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Sample records for resin bed calculations

  1. Method for loading resin beds

    International Nuclear Information System (INIS)

    Notz, K.J.; Rainey, R.H.; Greene, C.W.; Shockley, W.E.

    1978-01-01

    An improved method of preparing nuclear reactor fuel by carbonizing a uranium loaded cation exchange resin provided by contacting a H+ loaded resin with a uranyl nitrate solution deficient in nitrate, comprises providing the nitrate deficient solution by a method comprising the steps of reacting in a reaction zone maintained between about 145 to 200 0 C, a first aqueous component comprising a uranyl nitrate solution having a boiling point of at least 145 0 C with a second aqueous component to provide a gaseous phase containing HNO 3 and a reaction product comprising an aqueous uranyl nitrate solution deficient in nitrate

  2. Assessment of Service Life for Regenerative ECLSS Resin Beds

    Science.gov (United States)

    Cloud, Dale L.; Keilich, Maria C.; Polis, Peter C.; Yanczura, Stephen J.

    2013-01-01

    The International Space Station (ISS) Water Processor Assembly (WPA) and Oxygen Generation Assembly (OGA) manage and process water at various levels of cleanliness for multiple purposes. The effluent of theWPA and the influent of the OGA require water at very high levels of purity. The bulk of the water purification that occurs in both systems is performed by consumable activated carbon and ion exchange resin beds. Replacement beds must be available on orbit in order to continue the ISS critical processes of water purification and oxygen generation. Various hurdles exist in order to ensure viable spare resin beds. These include the characteristics of resin beds such as: storage environment, shelf life requirements, microbial growth, and variations in the levels and species of contaminants the beds are required to remove. Careful consideration has been given to match water models, bed capacities and spares traffic models to ensure that spares are always viable. The results of these studies and considerations, in particular, how shelf life requirements affect resin bed life management, are documented in this paper.

  3. CAREM 25: Design of resin bed for purification and boron removal systems

    International Nuclear Information System (INIS)

    Chocron, Mauricio; Iglesias, Alberto M.; Jimenez Rebagliati, Raul; Raffo Calderon, Maria C.; La Gamma, Ana M.

    2000-01-01

    The purification of the water the primary coolant of a water cooled nuclear reactor as well as the water of many auxiliary systems is controlled by the use of ion exchange resins. In the present paper, the resin beds for three different systems are specified: the purification and control volume system, the suppression pool water and the spent fuel pool water for the reactor CAREM-25. In all cases the dimensioning calculations have been done taking in consideration the amount of contaminants and corrosion products generated under normal operation or post-accident. Also, the results have been contrasted with the experience of the nuclear power plants in operation in Argentina, international design criteria and international standards. For the primary coolant, the boron-removal beds have been sized and an estimation of the maximum dose received by the resins have been calculated. It have been found that the result is well below the damaging threshold reported in the literature. (author)

  4. HIGH ASPECT RATIO ION EXCHANGE RESIN BED - HYDRAULIC RESULTS FOR SPERICAL RESIN BEADS

    International Nuclear Information System (INIS)

    Duignan, M; Charles Nash, C; Timothy Punch, T

    2007-01-01

    A principal role of the DOE Savannah River Site is to safely dispose of a large volume of liquid nuclear waste held in many storage tanks. An in-tank ion exchange unit is being considered for cesium removal to accelerate waste processing. This unit is planned to have a relatively high bed height to diameter ratio (10:1). Complicating the design is the need to cool the ion exchange media; therefore, the ion exchange column will have a central cooling core making the flow path annular. To separate cesium from waste the media being considered is made of resorcinol formaldehyde resin deposited on spherical plastic beads and is a substitute for a previously tested resin made of crystalline silicotitanate. This spherical media not only has an advantage of being mechanically robust, but, unlike its predecessor, it is also reusable, that is, loaded cesium can be removed through elution and regeneration. Resin regeneration leads to more efficient operation and less spent resin waste, but its hydraulic performance in the planned ion exchange column was unknown. Moreover, the recycling process of this spherical resorcinol formaldehyde causes its volume to significantly shrink and swell. To determine the spherical media's hydraulic demand a linearly scaled column was designed and tested. The waste simulant used was prototypic of the wastes' viscosity and density. This paper discusses the hydraulic performance of the media that will be used to assist in the design of a full-scale unit

  5. Supporting Calculations For Submerged Bed Scrubber Condensate Disposal Preconceptual Study

    Energy Technology Data Exchange (ETDEWEB)

    Pajunen, A. J.; Tedeschi, A. R.

    2012-09-18

    This document provides supporting calculations for the preparation of the Submerged Bed Scrubber Condensate Disposal Preconceptual Study report The supporting calculations include equipment sizing, Hazard Category determination, and LAW Melter Decontamination Factor Adjustments.

  6. Supporting Calculations For Submerged Bed Scrubber Condensate Disposal Preconceptual Study

    International Nuclear Information System (INIS)

    Pajunen, A. J.; Tedeschi, A. R.

    2012-01-01

    This document provides supporting calculations for the preparation of the Submerged Bed Scrubber Condensate Disposal Preconceptual Study report. The supporting calculations include equipment sizing, Hazard Category determination, and LAW Melter Decontamination Factor Adjustments

  7. Finite difference program for calculating hydride bed wall temperature profiles

    International Nuclear Information System (INIS)

    Klein, J.E.

    1992-01-01

    A QuickBASIC finite difference program was written for calculating one dimensional temperature profiles in up to two media with flat, cylindrical, or spherical geometries. The development of the program was motivated by the need to calculate maximum temperature differences across the walls of the Tritium metal hydrides beds for thermal fatigue analysis. The purpose of this report is to document the equations and the computer program used to calculate transient wall temperatures in stainless steel hydride vessels. The development of the computer code was motivated by the need to calculate maximum temperature differences across the walls of the hydrides beds in the Tritium Facility for thermal fatigue analysis

  8. A STUDY ON ADSORPTION AND DESORPTION BEHAVIORS OF 14C FROM A MIXED BED RESIN

    Directory of Open Access Journals (Sweden)

    SEUNG-CHUL PARK

    2014-12-01

    Full Text Available Spent resin waste containing a high concentration of 14C radionuclide cannot be disposed of directly. A fundamental study on selective 14C stripping, especially from the IRN-150 mixed bed resin, was carried out. In single ion-exchange equilibrium isotherm experiments, the ion adsorption capacity of the fresh resin for non-radioactive HCO3− ion, as the chemical form of 14C, was evaluated as 11mg-C/g-resin. Adsorption affinity of anions to the resin was derived in order of NO3− > HCO3− ≥ H2PO4−. Thus the competitive adsorption affinity of NO3− ion in binary systems appeared far higher than that of HCO3− or H2PO4−, and the selective desorption of HCO3− from the resin was very effective. On one hand, the affinity of Co2+ and Cs+ for the resin remained relatively higher than that of other cations in the same stripping solution. Desorption of Cs+ was minimized when the summation of the metal ions in the spent resin and the other cations in solution was near saturation and the pH value was maintained above 4.5. Among the various solutions tested, from the view-point of the simple second waste process, NH4H2PO4 solution was preferable for the stripping of 14C from the spent resin.

  9. Design and assembling of a moving bed column to operate with ion exchange resin

    International Nuclear Information System (INIS)

    Franca Junior, J.M.; Abrao, A.

    1976-01-01

    A new moving bed column specially designed to operate with ion exchange resins in such peculiar situations where there is gas evolution is reported. The second part reports the use of the column in the preparation of nuclear grade ammonium uranyl tricarbonate (AUTC), from crude uranyl nitrate solution. Uranium-VI is binded into a strong cationic ion exchanger and then eluted with (NH 4 ) 2 CO 3 . The final product is crystallized from the eluate by simply cooling down the temperature to 5 0 or by addition of ethanol. Loading of resin with uranyl ion, its elution with ammonium carbonate and the crystallization of AUTC is described [pt

  10. The benefits of heavy resins in fluidized-bed ion-exchange columns

    International Nuclear Information System (INIS)

    Giddey, T.B.S.

    1980-01-01

    The advantages to be gained from the use of a high-density ion-exchange resin in a uranium-recovery circuit are shown. It is concluded that, in existing fluidized-bed plants, the throughput of solution can be increased by up to 40 per cent at the same uranium recovery. Alternatively, the values in the barren solution can be improved at the same flow-rate of solution [af

  11. Incineration of ion-exchange resins in fluidized bed. Part of a coordinated programme on treatment of spent ion exchange resins

    International Nuclear Information System (INIS)

    Valkianinen, M.

    1980-10-01

    Incineration of ion-exchange resins in a fluidized bed was studied on the pilot plant scale. The test programme performed consisted of the testing of various bed materials and finding the optimal conditions of incineration of spent resins. Granular resins were incinerated in an ethanol-water mixture. Incinernation converts the organic resin into inert oxide material, which can be solidified for instance with cement. The weight of the ash was 1...20% and the volume 2...30% of the original resins, which contained 15...25% moisture. When solidified with cement the volume of the ash-concrete is 4...22% of the concrete of equal compressive strength acquired by direct solidification. Water immersion and heat tests of solidified ash showed satisfactory results. The absorption of Cs and Co in various bed materials was studied by means of inactive tracer materials. Biotite and chamotte absorbed significantly, but this absorption does not drastically help on the off gas side. The sintering of the bed materials in the presence of sodium was studied. Corundum, chamotte and biotite have a safety limit of 5% sodium of the bed's weight at 850 0 C

  12. Kinetics of filtration of model crud with ion exchange resin bed

    International Nuclear Information System (INIS)

    Takahashi, M.; Ishigure, K.; Fujita, N.

    1987-01-01

    A simple mathematical model is presented to depict the filtration mechanism of crud or colloidal particles in the ion exchange resin bed. In this model the filtration process is classified into four stages, corresponding to the increase in the deposited amounts of the particles on the surfaces of the resins during the filtration process. In the first stage, it is assumed that the adhesion of crud particles is mainly controlled by the electrokinetic interaction between the particle and the virgin surfaces of the resins, while in the third stage the crud particles interact with the particles already adsorbed in the resins. The second stage is a transient period between the first and third stages. In the final stage, the clogging effect becomes significant. At the first stage of filtration, the model explains the rapid decrease of filtration efficiency, which is a matter of great concern from the practical point of view. A comparison is made between the model and laboratory experiments, using monodispersed α-Fe/sub 2/O/sub 3/ particles as model crud, and it is found that the proposed mechanism of filtration process seems quite reasonable

  13. Characterization of radioactive wastes - spent ion-exchange resins and charcoal filter beds

    International Nuclear Information System (INIS)

    Silva, Rozilene Elaine; Isiki, Vera Lucia Keiko; Goes, Marcos Maciel de; Potiens Junior, Ademar Jose; Dellamano, Jose Claudio; Vicente, Roberto

    2009-01-01

    In the present paper we report the initial results of the work undertaken at the Radioactive Waste Management Laboratory (RWML), in Sao Paulo, Brazil, to develop sampling procedures and analytical methods applied to the characterization of radioactive wastes, specifically spent ion-exchange resins and charcoal filter beds generated at the IEA-R1 Research Reactor operated by the Nuclear Energy Research Institute. The work objectives are to characterize those wastes to comply with regulatory requirements, to generate data to support the development of treatment processes, and to improve characterization methods and laboratorial infrastructure. (author)

  14. Performance of fixed-bed charged with chelating resin of capillary fiber form for recovery of uranium from seawater

    International Nuclear Information System (INIS)

    Uezu, Kazuya; Saito, Kyoichi; Hori, Takahiro; Furusaki, Shintaro; Sugo, Takanobu; Okamoto, Jiro.

    1988-01-01

    A chelating resin adsorbent containing an amidoxime group of capillary fiber form (AO-C fiber) was prepared by a radiation-induced grafting method. The reaction condition in amidoximation, for an optimized conversion of cyano group into an amidoxime group, was examined to obtain an adsorbent having an amount of amidoxime group, i.e. 5.6 mol/kg of base polymer. The seawater was continuously pumped upwards through a novel fixed-bed, 30 cm in length and charged with a bundle of AO-C fibers. The adsorption rate and pressure drop were determined as a function of superficial velocity of seawater u. For a superficial velocity of 36 m/h, the adsorption column was found to adsorb U from natural seawater at a high rate, i.e. 0.27 g-U/Kg of adsorbent of HCl type in 25 days. The cross-sectional area of the adsorption bed S required to produce 10 kg of U/yr using our AO-C fiber adsorbent was calculated to be S(m 2 ) = 404 u -0.50 . (author)

  15. Calculations of Bed-Material Transport, Chetco River, Oregon

    Science.gov (United States)

    Anderson, S.; Wallick, R.; Cannon, C.; O'Connor, J. E.

    2009-12-01

    The Chetco River drains 914 square kilometers of the Klamath Mountains in far southwestern Oregon. The lower 18 kilometers of the river are flanked by large and abundant gravel bars, which have been commercially mined for aggregate during most of the last century. Increasing concern regarding the impact of this mining on aquatic habitats motivated an assessment of historical channel change and sediment transport rates along this lower reach. A key component of this research was estimating bed-material transport through the application of sediment transport equations at multiple locations along the study reach. Flow hydraulics were estimated with a 1-D hydraulic model constructed in HEC-RAS, using a combination of LiDAR and bathymetric surveys to characterize the valley morphology. Once calibrated to USGS rating curves, low flow water surfaces, and several high flow photos, this model allowed us to calculate energy slopes for a given cross section at a variety of flows. These flow-energy slope pairs, along with cross sections and sediment data collected from surface pebble counts, were then applied to a number of different modern bedload transport equations. This process was facilitated by the Bedload Assessment in Gravel-bedded Streams Excel macro, or BAGS, which allows users to quickly apply multiple transport equations using a single set of inputs (Pitlick et al., 2009). A review of the literature, along with tests of internal consistency and comparisons to direct bedload measurements taken in the winter of 2008-09, led us to choose the Parker (1991) and Wilcock-Crowe (2003) equations as the two most applicable to the Chetco River. Sediment transport-flow curves for both equations were calculated for seven cross sections spanning the study area. For each of these cross sections, we estimated annual transport fluxes using derived transport rating curves in conjunction with unit flow data from a USGS gage at the upstream end of study reach, with data extending back

  16. Continuous biodiesel production in a fixed bed reactor packed with anion-exchange resin as heterogeneous catalyst.

    Science.gov (United States)

    Ren, Yanbiao; He, Benqiao; Yan, Feng; Wang, Hong; Cheng, Yu; Lin, Ligang; Feng, Yaohui; Li, Jianxin

    2012-06-01

    A continuous biodiesel production from the transesterification of soybean oil with methanol was investigated in a fixed bed reactor packed with D261 anion-exchange resin as a heterogeneous catalyst. The conversion to biodiesel achieved 95.2% within a residence time 56 min under the conditions: reaction temperature of 323.15K, n-hexane/soybean oil weight rate of 0.5, methanol/soybean oil molar ratio of 9:1 and feed flow rate of 1.2 ml/min. The resin can be regenerated in-situ and restored to the original activity to achieve continuous production after the resin deactivation. The product obtained was mainly composed of methyl esters. No glycerol in the product was detected due to the resin adsorbing glycerol in the fixed bed, which solved the issue of glycerol separation from biodiesel. It is believed that the fixed bed reactor with D261 has a potential commercial application in the transesterification of triglyceride. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Esterification of oleic acid in a three-phase, fixed-bed reactor packed with a cation exchange resin catalyst.

    Science.gov (United States)

    Son, Sung Mo; Kimura, Hiroko; Kusakabe, Katsuki

    2011-01-01

    Esterification of oleic acid was performed in a three-phase fixed-bed reactor with a cation exchange resin catalyst (Amberlyst-15) at high temperature, which was varied from 80 to 120 °C. The fatty acid methyl ester (FAME) yields in the fixed-bed reactor were increased with increases in the reaction temperature, methanol flow rate and bed height. Moreover, the FAME yields were higher than those obtained using a batch reactor due to an equilibrium shift toward the product that resulted from continuous evaporation of the produced water. In addition, there was no catalyst deactivation during the esterification of oleic acid. However, addition of sunflower oil to the oleic acid reduced the FAME yield obtained from simultaneous esterification and transesterification. The FAME yield was 97.5% at a reaction temperature of 100 °C in the fixed-bed with a height of 5 cm when the methanol and oleic acid feed rates were 8.6 and 9.0 mL/h, respectively. Copyright © 2010 Elsevier Ltd. All rights reserved.

  18. The degradation of strong basic anion exchange resins and mixed-bed ion-exchange resins: Effect of degradation products on radionuclide speciation

    International Nuclear Information System (INIS)

    Loon, L.R. van; Hummel, W.

    1999-01-01

    The most important water-soluble products of the radiolytic degradation of anion exchange resins in a cementitious environment are ammonia and methylamines. These ligands do not form complexes with most radionuclides. Exceptions are Ni, Ag, and Pd, which form strong complexes with amines. Other degradation products of anion and mixed-bed ion-exchange resins are of no importance concerning the complexation of trivalent radionuclides. This is shown indirectly by adsorption experiments: The degradation products do not have a significant effect on the adsorption of Eu(III) on calcite. The effect of ammonia and methylamines on the complexation of Ni, Ag, and Pd is investigated by chemical modeling. For Ni and Ag, rather reliable predictions can be made using available thermodynamic data. In the case of Pd, large uncertainties are encountered due to unreliable data and gaps in the set of important species. The system Pd(II)-ammonia-water is explored in detail. Predominant species are inferred by chemical analogy, and their thermodynamic data are estimated. The uncertainty in these estimated and measured but unreliable data is bound by qualitative and quantitative chemical reasoning

  19. Analytical calculation of detailed model parameters of cast resin dry-type transformers

    International Nuclear Information System (INIS)

    Eslamian, M.; Vahidi, B.; Hosseinian, S.H.

    2011-01-01

    Highlights: → In this paper high frequency behavior of cast resin dry-type transformers was simulated. → Parameters of detailed model were calculated using analytical method and compared with FEM results. → A lab transformer was constructed in order to compare theoretical and experimental results. -- Abstract: Non-flammable characteristic of cast resin dry-type transformers make them suitable for different kind of usages. This paper presents an analytical method of how to obtain parameters of detailed model of these transformers. The calculated parameters are compared and verified with the corresponding FEM results and if it was necessary, correction factors are introduced for modification of the analytical solutions. Transient voltages under full and chopped test impulses are calculated using the obtained detailed model. In order to validate the model, a setup was constructed for testing on high-voltage winding of cast resin dry-type transformer. The simulation results were compared with the experimental data measured from FRA and impulse tests.

  20. Method for removing cesium from aqueous liquid, method for purifying the reactor coolant in boiling water and pressurized water reactors and a mixed ion exchanged resin bed, useful in said purification

    International Nuclear Information System (INIS)

    Otte, J.N.A.; Liebmann, D.

    1989-01-01

    The invention relates to a method for removing cesium from an aqueous liquid, and to a resin bed containing a mixture of an anion exchange resin and cation exchange resin useful in said purification. In a preferred embodiment, the present invention is a method for purifying the reactor coolant of a presurized water or boiling water reactor. Said method, which is particularly advantageously employed in purifying the reactor coolant in the primary circuit of a pressurized reactor, comprises contacting at least a portion of the reactor coolant with a strong base anion exchange resin and the strong acid cation exchange resin derived from a highly cross-linked, macroporous copolymer of a monovinylidene aromatic and a cross-linking monomer copolymerizable therewith. Although the reactor coolant can sequentially be contacted with one resin type and thereafter with the second resin type, the contact is preferably conducted using a resin bed comprising a mixture of the cation and anion exchange resins. 1 fig., refs

  1. Sorptive Removal of Cesium and Cobalt Ions in a Fixed bed Column Using Lewatit S100 Cation Exchange Resin

    International Nuclear Information System (INIS)

    El-Naggar, M.R.; Ibrahim, H.A.; El-Kamash, A.M.

    2014-01-01

    The sorptive removal of cesium and cobalt ions from aqueous solutions in a fixed bed column packed with Lewatit S100® cation exchange resin has been investigated. A preliminary batch studies were performed to estimate the effect of pH and contact time on the sorption process. Results indicated that Cs + and Co 2+ could be efficiently removed using Lewatit S100® at a ph range of 4-7 with more affinity towards Cs than Co 2+ . Kinetic models have been applied to the sorption rate data and the relevant parameters were determined. The obtained results indicated that the sorption of both Cs + and Co 2+ on Lewatit S100 followed pseudo second-order rather than pseudo first-order or Morris-Webber model. Fixed bed experiments were conducted at a constant initial concentration of 100 mg/l whereas the effect of bed depth (3, 4.5 and 6 cm) and volumetric flow rate (3 and 5 ml/min.) on the breakthrough characteristics of the fixed bed sorption systems were determined. The experimental sorption data were fitted to the well-established column models namely; Thomas and BDST models to compute the different model parameters. The higher column sorption capacities were obtained at bed depth of 3 cm with a flow rate of 3 ml/min., for both Cs + and Co 2+ . The BDST model appeared to describe experimental results better than Thomas model. Results indicate that Lewatit S100® is an efficient material for the removal of cesium and cobalt ions from aqueous solutions.

  2. Calculation of isotopic profile during band displacement on ion exchange resins

    International Nuclear Information System (INIS)

    Sonwalkar, A.S.; Puranik, V.D.; D'Souza, A.B.

    1981-01-01

    A method has been developed to calculate the isotopic profile during band displacement on ion exchange resins using computer simulation. Persoz had utilized this technique earlier for calculating the isotopic profile during band displacement as well as frontal analysis. The present report deals with a simplification of the method used by Persoz by reducing the number of variables and making certain approximations where the separation factor is not far from unity. Calculations were made for the typical case of boron isotope separation. The results obtained by the modified method were found to be in very good agreement with those obtained by using an exact equation, at the same time requiring conside--rably less computer time. (author)

  3. Sorption of Pb(II) onto a mixture of algae waste biomass and anion exchanger resin in a packed-bed column.

    Science.gov (United States)

    Bulgariu, Dumitru; Bulgariu, Laura

    2013-02-01

    Sorption of Pb(II) was studied by using a biosorbent mixture of algae waste biomass and Purolite A-100 resin in a packed-bed column. Mixing these two components was done to prevent the clogging of the column and to ensure adequate flow rates. Increasing of solution flow rate and initial Pb(II) concentration make that the breakthrough and saturation points to be attained earlier. The experimental breakthrough curves were modeled using Bohart-Adams, Thomas and Yoon-Nelson models, and the parameters for all these models were calculated. A regeneration efficiency of 98% was achieved using 0.1 mol L(-1) HCl and not significant changes in lead uptake capacity after three biosorption/desorption cycles were noted. The biosorbent mixture was able to remove Pb(II) from synthetic wastewater at pH 5.0 and flow rate of 3.5 mL min(-1), and the obtained effluent has better quality characteristics. The biosorbent mixture it is suitable for a continuous system for large-scale applications. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Comparison of Several Thermal Conductivity Constants for Thermal Hydraulic Calculation of Pebble Bed Reactor

    Science.gov (United States)

    Irwanto, Dwi; Setiadipura, Topan; Pramutadi, Asril

    2017-07-01

    There are two type of High Temperature Gas Reactor (HTGR), prismatic and pebble bed. Pebble Bed type has unique configuration because the fuels are randomly distributed inside the reactor core. In term of safety features, Pebble Bed Reactor (PBR) is one of the most promising reactor type in avoiding severe nuclear accidents. In order to analyze heat transfer and safety of this reactor type, a computer code is now under development. As a first step, calculation method proposed by Stroh [1] is adopted. An approach has been made to treat randomly distributed pebble balls contains fissile material inside the reactor core as a porous medium. Helium gas act as coolant on the reactor system are carrying heat flowing in the area between the pebble balls. Several parameters and constants are taken into account in the new developed code. Progress of the development of the code especially comparison of several thermal conductivity constants for a certain PBR-case are reported in the present study.

  5. Hydrodynamic calculation of a filter sand bed type used in the containment venting systems

    International Nuclear Information System (INIS)

    Cuevas V, D.; Sainz M, E.; Ortiz V, J.

    2015-09-01

    The filtered venting of the containment has been adopted in European countries to mitigate the consequences of excess pressure containment during a severe accident. When venting has taken place, the fission products are released directly into the environment, unless a filter on the same path is placed, so that various types of filters are used to trap the fission products. The venting filters of the containment currently installed use different filtration technologies that involve more than one medium. Those using water as the first stage of filtration are called wet systems and are equipped with additional steps to remove water drops and fine aerosols emissions. And even they may also be equipped with an element containing certain absorption means for the filtration of gaseous iodine species. Other designs based on filtration of deep bed as the primary retention step; called dry filters, use filtration media of metal fiber, ceramic or sand to trap aerosols. This paper evaluates the hydraulic characteristics of the filter sand bed type designed by EDF as a candidate to be installed in the containment of BWR Mark II (type of primary containment of the nuclear power plant of Laguna Verde). The evaluation of filter sand bed type was performed using the software package of open source OpenFOAM. Models of each zone of the filtered device were generated and through a series of parametric calculations of computational fluid mechanics relevant hydrodynamic characteristics of the device were obtained, such as pressure drops against mass flow rate and pressure fields and speed at different operating conditions. On the other hand, the model validation of the sand bed filter when comparing the results of experimental tests on a sand column of PITEAS program (1985-1986) against OpenFOAM simulation was realized. The results are very close to those obtained experimentally. (Author)

  6. Fundamental aspects related to batch and fixed-bed sulfate sorption by the macroporous type 1 strong base ion exchange resin Purolite A500.

    Science.gov (United States)

    Guimarães, Damaris; Leão, Versiane A

    2014-12-01

    Acid mine drainage is a natural process occurring when sulfide minerals such as pyrite are exposed to water and oxygen. The bacterially catalyzed oxidation of pyrite is particularly common in coal mining operations and usually results in a low-pH water polluted with toxic metals and sulfate. Although high sulfate concentrations can be reduced by gypsum precipitation, removing lower concentrations (below 1200 mg/L) remains a challenge. Therefore, this work sought to investigate the application of ion exchange resins for sulfate sorption. The macroporous type 1 strong base IX resin Purolite A500 was selected for bath and fixed-bed sorption experiments using synthetic sulfate solutions. Equilibrium experiments showed that sulfate loading on the resin can be described by the Langmuir isotherm with a maximum uptake of 59 mg mL-resin(-1). The enthalpy of sorption was determined as +2.83 kJ mol(-1), implying an endothermic physisorption process that occurred with decreasing entropy (-15.5 J mol(-1).K(-1)). Fixed-bed experiments were performed at different bed depths, flow rates, and initial sulfate concentrations. The Miura and Hashimoto model predicted a maximum bed loading of 25-30 g L-bed(-1) and indicated that both film diffusion (3.2 × 10(-3) cm s(-1) to 22.6 × 10(-3) cm s(-1)) and surface diffusion (1.46 × 10(-7) cm(2) s(-1) to 5.64 × 10(-7) cm(2) s(-1)) resistances control the sorption process. It was shown that IX resins are an alternative for the removal of sulfate from mine waters; they ensure very low residual concentrations, particularly in effluents where the sulfate concentration is below the gypsum solubility threshold. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Microbial community evolution of black and stinking rivers during in situ remediation through micro-nano bubble and submerged resin floating bed technology.

    Science.gov (United States)

    Sun, Yanmei; Wang, Shiwei; Niu, Junfeng

    2018-06-01

    Microbes play important roles during river remediation and the interaction mechanism illustration between microorganisms and sewage is of great significance to improve restoration technology. In this study, micro-nano bubble and submerged resin floating bed composite technology (MBSR) was firstly used to restore two black and stinking urban rivers. After restoration, the water pollution indices such as dissolved oxygen (DO), ammonia nitrogen (NH 4 + -N), total phosphorous (TP), chemical oxygen demand (COD Cr ), water clarity, and the number of facial coliform were significantly improved. Microbial community composition and relative abundance both varied and more aerobic microbes emerged after remediation. The microbial changes showed correlation with DO, NH 4 + -N, TP and COD Cr of the rivers. In summary, the MBSR treatment improved the physiochemical properties of the two black and stinking urban rivers probably through oxygen enrichment of micro-nano bubble and adsorption of submerged resin floating bed, which thereby stimulated functional microbes to degrade pollutants. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. CFD Analysis to Calculate the Optimal Air Velocity in Drying Green Tea Process Using Fluidized Bed Dryer

    Science.gov (United States)

    Yohana, Eflita; Nugraha, Afif Prasetya; Diana, Ade Eva; Mahawan, Ilham; Nugroho, Sri

    2018-02-01

    Tea processing is basically distinguished into three types which black tea, green tea, and oolong tea. Green tea is processed by heating and drying the leaves. Green tea factories in Indonesia are generally using the process of drying by panning the leaves. It is more recommended to use the fluidization process to speed up the drying process as the quality of the tea can be maintained. Bubbling fluidization is expected to occur in this research. It is a process of bubbles are formed in the fluidization. The effectiveness of the drying process in a fluidized bed dryer machine needs to be improved by using a CFD simulation method to proof that umf < u < ut, where the average velocity value is limited by the minimum and the maximum velocity of the calculation the experimental data. The minimum and the maximum velocity value of the fluidization is 0.96 m/s and 8.2 m/s. The result of the simulation obtained that the average velocity of the upper bed part is 1.81 m/s. From the results obtained, it can be concluded that the calculation and the simulation data is in accordance with the condition of bubbling fluidization in fluidized bed dryer.

  9. CFD Analysis to Calculate the Optimal Air Velocity in Drying Green Tea Process Using Fluidized Bed Dryer

    Directory of Open Access Journals (Sweden)

    Yohana Eflita

    2018-01-01

    Full Text Available Tea processing is basically distinguished into three types which black tea, green tea, and oolong tea. Green tea is processed by heating and drying the leaves. Green tea factories in Indonesia are generally using the process of drying by panning the leaves. It is more recommended to use the fluidization process to speed up the drying process as the quality of the tea can be maintained. Bubbling fluidization is expected to occur in this research. It is a process of bubbles are formed in the fluidization. The effectiveness of the drying process in a fluidized bed dryer machine needs to be improved by using a CFD simulation method to proof that umf < u < ut, where the average velocity value is limited by the minimum and the maximum velocity of the calculation the experimental data. The minimum and the maximum velocity value of the fluidization is 0.96 m/s and 8.2 m/s. The result of the simulation obtained that the average velocity of the upper bed part is 1.81 m/s. From the results obtained, it can be concluded that the calculation and the simulation data is in accordance with the condition of bubbling fluidization in fluidized bed dryer.

  10. METHOD OF CALCULATION OF THE NON-STATIONARY TEMPERATURE FIELD INSIDE OF THERMAL PACKED BED ENERGY STORAGE

    Directory of Open Access Journals (Sweden)

    Ermuratschii V.V.

    2014-04-01

    Full Text Available e paper presents a method of the approximate calculation of the non-stationary temperature field inside of thermal packed bed energy storages with feasible and latent heat. Applying thermoelectric models and computational methods in electrical engineering, the task of computing non-stationary heat transfer is resolved with respect to third type boundary conditions without applying differential equations of the heat transfer. For sub-volumes of the energy storage the method is executed iteratively in spatiotemporal domain. Single-body heating is modeled for each sub-volume, and modeling conditions are assumed to be identical for remained bod-ies, located in the same sub-volume. For each iteration step the boundary conditions will be represented by re-sults at the previous step. The fulfillment of the first law of thermodynamics for system “energy storage - body” is obtained by the iterative search of the mean temperature of the energy storage. Under variable boundary con-ditions the proposed method maybe applied to calculating temperature field inside of energy storages with packed beds consisted of solid material, liquid and phase-change material. The method may also be employed to compute transient, power and performance characteristics of packed bed energy storages.

  11. Practical aspects and uncertainty analysis of biological effective dose (BED) regarding its three-dimensional calculation in multiphase radiotherapy treatment plans.

    Science.gov (United States)

    Kauweloa, Kevin I; Gutierrez, Alonso N; Bergamo, Angelo; Stathakis, Sotirios; Papanikolaou, Nikos; Mavroidis, Panayiotis

    2014-07-01

    There is a growing interest in the radiation oncology community to use the biological effective dose (BED) rather than the physical dose (PD) in treatment plan evaluation and optimization due to its stronger correlation with radiobiological effects. Radiotherapy patients may receive treatments involving a single only phase or multiple phases (e.g., primary and boost). Since most treatment planning systems cannot calculate the analytical BED distribution in multiphase treatments, an approximate multiphase BED expression, which is based on the total physical dose distribution, has been used. The purpose of this paper is to reveal the mathematical properties of the approximate BED formulation, relative to the true BED. The mathematical properties of the approximate multiphase BED equation are analyzed and evaluated. In order to better understand the accuracy of the approximate multiphase BED equation, the true multiphase BED equation was derived and the mathematical differences between the true and approximate multiphase BED equations were determined. The magnitude of its inaccuracies under common clinical circumstances was also studied. All calculations were performed on a voxel-by-voxel basis using the three-dimensional dose matrices. Results showed that the approximate multiphase BED equation is accurate only when the dose-per-fractions (DPFs) in both the first and second phases are equal, which occur when the dose distribution does not significantly change between the phases. In the case of heterogeneous dose distributions, which significantly vary between the phases, there are fewer occurrences of equal DPFs and hence the inaccuracy of the approximate multiphase BED is greater. These characteristics are usually seen in the dose distributions being delivered to organs at risk rather than to targets. The finding of this study indicates that the true multiphase BED equation should be implemented in the treatment planning systems due to the inconsistent accuracy of

  12. Liver Selective Internal Radiation Therapy with (90)Y resin microspheres: comparison between pre-treatment activity calculation methods.

    Science.gov (United States)

    Bernardini, M; Smadja, C; Faraggi, M; Orio, S; Petitguillaume, A; Desbrée, A; Ghazzar, N

    2014-11-01

    Different methods to calculate (90)Y resin microspheres activity for Selective Internal Radiation Therapy (SIRT) were compared. Such comparison is not yet available and is needed in clinical practice to optimize patient specific treatment planning. 32 (99m)Tc-macroagregates (MAA) evaluations were performed, followed by 26 treatments. Four methods to calculate (90)Y-activity were applied retrospectively: three based on Body Surface Area and one based on MIRD formalism, partition model (PM). Relationships between calculated activities, lung breakthrough (LB), the activity concentration ratio between lesions and healthy liver (T/N) and tumour involvement were investigated, where lobar and whole liver treatments were analysed separately. Without attenuation correction, overestimation of LB was 65%. In any case, the estimated lungs' doses remained below 30 Gy. Thus, the maximal injectable activity (MIA) is not limited by lungs' irradiation. Moreover, LB was not significantly related to T/N, neither to tumour involvement nor radiochemical purity (RP). Differences in calculated activity with the four methods were extremely large, in particular they were greater between BSA-based and PM activities for lobar treatments (from -85% to 417%) compared to whole liver treatments (from -49% to 61%). Two values of T/N ratio were identified as thresholds: for BSA-based methods, healthy liver doses are much higher than 30 Gy when T/N  4. As PM accounts for uptake ratio between normal and tumour liver, this method should be employed over BSA-based methods. Copyright © 2014 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  13. Anion-exchange resin-based desulfurization process

    Energy Technology Data Exchange (ETDEWEB)

    Sheth, A.C.; Strevel, S.D.; Dharmapurikar, R.

    1992-01-01

    Under the current grant, the University of Tennessee Space Institute (UTSI) will carry out the bench scale evaluation and further development of the anion-exchange resin-based desulfurization concept to desulfurize alkali metal sulfates. This concept has been developed and patented by UTSI under US Patent No. 4,917,874. The developmental program proposed under this DOE grant includes screening of commercially available resins to select three candidate resins for further study. These three resins will undergo a series of experiments designed to test the resins' performance under different process conditions (including the use of spent MHD seed material). The best of these resins will be used in optimizing the regeneration step and in testing the effects of performance enhancers. The process schematic developed from the results will be used to estimate the related economics. During this reporting period, October 1, 1991 to September 30, 1992, analysis of batch mode screening experiments was completed to select three candidate resins for process variables study in the fixed-bed set-up. This setup was modified and the experiments were carded out to evaluate effects of major process variables. The analysis of fixed-bed experiments is going on and we have also started simple batch mode experiments to identify desirable conditions for resin regeneration step. We have also started simple process engineering type calculations to determine the trade-off between the solution concentration and the resulting evaporation/concentration load.

  14. Methods For The Calculation Of Pebble Bed High Temperature Reactors With High Burnup Plutonium And Minor Actinide Based Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Meier, Astrid; Bernnat, Wolfgang; Lohnert, Guenter [Institute for Nuclear Technology and Energy Systems, University of Stuttgart, Pfaffenwaldring 31, 70569 Stuttgart (Germany)

    2008-07-01

    The graphite moderated Modular High Temperature Pebble Bed Reactor enables very flexible loading strategies and is one candidate of the Generation IV reactors. For this reactor fuel cycles with high burnup (about 600 MWd/kg HM) based on plutonium (Pu) and minor actinides (MA) fuel will be investigated. The composition of this fuel is defined in the EU-PuMA-project which aims the reduction of high level waste. There exist nearly no neutronic full core calculations for this fuel composition with high burnup. Two methods (deterministic and Monte Carlo) will be used to determine the neutronics in a full core. The detailed results will be compared with respect to the influence on criticality and safety related parameters. (authors)

  15. Methods For The Calculation Of Pebble Bed High Temperature Reactors With High Burnup Plutonium And Minor Actinide Based Fuel

    International Nuclear Information System (INIS)

    Meier, Astrid; Bernnat, Wolfgang; Lohnert, Guenter

    2008-01-01

    The graphite moderated Modular High Temperature Pebble Bed Reactor enables very flexible loading strategies and is one candidate of the Generation IV reactors. For this reactor fuel cycles with high burnup (about 600 MWd/kg HM) based on plutonium (Pu) and minor actinides (MA) fuel will be investigated. The composition of this fuel is defined in the EU-PuMA-project which aims the reduction of high level waste. There exist nearly no neutronic full core calculations for this fuel composition with high burnup. Two methods (deterministic and Monte Carlo) will be used to determine the neutronics in a full core. The detailed results will be compared with respect to the influence on criticality and safety related parameters. (authors)

  16. Criticality calculations of the HTR-10 pebble-bed reactor with SCALE6/CSAS6 and MCNP5

    International Nuclear Information System (INIS)

    Wang, Meng-Jen; Sheu, Rong-Jiun; Peir, Jinn-Jer; Liang, Jenq-Horng

    2014-01-01

    Highlights: • Comparisons of the HTR-10 criticality calculations with SCALE6/CSAS6 and MCNP5 were performed. • The DOUBLEHET unit-cell treatment provides the best k eff estimation among PBR criticality calculations using SCALE6. • The continuous-energy SCALE6 calculations present a non-negligible discrepancy with MCNP5 in three PBR cases. - Abstract: HTR-10 is a 10 MWt prototype pebble-bed reactor (PBR) that presents a doubly heterogeneous geometry for neutronics calculations. An appropriate unit-cell treatment for the associated fuel elements is vital for creating problem-dependent multigroup cross sections. Considering four unit-cell options for resonance self-shielding correction in SCALE6, a series of HTR-10 core models were established using the CSAS6 sequence to systematically investigate how they affected the computational accuracy and efficiency of PBR criticality calculations. Three core configurations, which ranged from simplified infinite lattices to a detailed geometry, were examined. Based on the same ENDF/B-VII.0 cross-section library, multigroup results were evaluated by comparing with continuous-energy SCALE6/CSAS6 and MCNP5 calculations. The comparison indicated that the INFHOMMEDIUM results overestimated the effective multiplication factor (k eff ) by about 2800 pcm, whereas the LATTICECELL and MULTIREGION treatments overestimated k eff values with similar biases at approximately 470–680 pcm. The DOUBLEHET results attained further improvement, reducing the k eff overestimation to approximately 280 pcm. The comparison yielded two unexpected problems from using SCALE6/CSAS6 in HTR-10 criticality calculations. In particular, the continuous-energy CSAS6 calculations in this study present a non-negligible discrepancy with MCNP5, potentially causing a k eff value overestimate of approximately 680 pcm. Notably, using a cell-weighted mixture instead of an explicit model of individual TRISO particles in the pebble fuel zone does not shorten the

  17. IsoBED: a tool for automatic calculation of biologically equivalent fractionation schedules in radiotherapy using IMRT with a simultaneous integrated boost (SIB technique

    Directory of Open Access Journals (Sweden)

    Benassi Marcello

    2011-05-01

    Full Text Available Abstract Background An advantage of the Intensity Modulated Radiotherapy (IMRT technique is the feasibility to deliver different therapeutic dose levels to PTVs in a single treatment session using the Simultaneous Integrated Boost (SIB technique. The paper aims to describe an automated tool to calculate the dose to be delivered with the SIB-IMRT technique in different anatomical regions that have the same Biological Equivalent Dose (BED, i.e. IsoBED, compared to the standard fractionation. Methods Based on the Linear Quadratic Model (LQM, we developed software that allows treatment schedules, biologically equivalent to standard fractionations, to be calculated. The main radiobiological parameters from literature are included in a database inside the software, which can be updated according to the clinical experience of each Institute. In particular, the BED to each target volume will be computed based on the alpha/beta ratio, total dose and the dose per fraction (generally 2 Gy for a standard fractionation. Then, after selecting the reference target, i.e. the PTV that controls the fractionation, a new total dose and dose per fraction providing the same isoBED will be calculated for each target volume. Results The IsoBED Software developed allows: 1 the calculation of new IsoBED treatment schedules derived from standard prescriptions and based on LQM, 2 the conversion of the dose-volume histograms (DVHs for each Target and OAR to a nominal standard dose at 2Gy per fraction in order to be shown together with the DV-constraints from literature, based on the LQM and radiobiological parameters, and 3 the calculation of Tumor Control Probability (TCP and Normal Tissue Complication Probability (NTCP curve versus the prescribed dose to the reference target.

  18. The biologically equivalent dose BED - Is the approach for calculation of this factor really a reliable basis?

    International Nuclear Information System (INIS)

    Jensen, J.M.; Zimmermann, J.

    2000-01-01

    To predict the effect on tumours in radiotherapy, especially relating to irreversible effects, but also to realize the retrospective assessment the so called L-Q-model is relied on at present. Internal specific organ parameters, such as α, β, γ, T p , T k , and ρ, as well as external parameters, so as D, d, n, V, and V ref , were used for determination of the biologically equivalent dose BED. While the external parameters are determinable with small deviations, the internal parameters depend on biological varieties and dispersons: In some cases the lowest value is assumed to be Δ=±25%. This margin of error goes on to the biologically equivalent dose by means of the principle of superposition of errors. In some selected cases (lung, kidney, skin, rectum) these margins of error were calculated exemplarily. The input errors especially of the internal parameters cause a mean error Δ on the biologically equivalent dose and a dispersion of the single fraction dose d dependent on the organ taking into consideration, of approximately 8-30%. Hence it follows only a very critical and cautious application of those L-Q-algorithms in expert proceedings, and in radiotherapy more experienced based decisions are recommended, instead of acting only upon simple two-dimensional mechanistic ideas. (orig.) [de

  19. Analytical calculation of the fuel temperature reactivity coefficient for pebble bed and prismatic high temperature reactors for plutonium and uranium-thorium fuels

    International Nuclear Information System (INIS)

    Talamo, Alberto

    2007-01-01

    We analytically evaluated the fuel coefficient of temperature both for pebble bed and prismatic high temperature reactors when they utilize as fuel plutonium and minor actinides from light water reactors spent fuel or a mixture of 50% uranium, enriched 20% in 235 U, and 50% thorium. In both cores the calculation involves the evaluation of the resonances integrals of the high absorbers fuel nuclides 240 Pu, 238 U and 232 Th and it requires the esteem of the Dancoff-Ginsburg factor for a pebble bed or prismatic core. The Dancoff-Ginsburg factor represents the only discriminating parameter in the results for the two different reactors types; in fact, both the pebble bed and the prismatic reactors share the same the pseudo-cross-section describing an infinite medium made of graphite filled by TRISO particles. We considered only the resolved resonances with a statistical spin factor equal to one and we took into account 267, 72, 212 resonances in the range 1.057-5692, 6.674-14485, 21.78-3472 eV for 240 Pu, 238 U and 232 Th, respectively, for investigating the influence on the fuel temperature reactivity coefficient of the variation of the TRISO kernel radius and TRISO particles packing fraction from 100, 200 to 300 μm and from 10% to 50%, respectively. Finally, in the pebble bed core, we varied the radius of the pebble for setting a fuel temperature reactivity coefficient similar to the one of a prismatic core

  20. Anion-exchange resin-based desulfurization process. Annual technical progress report, October 1, 1991--September 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Sheth, A.C.; Strevel, S.D.; Dharmapurikar, R.

    1992-12-31

    Under the current grant, the University of Tennessee Space Institute (UTSI) will carry out the bench scale evaluation and further development of the anion-exchange resin-based desulfurization concept to desulfurize alkali metal sulfates. This concept has been developed and patented by UTSI under US Patent No. 4,917,874. The developmental program proposed under this DOE grant includes screening of commercially available resins to select three candidate resins for further study. These three resins will undergo a series of experiments designed to test the resins` performance under different process conditions (including the use of spent MHD seed material). The best of these resins will be used in optimizing the regeneration step and in testing the effects of performance enhancers. The process schematic developed from the results will be used to estimate the related economics. During this reporting period, October 1, 1991 to September 30, 1992, analysis of batch mode screening experiments was completed to select three candidate resins for process variables study in the fixed-bed set-up. This setup was modified and the experiments were carded out to evaluate effects of major process variables. The analysis of fixed-bed experiments is going on and we have also started simple batch mode experiments to identify desirable conditions for resin regeneration step. We have also started simple process engineering type calculations to determine the trade-off between the solution concentration and the resulting evaporation/concentration load.

  1. Thermal–hydraulic calculation and analysis of a 600 MW supercritical circulating fluidized bed boiler with annular furnace

    International Nuclear Information System (INIS)

    Wang, Long; Yang, Dong; Shen, Zhi; Mao, Kaiyuan; Long, Jun

    2016-01-01

    Highlights: • Non-linear model of supercritical CFB boiler with annular furnace is developed. • Many empirical correlations are used to solve the model. • The thermal–hydraulic characteristics of boiler are analyzed. • The results show that the design of the annular furnace is reasonable. - Abstract: The development of supercritical Circulating Fluidized Bed (CFB) boiler has great economic and environmental value. An entirely new annular furnace structure with outer and inner ring sidewalls for supercritical CFB boiler has been put forward by Institute of Engineering Thermophysics (IET), Chinese Academy of Sciences and Dongfang Boiler Group Co., Ltd. (DBC). Its outer and inner ring furnace structure makes more water walls arranged and reduces furnace height availably. In addition, compared with other additional evaporating heating surface structures such as mid-partition and water-cooled panels, the integrative structure can effectively avoid the bed-inventory overturn and improve the penetrability of secondary air. The conditions of the 600 MW supercritical CFB boiler including capability, pressure and mass flux are harsh. In order to insure the safety of boiler operation, it is very necessary to analyze the thermal–hydraulic characteristics of water-wall system. The water-wall system with complicated pipe arrangement is regarded as a network consisting of series-parallel circuits, pressure nodes and linking circuits, which represent vertical water-wall tubes, different headers and linking tubes, respectively. Based on the mass, momentum and energy conservation, a mathematical model is built, which consists of some simultaneous nonlinear equations. The mass flux in circuits, pressure drop between headers, outer vapor temperature of water-wall system and metal temperature data of tubes at the boiler maximum continuous rating (BMCR), 75% BMCR and 30% BMCR loads are obtained by solving the mathematical model. The results show that the vertical water

  2. Updated Performance Evaluation of the ISS Water Processor Multifiltration Beds

    Science.gov (United States)

    Bowman, Elizabeth M.; Carter, Layne; Carpenter, Joyce; Orozco, Nicole; Weir, Natalee; Wilson, Mark

    2014-01-01

    The ISS Water Processor Assembly (WPA) produces potable water from a waste stream containing humidity condensate and urine distillate. The primary treatment process is achieved in the Multifiltration Beds, which include adsorbent media and ion exchange resin for the removal of dissolved organic and inorganic contaminants. Two Multifiltration Beds (MF Beds) were replaced on ISS in July 2010 after initial indication of inorganic breakthrough of the first bed and an increasing Total Organic Carbon (TOC) trend in the product water. The first bed was sampled and analyzed Sept 2011 through March 2012. The second MF Bed was sampled and analyzed June 2012 through August 2012. The water resident in the both beds was analyzed for various parameters to evaluate adsorbent loading, performance of the ion exchange resin, microbial activity, and generation of leachates from the ion exchange resin. Portions of the adsorbent media and ion exchange resin were sampled and subsequently desorbed to identify the primary contaminants removed at various points in the bed in addition to microbial analysis. Analysis of the second bed will be compared to results from the first bed to provide a comprehensive overview of how the Multifiltration Beds function on orbit. New data from the second bed supplements the analysis of the first bed (previously reported) and gives a more complete picture of breakthrough compounds, resin breakdown products, microbial activity, and difficult to remove compounds. The results of these investigations and implications to the operation of the WPA on ISS are documented in this paper.

  3. Study on the Calculation of Pebble-Bed Reactor Multiplication Factor As a Function of Fuel Kernel Radius at Various Enrichments

    International Nuclear Information System (INIS)

    Zuhair; Suwoto

    2009-01-01

    Main characteristics of PBR comes from utilization of coated particle fuels dispersed in pebble fuels . Because of vibration, fuel kernel can be grouped into cluster and in these cases, neutronic characteristics of pebble fuel significantly changes . In this study, cluster is modeled structural form consisting of uniform cubic cells with eight neighborhood TRISO particles . Neutronic characteristics was investigated by calculating pebble-bed reactor multiplication factor as a function of fuel kernel radius at various enrichments . The calculation results using MCNP5 code with ENDF/BVI neutron library show that k eff value depends on the average fuel radius and reaches its minimum when all kernels have the same radius, i.e. 0.0280 cm . With this radius, the total kernel surface area achieves maximum value . The dependence of k eff on fuel kernel radius decreases in relation to the increase in uranium enrichment . However, k eff value is not affected by fuel kernel radius when the uranium is 100% enriched . From these result, it can be concluded that, exception of uranium enrichment, the selection of fuel kernel radius should be considered thoroughly in designing a PBR, since this parameter provides significant influences on neutronic characteristics of the reactor. (author)

  4. EDF specifications on nuclear grade resins

    International Nuclear Information System (INIS)

    Mascarenhas, Darren; Gressier, Frederic; Taunier, Stephane; Le-Calvar, Marc; Ranchoux, Gilles; Marteau, Herve; Labed, Veronique

    2012-09-01

    Ion exchange resins are widely used across EDF, especially within the nuclear division for the purification of water. Important applications include primary circuit, secondary circuit and effluent treatment, which require high quality nuclear grade resins to retain the dissolved species, some of which may be radioactive. There is a need for more and more efficient purification in order to decrease worker dose during maintenance but also to decrease volumes of radioactive resin waste. Resin performance is subject to several forms of degradation, including physical, chemical, thermal and radioactive, therefore appropriate resin properties have to be selected to reduce such effects. Work has been done with research institutes, manufacturers and on EDF sites to select these properties, create specifications and to continuously improve on these specifications. An interesting example of research regarding resin performance is the resin degradation under irradiation. Resins used in the CVCS circuit of EDF nuclear power plants are subject to irradiation over their lifetime. A study was carried out on the effects of total integrated doses of 0.1, 1 and 10 MGy on typically used EDF mixed bed resins in a 'mini-CVCS' apparatus to simultaneously test actual primary circuit fluid. The tests confirmed that the resins still perform efficiently after a typical CVCS radiation dose. Certain resins also need additional specifications in order to maintain the integrity of the particular circuits they are used in. Recently, EDF has updated its requirements on these high purity nuclear grade resins, produced generic doctrines for all products and materials used on site which include resins of all grades, and as a result have also updated a guide on recommended resin usage for the French fleet of reactors. An overview of the evolutions will be presented. (authors)

  5. Calculation of the packing fraction in a pebble-bed ADS and redesigning of the Transmutation Advanced Device for Sustainable Energy Applications (TADSEA)

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, L., E-mail: maiden@instec.cu [Instituto Superior de Tecnologias y Ciencias Aplicadas (InSTEC), Av. Salvador Allende y Luaces, Ciudad de la Habana, 10400 (Cuba); Perez, J., E-mail: jcurbelo@instec.cu [Instituto Superior de Tecnologias y Ciencias Aplicadas (InSTEC), Av. Salvador Allende y Luaces, Ciudad de la Habana, 10400 (Cuba); Garcia, C., E-mail: cgh@instec.cu [Instituto Superior de Tecnologias y Ciencias Aplicadas (InSTEC), Av. Salvador Allende y Luaces, Ciudad de la Habana, 10400 (Cuba); Escriva, A., E-mail: aescriva@iqn.upv.es [Instituto de Ingenieria Energetica (IIE), Universidad Politecnica de Valencia (UPV), Camino de Vera s/n, 46022 Valencia (Spain); Rosales, J., E-mail: jrosales@instec.cu [Instituto Superior de Tecnologias y Ciencias Aplicadas (InSTEC), Av. Salvador Allende y Luaces, Ciudad de la Habana, 10400 (Cuba); Abanades, A., E-mail: abanades@etsii.upm.es [Escuela Superior de Ingenieros Industriales (ETSII), Universidad Politecnica de Madrid (UPM), J. Gutierrez Abascal, 2, 28006 Madrid (Spain)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer We based our study on an ADS for TRU transmutation and high temperature production. Black-Right-Pointing-Pointer We calculated the number of pebbles that fit in a cylindrical ADS core. Black-Right-Pointing-Pointer In both ADS design options studied, the mass of Pu isotopes reduces considerably. Black-Right-Pointing-Pointer The system can reach coolant outlet temperatures high enough for hydrogen production. Black-Right-Pointing-Pointer The maximum temperature values obtained in the ADS are not dangerous for TRISO fuel. - Abstract: One of the main problems that should be addressed in the use of nuclear fuels for heat and electricity production is the management of nuclear waste from conventional nuclear power plants and its inventory minimization. Fast reactors and Accelerator Driven Systems (ADSs) are the main options for reducing the long-lived radioactive waste inventory. In previous studies, the conceptual design of a Transmutation Advanced Device for Sustainable Energy Applications (TADSEA) has been made. The TADSEA is a pebble-bed ADS cooled by helium and moderated by graphite; it uses as fuel small amounts of transuranic elements in the form of TRISO particles, confined in 3 cm radius graphite pebbles. It has been conceived for Plutonium (Pu) and Minor Actinides (MA) transmutation and for achieving very high helium temperatures at the core's outlet to match the thermal requirements for hydrogen production by high temperature electrolysis (HTE) or by the iodine-sulfur (I-S) thermo-chemical cycle. In this paper, a geometrical method for calculating the real number of pebbles that fit in a cylindrical ADS core, according to its size and pebble configuration, is described. Based on its results, the packing fraction influence on the TADSEA's main work parameters is studied, and the redesign of the previous configuration is done in order to maintain the exit thermal power established in the preliminary design

  6. Optimization of the resin application on the purification system of ISFSF RSG-GAS

    International Nuclear Information System (INIS)

    Junaidi

    1998-01-01

    The purification system in the spent fuel storage is to maintain the coolant water quality to the constant. This system uses the resin of IRN 77-Anion in the mixed bed filter as contamination capture. The returned water flow to the storage will be analyzed to the monitor the bed efficiency. This system can be optimally operated if the mixed bed is contained by 200 liters of resin and this is equivalent with the 0.5 m high of bed and 0.75 m in diameter. The resin must be flushed to be cleaned or changed when the pressure difference in the bed filter is higher than 0.5 bar

  7. Plastic casting resin poisoning

    Science.gov (United States)

    Epoxy poisoning; Resin poisoning ... Epoxy and resin can be poisonous if they are swallowed or their fumes are breathed in. ... Plastic casting resins are found in various plastic casting resin products.

  8. Resin composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Peutzfeldt, Anne; Lussi, Adrian

    2014-01-01

    OBJECTIVE: To investigate how the modulus of elasticity of resin composites influences marginal quality in restorations submitted to thermocyclic and mechanical loading. METHODS: Charisma, Filtek Supreme XTE and Grandio were selected as they were found to possess different moduli of elasticity...... of resin composite (p=0.81) on the quality of dentine margins was observed, before or after loading. Deterioration of all margins was evident after loading (p....008). CONCLUSIONS: The resin composite with the highest modulus of elasticity resulted in the highest number of gap-free enamel margins but with an increased incidence of paramarginal enamel fractures. CLINICAL SIGNIFICANCE: The results from this study suggest that the marginal quality of restorations can...

  9. Electrodialytic decontamination of spent ion exchange resins

    International Nuclear Information System (INIS)

    Nott, B.R.

    1982-01-01

    Development of a novel electrodialytic decontamination process for the selective removal of radioactive Cs from spent ion exchange resins containing large amounts of Li is described. The process involves passage of a dc electric current through a bed of the spent ion exchange resin in a specially designed electrodialytic cell. The radiocesium so removed from a volume of the spent resin is concentrated onto a much smaller volume of a Cs selective sorbent to achieve a significant radioactive waste volume reduction. Technical feasibility of the electrodialytic resin decontamination process has been demonstrated on a bench scale with a batch of simulated spent ion exchange resin and using potassium cobalt ferrocyanide as the Cs selective sorbent. A volume reduction factor between 10 and 17 has been estimated. The process appears to be economically attractive. Improvements in process economics can be expected from optimization of the process. Other possible applications of the EDRD process have been identified

  10. Ontario Hydro Research Division's program for treatment of spent ion-exchange resins

    International Nuclear Information System (INIS)

    Nott, B.R.; Dodd, D.J.R.

    1981-09-01

    A brief review of the evolution of work programmes for chemical treatment of spent ion-exchange resins in Ontario Hydro's Research Division is presented. Attention has been focussed on pre-treatment processes for the treatment of the spent resins prior to encapsulation of the products in solid matrices. Spent Resin Regeneration and Acid Stripping processes were considered in some detail. Particular attention was paid to carbon-14 on spent resins, its determination in and removal from the spent resins (with the acid stripping technique). The use of separate cation and anion resin beds instead of mixed bed resins was examined with a view to reducing the volume of resin usage and consequently the volume of waste radioactive ion-exchange resin generated. (author)

  11. Dynamics of Pb(II) adsorption on nanostructured γ-alumina: calculations of axial dispersion and overall mass transfer coefficients in the fixed-bed column.

    Science.gov (United States)

    Saadi, Zahra; Saadi, Reyhaneh; Fazaeli, Reza

    2015-09-01

    In the present study, the removal of metal ions Pb(II) using nanostructured γ-alumina was investigated by tests on batch operations and fixed-bed columns. Optimization was determined for factors effective on adsorption such as pH, contact time of metal solution with adsorbent and initial solution concentration. The optimum pH level was determined at 4.5 and the maximum adsorption percentage was achieved at 150 minutes. pHpzc was measured 8.3 for nanostructured γ-Al2O3. The Langmuir, Freundlich and Temkin isotherms were used to analyze the experimental data. The Langmuir isotherm model showed the best agreement with the experimental data. The model showed evaluations for maximum adsorption capacity of adsorbent at 119.04 mg/g and adsorbent bed performance for different flow rates, bed heights and influent concentrations were also investigated. The lumped method was used to solve the bed equations, to predict the breakthrough curve and model overall mass transfer coefficient (Koverall) and axial dispersion coefficient (Dz) parameters to make comparisons with experimental results.

  12. Resin screening for the removal of pyridine-derivatives from waste-water by solvent impregnated resin technology

    NARCIS (Netherlands)

    Bokhove, J.; Schuur, Boelo; de Haan, A.B.

    2013-01-01

    The selective removal of pyridine derivatives by solvent impregnated resins has been studied. A solvent impregnated resin consists of a macro-porous particle that is impregnated with a solvent. This technology allows the use liquid–liquid extraction in fixed-bed operation, and prevents problems like

  13. Theory of the computer code RET 1 for the calculation of space-time dependent temperature and composition properties of metal hydride hydrogen storage beds

    Energy Technology Data Exchange (ETDEWEB)

    El Osery, I.A.

    1983-01-01

    The work presented is a part of an extensive hydrogen energy research program conducted by the Inshas Nuclear Research Center (Egypt). The physical and mathematical modelling of the metal hydride hydrogen storage beds considered in the RET 1 computer code is described. A cylindrical conduction bed model is used. Two alternatives are considered for heat exchange: either fluid is passing through tubes surrounded by solid alloy, or solid alloy rods surrounded by annular fluid tubes. The numerical solution of the associated mass and heat transfer problem is discussed. In this solution, implicit finite difference approximations derived by Taylor expansions are applied. Some of the numerical results obtained by the RET 1 computer code are interpreted. (12 refs., 4 tabs., 3 figs.)

  14. Anion-exchange resin-based desulfurization process. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sheth, A C; Dharmapurikar, R; Strevel, S D

    1994-01-01

    The following investigations were performed: (1) batch mode screening of eleven(11) commercially available resins and selection of three candidate resins for further evaluation in a fixed-bed setup. (2) Process variables study using three candidate resins in the fixed-bed setup and selection of the ``best`` resin for process economics development. (3) Exhaustion efficiency and solution concentration were found to be inversely related necessitating a trade-off between the resin cost versus the cost of evaporation/concentration of ensuing effluents. (4) Higher concentration of the HCO{sub 3}{sup {minus}} form of active sites over less active CO{sub 3}{sup 2{minus}} form of sites in the resin was believed to be the main reason for the observed increase in the equilibrium capacity of the resin at an elevated static CO{sub 2}-pressure. This Increase in capacity was found to level off around 80--120 psig range. The increase in CO{sub 2}-pressure, however, did not appear to affect the overall ion-exchange kinetics. (5) In the fixed-bed mode, the solution concentration was found to affect the equilibrium capacity of candidate resins. Their relationship was well satisfied by the Langmuir type non-linear equilibrium isotherm. Alternatively, the effect of solution concentration on overall ion-exchange kinetics varied from resin to resin. (6) Product inhibition effect on the resin was observed as an initial increase followed by a significant decrease in the resin`s equilibrium capacity for SO{sub 4}{sup 2{minus}} as the HCO{sub 3}{sup {minus}}/SO{sub 4}{sup 2{minus}} molar ratio in the solution was increased from 0 to 1.0. This ratio, however, did not affect the overall ion-exchange kinetics.

  15. Review: Resin Composite Filling

    OpenAIRE

    Desmond Ng; Jimmy C. M. Hsiao; Keith C. T. Tong; Harry Kim; Yanjie Mai; Keith H. S. Chan

    2010-01-01

    The leading cause of oral pain and tooth loss is from caries and their treatment include restoration using amalgam, resin, porcelain and gold, endodontic therapy and extraction. Resin composite restorations have grown popular over the last half a century because it can take shades more similar to enamel. Here, we discuss the history and use of resin, comparison between amalgam and resin, clinical procedures involved and finishing and polishing techniques for resin restoration. Although resin ...

  16. Hydrodynamic calculation of a filter sand bed type used in the containment venting systems; Calculo hidrodinamico de un filtro tipo lecho de arena usado en los sistemas de venteo de la contencion

    Energy Technology Data Exchange (ETDEWEB)

    Cuevas V, D.; Sainz M, E.; Ortiz V, J., E-mail: delfy.cu@gmail.com [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2015-09-15

    The filtered venting of the containment has been adopted in European countries to mitigate the consequences of excess pressure containment during a severe accident. When venting has taken place, the fission products are released directly into the environment, unless a filter on the same path is placed, so that various types of filters are used to trap the fission products. The venting filters of the containment currently installed use different filtration technologies that involve more than one medium. Those using water as the first stage of filtration are called wet systems and are equipped with additional steps to remove water drops and fine aerosols emissions. And even they may also be equipped with an element containing certain absorption means for the filtration of gaseous iodine species. Other designs based on filtration of deep bed as the primary retention step; called dry filters, use filtration media of metal fiber, ceramic or sand to trap aerosols. This paper evaluates the hydraulic characteristics of the filter sand bed type designed by EDF as a candidate to be installed in the containment of BWR Mark II (type of primary containment of the nuclear power plant of Laguna Verde). The evaluation of filter sand bed type was performed using the software package of open source OpenFOAM. Models of each zone of the filtered device were generated and through a series of parametric calculations of computational fluid mechanics relevant hydrodynamic characteristics of the device were obtained, such as pressure drops against mass flow rate and pressure fields and speed at different operating conditions. On the other hand, the model validation of the sand bed filter when comparing the results of experimental tests on a sand column of PITEAS program (1985-1986) against OpenFOAM simulation was realized. The results are very close to those obtained experimentally. (Author)

  17. Resin Characterization

    Science.gov (United States)

    2015-06-01

    to see plastic deformation of the surface. 8.1.4.3 Density: Density using the Archimedes principle (ASTM D 792). 8.1.4.4 Density as a Function of...the cure and postcure, quickly cool the sample to 0 °C or lower the temperature to quench the reaction, and then ramp the temperature at 5 °C/min to...prepared by pouring 10 g of resin into a 30-mL screw-cap scintillation vial and adding appropriate amounts of initiator, catalyst, and inhibitor

  18. Solidification of ion exchange resin wastes

    International Nuclear Information System (INIS)

    1982-08-01

    Solidification media investigated included portland type I, portland type III and high alumina cements, a proprietary gypsum-based polymer modified cement, and a vinyl ester-styrene thermosetting plastic. Samples formulated with hydraulic cement were analyzed to investigate the effects of resin type, resin loading, waste-to-cement ratio, and water-to-cement ratio. The solidification of cation resin wastes with portland cement was characterized by excessive swelling and cracking of waste forms, both after curing and during immersion testing. Mixed bed resin waste formulations were limited by their cation component. Additives to improve the mechanical properties of portland cement-ion exchange resin waste forms were evaluated. High alumina cement formulations dislayed a resistance to deterioration of mechanical integrity during immersion testing, thus providing a significant advantage over portland cements for the solidification of resin wastes. Properties of cement-ion exchange resin waste forms were examined. An experiment was conducted to study the leachability of 137 Cs, 85 Sr, and 60 Co from resins modified in portland type III and high alumina cements. The cumulative 137 Cs fraction release was at least an order of magnitude greater than that of either 85 Sr or 60 Co. Release rates of 137 Cs in high alumina cement were greater than those in portland III cement by a factor of two.Compressive strength and leach testing were conducted for resin wastes solidified with polymer-modified gypsum based cement. 137 Cs, 85 Sr, and 60 Co fraction releases were about one, two and three orders of magnitude higher, respectively, than in equivalent portland type III cement formulations. As much as 28.6 wt % dry ion exchange resin was successfully solidified using vinyl ester-styrene compared with a maximum of 25 wt % in both portland and gypsum-based cement

  19. PILOT-SCALE HYDRAULIC TESTING OF RESORCINOL FORMALDEHYDE ION EXCHANGE RESIN

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, D

    2007-01-09

    Savannah River National Laboratory (SRNL) performed pilot-scale hydraulic/chemical testing of spherical resorcinol formaldehyde (RF) ion exchange (IX) resin for the River Protection Project Hanford Tank Waste Treatment & Immobilization Plant (WTP) Project. The RF resin cycle testing was conducted in two pilot-scale IX columns, 1/4 and 1/2 scale. A total of twenty-three hydraulic/chemical cycles were successfully completed on the spherical RF resin. Seven of the cycles were completed in the 12-inch IX Column and sixteen cycles were completed in the 24-inch IX Column. Hydraulic testing showed that the permeability of the RF resin remained essentially constant, with no observed trend in the reduction of the permeability as the number of cycles increased. The permeability during the pilot-scale testing was 2 1/2 times better than the design requirements of the WTP full-scale system. The permeability of the resin bed was uniform with respect to changes in bed depth. Upflow Regeneration and Simulant Introduction in the IX columns revealed another RF resin benefit; negligible radial pressures to the column walls from the swelling of resin beads. In downflow of the Regeneration and Simulant Introduction steps, the resin bed particles pack tightly together and produce higher hydraulic pressures than that found in upflow. Also, upflow Simulant Introduction produced an ideal level bed for the twenty cycles completed using upflow Simulant Introduction. Conversely, the three cycles conducted using downflow Simulant Introduction produced an uneven bed surface with erosion around the thermowells. The RF resin bed in both columns showed no tendency to form fissures or pack more densely as the number of cycles increased. Particle size measurements of the RF resin showed no indication of particle size change (for a given chemical) with cycles and essentially no fines formation. Micrographs comparing representative bead samples before and after testing indicated no change in bead

  20. PILOT-SCALE HYDRAULIC TESTING OF RESORCINOL FORMALDEHYDE ION EXCHANGE RESIN

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, D

    2006-11-08

    Savannah River National Laboratory (SRNL) performed pilot-scale hydraulic/chemical testing of spherical resorcinol formaldehyde (RF) ion exchange (IX) resin for the River Protection Project-Hanford Tank Waste Treatment & Immobilization Plant (WTP) Project. The RF resin cycle testing was conducted in two pilot-scale IX columns, 1/4 and 1/2 scale. A total of twenty-three hydraulic/chemical cycles were successfully completed on the spherical RF resin. Seven of the cycles were completed in the 12 inch IX Column and sixteen cycles were completed in the 24 inch IX Column. Hydraulic testing showed that the permeability of the RF resin remained essentially constant, with no observed trend in the reduction of the permeability as the number of cycles increased. The permeability during the pilot-scale testing was 2 1/2 times better than the design requirements of the WTP full-scale system. The permeability of the resin bed was uniform with respect to changes in bed depth. Upflow Regeneration and Simulant Introduction in the IX columns revealed another RF resin benefit; negligible radial pressures to the column walls from the swelling of resin beads. In downflow of the Regeneration and Simulant Introduction steps, the resin bed particles pack tightly together and produce higher hydraulic pressures than that found in upflow. Also, upflow Simulant Introduction produced an ideal level bed for the twenty cycles completed using upflow Simulant Introduction. Conversely, the three cycles conducted using downflow Simulant Introduction produced an uneven bed surface with erosion around the thermowells. The RF resin bed in both columns showed no tendency to form fissures or pack more densely as the number of cycles increased. Particle size measurements of the RF resin showed no indication of particle size change (for a given chemical) with cycles and essentially no fines formation. Micrographs comparing representative bead samples before and after testing indicated no change in bead

  1. PILOT-SCALE HYDRAULIC TESTING OF RESORCINOL FORMALDEHYDE ION EXCHANGE RESIN

    International Nuclear Information System (INIS)

    Adamson, D

    2007-01-01

    Savannah River National Laboratory (SRNL) performed pilot-scale hydraulic/chemical testing of spherical resorcinol formaldehyde (RF) ion exchange (IX) resin for the River Protection Project Hanford Tank Waste Treatment and Immobilization Plant (WTP) Project. The RF resin cycle testing was conducted in two pilot-scale IX columns, 1/4 and 1/2 scale. A total of twenty-three hydraulic/chemical cycles were successfully completed on the spherical RF resin. Seven of the cycles were completed in the 12-inch IX Column and sixteen cycles were completed in the 24-inch IX Column. Hydraulic testing showed that the permeability of the RF resin remained essentially constant, with no observed trend in the reduction of the permeability as the number of cycles increased. The permeability during the pilot-scale testing was 2 1/2 times better than the design requirements of the WTP full-scale system. The permeability of the resin bed was uniform with respect to changes in bed depth. Upflow Regeneration and Simulant Introduction in the IX columns revealed another RF resin benefit; negligible radial pressures to the column walls from the swelling of resin beads. In downflow of the Regeneration and Simulant Introduction steps, the resin bed particles pack tightly together and produce higher hydraulic pressures than that found in upflow. Also, upflow Simulant Introduction produced an ideal level bed for the twenty cycles completed using upflow Simulant Introduction. Conversely, the three cycles conducted using downflow Simulant Introduction produced an uneven bed surface with erosion around the thermowells. The RF resin bed in both columns showed no tendency to form fissures or pack more densely as the number of cycles increased. Particle size measurements of the RF resin showed no indication of particle size change (for a given chemical) with cycles and essentially no fines formation. Micrographs comparing representative bead samples before and after testing indicated no change in bead

  2. Immobilization of spent resin with epoxy resin

    International Nuclear Information System (INIS)

    Gultom, O.; Suryanto; Sayogo; Ramdan

    1997-01-01

    immobilization of spent resin using epoxy resin has been conducted. The spent resin was mixtured with epoxy resin in variation of concentration, i.e., 30, 40, 50, 60, 70 weight percent of spent resin. The mixture were pour into the plastic tube, with a diameter of 40 mm and height of 40 mm. The density, compressive strength and leaching rate were respectively measured by quanta chrome, paul weber apparatus and gamma spectrometer. The results showed that the increasing of waste concentration would be decreased the compressive strength, and increased density by immobilized waste. The leaching rate of 137 Cs from waste product was not detected in experiment (author)

  3. Epoxidation of linseed oil-Alkyd resins

    International Nuclear Information System (INIS)

    Motawie, A.M.; Ismail, E.A.; Mazroua, A.M.; Abd EI Aziem, M.S.; Ramadan, A.M.

    2004-01-01

    Three types of different linseed oil-alkyd resin ( Alk (I), Alk (II), and Alk (III) ) were prepared with the calculated amounts of mono glycerides and adipic acid (1:1, 1:2, and 2:1 Eq.Wt) respectively via monoglyceride method. The obtained alkyd resins were epoxidized via reaction with the calculated quantities of peracetic acid, which was prepared by the reaction of acetic anhydride with H 2 O 2 . Epoxidation occurred with the ratio (1: 1, 1 :3, and 1:6 Eq. Wt) of alkyd to peracetic acid. The effect of reaction time on the epoxy group content was measured during the epoxidation process. The prepared alkyd resins were analyzed by IR and H 1 NMR. The metal coated film properties of epoxidized alkyd resins were compared with those of unmodified alkyd resins. It was observed that the coating films of epoxidized alkyd resins have better in drying properties, hardness, adhesion, impact and flexibility than those of un epoxidized alkyd resins. The flammability properties of the paper coated films for the prepared brominated epoxidized alkyd resins were found to be fire retardant

  4. Performance Evaluation of the ISS Water Processor Multifiltration Beds

    Science.gov (United States)

    Bowman, Elizabeth M.; Carter, Layne; Wilson, Mark; Cole, Harold; Orozco, Nicole; Snowdon, Doug

    2012-01-01

    The ISS Water Processor Assembly (WPA) produces potable water from a waste stream containing humidity condensate and urine distillate. The primary treatment process is achieved in the Multifiltration Bed, which includes adsorbent media and ion exchange resin for the removal of dissolved organic and inorganic contaminants. The first Multifiltration Bed was replaced on ISS in July 2010 after initial indication of inorganic breakthrough. This bed was returned to ground in July 2011 for an engineering investigation. The water resident in the bed was analyzed for various parameters to evaluate adsorbent loading, performance of the ion exchange resin, microbial activity, and generation of leachates from the ion exchange resin. Portions of the adsorbent media and ion exchange resin were sampled and subsequently desorbed to identify the primary contaminants removed at various points in the bed. In addition, an unused Multifiltration Bed was evaluated after two years in storage to assess the generation of leachates during storage. This assessment was performed to evaluate the possibility that these leachates are impacting performance of the Catalytic Reactor located downstream of the Multifiltration Bed. The results of these investigations and implications to the operation of the WPA on ISS are documented in this paper.

  5. Heat-transfer characteristics of flowing and stationary particle-bed-type fusion-reactor blankets

    Energy Technology Data Exchange (ETDEWEB)

    Nietert, R.E.

    1983-02-01

    The following five appendices are included: (1) physical properties of materials, (2) thermal entrance length Nusselt number variations, (3) stationary particle bed temperature variations, (4) falling bed experimental data and calculations, and (5) stationary bed experimental data and calculations. (MOW)

  6. Heat-transfer characteristics of flowing and stationary particle-bed-type fusion-reactor blankets

    International Nuclear Information System (INIS)

    Nietert, R.E.

    1983-02-01

    The following five appendices are included: (1) physical properties of materials, (2) thermal entrance length Nusselt number variations, (3) stationary particle bed temperature variations, (4) falling bed experimental data and calculations, and (5) stationary bed experimental data and calculations

  7. Review: Resin Composite Filling

    Directory of Open Access Journals (Sweden)

    Desmond Ng

    2010-02-01

    Full Text Available The leading cause of oral pain and tooth loss is from caries and their treatment include restoration using amalgam, resin, porcelain and gold, endodontic therapy and extraction. Resin composite restorations have grown popular over the last half a century because it can take shades more similar to enamel. Here, we discuss the history and use of resin, comparison between amalgam and resin, clinical procedures involved and finishing and polishing techniques for resin restoration. Although resin composite has aesthetic advantages over amalgam, one of the major disadvantage include polymerization shrinkage and future research is needed on reaction kinetics and viscoelastic behaviour to minimize shrinkage stress.

  8. Review: Resin Composite Filling

    Science.gov (United States)

    Chan, Keith H. S.; Mai, Yanjie; Kim, Harry; Tong, Keith C. T.; Ng, Desmond; Hsiao, Jimmy C. M.

    2010-01-01

    The leading cause of oral pain and tooth loss is from caries and their treatment include restoration using amalgam, resin, porcelain and gold, endodontic therapy and extraction. Resin composite restorations have grown popular over the last half a century because it can take shades more similar to enamel. Here, we discuss the history and use of resin, comparison between amalgam and resin, clinical procedures involved and finishing and polishing techniques for resin restoration. Although resin composite has aesthetic advantages over amalgam, one of the major disadvantage include polymerization shrinkage and future research is needed on reaction kinetics and viscoelastic behaviour to minimize shrinkage stress.

  9. Sequestration Resins for Accelerating Removal of Radioactive Contaminants

    International Nuclear Information System (INIS)

    Frattini, Paul-L.; Wells, Daniel-M.; Garcia, Susan-E.; Richard, Kohlmann; Asay, Roger; Yengoyan, Leon

    2012-09-01

    The Electric Power Research Institute (EPRI) is developing sequestration resins that can be used in the treatment of nuclear plant water streams for the enhanced removal of ionic cobalt. EPRI is focusing on three key areas of success: 1. Plant safety. The resins that are synthesized must be fully tested to determine that no leachable species or decomposition products (in the event of a resin bed failure) would be introduced to the plant. 2. Acceptable system performance. The resins are currently being synthesized in a powdered form for use in the reactor water clean-up and fuel pool clean-up systems that utilize pre-coatable filter elements. The resins must have effective flocking behavior; uniform application over the underlay resin and efficient removal from the septa elements after use. Bead type resins are also under development. 3. Enhanced cobalt removal. The resins are expected to out-perform the currently used ion exchange resins in the removal of ionic cobalt. During nuclear plant maintenance or refueling outages, current ion exchange resins may require several days to reduce concentrations of cobalt (for example, radio-cobalt 60 Co and 58 Co) and other activated corrosion products to safe levels in reactor coolant streams. This performance limitation often delays key maintenance activities. EPRI's resins are expected to provide at least a three-fold increase in removal capacity in light water reactor coolants. These resins also offer the potential for higher overall removal efficiencies reducing occupational exposures and waste management costs. This paper addresses issues from the range of novel resin development for radio-cobalt removal from synthesis at the bench-top level through scale-up to demonstration of use in an actual operating nuclear power plant. (authors)

  10. Manual for computing bed load transport using BAGS (Bedload Assessment for Gravel-bed Streams) Software

    Science.gov (United States)

    John Pitlick; Yantao Cui; Peter Wilcock

    2009-01-01

    This manual provides background information and instructions on the use of a spreadsheet-based program for Bedload Assessment in Gravel-bed Streams (BAGS). The program implements six bed load transport equations developed specifically for gravel-bed rivers. Transport capacities are calculated on the basis of field measurements of channel geometry, reach-average slope,...

  11. Resin-Powder Dispenser

    Science.gov (United States)

    Standfield, Clarence E.

    1994-01-01

    Resin-powder dispenser used at NASA's Langley Research Center for processing of composite-material prepregs. Dispenser evenly distributes powder (resin polymer and other matrix materials in powder form) onto wet uncured prepregs. Provides versatility in distribution of solid resin in prepreg operation. Used wherever there is requirement for even, continuous distribution of small amount of powder.

  12. Maximum Potential Hydrogen Gas Retention in the sRF Resin Ion Exchange Column for the LAWPS Process

    Energy Technology Data Exchange (ETDEWEB)

    Gauglitz, Phillip A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wells, Beric E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bottenus, Courtney LH [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schonewill, Philip P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2018-01-22

    The Low-Activity Waste Pretreatment System (LAWPS) is being developed to provide treated supernatant liquid from the Hanford tank farms directly to the Low-Activity Waste (LAW) Vitrification Facility at the Hanford Tank Waste Treatment and Immobilization Plant. The design and development of the LAWPS is being conducted by Washington River Protection Solutions, LLC. A key process in LAWPS is the removal of radioactive Cs in ion exchange (IX) columns filled with spherical resorcinol-formaldehyde (sRF) resin. One accident scenario being evaluated is the loss of liquid flow through the sRF resin bed after it has been loaded with radioactive Cs and hydrogen gas is being generated by radiolysis. In normal operations, the generated hydrogen is expected to remain dissolved in the liquid and be continuously removed by liquid flow. For an accident scenario with a loss of flow, hydrogen gas can be retained within the IX column both in the sRF resin and below the bottom screen that supports the resin within the column. The purpose of this report is to summarize calculations that estimate the upper-bound volume of hydrogen gas that can be retained in the column and potentially be released to the headspace of the IX column or to process equipment connected to the IX column and, thus, pose a flammability hazard.

  13. Volumetric polymerization shrinkage of contemporary composite resins

    Directory of Open Access Journals (Sweden)

    Halim Nagem Filho

    2007-10-01

    Full Text Available The polymerization shrinkage of composite resins may affect negatively the clinical outcome of the restoration. Extensive research has been carried out to develop new formulations of composite resins in order to provide good handling characteristics and some dimensional stability during polymerization. The purpose of this study was to analyze, in vitro, the magnitude of the volumetric polymerization shrinkage of 7 contemporary composite resins (Definite, Suprafill, SureFil, Filtek Z250, Fill Magic, Alert, and Solitaire to determine whether there are differences among these materials. The tests were conducted with precision of 0.1 mg. The volumetric shrinkage was measured by hydrostatic weighing before and after polymerization and calculated by known mathematical equations. One-way ANOVA (a or = 0.05 was used to determine statistically significant differences in volumetric shrinkage among the tested composite resins. Suprafill (1.87±0.01 and Definite (1.89±0.01 shrank significantly less than the other composite resins. SureFil (2.01±0.06, Filtek Z250 (1.99±0.03, and Fill Magic (2.02±0.02 presented intermediate levels of polymerization shrinkage. Alert and Solitaire presented the highest degree of polymerization shrinkage. Knowing the polymerization shrinkage rates of the commercially available composite resins, the dentist would be able to choose between using composite resins with lower polymerization shrinkage rates or adopting technical or operational procedures to minimize the adverse effects deriving from resin contraction during light-activation.

  14. Curing kinetics of alkyd/melamine resin mixtures

    Directory of Open Access Journals (Sweden)

    Jovičić Mirjana C.

    2009-01-01

    Full Text Available Alkyd resins are the most popular and useful synthetic resins applied as the binder in protective coatings. Frequently they are not used alone but are modified with other synthetic resins in the manufacture of the coatings. An alkyd/melamine resin mixture is the usual composition for the preparation of coating called 'baking enamel' and it is cured through functional groups of resins at high temperatures. In this paper, curing kinetics of alkyd resins based on castor oil and dehydrated castor oil with melamine resin, has been studied by DSC method with programmed heating and in isothermal mode. The results determined from dynamic DSC curves were mathematically transformed using the Ozawa isoconversional method for obtaining the isothermal data. These results, degree of curing versus time, are in good agreement with those determined by the isothermal DSC experiments. By applying the Ozawa method it is possible to calculate the isothermal kinetic parameters for the alkyd/melamine resin mixtures curing using only calorimetric data obtained by dynamic DSC runs. Depending on the alkyd resin type and ratio in mixtures the values of activation energies of curing process of resin mixtures are from 51.3 to 114 kJ mol-1. The rate constant of curing increases with increasing the content of melamine resin in the mixture and with curing temperature. The reaction order varies from 1.12 to 1.37 for alkyd based on dehydrated castor oil/melamine resin mixtures and from 1.74 to 2.03 for mixtures with alkyd based on castor oil. Based on the results obtained, we propose that dehydrated castor oil alkyd/melamine resin mixtures can be used in practice (curing temperatures from 120 to 160°C.

  15. Enhanced DOC removal using anion and cation ion exchange resins.

    Science.gov (United States)

    Arias-Paic, Miguel; Cawley, Kaelin M; Byg, Steve; Rosario-Ortiz, Fernando L

    2016-01-01

    Hardness and DOC removal in a single ion exchange unit operation allows for less infrastructure, is advantageous for process operation and depending on the water source, could enhance anion exchange resin removal of dissolved organic carbon (DOC). Simultaneous application of cationic (Plus) and anionic (MIEX) ion exchange resin in a single contact vessel was tested at pilot and bench scales, under multiple regeneration cycles. Hardness removal correlated with theoretical predictions; where measured hardness was between 88 and 98% of the predicted value. Comparing bench scale DOC removal of solely treating water with MIEX compared to Plus and MIEX treated water showed an enhanced DOC removal, where removal was increased from 0.5 to 1.25 mg/L for the simultaneous resin application compared to solely applying MIEX resin. A full scale MIEX treatment plant (14.5 MGD) reduced raw water DOC from 13.7 mg/L to 4.90 mg/L in the treated effluent at a bed volume (BV) treatment rate of 800, where a parallel operation of a simultaneous MIEX and Plus resin pilot (10 gpm) measured effluent DOC concentrations of no greater than 3.4 mg/L, even at bed volumes of treatment 37.5% greater than the full scale plant. MIEX effluent compared to simultaneous Plus and MIEX effluent resulted in differences in fluorescence intensity that correlated to decreases in DOC concentration. The simultaneous treatment of Plus and MIEX resin produced water with predominantly microbial character, indicating the enhanced DOC removal was principally due to increased removal of terrestrially derived organic matter. The addition of Plus resin to a process train with MIEX resin allows for one treatment process to remove both DOC and hardness, where a single brine waste stream can be sent to sewer at a full-scale plant, completely removing lime chemical addition and sludge waste disposal for precipitative softening processes. Published by Elsevier Ltd.

  16. Experiences on reduction of reactor water silica and fresh resin leaching organics for Kuo-Sheng Nuclear Power Plant

    International Nuclear Information System (INIS)

    Wen, T-J.; Wang, C-H.

    2010-01-01

    The silica level in reactor water of Kuo-Sheng nuclear power plants has been slowly increased from 200 ppb to the high level above 500 ppb in recent years. The results obtained from steam/liquid mass balance calculation indicated that an increase of reactor water silica was mainly caused by continuing equilibrium leakage from deep bed condensate demineralizers, where the ion exchange zone was periodically disturbed by resin backwashing - scrubbing operation. The fastest and the most effective way to reduce the silica inventory in reactor system is to operate by continuously precoating of two sets of the reactor water clean up filter demineralizers to a lower effluent silica end point, and perhaps as frequently as three or four days. Leaching organic contaminants into feed water from the ion exchange resin becomes a key greater problem of current concern for the stable water quality promotion of condensate demineralizer. The presence of those impurities have practically been difficult to analyze by simple quality testing of the resin, and may result in as much as a hundred fold increase in chloride and sulfate in reactor water. As resin displacement with high leachable TOC, a repeated continuous soaking and effectively rinsing is required so that steady state TOC content less than 150 ppb should be achieved in an acceptably short period of time before put in-service. It is clear that cation resin containing high leachables generates high level of sulfates and sometimes also gives unexpected level of chlorides. The current TOC limits in condensate demineralizer effluent with 0.1 ppb become a significant experience to maintain reactor water soluble impurity in low levels. New resin should be subjected to TOC quality control testing prior to acceptance especially when first placed into service. TOC and organic chloride leachables for as-received virgin cation resin that are to be used in condensate polisher should be limited to be less than 100 mg-TOC and 0.5 mg-Cl per

  17. The solidification of spent resin

    International Nuclear Information System (INIS)

    Shiao, S. J.; Tsai, C. M.; Shyu, Y. H.

    1991-01-01

    A quasi-steady apparatus was applied to measure the thermal conductivity of solids ranging in size for 0.3 to 200 L, and temperature distributions in the solids were recorded during the curing, and theoretical equation for conduction in a cylindrical form with uniform energy generation was established to define the thermal state of reaction. The heat of reaction calculated from the theoretical equation with experimental values for the maximum temperature and thermal conductivity agrees very well with the data reported. The relationships among heat of reaction and amount of curing agent, retardant, loading of spent resin, and water were established

  18. Reduction of polyester resin shrinkage by means of epoxy resin

    International Nuclear Information System (INIS)

    Pietrzak, M.; Brzostowski, A.

    1981-01-01

    An attempt was made to decrease the shrinkage of unsaturated polyester resin, taking place during radiation-induced curing, by the addition of epoxy resin. In order to combine chemically both resins, the epoxy component was modified with cinnamic and acrylic acids. A composition of 90 parts of polyester resin, 10 parts of epoxy resin modified with cinnamic acid, and 150 parts of a silica filler showed a volume shrinkage of 1.2%. (author)

  19. Separation of ethylene glycol and sodium salt of serine by use of a simulated moving-bed adsorber; Giji idoso ni yoru ethylene glycol to serine no Na en no bunri

    Energy Technology Data Exchange (ETDEWEB)

    Seto, T.; Hirata, K.; Odagiri, M.; Imanari, M. [Mitsubishi Chemical Corp., Tokyo (Japan)

    1998-05-10

    Separation of ethylene glycol and sodium salt of serine is important in the processing of serine by the Strecker method using glycol aldehyde produced from ethylene glycol. The separations were successfully carried out using a simulated moving-bed four-zone type adsorber which was composed of a sodium salt of strongly acidic cation exchange resin. The moving-bed adsorber used was slightly different from a conventional one in the manner of setting up Raffinate 2. Separation of this type was simulated by calculations using an analytical solution of steady state rate equation concerning the adsorption and desorption of the ingredients and the moving bed. The condition needed for separation in the four-zone type with Raffinate 2 was discriminated, being generally coincident with the conventional condition of {beta} value. 13 refs., 5 figs., 2 tabs.

  20. Application of the pentaiodide strong base resin disinfectant to the U.S. space program

    Science.gov (United States)

    Marchin, George L.

    1990-01-01

    A pentaiodide resin is described which has 70 percent of its weight composed of elemental iodine, has a relatively low iodine residual, and may offer superior disinfection capability for applications on long-duration space vehicles. Such a disinfectant is crucial for use on spacecraft for long periods of time where water would be recycled through various systems. The pentaiodide resin is capable of devitalizing 1 x 10 to the 9th bacteria per ml in aqueous suspension within 10 seconds of contact with the resin bed. A number of organisms have already been tested and the resin continues to prove effective. Resin properties and composition are discussed and a detailed account of the first investigation of the pentaiodide resin as a disinfectant against the intestinal parasite Giardia lamblia is provided.

  1. Color of bulk-fill composite resin restorative materials.

    Science.gov (United States)

    Barutcigil, Çağatay; Barutcigil, Kubilay; Özarslan, Mehmet Mustafa; Dündar, Ayşe; Yilmaz, Burak

    2017-09-28

    To evaluate the color stability of novel bulk-fill composite resins. Color measurements of a nanohybrid composite resin (Z550) and 3 bulk-fill composite resins (BLK, AFX, XTF; n = 45) were performed before polymerization. After polymerization, color measurements were repeated and specimens were immersed in distilled water or red wine, or coffee. Color change [CIEDE2000 (ΔE 00 )] was calculated after 24 h, 1 and 3 weeks. Data were analyzed with Kruskal-Wallis, Mann-Whitney U and Wilcoxon tests (α = 0.05). Color changes observed after polymerization were significant for all groups. Color changes observed in distilled water for Z550 and AFX were significant. Color changes after stored in red wine and coffee were significant for all groups. Bulk-fill composite resin color change increased over time for all groups in red wine and coffee (P composite resin and bulk-fill composite resins. AFX had the highest color change in distilled water. The color of tested bulk-fill composite resins significantly changed after immersion in beverages and over time. Color change observed with the nanohybrid composite resin after 1 week was stable. Clinicians should keep in mind that tested composite resins may change color when exposed to water and significantly change color immediately after they are polymerized. In addition, the color change continues over time should the patient is a coffee and/or red wine consumer. © 2017 Wiley Periodicals, Inc.

  2. Determination of true bed thickness using folded bed model and borehole data

    Energy Technology Data Exchange (ETDEWEB)

    Xu, S.S.; Velasquillo-Martinez, L.G.; Grajales-Nishimura, J.M.; Murillo-Muneton, G. [Inst. Mexicano del Petroleo, Mexico City (Mexico); Garcia-Hernandez, J. [Petroleos Mexicanos Exploracion y Produccion, Tamaulipas (Mexico); Nieto-Samaniego, A.F. [Nacional Autonoma de Mexico Univ., Veracruz (Mexico). Centro de Geociencias

    2007-11-15

    The actual thickness of a given formation perpendicular to the bedding plane is known as the true bed thickness. Petroleum engineers rely on information regarding true bed thickness, particularly in dipping beds and in deviated holes because reservoir volume and isochore maps depend on these properties and not on the measured thickness. True bed thickness can be estimated from information gathered from well logs such as the dipmeter and borehole images. However, when deviations and dips exceed 10 degrees, corrections are needed. In this paper, a folded bed model was proposed to calculate the true bed thickness in the subsurface utilizing well log data. The value of true bed thickness (t) was shown to depend on the angle and the direction of the dip of the measured formation, as well as the drift angle and azimuth of the borehole. A case study from the Cantarell oil field in the southern Gulf of Mexico, offshore Campeche, was used to test the folded bed method. The model was shown to yield more uniform spatial change of the values of t, compared to the monoclinal bed model that often overestimates the average value of t. The maximum relative deviation of t from the monoclinal bed model reached 22.3 per cent and the maximum absolute deviation of t reached 34.5 m. The key factors that influence the values of t were found to be the bed dip, the dip difference between the top and base of the bed and the deviated angle of the well. The folded bed model yielded fewer changed values of the true bed thickness. 10 refs., 2 tabs., 9 figs.

  3. Resin composite repair: Quantitative microleakage evaluation of resin-resin and resin-tooth interfaces with different surface treatments

    OpenAIRE

    Celik, Cigdem; Cehreli, Sevi Burcak; Arhun, Neslihan

    2015-01-01

    Objective: The aim was to evaluate the effect of different adhesive systems and surface treatments on the integrity of resin-resin and resin-tooth interfaces after partial removal of preexisting resin composites using quantitative image analysis for microleakage testing protocol. Materials and Methods: A total of 80 human molar teeth were restored with either of the resin composites (Filtek Z250/GrandioSO) occlusally. The teeth were thermocycled (1000?). Mesial and distal 1/3 parts of the res...

  4. Breakfast in bed?

    International Nuclear Information System (INIS)

    Cheong, D.

    1999-01-01

    Full text: Gastric emptying study protocols usually reflect staff preference and the computer processing available on the gamma camera system. Should the standard protocol always be used? What special circumstances demand a change of protocol? A major consideration is the ability to define a normal range for the particular protocol used. This is a case study of a patient who had undergone gastric surgery on four occasions. He had continuing epigastric discomfort and regular acute symptoms, which were thought to be due to 'dumping syndrome'. Two previous gastric emptying studies had demonstrated markedly delayed gastric emptying. A small bowel reversal operation was being considered, but 'dumping' still had to be proved. A standard gastric emptying study was undertaken using a mixed meal of minced meat with 99 Tc m -labelled resin plus orange juice. Imaging was conducted with the patient in the semi-recumbent position and once again markedly delayed emptying was demonstrated. The study was repeated using a similar mixed meal but with imaging in the erect position. Gastric emptying was precipitous with a calculated emptying halftime of 5 min. This study elegantly confirmed the pathophysiology of gastric emptying in this patient

  5. Effect of various teas on color stability of resin composites.

    Science.gov (United States)

    Dinç Ata, Gül; Gokay, Osman; Müjdeci, Arzu; Kivrak, Tugba Congara; Mokhtari Tavana, Armin

    2017-12-01

    To investigate the effect of various teas on color stability of resin composites. Two methacrylate-based (Arabesk Top, Grandio) and a silorane-based (Filtek Silorane) resin composites were used. 110 cylindrical samples of each resin composite were prepared (2 mm thickness and 8 mm diameter), polished and stored in distilled water (37°C for 24 hours). They were randomly divided into 11 groups (n= 10) and color measurements were taken. Then the samples were immersed in tap water (control), a black tea, a green tea or one of the eight herbal-fruit teas (37°C for 1 week) and subsequently subjected to the final color measurements. The color change of samples (ΔE*) was calculated, data were subjected to two-way ANOVA and Tukey's HSD tests. Teas, resin composites and their interactions were significant (P= 0.000). All the teas and control caused color changes in all three resin composites. Rosehip tea caused the most color changes, while tap water showed the least in all resin composites. Arabesk Top had the most staining potential in all the teas and control, whereas Filtek Silorane was the most stain resistant except Grandio immersed in sage tea. Color stability of all resin composites used were affected from both structure of resin materials and constituents of teas used. All resin composites were susceptible to staining by all teas especially rosehip tea. Arabesk Top composite showed the greatest color susceptibility in all teas and Filtek Silorane the least with one exception. Color of resin composites can be negatively affected from teas consumed. Clinicians should advise patients that drinking different kind of teas could intensify surface staining of resin based restorations.

  6. Metameric effect between dental porcelain and porcelain repairing resin composite.

    Science.gov (United States)

    Kim, Sung-Hee; Lee, Yong-Keun; Lim, Bum-Soon; Rhee, Sang-Hoon; Yang, Hyeong-Cheol

    2007-03-01

    The objectives were to evaluate the metameric color and hue angle (degrees) changes between dental porcelain and porcelain repairing resin composites. Color of three shades (A2, A3, A3.5) of one brand of dental porcelain and three original shades (A2, A3, A3.5) and three combinations (A2-A3, A3-3.5, A2-A3.5) of three brands of porcelain repairing resin composites (ABT, FSP, TCR) were measured relative to the three standard illuminants (D65, A and F2). Specimen was 2mm in thickness, and 1mm of each shade was layered to make combined shades. Color differences (DeltaEab*) between each shade of dental porcelain and repairing resin composites relative to the three illuminants were calculated, and the ratios of color difference (modified metamerism index) by the change of illuminant were calculated. The ratios of hue angle changes were also compared. Differences in modified metamerism index and the ratio of hue angle changes were influenced by the porcelain shade, brand of resin composites and shade of resin composites. In all three brands of resin composites, A3.5 shade showed the smallest values in modified metamerism index regardless of the shade of porcelain. The average ratio of hue angle changes between each porcelain shade and all the shades of each resin composites showed similar trend when illuminant was changed from D65 to F2. Metameric effect between dental porcelain and repairing resin composites varied depending on the shade of porcelain, brand of resin composite and the illuminant. Therefore, shade matching between porcelain and repairing resin composite should be performed carefully. This study confirmed that shades should be matched under the light corresponding to that of use.

  7. Sediment transport primer: estimating bed-material transport in gravel-bed rivers

    Science.gov (United States)

    Peter Wilcock; John Pitlick; Yantao Cui

    2009-01-01

    This primer accompanies the release of BAGS, software developed to calculate sediment transport rate in gravel-bed rivers. BAGS and other programs facilitate calculation and can reduce some errors, but cannot ensure that calculations are accurate or relevant. This primer was written to help the software user define relevant and tractable problems, select appropriate...

  8. Electrostatic collection efficiency in binary fluidized beds

    Energy Technology Data Exchange (ETDEWEB)

    Romero, A.; Guardiola, J.; Rincon, J. (Univ. of Alcala de Henares, Madrid (Spain))

    1992-01-01

    Fluidized beds of binary mixtures have been used to clean air streams containing dust particles in the size range 4.4 to 14 {mu}m. All beds were composed of glass beads and plastic granules mixed at different proportions. The effect on the electrostatic collection efficiency of a number of variables, including type of collecting mixture, bed height, and gas velocity, was examined. To calculate the single collection efficiency from experimental results, an early model proposed by Clift et al. was used. The electrostatic collection efficiency was determined by subtracting the other individual mechanism efficiencies from the single particle collection efficiency.

  9. Method for removing contaminants from plastic resin

    Science.gov (United States)

    Bohnert, George W [Harrisonville, MO; Hand, Thomas E [Lee's Summit, MO; DeLaurentiis, Gary M [Jamestown, CA

    2008-12-09

    A resin recycling method that produces essentially contaminant-free synthetic resin material in an environmentally safe and economical manner. The method includes receiving the resin in container form. The containers are then ground into resin particles. The particles are exposed to a solvent, the solvent contacting the resin particles and substantially removing contaminants on the resin particles. After separating the particles and the resin, a solvent removing agent is used to remove any residual solvent remaining on the resin particles after separation.

  10. In-Bed Accountability Development for a Passively Cooled, Electrically Heated Hydride (PACE) Bed

    International Nuclear Information System (INIS)

    Klein, J.E.

    2005-01-01

    A nominal 1500 STP-L PAssively Cooled, Electrically heated hydride (PACE) Bed has been developed for implementation into a new Savannah River Site tritium project. The 1.2 meter (four-foot) long process vessel contains on internal 'U-tube' for tritium In-Bed Accountability (IBA) measurements. IBA will be performed on six, 12.6 kg production metal hydride storage beds.IBA tests were done on a prototype bed using electric heaters to simulate the radiolytic decay of tritium. Tests had gas flows from 10 to 100 SLPM through the U-tube or 100 SLPM through the bed's vacuum jacket. IBA inventory measurement errors at the 95% confidence level were calculated using the correlation of IBA gas temperature rise, or (hydride) bed temperature rise above ambient temperature, versus simulated tritium inventory.Prototype bed IBA inventory errors at 100 SLPM were the largest for gas flows through the vacuum jacket: 15.2 grams for the bed temperature rise and 11.5 grams for the gas temperature rise. For a 100 SLPM U-tube flow, the inventory error was 2.5 grams using bed temperature rise and 1.6 grams using gas temperature rise. For 50 to 100 SLPM U-tube flows, the IBA gas temperature rise inventory errors were nominally one to two grams that increased above four grams for flows less than 50 SLPM. For 50 to 100 SLPM U-tube flows, the IBA bed temperature rise inventory errors were greater than the gas temperature rise errors, but similar errors were found for both methods at gas flows of 20, 30, and 40 SLPM.Electric heater IBA tests were done for six production hydride beds using a 45 SLPM U-tube gas flow. Of the duplicate runs performed on these beds, five of the six beds produced IBA inventory errors of approximately three grams: consistent with results obtained in the laboratory prototype tests

  11. In-Bed Accountability Development for a Passively Cooled, Electrically Heated Hydride (PACE) Bed

    International Nuclear Information System (INIS)

    KLEIN, JAMES

    2004-01-01

    A nominal 1500 STP-L PAssively Cooled, Electrically heated hydride (PACE) Bed has been developed for implementation into a new Savannah River Site tritium project. The 1.2 meter (four-foot) long process vessel contains an internal ''U-tube'' for tritium In-Bed Accountability (IBA) measurements. IBA will be performed on six, 12.6 kg production metal hydride storage beds. IBA tests were done on a prototype bed using electric heaters to simulate the radiolytic decay of tritium. Tests had gas flows from 10 to 100 SLPM through the U-tube or 100 SLPM through the bed's vacuum jacket. IBA inventory measurement errors at the 95 percent confidence level were calculated using the correlation of IBA gas temperature rise, or (hydride) bed temperature rise above ambient temperature, versus simulated tritium inventory. Prototype bed IBA inventory errors at 100 SLPM were the largest for gas flows through the vacuum jacket: 15.2 grams for the bed temperature rise and 11.5 grams for the gas temperature rise. For a 100 SLPM U-tube flow, the inventory error was 2.5 grams using bed temperature rise and 1.6 grams using gas temperature rise. For 50 to 100 SLPM U-tube flows, the IBA gas temperature rise inventory errors were nominally one to two grams that increased above four grams for flows less than 50 SLPM. For 50 to 100 SLPM U-tube flows, the IBA bed temperature rise inventory errors were greater than the gas temperature rise errors, but similar errors were found for both methods at gas flows of 20, 30, and 40 SLPM. Electric heater IBA tests were done for six production hydride beds using a 45 SLPM U-tube gas flow. Of the duplicate runs performed on these beds, five of the six beds produced IBA inventory errors of approximately three grams: consistent with results obtained in the laboratory prototype tests

  12. Comparison of stabilities in translucency, fluorescence and opalescence of direct and indirect composite resins.

    Science.gov (United States)

    Yu, Bin; Lee, Young-Keun

    2013-01-01

    To evaluate translucency, fluorescence and opalescence stabilities of direct and indirect composite resins after aging. One direct (16 shades) and two indirect composite resins (16 and 26 shades) were investigated. Resins were filled in a mold (1 mm thick) and light cured; post-curings were performed for indirect resins. Color was measured before and after 5,000 cycles of thermocycling on a reflection spectrophotometer in reflectance and transmittance modes to calculate parameters for translucency (TP), fluorescence (FL) and opalescence (OP). Differences in the changes of TP, FL and OP after aging by the type of resin were determined by t test, and those were also determined by one-way ANOVA with the factor of the brand or the shade group (P resins; and were -2.0 to 1.8, -0.9 to 0.4 and -2.9 to 3.7, respectively, for indirect resins. Changes in TP were not significantly different by the type of resin, but those in FL and OP were different (P = 0.05). Changes in optical parameters were influenced by the brand or the shade group of the resins (P resins varied depending on type, brand or shade group. Aging significantly affected fluorescence and opalescence, but not translucency, of indirect resins compared to those of direct resins.

  13. Shear Bond Strength between Fiber-Reinforced Composite and Veneering Resin Composites with Various Adhesive Resin Systems.

    Science.gov (United States)

    AlJehani, Yousef A; Baskaradoss, Jagan K; Geevarghese, Amrita; AlShehry, Marey A; Vallittu, Pekka K

    2016-07-01

    The aim of this research was to evaluate the shear bond strength of different laboratory resin composites bonded to a fiber-reinforced composite substrate with some intermediate adhesive resins. Mounted test specimens of a bidirectional continuous fiber-reinforced substrate (StickNet) were randomly assigned to three equal groups. Three types of commercially available veneering resin composites - BelleGlass®, Sinfony®, and GC Gradia® were bonded to these specimens using four different adhesive resins. Half the specimens per group were stored for 24 hours; the remaining were stored for 30 days. There were 10 specimens in the test group (n). The shear bond strengths were calculated and expressed in MPa. Data were analyzed statistically, and variations in bond strength within each group were additionally evaluated by calculating the Weibull modulus. Shear bond values of those composites are influenced by the different bonding resins and different indirect composites. There was a significant difference in the shear bond strengths using different types of adhesive resins (p = 0.02) and using different veneering composites (p veneering composite to bidirectional continuous fiber-reinforced substrate is influenced by the brand of the adhesive resin and veneering composite. © 2015 by the American College of Prosthodontists.

  14. Contact allergy to epoxy resin

    DEFF Research Database (Denmark)

    Bangsgaard, Nannie; Thyssen, Jacob Pontoppidan; Menné, Torkil

    2012-01-01

    to epoxy resin remained stable over the study period. Of the patients with an epoxy resin-positive patch test, 71% returned a questionnaire; 95 patients had worked with epoxy resin in the occupational setting, and, of these, one-third did not use protective gloves and only 50.5% (48) had participated...

  15. Radial voidage variation in fixed beds of fuel wood pellets

    International Nuclear Information System (INIS)

    Hamel, Stefan; Krumm, Wolfgang

    2012-01-01

    Fixed beds of fuel wood are commonly found in numerous processes: storage and transportation, drying and thermal conversion such as combustion or gasification. Pellets in particular are mostly used as fuel for domestic heating boilers. The characterization of spatial voidage distribution is of great importance for flow and reactor modelling. The present study focuses on the radial porosity variations of cylindrical beds of commercially available wood pellets. The experimental procedure is based on the classical technique of consolidating packed beds with a resin. The radial voidage distribution of three different cylindrical beds is determined by image analysis of sections of the solidified packing. The results are discussed and summarized in a mathematical expression correlating the radial voidage distribution depending on packing core porosity and dimensionless distance from the tube wall. -- Highlights: ► Packing characteristics for commercially available wood pellets were investigated. ► Radial porosity variations of cylindrical pellets beds were investigated. ► Epoxy resin consolidated packings were investigated by image analysis. ► Mathematical term for radial voidage distribution of pellet packing was derived.

  16. Fluid-bed combustion

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, G.; Schoebotham, N.

    1981-02-01

    In Energy Equipment Company's two-stage fluidized bed system, partial combustion in a fluidized bed is followed by burn-off of the generated gases above the bed. The system can be retrofitted to existing boilers, and can burn small, high ash coal efficiently. It has advantages when used as a hot gas generator for process drying. Tests on a boiler at a Cadbury Schweppes plant are reported.

  17. Enhancement of adhesion between resin coating materials and resin cements.

    Science.gov (United States)

    Udo, Tomoaki; Nikaido, Toru; Ikeda, Masaomi; Weerasinghe, Dinesh S; Harada, Naoko; Foxton, Richard M; Tagami, Junji

    2007-07-01

    Resin coating technique is a unique method that improves the dentin bond strength of resin cements in indirect restorations. However, the weak link of a specimen bonded using the resin coating technique was reported to be the bonded interface between the resin coating material and resin cement. The purpose of this study, therefore, was to enhance the bonding performance between a resin coating material and a resin cement. Two light-cured flowable composites, Protect Liner F and Clearfil Flow FX, were used as coating materials, and two dual-cure composite materials, Panavia F 2.0 and Clearfil DC Core Automix, were used as resin cements. The ultimate tensile strength of each material and the microtensile bond strengths of the bonded specimens of resin coating material and resin cement were measured using a crosshead speed of 1.0 mm/min. Three-way ANOVA (p=0.05) revealed that the highest microtensile bond strength was obtained using a combination of Clearfil Flow FX and Clearfil DC Core Automix, and when the surface of the coating material was treated with ED Primer II. It was strongly suggested that materials with a higher ultimate tensile strength, when used in both resin coating and cementation, could enhance the bond strength between the two.

  18. Resin impregnation process for producing a resin-fiber composite

    Science.gov (United States)

    Palmer, Raymond J. (Inventor); Moore, William E. (Inventor)

    1994-01-01

    Process for vacuum impregnation of a dry fiber reinforcement with a curable resin to produce a resin-fiber composite, by drawing a vacuum to permit flow of curable liquid resin into and through a fiber reinforcement to impregnate same and curing the resin-impregnated fiber reinforcement at a sufficient temperature and pressure to effect final curing. Both vacuum and positive pressure, e.g. autoclave pressure, are applied to the dry fiber reinforcement prior to application of heat and prior to any resin flow to compact the dry fiber reinforcement, and produce a resin-fiber composite of reduced weight, thickness and resin content, and improved mechanical properties. Preferably both a vacuum and positive pressure, e.g. autoclave pressure, are also applied during final curing.

  19. Measurement of net nitrogen and phosphorus mineralization in wetland soils using a modification of the resin-core technique

    Science.gov (United States)

    Noe, Gregory B.

    2011-01-01

    A modification of the resin-core method was developed and tested for measuring in situ soil N and P net mineralization rates in wetland soils where temporal variation in bidirectional vertical water movement and saturation can complicate measurement. The modified design includes three mixed-bed ion-exchange resin bags located above and three resin bags located below soil incubating inside a core tube. The two inner resin bags adjacent to the soil capture NH4+, NO3-, and soluble reactive phosphorus (SRP) transported out of the soil during incubation; the two outer resin bags remove inorganic nutrients transported into the modified resin core; and the two middle resin bags serve as quality-control checks on the function of the inner and outer resin bags. Modified resin cores were incubated monthly for a year along the hydrogeomorphic gradient through a floodplain wetland. Only small amounts of NH4+, NO3-, and SRP were found in the two middle resin bags, indicating that the modified resin-core design was effective. Soil moisture and pH inside the modified resin cores typically tracked changes in the surrounding soil abiotic environment. In contrast, use of the closed polyethylene bag method provided substantially different net P and N mineralization rates than modified resin cores and did not track changes in soil moisture or pH. Net ammonification, nitrifi cation, N mineralization, and P mineralization rates measured using modified resin cores varied through space and time associated with hydrologic, geomorphic, and climatic gradients in the floodplain wetland. The modified resin-core technique successfully characterized spatiotemporal variation of net mineralization fluxes in situ and is a viable technique for assessing soil nutrient availability and developing ecosystem budgets.

  20. Relined fiberglass post: an ex vivo study of the resin cement thickness and dentin-resin interface

    Directory of Open Access Journals (Sweden)

    Niélli Caetano de SOUZA

    Full Text Available Abstract The aim of this study was to evaluate the thickness of resin cements in the root thirds when using conventional fiberglass posts (CP and relined fiberglass posts (RP in weakened roots and to evaluate the morphological characteristics of the dentin-resin interface. Forty human maxillary anterior teeth had the crown sectioned below the cemento-enamel junction. The canals were endodontically treated and weakened with diamond burs. Teeth were divided into four groups (n = 10: Group 1 – CP + RelyX ARC; Group 2 – CP + RelyX U200; Group 3 – RP + RelyX ARC; and Group 4 – RP + RelyX U200. Prior to luting, 0.1% Fluorescein and 0.1% Rhodamine B dyes were added to an adhesive and resin cement, respectively. Slices were obtained from the apical, middle, and cervical thirds of the root. Confocal laser scanning microscopy images were recorded in four areas (buccal, lingual, mesial, distal of each third. In each area, four equidistant measures of the resin cement were made and the mean value was calculated. The interface morphology was observed. The data were submitted to three-way ANOVA and Tukey’s test (α = 0.05. The interaction between fiberglass posts, resin cement, and root thirds was significant (p < 0.0001. The resin cement thicknesses were significantly lower for RP in comparison with CP, except in the apical third. There was no significant difference between the resin cements for RP. There was formation of resin cement tags and adhesive tags along the root for RP. RP favored the formation of thin and uniform resin cement films and resin tags in weakened roots.

  1. Relined fiberglass post: an ex vivo study of the resin cement thickness and dentin-resin interface.

    Science.gov (United States)

    Souza, Niélli Caetano de; Marcondes, Maurem Leitão; Breda, Ricardo Vaz; Weber, João Batista Blessmann; Mota, Eduardo Gonçalves; Spohr, Ana Maria

    2016-08-18

    The aim of this study was to evaluate the thickness of resin cements in the root thirds when using conventional fiberglass posts (CP) and relined fiberglass posts (RP) in weakened roots and to evaluate the morphological characteristics of the dentin-resin interface. Forty human maxillary anterior teeth had the crown sectioned below the cemento-enamel junction. The canals were endodontically treated and weakened with diamond burs. Teeth were divided into four groups (n = 10): Group 1 - CP + RelyX ARC; Group 2 - CP + RelyX U200; Group 3 - RP + RelyX ARC; and Group 4 - RP + RelyX U200. Prior to luting, 0.1% Fluorescein and 0.1% Rhodamine B dyes were added to an adhesive and resin cement, respectively. Slices were obtained from the apical, middle, and cervical thirds of the root. Confocal laser scanning microscopy images were recorded in four areas (buccal, lingual, mesial, distal) of each third. In each area, four equidistant measures of the resin cement were made and the mean value was calculated. The interface morphology was observed. The data were submitted to three-way ANOVA and Tukey's test (α = 0.05). The interaction between fiberglass posts, resin cement, and root thirds was significant (p < 0.0001). The resin cement thicknesses were significantly lower for RP in comparison with CP, except in the apical third. There was no significant difference between the resin cements for RP. There was formation of resin cement tags and adhesive tags along the root for RP. RP favored the formation of thin and uniform resin cement films and resin tags in weakened roots.

  2. Selective separation of indium by iminodiacetic acid chelating resin

    Energy Technology Data Exchange (ETDEWEB)

    Fortes, M.C.B.; Benedetto, J.S. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Martins, A.H. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Metalurgica e de Materiais]. E-mail: ahmartin@demet.ufmg.br

    2007-04-15

    - Indium can be recovered by treating residues, flue dusts, slags, and metallic intermediates in zinc smelting. This paper investigates the adsorption characteristics of indium and iron on an iminodiacetic acid chelating resin, Amberlite{sup R} IRC748 (Rohm and Haas Co.-USA). High concentrations of iron are always present in the aqueous feed solution of indium recovery. In addition, the chemical behaviour of iron in adsorptive systems is similar to that of indium. The metal concentrations in the aqueous solution were based on typical indium sulfate leach liquor obtained from zinc hydrometallurgical processing in a Brazilian plant. The ionic adsorption experiments were carried out by the continuous column method. Amberlite{sup R} IRC748 resin had a high affinity for indium under acidic conditions. Indium ions adsorbed onto the polymeric resin were eluted with a 0.5 mol/dm{sup 3} sulphuric acid solution passed through the resin bed in the column. 99.5% pure indium sulfate aqueous solution was obtained using the iminodiacetic acid chelating resin Amberlite{sup R} IRC748. (author)

  3. In vitro enamel remineralization capacity of composite resins containing sodium trimetaphosphate and fluoride.

    Science.gov (United States)

    Tiveron, Adelisa Rodolfo Ferreira; Delbem, Alberto Carlos Botazzo; Gaban, Gabriel; Sassaki, Kikue Takebayashi; Pedrini, Denise

    2015-11-01

    This study evaluated the in vitro enamel remineralization capacity of experimental composite resins containing sodium trimetaphosphate (TMP) combined or not with fluoride (F). Bovine enamel slabs were selected upon analysis of initial surface hardness (SH1) and after induction of artificial carious lesions (SH2). Experimental resins were as follows: resin C (control—no sodium fluoride (NaF) or TMP), resin F (with 1.6% NaF), resin TMP (with 14.1% TMP), and resin TMP/F (with NaF and TMP). Resin samples were made and attached to enamel slabs (n = 12 slabs per material). Those specimens (resin/enamel slab) were subjected to pH cycling to promote remineralization, and then final surface hardness (SH3) was measured to calculate the percentage of surface hardness recovery (%SH). The integrated recovery of subsurface hardness (ΔKHN) and F concentration in enamel were also determined. Data was analyzed by ANOVA and Student-Newman-Keuls test (p Resins F and TMP/F showed similar SH3 values (p = 0.478) and %SH (p = 0.336) and differed significantly from the other resins (p resin TMP/F presented the lowest area of lesion (p resins (p = 0.042), but higher than in the other resins (p composite resin enhanced its capacity for remineralization of enamel in vitro. The combination of two agents with action on enamel favored remineralization, suggesting that composite resins containing sodium trimetaphosphate and fluoride could be indicated for clinical procedures in situations with higher cariogenic challenges.

  4. Fluidized bed incinerator development

    International Nuclear Information System (INIS)

    Ziegler, D.L.; Johnson, A.J.

    1976-01-01

    A fluidized bed incinerator is being developed for burning rad contaminated solid and liquid waste materials. In situ neutralization of acid gases by the bed material, catalytic afterburning, and gas filtration are used to produce a clean flue gas without the use of aqueous scrubbing

  5. Differences in color, translucency and fluorescence between flowable and universal resin composites.

    Science.gov (United States)

    Yu, Bin; Lee, Yong-Keun

    2008-10-01

    To evaluate the optical properties such as color, translucency and fluorescence of flowable resin composites, and compare them with the corresponding shade universal resin composites of the same brand. Four brands of flowable and universal resin composites of the same shade designation (A2) were investigated. Color of specimens (2mm in thickness) was measured after polymerization on a reflection spectrophotometer over background of white, black and each corresponding composite material itself. Color differences (DeltaE(ab)(*)) between each combination of resin composites were determined. Translucency parameter (TP) and color difference by the fluorescent emission (DeltaE(ab)(*)-FL) of materials were also calculated. Differences in the optical properties of flowable and universal resin composites were analyzed with one-way ANOVA. DeltaE(ab)(*) between the flowable and the corresponding universal resin composites was in the range of 1.0-6.0 DeltaE(ab)(*) units, which was perceptible (DeltaE(ab)(*)>2.6) in three brands. Flowable resin composites revealed lower TP values in two of the four brands. DeltaE(ab)(*) between flowable and the corresponding universal resin composites was influenced by their difference in translucency. All the four universal resin composites and two flowable resin composites showed fluorescent peak, and the range of DeltaE(ab)(*)-FL was 0.3-2.3 DeltaE(ab)(*) units. Optical properties of flowable and universal resin composites was significantly different (presin composites should be considered for clinically acceptable color matching.

  6. Improved management of SG BD demineralizer for reduced generation of low-level radioactive spent resin in Korean nuclear power plants

    International Nuclear Information System (INIS)

    Rhee, I.; Cho, D.; Yeon, J.

    2003-01-01

    Most nuclear power plants in Korea have adopted Ethanolamine(ETA) as a secondary pH control agent to increase the pH at the liquid phase, which may reduce the corrosion in steam generator tubes and moisture separator/reheat system. Along with its beneficial effect of SG protection from corrosion and degradation, the replacement of ammonia with ETA causes the increased generation of spent resin and the reduced run time of demineralizer in steam generator blowdown(SG BD) system. The composition ratio of cation- to anion- exchange resin in SG BD mixed bed should be increased in the ETA chemistry environment to meet the ratio of cation to anion in the aqueous solution, which results in the simultaneous exhaustion of cation and anion exchange resins. The utilization rate of mixed bed is greatest at the cation-to-anion ratio of 95:1 on the theoretical equivalent basis in the solution, but practically highest at that of 22:1 due to the possible inhomogeneous distribution of cation and anion exchange resins in SG BD bed. The run time of the bed could be extended by 30% such that, at that much, the purchase cost of new resin is saved and the production rate of spent resin is reduced. The guideline on the replacement of resin in SG BD bed is not necessary to secure the removal of radioactive particles without the leakage of the primary coolant into the secondary side since all the radioactive ions can be eliminated by SG BD bed with the sufficient time. They are retained during more than one month after their ingress into the SG BD bed without leakage. With the reduced replacement, thus, the SG BD spent resin that comprises 65% of low-level radioactive solid waste can be much cut down

  7. Quantification and Purification of Mulberry Anthocyanins with Macroporous Resins

    Directory of Open Access Journals (Sweden)

    Xueming Liu

    2004-01-01

    Full Text Available Total anthocyanins in different cultivars of mulberry were measured and a process for the industrial preparation of mulberry anthocyanins as a natural food colorant was studied. In 31 cultivars of mulberry, the total anthocyanins, calculated as cyanidin 3-glucoside, ranged from 147.68 to 2725.46 mg/L juice. Extracting and purifying with macroporous resins was found to be an efficient potential method for the industrial production of mulberry anthocyanins as a food colorant. Of six resins tested, X-5 demonstrated the best adsorbent capability for mulberry anthocyanins (91 mg/mL resin. The adsorption capacity of resins increased with the surface area and the pore radius. Residual mulberry fruit juice after extraction of pigment retained most of its nutrients, except for anthocyanins, and may provide a substrate for further processing.

  8. Flame Retardant Epoxy Resins

    Science.gov (United States)

    Thompson, C. M.; Smith, J. G., Jr.; Connell, J. W.; Hergenrother, P. M.; Lyon, R. E.

    2004-01-01

    As part of a program to develop fire resistant exterior composite structures for future subsonic commercial aircraft, flame retardant epoxy resins are under investigation. Epoxies and their curing agents (aromatic diamines) containing phosphorus were synthesized and used to prepare epoxy formulations. Phosphorus was incorporated within the backbone of the epoxy resin and not used as an additive. The resulting cured epoxies were characterized by thermogravimetric analysis, propane torch test, elemental analysis and microscale combustion calorimetry. Several formulations showed excellent flame retardation with phosphorous contents as low as 1.5% by weight. The fracture toughness of plaques of several cured formulations was determined on single-edge notched bend specimens. The chemistry and properties of these new epoxy formulations are discussed.

  9. Bismaleimide Copolymer Matrix Resins

    Science.gov (United States)

    Parker, John A.; Heimbuch, Alvin H.; Hsu, Ming-Ta S.; Chen, Timothy S.

    1987-01-01

    Graphite composites, prepared from 1:1 copolymer of two new bismaleimides based on N,N'-m-phenylene-bis(m-amino-benzamide) structure have mechanical properties superior to those prepared from other bismaleimide-type resins. New heat-resistant composites replace metal in some structural applications. Monomers used to form copolymers with superior mechanical properties prepared by reaction of MMAB with maleic or citraconic anhydride.

  10. System for removing contaminants from plastic resin

    Science.gov (United States)

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    2010-11-23

    A resin recycling system that produces essentially contaminant-free synthetic resin material in an environmentally safe and economical manner. The system includes receiving the resin in container form. A grinder grinds the containers into resin particles. The particles are exposed to a solvent in one or more solvent wash vessels, the solvent contacting the resin particles and substantially removing contaminants on the resin particles. A separator is used to separate the resin particles and the solvent. The resin particles are then placed in solvent removing element where they are exposed to a solvent removing agent which removes any residual solvent remaining on the resin particles after separation.

  11. Paramagnetic epoxy resin

    Directory of Open Access Journals (Sweden)

    E. C. Vazquez Barreiro

    2017-01-01

    Full Text Available This work illustrates that macrocycles can be used as crosslinking agents for curing epoxy resins, provided that they have appropriate organic functionalities. As macrocycles can complex metal ions in their structure, this curing reaction allows for the introduction of that metal ion into the resin network. As a result, some characteristic physical properties of the metallomacrocycle could be transferred to the new material. The bisphenol A diglycidyl ether (BADGE, n = 0 and hemin (a protoporphyrin IX containing the Fe(III ion, and an additional chloride ligand have been chosen. The new material has been characterized by differential scanning calorimetry (DSC, thermogravimetric analysis (TGA, Fourier Transform Infrared (FT-IR, Nuclear Magnetic Resonance (NMR, Transmission Electron Microscopy (TEM, and magnetic susceptibility measurements. Fe(III remains in the high-spin state during the curing process and, consequently, the final material exhibits the magnetic characteristics of hemin. The loss of the chlorine atom ligand during the cure of the resin allows that Fe(III can act as Lewis acid, catalyzing the crosslinking reactions. At high BADGE n = 0/hemin ratios, the formation of ether and ester bonds occurs simultaneously during the process.

  12. Biokompatibilitas Gelas Ionomer Modifikasi Resin

    OpenAIRE

    Rotua Lestari M

    2008-01-01

    Saat ini banyak berkembang material baru dalam dunia kedokteran gigi diantaranya adalah Gelas ionomer modifikasi resin yang dikembangkan untuk mengatasi kekurangan-kekurangan dari gelas ionomer konvensional. Adanya penambahan monomer resin daIam bentuk 2-hydroxyethylmetacylate (HEMA) telah meningkatkan kekuatan dari bahan ini. Gelas ionomer modifikasi resin mempunyai sifat-sifat fisis dan mekanis yang lebih baik dibandingkan dengan gelas ionomer konvensional. Gelas ionomer modifikasi ...

  13. Bed rest during pregnancy

    Science.gov (United States)

    ... Belizán JM, Bergel E. Bed rest in singleton pregnancies for preventing preterm birth. Cochrane Database ... and Gynecology, Loma Linda University School of Medicine, Loma Linda Center for Fertility, ...

  14. Enuresis (Bed-Wetting)

    Science.gov (United States)

    ... Symptoms of enuresis Enuresis is when an older child (age 7 or older) wets the bed at night ... feel guilt and embarrassment. It’s true that your child should take responsibility for bedwetting. He or she could do this ...

  15. Particle fuel bed tests

    International Nuclear Information System (INIS)

    Horn, F.L.; Powell, J.R.; Savino, J.M.

    1985-01-01

    Gas-cooled reactors, using packed beds of small diameter coated fuel particles have been proposed for compact, high-power systems. The particulate fuel used in the tests was 800 microns in diameter, consisting of a thoria kernel coated with 200 microns of pyrocarbon. Typically, the bed of fuel particles was contained in a ceramic cylinder with porous metallic frits at each end. A dc voltage was applied to the metallic frits and the resulting electric current heated the bed. Heat was removed by passing coolant (helium or hydrogen) through the bed. Candidate frit materials, rhenium, nickel, zirconium carbide, and zirconium oxide were unaffected, while tungsten and tungsten-rhenium lost weight and strength. Zirconium-carbide particles were tested at 2000 K in H 2 for 12 hours with no visible reaction or weight loss

  16. Rehydration ratio of fluid bed-dried vegetables

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    The goal has been to obtain dry vegetables with 6% to 10% water content and of good rehydration quality. Experimental data. (bed height, gas temperature and velocity, pressure drop over the bed, drying time) have been measured and relevant values have been calculated. The results have shown that drying of ...

  17. Innovative rock bed construction

    Energy Technology Data Exchange (ETDEWEB)

    Cook, J.

    1983-06-01

    A general discussion of the use of rock beds for heating and cooling thermal storage is particularized for design and construction in Phoenix, Arizona. The rock bed parameters for three two-story condominium apartments constructed in 1982 are discussed, including sizing criteria and original construction details. A revised construction method using gabions that are self-supporting chain link cylinders provided a much more economical construction method as well as other advantages of speed and structural flexibility.

  18. Determination of viscosity in recirculating fluidized bed using radioactive tracer

    International Nuclear Information System (INIS)

    Silva, G.G. da.

    1986-01-01

    The use of radioactive tracer for measuring viscosity is proposed. The methodology relates the terminal velocity of a radioactive sphere in interior of fluid with the viscosity, which can be a fluidized bed or total flow of solids. The arrangement is composed by two γ detectors placed externally and along the bed. Both detectors are coupled by amplifier to electronic clock. The drop time of sphere between two detectors is measured. The bed viscosity two detectors is measured. The bed viscosity is calculated from mathematical correlations of terminal velocity of the sphere. (M.C.K.)

  19. Solidification of spent ion exchange resin using new cementitious material, (1)

    International Nuclear Information System (INIS)

    Matsuda, Masami; Nishi, Takashi; Chino, Koichi; Kikuchi, Makoto

    1992-01-01

    Cement solidification is a conventional technique to solidify spent ion exchange resin. Swelling property of the ion exchange resin was investigated theoretically and experimentally, as the first step to improve resin content in a cement package. Swelling pressure of the resin was first formulated based on Gregor's swelling model. It was shown that the pressure depended on such factors as ion exchange capacity, type of functional group, crosslinkage and water content. Subsequently, swelling pressures for over forty properties of cation exchange resin (DIAION SK-series) with different exchange capacities, water contents and others were experimentally evaluated using an originally developed method. The pressure changed over a range of 0 ∼ 60 MPa, depending on properties of the ion exchange resin. These results were in close agreement with values calculated by Gregor's model, indicating that the swelling pressure could be evaluated without resorting to experiments. (author)

  20. Properties of the Carboxylate ion exchange resins

    International Nuclear Information System (INIS)

    Allard, Bert; Dario, Maarten; Boren, Hans; Torstenfelt, Boerje; Puigdomenech, Ignasi; Johansson, Claes

    2002-09-01

    Weakly acidic, carboxylic resin has been selected, together with strong base anion resins, for water purification at the Forsmark 1 and 2 reactors. For the strong (but not the weak) ion exchange resin the Nuclear Power Inspectorate has given permission to dispose the spent resins in the SFR 1 (the Final Repository for Radioactive Operational Waste). This report gives a review of the carboxylic resins and comes to the conclusion that the resins are very stable and that there should not exist any risks for increased leaching of radionuclides from SFR 1 if these resins are disposed (compared to the strong resins)

  1. Loading and Unloading Weaned Pigs: Effects of Bedding Types, Ramp Angle, and Bedding Moisture

    Directory of Open Access Journals (Sweden)

    Arlene Garcia

    2014-12-01

    Full Text Available The use of non-slip surfaces during loading and unloading of weaned pigs plays an important role in animal welfare and economics of the pork industry. Currently, the guidelines available only suggest the use of ramps below 20° to load and unload pigs. Three ramp angles (0°, 10° or 20°, five bedding materials (nothing, sand, feed, wood shavings or wheat straw hay, two moistures (dry or wet bedding; >50% moisture over two seasons (>23.9 °C summer, <23.9 °C winter were assessed for slips/falls/vocalizations (n = 6,000 pig observations. “Score” was calculated by the sum of slips, falls, and vocalizations. With the exception of using feed as a bedding, all beddings provided some protection against elevated slips, falls, and vocalizations (P < 0.01. Providing bedding reduced (P < 0.05 scores regardless of whether the bedding was dry or wet. Scores increased as the slope increased (P < 0.01. Provision of bedding, other than feed, at slopes greater than zero, decreased slips, falls and vocalizations. The total time it took to load and unload pigs was

  2. Surface discoloration of composite resins: Effects of staining and bleaching

    Science.gov (United States)

    Poggio, Claudio; Beltrami, Riccardo; Scribante, Andrea; Colombo, Marco; Chiesa, Marco

    2012-01-01

    Background: The purpose of this in vitro study was to evaluate surface discoloration of three microhybrid composite resins (Esthet•X HD, Clearfil AP-X, Gradia Direct) and five nanohybrid composite resins (Ceram•X, GC Kalore, G-aenial, Grandio, GrandioSO), after staining and bleaching procedures. Materials and Methods: The composite resins were polymerized with a curing light (Celalux II, Voco, Cuxhaven, Germany) into 160 silicon molds (6,4 mm in diameter and 2 mm in thickness) to obtain identical specimens. Twenty samples for each composite resin were prepared. The specimens were polished using an automated polishing machine with the sequence of 600-, 800-, 1000-grit abrasive paper under water irrigation. The specimens were immersed in tea and distilled water: the specimens were dipped for 20 min, once a day (every 24 h), for 14 days into the drinks. The specimens were then bleached with carbamide peroxide at 17% (Perfect Bleach-Voco). The color of specimens was measured with a spectrophotometer according to the CIE L*a*b* system after light-polymerization of composite resin specimens, after 7 days, after 14 days, and after bleaching. The color difference h index (DEab*) between each measurement was calculated. Statistical analysis was made using analysis of variance (ANOVA). Results: All specimens showed a significant increase in staining with a similar trend and no significant differences between microhybrid and nanohybrid composite resins. After whitening procedures, materials tested showed both significant and unsignificant differences of the h index. Conclusions: Microhybrid and nanohybrid composite resins had similar in vitro surface discoloration in tea. After bleaching, discoloration was removed from some composite resins tested. PMID:23559921

  3. Surface discoloration of composite resins: Effects of staining and bleaching

    Directory of Open Access Journals (Sweden)

    Claudio Poggio

    2012-01-01

    Full Text Available Background: The purpose of this in vitro study was to evaluate surface discoloration of three microhybrid composite resins (Esthet·X HD, Clearfil AP-X, Gradia Direct and five nanohybrid composite resins (Ceram·X, GC Kalore, G-aenial, Grandio, GrandioSO, after staining and bleaching procedures. Materials and Methods: The composite resins were polymerized with a curing light (Celalux II, Voco, Cuxhaven, Germany into 160 silicon molds (6,4 mm in diameter and 2 mm in thickness to obtain identical specimens. Twenty samples for each composite resin were prepared. The specimens were polished using an automated polishing machine with the sequence of 600-, 800-, 1000-grit abrasive paper under water irrigation. The specimens were immersed in tea and distilled water: the specimens were dipped for 20 min, once a day (every 24 h, for 14 days into the drinks. The specimens were then bleached with carbamide peroxide at 17% (Perfect Bleach-Voco. The color of specimens was measured with a spectrophotometer according to the CIE LFNx01aFNx01bFNx01 system after light-polymerization of composite resin specimens, after 7 days, after 14 days, and after bleaching. The color difference h index (DE abFNx01 between each measurement was calculated. Statistical analysis was made using analysis of variance (ANOVA. Results: All specimens showed a significant increase in staining with a similar trend and no significant differences between microhybrid and nanohybrid composite resins. After whitening procedures, materials tested showed both significant and unsignificant differences of the h index. Conclusions: Microhybrid and nanohybrid composite resins had similar in vitro surface discoloration in tea. After bleaching, discoloration was removed from some composite resins tested.

  4. Surface discoloration of composite resins: Effects of staining and bleaching.

    Science.gov (United States)

    Poggio, Claudio; Beltrami, Riccardo; Scribante, Andrea; Colombo, Marco; Chiesa, Marco

    2012-09-01

    The purpose of this in vitro study was to evaluate surface discoloration of three microhybrid composite resins (Esthet•X HD, Clearfil AP-X, Gradia Direct) and five nanohybrid composite resins (Ceram•X, GC Kalore, G-aenial, Grandio, GrandioSO), after staining and bleaching procedures. The composite resins were polymerized with a curing light (Celalux II, Voco, Cuxhaven, Germany) into 160 silicon molds (6,4 mm in diameter and 2 mm in thickness) to obtain identical specimens. Twenty samples for each composite resin were prepared. The specimens were polished using an automated polishing machine with the sequence of 600-, 800-, 1000-grit abrasive paper under water irrigation. The specimens were immersed in tea and distilled water: the specimens were dipped for 20 min, once a day (every 24 h), for 14 days into the drinks. The specimens were then bleached with carbamide peroxide at 17% (Perfect Bleach-Voco). The color of specimens was measured with a spectrophotometer according to the CIE L(*)a(*)b(*) system after light-polymerization of composite resin specimens, after 7 days, after 14 days, and after bleaching. The color difference h index (DEab(*)) between each measurement was calculated. Statistical analysis was made using analysis of variance (ANOVA). All specimens showed a significant increase in staining with a similar trend and no significant differences between microhybrid and nanohybrid composite resins. After whitening procedures, materials tested showed both significant and unsignificant differences of the h index. Microhybrid and nanohybrid composite resins had similar in vitro surface discoloration in tea. After bleaching, discoloration was removed from some composite resins tested.

  5. [Acrylic resin removable partial dentures

    NARCIS (Netherlands)

    Baat, C. de; Witter, D.J.; Creugers, N.H.J.

    2011-01-01

    An acrylic resin removable partial denture is distinguished from other types of removable partial dentures by an all-acrylic resin base which is, in principle, solely supported by the edentulous regions of the tooth arch and in the maxilla also by the hard palate. When compared to the other types of

  6. Cure shrinkage in casting resins

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, J. Brock [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-02-01

    A method is described whereby the shrinkage of a casting resin can be determined. Values for the shrinkage of several resin systems in frequent use by Sandia have been measured. A discussion of possible methods for determining the stresses generated by cure shrinkage and thermal contraction is also included.

  7. Bed-Load Dispersion: A Literature Review

    Science.gov (United States)

    2016-12-01

    ER D C/ CH L SR -1 6- 5 Coastal Inlets Research Program Bed-Load Dispersion: A Literature Review Co as ta l a nd H yd ra ul ic s La bo...ERDC/CHL SR-16-5 December 2016 Bed-Load Dispersion: A Literature Review James W. Lewis, Alejandro Sanchez, Travis Dahl, and Ian Floyd Coastal and...calculated at all nodes of each cross-section. 1.2 Objective The objective of this literature review is to prepare the conceptual founda- tion for the

  8. Effect of sealant agents on the color stability and surface roughness of nanohybrid composite resins.

    Science.gov (United States)

    Dede, Doğu Ömür; Şahin, Onur; Koroglu, Aysegül; Yilmaz, Burak

    2016-07-01

    The effect of sealant agents on the surface roughness and color stability of nanohybrid composite resins is unknown. The purpose of this in vitro study was to evaluate the effect of sealant agents on the surface roughness and color stability of 4 nanohybrid composite resin materials. Forty disks (10×2 mm) were fabricated for each nanohybrid composite resin material (Z-550, Tetric EvoCeram, Clearfill Majesty, Ice) (N=160) and divided into 4 surface treatment groups: 1 conventional polishing (control) and 3 different sealant agent (Palaseal, Optiglaze, BisCover) coupling groups (n=10). The specimens were thermocycled, and surface roughness (Ra) values were obtained with a profilometer. Scanning electron microscope images were also recorded. CIELab color parameters of each specimen were measured with a spectrophotometer before and after 7 days of storage in a coffee solution. Color differences were calculated by the CIEDE 2000 (ΔE00) formula. The data were statistically analyzed by 2-way ANOVA and by the Tukey HSD test (α=.05). The surface treatment technique significantly affected the Ra values of the composite resins tested (Pcomposite resin material was also significant for ΔE00 values (Pcomposite resin groups, significant decreases in Ra were observed only for the Palaseal agent coupled composite resin groups (except Ice) compared with the control groups (Pcomposite resin group, except for BisCover applied Clearfill Majesty (Pcomposite resin groups, significant differences were observed between the color change seen with BisCover and other sealants for Clearfill Majesty composite resin (Pcomposite resins except for Ice produced smoother surfaces. All surface sealant agents provided less discoloration of nanohybrid composite resins after coffee staining compared with conventional polishing except for BisCover applied Clearfill Majesty composite resin. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All

  9. Stability of IRA-45 solid amine resin as a function of carbon dioxide absorption and steam desorption cycling

    Science.gov (United States)

    Wood, Peter C.; Wydeven, Theodore

    1987-01-01

    The removal of CO2 from the NASA Space Station's cabin atmosphere, which may be undertaken by a solid-amine water (steam)-desorbed system, is presently evaluated with a view to long-term amine resin stability and adsorption/desorption cycling by means of an automated laboratory flow-testing facility. While the CO2-adsorption capacity of the IRA-45 amine resin used gradually decreased over time, the rate of degradation significantly decreased after the first 10 cycles. Attention is given to the presence (and possible need for removal) of trimethylamine in the process air downstream of the resin bed.

  10. Large scale purification of puerarin from Puerariae Lobatae Radix through resins adsorption and acid hydrolysis.

    Science.gov (United States)

    Guo, Hai-Dong; Zhang, Qing-Feng; Chen, Ji-Guang; Shangguang, Xin-Cheng; Guo, Yu-Xian

    2015-02-01

    Puerarin is the major isoflavone of Puerariae Lobatae Radix. A method for large scale purification of puerarin was developed through resins adsorption and acid hydrolysis. The adsorption properties of six macroporous resins (D101, S-8, H103, X-5, HPD600, AB-8) were compared through the adsorption kinetics and equilibrium adsorption isotherms. Results showed that H103 resin had the best adsorption rate and capacity. The mass transfer zone motion model was further used for analyzing the fixed bed adsorption of H103 resin. Its length of mass transfer zone with 2mg/ml of puerarin in water and 10% ethanol at flow rate of 10ml/min were 41.6 and 47.5cm, while the equilibrium adsorption capacity was 165.03 and 102.88mg/g, respectively. By using 75% ethanol, puerarin could be well desorbed from the resin with recovery of 97.4%. Subsequently, H103 resin was successfully used for puerarin purification from Puerariae Lobatae Radix. The content of total isoflavones and puerarin in the resin adsorption product were 69.25% and 41.78%, respectively, which were about three times increased compared to the crude extract. Then, the product was hydrolyzed by 2.5M HCl at 90°C for 1h. Puerarin with purity of 90% and a byproduct daidzein with purity of 78% were obtained. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Degree of cure and viscosity of Hercules HBRF-55 resin

    Science.gov (United States)

    Bhi, S. T.; Hansen, R. Scott; Wilson, Brian A.; Calius, Emilo P.; Springer, George S.

    1987-01-01

    The rate of cure and viscosity were measured for Hercules HBRF-55 resin. The rate of cure was measured by differential scanning calorimetry, while the viscosity was measured by a parallel disk and plate type apparatus. The data were fitted to analytic expressions to make them suitable for use in numerical calculations.

  12. The study of epoxy polyamide and polyvinyl resins as corrosion ...

    African Journals Online (AJOL)

    The corrosion resistance of two commonly used protective coatings (epoxy polyamide and polyvinyl resins) in the Niger Delta area of Nigeria has been assessed. The coatings on low carbon steel were subjected to varying conditions of pH, temperature and exposure time and the corrosion rates calculated. At a pH of 2, 3, 4, ...

  13. Bed bug deterrence

    Directory of Open Access Journals (Sweden)

    Haynes Kenneth F

    2010-09-01

    Full Text Available Abstract A recent study in BMC Biology has determined that the immature stage of the bed bug (the nymph signals its reproductive status to adult males using pheromones and thus avoids the trauma associated with copulation in this species. The success of this nymphal strategy of deterrence is instructive. Against the background of increasing problems with bed bugs, this research raises the question whether pheromones might be used to control them. See research article http://www.biomedcentral.com/1741-7007/8/121

  14. The Safety of Hospital Beds

    Science.gov (United States)

    Gervais, Pierre; Pooler, Charlotte; Merryweather, Andrew; Doig, Alexa K.; Bloswick, Donald

    2015-01-01

    To explore the safety of the standard and the low hospital bed, we report on a microanalysis of 15 patients’ ability to ingress, move about the bed, and egress. The 15 participants were purposefully selected with various disabilities. Bed conditions were randomized with side rails up or down and one low bed with side rails down. We explored the patients’ use of the side rails, bed height, ability to lift their legs onto the mattress, and ability to turn, egress, and walk back to the chair. The standard bed was too high for some participants, both for ingress and egress. Side rails were used by most participants when entering, turning in bed, and exiting. We recommend that side rails be reconsidered as a means to facilitate in-bed movement, ingress, and egress. Furthermore, single deck height settings for all patients are not optimal. Low beds as a safety measure must be re-evaluated. PMID:28462302

  15. New ion exchange resin designs and regeneration procedures yield improved performance for various condensate polishing applications

    International Nuclear Information System (INIS)

    Najmy, S.W.

    2002-01-01

    Condensate polishing is an application with many different design and operational aspects. The past decade has brought new challenges for improved water quality with respect to both soluble and insoluble contaminants. Nonetheless, the endeavors to understand the compositional complexities of the ion exchange resin bead and the convoluted dynamics of ion exchange chemistry and chemical engineering mechanisms occurring within the mixed bed condensate polisher have brought new ideas and expectations for ion exchange resin in deep-bed condensate polishers than ever before. The new products and procedures presented here are a collaboration of a great deal of effort on the part of researchers, consultants, system engineers, station chemists, lab technicians and others. The studies discussed in this paper unequivocally demonstrate the merits of: 1. A specially designed cation resin to achieve greater than 95% insoluble iron removal efficiency, 2. A less-separable mixed resin for improved control of reactor water sulfate in BWR primary cycles, 3. Applying increased levels of regeneration chemicals and retrofitting the service vessels with re-mixing capability to improve the operation of deep-bed condensate polishers in PWR secondary cycles. (authors)

  16. [Acrylic resin removable partial dentures].

    Science.gov (United States)

    de Baat, C; Witter, D J; Creugers, N H J

    2011-01-01

    An acrylic resin removable partial denture is distinguished from other types of removable partial dentures by an all-acrylic resin base which is, in principle, solely supported by the edentulous regions of the tooth arch and in the maxilla also by the hard palate. When compared to the other types of removable partial dentures, the acrylic resin removable partial denture has 3 favourable aspects: the economic aspect, its aesthetic quality and the ease with which it can be extended and adjusted. Disadvantages are an increased risk of caries developing, gingivitis, periodontal disease, denture stomatitis, alveolar bone reduction, tooth migration, triggering of the gag reflex and damage to the acrylic resin base. Present-day indications are ofa temporary or palliative nature or are motivated by economic factors. Special varieties of the acrylic resin removable partial denture are the spoon denture, the flexible denture fabricated of non-rigid acrylic resin, and the two-piece sectional denture. Furthermore, acrylic resin removable partial dentures can be supplied with clasps or reinforced by fibers or metal wires.

  17. Chromatography resin support

    Science.gov (United States)

    Dobos, James G.

    2002-01-01

    An apparatus and method of using an improved chromatography resin support is disclosed. The chromatography support platform is provided by a stainless steel hollow cylinder adapted for being inserted into a chromatography column. An exterior wall of the stainless steel cylinder defines a groove for carrying therein an "O"-ring. The upper surface of the stainless steel column is covered by a fine stainless steel mesh welded to the edges of the stainless steel cylinder. When placed upon a receiving ledge defined within a chromatography column, the "O"-ring provides a fluid tight seal with the inner edge wall of the chromatography cylinder. The stainless steel mesh supports the chromatography matrix and provides a back flushable support which is economical and simple to construct.

  18. 21 CFR 872.3140 - Resin applicator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Resin applicator. 872.3140 Section 872.3140 Food... DEVICES DENTAL DEVICES Prosthetic Devices § 872.3140 Resin applicator. (a) Identification. A resin applicator is a brushlike device intended for use in spreading dental resin on a tooth during application of...

  19. Concentrating cesium-137 from seawater using resorcinol-formaldehyde resin for radioecological monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Egorin, Andrei; Tokar, Eduard; Tutov, Mikhail; Avramenko, Valentin [Institute of Chemistry FEBRAS, Vladivostok (Russian Federation); Far Eastern Federal Univ., Vladivostok (Russian Federation); Palamarchuk, Marina; Marinin, Dmitry [Institute of Chemistry FEBRAS, Vladivostok (Russian Federation)

    2017-04-01

    A method of preconcentrating cesium-137 from seawater using a resorcinol-formaldehyde resin, which enables one to optimize the ecological monitoring procedure, has been suggested. Studies of sorption of cesium-137 from seawater by resorcinol-formaldehyde resin have been performed, and it has been demonstrated that the cation exchanger is characterized by high selectivity with respect to cesium-137. It was found that the selectivity depended on the temperature of resin solidification and the seawater pH value. The maximal value of the cesium-137 distribution coefficient is equal to 4.1-4.5 x 10{sup 3} cm{sup 3} g{sup -1}. Under dynamic conditions, the ion-exchange resin capacity is 310-910 bed volumes depending on the seawater pH, whereas the efficiency of cesium removal exceeds 95%. The removal of more than 95% of cesium-137 has been attained using 1-3 M solutions of nitric acid: here, the eluate volume was 8-8.4 bed volumes. Application of 3 M solution of nitric acid results in resin degradation with the release of gaseous products.

  20. SuperLig® 639 Resin Performance using 8 Molar LAW Feed

    Energy Technology Data Exchange (ETDEWEB)

    Nash, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Williams, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Restivo, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hamm, L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); McCabe, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-01-15

    All prior testing with SuperLig® 639 has been done with the aqueous concentration of LAW at ~5 M [Na+], where the resin sinks, and can be used in a conventional down-flow column orientation. However, the aqueous LAW stream from the Waste Treatment Plant is expected to be ~8 M [Na+]. The resin would float in this higher density liquid, potentially disrupting the ability to achieve a good decontamination due to poor packing of the resin that leads to channeling. Testing was completed with a higher salt concentration in the feed simulant (7.8 M [Na+]) in an engineering-scale apparatus with two columns, each containing ~0.9 L of resin. Testing of this system used a simulant of the LAW solution, and substituted ReO4 - as a surrogate for TcO4 -. Results were then compared using computer modeling. Bench-scale testing was also performed, and examined an unconstrained resin bed, while engineering-scale tests used both constrained and unconstrained beds in a two-column, lead and lag sequential arrangement.

  1. Flexural Strength of Cold and Heat Cure Acrylic Resins Reinforced with Different Materials.

    Science.gov (United States)

    Heidari, Bijan; Firouz, Farnaz; Izadi, Alireza; Ahmadvand, Shahbaz; Radan, Pegah

    2015-05-01

    Heat-polymerized acrylic resin has been the most commonly used denture base material for over 60 years. However, the mechanical strength of acrylic resin is not adequate for long-term clinical performance of dentures. Consequently, fracture is a common clinical occurrence, which often develops in the midline of the denture base. This study aimed to evaluate the efficacy of cold-cure and heat-cure acrylic resins, reinforced with glass fibers, polyethylene fibers, and metal wire for denture base repair. Ninety specimens were prepared and allocated to nine groups. Ten specimens were considered as controls, and 80 were divided into 8 experimental groups. In the experimental groups, the specimens were sectioned into two halves from the middle, and were then divided into two main groups: one group was repaired with heat cure acrylic resin, and the other with cold cure acrylic resin. Each group was divided into 4 subgroups: unreinforced, reinforced with glass fibers, polyethylene fibers, and metal wire. All specimens were subjected to a 3-point bending test, and the flexural strength was calculated. The group repaired with heat cure acrylic resin and reinforced with glass fiber showed the highest flexural strength; however, the group repaired with cold cure acrylic resin and reinforced with polyethylene fibers had the lowest flexural strength. There was no significant difference between the groups repaired with heat cure and cold cure acrylic resins without reinforcement. Repairing denture base with heat cure acrylic resin, reinforced with glass fibers increases the flexural strength of denture base.

  2. Bed Prism Spectacles

    Science.gov (United States)

    Ribeiro, Jair Lúcio Prados

    2018-01-01

    We only became aware of the existence of bed prism spectacles when a student brought them to the classroom and asked us about how they work. The device proved to be a fertile source of curiosity among the students, and, to be properly understood, it required us to develop a comparison between reflection in a typical mirror and total internal…

  3. Practice Hospital Bed Safety

    Science.gov (United States)

    ... the mattress end Subscribe: FDA Consumer Health Information "Hospital beds are found in nearly all patient care settings or environments," says Joan Ferlo Todd, RN, a senior nurse-consultant at the Food and Drug Administration’s (FDA) Center for Devices and Radiological Health (CDRH). " ...

  4. Hardening of a dual-cure resin cement using QTH and LED curing units

    Science.gov (United States)

    SANTOS, Maria Jacinta Moraes Coelho; PASSOS, Sheila Pestana; da ENCARNAÇÃO, Monalisa Olga Lessa; SANTOS, Gildo Coelho; BOTTINO, Marco Antonio

    2010-01-01

    Objective This study evaluated the surface hardness of a resin cement (RelyX ARC) photoactivated through indirect composite resin (Cristobal) disks of different thicknesses using either a light-emitting diode (LED) or quartz tungsten halogen (QTH) light source. Material and Methods Eighteen resin cement specimens were prepared and divided into 6 groups according to the type of curing unit and the thickness of resin disks interposed between the cement surface and light source. Three indentations (50 g for 15 s) were performed on the top and bottom surface of each specimen and a mean Vickers hardness number (VHN) was calculated for each specimen. The data were analyzed using two-way ANOVA and Tukey-Kramer test was used for post-hoc pairwise comparisons. Results Increased indirect resin disk thickness resulted in decreased mean VHN values. Mean VHN values for the top surfaces of the resin cement specimens ranged from 23.2 to 46.1 (QTH) and 32.3 to 41.7 (LED). The LED curing light source produced higher hardness values compared to the QTH light source for 2- and 3-mm-thick indirect resin disks. The differences were clinically, but not statistically significant. Increased indirect resin disk thickness also resulted in decreased mean VHN values for the bottom surfaces of the resin cement: 5.8 to 19.1 (QTH) and 7.5 to 32.0 (LED). For the bottom surfaces, a statistically significant interaction was also found between the type of curing light source and the indirect resin disk thickness. Conclusions Mean surface hardness values of resin cement specimens decreased with the increase of indirect resin disk thickness. The LED curing light source generally produced higher surface hardness values. PMID:20485920

  5. Hardening of a dual-cure resin cement using QTH and LED curing units

    Directory of Open Access Journals (Sweden)

    Maria Jacinta Moraes Coelho Santos

    2010-04-01

    Full Text Available OBJECTIVE: This study evaluated the surface hardness of a resin cement (RelyX ARC photoactivated through indirect composite resin (Cristobal disks of different thicknesses using either a light-emitting diode (LED or quartz tungsten halogen (QTH light source. MATERIAL AND METHODS: Eighteen resin cement specimens were prepared and divided into 6 groups according to the type of curing unit and the thickness of resin disks interposed between the cement surface and light source. Three indentations (50 g for 15 s were performed on the top and bottom surface of each specimen and a mean Vickers hardness number (VHN was calculated for each specimen. The data were analyzed using two-way ANOVA and Tukey-Kramer test was used for post-hoc pairwise comparisons. RESULTS: Increased indirect resin disk thickness resulted in decreased mean VHN values. Mean VHN values for the top surfaces of the resin cement specimens ranged from 23.2 to 46.1 (QTH and 32.3 to 41.7 (LED. The LED curing light source produced higher hardness values compared to the QTH light source for 2- and 3-mm-thick indirect resin disks. The differences were clinically, but not statistically significant. Increased indirect resin disk thickness also resulted in decreased mean VHN values for the bottom surfaces of the resin cement: 5.8 to 19.1 (QTH and 7.5 to 32.0 (LED. For the bottom surfaces, a statistically significant interaction was also found between the type of curing light source and the indirect resin disk thickness. CONCLUSION: Mean surface hardness values of resin cement specimens decreased with the increase of indirect resin disk thickness. The LED curing light source generally produced higher surface hardness values.

  6. Modeling and mechanical performance of carbon nanotube/epoxy resin composites

    International Nuclear Information System (INIS)

    Srivastava, Vijay Kumar

    2012-01-01

    Highlights: ► The MWCNT fillers are uniformly dispersed in the epoxy resin, which improved the mechanical properties of epoxy resin. ► Modified Halpin–Tsai model is useful to calculate the Young’s modulus of MWCNT/epoxy resin composite. ► The experimental moduli are within the variation of 27% with the theoretical values. -- Abstract: The effect of multi-walled carbon nanotube (MWCNT) addition on mechanical properties of epoxy resin was investigated to obtain the tensile strength, compressive strength and Young’s modulus from load versus displacement graphs. The result shows that the tensile strength, compressive strength and Young’s modulus of epoxy resin were increased with the addition of MWCNT fillers. The significant improvements in tensile strength, compressive strength and Young’s modulus were obtained due to the excellent dispersion of MWCNT fillers in the epoxy resin. The dispersion of MWCNT fillers in epoxy resin was observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis. Also, Halpin–Tsai model was modified by considering the average diameter of internal/external of multi-walled nanotube and orientation factor (α) to calculate the Young’s modulus of multi-walled carbon nanotubes (MWCNTs)/epoxy resin composite. There was a good correlation between the experimentally obtained Young’s modulus and modified Halpin–Tsai model.

  7. Hydraulic Permeability of Resorcinol-Formaldehyde Ion-Exchange Resin - Effects of Oxygen Uptake and Radiation

    International Nuclear Information System (INIS)

    Taylor, Paul Allen

    2009-01-01

    An ion-exchange process, using spherical resorcinol-formaldehyde (RF) resin is the baseline process for removing cesium from the dissolved salt solution in the high-level waste tanks at the U.S. Department of Energy's (DOE) Hanford site in Washington State. The RF resin is also being evaluated for use in the proposed Small Column Ion Exchange (SCIX) system, which is an alternative treatment option at DOE's Savannah River Site (SRS)in South Carolina. Testing at ORNL will determine the impact of radiation exposure and oxygen uptake by the RF resin on the hydraulic permeability of the resin. Samples of the resin will be removed periodically to measure physical properties (bead size and compressibility) and cesium capacity. The proposed full-scale treatment system at Hanford, the Waste Treatment Plant (WTP), will use an ion-exchange column containing nominally 680 gal of resin, which will treat 30 gpm of waste solution. The ion-exchange column is designed for a typical pressure drop of 6 psig, with a maximum of 9.7 psig. The lab-scale column is 3-in. clear PVC pipe and is prototypic of the proposed Hanford column. The fluid velocity in the lab-scale test will be much higher than for the full-scale column, in order to generate the maximum pressure drop expected in that column (9.7 psig). The frictional drag from this high velocity will produce similar forces on the resin in the lab-scale column as would be expected at the bottom of the full-scale column. The chemical changes in the resin caused by radiation exposure and oxygen uptake are expected to cause physical changes in the resin that could reduce the bed porosity and reduce the hydraulic permeability of the resin bed. These changes will be monitored by measuring the pressure drop through the lab-scale column and by measuring the physical properties of samples of the resin. The test loop with the lab-scale column is currently being fabricated, and operation will start by late May. Testing will be completed by the

  8. Treatment by absorbers of oil contaminated process waters. Ion exchange resins and filtration

    International Nuclear Information System (INIS)

    La Gamma, Ana M.; Becquart, Elena T.; Chocron, Mauricio; Ambrosioni, P.M.; Schoenbrod, B.

    2003-01-01

    Pressurized Heavy Water Reactors have a system devoted to the purification and upgrading of the collected heavy water leaks. The purification train is fed with different degradation ratios (D 2 O/H 2 O) activities and impurities. The water is distilled in a packed bed column filled with a mesh type packing. With the purpose of minimizing the column stack corrosion, the water is pretreated in a train consisting on an activated charcoal bed-strong cationic-anionic resin and a final polishing mixed bed resin. Traces of oils are retained by the charcoal bed but some compounds extracted by the aqueous phase are suspected to be responsible for the resins fouling or precursors of potentially aggressive agents inside the distillation column. In the present work, the identification, evaluation of alternatives for the retention like dead end and cross flow micro filtration, adsorption and ion exchange were tested and the results compared to the original products present in the water upgrading purification train. (author)

  9. Fixation of metallic sulfosalicylate complexes on an anionic exchange resin

    International Nuclear Information System (INIS)

    Cahuzac, S.

    1969-06-01

    Since sulfosalicylate ions have acid-base properties, sulfosalicylate complexes have an apparent stability which varies with the ph. As a result, the fixation of sulfo-salicylates on an anionic exchange resin depends on the ph of the solution in equilibrium with the resin. This research has been aimed at studying the influence of the ph on the fixation on an anionic exchange resin (Dowex 1 x 4) of sulfosalicylate anions on the one hand, and of metallic sulfosalicylate complexes on the other hand. In the first part of this work, a determination has been made, by frontal analysis of the distribution of sulfosalicylate ions in the resin according to the total sulfosalicylate I concentration in the aqueous solution in equilibrium with the resin. The exchange constants of these ions between the resin and the solution have been calculated. In the second part, a study has been made of the fixation of anionic sulfosalicylate complexes of Fe(III), Al(III), Cr(III), Cu(II), Ni(II), Co(II), Zn(II), Mn(II), Cd(II), Fe(II) and UO 2 2+ . By measuring the partition coefficients of these different elements between the resin and the solution it has been possible to give interpretation for the modes of fixation of the metallic ions, and to calculate their exchange constant between the resin and the solution. The relationship has been established for each metallic element studied, between its partition coefficient, the ph and the total concentration of the complexing agent in solution. Such a relationship makes it possible to predict, for given conditions, the nature of the species in solution and in the resin, as well as the partition coefficient of a metallic, element. Finally, in the third part of the work, use has been made of results obtained previously, to carry out some separations (Ni 2+ - Co 2+ ; Ni 2+ - Co 2+ - Cu 2+ ; UO 2 2+ - Fe 3+ ; UO 2 2+ - Cr 3+ ; UO 2 2+ - Cu 2+ ; UO 2 2+ - Ni 2+ ; UO 2 2+ - Co 2+ ; UO 2 2+ - Mn 2+ and UO 2 2+ - Cd 2+ ), as well as the purification

  10. Bulk-Fill Resin Composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Havndrup-Pedersen, Cæcilie; Honoré, Daniel

    2015-01-01

    the restorative procedure. The aim of this study, therefore, was to compare the depth of cure, polymerization contraction, and gap formation in bulk-fill resin composites with those of a conventional resin composite. To achieve this, the depth of cure was assessed in accordance with the International Organization...... for Standardization 4049 standard, and the polymerization contraction was determined using the bonded-disc method. The gap formation was measured at the dentin margin of Class II cavities. Five bulk-fill resin composites were investigated: two high-viscosity (Tetric EvoCeram Bulk Fill, SonicFill) and three low......-viscosity (x-tra base, Venus Bulk Fill, SDR) materials. Compared with the conventional resin composite, the high-viscosity bulk-fill materials exhibited only a small increase (but significant for Tetric EvoCeram Bulk Fill) in depth of cure and polymerization contraction, whereas the low-viscosity bulk...

  11. and phenol–formaldehyde resin

    Indian Academy of Sciences (India)

    formaldehyde resin (PFR) modified with tetraethylorthosilicate are investigated in detail. The chemical synthesis of PFR, its modification with nanometer- sized SiO2 particles created by sol–gel method and subsequent coating, enables a preparation of ...

  12. Bending characteristics of resin concretes

    Directory of Open Access Journals (Sweden)

    Ribeiro Maria Cristina Santos

    2003-01-01

    Full Text Available In this research work the influence of composition and curing conditions in bending strength of polyester and epoxy concrete is analyzed. Various mixtures of resin and aggregates were considered in view of an optimal combination. The Taguchi methodology was applied in order to reduce the number of tests, and in order to evaluate the influence of various parameters in concrete properties. This methodology is very useful for the planning of experiments. Test results, analyzed by this methodology, shown that the most significant factors affecting bending strength properties of resin concretes are the type of resin, resin content and charge content. An optimal formulation leading to a maximum bending strength was achieved in terms of material parameters.

  13. Epoxy hydantoins as matrix resins

    Science.gov (United States)

    Weiss, J.

    1983-01-01

    Tensile strength and fracture toughness of castings of the hydantoin resins cured with methylenedianiline are significantly higher than MY 720 control castings. Water absorption of an ethyl, amyl hydantoin formulation is 2.1 percent at equilibrium and Tg's are about 160 C, approximately 15 deg below the final cure temperature. Two series of urethane and ester-extended hydantoin epoxy resins were synthesized to determine the effect of crosslink density and functional groups on properties. Castings cured with methylenedianiline or with hexahydrophthalic anhydride were made from these compounds and evaluated. The glass transition temperatures, tensile strengths and moduli, and fracture toughness values were all much lower than that of the simple hydantoin epoxy resins. Using a methylene bishydantoin epoxy with a more rigid structure gave brittle, low-energy fractures, while a more flexible, ethoxy-extended hydantoin epoxy resin gave a very low Tg.

  14. VA National Bed Control System

    Data.gov (United States)

    Department of Veterans Affairs — The VA National Bed Control System records the levels of operating, unavailable and authorized beds at each VAMC, and it tracks requests for changes in these levels....

  15. Resin glycosides from Porana duclouxii.

    Science.gov (United States)

    Ding, Wen-Bing; Zhang, Dai-Gui; Liu, Chun-Jie; Li, Guan-Hua; Li, You-Zhi

    2014-01-01

    A new intact resin glycoside (3) and two glycosidic acids (1 and 2), all having a common trisaccharide moiety and (11S)-hydroxytetradecanoic acid or (3S,11S)-dihydroxytetradecanoic acid as the aglycone, were obtained from the roots of Porana duclouxii. Their structures were elucidated by spectroscopic analyses and chemical correlations. These compounds represent the first examples of resin glycosides from the genus Porana.

  16. Karakteristik Komposit Resin Berkemampuan Mengalir

    Directory of Open Access Journals (Sweden)

    Bambang Irawan

    2015-10-01

    Full Text Available The use of resin composites as posterior restoratives has markedly increased over the past decade. The patients demand for better esthetics, concerns related to possible mercury toxicity from amalgam and improvements in resin composite materials have significantly contributed the popularity of these materials. Early problems related to composites included excessive wear, less of anatomic form, post operative sensitivity, secondary caries and marginal leakage. Marginal adaptation still remains an unavoidable problem for composite restoration, especially at the gingival wall of cervical or Class II restoration. In an attempt to improve marginal sealing, many techniques and lining materials have been designed. To reduce stress generated by polymerization shrinkage, applying and curing of resin composites in layers is often recommended. Using a thick adhesive layer or low-viscosity resin may, due to its elastic properties, serve as a flexible intermediate layer and compensate for the polymerization stress created in resin composite. Flowable composites were created by retaining the same small particle size of traditional hybrid composite but reducing the filler content and allowing the increased resin to reduce the viscosity of the mixture. Flowable composites were introduced in 1996 as liners, fissure sealants and also in tunnel preparations. They have been suggested for Class I, II, III and V cavity restorations, preventive resin restorations and composite, porcelain and amalgam repairing. Their usage as a liner under high filled resins in posterior restorations has been shown to improve the adaptation of composites and effectively achieve clinically acceptable results. This article attempts to give a broad characteristics of different types of flowable composites. 

  17. Liquid monobenzoxazine based resin system

    Science.gov (United States)

    Tietze, Roger; Nguyen, Yen-Loan; Bryant, Mark

    2014-10-07

    The present invention provides a liquid resin system including a liquid monobenzoxazine monomer and a non-glycidyl epoxy compound, wherein the weight ratio of the monobenzoxazine monomer to the non-glycidyl epoxy compound is in a range of about 25:75 to about 60:40. The liquid resin system exhibits a low viscosity and exceptional stability over an extended period of time making its use in a variety of composite manufacturing methods highly advantageous.

  18. Characteristics of resin floc dispersion of anion and cation exchange resin in precoat filter using powdered ion exchange resin

    Energy Technology Data Exchange (ETDEWEB)

    Adachi, Tetsurou (Nitto Denko Corp., Ibaraki, Osaka (Japan)); Sawa, Toshio; Shindoh, Toshikazu

    1989-09-01

    The filtration performance of mixed filter aid consisting of powdered anion and cation exchange resins used in the precoat filter is closely related to the characteristics of resin floc dispersion. The factors related to resin floc dispersion of anion and cation exchange resin were investigated by measuring the specific settle volume of resin floc as an evaluating index in addition to the measurement of physical, chemical and electrochemical properties of powdered ion exchange resin. The effect of adsorption of iron oxide and polymer electrolyte and of ion exchange were determined. In addition, considered floc dispersion with adsorbing iron oxide, it was assumed that the amount and filling ratio of resin floc were related to summation and multiplication of surface electric charge respectively. An experimental expression was obtained for simulation of the change of specific settle volume of resin floc by particle size, surface area, ion exchange capacity and degree of ionization of the powdered ion exchange resin. (author).

  19. Characteristics of resin floc dispersion of anion and cation exchange resin in precoat filter using powdered ion exchange resin

    International Nuclear Information System (INIS)

    Adachi, Tetsurou; Sawa, Toshio; Shindoh, Toshikazu.

    1989-01-01

    The filtration performance of mixed filter aid consisting of powdered anion and cation exchange resins used in the precoat filter is closely related to the characteristics of resin floc dispersion. The factors related to resin floc dispersion of anion and cation exchange resin were investigated by measuring the specific settle volume of resin floc as an evaluating index in addition to the measurement of physical, chemical and electrochemical properties of powdered ion exchange resin. The effect of adsorption of iron oxide and polymer electrolyte and of ion exchange were determined. In addition, considered floc dispersion with adsorbing iron oxide, it was assumed that the amount and filling ratio of resin floc were related to summation and multiplication of surface electric charge respectively. An experimental expression was obtained for simulation of the change of specific settle volume of resin floc by particle size, surface area, ion exchange capacity and degree of ionization of the powdered ion exchange resin. (author)

  20. Dynamic and static mechanical analysis of resin luting cements.

    Science.gov (United States)

    Tolidis, K; Papadogiannis, D; Papadogiannis, Y; Gerasimou, P

    2012-02-01

    Various types of indirect restorations are available for dental treatment and resin cements are commonly used as a luting medium. The aim of this study was to evaluate the mechanical properties of contemporary resin luting agents under different testing conditions and temperatures. The materials tested were Choice 2 (CH), Clearfil Esthetic Cement (EC), Resicem (RC) and RelyX Unicem (RX). Each material was examined after 24 h of storage at 21 °C dry and wet at 21, 37 and 50 °C under dynamic and static testing and parameters such as shear and flexural modulus, loss tangent, dynamic viscosity and Poisson's ratio were calculated. The resin cements were also subjected to creep testing under different constant loads for 3 h and a recovery time of 50 h. The material with the highest modulus was CH, while RX had the lowest. All resin cements were affected by the presence of water with RX being the least affected and by the increase of temperature, with RC being the least susceptible. None of the materials exhibited full recovery after creep testing and permanent deformation ranged from 0.43% to 5.53%. The resin cements tested in this study showed no major transitions under the different testing conditions. Their behavior was satisfactory for restorations that do not require increased mechanical properties. However, in the case of stress-bearing restorations the conditions in the oral cavity may affect the performance of these materials. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Wear resistance of injection-molded thermoplastic denture base resins

    Science.gov (United States)

    Hamanaka, Ippei; Iwamoto, Misa; Lassila, Lippo V. J.; Vallittu, Pekka K.; Takahashi, Yutaka

    2016-01-01

    Abstract Objective This study investigated the wear resistance of injection-molded thermoplastic denture base resins using nanoindentation instrument. Materials and methods Six injection-molded thermoplastic denture base resins (two polyamides, two polyesters, one polycarbonate, one polymethylmethacrylate [PMMA]) and a PMMA conventional heat-polymerized denture-based polymer control were tested. Elastic modulus, hardness, wear depth, and roughness were calculated using a nanoindentation instrument. Results Elastic modulus and hardness of the injection-molded thermoplastic denture base resins were significantly lower than those of the PMMA conventional heat-polymerized denture-based polymer. Wear depth of polycarbonate and PMMA conventional heat-polymerized denture-based polymer were significantly higher than that of other injection-molded thermoplastic denture base resins. The roughness of injection-molded thermoplastic denture base resins was significantly more than that of PMMA conventional heat-polymerized denture-based polymer after testing. Conclusions Wear resistance of injection-molded thermoplastic denture base was low compared to PMMA conventional heat-polymerized denture-based polymers. PMID:28642909

  2. Color stability of provisional crown and fixed partial denture resins.

    Science.gov (United States)

    Haselton, Debra R; Diaz-Arnold, Ana M; Dawson, Deborah V

    2005-01-01

    Provisional resins are used extensively during fixed prosthodontic treatment and exhibit varying degrees of color change/discoloration over time. Data are needed to help predict color stability of provisional resins. The purpose of this in vitro study was to measure the color change of 12 provisional prosthodontic materials after immersion in artificial saliva and artificial saliva-coffee solutions for 1, 2, and 4 weeks. Twelve provisional materials were studied. Methacrylates consisted of Alike, Jet, Temporary Bridge Resin, Unifast, and Zeta CC. Bis-acryl resins included Instatemp, Integrity, Luxatemp, Protemp Garant, Provipont, Provitec, and Temphase. Ten specimens (25.4 mm x 25.4 mm x 2.4 mm) of each material were fabricated. Five specimens were stored at 37 degrees C in artificial saliva and 5 were stored in a solution of artificial saliva (400 cc) and coffee (800 cc). Baseline color was measured using a colorimeter. Further color measurements were made after 1, 2, and 4 weeks of immersion. CIE L *a *b * values were recorded and color differences (DeltaE) between baseline and each storage interval were calculated using a 2-way ANOVA with Bonferroni adjustment for multiple comparisons in conjunction with an overall alpha=.05. Results indicated the presence of strong interaction between material and storage solution regardless of the aspect of color considered (Pprovisional crown and fixed partial denture resins demonstrated varying tendency to discolor over a range of time periods when immersed in artificial saliva and artificial saliva-coffee solutions.

  3. Production of fungal volatile organic compounds in bedding materials

    OpenAIRE

    S. LAPPALAINEN; A. PASANEN; P. PASANEN

    2008-01-01

    The high relative humidity of the air and many potential growth media, such as bedding materials, hay and grains in the horse stable, for example, provide suitable conditions for fungal growth. Metabolic activity of four common agricultural fungi incubated in peat and wood shavings at 25°C and 4°C was characterized in this study using previously specified volatile metabolites of micro-organisms and CO 2 production as indicators. The volatile organic compounds were collected into Tenax resin a...

  4. Nail bed onychomatricoma.

    Science.gov (United States)

    Wang, Lei; Gao, Tianwen; Wang, Gang

    2014-10-01

    Onychomatricoma is a rare tumor originating from the nail matrix, and, in rare conditions, from the ventral aspect of the proximal nailfold. Here we report a rare case of a 51-year-old man presenting with melanonychia mainly involving the distal nail plate. Histopathologic examination showed typical findings of onychomatricoma mainly involving the nail bed, while the nail matrix was largely uninvolved. We also identified fungal infection in a focal area of the distal nail plate. Our findings indicate that onychomatricoma can develop in the surrounding epithelial tissue of the nail unit, including the nail bed, and suggest that fungal infection may represent a secondary phenomenon of onychomatricoma. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Geomechanics of bedded salt

    International Nuclear Information System (INIS)

    Serata, S.; Milnor, S.W.

    1979-01-01

    Creep data from the literature search is reinterpreted by SGI, resulting in a better understanding of the temperature and stress state dependence of the octahedral creep rate and the octahedral shear strength. The concept of a transition strength between the elastic and the plastic states is in agreement with the data. The elastic and rheological properties of salt are described, and a set of constitutive equations is presented. The dependence of material properties on parameters such as temperature is considered. Findings on the permeability of salt are summarized, and the in-situ behavior of openings in bedded salt is described based on extensive engineering experience. A stress measuring system utilizing a finite element computer code is discussed. Geological factors affecting the stability of salt openings are considered, and the Stress Control Technique for designing stable openings in bedded salt formations is explained

  6. Survey of Dust Production in Pebble Bed Reactors Cores

    Energy Technology Data Exchange (ETDEWEB)

    Joshua J. Cogliati; Abderafi M. Ougouag; Javier Ortensi

    2011-06-01

    Graphite dust produced via mechanical wear from the pebbles in a pebble bed reactor is an area of concern for licensing. Both the German pebble bed reactors produced graphite dust that contained activated elements. These activation products constitute an additional source term of radiation and must be taken under consideration during the conduct of accident analysis of the design. This paper discusses the available literature on graphite dust production and measurements in pebble bed reactors. Limited data is available on the graphite dust produced from the AVR and THTR-300 pebble bed reactors. Experiments that have been performed on wear of graphite in pebble-bed-like conditions are reviewed. The calculation of contact forces, which are a key driving mechanism for dust in the reactor, are also included. In addition, prior graphite dust predictions are examined, and future areas of research are identified.

  7. Irradiation effects in the storage and disposal of radioactive ion-exchange resins

    International Nuclear Information System (INIS)

    Swyler, K.J.; Dodge, C.E.; Dayal, R.; Weiss, A.J.

    1982-01-01

    Research is under way to characterize the effects of self-irradiation on radwastes which may be generated when organic ion-exchange media are used in water demineralization or decontamination operations at nuclear facilities. External factors affecting the relation between laboratory evaluations and field performance are emphasized. Initial experiments do not yet indicate substantial radiation dose-rate effects on radiolytic gas yields or acid product formation, when (fully swollen) sulfonic acid resins are irradiated in a sealed air environment. At the same time, oxygen gas is removed from the environment of irradiated resins. Interaction between mild steel coupons and acidic species produced in the irradiation induced decomposition of sulfonic acid resin results in irradiation enhanced corrosion. Corrosion rates depend on radiation dose rate, moisture content and resin chemical loading. In some cases, corrosion rates decrease with time, suggesting depletion of acidic species within the resin bed, or a synergistic interaction between resin and corrosion coupon. Implications of these and other results on evaluating field behavior of radwaste containing ion-exchange media are discussed. 4 figures, 2 tables

  8. Effect of 180 days of water storage on the transverse strength of acetal resin denture base material.

    Science.gov (United States)

    Arikan, Ayla; Ozkan, Yasemin Kulak; Arda, Tugberk; Akalin, Buket

    2010-01-01

    Acetal resin has been used as an alternative denture base and clasp material since 1986. The manufacturers claim that acetal resin has superior physical properties when compared to conventional denture base acrylic resins. Limited information is available about transverse strengths of acetal resin. The purpose of this investigation was to compare transverse strengths of pink and white acetal resins to transverse strengths of conventional heat-polymerized polymethylmethacrylate (PMMA) resin in increasing durations of water storage. A transverse strength test was performed in accordance with International Standards Organization (ISO) specification No 1567. Twenty 65 x 10 x 2.5 mm(3) specimens of each resin were prepared; five specimens of each resin group were subjected to three-point bending test after 50 hours, 30 days, 60 days, and 180 days of water storage in distilled water at 37 degrees C. Experimental groups' transverse strengths were compared by three-way ANOVA and Duncan's multiple range tests. Transverse strength of PMMA denture base material was found to be in accordance with the requirements of ISO specification No 1567. Transverse strengths of white and pink acetal resin could not be calculated in this study, as white and pink acetal resin specimens did not break at the maximum applied force in the three-point bending test. Flexural strength of acetal resin was found to be within the ISO specification limits. As the water storage time increased, the deflection values of PMMA showed no significant difference (p > 0.05). Both the white and pink acetal resin showed significant increase in deflection as the water storage time was increased from 50 hours to 180 days (p resin suffered from permanent deformation, but did not break in the three-point bending test. Acetal resin showed significant increase in deflection as the water storage time was increased from 50 hours to 180 days. All materials tested demonstrated deflection values in compliance with ISO

  9. Inert blanketing of a hydride bed using typical grade protium

    Energy Technology Data Exchange (ETDEWEB)

    Klein, J.E. [Savannah River National Laboratory, Aiken (United States)

    2015-03-15

    This paper describes the impact of 500 ppm (0.05%) impurities in protium on the absorption rate of a 9.66 kg LaNi{sub 4.25}Al{sub 0.75} (LANA0.75) metal hydride bed. The presence of 500 ppm or less inerts (i.e. non-hydrogen isotopes) can significantly impact hydrogen bed absorption rates. The impact on reducing absorption rates is significantly greater than predicted assuming uniform temperature, pressure, and compositions throughout the bed. Possible explanations are discussed. One possibility considered was the feed gas contained impurity levels higher than 500 ppm. It was shown that a level of 5000 ppm of inerts would have been necessary to fit the experimental result so this possibility wa dismissed. Another possibility is that the impurities in the protium supply reacted with the hydride material and partially poisoned the hydride. If the hydride were poisoned with CO or another impurity, the removal of the over-pressure gas in the bed would not be expected to allow the hydride loading of the bed to continue as the experimental results showed, so this possibility was also dismissed. The last possibility questions the validity of the calculations. It is assumed in all the calculations that the gas phase composition, temperature, and pressure are uniform throughout the bed. These assumptions are less valid for large beds where there can be large temperature, pressure, and composition gradients throughout the bed. Eventually the impact of 0.05% inerts in protium on bed absorption rate is shown and explained in terms of an increase in inert partial pressure as the bed was loaded.

  10. Effect of green tea extract and mouthwash without alcohol on Candida albicans biofilm on acrylic resin.

    Science.gov (United States)

    Antunes, Débora P; Salvia, Ana Carolina R D; de Araújo, Rodrigo M; Di Nicoló, Rebeca; Koga Ito, Cristiane Y; de Araujo, Maria A M

    2015-12-01

    To evaluate the effect of aqueous extract of green tea and the oral antiseptic without alcohol, on Candida albicans biofilm formation to heat-curing acrylic resin plates. Candida is associated with oral candidiasis in poorly cleaned dentures. Standardised specimens of heat-cured (Conv; n = 30) or microwave-cured acrylic resin (Mw; n = 30) were obtained and divided into six groups (n = 10): G1 = Conv resin and green tea aqueous extract, G2 = Conv resin and mouthwash, G3 = control of Conv resin, G4 = Mw resin and green tea aqueous extract, G5 = Mw resin and mouthwash and G6 = control of Mw-cured resin. The specimens were contaminated with 10 ml of Sabouraud dextrose broth inoculated with 0.1 ml of standard suspension containing 1 × 10(6) cells/ml of C. albicans and incubated for 24 h at 37°C. After this period, they were immersed in the aqueous extract or in mouthwash for 15 min. The control groups were treated with sterile distilled water. Aliquots of 0.1 ml were plated on Sabouraud dextrose agar and incubated at 37°C for 24 h. The numbers of colony-forming units per test specimen (CFU/TS) were calculated, and the results statistically analysed by two-way anova and Tukey's tests (5%). Statistically significant difference was observed for the aqueous extract groups (G1; 33.65%) and mouthwash (G2; 17.06%), when compared to control (G3; 100%), for Conv resin. For the Mw resin, there was significant difference between mouthwash (G5; 43.16%) and control (G6; 100%). The aqueous extract of green tea and mouthwash led to a reduction in the number of viable fungal cells in biofilm formed on acrylic resin. © 2014 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd.

  11. Shade distribution of commercial resin composites and color difference with shade guide tabs.

    Science.gov (United States)

    Park, Seung-Kook; Lee, Yong-Keun

    2007-10-01

    To determine the shade distribution of varied shades of contemporary resin composites, and to measure the color difference (deltaE*ab) between individual shades of resin composites and the nearest shade tabs, which showed the smallest color difference with each shade of resin composite, in the VITA shade guide. Eight light-curing resin composites, with a total of 41 shades, were studied. Color of specimens was measured on a reflection spectrophotometer over a white background. Ranges and distributions of CIE L*, C*ab, a* and b* values of each brand of resin composites were determined. Color difference between each shade of resin composites and each shade of the shade guide tabs were calculated, and the nearest shade guide tab was selected. The range of CIE L* value for eight brands of resin composites was 3.2-9.0, that of C*ab was 2.5-11.6, that of CIE a* value was 1.1-5.8, and that of CIE b* value was 5.9-11.5. Color differences (deltaE*ab) between each shade of resin composites and the nearest shade tab of the shade guide was 0.9-12.8.

  12. [Effect of bleaching agents on the color of indirect and direct composite resins].

    Science.gov (United States)

    Xing, Wenzhong; Jiang, Tao; Chen, Xiaodong; Wang, Yining

    2014-09-01

    To evaluate the effect of bleaching agents on the color of indirect and direct composite resins. Five resin composite materials were tested in this in vitro study. The five composites were as follow: two indirect composite resins (Adoro SR, Ceramage) and three direct composite resins (Filtek Z350, Clearfil Majesty Esthetic, and Gradia Direct Anterior). For each material, twenty disk-shaped specimens were prepared and randomly divided into five groups according to the color parameters of specimens before bleaching treatment. The composite resin specimens were treated by one of five sample solutions which were at-home bleaching agents (10% and 15% carbarmide peroxide), in- office bleaching agents (38% H(2)O(2) and 35%H(2)O(2)) and deionized water (control group). The color parameters of specimens were measured by spectrophotometer at baseline and after bleaching treatments. The color differences (ΔE values) between baseline and post-treatments were calculated. The data of color differences were evaluated statistically using two-way analysis with a significance level of 0.05. The color changes of the resin composites were less than 2.0 after bleaching agent treatment, therefore were not perceptible. Slight increase of L(*) values and decrease of C(*)ab values in color parameters of specimens were observed. There were statistically significant differences in ΔE values for different bleaching treatments and resin materials (P = 0.001). The bleaching agents did not affect the color of indirect and direct composite resins tested.

  13. Cross-Sectional Study of Respiratory Symptoms, Spirometry, and Immunologic Sensitivity in Epoxy Resin Workers.

    Science.gov (United States)

    Hines, Stella E; Barker, Elizabeth A; Robinson, Maura; Knight, Vijaya; Gaitens, Joanna; Sills, Michael; Duvall, Kirby; Rose, Cecile S

    2015-12-01

    An epoxy resin worker developed hypersensitivity pneumonitis requiring lung transplantation and had an abnormal blood lymphocyte proliferation test (LPT) to an epoxy hardener. We assessed the prevalence of symptoms, abnormal spirometry, and abnormal epoxy resin LPT results in epoxy resin workers compared to unexposed workers. Participants completed questionnaires and underwent spirometry. We collected blood for epoxy resin LPT and calculated stimulation indices for five epoxy resin products. We compared 38 exposed to 32 unexposed workers. Higher exposed workers were more likely to report cough (OR 10.86, [1.23-infinity], p = 0.030) or wheeze (OR 4.44, [1.00-22.25], p = 0.049) than unexposed workers, even controlling for smoking. Higher exposed workers were more likely to have abnormal FEV1 than unexposed workers (OR 10.51, [0.86-589.9], p = 0.071), although not statistically significant when adjusted for smoking. There were no differences in proportion of abnormal epoxy resin system LPTs between exposed and unexposed workers. In summary, workers exposed to epoxy resin system chemicals were more likely to report respiratory symptoms and have abnormal FEV1 than unexposed workers. Use of epoxy resin LPT was not helpful as a biomarker of exposure and sensitization. © 2015 Wiley Periodicals, Inc.

  14. Cross‐Sectional Study of Respiratory Symptoms, Spirometry, and Immunologic Sensitivity in Epoxy Resin Workers

    Science.gov (United States)

    Barker, Elizabeth A.; Robinson, Maura; Knight, Vijaya; Gaitens, Joanna; Sills, Michael; Duvall, Kirby; Rose, Cecile S.

    2015-01-01

    Abstract Objectives An epoxy resin worker developed hypersensitivity pneumonitis requiring lung transplantation and had an abnormal blood lymphocyte proliferation test (LPT) to an epoxy hardener. We assessed the prevalence of symptoms, abnormal spirometry, and abnormal epoxy resin LPT results in epoxy resin workers compared to unexposed workers. Methods Participants completed questionnaires and underwent spirometry. We collected blood for epoxy resin LPT and calculated stimulation indices for five epoxy resin products. Results We compared 38 exposed to 32 unexposed workers. Higher exposed workers were more likely to report cough (OR 10.86, [1.23‐infinity], p = 0.030) or wheeze (OR 4.44, [1.00‐22.25], p = 0.049) than unexposed workers, even controlling for smoking. Higher exposed workers were more likely to have abnormal FEV1 than unexposed workers (OR 10.51, [0.86‐589.9], p = 0.071), although not statistically significant when adjusted for smoking. There were no differences in proportion of abnormal epoxy resin system LPTs between exposed and unexposed workers. Conclusions In summary, workers exposed to epoxy resin system chemicals were more likely to report respiratory symptoms and have abnormal FEV1 than unexposed workers. Use of epoxy resin LPT was not helpful as a biomarker of exposure and sensitization. PMID:26553118

  15. Accurate determination of 129I concentrations and 129I/137Cs ratios in spent nuclear resins by Accelerator Mass Spectrometry

    International Nuclear Information System (INIS)

    Nottoli, Emmanuelle; Bienvenu, Philippe; Labet, Alexandre; Bourlès, Didier; Arnold, Maurice; Bertaux, Maité

    2014-01-01

    Determining long-lived radionuclide concentrations in radioactive waste has fundamental implications for the long-term management of storage sites. This paper focuses on the measurement of low 129 I contents in ion exchange resins used for primary fluid purification in Pressurised Water Reactors (PWR). Iodine-129 concentrations were successfully determined using Accelerator Mass Spectrometry (AMS) following a chemical procedure which included (1) acid digestion of resin samples in HNO 3 /HClO 4 , (2) radioactive decontamination by selective iodine extraction using a new chromatographic resin (CL Resin), and (3) AgI precipitation. Measured 129 I concentrations ranged from 4 to 12 ng/g, i.e. from 0.03 to 0.08 Bq/g. The calculation of 129 I/ 137 Cs activity ratios used for routine waste management produced values in agreement with the few available data for PWR resin samples. - Highlights: • In the context of radioactive waste management, this study aimed at measuring 129 I in spent resins using accelerator mass spectrometry. • The treatment procedure included microwave acid digestion of samples, iodine extraction by CL resins and AgI precipitation. • Developed first on synthetic matrices, the chemical treatment procedure was then successfully applied to real resin samples. • 129 I concentrations ranged from 4 to 12 ng/g of dry resin. • Results are in agreement with previous measurements and support reference values currently used for nuclear resin management

  16. Sampling and characterization of spent exchange resins of Atucha I nuclear power plant

    International Nuclear Information System (INIS)

    Varani, Jose L.; Cernadas, D.; Iglesias, Alberto M.; Raffo Calderon, Maria del C.

    2004-01-01

    The present storage facilities for spent resins in Atucha I NPP would be full within the next 5 years, accordingly some tasks are being planned to conditioning these waste and so generate enough storage capacity for the remaining life of the plant. Among this tasks is the characterization of spent resins that has several objectives: to know their chemical and radiochemical composition; the homogeneity of these parameters in the total volume of spent resins; the existence or not of compact zones; the proportion of 'crud'; the breakage degree of the micro-spheres; etc. The first step was to analyse the criterion to follow for sampling resins in the storage deposit of 40 m 3 . In order to take some samples from different points, a special device was required. It had to be introduced closed in the resin bed, opened to take the sample and then closed again to return to the surface. A device used in cereal industry for sampling silos to different depths was modified in its internal capacity for reducing operator dose and increasing the length of rod in order to reaching the bottom of the pit. The device was tested in cold mock up before to taking actual samples. Active resins samples, five in total up to now, were taken from deposit to different depths and kept in lead containers. After analysing the samples, the following average results were extracted: 1.7 x 10 5 Bq/g of Co-60, 9.7 x 10 5 Bq/g of Cs-137 and 774 Bq/g of total alpha, which corresponds to intermediate activity waste. The differences between the values of activity of the different samples are of up to 310 % for Co-60 and of up to 788 % for the Cs-137 what indicates a great inhomogeneity. The direct observation of resin grains, placed in a transparent glass burette, did not demonstrate an important proportion of broken or divided resins. (author)

  17. Resin technologies: construction and staining of resin TMA's.

    Science.gov (United States)

    Howat, William J; Wilson, Susan J

    2010-01-01

    The traditional formaldehyde-fixed paraffin-embedded tissue, and therefore the tissue microarrays created from it, provide good morphology but with a compromised antigenicity when compared to frozen tissue. In contrast, while solving the issue of antigenicity, frozen tissue suffers from a lack of morphology. We have demonstrated that tissue microarrays constructed in glycol methacrylate resin, when combined with a cold acetone fixation step, have been able to combine the superior morphology of resin-embedded sections with the superior antigenicity of frozen tissue for prospectively collected material.

  18. Adsorption of aromatic amino acids in a fixed bed column

    Directory of Open Access Journals (Sweden)

    Cremasco M.A.

    2003-01-01

    Full Text Available Phenylalanine (Phe and tyrosine (Tyr are two of the twenty amino acids in proteins; they are classified as aromatic amino acids, because both have a benzene ring in their structures. These amino acids are important in the synthesis of several biologically active amines, such as beta-endorphin, a neurotransmitter. Amino acids can be separated by ion-exchange chromatography. In this case, it is important that fixed-bed adsorber design adequately predict the breakthrough curve. This work presents a mathematical model for both fluid and porous phases. In the solution proposed for this model the liquid-phase concentration inside the particles is solved analytically and is related to the liquid-phase concentration in the bed using Duhamel's theorem. The solution for liquid-phase concentration in the bed is then solved numerically instead of analytically. The basic mass transfer parameters are from the literature. The results from the model are compared with those obtained experimentally using Phe and Tyr diluted in aqueous solutions in a fixed bed of PVP (poly-4-vinylpyridine resin.

  19. Understanding and predicting bed humidity in fluidized bed granulation.

    Science.gov (United States)

    Hu, Xinhui; Cunningham, John; Winstead, Denita

    2008-04-01

    Bed humidity is a critical parameter that needs to be controlled in a fluidized bed granulation to ensure reliability. To predict and control the bed humidity during the fluidized bed granulation process, a simple model based on the mass conservation of moisture was developed. The moisture mass balance model quantitatively simulates the effects of spray rate, binder solution concentration, airflow rate, inlet air temperature, and dew point on the bed humidity. The model was validated by a series of granulations performed in different scale granulators including Glatt GPCG-1, GPCG-15, and GPCG-60. Good agreement was observed between the theoretical prediction and the measured loss on drying (LOD). The model developed in the current work enables us to choose the appropriate parameters for the fluidized bed granulation and can be used as a valuable tool in process scaling-up. 2007 Wiley-Liss, Inc

  20. The effects of fouled anion resin on condensate polishing plant performance at Dungeness B power station

    Energy Technology Data Exchange (ETDEWEB)

    Bates, Chris [British Energy, Barnwood, Gloucester (United Kingdom)

    2008-10-15

    The return to power, after an outage, at Dungeness B Power Station was delayed because of problems in achieving an in-specification feedwater acid conductivity. Dungeness B has a full flow cation/mixed bed condensate polishing plant (CPP). Investigations showed that the acid conductivity was produced by carbon dioxide and organic impurities both by-passing the CPP and slipping through it. Resin analysis showed that the anion resin had severely impaired sulfate removal kinetics. The paper covers the work done to try and identify the nature and source of the organics and their effect on the anion resin. One significant finding was that the carbonate removal kinetics were as impaired as those for sulfate removal; this had not been previously experienced in the CPP at any British Energy plant. (orig.)

  1. Coal Bed Methane Primer

    Energy Technology Data Exchange (ETDEWEB)

    Dan Arthur; Bruce Langhus; Jon Seekins

    2005-05-25

    During the second half of the 1990's Coal Bed Methane (CBM) production increased dramatically nationwide to represent a significant new source of income and natural gas for many independent and established producers. Matching these soaring production rates during this period was a heightened public awareness of environmental concerns. These concerns left unexplained and under-addressed have created a significant growth in public involvement generating literally thousands of unfocused project comments for various regional NEPA efforts resulting in the delayed development of public and fee lands. The accelerating interest in CBM development coupled to the growth in public involvement has prompted the conceptualization of this project for the development of a CBM Primer. The Primer is designed to serve as a summary document, which introduces and encapsulates information pertinent to the development of Coal Bed Methane (CBM), including focused discussions of coal deposits, methane as a natural formed gas, split mineral estates, development techniques, operational issues, producing methods, applicable regulatory frameworks, land and resource management, mitigation measures, preparation of project plans, data availability, Indian Trust issues and relevant environmental technologies. An important aspect of gaining access to federal, state, tribal, or fee lands involves education of a broad array of stakeholders, including land and mineral owners, regulators, conservationists, tribal governments, special interest groups, and numerous others that could be impacted by the development of coal bed methane. Perhaps the most crucial aspect of successfully developing CBM resources is stakeholder education. Currently, an inconsistent picture of CBM exists. There is a significant lack of understanding on the parts of nearly all stakeholders, including industry, government, special interest groups, and land owners. It is envisioned the Primer would being used by a variety of

  2. Bed Rest Muscular Atrophy

    Science.gov (United States)

    Greenleaf, John E.

    2000-01-01

    A major debilitating response from prolonged bed rest (BR) is muscle atrophy, defined as a "decrease in size of a part of tissue after full development has been attained: a wasting away of tissue as from disuse, old age, injury or disease". Part of the complicated mechanism for the dizziness, increased body instability, and exaggerated gait in patients who arise immediately after BR may be a result of not only foot pain, but also of muscular atrophy and associated reduction in lower limb strength. Also, there seems to be a close association between muscle atrophy and bone atrophy. A discussion of many facets of the total BR homeostatic syndrome has been published. The old adage that use determines form which promotes function of bone (Wolff's law) also applies to those people exposed to prolonged BR (without exercise training) in whom muscle atrophy is a consistent finding. An extreme case involved a 16-year-old boy who was ordered to bed by his mother in 1932: after 50 years in bed he had "a lily-white frame with limbs as thin as the legs of a ladder-back chair". These findings emphasize the close relationship between muscle atrophy and bone atrophy. In addition to loss of muscle mass during deconditioning, there is a significant loss of muscle strength and a decrease in protein synthesis. Because the decreases in force (strength) are proportionately greater than those in fiber size or muscle cross-sectional area, other contributory factors must be involved; muscle fiber dehydration may be important.

  3. Particle bed reactor modeling

    Science.gov (United States)

    Sapyta, Joe; Reid, Hank; Walton, Lew

    The topics are presented in viewgraph form and include the following: particle bed reactor (PBR) core cross section; PBR bleed cycle; fuel and moderator flow paths; PBR modeling requirements; characteristics of PBR and nuclear thermal propulsion (NTP) modeling; challenges for PBR and NTP modeling; thermal hydraulic computer codes; capabilities for PBR/reactor application; thermal/hydralic codes; limitations; physical correlations; comparison of predicted friction factor and experimental data; frit pressure drop testing; cold frit mask factor; decay heat flow rate; startup transient simulation; and philosophy of systems modeling.

  4. Epoxy Resins in Electron Microscopy

    Science.gov (United States)

    Finck, Henry

    1960-01-01

    A method of embedding biological specimens in araldite 502 (Ciba) has been developed for materials available in the United States. Araldite-embedded tissues are suitable for electron microscopy, but the cutting qualities of the resin necessitates more than routine attention during microtomy. The rather high viscosity of araldite 502 also seems to be an unnecessary handicap. The less viscous epoxy epon 812 (Shell) produces specimens with improved cutting qualities, and has several features—low shrinkage and absence of specimen damage during cure, minimal compression of sections, relative absence of electron beam-induced section damage, etc.—which recommends it as a routine embedding material. The hardness of the cured resin can be easily adjusted by several methods to suit the materials embedded in it. Several problems and advantages of working with sections of epoxy resins are also discussed. PMID:13822825

  5. Process for Molding Nonreinforced (Neat) Resins

    Science.gov (United States)

    Dickerson, G. E.

    1983-01-01

    Void free moldings obtained for neat, condensation, thermosetting resins. Thermally and mechanically treat resin prior to molding to reduce amount of volatiles. With volatiles reduced molding temperature and pressure are applied in way to drive out remaining volatiles during molding.

  6. 21 CFR 172.280 - Terpene resin.

    Science.gov (United States)

    2010-04-01

    ... CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Coatings, Films and Related Substances § 172.280 Terpene resin. The food additive terpene resin may be safely used...

  7. Action of ionizing radiation on epoxy resins

    Energy Technology Data Exchange (ETDEWEB)

    Van de Voorde, M. E.

    1970-12-01

    The resistance of classical and experimental epoxy resins to irradiation was studied. The resistance to irradiation of epoxy resins of diverse compositions as well as the development of resins having a radioresistance that approaches that of certain ceramics are discussed. Sources of irradiation and the techniques of dosimetry used are described. The structures of certain epoxy resins and of hardeners are given. The preparation of these resins and their physical properties is described. The effects of radiation on epoxy resins, as well as conditions of irradiation, and suggested mechanisms for degradation of the irradiated resins are discussed. The relationship between chemical structure of the resins and their physical properties is evaluated. (115 references) (JCB)

  8. Boron removal from water and wastewater using new polystyrene-based resin grafted with glycidol

    OpenAIRE

    Kluczka, Joanna; Korolewicz, Teofil; Zołotajkin, Maria; Adamek, Jakub

    2015-01-01

    A divinylbenzene cross-linked polystyrene resin with amine functional groups (Purolite A170) was grafted with glycidol and characterized as a novel sorbent, GLY-resin, for the oxoborate removal from model solutions and post-crystallization lye. The sorption behavior of GLY-resin was investigated using a batch system. The results showed that the sorption was maximal at pH=9.5. The equilibrium was achieved after 24 h. Calculations based on Langmuir model show the monolayer sorption capacity qm=...

  9. A novel calorimetry technique for monitoring electron beam curing of polymer resins

    International Nuclear Information System (INIS)

    Chen, J.H.; Johnston, A.; Petrescue, L.; Hojjati, M.

    2006-01-01

    This paper describes the development of a calorimetry-based technique for monitoring of the curing of electron beam (EB) curable resins, including design of the calorimeter hardware and the development of an analytical model for calculating resin cure rates and radiation dose. Factors affecting the performance of the calorimeter were investigated. Experimental trials monitoring the curing of epoxy resin were conducted under single pass and multiple passes of EB irradiation. Results show that the developed calorimeter is a simple, inexpensive and reasonably accurate technique for monitoring the EB curing of cationic epoxies

  10. Phosphorus-modified poly(styrene-co-divinylbenzene)–PAMAM chelating resin for the adsorption of uranium(VI) in aqueous

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Qiong [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Liu, Yaochi, E-mail: liuyaochi72@163.com [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Wang, Chunzhi [Baling Company, China Petroleum and Chemical Corporation (China); Cheng, Jiashun [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China)

    2013-12-15

    Highlights: • A series of phosphorus-modified poly(styrene-co-divinylbenzene)–PAMAM chelating resins were synthesized. • The materials were commercially available and economic. • The new resins were high effective and selective adsorbents. • U(VI) adsorption is fitted with pseudo-second-order equation and Langmuir model. • The new resins can be regenerated. -- Abstract: Polyamidoamine (PAMAM) modified poly(styrene-co-divinylbenzene) absorbents carrying phosphorus functional groups (PS-PAMAM-PPA) were prepared and used as adsorbents for the adsorption of uranium(VI) from aqueous solution. Different generations of PAMAM were used for obtaining different chelating resins, PS-PPA, PS-1.0G PAMAM-PPA, PS-2.0G PAMAM-PPA, PS-3.0G PAMAM-PPA and PS-4.0G PAMAM-PPA. The synthesized resins were characterized by FTIR and XPS. The effects of many physio-chemical properties on metal ion adsorption to adsorbent phase, such as solution pH, kinetic studies, initial uranium concentration, temperature, were investigated using batch method. The results showed that the maximum adsorption capacity (99.89 mg/g) was observed at the pH 5.0 and 25 °C with initial U(VI) concentration 100 mg/L and adsorbent dose 1 g/L. PS-1.0G PAMAM-PPA had the largest adsorption capacity for U(VI) compared with other prepared adsorbents. The adsorption kinetics of U(VI) onto PS-1.0G PAMAM-PPA followed the mechanism of the pseudo-second-order equation, indicating that the chemical adsorption was a rate-limiting step. The calculated thermodynamic parameters (ΔG, ΔH, ΔS) stated that the adsorption of U(VI) onto PS-1.0G PAMAM-PPA were spontaneous, endothermic and feasible. The adsorption isotherms obeyed the Langmuir isotherm models. The desorption studies showed that PS-1.0G PAMAM-PPA could be used repeatedly and adsorption and desorption percentage did not have any noticeable loss after 27 cycles in a fixed bed.

  11. Sustainable nitrate-contaminated water treatment using multi cycle ion-exchange/bioregeneration of nitrate selective resin.

    Science.gov (United States)

    Ebrahimi, Shelir; Roberts, Deborah J

    2013-11-15

    The sustainability of ion-exchange treatment processes using high capacity single use resins to remove nitrate from contaminated drinking water can be achieved by regenerating the exhausted resin and reusing it multiple times. In this study, multi cycle loading and bioregeneration of tributylamine strong base anion (SBA) exchange resin was studied. After each cycle of exhaustion, biological regeneration of the resin was performed using a salt-tolerant, nitrate-perchlorate-reducing culture for 48 h. The resin was enclosed in a membrane to avoid direct contact of the resin with the culture. The results show that the culture was capable of regenerating the resin and allowing the resin to be used in multiple cycles. The concentrations of nitrate in the samples reached a peak in first 0.5-1h after placing the resin in medium because of desorption of nitrate from resin with desorption rate of 0.099 ± 0.003 hr(-1). After this time, since microorganisms began to degrade the nitrate in the aqueous phase, the nitrate concentration was generally non-detectable after 10h. The average of calculated specific degradation rate of nitrate was -0.015 mg NO3(-)/mg VSS h. Applying 6 cycles of resin exhaustion/regeneration shows resin can be used for 4 cycles without a loss of capacity, after 6 cycles only 6% of the capacity was lost. This is the first published research to examine the direct regeneration of a resin enclosed in a membrane, to allow reuse without any disinfection or cleaning procedures. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Uranium sorption by tannin resins

    International Nuclear Information System (INIS)

    Olivares Rieumont, S.; Martinez Luzardo, J.; Torres Hernandez, J.; Lima Cazorla, D. de la Rosa.

    1998-01-01

    The sorption of uranium by immobilised Eucalyptus Saligna Sm. and Lysiloma latisiliqua L tannins was investigated. Immobilization condition were analyzed. These resins resulted suitable adsorbent for the concentration of uranium from aqueous systems. The sorption of uranium is pH dependent. At pH 5.5 maximum in sorption capacity is registered. The presence of appreciable amount of sodium chloride do not have any effect on uranium removal. Carbonate and calcium ions in concentrations similar to these that could be found in sea water and other natural water do not decrease the uranium uptake. Tannin resins can be used several times without an appreciable decay of their sorption capacity

  13. Method of removing contaminants from plastic resins

    Energy Technology Data Exchange (ETDEWEB)

    Bohnert, George W. (Harrisonville, MO); Hand, Thomas E. (Lee' s Summit, MO); DeLaurentiis, Gary M. (Jamestown, CA)

    2008-11-18

    A method for removing contaminants from synthetic resin material containers using a first organic solvent system and a second carbon dioxide system. The organic solvent is utilized for removing the contaminants from the synthetic resin material and the carbon dioxide is used to separate any residual organic solvent from the synthetic resin material.

  14. Method of removing contaminants from plastic resins

    Energy Technology Data Exchange (ETDEWEB)

    Bohnert,George W. (Harrisonville, MO); Hand,Thomas E. (Lee' s Summit, MO); Delaurentiis,Gary M. (Jamestown, CA)

    2007-08-07

    A method for removing contaminants from synthetic resin material containers using a first organic solvent system and a second carbon dioxide system. The organic solvent is utilized for removing the contaminants from the synthetic resin material and the carbon dioxide is used to separate any residual organic solvent from the synthetic resin material.

  15. Method for removing contaminants from plastic resin

    Science.gov (United States)

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    2008-12-30

    A method for removing contaminants from synthetic resin material containers using a first organic solvent system and a second carbon dioxide system. The organic solvent is utilized for removing the contaminants from the synthetic resin material and the carbon dioxide is used to separate any residual organic solvent from the synthetic resin material.

  16. Declination Calculator

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Declination is calculated using the current International Geomagnetic Reference Field (IGRF) model. Declination is calculated using the current World Magnetic Model...

  17. Equilibrium modeling of gasification: Gibbs free energy minimization approach and its application to spouted bed and spout-fluid bed gasifiers

    International Nuclear Information System (INIS)

    Jarungthammachote, S.; Dutta, A.

    2008-01-01

    Spouted beds have been found in many applications, one of which is gasification. In this paper, the gasification processes of conventional and modified spouted bed gasifiers were considered. The conventional spouted bed is a central jet spouted bed, while the modified spouted beds are circular split spouted bed and spout-fluid bed. The Gibbs free energy minimization method was used to predict the composition of the producer gas. The major six components, CO, CO 2 , CH 4 , H 2 O, H 2 and N 2 , were determined in the mixture of the producer gas. The results showed that the carbon conversion in the gasification process plays an important role in the model. A modified model was developed by considering the carbon conversion in the constraint equations and in the energy balance calculation. The results from the modified model showed improvements. The higher heating values (HHV) were also calculated and compared with the ones from experiments. The agreements of the calculated and experimental values of HHV, especially in the case of the circular split spouted bed and the spout-fluid bed were observed

  18. Mathematical modelling of MSW incineration on a travelling bed.

    Science.gov (United States)

    Yang, Y B; Goh, Y R; Zakaria, R; Nasserzadeh, V; Swithenbank, J

    2002-01-01

    The rising popularity of incineration of municipal solid waste (MSW) calls for detailed mathematical modelling and understanding of the incineration process. In this paper, governing equations for mass, momentum and heat transfer for both solid and gaseous phases in a moving bed in a solid-waste incineration furnace are described and relevant sub-models are presented. The burning rates of volatile hydrocarbons in the moving bed of solids are limited not only by the reaction kinetics but also the mixing of the volatile fuels with the under-fire air. The mixing rate is averaged across a computation cell and correlated to a number of parameters including local void fraction of the bed, gas velocity and a length scale comparable to the particle size in the bed. A correlation equation is also included to calculate the mixing in the freeboard area immediately next to the bed surface. A small-scale fixed bed waste incinerator was built and test runs were made in which total mass loss from the bed, temperature and gas composition at different locations along the bed height were measured. A 2-D bed-modelling program (FLIC) was developed which incorporates the various sub-process models and solves the governing equations for both gases and solids. Thermal and chemical processes are mainly confined within a layer about 5-9 times in thickness of the averaged particle size in the burning bed. For a large part of the burning process, the total mass loss rate was constant until the solid waste was totally dried out and a period of highly rising CO emission followed. The maximum bed temperature was around 1200 K. The whole burning process ended within 60 min. Big fluctuations in species concentration were observed due to channelling and subsequent 'catastrophic' changes in the local bed conditions. Reasonably good agreement between modelling and measurements has been achieved. Yet the modelling work is complicated by the channelling phenomenon in the bed. Numerical simulations

  19. Effect of resin shades on opacity of ceramic veneers and polymerization efficiency through ceramics.

    Science.gov (United States)

    Öztürk, Elif; Chiang, Yu-Chih; Coşgun, Erdal; Bolay, Şükran; Hickel, Reinhard; Ilie, Nicoleta

    2013-11-01

    The aim of this study was to assess the effect of different resin cement shades on the opacity and color difference of ceramics and to determine the polymerization efficiency of the resin cement at different shades after curing through ceramics. Two different ceramics (IPS e.max Press and IPS Empress(®)CAD, Ivoclar Vivadent) were used for this study. A light-cured veneer luting resin (Variolink Veneer, Ivoclar Vivadent) in four different shades of HV+1, HV+3, LV-1, and LV-3 was used for the colorimetric measurements. The color and spectral reflectance of the ceramics were measured according to the CIELab color scale relative to the standard illuminant D65 on a reflection spectrophotometer (ColorEye7000A, USA). Color differences (ΔE values) and the contrast ratios (CR) of the different groups of samples were calculated. In order to analyse the polymerization efficiency of the resin cements, the micromechanical properties of the resins were measured with an automatic microhardness indenter (Fisherscope H100C, Germany). The results were analysed using one-way ANOVA and Tukey's HSD post hoc tests (SPSS 18.0). The one-way ANOVA test showed that the values of ΔE and CR of the different specimen groups were significantly different (p<0.05). Group 1 (20.7 ± 0.5) (IPS-CAD without resin cement) exhibited the highest and group 10 (14.8 ± 0.5) (e.max:HV+3) exhibited the lowest ΔE value. Significant differences in the micromechanical properties were identified among the tested resin cements in different shades (p<0.05). Resin cement shade is an important factor for the opacity of a restoration. Furthermore, the resin shade affects the micromechanical properties of the underlying resin cement. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Shear bond strength evaluation of resin composite to resin-modified glass-ionomer cement using three different resin adhesives vs. glass-ionomer based adhesive

    Directory of Open Access Journals (Sweden)

    Mostafa Sadeghi

    2015-12-01

    Full Text Available Background: The clinical success of sandwich technique depends on the strength of resin-modified glass ionomer cement (RMGIC bonding to both dentin and resin composite. Therefore, the shear bond strength (SBS of resin composite bonded to RMGIC utilizing different resin adhesives versus a GIC-based adhesive was compared. Materials and methods: In this in vitro study, 84 holes (5×2 mm were prepared in acrylic blocks, randomly divided into seven groups (n=12 and filled with RMGIC (Light-Cured Universal Restorative, GC. In the Group I; no adhesive was applied on the RMGIC. In the Group II, non-etched and Group III was etched with phosphoric acid. In groups II and III, after rinsing, etch-and-rinse adhesive (OptiBond Solo Plus; in the Group IV; a two-step self-etch adhesive (OptiBond XTR and in Group V; a one-step self-etch (OptiBond All-in-One were applied on the cement surfaces. Group VI; a GIC-based adhesive (Fuji Bond LC was painted over the cement surface and cured. Group VII; the GIC-based adhesive was brushed over RMGIC followed by the placement of resin composite and co-cured. Afterward; resin composite (Point 4 cylinders were placed on the treated cement surfaces. The specimens were placed in 100% humidity at 37 ± 1°C and thermo cycled. The shear bond test was performed at a cross-head speed of 1 mm/min and calculated in MPa; the specimens were examined to determine mode of failure. The results were analyzed using one-way ANOVA and Tukey test. Results: The maximum (24.62±3.70 MPa and minimum (18.15±3.38 MPa SBS mean values were recorded for OptiBond XTR adhesive and the control group, respectively. The pairwise comparisons showed no significant differences between the groups that bonded with different adhesives. The adhesive failure was the most common failure mode observed. Conclusion: This study suggests that GIC-based adhesive could be applied over RMGIC as co-cure technique for sandwich restorations in lieu of employing the resin

  1. Variability of Bed Drag on Cohesive Beds under Wave Action

    Directory of Open Access Journals (Sweden)

    Ilgar Safak

    2016-04-01

    Full Text Available Drag force at the bed acting on water flow is a major control on water circulation and sediment transport. Bed drag has been thoroughly studied in sandy waters, but less so in muddy coastal waters. The variation of bed drag on a muddy shelf is investigated here using field observations of currents, waves, and sediment concentration collected during moderate wind and wave events. To estimate bottom shear stress and the bed drag coefficient, an indirect empirical method of logarithmic fitting to current velocity profiles (log-law, a bottom boundary layer model for combined wave-current flow, and a direct method that uses turbulent fluctuations of velocity are used. The overestimation by the log-law is significantly reduced by taking turbulence suppression due to sediment-induced stratification into account. The best agreement between the model and the direct estimates is obtained by using a hydraulic roughness of 10 - 4 m in the model. Direct estimate of bed drag on the muddy bed is found to have a decreasing trend with increasing current speed, and is estimated to be around 0.0025 in conditions where wave-induced flow is relatively weak. Bed drag shows an increase (up to fourfold with increasing wave energy. These findings can be used to test the bed drag parameterizations in hydrodynamic and sediment transport models and the skills of these models in predicting flows in muddy environments.

  2. Prediction of bed level variations in nonuniform sediment bed channel

    Indian Academy of Sciences (India)

    B R Andharia

    2018-04-12

    Apr 12, 2018 ... have been undertaken for measurements of bed and water levels in an aggrading channel due to overloading of nonuniform sediments ..... 2.4 Thickness of active bed layer. The mixing zone of sediment remaining in contact with the flow is referred as active layer (ABL). The thickness and particle size ...

  3. Variability of bed drag on cohesive beds under wave action

    Science.gov (United States)

    Safak, Ilgar

    2016-01-01

    Drag force at the bed acting on water flow is a major control on water circulation and sediment transport. Bed drag has been thoroughly studied in sandy waters, but less so in muddy coastal waters. The variation of bed drag on a muddy shelf is investigated here using field observations of currents, waves, and sediment concentration collected during moderate wind and wave events. To estimate bottom shear stress and the bed drag coefficient, an indirect empirical method of logarithmic fitting to current velocity profiles (log-law), a bottom boundary layer model for combined wave-current flow, and a direct method that uses turbulent fluctuations of velocity are used. The overestimation by the log-law is significantly reduced by taking turbulence suppression due to sediment-induced stratification into account. The best agreement between the model and the direct estimates is obtained by using a hydraulic roughness of 10 -4">−4 m in the model. Direct estimate of bed drag on the muddy bed is found to have a decreasing trend with increasing current speed, and is estimated to be around 0.0025 in conditions where wave-induced flow is relatively weak. Bed drag shows an increase (up to fourfold) with increasing wave energy. These findings can be used to test the bed drag parameterizations in hydrodynamic and sediment transport models and the skills of these models in predicting flows in muddy environments.

  4. Absorbencies of six different rodent beddings: commercially advertised absorbencies are potentially misleading.

    Science.gov (United States)

    Burn, C C; Mason, G J

    2005-01-01

    Moisture absorbency is one of the most important characteristics of rodent beddings for controlling bacterial growth and ammonia production. However, bedding manufacturers rarely provide information on the absorbencies of available materials, and even when they do, absorption values are usually expressed per unit mass of bedding. Since beddings are usually placed into cages to reach a required depth rather than a particular mass, their volumetric absorbencies are far more relevant. This study therefore compared the saline absorbencies of sawdust, aspen woodchips, two virgin loose pulp beddings (Alpha-Dri and Omega-Dri), reclaimed wood pulp (Tek-Fresh), and corncob, calculated both by volume and by mass. Absorbency per unit volume correlated positively with bedding density, while absorbency per unit mass correlated negatively. Therefore, the relative absorbencies of the beddings were almost completely reversed depending on how absorbency was calculated. By volume, corncob was the most absorbent bedding, absorbing about twice as much saline as Tek-Fresh, the least absorbent bedding. Conversely, when calculated by mass, Tek-Fresh appeared to absorb almost three times as much saline as the corncob. Thus, in practical terms the most absorbent bedding here was corncob, followed by the loose pulp beddings; and this is generally supported by their relatively low ammonia production as seen in previous studies. Many factors other than absorbency determine whether a material is suitable as a rodent bedding, and they are briefly mentioned here. However, manufacturers should provide details of bedding absorbencies in terms of volume, in order to help predict the relative absorbencies of the beddings in practical situations.

  5. Diterpene resin acids in conifers.

    Science.gov (United States)

    Keeling, Christopher I; Bohlmann, Jörg

    2006-11-01

    Diterpene resin acids are a significant component of conifer oleoresin, which is a viscous mixture of terpenoids present constitutively or inducibly upon herbivore or pathogen attack and comprises one form of chemical resistance to such attacks. This review focuses on the recent discoveries in the chemistry, biosynthesis, molecular biology, regulation, and biology of these compounds in conifers.

  6. Occupational exposure to epoxy resins

    NARCIS (Netherlands)

    Terwoert, J.; Kersting, K.

    2014-01-01

    Products based on epoxy resins as a binder have become popular in various settings, among which the construction industry and in windmill blade production, as a result of their excellent technical properties. However, due to the same properties epoxy products are a notorious cause of allergic skin

  7. Bitumen stabilized ballast: a potential solution for railway track-bed

    OpenAIRE

    D'Angelo, Giacomo; Thom, Nicholas; Lo Presti, Davide

    2016-01-01

    Railway ballast degradation under dynamic loads progressively leads to loss of mechanical performance and geometry of the track, so that maintenance interventions are frequently needed. In order to systematically avoid this issue, recently solutions have been proposed to reinforce track-bed by using polyurethane and/or resins as well as asphalt layers among others. Nonetheless, their main limitations are related to the high initial cost and low productivity.\\ud To cope with these limitations,...

  8. Survey of dust production in pebble bed reactor cores

    Energy Technology Data Exchange (ETDEWEB)

    Cogliati, Joshua J., E-mail: Joshua.Cogliati@inl.gov [Idaho National Laboratory, Reactor Physics Analysis and Design, 2525 N Fremont Ave, Idaho Falls, ID (United States); Ougouag, Abderrafi M., E-mail: Abderrafi.Ougouag@inl.gov [Idaho National Laboratory, Reactor Physics Analysis and Design, 2525 N Fremont Ave, Idaho Falls, ID (United States); Ortensi, Javier, E-mail: Javier.Ortensi@inl.gov [Idaho National Laboratory, Reactor Physics Analysis and Design, 2525 N Fremont Ave, Idaho Falls, ID (United States)

    2011-06-15

    Highlights: > We review potential sources of the graphite dust found in the German pebble bed reactors. > Available literature on graphite wear coefficients in pebble bed core-like conditions is reviewed. > Limited conclusions and remaining open questions are discussed. - Abstract: Graphite dust produced via mechanical wear from the pebbles in a pebble bed reactor is an area of concern for licensing. Both the German pebble bed reactors produced graphite dust that contained activated elements. These activation products constitute an additional source term of radiation and must be taken under consideration during the conduct of accident analysis of the design. This paper discusses the available literature on graphite dust production and measurements in pebble bed reactors. Limited data is available on the graphite dust produced from the AVR and THTR-300 pebble bed reactors. Experiments that have been performed on wear of graphite in pebble-bed-like conditions are reviewed. The calculation of contact forces, which are a key driving mechanism for dust in the reactor, are also included. In addition, prior graphite dust predictions are examined, and future areas of research are identified.

  9. Resin composite repair for implant-supported crowns.

    Science.gov (United States)

    Bonfante, Estevam A; Suzuki, Marcelo; Hirata, Ronaldo; Bonfante, Gerson; Fardin, Vinicius P; Coelho, Paulo G

    2017-08-01

    This study evaluated the reliability of implant-supported crowns repaired with resin composites. Fifty-four titanium abutments were divided in three groups (n = 18 each) to support resin nanoceramic molar crowns, as follows: (LU) (Lava Ultimate, 3M ESPE); LU repaired with either a direct or an indirect resin composite. Samples were subjected to mouth-motion accelerated-life testing in water (n = 18). Cumulative damage with a use stress of 300 N was used to plot Weibull curves for group comparison. Reliability was calculated for a mission of 100,000 cycles at 400 N load. Beta values were 0.83 for LU, 0.31 and 0.27 for LU repaired with Filtek and Ceramage, respectively. Weibull modulus for LU was 9.5 and η = 1047 N, m = 6.85, and η = 1002 N for LU repaired with Ceramage, and m = 4.65 and η = 766 N for LU repaired with Filtek (p material, and detailed fractography is presented. The performance of resin nanoceramic material repaired with an indirect composite was maintained after accelerated-life testing compared to unrepaired controls. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1481-1489, 2017. © 2016 Wiley Periodicals, Inc.

  10. Effect of Ingested Liquids on Color Change of Composite Resins.

    Science.gov (United States)

    Malek Afzali, Beheshteh; Ghasemi, Amir; Mirani, Asrin; Abdolazimi, Zahra; Akbarzade Baghban, Alireza; Kharazifard, Mohammad Javad

    2015-08-01

    Color change of composite restorations is well known to dentists. However, the effect of commonly consumed drinks on discoloration of composite resins has yet to be determined. This study sought to assess the color change of a nanofilled (Premise) and a flowable composite resin (Premise flowable) following simulated consumption of tea, cola, iron drops and multivitamin syrup. Forty disk-shaped specimens (7 mm in diameter and 2 mm thick) were fabricated from each composite resin. The baseline color values were measured according to the CIE L*a*b* system using digital imaging. The specimens of each restorative material were randomly divided into five groups (eight each) according to the storage media namely tea, cola, iron drops, multivitamin syrup or distilled water (control). The specimens were immersed in staining solutions for three hours daily over a 40-day test period. Following this, the color change values (ΔE*) were calculated. For statistical analyses, the color differences were analyzed using two-way ANOVA and Tukey's test (Pcomposite resins (P>0.05). In both composite materials, the difference among the solutions was not significant (P>0.05). Under the tested experimental conditions, both restorative materials were susceptible to discoloration by all four staining solutions. The color change values were not related to the solution or the type of material used.

  11. Fixing of metallic acetates on an anion-exchange resin

    International Nuclear Information System (INIS)

    Brigaudeau-Vaissiere, M.

    1966-06-01

    After giving a brief review of the theoretical principles governing the fixation of anionic complexes of metallic elements on an anion exchange resin, we consider the particular case of uranyl acetate. By plotting the partition curves we have been able to calculate the exchange constants in the resin. By studying the changes in the logarithm of the limiting partition coefficient as a function of the logarithm of the free acetate ion concentration, it has been possible to calculate the dissociation constants for the complexes in solution. The fixation of a large number of metallic acetates has been studied. All the tests have been negative except in the case of mercury. For this reason we have been able to consider the possibility of separating uranium from a certain number of elements. Some of these separations are possible even in the presence of interfering anions such as chlorides which have a greater affinity for the resin than have the acetate ions. In the case of water-ethanol and water-isopropanol mixtures, we have improved the conditions under which copper acetate and mercury acetate may be fixed. This study has enabled us to calculate the dissociation constant for the CuAc 3 - complex in the mixtures water +40% (by weight) isopropanol and water +50% (by weight) isopropanol. It should also make it possible to use separation conditions which could not hitherto be applied in aqueous media. (author) [fr

  12. Phosphorus-modified poly(styrene-co-divinylbenzene)-PAMAM chelating resin for the adsorption of uranium(VI) in aqueous.

    Science.gov (United States)

    Cao, Qiong; Liu, Yaochi; Wang, Chunzhi; Cheng, Jiashun

    2013-12-15

    Polyamidoamine (PAMAM) modified poly(styrene-co-divinylbenzene) absorbents carrying phosphorus functional groups (PS-PAMAM-PPA) were prepared and used as adsorbents for the adsorption of uranium(VI) from aqueous solution. Different generations of PAMAM were used for obtaining different chelating resins, PS-PPA, PS-1.0G PAMAM-PPA, PS-2.0G PAMAM-PPA, PS-3.0G PAMAM-PPA and PS-4.0G PAMAM-PPA. The synthesized resins were characterized by FTIR and XPS. The effects of many physio-chemical properties on metal ion adsorption to adsorbent phase, such as solution pH, kinetic studies, initial uranium concentration, temperature, were investigated using batch method. The results showed that the maximum adsorption capacity (99.89 mg/g) was observed at the pH 5.0 and 25°C with initial U(VI) concentration 100mg/L and adsorbent dose 1g/L. PS-1.0G PAMAM-PPA had the largest adsorption capacity for U(VI) compared with other prepared adsorbents. The adsorption kinetics of U(VI) onto PS-1.0G PAMAM-PPA followed the mechanism of the pseudo-second-order equation, indicating that the chemical adsorption was a rate-limiting step. The calculated thermodynamic parameters (ΔG, ΔH, ΔS) stated that the adsorption of U(VI) onto PS-1.0G PAMAM-PPA were spontaneous, endothermic and feasible. The adsorption isotherms obeyed the Langmuir isotherm models. The desorption studies showed that PS-1.0G PAMAM-PPA could be used repeatedly and adsorption and desorption percentage did not have any noticeable loss after 27 cycles in a fixed bed. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Treatment of alpha active organic liquid scintillator waste with ion exchange resins-column studies

    International Nuclear Information System (INIS)

    Venugopal Chetty, K.; Vaidya, V.N.; Venugopal, V.; Rao, P.R.V.

    2002-01-01

    The distribution ratios and percentage extraction for americium and total alpha due to plutonium and americium were determined using mixture of resins from the simulated alpha active organic liquid scintillator waste solution. Macroporous Bifunctional Phosphinic Acid (MPBPA) resin along with Amberlite IR-120 or AG 50WX8 in the ratios 1 : 1 to 1 : 6 were studied and the percentage extraction of better than 97% and distribution ratio of more than 480 were obtained. The data indicated the usefulness of these resins to remove alpha activity from these organic waste solutions. The column experiments were carried out using the active organic liquid scintillator waste with and without dilution with alcohol, and only alcoholic waste generated in the laboratory during the washing of the used liquid scintillator vials. The column containing either single MPBPA resin or with additional resin bed of Amberlite IR-120 were used for the treatment of the wastes. In the case of alcoholic waste after removal of activity it was reused for rinsing of the used vials. (author)

  14. Effectiveness of Bed Bug Pesticides

    Science.gov (United States)

    Before EPA allows a bed bug claim on a label, the product must be supported by data showing it will kill bed bugs when applied according to the label. Also consider factors such as extent of infestation, site preparation, and insect life stages.

  15. Turning patients over in bed

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000426.htm Turning patients over in bed To use the sharing features on this page, ... Patient The following steps should be followed when turning a patient: If you can, raise the bed to a level that reduces back strain for ...

  16. Biobased Carbon Fibers and High-Performance Thermosetting Resins for Use in U.S. Department of Defense Applications

    Science.gov (United States)

    2012-06-01

    using Archimedes principle and were used to calculate MC. The theory of rubber elasticity was used to calculate MC (3, 38). 113 5.3 Results and...and the polymer density (measured using Archimedes ’ principle ) (2, 18, 19). 6.3 Results and Discussion of Vanillin-Based Thermosetting Resin...Biobased Carbon Fibers and High-Performance Thermosetting Resins for Use in U.S. Department of Defense Applications by John J. La Scala

  17. Use of an Italian pozzolanic cement for the solidification of bead ion exchange resins

    International Nuclear Information System (INIS)

    De Angelis, G.

    1988-05-01

    Granular ion-exchange resins represent a large portion of the medium-active wastes generated at nuclear power stations. The most common practice for their confinement is to mix them with cement paste and cast the mixture in a concrete shell. Such a procedure however does not prove successful in many cases, because of the extreme swelling to which the embedded resin can give rise. This phenomenon has been investigated carefully. In particular, measurements of the swelling pressure have been made together with evaluation of the volume changes of the resin beads due to ion exchange and of the weight increase as a function of relative humidity. The ion exchange capacity, which continues even after incorporation in the cement matrix has also been put into evidence. The conclusion was drawn that a three component diagram (water - dry resin- cement) has to be prepared every time in order to identify the region corresponding to the better formulations. With this in mind the optimum waste loading of 11.5 wt% of dry resin was chosen to incorporate a mixed bed resin (Amberlite IR 120 Na + and IRA 400 Cl - in the weight ratio of 1:1) into an Italian pozzolanic cement (425 type). Several properties of the final waste form have been investigated, ranging from mechanical (crushing strength, tensile strength, flexural strength, ultrasonic pulse velocity, elastic modulus and Poisson ratio), to thermal stability, radiation stability, permeability, leachability and resistance to bacterial attack. Dimensional stability was also measured with the aim of examining the expansion phenomena which can take place in the presence of resin beads. The data obtained are encouraging for future application of the type 425 cement tested in the field of radwastes. An attempt to explain the performance of this binder, based on its intrinsic properties, was also made. (author)

  18. Effect of resin cements and aging on cuspal deflection and fracture resistance of teeth restored with composite resin inlays.

    Science.gov (United States)

    Salaverry, Aurélio; Borges, Gilberto Antonio; Mota, Eduardo Gonçalves; Burnett Júnior, Luiz Henrique; Spohr, Ana Maria

    2013-12-01

    To evaluate the influence of resin cements and aging on cuspal deflection, fracture resistance, and mode of failure of endodontically treated teeth restored with composite resin inlays. Seventy-two maxillary premolars were divided into 6 groups: 1: sound teeth as control (C); 2: preparations without restoration (WR); 3: inlays luted with RelyX ARC (ARC); 4: inlays luted with RelyX Unicem (RLXU); 5: inlays luted with Maxcem Elite (MCE); 6: inlays luted with SeT (ST). Groups 2 to 6 received mesio-occlusal-distal preparations and endodontic treatment. Stone casts were made for groups 3 to 6. Composite resin inlays were built over each cast and luted with the resin cements. A 200-N load was applied on the occlusal aspect and the cuspal deflection was measured using a micrometer before and after 500,000 cycles of fatigue loading (200 N; 500,000 cycles). The specimens were then submitted to an axial load until failure. The median cuspal deflection (µm) and median fracture resistance (N) were calculated and statistically analyzed using Kruskal-Wallis and Mann-Whitney tests (p inlays luted with RelyX ARC maintained cuspal deflection stability and showed higher fracture resistance of the teeth than did inlays luted with the other cements tested.

  19. Influence of fluorescent whitening agent on the fluorescent emission of resin composites.

    Science.gov (United States)

    Park, Min-Young; Lee, Yong-Keun; Lim, Bum-Soon

    2007-06-01

    The objective of this study was to determine the fluorescent emission of experimental resin composites after addition of a fluorescent whitening agent in varied concentrations. The effects of thermocycling and composition of resin matrix on the fluorescent emission were also determined. An experimental light curing resin matrix was made by mixing Bis-GMA, UDMA and TEGDMA in the ratio of 1:1:1 by weight, and silane coated glass filler was added in the ratio of 50 wt.% of resin composite. A fluorescent whitening agent [FWA, 1,4-double-(benzoxazole-group-2-group)naphthalene] was added with the concentration of 0.01-0.1%. To determine the difference by the resin matrix, two resin composites (60 wt.% Bis-GMA or UDMA with 40 wt.% TEGDMA) with the same filler content were made, and the FWA was added. Five specimens of 2mm in thickness were made for each group. Spectral reflectance was measured relative to the illuminant D65 on a reflection spectrophotometer. From the spectral reflectance values, the difference in reflectance (fluorescence spectra) by the inclusion or exclusion of UV component was calculated. After the baseline measurement, thermocycling was performed for 500 and 1000 cycles, and the fluorescent emission was measured again. The concentration of FWA influenced the fluorescent peak heights and areas (presin matrix, but peak height and area were influenced by the resin matrix (presin composites.

  20. Fabrication of detail parts for superconducting magnets by resin transfer molding

    International Nuclear Information System (INIS)

    Behan, M.R.; Hartmann, J.G.

    1993-01-01

    A method is described of fabricating a detail part for a superconducting magnet and also of fabricating a coil winding assembly for a superconducting magnet, comprising the steps of: (a) utilizing engineering specifications for a detail part to produce a master mold part for the detail part, while taking into account a calculated resin shrinkage factor; (b) utilizing the master mold part to fabricate a resin transfer mold for the detail part; (c) placing a preform for the detail part into the resin transfer mold and closing the mold with the preform therein; (d) injecting a two-stage curing resin into the resin transfer mold; (e) heating the resin transfer mold to partially cure the molded detail part; (f) removing the partially cured detail part from the resin transfer mold; (g) fabricating a coil winding assembly, while precisely positioning the partially cured detail part relative to the coil windings to produce a coil winding assembly; (h) placing the coil winding assembly into a curing press, and pressing and heating the coil winding assembly in the curing press, during which the detail part conforms to the coil winding and cures completely to produce a final coil winding assembly for a superconducting magnet

  1. Column adsorption of perchlorate by amine-crosslinked biopolymer based resin and its biological, chemical regeneration properties.

    Science.gov (United States)

    Song, Wen; Xu, Xing; Tan, Xin; Wang, Yan; Ling, Jianya; Gao, Baoyu; Yue, Qinyan

    2015-01-22

    Column adsorption of perchlorate by amine-crosslinked biopolymer based resin was investigated by considering the bed depth, stream flow rate and influent pH. The empty bed contact time (EBCT) increased with the growth of bed depths, meanwhile rising flow rate at constant bed depth (3.4 cm) decreased the breakthrough time. It was observed that perchlorate adsorption capacity was optimum at neutral condition (pH: 6.0, 170.4 mg/g), and decreased at acidic (pH: 3.0, 96.4 mg/g) or alkalic (pH: 12.0, 72.8 mg/g) influents. The predominant strains of the acclimated sludge for resin biological regeneration were the β-subclass of Proteobacteria. Biological regeneration of the saturated amine-crosslinked biopolymer based resin with mixed bacteria have shown its merit with regeneration and biological perchlorate destruction simultaneously, although its regeneration efficiency was only 61.2-84.1% by contrast to chemical regeneration with efficiency more than 95%. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. A study of ion-exchange chromatography in an expanded bed for bovine albumin recovery

    Directory of Open Access Journals (Sweden)

    João Batista Severo Jr.

    2009-04-01

    Full Text Available In the present work, the effect of bed expansion on BSA adsorption on Amberlite IRA 410 ion-exchange resin was studied. The hydrodynamic behavior of an expanded bed adsorption column on effects of the biomolecules and salt addition and temperature were studied to optimize the conditions for BSA recovery on ion-exchange resin. Residence time distribution showed that HEPT, axial dispersion and the Pecletl number increased with temperature and bed height, bed voidage and linear velocity. The binding capacity of the resin increased with bed height. The Amberlite IRA 410 ion-exchange showed an affinity for BSA with a recovery yield of 78.36 % of total protein.No presente trabalho foi estudado o efeito da expansão do leito sobre a adsorção de BSA na resina de troca iônica Amberlite IRA 410. O comportamento hidrodinâmico de uma coluna de adsorção em leito expandido sob efeito da adição de biomoléculas, sal e variação da temperatura também foi estudado para obter as condições ótimas de recuperação da BSA sob a resina de troca iônica. A distribuição do tempo de residência mostrou que a HEPT, a dispersão axial e o número de Pecletl aumentaram com a temperatura, altura do leito, porosidade do leito e velocidade linear. A capacidade de ligação da resina aumentou com a expansão do leito. A resina de troca iônica Amberlite IRA 410 mostrou ter afinidade pela BSA, com uma recuperação de 78,36 % da proteína total.

  3. Foam, Foam-resin composite and method of making a foam-resin composite

    Science.gov (United States)

    Cranston, John A. (Inventor); MacArthur, Doug E. (Inventor)

    1995-01-01

    This invention relates to a foam, a foam-resin composite and a method of making foam-resin composites. The foam set forth in this invention comprises a urethane modified polyisocyanurate derived from an aromatic amino polyol and a polyether polyol. In addition to the polyisocyanurate foam, the composite of this invention further contains a resin layer, wherein the resin may be epoxy, bismaleimide, or phenolic resin. Such resins generally require cure or post-cure temperatures of at least 350.degree. F.

  4. Bolus calculators.

    Science.gov (United States)

    Schmidt, Signe; Nørgaard, Kirsten

    2014-09-01

    Matching meal insulin to carbohydrate intake, blood glucose, and activity level is recommended in type 1 diabetes management. Calculating an appropriate insulin bolus size several times per day is, however, challenging and resource demanding. Accordingly, there is a need for bolus calculators to support patients in insulin treatment decisions. Currently, bolus calculators are available integrated in insulin pumps, as stand-alone devices and in the form of software applications that can be downloaded to, for example, smartphones. Functionality and complexity of bolus calculators vary greatly, and the few handfuls of published bolus calculator studies are heterogeneous with regard to study design, intervention, duration, and outcome measures. Furthermore, many factors unrelated to the specific device affect outcomes from bolus calculator use and therefore bolus calculator study comparisons should be conducted cautiously. Despite these reservations, there seems to be increasing evidence that bolus calculators may improve glycemic control and treatment satisfaction in patients who use the devices actively and as intended. © 2014 Diabetes Technology Society.

  5. An Overview of Atmospheric Fluidized Bed Combustion Systems as Applied to Army Scale Central Heat Plants

    Science.gov (United States)

    1992-11-01

    or burned in a separate fluidizcd bed combustor called a carbon burnup cell. Fuel and Sorbent Feed. To achieve high combustion efficier.cy and maximum...AFBC tecnnology is relatively new, calculating the boiler efficiency of fluidized bed boilers is not as well defined as it is for conventional boilers...paragraphs will highlight some options to improve the combustion efficiency. A carbon burnup cell (CBC) uses a separate fluidized bed operated at a much

  6. Study PWA8 resin for chromatographic uranium concentration

    International Nuclear Information System (INIS)

    Coceancigh, Herman; Ramella, J. L.; Marrero, Julieta; Jiménez Rebagliati, Raúl

    2013-01-01

    For many years nuclear industry have been using resins as filler of chromatographic columns. These methods are specific and give reliable results in different applications, for those reasons are extremely useful as separation process. Currently the nuclear industry is growing and this brings new issues such as the need of reduction of the amount of waste, the optimization of the production process and others that the chromatography could solve with great results. AMBERLITETM PWA8 resin is an anion exchange resin which can be used for the removal of uranium from drinking water. In addition to high exchange capacity, this resin has excellent physical stability and a wide range of pH in which is operational. With the idea of concentrating uranium from wastes solution as main goal we made different experiments to understand the AMBERLITETM PWA8 and obtain the most important characteristics like; pH working range; capacity; activation and elution procedures. These procedures were developed and optimized the capacity was determined using a batch experiment and we obtain that the maximum capacity is 882,5 U ug /resin gr at a pH of 4,2. Following on from these results chromatographic experiments were performed in which both were obtained the percentage of recovery and the concentration factor. The percent recovery (% R) calculated as the percentage ratio between the total mass and the load mass eluted (% R = eluted mass / total mass * 100) was 94% with a concentration factor of 5 times From these results it is intended to concentrate wastes solutions from the fuel cycle processes with two main goals: decreasing volume for storage and for future reusing of the uranium coming from production. (author)

  7. Woodpecker-inspired shock isolation by microgranular bed

    International Nuclear Information System (INIS)

    Yoon, Sang-Hee; Roh, Jin-Eep; Kim, Ki Lyug

    2009-01-01

    This paper presents a woodpecker-inspired shock isolation (SI) using a microgranular bed to protect micromachined electronic devices (MEDs) for high-g military applications where mechanical excitations reach up to tens of thousands of gs and several hundreds of kHz. The shock isolating phenomenon in the microgranular bed within a metal housing, biomimetically inspired from a spongy bone within a skull of the woodpecker, controls unwanted high-frequency mechanical excitations so that their adverse effects on the embedded MEDs are kept within acceptable limit. The microgranular bed composed of close-packed microglass beads reduces the mechanical excitations transmitted to the MEDs through kinetic energy absorption. Two kinds of tests, a laboratory test and a 60 mm air-gun test, have been made. The laboratory test using a vibration exciter up to 25 kHz has demonstrated that the cut-off frequency (2.2-15.8 kHz) and roll-off steepness (-155.0 to -78.7 dB decade -1 ) are inversely proportional to the diameter of the close-packed microglass beads (68-875 μm), whereas the vibration absorptivity (0.23-0.87) is proportional. The 60 mm air-gun test under high-g environments of up to 60 000 g has verified that the woodpecker-inspired SI is superior in improving the shock survivability of the MEDs to the conventional one using hard resin.

  8. Sorption of Pu(IV) from nitric acid by bifunctional anion-exchange resins

    International Nuclear Information System (INIS)

    Bartsch, R.A.; Zhang, Z.Y.; Elshani, S.; Zhao, W.; Jarvinen, G.D.; Barr, M.E.; Marsh, S.F.; Chamberlin, R.M.

    1999-01-01

    Anion exchange is attractive for separating plutonium because the Pu(IV) nitrate complex is very strongly sorbed and few other metal ions form competing anionic nitrate complexes. The major disadvantage of this process has been the unusually slow rate at which the Pu(IV) nitrate complex is sorbed by the resin. The paper summarizes the concept of bifunctional anion-exchange resins, proposed mechanism for Pu(IV) sorption, synthesis of the alkylating agent, calculation of K d values from Pu(IV) sorption results, and conclusions from the study of Pu(IV) sorption from 7M nitric acid by macroporous anion-exchange resins including level of crosslinking, level of alkylation, length of spacer, and bifunctional vs. monofunctional anion-exchange resins

  9. Synthesis, characterization and thermal analysis of urea–formaldehyde/nanoSiO2 resins

    International Nuclear Information System (INIS)

    Roumeli, E.; Papadopoulou, E.; Pavlidou, E.; Vourlias, G.; Bikiaris, D.; Paraskevopoulos, K.M.; Chrissafis, K.

    2012-01-01

    Highlights: ► UF/nanosilica resins have been produced using the minimum cost method. ► The new resins had good dispersion and enhanced properties. ► Nanosilica interacts with polymer chains as was proved by FTIR and DSC. ► Nanosilica does not affect the resin's thermal stability but enhances its mechanical properties. - Abstract: In the present work urea–formaldehyde resins (UF) containing different amounts of SiO 2 nanoparticles were synthesized and studied in depth. All the hybrids were characterized with Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffractometry (XRD), while the dispersion of nanoparticles was studied with scanning electron microscopy with associated energy dispersive X-ray spectrometer (SEM/EDS). It was found that even though silanol groups of SiO 2 can interact with UF resin and form hydrogen bonds, aggregates of SiO 2 nanoparticles can still be formed in UF resin. Their size increases as SiO 2 content is increased. The curing reactions were examined with differential scanning calorimetry (DSC) and it was revealed that curing temperature of UF resin is slightly affected by the addition of nanoparticles. Furthermore, the activation energy of the curing reactions, for every hybrid, was calculated using the Kissinger's method, which implied the existence of interactions between the nanoparticles and the polymer chain. Thermogravimetric analysis (TGA) revealed that SiO 2 nanoparticles do not have an effect in the thermal stability of the resin. From the application of the prepared UF/SiO 2 resins in wood panels it was found that the mechanical properties of the panels, like the internal bond and the modulus of rapture, are enhanced with increasing nanoSiO 2 concentration.

  10. Flexural Strength of Cold and Heat Cure Acrylic Resins Reinforced with Different Materials

    Science.gov (United States)

    Heidari, Bijan; Firouz, Farnaz; Izadi, Alireza; Ahmadvand, Shahbaz

    2015-01-01

    Objectives: Heat-polymerized acrylic resin has been the most commonly used denture base material for over 60 years. However, the mechanical strength of acrylic resin is not adequate for long-term clinical performance of dentures. Consequently, fracture is a common clinical occurrence, which often develops in the midline of the denture base. This study aimed to evaluate the efficacy of cold-cure and heat-cure acrylic resins, reinforced with glass fibers, polyethylene fibers, and metal wire for denture base repair. Materials and Methods: Ninety specimens were prepared and allocated to nine groups. Ten specimens were considered as controls, and 80 were divided into 8 experimental groups. In the experimental groups, the specimens were sectioned into two halves from the middle, and were then divided into two main groups: one group was repaired with heat cure acrylic resin, and the other with cold cure acrylic resin. Each group was divided into 4 subgroups: unreinforced, reinforced with glass fibers, polyethylene fibers, and metal wire. All specimens were subjected to a 3-point bending test, and the flexural strength was calculated. Results: The group repaired with heat cure acrylic resin and reinforced with glass fiber showed the highest flexural strength; however, the group repaired with cold cure acrylic resin and reinforced with polyethylene fibers had the lowest flexural strength. There was no significant difference between the groups repaired with heat cure and cold cure acrylic resins without reinforcement. Conclusion: Repairing denture base with heat cure acrylic resin, reinforced with glass fibers increases the flexural strength of denture base. PMID:26877726

  11. Flexural Strength of Cold and Heat Cure Acrylic Resins Reinforced with Different Materials

    Directory of Open Access Journals (Sweden)

    Bijan Heidari

    2015-10-01

    Full Text Available Objectives: Heat-polymerized acrylic resin has been the most commonly used denture base material for over 60 years. However, the mechanical strength of acrylic resin is not adequate for long-term clinical performance of dentures. Consequently, fracture is a com- mon clinical occurrence, which often occurs in the midline of denture base.This study aimed to evaluate the efficacy of cold cure and heat cure acrylic resins, rein- forced with glass fibers, polyethylene fibers, and metal wire for denture base repair.Materials and Methods: Ninety specimens were prepared and allocated to nine groups. Ten specimens were included in the control group, and 80 were allocated to 8 experi- mental groups. In the experimental groups, the specimens were sectioned into two halves from the middle, and were then divided into two main groups: one group was repaired with heat cure acrylic resin, and the other with cold cure acrylic resin. Each group was di- vided into 4 subgroups: unreinforced, reinforced with glass fibers, polyethylene fibers, and metal wire. All specimens were then subjected to a 3-point bending test, and the flexural strength was calculated.Results: The group repaired with heat cure acrylic resin and reinforced with glass fiber showed the highest flexural strength; however, the group repaired with cold cure acrylic resin and reinforced with polyethylene fibers had the lowest flexural strength. There was no significant difference between the groups repaired with heat cure and cold cure acrylic resins without reinforcement.Conclusion: Repairing denture base with heat cure acrylic resin, reinforced with glass fi- bers increases the flexural strength of denture base.

  12. Synthesis of Hydrophobic, Crosslinkable Resins.

    Science.gov (United States)

    1984-12-01

    Bismaleimides have also been crosslinked with radical initiators to produce brittle networks [4].If a damine is added, chain extension and radical crosslinkinq...are produced during cure.The company also produced a similar phenylene based resin, with pendant nitrile groups which could be crosslinked without the...benzenes and tetra substituted cyclopentadienones [881. g. Preparation of poly 1,4 phenylene by nickel (0> catalysed electropolymerisation 1891. Cont’d

  13. Torsion testing of bed joints

    DEFF Research Database (Denmark)

    Hansen, Klavs Feilberg; Pedersen, Carsten Mørk

    2008-01-01

    be carried out directly in a normal testing machine. The torsion strength is believed to be the most important parameter in out-of-plane resistance of masonry walls subjected to bending about an axis perpendicular to the bed joints. The paper also contains a few test results from bending of small walls about...... an axis perpendicular to the bed joints, which indicate the close connection between these results and results from torsion tests. These characteristics make the torsion strength well suited to act as substitute parameter for the bending strength of masonry about an axis perpendicular to the bed joints....

  14. MEMS Calculator

    Science.gov (United States)

    SRD 166 MEMS Calculator (Web, free access)   This MEMS Calculator determines the following thin film properties from data taken with an optical interferometer or comparable instrument: a) residual strain from fixed-fixed beams, b) strain gradient from cantilevers, c) step heights or thicknesses from step-height test structures, and d) in-plane lengths or deflections. Then, residual stress and stress gradient calculations can be made after an optical vibrometer or comparable instrument is used to obtain Young's modulus from resonating cantilevers or fixed-fixed beams. In addition, wafer bond strength is determined from micro-chevron test structures using a material test machine.

  15. Ion exchange removal of cesium from Hanford tank waste supernates with SuperLigR 644 resin

    International Nuclear Information System (INIS)

    Hassan, N.M.; McCabe, D.J.; King, W.D.; Hamm, L.L.

    2002-01-01

    SuperLig R 644 ion exchange resin is currently being evaluated for cesium ( 137 Cs) removal from radioactive Hanford tank waste supernates as part of the River Protection Project. Testing was performed with actual Hanford tank wastes of widely different compositions using two identical ion exchange columns connected in series each containing approximately 5.5-6.5 ml of SuperLig R 644 resin. The ion exchange columns utilized the same resin material that was eluted between the column tests. This was done to demonstrate the performance of the SuperLig R 644 resin for cesium removal from waste samples of different compositions, determine the loading and elution profiles, and to validate design assumptions for full-scale column performances. Decontaminated product solutions generated at the same operating temperature and constant residence times (bed volumes per hour) exhibited the same chemical compositions as their feed samples. The compositions of eluate solutions were generally as expected with the exception of uranium and total organic carbon, which where concentrated by the resin. Development of a pretreatment method for the SuperLig R 644 resin has been critical to successful column operation with different waste solutions. (author)

  16. Ion exchange resins for water purification : properties and characterisation

    International Nuclear Information System (INIS)

    Gokhale, A.S.; Mathur, P.K.; Venkateswarlu, K.S.

    1987-01-01

    The report is divided into three sections. The first section contains a general introduction to ion exchange resins used in various processes, the second section describes characteristic properties of the polymer materials and the inter relation between them. This will, in turn, be useful to interpret the data obtained from the various tests carried out on the resins in the laboratory. In the third section of the report, are given the details of each method used for a particular test to be carried out on a routine basis. Each method describes the principle involved, the reagents and apparatus used in the experiment, the actual procedure and calculations and recording of the data. 3 refs. (author)

  17. Evaluation of adhesion of reline resins to the thermoplastic denture base resin for non-metal clasp denture.

    Science.gov (United States)

    Kim, Ji Hye; Choe, Han Cheol; Son, Mee Kyoung

    2014-01-01

    This study aimed to evaluate the tensile and transverse bond strength of chairside reline resins (Tokuyama Rebase II, Mild Rebaron LC) to a thermoplastic acrylic resin (Acrytone) used for non metal clasp denture. The results were compared with those of a conventional heat polymerized acrylic resin (Paladent 20) and a thermoplastic polyamide resin (Biotone). The failure sites were examined by scanning electron microscopy to evaluate the mode of failure. As results, the bond strength of reline resins to a thermoplastic acrylic resin was similar to the value of a conventional heat polymerized acrylic resin. However, thermoplastic polyamide resin showed the lowest value. The results of this study indicated that a thermoplastic acrylic resin for non metal clasps denture allows chairside reline and repair. It was also found that the light-polymerized reline resin had better bond strength than the autopolymerizing reline resin in relining for a conventional heat polymerized acrylic resin and a thermoplastic acrylic resin.

  18. Bed Bugs: The Australian Response

    Directory of Open Access Journals (Sweden)

    Richard C. Russell

    2011-04-01

    Full Text Available Australia has experienced a sudden and unexpected resurgence in bed bug infestations from both Cimex lectularius L. and Cimex hemipterus F. A survey in 2006 revealed that infestations had increased across the nation by an average of 4,500% since the start of the decade. In response, a multi-disciplinary approach to combat the rise of this public health pest was implemented and involved the coordinated efforts of several organizations. The key components of the strategy included the introduction of a pest management standard ‘A Code of Practice for the Control of Bed Bug Infestations in Australia’ that defines and promotes ‘best practice’ in bed bug eradication, the development of a policy and procedural guide for accommodation providers, education of stakeholders in best management practices, and research. These strategies continue to evolve with developments that lead to improvements in ‘best practice’ while bed bugs remain problematic in Australia.

  19. Getting Rid of Bed Bugs

    Science.gov (United States)

    ... control is very important whether you are considering hiring a professional or planning to do it yourself. Controlling bed ... control methods, as others may cause serious harm. Hiring a pest management professional is a good option in many cases, but ...

  20. Sea bed mapping and inspection

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    The conference has 24 presentations on the topics: Sea bed mapping, inspection, positioning, hydrography, marine archaeology, remote operation vehicles and computerized simulation technologies, oil field activities and plans, technological experiences and problems. (tk)

  1. Live-bed scour experiments with 45 wing-wall abutments

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana; Volume 39; Issue 5. Live-bed scour experiments with 45° wing-wall ... Keywords. Scour; bridge foundation; abutments; hydraulics; rivers. ... A design equation is proposed for estimating maximum scour depth at 45°wing-wall abutment under live-bed condition. The calculated values of scour ...

  2. Live-bed scour experiments with 45° wing-wall abutments

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana; Volume 39; Issue 5. Live-bed scour experiments with 45° wing-wall abutments ... Keywords. Scour; bridge foundation; abutments; hydraulics; rivers. ... A design equation is proposed for estimating maximum scour depth at 45°wing-wall abutment under live-bed condition. The calculated values of ...

  3. REMOVING AGGRESSIVE CARBON DIOXIDE FROM WATER USING MELAPHYRE BED

    Directory of Open Access Journals (Sweden)

    Magdalena Maria Michel

    2017-09-01

    Full Text Available The experiment was based on filtration of the highly aggressive water through the melaphyre bed. The quartz bed was non-reactive reference material. The aim of this work was to determine the ability of the melaphyre to remove aggressive CO2 during the chemical reaction. It was noted that a decrease of acidity of the filtrate in comparison to the feed and an increase of its alkalinity and pH. It was calculated that until the moment of exhaustion of the de-acidifying properties of the melaphyre, maximum amount of bound CO2 added to the water was 29.7 g CO2/L of the bed, and maximum amount of the aggressive CO2 removed from the water was 33.3 g CO2/L of the bed. Regarding very high content of the aggressive CO2 (116 mg/L average in the feed only 28.76% of this component was subject to transformation into bound and affiliated CO2 in the filtrate. For the melaphyre bed the CO2 loss from the experiment system following from desorption was 7.80% of the total load of CO2 added with the feed. On the quartz bed the loss was slightly lower 4.56%.

  4. Predicting Bed Mobility in a Simple River Channel

    Science.gov (United States)

    Wydzga, M. A.; Legleiter, C.; Dunne, T.

    2007-12-01

    , encompassing a wide range of grain sizes, placed in the bed. Bed state is characterized by measuring the local microtopography, vertical plucking force (used to calculate the degree of grain interlocking), and the bed-parallel force required to roll or slide a grain (used to calculate the grain friction angle). To date these measurements have been made for two flow conditions: a low flow and a 3/4 bankfull flow. Preliminary data show that sedimentological conditions vary greatly from those typically created in laboratory flume studies. For example, coarse grains embedded in and reinforced by fine sediments have significantly higher friction angles than grains in loose beds. During the 3/4 bankfull event, approximately 30% of all tracers were entrained and transported. Areas of both full mobility (all grain sizes become entrained) and partial mobility (some grain sizes become entrained) were measured. Using existing and future data, we plan to develop a calibrated, predictive model of bed mobility based on a range of naturally occurring bed states.

  5. Resin selection criteria for tough composite structures

    Science.gov (United States)

    Chamis, C. C.; Smith, G. T.

    1983-01-01

    Resin selection criteria are derived using a structured methodology consisting of an upward integrated mechanistic theory and its inverse (top-down structured theory). These criteria are expressed in a "criteria selection space" which are used to identify resin bulk properties for improved composite "toughness". The resin selection criteria correlate with a variety of experimental data including laminate strength, elevated temperature effects and impact resistance.

  6. Solidifying power station resins and sludges

    International Nuclear Information System (INIS)

    Willis, A.S.D.; Haigh, C.P.

    1984-01-01

    Radioactive ion exchange resins and sludges arise at nuclear power stations from various operations associated with effluent treatment and liquid waste management. As the result of an intensive development programme, the Central Electricity Generating Board (CEGB) has designed a process to convert power station resins and sludges into a shielded, packaged solid monolithic form suitable for final disposal. Research and development, the generic CEGB sludge/resin conditioning plant and the CEGB Active Waste Project are described. (U.K.)

  7. Volumetric polymerization shrinkage of contemporary composite resins

    OpenAIRE

    Nagem Filho, Halim; Nagem, Haline Drumond; Francisconi, Paulo Afonso Silveira; Franco, Eduardo Batista; Mondelli, Rafael Francisco Lia; Coutinho, Kennedy Queiroz

    2007-01-01

    The polymerization shrinkage of composite resins may affect negatively the clinical outcome of the restoration. Extensive research has been carried out to develop new formulations of composite resins in order to provide good handling characteristics and some dimensional stability during polymerization. The purpose of this study was to analyze, in vitro, the magnitude of the volumetric polymerization shrinkage of 7 contemporary composite resins (Definite, Suprafill, SureFil, Filtek Z250, Fill ...

  8. Porous Ceramic Spheres from Ion Exchange Resin

    Science.gov (United States)

    Dynys, Fred

    2005-01-01

    A commercial cation ion exchange resin, cross-linked polystyrene, has been successfully used as a template to fabricate 20 to 50 micron porous ceramic spheres. Ion exchange resins have dual template capabilities. Pore architecture of the ceramic spheres can be altered by changing the template pattern. Templating can be achieved by utilizing the internal porous structure or the external surface of the resin beads. Synthesis methods and chemical/physical characteristics of the ceramic spheres will be reported.

  9. Parameters estimation for amino acids adsorption in a fixed bed by moment analysis

    Directory of Open Access Journals (Sweden)

    M.A. Cremasco

    2001-06-01

    Full Text Available Equilibrium constant and mass transfer parameters are needed for the study of amino acid separation in any process involving adsorption in fixed beds. The adsorption constants, effective diffusion coefficients, and axial dispersion coefficients for two amino acids, L-phenylalanine (Phe and L-tyrosine (Tyr, are determined from a series of pulse tests in a fixed bed packed with PVP (poly-4-vinylpyridine resin. Total bed voidage at different flow rates is estimated from NaCl pulse test data. The effective pore diffusivities of Phe, Tyr, and NaCl are estimated from moment analysis of pulse data. A detailed rate model is then solved numerically and adsorption constants, effective diffusion coefficients, axial dispersion coefficients are determined by moment analysis and compared with the pulse data. The advantage of this method is that the effective intraparticle diffusivities can be determined without the influence of extracolumn dispersion or intracolumn axial dispersion effects.

  10. Bond strength of resin-resin interfaces contaminated with saliva and submitted to different surface treatments

    OpenAIRE

    Furuse, Adilson Yoshio; Cunha, Leonardo Fernandes da; Benetti, Ana Raquel; Mondelli, José

    2007-01-01

    The purpose of this study was to investigate the effect of different surface treatments on shear bond strength of saliva-contaminated resin-resin interfaces. Flat resin surfaces were fabricated. In the control group, no contamination or surface treatment was performed. The resin surfaces of the experimental groups were contaminated with saliva and air-dried, and then submitted to: (G1) rinsing with water and drying; (G2) application of an adhesive system; (G3) rinsing and drying, abrasion wit...

  11. Operating characteristics of rotating beds

    Energy Technology Data Exchange (ETDEWEB)

    Keyvani, M.; Gardner, N.C.

    1988-01-01

    Vapor-liquid contacting in high gravitational fields offers prospects for significant reductions in the physical size, capital, and operating costs of packed towers. Pressure drops, power requirements, mass transfer coefficients and liquid residence time distributions are reported for a rotating bed separator. The beds studied were rigid, foamed aluminum, with specific surface areas ranging from 650 to 3000 m{sup 2}/m{sup 2}. Gravitational fields were varied from 50 to 300g.

  12. Novel silica-based ion exchange resin

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-11-01

    Eichrom`s highly successful Diphonixo resin resembles a conventional ion exchange resin in its use of sulfonic acid ligands on a styrene- divinylbenzene matrix. Diphonix resin exhibits rapid exchange kinetics that allow economical operation of ion exchange systems. Unlike conventional resins, Diphonix resin contains chelating ligands that are diphosphonic acid groups that recognize and remove the targeted metals and reject the more common elements such as sodium, calcium and magnesium. This latter property makes Diphonix ideal for many industrial scale applications, including those involving waste treatment. For treatment of low-level, transuranic (TRU) and high- level radioactive wastes, Diphonix`s polystyrene backbone hinders its application due to radiolytic stability of the carbon-hydrogen bonds and lack of compatibility with expected vitrification schemes. Polystyrene-based Diphonix is approximately 60% carbon- hydrogen. In response to an identified need within the Department of Energy for a resin with the positive attributes of Diphonix that also exhibits greater radiolytic stability and final waste form compatibility, Eichrom has successfully developed a new, silica-based resin version of Diphonix. Target application for this new resin is for use in environmental restoration and waste management situations involving the processing of low-level, transuranic and high-level radioactive wastes. The resin can also be used for processing liquid mixed waste (waste that contains low level radioactivity and hazardous constituents) including mixed wastes contaminated with organic compounds. Silica-based Diphonix is only 10% carbon-hydrogen, with the bulk of the matrix silica.

  13. Microbiological study of water-softener resins.

    Science.gov (United States)

    Stamm, J M; Engelhard, W E; Parsons, J E

    1969-09-01

    Microbial identification using effluents backflushed from exhausted urban and rural tank resins and cleaned resins containing the sulfonated copolymer of styrene and divinylbenzene (SDB) were completed, along with microbial assessment of the concentrated stock salt brine. Forty-four different bacterial and fungal genera were identified. Extensive biochemical and animal virulence tests completed on one of the six bacterial salt brine isolates indicated a pathogenic staphylococcal strain. The retention of Staphylococcus aureus, a Flavobacterium sp, and Escherichia coli B bacteriophage was demonstrated both by using the nonexhausted sodium-regenerated resin and by using the same resin exchanged with different mono-, di-, and trivalent cations. Effluent counts completed after bacterial seepage through the resins indicated the Pb(++) exchanged resin removed 55% of the bacteria; Na(+), Fe(++), and Al(+++) removed 31 to 36% and Ca(++) and Cu(++) removed about 10 to 15%. Seventy per cent or more of the bacteriophage was removed by Fe(++), Cu(++), and Al(+++), whereas the Ca(++) and Na(++) cations removed 25 to 31%. Over a 77-day period, nonsterile tap water was passed through bacterial seeded and uninoculated SDB (Na) resin columns. Effluent and resin elution counts demonstrated the growth and survival of 2 different bacteria per column. Increased bacterial retention, survival, and multiplication occurred concomitantly with accumulation of organic and inorganic materials and the Ca(++) and Mg(++) cations from the tap water. Furthermore, microbial elution from resin particles taken from column depths of 1, 8, and 16 cm indicated a bacterial diminution with increasing depths.

  14. Heat-cured Acrylic Resin versus Light-activated Resin: A Patient ...

    African Journals Online (AJOL)

    Context: Although light-activated resins (Eclipse) have been reported to possess superior physical and mechanical properties compared with the heat-cured acrylic resins (Lucitone-199), a few studies have compared overdentures with a locator attachment constructed from heat-cured acrylic resins with those constructed ...

  15. Determination of the effective anticandidal concentration of denture cleanser tablets on some denture base resins

    Directory of Open Access Journals (Sweden)

    Yeliz Hayran

    2018-01-01

    Full Text Available Abstract Objective Although the effectiveness of chemical cleansing against Candida albicans biofilm has been shown, the effective concentration of denture cleanser tablets has not been studied. The aim of this study was to assess the effect of three denture materials against Candida albicans biofilm and to determine effective concentrations of denture cleanser tablets. Material and methods The surface-roughness of Acron-hi™, QC-20™ and Deflex™ (n=45 per resin resins was standardized by using a profilometer and their contact angle or surface free energy was calculated. C. albicans biofilm was formed on all three resins and were treated with Polident 3 min™, Corega™ and Fittydent™ cleanser solutions at various concentrations and both resin-biofilm and cleanser-biofilm interest were determined by using a MTT protocol according to the European Committee on Antimicrobial Susceptibility Testing's antifungal susceptibility testing (AFST-EUCAST. Scanning electron microscopy was used to compare the efficacy of different resin materials against C. albicans biofilm. Anticandidal activity and surface free energy statistical parameters were calculated by using 3-way and 1-way ANOVA, respectively (p<0.05. Results Polident 3 min™ and Corega™ tablets significantly inhibited (p<0.05 the proliferation of C. albicans against all denture resins at 27-37 mg/mL. Scanning electron microscopy results indicated that there was no significant difference among resin specimens regarding biofilm formation on dentures. We failed to find a significant relationship between surface free energy and the anticandidal effect of resin types. However, the polarity value of the resins was statistically associated with their anticandidal activity. Conclusions The polarity of the resins, the concentrations of tablets and the chemical content of the cleanser may directly affect C. albicans biofilm formations. Polident 3 min™ and Corega™ tablets should be suggested for

  16. New system applying image processor to automatically separate cation exchange resin and anion exchange resin for condensate demineralizer

    International Nuclear Information System (INIS)

    Adachi, Tsuneyasu; Nagao, Nobuaki; Yoshimori, Yasuhide; Inoue, Takashi; Yoda, Shuji

    2014-01-01

    In PWR plant, condensate demineralizer is equipped to remove corrosive ion in condensate water. Mixed bed packing cation exchange resin (CER) and anion exchange resin (AER) is generally applied, and these are regenerated after separation to each layer periodically. Since the AER particle is slightly lighter than the CER particle, the AER layer is brought up onto the CER layer by feeding water upward from the bottom of column (backwashing). The separation performance is affected by flow rate and temperature of water for backwashing, so normally operators set the proper condition parameters regarding separation manually every time for regeneration. The authors have developed the new separation system applying CCD camera and image processor. The system is comprised of CCD camera, LED lamp, image processor, controller, flow control valves and background color panel. Blue color of the panel, which is corresponding to the complementary color against both ivory color of AER and brown color of CER, is key to secure the system precision. At first the color image of the CER via the CCD camera is digitized and memorized by the image processor. The color of CER in the field of vision of the camera is scanned by the image processor, and the position where the maximum difference of digitized color index is indicated is judged as the interface. The detected interface is able to make the accordance with the set point by adjusting the flow rate of backwashing. By adopting the blue background panel, it is also possible to draw the AER out of the column since detecting the interface of the CER clearly. The system has provided the reduction of instability factor concerning separation of resin during regeneration process. The system has been adopted in two PWR plants in Japan, it has been demonstrating its stable and precise performance. (author)

  17. Resin-based luting agents and color stability of bonded ceramic veneers.

    Science.gov (United States)

    Almeida, Júlia R; Schmitt, Gabriela U; Kaizer, Marina R; Boscato, Noéli; Moraes, Rafael R

    2015-08-01

    The type of resin-based luting agent might influence the color stability of ceramic veneers. The purpose of this study was to investigate the effects of resin-based agents and aging on the color stability of ceramic veneers bonded to enamel. Ceramic disks were cemented to bovine enamel disks with 4 resin-based luting agents (n=10): dual-polymerizing cement (RelyX ARC), light-polymerizing cement (RelyX Veneer), flowable composite resin (Filtek Z350 Flow), or composite resin preheated for 30 minutes at 60°C (Filtek Z350 XT). CIE L*, a*, and b* color coordinates were measured 24 hours after cementation (baseline) with a color spectrophotometer and reevaluated after 10,000 and 20,000 thermal cycles. Color variation was calculated by using CIELab (ΔE*(ab)) and CIEDE2000 (ΔE00) methods. Then 95% confidence intervals were calculated for color variation means between baseline and 10,000 thermal cycles and between 10,000 and 20,000 thermal cycles. The 95% confidence intervals were also calculated for the means of individual color coordinates (L*, a*, and b*). The dual-polymerizing cement had the highest color variation among all luting agents. No significant differences were found in color variation among the light-polymerizing materials. All agents showed ΔE*(ab)>3.46 and ΔE00>2.25 after 20,000 thermal cycles. Variations in L*, a*, and b* coordinates were material dependent. The dual-polymerizing agent was yellowish and reddish after aging. The dual-polymerizing cement had higher color variation than the light-polymerized materials when used for bonding ceramic veneers to enamel. Flowable and preheated composite resins had similar color stability to that of light-polymerizing resin-based cement. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  18. Mid-infrared reflectance of silicone resin coating on metal substrates: Effect of polymeric binders' absorption

    Science.gov (United States)

    Ho, Wen-Dar; Ma, Chen-Chi M.

    1997-04-01

    This study examines the infrared reflectance of polymeric coatings of silicone resin, silicone modified alkyd resin, and alkyd resin on aluminum substrates. The Kubelka-Munk's two constants theory is applied to calculate the reflectance while considering the surface reflection. An integrating sphere, infrared spectroradiometer and blackbody source are utilized as the measurement systems. The extinction coefficients are determined and used to calculate the reflectances of coatings on aluminum. Coefficients in the mid-infrared region display the quantitative difference between the polymers' structure. Silicone content enhances the absorptance of the coating in the mid-IR region. The coefficients of miscible silicone resin/alkyd resin blends are determined as well. Comparing the measured and calculated reflectances reveals that the discrepancies in thinner coatings or at the IR transparent wavelength are higher and around 0.1. Such a discrepancy is owing to the polymers' non-scattering with absorption properties which affect the validity of the values involving internal reflectances considered in the model. The internal reflectance can be assigned a negligible value in the high absorption region and is also a variable depending on thickness and transparency.

  19. Study of reactivity of fluidized bed nuclear reactor

    International Nuclear Information System (INIS)

    Rammsy, J.E.M.

    1985-01-01

    The reactor physics calculations of a 19 module Fluidized Bed Nuclear Reactor using Leopard and Odog codes are performed. The behaviour of the reactor was studied by calculating the reactivity of the reactor as a function of the parameters governing the operational and accidental conditions of the reactor. The effects of temperature, pressure, and vapor generation in the core on the reactivity are calculated. Also the start up behaviour of the reactor is analyzed. For the purpose of the study of a prototype research reactor, the calculations on a one module reactor have been performed. (Author) [pt

  20. Comparison of Cashew Nut Shell Liquid (CNS ) Resin with ...

    African Journals Online (AJOL)

    synthetic) resin. Compressive and tensile strength tests conducted proved that composites developed with cashew nut shell liquid (CNSL) resin were comparable to those developed with polyester resin. In the results, CNSL has an ultimate ...

  1. Production of fungal volatile organic compounds in bedding materials

    Directory of Open Access Journals (Sweden)

    S. LAPPALAINEN

    2008-12-01

    Full Text Available The high relative humidity of the air and many potential growth media, such as bedding materials, hay and grains in the horse stable, for example, provide suitable conditions for fungal growth. Metabolic activity of four common agricultural fungi incubated in peat and wood shavings at 25°C and 4°C was characterized in this study using previously specified volatile metabolites of micro-organisms and CO 2 production as indicators. The volatile organic compounds were collected into Tenax resin and analysed by gas chromatography. Several microbial volatile organic compounds (MVOCs, e.g. 1-butanol, 2-hexanone, 2-heptanone, 3-octanone, 1-octen-3-ol and 1-octanol were detected in laboratory experiments; however, these accounted for only 0.08-1.5% of total volatile organic com-pounds (TVOCs. Emission rates of MVOCs were 0.001-0.176 mg/kg of bedding materials per hour. Despite some limitations of the analytical method, certain individual MVOCs, 2-hexanone, 2-hep-tanone and 3-octanone, were also detected in concentrations of less than 4.6 mg/m 3 (0.07-0.31% of TVOC in a horse stable where peat and shavings were used as bedding materials. MVOC emission rate was estimated to be 0.2-2.0 mg/kg ´ h -1 from bedding materials in the stable, being about ten times higher than the rates found in the laboratory experiments. Some compounds, e.g. 3-octanone and 1-octen-3-ol, can be assumed to originate mainly from microbial metabolisms.;

  2. The effect of fiber placement or flowable resin lining on microleakage in Class II adhesive restorations.

    Science.gov (United States)

    Belli, Sema; Orucoglu, Hasan; Yildirim, Cihan; Eskitascioglu, Gürcan

    2007-04-01

    The aim of this in vitro study was to evaluate the effect of two fibers (polyethylene or glass) and a flowable resin liner on microleakage in Class II adhesive restorations. Class II adhesive cavities were prepared on mesial and distal surfaces of 40 extracted sound human molars. The cavity margins were below or above the CEJ. The teeth were randomly divided into four groups according to the restoration technique: group 1: restored with a resin composite (AP-X, Kuraray) in bulk after SE Bond (Kuraray) treatment; group 2: flowable resin liner (Protect Liner F, Kuraray) was used before composite restoration; in group 3, a polyethylene fiber (Ribbond) and in group 4, a glass fiber (everStick NET, StickTech) was placed into the bed of flowable resin before composite restoration. Samples were finished, stored in distilled water for 7 days at room temperature, and then thermocycled for 300 cycles between 5 degrees C and 55 degrees C. After sealing the apices, the teeth were varnished within 1 mm of the margins and placed in 0.5% basic fuchsin dye for 24 h at 37 degrees C. After rinsing, the teeth were sectioned longitudinally through the restorations and microleakage was evaluated with a stereomicroscope. Marginal penetration was scored on a 0 to 4 scale, and the data were statistically analyzed using Kruskal-Wallis and the Mann-Whitney U-test. Flowable resin, everStick NET, and Ribbond THM used in combination with flowable resin significantly reduced leakage at occlusal margins in cavities with enamel margins (p 0.05). Use of flowable composite alone or in combination with polyethylene or glass fibers reduces occlusal leakage in Class II adhesive cavities with enamel margins.

  3. Resin composite for sealing and its use in a solar cell. Fushiyo jushi soseibutsu oyobi sore wo mochiita taiyo denchi

    Energy Technology Data Exchange (ETDEWEB)

    Toma, H.; Mimura, T.; Takehara, N.

    1994-01-28

    This invention presents resin composites for sealing of a solar cell composed of a hardening resin and a thermoplastic resin which has a number average molecular weight larger than that of the hardening resin and is soluble in the hardening resin, and the invention affords a solar cell to endure a long-term stable operation and to give a good performance. The hardening resin includes unsaturated polyester resin, phenolic resin, alkyd resin, unsaturated acrylic resin, epoxy resin, polyurethane resin, melamine resin, diallyl phthalate resin, their oligomers and their modifications. The thermoplastic resin includes saturated polyester resin, phenolic resin, acrylic resin, styrene resin, epoxy resin, polyurethane resin, polyvinyl acetate resin, polyvinyl chloride resin, polyvinyl alcohol resin, polyacetal resin, their modifications and their copolymer resin. 2 figs., 3 tabs.

  4. Biomass gasification with air in a fluidized bed: Effect of the in-bed use of dolomite under different operation conditions

    Energy Technology Data Exchange (ETDEWEB)

    Gil, J.; Caballero, M.A.; Martin, J.A.; Aznar, M.P.; Corella, J.

    1999-11-01

    The performance of a biomass gasifier, fluidized-bed type, is improved by in-bed use of calcined dolomite. Tar contents in the raw flue gas below 1 g/m{sub n}{sup 3} are obtained by using a bed with a percentage between 15 and 30 wt% of dolomite (the rest being silica sand). The work is carried out at small pilot-plant scale (10 kg of biomass/h) with equivalence ratios (ER) between 0.20 and 0.35 and temperatures of 800--840 C in the gasifier bed. To replace the eroded and elutriated dolomite (from the gasifier bed), an amount of dolomite (0.40--0.63 mm) is continuously fed, mixed with the biomass at 3 wt%. When the results obtained with in-bed dolomite are compared to the ones gained in a gasifier bed without dolomite, change of the following variables is reported: gas composition and its corresponding heating value, gas and char yields, apparent thermal efficiency, and tar contents. Once the usefulness of the in-bed use of dolomite is established, three main operation variables (ER and temperature of the gasifier bed and freeboard) are studied in the improved gasifier. Carryover of solids from the gasifier also increases when calcined dolomite is used because of its softness. Elutriation rate constants are calculated for several operational parameters.

  5. Curing kinetics of alkyd/melamine resin mixtures

    OpenAIRE

    Jovičić Mirjana C.; Radičević Radmila Ž.

    2009-01-01

    Alkyd resins are the most popular and useful synthetic resins applied as the binder in protective coatings. Frequently they are not used alone but are modified with other synthetic resins in the manufacture of the coatings. An alkyd/melamine resin mixture is the usual composition for the preparation of coating called 'baking enamel' and it is cured through functional groups of resins at high temperatures. In this paper, curing kinetics of alkyd resins based on castor oil and dehydrated castor...

  6. Input to Resin Column Structural Analysis if Autocatalytic Resin Reaction Occurs in HB-Line Phase II

    Energy Technology Data Exchange (ETDEWEB)

    Hallman, D.F.

    2001-07-10

    Solutions of plutonium in nitric acid are purified and concentrated using anion resin prior to precipitation. There have been instances of resin column explosions caused by autocatalytic reactions of anion resins in nitric acid within the DOE complex

  7. Gold Loading on Ion Exchange Resins in Non-Ammoniacal Resin-Solution Systems

    Directory of Open Access Journals (Sweden)

    Abrar Muslim

    2010-12-01

    Full Text Available The loading of gold using strong base anion exchange resin in non-ammoniac resin-solution (NARS systems has been studied. The loading of gold onto ion exchange resins is affected by polythionate concentration, and trithionate can be used as the baseline in the system. The results also show that resin capacity on gold loading increases due to the increase in the equilibrium thiosulfate concentration in the NARS system. Gold loading performances show the need of optimization the equilibrium concentrations of thiosulfate in the NARS system. Keywords: equilibrium, gold loading, resin capacity, thiosulfate, trithionate

  8. Polyimide Resins Resist Extreme Temperatures

    Science.gov (United States)

    2009-01-01

    Spacecraft and aerospace engines share a common threat: high temperature. The temperatures experienced during atmospheric reentry can reach over 2,000 F, and the temperatures in rocket engines can reach well over 5,000 F. To combat the high temperatures in aerospace applications, Dr. Ruth Pater of Langley Research Center developed RP-46, a polyimide resin capable of withstanding the most brutal temperatures. The composite material can push the service temperature to the limits of organic materials. Designed as an environmentally friendly alternative to other high-temperature resins, the RP-46 polyimide resin system was awarded a 1992 "R&D 100" award, named a "2001 NASA Technology of the Year," and later, due to its success as a spinoff technology, "2004 NASA Commercial Invention of the Year." The technology s commercial success also led to its winning the Langley s "Paul F. Holloway Technology Transfer Award" as well as "Richard T. Whitcom Aerospace Technology Transfer Award" both for 2004. RP-46 is relatively inexpensive and it can be readily processed for use as an adhesive, composite, resin molding, coating, foam, or film. Its composite materials can be used in temperatures ranging from minus 150 F to 2,300 F. No other organic materials are known to be capable of such wide range and extreme high-temperature applications. In addition to answering the call for environmentally conscious high-temperature materials, RP-46 provides a slew of additional advantages: It is extremely lightweight (less than half the weight of aluminum), chemical and moisture resistant, strong, and flexible. Pater also developed a similar technology, RP-50, using many of the same methods she used with RP-46, and very similar in composition to RP-46 in terms of its thermal capacity and chemical construction, but it has different applications, as this material is a coating as opposed to a buildable composite. A NASA license for use of this material outside of the Space Agency as well as

  9. The influence of powder liquid ratio on the flexural strength of fibre reinforced acrylic resin material.

    Science.gov (United States)

    Geerts, G A V M; du Rand, M

    2009-04-01

    Often the powder liquid (P/L) ratio of polymethyl methacrylate (PMMA) resins is changed to modify the handling properties of the material. While it is known that this may influence the mechanical properties of unreinforced PMMA resin, little is known about its effect on fibre reinforced resin. The purpose of this study was to determine how different P/L ratios influence the flexural strength (FS) of a glass fibre reinforced autopolymerizing PMMA resin used for fabricating fixed partial dentures. Two main groups of PMMA resin, 1 unreinforced and 1 reinforced with glass fibre, had 3 subgroups (n=21) each representing a different P/L ratio. The manufacturer's recommended ratio served as control. The specimens were prepared for a 3-point bending test. Using a universal testing machine, maximum force was recorded and the FS was calculated. Median FS values were compared by means of non-parametric analysis of variance (Kruskal-Wallis). A p-value of less than 0.05 was considered significant. FS values of all reinforced subgroups were significantly higher than the values of the unreinforced subgroups (p0.05). Within the reinforced group there was a significant difference between the control group, which had a higher median FS value than the two other subgroups (presin with glass fibre, it is important to use the recommended P/L ratio. For unreinforced PMMA resin the P/L ratio can be changed within limits without adverse effects on the FS.

  10. Radiopacity of Methacrylate and Silorane Composite Resins Using a Digital Radiographic System.

    Science.gov (United States)

    Firoozmand, Leily Macedo; Cordeiro, Mariana Gonçalves; Da Silva, Marcos André Dos Santos; De Jesus Tavarez, Rudys Rodolfo; Matos Maia Filho, Etevaldo

    The aim of this study was to evaluate the radiopacity of silorane and methacrylate resin composites, comparing them to the enamel, dentin, and aluminum penetrometer using a digital image. From six resin composites (Filtek ™ P90, Filtek Z350, Filtek Z350 XT flow, Tetric Ceram, TPH Spectrum, and SureFil SDR flow) cylindrical disks (5 × 1 mm) were made and radiographed by a digital method, together with a 15-step aluminum step-wedge and a 1 mm slice of human tooth. The degree of radiopacity of each image was quantified using digital image processing. The mean values of the shades of gray of the tested materials were measured and the equivalent width of aluminum was calculated for each resin. The results of our work yielded the following radiopacity values, given here in descending order: Tetric Ceram > TPH > SDR > Z350 > Z350 flow > P90 > enamel > dentin. The radiopacity of the materials was different both for the enamel and for the dentin, except for resin P90, which was no different than enamel. In conclusion, silorane-based resin exhibited a radiopacity higher than dentin and closest to the enamel; a large portion of the methacrylate-based flow and conventional resins demonstrated greater radiopacity in comparison to dentin and enamel.

  11. Radiopacity of Methacrylate and Silorane Composite Resins Using a Digital Radiographic System

    Directory of Open Access Journals (Sweden)

    Leily Macedo Firoozmand

    2016-01-01

    Full Text Available The aim of this study was to evaluate the radiopacity of silorane and methacrylate resin composites, comparing them to the enamel, dentin, and aluminum penetrometer using a digital image. From six resin composites (Filtek™ P90, Filtek Z350, Filtek Z350 XT flow, Tetric Ceram, TPH Spectrum, and SureFil SDR flow cylindrical disks (5 × 1 mm were made and radiographed by a digital method, together with a 15-step aluminum step-wedge and a 1 mm slice of human tooth. The degree of radiopacity of each image was quantified using digital image processing. The mean values of the shades of gray of the tested materials were measured and the equivalent width of aluminum was calculated for each resin. The results of our work yielded the following radiopacity values, given here in descending order: Tetric Ceram > TPH > SDR > Z350 > Z350 flow > P90 > enamel > dentin. The radiopacity of the materials was different both for the enamel and for the dentin, except for resin P90, which was no different than enamel. In conclusion, silorane-based resin exhibited a radiopacity higher than dentin and closest to the enamel; a large portion of the methacrylate-based flow and conventional resins demonstrated greater radiopacity in comparison to dentin and enamel.

  12. Moisture diffusivity in structure of random fractal fiber bed

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Fanglong, E-mail: zhufanglong_168@163.com [College of Textile, Zhongyuan University of Technology, Zhengzhou City (China); The Chinese People' s Armed Police Forces Academy, Langfan City (China); Zhou, Yu; Feng, Qianqian [College of Textile, Zhongyuan University of Technology, Zhengzhou City (China); Xia, Dehong [School of Mechanical Engineering, University of Science and Technology, Beijing (China)

    2013-11-08

    A theoretical expression related to effective moisture diffusivity to random fiber bed is derived by using fractal theory and considering both parallel and perpendicular channels to diffusion flow direction. In this Letter, macroporous structure of hydrophobic nonwoven material is investigated, and Knudsen diffusion and surface diffusion are neglected. The effective moisture diffusivity predicted by the present fractal model are compared with water vapor transfer rate (WVTR) experiment data and calculated values obtained from other theoretical models. This verifies the validity of the present fractal diffusivity of fibrous structural beds.

  13. REMOVING AGGRESSIVE CARBON DIOXIDE FROM WATER USING MELAPHYRE BED

    OpenAIRE

    Magdalena Maria Michel; Tadeusz Siwiec; Lidia Reczek; Celina Duda

    2017-01-01

    The experiment was based on filtration of the highly aggressive water through the melaphyre bed. The quartz bed was non-reactive reference material. The aim of this work was to determine the ability of the melaphyre to remove aggressive CO2 during the chemical reaction. It was noted that a decrease of acidity of the filtrate in comparison to the feed and an increase of its alkalinity and pH. It was calculated that until the moment of exhaustion of the de-acidifying properties of the melaphyre...

  14. Moisture diffusivity in structure of random fractal fiber bed

    International Nuclear Information System (INIS)

    Zhu, Fanglong; Zhou, Yu; Feng, Qianqian; Xia, Dehong

    2013-01-01

    A theoretical expression related to effective moisture diffusivity to random fiber bed is derived by using fractal theory and considering both parallel and perpendicular channels to diffusion flow direction. In this Letter, macroporous structure of hydrophobic nonwoven material is investigated, and Knudsen diffusion and surface diffusion are neglected. The effective moisture diffusivity predicted by the present fractal model are compared with water vapor transfer rate (WVTR) experiment data and calculated values obtained from other theoretical models. This verifies the validity of the present fractal diffusivity of fibrous structural beds.

  15. Efficiency of lead removal from drinking water using cationic resin Purolite

    Directory of Open Access Journals (Sweden)

    Ashour Mohammad Merganpour

    2015-01-01

    Full Text Available Background: Today, issues such as water shortage, difficulties and costs related to supplying safe water, and anomalous concentrations of heavy metals in groundwater and surface water resources, doubled the necessity of access to technical methods on removing these pollutants from water resources. Methods: In this lab study, cationic resin Purolite S-930 (with co-polymer styrene di-vinyl benzene structure was used for lead removal from drinking water containing up to 22 μg/L. Using statistical analysis and designing a full factorial experiment are the most important effective parameters on lead removal obtained through ion exchange process. Results: Analysis of response and interaction parameters of ion exchange showed that the resin column height has maximum and pH value has minimum effect on the efficiency of lead removal from aquatic environment. Trinary interaction of “effective size, flow rate, resin column high” has the most important for lead removal efficiency in this system. So the maximum efficiency was obtained at the mesh = 40, bed height =1.6 meter, and pH= 6.5. At the best operation conditions, ability to remove 95.42% of lead concentration can be achieved. Conclusion: Using the resin Purolite S-930 during 21-day service with 91.12% of mean lead removal ratio from drinking water is an economic and technical feasibility.

  16. Particle flow of ceramic breeder pebble beds in bi-axial compression experiments

    International Nuclear Information System (INIS)

    Hermsmeyer, S.; Reimann, J.

    2002-01-01

    Pebble beds of Tritium breeding ceramic material are investigated within the framework of developing solid breeder blankets for future nuclear fusion power plants. For the thermo-mechanical characterisation of such pebble beds, bed compression experiments are the standard tools. New bi-axial compression experiments on 20 and 30 mm high pebble beds show pebble flow effects much more pronounced than in previous 10 mm beds. Owing to the greater bed height, conditions are reached where the bed fails in cross direction and unhindered flow of the pebbles occurs. The paper presents measurements for the orthosilicate and metatitanate breeder materials that are envisaged to be used in a solid breeder blanket. The data are compared with calculations made with a Drucker-Prager soil model within the finite-element code ABAQUS, calibrated with data from other experiments. It is investigated empirically whether internal bed friction angles can be determined from pebble beds of the considered heights, which would simplify, and broaden the data base for, the calibration of the Drucker-Prager pebble bed models

  17. Effect of siloxane quantity and ph of silane coupling agents and contact angle of resin bonding agent on bond durability of resin cements to machinable ceramic.

    Science.gov (United States)

    Meng, Xiangfeng; Yoshida, Keiichi; Taira, Yohsuke; Kamada, Kohji; Luo, Xiaoping

    2011-02-01

    The aim of this study was to measure siloxane quantity, pH value, and resin wettability on ceramics silanized by five silane coupling agents, and to test the correlation of these parameters of silane coupling agents with bond durability between a machinable glass ceramic and resin cements. 1.5-mm-thick ceramic plates (ProCAD, Ivoclar Vivadent) were polished, cleaned, and bonded with ten combinations of five silane coupling agents (Monobond S [Ivoclar Vivadent], Rely X Ceramic Primer [3M], Clearfil Ceramic Primer [Kuraray], GC Ceramic Primer [GC], Porcelain Liner M [Sun Medical]) and two dual-curing resin cements (VariolinkII [VLII, Ivoclar Vivadent], Linkmax HV [LMHV, GC]). Their microshear bond strength was measured after 0, 10,000, and 30,000 thermal cycles. Siloxane quantity, pH value of silane coupling agents and contact angle of Heliobond (Ivoclar Vivadent) to silanized ceramic were measured using a FTIR spectrophotometer, pH-indicator strips, and a contact-angle meter, respectively. Bond strength data were analyzed by three-way ANOVA. For each cement, Pearson's correlation coefficient was calculated to analyze possible correlation between bond strength under different thermocycling conditions and absorbance peak of siloxane, pH value of silane coupling agents, and contact angle of resin to the silanized ceramic surface. The bond strength of ceramic was significantly influenced by the silane coupling agent and thermal cycles, not by resin cement. For both cements, only a negative correlation was found to be significant between the contact angle of resin to silanized ceramic surfaces and bond strength after 30,000 thermal cycles. The better the wettability of resin on different silanized ceramic surfaces could improve their bond durability.

  18. Feasibility Study of a Lunar Analog Bed Rest Model

    Science.gov (United States)

    Cromwell, Ronita L.; Platts, Steven H.; Yarbough, Patrice; Buccello-Stout, Regina

    2010-01-01

    The purpose of this study was to determine the feasibility of using a 9.5deg head-up tilt bed rest model to simulate the effects of the 1/6 g load to the human body that exists on the lunar surface. The lunar analog bed rest model utilized a modified hospital bed. The modifications included mounting the mattress on a sled that rolled on bearings to provide freedom of movement. The weight of the sled was off-loaded using a counterweight system to insure that 1/6 body weight was applied along the long axis (z-axis) of the body. Force was verified through use of a force plate mounted at the foot of the bed. A seating assembly was added to the bed to permit periods of sitting. Subjects alternated between standing and sitting positions throughout the day. A total of 35% of the day was spent in the standing position and 65% was spent sitting. In an effort to achieve physiologic fluid shifts expected for a 1/6 G environment, subjects wore compression stockings and performed unloaded foot and ankle exercises. Eight subjects (3 females and 5 males) participated in this study. Subjects spent 13 days in the pre-bed rest phase, 6 days in bed rest and 3 days post bed rest. Subjects consumed a standardized diet throughout the study. To determine feasibility, measures of subject comfort, force and plasma volume were collected. Subject comfort was assessed using a Likert scale. Subjects were asked to assess level of comfort (0-100) for 11 body regions and provide an overall rating. Results indicated minimal to no discomfort as most subjects reported scores of zero. Force measures were performed for each standing position and were validated against subject s calculated 1/6 body weight (r(sup 2) = 0.993). The carbon monoxide rebreathing technique was used to assess plasma volume during pre-bed rest and on the last day of bed rest. Plasma volume results indicated a significant decrease (p = 0.001) from pre to post bed rest values. Subjects lost on average 8.3% (sd = 6.1%) during the

  19. Comparison of Cashew Nut Shell Liquid (CNS Resin with Polyester Resin in Composite Development

    Directory of Open Access Journals (Sweden)

    C. C. Ugoamadi

    2013-12-01

    Full Text Available Natural resins can compete effectively with the synthetic ones in composite development. In this research, cashew nuts were picked and processed for the extraction of the resin content. The resin (natural resin so obtained was mixed with cobalt amine (accelerator, methyl ethyl ketone peroxide (catalyst to develop two sets of composite specimens – specimens without fibres and specimens reinforced with glass fibres. This method of sample specimen development was repeated with polyester (synthetic resin. Compressive and tensile strength tests conducted proved that composites developed with cashew nut shell liquid (CNSL resin were comparable to those developed with polyester resin. In the results, CNSL has an ultimate compressive strength of 55MPa compared to that of polyester resin with an ultimate strength of 68MPa. The result of tensile strength proved cashew nut shell liquid resin (with ultimate strength of 44MPa to be better than polyester resin with 39MPa as ultimate tensile strength. This means that natural resins could be a better substitute for the synthetic ones when the required quantities of fibers (reinforcements and fillers are used in the fibre-reinforced plastic composite developments.

  20. Bond strength of resin-resin interfaces contaminated with saliva and submitted to different surface treatments.

    Science.gov (United States)

    Furuse, Adilson Yoshio; da Cunha, Leonardo Fernandes; Benetti, Ana Raquel; Mondelli, José

    2007-12-01

    The purpose of this study was to investigate the effect of different surface treatments on shear bond strength of saliva-contaminated resin-resin interfaces. Flat resin surfaces were fabricated. In the control group, no contamination or surface treatment was performed. The resin surfaces of the experimental groups were contaminated with saliva and air-dried, and then submitted to: (G1) rinsing with water and drying; (G2) application of an adhesive system; (G3) rinsing and drying, abrasion with finishing disks, etching and application of adhesive system; (G4) rinsing and drying, etching, application of silane and adhesive system. Resin cylinders were placed over the treated surfaces. The specimens were stored in water or ethanol. Shear bond strength tests were performed and the mode of failure was evaluated. Data were submitted to two-way ANOVA and Dunnett T3 test. Contamination of resin-resin interfaces with saliva significantly reduced shear strength, especially after prolonged storage (presin increments.

  1. Particle motion in fluidised beds

    International Nuclear Information System (INIS)

    Stein, M.G.

    1999-07-01

    Gas fluidised beds are important components in many process industries, e.g. coal combustors and granulators, but not much is known about the movement of the solids. Positron Emission Particle Tracking (PEPT) enables the movement of a single, radioactive tracer particle to be followed rapidly and faithfully. Experiments were carried out in columns sized between 70 and 240mm. diameter, operating in the bubbling regime at ambient process conditions using particles of group B and D (Geldart Classification). Particle motion was tracked and the data applied to models for particle movement at the gas distributor as well as close to other surfaces and to models for particle circulation in beds of cohesive particles. In the light of these data, models for particle and bubble interaction, particle circulation, segregation, attrition, erosion, heat transfer and fluidised bed scale-up rules were reassessed. Particle motion is directly caused by bubble motion, and their velocities were found to be equal for particles travelling in a bubble. PEPT enables particle circulation to be measured, giving a more accurate correlation for future predictions. Particle motion follows the scale-up rules based on similarities of the bubble motion in the bed. A new group of parameters was identified controlling the amount of attrition in fluidised beds and a new model to predict attrition is proposed. (author)

  2. Clinical physiology of bed rest

    Science.gov (United States)

    Greenleaf, John E.

    1993-01-01

    Maintenance of optimal health in humans requires the proper balance between exercise, rest, and sleep as well as time in the upright position. About one-third of a lifetime is spent sleeping; and it is no coincidence that sleeping is performed in the horizontal position, the position in which gravitational influence on the body is minimal. Although enforced bed rest is necessary for the treatment of some ailments, in some cases it has probably been used unwisely. In addition to the lower hydrostatic pressure with the normally dependent regions of the cardiovascular system, body fuid compartments during bed rest in the horizontal body position, and virtual elimination of compression on the long bones of the skeletal system during bed rest (hypogravia), there is often reduction in energy metabolism due to the relative confinement (hypodynamia) and alteration of ambulatory circadian variations in metabolism, body temperature, and many hormonal systems. If patients are also moved to unfamiliar surroundings, they probably experience some feelings of anxiety and some sociopsychological problems. Adaptive physiological responses during bed rest are normal for that environment. They are attempts by the body to reduce unnecessary energy expenditure, to optimize its function, and to enhance its survival potential. Many of the deconditioning responses begin within the first day or two of bed rest; these early responses have prompted physicians to insist upon early resumption of the upright posture and ambulation of bedridden patients.

  3. The influence of resin cements on the final color of ceramic veneers.

    Science.gov (United States)

    Chen, Xiao-Dong; Hong, Guang; Xing, Wen-Zhong; Wang, Yi-Ning

    2015-07-01

    To evaluate the effect of three brands of resin cement on the final color of ceramic veneers. 50 disk-shaped ceramic specimens (IPS e.Max, 0.6mm×8.0mm diameter) and disk-shaped composite resin background specimens (4.0mm×8.0mm diameter) were prepared and divided into 10 groups (n=5). These paired specimens were bonded using ten shades of resin cement (Variolink Veneer, shades LV-3, LV-2, MV, HV+2, HV+3; Panavia F, shades light and brown; and RelyX™ Veneer, shades WO, TR, A3). A spectrophotometer (VITA Easyshade) was used to measure the color parameters (CIE L*a*b* values) of the paired disks before and after cementation. The color differences (ΔE values) after cementation were calculated and statistically analyzed by the One-way ANOVA (at the significant level pceramic disks were measured in terms of the increase in L* value, and the decrease in Cab(*) value after bonding with the resin cement. The ΔE values of ceramic disks after cementation ranged from 1.38 to 7.16. The ΔE values were more than 3.3 when the ceramic disks were cemented with resin cements in shade HV+3 (4.90) and shade WO (7.16). One-way ANOVA of ΔE values revealed significant differences in the resin cement shades. Resin cements can affect the final color of ceramic veneer restorations, and the extent of this effect varies according to the resin cement shades. Copyright © 2015 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  4. resin as polymer-supported synthesis support

    Indian Academy of Sciences (India)

    Administrator

    dichloro-5,6-dicyano- benzoqunone ... ports used most widely in SPOS are Merrifield resin .... (2 × 10 mL). The resin was dried at 50°C for one hour to give white beads. IR (KBr): 3108, 3312 cm–1. 1H-NMR (500 MHz, CDCl3): δ 7⋅13 (br s, PS), 7⋅01.

  5. [Delayed asthma bronchiale due to epoxy resin].

    Science.gov (United States)

    Authried, Georg; Al-Asadi, Haifaa; Møller, Ulla; Sherson, David Lee

    2013-10-28

    Epoxy resin is a low molecular weight agent, which can cause both acute and delayed allergic reactions. However, it is known causing skin reactions with direct or airborne contact. Rarely it can cause airway reactions like asthma bronchiale. We describe a case of a windmill worker who developed delayed asthma bronchiale due to airborne contact with epoxy resin.

  6. Facile synthesis of hypercrosslinked resins via chloromethylation ...

    Indian Academy of Sciences (India)

    A sort of non-polystyrene type hypercrosslinked resin was firstly synthesized through chloromethylation of simple aryl molecules (benzene, toluene, naphthalene, diphenyl), succedent continuous Friedel–Crafts alkylation polymerization and post-crosslinking reaction. The chemical and porous structures of these novel resins ...

  7. MWCNTs/Resin Nanocomposites: Structural, Thermal, Mechanical and Dielectric Investigation

    Directory of Open Access Journals (Sweden)

    N. D. Alexopoulos

    2015-11-01

    Full Text Available Multi-wall carbon nanotubes (MWCNTs were manufactured, characterized and added to a typical aeronautical resin matrix at different concentrations as nano-reinforcement. The carbon content of produced MWCNTs was determined to be around 98.5% while they consisted of 13-20 wall-layers and their external diameter had an average size in between 20 and 50 nm. MWCNTs were dispersed in an epoxy resin system and tensile specimens for different MWCNTs concentrations were prepared in an open mould. Electrical wiring was attached to the specimens’ surface and surface electrical resistance change was in-situ monitored during monotonic tension till fracture. Performed tensile tests showed that the MWCNTs addition increased both modulus of elasticity and ultimate tensile strength on the nano-composites with a simultaneously dramatic ductility decrease. The MWCNTs addition enhanced the investigated resin matrix with monitoring ability; electrical resistance change of the investigated tensile tests was correlated in the elastic regime with axial nominal strain and the gauge factor of the different MWCNTs concentration specimens were calculated. It was found that lowest MWCNTs concentration gave the best results in terms of piezo-resistivity and simultaneously the least enhancement in the mechanical properties.

  8. Thermal degradation kinetics and antimicrobial studies of terpolymer resins

    Directory of Open Access Journals (Sweden)

    Abdul R. Burkanudeen

    2016-09-01

    Full Text Available The terpolymer (ASF was synthesized by condensation of anthranilic acid and salicylic acid with formaldehyde in the presence of glacial acetic acid as a catalyst at 140 ± 2 °C for 6 h with varying proportions of reactants. The terpolymer ASF-I was characterized by elemental analysis, FTIR, 1H NMR and 13C NMR spectroscopy. The thermal decomposition behavior of ASF-I, II and III terpolymers was studied using thermogravimetric analysis (TGA in a static nitrogen atmosphere at a heating rate of 20 °C/min. Freeman–Carroll, Sharp–Wentworth and Phadnis–Deshpande methods were used to calculate the thermal activation energy (Ea the order of reaction (n, entropy change (ΔS, free energy change (ΔF, apparent entropy (S∗ and frequency factor (Z. Phadnis–Deshpande method was used to propose the thermal degradation model for the decomposition pattern of ASF-I terpolymer resin. The order of the decomposition reaction was found to be 0.901. The thermal activation energy determined with the help of these methods was in good agreement with each other. The ASF-I, II and III resins were tested for their inhibitory action against pathogenic bacteria and fungi. The resins show potent inhibitory action against bacteria, such as Escherichia coli, Klebsiella, Staphylococcus aureus and Pseudomonas aeruginosa and fungi viz. Aspergillus flavus, Aspergillus niger, Penicillium sp., Candida albicans, Cryptococcus neoformans and Mucor sp.

  9. Burnout calculation

    International Nuclear Information System (INIS)

    Li, D.

    1980-01-01

    Reviewed is the effect of heat flux of different system parameters on critical density in order to give an initial view on the value of several parameters. A thorough analysis of different equations is carried out to calculate burnout is steam-water flows in uniformly heated tubes, annular, and rectangular channels and rod bundles. Effect of heat flux density distribution and flux twisting on burnout and storage determination according to burnout are commended [ru

  10. Physical Properties of Synthetic Resin Materials

    Science.gov (United States)

    Fishbein, Meyer

    1939-01-01

    A study was made to determine the physical properties of synthetic resins having paper, canvas, and linen reinforcements, and of laminated wood impregnated with a resin varnish. The results show that commercial resins have moduli of elasticity that are too low for structural considerations. Nevertheless, there do exist plastics that have favorable mechanical properties and, with further development, it should be possible to produce resin products that compare favorably with the light-metal alloys. The results obtained from tests on Compound 1840, resin-impregnated wood, show that this material can stand on its own merit by virtue of a compressive strength four times that of the natural wood. This increase in compressive strength was accomplished with an increase of density to a value slightly below three times the normal value and corrected one of the most serious defects of the natural product.

  11. Embedding of reactor wastes in plastic resins

    International Nuclear Information System (INIS)

    1979-01-01

    STEAG Kernenergie GmbH is so far the only firm commercially to condition radioactive bead ion exchange resins by embedding in polystyrene resins. The objective of the work reported here was to study and develop methods for immobilization of other reactor wastes in plastic resins. Comparison studies on high quality cement however showed favourable results for cement with respect to process safety and economy. For this reason STEAG interrupted its work in the field of resin embedding after about one year. The work carried out during this period is surveyed in this report, which includes a comprehensive literature study on reactor wastes and their solidification in plastic resins as well as on regulations with regard to radioactive waste disposal in the member states of the European Communities

  12. Disinfection of denture base acrylic resin.

    Science.gov (United States)

    Lin, J J; Cameron, S M; Runyan, D A; Craft, D W

    1999-02-01

    During repair or adjustments of acrylic resin removable complete and partial dentures, particles of the acrylic resin from the interior of the prosthesis may expose dental personnel to microbial health hazards if the prosthesis has not been thoroughly disinfected. This study investigates the efficacy of a commercially prepared microbial disinfectant (Alcide) on the external and internal surfaces of acrylic resins. Four groups of acrylic resin were incubated in an experimental model to simulate the oral environment over time. Specimens were treated in 2 groups, disinfected and not disinfected, and then further grouped by breaking and not breaking. Analysis was performed with microbial colony counts, SEM, and statistical analyses. Viable microorganisms still remain on the internal and external surfaces of treated resins. Chlorine dioxide reduces, but does not eliminate, viable microorganisms on these dental prostheses.

  13. Particle Bed Reactor scaling relationships

    International Nuclear Information System (INIS)

    Slovik, G.; Araj, K.; Horn, F.L.; Ludewig, H.; Benenati, R.

    1987-01-01

    Scaling relationships for Particle Bed Reactors (PBRs) are discussed. The particular applications are short duration systems, i.e., for propulsion or burst power. Particle Bed Reactors can use a wide selection of different moderators and reflectors and be designed for such a wide range of power and bed power densities. Additional design considerations include the effect of varying the number of fuel elements, outlet Mach number in hot gas channel, etc. All of these variables and options result in a wide range of reactor weights and performance. Extremely light weight reactors (approximately 1 kg/MW) are possible with the appropriate choice of moderator/reflector and power density. Such systems are very attractive for propulsion systems where parasitic weight has to be minimized

  14. Fluidized-bed nuclear reactor

    International Nuclear Information System (INIS)

    Grimmett, E.S.; Kunze, J.F.

    1975-01-01

    A reactor vessel containing a fluidized-bed region of particulate material including both a neutron-moderating and a fertile substance is described. A gas flow including fissile material passes through the vessel at a sufficient rate to fluidize the particulate material and at a sufficient density to support a thermal fission reaction within the fluidized-bed region. The high-temperature portion of a heat transfer system is located within the fluidized-bed region of the reactor vessel in direct contact with the fluidized particles. Heat released by fission is thereby transferred at an enhanced rate to a coolant circulating within the heat transfer system. Fission products are continuously removed from the gas flow and supplemental fissile material added during the reactor operation. (U.S.)

  15. Hydrodynamic studies in designing of fluidized bed system

    International Nuclear Information System (INIS)

    Mohamad Puad Abu; Muhd Noor Muhd Yunus; Syed Nasaruddin Syed Idris

    2002-01-01

    Fluidized bed process have been used mostly in the petroleum and paper industries, and for processing nuclear wastes, spent cook liquor, wood chips, and sewage sludge disposal. Even at MINT some of the equipment available used this principal. Before we use or purchase this equipment, it is very grateful if we could understand how the system has been designed. The hydrodynamic fluidization studies is very important in designing of fluidized bed system especially in determining the minimum fluidizing velocity, terminal velocity, flexibility of operation, slugging condition, bubble size and velocity, and transport disengaging height. They can be determined either by calculation or experimentation. This paper will highlight the hydrodynamic study that need to be performed in designing of fluidized bed system so that its can be used appropriately. (Author)

  16. Alternative methods for determining shrinkage in restorative resin composites.

    Science.gov (United States)

    de Melo Monteiro, Gabriela Queiroz; Montes, Marcos Antonio Japiassú Resende; Rolim, Tiago Vieira; de Oliveira Mota, Cláudia Cristina Brainer; de Barros Correia Kyotoku, Bernardo; Gomes, Anderson Stevens Leônidas; de Freitas, Anderson Zanardi

    2011-08-01

    The purpose of this study was to evaluate polymerization shrinkage of resin composites using a coordinate measuring machine, optical coherence tomography and a more widely known method, such as Archimedes Principle. Two null hypothesis were tested: (1) there are no differences between the materials tested; (2) there are no differences between the methods used for polymerization shrinkage measurements. Polymerization shrinkage of seven resin-based dental composites (Filtek Z250™, Filtek Z350™, Filtek P90™/3M ESPE, Esthet-X™, TPH Spectrum™/Dentsply 4 Seasons™, Tetric Ceram™/Ivoclar-Vivadent) was measured. For coordinate measuring machine measurements, composites were applied to a cylindrical Teflon mold (7 mm × 2 mm), polymerized and removed from the mold. The difference between the volume of the mold and the volume of the specimen was calculated as a percentage. Optical coherence tomography was also used for linear shrinkage evaluations. The thickness of the specimens was measured before and after photoactivation. Polymerization shrinkage was also measured using Archimedes Principle of buoyancy (n=5). Statistical analysis of the data was performed with ANOVA and the Games-Howell test. The results show that polymerization shrinkage values vary with the method used. Despite numerical differences the ranking of the resins was very similar with Filtek P90 presenting the lowest shrinkage values. Because of the variations in the results, reported values could only be used to compare materials within the same method. However, it is possible rank composites for polymerization shrinkage and to relate these data from different test methods. Independently of the method used, reduced polymerization shrinkage was found for silorane resin-based composite. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  17. Effects of polishing procedures on color stability of composite resins.

    Science.gov (United States)

    Güler, Ahmet Umut; Güler, Eda; Yücel, Ali Cağin; Ertaş, Ertan

    2009-01-01

    The purpose of this study was to investigate the effect of different polishing methods on color stability of posterior, universal and nanohybrid composite resin restorative materials upon exposure to a staining agent. Twenty-five specimens were prepared for each of 5 different composite resins (Filtek Z250, Filtek P60, Quadrant LC, Grandio and Filtek Supreme). Specimens were divided into 5 groups and different polishing procedures, including polishing discs (Pd), polishing discs then diamond polishing paste (PdP), polishing discs then a liquid polishing system (Biscover) (PdB), and combinations of these (PdPB) were used. Unpolished specimens served as the control (C). The specimens were stored for 48 h in a coffee solution. The color of all specimens was measured before and after exposure with a colorimeter, and total color change (DeltaE*) were calculated. The data were analyzed with a two-way ANOVA and the means were compared by Tukey HSD test (alpha=0.05). The lowest color difference was observed in the groups PdP and C, while the highest color difference was observed in PdPB, and PdB. When comparing the five different restorative materials, no significant difference was observed between FiltekP60 and FiltekZ250, and these materials demonstrated significantly less color change than Quadrant LC and the nanohybrid materials (Grandio, Filtek Supreme). The posterior (Filtek P60) and universal (Filtek Z250) composite resin restorative materials, which do not contain tetraethyleneglycol dimethacrylate (TEGDMA), were found to be less stainable than the nanohybrid (Grandio, Filtek Supreme) and universal (Quadrant LC) composite resins, which contain TEGDMA. The use of diamond polishing paste after polishing with polishing discs significantly decreased staining when compared to the groups that used polishing discs alone, for all restorative materials tested. The highest color change values were obtained for the specimens that were polished with the Biscover liquid polish

  18. Effects of polishing procedures on color stability of composite resins

    Directory of Open Access Journals (Sweden)

    Ahmet Umut Güler

    2009-04-01

    Full Text Available The purpose of this study was to investigate the effect of different polishing methods on color stability of posterior, universal and nanohybrid composite resin restorative materials upon exposure to a staining agent. Twenty-five specimens were prepared for each of 5 different composite resins (Filtek Z250, Filtek P60, Quadrant LC, Grandio and Filtek Supreme. Specimens were divided into 5 groups and different polishing procedures, including polishing discs (Pd, polishing discs then diamond polishing paste (PdP, polishing discs then a liquid polishing system (Biscover (PdB, and combinations of these (PdPB were used. Unpolished specimens served as the control (C. The specimens were stored for 48 h in a coffee solution. The color of all specimens was measured before and after exposure with a colorimeter, and total color change (DE* were calculated. The data were analyzed with a two-way ANOVA and the means were compared by Tukey HSD test (a=0.05. The lowest color difference was observed in the groups PdP and C, while the highest color difference was observed in PdPB, and PdB. When comparing the five different restorative materials, no significant difference was observed between FiltekP60 and FiltekZ250, and these materials demonstrated significantly less color change than Quadrant LC and the nanohybrid materials (Grandio, Filtek Supreme. The posterior (Filtek P60 and universal (Filtek Z250 composite resin restorative materials, which do not contain tetraethyleneglycol dimethacrylate (TEGDMA, were found to be less stainable than the nanohybrid (Grandio, Filtek Supreme and universal (Quadrant LC composite resins, which contain TEGDMA. The use of diamond polishing paste after polishing with polishing discs significantly decreased staining when compared to the groups that used polishing discs alone, for all restorative materials tested. The highest color change values were obtained for the specimens that were polished with the Biscover liquid polish

  19. Survival of resin infiltrated ceramics under influence of fatigue.

    Science.gov (United States)

    Aboushelib, Moustafa N; Elsafi, Mohamed H

    2016-04-01

    to evaluate influence of cyclic fatigue on two resin infiltrated ceramics and three all-ceramic crowns manufactured using CAD/CAM technology. CAD/CAM anatomically shaped crowns were manufactured using two resin infiltrated ceramics (Lava Ultimate and Vita Enamic), two reinforced glass ceramic milling blocks ((IPS)Empress CAD and (IPS)e.max CAD) and a veneered zirconia core ((IPS)Zir CAD). (IPS)e.max CAD and (IPS)Zir CAD were milled into 0.5mm thick anatomically shaped core structure which received standardized press-on veneer ceramic. The manufactured crowns were cemented on standardized resin dies using a resin adhesive (Panavia F2.0). Initial fracture strength of half of the specimens was calculated using one cycle load to failure in a universal testing machine. The remaining crowns were subjected to 3.7 million chewing cycles (load range 50-200N at 3s interval) in a custom made pneumatic fatigue tester. Survival statistics were calculated and Weibull modulus was measured from fitted load-cycle-failure diagrams. Scanning electron microscopy was performed to fractographically analyze fractured surfaces. Data were analyzed using two way analysis of variance and Bonferroni post hoc tests (α=0.05). Dynamic fatigue resulted in significant reduction (F=7.54, Pceramics and (IPS)Empress demonstrated the highest percent of fracture incidences under the influence of fatigue (35-45% splitting). None of the tested veneered zirconia restorations were fractured during testing, however, chipping of the veneer ceramics was observed in 6 crowns. The lowest percent of failure was observed for (IPS)e.max crowns manifested as 3 cases of minor chipping in addition to two complete fracture incidences. SEM images demonstrated the internal structure of the tested materials and detected location and size of the critical crack. The internal structure of the tested materials significantly influenced their fatigue behavior. Resin infiltrated ceramics were least influenced by fatigue while

  20. Boron removal from water and wastewater using new polystyrene-based resin grafted with glycidol

    Directory of Open Access Journals (Sweden)

    Joanna Kluczka

    2015-09-01

    Full Text Available A divinylbenzene cross-linked polystyrene resin with amine functional groups (Purolite A170 was grafted with glycidol and characterized as a novel sorbent, GLY-resin, for the oxoborate removal from model solutions and post-crystallization lye. The sorption behavior of GLY-resin was investigated using a batch system. The results showed that the sorption was maximal at pH=9.5. The equilibrium was achieved after 24 h. Calculations based on Langmuir model show the monolayer sorption capacity qm=1.3 mg/g and the fitted experimental data chemisorption as a dominating mechanism of boron sorption on GLY-resin. Boron removal from the solution containing 5 mg B/L and post-crystallization lye having a 9.1 mg B/L was 99% and 80% respectively. The thermodynamic calculations indicated the spontaneous and endothermic nature of the sorption process. The pseudo-second-order model adequately described the boron sorption on GLY-resin. Sorption−desorption efficiency was 100%, which means the boron sorption at next cycle did not decrease.

  1. Better backs by better beds?

    DEFF Research Database (Denmark)

    Bergholdt, Kim; Fabricius, Rasmus N; Bendix, Tom

    2008-01-01

    STUDY DESIGN: A "randomized"/stratified, single-blinded, parallel-group study. OBJECTIVE.: To evaluate 3 structurally different mattresses relative influence on patients with chronic low back pain (CLBP). SUMMARY OF BACKGROUND DATA: In several advertisements, it is proclaimed that certain...... using the probably most relevant "worst case" data. There were no relevant difference between the effects of the water bed and the foam bed. CONCLUSION: The Waterbed and foam mattress' did influence back symptoms, function and sleep more positively as apposed to the hard mattress, but the differences...

  2. Continuous separation of protein loaded nanoparticles by simulated moving bed chromatography.

    Science.gov (United States)

    Satzer, Peter; Wellhoefer, Martin; Jungbauer, Alois

    2014-07-04

    For scale up and efficient production of protein loaded nanoparticles continuous separation by size exclusion chromatography in simulated moving bed (SMB) mode helps do reduce unbound protein concentration and increase yields for perfectly covered particles. Silica nanoparticles were loaded with an excess of beta casein or bovine serum albumin (BSA) and the loaded particles purified by size exclusion chromatography using Sephacryl300 as stationary phase in a four zone SMB. We determined our working points for the SMB from batch separations and the triangle theory described by Mazzotti et al. with an SMB setup of one Sephacryl300 26/70mm column per zone with switch times of 5min for BSA and 7min for beta casein. In the case of BSA the Raffinate contained loaded nanoparticles of 63% purity with 98% recovery and the extract was essentially particle free (95% purity). We showed that the low purity of the Raffinate was only due to BSA multimers present in the used protein solution. In the case of beta casein where no multimers are present we achieved 89% purity and 90% recovery of loaded nanoparticles in the Raffinate and an extract free of particles (92% purity). Using a tangential flow filtration unit with 5kDa cutoff membrane we proved that the extract can be concentrated for recycling of protein and buffer. The calculated space-time-yield for loaded nanoparticles was 0.25g of loaded nanoparticles per hour and liter of used resin. This proves that the presented process is suitable for large scale production for industrial purposes. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  3. Low HAP/VOC Compliant Resins for Military Applications

    Science.gov (United States)

    2011-09-01

    is the absolute temperature, and q is the sample density.17,18 The temperature T and rub - bery modulus E are determined for the calculation of eq. (1...along with the fracture toughness of other commercial VE resins for comparison. The rub - ber modifiers used in this study did not show good miscibility...s (in .) Pe ak L oa d (lb f) Te ns ile St re ng th (k si ) E (M SI ) R an ge o f 1 00 0 to 3 00 0i n/ in 26 -J ul -0 7 LV O -R TD -0

  4. Radiotracer application for characterization of nuclear grade anion exchange resins Tulsion A-23 and Dowex SBR LC

    International Nuclear Information System (INIS)

    Singare, P.U.

    2015-01-01

    Radio isotopic tracer technique as one of the versatile nondestructive technique is employed to evaluate the performance of nuclear grade anion exchange resins Tulsion A-23 and Dowex SBR LC. The evaluation was made on the basis of ion-isotopic exchange reaction kinetics by using 131 I and 82 Br radioactive tracer isotopes. It was observed that for both the resins, the values of specific reaction rate (min -1 ), amount of ion exchanged (mmol) and initial rate of ion exchange (mmol/min) were calculated to be lower for bromide ion-isotopic exchange reaction than that for iodide ion-isotopic exchange reaction. It was observed that for iodide ion-isotopic exchange reaction under identical experimental conditions of 30.0 C, 1.000 g of ion exchange resins and 0.001 mol/L labeled iodide ion solution, the values of specific reaction rate (min -1 ), amount of iodide ion exchanged (mmol), initial rate of iodide ion exchange (mmol/min) and log K d were calculated as 0.377, 0.212, 0.080 and 15.5 respectively for Dowex SBR LC resin, which was higher than 0.215, 0.144, 0.031 and 14.1 respectively as that obtained for Tulsion A23 resins. Also at a constant temperature of 30.0 C, as the concentration of labeled iodide ion solution increases from 0.001 mol/L to 0.004 mol/L, the percentage of iodide ions exchanged increases from 84.75 % to 90.20 % for Dowex SBR LC resins which was higher than increases from 57.66 % to 62.38 % obtained for Tulsion A23 resins. The identical trend was observed for the two resins during bromide ion-isotopic exchange reaction. The overall results indicate superior performance of Dowex SBR LC over Tulsion A23 resins under identical experimental conditions.

  5. Fatigue behavior of dental resin composites: flexural fatigue in vitro versus 6 years in vivo

    NARCIS (Netherlands)

    Garcia-Godoy, F.; Frankenberger, R.; Lohbauer, U.; Feilzer, A.J.; Krämer, N.

    2012-01-01

    Objectives: To evaluate fatigue behavior of direct resin composite restorations (Tetric Ceram vs. Grandio) in vitro and in vivo over an observation period of 6 years. Methods: For the in vitro part, Young's moduli (YM) were calculated and both initial (FS: flexural strength) and fatigue flexural

  6. Modelling of dynamics of combustion of biomass in fluidized beds

    Directory of Open Access Journals (Sweden)

    Saastamoinen Jaakko J.

    2004-01-01

    Full Text Available New process concepts in energy production and biofuel, which are much more reactive than coal, call for better controllability of the combustion in circulating fluidized bed boilers. Simplified analysis describing the dynamics of combustion in fluidized bed and circulating fluidized bed boilers is presented. Simple formulas for the estimation of the responses of the burning rate and fuel inventory to changes in fuel feeding are presented. Different changes in the fuel feed, such as an impulse, step change, linear increase and cyclic variation are considered. The dynamics of the burning with a change in the feed rate depends on the fuel reactivity and particle size. The response of a fuel mixture with a wide particle size distribution can be found by summing up the effect of different fuel components and size fractions. Methods to extract reaction parameters form dynamic tests in laboratory scale reactors are discussed. The residence time of fuel particles in the bed and the resulting char inventory in the bed decrease with increasing fuel reactivity and differences between coal and biomass is studied. The char inventory affects the stability of combustion. The effect of char inventory and oscillations in the fuel feed on the oscillation of the flue gas oxygen concentration is studied by model calculation. A trend found by earlier measurements is explained by the model.

  7. Borehole-inclusion stressmeter measurements in bedded salt

    International Nuclear Information System (INIS)

    Cook, C.W.; Ames, E.S.

    1980-07-01

    Sandia purchased borehole-inclusion stressmeters from a commercial supplier to measure in situ stress changes in bedded salt. However, the supplied stressmeters were difficult to set in place and gave erratic results in bedded salt. These problems were overcome with a new extended platen design. Also a straingaged transducer was designed which can be read with a conventional data logger. Due to the nonlinear behavior of bedded salt under uniaxial loading, a new empirical calibration scheme was devised. In essence, the stressmeters are calibrated as force transducers and this calibration curve is then used to determine the relationship between uniaxial stress changes in bedded salt and the gage's output. The stressmeter and calibration procedures have been applied under mine conditions and produced viable results. Future work will involve finite element analysis to calculate the observed behavior of the stressmeters. The response of the stressmeters in bedded salt is neither that of a true stressmeter or of a true strainmeter. However, repeatable calibrations make the gages very useful

  8. Evaluation of Resin-Resin Interface in Direct Composite Restoration Repair

    Science.gov (United States)

    Stoleriu, S.; Andrian, S.; Pancu, G.; Nica, I.; Iovan, G.

    2017-06-01

    The aim of this study was to evaluate the resin-resin interface when a universal bonding agent was used in two different strategies in direct restoration repair. Two composite resins (a micro-filled hybrid and a nano-filled hybrid) as old restorations that have to be repair, a universal bonding agent and a micro-filled hybrid composite resin (different then that aged) as new material for repair were chosen for the study. Non-aged samples were used as control and aged samples were used as study groups. The universal bonding agent was applied in etch-and-rinse and in self-etch strategies. The interface between old and new composite resins was evaluated by SEM and the microleakage was assessed by scoring the dye penetration. Very good adaptation of the two different composite resins placed in direct contact in non-aged samples was recorded. No gaps or defects were visible and strong resin-resin contact was observed. After aging, enlargement of resin-resin junction were observed in most of the samples and a increased dye penetration was recorded irrespective of the strategy (etch-and-rinse or self-etch) used for bonding agent application.

  9. Bond strength of a chairside autopolymerizing reline resin to injection-molded thermoplastic denture base resins.

    Science.gov (United States)

    Hamanaka, Ippei; Shimizu, Hiroshi; Takahashi, Yutaka

    2017-01-01

    This study evaluated the shear bond strength of a chairside autopolymerizing reline resin to injection-molded thermoplastic denture base resins. Four kinds of injection-molded thermoplastic resins (two polyamides, a polyethylene terephthalate copolymer and a polycarbonate) and PMMA, as a control, were tested. The eight types of surface treatment: ((1) no treatment, (2) air abrasion, (3) dichloromethane, (4) ethyl acetate, (5) 4-META/MMA-TBB resin, (6) air abrasion and 4-META/MMA-TBB resin, (7) tribochemical silica coating, and (8) tribochemical silica coating and 4-META/MMA-TBB resin) were applied to each specimen. The chairside autopolymerizing reline resins were bonded to disks of the injection-molded thermoplastic denture base resins. All of the specimens were immersed in water for 4 months and then thermocycled for 10,000 cycles in water between 5 and 55°C. The shear bond strengths were determined. The shear bond strengths of the two polyamides treated using air abrasion, dichloromethane and ethyl acetate and no treatment were exceedingly low. The greatest bond strength was recorded for the polyethylene terephthalate copolymer specimens treated with tribochemical silica coating and 4-META/MMA-TBB resin (22.5MPa). The bond strengths of the other injection-molded thermoplastic denture base resins increased using 4-META/MMA-TBB resin. Tribochemical silica coating and 4-META/MMA-TBB resin were the most effective surface treatments among all denture base resins tested. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  10. Calculator calculus

    CERN Document Server

    McCarty, George

    1982-01-01

    How THIS BOOK DIFFERS This book is about the calculus. What distinguishes it, however, from other books is that it uses the pocket calculator to illustrate the theory. A computation that requires hours of labor when done by hand with tables is quite inappropriate as an example or exercise in a beginning calculus course. But that same computation can become a delicate illustration of the theory when the student does it in seconds on his calculator. t Furthermore, the student's own personal involvement and easy accomplishment give hi~ reassurance and en­ couragement. The machine is like a microscope, and its magnification is a hundred millionfold. We shall be interested in limits, and no stage of numerical approximation proves anything about the limit. However, the derivative of fex) = 67.SgX, for instance, acquires real meaning when a student first appreciates its values as numbers, as limits of 10 100 1000 t A quick example is 1.1 , 1.01 , 1.001 , •••• Another example is t = 0.1, 0.01, in the functio...

  11. Apparatus and process for controlling fluidized beds

    Science.gov (United States)

    Rehmat, Amirali G.; Patel, Jitendra G.

    1985-10-01

    An apparatus and process for control and maintenance of fluidized beds under non-steady state conditions. An ash removal conduit is provided for removing solid particulates from a fluidized bed separate from an ash discharge conduit in the lower portion of the grate supporting such a bed. The apparatus and process of this invention is particularly suitable for use in ash agglomerating fluidized beds and provides control of the fluidized bed before ash agglomeration is initiated and during upset conditions resulting in stable, sinter-free fluidized bed maintenance.

  12. Mineralogy of fossil resins in Northern Eurasia

    Science.gov (United States)

    Bogdasarov, M. A.

    2007-12-01

    The investigation is focused on identification and origin of fossil resins from the Cretaceous, Tertiary, and Quaternary sediments of Northern Eurasia on the basis of detailed study of their physical and chemical characteristics: morphology; size; mass; density; optical, mechanical, and thermal properties; chemical composition; etc. The composition of amorphous organic minerals with polymeric structure, fossil resins included, is studied with IR spectrometry, the EPR method, derivatography at low heating rates, XRD, chemical analysis, emission spectrometry, etc. The results of investigation summarized for the Baltic-Dnieper, North Siberian, and Far East amber-bearing provinces show some similarity of fossil resins in combination with specific features inherent to each province. Resins from the Baltic-Dnieper province should be termed as amber (succinite). Their variety is the most characteristic of Northern and Eastern Europe. Amber-like fossil resins from the North Siberian and Far East provinces are irrelevant to succinite. They usually occur as brittle resins, namely, retinite and gedanite, without jewelry value. Viscous fossil resin rumänite with an expected high economic value occurs in the Far East, on the shore of Sakhalin Island.

  13. Investigation of fossil resins and amber

    Directory of Open Access Journals (Sweden)

    E.Yu. Makarova

    2017-05-01

    Full Text Available Fossil resins and amber are a product of lithogenesis of resinous substances of higher plants – resinite. These components of plants, like other lipoid ingredients (suberins, coutines, sporinins, natural rubbers are resistant to microbial action, so they are well preserved in bacterial processing of organic matter in the stages of sedimento- and diagenesis, and are well diagnosed in microscopic studies. They occur in a rather wide age range of sedimentary rocks. The amber of the Baltic region of the Eocene age is most fully studied. The article presents the results of a study of the collection of fossil resins and amber from various regions of the world. Samples were studied microscopically; carbon isotope analysis, infrared spectroscopy (IR spectroscopy were performed. The most informative analysis of high-molecular polymeric compounds is IR spectroscopy. It was found that in the analyzed samples of fossil resins of different ages, aromatic compounds are not observed, most of which are first volatilized in fossilization processes. The possibility of influencing the group composition of amber and amber-like resins for sedimentation, diagenesis and catagenesis is discussed. The IR spectra of fossil and modern resin conifers are compared. Using the IR spectroscopy method, an attempt was made to identify the botanical origin of fossil resins.

  14. Physiology Of Prolonged Bed Rest

    Science.gov (United States)

    Greenleaf, John E.

    1991-01-01

    Report describes physiological effects of prolonged bed rest. Rest for periods of 24 hours or longer deconditions body to some extent; healing proceeds simultaneously with deconditioning. Report provides details on shifts in fluid electrolytes and loss of lean body mass, which comprises everything in body besides fat - that is, water, muscle, and bone. Based on published research.

  15. Development of sustained release fast-disintegrating tablets using various polymer-coated ion-exchange resin complexes.

    Science.gov (United States)

    Jeong, Seong Hoon; Park, Kinam

    2008-04-02

    Complex formation between drugs and ion-exchange resins was investigated and the effects of coating by various aqueous polymeric dispersions on the complexes were evaluated for developing new sustained-release fast-disintegrating tablets (FDTs). Complexes of ion-exchange resin and dextromethorphan, a model drug, were prepared using different particle sizes of the resins. Aqueous colloidal dispersions of ethylcellulose (EC) and poly(vinyl acetate) (Kollicoat SR30D) were used for fluid-bed coating. Based on drug loading, release profiles, and scanning electron microscopy (SEM) images, the coated particles were granulated with suitable tablet excipients and then compressed into the tablets. Drug release profiles and SEM pictures were compared before and after the manufacturing processes. As the particle size of resins increased, the drug loading and release rate decreased due to the reduced effective diffusion coefficient and surface area. Higher coating level decreased the release rate further. In contrast to EC, Kollicoat SR30D coated particles could be compressed into tablets without any rupture or cracks on the coating since the mechanical properties of the polymer was more resistant to the manufacturing processes. This resulted in no significant changes in release rates. SEM showed the mechanical strength of the polymers affected the morphological change after compression. When the drug release profiles were applied into Boyd model and Higuchi equation, the linear relationship was observed, indicating that the diffusion within the resin matrix is the rate-controlling step.

  16. Potential problems associated with ion-exchange resins used in the decontamination of light-water reactor systems

    International Nuclear Information System (INIS)

    Soo, P.; Adams, J.W.; Kempf, C.R.

    1987-01-01

    During a typical decontamination event, ion-exchange resin beds are used to remove corrosion products (radioactive and nonradioactive) and excess decontamination reagents from waste streams. The spent resins may be solidified in a binder, such as cement, or sealed in a high-integrity container (HIC) in order to meet waste stability requirements specified by the Nuclear Regulatory Commission. Lack of stability of low-level waste in a shallow land burial trench may lead to trench subsidence, enhanced water infiltration and waste leaching, which would result in accelerated transport of radionuclides and the complexing agents used for decontamination. The current program is directed at investigating safety problems associated with the handling, solidification and containerization of decontamination resin wastes. The three tasks currently underway include freeze-thaw cycling of cementitious and vinyl ester-styrene forms to determine if mechanical integrity is compromised, a study of the corrosion of container materials by spent decontamination waste resins, and investigations of resin degradation mechanisms

  17. Melamine-modified urea formaldehyde resin for bonding particleboards

    Science.gov (United States)

    Chung-Yun Hse; Feng Fu; Hui Pan

    2008-01-01

    For the development of a cost-effective melamine-modified urea formaldehyde resin (MUF), the study evaluated the effects of reaction pH and melamine content on resin properties and bond performance of the MUF resin adhesive systems. Eight resins, each with three replicates, were prepared in a factorial experiment that included two formulation variables: two reaction...

  18. Traumatic resin ducts as indicators of bark beetle outbreaks

    Science.gov (United States)

    R. Justin DeRose; Matthew F. Bekker; James N. Long

    2017-01-01

    The formation of traumatic resin ducts (TRDs) represents an important induced defense in woody plants that enhances oleoresin production and flow in response to environmental perturbations. In some genera (Pinus), resin ducts are copious and conspicuous; however, in others (Picea), resin ducts are relatively rare. The occurrence and strength of resin ducts, in...

  19. Reliability Calculations

    DEFF Research Database (Denmark)

    Petersen, Kurt Erling

    1986-01-01

    Risk and reliability analysis is increasingly being used in evaluations of plant safety and plant reliability. The analysis can be performed either during the design process or during the operation time, with the purpose to improve the safety or the reliability. Due to plant complexity and safety...... and availability requirements, sophisticated tools, which are flexible and efficient, are needed. Such tools have been developed in the last 20 years and they have to be continuously refined to meet the growing requirements. Two different areas of application were analysed. In structural reliability probabilistic...... approaches have been introduced in some cases for the calculation of the reliability of structures or components. A new computer program has been developed based upon numerical integration in several variables. In systems reliability Monte Carlo simulation programs are used especially in analysis of very...

  20. Deep space test bed for radiation studies

    International Nuclear Information System (INIS)

    The Deep Space Test-Bed (DSTB) Facility is designed to investigate the effects of galactic cosmic rays on crews and systems during missions to the Moon or Mars. To gain access to the interplanetary ionizing radiation environment the DSTB uses high-altitude polar balloon flights. The DSTB provides a platform for measurements to validate the radiation transport codes that are used by NASA to calculate the radiation environment within crewed space systems. It is also designed to support other exploration related investigations such as measuring the shielding effectiveness of candidate spacecraft and habitat materials, testing new radiation monitoring instrumentation, flight avionics and investigating the biological effects of deep space radiation. We describe the work completed thus far in the development of the DSTB and its current status

  1. Characterising shock propagation through inert beds

    Science.gov (United States)

    Edgeley, James; Braithwaite, Christopher

    2017-06-01

    Optical velocimetry methods have been used extensively to measure the detonation wave velocity in explosives. The reaction zone length can subsequently be inferred using one of several methods, most involving transmitting the shock into an acceptor component made of another material and observing the wave's attenuation. The ultimate aim of this investigation is to develop a method optimised for characterising the reaction zone in low density PETN. The initial procedure involves a shock imparted by a gas gun into an inert bed in otherwise similar conditions. The design of the acceptor component is varied, and in each case an appropriate calculation is done to determine the size and profile of the shock. Laser interferometry is used to take velocity measurements where necessary. The results are compared against the input shock from the gun to assess the suitability of the apparatus.

  2. GIS-based modelling of (all) glacier beds in Switzerland

    Science.gov (United States)

    Linsbauer, A.; Paul, F.; Hoelzle, M.; Haeberli, W.

    2009-04-01

    Due to the ongoing and expected future increase in global mean temperature, the Alpine environment will continue to get further away from equilibrium. Glaciers are a part of the high-mountain cryosphere, and their changes are considered to be the best natural indicators of climatic changes. The calculation and visualization of future glacier development is thus an important task of communicating climate change effects to a wider public. One of the most challenging topics in the assessment of climate change impacts on future glacier development is the unknown glacier bed and the related uncertainties in glacier volume estimations (Driedger and Kennard, 1986). In this respect, an estimated topography of the glacier bed would facilitate the calculation of glacier volume, the detection of local depressions, and the visualization of future ice-free grounds. We here present a simple but robust GIS-tool which allows to calculate an approximate bed topography for a large sample of glaciers. The only input used is a DEM, glacier outlines, and a set of flow lines. The method is based on the calculation of the ice thickness along selected points of the flow lines from the shallow ice approximation and subsequent spatial interpolation using topogrid and is independent of glacier size, type or climatic setting. The generated ice thickness distribution is in good agreement with direct measurements (GPR profiles) and results from more sophisticated methods that include assumptions on glacier flow. However, local derivations exist due to the very sensitive dependence on surface slope.

  3. Properties of a nanodielectric cryogenic resin

    Energy Technology Data Exchange (ETDEWEB)

    Polyzos, Georgios [ORNL; Tuncer, Enis [ORNL; Sauers, Isidor [ORNL; More, Karren Leslie [ORNL

    2010-01-01

    Physical properties of a nanodielectric composed of in situ synthesized titanium dioxide (TiO{sub 2}) nanoparticles ({le} 5 nm in diameter) and a cryogenic resin are reported. The dielectric losses were reduced by a factor of 2 in the nanocomposite, indicating that the presence of small TiO{sub 2} nanoparticles restricted the mobility of the polymer chains. Dielectric breakdown data of the nanodielectric was distributed over a narrower range than that of the unfilled resin. The nanodielectric had 1.56 times higher 1% breakdown probability than the resin, yielding 0.64 times thinner insulation thickness for the same voltage level, which is beneficial in high voltage engineering.

  4. SEM and elemental analysis of composite resins

    International Nuclear Information System (INIS)

    Hosoda, H.; Yamada, T.; Inokoshi, S.

    1990-01-01

    Twenty-four chemically cured, 21 light-cured anterior, three light-cured anterior/posterior, and 18 light-cured posterior composite resins were examined using scanning electron microscopy, and the elemental composition of their filler particles was analyzed with an energy dispersive electron probe microanalyzer. According to the results obtained, the composite resins were divided into five groups (traditional, microfilled type, submicrofilled type, hybrid type, and semihybrid), with two additional hypothetical categories (microfilled and hybrid). Characteristics of each type were described with clinical indications for selective guidance of respective composite resins for clinical use

  5. In-depth disinfection of acrylic resins.

    Science.gov (United States)

    Chau, V B; Saunders, T R; Pimsler, M; Elfring, D R

    1995-09-01

    This study demonstrated that bacteria penetrate three kinds of dental acrylic resin after a short time period. Samples of acrylic resin were contaminated with a variety of bacteria and were then placed in three different disinfecting solutions as directed by the manufacturers. After the specific dilution and immersion time, cultures were made from the resin samples. The only effective disinfectant was a 0.525% solution of sodium hypochlorite at a 10-minute immersion. It disinfected not only the surfaces but also the bacteria that penetrated the surfaces to a depth of 3 mm.

  6. Immobilisation of ion exchange resins in cement

    International Nuclear Information System (INIS)

    Howard, C.G.; Jolliffe, C.B.; Lee, D.J.

    1990-09-01

    The removal of activity from spent decontaminating solutions eg LOMI can be achieved using organic ion exchange resins. These resins can be successfully immobilised in cement based matrices. The optimum cement system contained 10% ordinary Portland cement 84% gg blast furnace slag, 6% microsilica with a water cement ratio of 0.5 and a dry resin loading of 36% with respect to total weight. This formulation was successfully scaled up to 200 litres giving a product with acceptable compressive strength, dimensional stability and elastic modulus. Storage of samples under water appears to have no detrimental effects on the product's properties. (author)

  7. [Dental plaque microcosm biofilm behavior on a resin composite incorporated with nano-antibacterial inorganic filler containing long-chain alkyl quaternary ammonium salt].

    Science.gov (United States)

    Junling, Wu; Qiang, Zhang; Ruinan, Sun; Ting, Zhu; Jianhua, Ge; Chuanjian, Zhou

    2015-12-01

    To develop a resin composite incorporated with nano-antibacterial inorganic filler containing long-chain alkyl quaternary ammonium salt, and to measure its effect on human dental plaque microcosm biofilm. A novel nano-antibacterial inorganic filler containing long-chain alkyl quaternary ammonium salt was synthesized according to methods introduced in previous research. Samples of the novel nano-antibacterial inorganic fillers were modified by a coupling agent and then added into resin composite at 0%, 5%, 10%, 15% or 20% mass fractions; 0% composite was used as control. A flexural test was used to measure resin composite mechanical properties. Results showed that a dental plaque microcosm biofilm model with human saliva as inoculum was formed. Colony-forming unit (CFU) counts, lactic acid production, and live/dead assay of biofilm on the resin composite were calculated to test the effect of the resin composite on human dental plaque microcosm biofilm. The incorporation of nano-antibacterial inorganic fillers with as much as 15% concentration into the resin composite showed no adverse effect on the mechanical properties of the resin composite (P > 0.05). Resin composite containing 5% or more nano-antibacterial inorganic fillers significantly inhibited the metabolic activity of dental plaque microcosm biofilm, suggesting its strong antibacterial potency (P < 0.05). This novel resin composite exhibited a strong antibacterial property upon the addition of up to 5% nano-antibacterial inorganic fillers, thereby leading to effective caries inhibition in dental application.

  8. Cobalt Ions Improve the Strength of Epoxy Resins

    Science.gov (United States)

    Stoakley, D. M.; St. Clair, A. K.

    1986-01-01

    Technique developed for improving mechanical strength of epoxy resins by adding cobalt ions in form of tris(acetylacetonato)cobalt (III) complex. Solid cast disks prepared from cobalt ion-containing epoxy resins tested for flexural strength and stiffness. Incorporation of cobalt ions into epoxies increased flexural strength of resins by 10 to 95 percent. Suitable resins for this technique include any liquid or solid TGMDA resins. Improved epoxy formulation proves useful as composite matrix resin, adhesive, or casting resin for applications on commercial and advanced aircraft.

  9. Multiscale Analysis of Pebble Bed Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hans Gougar; Woo Yoon; Abderrafi Ougouag

    2010-10-01

    – The PEBBED code was developed at the Idaho National Laboratory for design and analysis of pebble-bed high temperature reactors. The diffusion-depletion-pebble-mixing algorithm of the original PEBBED code was enhanced through coupling with the THERMIX-KONVEK code for thermal fluid analysis and by the COMBINE code for online cross section generation. The COMBINE code solves the B-1 or B-3 approximations to the transport equation for neutron slowing down and resonance interactions in a homogeneous medium with simple corrections for shadowing and thermal self-shielding. The number densities of materials within specified regions of the core are averaged and transferred to COMBINE from PEBBED for updating during the burnup iteration. The simple treatment of self-shielding in previous versions of COMBINE led to inaccurate results for cross sections and unsatisfactory core performance calculations. A new version of COMBINE has been developed that treats all levels of heterogeneity using the 1D transport code ANISN. In a 3-stage calculation, slowing down is performed in 167 groups for each homogeneous subregion (kernel, particle layers, graphite shell, control rod absorber annulus, etc.) Particles in a local average pebble are homogenized using ANISN then passed to the next (pebble) stage. A 1D transport solution is again performed over the pebble geometry and the homogenized pebble cross sections are passed to a 1-d radial model of a wedge of the pebble bed core. This wedge may also include homogeneous reflector regions and a control rod region composed of annuli of different absorbing regions. Radial leakage effects are therefore captured with discrete ordinates transport while axial and azimuthal effects are captured with a transverse buckling term. In this paper, results of various PBR models will be compared with comparable models from literature. Performance of the code will be assessed.

  10. Effect of in-office bleaching agents on the color changes of stained ceromers and direct composite resins.

    Science.gov (United States)

    Xing, Wenzhong; Jiang, Tao; Liang, Shanshan; Sa, Yue; Wang, Zhejun; Chen, Xiaodong; Wang, Yining

    2014-11-01

    To evaluate the effect of two in-office bleaching agents on the color changes of two ceromers (Ceramage and Adoro SR) and one direct composite resin (Gradia Direct Anterior) after staining by tea and coffee. Twenty-four disk-shaped specimens were fabricated for each resin material and randomly divided into three groups (n = 8). The specimens were immersed in tea, coffee or deionized water, respectively, for 7 days. Each group was then equally divided into two sub-groups (n = 4), which were subjected to two in-office bleaching agents (BEYOND and Opalescence Boost), respectively. The color of the specimens was measured by a spectrophotometer at baseline, after staining and after bleaching. The color differences (ΔE values) between baseline and after treatments were calculated. Statistical analysis indicated that the staining solution had significant influence on the color change of resin composites tested (p 2.0). There was no statistically significant difference between BEYOND and Opalescence Boost in stains removal from discolored resins (p = 0.550). The color changes in ΔE value between baseline and after bleaching were less than 2.0 for all resin composite groups. Tea solution produces severe discoloration of three resin composites tested. The two in-office bleaching agents can effectively remove the stains from two ceromers and one direct composite resin tested in this study.

  11. Surface Engineering of PAMAM-SDB Chelating Resin with Diglycolamic Acid (DGA) Functional Group for Efficient Sorption of U(VI) and Th(IV) from Aqueous Medium

    Energy Technology Data Exchange (ETDEWEB)

    Ilaiyaraja, P.; Venkatraman, B., E-mail: chemila07@gmail.com [Radiological Safety Division, Indira Gandhi Centre for Atomic Research, Kalpakkam (India); Deb, A.K. Singha [Chemical Engineering Division, Bhabha Atomic Research Centre, Mumbai (India); Ponraju, D. [Safety Engineering Division, Indira Gandhi Centre for Atomic Research, Kalpakkam (India); Ali, Sk. Musharaf [Chemical Engineering Division, Bhabha Atomic Research Centre, Mumbai (India)

    2017-04-15

    Highlights: • A new DGA-PAMAM-SDB chelating resin has been synthesized for actinide sorption. • Maximum sorption capacities of resin are 682 and 544.2 mg g{sup −1}for U(VI) and Th(IV). • DGA-PAMAM-SDB chelating resin could be regenerated and reused. • DFT calculation of actinides interaction with resin corroborates the experimental. • Resin is effective for sorption of actinides from both aqueous and HNO{sub 3} medium. - Abstract: A novel chelating resin obtained via growth of PAMAM dendron on surface of styrene divinyl benzene resin beads, followed by diglycolamic acid functionalization of the dendrimer terminal. Batch experiments were conducted to study the effects of pH, nitric acid concentration, amount of adsorbent, shaking time, initial metal ion concentration and temperature on U(VI) and Th(IV) adsorption efficiency. Diglycolamic acid terminated PAMAM dendrimer functionalized styrene divinylbenzene chelating resin (DGA-PAMAM-SDB) is found to be an efficient candidate for the removal of U(VI) and Th(IV) ions from aqueous (pH > 4) and nitric acid media (> 3 M). The sorption equilibrium could be reached within 60 min, and the experimental data fits with pseudo-second-order model. Langmuir sorption isotherm model correlates well with sorption equilibrium data. The maximum U(VI) and Th(IV) sorption capacity onto DGA-PAMAMG{sub 5}-SDB was estimated to be about 682 and 544.2 mg g{sup −1} respectively at 25 °C. The interaction of actinides and chelating resin is reversible and hence, the resin can be regenerated and reused. DFT calculation on the interaction of U(VI) and Th(IV) ions with chelating resin validates the experimental findings.

  12. Shear bond strength of an autopolymerizing repair resin to injection-molded thermoplastic denture base resins.

    Science.gov (United States)

    Hamanaka, Ippei; Shimizu, Hiroshi; Takahashi, Yutaka

    2013-09-01

    This study investigated the shear bond strength of an autopolymerizing repair resin to injection-molded thermoplastic denture base resins. Four injection-molded thermoplastic resins (two polyamides, a polyethylene terephthalate copolymer and a polycarbonate) were used in this study. The specimens were divided into eight groups according to the type of surface treatment given: (1) no treatment, (2) air abrasion with alumina, (3) dichloromethane, (4) ethyl acetate, (5) 4-META/MMA-TBB resin, (6) alumina and 4-META/MMA-TBB resin, (7) tribochemical silica coating or (8) tribochemical silica coating and 4-META/MMA-TBB resin. Half of the specimens in groups 1, 5, 6 and 8 were thermocycled for 10,000 cycles in water between 5-55°C with a dwell time of 1 min at each temperature. The shear bond strengths were determined. The shear bond strengths to the two polyamides treated with alumina, dichloromethane and ethyl acetate and no treatment were very low. The greatest post-thermocycling bond strengths to polyamides were recorded for the specimens treated with tribochemical silica coating and 4-META/MMA-TBB resin (PA12: 16.4 MPa, PACM12: 17.5 MPa). The greatest post-thermocycling bond strengths to polyethylene terephthalate copolymer and polycarbonate were recorded for the treatment with alumina and 4-META/MMA-TBB resin (22.7 MPa, 20.8 MPa). Polyamide was exceedingly difficult to bond to an autopolymerizing repair resin; the shear bond strength improved using tribochemical silica coating followed by the application of 4-META/MMA-TBB resin. Both polyethylene terephthalate copolymer and polycarbonate were originally easy to bond to an autopolymerizing repair resin. However, with 4-META/MMA-TBB resin, the bond was more secure.

  13. Magnetic ion-exchange resin treatment: Impact of water type and resin use

    OpenAIRE

    Mergen, Maxime Rodolphe Denis; Jefferson, Bruce; Parsons, Simon A.; Jarvis, Peter

    2008-01-01

    Three raw waters of fundamentally different natural organic matter (NOM) character were treated by magnetic resin using a bench-scale method designed to mimic how the resin is used in continuous operation. Increasing water hydrophobicity resulted in reduced dissolved organic carbon (DOC) removal with removal of 56%, 33% and 25% for waters containing 21%, 50% and 75% hydrophobic NOM, respectively. Study of consecutive resin uses showed that the NOM in the hydrophobic water ha...

  14. 5-year clinical performance of resin composite versus resin modified glass ionomer restorative system in non-carious cervical lesions

    DEFF Research Database (Denmark)

    Franco, Eduardo Batista; Benetti, Ana Raquel; Ishikiriama, Sérgio Kiyoshi

    2006-01-01

    To comparatively assess the 5-year clinical performance of a 1-bottle adhesive and resin composite system with a resin-modified glass ionomer restorative in non-carious cervical lesions.......To comparatively assess the 5-year clinical performance of a 1-bottle adhesive and resin composite system with a resin-modified glass ionomer restorative in non-carious cervical lesions....

  15. 21 CFR 175.380 - Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins.

    Science.gov (United States)

    2010-04-01

    ...-isopropylidenediphenol-epichlorohydrin epoxy resins. 175.380 Section 175.380 Food and Drugs FOOD AND DRUG ADMINISTRATION... Xylene-formaldehyde resins condensed with 4,4′-isopropylidenediphenol-epichlorohydrin epoxy resins. The...′-isopropylidenediphenol-epichlorohydrin epoxy resins, to which may have been added certain optional adjuvant substances...

  16. Non Destructive Application of Radioactive Tracer Technique for Characterization of Industrial Grade Anion Exchange Resins Indio GS-300 and Indion-860

    International Nuclear Information System (INIS)

    Singare, P. U.

    2014-01-01

    The paper deals with the application of radio isotopic non-destructive technique in the characterization of two industrial grade anion exchange resins Indion GS-300 and Indion-860. For the characterization of the two resins, 131 I and 82 Br were used as tracer isotopes to trace the kinetics of iodide and bromide ion-isotopic exchange reactions. It was observed that the values of specific reaction rate (min -1 ), amount of iodide ion exchanged (mmol), initial rate of iodide ion exchange (mmol/min) and log K d were calculated as 0.328, 0.577, 0.189 and 19.7 respectively for Indion GS-300 resin, which was higher than the respective values of 0.180, 0.386, 0.070 and 17.0 calculated for Indion-860 resins when measured under identical experimental conditions. Also at a constant temperature of 40.0 .deg. C, as the concentration of labeled iodide ion solution increases 0.001 M to 0.004 M, the percentage of iodide ions exchanged increases from 75.16 % to 78.36 % for Indion GS-300 resins, which was higher than the increases from 49.65 % to 52.36 % compared to that obtained for Indion-860 resins. The overall results indicate that under identical experimental conditions, Indion GS-300 resins show superior performance over Indion-860 resins

  17. Protecting Your Home from Bed Bugs

    Science.gov (United States)

    ... your home: Inspect the luggage rack in your hotel room for bed bugs. Check secondhand furniture, beds, ... Grants January 19, 2017 Web Snapshot No FEAR Act Data Privacy Privacy and Security Notice Connect. Data. ...

  18. Videos, Webinars, Blogs Related to Bed Bugs

    Science.gov (United States)

    These tools provide practical insight on issues such as integrated pest management (IPM) for schools, bed bug bites, how carpet beetles can help, bed bugs as hitchhikers, and preventing and controlling infestations.

  19. EPA-Registered Bed Bug Products

    Science.gov (United States)

    ... treat your bed bug infestation. Foggers and bug bombs should not be used as the only method ... effective but take some time to kill the population); or Bed bugs’ becoming resistant to a specific ...

  20. The effect of tooth age on colour adjustment potential of resin composite restorations.

    Science.gov (United States)

    Tanaka, A; Nakajima, M; Seki, N; Foxton, R M; Tagami, J

    2015-02-01

    The purpose of this study was to investigate the effect of tooth age on colour adjustment potential of resin composite restorations in human teeth. Twenty extracted human premolars with an A2 shade, extracted for orthodontic reasons from younger patients (20-28yrs) (younger teeth) and periodontal reasons from older patients (45-69yrs) (older teeth), were used in this study. Cylindrical shaped cavities (3.0mm depth; 2.0mm diameter) were prepared in the centre of the crowns on the buccal surface. One of four resin composites of A2 shade (Kalore, KA; Solare, SO; Clearfil Majesty, MJ; Beautifil II, BF) was placed in the cavity, and the colour was measured at four areas (0.4mm×0.4mm) on the restored teeth (area 1; tooth area 1.0mm away from the border of resin composite restoration: area 2; tooth border area 0.3mm away from margin of resin composite restoration: area 3; resin composite border area 0.3mm away from margin of resin composite restoration: area 4; resin composite area at the centre of resin composite restoration) using a spectrophotometer (Crystaleye). The colour of each area was determined according to the CIELAB colour scale. Colour differences (ΔE*) between the areas of 1 and 2, 2 and 3, 3 and 4 and 1 and 4 were calculated, and also the ratio of ΔE*area2-3 to ΔE*area1-4 (ΔE*area2-3/1-4), ΔE*area3-4 to ΔE*area1-4 (ΔE*area3-4/1-4) and ΔE*area1-2 to ΔE*area1-4 (ΔE*area1-2/1-4) as a parameter of the colour shift in resin composite restoration, were determined. Moreover, the light transmission characteristics of the resin materials and dentine discs from the younger and older teeth were measured using a goniophotometer. The data were statistically analyzed using two-way ANOVA, and Dunnett's T3 and t-test for the post hoc test. ΔE*area2-3 (colour difference between resin composite and tooth at the border) and ΔE*area1-4 (colour difference between resin composite and tooth) of the older teeth groups were significantly larger than those of younger

  1. The strengthening of resin cemented dental ceramic materials

    OpenAIRE

    Hooi, Paul

    2013-01-01

    The aim of the current investigation was to advance the understanding of the mechanism of resin-strengthening conferred to dental ceramic materials by resin-based composite materials. The investigation is presented as a series of manuscripts. In the first study (Manuscript 3.1), dental porcelain disc-shaped specimens were resin-coated with three resin-based composite materials with different flexural moduli at discrete resin thicknesses. The discs were loaded to failure in a biaxial flexure t...

  2. Pengaruh Sifat-Sifat Fisik Resin Akrilik Terhadap Basis Protesa

    OpenAIRE

    Amriani Syahfitri

    2008-01-01

    Saat ini resin akrilik banyak digunakan secara umum untuk konstruksi gigi tiruan. Sebagai bahan basis prothesa, penggunaan resin akrilik terutama resin heat cured adalah yang paling sering digunakan selain bernilai estetis, juga lebih ekonomis. Pada prothesa yang ideal memerlukan suatu basis yang kuat, Syarat- syarat basis protesa tidak semuanya dapat dipenuhi oleh basis resin akrilik. Sifat-sifat fisik resin akrilik mempunyai pengaruh terhadap basis protesa. Untuk menghindari k...

  3. Effects of air-polishing powders on color stability of composite resins

    Science.gov (United States)

    GÜLER, Ahmet Umut; DURAN, Ibrahim; YÜCEL, Ali Çagin; ÖZKAN, Pelin

    2011-01-01

    Objectives The purpose of this study was to investigate the effect of different air-polishing powders on the color stability of different types of composite resin restorative materials. Material and methods Thirty cylindrical specimens (15×2 mm) were prepared for each of 7 composite resin restorative materials. All specimens were polished with a series of aluminum oxide polishing discs (Sof-Lex). The prepared specimens of each composite resin were randomly divided into 3 groups of 10 specimens each, for control (Group-C) and two air-powder applications (Group-CP: Cavitron Prophy-Jet; Group-PS: Sirona ProSmile prophylaxis powder). A standard air-polishing unit (ProSmile Handly) was used. All specimens were air-powdered for 10 s at 4-bar pressure. The distance of the spray nosel from the specimens was approximately 10 mm and angulation of the nosel was 90º. Specimens were stored in 100 mL of coffee (Nescafe Classic) for 24 h at 37ºC. Color measurement of all specimens was recorded before and after exposure to staining agent with a colorimeter (Minolta CR-300). Color differences (∆E*) between the 2 color measurements (baseline and after 24 h storage) were calculated. The data were analyzed with a 2-way ANOVA test, and mean values were compared by the Tukey HSD test (p≤0.05). Results According to the 2-way ANOVA results, composite resin restorative materials, air-polishing powders, and their interaction were statistically significant (pGrandio, CeramX Mono, and Quixfil composite resin restorative materials, no significant difference was observed between Group-PS and Group-CP (p>.05) and these groups demonstrated the highest ∆E* values. For Filtek Silorane and IntenS, the highest ∆E* values were observed in Group-PS. The lowest ∆E* values for all composite resin groups were observed in Group-C. When comparing the 7 composite resin restorative materials, Aelite Aesthetic Enemal demonstrated significantly less ∆E* values than the other composite resins

  4. Resin Flow Analysis in the Injection Cycle of a Resin Transfer Molded Radome

    Science.gov (United States)

    Golestanian, Hossein; Poursina, Mehrdad

    2007-04-01

    Resin flow analysis in the injection cycle of an RTM process was investigated. Fiberglass and carbon fiber mats were used as reinforcements with EPON 826 epoxy resin. Numerical models were developed in ANSYS finite element software to simulate resin flow behavior into a mold of conical shape. Resin flow into the woven fiber mats is modeled as flow through porous media. The injection time for fiberglass/epoxy composite is found to be 4407 seconds. Required injection time for the carbon/epoxy composite is 27022 seconds. Higher injection time for carbon/epoxy part is due to lower permeability value of the carbon fibers compared to glass fiber mat.

  5. Dental repair material: a resin-modified glass-ionomer bioactive ionic resin-based composite.

    Science.gov (United States)

    Croll, Theodore P; Berg, Joel H; Donly, Kevin J

    2015-01-01

    This report documents treatment and repair of three carious teeth that were restored with a new dental repair material that features the characteristics of both resin-modified glass-ionomer restorative cement (RMGI) and resin-based composite (RBC). The restorative products presented are reported by the manufacturer to be the first bioactive dental materials with an ionic resin matrix, a shock-absorbing resin component, and bioactive fillers that mimic the physical and chemical properties of natural teeth. The restorative material and base/liner, which feature three hardening mechanisms, could prove to be a notable advancement in the adhesive dentistry restorative materials continuum.

  6. Nanosilica Modification of Elastomer-Modified VARTM Epoxy Resins for Improved Resin and Composite Toughness

    National Research Council Canada - National Science Library

    Robinette, Jason; Bujanda, Andres; DeSchepper, Daniel; Dibelka, Jessica; Costanzo, Philip; Jensen, Robert; McKnight, Steven

    2007-01-01

    Recent publications have reported a synergy between rubber and silica in modified epoxy resins that results in significantly improved fracture toughness without reductions in other material properties...

  7. Color management of porcelain veneers: influence of dentin and resin cement colors.

    Science.gov (United States)

    Dozic, Alma; Tsagkari, Maria; Khashayar, Ghazal; Aboushelib, Moustafa

    2010-01-01

    Porcelain veneers have become an interesting treatment option to correct the shape and color of anterior teeth. Because of their limited thickness and high translucency, achieving a good color match is influenced by several variables. The aim of this work was to investigate the influence of natural dentin and resin cement colors on final color match of porcelain veneers. A preselected shade tab (A1) was chosen as the target color for a maxillary central incisor, and its color parameters (L*a*b*) were measured using a digital spectrophotometer (SpectroShade, MHT). Nine natural dentin colors (Natural Die Material, Ivoclar Vivadent) representing a wide range of tooth colors were used to prepare resin replicas of the maxillary central incisor with a standard preparation for porcelain veneers. The prepared porcelain veneers (IPS Empress Esthetic, A1, 0.6 mm thick, Ivoclar Vivadent) were cemented on the resin dies (nine groups of natural dentin colors) using seven shades of resin cement (Variolink Veneers, Ivoclar Vivadent). The L*a*b* values of the cemented veneers were measured, and DE values were calculated against the preselected target color (A1). DE greater than 3.3 was considered as a significant color mismatch detectable by the human eye. The seven shades of resin cement had no significant influence on the final color of the veneers, as the measured DE values were almost identical for every test group. On the other hand, the color of natural dentin was a significant factor that influenced final color match. None of the 63 tested combinations (nine natural dentin colors and seven resin cement colors) produced an acceptable color match. Thin porcelain veneers cannot mask underlying tooth color even when different shades of resin cement are used. Incorporation of opaque porcelain (high chroma) may improve final color match.

  8. Color stability of visible light cured composite resin after soft drink immersion

    Directory of Open Access Journals (Sweden)

    Alizatul Khairani Hasan

    2009-09-01

    Full Text Available Background: Composite resin is a tooth-colored filling material containing Bis-GMA which exhibits water sorption properties. People tend to consume soft drink with various colors. Water sorption properties can alter the color stability of composite resin purpose. Purpose: This study was to determine the influence of immersion durations of composite resin in soft drink on color stability. Methods: The visible-light cured hybrid composite resin and soft drink were used. Ten disk specimens (2.5 mm thickness and 15 mm diameter of composite resin were prepared and light cured for 20 seconds, then stored in distilled water for 24 hours at 37° C. The initial color of specimens were measured by Chromameter. After that, each specimen was immersed in 30 ml of soft drink up to 48, 72, and 96 hours at 37° C. The specimens’ color were measured again after each immersion. The color changes were calculated by CIE L*a*b* system formula. The data was analyzed by One-Way ANOVA and LSD (α = 0.05. Result: The ANOVA showed that the immersion durations of composite resin in soft drinks had significant influence on the color stability (p < 0.05. The LSD0.05 tests showed significant differences among all groups. The least color change was detected from the group of 48 hours immersion, while the greatest color change was from the group of 96 hours immersion. Conclusions: The immersion of composite resin in soft drinks influenced the color stability (began after 48 hours immersion.

  9. [Color stability of ceromer veneers/resin cements after accelerated ageing].

    Science.gov (United States)

    Wang, Likai; Liu, Yanan; Zheng, Yan; Li, Pingping; Shi, Lianshui

    2014-02-01

    To investigate the color stability of ceromer veneers/resin cements after accelerated ageing, and to provide the reference for clinical application and choice. Fifteen groups of ceromer veneers/resin cements samples, five samples in each group, were prepared as experimental groups.In the fifteen groups, ceromer veneers in three thickness (1.00, 0.75, 0.50 mm) and resin cements of five shades(A1,A3, B 0.5, WO, TR), were matched through permutation and combination. Three groups of ceromer veneers with different thickness (1.00, 0.75, 0.50 mm) were used as control groups. All samples were put into xenon lamp ageing instrument to accelerate ageing.Spectrophotometer were used to measure the lightness(L(*)), red green color(a(*)) and blue yellow color(b(*)) of samples before and after accelerated ageing process, and the change of lightness (ΔL) , red green color (Δa) , blue yellow color (Δb) and color variation(ΔE) were calculated.We investigated the effect of thickness of ceromer veneer and color of resin cement on color variation by using analysis of variance. The thickness factor and color factor showed significant effect on ΔE values, and they have interaction (P ceromer veneer and the color of resin cement could both affect the color stability of ceromer veneers/resin cements. The changes of lightness and color in ceromer veneers/resin cements were considered clinically acceptable after accelerated ageing.

  10. Synthesis of improved phenolic and polyester resins

    Science.gov (United States)

    Delano, C. B.

    1980-01-01

    Thirty-seven cured phenolic resin compositions were prepared and tested for their ability to provide improved char residues and moisture resistance over state of the art epoxy resin composite matrices. Cyanate, epoxy novolac and vinyl ester resins were investigated. Char promoter additives were found to increase the anaerobic char yield at 800 C of epoxy novolacs and vinyl esters. Moisture resistant cyanate and vinyl ester compositions were investigated as composite matrices with Thornel 300 graphite fiber. A cyanate composite matrix provided state of the art composite mechanical properties before and after humidity exposure and an anaerobic char yield of 46 percent at 800 C. The outstanding moisture resistance of the matrix was not completely realized in the composite. Vinyl ester resins showed promise as candidates for improved composite matrix systems.

  11. Posterior bulk-filled resin composite restorations.

    DEFF Research Database (Denmark)

    van Dijken, Jan WV; Pallesen, Ulla

    2016-01-01

    Purpose/aim: To evaluate in a randomized controlled study the 5-year clinical durability of a flowable resin composite bulk-fill technique in Class I and Class II restorations. Materials and methods: 38 pairs Class I and 62 pairs Class II restorations were placed in 44 male and 42 female (mean age...... 52.4 years). Each patient received at least two, as similar as possible, extended Class I or Class II restorations. In all cavities, a 1-step self-etch adhesive (Xeno V+) was applied. Randomized, one of the cavities of each pair received the flowable bulk-filled resin composite (SDR), in increments...... up to 4mm as needed to fill the cavity 2mm short of the occlusal cavosurface. The occlusal part was completed with the nano-hybrid resin composite (Ceram X mono+). In the other cavity, the resin composite-only (Ceram X mono+) was placed in 2mm increments. The restorations were evaluated using...

  12. 21 CFR 177.1380 - Fluorocarbon resins.

    Science.gov (United States)

    2010-04-01

    ...) Chlorotrifluoroethylene-1,1-difluoroethylene-tetrafluoroethylene co-polymer resins produced by copolymerization of..., Extrusion, and Coating Materials,” which is incorporated by reference in accordance with 5 U.S.C. 552(a) and...

  13. Liquid Resins With Low VOC Emissions

    National Research Council Canada - National Science Library

    LaScala, John J; Sands, James M; Palmese, Guiseppe R

    2004-01-01

    .... The polymer properties were similar to that of commercial resins, including Tg greater than 120 C, flex strength greater than 100 MPa, modulus of approximately 3 GPa, and fracture toughness greater than 200 J/m2...

  14. 21 CFR 177.1655 - Polysulfone resins.

    Science.gov (United States)

    2010-04-01

    ... by osmotic pressure in monochlorobenzene; or (2) 1,1′-Sulfonylbis[4-chlorobenzene] polymer with 4,4... determined by osmotic pressure in dimethylformamide. (b) The basic polysulfone resins identified in paragraph...

  15. Fluidization quality analyzer for fluidized beds

    Science.gov (United States)

    Daw, C.S.; Hawk, J.A.

    1995-07-25

    A control loop and fluidization quality analyzer for a fluidized bed utilizes time varying pressure drop measurements. A fast-response pressure transducer measures the overall bed pressure drop, or over some segment of the bed, and the pressure drop signal is processed to produce an output voltage which changes with the degree of fluidization turbulence. 9 figs.

  16. Influence of water sorption on mechanical properties of injection-molded thermoplastic denture base resins.

    Science.gov (United States)

    Hamanaka, Ippei; Iwamoto, Misa; Lassila, Lippo; Vallittu, Pekka; Shimizu, Hiroshi; Takahashi, Yutaka

    2014-11-01

    This study investigated the influence of water sorption on certain mechanical properties of injection-molded thermoplastic denture base resins. Six thermoplastic resins (two polyamides, two polyesters, one polycarbonate, one polymethylmethacrylate) and a polymethylmethacrylate (PMMA) conventional heat-polymerized denture-based polymer, selected as a control, were tested. Specimens of each denture base material were fabricated according to ISO 1567 specifications and were either dry or water-immersed for 30 days (n = 10). The ultimate flexural strength, the flexural strength at the proportional limit and the elastic modulus of the denture base materials were calculated. Water sorption significantly decreased the ultimate flexural strength, the flexural strength at the proportional limit and the elastic modulus of one of the polyamides and the PMMAs. It also significantly increased the ultimate flexural strength of the polycarbonate. The mechanical properties of some injection-molded thermoplastic denture base resins changed after water sorption.

  17. RELATION BETWEEN MECHANICAL PROPERTIES AND PYROLYSIS TEMPERATURE OF PHENOL FORMALDEHYDE RESIN FOR GAS SEPARATION MEMBRANES

    Directory of Open Access Journals (Sweden)

    MONIKA ŠUPOVÁ

    2012-03-01

    Full Text Available The aim of this paper has been to characterize the relation between the pyrolysis temperature of phenol-formaldehyde resin, the development of a porous structure, and the mechanical properties for the application of semipermeable membranes for gas separation. No previous study has dealt with this problem in its entirety. Phenol-formaldehyde resin showed an increasing trend toward micropore porosity in the temperature range from 500 till 1000°C, together with closure of mesopores and macropores. Samples cured and pyrolyzed at 1000°C pronounced hysteresis of desorption branch. The ultimate bending strength was measured using a four-point arrangement that is more suitable for measuring of brittle materials. The chevron notch technique was used for determination the fracture toughness. The results for mechanical properties indicated that phenol-formaldehyde resin pyrolyzates behaved similarly to ceramic materials. The data obtained for the material can be used for calculating the technical design of gas separation membranes.

  18. Cycloaliphatic epoxide resins for cationic UV - cure

    International Nuclear Information System (INIS)

    Verschueren, K.; Balwant Kaur

    1999-01-01

    This paper introduces the cyclo - aliphatic epoxide resins used for the various applications of radiation curing and their comparison with acrylate chemistry. Radiation curable coatings and inks are pre - dominantly based on acrylate chemistry but over the last few years, cationic chemistry has emerged successfully with the unique properties inherent with cyclo - aliphatic epoxide ring structures. Wide variety of cationic resins and diluents, the formulation techniques to achieve the desired properties greatly contributes to the advancement of UV - curing technology

  19. Damage evolution in a filled epoxy resin

    International Nuclear Information System (INIS)

    Depoorter, Nicolas; Coutellier, Daniel; Muzic, Markus; Berg-Pollack, Antje; Cai Ye; Zimmermann, Andre

    2006-01-01

    A method is proposed for studying damage evolution in a filled epoxy resin submitted to low-cycle fatigue loading. Transmission electron microscopy analysis was performed, which indicates a damage mechanism that corresponds well to the decreasing slope of the stress-strain hysteresis observed in strain-controlled fatigue experiments. Also, the suggested damage model appears to be suitable for the simulation of strain-controlled cyclic tests and fits the damage evolution of the filled epoxy resin fairly well [de

  20. Designing a CR Test bed

    DEFF Research Database (Denmark)

    Cattoni, Andrea Fabio; Buthler, Jakob Lindbjerg; Tonelli, Oscar

    2014-01-01

    with their own set up, since the potential costs and efforts could not pay back in term of expected research results. Software Defined Radio solutions offer an easy way to communication researchers for the development of customized research test beds. While several hardware products are commercially available......Research on intelligent and reconfigurable wireless systems is in continuous evolution. Nevertheless, in order to fix some keystones, more and more researchers are entering the idea of research-oriented test beds. Unfortunately, it is very difficult for a wide number of research groups to start......, the software is most of the times open source and ready to use for third party users. Even though the software solution developers claim complete easiness in the development of custom applications, in reality there are a number of practical hardware and software issues that research groups need to face, before...

  1. Review of acute cancer beds.

    LENUS (Irish Health Repository)

    Evans, D S

    2012-01-01

    A review of admissions to cancer services at University Hospital Galway (UHG) was undertaken to assess the appropriateness of hospital usage. All cancer specialty patients admitted from 26-28 May 2009 were reviewed (n = 82). Chi square tests, Exact tests, and One-way ANOVA were utilised to analyse key issues emerging from the data. Fifty (61%) were classified as emergencies. Twenty three (67%) occupied a designated cancer bed with 24 (30%) in outlying non-oncology wards. The mean length of stay was 29.3 days. Possible alternatives to admission were identified for 15 (19%) patients. There was no evidence of discharge planning for 50 (60%) admissions. There is considerable potential to make more appropriate utilisation of UHG for cancer patients, particularly in terms of reducing bed days and length of stay and the proportion of emergency cancer admissions, and further developing integrated systems of discharge planning.

  2. Device for measuring bed pressure

    Energy Technology Data Exchange (ETDEWEB)

    Gulin, B.M.; Chubar, V.G.

    1979-03-05

    The invention refers to studies in wells and is designed for piezomeasurements for the processes of undergrond leaching out associated with the movement of fluids of variable density to the productive beds. The purpose of he invention is to increase the accuracy of measurements of bed pressure by reducing the influence of changes of fluid density in the well. The goal is achieved because the device is equipped with a piezometric pipe arranged in the well and filled with liquid whose density is less than the density of the solution, and the transformer of the level is installed in the pipe. The pipe can have a throttle. A drawing and description of the proposed device are presented.

  3. Cleaning of porous filters in fossilized bed reactors

    International Nuclear Information System (INIS)

    Rodrigo Otero, A.; Sancho Rod, J.

    1965-01-01

    In this report are established the optimum working conditions of a filter cleaning system by blow back. For this purpose it was determined in the first place the blow back air rate necessary to have a good cleaning. The reasons for which it was not possible until now to control the pressure in a fluidized bed calcination reactor are analyzed and a criteria is established to calculate the optimum floe necessary to clean efficiently a porous by this procedures. (Author)

  4. Influence of polymerization time and depth of cure of resin composites determined by Vickers hardness

    Science.gov (United States)

    Lombardini, Marco; Chiesa, Marco; Scribante, Andrea; Colombo, Marco; Poggio, Claudio

    2012-01-01

    Background: Adequate polymerization of resin composites could be considered as a crucial factor in obtaining good clinical performance, particularly in stress-bearing areas. An insufficient curing degree affects the resin composite's chemical properties The current in vitro study evaluated the influence of polymerization time and depth of cure of six commercial resin composites by Vickers microhardness (VK). Materials and Methods: Six resin composites were selected: Three microhybrid (Esthet.X HD, Amaris, Filtek Silorane), two nanohybrid (Grandio, Ceram.X mono), and one nanofilled (Filtek Supreme XT). The VK of the surface was determined by a microhardness tester using a Vickers diamond indenter and a 200 g load applied for 15 s. The bottom to top mean VK ratio was calculated using the formula: Hardness ratio = VK of bottom surface/VK of top surface. Vickers hardness values of test materials during exposure time of 20 and 40 s and depths of cure of 2 and 3 mm were determined and compared. Data were analyzed using analysis of variance (ANOVA) test. Results: For all the tested materials and with all the exposure time periods, hardness ratio was higher than the minimum value indicated in literature (0.8). Exposure time and depth of cure did not affect hardness ratio values for Filtek Silorane, Grandio, and Filtek Supreme XT. Conclusion: Among the materials tested, the nanofilled and the nanohybrid resin composites were rather insensible to thickness variations. Miicrohybrid composites, instead, had features different from one another. PMID:23559951

  5. Comparison of temperature change among different adhesive resin cement during polymerization process

    Directory of Open Access Journals (Sweden)

    Murat Alkurt

    2017-01-01

    Full Text Available Purpose: The aim of this study was to assess the intra-pulpal temperature changes in adhesive resin cements during polymerization. Materials and Methods: Dentin surface was prepared with extracted human mandibular third molars. Adhesive resin cements (Panavia F 2.0, Panavia SA, and RelyX U200 were applied to the dentin surface and polymerized under IPS e.max Press restoration. K-type thermocouple wire was positioned in the pulpal chamber to measure temperature change (n = 7. The temperature data were recorded (0.0001 sensible and stored on a computer every 0.1 second for sixteen minutes. Differences between the baseline temperature and temperatures of various time points (2, 4, 6, 8, 10, 12, 14, and 16 minute were determined and mean temperature changes were calculated. At various time intervals, the differences in temperature values among the adhesive resin cements were analyzed by two-way ANOVA and post-hoc Tukey honestly test (α = 0.05. Results: Significant differences were found among the time points and resin cements (P < 0.05. Temperature values of the Pan SA group were significantly higher than Pan F and RelyX (P < 0.05. Conclusion: Result of the study on self-adhesive and self-etch adhesive resin cements exhibited a safety intra-pulpal temperature change.

  6. Effect of water storage on the translucency of silorane-based and dimethacrylate-based composite resins with fibres.

    Science.gov (United States)

    Ozakar Ilday, Nurcan; Celik, Neslihan; Bayindir, Yusuf Ziya; Seven, Nilgün

    2014-06-01

    The purposes of this study were (1) to determine the translucency of silorane and dimethacrylate-based composite resins and (2) to evaluate the effect of water storage and reinforcement with fibre on the translucency of composite resins. Two light-cured composite resins (A2 shade), Filtek Silorane (silorane-based composite) and Valux Plus (dimethacrylate-based composite), were used in this study. The first group was used as the control with no reinforcements, the second was reinforced with polyethylene (Ribbond THM) and the third was reinforced with a glass fibre (Everstick Net) for each composite resin. Colour measurements were measured against white and black backgrounds with a Shadepilot (Degu Dent Gmbh, Hanau, Germany) spectrophotometer and recorded under a D65 light source, which reflects daylight. CIELAB parameters of each specimen were recorded at baseline and at 24 h, 168 h and 504 h. Translucency of materials was calculated using the translucency parameter (TP) formula. Data were analyzed using repeated measures ANOVA and LSD post hoc tests (α=0.05). The highest baseline TP value was in the Valux Plus/non-fibre reinforced group (14.06±1) and the lowest in the Filtek Silorane/Ribond THM group (8.98±1.11). Repeated measures ANOVA revealed significant effects from the factors storage time, composite resin, composite resin×storage time and fibre×time (p=0.047; p=0.001; p=0.013; p=0.022, respectively). Within the limitations of the study, we concluded that inclusion of polyethylene and glass fibres did not alter the translucency of the different-based composite resins. The longest storage time resulted in the greatest change in translucency values of Filtek Silorane composite resins. Considering the translucencies of composites with different formulations in the selection of composite resins for aesthetic restorations is important in terms of obtaining optimal aesthetic outcomes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. [Effect of ceramic thickness and resin cement shades on final color of heat-pressed ceramic veneers].

    Science.gov (United States)

    Ren, D F; Zhan, K R; Chen, X D; Xing, W Z

    2017-02-09

    Objective: To analyze the effect of ceramic materials thickness and resin cement shades on the final color of ceramic veneers in the discolored teeth, and to investigate the color agreement of try-in pastes to the corresponding resin cements. Methods: Sixty artificial maxillary central incisor teeth (C2 shade) were used to simulate the natural discolored teeth and prepared according to veneer tooth preparation protocol. Veneers of different thickness in the body region (0.50 and 0.75 mm) were fabricated using ceramic materials (LT A2 shade, IPS e.max Press). The ceramic veneer specimens were bonded to the artificial teeth using the 6 shades of resin cements (Variolink Veneer: shades of LV-3, LV-2, HV+3; RelyX™ Veneer: shades of TR, A3, WO) ( n= 5). A clinical spectrophotometer was used to measure the color parameters of ceramic veneers at the cervical, body and incisal regions. Color changes of veneers before and after cementation were calculated and registered as ΔE1, and the changes between try-in paste and the corresponding resin cements were registered as ΔE2. Results: Three-way ANOVA indicated that ΔE1 and ΔE2 values were significantly affected by the ceramic thickness, resin cement shades and measuring regions ( Pceramic veneers were cemented with resin cements in shades of HV+3 and WO. The ΔE2 values of six shades ranged from 0.60-2.56. The shades of HV+3, WO and A3 resin cements were more than 1.60. Conclusions: Different thickness of ceramic materials, resin cement shades and measuring regions could affect the final color of ceramic veneers. The color differences of some resin cements and corresponding try-in pastes might be observed in clinical practice.

  8. THE BAUXITES AND JELAR - BEDS

    Directory of Open Access Journals (Sweden)

    Krešimir Sakač

    1993-12-01

    Full Text Available Minor bauxite deposits and occurrences were formed in technically disturbed environments in the middle part of the Adriatic geotectonic unit in Dinarides, contemporary with the clastic Jelar-beds in the Late Lutetian time. Uneven chemical composition of these Eocene bauxites, their sporadic occurrences in developed paleorelief as well as characteristic petrographic composition of the immediate overlying rocks point out at different genetical conditions (the paper is published in Croatian.

  9. Dynometer test bed (fact sheet)

    Energy Technology Data Exchange (ETDEWEB)

    O' Dell, K.

    2000-04-24

    The National Renewable Energy Laboratory's (NREL's) Dynamometer Test Bed is one of a kind. It offers wind industry engineers a unique opportunity to conduct lifetime endurance tests on a wide range of wind turbine drivetrains and gearboxes at various speeds, using low or high torque. By testing full-scale wind turbines, engineers from NREL and industry hope to understand the impact of various wind conditions with the goal of improving hardware design.

  10. The effect of home-bleaching application on the color and translucency of five resin composites.

    Science.gov (United States)

    Kurtulmus-Yilmaz, Sevcan; Cengiz, Esra; Ulusoy, Nuran; Ozak, Sule Tugba; Yuksel, Ece

    2013-11-01

    The aim of this study was to investigate the effect of home bleaching agents on the color and translucency of resin composites. Thirty disc shaped specimens (1mm thick) were fabricated from each resin composite (Reflexions, Grandio, Gradia Direct, Clearfil Majesty Esthetic, Ceram-X Mono) and divided into 3 subgroups as carbamide peroxide (CP, Opalescence 10% PF), hydrogen peroxide (HP, 10% Opalescence Treswhite Supreme) and control group (n=10). Baseline CIE L*a*b* color coordinates were measured with spectrophotometer and translucency parameters (TP) were calculated. CP and HP groups were treated with bleaching agents according to manufacturers' instructions and control group was stored in distilled water (DW) for 14 days. Color and translucency measurements were repeated and color differences were calculated, ΔE values>3.3 were considered as clinically unacceptable. Clinically unacceptable color change was detected for all resin composites exposed to bleaching agents and there was significant color difference between the control group and bleached specimens (P<0.05). However no significant color difference was found between CP and HP groups. Intragroup comparison revealed that Ceram-X Mono showed the highest color change but there was no significant difference among the other tested materials for both CP and HP groups. Intergroup comparison of TP values of CP, HP and control groups at the end of 14th day revealed that there was no statistical significant translucency difference among the groups. Application of CP and HP resulted in clinically unacceptable color change for all resin composites. Translucencies of the resin composites were not affected by bleaching procedure. The results of this in vitro study suggest that patients should be informed regarding a potential color change of existing resin composite restorations with the use of home bleaching agents. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Advances in fluidized bed technologies

    International Nuclear Information System (INIS)

    Mutanen, K.

    1992-01-01

    Atmospheric fluidized bed combustion (AFBC) has advanced into industrial cogeneration and utility-scale electric generation. During the 1980's AFBC became the dominant technology in the United States for power generation systems fired with solid fuels. Development of pressurized fluidized bed combustion/gasification (PFB/G) has grown rapidly from small bench-scale rigs to large pilot and demonstration plants. AFBC as large as 160 MWe in capacity are now in operation, while pressurized combustion systems generating 80 MWe have started up two years ago. The major driving forces behind development of fluidized bed technologies are all the time strictening emission control regulations, need for fuel flexibility, repowering of older power plants and need for higher efficiency in electricity generation. Independent power producers (IPP) and cogenerators were the first ones in the United States who accepted AFBC for wide commercial use. Their role will be dominant in the markets of the 1990's also. Developers of AFBC systems are working on designs that reduce investment costs, decrease emissions and offer even higher reliability and availability in utility-scale applications while developers of PFBC/G work on designs that increase plant efficiencies, allow modular construction, decrease emissions further and reduce the cost of generating power. This paper presents technological background, commercial status, boiler performance, emissions and future developments for both AFBC and PFBC/G systems

  12. Natural gas in coal beds

    Energy Technology Data Exchange (ETDEWEB)

    Kravtsov, A.I.; Voytov, G.I.

    1983-01-01

    The special importance is noted of the problem of computing and careful use of the energy raw material, coal, oil and natural gases. An examination is made of the mechanism for the formation of carboniferous gases in the beds with the use of the model of coal macromolecule. A schematic section is presented for the coal field and plan for vertical gas zonality. The change in chemical composition of the natural gases with depth is governed by the countermovement of the natural gases: from top to bottom the gases of the earth's atmosphere move, mainly oxygenand nitrogen, from bottom to top, the gases of metamorphic and deep origin. Constant isotope composition of the carbon in the fossil coals is noted. The distribution of the quanitity deltaC/sup 13/ of carbon in the fossil coals of the Donets basin is illustrated. The gas content of the coal beds and gas reserves are discussed. The flowsheet is shown for the unit for degasification of the coal bed before the cleaning face.

  13. The characteristics of bed agglomeration during fluidized bed combustion of eucalyptus bark

    International Nuclear Information System (INIS)

    Chaivatamaset, Pawin; Tia, Suvit

    2015-01-01

    The bed agglomeration behaviors were investigated experimentally when eucalyptus bark was burning tested in a laboratory scale fluidized bed reactor. The focuses of this work were the influences of operating conditions and bed materials on the bed agglomeration tendency and the elucidation in the behaviors of fuel inorganic elements and the governing mode of the agglomeration. It was found that the defluidization caused by the bed agglomeration was clearly detectable from the decrease in measured bed pressure. The growth of bed particle and accumulation of agglomerates during combustion provided the partial to complete defluidization. The defluidization was promoted by the increase of bed temperature and bed particle size, and the decrease of fluidizing air velocity. The SEM-EDS analyses revealed that the bed agglomeration was mainly attributed to the formation of potassium silicate compounds as liquid phase during the combustion. This was initiated by the chemical reaction between the bed particle and the released ash constituents. In this study, the inorganic migration from fuel particle to bed particle was likely dominated by the condensation/reaction. The thermodynamic examination by ternary phase diagram analysis corroborated that the liquid phase formation of the ash derived materials controlled the agglomeration. The alumina sand prevented the bed agglomeration since it was inactive in the formation of viscous molten substances during combustion at the observed temperatures. - Highlights: • The behaviors of bed agglomeration were studied during the fluidized bed combustion of eucalyptus bark. • The increase in bed temperature and sand size, and the decrease of air velocity promoted bed defluidization. • The formation of molten potassium silicate compounds conduced to the bed agglomeration. • Condensation/reaction was the dominant inorganic migration mechanism from fuel particle to bed particle. • The alumina sand prevented effectively the bed

  14. Bed agglomeration characteristics of palm shell and corncob combustion in fluidized bed

    International Nuclear Information System (INIS)

    Chaivatamaset, Pawin; Sricharoon, Panchan; Tia, Suvit

    2011-01-01

    Bed particle agglomeration was studied experimentally in an atmospheric laboratory scale fluidized bed combustor using quartz sand as bed material. Palm shell and corncob were tested. The objectives of the study were (i) to describe the contributions of the biomass ash properties and the operating conditions on the bed agglomeration tendency in term of the bed defluidization time (t def ) and the extent of potassium accumulation in the bed (K/Bed) and (ii) to further elucidate the ash inorganic behaviors and the governing bed agglomeration mechanisms. Defluidization caused by the bed agglomeration was experienced in all experiments during combustion of these biomasses, as a consequence of the presence of potassium in biomass. The experimental results indicated that biomass ash characteristics were the significant influence on the bed agglomeration. The increasing bed temperature, bed particle size and static bed height and the decreasing fluidizing air velocity enhanced the bed agglomeration tendency. The SEM/EDS analyses on the agglomerates confirmed that the agglomeration was attributed to the formation of potassium silicate liquid enriched on the surface of quartz sand particles in conjunction with the high surface temperature of the burning biomass char particles. Thermodynamic examination based on the phase diagram analysis confirmed that the molten phase formation was responsible for the agglomeration. In this study, the high molten ash fraction resulting from the high potassium content in biomass promoted the agglomeration and thus defluidization. - Highlights: → Palm shell and corncob of Thailand are tested their bed agglomeration behaviors during fluidized bed combustion. → The increase of bed temperature, bed particle size and static bed height and the decrease of air velocity enhance bed agglomeration. → The formation of ash derived potassium silicate melts enriched on sand surface is the key process. → The collision between char and sand

  15. The Factors Influencing Economic Efficiency of the Hospital Bed Care in Terms of the Regional Allowance Organizations

    Directory of Open Access Journals (Sweden)

    Vaňková Ivana

    2014-09-01

    Full Text Available This paper aims to provide an efficiency evaluation of selected hospital bed care providers during years 2010 -2012 with respect to selected factors: The size of the hospital establishment according to number of beds, number of hospitalized patients, the average length of stay per a patient in care, total staff cost calculated per bed, total revenues calculated per bed, and total costs calculated per bed. For this purpose, hospitals providing primarily acute bed care were chosen. From the legal point of view, they are allowance organizations of a particular region. The evaluation concerns both allocative efficiency and technical efficiency. The allocative efficiency is treated from the proper algorithm point of view and it compares total costs calculated per bed with total revenues calculated per bed. A method denominated Data Envelopment Analysis was applied for the calculation of the technical efficiency of units. To be more specific, it was input-oriented model with constant returns to scale (CCR. The input parameters involve the number of beds, the average length of stay and costs per day of stay. Output parameters were as follows: Bed occupancy in days and the number of hospitalized patients. The data published by the Institute of Health Information and Statistic of the Czech Republic and by ÚFIS system (the Data Base of Ministry of Finance of the Czech Republic were used as the source of data. The evaluation implies that only three hospitals were economically-effective: Silesian Hospital in Opava, Hospital Jihlava, and TGM Hospital Hodonín. The most significant factor influencing the efficiency was determined - the average length of stay.

  16. Recovery of uranium from seawater. 14. System arrangements for the recovery of uranium from seawater by spherical amidoxime chelating resins utilizing natural seawater motions

    International Nuclear Information System (INIS)

    Egawa, Hiroaki; Kabay, Nalan; Shuto, Taketomi; Jyo, Akinori

    1993-01-01

    In order to evaluate performances of lightly cross-linked highly porous amidoxime resins in uranium-adsorption systems utilizing natural seawater motions, uranium uptake by the resins from seawater was studied by different approaches, such as simulated sea current exposure tests, towing trials, and/or mooring trials. In general, the efficiency of uranium uptake became higher with a decrease in the thickness of packing layers, indicating important roles of fluidization of the resin particles. On the basis of these fundamental data, mooring tests in the natural sea current were designed and conducted. By mooring flat adsorption beds (base area 260 cm 2 , height 3.0 cm) packed with 780 ml of the resin for 40 h, promising uranium uptake as high as 44 mg/kg of resin (9.9 mg/l of resin) was achieved under sea conditions in which the velocity of sea currents and the vertical velocity of waves were 5.5-49.7 cm/s and 3.4-27 cm/s, respectively

  17. Imide modified epoxy matrix resins

    Science.gov (United States)

    Scola, D. A.

    1984-01-01

    The results of a program designed to develop tough imide modified epoxy resins cured by bisimide amine (BIA) hardeners are described. State-of-the-art epoxides MY720 and DER383 were used, and four bismide amines were evaluated. These were the BIA's derived from the 6F anhydride (4,4'-(hexafluoroisopropylidene) bis(phthalic anhydride) and the diamines 3,3'-diaminodiphynyl sulfone, 4,4'-oxygianiline, 4,4'-methylene dianiline, and 1,12-dodecane diamine. A key intermediate, designated 6F anhydride, is required for the synthesis of the bisimide amines. Reaction parameters to synthesize a precursor to the 6F anhydride (6FHC) in high yields were investigated. The catalyst trifluoromethane sulfonic acid was studied. Although small scale runs yielded the 6FHC in 50 percent yield, efforts to ranslate these results to a larger scale synthesis gave the 6FHC in only 9 percent yield. Results show that the concept of using bisimide amine as curing agents to improve the toughness properties of epoxies is valid.

  18. Resin elasticity and the strengthening of all-ceramic restorations.

    Science.gov (United States)

    Addison, O; Marquis, P M; Fleming, G J P

    2007-06-01

    Resin luting of all-ceramic restorations results in increased performance; however, the strengthening mechanism and the role of the mechanical properties of the resin are not fully understood. The hypothesis tested is that ceramic strength enhancement is dependent on the elastic modulus of the resin. Three-point flexural moduli of a flowable, luting, and hybrid composite resin were characterized. Two hundred forty porcelain discs were air-abraded. One group acted as a control, and 3 additional groups were coated with 120 +/- 20 microm of each resin prior to bi-axial flexure testing. All resins significantly increased in mean strength, and the associated strength increase was related to the elastic modulus of the resin (R(2) = 0.9885), so the hypothesis was accepted. The combination of Poisson constraint and the creation of a resin-inter-penetrating layer sensitive to the elastic modulus of the resin may provide an explanation of the strengthening mechanism.

  19. Clinical evaluation of an automated turning bed.

    Science.gov (United States)

    Melland, H I; Langemo, D; Hanson, D; Olson, B; Hunter, S

    1999-01-01

    The purposes of this study were to assess client comfort and sleep quality, client physiologic response (skin and respiratory status), the effect on the need for caregiver assistance, and cost when using an automated turning bed. Nonexperimental, evaluative study. Twenty-four adult home or long-term care resident subjects who had a degenerative disease, spinal cord injury, stroke, cerebral palsy, or back surgery. Each subject agreed to use the automated turning bed for four weeks. Researchers completed a demographic survey and skin assessment, and assessed each subject for pressure ulcer risk and for the need of assistance of a care giver for turning before and after the four weeks of using the turning bed. Subjects rated the turning bed in terms of comfort and sleep quality. Subjects rated the turning bed as more comfortable than their own bed and expressed satisfaction at the pain relief attained when on the turning bed. While using the turning bed, there was a significant improvement in sleep quality. No skin breakdown or deterioration in respiratory status occurred. Fewer subjects required the assistance of a caregiver for turning when on the turning bed. This automated turning bed shows great promise in meeting a need for patients with limited mobility whether they are homebound or in a residential community. Future studies that further investigate use of the turning bed for postoperative back patients while still in the acute care setting are indicated. Replicative studies with a larger sample size are also indicated.

  20. Investigation of the suspected presence of solid hydrocarbon in bedded salt samples from the Palo Duro Basin, Texas

    International Nuclear Information System (INIS)

    1985-10-01

    This report contains laboratory test results for two bedded salt samples from the Grabbe No. 1 (PD-2) Well of the Palo Duro Basin, Texas. This study was commissioned to determine whether or not solid hydrocarbons exist in bedded salt samples in the Palo Duro Basin. Laboratory investigations include electron microprobe examinations on polished thin sections and optical examinations and chemical tests on insoluble residues of the salt samples. No direct evidence was found that identifiable solid hydrocarbons are present in either sample of the bedded salt core. The total carbon content of the two salt samples was measured yielding 0.016 and 0.022 weight percent carbon. Detailed microscopic analyses showed that the carbon in the samples was associated with calcite, clays, and the epoxy resin used in sample preparation

  1. Effect of resin coating on dentin bonding of resin cement in Class II cavities.

    Science.gov (United States)

    Sultana, Shamim; Nikaido, Toru; Matin, Khairul; Ogata, Miwako; Foxton, Richard M; Tagami, Junji

    2007-07-01

    This study was designed to evaluate the efficacy of resin coating on the regional microtensile bond strength (MTBS) of a resin cement to the dentin walls of Class II cavities. Twenty mesio-occlusal cavities were prepared in human molars. In 10 cavities, a resin coating consisting of a self-etching primer bonding system, Clearfil SE Bond, and a low-viscosity microfilled resin, Protect Liner F, was applied. The other 10 teeth served as a non-coating group. After impression taking and temporization, they were kept in water for one day. Composite inlays were then cemented with a dual-cure resin cement, Panavia F 2.0, and stored in water for one day. Thereafter, MTBSs were measured. Two-way ANOVA (p=0.05) revealed that the MTBS of resin cement to dentin was influenced by resin coating, but not by regional difference. In conclusion, application of a resin coating to the dentin surface significantly improved the MTBS in indirect restorations.

  2. Bond strength of resin-resin interfaces contaminated with saliva and submitted to different surface treatments

    Directory of Open Access Journals (Sweden)

    Adilson Yoshio Furuse

    2007-12-01

    Full Text Available The purpose of this study was to investigate the effect of different surface treatments on shear bond strength of saliva-contaminated resin-resin interfaces. Flat resin surfaces were fabricated. In the control group, no contamination or surface treatment was performed. The resin surfaces of the experimental groups were contaminated with saliva and air-dried, and then submitted to: (G1 rinsing with water and drying; (G2 application of an adhesive system; (G3 rinsing and drying, abrasion with finishing disks, etching and application of adhesive system; (G4 rinsing and drying, etching, application of silane and adhesive system. Resin cylinders were placed over the treated surfaces. The specimens were stored in water or ethanol. Shear bond strength tests were performed and the mode of failure was evaluated. Data were submitted to two-way ANOVA and Dunnett T3 test. Contamination of resin-resin interfaces with saliva significantly reduced shear strength, especially after prolonged storage (p<0.05. Similar values to the original bond strength were obtained after abrasion and application of adhesive (G3 or etching and application of silane and adhesive (G4. If contamination occurs, a surface treatment is required to guarantee an adequate interaction between the resin increments.

  3. Bond strength of resin-resin interfaces contaminated with saliva and submitted to different surface treatments

    DEFF Research Database (Denmark)

    Furuse, Adilson Yoshio; da Cunha, Leonardo Fernandes; Benetti, Ana Raquel

    2007-01-01

    of silane and adhesive system. Resin cylinders were placed over the treated surfaces. The specimens were stored in water or ethanol. Shear bond strength tests were performed and the mode of failure was evaluated. Data were submitted to two-way ANOVA and Dunnett T3 test. Contamination of resin...

  4. Bed Load Transport in Channels with Bank Vegetation

    Science.gov (United States)

    Specht, F.-J.

    2003-04-01

    Natural and restored rivers are dominated to a high extent by the vegetation at the banks and on the flood plains of the river. Especially, the interactive zone between the region of water flow through the vegetation and the region of free flowing water in the main channel is of great importance. It is characterized by large vortices at the interface of these two regions. The vortices have an influence on the flow resistance, especially on bed shear stress and thus on bed load transport and dune shape. The aim of the study was to investigate the hydraulic/sedimentological processes in a trapezoidal channel depending on the arrangement of the vegetation and channel width. Laboratory experiments were carried out in a 30 m long and 2.0 m wide tilting flume. The sand of the bed (d50 = 0.82 mm) was recirculated. The arrangement of the bank vegetation (made of rigid PVC-sticks with a diameter of 10 mm, bank slope 1:1) and the width B of the channel bed was variied from B = 0.4 m to B = 1.2 m to investigate the influence of channel width on the overall processes. Based on the experimental results, the existing bed load formulas were verified to determine the influence of rigid bank vegetation on bed load transport. In the case of wide channels (B/h > 3, with h = water depth) the deviation between measured and calculated values was low. However, in the case of narrow channels (B/h bank vegetation down to the river bed the measured transport rates were 52% higher than the calculated ones and in the extreme case of B/h load transport formulas could be modified. In the experiments a significant influence of the vegetation on the occurring dunes was observed. In the series without vegetation the dune crests and vales were horizontally distributed over the width. Especially, the dune vales close to the vegetation zones are scoured in the series with vegetation. The dune crests were tilted in the cross-section of the channel in the series with vegetation on one bank only. As a

  5. Bulk-filled posterior resin restorations based on stress-decreasing resin technology

    DEFF Research Database (Denmark)

    van Dijken, Jan W.V.; Pallesen, Ulla

    2017-01-01

    This randomized study evaluated a flowable resin composite bulk-fill technique in posterior restorations and compared it intraindividually with a conventional 2-mm resin composite layering technique over a 6-yr follow-up period. Thirty-eight pairs of Class II restorations and 15 pairs of Class I...... restorations were placed in 38 adults. In all cavities a single-step self-etch adhesive (Xeno V) was applied. In the first cavity of each pair, the flowable resin composite (SDR) was placed, in bulk increments of up to 4 mm. The occlusal part was completed with a layer of nanohybrid resin composite (Ceram X...... mono). In the second cavity of each pair, the hybrid resin composite was placed in 2-mm increments. The restorations were evaluated using slightly modified US Public Health Service (USPHS) criteria at baseline and then annually for a time period of 6 yr. After 6 yr, 72 Class II restorations and 26...

  6. [Application of macroporous resin in purification for effective part from Polygonum cuspidatum].

    Science.gov (United States)

    Liu, Dan; Tang, Hai-feng; Zhang, San-qi; Ding, Yu; Yang, Chun-e

    2007-06-01

    To study the technological parameters of the purification process for effective part from Polygonum cuspidatum. Using adsorption capacities and desorption rates of polydatin, resveratrol,emodin,physcion and total anthraquinone as the primary screening indexes, six resins were surveyed,and the optimized conditions of adsorption and desorption of the effective ingredients were studied. Resin D101 gave good separation performance and was selected to purify the effective part in Polygonum cuspidatum. The optimum parameters were established as the following: 1 BV (bed volume) sample extract was passed through the column with a flow rate of 2.4 BV x h(-1), 30 min later,the column was washed with 2 BV water, 2 BV 20% ethanol, 5 BV 50% ethanol, 2 BV 70% ethanol and 5 BV 95% ethanol, respectively. The combined 50% and 95% ethanolic elutes were concentrated to yield the purified effctive part. The purity of the total effective ingredients in the product was up to 36. 87%. Macroporous resin D101 could be well used in separating and purifying the effective part from Polygonum cuspidatum.

  7. Preparative Separation and Purification of the Total Flavonoids in Scorzonera austriaca with Macroporous Resins.

    Science.gov (United States)

    Xie, Yang; Guo, Qiu-Shi; Wang, Guang-Shu

    2016-06-13

    The use of macroporous resins for the separation and purification of total flavonoids to obtain high-purity total flavonoids from Scorzonera austriaca was studied. The optimal conditions for separation and purification of total flavonoids in S. austriaca with macroporous resins were as follows: D4020 resin columns were loaded with crude flavonoid extract solution, and after reaching adsorptive saturation, the columns were eluted successively with 5 bed volumes (BV) of water, 5 BV of 5% (v/v) aqueous ethanol and 5 BV of 30% (v/v) aqueous ethanol at an elute flow rate of 2 BV·h(-1). Total flavonoids were obtained from the 30% aqueous ethanol eluate by vacuum distillation recovery. The content of flavonoid compounds in the total flavonoids was 93.5%, which represents an improvement by about 150%. In addition, five flavonoid compounds in the product were identified as 2″-O-β-d-xylopyranosyl isoorientin, 6-C-α-l-arabipyranosyl orientin, orientin, isoorientin and vitexin by LC-ESI-MS analysis and internal standard methods. The results in this study could represent a method for the large-scale production of total flavonoids from S. austriaca.

  8. Optimization of polyphenol removal from kiwifruit juice using a macroporous resin.

    Science.gov (United States)

    Gao, Zhenpeng; Yu, Zhifang; Yue, Tianli; Quek, Siew Young

    2017-06-01

    The separation of polyphenols from kiwifruit juice is essential for enhancing sensory properties and prevent the browning reaction in juice during processing and storage. The present study investigated the dynamic adsorption and desorption of polyphenols in kiwifruit juice using AB-8 resin. The model obtained could be successfully applied to predict the experimental results of dynamic adsorption capacity (DAC) and dynamic desorption quantity (DDQ). The results showed that dynamic adsorption of polyphenols could be optimised in a juice concentration of 19 °Brix, with a feed flow-rate of 1.3 mL min -1 and a feed volume of 7 bed volume (BV). The optimum conditions for dynamic desorption of polyphenols from the AB-8 resin were an ethanol concentration of 43% (v/v), an elute flow-rate of 2.2 mL min -1 and an elute volume of 3 BV. The optimized DAC value was 3.16 g of polyphenols kg -1 resin, whereas that for DDQ was 917.5 g kg -1 , with both values being consistent with the predicted values generated by the regression models. The major polyphenols in the dynamic desorption solution consisted of seven compositions. The present study could be scaled-up using a continuous column system for industrial application, thus contributing to the improved flavor and color of kiwifruit juice. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  9. The effect of transmitted Er:YAG laser energy through a dental ceramic on different types of resin cements.

    Science.gov (United States)

    Tak, Onjen; Sari, Tugrul; Arslan Malkoç, Meral; Altintas, Subutayhan; Usumez, Aslihan; Gutknecht, Norbert

    2015-07-06

    The laser debonding procedure of adhesively luted all-ceramic restorations is based on the ablation of resin cement due to the transmitted laser energy through the ceramic. The purpose of this study was to determine the effect of Er:YAG laser irradiation transmitted through a dental ceramic on five different resin cements. Five different resin cements were evaluated in this study: G-Cem LinkAce, Multilink Automix, Variolink II, Panavia F, and Rely X Unicem U100. Disc shaped resin cement specimens (n = 10) were fabricated for each group. A ceramic disc was placed between the resin cement discs and the tip of the handpiece of Er:YAG laser device. The resin cement discs were irradiated through the ceramic and the volume of the resin cement discs were measured using a micro-CT system before and after Er:YAG laser irradiation. The volume loss of the resin cement discs was calculated and analyzed with one-way ANOVA and Tukey-HSD tests. The highest volume loss was determined in G-Cem (1.1 ± 0.6 mm 3 ) and Multilink (1.3 ± 0.1 mm 3 ) (P < 0.05) groups, and the lowest volume loss was determined in Rely X (0.3 ± 0.07 mm 3 ), Variolink (0.4 ± 0.2 mm 3 ), and Panavia (0.6 ± 0.2 mm 3 ) groups (P < 0.05). All resin cements were affected by the laser irradiation resulting in the volume loss of the cement; however, there are significant differences among different resin cements. All the resin cements tested in this study were effected by the Er:YAG laser irradiation and there were significant differences among the resin cements with regard to ablation volume. Lasers Surg. Med. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  10. Alcohol Calorie Calculator

    Science.gov (United States)

    ... Alcohol Calorie Calculator Weekly Total 0 Calories Alcohol Calorie Calculator Find out the number of beer and ... Calories College Alcohol Policies Interactive Body Calculators Alcohol Calorie Calculator Alcohol Cost Calculator Alcohol BAC Calculator Alcohol ...

  11. Thermal rearrangement of novolak resins used in microlithography

    Science.gov (United States)

    Hardy, Ricky; Zampini, Anthony; Monaghan, Michael J.; O'Leary, Michael J.; Cardin, William J.; Eugster, Timothy J.

    1995-06-01

    Changes in phenolic-formaldehyde resin properties are described in terms of thermal exposure. At high temperature, resin molecular weight, dissolution properties and chemical composition change depending on the presence or absence of monomers. Without monomer in the resin melt at 220 degree(s)C, resin molecular weight increases with a corresponding decrease in dissolution rate. In the presence of monomer, molecular weight generally decreases. Dissolution rate may fluctuate depending on the monomer mixture. Three,five- Xylenol and 2,3,5-trimethylphenol co-monomers induced the most extreme changes in resin properties with thermal treatment. Resin degradation-recombination processes suggest a classical Friedel-Craft rearrangement mechanism.

  12. New bismaleimide matrix resins for graphite fiber composites

    Science.gov (United States)

    Hsu, M.-T. S.; Chen, T. S.; Parker, J. A.; Heimbuch, A. H.

    1985-01-01

    Two new bismaleimide resins based on the N,N'-m-phenylene-bis(m-amino-benzamide) structure have been synthesized and characterized. The mixtures of the two resins gave better handling, processing, mechanical, and thermal properties in graphite composites than did the individual resins. The mechanical strength of the cured graphite composites prepared from the 1:1 copolymer of the two bismaleimide resins was excellent at both ambient and elevated temperatures. The physical and mechanical properties of the composites from the new bismaleimide matrix resin systems are compared with conventional composites based on epoxy and other bismaleimide systems. The copolymer system provides another method for improving bismaleimide resins.

  13. Thermal cycling effects on adhesion of resin-bovine enamel junction among different composite resins.

    Science.gov (United States)

    Chen, Wen-Cheng; Ko, Chia-Ling; Wu, Hui-Yu; Lai, Pei-Ling; Shih, Chi-Jen

    2014-10-01

    Thermal cycling is used to mimic the changes in oral cavity temperature experienced by composite resins when used clinically. The purpose of this study is to assess the thermal cycling effects of in-house produced composite resin on bonding strength. The dicalcium phosphate anhydrous filler surfaces are modified using nanocrystals and silanization (w/NP/Si). The resin is compared with commercially available composite resins Filtek Z250, Z350, and glass ionomer restorative material GIC Fuji-II LC (control). Different composite resins were filled into the dental enamel of bovine teeth. The bond force and resin-enamel junction graphical structures of the samples were determined after thermal cycling between 5 and 55°C in deionized water for 600 cycles. After thermal cycling, the w/NP/Si 30wt%, 50wt% and Filtek Z250, Z350 groups showed higher shear forces than glass ionomer GIC, and w/NP/Si 50wt% had the highest shear force. Through SEM observations, more of the fillings with w/NP/Si 30wt% and w/NP/Si 50wt% groups flowed into the enamel tubule, forming closed tubules with the composite resins. The push-out force is proportional to the resin flow depth and uniformity. The push-out tubule pore and resin shear pattern is the most uniform and consistent in the w/NP/Si 50wt% group. Accordingly, this developed composite resin maintains great mechanical properties after thermal cycling. Thus, it has the potential to be used in a clinical setting when restoring non-carious cervical lesions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Radiotracers in performance evaluation of nuclear grade resins Amberlite IRN-78 and Purolite NRW-8000

    International Nuclear Information System (INIS)

    Singare, P.U.

    2014-01-01

    The present paper deals with evaluation of organic base nuclear grade anion exchange resins Amberlite IRN-78 and Purolite NRW-8000 by application of radioactive tracer isotopes 131 I and 82 Br. The evaluation was made on the basis of their performance in iodide and bromide ion-isotopic exchange reactions carried out under different experimental conditions like temperature and ionic concentration. It was observed that during iodide ion-isotopic exchange reaction at a constant temperature of 30.0 C, as the concentration of labeled iodide ion solution increases from 0.001 mol/L to 0.004 mol/L, the percentage of iodide ions exchanged increases from 70.10 % to 77.10 % for Amberlite IRN-78, which was higher than an increase of 63.90 % to 71.00 % as obtained for Purolite NRW-8000 resins. Also at a constant temperature of 30.0 C, using 1.000 g of ion exchange resins and 0.001 mol/L labeled iodide ion solution, the values of specific reaction rate (min -1 ), amount of iodide ion exchanged (mmol), initial rate of iodide ion exchange (mmol/min) and log K d were calculated to be 0.280, 0.175, 0.049 and 11.4 respectively for Amberlite IRN-78 resin, which was higher than the values of 0.258, 0.160, 0.041 and 10.6 respectively as that obtained by using Purolite NRW-8000 resins. The identical trend was observed for the two resins during bromide ion-isotopic exchange reaction. The results of present investigation also indicate that during the two ion-isotopic exchange reactions, for both the resins, there exists a strong positive linear correlation between amount of ions exchanged and concentration of ionic solution; and strong negative correlation between amount of ions exchanged and temperature of exchanging medium. The overall results indicate that under identical experimental conditions, Amberlite IRN-78 resins show superior performance over Purolite NRW-8000 resins. (orig.)

  15. The elution of erbium from a cation exchanger bed by means of the N-hydroxyethyl-ethylene-diamine triacetic acid

    International Nuclear Information System (INIS)

    Amer Amezaga, S.

    1963-01-01

    A physicochemical study of the phenomena resulting when erbium is eluted from a cation-exchanger bed at a steady by means of the N-hydroxyethyl-ethylene-diamine-triacetic acid (HEDTA) is made. Two different retaining beds are used, a hydrogen bed, in which no ammonium passes through, and a zinc bed, which leaks ammonium ion. Good agreement between experimental and calculated values by using the equations deduced for the concentrations of the main species has been achieved, with errors around 1-2% in most of the experiments. (Author) 69 refs

  16. Fluidization calculation on nuclear fuel kernel coating

    International Nuclear Information System (INIS)

    Sukarsono; Wardaya; Indra-Suryawan

    1996-01-01

    The fluidization of nuclear fuel kernel coating was calculated. The bottom of the reactor was in the from of cone on top of the cone there was a cylinder, the diameter of the cylinder for fluidization was 2 cm and at the upper part of the cylinder was 3 cm. Fluidization took place in the cone and the first cylinder. The maximum and the minimum velocity of the gas of varied kernel diameter, the porosity and bed height of varied stream gas velocity were calculated. The calculation was done by basic program

  17. Calculation of integrated biological response in brachytherapy

    International Nuclear Information System (INIS)

    Dale, Roger G.; Coles, Ian P.; Deehan, Charles; O'Donoghue, Joseph A.

    1997-01-01

    Purpose: To present analytical methods for calculating or estimating the integrated biological response in brachytherapy applications, and which allow for the presence of dose gradients. Methods and Materials: The approach uses linear-quadratic (LQ) formulations to identify an equivalent biologically effective dose (BED eq ) which, if applied to a specified tissue volume, would produce the same biological effect as that achieved by a given brachytherapy application. For simple geometrical cases, BED multiplying factors have been derived which allow the equivalent BED for tumors to be estimated from a single BED value calculated at a dose reference point. For more complex brachytherapy applications a voxel-by-voxel determination of the equivalent BED will be more accurate. Equations are derived which when incorporated into brachytherapy software would facilitate such a process. Results: At both high and low dose rates, the BEDs calculated at the dose reference point are shown to be lower than the true values by an amount which depends primarily on the magnitude of the prescribed dose; the BED multiplying factors are higher for smaller prescribed doses. The multiplying factors are less dependent on the assumed radiobiological parameters. In most clinical applications involving multiple sources, particularly those in multiplanar arrays, the multiplying factors are likely to be smaller than those derived here for single sources. The overall suggestion is that the radiobiological consequences of dose gradients in well-designed brachytherapy treatments, although important, may be less significant than is sometimes supposed. The modeling exercise also demonstrates that the integrated biological effect associated with fractionated high-dose-rate (FHDR) brachytherapy will usually be different from that for an 'equivalent' continuous low-dose-rate (CLDR) regime. For practical FHDR regimes involving relatively small numbers of fractions, the integrated biological effect to

  18. Improved resins and novel materials and methods for solid phase extraction and high performance liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Freeze, Ronald [Iowa State Univ., Ames, IA (United States)

    1997-10-08

    Solid-phase extraction (SPE) has grown to be one of the most widely used methods for isolation and preconcentration of a vast range of compounds from aqueous solutions. By modifying polymeric SPE resins with chelating functional groups, the selective uptake of metals was accomplished. The resin, along with adsorbed metals, was vaporized in the ICP and detection of the metals was then possible using either mass or emission spectroscopy. Drug analyses in biological fluids have received heightened attention as drug testing is on the increase both in sports and in the work environment. By using a direct-injection technique, biological fluids can be injected directly into the liquid chromatographic system with no pretreatment. A new surfactant, a sulfonated form of Brij-30 (Brij-S) is shown to prevent the uptake of serum proteins on commercial HPLC columns by forming a thin coating on the silica C18 surface. Excellent separations of eight or more drugs with a wide range of retention times were obtained. The separations had sharper peaks and lower retention times than similar separations performed with the surfactant sodium dodecylsulfate (SDS). Quantitative recovery of a number of drugs with limits of detection near 1 ppm with a 5 μl injection volume were obtained. Finally, a method for solid-phase extraction in a syringe is introduced. The system greatly reduced the volume of solvent required to elute adsorbed analytes from the SPE bed while providing a semi-automated setup. SPE in a syringe consists of a very small bed of resin-loaded membrane packed into a GC or HPLC syringe. After extraction, elution was performed with just a few μl of solvent. This small elution volume allowed injection of the eluent directly from the syringe into the chromatographic system, eliminating the handling problems associated with such small volumes.

  19. The Safety of Hospital Beds: Ingress, Egress, and In-Bed Mobility.

    Science.gov (United States)

    Morse, Janice M; Gervais, Pierre; Pooler, Charlotte; Merryweather, Andrew; Doig, Alexa K; Bloswick, Donald

    2015-01-01

    To explore the safety of the standard and the low hospital bed, we report on a microanalysis of 15 patients' ability to ingress, move about the bed, and egress. The 15 participants were purposefully selected with various disabilities. Bed conditions were randomized with side rails up or down and one low bed with side rails down. We explored the patients' use of the side rails, bed height, ability to lift their legs onto the mattress, and ability to turn, egress, and walk back to the chair. The standard bed was too high for some participants, both for ingress and egress. Side rails were used by most participants when entering, turning in bed, and exiting. We recommend that side rails be reconsidered as a means to facilitate in-bed movement, ingress, and egress. Furthermore, single deck height settings for all patients are not optimal. Low beds as a safety measure must be re-evaluated.

  20. Introduction to Radcalc: A computer program to calculate the radiolytic production of hydrogen gas from radioactive wastes in packages

    International Nuclear Information System (INIS)

    Green, J.R.; Hillesland, K.E.; Field, J.G.

    1995-04-01

    A calculational technique for quantifying the concentration of hydrogen generated by radiolysis in sealed radioactive waste containers was developed in a U.S. Department of Energy (DOE) study conducted by EG ampersand G Idaho, Inc., and the Electric Power Research Institute (EPRI) TMI-2 Technology Transfer Office. The study resulted in report GEND-041, entitled open-quotes A Calculational Technique to Predict Combustible Gas Generation in Sealed Radioactive Waste Containersclose quotes. The study also resulted in a presentation to the U.S. Nuclear Regulatory Commission (NRC) which gained acceptance of the methodology for use in ensuring compliance with NRC IE Information Notice No. 84-72 (NRC 1984) concerning the generation of hydrogen within packages. NRC IE Information Notice No. 84-72: open-quotes Clarification of Conditions for Waste Shipments Subject to Hydrogen Gas Generationclose quotes applies to any package containing water and/or organic substances that could radiolytically generate combustible gases. EPRI developed a simple computer program in a spreadsheet format utilizing GEND-041 calculational methodology to predict hydrogen gas concentrations in low-level radioactive wastes containers termed Radcalc. The computer code was extensively benchmarked against TMI-2 (Three Mile Island) EPICOR II resin bed measurements. The benchmarking showed that the model developed predicted hydrogen gas concentrations within 20% of the measured concentrations. Radcalc for Windows was developed using the same calculational methodology. The code is written in Microsoft Visual C++ 2.0 and includes a Microsoft Windows compatible menu-driven front end. In addition to hydrogen gas concentration calculations, Radcalc for Windows also provides transportation and packaging information such as pressure buildup, total activity, decay heat, fissile activity, TRU activity, and transportation classifications

  1. Particle bed reactor scaling relationships

    Science.gov (United States)

    Slovik, G.; Araj, K.; Horn, F. L.; Ludewig, H.; Benenati, R.

    The Particle Bed Reactor (PBR) concept can be used in several applications both as part of a power generating system or as a direct propulsion unit. In order to carry out optimization studies of systems involving a PBR, it is necessary to know the variation of the critical mass with pertinent system parameters such as weight, size, power level and thrust level. A parametric study is presented for all the practical combinations of fuel and moderating material. The PBR is described, the practical combinations of materials and dimensions are discussed, and an example is presented.

  2. Durability of resin-dentin bonds.

    Science.gov (United States)

    Shono, Y; Terashita, M; Shimada, J; Kozono, Y; Carvalho, R M; Russell, C M; Pashley, D H

    1999-01-01

    The purpose of this study was to determine if the durability of resin-dentin bonds could be evaluated more quickly if the bond specimen was divided into 1 x 1 x 8 mm beams incubated at 37 degrees C for a 90-day period. Extracted human third molars were prepared for bonding by removing the occlusal surface near the dento-enamel junction (superficial dentin group) or near the pulp (deep dentin group). The teeth were bonded either with MacBond, One Step or Clearfil Liner Bond 2, and then builtup to form a flat resin composite crown. After 24 hours in water, each buildup was vertically divided into slabs 1 mm thick, the top half of which was resin, with the bottom half as dentin. Each slab was then vertically sectioned at 1-mm increments to create 1 x 1 x 8-mm beams of resin-bonded dentin. They were incubated for 1 day or 90 days at 37 degrees C, followed by measurement of the tensile bond strengths. The results were analyzed by the Least-Squares Means method at the 95% confidence level. MacBond gave the highest (p durability of resin-dentin bonds.

  3. Processing of exhausted resins for Trino NPP,

    International Nuclear Information System (INIS)

    Benvenuto, F.; Bitetti, G.; Maggini, F.; Scarsi, G.

    2009-01-01

    Decomposition of organic compounds contained in the spent ion exchange resins is considered effective in reducing the waste volume. A system using the wet-oxidation process has been studied for the treatment of the spent resins stored at Trino Nuclear Power Plant owned by SOGIN. Compared with various processes for treating sludge and resin, the wet-oxidation system is rather simple and the process conditions are mild. Not contaminated ion exchange resin samples similar to those ones used in Trino NPP were processed by wet-oxidation and appropriate decomposition of the organic compounds was verified. After decomposition the residue can be solidified with cement for final disposal. When compared with direct solidification without decomposition, the number of waste packages can be significantly reduced. Additional measures for conditioning secondary waste products have also been studied, and their applicability to the Trino Nuclear Power Plant was verified. Some of conditions studied were specific to the Trino Nuclear Power Plant, but it is expected that the system will provide an effective solution for resin treatment at other Italian NPPs. (authors)

  4. Ponderosa pine resin defenses and growth: metrics matter.

    Science.gov (United States)

    Hood, Sharon; Sala, Anna

    2015-11-01

    Bark beetles (Coleoptera: Curculionidae, Scolytinae) cause widespread tree mortality in coniferous forests worldwide. Constitutive and induced host defenses are important factors in an individual tree's ability to survive an attack and in bottom-up regulation of bark beetle population dynamics, yet quantifying defense levels is often difficult. For example, in Pinus spp., resin flow is important for resistance to bark beetles but is extremely variable among individuals and within a season. While resin is produced and stored in resin ducts, the specific resin duct metrics that best correlate with resin flow remain unclear. The ability and timing of some pine species to produce induced resin is also not well understood. We investigated (i) the relationships between ponderosa pine (Pinus ponderosa Lawson & C. Lawson) resin flow and axial resin duct characteristics, tree growth and physiological variables, and (ii) if mechanical wounding induces ponderosa pine resin flow and resin ducts in the absence of bark beetles. Resin flow increased later in the growing season under moderate water stress and was highest in faster growing trees. The best predictors of resin flow were nonstandardized measures of resin ducts, resin duct size and total resin duct area, both of which increased with tree growth. However, while faster growing trees tended to produce more resin, models of resin flow using only tree growth were not statistically significant. Further, the standardized measures of resin ducts, density and duct area relative to xylem area, decreased with tree growth rate, indicating that slower growing trees invested more in resin duct defenses per unit area of radial growth, despite a tendency to produce less resin overall. We also found that mechanical wounding induced ponderosa pine defenses, but this response was slow. Resin flow increased after 28 days, and resin duct production did not increase until the following year. These slow induced responses may allow

  5. HTGR fuel development: loading of uranium on carboxylic acid cation-exchange resins using solvent extraction of nitrate

    International Nuclear Information System (INIS)

    Haas, P.A.

    1975-09-01

    The reference fuel kernel for recycle of 233 U to HTGR's (High-Temperature Gas-Cooled Reactors) is prepared by loading carboxylic acid cation-exchange resins with uranium and carbonizing at controlled conditions. The purified 233 UO 2 (NO 3 ) 2 solution from a fuel reprocessing plant contains excess HNO 3 (NO 3 - /U ratio of approximately 2.2). The reference flowsheet for a 233 U recycle fuel facility at Oak Ridge uses solvent extraction of nitrate by a 0.3 M secondary amine in a hydrocarbon diluent to prepare acid-deficient uranyl nitrate. This nitrate extraction, along with resin loading and amine regeneration steps, was demonstrated in 14 runs. No significant operating difficulties were encountered. The process is controlled via in-line pH measurements for the acid-deficient uranyl nitrate solutions. Information was developed on pH values for uranyl nitrate solution vs NO 3 - /U mole ratios, resin loading kinetics, resin drying requirements, and other resin loading process parameters. Calculations made to estimate the capacities of equipment that is geometrically safe with respect to control of nuclear criticality indicate 100 kg/day or more of uranium for single nitrate extraction lines with one continuous resin loading contactor or four batch loading contactors. (auth)

  6. Bio-active glass air-abrasion has the potential to remove resin composite restorative material selectively

    International Nuclear Information System (INIS)

    Milly, Hussam; Andiappan, Manoharan; Thompson, Ian; Banerjee, Avijit

    2014-01-01

    The aims of this study were to assess: (a) the chemistry, morphology and bioactivity of bio-active glass (BAG) air-abrasive powder, (b) the effect of three air-abrasion operating parameters: air pressure, powder flow rate (PFR) and the abrasive powder itself, on the selective removal of resin composite and (c) the required “time taken”. BAG abrasive particles were characterised using scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX) and Fourier-transform infrared spectroscopy (FTIR). Standardised resin composite restorations created within an enamel analogue block (Macor™) in vitro, were removed using air-abrasion undersimulated clinical conditions. 90 standardised cavities were scanned before and after resin composite removal using laser profilometry and the volume of the resulting 3D images calculated. Multilevel linear model was used to identify the significant factors affecting Macor™ removal. BAG powder removed resin composite more selectively than conventional air-abrasion alumina powder using the same operating parameters (p < 0.001) and the effect of altering the unit's operating parameters was significant (p < 0.001). In conclusion, BAG powder is more efficient than alumina in the selective removal of resin composite particularly under specific operating parameters, and therefore may be recommended clinically as a method of preserving sound enamel structure when repairing and removing defective resin composite restorations.

  7. Bio-active glass air-abrasion has the potential to remove resin composite restorative material selectively

    Energy Technology Data Exchange (ETDEWEB)

    Milly, Hussam [Biomaterials, Biomimetics and Biophotonics Research Group, Kings College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom); Andiappan, Manoharan [Unit of Dental Public Health, Kings College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom); Thompson, Ian [Biomaterials, Biomimetics and Biophotonics Research Group, Kings College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom); Banerjee, Avijit, E-mail: avijit.banerjee@kcl.ac.uk [Biomaterials, Biomimetics and Biophotonics Research Group, Kings College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom); Unit of Conservative Dentistry, King' s College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom)

    2014-06-01

    The aims of this study were to assess: (a) the chemistry, morphology and bioactivity of bio-active glass (BAG) air-abrasive powder, (b) the effect of three air-abrasion operating parameters: air pressure, powder flow rate (PFR) and the abrasive powder itself, on the selective removal of resin composite and (c) the required “time taken”. BAG abrasive particles were characterised using scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX) and Fourier-transform infrared spectroscopy (FTIR). Standardised resin composite restorations created within an enamel analogue block (Macor™) in vitro, were removed using air-abrasion undersimulated clinical conditions. 90 standardised cavities were scanned before and after resin composite removal using laser profilometry and the volume of the resulting 3D images calculated. Multilevel linear model was used to identify the significant factors affecting Macor™ removal. BAG powder removed resin composite more selectively than conventional air-abrasion alumina powder using the same operating parameters (p < 0.001) and the effect of altering the unit's operating parameters was significant (p < 0.001). In conclusion, BAG powder is more efficient than alumina in the selective removal of resin composite particularly under specific operating parameters, and therefore may be recommended clinically as a method of preserving sound enamel structure when repairing and removing defective resin composite restorations.

  8. [Color stability of ceromer of different thicknesses and resin adhesive materials of different types after accelerated aging].

    Science.gov (United States)

    Likai, Wang; Yanan, Liu; Yan, Zheng; Pingping, Li

    2015-04-01

    This study aims to investigate the color stability of ceromer with different thicknesses and different types of resin adhesive materials after accelerated aging and provide references for clinical application and selections. Nine groups of experimental samples were used, and each group contained five samples. We made joint samples with ceromer having three different thicknesses (1.00, 0.75, 0.50 mm) combined with three different resin adhesive materials (RelyX Veneer, RelyX Unicem, Filtek Z350 Flow), respectively. All samples were placed into Xenon Lamp Aging Instrument to implement accelerated aging. Spectrophotometer was used to measure the lightness (L*), red green color value (a*), and blue yellow color value (b*) of all samples before and after accelerated aging. The change of lightness (ΔL), red green color value (Δa), blue yellow color value (Δb), and color variation (ΔE) were also calculated. We investigated the influence of ceromer veneer thicknesses and resin adhesive material types on color variation by two-factor analysis of variance. The thickness and type factors showed significant influence on ΔE values, and exhibited interactions (P Ceromer veneer thickness and resin adhesive material types could affect the color stability of ceromer veneer and resin adhesive materials. The changes in lightness and color in ceromer veneer and resin adhesive materials are considered clinically acceptable after accelerated aging.

  9. Sensitization to reactive diluents and hardeners in epoxy resin systems. IVDK data 2002-2011. Part I: reaction frequencies.

    Science.gov (United States)

    Geier, Johannes; Lessmann, Holger; Hillen, Uwe; Skudlik, Christoph; Jappe, Uta

    2016-02-01

    Epoxy resin systems (ERSs), consisting of resins, reactive diluents, and hardeners, are indispensable in many branches of industry. In order to develop less sensitizing ERS formulations, knowledge of the sensitizing properties of single components is mandatory. To analyse the frequency of sensitization in the patients concerned, as one integral part of a research project on the sensitizing potency of epoxy resin compounds (FP-0324). A retrospective analysis of data from the Information Network of Departments of Dermatology (IVDK), 2002-2011, and a comparison of reaction frequencies with (surrogate) exposure data, were performed. Almost half of the patients sensitized to epoxy resin were additionally sensitized to reactive diluents or hardeners. Among the reactive diluents, 1,6-hexanediol diglycidyl ether was the most frequent allergen, followed by 1,4-butanediol diglycidyl ether, phenyl glycidyl ether, and p-tert-butylphenyl glycidyl ether. Among the hardeners, m-xylylene diamine (MXDA) and isophorone diamine (IPDA) were the most frequent allergens. According to the calculated exposure-related frequency of sensitization, MXDA seems to be a far more important sensitizer than IPDA. Up to 60% of the patients sensitized to hardeners and 15-20% of those sensitized to reactive diluents do not react to epoxy resin. In cases of suspected contact allergy to an ERS, a complete epoxy resin series must be patch tested from the start. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. ANALISIS TRANSIEN PADA FIXED BED NUCLEAR REACTOR

    Directory of Open Access Journals (Sweden)

    M. Rizaal

    2015-03-01

    Full Text Available Desain teras Fixed Bed Nuclear Reactor (FBNR yang modular memungkinkan pengendalian daya dapat dilakukan dengan mengatur ketinggian suspended core dan laju aliran massa pendingin. Tujuan penelitian ini adalah mempelajari perubahan daya termal teras sebagai akibat perubahan laju aliran massa pendingin yang masuk ke teras reaktor dan perubahan ketinggian suspended core serta mempelajari karakteristik keselamatan melekat yang dimiliki FBNR saat terjadi kegagalan pelepasan kalor (loss of heat sink. Keadaan neutronik teras dimodelkan pada kondisi tunak dengan menggunakan paket program Standard Reactor Analysis Code (SRAC untuk memperoleh data fluks neutron, konstanta grup, fraksi neutron kasip, konstanta peluruhan prekursor neutron kasip, dan beberapa parameter teras penting lainnya. Selanjutnya data tersebut digunakan pada perhitungan transien sebagai syarat awal. Analisis transien dilakukan pada tiga kondisi, yaitu saat terjadi penurunan laju aliran massa pendingin, saat terjadi penurunan ketinggian suspended core, dan saat terjadi kegagalan sistem pelepasan kalor. Hasil yang diperoleh dari penelitian ini menunjukkan bahwa penurunan laju aliran massa pendingin sebesar 50%, dari kondisi normal, menyebabkan daya termal teras turun 28% dibanding daya sebelumnya. Penurunan ketinggian suspended core sebesar 30% dari ketinggian normal menyebabkan daya termal teras turun 17% dibanding daya sebelumnya. Sementara untuk kondisi kegagalan sistem pelepasan kalor, daya termal teras mengalami penurunan sebesar 76%. Dengan demikian, pengendalian daya pada FBNR dapat dilakukan dengan mengatur laju aliran massa pendingin dan ketinggian suspended core, serta keselamatan melekat yang handal pada kondisi kegagalan sistem pelepasan kalor. Kata kunci: FBNR, transien, daya, laju aliran massa, suspended core Modular in design enables Fixed Bed Nuclear Reactor (FBNR power controlled by the adjustment of suspended core and coolant flow rate. The main purposes of this paper

  11. Pebble bed pebble motion: Simulation and Application

    Science.gov (United States)

    Cogliati, Joshua J.

    Pebble bed reactors (PBR) have moving graphite fuel pebbles. This unique feature provides advantages, but also means that simulation of the reactor requires understanding the typical motion and location of the granular flow of pebbles. This dissertation presents a method for simulation of motion of the pebbles in a PBR. A new mechanical motion simulator, PEBBLES, efficiently simulates the key elements of motion of the pebbles in a PBR. This model simulates gravitational force and contact forces including kinetic and true static friction. It's used for a variety of tasks including simulation of the effect of earthquakes on a PBR, calculation of packing fractions, Dancoff factors, pebble wear and the pebble force on the walls. The simulator includes a new differential static friction model for the varied geometries of PBRs. A new static friction benchmark was devised via analytically solving the mechanics equations to determine the minimum pebble-to-pebble friction and pebble-to-surface friction for a five pebble pyramid. This pyramid check as well as a comparison to the Janssen formula was used to test the new static friction equations. Because larger pebble bed simulations involve hundreds of thousands of pebbles and long periods of time, the PEBBLES code has been parallelized. PEBBLES runs on shared memory architectures and distributed memory architectures. For the shared memory architecture, the code uses a new O(n) lock-less parallel collision detection algorithm to determine which pebbles are likely to be in contact. The new collision detection algorithm improves on the traditional non-parallel O(n log(n)) collision detection algorithm. These features combine to form a fast parallel pebble motion simulation. The PEBBLES code provides new capabilities for understanding and optimizing PBRs. The PEBBLES code has provided the pebble motion data required to calculate the motion of pebbles during a simulated earthquake. The PEBBLES code provides the ability to

  12. Carbon nanotubes-A resin for electrochemically modulated liquid chromatography.

    Science.gov (United States)

    Brammen, Markus; Fraga-García, Paula; Berensmeier, Sonja

    2017-03-01

    Electrochemically modulated liquid chromatography is a special form of ion exchange chromatography in which the separation process is controlled by applying an electric potential to the stationary phase. This form of chromatography has so far only been applied in research studies. The present study shows that multiwalled carbon nanotubes are an effective resin material for an electrochemically modulated chromatography process. The experiments are carried out in a newly designed column that enables the packing of nanomaterials. We investigate the influence of the applied potential on the retention and elution of maleic acid, determine the dynamic binding capacity, and calculate the utilization degree of the electrical charge in the adsorption process. Moreover, the stability of the resin and the membrane over more than 200 working hours are presented. In addition to the stability, their sturdiness and inexpensive price are important qualities that make multiwalled carbon nanotubes interesting for application as the stationary phase in an electrochemically driven process. The investigated chromatography technique represents a promising separation process for future applications as a preparative step in biotechnology as well as other life science fields. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Apparent Interfacial Fracture Toughness of Resin/Ceramic Systems

    Science.gov (United States)

    Della Bona, A.; Anusavice, K.J.; Mecholsky, J.J.

    2008-01-01

    We suggest that the apparent interfacial fracture toughness (KA) may be estimated by fracture mechanics and fractography. This study tested the hypothesis that the KA of the adhesion zone of resin/ceramic systems is affected by the ceramic microstructure. Lithia disilicate-based (Empress2-E2) and leucite-based (Empress-E1) ceramics were surface-treated with hydrofluoric acid (HF) and/or silane (S), followed by an adhesive resin. Microtensile test specimens (n = 30; area of 1 ± 0.01 mm2) were indented (9.8 N) at the interface and loaded to failure in tension. We used tensile strength (σ) and the critical crack size (c) to calculate KA (KA = Yσc1/2) (Y = 1.65). ANOVA and Weibull analyses were used for statistical analyses. Mean KA (MPa•m1/2) values were: (E1HF) 0.26 ± 0.06; (E1S) 0.23 ± 0.06; (E1HFS) 0.30 ± 0.06; (E2HF) 0.31 ± 0.06; (E2S) 0.13 ± 0.05; and (E2HFS) 0.41 ± 0.07. All fractures originated from indentation sites. Estimation of interfacial toughness was feasible by fracture mechanics and fractography. The KA for the systems tested was affected by the ceramic microstructure and surface treatment. PMID:17062746

  14. Microshear bond strength of composite resins to enamel and porcelain substrates utilizing unfilled versus filled resins.

    Science.gov (United States)

    Najafi-Abrandabadi, Ahmad; Najafi-Abrandabadi, Siamak; Ghasemi, Amir; Kotick, Philip G

    2014-11-01

    Failures such as marginal discoloration and composite chipping are still the problems of tooth-colored restorations on the substrate of enamel and porcelain, which some of these problems are consequently as a result of failures in the bonding layer. Using filled resin has been recently introduced to increase the bond strength of this layer. The aim of this study was to compare the microshear bond strength (μ-SBS) of composite resins to enamel incubated in periods of 24 h and 9 months and porcelain with unfilled resin and flowable composites (filled resin). In this in vitro study, two groups of 75 enamel samples with different storage times (24 h and 9 months) and a group of 75 porcelain samples were used. They were divided into 5 experimental groups of 15 samples in each. Composite cylinders in tygon tubes were bonded on the surface of acid-etched enamel and pretreated porcelain. Wave, Wave MV, Wave HV, Grandioflow and Margin Bond were used as bonding agents. The μ-SBS was measured at the speed of 1.0 mm/min. The bond strengths were analyzed with one-way analysis of variance (ANOVA) test followed by Tukey test. P composites (filled resins) can be used instead of unfilled resins in bonding composite resins to enamel and porcelain substrates.

  15. Comparative study of resin sealant and resin modified glass ionomer as pit and fissure sealant

    Directory of Open Access Journals (Sweden)

    Shirin Malek

    2017-02-01

    Full Text Available The purpose of the present study was to compare the marginal integrity of resin modified glass ionomer cement with that of resin sealant, in vitro. Forty artificial pit and fissure cavities were prepared in occlusal surface of extracted premolar teeth by using ¼ round carbide bur. Cavities were condensed with artificial organic debris followed by cleaning with prophylaxis pumice brush and paste and then separated into two treatment groups. In Group A, 15 fissure cavities were sealed by resin sealant and in Group B, 15 fissure cavities were sealed by resin modified glass ionomer sealant. These specimens were subjected to thermo-cycling followed by dye penetration test. The remaining 5 cavities from each group were analyzed for debris score by the SEM. The results of the microleakage test showed that the efficacy of preventing microleakage of samples sealed by resin modified glass ionomer sealant was higher than the samples sealed by resin sealant. However, no significant differences were found. It can be concluded that use of resin modified glass ionomer sealant is a good alternative for sealing pits and fissures.

  16. Shear bond strength of four resin cements used to lute ceramic core material to human dentin.

    Science.gov (United States)

    Altintas, Subutayhan; Eldeniz, Ayçe Unverdi; Usumez, Aslihan

    2008-12-01

    This study evaluated the effect of four resin cements on the shear bond strength of a ceramic core material to dentin. One hundred twenty molar teeth were embedded in a self-curing acrylic resin. The occlusal third of the crowns were sectioned under water cooling. All specimens were randomly divided into four groups of 30 teeth each according to the resin cement used. One hundred twenty cylindrical-shaped, 2.7-mm wide, 3-mm high ceramic core materials were heat-pressed. The core cylinders were then luted with one of the four resin systems to dentin (Super-Bond C&B, Chemiace II, Variolink II, and Panavia F). Half of the specimens (n = 15) were tested after 24 hours; the other half (n = 15) were stored in distilled water at 37 degrees C for 1 day and then thermocycled 1000 times between 5 degrees C and 55 degrees C prior to testing. Shear bond strength of each specimen was measured using a universal testing machine at a crosshead speed of 1 mm/min. The bond strength values were calculated in MPa, and the results were statistically analyzed using a two-way analysis of variance (ANOVA) and Tukey HSD tests. The shear bond strength varied significantly depending on the resin cement used (p 0.05). Significant interactions were present between resin cement and thermocycling (p 0.05). The increase in the shear bond strength values in the Panavia F (4.5 +/- 0.7 MPa) and Variolink II (5.5 +/- 2.1 MPa) groups after thermocycling was also not statistically significant (p > 0.05). Variolink II and Panavia F systems showed higher shear bond strength values than Chemiace II and Super-Bond C&B. They can be recommended for luting ceramic cores to dentin surfaces.

  17. Evaluation of Polymerization Efficacy in Composite Resins via FT-IR Spectroscopy and Vickers Microhardness Test.

    Science.gov (United States)

    Jafarzadeh, Tahereh-Sadat; Erfan, Mohammad; Behroozibakhsh, Marjan; Fatemi, Mostafa; Masaeli, Reza; Rezaei, Yashar; Bagheri, Hossein; Erfan, Yasaman

    2015-01-01

    Background and aims. Polymerization efficacy affects the properties and performance of composite resin restorations.The purpose of this study was to evaluate the effectiveness of polymerization of two micro-hybrid, two nano-hybrid and one nano-filled ormocer-based composite resins, cured by two different light-curing systems, using Fourier transformation infrared (FT-IR) spectroscopy and Vickers microhardness testing at two different depths (top surface, 2 mm). Materials and methods. For FT-IR spectrometry, five cylindrical specimens (5mm in diameter × 2 mm in length) were prepared from each composite resin using Teflon molds and polymerized for 20 seconds. Then, 70-μm wafers were sectioned at the top surface and at2mm from the top surface. The degree of conversion for each sample was calculated using FT-IR spectroscopy. For Vickers micro-hardness testing, three cylindrical specimens were prepared from each composite resin and polymerized for 20 seconds. The Vickers microhardness test (Shimadzu, Type M, Japan) was performed at the top and bottom (depth=2 mm) surfaces of each specimen. Three-way ANOVA with independent variables and Tukey tests were performed at 95% significance level. Results. No significant differences were detected in degree of conversion and microhardness between LED and QTH light-curing units except for the ormocer-based specimen, CeramX, which exhibited significantly higher DC by LED. All the composite resins showed a significantly higher degree of conversion at the surface. Microhardness was not significantly affected by depth, except for Herculite XRV Ultra and CeramX, which showed higher values at the surface. Conclusion. Composite resins containing nano-particles generally exhibited more variations in degree of conversion and microhardness.

  18. Characterization of water sorption, solubility, and roughness of silorane- and methacrylate-based composite resins.

    Science.gov (United States)

    Giannini, M; Di Francescantonio, M; Pacheco, R R; Cidreira Boaro, L C; Braga, R R

    2014-01-01

    The objective of this study was to evaluate the surface roughness (SR), water sorption (WS), and solubility (SO) of four composite resins after finishing/polishing and after one year of water storage. Two low-shrinkage composites (Filtek Silorane [3M ESPE] and Aelite LS [Bisco Inc]) and two composites of conventional formulations (Heliomolar and Tetric N-Ceram [Ivoclar Vivadent]) were tested. Their respective finishing and polishing systems (Sof-Lex Discs, 3M ESPE; Finishing Discs Kit, Bisco Inc; and Astropol F, P, HP, Ivoclar Vivadent) were used according to the manufacturers' instructions. Ten disc-shaped specimens of each composite resin were made for each evaluation. Polished surfaces were analyzed using a profilometer after 24 hours and one year. For the WS and SO, the discs were stored in desiccators until constant mass was achieved. Specimens were then stored in water for seven days or one year, at which time the mass of each specimen was measured. The specimens were dried again and dried specimen mass determined. The WS and SO were calculated from these measurements. Data were analyzed by two-way analysis of variance and Tukey post hoc test (α=0.05). Filtek Silorane showed the lowest SR, WS, and SO means. Water storage for one year increased the WS means for all composite resins tested. The silorane-based composite resin results were better than those obtained for methacrylate-based resins. One-year water storage did not change the SR and SO properties in any of the composite resins.

  19. Evaluation of Polymerization Efficacy in Composite Resins via FT-IR Spectroscopy and Vickers Microhardness Test

    Directory of Open Access Journals (Sweden)

    Tahereh-Sadat Jafarzadeh

    2015-12-01

    Full Text Available Background and aims. Polymerization efficacy affects the properties and performance of composite resin restorations.The purpose of this study was to evaluate the effectiveness of polymerization of two micro-hybrid, two nano-hybrid and one nano-filled ormocer-based composite resins, cured by two different light-curing systems, using Fourier transformation infrared (FT-IR spectroscopy and Vickers microhardness testing at two different depths (top surface, 2 mm. Materials and methods. For FT-IR spectrometry, five cylindrical specimens (5mm in diameter × 2 mm in length were prepared from each composite resin using Teflon molds and polymerized for 20 seconds. Then, 70-μm wafers were sectioned at the top surface and at2mm from the top surface. The degree of conversion for each sample was calculated using FT-IR spectroscopy. For Vickers micro-hardness testing, three cylindrical specimens were prepared from each composite resin and polymerized for 20 seconds. The Vickers microhardness test (Shimadzu, Type M, Japan was performed at the top and bottom (depth=2 mm surfaces of each specimen. Three-way ANOVA with independent variables and Tukey tests were performed at 95% significance level. Results. No significant differences were detected in degree of conversion and microhardness between LED and QTH light-curing units except for the ormocer-based specimen, CeramX, which exhibited significantly higher DC by LED. All the composite resins showed a significantly higher degree of conversion at the surface. Microhardness was not significantly affected by depth, except for Herculite XRV Ultra and CeramX, which showed higher values at the surface. Conclusion. Composite resins containing nano-particles generally exhibited more variations in degree of conversion and microhardness.

  20. Effect of filler size and filler loading on wear of experimental flowable resin composites

    Directory of Open Access Journals (Sweden)

    Koichi Shinkai

    2018-02-01

    Full Text Available Abstract The relationship between wear resistance and filler size or filler loading was clarified for the universal resin composite; however, their relationship in flowable resin composites has not been clarified. Objectives: The purpose of this study was to investigate the effect of filler size and filler loading on wear of experimental flowable resin composites by using a cyclic loading device. Material and Methods: Nine experimental flowable resin composites consisting of three different sizes (70, 200 and 400 nm and loading (50, 55 and 60 wt% of filler were prepared. Bowl-shaped cavities were prepared on a flat surface of ceramic blocks using a No. 149 regular cut diamond point. The cavities were treated with a silane coupling agent and an all-in-one adhesive and then filled with each experimental flowable resin composite. The restored surfaces were finished and polished with a 1500-grit silicon carbide paper. The specimens were subjected to an in vitro two-body wear test using a cyclic loading device. The localized worn surfaces were evaluated at 10,000, 20,000, 30,000, and 40,000 cycles using a computer-controlled three-dimensional measuring microscope (n=5. The volumetric wear loss of the materials was calculated automatically by the equipment. Data were statistically analyzed with two-way ANOVA and post hoc Tukey test. Results: Two-way ANOVA showed that the filler size significantly influenced wear volume (p0.05. A post hoc Tukey test detected significant differences in filler size between 70 nm and 400 nm, and 200 nm and 400 nm (p<0.007. Conclusion: The experimental flowable resin composite containing a mean filler size of 400 nm exhibited significantly lower wear resistance in two-body wear compared with those containing mean filler sizes of 200 nm or 70 nm.

  1. On partial fluidization in rotating fluidized beds

    International Nuclear Information System (INIS)

    Kao, J.; Pfeffer, R.; Tardos, G.I.

    1987-01-01

    In a rotating fluidized bed, unlike in a conventional fluidized bed, the granules are fluidized layer by layer from the (inner) free surface outward at increasing radius as the gas velocity is increased. This is a very significant and interesting phenomenon and is extremely important in the design of these fluidized beds. The phenomenon was first suggested in a theoretical analysis and recently verified experimentally in the authors' laboratory. However, in the first paper, the equations presented are too cumbersome and the influence of bed thickness is not clearly stated. In this note the authors present simplified equations, based on that paper, for the pressure drop and the minimum fluidizing velocities in a rotating fluidized bed. Experimental data are also shown and compared with the theoretical model, and the effect of bed thickness is shown. Furthermore, an explanation for the observation of a maximum in the pressure drop vs. velocity curve instead of the plateau derived by Chen is proposed

  2. Gruppebaseret behandling af BED - et faseopdelt behandlingstilbud

    DEFF Research Database (Denmark)

    Laust, Jakob; Lau, Marianne Engelbrecht; Waaddegaard, Mette

    2015-01-01

    Titel: Afrapportering vedr. SATS-puljemidler til behandling og erfaringsopsamling vedr. BED for perioden 1. marts 2013 – 1. maj 2015. Baggrund: Binge Eating Disorder (BED), på dansk tvangsoverspisning, er en udbredt, men overset spiseforstyrrelse med alvorlige psykiske, fysiske og sociale...... konsekvenser. BED blev i 2013 optaget i DSM-5 (Diagnostic and Statistical Manual of Mental Disorders) som en selvstændig diagnose og BED forventes medtaget i den forestående revision af det internationale diagnose system, ICD-11. Sundhedsstyrelsen gav på denne baggrund satspuljemidler til erfaringsopsamling...... vedr. BED. I den forbindelse ansøgte Ambulatorium for Spiseforstyrrelser på Psykoterapeutisk Center Stolpegård ovenstående midler til at udvikle en ambulant, primært psykoterapeutisk gruppebehandling til patienter med moderat til svær BED med fokus på såvel spiseforstyrrelse såvel som overvægt. Metode...

  3. Aging in CTBN modified epoxy resin stocks

    International Nuclear Information System (INIS)

    Creed, K.E. Jr.

    1979-01-01

    The cause of degradation in the glass transition temperature (T/sub G/) of a partially crystallized polymer was investigated. Sample epoxy resin filled capacitors were cured at 90 0 C for 24 hours, then stored at room atmospheric conditions. These showed typical degradation in T/sub G/ after storage for one month. One set of epoxy resin castings was stored at room atmosphere and another set was stored in a dry box at 0% relative humidity and 27 0 C. The samples at room atmospheric conditions showed typical degradation in T/sub G/, while the T/sub G/ for those stored in the dry box increased. Further tests were then made on epoxy resin castings at various curing temperatures and times at both room atmosphere and 0% humidity. Resulting data indicated that absorption of moisture during storage was the predominant cause of T/sub G/ degradation, with stress relaxation another, though smaller, contributing factor

  4. Resin injection in clays with high plasticity

    Science.gov (United States)

    Nowamooz, Hossein

    2016-11-01

    Regarding the injection process of polyurethane resins in clays with high plasticity, this paper presents the experimental results of the pressuremeter and cone penetration tests before and after injection. A very important increase in pressure limit or in soil resistance can be observed for all the studied depths close to the injection points. An analytical analysis for cylindrical pore cavity expansion in cohesive frictional soils obeying the Mohr-Coulomb criterion was then used to reproduce the pressuremeter tests before and after injection. The model parameters were calibrated by maintaining constant the elasticity parameters as well as the friction angel before and after injection. A significant increase in cohesion was observed because of soil densification after resin expansion. The estimated undrained cohesions, derived from the parameters of the Mohr-Coulomb criterion, were also compared with the cone penetration tests. Globally, the model predictions show the efficiency of resin injection in clay soils with high plasticity.

  5. Restoration of traumatized teeth with resin composites

    DEFF Research Database (Denmark)

    Pallesen, Ulla; van Dijken, Jan WV

    2018-01-01

    For a long time, the primary choice for initial restoration of a crown-fractured front tooth has been resin composite material. The restoration can in most cases be performed immediately after injury if there is no sign of periodontal injury. The method’s adhesive character is conservative to tooth......-structure and with minimal risk of pulpal complication. In addition, it offers an aesthetic solution to the patient immediately after an injury, which may bring a little comfort in a sad situation. The resin composite build-up is often changed or repaired a couple of times, before the tooth is restored with a porcelain...... present an aesthetic problem due to exposure of un-aesthetic crown-margins. The invasive permanent crown restorations are therefore often not suc-cessful on a long-term scale. On the other hand, a conservative direct restoration of an extensively fractured incisor crown with resin composite may...

  6. Investigations of toughening mechanisms of epoxy resins

    Science.gov (United States)

    Koenig, T.

    1986-01-01

    Composite material technology was applied to the solid rocket booster by the development of a carbon filament-epoxy resin case which yields a net increase of 4000 lbs. in payload in the shuttle. The question of reusability of the new composite tanks has not yet been answered and will depend on the toughness of the matrix resin. The present study was aimed at providing conditions whereby test specimens of the epoxy resin (EPON/85) and curing agents of systematically varied structures could be produced in a controlled manner. Three sets of conditions were found that might allow the isolation of the structural effects on toughness from the cure effects. The kinetic methods leading to the determination of these conditions are described.

  7. Advanced sorbent development progam; development of sorbents for moving-bed and fluidized-bed applications

    International Nuclear Information System (INIS)

    Ayala, R.E.; Venkataramani, V.S.

    1998-01-01

    a market plan for large-scale fabrication of sorbents were developed. As an optional task, long-term bench-scale tests of the best moving-bed sorbents were conducted. Starting from thermodynamic calculations, several metal oxides were identified for potential use as hot gas cleanup sorbents using constructed phase stability diagrams and laboratory screening of various mixed-metal oxide formulations. Modified zinc titanates and other proprietary metal oxide formulations were evaluated at the bench scale and many of them found to be acceptable for operation in the target desulfurization temperature range of 370 C (700 F) to 538 C (1000 F) and regeneration temperatures up to 760 C (1400 F). Further work is still needed to reduce the batch-to-batch repeatability in the fabrication of modified zinc titanates for larger scale applications. The information presented in this Volume 1 report contains the results of moving-bed sorbent develop-ment at General Electrics Corporate Research and Development (GE-CRD). A separate Volume 2 report contains the results of the subcontract on fluidized-bed sorbent development at the Institute of Gas Technology (IGT)

  8. ADVANCED SORBENT DEVELOPMENT PROGRAM DEVELOPMENT OF SORBENTS FOR MOVING-BED AND FLUIDIZED-BED APPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    R.E Ayala; V.S. Venkataramani; Javad Abbasian; Rachid B. Slimane; Brett E. Williams; Minoo K. Zarnegar; James R. Wangerow; Andy H. Hill

    2000-03-31

    assessment and a market plan for large-scale fabrication of sorbents were developed. As an optional task, long-term bench-scale tests of the best moving-bed sorbents were conducted. Starting from thermodynamic calculations, several metal oxides were identified for potential use as hot gas cleanup sorbents using constructed phase stability diagrams and laboratory screening of various mixed-metal oxide formulations. Modified zinc titanates and other proprietary metal oxide formulations were evaluated at the bench scale and many of them found to be acceptable for operation in the target desulfurization temperature range of 370 C (700 F) to 538 C (1000 F) and regeneration temperatures up to 760 C (1400 F). Further work is still needed to reduce the batch-to-batch repeatability in the fabrication of modified zinc titanates for larger scale applications. The information presented in this Volume 1 report contains the results of moving-bed sorbent development at General Electric's Corporate Research and Development (GE-CRD). A separate Volume 2 report contains the results of the subcontract on fluidized-bed sorbent development at the Institute of Gas Technology (IGT).

  9. Effect of proximal box elevation with resin composite on marginal quality of resin composite inlays in vitro.

    Science.gov (United States)

    Roggendorf, Matthias J; Krämer, Norbert; Dippold, Christoph; Vosen, Vera E; Naumann, Michael; Jablonski-Momeni, Anahita; Frankenberger, Roland

    2012-12-01

    To evaluate marginal quality and resin-resin transition of lab made resin composite inlays in deep proximal cavities with and without 3 mm proximal box elevation (PBE) using resin composites before and after thermo-mechanical loading (TML). MOD cavities with one proximal box beneath the cementoenamel junction were prepared in 40 extracted human third molars. Proximal boxes ending in dentine were elevated 3 mm with different resin composites (G-Cem, Maxcem Elite as self-adhesive resin cements and Clearfil Majesty Posterior as restorative resin composite in one or three layers bonded with AdheSE), or left untreated. Clearfil Majesty Posterior inlays were luted with Syntac and Variolink II (n = 8). Marginal quality as well as the PBE-composite inlay interface was analyzed under an SEM using epoxy resin replicas before and after thermomechanical loading (100,000 × 50 N and 2500 thermocylces between +5 °C and +55 °C). Bonding resin composite inlays directly to dentine showed similar amounts of gap-free margins in dentine compared to PBE applied in three consecutive layers (p > 0.05). The groups with self-adhesive resin cements for PBE exhibited significantly more gaps in dentine (p < 0.05). With layered resin composite, PBE is effective in indirect resin composite bonding to deep proximal boxes. Self-adhesive resin cements are not suitable for this indication. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. 76 FR 8774 - Granular Polytetrafluoroethylene Resin From Japan

    Science.gov (United States)

    2011-02-15

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Granular Polytetrafluoroethylene Resin From Japan AGENCY: United States International Trade... polytetrafluoroethylene resin from Japan would be likely to lead to continuation or recurrence of material injury. On...

  11. Composite resin fillings and inlays: An 11-year evaluation

    DEFF Research Database (Denmark)

    Pallesen, U.; Qvist, V.

    2003-01-01

    Clinical trial, composite resin, direct restorations, indirect restorations, long-term behaviour, posterior teeth......Clinical trial, composite resin, direct restorations, indirect restorations, long-term behaviour, posterior teeth...

  12. Development of 3-methoxy-4-benzyloxybenzyl alcohol (MBBA) resin ...

    Indian Academy of Sciences (India)

    step sequence under microwave irradiation involving the reaction of commercially available Merrifield resin with vanillin, followed by reduction with sodium borohydride. MBBA resin was treated with bromides in the presence of sodium hydride to ...

  13. Fluorinated Alkyl Ether Epoxy Resin Compositions and Applications Thereof

    Science.gov (United States)

    Wohl, Christopher J. (Inventor); Connell, John W. (Inventor); Smith, Joseph G. (Inventor); Siochi, Emilie J. (Inventor); Gardner, John M. (Inventor); Palmieri, Frank M. (Inventor)

    2017-01-01

    Epoxy resin compositions prepared using amino terminated fluoro alkyl ethers. The epoxy resin compositions exhibit low surface adhesion properties making them useful as coatings, paints, moldings, adhesives, and fiber reinforced composites.

  14. Exercise thermoregulation with bed rest, confinement, and immersion deconditioning

    Science.gov (United States)

    Greenleaf, J. E.

    1997-01-01

    Altered thermoregulation following exposure to prolonged (12-14 days) of bed rest and 6 hr of head-down thermoneutral water immersion in humans, and cage confinement (8 weeks) in male, mongrel dogs resulted in occasional increased core temperature (Tcore) at rest, but consistent "excessive" increase in Tcore during submaximal exercise. This excessive increase in Tcore in nonexercising and exercising subjects was independent of the mode (isometric or isotonic) of exercise training during bed rest, and was associated with the consistent hypovolemia in men but not in women taking estrogen supplementation (1.25 mg premarin/ day) which restored plasma volume during bed rest to ambulatory control levels. Post-bed rest exercise sweating (evaporative heat loss) was unchanged or higher than control levels; however, calculated tissue heat conductance was significantly lower in men, and forearm venoconstriction was greater (venous volume was reduced) in women during exercise after bed rest. Because sweating appeared proportional to the increased level of Tcore, these findings suggest that one major factor for the excessive hyperthermia is decreased core to periphery heat conduction. Exercising dogs respond like humans with excessive increase in both rectal (Tre) and exercising muscle temperatures (Tmu) after confinement and, after eight weeks of exercise training on a treadmill following confinement, they had an attenuated rate of increase of Tre even below ambulatory control levels. Intravenous infusion of glucose also attenuated not only the rise in Tre during exercise in normal dogs, but also the excessive rise in Tre and exercising Tmu after confinement. Oral glucose also appeared to reduce the rate of increase in excessive Tre in men after immersion deconditioning. There was a greater rate of rise in Tcore in two cosmonauts during supine submaximal exercise (65% VO2 max) on the fifth recovery day after the 115-day Mir 18 mission. Thus, the excessive rise in core

  15. Biphenyl liquid crystalline epoxy resin as a low-shrinkage resin-based dental restorative nanocomposite.

    Science.gov (United States)

    Hsu, Sheng-Hao; Chen, Rung-Shu; Chang, Yuan-Ling; Chen, Min-Huey; Cheng, Kuo-Chung; Su, Wei-Fang

    2012-11-01

    Low-shrinkage resin-based photocurable liquid crystalline epoxy nanocomposite has been investigated with regard to its application as a dental restoration material. The nanocomposite consists of an organic matrix and an inorganic reinforcing filler. The organic matrix is made of liquid crystalline biphenyl epoxy resin (BP), an epoxy resin consisting of cyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (ECH), the photoinitiator 4-octylphenyl phenyliodonium hexafluoroantimonate and the photosensitizer champhorquinone. The inorganic filler is silica nanoparticles (∼70-100 nm). The nanoparticles were modified by an epoxy silane of γ-glycidoxypropyltrimethoxysilane to be compatible with the organic matrix and to chemically bond with the organic matrix after photo curing. By incorporating the BP liquid crystalline (LC) epoxy resin into conventional ECH epoxy resin, the nanocomposite has improved hardness, flexural modulus, water absorption and coefficient of thermal expansion. Although the incorporation of silica filler may dilute the reinforcing effect of crystalline BP, a high silica filler content (∼42 vol.%) was found to increase the physical and chemical properties of the nanocomposite due to the formation of unique microstructures. The microstructure of nanoparticle embedded layers was observed in the nanocomposite using scanning and transmission electron microscopy. This unique microstructure indicates that the crystalline BP and nanoparticles support each other and result in outstanding mechanical properties. The crystalline BP in the LC epoxy resin-based nanocomposite was partially melted during exothermic photopolymerization, and the resin expanded via an order-to-disorder transition. Thus, the post-gelation shrinkage of the LC epoxy resin-based nanocomposite is greatly reduced, ∼50.6% less than in commercialized methacrylate resin-based composites. This LC epoxy nanocomposite demonstrates good physical and chemical properties and good biocompatibility

  16. The influence of resin flexural modulus on the magnitude of ceramic strengthening.

    LENUS (Irish Health Repository)

    Fleming, Garry J P

    2012-07-01

    The aim was to determine the magnitude of ceramic resin-strengthening with resin-based materials with varying flexural moduli using a regression technique to assess the theoretical strengthening at a \\'zero\\' resin-coating thickness. The hypothesis tested was that experimentally, increasing resin flexural modulus results in increased resin-strengthening observed at a theoretical \\'zero\\' resin-coating thickness.

  17. Gas distributor for fluidized bed coal gasifier

    Science.gov (United States)

    Worley, Arthur C.; Zboray, James A.

    1980-01-01

    A gas distributor for distributing high temperature reaction gases to a fluidized bed of coal particles in a coal gasification process. The distributor includes a pipe with a refractory reinforced lining and a plurality of openings in the lining through which gas is fed into the bed. These feed openings have an expanding tapered shape in the downstream or exhaust direction which aids in reducing the velocity of the gas jets as they enter the bed.

  18. Performances and improvement of copper-hydrazine complexation deoxidising resin

    International Nuclear Information System (INIS)

    Liu Fenfen; Zhang Hao; Sun Haijun; Liu Xiaojie

    2012-01-01

    Copper-hydrazine complexation deoxidising resin is tested to examine its performances including effluent water quality and capacity of deoxidisation. By the means of changing the resin type and regeneration, the deoxidising capacity of the resin can be improved to 13 times more than before. At the same time, physical performances of the resin are also greatly improved while maintaining its velocity of deoxidisation and effluent quality. (authors)

  19. Recovery of tretrachloroaurate through ion exchange with Dowex 11 resin

    International Nuclear Information System (INIS)

    Alguacil, F.J.

    1998-01-01

    The recovery of the tretrachloroaurate complex by the anionic ion exchange resin Dowex 11 has been studied. The kinetics of gold adsorption were dependent of both gold and resin concentrations and temperature. The adsorption isotherm can be described by the expression Q=kC''n. The loaded resin could be eluted by an acidic thiourea solution at 20 degree centigree. After several adsorption-elution cycles there is not any apparent loss in the adsorption properties of the resin. (Author) 6 refs

  20. Interacting Blends of Novel Unsaturated Polyester Amide Resin with Styrene

    OpenAIRE

    Patel, Hasmukh S.; Panchal, Kumar K.

    2004-01-01

    Novel unsaturated poly (ester-amide) resins (UPEAs) were prepared by the reaction between an epoxy resin, namely diglycidyl ether of bisphenol–A (DGEBA) and unsaturated aliphatic bisamic acids using a base catalyst. These UPEAs were then blended with a vinyl monomer namely, Styrene (STY.) to produce a homogeneous resin syrup. The curing of these UPEAs-STY. resin blends was carried out by using benzoyl peroxide (BPO) as a catalyst and was monitored by using a differential scanning calorimeter ...

  1. Gamma-irradiation on cured glycidyl amino-epoxy resin

    International Nuclear Information System (INIS)

    Yang, Ting; Wei, Chengsha; Liu, Hewen

    2010-01-01

    ITER is an international project to design and build an experimental fusion reactor based on the superconductive 'tokamak' concept. Amounts of epoxy resin are used in the superconductive tokamak device as impregnant resins, insulation breaks, etc. Resistance to ionizing radiation is a demanding performance of those epoxy resins. In this work, we study the effects of γ-irradiation on the mechanical properties and chemical structures of glycidyl amino-epoxy resins

  2. Synthesis of a boron modified phenolic resin

    Directory of Open Access Journals (Sweden)

    Aparecida M. Kawamoto

    2010-08-01

    Full Text Available Phenolic resin has long been used as matrix for composites mainly because of its flame retardant behavior and high char yield after pyrolysis, which results in a self supporting structure. The addition of ceramic powders, such as SiC and B4C, as fillers to the phenolic resin, results in better thermo-oxidative stability, but as drawbacks, it has poor homogeneity, adhesion and processing difficulties during molding of the composites. The addition of single elements, such as boron, silicon and phosphorus in the main backbone of the thermo-set resin is a new strategy to obtain special high performance resins, which results in higher mechanical properties, avoiding the drawbacks of simply adding fillers, which results in enhanced thermo-oxidative stability compared to conventional phenol-formaldehyde resins. Therefore, the product can have several applications, including the use as ablative thermal protection for thermo-structural composites. This work describes the preparation of a boron-modified phenolic resin (BPR using salicyl alcohol and boric acid. The reaction was performed in refluxing toluene for a period of four hours, which produced a very high viscosity amber resin in 90% yield.The final structure of the compound, the boric acid double, substituted at the hydroxyl group of the aromatic ring, was determined with the help of the Infrared Spectroscopy, ¹H-NMR, TGA-DSC and boron elemental analysis. The absorption band of the group B-O at 1349 cm ˉ¹ can be visualized at the FT-IR spectrum. ¹H-NMR spectra showed peaks at 4.97-5.04 ppm and 3.60-3.90 ppm assigned to belong to CH2OH groups from the alcohol. The elemental analysis was also performed for boron determination.The product has also been tested in carbon and silicon fibers composite for the use in thermal structure. The results of the tests showed composites with superior mechanical properties when compared with the conventional phenolic resin.

  3. Gas filtration in binary fluidized beds

    Energy Technology Data Exchange (ETDEWEB)

    Rincon, J. (Univ. de Castilla-La Mancha, Ciudad Real (Spain)); Guardiola, J.; Romero, A. (Univ. de Alcala de Henares, Madrid (Spain))

    1992-12-01

    A systematic experimental study of aerosol filtration in a binary fluidized bed of dielectric material is carried out. Measurements of the collection efficiency when such parameters as gas velocity, bed height, collecting mixture, and column diameter are varied over a wide range have been made. Experimental evidence is given to show that charges generated naturally by triboelectrification of the bed dielectric particles can considerably increase the efficiency of such beds. Furthermore, it is demonstrated that a proper choice of the fluidized mixture can significantly improve the performance of such filters.

  4. Curing reaction of bisphenol-A based benzoxazine with cyanate ester resin and the properties of the cured thermosetting resin

    Directory of Open Access Journals (Sweden)

    H. Kimura

    2011-12-01

    Full Text Available Curing reaction of bisphenol-A based benzoxazine with cyanate ester resin and the properties of the cured thermosetting resin were investigated. The cure behavior of benzoxazine with cyanate ester resin was monitored by model reaction using nuclear magnetic resonance (NMR. As a result of the model reaction, the ring opening reaction of benzoxazine ring and thermal self-cyclotrimerization of cyanate ester group occurred, and then the phenolic hydoroxyl group generated by the ring opening reaction of benzoxazine ring co-reacted with cyanate ester group. The properties of the cured thermosetting resin were estimated by mechanical properties, electrical resistivity, water resistance and heat resistance. The cured thermosetting resin from benzoxazine and cyanate ester resin showed good heat resistance, high electrical resistivity and high water resistance, compared with the cured thermosetting resin from benzoxazine and epoxy resin.

  5. Development of amino resin for paint formulation: Copolymerization ...

    African Journals Online (AJOL)

    SERVER

    2007-06-18

    Jun 18, 2007 ... The moisture uptake of the different resin films was determined gravimetrically. Known weights of each of ... as the moisture intake by the resin (Barminas and Osemeahon,. 2006). All determinations were performed ... Therefore during the condensation reactions of methylol urea resins into polymer chains, ...

  6. Facile synthesis of allyl resinate monomer in an aqueous solution ...

    Indian Academy of Sciences (India)

    as oligomer products such as inks and coatings. Com- pared with the oligomer from fossil resources such as acrylic resins and styrene resins, we believe the intro- duction of the resin structure into polymer products can provide specific mechanical properties, such as hardness and flexibility. GC analysis of each component ...

  7. 21 CFR 872.3670 - Resin impression tray material.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3670 Resin impression tray material. (a) Identification. Resin impression tray material is a device intended for use in a two-step dental mold fabricating... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Resin impression tray material. 872.3670 Section...

  8. Evaluation of some anionic exchange resins as potential tablet ...

    African Journals Online (AJOL)

    The effect of resin concentration and compression force on the properties of tablets using the selected resin was investigated. In addition, the disintegrant efficacy of the selected resin in the tablet formulations containing either a basic drug, e.g., dextromethorphan hydrobromide (DMP), or an acidic drug, e.g., diclofenac ...

  9. 21 CFR 173.40 - Molecular sieve resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Molecular sieve resins. 173.40 Section 173.40 Food... Polymer Substances and Polymer Adjuvants for Food Treatment § 173.40 Molecular sieve resins. Molecular sieve resins may be safely used in the processing of food under the following prescribed conditions: (a...

  10. 75 FR 67105 - Granular Polytetrafluoroethylene Resin From Italy and Japan

    Science.gov (United States)

    2010-11-01

    ... COMMISSION Granular Polytetrafluoroethylene Resin From Italy and Japan AGENCY: United States International... granular polytetrafluoroethylene resin from Italy and Japan. SUMMARY: The Commission hereby gives notice... polytetrafluoroethylene resin from Italy and Japan would be likely to lead to continuation or recurrence of material...

  11. Photosensitive filler minimizes internal stresses in epoxy resins

    Science.gov (United States)

    Dillon, J. N.

    1967-01-01

    Photosensitive filler is added to curable epoxy resins to minimize stress from internal shrinkage during curing or polymerization. Cinnamic acid resins and cinnamal ketones may be added in the amount of 1 to 3 percent by weight of the resin mixture.

  12. Color change of composite resins subjected to accelerated artificial aging.

    Science.gov (United States)

    Tornavoi, Denise Cremonezzi; Agnelli, José Augusto Marcondes; Panzeri, Heitor; Dos Reis, Andréa Cândido

    2013-01-01

    The aim of this study was to evaluate the influence of accelerated artificial aging (AAA) on the color change of composite resins used in dentistry. Three composite resins were evaluated: Two microhybrids and one hybrid of higher viscosity, with different amounts and sizes of filler particles, shades C2 and B2. A total of 54 specimens were obtained (18 for each composite resin), made of a Teflon matrix (15 mm in diameter and 2 mm in height). The color measurements were obtained with a Spectrophotometer, (PCB 6807 BYK Gardner) before and after AAA. Data were submitted to the Kolmogorov-Smirnov test (α >0.05), ANOVA and Tukey test (α composite resins with the same shades was analyzed. All composite resins showed unacceptable color changes after AAA (ΔE > 3). Considering the variable ∆E, it was observed that the color tone C2 was already statistically different for the microhybrid composite resin prior to AAA (P composite resins (P composite resin group, before aging the composite resin hybrid of higher viscosity B2 showed the highest color variation rate and microhybrid with zirconium/silica C2 showed the lowest. All composite resins presented unacceptable color changes after 382 h of aging and different composite resins with same hue, presented different colors before being subjected to the aging process (B2 and C2) and after (B2). It was also observed color difference within a group of the same composite resin and same hue.

  13. Development of radiation-curable resin based on natural rubber

    International Nuclear Information System (INIS)

    Dahlan Mohd; Abdul Ghani Harun

    1993-01-01

    A new radiation curable resin based on natural rubber has been developed. The resin was based on the reaction between low molecular weight epoxidised natural rubber and acrylic acid. When formulated with reactive monomers and photoinitiator, it solidified upon irradiation with UV light. The resin may find applications in coating for cellulosic-based substrates and pressure-sensitive adhesive

  14. Resin impregnation of cellulose nanofibril films facilitated by water swelling

    Science.gov (United States)

    Yan Qing; Ronald Sabo; Zhiyong Cai; Yiqiang Wu

    2013-01-01

    Flexible composite films were produced by impregnating aqueous phenol formaldehyde (PF) resin into water-swollen cellulose nanofibril (CNF) films. CNF films were prepared using a pressurized filtration method in combination with freeze drying. The freeze-dried films were swollen with water then impregnated with PF resin by soaking in aqueous resin solutions of varying...

  15. 21 CFR 177.2355 - Mineral reinforced nylon resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Mineral reinforced nylon resins. 177.2355 Section... as Components of Articles Intended for Repeated Use § 177.2355 Mineral reinforced nylon resins. Mineral reinforced nylon resins identified in paragraph (a) of this section may be safely used as articles...

  16. 21 CFR 177.2260 - Filters, resin-bonded.

    Science.gov (United States)

    2010-04-01

    ... a pH above 5.0. (j) Resin-bonded filters conforming with the specifications of paragraph (j) (1) of... bulk quantities of nonalcoholic, aqueous foods having a pH of 5.0 or below. (k) Resin-bonded filters...: List of Substances and Limitations (1) Fibers: Cellulose pulp. Cotton. Nylon. (From nylon resins...

  17. 40 CFR 721.5908 - Modified phenolic resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified phenolic resin (generic). 721... Substances § 721.5908 Modified phenolic resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as modified phenolic resin (PMN P...

  18. 40 CFR 721.2673 - Aromatic epoxide resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aromatic epoxide resin (generic). 721... Substances § 721.2673 Aromatic epoxide resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as aromatic epoxide resin (PMN P...

  19. Treatment of White Spot Lesions with Icon (Resin Infiltration)

    Science.gov (United States)

    2017-03-23

    FROM: 59 MDW/SGVU SUBJECT: Professional Presentation Approval 8 MAR2017 1. Your paper, entitled T reatment of White Spot Lesions with Icon ( Resin ... Resin Infiltration) 6. TITLE OF MATERIAL TO BE PUBLISHED OR PRESENTED: Treatment of White Spot lesions with Icon ( Resin In filtration) 7. FUNDING

  20. 21 CFR 573.120 - Acrylamide-acrylic acid resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573.120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid resin...

  1. 40 CFR 721.9499 - Modified silicone resin.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified silicone resin. 721.9499... Substances § 721.9499 Modified silicone resin. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a modified silicone resin (PMN P-96-1649) is...

  2. 40 CFR 721.4380 - Modified hydrocarbon resin.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified hydrocarbon resin. 721.4380... Substances § 721.4380 Modified hydrocarbon resin. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a modified hydrocarbon resin (P-91-1418) is...

  3. 40 CFR 721.5905 - Modified phenolic resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified phenolic resin (generic). 721... Substances § 721.5905 Modified phenolic resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a modified phenolic resin (PMN...

  4. 21 CFR 872.3200 - Resin tooth bonding agent.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Resin tooth bonding agent. 872.3200 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3200 Resin tooth bonding agent. (a) Identification. A resin tooth bonding agent is a device material, such as methylmethacrylate, intended to be painted...

  5. 40 CFR 721.5762 - Aromatic aldehyde phenolic resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aromatic aldehyde phenolic resin... Specific Chemical Substances § 721.5762 Aromatic aldehyde phenolic resin (generic). (a) Chemical substance... aromatic aldehyde phenolic resin (PMN P-01-573) is subject to reporting under this section for the...

  6. 21 CFR 872.3690 - Tooth shade resin material.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tooth shade resin material. 872.3690 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3690 Tooth shade resin material. (a) Identification. Tooth shade resin material is a device composed of materials such as bisphenol-A glycidyl...

  7. Development of 3-methoxy-4-benzyloxybenzyl alcohol (MBBA) resin ...

    Indian Academy of Sciences (India)

    Administrator

    Abstract. 3-Methoxy-4-benzyloxybenzyl alcohol (MBBA) resin was synthesized by a two-step se- quence under microwave irradiation involving the reaction of commercially available Merrifield resin with vanillin, followed by reduction with sodium borohydride. MBBA resin was treated with bromides in the presence of sodium ...

  8. Color change of composite resins subjected to accelerated artificial aging

    Directory of Open Access Journals (Sweden)

    Denise Cremonezzi Tornavoi

    2013-01-01

    Conclusions: All composite resins presented unacceptable color changes after 382 h of aging and different composite resins with same hue, presented different colors before being subjected to the aging process (B2 and C2 and after (B2. It was also observed color difference within a group of the same composite resin and same hue.

  9. 21 CFR 177.2510 - Polyvinylidene fluoride resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyvinylidene fluoride resins. 177.2510 Section... as Components of Articles Intended for Repeated Use § 177.2510 Polyvinylidene fluoride resins. Polyvinylidene fluoride resins may be safely used as articles or components of articles intended for repeated use...

  10. 21 CFR 872.3300 - Hydrophilic resin coating for dentures.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hydrophilic resin coating for dentures. 872.3300... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3300 Hydrophilic resin coating for dentures. (a) Identification. A hydrophilic resin coating for dentures is a device that consists of a water...

  11. 21 CFR 872.3310 - Coating material for resin fillings.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Coating material for resin fillings. 872.3310... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3310 Coating material for resin fillings. (a) Identification. A coating material for resin fillings is a device intended to be applied to the...

  12. 76 FR 4936 - Granular Polytetrafluoroethylene Resin From Italy

    Science.gov (United States)

    2011-01-27

    ... Polytetrafluoroethylene Resin From Italy AGENCY: United States International Trade Commission. ACTION: Revised schedule... granular polytetrafluoroethylene resin (``granular PTFE resin'') from Italy. DATES: Effective Date: January... from Italy and Japan (75 FR 67082-67083 and 67105-67108, November 1, 2010). However, Commerce's notice...

  13. 76 FR 39896 - Granular Polytetrafluoroethylene Resin From Italy

    Science.gov (United States)

    2011-07-07

    ... Polytetrafluoroethylene Resin From Italy Determination On the basis of the record \\1\\ developed in the subject five-year... granular polytetrafluoroethylene resin from Italy would be likely to lead to continuation or recurrence of... Polytetrafluoroethylene Resin from Italy: Investigation No. 731-TA-385 (Third Review). By order of the Commission. Issued...

  14. 21 CFR 872.3820 - Root canal filling resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Root canal filling resin. 872.3820 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3820 Root canal filling resin. (a) Identification. A root canal filling resin is a device composed of material, such as methylmethacrylate, intended...

  15. 40 CFR 721.3135 - Phosphorous modified epoxy resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Phosphorous modified epoxy resin... Specific Chemical Substances § 721.3135 Phosphorous modified epoxy resin (generic). (a) Chemical substance... phosphorous modified epoxy resin (PMNs P-00-992 and P-01-471) is subject to reporting under this section for...

  16. 40 CFR 721.2752 - Epoxy resin containing phosphorus (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Epoxy resin containing phosphorus... Specific Chemical Substances § 721.2752 Epoxy resin containing phosphorus (generic). (a) Chemical substance... epoxy resin containing phosphorus (PMN P-00-912) is subject to reporting under this section for the...

  17. 40 CFR 721.2755 - Cycloaliphatic epoxy resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Cycloaliphatic epoxy resin (generic... Substances § 721.2755 Cycloaliphatic epoxy resin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as cycloaliphatic epoxy resin (PMN...

  18. The effect of bed particle size and deposit morphology on the filtration of magnetite through granular graphite beds

    International Nuclear Information System (INIS)

    Barbieri, R.R.; Bercovich, E.J.; Liberman, S.J.

    1980-01-01

    Graphite filters are of great interest for water purification in nuclear power reactors' primary systems due to their possible operation at high temperature. The influence of the bed particle size on the retention of magnetite from aqueous suspensions at room temperature was studied. The filtration coefficient changes from 0.0 to 0.18 as the mean graphite particle diameter decreases from 1.2 to 0. mm. As the retention increases, there is also an increase in the differential pressure across the bed, so both effects must be considered in order to optimize filter's operation. The specific effective volume of the deposit was calculated with the Blake-Kozeny equation and the experimental specific volumes. These are much larger than the specific volume of solid magnetite. From the results, information regarding the morphology of the deposit in the filter is obtained. (M.E.L) [es

  19. Characterization of hydroxybenzoic acid chelating resins: equilibrium, kinetics, and isotherm profiles for Cd(II and Pb(II uptake

    Directory of Open Access Journals (Sweden)

    BHAVNA A. SHAH

    2011-06-01

    Full Text Available Chelating ion-exchange resins were synthesized by polycondensation of ortho/para hydroxybenzoic acid with resorcinol/catechol employing formaldehyde as cross-linking agent at 80±5 °C in DMF. The resins were characterized by FTIR and XRD. The uptake behaviour of synthesized resins for Cd(II and Pb(II ions have been studied depending on contact time, pH, metal ion concentration and temperature. The sorption data obtained at optimized conditions were analyzed by the Langmuir and Freundlich isotherms. Experimental data of all metal–resin system were best represented by the Freundlich isotherm. The maximum obtained sorption capacity for cadmium was 69.53 mg g-1 and 169.32 mg g-1 for Lead. The adsorption process follows first order kinetics and the specific rate constant Kr was obtained by the application of the Lagergan equation. Thermodynamic parameters ∆Gads, ∆Sads and ∆Hads were calculated for the metal–resin systems. The external diffusion rate constant (KS and the intra-particle diffusion rate constant (Kid were calculated by the Spahn–Schlunder and Weber–Morris models, respectively. The sorption process was found to follow an intra-particle diffusion phenomenon.

  20. Metabolic Resistance in Bed Bugs

    Directory of Open Access Journals (Sweden)

    Omprakash Mittapalli

    2011-03-01

    Full Text Available Blood-feeding insects have evolved resistance to various insecticides (organochlorines, pyrethroids, carbamates, etc. through gene mutations and increased metabolism. Bed bugs (Cimex lectularius are hematophagous ectoparasites that are poised to become one of the major pests in households throughout the United States. Currently, C. lectularius has attained a high global impact status due to its sudden and rampant resurgence. Resistance to pesticides is one factor implicated in this phenomenon. Although much emphasis has been placed on target sensitivity, little to no knowledge is available on the role of key metabolic players (e.g., cytochrome P450s and glutathione S-transferases towards pesticide resistance in C. lectularius. In this review, we discuss different modes of resistance (target sensitivity, penetration resistance, behavioral resistance, and metabolic resistance with more emphasis on metabolic resistance.

  1. Particle Bed Reactor engine technology

    International Nuclear Information System (INIS)

    Sandler, S.; Feddersen, R.

    1992-01-01

    This paper discusses the Particle Bed Reactor (PBR) based propulsion system being developed under the Space Nuclear Thermal Propulsion (SNTP) program. A PBR engine is a light weight, compact propulsion system which offers significant improvement over current technology systems. Current performance goals are a system thrust of 75,000 pounds at an Isp of 1000 sec. A target thrust to weight ratio (T/W) of 30 has been established for an unshielded engine. The functionality of the PBR, its pertinent technology issues and the systems required to make up a propulsion system are described herein. Accomplishments to date which include hardware development and tests for the PBR engine are also discussed. This paper is intended to provide information on and describe the current state-of-the-art of PBR technology. 4 refs

  2. Particle Bed Reactor engine technology

    Science.gov (United States)

    Sandler, S.; Feddersen, R.

    1992-03-01

    This paper discusses the Particle Bed Reactor (PBR) based propulsion system being developed under the Space Nuclear Thermal Propulsion (SNTP) program. A PBR engine is a light weight, compact propulsion system which offers significant improvement over current technology systems. Current performance goals are a system thrust of 75,000 pounds at an Isp of 1000 sec. A target thrust to weight ratio (T/W) of 30 has been established for an unshielded engine. The functionality of the PBR, its pertinent technology issues and the systems required to make up a propulsion system are described herein. Accomplishments to date which include hardware development and tests for the PBR engine are also discussed. This paper is intended to provide information on and describe the current state-of-the-art of PBR technology.

  3. Building Controls Virtual Test Bed

    Energy Technology Data Exchange (ETDEWEB)

    2008-04-01

    The Building Controls Virtual Test Bed (BCVTB) is a modular software environment that is based on the Ptolemy II software environment. The BCVTB can be used for design and analysis of heterogenous systems, such as building energy and controls systems. Our additions to Ptolemy II allow users to Couple to Ptolemy II simulation software such as EnergyPlus, MATLAB/Simulink or Dymola for data exchange during run-time. Future versions of the BCVTS will also contain an interface to BACnet which is a communication protocol for building Control systems, and interfaces to digital/analog converters that allow communication with controls hardware. Through Ptolemy II, the BCVTB provides a graphical model building environment, synchronizes the exchanged data and visualizes the system evolution during run- time.

  4. Flue gas desulfurization by rotating beds

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, N.; Keyvani, M.; Coskundeniz, A.

    1992-01-01

    The operating and mass transfer characteristics of rotating foam metal beds were studied to determine the potential for flue gas desulfurization. This is a final technical report on the work supported by DOE [number sign]FG22-87-PC79924. The report is divided into two sections, Part 1 deals primarily with the operating characteristics of rotating beds, and Part 2 covers the mass transfer characteristics of S0[sub 2] absorption in water-lime slurries. Rotating foam metal beds are in essence packed towers operated in high gravitational fields. The foam metal bed is in the form of a cylindrical donut, or torus, and is rotated to produced the high centrifugal forces. The liquid phase enters the bed at the inner surface of the torus and is pulled by the field through the bed. Gas flows countercurrent to the liquid. The bed packing can have a very large specific surface areas and not flood. Possible benefits include much smaller height of a transfer unit resulting in smaller equipment and supporting structures, reduced solvent inventory, faster response with improved process control, reduced pressure drop, and shorter startup and shut-down times. This work is concerned broadly with the operating characteristics of rotating beds, the objectives being to (1) determine the pressure drop through the rotating bed; (2) determine the power required to operate the beds, (3) investigate the residence time distribution of the liquid phase in the beds; and (4) determine the mass transfer coefficients of S0[sub 2] absorption. Three packings of differing specific surface areas were studied, with areas ranging from 656 to 2952 m[sub 2]/m[sub 3]. Liquid flow rates to 36 kg/s*m[sub 2], gas flow rate to 2.2 kg/s*m[sub 2], and gravitational fields to 300 g were covered in this study.

  5. Effects of air-polishing powders on color stability of composite resins

    Directory of Open Access Journals (Sweden)

    Ahmet Umut Güler

    2011-10-01

    Full Text Available OBJECTIVES: The purpose of this study was to investigate the effect of different air-polishing powders on the color stability of different types of composite resin restorative materials. MATERIAL AND METHODS: Thirty cylindrical specimens (15×2 mm were prepared for each of 7 composite resin restorative materials. All specimens were polished with a series of aluminum oxide polishing discs (Sof-Lex. The prepared specimens of each composite resin were randomly divided into 3 groups of 10 specimens each, for control (Group-C and two air-powder applications (Group-CP: Cavitron Prophy-Jet; Group-PS: Sirona ProSmile prophylaxis powder. A standard air-polishing unit (ProSmile Handly was used. All specimens were air-powdered for 10 s at 4-bar pressure. The distance of the spray nosel from the specimens was approximately 10 mm and angulation of the nosel was 90°. Specimens were stored in 100 mL of coffee (Nescafe Classic for 24 h at 37°C. Color measurement of all specimens was recorded before and after exposure to staining agent with a colorimeter (Minolta CR-300. Color differences (∆E* between the 2 color measurements (baseline and after 24 h storage were calculated. The data were analyzed with a 2-way ANOVA test, and mean values were compared by the Tukey HSD test (p.05 and these groups demonstrated the highest ∆E* values. For Filtek Silorane and IntenS, the highest ∆E* values were observed in Group-PS. The lowest ∆E* values for all composite resin groups were observed in Group-C. When comparing the 7 composite resin restorative materials, Aelite Aesthetic Enemal demonstrated significantly less ∆E* values than the other composite resins tested. The highest ∆E* values were observed in Quixfil. CONCLUSION: Except for Quixfil, all control groups of composite resins that were polished Sof-Lex exhibited clinically acceptable ∆E values (<3.7. Air-polishing applications increased the color change for all composite resin restorative materials

  6. Pulsed atmospheric fluidized bed combustion

    Energy Technology Data Exchange (ETDEWEB)

    1989-11-01

    In order to verify the technical feasibility of the MTCI Pulsed Atmospheric Fluidized Bed Combustor technology, a laboratory-scale system was designed, built and tested. Important aspects of the operational and performance parameters of the system were established experimentally. A considerable amount of the effort was invested in the initial task of constructing an AFBC that would represent a reasonable baseline against which the performance of the PAFBC could be compared. A summary comparison of the performance and emissions data from the MTCI 2 ft {times} 2 ft facility (AFBC and PAFBC modes) with those from conventional BFBC (taller freeboard and recycle operation) and circulating fluidized bed combustion (CFBC) units is given in Table ES-1. The comparison is for typical high-volatile bituminous coals and sorbents of average reactivity. The values indicated for BFBC and CFBC were based on published information. The AFBC unit that was designed to act as a baseline for the comparison was indeed representative of the larger units even at the smaller scale for which it was designed. The PAFBC mode exhibited superior performance in relation to the AFBC mode. The higher combustion efficiency translates into reduced coal consumption and lower system operating cost; the improvement in sulfur capture implies less sorbent requirement and waste generation and in turn lower operating cost; lower NO{sub x} and CO emissions mean ease of site permitting; and greater steam-generation rate translates into less heat exchange surface area and reduced capital cost. Also, the PAFBC performance generally surpasses those of conventional BFBC, is comparable to CFBC in combustion and NO{sub x} emissions, and is better than CFBC in sulfur capture and CO emissions even at the scaled-down size used for the experimental feasibility tests.

  7. Neutron shielding material based on colemanite and epoxy resin.

    Science.gov (United States)

    Okuno, Koichi

    2005-01-01

    In recent years, there has been a need for compact shielding design such as self-shielding of a PET cyclotron or upgradation of radiation machinery in existing facilities. In these cases, high performance shielding materials are needed. Concrete or polyethylene have been used for a neutron shield. However, for compact shielding, they fall short in terms of performance or durability. Therefore, a new type of neutron shielding material based on epoxy resin and colemanite has been developed. Slab attenuation experiments up to 40 cm for the new shielding material were carried out using a 252Cf neutron source. Measurement was carried out using a REM-counter, and compared with calculation. The results show that the shielding performance is better than concrete and polyethylene mixed with 10 wt% boron oxide. From the result, we confirmed that the performance of the new material is suitable for practical use.

  8. Low-melt Viscosity Polyimide Resins for Resin Transfer Molding (RTM) II

    Science.gov (United States)

    Chuang, Kathy C.; Criss, Jim M.; Mintz, Eric A.; Scheiman, Daniel A.; Nguyen, Baochau N.; McCorkle, Linda S.

    2007-01-01

    A series of polyimide resins with low-melt viscosities in the range of 10-30 poise and high glass transition temperatures (Tg s) of 330-370 C were developed for resin transfer molding (RTM) applications. These polyimide resins were formulated from 2,3,3 ,4 -biphenyltetracarboxylic dianhydride (a-BPDA) with 4-phenylethynylphthalic anhydride endcaps along with either 3,4 - oxyaniline (3,4 -ODA), 3,4 -methylenedianiline, (3,4 -MDA) or 3,3 -methylenedianiline (3,3 -MDA). These polyimides had pot lives of 30-60 minutes at 260-280 C, enabling the successful fabrication of T650-35 carbon fiber reinforced composites via RTM process. The viscosity profiles of the polyimide resins and the mechanical properties of the polyimide carbon fiber composites will be discussed.

  9. Resin Flow in Fiber Preformed by Vacuum Assisted Resin Transfer Molding with Flexible Tools

    Directory of Open Access Journals (Sweden)

    M.M. Shokrieh

    2008-12-01

    Full Text Available Vacuum assisted resin transfer molding, as a sub-branch of RTM is a method of manufacturing composite specimens. Considering the industrial development of this method, different modified techniques are designed to improve its performance. Among these techniques, using a half flexible mold is regarded as an important method. In this work, dominant equations of resin flow through the mold in polar coordinates are solved analytically. Based on this approach, closed-form solutions have been presented for different parameters such as thickness variation of preformed fiber, resin pressure, resin velocity and fiber volume fraction as functions of two variables, namely, time and the distance from injection port. After verification of the approach employed in this work, the results are presented. Important parameters influencing the quality and the rate production are studied in detail.

  10. Friction factor for water flow through packed beds of spherical and non-spherical particles

    Directory of Open Access Journals (Sweden)

    Kaluđerović-Radoičić Tatjana

    2017-01-01

    Full Text Available The aim of this work was the experimental evaluation of different friction factor correlations for water flow through packed beds of spherical and non-spherical particles at ambient temperature. The experiments were performed by measuring the pressure drop across the bed. Packed beds made of monosized glass spherical particles of seven different diameters were used, as well as beds made of 16 fractions of quartz filtration sand obtained by sieving (polydisperse non-spherical particles. The range of bed voidages was 0.359–0.486, while the range of bed particle Reynolds numbers was from 0.3 to 286 for spherical particles and from 0.1 to 50 for non-spherical particles. The obtained results were compared using a number of available literature correlations. In order to improve the correlation results for spherical particles, a new simple equation was proposed in the form of Ergun’s equation, with modified coefficients. The new correlation had a mean absolute deviation between experimental and calculated values of pressure drop of 9.04%. For non-spherical quartz filtration sand particles the best fit was obtained using Ergun’s equation, with a mean absolute deviation of 10.36%. Surface-volume diameter (dSV necessary for correlating the data for filtration sand particles was calculated based on correlations for dV = f(dm and Ψ = f(dm. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. ON172022

  11. 21 CFR 177.1580 - Polycarbonate resins.

    Science.gov (United States)

    2010-04-01

    ... condensation of 4,4′-iso-propylidenediphenol and carbonyl chloride to which may have been added certain optional adjuvant substances required in the production of the resins; or by (2) The reaction of molten 4,4′-iso-propylidenediphenol with molten diphenyl carbonate in the presence of the disodium salt of 4,4...

  12. Effect of Resin Extract from Commiphora swynnertonii

    African Journals Online (AJOL)

    Dr Olaleye

    of Commiphora swynnertonii resin on biochemical parameters in rats was investigated. Sixty rats were ... significantly elevated protein and albumin levels but had no significant effect on bilirubin and all the liver enzymes in the rats. These findings are ... hypoglycemic and hypolipidemic effects against high fat diet- induced ...

  13. Microbial treatment of ion exchange resins

    International Nuclear Information System (INIS)

    Kouznetsov, A.; Kniazev, O.

    2001-01-01

    A bioavailability of ion exchange resins to a microbial destruction as one of the alternative methods of compacting used ionites from the nuclear fuel manufacturing cycle enterprises has been investigated. The bio-destruction was studied after a preliminary chemical treatment or without it. A sensitivity of the ion exchange resins (including highly acidic cationite KU-2-8) to the microbial destruction by heterotrophic and chemo-litho-trophic microorganisms under aerobic conditions was shown in principle. The biodegradation of the original polymer is possible in the presence of the water soluble fraction of the resin obtained after its treatment by Fenton reagent and accelerated in the presence of Mn-ions in optimal concentration 1-2 g of Mn per liter of medium. Thus, the process of bio-destruction of ionite polymer by heterotrophic microorganisms can be compared with the bio-destruction of lignin or humic substances. The optimum parameters of bio-destruction and microorganisms used must be different for resins with different functional groups. (authors)

  14. Liquid Resins-Based Additive Manufacturing

    Science.gov (United States)

    Wang, Fei; Wang, Fuke

    In this review, additive manufacturing technologies using liquid resins as materials are reviewed from the perspective of printing technologies and materials. Most importantly, recent progress of new printing technologies and printers as well as novel printing materials and their applications are summarized, based on which potential future research directions are discussed at the end of this review.

  15. Evaluation of resins for use in brachytherapy

    International Nuclear Information System (INIS)

    Carvalho, Luiz Claudio F.M. Garcia; Ferraz, Wilmar Barbosa; Chrcanovic, Bruno Ramos; Santos, Ana Maria M.

    2011-01-01

    Brachytherapy is an advanced cancer treatment where radioactive seeds or sources are placed near or directly into the tumor thus reducing the radiation exposure in the surrounding healthy tissues. Prostate cancer can be treated with interstitial brachytherapy in initial stage of the disease in which tiny radioactive seeds with cylindrical geometry are used. Several kinds of seeds have been developed in order to obtain a better dose distribution around them and with a lower cost manufacturing. These seeds consist of an encapsulation, a radionuclide carrier, and X-ray marker. Among the materials that have potential for innovation in the construction of seeds, biocompatible resins appear as an important option. In this paper, we present some characterization results with Fourier transform infrared spectroscopic (FTIR) and ultraviolet-visible spectroscopy (UV-vis) performed on two types of resins in which curing temperatures for each one were varied as also the results of coatings with these resins under titanium substrates. Interactions of these resins in contact with the simulated body fluid were evaluated by atomic force microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. (author)

  16. Biodegradation of acrylic based resins: A review.

    Science.gov (United States)

    Bettencourt, Ana F; Neves, Cristina B; de Almeida, Marise S; Pinheiro, Lídia M; Oliveira, Sofia Arantes e; Lopes, Luís P; Castro, Matilde F

    2010-05-01

    The development of different types of materials with application in dentistry is an area of intense growth and research, due to its importance in oral health. Among the different materials there are the acrylic based resins that have been extensively used either in restorations or in dentures. The objective of this manuscript was to review the acrylic based resins biodegradation phenomena. Specific attention was given to the causes and consequences of materials degradation under the oral environment. Information from scientific full papers, reviews or abstracts published from 1963 to date were included in the review. Published material was searched in dental literature using general and specialist databases, like the PubMED database. Published studies regarding the description of biodegradation mechanisms, in vitro and in vivo release experiments and cell based studies conducted on acrylic based resins or their components were evaluated. Studies related to the effect of biodegradation on the physical and mechanical properties of the materials were also analyzed. Different factors such as saliva characteristics, chewing or thermal and chemical dietary changes may be responsible for the biodegradation of acrylic based resins. Release of potential toxic compounds from the material and change on their physical and mechanical properties are the major consequences of biodegradation. Increasing concern arises from potential toxic effects of biodegradation products under clinical application thus justifying an intensive research in this area. 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  17. 21 CFR 177.1585 - Polyestercarbonate resins.

    Science.gov (United States)

    2010-04-01

    .... Copies are available from the Office of Premarket Approval, Center for Food Safety and Applied Nutrition... examined at the Center for Food Safety and Applied Nutrition's Library, Food and Drug Administration, 5100...) Extractives limitations. The polyestercarbonate resins to be tested shall be ground or cut into small...

  18. Facile synthesis of hypercrosslinked resins via chloromethylation ...

    Indian Academy of Sciences (India)

    Administrator

    Abstract. A sort of non-polystyrene type hypercrosslinked resin was firstly synthesized through chloromethyla- tion of simple aryl molecules (benzene, toluene, naphthalene, diphenyl), succedent continuous Friedel–Crafts alkylation polymerization and post-crosslinking reaction. The chemical and porous structures of these ...

  19. Triterpenes from the resin of Boswellia neglecta

    African Journals Online (AJOL)

    Boswellia neglecta S. Moore (Burseraceae) is found in Bale, Gamo Gofa, Hararghe and Sidamo. (Ethiopia) and also in neighbouring countries such as Kenya, Somalia, Tanzania and Uganda [1]. The plant produces aromatic resins used widely as incense known as “Dakara” (Oromifa),. "Borena Etan" (Amharic) or "Borena ...

  20. Extended Resin Composite Restorations: Techniques and Procedures

    NARCIS (Netherlands)

    Loomans, B.A.C.; Hilton, T.

    2016-01-01

    This article gives an overview of the state of the art of different restorative treatment procedures and techniques needed for placing extended posterior resin composite restorations. Clinical aspects related to the procedure are discussed and reviewed based on the current literature, such as the