' motivation. While financial factors play important role on increasing employees' motivation, non-financial factors are considered more important.

  4. Evaluation of rubber modified asphalt demonstration projects

    Energy Technology Data Exchange (ETDEWEB)

    1994-01-01

    As part of the Ontario Government's medium-term scrap tire management strategy, 11 rubber modified asphalt demonstration projects were funded or completed, with 13 additional projects from small to large (1,500-65,000 passenger tire equivalents) approved for the 1993 paving season. This report presents the results of an August to November 1993 study of the 11 demonstration projects. The evaluation included a description of the technology; technical review of the projects; economic analysis; review of the environmental literature; environmental review of the projects; comparison of the projects with similar ones in other jurisdictions; and recommendations. Detailed information on asphalt technology is included in an appendix.

  5. Purification, crystallization and preliminary X-ray diffraction studies of parakeet (Psittacula krameri) haemoglobin.

    Science.gov (United States)

    Jaimohan, S M; Naresh, M D; Arumugam, V; Mandal, A B

    2009-10-01

    Birds often show efficient oxygen management in order to meet the special demands of their metabolism. However, the structural studies of avian haemoglobins (Hbs) are inadequate for complete understanding of the mechanism involved. Towards this end, purification, crystallization and preliminary X-ray diffraction studies have been carried out for parakeet Hb. Parakeet Hb was crystallized as the met form in low-salt buffered conditions after extracting haemoglobin from crude blood by microcentrifugation and purifying the sample by column chromatography. Good-quality crystals were grown from 10% PEG 3350 and a crystal diffracted to about 2.8 A resolution. Preliminary diffraction data showed that the Hb crystal belonged to the monoclinic system (space group C2), with unit-cell parameters a = 110.68, b = 64.27, c = 56.40 A, beta = 109.35 degrees . Matthews volume analysis indicated that the crystals contained a half-tetramer in the asymmetric unit.

  6. Study of Te Inclusions in CdMnTe Crystals for Nuclear Detector Applications

    International Nuclear Information System (INIS)

    Babalola, O.S.; Bolotnikov, A.; Groza, M.; Hossain, A.; Egarievwe, S.; James, R.; Burger, A.

    2009-01-01

    The concentration, size and spatial distribution of Te inclusions in the bulk of CdMnTe crystals mined from two batches of ingots were studied. An isolated planar layer decorated with Te inclusions was identified in CdMnTe crystals from the second ingot. The internal electric field of a CMT crystal was probed by infrared (IR) imaging employing Pockels electro-optic effect. The effect of an isolated plane of Te inclusions on the internal electric-field distribution within the CdMnTe crystal was studied. Space charge accumulation around the plane of Te inclusions was observed, which was found to be higher when the detector was reverse-biased. The effects of the plane of Te inclusions on the electric-field distribution within the CdMnTe crystal, and the quality of CdMnTe crystals for nuclear detector applications are discussed.

  7. Rheological behavior of raw natural rubber coagulated by microorganisms

    Directory of Open Access Journals (Sweden)

    Zhifen Wang

    2014-01-01

    Full Text Available Tests of the strain sweep, frequency sweep and stress relaxation for raw natural rubber coagulated by microorganisms (NR-m and raw natural rubber coagulated by acid (NR-a were carried out with the use of a rubber process analyzer (RPA. The results showed that the storage torque, complex viscosity of NR-m were higher than those of NR-a while the loss factor was lower. The effect of temperature on viscosity of raw NR was studied following the Arrhenious-Frenkel-Eyring model. The viscous flow behavior of NR-m was poorer than those of NR-a. Furthermore, stress relaxation measurements of raw NR showed a longer period of relaxation for NR-m.

  8. Direct molding of pavement tiles made of ground tire rubber

    Science.gov (United States)

    Quadrini, Fabrizio; Gagliardi, Donatella; Tedde, Giovanni Matteo; Santo, Loredana; Musacchi, Ettore

    2016-10-01

    Large rubber products can be molded by using only ground tire rubber (GTR) without any additive or binder due to a new technology called "direct molding". Rubber granules and powders from tire recycling are compression molded at elevated temperatures and pressures. The feasibility of this process was clearly shown in laboratory but the step to the industrial scale was missing. Thanks to an European Project (SMART "Sustainable Molding of Articles from Recycled Tires") this step has been made and some results are reported in this study. The press used for compression molding is described. Some tests were made to measure the energy consumption so as to evaluate costs for production in comparison with conventional technologies for GTR molding (by using binders). Results show that 1 m2 tiles can be easily molded with several thicknesses in a reasonable low time. Energy consumption is higher than conventional technologies but it is lower than the cost for binders.

  9. EB-promoted recycling of waste tire rubber with polyolefins

    Science.gov (United States)

    Mészáros, László; Bárány, Tamás; Czvikovszky, Tibor

    2012-09-01

    Despite the fact that more and more methods and solutions are used in the recycling of polymers, there are still some problems, especially in the recycling of cross-linked materials such as rubber. Usually the biggest problem is the lack of compatibility between the cross-linked rubber and the thermoplastic matrix. In this study we applied ground tire rubber (GTR) as recycled material. The GTR was embedded into polyethylene (PE) and polyethylene/ethylene-vinyl acetate copolymer (PE/EVA) matrices. In order to increase the compatibility of the components electron beam (EB) irradiation was applied. The results showed that the irradiation has a beneficial effect on the polymer-GTR interfacial connection. The EB treatment increased not only the tensile strength but also the elongation at break. The irradiation had also positive effect on the impact strength properties.

  10. Thermal, Morphological and Physic-Mechanical Properties of Natural Rubber - CaCO3 Composites Using Jatropha Oil as Softener.

    Directory of Open Access Journals (Sweden)

    Nasruddin

    2018-01-01

    Full Text Available The urgency of green technology in rubber compounding has become a critical issue recently. In this research, the effect of using renewable resources in rubber compounding has been studied. Commercial Calcium Carbonate, Silica and Jatropha Oil were used in natural rubber composite. The research was designed by varying the types of commercial filler namely CaCO3 (47-51 phr, silica (47-51 phr and Jatropha Oil (4-6 phr in natural rubber composites (SIR-20. The formulas were intentionally designed for rubber tips vulcanizates. The samples were characterized by the determination of physic-mechanical, thermal (TGA and morphological (SEM properties. From the measured results, there is no significant effect on the tensile strength, specific gravity, and hardness on the loading of commercial CaCO3 and Silica in natural rubber composites using Jatropha Oil. However, a slight difference in elongation at break and abrasion resistance could be detected. Compared to the commercial rubber tips, the rubber tips produced in this research have higher tensile strength, elongation at break and abrasion resistance. Due to the usage of commercial CaCO3 and Silica, the SEM micrographs show rough surface because of the agglomeration. The thermogram shows clearly the compositional analysis of the rubber tips vulcanizates consist of Jatropha Oil and natural rubber, CaCO3, ash and other filler residues such as Silica.

  11. Growth, morphology, spectral and thermal studies of gel grown diclofenac acid crystals

    Science.gov (United States)

    Ramachandran, E.; Ramukutty, S.

    2014-03-01

    The crystal growth of diclofenac acid in silica gel is the first to be reported in literature. The growth parameters were varied to optimize the suitable growth condition. Single crystal X-ray diffraction method was used for the conformation of the crystal structure. Morphology studies showed that the growth is prominent along the b-axis and the prominent face is {002}. Fourier transform infrared spectral study was performed to identify the functional groups present in the crystal. Thermal stability and decomposition of the material were analyzed using thermo calorimetry in the temperature range 30-500 °C.

  12. Radiation Hardness Study of CsI(Tl) Crystals for Belle II Calorimeter

    CERN Document Server

    Matvienko, D V; Sedov, E V; Shwartz, B A

    2017-01-01

    The Belle II calorimeter (at least, its barrel part) consists of CsI(Tl) scintillation crystals which have been used at the Belle experiment. We perform the radiation hardness study of some typical Belle crystals and conclude their light output reductions are acceptable for Belle II experiment where the absorption dose can reach 10 krad during the detector operation. CsI(Tl) crystals have high stablity and low maintenance cost and are considered as possible option for the calorimeter of the future Super-Charm-Tau factory (SCT) in Novosibirsk. Our study demonstrates sufficiently high radiation hardness of CsI(Tl) crystals for SCT conditions.

  13. Liquid natural rubber (LNR) as a compatibiliser in NR/LLDPE blends: the mixing and mechanical property studies

    International Nuclear Information System (INIS)

    Dahlan Mohd; Khairul Zaman Mohd Dahlan; Ibrahim Abdullah

    2000-01-01

    The plastograms of mixing were able to give information on the compatibility of NR/LLDPE 60/40 blends studied. Using the conversion method, torques obtained from a plasticorder mixer could be converted to standard rheological properties in order to investigate fusing behaviour of the blends as the results of LNR additions. Improvements in the mechanical properties such as tensile, elongation and hardness were found in consonance with the increase in gel contents of the blends. The additions of LNR in the blends were able to reduce the interfacial tension, therefore improved the interaction between the phases of the blends. (author)

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

    Science.gov (United States)

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

    2017-06-01

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

  15. A review on fatigue life prediction methods for anti-vibration rubber materials

    Directory of Open Access Journals (Sweden)

    Xiaoli WANG

    2016-08-01

    Full Text Available Anti-vibration rubber, because of its superior elasticity, plasticity, waterproof and trapping characteristics, is widely used in the automotive industry, national defense, construction and other fields. The theory and technology of predicting fatigue life is of great significance to improve the durability design and manufacturing of anti-vibration rubber products. According to the characteristics of the anti-vibration rubber products in service, the technical difficulties for analyzing fatigue properties of anti-vibration rubber materials are pointed out. The research progress of the fatigue properties of rubber materials is reviewed from three angles including methods of fatigue crack initiation, fatigue crack propagation and fatigue damage accumulation. It is put forward that some nonlinear characteristics of rubber under fatigue loading, including the Mullins effect, permanent deformation and cyclic stress softening, should be considered in the further study of rubber materials. Meanwhile, it is indicated that the fatigue damage accumulation method based on continuum damage mechanics might be more appropriate to solve fatigue damage and life prediction problems for complex rubber materials and structures under fatigue loading.

  16. Pengaruh penggunaan nitril butadiene rubber dan pale crepe pada pembuatan sol karet untuk sepatu pengaman

    Directory of Open Access Journals (Sweden)

    Arum Yuniari

    2010-06-01

    Full Text Available Abstract Rubber sole for safety shoes was different on physical specification with general sole, especially on abrasion resistance and oil resistance. The objective of the study was to determine the effect of nitril butadiene rubber and pale crepe on physical properties of vulcanized rubber sole for safety shoes. Rubber sole for safety shoes was produced by blending pale crepe and nitril butadiene rubber with ratio of : 50/50; 60/40; 70/30 and 80/20 phr, respectively. Carbon black as filler was also variated with, 40 ; 50 and 60 phr. Compounding processing used two roll mill machine and vulcanized rubber sole was by using pressed use hydraulic press machine. The results showed that vulcanized rubber sole for safety shoes with good quality consist of pale crepe and NBR 80/20 phr and carbon black 40 phr, which was characterized by tensile strength 16.81 N/mm2, tear strength 11.68 N/mm, density 1.12 g/cm3, abrasion resistance 58.51 mm3, hardness 71.60 shore A, resistance to cut growth 30.000 times was 1.15 mm and oil resistance 65.44%, respectively. The quality parameters was complied with standard quality of SNI 0111 : 2009, for safety shoes from leather and vulcanized rubber sole that fulfill oil reistance parameter.

  17. Determination of the Mechanical Properties of Rubber by FT-NIR

    Directory of Open Access Journals (Sweden)

    Rattapol Pornprasit

    2016-01-01

    Full Text Available Mechanical tests, for example, tensile and hardness tests, are usually used to evaluate the properties of rubber materials. In this work, mechanical properties of selected rubber materials, that is, natural rubber (NR, styrene butadiene rubber (SBR, nitrile butadiene rubber (NBR, and ethylene propylene diene monomer (EPDM, were evaluated using a near infrared (NIR spectroscopy technique. Here, NR/NBR and NR/EPDM blends were first prepared. All of the samples were then scanned using a FT-NIR spectrometer and fitted with an integration sphere working in a diffused reflectance mode. The spectra were correlated with hardness and tensile properties. Partial least square (PLS calibration models were built from the spectra datasets with preprocessing techniques, that is, smoothing and second derivative. This indicated that reasonably accurate models, that is, with a coefficient of determination [R2] of the validation greater than 0.9, could be achieved for the hardness and tensile properties of rubber materials. This study demonstrated that FT-NIR analysis can be applied to determine hardness and tensile values in rubbers and rubber blends effectively.

  18. Gamma-radiation effect on thermal ageing of butyl rubber compounds

    International Nuclear Information System (INIS)

    Scagliusi, Sandra R.; Cardoso, Elizabeth C.L.; Lugao, Ademar B.

    2015-01-01

    Butyl rubber has a comprehensive use in sealing systems, especially in tires inner tubes, due to their low permeability to gases. So, it is required that butyl rubber compounds show a better performance, more and more. Butyl rubber is provided with excellent mechanical properties and oxidation resistance. Besides showing these properties, radiation exposures impart modifications in physical-chemical and morphological properties on butyl rubber materials. When exposed to gamma-radiation, rubbers suffer changes in their mechanical and physical properties, caused by material degradation. The major radiation effect in butyl rubbers is chain scission; besides, ageing promotes too the same effect with further build-up of free radicals. This work aims to the study of gamma-radiation in physical-chemical properties of butyl rubber subjected to thermal ageing. Doses used herein were: 25 kGy, 50 kGy, 100 kGy, 150 kGy and 200 KGy. Samples were evaluated before and after ageing according to traditional essays, such as: hardness, tensile strength and elongation at break. From accomplished assessments it is possible to affirm that at doses higher than 50 kGy it was observed a sharp decreasing in butyl rubber physical-chemical properties, before and after exposure to ageing. (author)

  19. Gamma-radiation effect on thermal ageing of butyl rubber compounds

    Energy Technology Data Exchange (ETDEWEB)

    Scagliusi, Sandra R.; Cardoso, Elizabeth C.L.; Lugao, Ademar B., E-mail: srscagliusi@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Butyl rubber has a comprehensive use in sealing systems, especially in tires inner tubes, due to their low permeability to gases. So, it is required that butyl rubber compounds show a better performance, more and more. Butyl rubber is provided with excellent mechanical properties and oxidation resistance. Besides showing these properties, radiation exposures impart modifications in physical-chemical and morphological properties on butyl rubber materials. When exposed to gamma-radiation, rubbers suffer changes in their mechanical and physical properties, caused by material degradation. The major radiation effect in butyl rubbers is chain scission; besides, ageing promotes too the same effect with further build-up of free radicals. This work aims to the study of gamma-radiation in physical-chemical properties of butyl rubber subjected to thermal ageing. Doses used herein were: 25 kGy, 50 kGy, 100 kGy, 150 kGy and 200 KGy. Samples were evaluated before and after ageing according to traditional essays, such as: hardness, tensile strength and elongation at break. From accomplished assessments it is possible to affirm that at doses higher than 50 kGy it was observed a sharp decreasing in butyl rubber physical-chemical properties, before and after exposure to ageing. (author)

  20. 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.

  1. Aging Depth Test of Rubber Blocks by Accelerated Thermal Oxidation Test

    International Nuclear Information System (INIS)

    Park, Junhee; Choun, Young-Sun; Kim, Min Kyu

    2015-01-01

    In this study, the accelerated thermal oxidation tests of rubber block were performed to investigate the aging depth of rubber bearing. From the tests, it was found the critical aging depth in rubber block. Also the property variation of rubber was investigated along the depth. The deterioration pattern from the aging depth tests was found from surface to inside and the critical aging depth was to be about 10 mm. The analytical model for rubber bearing with aging can be developed based on the relationship between the property variation and aging depth investigated from this study. The mechanical properties of rubber bearings were changed with time. Because the aging effect of rubber material was generally higher than that of other structure materials it is needed that the aging properties of seismically isolators should be evaluated to ensure the safety of seismically isolated nuclear power plants (NPPs) over the lifetime. NRC and ASCE required the tests of seismically isolators for investigating the aging properties. JNES also required the seismic response analysis for the seismically isolated NPPs when the properties of seismically isolators were extremely changed. If the aging properties of seismically isolators such as rubber bearings are evaluated by analysis the analytical model of seismically isolators should be developed considering aging effect of rubber material. From the previous research, it was reported that the behavior of aged rubber material mainly affected by temperature and oxidation. The material properties between surface and inside can be different by the oxidation of rubber. Therefore, the aging depth should be investigated for exactly evaluating the seismic behavior of aged rubber bearing. The aging depth of rubber baring was not influenced by the size of seismically isolators but environment condition. Therefore, the detail analysis considering aging depth was not required for NPPs with large seismically isolators. But the seismic response

  2. Why dentists don't use rubber dam during endodontics and how to promote its usage?

    Science.gov (United States)

    Madarati, Ahmad A

    2016-02-25

    This survey study aimed at investigating the frequency of rubber dam use during root canal treatment, identifying influencing factors for not using it by Saudi general dental practitioners (GDPs) and endodontists. It also aimed at identifying measures that increase rubber dam usage. After obtaining an ethical approval, two pilot studies were conducted on staff members at Taibah University College of Dentistry and a group of GDPs. A final online survey was constructed comprising 17 close-ended questions divided into six categories: demographics, endodontic practice, rubber dam use, alternative isolation methods, reasons for not using rubber dam, and measures and policies that increase its usage. The survey was emailed to 375 GDPs randomly selected from the dental register and all endodontists (n = 53) working in the western province, Saudi Arabia. Data were analyzed using the Chi-square and Linear-by-Linear association tests at p ≤ 0.05. The proportion of endodontists who used rubber dam (84.8 %) was significantly greater than that of GDPs (21.6 %) (p < 0.001). Significantly the highest proportion (40.5 %) did not use rubber dam because of unavailability at working place. Most rubber dam none-users (69.25 %) used a combination of other isolation means. The highest proportion of those who used rubber dam were working in the governmental sector (54.3 %). Among rubber dam users, the greatest proportion graduated from Saudi Arabia (57.8 %) compared to those graduated from Egypt (34.3 %) and Syria (22.4 %). There was a significant correlation between the patterns of rubber dam use during undergraduate training and its usage after graduation (p = 0.001). The highest proportion of participants (48.1 %) reported better undergraduate education as the most important factor that would increase rubber dam use in dental practice. Using of rubber dam was not common in Saudi general dental practice. Dentists must follow the recommended standards of care. Place of work and

  3. Photoelectron diffraction studies of small adsorbates on single crystal surfaces

    International Nuclear Information System (INIS)

    Pascal, Mathieu

    2002-01-01

    The structural determination of small molecules adsorbed on single crystal surfaces has been investigated using scanned energy mode photoelectron diffraction (PhD). The experimental PhD data were compared to theoretical models using a simulation program based on multiple scattering calculations. Three adsorption systems have been examined on Ag(110), Cu(110) and Cu(111) crystals. The structure of the (2x1)-O adsorption phase on Ag(110) revealed that the O atoms occupied the long bridge site and are almost co-planar with the top layer of Ag atoms. The best agreement between multiple scattering theory and experiment has been obtained for a missing-row (or equivalently an 'added- row') reconstruction. Alternative buckled-row and unreconstructed surface models can be excluded. The adsorption of the benzoate species on Cu(110) has been found to occur via the carboxylate group. The molecules occupy short bridge sites with the O atoms being slightly displaced from atop sites and are aligned along the close-packed azimuth. The tilt of the molecule with respect to the surface and the degree to which the surface is relaxed have also been investigated. The adsorption of methyl on Cu(111) was studied using either azomethane or methyl iodide to prepare the surface layers. At saturation coverage the preferred adsorption site is the fcc threefold hollow site, whereas at half saturation coverage ∼ 30 % of the methyl species occupy the hop threefold hollow sites. Best agreement between theory and experiment corresponded to a methyl group adsorbed with C 3v symmetry. The height of the C above the surface in a pure methyl layer was 1.66 ± 0.02 A, but was reduced to 1.62 ± 0.02 A in the presence of co-adsorbed iodine, suggesting that iodine increases the strength of adsorption. Iodine was also found to occupy the fee threefold hollow sites with a Cu-l bondlength of 2.61 ± 0.02 A. (author)

  4. Dynamic Performance Characteristic Tests of Real Scale Lead Rubber Bearing for the Evaluation of Performance Criteria

    International Nuclear Information System (INIS)

    Kim, Min Kyu; Kim, Jung-Han; Choi, In-Kil

    2014-01-01

    Dynamic characteristic tests of full scale lead rubber bearing were performed for the evaluation of performance criteria of isolation system for nuclear power plants. For the dynamic test for a full scale rubber bearing, two 1500mm diameter lead rubber bearings were manufactured. The viewpoints of this dynamic test are determination of an ultimate shear strain level of lead rubber bearing, behavior of rubber bearing according to static and dynamic input motion, sinusoidal and random (earthquake) motion, and 1-dimentional and 2-dimensional input motion. In this study, seismic isolation device tests were performed for the evaluation of performance criteria of isolation system. Through this test, it can be recognized that in the case of considering a mechanical property test, dynamic and multi degree of loading conditions should be determined. But these differences should be examined how much affect to the global structural behavior

  5. Kinetic study of ultrasonic antisolvent crystallization of sirolimus

    Energy Technology Data Exchange (ETDEWEB)

    Gandhi, P.J. [Chemical Engineering Department, S. V. National Institute of Technology, Surat 395007, Gujarat (India); Concept Medical Research Pvt. Ltd., Ground Floor, Narayan Darshan, Nr. Rupam Cinema, Salabatpura, Surat 395003, Gujarat (India); Murthy, Z.V.P.

    2010-03-15

    Sirolimus, generally used in organ transplantation, is derived from bacterium Streptomyces hygroscopicus. Mass transfer controlled ultrasonic antisolvent method was used for determining the precipitation kinetics of sirolimus. The effect of temperature was determined on the particles size, percentage recovery, critical radius of nucleus, mass transfer coefficient, etc. for sirolimus dissolved in methanol and antisolvent water using ultrasonic treatment. The study was done using classical nucleation theory, which can also be applied to precipitation processes. Experiments were carried out at various temperatures; viz: 45, 50, 60 and 70 C and the percentage recoveries of sirolimus were found to be 90.74, 91.5, 92.64 and 93.61%, respectively, for initial amount of 8 mg dissolved in 1 mL of solvent and further introduced into 12 mL of HPLC water. The final average diameters of crystals observed for the temperatures were 1371, 1287, 1063 and 863 nm, respectively. The systems were found to be mass transfer controlling and that the mass diffusivities were found to be about 3.97 x 10{sup -9}, 4.00 x 10{sup -9}, 3.01 x 10{sup -9} and 1.92 x 10{sup -9} m{sup 2}/s, respectively. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. Preparation of composites of national rubber latex (NRL) - portland cement mould. Vol. 3

    International Nuclear Information System (INIS)

    Dessouki, A.M.; Taher, N.H.; El-Nahas, H.H.

    1996-01-01

    The aim of this study is to prepare some polymeric mould using national rubber latex (NRL) - portland cement composites based on a delayed- action mechanism. Factors affecting the preparation process such as concentration, mixing percentage, additives and their effect on what is regarded as a delayed action coacervant combination was studied. Composites of national latex (NRL) - portland cement would were prepared as two separate parts. The stabilized natural rubber latex (NRL) 100 parts with hydroxy ethyl cellulose (HEC) 2 parts as stabilizer and a delayed - action coacervant (sodium meta silicate as a delaying agent) 5 parts on one hand and the dry blend of cement 65 parts soluble in 65 parts of water as a paste on the other hand were mixed thoroughly on site. (HEC) was added to the rubber latex to prevent the coagulation of the rubber latex with the electrolyte (sodium meta silicate) present in the rubber mixture. Two kinds of stabilization occurred in the rubber part, namely steric stabilization and the stabilization against electrolyte. The effect of delayed - action coacervant (sodium meta silicate) on the initial setting time of rubber - cement mould showed that the molding process did not occur at sodium meta silicate concentration less than 2.66 parts per 100 parts of rubber latex (phr), and the optimum concentration used was 5% parts of rubber latex. It was observed that addition of a delaying agent (Sodium meta silicate) to the rubber part enhanced the delaying mechanism in the time needed for the molding process, while the addition of the delaying agent to the cement part did not have any effect on retardation of the molding process. Chemical coacervants function mainly by reducing the ζ potential which is associated with the electrical double layer surrounding the latex particle. This reduction may brought about in at least three distinct ways which take place in the system studied. 5 figs., 3 tabs

  7. Preparation of composites of national rubber latex (NRL) - portland cement mould. Vol. 3

    Energy Technology Data Exchange (ETDEWEB)

    Dessouki, A M; Taher, N H; El-Nahas, H H [National Center for Radiation Research and Technology, Atomic Energy Athority, Cairo (Egypt)

    1996-03-01

    The aim of this study is to prepare some polymeric mould using national rubber latex (NRL) - portland cement composites based on a delayed- action mechanism. Factors affecting the preparation process such as concentration, mixing percentage, additives and their effect on what is regarded as a delayed action coacervant combination was studied. Composites of national latex (NRL) - portland cement would were prepared as two separate parts. The stabilized natural rubber latex (NRL) 100 parts with hydroxy ethyl cellulose (HEC) 2 parts as stabilizer and a delayed - action coacervant (sodium meta silicate as a delaying agent) 5 parts on one hand and the dry blend of cement 65 parts soluble in 65 parts of water as a paste on the other hand were mixed thoroughly on site. (HEC) was added to the rubber latex to prevent the coagulation of the rubber latex with the electrolyte (sodium meta silicate) present in the rubber mixture. Two kinds of stabilization occurred in the rubber part, namely steric stabilization and the stabilization against electrolyte. The effect of delayed - action coacervant (sodium meta silicate) on the initial setting time of rubber - cement mould showed that the molding process did not occur at sodium meta silicate concentration less than 2.66 parts per 100 parts of rubber latex (phr), and the optimum concentration used was 5% parts of rubber latex. It was observed that addition of a delaying agent (Sodium meta silicate) to the rubber part enhanced the delaying mechanism in the time needed for the molding process, while the addition of the delaying agent to the cement part did not have any effect on retardation of the molding process. Chemical coacervants function mainly by reducing the {zeta} potential which is associated with the electrical double layer surrounding the latex particle. This reduction may brought about in at least three distinct ways which take place in the system studied. 5 figs., 3 tabs.

  8. A study of the crystallization of ZrO

    International Nuclear Information System (INIS)

    Aguilar, D. H.; Torres-Gonzalez, L. C.; Torres-Martinez, L. M.; Lopez, T.; Quintana, P.

    2001-01-01

    ZrO(sub 2)-SiO(sub 2) sol-gel powders were produced using tetraethoxysilane (TEOS) and zirconium propoxide. After gellation, the ZrO(sub 2) crystallization process was investigated using X-ray diffraction (XRD), thermal analysis (DTA/TGA), and scanning electron microscopy (SEM). Fresh gels were amorphous. Thermal treatments were carried out from 100 to 1400 C for a total annealing time of 182 h. Tetragonal zirconia, (Z(t)) was the first phase to crystallize, between 300 and 500 C. Crystallization temperature was lower for zirconia-rich compositions, increasing as silica content was raised. DTA analysis showed that Z(t) crystallization occurred in two stages. Complete tetragonal-monoclinic zirconia transformation occurred near 1000 C, and was clearly observed only in ZrO(sub 2)-rich compositions ( and gt;80%). Silica remains amorphous until 1200 C, when ZrSiO(sub 4) formation took place. A metastable sol-gel phase diagram was proposed to show the crystallization process between 100 and 1400 C

  9. A thermodynamic framework for the study of crystallization in polymers

    Science.gov (United States)

    Rao, I. J.; Rajagopal, K. R.

    In this paper, we present a new thermodynamic framework within the context of continuum mechanics, to predict the behavior of crystallizing polymers. The constitutive models that are developed within this thermodynamic setting are able to describe the main features of the crystallization process. The model is capable of capturing the transition from a fluid like behavior to a solid like behavior in a rational manner without appealing to any adhoc transition criterion. The anisotropy of the crystalline phase is built into the model and the specific anisotropy of the crystalline phase depends on the deformation in the melt. These features are incorporated into a recent framework that associates different natural configurations and material symmetries with distinct microstructural features within the body that arise during the process under consideration. Specific models are generated by choosing particular forms for the internal energy, entropy and the rate of dissipation. Equations governing the evolution of the natural configurations and the rate of crystallization are obtained by maximizing the rate of dissipation, subject to appropriate constraints. The initiation criterion, marking the onset of crystallization, arises naturally in this setting in terms of the thermodynamic functions. The model generated within such a framework is used to simulate bi-axial extension of a polymer film that is undergoing crystallization. The predictions of the theory that has been proposed are consistent with the experimental results (see [28] and [7]).

  10. Phormidium phycoerythrin forms hexamers in crystals: a crystallographic study

    Science.gov (United States)

    Sonani, Ravi Raghav; Sharma, Mahima; Gupta, Gagan Deep; Kumar, Vinay; Madamwar, Datta

    2015-01-01

    The crystallographic analysis of a marine cyanobacterium (Phormidium sp. A09DM) phycoerythrin (PE) that shows distinct sequence features compared with known PE structures from cyanobacteria and red algae is reported. Phormidium PE was crystallized using the sitting-drop vapour-diffusion method with ammonium sulfate as a precipitant. Diffraction data were collected on the protein crystallography beamline at the Indus-2 synchrotron. The crystals diffracted to about 2.1 Å resolution at 100 K. The crystals, with an apparent hexagonal morphology, belonged to space group P1, with unit-cell parameters a = 108.3, b = 108.4 Å, c = 116.6 Å, α = 78.94, β = 82.50, γ = 60.34°. The molecular-replacement solution confirmed the presence of 12 αβ monomers in the P1 cell. The Phormidium PE elutes as an (αβ)3 trimer of αβ monomers from a molecular-sieve column and exists as [(αβ)3]2 hexamers in the crystal lattice. Unlike red algal PE proteins, the hexamers of Phormidium PE do not form higher-order structures in the crystals. The existence of only one characteristic visual absorption band at 564 nm suggests the presence of phycoerythrobilin chromophores, and the absence of any other types of bilins, in the Phormidium PE assembly. PMID:26249689

  11. Study of channeling phenomena in bent crystals the new frontiers

    CERN Document Server

    Bolognini, Davide; Scandale, Walter; Vallazza, Erik

    2008-01-01

    More or less 30 years ago, it was experimentally demonstrated how a bent crystal can become a magnet: an object 1 mm thick, a couple of mm wide and a few cm high is, in fact, capable of steering particles as a dipole of several tens of Tesla. Exploiting this feature, from September 2006 the H8RD22 collaboration is testing several bent crystals in order to develop a crystal based collimation system for LHC: in very high energy accelerators, in fact, the typical multi-stage collimation system (that must be very efficient and must tolerate very high radiation) is expected not to allow to reach the nominal luminosity, limiting it to 40% of the desired value. A bent crystal could play a key role being a clever collimator: it is able to steer particles in a given direction with a high efficiency, thus increasing the cleaning efficiency, reducing the constraints on the alignment of the secondary collimator and finally increasing luminosity. But bent crystals are not only collimation: the radiation emitted by light p...

  12. Laboratory studies on the uptake of aromatic hydrocarbons by ice crystals during vapor depositional crystal growth

    Science.gov (United States)

    Fries, Elke; Starokozhev, Elena; Haunold, Werner; Jaeschke, Wolfgang; Mitra, Subir K.; Borrmann, Stephan; Schmidt, Martin U.

    Uptake of aromatic hydrocarbons (AH) by ice crystals during vapor deposit growth was investigated in a walk-in cold chamber at temperatures of 242, 251, and 260 K, respectively. Ice crystals were grown from ambient air in the presence of gaseous AH namely: benzene (C 6H 6), toluene (methylbenzene, C 7H 8), the C 8H 10 isomers ethylbenzene, o-, m-, p-xylene (dimethylbenzenes), the C 9H 12 isomers n-propylbenzene, 4-ethyltoluene, 1,3,5-trimethylbenzene (1,3,5-TMB), 1,2,4-trimethylbenzene (1,2,4-TMB), 1,2,3-trimethylbenzene (1,2,3-TMB), and the C 10H 14 compound tert.-butylbenzene. Gas-phase concentrations calculated at 295 K were 10.3-20.8 μg m -3. Uptake of AH was detected by analyzing vapor deposited ice with a very sensitive method composed of solid-phase micro-extraction (SPME), followed by gas chromatography/mass spectrometry (GC/MS). Ice crystal size was lower than 1 cm. At water vapor extents of 5.8, 6.0 and 8.1 g m -3, ice crystal shape changed with decreasing temperatures from a column at a temperature of 260 K, to a plate at 251 K, and to a dendrite at 242 K. Experimentally observed ice growth rates were between 3.3 and 13.3×10 -3 g s -1 m -2 and decreased at lower temperatures and lower value of water vapor concentration. Predicted growth rates were mostly slightly higher. Benzene, toluene, ethylbenzene, and xylenes (BTEX) were not detected in ice above their detection limits (DLs) of 25 pg g ice-1 (toluene, ethylbenzene, xylenes) and 125 pg g ice-1 (benzene) over the entire temperature range. Median concentrations of n-propylbenzene, 4-ethyltoluene, 1,3,5-TMB, tert.-butylbenzene, 1,2,4-TMB, and 1,2,3-TMB were between 4 and 176 pg g ice-1 at gas concentrations of 10.3-10.7 μg m -3 calculated at 295 K. Uptake coefficients ( K) defined as the product of concentration of AH in ice and density of ice related to the product of their concentration in the gas phase and ice mass varied between 0.40 and 10.23. K increased with decreasing temperatures. Values of

  13. Soil methane and CO2 fluxes in rainforest and rubber plantations

    Science.gov (United States)

    Lang, Rong; Blagodatsky, Sergey; Goldberg, Stefanie; Xu, Jianchu

    2017-04-01

    Expansion of rubber plantations in South-East Asia has been a land use transformation trend leading to losses of natural forest cover in the region. Besides impact on ecosystem carbon stocks, this conversion influences the dynamics of greenhouse gas fluxes from soil driven by microbial activity, which has been insufficiently studied. Aimed to understand how land use change affects the soil CO2 and CH4 fluxes, we measured surface gas fluxes, gas concentration gradient, and 13C signature in CH4 and soil organic matter in profiles in a transect in Xishuangbanna, including a rainforest site and three rubber plantation sites with age gradient. Gas fluxes were measured by static chamber method and open chamber respiration system. Soil gases were sampled from installed gas samplers at 5, 10, 30, and 75cm depth at representative time in dry and rainy season. The soil CO2 flux was comparable in rainforest and old rubber plantations, while young rubber plantation had the lowest rate. Total carbon content in the surface soil well explained the difference of soil CO2 flux between sites. All sites were CH4 sinks in dry season and uptake decreased in the order of rainforest, old rubber plantations and young rubber plantation. From dry season to rainy season, CH4 consumption decreased with increasing CH4 concentration in the soil profile at all depths. The enrichment of methane by 13CH4 shifted towards to lowerδ13C, being the evidence of enhanced CH4 production process while net surface methane flux reflected the consumption in wet condition. Increment of CH4 concentration in the profile from dry to rainy season was higher in old rubber plantation compared to rainforest, while the shifting of δ13CH4 was larger in rainforest than rubber sites. Turnover rates of soil CO2 and CH4 suggested that the 0-5 cm surface soil was the most active layer for gaseous carbon exchange. δ13C in soil organic matter and soil moisture increased from rainforest, young rubber plantation to old

  14. Effects of Running Shoes with Abrasion Resistant Rubber Sole on the Exercise Capacity of the Human Body

    Directory of Open Access Journals (Sweden)

    Bo Wang

    2017-10-01

    Full Text Available With the development of industrialization, rubber has been gradually used in the manufacture of sports equipment for its favourable properties. This study involved the addition of C5 petroleum resin into brominated isobutylene-isoprene rubber (BIIR and butadiene rubber (BR while manufacturing the sole of running shoes. The effects of running shoes with abrasion resistant rubber sole on the exercise capacity of the human body were investigated by analysing the skid resistance and abrasion resistance of the running shoes, and conducting biomechanical study on naked feet and feet wearing the shoes. The results demonstrated that the rubber sole had favourable slip resistance property and mechanical properties such as stretching, abrasion resistance, and hardness. Compared to naked feet, the peak pressure intensity of the whole step of feet wearing the newly developed shoes, was significantly lower than that of feet wearing ordinary shoes. In the future, rubber can bring more comfortable experience because of its favourable properties.

  15. Effects of simulant mixed waste on EPDM and butyl rubber

    International Nuclear Information System (INIS)

    Nigrey, P.J.; Dickens, T.G.

    1997-11-01

    The authors have developed a Chemical Compatibility Testing Program for the evaluation of plastic packaging components which may be used in transporting mixed waste forms. In this program, they have screened 10 plastic materials in four liquid mixed waste simulants. These plastics were butadiene-acrylonitrile copolymer (Nitrile) rubber, cross-linked polyethylene, epichlorohydrin rubber, ethylene-propylene (EPDM) rubber, fluorocarbons (Viton and Kel-F trademark), polytetrafluoro-ethylene (Teflon), high-density polyethylene, isobutylene-isoprene copolymer (Butyl) rubber, polypropylene, and styrene-butadiene (SBR) rubber. The selected simulant mixed wastes were (1) an aqueous alkaline mixture of sodium nitrate and sodium nitrite; (2) a chlorinated hydrocarbon mixture; (3) a simulant liquid scintillation fluid; and (4) a mixture of ketones. The screening testing protocol involved exposing the respective materials to approximately 3 kGy of gamma radiation followed by 14-day exposures to the waste simulants at 60 C. The rubber materials or elastomers were tested using Vapor Transport Rate measurements while the liner materials were tested using specific gravity as a metric. The authors have developed a chemical compatibility program for the evaluation of plastic packaging components which may be incorporated in packaging for transporting mixed waste forms. From the data analyses performed to date, they have identified the thermoplastic, polychlorotrifluoroethylene, as having the greatest chemical compatibility after having been exposed to gamma radiation followed by exposure to the Hanford Tank simulant mixed waste. The most striking observation from this study was the poor performance of polytetrafluoroethylene under these conditions. In the evaluation of the two elastomeric materials they have concluded that while both materials exhibit remarkable resistance to these environmental conditions, EPDM has a greater resistance to this corrosive simulant mixed waste

  16. The role of linked phospholipids in the rubber-filler interaction in carbon nanotube (CNT) filler natural rubber (NR) composites

    NARCIS (Netherlands)

    Le, H.H.; Abhijeet, S.; Ilish, S.; Klehm, J.; Henning, S.; Beiner, M.; Sarkawi, S.S.; Dierkes, Wilma K.; Das, A.; Fischer, D.; Stöckelhuber, K.-W.; Wiessner, S.; Khatiwada, S.P.; Adhikari, R.; Pham, T.; Heinrich, G.; Radusch, H.-J.

    2014-01-01

    The aim of the present work is to evidence the role of the linked phospholipids of natural rubber (NR) in the rubber-carbon nanotube (CNT) interactions in rubber composites. Three rubbers namely NR, deproteinized NR (DPNR) and a synthetic rubber isoprene (IR) were used as matrix for CNTs. The

  17. Virtual Crystallizer

    Energy Technology Data Exchange (ETDEWEB)

    Land, T A; Dylla-Spears, R; Thorsness, C B

    2006-08-29

    Large dihydrogen phosphate (KDP) crystals are grown in large crystallizers to provide raw material for the manufacture of optical components for large laser systems. It is a challenge to grow crystal with sufficient mass and geometric properties to allow large optical plates to be cut from them. In addition, KDP has long been the canonical solution crystal for study of growth processes. To assist in the production of the crystals and the understanding of crystal growth phenomena, analysis of growth habits of large KDP crystals has been studied, small scale kinetic experiments have been performed, mass transfer rates in model systems have been measured, and computational-fluid-mechanics tools have been used to develop an engineering model of the crystal growth process. The model has been tested by looking at its ability to simulate the growth of nine KDP boules that all weighed more than 200 kg.

  18. Maleic anhydride grafting on EPDM rubber in the melt

    NARCIS (Netherlands)

    Oostenbrink, A.J.; Oostenbrink, A.J.; Gaymans, R.J.

    1992-01-01

    The grafting of maleic anhydride on a EPDM rubber was studied with a twin screw extruder. The effect of barrel temperatures, throughput, maleic anhydride concentration and peroxide concentration [bis(t-butyl peroxy isopropyl)benzene] on the degree of grafting and melt viscosity was studied. The

  19. Crystallization of some amorphous metallic alloys studied by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Sitek, J.; Miglierini, M.; Lipka, J.; Valko, P.; Toth, I.

    1990-01-01

    The present work provides an analysis of crystallization processes in amorphous metallic alloys Fe 80 Si 4 Cr 1.8 B 14 and Fe 67 Co 18 B 14 Si 1 . Crystallization of the first sample started at the temperature of 648 K. The fully crystalline state was observed after annealing at 748 K. We identified four sextets. One corresponds to crystalline Fe 2 B and the three others to FeSi solid solution with 10 at.% of Si. Crystallization of Fe 67 Co 18 B 14 Si 1 started at the temperature of 623 K. We identified two crystalline phases. The first may have its origin as (Fe 1-x Co x ) 3 B, the second one may correspond to a Fe-Co solid solution with a different Co content. (orig.)

  20. Study of crystallization kinetics of peek thermoplastics using Nakamura equation

    Science.gov (United States)

    Chalid, Mochamad; Muhammad Joshua Y., B.; Fikri, Arbi Irsyad; Gregory, Noel; Priadi, Dedi; Fatriansyah, Jaka Fajar

    2018-04-01

    We have simulated the time evolution of relative crystallization of PEEK at various cooling rates (10, 15, 20 °C/min) and made comparison with the experiments. The simulation was conducted using Nakamura model which is a modified Avrami model. The model is a 1 cm radius of circle with the cooling plate which was placed in the upper part of the circle. The cooling plate temperature was varied in order to obtain particular cooling rates. The measurement point is located near upper boundary in order to minimize the heat transfer effect. The general trend of time evolution of crystallization was well captured although some discrepancies occured. These discrepancies may be attributed to the heat transfer effect and secondary crystallization.

  1. Constructing better roads with asphalt rubber

    Directory of Open Access Journals (Sweden)

    Pais Jorge C.

    2015-12-01

    Full Text Available Brazilians mixtures containing asphalt rubber were evaluated by mechanical laboratory tests. A conventional mixture with asphalt CAP-50/70 was produced as a mixture control. With the aim of compare the Brazilians mixtures performance, a Portuguese asphalt rubber mixture was tested as well. The testing set involved the determination of the mechanical properties, fatigue and permanent deformation, of asphalt rubber produced by wet process through two different systems: continuous blend and terminal blend. The asphalt rubber morphology was evaluated in order to determine the compatibility of the systems. The asphalt rubber mixtures exhibit good resistance to permanent deformation and prolonged fatigue life in relation to mixture control. Therefore it is concluded that the application of asphalt rubber alters the characteristics of asphalt mixture in a very beneficial way.

  2. Theoretical study of Cherenkov radiation emission in anisotropic uniaxial crystals

    Energy Technology Data Exchange (ETDEWEB)

    Delbart, A; Derre, J

    1996-04-01

    A theoretical review of the Cherenkov radiation emission in uniaxial crystals is presented. The formalism of C. Muzicar in terms of energetic properties of the emitted waves are corrected. This formalism is used to simulate the Cherenkov radiation emission in a strongly birefringent sodium nitrate crystal (NaNO{sub 3}) and to investigate the consequences of the slight anisotropy of sapphire (Al{sub 2}O{sub 3}) on the design of the Optical Trigger. (author). 12 refs. Submitted to Physical Review, D (US).

  3. Physical studies of porphyrin-infiltrated opal crystals

    Energy Technology Data Exchange (ETDEWEB)

    Sabataityte, J. [Semiconductor Physics Institute, Gostauto 11, LT 01108 Vilnius (Lithuania)], E-mail: julija@pfi.lt; Simkiene, I.; Babonas, G.-J.; Reza, A. [Semiconductor Physics Institute, Gostauto 11, LT 01108 Vilnius (Lithuania); Baran, M.; Szymczak, R. [Institute of Physics, PAN, PL 02668, Warsaw (Poland); Vaisnoras, R.; Rasteniene, L. [Vilnius Pedagogical University, LT 08106, Vilnius (Lithuania); Golubev, V.; Kurdyukov, D. [Ioffe Physico-Technical Institute RAS, 194021, St. Petersburg (Russian Federation)

    2007-09-15

    Artificial opals made of silica spheres and infiltrated with aqueous solution of iron porphyrin (FeTPPS) possessing the absorption band in a visible spectral range were studied. The structural, optical and magnetic properties of composite structures were investigated. Bulk samples of opal structure were obtained by sedimentation technique from colloidal solution of SiO{sub 2} spheres of diameter 240 and 245 nm. The structure of the samples was examined by atomic force microscopy. The properties of photonic crystals were demonstrated by optical measurements in transmission and reflection modes. The stop band was observed in the region 510-550 nm. In samples annealed at 900 deg. C the width of the stop band increased to {approx} 70 nm. Aqueous solutions of FeTPPS of concentration {approx} 1.0 mM and various pH-values were used for infiltration. The infiltration has led to a change of photonic characteristics, position of the stop band and dependence on light incidence angle. The absorption bands typical of FeTPPS were observed in the vicinity of the stop band. The photonic properties of infiltrated opal structures were determined to depend on the acidity of aqueous solution, which was used in technological procedure. Magnetic properties of FeTPPS-infiltrated opal samples, which have been studied at 5-300 K in magnetic fields up to 5 T, were discussed. From magnetic measurements it followed that magnetic Fe-Fe interactions have practically vanished in hybrid samples and Fe centers should be treated as isolated ones.

  4. Physical studies of porphyrin-infiltrated opal crystals

    International Nuclear Information System (INIS)

    Sabataityte, J.; Simkiene, I.; Babonas, G.-J.; Reza, A.; Baran, M.; Szymczak, R.; Vaisnoras, R.; Rasteniene, L.; Golubev, V.; Kurdyukov, D.

    2007-01-01

    Artificial opals made of silica spheres and infiltrated with aqueous solution of iron porphyrin (FeTPPS) possessing the absorption band in a visible spectral range were studied. The structural, optical and magnetic properties of composite structures were investigated. Bulk samples of opal structure were obtained by sedimentation technique from colloidal solution of SiO 2 spheres of diameter 240 and 245 nm. The structure of the samples was examined by atomic force microscopy. The properties of photonic crystals were demonstrated by optical measurements in transmission and reflection modes. The stop band was observed in the region 510-550 nm. In samples annealed at 900 deg. C the width of the stop band increased to ∼ 70 nm. Aqueous solutions of FeTPPS of concentration ∼ 1.0 mM and various pH-values were used for infiltration. The infiltration has led to a change of photonic characteristics, position of the stop band and dependence on light incidence angle. The absorption bands typical of FeTPPS were observed in the vicinity of the stop band. The photonic properties of infiltrated opal structures were determined to depend on the acidity of aqueous solution, which was used in technological procedure. Magnetic properties of FeTPPS-infiltrated opal samples, which have been studied at 5-300 K in magnetic fields up to 5 T, were discussed. From magnetic measurements it followed that magnetic Fe-Fe interactions have practically vanished in hybrid samples and Fe centers should be treated as isolated ones

  5. A Study of Biomolecules as Growth Modifiers of Calcium Oxalate Crystals

    Science.gov (United States)

    Kwak, Junha John

    Crystallization processes are ubiquitous in nature, science, and technology. Controlling crystal growth is pivotal in many industries as material properties and functions can be tailored by tuning crystal habits (e.g. size, shape, phase). In biomineralization, organisms exert excellent control over bottom-up synthesis and assembly of inorganic-organic structures (e.g. bones, teeth, exoskeletons). This is made possible by growth modifiers that range from small molecules to macromolecules, such as proteins. Molecular recognition of the mineral phase allows proteins to function as nucleation templates, matrices, and growth inhibitors or promoters. We are interested in taking a biomimetic approach to control crystallization via biomolecular growth modifiers. We investigated calcium oxalate monohydrate (COM), found in plants and kidney stones, as a model system of crystallization. We studied the effects of four common proteins on COM crystallization: bovine serum albumin (BSA), transferrin, lactoferrin, and lysozyme. Through kinetic studies of COM crystallization, we classified BSA and lysozyme as COM growth inhibitor and promoter respectively. Their inhibition and promotion effects were also evident in the macroscopic crystal habit. Through adsorption and microscopy experiments, we showed that BSA exhibits binding specificity for the apical surfaces of macroscopic COM crystals. Lysozyme, on the other, functions via a non-binding mechanism at the surface to accelerate the growth of the apical surfaces. We also synthesized and studied peptides derived from the protein primary sequences to identify putative domains responsible for these inhibition and promotion effects. Collectively, our study of physiologically relevant biomolecules suggests potential roles of COM modifiers in pathological crystallization and helps to develop guidelines for rational design of biomolecular growth modifiers for applications in crystal engineering.

  6. Insights into crystal growth rates from a study of orbicular granitoids from western Australia

    Science.gov (United States)

    Zhang, J.; Lee, C. T.

    2017-12-01

    The purpose of this study is to develop new tools for constraining crystal growth rate in geologic systems. Of interest is the growth of crystals in magmatic systems because crystallization changes the rheology of a magma as well as provides surfaces on which bubbles can nucleate. To explore crystal growth in more detail, we conducted a case study of orbicular granitoids from western Australia. The orbicules occur as spheroids dispersed in a granitic matrix. Most orbicules have at least two to three concentric bands, composed of elongate and radially oriented hornblende surrounded by interstitial plagioclase. We show that mineral modes and hence bulk composition at the scale of the band is homogeneous from rim to core. Crystal number density decreases and crystal size increases from rim to core. These observations suggest that the orbicules crystallized rapidly from rim to core. We hypothesize that the orbicules are blobs of hot dioritic liquid injected into a cold granitic magma and subsequently cooled and solidified. Crystals stop growing when the mass transport rate tends to zero due to the low temperature. We estimated cooling timescales based on conductive cooling models, constraining crystal growth rates to be 10-6 to 10-5 m/s. We also show that the oscillatory banding is controlled by disequilibrium crystallization, wherein hornblende preferentially crystallizes, resulting in the diffusive growth of a chemical boundary layer enriched in plagioclase component, which in turns results in crystallization of plagioclase. We show that the correlation between the width of each crystallization couplet (band) with distance from orbicule rim is linear, with the slope corresponding to the square root of the ratio between chemical diffusivity in the growth medium and thermal diffusivity. We estimate chemical diffusivity of 2*10-7 m2/s, which is remarkably fast for silicate liquids but reasonable for diffusion in hot aqueous fluids, suggesting that crystallization

  7. Radiation cured silicone rubber articles

    International Nuclear Information System (INIS)

    DuPont, J.G.; Goodwin, P.A.

    1984-01-01

    A process for making radiation cured silicone rubber articles is disclosed wherein a hydroxyl-terminated polysilaxane having a molecular weight from about 50,000 to about 2,000,000, optionally modified by mixing with up to 85% of an end-stopped silicone rubber, is mixed with from about 10 to about 70 parts per hundred of rubber of a finely divided silica filler with a particle size in the reinforcing range and other inert fillers as determined by desired final properties; the composition so prepared is formed into the desired shape at room temperature; the article so formed is precured to improve the mechanical properties of the material with which it is made by exposure to ammonia gas, ammonium hydroxide, or to the vapors or solutions of a volatile amine at room temperature; and the precured article is irradiated with high energy electrons or gamma radiation to effect a permanent cure of the material from which the article is formed

  8. Sonocrystallization—Case Studies of Salicylamide Particle Size Reduction and Isoniazid Derivative Synthesis and Crystallization

    Directory of Open Access Journals (Sweden)

    Zhen-Yu Yang

    2018-06-01

    Full Text Available Two case studies of salicylamide particle size reduction and isoniazid derivative synthesis and crystallization realized using sonocrystallization were investigated. The size, habit, structure, thermal behavior, and spectrometric properties of sonocrystallized crystals were analyzed through scanning electron microscopy (SEM, powder X-ray diffractometry (PXRD, differential scanning calorimetry (DSC, and Fourier transform infrared (FTIR spectroscopy. The effects of the operating parameters, such as sonication intensity, sonication duration, and solution concentration, on sonocrystallization were compared. The crystal size of salicylamide was reduced from 595 μm (the original size and was efficiently manipulated to be between 40 and 80 μm. Moreover, compared with the crystal habits of unprocessed crystals and recrystallized crystals fabricated through conventional methods, the crystal habit of salicylamide could be modified to present a regular shape. The structure, thermal behavior, and spectrometric properties of sonocrystallized salicylamide were found to be in agreement with those of an unprocessed sample. For producing isoniazid derivative crystals, N′-(propan-2-ylidene-isonicotinohydrazide was synthesized using isoniazid in acetone at 318 K. The resulting solution was then cooled by applying power ultrasound to isolate N′-(propan-2-ylidene-isonicotinohydrazide crystals. The solid-state properties of the synthesized N′-(propan-2-ylidene-isonicotinohydrazide was verified through PXRD, DSC, and FTIR spectroscopy. The feasibility of particle size manipulation was then demonstrated through sonocrystallization.

  9. Effects of Thermal and Humidity Aging on the Interfacial Adhesion of Polyketone Fiber Reinforced Natural Rubber Composites

    OpenAIRE

    Lee, Han Ki; Kim, Dae Sik; Won, Jong Sung; Jin, Da Young; Lee, Hyun Jae; Lee, Seung Goo

    2016-01-01

    Polyketone fiber is considered as a reinforcement of the mechanical rubber goods (MRG) such as tires, automobile hoses, and belts because of its high strength and modulus. In order to apply it to those purposes, the high adhesion of fiber/rubber interface and good sustainability to aging conditions are very important. In this study, polyketone fiber reinforced natural rubber composites were prepared and they were subjected to thermal and humidity aging, to assess the changes of the interfacia...

  10. Application of gamma irradiation for incorporation of rubber powder in the formulations of acrylonitrile-butadiene rubber (NBR)

    International Nuclear Information System (INIS)

    Kiyan, Ludmila Y.P.; Parra, Duclerc Fernandes

    2013-01-01

    Full text: Polymeric materials do not decompose easily, disposal of waste polymers is a major environmental problem of global character. Recycling is an economical alternative and environmentally recommended for polymers consumed and discarded by society. As regards the rubber in object, its natural decomposition is much slower due to their highly crosslinked, in three-dimensional networks, structures which makes it an infusible and insoluble material. Moreover, these three dimensional structures entails several problems for their recovery and reprocessing. The aim of this paper was to study the behavior of NBR rubber recycle. It was used rubber powder from industry. The powder was irradiated in master-batch composition and used directly in classical formulations for rubber vulcanization. The master-batch processed was irradiated at doses of 50, 100 and 150kGy in 60 Co source at 5 kGy s -1 rate, at room temperature. Gamma radiation created active sites during devulcanization that promoted further integration of the rubber powder in formulations for commercial use. The processes were compared and their products were characterized by analytical methods of the physical properties such as tensile strength and elongation. The greatest change in the properties of polymeric materials by exposure to ionizing radiation resulted mainly of two main reactions occurring in the polymer molecule: chains scission (degradation) and crosslinking. Although these two processes occur simultaneously in all the polymers, the predominance of one or other effect depends mainly of the chemical structure of each polymer, and the irradiation conditions. In the results was observed the behavior of nitrile rubber under different doses and radiation improvement of the mechanical properties. (author)

  11. Application of gamma irradiation for incorporation of rubber powder in the formulations of acrylonitrile-butadiene rubber (NBR)

    Energy Technology Data Exchange (ETDEWEB)

    Kiyan, Ludmila Y.P.; Parra, Duclerc Fernandes, E-mail: ludmilapozzo@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Quimica e Meio Ambiente (CQMA)

    2013-07-01

    Full text: Polymeric materials do not decompose easily, disposal of waste polymers is a major environmental problem of global character. Recycling is an economical alternative and environmentally recommended for polymers consumed and discarded by society. As regards the rubber in object, its natural decomposition is much slower due to their highly crosslinked, in three-dimensional networks, structures which makes it an infusible and insoluble material. Moreover, these three dimensional structures entails several problems for their recovery and reprocessing. The aim of this paper was to study the behavior of NBR rubber recycle. It was used rubber powder from industry. The powder was irradiated in master-batch composition and used directly in classical formulations for rubber vulcanization. The master-batch processed was irradiated at doses of 50, 100 and 150kGy in {sup 60}Co source at 5 kGy s{sup -1} rate, at room temperature. Gamma radiation created active sites during devulcanization that promoted further integration of the rubber powder in formulations for commercial use. The processes were compared and their products were characterized by analytical methods of the physical properties such as tensile strength and elongation. The greatest change in the properties of polymeric materials by exposure to ionizing radiation resulted mainly of two main reactions occurring in the polymer molecule: chains scission (degradation) and crosslinking. Although these two processes occur simultaneously in all the polymers, the predominance of one or other effect depends mainly of the chemical structure of each polymer, and the irradiation conditions. In the results was observed the behavior of nitrile rubber under different doses and radiation improvement of the mechanical properties. (author)

  12. Thermal endurance tests on silicone rubber specimens

    International Nuclear Information System (INIS)

    Warburton, C.

    1977-07-01

    Thermal endurance tests have been performed on a range of silicone rubber specimens at temperature above 300 0 C. It is suggested that the rubber mix A2426, the compound from which Wylfa sealing rings are manufactured, will fail at temperatures above 300 0 C within weeks. Hardness measurements show that this particular rubber performs in a similar manner to Walker's S.I.L./60. (author)

  13. Rubber hand illusion affects joint angle perception.

    Directory of Open Access Journals (Sweden)

    Martin V Butz

    Full Text Available The Rubber Hand Illusion (RHI is a well-established experimental paradigm. It has been shown that the RHI can affect hand location estimates, arm and hand motion towards goals, the subjective visual appearance of the own hand, and the feeling of body ownership. Several studies also indicate that the peri-hand space is partially remapped around the rubber hand. Nonetheless, the question remains if and to what extent the RHI can affect the perception of other body parts. In this study we ask if the RHI can alter the perception of the elbow joint. Participants had to adjust an angular representation on a screen according to their proprioceptive perception of their own elbow joint angle. The results show that the RHI does indeed alter the elbow joint estimation, increasing the agreement with the position and orientation of the artificial hand. Thus, the results show that the brain does not only adjust the perception of the hand in body-relative space, but it also modifies the perception of other body parts. In conclusion, we propose that the brain continuously strives to maintain a consistent internal body image and that this image can be influenced by the available sensory information sources, which are mediated and mapped onto each other by means of a postural, kinematic body model.

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

    International Nuclear Information System (INIS)

    Syuhada Ramli; Sofian Ibrahim; Mohd Noorwadi Mat Lazim

    2016-01-01

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

  15. Treatment of wastewater from rubber industry in Malaysia ...

    African Journals Online (AJOL)

    Treatment of wastewater from rubber industry in Malaysia. ... Discharge of untreated rubber effluent to waterways resulted in water pollution that affected the human health. ... Key words: Rubber industry, effluent, waste management, Malaysia.

  16. Study of gel grown mixed crystals of Bax Ca ((IO3) 4

    Indian Academy of Sciences (India)

    The growth of mixed crystals of BaCa1–(IO3)4 were carried out with simple gel method. The effect of various parameters such as pH of gel solution, gel concentration, gel setting time, concentration of reactants on the growth was studied. Crystals having different morphologies and habits were obtained. The grown ...

  17. Ellipsometric studies of ErMnO3 single crystals

    DEFF Research Database (Denmark)

    Babonas, G.-J.; Grivel, Jean-Claude; Reza, A.

    2007-01-01

    Ellipsometric studies of ErMnO3 single crystals have been carried out in the spectral range of 1-5 eV by means of photometric ellipsometers. Experimental ellipsometric data were analysed in the uniaxial crystal model. For the first time, the components of dielectric function of ErMnO3 were...

  18. X-ray diffraction studies of NbTe 2 single crystal

    Indian Academy of Sciences (India)

    The composition of the grown crystals was confirmed on the basis of energy dispersive analysis by X-ray (EDAX) and remaining structural characterization was also accomplished by X-ray diffraction (XRD) studies. Lattice parameters, volume and X-ray density have been carried out for the grown crystals. The particle size ...

  19. Crystallization study of amorphous system Fe84-xWxB16 (x = 3;5)

    International Nuclear Information System (INIS)

    Novakova, A.A.; Sidorova, G.V.; Kiseleva, T.Yu.; Szasz, A.

    1992-01-01

    A complex study of the crystallization process of the amorphous system was carried out by Moessbauer spectroscopy, X-ray diffraction and DTA. Alloy samples crystallized at 600deg C contain the following phases: α-Fe, Fe 3 B and solid solution (Fe, W) 3 B. (orig.)

  20. Growth and study of barium oxalate single crystals in agar gel

    Indian Academy of Sciences (India)

    Barium oxalate was grown in agar gel at ambient temperature. The effect of various parameters like gel concentration, gel setting time and concentration of the reactants on the growth of these crystals was studied. Prismatic platy shaped spherulites and dendrites were obtained. The grown crystals were characterized by ...

  1. Study on crystallization behaviour of co-polyamide 66 containing ...

    Indian Academy of Sciences (India)

    Triaryl phosphine oxide (TPO) compounds, which as a type of flame ... The image of .... ation rate and crystallization properties of FR-PA66 were ..... Polarized optical microscopy images for (a) PA66 and (b) FR-PA66 after constant temperature ...

  2. Bulk study of a DyNiAl single crystal

    Czech Academy of Sciences Publication Activity Database

    Prchal, J.; Andreev, Alexander V.; Javorský, P.; Honda, F.; Jurek, Karel

    272-276, - (2004), e419-e420 ISSN 0304-8853 R&D Projects: GA ČR GA106/02/0943 Keywords : rare-earth * DyNiAl * magnetic anisotropy * single crystal Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.031, year: 2004

  3. Calorimetric studies of non-isothermal crystallization in amorphous

    Indian Academy of Sciences (India)

    Administrator

    the peak crystallization temperature. Amorphous alloys of Cu–Ti system are of special interest (Koster et al 1995) due to the fact that Cu–Ti is a congruently melting compound, which should allow static under-cooling experiments. Several works ... tion when mixed with another metal or rare earth metals. (Suzuki et al 2003).

  4. Characterization and study of photonic crystal fibres with bends

    International Nuclear Information System (INIS)

    Belhadj, W.; AbdelMalek, F.; Bouchriha, H.

    2006-01-01

    Analysis of a photonic crystal fibre (PRCF) with bends is presented. Using the versatile finite difference time domain method, the modal characteristics of the PCFs are found. Possibilities of employing PCFs with bends in sensing are discussed. It is found that a large evanescent field is present when the bend angle exceeds 45 o

  5. Chemical modifications of liquid natural rubber

    Science.gov (United States)

    Azhar, Nur Hanis Adila; Rasid, Hamizah Md; Yusoff, Siti Fairus M.

    2016-11-01

    Liquid natural rubber (LNR) was synthesized via photosentisized degradation of natural rubber (NR). LNR was modified into epoxidized liquid natural rubber (LENR) and hydroxylated liquid natural rubber (LNR-OH) using Na2WO4/CH3COOH/H2O2 catalytic system. Chemical structures of LNR and modified LNRs were characterized using Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) and 1H Nuclear Magnetic Resonance (NMR) spectroscopies. Integration of 1H NMR was used to calculate the epoxy content (%) of LENR. 1H NMR detected the formation of LNR-OH after prolonged heating and increased of catalyst in oxidation reaction.

  6. Rubber Flooring Impact on Health of Dairy Cows

    Science.gov (United States)

    Use of rubber flooring in dairies has become popular because of perceived cow comfort. The objective of this longitudinal study was to evaluate locomotion, health, production, and immunity over the first 180d of each of the 1st and 2nd lactations of cows assigned to free-stall housing with either r...

  7. Rubber contact mechanics: adhesion, friction and leakage of seals.

    Science.gov (United States)

    Tiwari, A; Dorogin, L; Tahir, M; Stöckelhuber, K W; Heinrich, G; Espallargas, N; Persson, B N J

    2017-12-13

    We study the adhesion, friction and leak rate of seals for four different elastomers: Acrylonitrile Butadiene Rubber (NBR), Ethylene Propylene Diene (EPDM), Polyepichlorohydrin (GECO) and Polydimethylsiloxane (PDMS). Adhesion between smooth clean glass balls and all the elastomers is studied both in the dry state and in water. In water, adhesion is observed for the NBR and PDMS elastomers, but not for the EPDM and GECO elastomers, which we attribute to the differences in surface energy and dewetting. The leakage of water is studied with rubber square-ring seals squeezed against sandblasted glass surfaces. Here we observe a strongly non-linear dependence of the leak rate on the water pressure ΔP for the elastomers exhibiting adhesion in water, while the leak rate depends nearly linearly on ΔP for the other elastomers. We attribute the non-linearity to some adhesion-related phenomena, such as dewetting or the (time-dependent) formation of gas bubbles, which blocks fluid flow channels. Finally, rubber friction is studied at low sliding speeds using smooth glass and sandblasted glass as substrates, both in the dry state and in water. The measured friction coefficients are compared to theory, and the origin of the frictional shear stress acting in the area of real contact is discussed. The NBR rubber, which exhibits the strongest adhesion both in the dry state and in water, also shows the highest friction both in the dry state and in water.

  8. Pyrolysis of rubber gloves in integral pyrolysis test plant

    International Nuclear Information System (INIS)

    Norasalwa Zakaria; Mohd Noor Muhd Yunus; Mohd Annuar Assadat Husain; Farid Nasir Ani

    2010-01-01

    Previously, pyrolysis of rubber gloves in laboratory study was described. In order to visualize the practical application of rubber gloves pyrolysis in terms of treating rubber gloves in medical waste, a new test plant was designed and constructed. The semi-continuous test plant was designed to accommodate rubber gloves that were not cut or shredded. The test plant has a capacity of 2kg/ hr and employed auxiliary fuel instead of the conventional electrical power for heating. The concept was based on moving bed reactor, but additional feature of sand jacket feature was also introduced in the design. Pyrolysis of the gloves was conducted at three temperatures, namely 350 degree Celsius, 400 degree Celsius and 450 degree Celsius. Oxygen presents inside of the reactor due to the combined effect of imperfect sealing and suction effect. This study addresses the performance of this test plant covering the time temperature profile, gas evolution profile and product yield. Comparison between the yield of the liquid, gas and char pyrolyzate was made against the laboratory study. It was found that the oil yield was less than the one obtained from bench scale study. Water formation was more pronounced. The presence of the oxygen also altered the tail gas composition but eliminate the sticky nature of solid residue, making it easier to handle. The chemical composition of the oil was determined and the main compounds in the oil were esters and phtalic acid. (author)

  9. Laterality in the rubber hand illusion.

    Science.gov (United States)

    Ocklenburg, Sebastian; Rüther, Naima; Peterburs, Jutta; Pinnow, Marlies; Güntürkün, Onur

    2011-03-01

    In patient studies, impairments of sense of body ownership have repeatedly been linked to right-hemispheric brain damage. To test whether a right-hemispheric dominance for sense of body ownership could also be observed in healthy adults, the rubber hand illusion was elicited on both hands of 21 left-handers and 22 right-handers. In this illusion, a participant's real hand is stroked while hidden from view behind an occluder, and a nearby visible hand prosthesis is repeatedly stroked in synchrony. Most participants experience the illusionary perception of touch sensations arising from the prosthesis. The vividness of the illusion was measured by subjective self-reports as well as by skin conductance responses to watching the rubber hand being harmed. Handedness did not affect the vividness of the illusion, but a stronger skin conductance response was observed, when the illusion was elicited on the left hand. These findings suggest a right-hemispheric dominance for sense of body ownership in healthy adults.

  10. Rubber dam may increase the survival time of dental restorations.

    Science.gov (United States)

    Keys, William; Carson, Susan J

    2017-03-01

    Data sourcesCochrane Oral Health's Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, LILACS, SciELO, Chinese BioMedical Literature Database, VIP, China National Knowledge Infrastructure, ClinicalTrials.gov, World Health Organization International Clinical Trials Registry Platform, OpenGrey and Sciencepaper Online databases. Handsearches in a number of journals.Study selectionRandomised controlled trials, including split-mouth studies assessing the effects of rubber dam isolation for restorative treatments in dental patients.Data extraction and synthesisTwo review authors independently screened the results of the electronic searches, extracted data and assessed the risk of bias of the included studies.ResultsFour studies involving a total of 1,270 patients were included. The studies were at high risk of bias. One trial was excluded from the analysis due to inconsistencies in the presented data. Restorations had a significantly higher survival rate in the rubber dam isolation group compared to the cotton roll isolation group at six months in participants receiving composite restorative treatment of non-carious cervical lesions (risk ratio (RR) 1.19, 95% confidence interval (CI) 1.04 to 1.37, very low-quality evidence). The rubber dam group had a lower risk of failure at two years in children undergoing proximal atraumatic restorative treatment in primary molars (hazard ratio (HR) 0.80, 95% CI 0.66 to 0.97, very low-quality evidence). One trial reported limited data showing that rubber dam usage during fissure sealing might shorten the treatment time. None of the included studies mentioned adverse effects or reported the direct cost of the treatment, or the level of patient acceptance/satisfaction. There was also no evidence evaluating the effects of rubber dam usage on the quality of the restorations.ConclusionsWe found some very low-quality evidence, from single studies, suggesting that rubber dam usage in dental direct

  11. Predisposition to out-of-body experience (OBE) is associated with aberrations in multisensory integration: Psychophysiological support from a "rubber hand illusion" study.

    Science.gov (United States)

    Braithwaite, Jason J; Watson, Derrick G; Dewe, Hayley

    2017-06-01

    It has been argued that disorders in body-ownership and aberrant experiences in self-consciousness are due to biases in multisensory integration. Here we examine whether such biases are also associated with spontaneous out-of-body experiences (OBEs) in a nonclinical population. One-hundred and 80 participants took part in a rubber hand illusion (RHI) experiment with synchronous and asynchronous visual and tactile stimulation. A realistic threat was delivered to the rubber hand after a fixed period of stimulation. Self-report exit questionnaires measured the subjective strength of the illusion and psychophysiological measures (skin conductance responses/finger temperature) provided an objective index of fear/anxiety toward the threat. Control participants reported a stronger RHI, and revealed larger threat-related skin conductance responses during synchronous compared with asynchronous brushing. For participants predisposed to OBEs, the magnitude of the skin conductance was not influenced by brushing synchrony-fear responses were just as strong in the asynchronous condition as they were in the synchronous condition. There were also no reliable effects of finger temperature for either group. Collectively, these findings are taken as support for the presence of particular biases in multisensory integration (perhaps via predictive coding mechanisms) in which imprecise top-down tuning occurs resulting in aberrant experiences in self-consciousness even in nonclinical hallucinators. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  12. Purification, crystallization and preliminary X-ray diffraction studies of parakeet (Psittacula krameri) haemoglobin

    International Nuclear Information System (INIS)

    Jaimohan, S. M.; Naresh, M. D.; Arumugam, V.; Mandal, A. B.

    2009-01-01

    Parakeet (Psittacula krameri) haemoglobin has been purified and crystallized under low salt buffered conditions. Preliminary analysis of the crystal that belonged to monoclinic system (C2) is reported. Birds often show efficient oxygen management in order to meet the special demands of their metabolism. However, the structural studies of avian haemoglobins (Hbs) are inadequate for complete understanding of the mechanism involved. Towards this end, purification, crystallization and preliminary X-ray diffraction studies have been carried out for parakeet Hb. Parakeet Hb was crystallized as the met form in low-salt buffered conditions after extracting haemoglobin from crude blood by microcentrifugation and purifying the sample by column chromatography. Good-quality crystals were grown from 10% PEG 3350 and a crystal diffracted to about 2.8 Å resolution. Preliminary diffraction data showed that the Hb crystal belonged to the monoclinic system (space group C2), with unit-cell parameters a = 110.68, b = 64.27, c = 56.40 Å, β = 109.35°. Matthews volume analysis indicated that the crystals contained a half-tetramer in the asymmetric unit

  13. “I can't tell whether it's my hand”: a pilot study of the neurophenomenology of body representation during the rubber hand illusion in trauma-related disorders

    Directory of Open Access Journals (Sweden)

    Daniela Rabellino

    2016-11-01

    Full Text Available Background: Early traumatic experiences are thought to be causal factors in the development of trauma-related dissociative experiences, including depersonalization and derealization. The rubber hand illusion (RHI, a well-known paradigm that measures multi-sensorial integration of a rubber hand into one's own body representation, has been used to investigate alterations in the experience of body ownership and of body representation. Critically, however, it has never been studied in individuals with trauma-related disorders. Objective: To investigate body representation distortions occurring in trauma-related disorders in response to the RHI. Method: The RHI was administered to three individuals with the dissociative subtype of posttraumatic stress disorder (PTSD, and subjective, behavioral, cardiovascular and skin conductance responses were recorded. Results: Participants’ subjective experiences of the RHI were differentiated and complex. The illusion was induced following both synchronous and asynchronous brushing and variably evoked subjective distress, depersonalization and derealization experiences, tonic immobility, increased physiological arousal and flashbacks. Conclusions: The present findings point towards the RHI as a strong provocation stimulus that elicits individual patterns of symptom presentation, including experiences of distress and dissociation, in individuals with trauma-related disorders, including the dissociative subtype of PTSD. Highlights of the article:

  14. Study of dopamine reactivity on platinum single crystal electrode surfaces

    International Nuclear Information System (INIS)

    Chumillas, Sara; Figueiredo, Marta C.; Climent, Víctor; Feliu, Juan M.

    2013-01-01

    Dopamine is the biological molecule responsible, among other functions, of the heart beat and blood pressure regulation. Its loss, in the human body, can result in serious diseases such as Parkinson's, schizophrenia or depression. Structurally, this molecule belongs to the group of catecholamines, together with epinephrine (adrenaline) and norepinephrine (noradrenaline). The hydroquinone moiety of the molecule can be easily oxidized to quinone, rendering the electrochemical methods a convenient approach for the development of dopamine biosensors. The reactivity of similar aromatic molecules, such as catechol and hydroquinone, at well-ordered platinum surfaces, has recently been investigated in our group. In this paper, we extend these studies to the structurally related molecule dopamine. The study has been performed in neutral pH, since this is closer to the natural conditions for these molecules in biological media. Cyclic voltammetry and in situ infra-red spectroscopy have been combined to extract information about the behavior of this molecule on well-defined platinum surfaces. Dopamine appears to be electrochemically active and reveals interesting adsorption phenomena at low potentials (0.15–0.25 V vs RHE), sensitive to the single crystal orientation. The adsorption of dopamine on these surfaces is very strong, taking place at much lower potentials than the electron transfer from solution species. Specifically, the voltammetry of Pt(1 1 1) and Pt(1 0 0) in dopamine solutions shows an oxidation peak at potentials close to the onset of hydrogen evolution, which is related to the desorption of hydrogen and the adsorption of dopamine. On the other hand, adsorption on Pt(1 1 0) is irreversible and the surface appears totally blocked. Spectroscopic results indicate that dopamine is adsorbed flat on the surface. At potentials higher than 0.6 V vs RHE the three basal planes show a common redox process. The initial formation of the quinone moiety is followed by a

  15. Natural Rubber Modification For Upper Layer Of Rubberized Asphalt Paving Block AS Shock Absorber

    OpenAIRE

    Nasruddin, Nasruddin

    2017-01-01

    The research of rubber compounding modification for upper layer of rubberized asphalt paving block as shock absorber using natural rubber, styrene butadiene rubber (SBR) as synthetic rubber, fly ash as filler and also vegetable oil as plasticizer has been conducted. The research design was varying the filler Si-69, fly ash and palm oil. The five formulas A, B, C, D, and E designed by varying the amount of Si-69 (48.5; 50.75; 53.00; 55.25; and 57.50) phr; coal fly ash (4.75, 7.00, 9.25, 11.50 ...

  16. A systematic study of the isothermal crystallization of the mono-alcohol n-butanol monitored by dielectric spectroscopy

    DEFF Research Database (Denmark)

    Jensen, Mikkel Hartmann; Hecksher, Tina; Niss, Kristine

    2015-01-01

    Isothermal crystallization of the mono-hydroxyl alcohol n-butanol was studied with dielectric spectroscopy in real time. The crystallization was carried out using two different sample cells at 15 temperatures between 120 K and 134 K. Crystallization is characterized by a decrease of the dielectric...... intensity. In addition, a shift in relaxation times to shorter times was observed during the crystallization process for all studied temperatures. The two different sample environments induced quite different crystallization behaviors, consistent and reproducible over all studied temperatures...... that a microscopic interpretation of crystallization measurements requires multiple probes, sample cells, and protocols....

  17. [The criterion prognostic significance of examinations of chemiluminescence of oral fluid under impact of chemical pollutants of manufacture of rubber and rubber technical production].

    Science.gov (United States)

    Galiullina, E F; Valiev, A v; Kamilov, R F; Shakirov, D F; Buliakov, P T

    2013-12-01

    The article presents the results of studies concerning the effect of unfavorable factors of chemical nature on fluid of oral cavity among workers of the Ufa plant of elastomer materials, articles and structures. It is established that in persons contacting with chemical pollutants of manufacture of rubber and rubber technical production the indicators of chemiluminescence of saliva fluid are significantly expressed and depend on professional standing.

  18. Strong crystal field effect in ? - optical absorption study

    Science.gov (United States)

    Gajek, Z.; Krupa, J. C.

    1998-12-01

    =-1 Results of optical absorption measurements in polarized light on tetravalent neptunium diluted in a 0953-8984/10/50/021/img6 single crystal are reported. The recorded spectra are complex, pointing to the presence of an 0953-8984/10/50/021/img7 impurity. The electronic transitions assigned to the 0953-8984/10/50/021/img8 ion are interpreted in terms of the usual model, following the actual understanding of the neptunium electronic structure and independent theoretical predictions. R.m.s. deviations of the order of 0953-8984/10/50/021/img9 have been obtained for 42 levels fitted with 11 free parameters. The crystal field effect resulting from the fitting is considerably larger than that observed for the uranium ion in the same host.

  19. A study on light collection of small scintillating crystals

    CERN Document Server

    Vittori, F; Malatesta, T; Puertolas, D

    2000-01-01

    Measurements are described concerning the light collection efficiency of YAP:Ce and CsI(Tl) crystals pillars with thicknesses ranging between 3 and 28 mm and cross-sections of 0.6 x 0.6 and 1 x 1 mm sup 2. These measurements have shown that the light collection is strongly dependent on the length of the pillar rather than on its cross-sectional area. A Monte Carlo code has been developed in order to evaluate the light collection efficiency as a function of the pillar geometry and surface treatment. Particular attention has been paid to the light transition through the crystal-photocathode window interface. The possibility to improve light detection by using a new photon detector provided with a YAP photocathode window has been verified.

  20. Crystal structure studies on plate/shelf like disodium ditungstate

    Indian Academy of Sciences (India)

    Inorganic materials; disodium ditungstate; crystal structure; scanning electron microscopy; X-ray ... generation, and horizontal electric furnace with quartz tube ... Unit cell dimensions: a = 7·22192(11) Е, b = 11·91559(17) Е, c = 14·74755(23) Е. Cell content: 8 Na2W2O7). Atom. Position. X(σ(X)). Y(σ(Y)). Z(σ(Z)). B(σ(B)). W (1).

  1. Multiple x-ray diffraction applied to the study of crystal impurities

    International Nuclear Information System (INIS)

    Cardoso, L.P.

    1983-06-01

    The x-ray multiple diffraction technique is used in the study of impurities concentration and localization in the crystal lattice, implemented with the fundamental observation that the impurities cannot be distributed with the same spatial group symmetry of the crystal. This fact could introduce scattered intensity in the crystal reciprocal lattice forbidden nodes. This effect was effectively observed in multiple diffraction diagrams, where a reinforcement of the scattered intensity in the pure crystal is produced, when choosing conveniently the involved reflections. The reflectivity theory was developed in the kinematic case, which take into account the scattering by the impurities atoms, and the analysis showed that, in the first approximation, the impurities can influence both in the allowed and forbidden positions for the pure crystal. (L.C.J.A.)

  2. Defect studies of ZnO single crystals electrochemically doped with hydrogen

    Science.gov (United States)

    Čížek, J.; Žaludová, N.; Vlach, M.; Daniš, S.; Kuriplach, J.; Procházka, I.; Brauer, G.; Anwand, W.; Grambole, D.; Skorupa, W.; Gemma, R.; Kirchheim, R.; Pundt, A.

    2008-03-01

    Various defect studies of hydrothermally grown (0001) oriented ZnO crystals electrochemically doped with hydrogen are presented. The hydrogen content in the crystals is determined by nuclear reaction analysis and it is found that already 0.3at.% H exists in chemically bound form in the virgin ZnO crystals. A single positron lifetime of 182ps is detected in the virgin crystals and attributed to saturated positron trapping at Zn vacancies surrounded by hydrogen atoms. It is demonstrated that a very high amount of hydrogen (up to ˜30at.%) can be introduced into the crystals by electrochemical doping. More than half of this amount is chemically bound, i.e., incorporated into the ZnO crystal lattice. This drastic increase of the hydrogen concentration is of marginal impact on the measured positron lifetime, whereas a contribution of positrons annihilated by electrons belonging to O-H bonds formed in the hydrogen doped crystal is found in coincidence Doppler broadening spectra. The formation of hexagonal shape pyramids on the surface of the hydrogen doped crystals by optical microscopy is observed and discussed.

  3. Dynamic characteristics of lead rubber bearings with dynamic two-dimensional test equipment

    International Nuclear Information System (INIS)

    Ohtori, Y.; Ishida, K.; Mazda, T.

    1994-01-01

    Although studies have previously been done on the static mechanical properties of lead rubber bearings, this study aims to grasp the dynamic characteristics of lead rubber bearings from experimental results, using two-dimensional dynamic test equipment which is designed to grasp in detail such dynamic characteristics as deformation capacity and proof stress. This paper describes the results from three types of tests: (1) dynamic mechanical properties tests, (2) cyclic loading tests, and (3) dynamic ultimate tests. Through these tests, it was confirmed that the dynamic characteristics of lead rubber bearings are independent of strain rate

  4. On some peculiarities of oil-resisting rubbers production from nitrile rubber of different composition by the use of Co60 gamma irradiation

    International Nuclear Information System (INIS)

    Mamedov, Sh.M.; Nelikzade, M.M.; Mamedov, A.A.

    1976-01-01

    The physicomechanical properties and swelling of vulcanizates were studied by means of radiation vulcanization. The test samples were preheated and formed by a press at 154 deg C for 3 min. Irradiation was performed in atmosphere on 60 Co (dosage 0.48 Mrad/hr). Irradiation caused decrease in tensile strength, as well as relative and permanent elongation; at the same time it considerably strengthened rubber hardness. All the rubber samples showed greater strength after irradiation under 5.7-13.8 Mrad. Depending on the dosage (3.6-13.8 Mrad), the relative and permanent elongation of vulcanizates obtained with the aid of altax was found to decrease, while strength and swelling increased. The swelling of rubber samples obtained with thiurad and thiuradaltax compounds decreased. Hence the advisability of using that rubber for manufacture of petroleum-resistant products

  5. Mammography imaging studies using a laue crystal analyzer

    International Nuclear Information System (INIS)

    Chapman, D.; Thomlinson, W.; Arfelli, F.

    1995-01-01

    Synchrotron based mammography imaging experiments have been performed with monochromatic x-rays in which a laue crystal placed after the object being imaged has been used to split the beam transmitted through the object. The X27C R ampersand D beamline at the National Synchrotron Light Source was used with the white beam monochromatized by a double crystal Si(111) monochromator tuned to 18 keV. The imaging beam was a thin horizontal line approximately 0.5 mm high by 100 mm wide. Images were acquired in line scan mode with the phantom and detector both scanned together. The detector for these experiments was an image plate. A thin Si(l11) laue analyzer was used to diffract a portion of the beam transmitted through the phantom before the image plate detector. This ''scatter free'' diffracted beam was then recorded on the image plate during the phantom scan. Since the thin laue crystal also transmitted a fraction of the incident beam, this beam was also simultaneously recorded on the image plate. The imaging results are interpreted in terms of an x-ray schliere or refractive index inhomogeneities. The analyzer images taken at various points in the rocking curve will be presented

  6. Radioisotopic determination methods of sulphur dispersion and sulphur blooming in rubber compounds

    International Nuclear Information System (INIS)

    Goraczka, W.; Koczorowska, E.

    1997-01-01

    It is well known that the concentration of sulphur in rubber compounds essentially effects the structure of the vulkanizate network. But there are no efficient and accurate methods to estimate the dispersion and migration (blooming) of curatives in raw rubber. In the work radioisotope methods have been analyzed to study the dispersion of curatives, physical and chemical processes in rubber and to optimize technical conditions of tire production. The radioactivity of the 35 S isotope introduced into rubber compounds has been measured by volumetric and surface methods. It was proved that the radioisotopic methods can be used in the studies. Experimental data of the effect of selected technological factors on these processes are presented. Rubber compounds containing soluble sulphur were made for such investigations. These methods permit detection of concentrations 10 -6 g of the radioactive isotope per 0.1 g of rubber compound. The sensitivity of these methods enables the investigation of radioisotope behaviour in rubber compounds during processing on an industrial scale without any hazards for workers

  7. Experimental Investigation on Damping Property of Coarse Aggregate Replaced Rubber Concrete

    Science.gov (United States)

    Sugapriya, P.; Ramkrishnan, R.; Keerthana, G.; Saravanamurugan, S.

    2018-02-01

    Rubber has good damping and vibrational characteristics and can reduce cracking significantly due to its elastic nature. This property of rubber can be incorporated in concrete to control vibrations and create better pavements. Crumb Rubber on being dumped in landfills has serious repercussions and causes soil and land pollution. An innovative use of waste tires is shredding them into small pieces and using them as a replacement for coarse aggregate. Crumb rubber is obtained by chopping scrap tires, and in this study it was added in two different sets named SET 1 - Treated Crumb Rubber and concrete, and SET 2 - Treated Crumb rubber with Ultra Fine GGBS as admixture in concrete. Coarse aggregate replaces Rubber in each of the 2 SET’s in proportions of 5, 10, 15 and 20%. Properties like Compressive Strength, Young’s Modulus, Direct and Semi direct Ultrasonic Pulse Velocity, Sorptivity, Damping ratio and Frequency were found out. Deformation and mode shape were studied with modal analysis and static analysis by applying a uniform pressure corresponding to the highest compressive strength of the slab, using ANSYS.

  8. The use of gamma radiation in preparing rubber materials for purification of waste water

    International Nuclear Information System (INIS)

    Abdel-Hamid, M.M.H.

    1997-01-01

    Waste rubber originates from rejected worn-out tyres and other waste rubber materials. To eliminate or reduce waste rubber from the environment and to reduce costs of some rubber goods, attempts are being made to reuse waste rubber. In the present work rubber powder is going to be subjected to graft copolymerization with different vinyl monomers such as acrylamide (A Am), acrylic acid (A Ac) and acrylonitrile (A N). Graft copolymerization of these monomers onto rubber powder will be carried out using gamma radiation. The effects of different parameters such as monomer concentration, radiation dose, inhibitor concentration and type of solvent used in the reaction mixture on the graft yield will be studied. The recovery of different metal ions and the parameters affecting the recovery efficiency will be studied. These parameters include the type of the metal ions such as copper, lead, cobalt, and nickel, organic pollutant such as phenol, temperature of surrounding and the type of monomers used as well as some of their derivatives

  9. Assessment of geotechnical properties of uncemented/cemented clayey soil incorporated with waste crumb rubber

    Directory of Open Access Journals (Sweden)

    JITENDRA SINGH YADAV

    2017-03-01

    Full Text Available Discarded waste tires are becoming a serious threat to health, environment, and ecological systems worldwide if it is not disposed of properly. Every year 1000 million of waste tires are discarded. This number may grow up to 1200 million by the year 2030. On the other hand, construction of civil engineering structures such as buildings, dams, highways, etc. are at high risk of differential settlement, especially in the case of weak or soft clay, which is due to its low shear strength and high compressibility. The paper aims to assess geotechnical properties of uncemented/cemented clayey soil incorporated with waste crumb rubber. Compaction parameters, unconfined compressive strength, split tensile strength, toughness index, CBR values and swelling pressure of rubberized uncemented/cemented clayey soil (3%, and 6% cement and different percentage of crumb rubber have been obtained. After rigorous extensive study, it has been concluded that unconfined compressive strength and split tensile strength of rubberized cemented clayey soil decreases with the increase of the percentage of crumb rubber whereas the axial, and diametral strain are found to be increased with the addition of crumb rubber up to 5% after that it starts to decrease. The CBR values, swelling pressure, and toughness index of uncemented/cemented clayey soil was significantly affected by incorporation of crumb rubber. SEM studies have also been incorporated in this investigation.

  10. Temperature and humidity effect on aging of silicone rubbers as sealing materials for proton exchange membrane fuel cell applications

    International Nuclear Information System (INIS)

    Chang, Huawei; Wan, Zhongmin; Chen, Xi; Wan, Junhua; Luo, Liang; Zhang, Haining; Shu, Shuiming; Tu, Zhengkai

    2016-01-01

    Highlights: • Aging of silicone rubbers with different hardness was investigated. • Existed water molecules from humidified gases can accelerate the aging process. • Silicone rubber with hardness of 40 is more suitable as sealing materials. • Silicone rubbers can be used as sealing materials below 80 °C but not above 100 °C. - Abstract: Durability and reliability of seals around perimeter of each unit are critical to the lifetime of proton exchange membrane fuel cells. In this study, we investigate the aging of silicone rubbers with different hardness, often used as sealing materials for fuel cells, subjected to dry and humidified air at different temperatures. The aging properties are characterized by variation of permanent compression set value under compression, mechanical properties, and surface morphology as well. The results show that aging of silicone rubbers becomes more severe with the increase in subjected temperature. At temperature above 100 °C, silicone rubbers are not suitable for fuel cell applications. The existed water molecules from humidified gases can accelerate the aging of silicone rubbers. Among the tested samples, silicone rubber with hardness of 40 is more durable than that with hardness of 30 and 50 for fuel cells. The change of chemical structure after aging suggests that the aging of silicone rubbers mainly results from the chemical decomposition of cross-linker units for connection of polysiloxane backbones and of methyl groups attached to silicon atoms.

  11. Studies of switching structures in ferroelectric liquid crystal devices

    International Nuclear Information System (INIS)

    Pabla, D.S.

    1998-01-01

    The fast, bistable electro-optic response of ferroelectric liquid crystal (FLC) devices has made them prime candidates for use in display applications. However, before these applications can become widely commercially viable a number of key issues relating to the switching within these devices need to be addressed. One of these is related to the fact that while there has been much work done on modelling the switching process in FLC devices, with some moderate success, in the main these models have not accurately accounted for the physical processes taking place. In order to rectify this situation we present a simple, multi-variable approach which includes important physical phenomenon such as stressed states, partial and domain switching. Through using this model we learn more about the dynamic molecular profiles which may exist in devices, and use this as a springboard to undertake a comprehensive theoretical and experimental study of the molecular profiles of chevron structures under different types of addressing pulses and voltages. This entails modelling the dynamic profiles using a simple non flow reorientation theory and comparing these simulations directly with experimental data obtained through the use of two different optical characterisation techniques. Our findings show quite conclusively that for monopolar addressing within low and high voltage regimes and for low voltage bipolar pulses during the early stages of switching, the dynamic reorientation near the surfaces and central regions of the device lags the reorientation within the bulk. The reverse however being true for the high voltage bipolar addressing case. These results for chevron structures differ from previous theoretical predictions made by others using equations derived from the flow coupled chiral smectic C continuum theory. These flow coupled simulations however, refer to reorientation in bookshelf structures rather than the chevron type structures thought to exist in FLC devices. As

  12. Studies of switching structures in ferroelectric liquid crystal devices

    Energy Technology Data Exchange (ETDEWEB)

    Pabla, D.S

    1998-07-01

    The fast, bistable electro-optic response of ferroelectric liquid crystal (FLC) devices has made them prime candidates for use in display applications. However, before these applications can become widely commercially viable a number of key issues relating to the switching within these devices need to be addressed. One of these is related to the fact that while there has been much work done on modelling the switching process in FLC devices, with some moderate success, in the main these models have not accurately accounted for the physical processes taking place. In order to rectify this situation we present a simple, multi-variable approach which includes important physical phenomenon such as stressed states, partial and domain switching. Through using this model we learn more about the dynamic molecular profiles which may exist in devices, and use this as a springboard to undertake a comprehensive theoretical and experimental study of the molecular profiles of chevron structures under different types of addressing pulses and voltages. This entails modelling the dynamic profiles using a simple non flow reorientation theory and comparing these simulations directly with experimental data obtained through the use of two different optical characterisation techniques. Our findings show quite conclusively that for monopolar addressing within low and high voltage regimes and for low voltage bipolar pulses during the early stages of switching, the dynamic reorientation near the surfaces and central regions of the device lags the reorientation within the bulk. The reverse however being true for the high voltage bipolar addressing case. These results for chevron structures differ from previous theoretical predictions made by others using equations derived from the flow coupled chiral smectic C continuum theory. These flow coupled simulations however, refer to reorientation in bookshelf structures rather than the chevron type structures thought to exist in FLC devices. As

  13. Prediction of heat generation in rubber or rubber-metal springs

    Directory of Open Access Journals (Sweden)

    Banić Milan S.

    2012-01-01

    Full Text Available The temperature of rubber or rubber-metal springs increases under cyclic loading, due to hysteresis losses and low rubber thermal conductivity. Hysteresis losses correspond to energy dissipation from the rubber, which is primarily converted into heat. This well-known phenomenon, called heat build-up, is the primary reason for rubber aging. Increase in temperature within the rubber compound leads to degradation of its physical and chemical properties, increase in stiffness and loss of damping capability. This paper presents a novel procedure of heat generation prediction in rubber or rubber-metal springs. The procedure encompasses the prediction of hysteresis loss, i. e. dissipated energy within the rubber, by finite element analysis and application of a modern visco-plastic rubber constitutive model. The obtained dissipated energy was used as an input for transient thermal analysis. Verification of the proposed procedure was performed by comparison of simulation results with experimentally obtained data during the dynamic loading of the rubber specimen. The proposed procedure is highly computationally efficient and it enables time integration, which can be problematic in coupled mechanical thermal analysis. [Projekat Ministarstva nauke Republike Srbije, br. TR35005: Research and Development of New Generation of Wind Turbines of High Energy Efficiency

  14. The use of gamma irradiation in preparation of polybutadiene rubber nanopowder; Its effect on particle size, morphology and crosslink structure of the powder

    Science.gov (United States)

    Rezaei Abadchi, Majid; Jalali-Arani, Azam

    2014-02-01

    The aim of this work was the preparation and characterization of polybutadiene rubber (BR) powder by irradiating of rubber lattices using 60Co radiation and spray-drying of them at the appropriate condition. The influences of absorbed dose on the volume swelling ratio, molecular weight between crosslinks, gel fraction, and glass transition temperature of obtained powder were studied. Morphology, size and size distribution of rubber particles were examined by using scanning electron microscopy (SEM) and laser particle size analyzer (LPSA) technique, respectively. Results obtained by LPSA revealed that radiation has no effect on particle size of rubber latex but after drying, adherence properties of rubber particle causes increase in particle size of rubber powder, as shown in SEM photograph. Fourier transform infrared spectroscopy of rubber powders confirmed that with increasing the irradiation dose, characteristic peak corresponds to the >Cdbnd C< double bands decreased. Also Charlesby-Pinner equation was used to evaluate radiation yield.

  15. Study of structural and optical properties of YAG and Nd:YAG single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Kostić, S. [Institute of Physics, University of Belgrade, P.O. Box 68, Pregrevica 118, Zemun, Belgrade (Serbia); Lazarević, Z.Ž., E-mail: lzorica@yahoo.com [Institute of Physics, University of Belgrade, P.O. Box 68, Pregrevica 118, Zemun, Belgrade (Serbia); Radojević, V. [Faculty of Technology and Metallurgy, University of Belgrade, Belgrade (Serbia); Milutinović, A.; Romčević, M.; Romčević, N.Ž. [Institute of Physics, University of Belgrade, P.O. Box 68, Pregrevica 118, Zemun, Belgrade (Serbia); Valčić, A. [Faculty of Technology and Metallurgy, University of Belgrade, Belgrade (Serbia)

    2015-03-15

    Highlights: • Transparent YAG and pale pink Nd:YAG single crystals were produced by the Czochralski technique. • Growth mechanisms and shape of the liquid/solid interface and incorporation of Nd{sup 3+} were studied. • The structure of the crystals was investigated by X-ray diffraction, Raman and IR spectroscopy. • The 15 Raman and 17 IR modes were observed. • The obtained YAG and Nd:YAG single crystals were without core and of good optical quality. - Abstract: Yttrium aluminum garnet (YAG, Y{sub 3}Al{sub 5}O{sub 12}) and yttrium aluminum garnet doped with neodymium (Nd:YAG) single crystals were grown by the Czochralski technique. The critical diameter and the critical rate of rotation were calculated. Suitable polishing and etching solutions were determined. As a result of our experiments, the transparent YAG and pale pink Nd:YAG single crystals were produced. The obtained crystals were studied by X-ray diffraction, Raman and IR spectroscopy. The crystal structure was confirmed by XRD. The 15 Raman and 17 IR modes were observed. The Raman and IR spectroscopy results are in accordance with X-ray diffraction analysis. The obtained YAG and Nd:YAG single crystals were without core and of good optical quality. The absence of a core was confirmed by viewing polished crystal slices. Also, it is important to emphasize that the obtained Nd:YAG single crystal has a concentration of 0.8 wt.% Nd{sup 3+} that is characteristic for laser materials.

  16. The use of gamma irradiation in preparation of polybutadiene rubber nanopowder; Its effect on particle size, morphology and crosslink structure of the powder

    Energy Technology Data Exchange (ETDEWEB)

    Rezaei Abadchi, Majid; Jalali-Arani, Azam, E-mail: ajalali@aut.ac.ir

    2014-02-01

    Highlights: • Vulcanized rubber powders were prepared by spray drying of irradiated rubber latexes. • Influence of absorbed dose on powder structure and characteristics was investigated. • The size of rubber latex particles did not changed by irradiation. • Crosslink density increased by increasing dose and 98% gel was obtained at 150 kGy. • T{sub g} of rubber powder increased with increasing the irradiation dose. -- Abstract: The aim of this work was the preparation and characterization of polybutadiene rubber (BR) powder by irradiating of rubber lattices using {sup 60}Co radiation and spray-drying of them at the appropriate condition. The influences of absorbed dose on the volume swelling ratio, molecular weight between crosslinks, gel fraction, and glass transition temperature of obtained powder were studied. Morphology, size and size distribution of rubber particles were examined by using scanning electron microscopy (SEM) and laser particle size analyzer (LPSA) technique, respectively. Results obtained by LPSA revealed that radiation has no effect on particle size of rubber latex but after drying, adherence properties of rubber particle causes increase in particle size of rubber powder, as shown in SEM photograph. Fourier transform infrared spectroscopy of rubber powders confirmed that with increasing the irradiation dose, characteristic peak corresponds to the >C=C< double bands decreased. Also Charlesby–Pinner equation was used to evaluate radiation yield.

  17. The use of gamma irradiation in preparation of polybutadiene rubber nanopowder; Its effect on particle size, morphology and crosslink structure of the powder

    International Nuclear Information System (INIS)

    Rezaei Abadchi, Majid; Jalali-Arani, Azam

    2014-01-01

    Highlights: • Vulcanized rubber powders were prepared by spray drying of irradiated rubber latexes. • Influence of absorbed dose on powder structure and characteristics was investigated. • The size of rubber latex particles did not changed by irradiation. • Crosslink density increased by increasing dose and 98% gel was obtained at 150 kGy. • T g of rubber powder increased with increasing the irradiation dose. -- Abstract: The aim of this work was the preparation and characterization of polybutadiene rubber (BR) powder by irradiating of rubber lattices using 60 Co radiation and spray-drying of them at the appropriate condition. The influences of absorbed dose on the volume swelling ratio, molecular weight between crosslinks, gel fraction, and glass transition temperature of obtained powder were studied. Morphology, size and size distribution of rubber particles were examined by using scanning electron microscopy (SEM) and laser particle size analyzer (LPSA) technique, respectively. Results obtained by LPSA revealed that radiation has no effect on particle size of rubber latex but after drying, adherence properties of rubber particle causes increase in particle size of rubber powder, as shown in SEM photograph. Fourier transform infrared spectroscopy of rubber powders confirmed that with increasing the irradiation dose, characteristic peak corresponds to the >C=C< double bands decreased. Also Charlesby–Pinner equation was used to evaluate radiation yield

  18. Growth and spectroscopic, thermodynamic and nonlinear optical studies of L-threonine phthalate crystal

    Science.gov (United States)

    Theras, J. Elberin Mary; Kalaivani, D.; Jayaraman, D.; Joseph, V.

    2015-10-01

    L-threonine phthalate (LTP) single crystal has been grown using a solution growth technique at room temperature. Single crystal X-ray diffraction analysis reveals that LTP crystallizes in monoclinic crystal system with space group C2/c. The optical absorption studies show that the crystal is transparent in the entire visible region with a cut-off wavelength 309 nm. The optical band gap is found to be 4.05 eV. The functional groups of the synthesized compound have been identified by FTIR spectral analysis. The functional groups present in the material were also confirmed by FT-RAMAN spectroscopy. Surface morphology and the presence of various elements were studied by SEM-EDAX analysis. The thermal stability of LTP single crystal has been analyzed by TGA/DTA studies. The thermodynamic parameters such as activation energy, entropy, enthalpy and Gibbs free energy were determined for the grown material using TG data and Coats-Redfern relation. Since the grown crystal is centrosymmetric, Z-Scan studies were carried out for analyzing the third order nonlinear optical property. The nonlinear absorption coefficient, nonlinear refractive index and susceptibility have been measured using Z-Scan technique.

  19. The computer-aided design of rubber-metal products

    Directory of Open Access Journals (Sweden)

    Pavlo S. Shvets

    2015-12-01

    Full Text Available The important problem in design of rubber-metal products is the optimization of their mass without sacrificing of proportionality factor is in the limits of standard. Aim: The aim of this work is to improve the computer-aided systems by development and implementation of improved optimization method in rubber-metal CAD systems for designers based on the reverse optimization. Materials and Methods: The paper studies the matters of computer-aided structural design of technical composite products composed of anisotropic materials that are essentially different in properties. Results: The structure of CAD systems for designers solving the problems of such design is offered and the work principles of its subsystems are described. It is shown that complicated systems optimization in CAD systems must consider as restrictions the entitative connection between separate elements of these systems within the area of the optimizing arguments. Conclusions: The problem of the “reverse” optimization when objective functions are the connectivity area parameters is considered. In many cases, this allows receiving solutions that are more effective during the computer-aided design process. The developed CAD system for designers was used during the production of rubber-metal shock absorbers at the Odessa Rubber Technical Articles Plant. The positive technical and economic effect was obtained.

  20. Effect of gamma irradiation on sulfur-cured chlorobutyl rubber

    International Nuclear Information System (INIS)

    Scagliusi, Sandra R.; Cardoso, Elisabeth E.L.; Ono, Lilian S.; Lugao, Ademar B.

    2011-01-01

    Chlorobutyl rubber (CIIR) is similarly manufactured to butyl rubber (IIR). The insertion of chlorine atom in isoprene group represents an improvement in its properties, such as: high vulcanizing speed, low permanent stress and compatibility with other types of rubber. The presence of reactive chlorine in butyl chlorate allows a variety of vulcanizing techniques, being the cure via sulfur, the most conventional. In these compounds carbon-halogen bonds are weaker than carbon-carbon and carbon-hydrogen bonds, and the main effect of radiation is to break the carbon-halogen bond to give an organic free radical. Irradiations of certain alkyl chlorides can bring about isomerism in which the location of the halogen atom is changed, the carbon skeleton of molecule remaining unaltered. Irradiation of n-butyl chlorides gives high yields of tertiary carbon. The major effect of high energy photon, such as gamma rays, in organic polymers is the generation of free radicals, along changes in mechanical properties. This work aims to the study of irradiation effect on mechanical properties of a sulfur cured chlorobutyl rubber compound, gamma irradiated within 25, 50, 100, 150 e 200 kGy doses range. The techniques used in their characterization were: strength - stress analysis and elasticity modulus. Results obtained were investigated, demonstrated and discussed. (author)