Atomistic simulations of dislocation processes in copper

DEFF Research Database (Denmark)

Vegge, T.; Jacobsen, K.W.

2002-01-01

We discuss atomistic simulations of dislocation processes in copper based on effective medium theory interatomic potentials. Results on screw dislocation structures and processes are reviewed with particular focus on point defect mobilities and processes involving cross slip. For example......, the stability of screw dislocation dipoles is discussed. We show that the presence of jogs will strongly influence cross slip barriers and dipole stability. We furthermore present some new results on jogged edge dislocations and edge dislocation dipoles. The jogs are found to be extended, and simulations...

Phenol-Formaldehyde Resin-Based Carbons for CO2 Separation at Sub-Atmospheric Pressures

Directory of Open Access Journals (Sweden)

Noelia Álvarez-Gutiérrez

2016-03-01

Full Text Available The challenge of developing effective separation and purification technologies that leave much smaller energy footprints is greater for carbon dioxide (CO2 than for other gases. In addition to its involvement in climate change, CO2 is present as an impurity in biogas and bio-hydrogen (biological production by dark fermentation, in post-combustion processes (flue gas, CO2-N2 and many other gas streams. Selected phenol-formaldehyde resin-based activated carbons prepared in our laboratory have been evaluated under static conditions (adsorption isotherms as potential adsorbents for CO2 separation at sub-atmospheric pressures, i.e., in post-combustion processes or from biogas and bio-hydrogen streams. CO2, H2, N2, and CH4 adsorption isotherms at 25 °C and up to 100 kPa were obtained using a volumetric equipment and were correlated by applying the Sips model. Adsorption equilibrium was then predicted for multicomponent gas mixtures by extending the multicomponent Sips model and the Ideal Adsorbed Solution Theory (IAST in conjunction with the Sips model. The CO2 uptakes of the resin-derived carbons from CO2-CH4, CO2-H2, and CO2-N2 at atmospheric pressure were greater than those of the reference commercial carbon (Calgon BPL. The performance of the resin-derived carbons in terms of equilibrium of adsorption seems therefore relevant to CO2 separation in post-combustion (flue gas, CO2-N2 and in hydrogen fermentation (CO2-H2, CO2-CH4.

Chemical recycling of carbon fibers reinforced epoxy resin composites in oxygen in supercritical water

International Nuclear Information System (INIS)

Bai, Yongping; Wang, Zhi; Feng, Liqun

2010-01-01

The carbon fibers in carbon fibers reinforced epoxy resin composites were recovered in oxygen in supercritical water at 30 ± 1 MPa and 440 ± 10 o C. The microstructure of the recovered carbon fibers was observed using scanning electron microscopy (SEM) and atom force microscopy (AFM). The results revealed that the clean carbon fibers were recovered and had higher tensile strength relative to the virgin carbon fibers when the decomposition rate was above 85 wt.%, although the recovered carbon fibers have clean surface, the epoxy resin on the surface of the recovered carbon fibers was readily observed. As the decomposition rate increased to above 96 wt.%, no epoxy resin was observed on the surface of the carbon fibers and the oxidation of the recovered carbon fibers was readily measured by X-ray photoelectron spectroscopy (XPS) analysis. The carbon fibers were ideally recovered and have original strength when the decomposition rates were between 94 and 97 wt.%. This study clearly showed the oxygen in supercritical water is a promising way for recycling the carbon fibers in carbon fibers reinforced resin composites.

SIMPLE METHOD TO PRODUCE NANOPOROUS CARBON FOR VARIOUS APPLICATIONS BY PYROLYSIS OF SPECIALLY SYNTHESIZED PHENOLIC RESIN

Directory of Open Access Journals (Sweden)

Imam Prasetyo

2013-08-01

Full Text Available Nanoporous carbon materials, a unique and useful material, have been widely used in many technologies such as separation processes, catalysis, energy storage, gas storage, energy conversion, etc. due to its high specific surface area and tunable porosity. In this research, nanoporous carbons were prepared using simple and innovative approach based on structural array of phenolic resin polymer without activation during carbonization process. The effect of phenolic reactant type and composition on pore structure and carbon surface morphologies was studied. Nanoporous carbon derived from resorcinol formaldehyde (RF and from resorcinol phenol formaldehyde (RPF polymers was suitable for electrode material supercapacitor and CO2 capture medium. RF-derived and RPF-derived carbons provide electrode material supercapacitor with specific capacitance up to 246 F/g, whereas carbonized RPF exhibited CO2 uptake of 10.63 mmol/g (at 3.5 MPa 298 K. Nanoporous carbon derived from resorcinol para-tert-butyl phenol formaldehyde (RTBPF polymer exhibited attractive characteristics as methane storage media with methane uptake capacity as high as 8.98 mmol/g (at 3.5 MPa 298 K.

Experimental Investigation on the Specific Heat of Carbonized Phenolic Resin-Based Ablative Materials

Science.gov (United States)

Zhao, Te; Ye, Hong; Zhang, Lisong; Cai, Qilin

2017-10-01

As typical phenolic resin-based ablative materials, the high silica/phenolic and carbon/phenolic composites are widely used in aerospace field. The specific heat of the carbonized ablators after ablation is an important thermophysical parameter in the process of heat transfer, but it is rarely reported. In this investigation, the carbonized samples of the high silica/phenolic and carbon/phenolic were obtained through carbonization experiments, and the specific heat of the carbonized samples was determined by a 3D DSC from 150 °C to 970 °C. Structural and compositional characterizations were performed to determine the mass fractions of the fiber and the carbonized product of phenolic which are the two constituents of the carbonized samples, while the specific heat of each constituent was also measured by 3D DSC. The masses of the carbonized samples were reduced when heated to a high temperature in the specific heat measurements, due to the thermal degradation of the carbonized product of phenolic resin in the carbonized samples. The raw experimental specific heat of the two carbonized samples and the carbonized product of phenolic resin was modified according to the quality changes of the carbonized samples presented by TGA results. Based on the mass fraction and the specific heat of each constituent, a weighted average method was adopted to obtain the calculated results of the carbonized samples. Due to the unconsolidated property of the fiber samples which impacts the reliability of the DSC measurement, there is a certain deviation between the experimental and calculated results of the carbonized samples. Considering the similarity of composition and structure, the data of quartz glass and graphite were used to substitute the specific heat of the high silica fiber and carbon fiber, respectively, resulting in better agreements with the experimental ones. Furthermore, the accurate specific heat of the high silica fiber and carbon fiber bundles was obtained by

Passing waves from atomistic to continuum

Science.gov (United States)

Chen, Xiang; Diaz, Adrian; Xiong, Liming; McDowell, David L.; Chen, Youping

2018-02-01

Progress in the development of coupled atomistic-continuum methods for simulations of critical dynamic material behavior has been hampered by a spurious wave reflection problem at the atomistic-continuum interface. This problem is mainly caused by the difference in material descriptions between the atomistic and continuum models, which results in a mismatch in phonon dispersion relations. In this work, we introduce a new method based on atomistic dynamics of lattice coupled with a concurrent atomistic-continuum method to enable a full phonon representation in the continuum description. This permits the passage of short-wavelength, high-frequency phonon waves from the atomistic to continuum regions. The benchmark examples presented in this work demonstrate that the new scheme enables the passage of all allowable phonons through the atomistic-continuum interface; it also preserves the wave coherency and energy conservation after phonons transport across multiple atomistic-continuum interfaces. This work is the first step towards developing a concurrent atomistic-continuum simulation tool for non-equilibrium phonon-mediated thermal transport in materials with microstructural complexity.

Carbon dioxide capture using resin-wafer electrodeionization

Science.gov (United States)

Lin, YuPo J.; Snyder, Seth W.; Trachtenberg, Michael S.; Cowan, Robert M.; Datta, Saurav

2015-09-08

The present invention provides a resin-wafer electrodeionization (RW-EDI) apparatus including cathode and anode electrodes separated by a plurality of porous solid ion exchange resin wafers, which when in use are filled with an aqueous fluid. The apparatus includes one or more wafers comprising a basic ion exchange medium, and preferably includes one or more wafers comprising an acidic ion exchange medium. The wafers are separated from one another by ion exchange membranes. The fluid within the acidic and/or basic ion exchange wafers preferably includes, or is in contact with, a carbonic anhydrase (CA) enzyme to facilitate conversion of bicarbonate ion to carbon dioxide within the acidic medium. A pH suitable for exchange of CO.sub.2 is electrochemically maintained within the basic and acidic ion exchange wafers by applying an electric potential across the cathode and anode.

Comparison of atomistic and elasticity approaches for carbon diffusion near line defects in {alpha}-iron

Energy Technology Data Exchange (ETDEWEB)

Veiga, R.G.A., E-mail: rgaveiga@gmail.com [Universite de Lyon, INSA Lyon, Laboratoire MATEIS, UMR CNRS 5510, 25 Avenue Jean Capelle, F69621, Villeurbanne (France); Perez, M. [Universite de Lyon, INSA Lyon, Laboratoire MATEIS, UMR CNRS 5510, 25 Avenue Jean Capelle, F69621, Villeurbanne (France); Becquart, C.S. [Unite Materiaux et Transformations (UMET), Ecole Nationale Superieure de Chimie de Lille, UMR CNRS 8207, Bat. C6, F59655 Villeneuve d' Ascq Cedex (France); Laboratoire commun EDF-CNRS Etude et Modelisation des Microstructures pour le Vieillissement des Materiaux (EM2VM) (France); Clouet, E. [Service de Recherches de Metallurgie Physique, CEA/Saclay, 91191 Gif-sur-Yvette (France); Domain, C. [EDF, Recherche et Developpement, Materiaux et Mecanique des Composants, Les Renardieres, F77250 Moret sur Loing (France); Laboratoire commun EDF-CNRS Etude et Modelisation des Microstructures pour le Vieillissement des Materiaux (EM2VM) (France)

2011-10-15

Energy barriers for carbon migration in the neighborhood of line defects in body-centered cubic iron have been obtained by atomistic simulations. For this purpose, molecular statics with an Fe-C interatomic potential, based on the embedded atom method, has been employed. Results of these simulations have been compared to the predictions of anisotropic elasticity theory. The agreement is better for a carbon atom sitting on an octahedral site (energy minimum) than one on a tetrahedral site (saddle point). Absolute differences in the energy barriers obtained by the two methods are usually below 5 meV at distances larger than 1.5 nm from a screw dislocation and 2 nm (up to 4 nm in the glide plane) from the edge dislocation. Atomistic kinetic Monte Carlo simulations performed at T = 300 K and additional analysis based on the activation energies obtained by both methods show that they are in good qualitative agreement, despite some important quantitative discrepancies due to the large absolute errors found near the dislocation cores.

Thermal behavior of phenol-furfuryl alcohol resin/carbon nanotubes composites

Science.gov (United States)

Conejo, L. S.; Costa, M. L.; Oishi, S. S.; Botelho, E. C.

2018-04-01

Phenol-furfuryl alcohol resins (PFA) are excellent candidates to replace existing thermoset matrices used in obtaining insulating systems or carbon materials, both in its pure form and reinforced with nanoscale structures. This work had as main purpose synthesize and investigate thermal characterization of PFA resin and its nanostructured composites with different concentrations of carbon nanotubes (0, 0.1, 0.5 and 1.0 wt%). The DSC analysis was performed to estimate the specific heat (cp) of the cured samples and thermomechanical analysis to find the linear thermal expansion coefficient (α). From these results, the cp values found for the PFA system was similar to that described in the literature for the phenolic resin. The cp increased with the increase in the CNT concentration in the system up to 0.5%. The coefficient of linear thermal expansion obtained by TMA technique for PFA sample was 33.10‑6/°C which was close to the α value of phenolic resin (40 to 80.10‑6/°C).

Ion beam processing of surfaces and interfaces. Modeling and atomistic simulations

International Nuclear Information System (INIS)

Liedke, Bartosz

2011-01-01

Self-organization of regular surface pattern under ion beam erosion was described in detail by Navez in 1962. Several years later in 1986 Bradley and Harper (BH) published the first self-consistent theory on this phenomenon based on the competition of surface roughening described by Sigmund's sputter theory and surface smoothing by Mullins-Herring diffusion. Many papers that followed BH theory introduced other processes responsible for the surface patterning e.g. viscous flow, redeposition, phase separation, preferential sputtering, etc. The present understanding is still not sufficient to specify the dominant driving forces responsible for self-organization. 3D atomistic simulations can improve the understanding by reproducing the pattern formation with the detailed microscopic description of the driving forces. 2D simulations published so far can contribute to this understanding only partially. A novel program package for 3D atomistic simulations called TRIDER (TRansport of Ions in matter with DEfect Relaxation), which unifies full collision cascade simulation with atomistic relaxation processes, has been developed. The collision cascades are provided by simulations based on the Binary Collision Approximation, and the relaxation processes are simulated with the 3D lattice kinetic Monte-Carlo method. This allows, without any phenomenological model, a full 3D atomistic description on experimental spatiotemporal scales. Recently discussed new mechanisms of surface patterning like ballistic mass drift or the dependence of the local morphology on sputtering yield are inherently included in our atomistic approach. The atomistic 3D simulations do not depend so much on experimental assumptions like reported 2D simulations or continuum theories. The 3D computer experiments can even be considered as 'cleanest' possible experiments for checking continuum theories. This work aims mainly at the methodology of a novel atomistic approach, showing that: (i) In general

Ion beam processing of surfaces and interfaces. Modeling and atomistic simulations

Energy Technology Data Exchange (ETDEWEB)

Liedke, Bartosz

2011-03-24

Self-organization of regular surface pattern under ion beam erosion was described in detail by Navez in 1962. Several years later in 1986 Bradley and Harper (BH) published the first self-consistent theory on this phenomenon based on the competition of surface roughening described by Sigmund's sputter theory and surface smoothing by Mullins-Herring diffusion. Many papers that followed BH theory introduced other processes responsible for the surface patterning e.g. viscous flow, redeposition, phase separation, preferential sputtering, etc. The present understanding is still not sufficient to specify the dominant driving forces responsible for self-organization. 3D atomistic simulations can improve the understanding by reproducing the pattern formation with the detailed microscopic description of the driving forces. 2D simulations published so far can contribute to this understanding only partially. A novel program package for 3D atomistic simulations called TRIDER (TRansport of Ions in matter with DEfect Relaxation), which unifies full collision cascade simulation with atomistic relaxation processes, has been developed. The collision cascades are provided by simulations based on the Binary Collision Approximation, and the relaxation processes are simulated with the 3D lattice kinetic Monte-Carlo method. This allows, without any phenomenological model, a full 3D atomistic description on experimental spatiotemporal scales. Recently discussed new mechanisms of surface patterning like ballistic mass drift or the dependence of the local morphology on sputtering yield are inherently included in our atomistic approach. The atomistic 3D simulations do not depend so much on experimental assumptions like reported 2D simulations or continuum theories. The 3D computer experiments can even be considered as 'cleanest' possible experiments for checking continuum theories. This work aims mainly at the methodology of a novel atomistic approach, showing that: (i) In

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.

Phenolic resin-based porous carbons for adsorption and energy storage applications

Science.gov (United States)

Wickramaratne, Nilantha P.

view. So far, carbons with high surface area and nitrogen content have been vastly studied. Also, there are several reports showing the importance of pore size towards CO2 adsorption at ambient conditions. In the case of nitrogen containing carbons, it was shown that the incorporation of nitrogen into carbon matrix is a challenging task. In chapter 3, we discussed how to improve the surface area and pore size distribution of phenolic resin-based carbons to obtain optimum CO 2 adsorption capacities at ambient conditions. The chemical and physical activation of polymer/carbon particles is used to generate necessary physical properties of the final carbons, which display unprecedented CO2 adsorption capacities at ambient conditions. Moreover, the modified Stober-like methods are used for the synthesis of nitrogen containing carbon particles. These facile synthesis methods afford highly porous nitrogen containing carbons with comparatively high CO2 adsorption capacities at ambient conditions. Chapter 4 begins with synthesis of ultra large mesoporous carbons using (ethylene oxide)38 (butylene oxide)46 (ethylene oxide) 38 triblock copolymer as a soft template and phenolic resins as the carbon precursors. Even though, there are many reports dealing with the synthesis of mesoporous silica with large pores for bio-molucular adsorption their high cost discourage them to use in industrial applications. However, cheap mesoporous carbons with large pores (>15 nm) are potential materials for bio-molecular adsorption on large scale. The first part of chapter 4 is demonstrates the synthesis of mesoporous carbons with ultra large pores for bio-molecular adsorption. Lysozyme was selected as a model biomolecule for adsorption processes. The second part of Chapter 4 is focused on functionalized polymer spheres for heavy metal ions adsorption. It is shown that the synthesis of functionalized polymer spheres can be achieved by using modified Stober method; the reacting spheres show very

Process for hardening synthetic resins by ionizing radiation

International Nuclear Information System (INIS)

Hesse, W.; Ritz, J.

1975-01-01

Synthetic resins containing hydroxy groups and polymerizable carbon-carbon bonds are reacted with diketenes to yield aceto ester derivatives, which when reacted with metal compounds to form chelates, and mixed with copolymerizable monomers, are capable of being hardened by unusually low radiation doses to form coatings and articles with superior properties. (E.C.B.)

Low activity resin processing and disposal options review

International Nuclear Information System (INIS)

Gardner, F.

1996-01-01

New processing options for low activity resin processing and disposal are available. This presentation reviews the economics and technical requirements associated with the following low activity resin processing options. (1) Bulk release resin. (2) Direct disposal. (3) Decontamination and bulk release of cleaned resin. New processing and disposal options have been developed during 1995. Commercial experience with each of these options will be reviewed and the economics associated with the processing method described in detail. Technical requirements for each option will be identified specifying the activity limits and operational requirements for implementation

Verification of a three-dimensional resin transfer molding process simulation model

Science.gov (United States)

Fingerson, John C.; Loos, Alfred C.; Dexter, H. Benson

1995-01-01

Experimental evidence was obtained to complete the verification of the parameters needed for input to a three-dimensional finite element model simulating the resin flow and cure through an orthotropic fabric preform. The material characterizations completed include resin kinetics and viscosity models, as well as preform permeability and compaction models. The steady-state and advancing front permeability measurement methods are compared. The results indicate that both methods yield similar permeabilities for a plain weave, bi-axial fiberglass fabric. Also, a method to determine principal directions and permeabilities is discussed and results are shown for a multi-axial warp knit preform. The flow of resin through a blade-stiffened preform was modeled and experiments were completed to verify the results. The predicted inlet pressure was approximately 65% of the measured value. A parametric study was performed to explain differences in measured and predicted flow front advancement and inlet pressures. Furthermore, PR-500 epoxy resin/IM7 8HS carbon fabric flat panels were fabricated by the Resin Transfer Molding process. Tests were completed utilizing both perimeter injection and center-port injection as resin inlet boundary conditions. The mold was instrumented with FDEMS sensors, pressure transducers, and thermocouples to monitor the process conditions. Results include a comparison of predicted and measured inlet pressures and flow front position. For the perimeter injection case, the measured inlet pressure and flow front results compared well to the predicted results. The results of the center-port injection case showed that the predicted inlet pressure was approximately 50% of the measured inlet pressure. Also, measured flow front position data did not agree well with the predicted results. Possible reasons for error include fiber deformation at the resin inlet and a lag in FDEMS sensor wet-out due to low mold pressures.

Integrating Porous Resins In Enzymatic Processes

DEFF Research Database (Denmark)

Al-Haque, Naweed

. Screening resins for moderately hydrophobic multi-component systems is challenging. Often it is found that the capacity of the resin is inversely related with product selectivity. Therefore a tradeoff has to be made between these parameters which can be crucial from an economic point of view. A low resin...... procedure. The screening therefore becomes a multi-objective task that has to be solved simultaneously. Such an approach has been applied in the method formulated in this framework. To overcome these challenges, different process strategies are required to obtain high yields. A number of different...... inhibition, has gained considerable recognition. The resins act as a reservoir for the inhibitory substrate and a sink for the inhibitory product and simultaneously attain the required high substrate loading to make the process economically feasible. In this way the potential benefit of the enzyme can...

Extraction of Co ions from ion-exchange resin by supercritical carbon dioxide

International Nuclear Information System (INIS)

Ju, Min Su; Koh, Moon Sung; Yang, Sung Woo; Park, Kwang Heon; Kim, Hak Won; Kim, Hong Doo

2005-01-01

well as low surface tension, it is potentially suitable for cleaning substance. The operational costs of CO 2 cleaning were estimated to be lower than other cleaning processes. In this paper, we considered the possible use of supercritical CO 2 fluid in extracting radioactive contaminants from contaminated resin (simulated). We measured the extraction efficiency of Co-ions from the resin using supercritical carbon dioxide, and discussed the possible use in decontamination

Fermi-level effects in semiconductor processing: A modeling scheme for atomistic kinetic Monte Carlo simulators

Science.gov (United States)

Martin-Bragado, I.; Castrillo, P.; Jaraiz, M.; Pinacho, R.; Rubio, J. E.; Barbolla, J.; Moroz, V.

2005-09-01

Atomistic process simulation is expected to play an important role for the development of next generations of integrated circuits. This work describes an approach for modeling electric charge effects in a three-dimensional atomistic kinetic Monte Carlo process simulator. The proposed model has been applied to the diffusion of electrically active boron and arsenic atoms in silicon. Several key aspects of the underlying physical mechanisms are discussed: (i) the use of the local Debye length to smooth out the atomistic point-charge distribution, (ii) algorithms to correctly update the charge state in a physically accurate and computationally efficient way, and (iii) an efficient implementation of the drift of charged particles in an electric field. High-concentration effects such as band-gap narrowing and degenerate statistics are also taken into account. The efficiency, accuracy, and relevance of the model are discussed.

From empirical to ab initio: transferable potentials in the atomistic simulation of amorphous carbons

International Nuclear Information System (INIS)

Marks, N.A.; Goringe, C.M.; McKenzie, D.R.; McCulloch, D.G.; Royal Melbourne Institute of Technology University, Melbourne, VIC

2000-01-01

Full text: Silicon is often described as the prototype covalent material, and when it comes to developing atomistic models this situation is well described by the sentiment that 'everything works for silicon'. The same cannot be said for carbon though, where the interaction potential has always proved problematical, be it with empirical, tight-binding or ab initio methods. Thus far the most decisive contributions to understanding amorphous carbon networks have come from ab initio simulations using the Car-Parrinello method, where the fully quantum treatment of the valence electrons has provided unexpected insight into the local structure. However such first principles calculations are restricted spatially and temporally to systems with approximately 100 atoms and times of order one picosecond. There is therefore demand for less expensive techniques capable of resolving important questions whose solution can only to found with larger simulations running for longer times. In the case of tetrahedral amorphous carbon, such issues include the release of compressive stress through annealing, the origin of graphitic surface layers and the nature of the film growth process and thermal spike. Against this background tight-binding molecular dynamics has emerged as a popular alternative to first principles methods, and our group has an ongoing program to understand film growth using one of the efficient variants of tight-binding. Another direction of research is a new empirical potential based on the Environment Dependent Interaction Potential (EDIP) recently developed for silicon. The EDIP approach represents a promising direction for empirical potentials through its use of ab initio data to motivate the functional form as well as the more conventional parametrisation. By inverting ab initio cohesive energy curves the authors of EDIP arrived at a pair potential expression which reduces to the well-known Stillinger-Weber form at integer coordination, while providing

Discussion on resin conversion related problems in the process of using ion exchange method to recover uranium from carbonate lixivium in a uranium mine

International Nuclear Information System (INIS)

Yu Suqin; Du Yuhai; Long Qing; Han Wei; Que Weimin

2012-01-01

Ion exchange method was used to recover uranium from carbonate lixivium in a uranium mine, lean resin was converted by sodium bicarbonate solution. Because of high sodium bicarbonate, chlorine and uranium concentration in the converted solution, it is difficult to effectively use. Combined with the production practices of the mine, the resin conversion related problems were analyzed. Some measures were taken for improving utilization rate of the converted solution, and good results were obtained. The utilization rate of the converted solution increased to about 20% from less than lO%, and the consumption of sodium bicarbonate reduced by about 30%. (authors)

High performance, rapid thermal/UV curing epoxy resin for additive manufacturing of short and continuous carbon fiber epoxy composites

Science.gov (United States)

Lewicki, James

2018-04-17

An additive manufacturing resin system including an additive manufacturing print head; a continuous carbon fiber or short carbon fibers operatively connected to the additive manufacturing print head; and a tailored resin operatively connected to the print head, wherein the tailored resin has a resin mass and wherein the tailored resin includes an epoxy component, a filler component, a catalyst component, and a chain extender component; wherein the epoxy component is 70-95% of the resin mass, wherein the filler component is 1-20% of the resin mass, wherein the catalyst component is 0.1-10% of the resin mass, and wherein the chain extender component is 0-50% of the resin mass.

Evaluation of the resin oxidation process using Fenton's reagent

International Nuclear Information System (INIS)

Araujo, Leandro G.; Goes, Marcos M.; Marumo, Julio T.

2013-01-01

The ion exchange resin is considered radioactive waste after its final useful life in nuclear reactors. Usually, this type of waste is treated with the immobilization in cement Portland, in order to form a solid monolithic matrix, reducing the possibility of radionuclides release in to environment. Because of the characteristic of expansion and contraction of the resins in presence of water, its incorporation in the common Portland cement is limited in 10% in direct immobilization, causing high costs in the final product. A pre-treatment would be able to reduce the volume, degrading the resins and increasing the load capacity of this material. This paper is about a method of degradation of ion spent resins from the nuclear research reactor of Nuclear and Energy Research Institute (IPEN/CNEN-SP), Brazil, using the Fenton's reagent. The resin evaluated was a mixture of cationic and anionic resins. The reactions were conducted by varying the concentration of the catalyst (25 to 80 mM), with and without external heat. The time of reaction was two hours. The concentration of 50 mM of catalyst was the most effective in degrading approximately 99%. The resin degradation was confirmed by the presence of CaCO 3 as a white precipitate resulting from the reaction between the Ca(OH) 2 and the CO 2 from the resin degradation. It was possible to degrade the resins without external heating. The calcium carbonates showed no correlation with the residual resin mass. (author)

Hierarchical porous carbons prepared by an easy one-step carbonization and activation of phenol-formaldehyde resins with high performance for supercapacitors

Energy Technology Data Exchange (ETDEWEB)

Zheng, Zhoujun [State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Graduate School, Shanghai Institute of Ceramics, Chinese Academy of Science, 1295 Dingxi Road, Shanghai 200050 (China); Gao, Qiuming [State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Graduate School, Shanghai Institute of Ceramics, Chinese Academy of Science, 1295 Dingxi Road, Shanghai 200050 (China); School of Chemistry and Environment, Beihang University, 37 Xueyuan Road, Haidian District, Beijing 100191 (China)

2011-02-01

Hierarchical porous carbons are prepared by an easy one-step process of carbonization and activation derived from phenol-formaldehyde resins, in which potassium hydroxide acts as both the catalyst of polymerization and the activation reagent. The simple one-step preparation saves the cost of carbons and leads to high yield. The porous carbons have high surface areas with abundant pore structures. The plenty of micropores and small mesopores increase the capacitance and make the electrolyte ions diffuse fast into the pores. These hierarchical porous carbons show high performance for supercapacitors possessing of the optimized capacitance of 234 F g{sup -1} in aqueous electrolyte and 137 F g{sup -1} in organic electrolyte with high capacitive retention. (author)

Large-scale synthesis of onion-like carbon nanoparticles by carbonization of phenolic resin

International Nuclear Information System (INIS)

Zhao Mu; Song Huaihe; Chen Xiaohong; Lian Wentao

2007-01-01

Onion-like carbon nanoparticles have been synthesized on a large scale by carbonization of phenolic-formaldehyde resin at 1000 o C with the aid of ferric nitrate (FN). The effects of FN loading content on the yield, morphology and structure of carbonized products were investigated using transmission electron microscopy (TEM), high-resolution TEM and X-ray diffraction. It was found that the onion-like carbon nanoparticles, which had a narrow size distribution ranging from 30 to 50 nm, were composed mainly of quasi-spherically concentric shells of well-aligned graphene layers with interlayer spacing of 0.336 nm. Based on the results of the investigation, the formation mechanism of onion-like carbon nanoparticles was also discussed

Alkydic resin wastewaters treatment by fenton and photo-Fenton processes

International Nuclear Information System (INIS)

Schwingel de Oliveira, Isadora; Viana, Lilian; Verona, Cenira; Fallavena, Vera Lucia Vargas; Azevedo, Carla Maria Nunes; Pires, Marcal

2007-01-01

Advanced oxidation processes are an emerging option to treatment of the painting industry effluents. The aim of this study was to compare the effectiveness of the Fenton and photo-Fenton processes in chemical oxygen demand (COD), total organic carbon (TOC) and phenolic compounds removal from wastewaters generated during alkydic resins manufacture. The optimized treatment conditions are the following: pH 3.0, 15.15 x 10 -3 mol L -1 FeSO 4 and 0.30 mol L -1 H 2 O 2 for a reaction time of 6 h. photo-Fenton experiments were carried out in the presence of sunlight or artificial radiation and complementary additions of H 2 O 2 were made for all experiments. The best results were obtained with photo-Fenton process assisted with solar radiation, with reductions of 99.5 and 99.1% of COD and TOC levels, respectively. Fenton and photo-Fenton (with artificial irradiation) processes presented lower but not insignificant removals, within 60-80% reduction for both COD and TOC. In addition, an excellent removal (95%) of total phenols was obtained using photo-Fenton process assisted with artificial irradiation. This study demonstrated that the use of photo-Fenton process on alkydic resins wastewater treatment is very promising especially when solar light is used

Radiation processing of carbon fiber-acrylated epoxy composites

International Nuclear Information System (INIS)

Singh, A.; Saunders, C.B.

1992-01-01

Advanced composites, specifically carbon fiber reinforced epoxies, are being used for a variety of demanding structural applications, primarily because of their high strength-to-weight and stiffness-to-weight ratios, corrosion resistance, and damage tolerance characteristics. For these composites the key advantages of using electron beam (EB), rather than thermal curing, are curing at ambient temperature, reduced curing times for individual components, improved resin stability, fewer volatiles, and better control of the profile of energy absorption. Epoxy compounds do, however, have to be modified to make them EB curable. The electron beam penetration limit, a function of beam energy, product density, and the thickness of any container required, must also be examined when considering EB processing. Research is being conducted to develop EB-curable carbon fiber-acrylated epoxy composites. The tensile properties of these laminates are comparable to those of thermally cured epoxy laminates. Research is continuing to develop suitable resin formulations and coupling agents to optimize the mechanical properties of EB-cured carbon fiber laminates. In this chapter the EB curing of epoxies, processing considerations, and typical properties of EB-cured carbon fiber-acrylated epoxy laminates are discussed. (orig.)

Preparation of carbon nanotubes/epoxy resin composites by using hollow glass beads as the carrier

International Nuclear Information System (INIS)

Wu, X.F.; Zhao, Y.K.; Zhang, D.; Chen, T.B.; Ma, L.Y.

2012-01-01

Hollow glass beads had been utilized as the carrier to assist dispersion of carbon nanotubes in epoxy resin. Hollow glass beads were firstly aminated with gamma-aminopropyl-triethoxysilane, sencondly reacted with carboxyl-functionalized carbon nanotubes via an amidation reaction and susequently mixed with epoxy resin and hardener. The experimental results showed that carbon nanotubes could be loaded on the surfaces of hollow glass beads and approximately a monolayer of carbon nanotubes was formed when the weight ratio of hollow glass beads to carbon nanotubes was 100:5. Moreover, the dispersity of carbon nanotubes in the matrix was improved as compared to the control samples prepared by using a conventional mixing method. (author)

The Physical and Chemical Properties of Fine Carbon Particles-Pinewood Resin Blends and Their Possible Utilization

Directory of Open Access Journals (Sweden)

Aviwe Melapi

2015-01-01

Full Text Available The application of biomass gasification technology is very important in the sense that it helps to relieve the dwindling supply of natural gas from fossil fuels, and the desired product of its gasification process is syngas. This syngas is a mixture of CO and H2; however, by-products such as char, tar, soot, ash, and condensates are also produced. This study, therefore, investigated selected by-products recovered from the gasification process of pinewood chips with specific reference to their potential application in other areas when used as blends. Three samples of the gasification by-products were obtained from a downdraft biomass gasifier system and were characterized in terms of chemical and physical properties. FTIR analysis confirmed similar spectra in all char-resin blends. For fine carbon particles- (soot- resin blends, almost the same functional groups as observed in char-resin blends appeared. In bomb calorimeter measurements, 70% resin/30% char blends gave highest calorific value, followed by 50% resin/50% soot blends with values of 35.23 MJ/kg and 34.75 MJ/kg consecutively. Provided these by-products meet certain criteria, they could be used in other areas such as varnishes, water purification, and wind turbine blades.

Potential Use Of Activated Carbon To Recover Tc-99 From 200 West Area Groundwater As An Alternative To More Expensive Resins Hanford Site, Richland, Washington

International Nuclear Information System (INIS)

Byrnes, M.E.; Rossi, A.J.; Tortoso, A.C.

2009-01-01

Recent treatability testing performed on groundwater at the 200-ZP-1 Operable Unit at the Hanford Site in Richland, Washington, has shown that Purolite(reg s ign) A530E resin very effectively removes Tc-99 from groundwater. However, this resin is expensive and cannot be regenerated. In an effort to find a less expensive method for removing Tc-99 from the groundwater, a literature search was performed. The results indicated that activated carbon may be used to recover technetium (as pertechnetate, TCO 4 - ) from groundwater. Oak Ridge National Laboratory used activated carbon in both batch adsorption and column leaching studies. The adsorption study concluded that activated carbon absorbs TCO 4 - selectively and effectively over a wide range of pH values and from various dilute electrolyte solutions ( 4 - . Since activated carbon is much less expensive than Purolite A530E resin, it has been determined that a more extensive literature search is warranted to determine if recent studies have reached similar conclusions, and, if so, pilot testing of 200-ZP-1 groundwater wi11 likely be implemented. It is possible that less expensive, activated carbon canisters could be used as pre-filters to remove Tc-99, followed by the use of the more expensive Purolite A530E resin as a polishing step.

Enhancement of uranium loading on ion exchange resin from carbonate leachate by lowering pH from 8 to 6.5

International Nuclear Information System (INIS)

Otto, J.B.

1984-01-01

This paper discusses a laboratory study that shows the saturation ion-exchange loading of uranium from carbonate leachate can be doubled by lowering the pH of the leachate from 8 to 6.5. Small column and batch resin loading tests using Dowex 21K ion-exchange resin are described. The leachate contained 3,300 ppm chloride, 2,400 ppm carbonate, and 220 ppm U 3 O 8 , and had a pH of 8. Even at this rather mild salinity the saturation ion-exchange loading was found to be only about 3 to 4 lbm U 3 O 8 /cu ft resin (48 to 64 g/dm 3 ) because of competition with the chloride ion for exchange sites on the anionic resin. Lowering the pH of the leachate to 6.5 by CO 2 gas addition, however, increased loading to about 8 lbm U 3 O 8 /cu ft resin (128 g/dm 3 ). The pH-lowering effect worked especially well at relatively high salt concentration. The same leachate, with its chloride content increased to 12,000 ppm, loaded only 0.5 lbm U 3 O 8 /cu ft resin (8 g/dm 3 ) at pH 8 but loaded 5.5 lbm U 3 O 8 /cu ft resin (88 g/dm 3 ) at pH 6.5

Perchlorate adsorption and desorption on activated carbon and anion exchange resin.

Science.gov (United States)

Yoon, In-Ho; Meng, Xiaoguang; Wang, Chao; Kim, Kyoung-Woong; Bang, Sunbaek; Choe, Eunyoung; Lippincott, Lee

2009-05-15

The mechanisms of perchlorate adsorption on activated carbon (AC) and anion exchange resin (SR-7 resin) were investigated using Raman, FTIR, and zeta potential analyses. Batch adsorption and desorption results demonstrated that the adsorption of perchlorate by AC and SR-7 resin was reversible. The reversibility of perchlorate adsorption by the resin was also proved by column regeneration test. Solution pH significantly affected perchlorate adsorption and the zeta potential of AC, while it did not influence perchlorate adsorption and the zeta potential of resin. Zeta potential measurements showed that perchlorate was adsorbed on the negatively charged AC surface. Raman spectra indicated the adsorption resulted in an obvious position shift of the perchlorate peak, suggesting that perchlorate was associated with functional groups on AC at neutral pH through interactions stronger than electrostatic interaction. The adsorbed perchlorate on the resin exhibited a Raman peak at similar position as the aqueous perchlorate, indicating that perchlorate was adsorbed on the resin through electrostatic attraction between the anion and positively charged surface sites.

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.

EFFECT OF HARDENER ON MECHANICAL PROPERTIES OF CARBON FIBRE REINFORCED PHENOLIC RESIN COMPOSITES

Directory of Open Access Journals (Sweden)

S. SULAIMAN

2008-04-01

Full Text Available In this paper the effect of hardener on mechanical properties of carbon reinforced phenolic resin composites is investigated. Carbon fibre is one of the most useful reinforcement materials in composites, its major use being the manufacture of components in the aerospace, automotive, and leisure industries. In this study, carbon fibres are hot pressed with phenolic resin with various percentages of carbon fibre and hardener contents that range from 5-15%. Composites with 15% hardener content show an increase in flexural strength, tensile strength and hardness. The ultimate tensile strength (UTS, flexural strength and hardness for 15% hardener are 411.9 MPa, 51.7 MPa and 85.4 HRR respectively.

Pore development of thermosetting phenol resin derived mesoporous carbon through a commercially nanosized template

Energy Technology Data Exchange (ETDEWEB)

Tang Zhihong [Key Laboratory of Carbon Materials, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Song Yan [Key Laboratory of Carbon Materials, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China)], E-mail: yansong1026@126.com; Tian Yongming [Key Laboratory of Carbon Materials, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Liu Lang; Guo Quangui [Key Laboratory of Carbon Materials, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China)

2008-01-25

Mesoporous carbons (MCs) with high specific surface area and pore volume were synthesized from thermosetting phenol resin (TPR) by using commercial nanosized silica particles as template. Based on the results of thermogravimetric analysis, nitrogen adsorption, mercury adsorption and high-resolution transmission electron microscopy (HRTEM), mechanism of the pore formation of MCs was proposed. Silica particles not only participated in the pore formation of MCs but also influenced the thermosetting process of the carbon precursor. The mechanism of pore formation in the MCs may be described as follows: mesopores were introduced by the removal of silica particles; small mesopores were created by the combination of aperture between TPR and silica particles and opened pores in the matrix generated by the release of small molecules in the carbon during carbonization process; macropores were produced by the aggregation of silica particles and the collapse of carbon wall.

Pore development of thermosetting phenol resin derived mesoporous carbon through a commercially nanosized template

International Nuclear Information System (INIS)

Tang Zhihong; Song Yan; Tian Yongming; Liu Lang; Guo Quangui

2008-01-01

Mesoporous carbons (MCs) with high specific surface area and pore volume were synthesized from thermosetting phenol resin (TPR) by using commercial nanosized silica particles as template. Based on the results of thermogravimetric analysis, nitrogen adsorption, mercury adsorption and high-resolution transmission electron microscopy (HRTEM), mechanism of the pore formation of MCs was proposed. Silica particles not only participated in the pore formation of MCs but also influenced the thermosetting process of the carbon precursor. The mechanism of pore formation in the MCs may be described as follows: mesopores were introduced by the removal of silica particles; small mesopores were created by the combination of aperture between TPR and silica particles and opened pores in the matrix generated by the release of small molecules in the carbon during carbonization process; macropores were produced by the aggregation of silica particles and the collapse of carbon wall

Atomistic mechanism of graphene growth on a SiC substrate: Large-scale molecular dynamics simulations based on a new charge-transfer bond-order type potential

Science.gov (United States)

Takamoto, So; Yamasaki, Takahiro; Nara, Jun; Ohno, Takahisa; Kaneta, Chioko; Hatano, Asuka; Izumi, Satoshi

2018-03-01

Thermal decomposition of silicon carbide is a promising approach for the fabrication of graphene. However, the atomistic growth mechanism of graphene remains unclear. This paper describes the development of a new charge-transfer interatomic potential. Carbon bonds with a wide variety of characteristics can be reproduced by the proposed vectorized bond-order term. A large-scale thermal decomposition simulation enables us to observe the continuous growth process of the multiring carbon structure. The annealing simulation reveals the atomistic process by which the multiring carbon structure is transformed to flat graphene involving only six-membered rings. Also, it is found that the surface atoms of the silicon carbide substrate enhance the homogeneous graphene formation.

2D Numerical Modelling of the Resin Injection Pultrusion Process Including Experimental Resin Kinetics and Temperature Validation

DEFF Research Database (Denmark)

Rasmussen, Filip Salling; Sonne, Mads Rostgaard; Larsen, Martin

In the present study, a two-dimensional (2D) transient Eulerian thermo-chemical analysis of a carbon fibre epoxy thermosetting Resin Injection Pultrusion (RIP) process is carried out. The numerical model is implemented using the well known unconditionally stable Alternating Direction Implicit (ADI......) scheme. The total heat of reaction and the cure kinetics of the epoxy thermosetting are determined using Differential Scanning Calorimetry (DSC). A very good agreement is observed between the fitted cure kinetic model and the experimental measurements. The numerical steady state temperature predictions...

In-situ development of carbon nanotubes network and graphitic carbon by catalytic modification of phenolic resin binder in Al2O3–MgO–C refractories

Directory of Open Access Journals (Sweden)

Atul V. Maldhure

2017-09-01

Full Text Available In-situ formation of cross-linked carbon nanotubes network reinforced the refractory matrix and helps to improve the mechanical properties at elevated temperature. In this paper, the effect of modified phenol-formaldehyde (PF resin binder on the various mechanical properties of alumina–magnesia–carbon (AMC refractories was investigated. Initially, PF resin was modified by adding a different proportion of nickel catalyst. The AMC specimens (with the 7% carbon were prepared by using 5% of modified PF resin. The pressed samples were cured at 180 °C for 24 h and characterized by XRD, Raman spectroscopy, and FE-SEM. The characterisation shows that, in-situ formation of graphitic carbon and carbon nanotubes network in the specimens due to modification of PF resin. In-situ formation of phases leads to enhancement of density and mechanical properties of refractory at elevated temperature due to the reinforcing effect.

Flexural properties of polyethylene, glass and carbon fiber-reinforced resin composites for prosthetic frameworks.

Science.gov (United States)

Maruo, Yukinori; Nishigawa, Goro; Irie, Masao; Yoshihara, Kumiko; Minagi, Shogo

2015-01-01

High flexural properties are needed for fixed partial denture or implant prosthesis to resist susceptibility to failures caused by occlusal overload. The aim of this investigation was to clarify the effects of four different kinds of fibers on the flexural properties of fiber-reinforced composites. Polyethylene fiber, glass fiber and two types of carbon fibers were used for reinforcement. Seven groups of specimens, 2 × 2 × 25 mm, were prepared (n = 10 per group). Four groups of resin composite specimens were reinforced with polyethylene, glass or one type of carbon fiber. The remaining three groups served as controls, with each group comprising one brand of resin composite without any fiber. After 24-h water storage in 37°C distilled water, the flexural properties of each specimen were examined with static three-point flexural test at a crosshead speed of 0.5 mm/min. Compared to the control without any fiber, glass and carbon fibers significantly increased the flexural strength (p glass fiber (p glass fibers (p > 0.05). Fibers could, therefore, improve the flexural properties of resin composite and carbon fibers in longitudinal form yielded the better effects for reinforcement.

Device for processing regenerative wastes of ion exchange resin

International Nuclear Information System (INIS)

Kuroda, Osamu; Ebara, Katsuya; Shindo, Toshikazu; Takahashi, Sankichi

1986-01-01

Purpose: To facilitate the operation and maintenance of a processing device by dividing radioactive wastes produced in the regenerative process of ion exchange resin into a regenerated usable recovery liquid and wastes. Constitution: Sulfuric acid is recovered by a diffusion dialysis method from wastes containing sulfuric acid that are generated in the regenerative process of cation-exchange resin and also caustic soda is recovered by the diffusion dialysis method from wastes containing caustic soda that are generated in the regenerative process of anion-exchange resin. The sulfuric acid and caustic soda thus recovered are used for the regeneration of ion-exchange resin. A concentrator is provided for concentrating the sulfuric acid and caustic soda water solution to concentration suitable for the regeneration of these ion-exchange resins. Also provided is a recovery device for recovering water generated from the concentrator. This device is of so simple a constitution that its operation and maintenance can be performed very easily, thereby greatly reducing the quantity of waste liquid required to be stored in drums. (Takahashi, M.)

Impact fatigue behaviour of carbon fibre-reinforced vinylester resin

Indian Academy of Sciences (India)

Two types of unidirectional carbon fibre, one of high strength (DHMS) and another of medium strength (VLMS) reinforced vinylester resin composites have been examined for their impact fatigue behaviour over 104 impact cycles for the first time. The study was conducted using a pendulum type repeated impact apparatus ...

Impact fatigue behaviour of carbon fibre-reinforced vinylester resin ...

Indian Academy of Sciences (India)

Unknown

Abstract. Two types of unidirectional carbon fibre, one of high strength (DHMS) and another of medium strength (VLMS) reinforced vinylester resin composites have been examined for their impact fatigue behaviour over 104 impact cycles for the first time. The study was conducted using a pendulum type repeated impact.

Oxidative degradation of ion-exchange resins in acid medium. Vol. 3

International Nuclear Information System (INIS)

Eskander, S.B.; Ghattas, N.K.

1996-01-01

Volume reduction of spent ion-exchange resins used in nuclear facilities receive increasing importance due to the increase in storage cost, unstable physical and chemical properties and their relatively high specific activity (in some cases up to 1 Ci per liter). The present study is part of research program on the treatment and immobilization of radioactive spent ion-exchange resins simulate; hydrogen peroxide was used for the oxidative degradation of spent ion-exchange resins simulate in sulphuric acid medium. Five liters ring digester developed in Karlsruhe nuclear research center-(KFK)- in germany was the chosen option to perform the oxidation process. The work reported focused on the kinetics and mechanism of the oxidation process. Heating the organic resins in sulphuric acid results in its carbonization and partial oxidation of only 1.7% of the carbon added. Results show that the oxidation reaction is a relatively slow process of first order with K value in the order of 10 -4 min -1 , and the main oxidation product was carbon dioxide. The production of carbon oxide in the off gas stream increased sharply by the addition of hydrogen peroxide to the hot sulphuric acid-resin mixture. The results obtained show that more than 97% of the carbon added was oxidized to carbon dioxide and carbon monoxide. The rate constant value (K) of this reaction was calculated to be (1.69±0.13) x 10 -2 min -1 . The results of gas chromatographic analysis indicate that no significant amounts of hazardous organic materials were detected in the off-gas streams. 6 figs., 4 tabs

Increase of porosity by combining semi-carbonization and KOH activation of formaldehyde resins to prepare high surface area carbons for supercapacitor applications

Science.gov (United States)

Heimböckel, Ruben; Kraas, Sebastian; Hoffmann, Frank; Fröba, Michael

2018-01-01

A series of porous carbon samples were prepared by combining a semi-carbonization process of acidic polymerized phenol-formaldehyde resins and a following chemical activation with KOH used in different ratios to increase specific surface area, micropore content and pore sizes of the carbons which is favourable for supercapacitor applications. Samples were characterized by nitrogen physisorption, powder X-ray diffraction, Raman spectroscopy and scanning electron microscopy. The results show that the amount of KOH, combined with the semi-carbonization step had a remarkable effect on the specific surface area (up to SBET: 3595 m2 g-1 and SDFT: 2551 m2 g-1), pore volume (0.60-2.62 cm3 g-1) and pore sizes (up to 3.5 nm). The carbons were tested as electrode materials for electrochemical double layer capacitors (EDLC) in a two electrode setup with tetraethylammonium tetrafluoroborate in acetonitrile as electrolyte. The prepared carbon material with the largest surface area, pore volume and pore sizes exhibits a high specific capacitance of 145.1 F g-1 at a current density of 1 A g-1. With a high specific energy of 31 W h kg-1 at a power density of 33028 W kg-1 and a short time relaxation constant of 0.29 s, the carbon showed high power capability as an EDLC electrode material.

High-capacitance supercapacitors using nitrogen-decorated porous carbon derived from novolac resin containing peptide linkage

Energy Technology Data Exchange (ETDEWEB)

Kim, Yong Jung [Institute of Carbon Science and Technology, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553 (Japan); Jang, In Young; Park, Ki Chul; Jung, Yong Chae; Oka, Takuyuki [Department of Electric and Electronic Engineering, Faculty of Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553 (Japan); Iinou, Satoshi [MEFS, Co. Ltd. Choei Nagano, Higasiguchi Bldg, 2F, 1000-1 Gentakubo, Kurita, Nagano 380-0921 (Japan); Komori, Yasuhiro; Kozutsumi, Toshihiko; Hashiba, Takashi [SHOWA HIGHPOLYMER, Co., Ltd. 1021 Tomizuka-cho, Isesaki-City, Gunma 372-0833 (Japan); Kim, Yoong Ahm, E-mail: yak@endomoribu.shinshu-u.ac.j [Department of Electric and Electronic Engineering, Faculty of Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553 (Japan); Endo, Morinobu [Institute of Carbon Science and Technology, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553 (Japan)] [Department of Electric and Electronic Engineering, Faculty of Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553 (Japan)

2010-08-01

We fabricated nitrogen-decorated porous carbon exhibiting high capacitance per unit volume and unit weight via chemical activation of novolac resin containing peptide linkage. The porosity and the amount of nitrogen atoms were controlled by changing the molecular weight of novolac resin, the added amount of potassium hydroxide, or both. After chemical activation, positively charged nitrogen atoms (i.e., pyridine/pyrrole) at 400.3 eV in photoemission spectra contributed to both a shift in the point of zero charge toward negative potential and the generation of pseudocapacitance. Suitably developed pores and the positively charged nitrogen atoms make nitrogen-decorated novolac resin-derived porous carbon a promising material for electrodes in high-performance supercapacitors.

Direct synthesis of graphitic mesoporous carbon from green phenolic resins exposed to subsequent UV and IR laser irradiations

Science.gov (United States)

Sopronyi, Mihai; Sima, Felix; Vaulot, Cyril; Delmotte, Luc; Bahouka, Armel; Matei Ghimbeu, Camelia

2016-01-01

The design of mesoporous carbon materials with controlled textural and structural features by rapid, cost-effective and eco-friendly means is highly demanded for many fields of applications. We report herein on the fast and tailored synthesis of mesoporous carbon by UV and IR laser assisted irradiations of a solution consisting of green phenolic resins and surfactant agent. By tailoring the UV laser parameters such as energy, pulse repetition rate or exposure time carbon materials with different pore size, architecture and wall thickness were obtained. By increasing irradiation dose, the mesopore size diminishes in the favor of wall thickness while the morphology shifts from worm-like to an ordered hexagonal one. This was related to the intensification of phenolic resin cross-linking which induces the reduction of H-bonding with the template as highlighted by 13C and 1H NMR. In addition, mesoporous carbon with graphitic structure was obtained by IR laser irradiation at room temperature and in very short time periods compared to the classical long thermal treatment at very high temperatures. Therefore, the carbon texture and structure can be tuned only by playing with laser parameters, without extra chemicals, as usually required. PMID:28000781

Copolymerization of carbon monoxide and styrene catalyzed by resin-supported palladium polymer

Directory of Open Access Journals (Sweden)

2007-02-01

Full Text Available Polyketone was prepared by the copolymerization of carbon monoxide (CO and styrene (ST catalyzed by o-phenylenediamine resin-supported palladium acetate. Effects of each catalytic system component such as 2,2’-bipyridine, 1,4-quinone and p-toluene-sulphonate on the copolymerization were investigated. The resin-supported catalyst and the copolymerization product were characterized by infrared spectroscopy (IR, differential scanning calorimetry (DSC, thermogravimetry (TG, X-ray photoelectron spectroscopy (XPS, Scanning Electron Microscopy (SEM. Results indicated that the resin-supported catalyst has excellent catalytic property. Furthermore, partial catalytic activity was maintained after the catalyst was used for five times.

Attribute based selection of thermoplastic resin for vacuum infusion process

DEFF Research Database (Denmark)

Prabhakaran, R.T. Durai; Lystrup, Aage; Løgstrup Andersen, Tom

2011-01-01

The composite industry looks toward a new material system (resins) based on thermoplastic polymers for the vacuum infusion process, similar to the infusion process using thermosetting polymers. A large number of thermoplastics are available in the market with a variety of properties suitable...... for different engineering applications, and few of those are available in a not yet polymerised form suitable for resin infusion. The proper selection of a new resin system among these thermoplastic polymers is a concern for manufactures in the current scenario and a special mathematical tool would...... be beneficial. In this paper, the authors introduce a new decision making tool for resin selection based on significant attributes. This article provides a broad overview of suitable thermoplastic material systems for vacuum infusion process available in today’s market. An illustrative example—resin selection...

Current-Voltage Characteristics of the Composites Based on Epoxy Resin and Carbon Nanotubes

Directory of Open Access Journals (Sweden)

Iwona Pełech

2015-01-01

Full Text Available Polymer composites based on epoxy resin were prepared. Multiwalled carbon nanotubes synthesized on iron-cobalt catalyst were applied as a filler in a polymer matrix. Chlorine or hydroxyl groups were incorporated on the carbon nanotubes surface via chlorination or chlorination followed by hydroxylation. The effect of functionalized carbon nanotubes on the epoxy resin matrix is discussed in terms of the state of CNTs dispersion in composites as well as electrical properties. For the obtained materials current-voltage characteristics were determined. They had a nonlinear character and were well described by an exponential-type equation. For all the obtained materials the percolation threshold occurred at a concentration of about 1 wt%. At a higher filler concentration >2 wt%, better conductivity was demonstrated by polymer composites with raw carbon nanotubes. At a lower filler concentration <2 wt%, higher values of electrical conductivity were obtained for polymer composites with modified carbon nanotubes.

An atomistic vision of the Mass Action Law: Prediction of carbon/oxygen defects in silicon

Energy Technology Data Exchange (ETDEWEB)

Brenet, G.; Timerkaeva, D.; Caliste, D.; Pochet, P. [CEA, INAC-SP2M, Atomistic Simulation Laboratory, F-38000 Grenoble (France); Univ. Grenoble Alpes, INAC-SP2M, L-Sim, F-38000 Grenoble (France); Sgourou, E. N.; Londos, C. A. [University of Athens, Solid State Physics Section, Panepistimiopolis Zografos, Athens 157 84 (Greece)

2015-09-28

We introduce an atomistic description of the kinetic Mass Action Law to predict concentrations of defects and complexes. We demonstrate in this paper that this approach accurately predicts carbon/oxygen related defect concentrations in silicon upon annealing. The model requires binding and migration energies of the impurities and complexes, here obtained from density functional theory (DFT) calculations. Vacancy-oxygen complex kinetics are studied as a model system during both isochronal and isothermal annealing. Results are in good agreement with experimental data, confirming the success of the methodology. More importantly, it gives access to the sequence of chain reactions by which oxygen and carbon related complexes are created in silicon. Beside the case of silicon, the understanding of such intricate reactions is a key to develop point defect engineering strategies to control defects and thus semiconductors properties.

Response behavior of an epoxy resin/amine curing agent/carbon black composite film to various solvents

Energy Technology Data Exchange (ETDEWEB)

Luo Yanling [School of Chemistry and Materials Science, Shaanxi Normal University, Xi' an 710062 (China)]. E-mail: luoyl0401@yahoo.com.cn; Li Zhanqing [School of Chemistry and Materials Science, Shaanxi Normal University, Xi' an 710062 (China); Lan Wenxiang [School of Chemistry and Materials Science, Shaanxi Normal University, Xi' an 710062 (China)

2007-04-25

A novel polymer based sensitive film was prepared from thermosetting epoxy resins (EP) filled with carbon blacks. The curing reaction of amine curing agents with epoxy resins and the response of the curing resultants to solvent vapors were dealt with. The influence of the types and content of carbon blacks and curing agents, and curing temperatures and time on curing reactions and response selectivity of the conductive films were investigated. The structural characterization was conducted on a Fourier transform infrared spectrophotometer (FTIR). The results indicated that the conductive films showed high response selectivity to polar solvent vapors, especially to chloroform vapor, while no response was observed in non-polar solvent vapors. The responsivity of the film increased with the decreased carbon black contents. The film filled with acetylene carbon black gave an optimal response, with responsivity of about 700 times. The response performances were improved with the amount of curing agents increased, and an optimal response appeared at the amount of the curing agent of 8%. The film's responsivity was remarkably enhanced, the reversibility property, however, rapidly declined in the order of diethyleneltriamine < triethylenetetramine < ethylenediamine. The curing reaction tended to complete with the curing temperature elevated and the curing time prolonged. But the response performance dropped because of over cross-linking as the temperature was too high or the time was too long.

Response behavior of an epoxy resin/amine curing agent/carbon black composite film to various solvents

International Nuclear Information System (INIS)

Luo Yanling; Li Zhanqing; Lan Wenxiang

2007-01-01

A novel polymer based sensitive film was prepared from thermosetting epoxy resins (EP) filled with carbon blacks. The curing reaction of amine curing agents with epoxy resins and the response of the curing resultants to solvent vapors were dealt with. The influence of the types and content of carbon blacks and curing agents, and curing temperatures and time on curing reactions and response selectivity of the conductive films were investigated. The structural characterization was conducted on a Fourier transform infrared spectrophotometer (FTIR). The results indicated that the conductive films showed high response selectivity to polar solvent vapors, especially to chloroform vapor, while no response was observed in non-polar solvent vapors. The responsivity of the film increased with the decreased carbon black contents. The film filled with acetylene carbon black gave an optimal response, with responsivity of about 700 times. The response performances were improved with the amount of curing agents increased, and an optimal response appeared at the amount of the curing agent of 8%. The film's responsivity was remarkably enhanced, the reversibility property, however, rapidly declined in the order of diethyleneltriamine < triethylenetetramine < ethylenediamine. The curing reaction tended to complete with the curing temperature elevated and the curing time prolonged. But the response performance dropped because of over cross-linking as the temperature was too high or the time was too long

Westinghouse Modular Grinding Process - Enhancement of Volume Reduction for Hot Resin Supercompaction - 13491

Energy Technology Data Exchange (ETDEWEB)

Fehrmann, Henning [Westinghouse Electric Germany GmbH, Dudenstr. 44, D-68167 Mannheim (Germany); Aign, Joerg [Westinghouse Electric Germany GmbH, Global D and D and Waste Management, Tarpenring 6, D-22419 Hamburg (Germany)

2013-07-01

In nuclear power plants (NPP) ion exchange (IX) resins are used in several systems for water treatment. Spent resins can contain a significant amount of contaminates which makes treatment for disposal of spent resins mandatory. Several treatment processes are available such as direct immobilization with technologies like cementation, bitumisation, polymer solidification or usage of a high integrity container (HIC). These technologies usually come with a significant increase in final waste volume. The Hot Resin Supercompaction (HRSC) is a thermal treatment process which reduces the resin waste volume significantly. For a mixture of powdered and bead resins the HRSC process has demonstrated a volume reduction of up to 75 % [1]. For bead resins only the HRSC process is challenging because the bead resins compaction properties are unfavorable. The bead resin material does not form a solid block after compaction and shows a high spring back effect. The volume reduction of bead resins is not as good as for the mixture described in [1]. The compaction properties of bead resin waste can be significantly improved by grinding the beads to powder. The grinding also eliminates the need for a powder additive.Westinghouse has developed a modular grinding process to grind the bead resin to powder. The developed process requires no circulation of resins and enables a selective adjustment of particle size and distribution to achieve optimal results in the HRSC or in any other following process. A special grinding tool setup is use to minimize maintenance and radiation exposure to personnel. (authors)

Composite Properties of Polyimide Resins Made From "Salt-Like" Solution Precursors

Science.gov (United States)

Cano, Roberto J.; Weiser, Erik S.; SaintClair, Terry L.; Echigo, Yoshiaki; Kaneshiro, Hisayasu

1997-01-01

Recent work in high temperature materials at NASA Langley Research Center (LaRC (trademark)) have led to the development of new polyimide resin systems with very attractive properties. The majority of the work done with these resin systems has concentrated on determining engineering mechanical properties of composites prepared from a poly(amide acid) precursor. Three NASA Langley-developed polyimide matrix resins, LaRC (trademark) -IA, LaRC (trademark) -IAX, and LaRC (trademark) -8515, were produced via a salt-like process developed by Unitika Ltd. The 'salt-like' solutions (sixty-five percent solids in NMP) were prepregged onto Hexcel IM7 carbon fiber using the NASA LaRC Multipurpose Tape Machine. Process parameters were determined and composite panels fabricated. Mechanical properties are presented for these three intermediate modulus carbon fiber/polyimide matrix composites and compared to existing data on the same polyimide resin systems and IM7 carbon fiber manufactured via poly(amide acid) solutions (thirty-five percent solids in NMP). This work studies the effects of varying the synthetic route on the processing and mechanical properties of polyimide composites.

Processing and Properties of Vacuum Assisted Resin Transfer Molded Phenylethynyl Terminated Imide Composites

Science.gov (United States)

Cano, Roberto J.; Ghose, Sayata; Watson, Kent A.; Chunchu, Prasad B.; Jensen, Brian J.; Connell, John W.

2012-01-01

Polyimide composites are very attractive for applications that require a high strength to weight ratio and thermal stability. Recent work at NASA Langley Research Center (LaRC) has concentrated on developing new polyimide resin systems that can be processed without the use of an autoclave for advanced aerospace applications. Due to their low melt viscosities and long melt stability, certain phenylethynyl terminated imides (PETI) can be processed into composites using high temperature vacuum assisted resin transfer molding (HT-VARTM). VARTM has shown the potential to reduce the manufacturing cost of composite structures. In the current study, two PETI resins, LARC(Trademark) PETI-330 and LARC(Trademark) PETI-9, were infused into carbon fiber preforms at 260 C and cured at temperatures up to 371 C. Photomicrographs of polished cross sections were taken and void contents, determined by acid digestion, were below 4.5%. Mechanical properties including short block compression (SBC), compression after impact (CAI), and open hole compression (OHC) were determined at room temperature, 177 C, and 288 C. Both PETI-9 and PETI-330 composites demonstrated very good retention of mechanical properties at elevated temperatures. SBC and OHC properties after aging for 1000 hours at temperatures up to 288 C were also determined.

Multiwall carbon nanotube embedded phenolic resin-based carbon foam for the removal of As (V) from contaminated water

Science.gov (United States)

Rani Agrawal, Pinki; Singh, Nahar; Kumari, Saroj; Dhakate, Sanjay R.

2018-03-01

It is well proposed that micron or nano size filters requires to separate adsorbent from water after removal of adsorbate. However, even after filtration trace quantity of adsorbent remains in purified water, which deteriorates the quality of water for potability. To overcome these problems, multi walled carbon nanotube (MWCNT) loaded Carbon Foam (CF) was fabricated by a sacrificial template process. In this process, multi walled carbon nanotubes (MWCNTs) and phenolic resin mixture was used for the impregnation of the polyurethane (PU) template. Impregnated PU Foam stabilized and carbonized to get MWCNTs embedded Carbon Foam (CF). The MWCNT loaded CF (MWCNTs-CF) was used for the removal of As (V) species from water. The proposed foam efficiently removes arsenic (As (V)) from water and it can be easily separated from water after purification without any sophisticated tools. The adsorption capacity of the proposed material was found to be 90.5 μg*g-1 at optimized condition of pH, time and concentration, which is excellent in comparison to several other materials utilized for removal of As (V). Kinetic and isotherm studies reveal that the multilayer adsorption over heterogeneous surface follows pseudo second order kinetics. The adsorption phenomena were further confirmed by several characterization techniques like scanning electron microscope (SEM), x-ray diffraction (XRD) spectroscopy and x-ray photoelectron spectroscopy (XPS).

Vertically aligned TiO2 nanorods-woven carbon fiber for reinforcement of both mechanical and anti-wear properties in resin composite

Science.gov (United States)

Fei, Jie; Zhang, Chao; Luo, Dan; Cui, Yali; Li, Hejun; Lu, Zhaoqing; Huang, Jianfeng

2018-03-01

A series of TiO2 nanorods were successfully grown on woven carbon fiber by hydrothermal method to reinforce the resin composite. The TiO2 nanorods improved the mechanical interlocking among woven carbon fibers and resin matrix, resulting in better fibers/resin interfacial bonding. Compared with desized-woven carbon fiber, the uniform TiO2 nanorods array resulted in an improvement of 84.3% and 73.9% in the tensile and flexural strength of the composite. However, the disorderly TiO2 nanorods on woven carbon fiber leaded to an insignificant promotion of the mechanical strength. The enhanced performance of well-proportioned TiO2 nanorods-woven carbon fiber was also reflected in the nearly 56% decrease of wear rate, comparing to traditional woven carbon fiber reinforced composite.

The Influence of Hydroxylated Carbon Nanotubes on Epoxy Resin Composites

Directory of Open Access Journals (Sweden)

Jiaoxia Zhang

2012-01-01

Full Text Available Hydroxylated multiwall carbon nanotubes (MWNTs/epoxy resin nanocomposites were prepared with ultrasonic dispersion and casting molding. The effect of hydroxylated MWNTs content on reactive activity of composites is discussed. Then the flexural and electrical properties were studied. Transmission electron microscope was employed to characterize the microstructure of nanocomposites. As a result, the reactive activity of nanocomposites obtained increases with the increasing content of MWNTs. When MWNTs content of the composites is 1 wt%, as compared to neat resin, the flexural strength increases from 143 Mpa to 156 MPa, the modulus increases from 3563 Mpa to 3691 MPa, and the volume and surface resistance of nanocomposites decrease by two orders of magnitude, respectively.

Atomistic simulations in Si processing: Bridging the gap between atoms and experiments

International Nuclear Information System (INIS)

Marques, Luis A.; Pelaz, Lourdes; Lopez, Pedro; Aboy, Maria; Santos, Ivan; Barbolla, Juan

2005-01-01

With devices shrinking to nanometric scale, process simulation tools have to shift from continuum models to an atomistic description of the material. However, the limited sizes and time scales accessible for detailed atomistic techniques usually lead to the difficult task of relating the information obtained from simulations to experimental data. The solution consists of the use of a hierarchical simulation scheme: more fundamental techniques are employed to extract parameters and models that are then feed into less detailed simulators which allow direct comparison with experiments. This scheme will be illustrated with the modeling of the amorphization and recrystallization of Si, which has been defined as a key challenge in the last edition of the International Technology Roadmap for Semiconductors. The model is based on the bond defect or IV pair, which is used as the building block of the amorphous phase. The properties of this defect have been studied using ab initio methods and classical molecular dynamics techniques. It is shown that the recombination of this defect depends on the surrounding bond defects, which accounts for the cooperative nature of the amorphization and recrystallization processes. The implementation of this model in a kinetic Monte Carlo code allows extracting data directly comparable with experiments. This approach provides physical insight on the amorphization and recrystallization mechanisms and a tool for the optimization of solid-phase epitaxial-related processes

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)

Use of Anion Exchange Resins for One-Step Processing of Algae from Harvest to Biofuel

Directory of Open Access Journals (Sweden)

Martin Poenie

2012-07-01

Full Text Available Some microalgae are particularly attractive as a renewable feedstock for biodiesel production due to their rapid growth, high content of triacylglycerols, and ability to be grown on non-arable land. Unfortunately, obtaining oil from algae is currently cost prohibitive in part due to the need to pump and process large volumes of dilute algal suspensions. In an effort to circumvent this problem, we have explored the use of anion exchange resins for simplifying the processing of algae to biofuel. Anion exchange resins can bind and accumulate the algal cells out of suspension to form a dewatered concentrate. Treatment of the resin-bound algae with sulfuric acid/methanol elutes the algae and regenerates the resin while converting algal lipids to biodiesel. Hydrophobic polymers can remove biodiesel from the sulfuric acid/methanol, allowing the transesterification reagent to be reused. We show that in situ transesterification of algal lipids can efficiently convert algal lipids to fatty acid methyl esters while allowing the resin and transesterification reagent to be recycled numerous times without loss of effectiveness.

Radioactive spent resins conditioning by the hot super-compaction process

International Nuclear Information System (INIS)

Roth, Andreas; Centner, Baudouin; Lemmens, Alain

2007-01-01

Spent ion exchanger media are considered to be problematic waste that, in many cases, requires special approaches and precautions during its immobilization to meet the acceptance criteria for disposal. The waste acceptance criteria define, among others, the quality of waste forms for disposal, and therefore will sometimes define appropriate treatment options. The selection of treatment options for spent ion exchange materials must consider their physical and chemical characteristics. Basically, the main methods for the treatment of spent organic ion exchange materials, following to pretreatment methods are: - Direct immobilization, producing a stable end product by using Cement, Bitumen, Polymer or High Integrity Containers, - The destruction of the organic compounds by using Thermochemical processes or Oxidation to produce an inorganic intermediate product that may or may not be further conditioned for storage and/or disposal, - The complete removal of the resin inner structural water by a thermal process. After a thorough technical economical analysis, Tractebel Engineering selected the Resin Hot Compaction Process to be installed at Tihange Nuclear Power Plant. The Resin Hot Compaction Process is used to make dense homogenous organic blocks from a wide range of particulate waste. In this process spent resins are first dewatered and dried to remove the inner structural water content. The drying takes place in a drying vessel that holds the contents of two 200 L drums (Figure). In the oil heated drying and mixing unit, the resins are heated to the necessary process temperature for the hot pressing step and then placed into special metal drums, which are automatically lidded and immediately transferred to a high force compactor. After high force compaction the pellets are transferred to a measuring unit, where the dose rate, height and weight are automatically measured and recorded. A volume reduction factor of approximately up to four (depending on the type of

Effect of epoxy coatings on carbon fibers during manufacture of carbon fiber reinforced resin matrix composites

International Nuclear Information System (INIS)

Guo, Hui; Huang, Yudong; Liu, Li; Shi, Xiaohua

2010-01-01

The changes in oxygen and nitrogen during manufacture of the carbon fiber reinforced resin matrix composites were measured using the X-ray photoelectron spectroscopy method. The effects of the change in oxygen and nitrogen on the strength of the carbon fibers were investigated and the results revealed that the change of the tensile strength with increasing heat curing temperature was attributed to the change in the surface flaws of the carbon fibers because the carbon fibers are sensitive to the surface flaws. The effect of the surface energy that was calculated using Kaelble's method on the strength of the carbon fibers was investigated. Furthermore, the surface roughness of the carbon fibers was measured using atom force microscopy. The change trend of roughness was reverse to that of the strength, which was because of the brittle fracture of the carbon fibers.

Radiation processing for PTFE composite reinforced with carbon fiber

International Nuclear Information System (INIS)

Akihiro Oshima; Akira Udagawa; Yousuke Morita

1999-01-01

The present work is an attempt to evaluate the performance of crosslinked PTFE as a polymer matrix for carbon fiber-reinforced composite materials. The carbon fiber-reinforced PTFE pre-composite, which is laminated with PTFE fine powder, is crosslinked by electron beam irradiation. Mechanical and frictional properties of the crosslinked PTFE composite obtained are higher than those of PTFE resin. The crosslinked PTFE composite with high mechanical and radiation resistant performance is obtained by radiation crosslinking process

Pathways to Mesoporous Resin/Carbon Thin Films with Alternating Gyroid Morphology

Energy Technology Data Exchange (ETDEWEB)

Zhang, Qi [Department; Matsuoka, Fumiaki [Department; Suh, Hyo Seon [Institute; Materials; Beaucage, Peter A. [Department; Xiong, Shisheng [Institute; Materials; Smilgies, Detlef-M. [Cornell; Tan, Kwan Wee [Department; School; Werner, Jörg G. [Department; Nealey, Paul F. [Institute; Materials; Wiesner, Ulrich B. [Department

2017-12-19

Three-dimensional (3D) mesoporous thin films with sub-100 nm periodic lattices are of increasing interest as templates for a number of nanotechnology applications, yet are hard to achieve with conventional top-down fabrication methods. Block copolymer self-assembly derived mesoscale structures provide a toolbox for such 3D template formation. In this work, single (alternating) gyroidal and double gyroidal mesoporous thin-film structures are achieved via solvent vapor annealing assisted co-assembly of poly(isoprene-block-styrene-block-ethylene oxide) (PI-b-PS-b-PEO, ISO) and resorcinol/phenol formaldehyde resols. In particular, the alternating gyroid thin-film morphology is highly desirable for potential template backfilling processes as a result of the large pore volume fraction. In situ grazing-incidence small-angle X-ray scattering during solvent annealing is employed as a tool to elucidate and navigate the pathway complexity of the structure formation processes. The resulting network structures are resistant to high temperatures provided an inert atmosphere. The thin films have tunable hydrophilicity from pyrolysis at different temperatures, while pore sizes can be tailored by varying ISO molar mass. A transfer technique between substrates is demonstrated for alternating gyroidal mesoporous thin films, circumventing the need to re-optimize film formation protocols for different substrates. Increased conductivity after pyrolysis at high temperatures demonstrates that these gyroidal mesoporous resin/carbon thin films have potential as functional 3D templates for a number of nanomaterials applications.

Morphological and mechanical analyses of laminates manufactured from randomly positioned carbon fibre/epoxy resin prepreg scraps

Science.gov (United States)

Souza, Christiane S. R.; Cândido, Geraldo M.; Alves, Wellington; Marlet, José Maria F.; Rezende, Mirabel C.

2017-10-01

This study aims to contribute to sustainability by proposing the reuse of composite prepreg scrap as an added value from discards. The research evaluates the microstructure and mechanical properties of laminates processed by the reuse of uncured carbon fibre/F155-epoxy resin prepreg scraps, waste from the ply cutting area of an aeronautical industry. The composite scraps were used as collected and were randomly positioned to produce laminates to be cured at an autoclave. The mechanical characterization shows a decrease of 39% for the compression property due to the discontinuous fibres in the laminate and an increase of 34% for the interlaminar shear strength, when compared to continuous fibre laminates. This increase is attributed to the higher crosslink density of the epoxy resin, as a result of the cure temperature used in autoclave (60 °C higher than suggested by supplier) and also to the randomly positioned scraps. Microscopic analyses confirm the consolidation of laminates, although show resin rich areas with different sizes and shapes attributed to the overlapping of the scraps with different sizes and shapes. These resin rich areas may contribute to decrease the mechanical properties of laminates. The correlation between mechanical and morphological results shows potential to be used on non-critical structural application, as composite jigs, contributing to sustainability.

Vitrification process for the volume reduction and stabilization of organic resins

International Nuclear Information System (INIS)

Buelt, J.L.

1982-10-01

Pacific Northwest Laboratory has completed a series of experimental tests sponsored by the US Department of Energy (DOE) to determine the feasibility of incinerating and vitrifying organic ion-exchange resins in a single-step process. The resins used in this study were identical to those used for decontaminating auxiliary building water at the Three Mile Island (TMI) Unit 2 reactor. The primarily organic resins were loaded with nonradioactive isotopes of cesium and strontium for processing in a pilot-scale, joule-heated glass melter modified to support resin combustion. The feasibility tests demonstrated an average process rate of 3.0 kg/h. Based on this rate, if 50 organic resin liners were vitrified in a six-month campaign, a melter 2.5 times the size of the pilot scale unit would be adequate. A maximum achievable volume reduction of 91% was demonstrated in these tests

Formation of carbon nanosheets via simultaneous activation and catalytic carbonization of macroporous anion-exchange resin for supercapacitors application.

Science.gov (United States)

Peng, Hui; Ma, Guofu; Sun, Kanjun; Mu, Jingjing; Zhang, Zhe; Lei, Ziqiang

2014-12-10

Two-dimensional mesoporous carbon nanosheets (CNSs) have been prepared via simultaneous activation and catalytic carbonization route using macroporous anion-exchange resin (AER) as carbon precursor and ZnCl2 and FeCl3 as activating agent and catalyst, respectively. The iron catalyst in the skeleton of the AER may lead to carburization to form a sheetlike structure during the carbonization process. The obtained CNSs have a large number of mesopores, a maximum specific surface area of 1764.9 m(2) g(-1), and large pore volume of 1.38 cm(3) g(-1). As an electrode material for supercapacitors application, the CNSs electrode possesses a large specific capacitance of 283 F g(-1) at 0.5 A g(-1) and excellent rate capability (64% retention ratio even at 50 A g(-1)) in 6 mol L(-1) KOH. Furthermore, CNSs symmetric supercapacitor exhibits specific energies of 17.2 W h kg(-1) at a power density of 224 W kg(-1) operated in the voltage range of 0-1.8 V in 0.5 mol L(-1) Na2SO4 aqueous electrolyte, and outstanding cyclability (retains about 96% initial capacitance after 5000 cycles).

Method of heat decomposition for chemical decontaminating resin waste

International Nuclear Information System (INIS)

Kikuchi, Akira.

1988-01-01

Purpose: To make resin wastes into non-deleterious state, discharge them into a resin waste storage tank of existent radioactive waste processing facility and store and dispose them. Constitution: In the processing of chemical decontaminating resin wastes, iron exchange resins adsorbing chemical decontaminating agents comprising a solution of citric acid, oxalic acid, formic acid and EDTA alone or as a mixture of them are heated to dry, thermally decomposed and then separated from the ion exchange resins. That is, the main ingredients of the chemical decontaminating agents are heat-decomposed when heated and dried at about 250 deg C in air and converted into non-toxic gases such as CO, CO 2 , NO, NO 2 or H 2 O. Further, since combustion or carbonization of the basic materials for the resin is not caused at such a level of temperature, the resin wastes removed with organic acid and chelating agents are transferred to an existent resin waste storage tank and stored therein. In this way, facility cost and radiation exposure can remarkably be decreased. (Kamimura, M.)

Elaboration of extracting, incinerable and/or conducting resins, for the grouped conversion of actinides; Conception de resines extractantes, incinerables et/ou conductrices, pour la conversion groupee d'actinides

Energy Technology Data Exchange (ETDEWEB)

Mokhtari, H. [Paris-11 Univ., 91 - Orsay (France)]|[CEA Valrho, Lab. de Chimie des Actinides (LCA), 30 - Marcoule (France)

2006-07-01

The first results obtained in the framework of the study called PEACE (Process for the Elaboration of Actinide Carbide from ion Exchange resin) concern the fixation of neodymium(III) (simulating trivalent actinides) on two carboxylic resins: the first one is of gel type and the second one of macroporous type. A kinetic study of the exchange NH{sub 4}{sup +}/Nd{sup 3+} has shown that: 1)neodymium is fixed under the form of a complexed or hydrolyzed specie of neodymium of charge 2+ 2)a high charge rate is reached (40% in mass for the dried resin which corresponds to an exchange capacity of 11 meq/g dry of introduced resin) 3)the exchange kinetics is better for the macroporous resin than for the gel resin. A heat treatment of the macroporous resin charged in neodymium has been carried out until the carbonization by the mean of thermal gravimetric analyses carried out under air and argon. A carbon/neodymium ratio of about 5 is obtained after carbonization under argon. Scanning electron microscopy analyses carried out on the macroporous resin charged in neodymium have revealed a conservation of the sphericity and a consequent reduction of the resin balls diameter after heat treatment and an homogeneous distribution of neodymium inside the sphere. (O.M.)

Carbon-14 behavior in a cement-dominated environment: Implications for spent CANDU resin waste disposal

International Nuclear Information System (INIS)

Dayal, R.; Reardon, E.J.

1994-01-01

Cement based waste forms and concrete engineered barriers are expected to play a key role in providing 14 C waste containment and control 14 C migration for time periods commensurate with its hazardous life of about 50,000 years. The main thrust of this study was, therefore, to evaluate the performance of cement based waste forms with regard to 14 C containment. Of particular importance are the geochemical processes controlling 14 C solubility and release under anticipated cement dominated low and intermediate level waste repository conditions. Immobilization of carbonate-form exchange resin in grout involves transfer of sorbed 14 CO 3 2- ions, through exchange for hydroxyl ions from the grout slurry, followed by localized precipitation of solid calcium carbonate at the cement/resin interface in the grout matrix. Carbon-14 release behavior can be attributed to the dissolution characteristics and solubility of calcite present in the cement based waste form. The groundwater flow regime can exert a pronounced effect both on the near-field chemistry and the leaching behavior of 14 C. For a cement dominated repository, at relatively low-flow or stagnant groundwater conditions, the alkaline near-field chemical environments inhibits the release of 14 C from the cemented waste form. Under high flow conditions, the near-field environment is characterized by relatively neutral pH conditions which promote calcite dissolution, thus resulting in 14 C release from the waste form

A numerical investigation of the resin flow front tracking applied to the RTM process

Directory of Open Access Journals (Sweden)

Jeferson Avila Souza

2011-09-01

Full Text Available Resin Transfer Molding (RTM is largely used for the manufacturing of high-quality composite components and the key stage during processing is the resin infiltration. The complete understanding of this phenomenon is of utmost importance for efficient mold construction and the fast production of high quality components. This paper investigates the resin flow phenomenon within the mold. A computational application was developed to track the resin flow-front position, which uses a finite volume method to determine the pressure field and a FAN (Flow Analysis Network technique to track the flow front. The mass conservation problem observed with traditional FE-CV (Finite Element-Control Volume methods is also investigated and the use of a finite volume method to minimize this inconsistency is proposed. Three proposed case studies are used to validate the methodology by direct comparison with analytical and a commercial software solutions. The results show that the proposed methodology is highly efficient to determine the resin flow front, showing an improvement regarding mass conservation across volumes.

Development of new and improved polymer matrix resin systems, phase 1

Science.gov (United States)

Hsu, M. S.

1983-01-01

Vinystilbazole (vinylstryrylpyridine) and vinylpolystyrulpyridine were prepared for the purpose of modifying bismaleimide composite resins. Cure studies of resins systems were investigated by differential scanning calorimetry. The vinylstyrylpyridine-modified bismaleimide composite resins were found to have lower cure and gel temperatures, and shorter cure times than the corresponding unmodified composite resins. The resin systems were reinforced with commercially avialable satin-weave carbon cloth. Prepregs were fabricated by solvent or hot melt techniques. Thermal stability, flammability, moisture absorption, and mechanical properties of the composites (such as flexural strength, modulus, tensile and short beam shear strength) were determined. Composite laminates showed substantial improvements in both processability and mechanical properties compared to he bismaleimide control systems. The vinylstyrylpyridine modified bismaleimide resins can be used as advanced matrix resins for graphite secondary structures where ease of processing, fireworthiness, and high temperature stability are required for aerospace applications.

In situ synthesis of N and Cu functionalized mesoporous FDU-14 resins and carbons for electrochemical hydrogen storage

Energy Technology Data Exchange (ETDEWEB)

Kong, AiGuo; Wang, WenJuan; Yang, Fan; Ding, HanMing; Shan, YongKui [Department of Chemistry, East China Normal University, ShangHai 200062 (China)

2010-07-15

N and Cu cooperatively functionalized mesoporous resin and carbon materials with bicontinuous cubic structure (FDU-14) were obtained by a novel synthesis method. In this method, block copolymers were used as the templates as well as the precursors for the preparation of these modifying mesoporous materials. The CuC{sub 2}O{sub 4} in the channels of mesoporous FDU-14 resins was gotten by in situ oxidation of the templates in a catalytic redox system containing Cu{sup 2+}, Al{sup 3+}, NO{sub 3}{sup -}, PO{sub 4}{sup 3-}, SO{sub 4}{sup 2-} ions. Simultaneously, the phenol-formaldehyde resin frameworks were in situ functionalized by the amine group resulting from the reduction of NO{sub 3}{sup -}, leading to the formation of N and CuC{sub 2}O{sub 4} modified mesoporous FDU-14 resin materials. Its pyrolysis at the different temperatures resulted in the production of N and Cu cooperatively functionalized mesoporous FDU-14 resin and carbon materials. The structure and composition of these materials were characterized by the X-ray power diffraction, transmission electron microscopy, N{sub 2} adsorption-desorption analysis, X-ray photoelectron spectroscopy, infrared spectroscopy, thermogravimetry analysis, and inductive coupled plasma emission spectroscopy. The electrochemical measurement indicated that N and Cu cooperatively functionalized mesoporous FDU-14 carbon materials possessed the enhanced electrochemical hydrogen storage performance. (author)

Method of removing contaminants from plastic resins

Science.gov (United States)

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

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.

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.

Electron spectroscopy of rubber and resin-based composites containing 2D carbon

International Nuclear Information System (INIS)

Kaciulis, S.; Mezzi, A.; Balijepalli, S.K.; Lavorgna, M.; Xia, H.S.

2015-01-01

Composite materials with 2D carbon (graphene and/or single wall carbon nanotubes) are very promising due to their extraordinary electrical and mechanical properties. Graphene and natural rubber composites, which may be used for the gaskets or sealants, were prepared by ultrasonically assisted latex-mixing exfoliation and in-situ reduction process, with two vulcanization approaches: roll-mixing and hot-pressing. Also the resin-based composites, filled with micro-particles of Ag and graphene or carbon nanotubes, have been studied. The standards for the compositional characterization of these materials still are not established. In addition to the mostly used techniques, such as Raman spectroscopy and electron microscopy, also Auger electron spectroscopy can be employed for the identification of graphene. In this study, the shape of C KVV peak, excited by electron beam and X-ray photons, has been investigated in different composite materials containing graphene and carbon nanotubes. A spectroscopic method for 2D carbon recognition, based on the D x parameter which is determined from C KVV signal excited by X-ray photons, was proposed and verified. Even a small content of graphene in different types of composites was sufficient for this recognition due to the dominating presence of graphene on the surface of composites. - Highlights: • Chemical composition of the rubber composites was determined by XPS. • Auger spectrum of carbon was used for graphene identification in composites. • Small content of graphene was sufficient for its recognition from the D parameter

Electron spectroscopy of rubber and resin-based composites containing 2D carbon

Energy Technology Data Exchange (ETDEWEB)

Kaciulis, S., E-mail: saulius.kaciulis@ismn.cnr.it [Institute for the Study of Nanostructured Materials, ISMN-CNR, P.O. Box 10, Monterotondo Stazione, 00015 Roma (Italy); Mezzi, A.; Balijepalli, S.K. [Institute for the Study of Nanostructured Materials, ISMN-CNR, P.O. Box 10, Monterotondo Stazione, 00015 Roma (Italy); Lavorgna, M. [Institute of Polymers, Composites and Biomaterials, IPCB-CNR, P.le Fermi, 80055 Napoli (Italy); Xia, H.S. [State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610065 Sichuan (China)

2015-04-30

Composite materials with 2D carbon (graphene and/or single wall carbon nanotubes) are very promising due to their extraordinary electrical and mechanical properties. Graphene and natural rubber composites, which may be used for the gaskets or sealants, were prepared by ultrasonically assisted latex-mixing exfoliation and in-situ reduction process, with two vulcanization approaches: roll-mixing and hot-pressing. Also the resin-based composites, filled with micro-particles of Ag and graphene or carbon nanotubes, have been studied. The standards for the compositional characterization of these materials still are not established. In addition to the mostly used techniques, such as Raman spectroscopy and electron microscopy, also Auger electron spectroscopy can be employed for the identification of graphene. In this study, the shape of C KVV peak, excited by electron beam and X-ray photons, has been investigated in different composite materials containing graphene and carbon nanotubes. A spectroscopic method for 2D carbon recognition, based on the D{sub x} parameter which is determined from C KVV signal excited by X-ray photons, was proposed and verified. Even a small content of graphene in different types of composites was sufficient for this recognition due to the dominating presence of graphene on the surface of composites. - Highlights: • Chemical composition of the rubber composites was determined by XPS. • Auger spectrum of carbon was used for graphene identification in composites. • Small content of graphene was sufficient for its recognition from the D parameter.

Distribution ratios on Dowex 50W resins of metal leached in the caron nickel recovery process

Energy Technology Data Exchange (ETDEWEB)

Reynolds, B.A.; Metsa, J.C.; Mullins, M.E.

1980-05-01

Pressurized ion exchange on Dowex 50W-X8 and 50W-X12 resins was investigated using elution techniques to determine distribution ratios for copper, nickel, and cobalt complexes contained in ammonium carbonate solution, a mixture which approximates the waste liquor from the Caron nickel recovery process. Results were determined for different feed concentrations, as well as for different concentrations and pH values of the ammonium carbonate eluant. Distribution ratios were compared with those previously obtained from a continuous annular chromatographic system. Separation of copper and nickel was not conclusively observed at any of the conditions examined.

Distribution ratios on Dowex 50W resins of metal leached in the caron nickel recovery process

International Nuclear Information System (INIS)

Reynolds, B.A.; Metsa, J.C.; Mullins, M.E.

1980-05-01

Pressurized ion exchange on Dowex 50W-X8 and 50W-X12 resins was investigated using elution techniques to determine distribution ratios for copper, nickel, and cobalt complexes contained in ammonium carbonate solution, a mixture which approximates the waste liquor from the Caron nickel recovery process. Results were determined for different feed concentrations, as well as for different concentrations and pH values of the ammonium carbonate eluant. Distribution ratios were compared with those previously obtained from a continuous annular chromatographic system. Separation of copper and nickel was not conclusively observed at any of the conditions examined

PETI-298 Prepared by Microwave Synthesis: Neat Resin and Composite Properties

Science.gov (United States)

Smith, Joseph G.; Connell, John W.; Li, Chao-Jun; Wu, Wei; Criss, Jim M., Jr.

2004-01-01

PETI-298 is a high temperature/high performance matrix resin that is processable into composites by resin transfer molding (RTM), resin infusion and vacuum assisted RTM techniques. It is typically synthesized in a polar aprotic solvent from the reaction of an aromatic anhydride and a combination of diamines and endcapped with phenylethynylphthalic anhydride. Microwave synthesis of PETI-298 was investigated as a means to eliminate solvent and decrease reaction time. The monomers were manually mixed and placed in a microwave oven for various times to determine optimum reaction conditions. The synthetic process was subsequently scaled-up to 330g. Three batches were synthesized and combined to give 1 kg of material that was characterized for thermal and rheological properties and compared to PETI-298 prepared by the classic solution based synthetic method. The microwave synthesized PETI-298 was subsequently used to fabricate flat laminates on T650 carbon fabric by RTM. The composite panels were analyzed and mechanical properties determined and compared with those fabricated from PETI-298 prepared by the classic solution method. The microwave synthesis process and characterization of neat resin and carbon fiber reinforced composites fabricated by RTM will be presented. KEY WORDS: Resin Transfer Molding, High Temperature Polymers, Phenylethynyl Terminated Imides, Microwave Synthesis

The Relix process for the resin-in-pulp recovery of uranium

International Nuclear Information System (INIS)

Cloete, F.L.D.

1981-01-01

The Relix process is based on direct contact between an ion-exchange resin and undiluted pulp, thus avoiding prior solid-liquid separation. The resin particles float near the surface of the pulp, forming an inverted fluidized bed with the pulp flowing downwards. The basic idea was demonstrated on a full-scale pachuca tank at Stilfontein Gold Mine in 1970, followed by a small-scale demonstration run in a laboratory at the National Institute for Metallurgy. A pilot plant based on a throughput of 60 tons of ore per day was subsequently operated at West Driefontein Gold Mine for several periods over two years. Although the plant proved operable from a mechanical point of view, the metallurgical performance was not up to expectation. The basic cause of the poor metallurgical performance was shown to be backmixing of both the resin and the pulp between stages. The values obtained for resin losses were inconclusive. Further development of resin-in-pulp processes for the recovery of uranium should be focused on the performance of various techniques for the screening of resin from pulp [af

Structural and adsorptive properties of activated carbons prepared by carbonization and activation of resins.

Science.gov (United States)

Leboda, R; Skubiszewska-Zieba, J; Tomaszewski, W; Gun'ko, V M

2003-07-15

Four activated carbons (S1-S4) possessing different structural characteristics were prepared by carbonization of commercial resins (used for ion exchange) and subsequent activation. Their textural parameters were determined on the basis of nitrogen adsorption-desorption at 77.4 K, analyzed by applying several local and overall adsorption isotherm equations. The nature of carbon surface functionalities was analyzed by FTIR spectroscopy. The GC and solid-phase extraction (SPE) techniques were applied to study the influence of the texture of carbonaceous materials on their adsorptive properties. The adsorption efficiency of synthesized carbons with respect to alkylhalides used as probe compounds in the GC measurements varied over a range from 28% (C(2)H(3)Cl(3)/S2) to 85% (CHBr(3)/S1) depending on the type of adsorbates and adsorbents. The concentrating efficiency of these carbons in SPE of explosive materials changed over a larger range from 12% (trinitroglycerin/S4) and 13% (trinitrotoluene/S2) up to 100% (octogen/S1). Active carbon prepared using Zerolite 225x8 as a precursor demonstrated better results than other carbons in two types of adsorption with average values of the efficiency of 75.4% for explosives and 60.8% for alkylhalides.

Method of burning ion-exchange resin contaminated with radioactivity

International Nuclear Information System (INIS)

Suzuki, Shigenori.

1986-01-01

Purpose: To process spent ion exchange resins to reduce their volume, without increasing the load on a off-gas system and in a stable state and at the same time not leaving any uncombusted portions. Method: The water slurries of the ion exchange resins contaminated with radioactive materials is dehydrated or dry combusted to reduce the water content. A binder is then added to solidify the ion exchange resin. The solidified ion exchange resins are then combusted in a furnace. This prevents the ion exchange resin from being dispersed by air and combustion gases. Furthermore, the solidified ion exchange resins in the form of small pellets burn from the surface inwards. Moreover the binder is carbonized by the combustion heat and promotes combustion to convert the ion exchange resins into a solid mass, making sure that no uncombusted portion is left. (Takahashi, M.)

A transformation theory of stochastic evolution in Red Moon methodology to time evolution of chemical reaction process in the full atomistic system.

Science.gov (United States)

Suzuki, Yuichi; Nagaoka, Masataka

2017-05-28

Atomistic information of a whole chemical reaction system, e.g., instantaneous microscopic molecular structures and orientations, offers important and deeper insight into clearly understanding unknown chemical phenomena. In accordance with the progress of a number of simultaneous chemical reactions, the Red Moon method (a hybrid Monte Carlo/molecular dynamics reaction method) is capable of simulating atomistically the chemical reaction process from an initial state to the final one of complex chemical reaction systems. In the present study, we have proposed a transformation theory to interpret the chemical reaction process of the Red Moon methodology as the time evolution process in harmony with the chemical kinetics. For the demonstration of the theory, we have chosen the gas reaction system in which the reversible second-order reaction H 2 + I 2  ⇌ 2HI occurs. First, the chemical reaction process was simulated from the initial configurational arrangement containing a number of H 2 and I 2 molecules, each at 300 K, 500 K, and 700 K. To reproduce the chemical equilibrium for the system, the collision frequencies for the reactions were taken into consideration in the theoretical treatment. As a result, the calculated equilibrium concentrations [H 2 ] eq and equilibrium constants K eq at all the temperatures were in good agreement with their corresponding experimental values. Further, we applied the theoretical treatment for the time transformation to the system and have shown that the calculated half-life τ's of [H 2 ] reproduce very well the analytical ones at all the temperatures. It is, therefore, concluded that the application of the present theoretical treatment with the Red Moon method makes it possible to analyze reasonably the time evolution of complex chemical reaction systems to chemical equilibrium at the atomistic level.

An activated microporous carbon prepared from phenol-melamine-formaldehyde resin for lithium ion battery anode

International Nuclear Information System (INIS)

Zhu, Yinhai; Xiang, Xiaoxia; Liu, Enhui; Wu, Yuhu; Xie, Hui; Wu, Zhilian; Tian, Yingying

2012-01-01

Highlights: ► Microporous carbon was prepared by chemical activation of phenol-melamine-formaldehyde resin. ► Activation leads to high surface area, well-developed micropores. ► Micropores lead to strong intercalation between carbon and lithium ion. ► Large surface area promotes to improve the lithium storage capacity. -- Abstract: Microporous carbon anode materials were prepared from phenol-melamine-formaldehyde resin by ZnCl 2 and KOH activation. The physicochemical properties of the obtained carbon materials were characterized by scanning electron microscope, X-ray diffraction, Brunauer–Emmett–Teller, and elemental analysis. The electrochemical properties of the microporous carbon as anode materials in lithium ion secondary batteries were evaluated. At a current density of 100 mA g −1 , the carbon without activation shows a first discharge capacity of 515 mAh g −1 . After activation, the capacity improved obviously. The first discharge capacity of the carbon prepared by ZnCl 2 and KOH activation was 1010 and 2085 mAh g −1 , respectively. The reversible capacity of the carbon prepared by KOH activation was still as high as 717 mAh g −1 after 20 cycles, which was much better than that activated by ZnCl 2 . These results demonstrated that it may be a promising candidate as an anode material for lithium ion secondary batteries.

Kinetic study of ion exchange in phosphoric acid chelating resin

International Nuclear Information System (INIS)

Brikci-Nigassa, Mounir; Hamouche, Hafida

1995-11-01

Uranium may be recovered as a by product of wet phosphoric acid using a method based on specific ion exchange resins. These resins called chelates contain amino-phosphonic functional groups. The resin studied in this work is a purolite S-940; uranium may be loaded on this resin from 30% P2O5 phosphoric acid in its reduced state. The influence of different parameters on the successive steps of the process have been studied in batch experiments: uranium reduction, loading and oxydation. Uranium may be eluted with ammonium carbonate and the resin regeneration may be done with hydrochloric acid.Ferric ions reduce the effective resin capacity considerably and inert fixation conditions are proposed to enhance uranium loading

Disintegration and dissolution of spent radioactive cationic exchange resins using Fenton-like oxidation process

International Nuclear Information System (INIS)

Wan, Zhong; Xu, Lejin; Wang, Jianlong

2015-01-01

Highlights: • The spent radioactive resins could be oxidized by Fenton-like process. • The influencing factors on resin oxidation were evaluated. • Chemical oxygen demand (COD) reduction rate was more than 99%. • SEM and Raman spectrum were used to analyze the resins morphological change. - Abstract: The treatment and disposal of the spent radioactive resins is essential for the sustainable development of the nuclear industry. In this paper, the disintegration and dissolution of spent cationic resins were studied by Fenton-like process. The influencing factors on resin dissolution, such as pH, temperature, type and concentration of catalysts were evaluated. The results showed that the spent resins could be effectively dissolved at pH < 1, [Fe 2+ ] = 0.2 M and T = 97 ± 2 °C. Chemical oxygen demand (COD) reduction rate was more than 99%. The scanning electron microscopy and the Raman spectrum were used to observe the morphological changes of the spent resins during the dissolution process. Fenton-like oxidation is an efficient method for the volume reduction and stabilization of the spent resins before further immobilization

Disintegration and dissolution of spent radioactive cationic exchange resins using Fenton-like oxidation process

Energy Technology Data Exchange (ETDEWEB)

Wan, Zhong; Xu, Lejin [Collaborative Innovation Center for Advanced Nuclear Energy Technology, INET, Tsinghua University, Beijing 100084 (China); Wang, Jianlong, E-mail: wangjl@tsinghua.edu.cn [Collaborative Innovation Center for Advanced Nuclear Energy Technology, INET, Tsinghua University, Beijing 100084 (China); Beijing Key Laboratory of Radioactive Wastes Treatment, Tsinghua University, Beijing 100084 (China)

2015-09-15

Highlights: • The spent radioactive resins could be oxidized by Fenton-like process. • The influencing factors on resin oxidation were evaluated. • Chemical oxygen demand (COD) reduction rate was more than 99%. • SEM and Raman spectrum were used to analyze the resins morphological change. - Abstract: The treatment and disposal of the spent radioactive resins is essential for the sustainable development of the nuclear industry. In this paper, the disintegration and dissolution of spent cationic resins were studied by Fenton-like process. The influencing factors on resin dissolution, such as pH, temperature, type and concentration of catalysts were evaluated. The results showed that the spent resins could be effectively dissolved at pH < 1, [Fe{sup 2+}] = 0.2 M and T = 97 ± 2 °C. Chemical oxygen demand (COD) reduction rate was more than 99%. The scanning electron microscopy and the Raman spectrum were used to observe the morphological changes of the spent resins during the dissolution process. Fenton-like oxidation is an efficient method for the volume reduction and stabilization of the spent resins before further immobilization.

Thermal behaviour of used resin during conditioning process

International Nuclear Information System (INIS)

Arsene, C.

2016-01-01

In the nuclear power plants using light water and heavy water as coolant, as well as in most waste treatment installations, the ion-exchange resins are used to purify water circuits. Since the resins retain both radionuclide and chemical impurities, it represents a low- and intermediate- radioactive waste that requires special management for storage and disposal. From experimental studies it was found that the conditioning of the used resin in bitumen has several advantages. But there are some disadvantages, too, one being the significant amount of gas produced during the bituminization process because of the high temperature (1200C). Besides water vapours, the condensable gas mixture (formed by a liquid fraction and an oil fraction) contains products generated from the partial decomposition of the resin and release of degradation products of bitumen: dimethyl and trimethylamine, methanol - compounds resulting from the destruction of functional groups and hydrocarbon fraction formed by n-paraffins (C6-C32), iso-paraffins and aromatics. (authors)

Evaluation of adsorbent and ion exchange resins for removal of organic matter from petroleum refinery wastewaters aiming to increase water reuse.

Science.gov (United States)

de Abreu Domingos, Rodrigo; da Fonseca, Fabiana Valéria

2018-05-15

The oil refinery industry seeks solutions to reduce its water uptake and consumption by encouraging the reuse of internal streams and wastewater from treatment systems. After conventional treatment the petroleum refinery wastewater still contains a considerable quantity of recalcitrant organics and the adsorption on activated carbon is currently used in Brazilian refineries, although it is still expensive due to the difficulty of its regeneration. This study evaluated the use of adsorbent and ion exchange resins for the removal of organic matter from refinery wastewater after conventional treatment in order to verify its feasibility, applying successive resin regenerations and comparing the results with those obtained for activated carbon process. Adsorption isotherms experiments were used to evaluate commercial resins, and the most efficient was subjected to column experiments, where absorbance (ABS) and total organic carbon (TOC) removal were measured. The adsorption isotherm of the best resin showed an adsorptive capacity that was 55% lower than that of activated carbon. On the other hand, the column experiments indicated good removal efficiency, and the amount of TOC in the treated wastewater was as good as has been reported in the literature for activated carbon. The regeneration efficiency of the retained organics ranged from 57 to 94%, while regenerant consumption ranged from 12 to 79% above the amount recommended by the resin supplier for the removal of organic material from natural sources, showing the great resistance of these recalcitrant compounds to desorption. Finally, an estimate of the service life of the resin using intermediate regeneration conditions found it to be seven times higher than that of activated carbon when the latter is not regenerated. Copyright © 2018 Elsevier Ltd. All rights reserved.

A theoretical study of resin flows for thermosetting materials during prepreg processing

Science.gov (United States)

Hou, T. H.

1984-01-01

A flow model which describes the process of resin consolidation during prepreg lamination was developed. The salient features of model predictions were explored. It is assumed that resin flows in all directions originate from squeezing action between two approaching adjacent fiber/fabric layers. In the horizontal direction, a squeezing flow between two nonporous parallel plates is analyzed, while in the vertical direction a poiseuille type pressure flow through porous media is assumed. Proper force and mass balance was established for the whole system which is composed of these two types of flow. A flow parameter, CF, shows to be a measure of processibility for the curing resin. For a given external load-F the responses of resin flow during prepreg lamination, as measured by CF, are categorized into three regions: (1) the low CF region where resin flows are inhibited by the high chemoviscosity during initial curing stages; (2) the median CF region where resin flows are properly controllable; and (3) the high CF region where resin flows are ceased due to fiber/fabric compression effects. Resin losses in both directions are calculated. Potential uses of this model and quality control of incoming prepreg material are discussed.

Magnetic properties of magnetic glass-like carbon prepared from furan resin alloyed with magnetic fluid

Energy Technology Data Exchange (ETDEWEB)

Nakamura, Kazumasa, E-mail: naka@sss.fukushima-u.ac.jp [Materials Science Area, Graduate School of Symbiotic Systems Science and Technology, Fukushima University, 1 Kanayagawa, Fukushima 960-1296 (Japan); Okuyama, Kyoko [Materials Science Area, Graduate School of Symbiotic Systems Science and Technology, Fukushima University, 1 Kanayagawa, Fukushima 960-1296 (Japan); Takase, Tsugiko [Institute of Environmental Radioactivity (IER), Fukushima University, 1 Kanayagawa, Fukushima 960-1296 (Japan)

2017-03-01

Magnetic glass-like carbons that were heat-treated at different temperatures or were filled with different magnetic nanoparticle contents were prepared from furan resin alloyed with magnetic fluid (MF) or Fe{sub 3}O{sub 4} powder in their liquid-phase states during mixing. Compared to the Fe{sub 3}O{sub 4} powder-alloyed carbon, the MF-alloyed carbon has highly dispersed the nanoparticles, and has the excellent saturation magnetization and coercivity. It is implied that saturation magnetizations are related to changes in the types of phases for the nanoparticles and the relative intensities of X-ray diffraction peaks for iron and iron-containing compounds in the carbons. Additionally, the coercivities are possibly affected by the size and crystallinity of the nanoparticles, the relative amounts of iron, and the existence of amorphous compounds on the carbon surfaces. - Highlights: • Magnetic glass-like carbons were prepared from furan resin alloyed with magnetic fluid. • The nanoparticles of MF-alloyed GLCs were highly dispersed. • MF-alloyed GLCs had excellent magnetic properties compared to powder-alloyed ones. • The magnetic properties changed with treatment temperature and nanoparticle content. • The changes in magnetic properties were investigated with XRD and FE-SEM.

High-capacitance supercapacitors using nitrogen-decorated porous carbon derived from novolac resin containing peptide linkage

OpenAIRE

Kim, Yong Jung; Jang, In Young; Park, Ki Chul; Jung, Yong Chae; Oka, Takuyuki; Iinou, Satoshi; Komori, Yasuhiro; Kozutsumi, Toshihiko; Hashiba, Takashi; Kim, Yoong Ahm; Endo, Morinobu

2010-01-01

We fabricated nitrogen-decorated porous carbon exhibiting high capacitance per unit volume and unit weight via chemical activation of novolac resin containing peptide linkage. The porosity and the amount of nitrogen atoms were controlled by changing the molecular weight of novolac resin, the added amount of potassium hydroxide, or both. After chemical activation, positively charged nitrogen atoms (i.e., pyridine/pyrrole) at 400.3 eV in photoemission spectra contributed to both a shift in the ...

Resin for processing radioactive waste water

International Nuclear Information System (INIS)

Onozuka, Teruo; Shindo, Manabu; Kiba, Hideaki; Kubota, Hirohisa; Sawada, Shintaro.

1995-01-01

The present invention concerns an anionic exchange resin having a long service life with less radiation degradation. The resin is an anionic exchange resin in which a trimethyl ammonium group is introduced to a copolymer of 4-bromo-butoxymethyl styrene and divinyl benzene. The resin is excellent in economic performance, and can reduce the frequency for the exchange of cross-linked anionic exchangers. (T.M.)

Resin for processing radioactive waste water

Energy Technology Data Exchange (ETDEWEB)

Onozuka, Teruo; Shindo, Manabu [Tohoku Electric Power Co., Inc., Sendai (Japan); Kiba, Hideaki; Kubota, Hirohisa; Sawada, Shintaro

1995-11-07

The present invention concerns an anionic exchange resin having a long service life with less radiation degradation. The resin is an anionic exchange resin in which a trimethyl ammonium group is introduced to a copolymer of 4-bromo-butoxymethyl styrene and divinyl benzene. The resin is excellent in economic performance, and can reduce the frequency for the exchange of cross-linked anionic exchangers. (T.M.).

Study on the pyrolysis of phenol-formaldehyde (PF) resin and modified PF resin

Energy Technology Data Exchange (ETDEWEB)

Wang, Jigang, E-mail: wangjigang@seu.edu.cn [Jiangsu Key Laboratory of Advanced Metallic Materials, School of Materials Science and Engineering, Southeast University, Nanjing 211189 (China); Jiang, Haiyun [Jiangsu Key Laboratory of Advanced Metallic Materials, School of Materials Science and Engineering, Southeast University, Nanjing 211189 (China); School of Materials Science and Engineering, Southeast University, Nanjing Institute of Technology, Nanjing 210013 (China); Jiang, Nan [Institute of Theoretical and Computational Chemistry, Nanjing University, Nanjing 210093 (China)

2009-12-10

The pyrolysis of pure phenol-formaldehyde (PF) resin and boron carbide (B{sub 4}C) modified PF resin was investigated by using thermogravimetry (TG) and pyrolysis gas-chromatography-mass-spectrometry (PY-GC/MS). Scanning electron microscope (SEM) and Fourier transform infrared (FT-IR) spectroscopy were also employed to investigate the micro-structural evolution. It was shown from the TG analysis that the char residues of pure PF resin were 62.9 and 60.5% after being pyrolyzed at 700 and 1000 {sup o}C, respectively. The degradation and failure of the resin matrix were mainly resulted from the release of volatiles. The phenol and its methyl derivates took a large proportion in the amount of volatiles. In comparison with the pure PF resin, the char residues of B{sub 4}C modified PF resin were obviously higher, with the values of 71.9 and 68.4% at 700 and 1000 {sup o}C, respectively. Due to the oxidation-reduction reactions between B{sub 4}C additive and oxygen-containing volatiles including CO and H{sub 2}O, partial carbon and oxygen elements in the volatiles remained in the resin matrix in the forms of amorphous carbon and B{sub 2}O{sub 3}, respectively. The results of SEM and FT-IR characterization demonstrated the occurrence of the modification, and the amorphous carbon existed in the form of reticular substance. In addition, the amount of the released phenol and its methyl derivates was also decreased drastically due to the formation of borate.

Carbon fiber content measurement in composite

Science.gov (United States)

Wang, Qiushi

Carbon fiber reinforced polymers (CFRPs) have been widely used in various structural applications in industries such as aerospace and automotive because of their high specific stiffness and specific strength. Their mechanical properties are strongly influenced by the carbon fiber content in the composites. Measurement of the carbon fiber content in CFRPs is essential for product quality control and process optimization. In this work, a novel carbonization-in-nitrogen method (CIN) is developed to characterize the fiber content in carbon fiber reinforced thermoset and thermoplastic composites. In this method, a carbon fiber composite sample is carbonized in a nitrogen environment at elevated temperatures, alongside a neat resin sample. The carbon fibers are protected from oxidization while the resin (the neat resin and the resin matrix in the composite sample) is carbonized under the nitrogen environment. The residue of the carbonized neat resin sample is used to calibrate the resin carbonization rate and calculate the amount of the resin matrix in the composite sample. The new method has been validated on several thermoset and thermoplastic resin systems and found to yield an accurate measurement of fiber content in carbon fiber polymer composites. In order to further understand the thermal degradation behavior of the high temperature thermoplastic polymer during the carbonization process, the mechanism and the kinetic model of thermal degradation behavior of carbon fiber reinforced poly (phenylene sulfide) (CPPS) are studied using thermogravimetry analysis (TGA). The CPPS is subjected to TGA in an air and nitrogen atmosphere at heating rates from 5 to 40°C min--1. The TGA curves obtained in air are different from those in nitrogen. This demonstrates that weight loss occurs in a single stage in nitrogen but in two stages in air. To elucidate this difference, thermal decomposition kinetics is analyzed by applying the Kissinger, Flynn-Wall-Ozawa, Coat-Redfern and

Simulation of the Vacuum Assisted Resin Transfer Molding (VARTM) process and the development of light-weight composite bridging

Science.gov (United States)

Robinson, Marc J.

A continued desire for increased mobility in the aftermath of natural disasters, or on the battlefield, has lead to the need for improved light-weight bridging solutions. This research investigates the development of a carbon/epoxy composite bridging system to meet the needs for light-weight bridging. The research focuses on two main topics. The first topic is that of processing composite structures and the second is the design and testing of these structures. In recent years the Vacuum Assisted Resin Transfer Molding (VARTM) process has become recognized as a low-cost manufacturing alternative for large Fiber Reinforced Polymer (FRP) composite structures for civil, military, and aerospace applications. The success of the VARTM process (complete wet-out) is very sensitive to the resin injection strategy used and the proper placement of flow distribution materials and inlet and vacuum ports. Predicting the flow front pattern, the time required for infusing a part with resin, and the time required to bleed excess resin at the end of filling, is critical to ensure that the part will become completely impregnated and desired fiber volume fractions achieved prior to the resin gelling (initiation of cure). In order to eliminate costly trial and error experiments to determine the optimal infusion strategy, this research presents a simulation model which considers in-plane flow as well as flow through the thickness of the preform. In addition to resin filling, the current model is able to simulate the bleeding of resin at the end of filling to predict the required bleeding time to reach desired fiber volume fractions for the final part. In addition to processing, the second portion of the dissertation investigates the design and testing of composite bridge deck sections which also serve as short-span bridging for gaps up to 4 m in length. The research focuses on the design of a light-weight core material for bridge decking as well as proof loading of short-span bridge

Uranium and sulphate values from carbonate leach process

International Nuclear Information System (INIS)

Berger, B.

1983-01-01

The process concerns the recovery of uraniferous and sulphur values from liquor resulting from the attack of sulphur containing uraniferous ores by an alkaline solution of sodium carbonate and/or bicarbonate. Ammonia is introduced into the liquor to convert any HCO 3 - to CO 3 2- . The neutralised liquor from this step is then contacted with an anion exchange resin to fix the uranium and sulphate ions, leaving a liquor containing ammonia, sodium carbonate and/or bicarbonate in solution. Uranium and sulphate ions are eluted with an ammonia carbonate and/or bicarbonate solution to yield a solution of ammonium uranyl carbonate complex and ammonium sulphate. The solution is subjected to thermal treatment until a suspension of precipitated ammonium uranate and/or diuranate is obtained in a solution of the ammonium sulphate. Carbon dioxide, ammonia and water vapor are driven off. The precipitated ammonium uranate and/or diuranate is then separated from the solution of ammonium sulphate and the precipitate is calcined to yield uranium trioxide and ammonia

Hierarchical activated mesoporous phenolic-resin-based carbons for supercapacitors.

Science.gov (United States)

Wang, Zhao; Zhou, Min; Chen, Hao; Jiang, Jingui; Guan, Shiyou

2014-10-01

A series of hierarchical activated mesoporous carbons (AMCs) were prepared by the activation of highly ordered, body-centered cubic mesoporous phenolic-resin-based carbon with KOH. The effect of the KOH/carbon-weight ratio on the textural properties and capacitive performance of the AMCs was investigated in detail. An AMC prepared with a KOH/carbon-weight ratio of 6:1 possessed the largest specific surface area (1118 m(2) g(-1)), with retention of the ordered mesoporous structure, and exhibited the highest specific capacitance of 260 F g(-1) at a current density of 0.1 A g(-1) in 1 M H2 SO4 aqueous electrolyte. This material also showed excellent rate capability (163 F g(-1) retained at 20 A g(-1)) and good long-term electrochemical stability. This superior capacitive performance could be attributed to a large specific surface area and an optimized micro-mesopore structure, which not only increased the effective specific surface area for charge storage but also provided a favorable pathway for efficient ion transport. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Quantum-CEP processing spent ion exchange resins from nuclear power stations

International Nuclear Information System (INIS)

Kaczmarsky, Myron

1997-01-01

Quantum-CEP (Q-CEP) is an innovative and proprietary technology developed by Molten Metal Technology, Inc, which can process radioactive and mixed waste streams to decontaminate and recover resources of commercial value while achieving significant volume reduction and radionuclide stabilization. A Q-CEP facility, located in Oak Ridge, Tennessee, processes low-level radioactive spent ion exchange resins (IER) from U.S commercial nuclear power plants. The first campaign processing low level radioactive spent IER was successfully completed in December 1996. Other milestones, since December, include operating parallel Trains A and B simultaneously and processing 25,000 lb. dry resin (50,000 lb. wet resin) or six equivalent High Integrity Containers (HICs) in one batch campaign, in March; and processing 50,000 lb. dry resin or 12 equivalent HICs in one batch campaign in May. This paper presents results from the March campaign (97-008) in which 25,000 lb. of dry spent IER from five nuclear power stations were processed. This campaign has been selected since it is representative of campaigns completed during the first five months of operation. Key highlights for this campaign include processing six HICs in batch campaign while achieving a volume reduction of 24: 1. Key performance targets for the facility are to process an average of six HICs per campaign batch and achieve a volume reduction of 30: 1. The average batch size and other performance parameters have steadily improved during the initial operating period with radioactive resin. The progress was dramatically demonstrated by the May campaign during which 12 HICs were processed - achieving a volume reduction estimated to exceed 50: 1. The campaigns in March and May demonstrate that the facility's design and technology are capable of achieving and even exceeding the facility's key target performance parameters

Evaluating the use of amber in palaeoatmospheric reconstructions: The carbon-isotope variability of modern and Cretaceous conifer resins

Science.gov (United States)

Dal Corso, Jacopo; Schmidt, Alexander R.; Seyfullah, Leyla J.; Preto, Nereo; Ragazzi, Eugenio; Jenkyns, Hugh C.; Delclòs, Xavier; Néraudeau, Didier; Roghi, Guido

2017-02-01

Stable carbon-isotope geochemistry of fossilized tree resin (amber) potentially could be a very useful tool to infer the composition of past atmospheres. To test the reliability of amber as a proxy for the atmosphere, we studied the variability of modern resin δ13C at both local and global scales. An amber δ13C curve was then built for the Cretaceous, a period of abundant resin production, and interpreted in light of data from modern resins. Our data show that hardening changes the pristine δ13C value by causing a 13C-depletion in solid resin when compared to fresh liquid-viscous resin, probably due to the loss of 13C-enriched volatiles. Modern resin δ13C values vary as a function of physiological and environmental parameters in ways that are similar to those described for leaves and wood. Resin δ13C varies between plant species and localities, within the same tree and between different plant tissues by up to 6‰, and in general increases with increasing altitudes of the plant-growing site. We show that, as is the case with modern resin, Cretaceous amber δ13C has a high variability, generally higher than that of other fossil material. Despite the high natural variability, amber shows a negative 2.5-3‰ δ13C trend from the middle Early Cretaceous to the Maastrichtian that parallels published terrestrial δ13C records. This trend mirrors changes in the atmospheric δ13C calculated from the δ13C and δ18O of benthic foraminiferal tests, although the magnitude of the shift is larger in plant material than in the atmosphere. Increasing mean annual precipitation and pO2 could have enhanced plant carbon-isotope fractionation during the Late Cretaceous, whereas changing pCO2 levels seem to have had no effect on plant carbon-isotope fractionation. The results of this study suggest that amber is a powerful fossil plant material for palaeoenvironmental and palaeoclimatic reconstructions. Improvement of the resolution of the existing data coupled with more detailed

HPLC Characterization of Phenol-Formaldehyde Resole Resin Used in Fabrication of Shuttle Booster Nozzles

Science.gov (United States)

Young, Philip R.

1999-01-01

A reverse phase High Performance Liquid Chromatographic method was developed to rapidly fingerprint a phenol-formaldehyde resole resin similar to Durite(R) SC-1008. This resin is used in the fabrication of carbon-carbon composite materials from which Space Shuttle Solid Rocket Booster nozzles are manufactured. A knowledge of resin chemistry is essential to successful composite processing and performance. The results indicate that a high quality separation of over 35 peaks in 25 minutes were obtained using a 15 cm Phenomenex LUNA C8 bonded reverse phase column, a three-way water-acetonitrile-methanol nonlinear gradient, and LTV detection at 280 nm.

Reducing resin use in floor drain processing system

International Nuclear Information System (INIS)

Flint, W.; Hobart, S.A.; Miller, A.D.

1995-01-01

The Kewaunee Nuclear Power Plant utilizes two mixed bed demineralizers for processing floor drain wastes. These demineralizers were originally designed for stream generator blowdown treatment, but were not needed for that purpose. Effluent from the resin beds is monitored for radioactivity and released for discharge. Plant radwaste inleakage volumes and resin disposal volumes were low in comparison with industry averages, but decontamination factors through the treatment system were less than desirable. Release criteria for discharges always had been met, but plant personnel wished to decrease their already low discharges of radioactive species, reduce their resin disposal costs, and provide a margin of safety in the unlikely event that fuel damage would be experienced during an operating cycle. This paper describes the study initiated to address those issues, the findings of the study, and results of implementing some of the study recommendations

Thermosetting behavior of pitch-resin from heavy residue

Energy Technology Data Exchange (ETDEWEB)

Qingfang, Z.; Yansheng, G.; Baohua, H.; Yuzhen, Z. [China Univ. of Petroleum, Dongying, Shandong (China). State Key LAboratory of Heavy Oil Processing, Heavy Oil Research Inst.

2006-07-01

Thermosetting resins are widely employed as a basic matrix for c/c composites in carbon materials production. A new type of synthesized thermosetting resin is called pitch resin. Pitch resin is a cheaper resin and possesses a potential opportunity for future use. However, the thermosetting behavior of pitch resin is not very clear. The hardening process and conditions for thermosetting are very important for future use of pitch resin. B-stage pitch resin is a soluble and meltable inter-media condensed polymer, which is not fully reacted and is of a low molecular weight. The insoluble and unmelted pitch resin can only be obtained from synthesized B-stage resin after a hardening stage. This paper presented an experiment that synthesized B-stage pitch resin with a link agent (PXG) under catalyst action from fluid catalytic cracking (FCC) of the slurry's aromatic enriched component (FCCDF). The paper discussed the experiment, including the synthesis of pitch resin and thermosetting of pitch resin. Two kinds of thermosetting procedures were used in the study called one-step thermosetting and two-step thermosetting. It was concluded that the B-stage pitch resin could be hardened after a thermosetting procedure by heat treatment. The thermosetting pitch resin from 2-step thermosetting possesses was found to have better thermal resistant properties than that of the 1-step thermosetting pitch resin. 13 refs., 2 tabs., 6 figs.

A summary of methods for conditioning and immobilizing ion-exchange resins

International Nuclear Information System (INIS)

Speranzini, R.A.; Buckley, L.P.

1983-02-01

Ion-exchange resins are used in CANDU-PHW nuclear power stations to purify heavy water in the primary heat transport (PHT) and moderator systems. Two promising techniques for conditioning spent ion-exchange resins for disposal have been evaluated: direct immobilization and incineration combined with immobilization of the ash and scrubbed off-gases. When ion-exchange resins were immobilized directly, volumes of bitumen products were about 0.75 times the volumes of untreated resin, while the volumes of cement and polyester products were 2 to 3 times larger. While incinerating the resin is an extra processing step, much smaller volumes result from the latter option. Bitumen and glass product volumes were six and ten times smaller, respectively, than the volumes of untreated resin, while cement and polyester product volumes were about one-half the volume of untreated resin. Since the releases of Cs-136 by leaching were lowest for products made by immobilization in glass, PHT resins which have high concentrations of Cs-137 should be vitrified. Moderator resins which have high concentrations of C-14 should be incinerated and the ash and C-14-contaminated scrubbing solutions should be immobilized. By pretreating such resins with calcium chloride or carbon dioxide, the C-14 present on resin could be released at temperatures below the ignition temperature of the resin. The pretreatment technique reduces the amount of inactive carbon dioxide that must be scrubbed to trap the C-14. The releases of C-14 from immobilized barium hydroxide scrubbing solution were the same as releases from immobilized resin

Iodine adsorption on ion-exchange resins and activated carbons: batch testing

Energy Technology Data Exchange (ETDEWEB)

Parker, Kent E.; Golovich, Elizabeth C.; Wellman, Dawn M.

2014-09-30

Iodine sorption onto seven resins and six carbon materials was evaluated using water from well 299-W19-36 on the Hanford Site. These materials were tested using a range of solution-to-solid ratios. The test results are as follows. The efficacy of the resin and granular activated carbon materials was less than predicted based on manufacturers’ performance data. It is hypothesized that this is due to the differences in speciation previously determined for Hanford groundwater. The sorption of iodine is affected by the iodine species in the source water. Iodine loading on resins using source water ranged from 1.47 to 1.70 µg/g with the corresponding K_d values from 189.9 to 227.0 mL/g. The sorption values when the iodine is converted to iodide ranged from 2.75 to 5.90 µg/g with the corresponding K_d values from 536.3 to 2979.6 mL/g. It is recommended that methods to convert iodine to iodide be investigated in fiscal year (FY) 2015. The chemicals used to convert iodine to iodate adversely affected the sorption of iodine onto the carbon materials. Using as-received source water, loading and K_d values ranged from 1.47 to 1.70 µg/g and 189.8 to 226.3 mL/g respectively. After treatment, loading and K_d values could not be calculated because there was little change between the initial and final iodine concentration. It is recommended the cause of the decrease in iodine sorption be investigated in FY15. In direct support of CH2M HILL Plateau Remediation Company, Pacific Northwest National Laboratory has evaluated samples from within the 200W pump and treat bioreactors. As part of this analysis, pictures taken within the bioreactor reveal a precipitate that, based on physical properties and known aqueous chemistry, is hypothesized to be iron pyrite or chalcopyrite, which could affect iodine adsorption. It is recommended these materials be tested at different solution-to-solid ratios in FY15 to determine their effect on iodine

Iodine adsorption on ion-exchange resins and activated carbons: batch testing

International Nuclear Information System (INIS)

Parker, Kent E.; Golovich, Elizabeth C.; Wellman, Dawn M.

2014-01-01

Iodine sorption onto seven resins and six carbon materials was evaluated using water from well 299-W19-36 on the Hanford Site. These materials were tested using a range of solution-to-solid ratios. The test results are as follows. The efficacy of the resin and granular activated carbon materials was less than predicted based on manufacturers' performance data. It is hypothesized that this is due to the differences in speciation previously determined for Hanford groundwater. The sorption of iodine is affected by the iodine species in the source water. Iodine loading on resins using source water ranged from 1.47 to 1.70 µg/g with the corresponding K d values from 189.9 to 227.0 mL/g. The sorption values when the iodine is converted to iodide ranged from 2.75 to 5.90 µg/g with the corresponding K d values from 536.3 to 2979.6 mL/g. It is recommended that methods to convert iodine to iodide be investigated in fiscal year (FY) 2015. The chemicals used to convert iodine to iodate adversely affected the sorption of iodine onto the carbon materials. Using as-received source water, loading and K d values ranged from 1.47 to 1.70 µg/g and 189.8 to 226.3 mL/g respectively. After treatment, loading and K d values could not be calculated because there was little change between the initial and final iodine concentration. It is recommended the cause of the decrease in iodine sorption be investigated in FY15. In direct support of CH2M HILL Plateau Remediation Company, Pacific Northwest National Laboratory has evaluated samples from within the 200W pump and treat bioreactors. As part of this analysis, pictures taken within the bioreactor reveal a precipitate that, based on physical properties and known aqueous chemistry, is hypothesized to be iron pyrite or chalcopyrite, which could affect iodine adsorption. It is recommended these materials be tested at different solution-to-solid ratios in FY15 to determine their effect on iodine sorption.

Research and development for decontamination system of spent resin in Hanbit Nuclear Power Plant

Energy Technology Data Exchange (ETDEWEB)

Sung, Gi Hong [Dept. of Nuclear Engineering, Chosun University, Gwangju (Korea, Republic of)

2015-12-15

When reactor coolant leaks occur due to cracks of a steam generator tube, radioactive materials contained in the primary cooling water in nuclear power plant are forced out toward the secondary systems. At this time the secondary water purification resin in the ion exchange resin tower of the steam generator blowdown system is contaminated by the radioactivity of the leaked radioactive materials, so we pack this in special containers and store temporarily because we could not dispose it by ourselves. If steam generator tube leakage occurs, it produces contaminated spent resins annually about 5,000-7,000 liters. This may increase the amount of nuclear waste productions, a disposal working cost and a unit price of generating electricity in the plant. For this reasons, it is required to develop a decontamination process technique for reducing the radioactive level of these resins enough to handle by the self-disposal method. In this research, First, Investigated the structure and properties of the ion exchange resin used in a steam generator blowdown system. Second, Checked for a occurrence status of contaminated spent resin and a disposal technology. Third, identified the chemical characteristics of the waste radionuclides of the spent resin, and examined ionic bonding and separation mechanism of radioactive nuclear species and a spent resin. Finally, we carried out the decontamination experiment using chemicals, ultrasound, microbubbles, supercritical carbon dioxide to process these spent resin. In the case of the spent resin decontamination method using chemicals, the higher the concentration of the drug decontamination efficiency was higher. In the ultrasound method, foreign matter of the spent resin was removed and was found that the level of radioactivity is below of the MDA. In the microbubbles method, we found that the concentration of the radioactivity decreased after the experiment, so it can be used to the decontamination process of the spent resin. In

Research and development for decontamination system of spent resin in Hanbit Nuclear Power Plant

International Nuclear Information System (INIS)

Sung, Gi Hong

2015-01-01

When reactor coolant leaks occur due to cracks of a steam generator tube, radioactive materials contained in the primary cooling water in nuclear power plant are forced out toward the secondary systems. At this time the secondary water purification resin in the ion exchange resin tower of the steam generator blowdown system is contaminated by the radioactivity of the leaked radioactive materials, so we pack this in special containers and store temporarily because we could not dispose it by ourselves. If steam generator tube leakage occurs, it produces contaminated spent resins annually about 5,000-7,000 liters. This may increase the amount of nuclear waste productions, a disposal working cost and a unit price of generating electricity in the plant. For this reasons, it is required to develop a decontamination process technique for reducing the radioactive level of these resins enough to handle by the self-disposal method. In this research, First, Investigated the structure and properties of the ion exchange resin used in a steam generator blowdown system. Second, Checked for a occurrence status of contaminated spent resin and a disposal technology. Third, identified the chemical characteristics of the waste radionuclides of the spent resin, and examined ionic bonding and separation mechanism of radioactive nuclear species and a spent resin. Finally, we carried out the decontamination experiment using chemicals, ultrasound, microbubbles, supercritical carbon dioxide to process these spent resin. In the case of the spent resin decontamination method using chemicals, the higher the concentration of the drug decontamination efficiency was higher. In the ultrasound method, foreign matter of the spent resin was removed and was found that the level of radioactivity is below of the MDA. In the microbubbles method, we found that the concentration of the radioactivity decreased after the experiment, so it can be used to the decontamination process of the spent resin. In

DEVELOPMENT OF A METHOD STATISTICAL ANALYSIS ACCURACY AND PROCESS STABILITY PRODUCTION OF EPOXY RESIN ED-20

Directory of Open Access Journals (Sweden)

N. V. Zhelninskaya

2015-01-01

Full Text Available Statistical methods play an important role in the objective evaluation of quantitative and qualitative characteristics of the process and are one of the most important elements of the quality assurance system production and total quality management process. To produce a quality product, one must know the real accuracy of existing equipment, to determine compliance with the accuracy of a selected technological process specified accuracy products, assess process stability. Most of the random events in life, particularly in manufacturing and scientific research, are characterized by the presence of a large number of random factors, is described by a normal distribution, which is the main in many practical studies. Modern statistical methods is quite difficult to grasp and wide practical use without in-depth mathematical training of all participants in the process. When we know the distribution of a random variable, you can get all the features of this batch of products, to determine the mean value and the variance. Using statistical control methods and quality control in the analysis of accuracy and stability of the technological process of production of epoxy resin ED20. Estimated numerical characteristics of the law of distribution of controlled parameters and determined the percentage of defects of the investigated object products. For sustainability assessment of manufacturing process of epoxy resin ED-20 selected Shewhart control charts, using quantitative data, maps of individual values of X and sliding scale R. Using Pareto charts identify the causes that affect low dynamic viscosity in the largest extent. For the analysis of low values of dynamic viscosity were the causes of defects using Ishikawa diagrams, which shows the most typical factors of the variability of the results of the process. To resolve the problem, it is recommended to modify the polymer composition of carbon fullerenes and to use the developed method for the production of

Optimal Design for Hybrid Ratio of Carbon/Basalt Hybrid Fiber Reinforced Resin Matrix Composites

Directory of Open Access Journals (Sweden)

XU Hong

2017-08-01

Full Text Available The optimum hybrid ratio range of carbon/basalt hybrid fiber reinforced resin composites was studied. Hybrid fiber composites with nine different hybrid ratios were prepared before tensile test.According to the structural features of plain weave, the unit cell's performance parameters were calculated. Finite element model was established by using SHELL181 in ANSYS. The simulated values of the sample stiffness in the model were approximately similar to the experimental ones. The stress nephogram shows that there is a critical hybrid ratio which divides the failure mechanism of HFRP into single failure state and multiple failure state. The tensile modulus, strength and limit tensile strain of HFRP with 45% resin are simulated by finite element method. The result shows that the tensile modulus of HFRP with 60% hybrid ratio increases by 93.4% compared with basalt fiber composites (BFRP, and the limit tensile strain increases by 11.3% compared with carbon fiber composites(CFRP.

Attribute Based Selection of Thermoplastic Resin for Vacuum Infusion Process: A Decision Making Methodology

DEFF Research Database (Denmark)

Raghavalu Thirumalai, Durai Prabhakaran; Lystrup, Aage; Løgstrup Andersen, Tom

2012-01-01

The composite industry looks toward a new material system (resins) based on thermoplastic polymers for the vacuum infusion process, similar to the infusion process using thermosetting polymers. A large number of thermoplastics are available in the market with a variety of properties suitable...... be beneficial. In this paper, the authors introduce a new decision making tool for resin selection based on significant attributes. This article provides a broad overview of suitable thermoplastic material systems for vacuum infusion process available in today’s market. An illustrative example—resin selection...... for vacuum infused of a wind turbine blade—is shown to demonstrate the intricacies involved in the proposed methodology for resin selection....

Purification of degraded TBP solvent using macroreticular anion exchange resin

International Nuclear Information System (INIS)

Kartha, P.K.S.; Kutty, P.V.E.; Janaradanan, C.; Ramanujam, A.; Dhumwad, R.K.

1989-01-01

Tri-n-butyl phosphate (TBP) diluted with a suitable diluent is commonly used for solvent extraction in Purex process for the recovery of uranium and plutonium from irradiated nuclear fuels. This solvent gets degraded due to various factors, the main degradation product being dibutyl phosphoric acid (HDBP). A solvent cleanup step is generally incorporated in the process for removing the degradation products from the used solvent. A liquid-liquid cleanup system using sodium carbonate or sodium hydroxide solution is routinely used. Considering certain advantages, like the possibility of loading the resin almost to saturation capacity and the subsequent disposal of the spent resin by incineration and the feasibility of adopting it to the process, a liquid-solid system has been tried as an alternate method, employing various available macroreticular anion exchange resins in OH - form for the sorption of HDBP from TBP. After standardizing the various conditions for the satisfactory removal of HDBP from TBP using synthetic mixtures, resins were tested with process solvent in batch contacts. The parameters studied were (1) capacity of different resins for HDBP sorption (2) influence of acidity, uranium and HDBP on the sorption behaviour of the latter (3) removal of fission products from the solvent by the resin and (4) regeneration and recycling of the resin. (author). 2 figs., 13 tabs., 17 refs

Ultrafiltration Membrane Fouling and the Effect of Ion Exchange Resins

KAUST Repository

Jamaly, Sanaa

2011-12-01

Membrane fouling is a challenging process for the ultrafiltration membrane during wastewater treatment. This research paper determines the organic character of foulants of different kinds of wastewater before and after adding some ion exchange resins. Two advanced organic characterization methods are compared in terms of concentration of dissolved organic carbons: The liquid chromatography with organic carbon (LC-OCD) and Shimadzu total organic carbon (TOC). In this study, two secondary wastewater effluents were treated using ultrafiltration membrane. To reduce fouling, pretreatment using some adsorbents were used in the study. Six ion exchange resins out of twenty were chosen to compare the effect of adsorbents on fouling membrane. Based on the percent of dissolved organic carbon’s removal, three adsorbents were determined to be the most efficient (DOWEX Marathon 11 anion exchange resin, DOWEX Optipore SD2 polymeric adsorbent, and DOWEX PSR2 anion exchange), and three other ones were determined to the least efficient (DOWEX Marathon A2 anion exchange resin, DOWEX SAR anion exchange resin, and DOWEX Optipore L493 polymeric adsorbent). Organic characterization for feed, permeate, and backwash samples were tested using LC-OCD and TOC to better understand the characteristics of foulants to prevent ultrafiltration membrane fouling. The results suggested that the polymeric ion exchange resin, DOWEX SD2, reduced fouling potential for both treated wastewaters. All the six ion exchange resins removed more humic fraction than other organic fractions in different percent, so this fraction is not the main for cause for UF membrane fouling. The fouling of colloids was tested before and after adding calcium. There is a severe fouling after adding Ca2+ to effluent colloids.

The resin-in-pulp process and its application to ores from Brosses ''BRS 10''; Le procede resin in pulp et son application aux minerais des Brosses ''BRS 10''

Energy Technology Data Exchange (ETDEWEB)

Kremer, M

1959-03-01

The resin-in-pulp process is a technical variant of the recovery process of uranium in dilute solution by means of ion exchanger resins. An anion resin, XE 123, of a well-defined grain size is placed in direct contact with the pulp produced by sulfuric acid attack on ore with a low uranium content. This process is of particular value in the treatment of pulps that cannot be filtered or decanted, such as those obtained with ore from Brosses. The preparation of the pulp, the elution of the uranium, and its fixation, as well as the various factors encountered in these operations, are discussed. (author) [French] Le procede ''resin in pulp'' est une variante technique du procede de recuperation de l'uranium en solution diluee par les resines echangeuses d'ions. Une resine anionique, la 'XE 123' a granulometrie bien determinee, est mise en contact direct avec la pulpe provenant de l'attaque a l'acide sulfurique d'un minerai d'uranium a faible teneur. Ce procede est particulierement interessant dans le cas de pulpes infiltrables ou indecantables, telles que celles obtenues dans l'attaque du minerai des Brosses. La preparation de la pulpe, la fixation et l'elution de l'uranium, ainsi que les facteurs intervenant dans ces diverses operations sont etudies dans le present rapport. (auteur)

Coupling of Spinosad Fermentation and Separation Process via Two-Step Macroporous Resin Adsorption Method.

Science.gov (United States)

Zhao, Fanglong; Zhang, Chuanbo; Yin, Jing; Shen, Yueqi; Lu, Wenyu

2015-08-01

In this paper, a two-step resin adsorption technology was investigated for spinosad production and separation as follows: the first step resin addition into the fermentor at early cultivation period to decrease the timely product concentration in the broth; the second step of resin addition was used after fermentation to adsorb and extract the spinosad. Based on this, a two-step macroporous resin adsorption-membrane separation process for spinosad fermentation, separation, and purification was established. Spinosad concentration in 5-L fermentor increased by 14.45 % after adding 50 g/L macroporous at the beginning of fermentation. The established two-step macroporous resin adsorption-membrane separation process got the 95.43 % purity and 87 % yield for spinosad, which were both higher than that of the conventional crystallization of spinosad from aqueous phase that were 93.23 and 79.15 % separately. The two-step macroporous resin adsorption method has not only carried out the coupling of spinosad fermentation and separation but also increased spinosad productivity. In addition, the two-step macroporous resin adsorption-membrane separation process performs better in spinosad yield and purity.

Vitrification of ion-exchange (IEX) resins: Advantages and technical challenges

International Nuclear Information System (INIS)

Jantzen, C.M.; Peeler, D.K.; Cicero, C.A.

1995-01-01

Technologies are being developed by the US Department of Energy's (DOE) Savannah River Site (SRS) in conjunction with the Electric Power Research Institute (EPRI) and the commercial sector to convert low-level radioactive ion exchange (IEX) resin wastes from the nuclear utilities to solid stabilized waste forms for permanent disposal. One of the alternative waste stabilization technologies is vitrification of the resin into glass. Wastes can be vitrified at elevated temperatures by thermal treatment. One alternative thermal treatment is conventional Joule heated melting. Vitrification of wastes into glass is an attractive option because it atomistically bonds both hazardous and radioactive species in the glass structure, and volume reduces the wastes by 70-80%. The large volume reductions allow for large associated savings in disposal and/or long term storage costs

[Studies on the process of Herba Clinopodii saponins purified with macroporous adsorption resin].

Science.gov (United States)

Zhang, Yi; Yan, Dan; Han, Yumei

2005-10-01

To study the technological parameters of the purification process of saponins with macroporous adsorption resin. The adsorptive characteristics and elutive parameters of the process were studied by taking the elutive and purified ratio of saponins as markers. 11.4 ml of the extraction of Herba Clinopodii (crude drugs 0.2 g/ml) was purified with a column of macroporous adsorption resin (phi15 mm x H90 mm, dry weight 2.5 g) and washed with 3BV of distilled water, then eluted with 3BV of 30% ethanol and 3BV of 70% ethanol. Most of saponins were collected in the 70% ethanol. With macroporous adsorption resin adsorbing and purifying,the elutive ratio of saponins is 86.8% and the purity reaches 153.2%. So this process of applying macroporous adsorption resin to adsorb and purify Saponins is feasible.

Atomistic Modeling of Corrosion Events at the Interface between a Metal and Its Environment

Directory of Open Access Journals (Sweden)

Christopher D. Taylor

2012-01-01

Full Text Available Atomistic simulation is a powerful tool for probing the structure and properties of materials and the nature of chemical reactions. Corrosion is a complex process that involves chemical reactions occurring at the interface between a material and its environment and is, therefore, highly suited to study by atomistic modeling techniques. In this paper, the complex nature of corrosion processes and mechanisms is briefly reviewed. Various atomistic methods for exploring corrosion mechanisms are then described, and recent applications in the literature surveyed. Several instances of the application of atomistic modeling to corrosion science are then reviewed in detail, including studies of the metal-water interface, the reaction of water on electrified metallic interfaces, the dissolution of metal atoms from metallic surfaces, and the role of competitive adsorption in controlling the chemical nature and structure of a metallic surface. Some perspectives are then given concerning the future of atomistic modeling in the field of corrosion science.

The PILO process: zeolites and titanates in the treatment of spent ion exchange resins

International Nuclear Information System (INIS)

Hultgren, Aa.; Thegerstroem, C.; Forberg, S.; Westermark, T.; Faelt, L.

1981-01-01

Spent ion exchange resins from power reactor operation contain more than 95% of the total radioactivity of wet reactor wastes. Cementation and bituminization are the two methods applied in Sweden up to now for the immobilization of spent resins. Over the last years, however, research and development work has resulted in a proposed process (PILO), where > 99.9 % of cesium and strontium and around 90 % of other radioactive nuclides are eluted from the spent resins and sorbed in zeolites and titanates in a chromatographic process. The inorganic sorbents are dried after loading and sintered to yield long-term stable products, while the treated resins may be incinerated to give ash residues of fairly short-lived activity. The development work has included production, characterization and testing of different zeolites and titanates, bench-scale optimization of the chromatographic process using actual spent resins, heat treatment of the loaded inorganic sorbents, and resin incineration. Over-all system design studies including transport requirements, integrated process flowsheets, and cost estimates are now in progress. The aim is to have a sufficient basis during spring 1982 to decide on the merits of a PILO plant at the planned repository for low and medium level waste (SFR), to be commissioned in 1988. (Auth.)

Prediction of Material Properties of Nanostructured Polymer Composites Using Atomistic Simulations

Science.gov (United States)

Hinkley, J.A.; Clancy, T.C.; Frankland, S.J.V.

2009-01-01

Atomistic models of epoxy polymers were built in order to assess the effect of structure at the nanometer scale on the resulting bulk properties such as elastic modulus and thermal conductivity. Atomistic models of both bulk polymer and carbon nanotube polymer composites were built. For the bulk models, the effect of moisture content and temperature on the resulting elastic constants was calculated. A relatively consistent decrease in modulus was seen with increasing temperature. The dependence of modulus on moisture content was less consistent. This behavior was seen for two different epoxy systems, one containing a difunctional epoxy molecule and the other a tetrafunctional epoxy molecule. Both epoxy structures were crosslinked with diamine curing agents. Multifunctional properties were calculated with the nanocomposite models. Molecular dynamics simulation was used to estimate the interfacial thermal (Kapitza) resistance between the carbon nanotube and the surrounding epoxy matrix. These estimated values were used in a multiscale model in order to predict the thermal conductivity of a nanocomposite as a function of the nanometer scaled molecular structure.

Synthesis of Y2O3-ZrO2-SiO2 composite coatings on carbon fiber reinforced resin matrix composite by an electro-plasma process

Science.gov (United States)

Zhang, Yuping; Lin, Xiang; Chen, Weiwei; Cheng, Huanwu; Wang, Lu

2016-05-01

In the present paper the Y2O3-ZrO2-SiO2 composite coating was successfully synthesized on carbon fiber reinforced resin matrix composite by an electro-plasma process. The deposition process, microstructures and oxidation resistance of the coatings with different SiO2 concentrations were systematically investigated. A relatively dense microstructure was observed for the Y2O3-ZrO2-SiO2 composite coating with the SiO2 concentration above 5 g/L. The coating exhibited very good oxidation resistance at 1273 K with the mass loss rate as low as ∼30 wt.%, compared to 100 wt.% of the substrate. The formation of the ceramic composites was discussed in detail based on the electrochemical mechanism and the deposition dynamics in order to explain the effect of the plasma discharge. We believe that the electro-plasma process will find wide applications in preparing ceramics and coatings in industries.

Effect of neutron irradiation on the dimension and the strength of carbon fiber/carbon composite derived from thermosetting resin precursor

International Nuclear Information System (INIS)

Yasuda, Eiichi; Tanabe, Yasuhiro; Kimura, Shiushichi; Maruyama, Tadashi; Iseki, Takayoshi; Yano, Toyohiko.

1988-01-01

Unidirectionally reinforced carbon fiber/carbon composite whose matrix was derived from thermosetting resin, was prepared. The heat-treatment temperature was 2800 deg C. The change in size and 4 point bending strength of the composite was measured after neutron irradiation (640 deg C, 6 x 10 24 n/m 2 , E > 1 MeV). Shrinkage in normal to the fiber direction was larger than that in fiber direction. Increase in strength and Young's modulus of the composite was observed after irradiation. Irradiated composite showed much higher deflection to fracture than unirradiated one. (author)

Thermal effect of laser ablation on the surface of carbon fiber reinforced plastic during laser processing

Science.gov (United States)

Ohkubo, Tomomasa; Sato, Yuji; Matsunaga, Ei-ichi; Tsukamoto, Masahiro

2018-02-01

Although laser processing is widely used for many applications, the cutting quality of carbon fiber reinforced plastic (CFRP) decreases around the heat-affected zone (HAZ) during laser processing. Carbon fibers are exposed around the HAZ, and tensile strength decreases with increasing length of the HAZ. Some theoretical studies of thermal conductions that do not consider fluid dynamics have been performed; however, theoretical considerations that include the dynamics of laser ablation are scarce. Using removed mass and depth observed from experiments, the dynamics of laser ablation of CFRP with high-temperature and high-pressure of compressive gas is simulated herein. In this calculation, the mushroom-like shape of laser ablation is qualitatively simulated compared with experiments using a high-speed camera. Considering the removal temperature of the resin and the temperature distribution at each point on the surface, the simulation results suggest that a wide area of the resin is removed when the processing depth is shallow, and a rounded kerf is generated as the processing depth increases.

Special Resins for Stereolithography: In Situ Generation of Silver Nanoparticles

Directory of Open Access Journals (Sweden)

Gabriele Taormina

2018-02-01

Full Text Available The limited availability of materials with special properties represents one of the main limitations to a wider application of polymer-based additive manufacturing technologies. Filled resins are usually not suitable for vat photo-polymerization techniques such as stereolithography (SLA or digital light processing (DLP due to a strong increment of viscosity derived from the presence of rigid particles within the reactive suspension. In the present paper, the possibility to in situ generate silver nanoparticles (AgNPs starting from a homogeneous liquid system containing a well dispersed silver salt, which is subsequently reduced to metallic silver during stereolithographic process, is reported. The simultaneous photo-induced cross-linking of the acrylic resin produces a filled thermoset resin with thermal-mechanical properties significantly enhanced with respect to the unfilled resin, even at very low AgNPs concentrations. With this approach, the use of silver salts having carbon-carbon double bonds, such as silver acrylate and silver methacrylate, allows the formation of a nanocomposite structure in which the release of by-products is minimized due to the active role of all the reactive components in the three dimensional (3D-printing processes. The synergy, between this nano-technology and the geometrical freedom offered by SLA, could open up a wide spectrum of potential applications for such a material, for example in the field of food packaging and medical and healthcare sectors, considering the well-known antimicrobial effects of silver nanoparticles.

Effect of silica concentration on electrical conductivity of epoxy resin-carbon black-silica nanocomposites

International Nuclear Information System (INIS)

Zhang Wei; Blackburn, Richard S.; Dehghani-Sanij, Abbas A.

2007-01-01

Electrical properties of nanocomposites are determined by the conductive paths of carbon black and influenced by a 'network' of silica. With increasing content of silica, carbon black (CB) particles are optimally dispersed, contributing to the generation of a conductive network between CB particles via direct particle contact and a tunneling effect; maximum conductivity for the epoxy resin-CB-silica nanocomposite described herein occurs at a ratio of 0.6:1.0 (SiO 2 :CB). As a non-conductive component, excessive silica will prevent electron flow, giving rise to low conductivity

Epoxy resin/phosphonium ionic liquid/carbon nanofiller systems: Chemorheology and properties

Directory of Open Access Journals (Sweden)

H. Maka

2014-10-01

Full Text Available Epoxy nanocomposites with commercial carbon nanotubes (CNT or graphene (GN have been prepared using phosphonium ionic liquid [trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl phosphinate, IL-f]. IL-f served simultaneously as nanofiller dispersing medium and epoxy resin catalytic curing agent. An influence of IL-f/epoxy weight ratio (3, 6 and 9/100, phr, carbon nanofiller type and content on viscosity of epoxy compositions during storage at ambient temperature was evaluated. Curing process was controlled for neat and CNT or GN modified epoxy compositions (0.25-1.0 wt.% load using differential scanning calorimetry and rheometry. Epoxy nanocomposites exhibited slightly increased glass transition temperature values (146 to 149°C whereas tan δ and storage modulus decreased (0.30 to 0.27 and 2087 to 1070 MPa, respectively as compared to reference material. Crosslink density regularly decreased for composites with increasing CNT content (11 094 to 7 020 mol/m3. Electrical volume resistivity of the nanocomposites was improved in case of CNT to 4•101 Ω•m and GN to 2•105 Ω•m (nanofiller content 1 wt.%. Flame retardancy was found for modified epoxy materials with as low GN and phosphorus content as 0.25 and 0.7 wt.%, respectively (increase of limiting oxygen index to 26.5%.

Three-Phase Carbon Fiber Amine Functionalized Carbon Nanotubes Epoxy Composite: Processing, Characterisation, and Multiscale Modeling

Directory of Open Access Journals (Sweden)

Kamal Sharma

2014-01-01

Full Text Available The present paper discusses the key issues of carbon nanotube (CNT dispersion and effect of functionalisation on the mechanical properties of multiscale carbon epoxy composites. In this study, CNTs were added in epoxy matrix and further reinforced with carbon fibres. Predetermined amounts of optimally amine functionalised CNTs were dispersed in epoxy matrix, and unidirectional carbon fiber laminates were produced. The effect of the presence of CNTs (1.0 wt% in the resin was reflected by pronounced increase in Young’s modulus, inter-laminar shear strength, and flexural modulus by 51.46%, 39.62%, and 38.04%, respectively. However, 1.5 wt% CNT loading in epoxy resin decreased the overall properties of the three-phase composites. A combination of Halpin-Tsai equations and micromechanics modeling approach was also used to evaluate the mechanical properties of multiscale composites and the differences between the predicted and experimental values are reported. These multiscale composites are likely to be used for potential missile and aerospace structural applications.

Dehydrating process experiment on spent ion-exchange resin sludge by Funda Filter

International Nuclear Information System (INIS)

Hasegawa, Tatsuo; Ishino, Kazuyuki

1977-01-01

In nuclear power plants, Funda Filters are employed to dehydrate spent powdery ion-exchange resin sludge. The Funda Filter is very effective for eliminating small rust components contained in spent powdery resin slurry; however, in the drying process, the complete drying of spent powdery resin is very difficult because the filter cake of resin on the horizontal filter leaf is likely to crack and let out steam and hot air through the cracks. This paper deals with the results of experiments conducted to clarify the detailed phenomena of dehydration so the above problem could be solved. The above experiments were made on the precoating and drying of granular ion-exchange resin slurry that had not yet been put to practical use. The experiments were composed of one fundamental and one operational stage. In the fundamental experiment, the dehydration properties and dehydration mechanism of resins were made clear, and the most effective operational method was established through the operational experiments conducted using large-scale Funda Filter test equipment under various conditions. (auth.)

Synthesis and Mechanism of Metal-Mediated Polymerization of Phenolic Resins

Directory of Open Access Journals (Sweden)

Zhao Yi

2016-04-01

Full Text Available Phenol-formaldehyde (PF resin is a high performance adhesive, but has not been widely developed due to its slow curing rate and high curing temperature. To accelerate the curing rate and to lower the curing temperature of PF resin, four types of metal-mediated catalysts were employed in the synthesis of PF resin; namely, barium hydroxide (Ba(OH2, sodium carbonate (Na2CO3, lithium hydroxide (LiOH, and zinc acetate ((CH3COO2Zn. The cure-acceleration effects of these catalysts on the properties of PF resins were measured, and the chemical structures of the PF resins accelerated with the catalysts were investigated by using Fourier transform infrared (FT-IR spectroscopy and quantitative liquid carbon-13 nuclear magnetic resonance (13C NMR. The results showed that the accelerated efficiency of these catalysts to PF resin could be ordered in the following sequence: Na2CO3 > (CH3COO2Zn > Ba(OH2 > LiOH. The catalysts (CH3COO2Zn and Na2CO3 increased the reaction activity of the phenol ortho position and the condensation reaction of ortho methylol. The accelerating mechanism of (CH3COO2Zn on PF resin is probably different from that of Na2CO3, which can be confirmed by the differences in the differential thermogravimetric (DTG curve and thermogravimetric (TG data. Compared to the Na2CO3-accelerated PF resin, the (CH3COO2Zn-accelerated PF resin showed different peaks in the DTG curve and higher weight residues. In the synthesis process, the catalyst (CH3COO2Zn may form chelating compounds (containing a metal-ligand bond, which can promote the linkage of formaldehyde to the phenolic hydroxyl ortho position.

Atomistic k ⋅ p theory

Energy Technology Data Exchange (ETDEWEB)

Pryor, Craig E., E-mail: craig-pryor@uiowa.edu [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States); Pistol, M.-E., E-mail: mats-erik.pistol@ftf.lth.se [NanoLund and Solid State Physics, Lund University, P.O. Box 118, 221 00 Lund (Sweden)

2015-12-14

Pseudopotentials, tight-binding models, and k ⋅ p theory have stood for many years as the standard techniques for computing electronic states in crystalline solids. Here, we present the first new method in decades, which we call atomistic k ⋅ p theory. In its usual formulation, k ⋅ p theory has the advantage of depending on parameters that are directly related to experimentally measured quantities, however, it is insensitive to the locations of individual atoms. We construct an atomistic k ⋅ p theory by defining envelope functions on a grid matching the crystal lattice. The model parameters are matrix elements which are obtained from experimental results or ab initio wave functions in a simple way. This is in contrast to the other atomistic approaches in which parameters are fit to reproduce a desired dispersion and are not expressible in terms of fundamental quantities. This fitting is often very difficult. We illustrate our method by constructing a four-band atomistic model for a diamond/zincblende crystal and show that it is equivalent to the sp{sup 3} tight-binding model. We can thus directly derive the parameters in the sp{sup 3} tight-binding model from experimental data. We then take the atomistic limit of the widely used eight-band Kane model and compute the band structures for all III–V semiconductors not containing nitrogen or boron using parameters fit to experimental data. Our new approach extends k ⋅ p theory to problems in which atomistic precision is required, such as impurities, alloys, polytypes, and interfaces. It also provides a new approach to multiscale modeling by allowing continuum and atomistic k ⋅ p models to be combined in the same system.

Epoxy-resin adhesive and method for bonding using such an epoxy resin adhesive

NARCIS (Netherlands)

Bhowmik, S.; Poulis, J.A.; Benedictus, R.

2008-01-01

The invention relates to an epoxy resin adhesive comprising a dotation of nano-substances, wherein the nano- substances are selected from the group comprising carbon-fibre nanotubes, carbon nano-fibres, silicate nano powders, and wherein the nano-substances are dispersed in the adhesive with a

Preparation of minor actinides targets or blankets by means of ionic exchange resin

Energy Technology Data Exchange (ETDEWEB)

Picart, S.; Mokhtari, H.; Jobelin, I. [CEA Marcoule, Nucl Energy Div, RadioChem and Proc Dept, Actinides Chem and Convers, F-30207 Bagnols Sur Ceze (France)

2010-07-01

The conversion of minor actinides to fuel starting materials for transmutation in a closed nuclear cycle is a big challenge for the next decades and the development of Gen(IV) nuclear systems. Conversion routes are numerous, but one needs to prove that they can be adapted to handle minor actinides. One of them is called the resin process and is particularly attractive because it stands for a 'dustless' process as it produces microspheres of oxide or carbide after thermal treatment of the loaded resin. The study presented herein focuses on the experiments and tests which enable us to optimize the fixation of minor actinides onto ionic exchange resin and their carbonization into oxide type materials. (authors)

Preparation of minor actinides targets or blankets by means of ionic exchange resin

International Nuclear Information System (INIS)

Picart, S; Mokhtari, H; Jobelin, I; Ramiere, I

2010-01-01

The conversion of minor actinides to fuel starting materials for transmutation in a closed nuclear cycle is a big challenge for the next decades and the development of Gen(IV) nuclear systems. Conversion routes are numerous, but one needs to prove that they can be adapted to handle minor actinides. One of them is called the resin process and is particularly attractive because it stands for a 'dustless' process as it produces microspheres of oxide or carbide after thermal treatment of the loaded resin. The study presented herein focuses on the experiments and tests which enable us to optimize the fixation of minor actinides onto ionic exchange resin and their carbonization into oxide type materials.

Design of carbon nanofiber embedded conducting epoxy resin

International Nuclear Information System (INIS)

Gantayat, Subhra; Sarkar, Niladri; Rout, Dibyaranjan; Swain, Sarat K.

2017-01-01

Acid treated carbon nanofiber (t-CNF) reinforced epoxy nanocomposites were fabricated by hand lay-up method with various wt % of t-CNF loadings. Pristine or unmodified carbon nano fibers (u-CNFs) were made compatible with epoxy matrix by means of mixed acid treatment. Fabricated nanocomposites were characterized with Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) study, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM). Mechanical and thermal properties of the nanocomposites were measured as a function of t-CNF content. Effect of acid treated CNFs on to the mechanical properties of epoxy nanocomposites was justified by comparing the mechanical properties of epoxy/t-CNF and epoxy/u-CNF nanocomposites with same loading level. The electrical conductivity was achieved by epoxy resin with a threshold at 1 wt % of t-CNF. Substantial improvement in thermal, mechanical and electrical properties of the synthesized epoxy/t-CNF nanocomposites may be suitable for fabricating electronic devices. - Highlights: • Epoxy/t-CNF nanocomposites are characterized by XRD, FTIR, SEM, AFM and TEM. • Electrical conductivity was achieved by epoxy with a threshold at 1 wt% of t-CNF. • Tensile strength is enhanced by 40% due to dispersion of t-CNF. • Synthesized nanocomposites are suitable for fabricating electronic devises.

Design of carbon nanofiber embedded conducting epoxy resin

Energy Technology Data Exchange (ETDEWEB)

Gantayat, Subhra [Department of Chemistry, Veer Surendra Sai University of Technology, Burla, Sambalpur 768018, Odisha (India); School of Applied Sciences, KIIT University, Bhubaneswar 751024, Odisha (India); Sarkar, Niladri [Department of Chemistry, Veer Surendra Sai University of Technology, Burla, Sambalpur 768018, Odisha (India); Rout, Dibyaranjan [School of Applied Sciences, KIIT University, Bhubaneswar 751024, Odisha (India); Swain, Sarat K., E-mail: swainsk2@yahoo.co.in [Department of Chemistry, Veer Surendra Sai University of Technology, Burla, Sambalpur 768018, Odisha (India)

2017-01-15

Acid treated carbon nanofiber (t-CNF) reinforced epoxy nanocomposites were fabricated by hand lay-up method with various wt % of t-CNF loadings. Pristine or unmodified carbon nano fibers (u-CNFs) were made compatible with epoxy matrix by means of mixed acid treatment. Fabricated nanocomposites were characterized with Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) study, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM). Mechanical and thermal properties of the nanocomposites were measured as a function of t-CNF content. Effect of acid treated CNFs on to the mechanical properties of epoxy nanocomposites was justified by comparing the mechanical properties of epoxy/t-CNF and epoxy/u-CNF nanocomposites with same loading level. The electrical conductivity was achieved by epoxy resin with a threshold at 1 wt % of t-CNF. Substantial improvement in thermal, mechanical and electrical properties of the synthesized epoxy/t-CNF nanocomposites may be suitable for fabricating electronic devices. - Highlights: • Epoxy/t-CNF nanocomposites are characterized by XRD, FTIR, SEM, AFM and TEM. • Electrical conductivity was achieved by epoxy with a threshold at 1 wt% of t-CNF. • Tensile strength is enhanced by 40% due to dispersion of t-CNF. • Synthesized nanocomposites are suitable for fabricating electronic devises.

Pyrolysis and oxidative pyrolysis experiments with organization exchange resin

International Nuclear Information System (INIS)

Chun, Ung Kyung

1997-01-01

Pyrolysis may be an important pretreatment step before vitrification in a cold crucible melter (CCM). During vitrification of organic resin the carbon or other remaining residues may harm the performance of the cold crucible melter of the eventual stability of the final glass product. Hence, it is important to reduce or prevent such harmful waste from entry into the cold crucible melter. Pretreatment with pyrolysis will generally provide volume reduction resulting in less amount of solid waste that needs to be handled by the CCM; in addition, the pyrolytic processes may breakdown much of the complex organics causing release through volatilization resulting in less carbon and other harmful substances. Hence, KEPRI has undertaken studies on the pyrolysis and oxidative pyrolysis of organic ion exchange resin. Pyrolysis and oxidative pyrolysis were examined with TGA and a tube furnace. TGA results for pyrolysis with the flow of nitrogen indicate that even after pyrolyzing from room temperature to about 900 deg C, a significant mass fraction of the original cationic resin remains, approximately 46 %. The anionic resin when pyrolytically heated in a flow of nitrogen only, from room temperature to about 900 deg C, produced a final residue mass fraction of about 8 percent. Oxidation at a ratio of air to nitrogen, 1:2, reduced the cationic resin to 5.3% when heated at 5 C/min. Oxidation of anionic resin at the same ratio and same heating rate left almost no solid residue. Pyrolysis (e.g. nitrogen-only environment) in the tube furnace of larger samples relative to the TGA produced very similar results to the TGA. The differences may be attributed to the scale effects such as surface area exposure to the gas stream, temperature distributions throughout the resin, etc. (author) 7 refs., 7 figs

Pyrolysis and oxidative pyrolysis experiments with organization exchange resin

Energy Technology Data Exchange (ETDEWEB)

Chun, Ung Kyung [Korea Electric Power Research Insititute, Taejon (Korea, Republic of)

1997-12-31

Pyrolysis may be an important pretreatment step before vitrification in a cold crucible melter (CCM). During vitrification of organic resin the carbon or other remaining residues may harm the performance of the cold crucible melter of the eventual stability of the final glass product. Hence, it is important to reduce or prevent such harmful waste from entry into the cold crucible melter. Pretreatment with pyrolysis will generally provide volume reduction resulting in less amount of solid waste that needs to be handled by the CCM; in addition, the pyrolytic processes may breakdown much of the complex organics causing release through volatilization resulting in less carbon and other harmful substances. Hence, KEPRI has undertaken studies on the pyrolysis and oxidative pyrolysis of organic ion exchange resin. Pyrolysis and oxidative pyrolysis were examined with TGA and a tube furnace. TGA results for pyrolysis with the flow of nitrogen indicate that even after pyrolyzing from room temperature to about 900 deg C, a significant mass fraction of the original cationic resin remains, approximately 46 %. The anionic resin when pyrolytically heated in a flow of nitrogen only, from room temperature to about 900 deg C, produced a final residue mass fraction of about 8 percent. Oxidation at a ratio of air to nitrogen, 1:2, reduced the cationic resin to 5.3% when heated at 5 C/min. Oxidation of anionic resin at the same ratio and same heating rate left almost no solid residue. Pyrolysis (e.g. nitrogen-only environment) in the tube furnace of larger samples relative to the TGA produced very similar results to the TGA. The differences may be attributed to the scale effects such as surface area exposure to the gas stream, temperature distributions throughout the resin, etc. (author) 7 refs., 7 figs.

Curing agent for polyepoxides and epoxy resins and composites cured therewith. [preventing carbon fiber release

Science.gov (United States)

Serafini, T. T.; Delvigs, P.; Vannucci, R. D. (Inventor)

1981-01-01

A curing for a polyepoxide is described which contains a divalent aryl radical such as phenylene a tetravalent aryl radical such as a tetravalent benzene radical. An epoxide is cured by admixture with the curing agent. The cured epoxy product retains the usual properties of cured epoxides and, in addition, has a higher char residue after burning, on the order of 45% by weight. The higher char residue is of value in preventing release to the atmosphere of carbon fibers from carbon fiber-epoxy resin composites in the event of burning of the composite.

Investigation of the removing process of cathode material in micro-EDM using an atomistic-continuum model

International Nuclear Information System (INIS)

Guo, Jianwen; Zhang, Guojun; Huang, Yu; Ming, Wuyi; Liu, Min; Huang, Hao

2014-01-01

Highlights: • An atomistic-continuum computational simulation model for single-discharge micro-EDM process of Cu cathode is constructed. • Cathode material is removed mainly in the form of single atoms or small clusters in micro-EDM. • Electric action leads to the formation of peaks on the surface of crater. • Removing process of cathode material under the hybrid action combining the thermal action and the electric action is studied, and the strength of either action needed for material to remove is much reduced. - Abstract: In micro-electrical discharge machining (micro-EDM), the discharge duration is ultra-short, and both the electric action and the thermal action by the discharge channel play important roles in the removing process of cathode material. However, in most researches on the machining mechanism of micro-EDM, only the thermal action is concerned. In this article, a combined atomistic-continuum modeling method in which the two-temperature model and the molecular dynamics simulation model are integrated is used to construct the simulation model for cathode in single-discharge micro-EDM process. With this simulation model, removing processes of Cu cathode material in micro-EDM under pure thermal action, pure electric action and the combination of them are investigated in a simulative way. By analyzing evolutions of temperature, stress and micro-structure of material as well as the dynamical behaviors of material in the removing process, mechanisms of the cathode material removal and crater formation are revealed. In addition, the removing process of cathode material under the combination of pure thermal action and pure electric action is compared with those under the two pure actions respectively to analyze the interactive effect between the thermal action and the electric action

The effect of bulk-resin CNT-enrichment on damage and plasticity in shear-loaded laminated composites

KAUST Repository

Ventura, Isaac Aguilar

2013-07-01

One way to improve multi functionality of epoxy-based laminated composites is to dope the resin with carbon nanotubes. Many investigators have focused on the elastic and fracture behavior of such nano-modified polymers under tensile loading. Yet, in real structural applications, laminated composites can exhibit plasticity and progressive damage initiated mainly by shear loading. We investigated the damage and plasticity induced by the addition of carbon nanotubes to the matrix of a glass fiber/epoxy composite system. We characterized both the modified epoxy resin and the associated modified laminates using classical mesoscale analysis. We used dynamic mechanical analysis, scanning electron microscopy, atomic force microscopy and classical mechanical testing to characterize samples with different concentrations of nanofillers. Since the samples were prepared using the solvent evaporation technique, we also studied the influence of this process. We found that in addition to the global increase in elastic regime properties, the addition of carbon nanotubes also accelerates the damage process in both the bulk resin and its associated glass-fiber composite. © 2013 Elsevier Ltd.

Pre design processing of waste of ex-resin without materials matrix from nuclear power plant type PWR 1000 MW

International Nuclear Information System (INIS)

Cerdas Tarigan

2010-01-01

Have been done pre design processing of waste ex-resin without capacities matrix materials from nuclear power plant type PWR 1000 MW During the time radioactive waste of ex-resin processed to use process of immobilization use matrix materials like mixture cement and epoxy resin and then conditioning. This process is not effective and efficient because end result volume of end product bigger than volume early operation system and maintenance of its installation more difficult. To overcome this created a design of technology processing of waste of ex- resin without matrix materials through process of strainer, drying and conditioning represent technological innovation newly processing of radioactive waste of ex-resin. Besides this process more effective and efficient, volume of end product waste much more small from volume early and operation system and maintenance of its easier installation. Pre design is expected to be used as a basis to make conceptual of pre design installation of strainer, drying and conditioning for the processing of waste of ex-resin from nuclear power plant type PWR 1000 MW. (author)

A contribution from dielectric analysis to the study of the formation of multi-wall carbon nanotubes percolated networks in epoxy resin under an electric field

International Nuclear Information System (INIS)

Risi, Celso L.S.; Hattenhauer, Irineu; Ramos, Airton; Coelho, Luiz A.F.; Pezzin, Sérgio H.

2015-01-01

The formation of percolation networks in epoxy matrix nanocomposites reinforced with multi-wall carbon nanotubes (MWNT) during the curing process, at different MWNT contents, was studied by using a parallel plate cell subjected to a 300 V/cm AC electric field at 1 kHz. The percolation was verified by the electrical current output measured during and after the resin curing. The behavior of electric dipoles was characterized by impedance spectroscopy and followed the Debye first order dispersion model, by which an average relaxation time of 6.0 × 10 −4 s and a cut-off frequency of 1.7 kHz were experimentally found. By applying the theory of percolation, a critical probability, p c , equal to 0.038 vol% and an exponent of conductivity of 2.0 were found. Both aligned and random samples showed dipole relaxation times typical of interfacial and/or charge-hopping polarization, while the permittivity exhibited an exponential decrease with frequency. This behavior can be related to the increased ability to trap electrical charges due to the formation of the carbon nanotubes network. Optical and electron microscopies confirm the theoretical prediction that the application of an electric field during cure helps the process of MWNT debundling in epoxy resin. - Highlights: • We report the formation of percolating networks of MWNTs under AC electric field. • MWNT/epoxy dielectric properties were measured by impedance spectroscopy. • Lower percolation thresholds were obtained for composites with aligned CNTs. • Application of AC electric field helps the debundling of CNTs. • CNT/Epoxy with percolated networks presents interfacial and hopping polarizations

Rheological and electrical properties of hybrid nanocomposites of epoxy resins filled with graphite nanoplatelets and carbon black.

Science.gov (United States)

Truong, Quang-Trung; Lee, Seon-Suk; Lee, Dai-Soo

2011-02-01

Graphite nanoplatelets (GNP) were prepared by microwave irradiation of natural graphites intercalated with ferric chloride in nitromethane (GIC). Intercalated structure of GIC was confirmed by X-ray diffraction patterns. SEM images of GIC after microwave irradiation showed the exfoliation of GIC, the formation of GNPs. Hybrid nanocomposites of bisphenol-A type epoxy resins filled with GNP and a conductive carbon black (CB) were prepared and rheological and electrical properties of the nanocomposites were investigated. Viscosity and electrical surface resistivity of the nanocomposites showed minima at certain mixtures of GNP and CB in the epoxy resins.

21 CFR 177.1580 - Polycarbonate resins.

Science.gov (United States)

2010-04-01

...′-iso-propylidenediphenol with molten diphenyl carbonate in the presence of the disodium salt of 4,4... chloride Monochlorobenzene Not to exceed 500 p.p.m. as residual solvent in finished resin. Pentaerythritol...-88-3) Not to exceed 800 parts per million as residual solvent in finished resin. Triethylamine (c...

Synthesis and characterisation of epoxy resins reinforced with carbon nanotubes and nanofibers.

Science.gov (United States)

Prolongo, S G; Gude, M R; Ureña, A

2009-10-01

Epoxy nanocomposites were fabricated using two kinds of nanofiller, amino-functionalized multi-walled carbon nanotubes (CNTs) and non-treated long carbon nanofibers (CNFs). The non-cured mixtures were analysed through viscosity measurements. The effect of the nanoreinforcement on the curing process was determined by differential scanning calorimetry. Finally, the characterisation of cured nanocomposites was carried out studying their thermo-mechanical and electrical behaviour. At room temperature, the addition of CNTs causes a viscosity increase of epoxy monomer much more marked than the introduction of CNFs due to their higher specific area. It was probed that in that case exists chemical reaction between amino-functionalized CNTs and the oxirane rings of epoxy monomer. The presence of nanoreinforcement induces a decrease of curing reaction rate and modifies the epoxy conversion reached. The glass transition temperature of the nanocomposites decreases with the contents of CNTs and CNFs added, which could be related to plasticization phenomena of the nanoreinforcements. The storage modulus of epoxy resin significantly increases with the addition of CNTs and CNFs. This augment is higher with amino-functionalized CNTs due, between other reasons, to the stronger interaction with the epoxy matrix. The electrical conductivity is greatly increased with the addition of CNTs and CNFs. In fact, the percolation threshold is lower than 0.25 wt% due to the high aspect ratio of the used nanoreinforcements.

Optimization‐based framework for resin selection strategies in biopharmaceutical purification process development

Science.gov (United States)

Liu, Songsong; Gerontas, Spyridon; Gruber, David; Turner, Richard; Titchener‐Hooker, Nigel J.

2017-01-01

This work addresses rapid resin selection for integrated chromatographic separations when conducted as part of a high‐throughput screening exercise during the early stages of purification process development. An optimization‐based decision support framework is proposed to process the data generated from microscale experiments to identify the best resins to maximize key performance metrics for a biopharmaceutical manufacturing process, such as yield and purity. A multiobjective mixed integer nonlinear programming model is developed and solved using the ε‐constraint method. Dinkelbach's algorithm is used to solve the resulting mixed integer linear fractional programming model. The proposed framework is successfully applied to an industrial case study of a process to purify recombinant Fc Fusion protein from low molecular weight and high molecular weight product related impurities, involving two chromatographic steps with eight and three candidate resins for each step, respectively. The computational results show the advantage of the proposed framework in terms of computational efficiency and flexibility. © 2017 The Authors Biotechnology Progress published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers Biotechnol. Prog., 33:1116–1126, 2017 PMID:28393478

Supercritical water oxidation of ion exchange resins: Degradation mechanisms

Energy Technology Data Exchange (ETDEWEB)

Leybros, A.; Roubaud, A. [CEA Marcoule, DEN DTCD SPDE LFSM, F-30207 Bagnols Sur Ceze (France); Guichardon, P. [Ecole Cent Marseille, F-13451 Marseille 20 (France); Boutin, O. [Aix Marseille Univ, UMR CNRS 6181, F-13545 Aix En Provence 4 (France)

2010-07-01

Spent ion exchange resins are radioactive process wastes for which there is no satisfactory industrial treatment. Supercritical water oxidation could offer a viable treatment alternative to destroy the organic structure of resins and contain radioactivity. IER degradation experiments were carried out in a continuous supercritical water reactor. Total organic carbon degradation rates in the range of 95-98% were obtained depending on operating conditions. GC-MS chromatography analyses were carried out to determine intermediate products formed during the reaction. Around 50 species were identified for cationic and anionic resins. Degradation of poly-styrenic structure leads to the formation of low molecular weight compounds. Benzoic acid, phenol and acetic acid are the main compounds. However, other products are detected in appreciable yields such as phenolic species or heterocycles, for anionic IERs degradation. Intermediates produced by intramolecular rearrangements are also obtained. A radical degradation mechanism is proposed for each resin. In this overall mechanism, several hypotheses are foreseen, according to HOO center dot radical attack sites. (authors)

Relationship Between the Process Parameters and Resin Content of a Glass/Epoxy Prepreg Produced by Dipping Method

Directory of Open Access Journals (Sweden)

Hamid Reza Khalafi

2015-02-01

Full Text Available The properties of prepregs are characterized in terms of their volatile content, resin content, the degree of pre-cure, void content, tack and flow ability. Resin content is one of the most important properties of prepregs so that its changing will result in altered properties such as, tack and resin flow. In order to monitor the resin content, a quantitative relation to the processing parameters such as line speed, viscosity and distance between the resin up taking rollers have to be determined. In this study, a tri-axial E-glass fabric with the areal weight of 1025 g/m2 and an epoxy resin (Epon 828 were used to produce the prepreg by the dipping method. In the theoretical part of this work, the free coating is studied and as a result the thickness layer of the coating resin through the resin bath is calculated by Landau-Levich model. In continuation, the achieved thickness was considered as a feed for the calendering process. Using the momentum equation for the passing impregnated fibres through the extra resin uptake rollers, the relation between the internal resin layer thickness and final coating resin layer thickness was achieved in an integral equation form. In order to solve this integral equation, MAPLE software was applied. The theoretical results were in good agreement with the experimental data and showed that the resin content increased linearly with increasing the distance between rollers, the radius and roller angular velocity. In contrast, the resin content decreased with increasing the line speed. According to our calculations, the effect of the resin viscosity variation on the resin content was negligibly small.

Multiscale Hybrid Micro-Nanocomposites Based on Carbon Nanotubes and Carbon Fibers

Directory of Open Access Journals (Sweden)

Fawad Inam

2010-01-01

Full Text Available Amino-modified double wall carbon nanotube (DWCNT-NH2/carbon fiber (CF/epoxy hybrid micro-nanocomposite laminates were prepared by a resin infusion technique. DWCNT-NH2/epoxy nanocomposites and carbon fiber/epoxy microcomposites were made for comparison. Morphological analysis of the hybrid composites was performed using field emission scanning electron microscope. A good dispersion at low loadings of carbon nanotubes (CNTs in epoxy matrix was achieved by a bath ultrasonication method. Mechanical characterization of the hybrid micro-nanocomposites manufactured by a resin infusion process included three-point bending, mode I interlaminar toughness, dynamic mechanical analysis, and drop-weight impact testing. The addition of small amounts of CNTs (0.025, 0.05, and 0.1 wt% to epoxy resins for the fabrication of multiscale carbon fiber composites resulted in a maximum enhancement in flexural modulus by 35%, a 5% improvement in flexural strength, a 6% improvement in absorbed impact energy, and 23% decrease in the mode I interlaminar toughness. Hybridization of carbon fiber-reinforced epoxy using CNTs resulted in a reduction in and dampening characteristics, presumably as a result of the presence of micron-sized agglomerates.

Behavior study of spend ion exchange resins immobilized in pyrolyzed polymer matrix

International Nuclear Information System (INIS)

Ramos, P.B; Fuentes, N.O; Luca, V.

2012-01-01

The pyrolysis of spent ion exchange resins contained in epoxy resins represents an attractive alternative to cementation as a confining method. In this sense, a significant reduction of volume can be achieved, as well as avoiding the dispersion of the exhausted ion exchange resin by the means of an epoxy resin used as a matrix, while potentially limiting the release of highly radioactive long life isotopes such us Cs-137, Sr-90 and Co-60 among others. Three types of monoliths were made: (i) epoxy resin, (ii) epoxy resin with carbon and (iii) a binder of epoxy resin and clay. In every case, the monolith contained the ion exchange resin. They were prepared by the mixing of resin pearl loaded with epoxy cations and a subsequent pyrolysis process with a temperature increase ratio of 2 o C /min reaching maximum values in the range between 200 o C - 800 o C, remaining in it for 1 hour. Monoliths obtained for each final temperature had been characterized to obtain data corresponding to the mass loss, volume reduction and lixiviation, as well as mechanical and microstructural properties (author)

Process for removing a mixture containing iodine and alkyl iodine compounds from a gas phase or aqueous solution with ion-exchange resins

Energy Technology Data Exchange (ETDEWEB)

Shimizu, H; Mizuuchi, A; Yokoyama, F

1968-10-04

Iodine and alkyl iodine compounds are removed from a gas phase or aqueous solution containing salts, iodine and iodine compounds, such as the ambient gas in a reactor, if an accident should occur. The process comprises contacting the phase or solution: (a) with a hydrogen type strongly acidic cationic exchange resin, (b) with an anionic exchange resin containing quarternary ammonium and (c) with an anionic exchange resin containing free basic type tertiary amine, in this order or by reversing the order of the two anionic exchange resins. Although no problems arise in the liquid phase reaction, the ion-exchange resins in the gas phase reaction are desired in the moist state in order to stable maintain the migration speed of the materials to be removed regardless of the relative humidity of the amibent gas. In example I, Amberlite IRA-900 of 200 mm thickness as the lowermost bed, Amberlite IRA93 of 200 mm thickness as the middle bed and Amberlite 200 of 200 mm thickness as the uppermost bed were filled respectively, in a methacrylate resin cylinder with an inner diameter of 25 mm. A solution containing 15.9 mg/1 of iodine, 41.2 mg/1 of methyl iodide and 550 mg/1 of sodium carbonate flows at a rate of 15 liter/hr downward through the beds. As a result of testing, no iodine, iodine ions, iodic acid ions and methyl iodine were detected. The amount of water the beds could treat was 60 times the total quantity of the filled resins.

Fossilization History of Fossil Resin from Jambi Province (Sumatra, Indonesia Based on Physico-Chemical Studies

Directory of Open Access Journals (Sweden)

Beata Naglik

2018-03-01

Full Text Available A unique specimen of fossil resin originating from the Dipterocarpaceae tree family found in Miocene brown coal deposits in Jambi Province (Sumatra, Indonesia was investigated via microscopic observations, microhardness testing and infrared and Raman spectroscopic methods. Its form is rare in nature, being an aggregate of three varieties of resin differing in colour, transparency and internal structure. This suggests the formation of the resins at different stages. Further alteration processes, including fossilization and maturation of the resin in a swamp environment resulted in stepwise aromatization of the cyclohexane ring in steroids and cross-linking through formation of ester bonds as well as carbon–carbon bonds between steroid molecules. The various environmental and geological conditions affecting the formation processes of the resins were recorded in their physico-chemical properties. Additionally, heating conditions accelerated by volcanism were proposed as a factor determining the maturation grade of the resin.

Polyvinyl chloride resin

International Nuclear Information System (INIS)

Kim, Hong Jae

1976-06-01

This book contains polyvinyl chloride resin industry with present condition such as plastic industry and polyvinyl chloride in the world and Japan, manufacture of polyvinyl chloride resin ; suspension polymerization and solution polymerization, extruding, injection process, hollow molding vinyl record, vacuum forming, polymer powders process, vinyl chloride varnish, vinyl chloride latex, safety and construction on vinyl chloride. Each chapter has descriptions on of process and kinds of polyvinyl chloride resin.

Optimization of the rheological properties of epoxy resins for glass and carbon reinforced plastics

Science.gov (United States)

Phyo Maung, Pyi; Malysheva, G.; Romanova, I.

2016-10-01

Vacuum assisted resin transfer moulding (VARTM) offers advantages such as simplicity, low cost of consumables, and the ability to carry out the impregnation process and curing without using expensive equipment and tooling. In the VARTM process, rheological properties of resin have a critical impact on the impregnation and curing process. In this article, the experimental results of viscosity are presented, including the glass transition temperature, and the tensile and bending strength of the epoxy binders with the amine hardener, which depend on the quantity of its active solvent composition. The active solvent used is diethylene glycol. It shows that for an increase in the content of the active solvent, a reduction in the viscosity and a reduction of the glass transition temperature and strength occurs. The optimum composition of the binder is selected by using the Pareto optimization criteria and the Cayley - Smorodinskaya method. By using the epoxy binder, the active solvent should not exceed 10-15% by weight. This approach helps to optimize the amount of active solvent added to the epoxy resins for the criterion of viscosity, strength, and heat resistance.

The effect of processing on autohesive strength development in thermoplastic resins and composites

Science.gov (United States)

Howes, Jeremy C.; Loos, Alfred C.; Hinkley, Jeffrey A.

1989-01-01

In the present investigation of processing effects on the autohesive bond strength of neat polysulfone resin and graphite-reinforced polysulfone-matrix composites measured resin bond strength development in precracked compact tension specimens 'healed' by heating over a contact period at a given temperature. The critical strain energy release rate of refractured composite specimens did not exhibit the strong time or temperature dependence of the neat resin tests; only 80-90 percent of the undamaged fracture energy is recoverable.

Atomistically-informed dislocation dynamics in FCC crystals

International Nuclear Information System (INIS)

Martinez, E.; Marian, J.; Arsenlis, A.; Victoria, M.; Martinez, E.; Victoria, M.; Perlado, J.M.

2008-01-01

Full text of publication follows. We will present a nodal dislocation dynamics (DD) model to simulate plastic processes in fcc crystals. The model explicitly accounts for all slip systems and Burgers vectors observed in fcc systems, including stacking faults and partial dislocations. We derive simple conservation rules that describe all partial dislocation interactions rigorously and allow us to model and quantify cross-slip processes, the structure and strength of dislocation junctions, and the formation of fcc-specific structures such as stacking fault tetrahedra. The DD framework is built upon isotropic non-singular linear elasticity, and supports itself on information transmitted from the atomistic scale. In this fashion, connection between the meso and micro scales is attained self-consistently with core parameters fitted to atomistic data. We perform a series of targeted simulations to demonstrate the capabilities of the model, including dislocation reactions and dissociations and dislocation junction strength. Additionally we map the four-dimensional stress space relevant for cross-slip and relate our fundings to the plastic behaviour of' monocrystalline fcc metals. (authors)

Adhesive contact: from atomistic model to continuum model

International Nuclear Information System (INIS)

Fan Kang-Qi; Jia Jian-Yuan; Zhu Ying-Min; Zhang Xiu-Yan

2011-01-01

Two types of Lennard-Jones potential are widely used in modeling adhesive contacts. However, the relationships between the parameters of the two types of Lennard-Jones potential are not well defined. This paper employs a self-consistent method to derive the Lennard-Jones surface force law from the interatomic Lennard-Jones potential with emphasis on the relationships between the parameters. The effect of using correct parameters in the adhesion models is demonstrated in single sphere-flat contact via continuum models and an atomistic model. Furthermore, the adhesion hysteresis behaviour is investigated, and the S-shaped force-distance relation is revealed by the atomistic model. It shows that the adhesion hysteresis loop is generated by the jump-to-contact and jump-off-contact, which are illustrated by the S-shaped force-distance curve. (atomic and molecular physics)

Preparation and characterization of hybrid materials of epoxy resin type bisphenol a with silicon and titanium oxides by sol-gel process

International Nuclear Information System (INIS)

Carrillo C, A.; Osuna A, J. G.

2011-01-01

Hybrid materials were synthesized from epoxy resins as a result bisphenol type A-silicon oxide and epoxy resin bisphenol type A-titanium oxide were obtained. The synthesis was done by sol-gel process using tetraethyl orthosilicate (Teos) and titanium isopropoxide (I Ti) as inorganic precursors. The molar ratio of bisphenol A to the inorganic precursors was the studied variable. The materials were characterized by thermal analysis, infrared spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy. The hybrid nature of the materials was demonstrated through thermal analysis and infrared spectroscopy. In both systems, as the amount of alkoxide increased, the bands described above were more defined. This behavior indicates the interactions between the resin and the alkoxides. Hybrids with Teos showed a smoother and homogeneous surface in its entirety, without irregularities. Hybrids with titanium isopropoxide had low roughness. Both Teos and I Ti hybrids showed a decrease on the atomic weight percentage of carbon due to a slight reduction of the organic part on the surface. (Author)

Preparation and characterization of hybrid materials of epoxy resin type bisphenol a with silicon and titanium oxides by sol-gel process

Energy Technology Data Exchange (ETDEWEB)

Carrillo C, A.; Osuna A, J. G., E-mail: acc.carrillo@gmail.com [Universidad Autonoma de Coahuila, Facultad de Ciencias Quimicas, Blvd. Venustiano Carranza y Jose Cardenas Valdes, 25000 Saltillo, Coahuila (Mexico)

2011-07-01

Hybrid materials were synthesized from epoxy resins as a result bisphenol type A-silicon oxide and epoxy resin bisphenol type A-titanium oxide were obtained. The synthesis was done by sol-gel process using tetraethyl orthosilicate (Teos) and titanium isopropoxide (I Ti) as inorganic precursors. The molar ratio of bisphenol A to the inorganic precursors was the studied variable. The materials were characterized by thermal analysis, infrared spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy. The hybrid nature of the materials was demonstrated through thermal analysis and infrared spectroscopy. In both systems, as the amount of alkoxide increased, the bands described above were more defined. This behavior indicates the interactions between the resin and the alkoxides. Hybrids with Teos showed a smoother and homogeneous surface in its entirety, without irregularities. Hybrids with titanium isopropoxide had low roughness. Both Teos and I Ti hybrids showed a decrease on the atomic weight percentage of carbon due to a slight reduction of the organic part on the surface. (Author)

Multi-scale modelling of ions in solution: from atomistic descriptions to chemical engineering

International Nuclear Information System (INIS)

Molina, J.J.

2011-01-01

Ions in solution play a fundamental role in many physical, chemical, and biological processes. The PUREX process used in the nuclear industry to the treatment of spent nuclear fuels is considered as an example. For industrial applications these systems are usually described using simple analytical models which are fitted to reproduce the available experimental data. In this work, we propose a multi-scale coarse graining procedure to derive such models from atomistic descriptions. First, parameters for classical force-fields of ions in solution are extracted from ab-initio calculations. Effective (McMillan-Mayer) ion-ion potentials are then derived from radial distribution functions measured in classical molecular dynamics simulations, allowing us to define an implicit solvent model of electrolytes. Finally, perturbation calculations are performed to define the best possible representation for these systems, in terms of charged hard-sphere models. Our final model is analytical and contains no free 'fitting' parameters. It shows good agreement with the exact results obtained from Monte-Carlo simulations for the thermodynamic and structural properties. Development of a similar model for the electrolyte viscosity, from information derived from atomistic descriptions, is also introduced. (author)

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.

The Impact of Pore Structure on Densification Efficiency of 2-D Carbon-Carbon Composites and Its Relationship to Mechanical Properties

Science.gov (United States)

2011-03-01

consolidation and eventually to add rigidity. This is called pre- impregnation, or prepregging . The fabric is then cut, stacked, and consolidated to create...Thermosetting resins are very easy to work with because they have low viscosities before curing allowing them to easily coat the fabric laminates ...these benefits, phenolic resin is also inexpensive [6]. For these reasons phenolic resin is an ideal prepreg material for carbon-carbon composites

Tensile Properties of Unsaturated Polyester and Epoxy Resin Reinforced with Recycled Carbon-Fiber-Reinforced Plastic

Science.gov (United States)

Okayasu, Mitsuhiro; Kondo, Yuta

2018-06-01

To better understand the mechanical properties of recycled carbon-fiber-reinforced plastic (rCFRP), CFRP crushed into small pieces was mixed randomly in different proportions (0-30 wt%) with two different resins: unsaturated polyester and epoxy resin. Two different sizes of crushed CFRP were used: 0.1 mm × 0.007 mm (milled CFRP) and 30 mm × 2 mm (chopped CFRP). The tensile strength of rCFRP was found to depend on both the proportion and the size of the CFRP pieces. It increased with increasing proportion of chopped CFRP, but decreased with increasing proportion of milled CFRP. There was no clear dependence of the tensile strength on the resin that was used. A low fracture strain was found for rCFRP samples made with chopped CFRP, in contrast to those made with milled CFRP. The fracture strain was found to increase with increasing content of milled CFRP up to 20 wt%, at which point, coalescence of existing microvoids occurred. However, there was a reduction in fracture strain for rCFRP with 30 wt% of milled CFRP, owing to the formation of defects (blow holes). Overall, the fracture strain was higher for rCFRPs based on epoxy resin than for those based on unsaturated polyester with the same CFRP content, because of the high ductility of the epoxy resin. The different tensile properties reflected different failure characteristics, with the use of chopped CFRP leading to a complicated rough fracture surface and with milled CFRP causing ductile failure through the presence of tiny dimple-like fractures. However, for a high content of milled CFRP (30 wt%), large blow holes were observed, leading to low ductility.

Ion exchange resins destruction in a stirred supercritical water oxidation reactor

International Nuclear Information System (INIS)

Leybros, A.; Roubaud, A.; Guichardon, P.; Boutin, O.

2010-01-01

Spent ion exchange resins (IERs) are radioactive process wastes for which there is no satisfactory industrial treatment. Supercritical water oxidation offers a viable treatment alternative to destroy the organic structure of resins, used to remove radioactivity. Up to now, studies carried out in supercritical water for IER destruction showed that degradation rates higher than 99% are difficult to obtain even using a catalyst or a large oxidant excess. In this study, a co-fuel, isopropanol, has been used in order to improve degradation rates by initiating the oxidation reaction and increasing temperature of the reaction medium. Concentrations up to 20 wt% were tested for anionic and cationic resins. Total organic carbon reduction rates higher than 99% were obtained from this process, without the use of a catalyst. The influence of operating parameters such as IERs feed concentration, nature and counterions of exchanged IERs were also studied. (authors)

1-Butanol absorption in poly(styrene-divinylbenzene) ion exchange resins for catalysis.

Science.gov (United States)

Pérez-Maciá, M A; Curcó, D; Bringué, R; Iborra, M; Rodríguez-Ropero, F; van der Vegt, N F A; Aleman, Carlos

2015-12-21

The swelling behaviour of poly(styrene-co-divinylbenzene), P(S-DVB), ion exchange resins in 1-butanol (BuOH) has been studied by means of atomistic classical molecular dynamics simulations (MD). The topological characteristics reported for the resin in the dry state, which exhibited complex internal loops (macropores), were considered for the starting models used to examine the swelling induced by BuOH contents ranging from 10% to 50% w/w. Experimental measurements using a laser diffraction particle size analyzer indicate that swelling causes a volume variation with respect to the dry resin of 21%. According to MD simulations, such a volume increment corresponds to a BuOH absorption of 31-32% w/w, which is in excellent agreement with the indirect experimental estimation (i.e. 31% w/w). Simulations reveal that, independently of the content of BuOH, the density of the swelled resin is higher than that of the dry resin, evidencing that the alcohol provokes important structural changes in the polymeric matrix. Thus, BuOH molecules cause a collapse of the resin macropores when the content of alcohol is ≤20% w/w. In contrast, when the concentration of BuOH is close to the experimental value (∼30% w/w), P(S-DVB) chains remain separated by pores faciliting the access of the reactants to the reaction centers. On the other hand, evaluation of both bonding and non-bonding interactions indicates that the mixing energy is the most important contribution to the absorption of BuOH into the P(S-DVB) resin. Overall, the results displayed in this work represent a starting point for the theoretical study of the catalytic conversion of BuOH into di-n-butyl ether in P(S-DVB) ion exchange resins using sophisticated electronic methods.

In situ observations of the atomistic mechanisms of Ni catalyzed low temperature graphene growth.

Science.gov (United States)

Patera, Laerte L; Africh, Cristina; Weatherup, Robert S; Blume, Raoul; Bhardwaj, Sunil; Castellarin-Cudia, Carla; Knop-Gericke, Axel; Schloegl, Robert; Comelli, Giovanni; Hofmann, Stephan; Cepek, Cinzia

2013-09-24

The key atomistic mechanisms of graphene formation on Ni for technologically relevant hydrocarbon exposures below 600 °C are directly revealed via complementary in situ scanning tunneling microscopy and X-ray photoelectron spectroscopy. For clean Ni(111) below 500 °C, two different surface carbide (Ni2C) conversion mechanisms are dominant which both yield epitaxial graphene, whereas above 500 °C, graphene predominantly grows directly on Ni(111) via replacement mechanisms leading to embedded epitaxial and/or rotated graphene domains. Upon cooling, additional carbon structures form exclusively underneath rotated graphene domains. The dominant graphene growth mechanism also critically depends on the near-surface carbon concentration and hence is intimately linked to the full history of the catalyst and all possible sources of contamination. The detailed XPS fingerprinting of these processes allows a direct link to high pressure XPS measurements of a wide range of growth conditions, including polycrystalline Ni catalysts and recipes commonly used in industrial reactors for graphene and carbon nanotube CVD. This enables an unambiguous and consistent interpretation of prior literature and an assessment of how the quality/structure of as-grown carbon nanostructures relates to the growth modes.

Challenges in process integration of catalytic DC plasma synthesis of vertically aligned carbon nanofibres

International Nuclear Information System (INIS)

Melechko, Anatoli V; Pearce, Ryan C; Hensley, Dale K; Simpson, Michael L; McKnight, Timothy E

2011-01-01

The ability to synthesize free-standing, individual carbon nanofibres (CNFs) aligned perpendicularly to a substrate has enabled fabrication of a large array of devices with nanoscale functional elements, including electron field emission sources, electrochemical probes, neural interface arrays, scanning probes, gene delivery arrays and many others. This was made possible by development of a catalytic plasma process, with DC bias directing the alignment of nanofibres. Successful implementation of prototypical devices has uncovered numerous challenges in the integration of this synthesis process as one of the steps in device fabrication. This paper is dedicated to these engineering and fundamental difficulties that hinder further device development. Relatively high temperature for catalytic synthesis, electrical conductivity of the substrate to maintain DC discharge and other difficulties place restrictions on substrate material. Balancing non-catalytic carbon film deposition and substrate etching, non-uniformity of plasma due to growth of the high aspect ratio structures, plasma instabilities and other factors lead to challenges in controlling the plasma. Ultimately, controlling the atomistic processes at the catalyst nanoparticle (NP) and the behaviour of the NP is the central challenge of plasma nanosynthesis of vertically aligned CNFs.

Influence of the vacuum resin process, on the ballistic behaviour of lightweight armouring solutions

Science.gov (United States)

Lefebvre, M.; Boussu, F.; Coutellier, D.; Vallee, D.

2012-08-01

The armour of vehicles against conventional threats is mainly composed with steel or aluminium panels. Efficient heavy solutions exist, but the involved industries require new lightweight structures. Moreover, unconventional threats as IEDs (Improvised Explosive Devices) may cause severe damages on these structural and protective panel solutions. Thus, combination of aluminium or steel plates with textile composite structures used as a backing, leads to the mass reduction and better performance under delamination behaviour against these new threats. This paper is a part of a study dealing with the impact behaviour of three warp interlocks weaving structures under Fragment Simulating Projectile (FSP) impact. During this research, several parameters has being studied as the influence of the yarns insertions [1-4], the degradation of the yarns during the weaving process [5-7], and the influence of the resin rate on the ballistic behaviour. The resin rate inside composite materials is dependant on the final application. In ballistic protection, we need to control the resin rate in order to have a deformable structure in order to absorb the maximum of energy. However, with the warp interlocks weaving structure, the yarns insertions induce empty spaces between the yarns where the resin takes place without being evacuated. The resin rate inside the warp interlocks structures is in the most of cases less than 50%, which lead to have brittle and hard material during the impact. Contrary to interlocks structures, the existing protection based on prepreg structure have a high fibres ratio around 88% of weight. That leads to have the best ballistic properties during the impact and good deformability of the structure. The aim of this paper is to evaluate the influence of the resin rate on the ballistic results of the composites materials. For that, we have chosen two kinds of warp interlocks fabrics which were infused with epoxy resin following two processes. The first is a

Application of THOR-Technology on resins

International Nuclear Information System (INIS)

Lorenzen, J.; Lindberg, M.

2003-01-01

The THermal Organic Reduction (THOR) process, developed and patented by studsvik utilises pyrolysis / steam reforming technology. The THOR-process provides a reliable and safe method for treating a wide variety of LLW in a unique, fluidised bed treatment system at moderate temperature. This technology is suitable for processing hazardous, mixed and dry active LLW with appropriate waste feed modifications. Both solid and liquid LLRW and ILRW streams including ion exchange resins, activated carbon (charcoal), graphite, oils, solvents and cleaning solutions with contact radiation levels of up to 4 Sv/hr can be processed. Studsvik has completed over four years of operation at its facility at Erwin, Tennessee, USA. During this period studsvik has processed more than 1,5 thousand tons of radioactive ion exchange bead resins. powdered filter media and active carbon, with a cumulative total radioactivity of about 7 (E+8) MBq. Operations have demonstrated consistent, reliable, robust operating characteristics. Due to the widely varying characteristics of the incoming waste streams various efficiencies and volume reductions have been experienced. Input waste has varied in total inorganic content from 90%. A substantial element of this variability has been the ''soluble salt'' content of the input waste streams. Final reformed residue comprises a non-dispersible, granular solid which is suitable for long-term storage or direct burial in a qualified container. Special containers, THOR-liners, are available from studsvik for the transport of waste from the customer to the Erwin facility and HICs (high integrity containers) for transport of the residues to Barnwell. The paper will give an overview of the last four years of commercial operations processing LLRW from commercial nuclear power plans. (orig.)

The removal of toxic metals from liquid effluents by ion exchange resins. Part V: Nickel(II/H+/Dowex C400

Directory of Open Access Journals (Sweden)

Francisco José Alguacil

2017-11-01

Full Text Available The cationic exchange resin Dowex C400 was used to remove nickel(II from aqueous solutions of different pH values and under various experimental conditions: stirring speed of the aqueous solution/resin system, temperature, resin dosage and aqueous ionic strength. The selectivity of the resin was investigated against the presence of various metals in the aqueous solution, and the removal of nickel(II from aqueous solutions was also compared with results obtained using multiwalled carbon nanotubes or functionalized (carboxylic groups multiwalled carbon nanotubes as adsorbents. According to batch experimental data, best fit of the results is obtained with the Freundlich model, whereas the ion exchange process is best explained by the pseudo-first order model. Experimental data fit well to the moving boundary controlled model. Elution of the nickel(II loaded onto Dowex C400 resin is fully possible using acidic solutions.

Optimized process for recovery of glass- and carbon fibers with retained mechanical properties by means of near- and supercritical fluids

DEFF Research Database (Denmark)

Sokoli, Hülya U.; Beauson, Justine; Simonsen, Morten E.

2017-01-01

on the resin degradation efficiency and the quality of the recovered glass and carbon fibers. Supercritical acetone at 260 ºC, 60 bar and a c/s ratio up to 2.1 g/mL could achieve nearly complete degradation of the resin. The glass fibers were recovered with up to 89% retained tensile strength compared...... to the virgin glass fibers. The use of near-critical water reduced the tensile strength of the glass fibers by up to 65%, whereas the carbon fibers were recovered with retained tensile strength compared to the virgin carbon fibers using water or acetone.......Degradation of hybrid fiber composites using near-critical water or supercritical acetone has been investigated in this study. Process parameters such as temperature (T= 260-300 ºC), pressure (p = 60-300 bar) and composite/solvent (c/s = 0.29-2.1 g/mL) ratio were varied to determine the effect...

Calculation of phonon dispersion in carbon nanotubes using a continuum-atomistic finite element approach

Directory of Open Access Journals (Sweden)

Michael J. Leamy

2011-12-01

Full Text Available Dispersion calculations are presented for cylindrical carbon nanotubes using a manifold-based continuum-atomistic finite element formulation combined with Bloch analysis. The formulated finite elements allow any (n,m chiral nanotube, or mixed tubes formed by periodically-repeating heterojunctions, to be examined quickly and accurately using only three input parameters (radius, chiral angle, and unit cell length and a trivial structured mesh, thus avoiding the tedious geometry generation and energy minimization tasks associated with ab initio and lattice dynamics-based techniques. A critical assessment of the technique is pursued to determine the validity range of the resulting dispersion calculations, and to identify any dispersion anomalies. Two small anomalies in the dispersion curves are documented, which can be easily identified and therefore rectified. They include difficulty in achieving a zero energy point for the acoustic twisting phonon, and a branch veering in nanotubes with nonzero chiral angle. The twisting mode quickly restores its correct group velocity as wavenumber increases, while the branch veering is associated with a rapid exchange of eigenvectors at the veering point, which also lessens its impact. By taking into account the two noted anomalies, accurate predictions of acoustic and low-frequency optical branches can be achieved out to the midpoint of the first Brillouin zone.

[Fusion implants of carbon fiber reinforced plastic].

Science.gov (United States)

Früh, H J; Liebetrau, A; Bertagnoli, R

2002-05-01

Carbon fiber reinforced plastics (CFRP) are used in the medical field when high mechanical strength, innovative design, and radiolucency (see spinal fusion implants) are needed. During the manufacturing process of the material CFRP carbon fibers are embedded into a resin matrix. This resin material could be thermoset (e.g., epoxy resin EPN/DDS) or thermoplastic (e.g., PEAK). CFRP is biocompatible, radiolucent, and has higher mechanical capabilities compared to other implant materials. This publication demonstrates the manufacturing process of fusion implants made of a thermoset matrix system using a fiber winding process. The material has been used clinically since 1994 for fusion implants of the cervical and lumbar spine. The results of the fusion systems CORNERSTONE-SR C (cervical) and UNION (lumbar) showed no implant-related complications. New implant systems made of this CFRP material are under investigation and are presented.

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.

Cementation of secondary wastes generated from carbonisation of spent organic ion exchange resins from nuclear power plants

International Nuclear Information System (INIS)

Sathi Sasidharan, N.; Deshingkar, D.S.; Wattal, P.K.

2004-07-01

The spent IX resins containing radioactive fission and activation products from power reactors are highly active solid wastes generated during operations of nuclear reactors. Process for carbonization of IX resins to achieve weight and volume reduction has been optimized on 50 dm 3 /batch pilot test rig. The process generates carbonaceous residue, organic liquid condensates (predominantly styrene) and aqueous alkaline scrubber solutions as secondary wastes. The report discusses laboratory tests on leaching of 137 Cs from cement matrix incorporating carbonaceous residues and extrapolation of results to 200 liter matrix block. The cumulative fraction of 137 Cs leached from 200 liter cement matrix was estimated to be 0.0021 in 200 days and 0.0418 over a period of 30 years. Incorporation of organic liquid condensates into cement matrix has been tried out successfully. Thus two types of secondary wastes generated during carbonization of spent IX resins can be immobilized in cement matrix. (author)

Processing of carbon composite paper as electrode for fuel cell

Energy Technology Data Exchange (ETDEWEB)

Mathur, R.B.; Maheshwari, Priyanka H.; Dhami, T.L. [Carbon Technology Unit, National Physical Laboratory, New Delhi 110012 (India); Sharma, R.K.; Sharma, C.P. [Soft Polymeric Group, Division of Engineering Materials, National Physical Laboratory, New Delhi 110012 (India)

2006-10-27

The porous carbon electrode in a fuel cell not only acts as an electrolyte and a catalyst support, but also allows the diffusion of hydrogen fuel through its fine porosity and serves as a current-carrying conductor. A suitable carbon paper electrode is developed and possesses the characteristics of high porosity, permeability and strength along with low electrical resistivity so that it can be effectively used in proton-exchange membrane and phosphoric acid fuel cells. The electrode is prepared through a combination of two important techniques, viz., paper-making technology by first forming a porous chopped carbon fibre preform, and composite technology using a thermosetting resin matrix. The study reveals an interdependence of one parameter on another and how judicious choice of the processing conditions are necessary to achieve the desired characteristics. The current-voltage performance of the electrode in a unit fuel cell matches that of a commercially-available material. (author)

Modeling the curing process of thermosetting resin matrix composites

Science.gov (United States)

Loos, A. C.

1986-01-01

A model is presented for simulating the curing process of a thermosetting resin matrix composite. The model relates the cure temperature, the cure pressure, and the properties of the prepreg to the thermal, chemical, and rheological processes occurring in the composite during cure. The results calculated with the computer code developed on the basis of the model were compared with the experimental data obtained from autoclave-curved composite laminates. Good agreement between the two sets of results was obtained.

Engineering study for the treatment of spent ion exchange resin resulting from nuclear process applications

International Nuclear Information System (INIS)

Place, B.G.

1990-09-01

This document is an engineering study of spent ion exchange resin treatment processes with the purpose of identifying one or more suitable treatment technologies. Classifications of waste considered include all classes of low-level waste (LLW), mixed LLW, transuranic (TRU) waste, and mixed TRU waste. A total of 29 process alternatives have been evaluated. Evaluation parameters have included economic parameters (both total life-cycle costs and capital costs), demonstrated operability, environmental permitting, operational availability, waste volume reduction, programmatic consistency, and multiple utilization. The results of this study suggest that there are a number of alternative process configurations that are suitable for the treatment of spent ion exchange resin. The determinative evaluation parameters were economic variables (total life-cycle cost or capital cost) and waste volume reduction. Immobilization processes are generally poor in volume reduction. Thermal volume reduction processes tend to have high capital costs. There are immobilization processes and thermal volume reduction processes that can treat all classifications of spent ion exchange resin likely to be encountered. 40 refs., 19 figs., 17 tabs

Process to produce pellet-shaped neutron activation detector elements

International Nuclear Information System (INIS)

Ambardanischvili, T.S.; Dundua, V.J.; Kiknadse, G.I.; Kolomijzev, M.A.; Zezchladse, T.V.; Gromov, V.A.; Bagdavadse, N.V.

1979-01-01

The neutron activator detector elements to measure integral neutron flux contain cobalt, zinc, phosphorous, iron, gold, indium, nickel or aluminium as detector material. Its non-aqueous nitric or acetic acid salts are solvated in an alcohol solution and mixed with an alcohol solution of phenol formaldehyde resol resin. The alcohol is destilled off under vacuum at a temperature of 60 to 90 0 C whereby the detector material in the resin matrix is homogenized. This mass is their ground, pressed to pellets and is heated to convert the resin into its unsoluble state. In order to improve the radioresistance, one can add powdered carbon to the alcohol mixture, where the carbon itself can be prepared by pyrolysis and carbonization of phenol formaldehyde resin. To improve the temperature change resistance, the pellets may be additionally heated giving rise to puyrolysis of the polycondensation resin. (DG) [de

Multi-wall carbon nanotubes/epoxy resin composites characterization of the starting materials and evaluation of thermal and electrical conductivity

International Nuclear Information System (INIS)

Silva, Wellington Marcos da

2009-01-01

In this study we investigate the electrical and thermal properties of I) composite materials fabricated with O, I, 0,5 and I wt% of concentric multi-wall carbon nanotubes/epoxy resin (MWNT) dispersed randomly in the resin; 2) MWNT buckypaper/resin composite materials; 3) and neat MWNT buckypaper. Initially, we use the techniques of thermogravimetry, infrared spectroscopy, nuclear magnetic resonance, energy dispersive spectroscopy, x-ray fluorescence, scanning and transmission electron microscopy for a broadening characterization of the starting materials, to evaluate its morphology, purity, chemical composition and structure, in order to optimize the properties of crosslinked resin and, consequently, of the composite systems. Important parameters such as the average molecular mass and the equivalent weight of epoxy resin (DGEBA) were determined by 1 H-NMR analysis and, after that, resin/curing agent relations with Phr 10, 15, 20 and 53,2 were elaborated and investigated by thermogravimetry, the resin/curing agent relation with Phr 10 showed to be the most thermally stable. This stoichiometric relation was used to elaborate the composites. We have evaluated that the effect of adding 10 wt% of the solvent acetone to the epoxy resin preparation does not alter its properties so we have adopted two routes to fabricate the composites. In the first route we used 10 wt% of acetone and, in the second the MWNT were dispersed in the matrix without using the solvent. However, no significant difference was observed for the dispersion of the bundle tubes in both systems. The electrical conductivity of the composites and buckypapers was evaluated by impedance spectroscopy and the thermal conductivity by the flash laser flash method. Only the buckypapers presented high values for electrical conductivity (10 3 S.m -1 ). The composite systems presented values of 10 -3 S.m -1 , only a bit different from the value of the crosslinked resin. For thermal conductivity, the values for the

A simulated RTM process for fabricating polyimide (AMB-21) carbon fiber composites

Science.gov (United States)

Avva, V. Sarma; Sadler, Robert L.; Thomas, Shanon

1995-01-01

An experimental polyimide matrix, AMB-21 - supplied by NASA/LeRC, was especially formulated to be non-carcinogenic. It was also expected to be amenable to a Resin Transfer Molding Process (RTM). AMB-21 is a solid at room temperature and must be heated to a very high temperature to obtain a fluid state. However, even after heating it to a realistic high temperature, it was found to be too viscous for use in a RTM process. As a result, a promising approach was experimented leading to the introduction of the resin into a solvent solution in order to obtain a viscosity suitable for RTM. A mixture of methanol and tetrahydroferone was found to be a suitable solvent mixture. The matrix solution was introduced into carbon-fiber preform using two techniques: (1) injection of matrix into a Resin Transfer Mold after positioning the preform into the 'mold cavity', and (2) infiltration of matrix into the preform using the 'autoclave through-the-thickness transfer process'. After completing the resin transfer (infiltration) process, the 'filled' preform was heated to 300 F for one hour to reduce the solvent content. The temperature was then increased to 400 F under a vacuum to complete the solvent evaporation and to remove volatile products of the polyimide imidization. The impregnated preform was removed from the mold and press-cured at 200 psi and 600 FF for two hours. The resulting panel was found to be of reasonably good quality. This observation was based on the results obtained from short beam shear strength (700-8000 psi) tests and microscopic examination of the cross-section indicating a very low level of porosity. Further, the flash around the molded panels from the compression molding was free of porosity indicating the removal of volatiles, solvents, and other imidization products. Based on these studies, a new RTM mold containing a diaphragm capable of applying 200 psi at 600 F has been designed and constructed with the expectation that it will allow the

Using a scalar parameter to trace dislocation evolution in atomistic modeling

Energy Technology Data Exchange (ETDEWEB)

Yang, Jinbo [ORNL; Zhang, Z F [Shenyang National Laboratory for Materials Science; Osetskiy, Yury N [ORNL; Stoller, Roger E [ORNL

2015-01-01

A scalar gamma-parameter is proposed from the Nye tensor. Its maximum value occurs along a dislocation line, either straight or curved, when the coordinate system is purposely chosen. This parameter can be easily obtained from the Nye tensor calculated at each atom in atomistic modeling. Using the gamma-parameter, a fully automated approach is developed to determine core atoms and the Burgers vectors of dislocations simultaneously. The approach is validated by revealing the smallest dislocation loop and by tracing the whole formation process of complicated dislocation networks on the fly.

Modeling of carbon nanotubes, graphene and their composites

CERN Document Server

Silvestre, Nuno

2014-01-01

This book contains ten chapters, authored by world experts in the field of simulation at nano-scale and aims to demonstrate the potentialities of computational techniques to model the mechanical behavior of nano-materials, such as carbon nanotubes, graphene and their composites. A large part of the research currently being conducted in the fields of materials science and engineering mechanics is devoted to carbon nanotubes, graphene and their applications. In this process, computational modeling is a very attractive research tool due to the difficulties in manufacturing and testing of nano-materials. Both atomistic modeling methods, such as molecular mechanics and molecular dynamics, and continuum modeling methods are being intensively used. Continuum modeling offers significant advantages over atomistic modeling such as the reduced computational effort, the capability of modeling complex structures and bridging different analysis scales, thus enabling modeling from the nano- to the macro-scale. On the oth...

Synthesis of multi-walled carbon nanotubes and their application in resin based nanocomposites

International Nuclear Information System (INIS)

Ahmad, Shahid Nisar; Hakeem, Saira; Alvi, Rashid Ahmed; Farooq, Khawar; Farooq, Naveed; Yasmin, Farida; Saeed, Sadaf

2013-01-01

Multi-walled carbon nanotubes (MWCNTs) were synthesized by catalytic decomposition of hydrocarbon gas using chemical vapor deposition method. Synthesis was done at different growth temperatures and catalyst ratios. These MWCNTs were dispersed in epoxy resin (E-51) and their effect on mechanical strength of epoxy nanocomposites was studied. Increase in the mechanical strength of epoxy was observed with the addition of CNTs. The surface characterization was done by using optical microscope and scanning electron microscope (SEM). Mechanical properties were determined by the general tensile strength testing method.

Influence of the vacuum resin process, on the ballistic behaviour of lightweight armouring solutions

Directory of Open Access Journals (Sweden)

Coutellier D.

2012-08-01

Full Text Available The armour of vehicles against conventional threats is mainly composed with steel or aluminium panels. Efficient heavy solutions exist, but the involved industries require new lightweight structures. Moreover, unconventional threats as IEDs (Improvised Explosive Devices may cause severe damages on these structural and protective panel solutions. Thus, combination of aluminium or steel plates with textile composite structures used as a backing, leads to the mass reduction and better performance under delamination behaviour against these new threats. This paper is a part of a study dealing with the impact behaviour of three warp interlocks weaving structures under Fragment Simulating Projectile (FSP impact. During this research, several parameters has being studied as the influence of the yarns insertions [1–4], the degradation of the yarns during the weaving process [5–7], and the influence of the resin rate on the ballistic behaviour. The resin rate inside composite materials is dependant on the final application. In ballistic protection, we need to control the resin rate in order to have a deformable structure in order to absorb the maximum of energy. However, with the warp interlocks weaving structure, the yarns insertions induce empty spaces between the yarns where the resin takes place without being evacuated. The resin rate inside the warp interlocks structures is in the most of cases less than 50%, which lead to have brittle and hard material during the impact. Contrary to interlocks structures, the existing protection based on prepreg structure have a high fibres ratio around 88% of weight. That leads to have the best ballistic properties during the impact and good deformability of the structure. The aim of this paper is to evaluate the influence of the resin rate on the ballistic results of the composites materials. For that, we have chosen two kinds of warp interlocks fabrics which were infused with epoxy resin following two

Experimental Characterization Of The Interaction Between Carbon Fiber Composite Prepregs During The Preforming Process

Energy Technology Data Exchange (ETDEWEB)

Zhang, Weizhao; Zhang, Zixuan; Lu, Jie; Wang, Q Jane; Su, Xuming; Zeng, Danielle; Mirdamadi, Mansour; Cao, Jian

2016-04-06

Carbon fiber composites have received growing attention because of their high performance. One economic method to manufacturing the composite parts is the sequence of forming followed by the compression molding process. In this sequence, the preforming procedure forms the prepreg, which is the composite with the uncured resin, to the product geometry while the molding process cures the resin. Slip between different prepreg layers is observed in the preforming step and this paper reports a method to characterize the properties of the interaction between different prepreg layers, which is critical to predictive modeling and design optimization. An experimental setup was established to evaluate the interactions at various industrial production conditions. The experimental results were analyzed for an in-depth understanding about how the temperature, the relative sliding speed, and the fiber orientation affect the tangential interaction between two prepreg layers. The interaction factors measured from these experiments will be implemented in the computational preforming program.

Mechanical performance optimization of neutron shielding material based on short carbon fiber reinforced B4C/epoxy resin

International Nuclear Information System (INIS)

Wang Peng; Tang Xiaobin; Chen Feida; Chen Da

2013-01-01

To satisfy engineering requirements for mechanics performance of neutron shielding material, short carbon fiber was used to reinforce the traditional containing B 4 C neutron shielding material and effects of fiber content, length and surface treatment to mechanics performance of material was discussed. Based on Americium-Beryllium neutron source, material's neutron shielding performance was tested. The result of experiment prove that tensile strength of material which the quality ratio of resin and fiber is 5:1 is comparatively excellent for 10wt% B 4 C of carbon fiber reinforced epoxy resin. The tensile properties of material change little with the fiber length ranged from 3-10 mm The treatment of fiber surface with silane coupling agent KH-550 can increase the tensile properties of materials by 20% compared with the untreated of that. A result of shielding experiment that the novel neutron shielding material can satisfy the neutron shielding requirements can be obtained by comparing with B 4 C/polypropylene materials. The material has good mechanical properties and wide application prospect. (authors)

Decomposing method for ion exchange resin

International Nuclear Information System (INIS)

Sako, Takeshi; Sato, Shinshi; Akai, Yoshie; Moniwa, Shinobu; Yamada, Kazuo

1998-01-01

The present invention concerns a method of decomposing ion exchange resins generated in a nuclear power plant to carbon dioxide reliably in a short period of time. (1) The ion exchange resins are mixed with water, and then they are kept for a predetermined period of time in the presence of an inert gas at high temperature and high pressure exceeding the critical point of water to decompose the ion exchange resins. (2) The ion exchange resins is mixed with water, an oxidant is added and they are kept for a predetermined time in the presence of an inert gas at a high temperature and a high pressure exceeding a critical point of water of an inert gas at a high temperature to decompose the ion exchange resins. (3) An alkali or acid is added to ion exchange resins and water to control the hydrogen ion concentration in the solution and the ion exchange resins are decomposed in above-mentioned (1) or (2). Sodium hydroxide is used as the alkali and hydrochloric acid is used as the acid. In addition, oxygen, hydrogen peroxide or ozone is used as an oxidant. (I.S.)

Simulation and Validation of Injection-Compression Filling Stage of Liquid Moulding with Fast Curing Resins

Science.gov (United States)

Martin, Ffion A.; Warrior, Nicholas A.; Simacek, Pavel; Advani, Suresh; Hughes, Adrian; Darlington, Roger; Senan, Eissa

2018-03-01

Very short manufacture cycle times are required if continuous carbon fibre and epoxy composite components are to be economically viable solutions for high volume composite production for the automotive industry. Here, a manufacturing process variant of resin transfer moulding (RTM), targets a reduction of in-mould manufacture time by reducing the time to inject and cure components. The process involves two stages; resin injection followed by compression. A flow simulation methodology using an RTM solver for the process has been developed. This paper compares the simulation prediction to experiments performed using industrial equipment. The issues encountered during the manufacturing are included in the simulation and their sensitivity to the process is explored.

Utilisation of the binders prepared from coal tar pitch and phenolic resins for the production metallurgical quality briquettes from coke breeze and the study of their high temperature carbonization behaviour

Energy Technology Data Exchange (ETDEWEB)

Benk, Ayse [University of Erciyes, Faculty of Art and Science, Department of Chemistry, 38039, Kayseri (Turkey)

2010-09-15

To reduce the cost of the formed coke briquettes which can be used as a substitute fuel to the metallurgical coke for the blast furnace from the coke breeze alternative binders and their blends were used. The high temperature behavior was investigated. The binders tested were: the nitrogen blown, air blown coal tar pitch and the blend of air blown coal tar pitch with the phenolic resins blends. The phenolic resin blends were prepared by mixing equal amount of resole and novalac. From the results, nitrogen blowing resulted in the weakest briquettes. The air blowing procedure should be preferred in place of nitrogen blowing for this purpose. When the air blown coal tar pitch was used alone as a binder, the briquettes must be cured at 200 C for 2 h, then carbonized at a temperature above 670 C. Since it requires higher temperature at carbonization stage, using air blown coal tar pitch alone as a binder was not economical. Therefore, the briquettes were prepared from the blended binder, containing air blown coal tar pitch and phenolic resins blend. The optimum amount of air blown coal tar pitch was found to be 50% w/w in the blended binder. Curing the briquettes at 200 C for 2 h was found to be sufficient for producing strong briquettes with a tensile strength of 50.45 MN/m{sup 2}. When these cured briquettes were carbonized at temperatures 470 C, 670 C and 950 C, their strength were increasing continuously, reaching to 71.85 MN/m{sup 2} at the carbonization temperature of 950 C. These briquettes can be used as a substitute for the metallurgical coke after curing; the process might not require un-economical high temperature carbonization stage. (author)

Properties and processing characteristics of low density carbon cloth phenolic composites

Science.gov (United States)

Wang, C. Jeff

1993-01-01

Ply-lift and pocketing are two critical anomalies of carbon cloth phenolic composites (CCPC) in rocket nozzle applications. Ply lift occurs at low temperatures when the A/P and in-plane permeabilities of the composite materials are still very low and in-plane porous paths are blocked. Pocketing occurs at elevated temperatures when in-plane permeability is reduced by the A/P compressive stress. The thermostructural response of CCPC in a rapid heating environment involves simultaneous heat, mass, and momentum transfer along with the degradation of phenolic resin in a multiphase system with temperature- and time-dependent material properties as well as dynamic processing conditions. Three temperature regions represent the consequent chemical reactions, material transformations, and property transitions, and provide a quick qualitative method for characterizing the thermostructural behavior of a CCPC. In order to optimize the FM5939 LDCCP (low density carbon cloth phenolic) for the nozzle performance required in the Advanced Solid Rocket Motor (ASRM) program, a fundamental study on LDCCP materials was conducted. The cured composite has a density of 1.0 +/- 0.5 gm/cc which includes 10 to 25 percent void volume. The weight percent of carbon microballoon is low (7-15 percent). However, they account for approximately one third of the volume and historically their percentages have not been controlled very tightly. In addition, the composite properties show no correlation with microballoon weight percent or fiber properties (e.g. fiber density or fiber moisture adsorption capacity). Test results concerning the ply-lift anomaly in the MNASA motor firings were: (1) Steeper ply angle (shorter path lenght) designs minimized/eliminated by lifting, (2) material with higher void volume ply lifted less frequently, (3) materials with high (greater than 9 percent) microballoon content had a higher rate of ply lifting, and (4) LDCCP materials failed at microballoon-resin interfaces

Epoxy resins used to seal brachytherapy seed

International Nuclear Information System (INIS)

Ferreira, Natalia Carolina Camargos; Ferraz, Wilmar Barbosa; Reis, Sergio Carneiro dos; Santos, Ana Maria Matildes dos

2013-01-01

Prostate cancer treatment with brachytherapy is recommended for patients with cancer at an early stage. In this treatment, small radioactive seeds are implanted directly in the prostate gland. These seeds are composed at least of one radionuclide carrier and an X-ray marker enclosed within a metallic tube usually sealed by laser process. This process is expensive and, furthermore, it can provoke a partial volatilization of the radionuclide and change the isotropy in dose distribution around the seed. In this paper, we present a new sealing process using epoxy resin. Three kinds of resins were utilized and characterized by scanning electron microscopy (SEM), energy dispersive X ray (EDS) and by differential scanning calorimetry (DSC) after immersion in simulated body fluid (SBF) and in sodium iodine solution (NaI). The sealing process showed excellent potential to replace the sealing laser usually employed. (author)

Simulation of Air Entrapment and Resin Curing During Manufacturing of Composite Cab Front by Resin Transfer Moulding Process

Directory of Open Access Journals (Sweden)

Kuppusamy Raghu Raja Pandiyan

2017-09-01

Full Text Available Mould filling and subsequent curing are the significant processing stages involved in the production of a composite component through Resin Transfer Moulding (RTM fabrication technique. Dry spot formation and air entrapment during filling stage caused by improper design of filling conditions and locations that lead to undesired filling patterns resulting in defective RTM parts. Proper placement of inlet ports and exit vents as well as by adjustment of filling conditions can alleviate the problems during the mould filling stage. The temperature profile used to polymerize the resin must be carefully chosen to reduce the cure time. Instead of trial and error methods that are expensive, time consuming, and non-optimal, we propose a simulation-based optimization strategy for a composite cab front component to reduce the air entrapment and cure stage optimization. In order to be effective, the optimization strategy requires an accurate simulation of the process utilizing submodels to describe the raw material characteristics. Cure reaction kinetics and chemo-rheology were the submodels developed empirically for an unsaturated polyester resin using experimental data. The simulations were performed using commercial software PAM RTM 2008, developed by ESI Technologies. Simulation results show that the use of increase in injection pressure at the inlet filling conditions greatly reduce the air entrapped. For the cab front, the alteration of injection pressure with proper timing of vent opening reduced the air entrapped during mould filling stage. Similarly, the curing simulation results show that the use of higher mould temperatures effectively decreases the cure time as expected.

Annealing effects of carbon fiber-reinforced epoxy resin composites irradiated by electron beams

International Nuclear Information System (INIS)

Udagawa, Akira; Sasuga, Tuneo; Ito, Hiroshi; Hagiwara, Miyuki

1987-01-01

Carbon cloth-reinforced epoxy resin composites were irradiated with 2 MeV electrons at room temperature and then annealed in air for 2 h at temperatures up to 180 deg C. A considerable decrease in the three-point bending strength occurred when the irradiated composites were annealed in the temperature range of 115 - 135 deg C which is below the glass transition temperature T g of the matrix resin, while the bending strength remained unchanged up to 180 deg C for the unirradiated composites. In the dynamic viscoelastic spectra of the irradiated matrix, a new relaxation appeared at the temperature extending from 50 deg C to just below the matrix T g and disappeared on annealing for 2 h at 135 deg C. Annealing also decreased the concentration of free radicals existing stably in the irradiated matrix at room temperature. After annealing, a large amount of clacks and voids were observed in the fractography of the composites by scanning electron microscopy. These results indicate: (1) Annealing brings about rearrangement of the radiation-induced molecular chain scission in the matrix; (2) The bending strength of the irradiated composites decreased owing to the increased brittleness of the matrix by annealing. (author)

Preparation of carbon fiber unsaturated sizing agent for enhancing interfacial strength of carbon fiber/vinyl ester resin composite

Science.gov (United States)

Jiao, Weiwei; Cai, Yemeng; Liu, Wenbo; Yang, Fan; Jiang, Long; Jiao, Weicheng; Wang, Rongguo

2018-05-01

The practical application of carbon fiber (CF) reinforced vinyl ester resin (VE) composite was hampered seriously by the poor interfacial adhesion property. In this work, a novel unsaturated sizing agent was designed and prepared to improve the interfacial strength by covalently bonding CF with VE matrix. The main component of the sizing agent, N-(4‧4-diaminodiphenyl methane)-2-hydroxypropyl methacrylate (DMHM), was synthesized and confirmed by FTIR and NMR. XPS results of sized carbon fiber (SCF) showed that DMHM has adhered to desized fiber surface and reacted with some active functional groups on the surface. The SCF was characterized by high surface roughness and surface energy (especially the polar component), which means better wettability by VE. As a result, the interface shear strength and interlaminar shear strength of SCF/VE composite were enhanced by 96.56% and 66.07% respectively compared with CF/VE composite, benefited mainly from the strong and tough interphase.

Application conditions for ester cured alkaline phenolic resin sand

Directory of Open Access Journals (Sweden)

Ren-he Huang

2016-07-01

Full Text Available Five organic esters with different curing speeds: propylene carbonate (i.e. high-speed ester A; 1, 4-butyrolactone; glycerol triacetate (i.e. medium-speed ester B; glycerol diacetate; dibasic ester (DBE (i.e. low-speed ester C, were chosen to react with alkaline phenolic resin to analyze the application conditions of ester cured alkaline phenolic resin. The relationships between the curing performances of the resin (including pH value, gel pH value, gel time of resin solution, heat release rate of the curing reaction and tensile strength of the resin sand and the amount of added organic ester and curing temperature were investigated. The results indicated the following: (1 The optimal added amount of organic ester should be 25wt.%-30wt.% of alkaline phenolic resin and it must be above 20wt.%-50 wt.% of the organic ester hydrolysis amount. (2 High-speed ester A (propylene carbonate has a higher curing speed than 1, 4-butyrolactone, and they were both used as high-speed esters. Glycerol diacetate is not a high-speed ester in alkaline phenolic resin although it was used as a high-speed ester in ester cured sodium silicate sand; glycerol diacetate and glycerol triacetate can be used as medium-speed esters in alkaline phenolic resin. (3 High-speed ester A, medium-speed ester B (glycerol triacetate and low-speed ester C (dibasic ester, i.e., DBE should be used below 15 ìC, 35 ìC and 50 ìC, respectively. High-speed ester A or low-speed ester C should not be used alone but mixed with medium-speed ester B to improve the strength of the resin sand. (4 There should be a suitable solid content (generally 45wt.%-65wt.% of resin, alkali content (generally 10wt.%-15wt.% of resin and viscosity of alkaline phenolic resin (generally 50-300 mPa≤s in the preparation of alkaline phenolic resin. Finally, the technique conditions of alkaline phenolic resin preparation and the application principles of organic ester were discussed.

Nanocomposite of photocurable epoxy-acrylate resin and carbon nanotubes: dynamic-mechanical, thermal and tribological properties

Directory of Open Access Journals (Sweden)

Marcos Nunes dos Santos

2013-04-01

Full Text Available In this study, the thermal, dynamic-mechanical and tribological behavior of nanocomposites of a photocurable epoxy-acrylate resin and multiwalled carbon nanotubes (MWCNT are investigated. A route consisting of a combination of sonication, mechanical and magnetic stirring is used to disperse 0.25-0.75 wt. (% MWCNT into the resin. Two photocuring cycles using 12 hours and 24 hours of UV-A radiation are studied. The storage modulus, the loss modulus and the tan delta are obtained by dynamic mechanical analysis. Thermal stability is investigated by thermogravimetry, morphology by transmission electronic microscopy (TEM and tribological performance using a pin-on-disk apparatus. The results indicate an increase in stiffness and higher ability to dissipate energy, as well as a shift in the glass transition temperature for the nanocomposites. The addition of nanofillers also decreased friction coefficient and wear rate of the nanocomposites but did not change the observed wear mechanisms.

Nanocomposite of photocurable epoxy-acrylate resin and carbon nanotubes: dynamic-mechanical, thermal and tribological properties

Directory of Open Access Journals (Sweden)

Marcos Nunes dos Santos

2012-01-01

Full Text Available In this study, the thermal, dynamic-mechanical and tribological behavior of nanocomposites of a photocurable epoxy-acrylate resin and multiwalled carbon nanotubes (MWCNT are investigated. A route consisting of a combination of sonication, mechanical and magnetic stirring is used to disperse 0.25-0.75 wt. (% MWCNT into the resin. Two photocuring cycles using 12 hours and 24 hours of UV-A radiation are studied. The storage modulus, the loss modulus and the tan delta are obtained by dynamic mechanical analysis. Thermal stability is investigated by thermogravimetry, morphology by transmission electronic microscopy (TEM and tribological performance using a pin-on-disk apparatus. The results indicate an increase in stiffness and higher ability to dissipate energy, as well as a shift in the glass transition temperature for the nanocomposites. The addition of nanofillers also decreased friction coefficient and wear rate of the nanocomposites but did not change the observed wear mechanisms.

Low Temperature Mechanical Testing of Carbon-Fiber/Epoxy-Resin Composite Materials

Science.gov (United States)

Nettles, Alan T.; Biss, Emily J.

1996-01-01

The use of cryogenic fuels (liquid oxygen and liquid hydrogen) in current space transportation vehicles, in combination with the proposed use of composite materials in such applications, requires an understanding of how such materials behave at cryogenic temperatures. In this investigation, tensile intralaminar shear tests were performed at room, dry ice, and liquid nitrogen temperatures to evaluate the effect of temperature on the mechanical response of the IM7/8551-7 carbon-fiber/epoxy-resin system. Quasi-isotropic lay-ups were also tested to represent a more realistic lay-up. It was found that the matrix became both increasingly resistant to microcracking and stiffer with decreasing temperature. A marginal increase in matrix shear strength with decreasing temperature was also observed. Temperature did not appear to affect the integrity of the fiber-matrix bond.

Molecular Simulations of Cyclic Loading Behavior of Carbon Nanotubes Using the Atomistic Finite Element Method

Directory of Open Access Journals (Sweden)

Jianfeng Wang

2009-01-01

Full Text Available The potential applications of carbon nanotubes (CNT in many engineered bionanomaterials and electromechanical devices have imposed an urgent need on the understanding of the fatigue behavior and mechanism of CNT under cyclic loading conditions. To date, however, very little work has been done in this field. This paper presents the results of a theoretical study on the behavior of CNT subject to cyclic tensile and compressive loads using quasi-static molecular simulations. The Atomistic Finite Element Method (AFEM has been applied in the study. It is shown that CNT exhibited extreme cyclic loading resistance with yielding strain and strength becoming constant within limited number of loading cycles. Viscoelastic behavior including nonlinear elasticity, hysteresis, preconditioning (stress softening, and large strain have been observed. Chiral symmetry was found to have appreciable effects on the cyclic loading behavior of CNT. Mechanisms of the observed behavior have been revealed by close examination of the intrinsic geometric and mechanical features of tube structure. It was shown that the accumulated residual defect-free morphological deformation was the primary mechanism responsible for the cyclic failure of CNT, while the bond rotating and stretching experienced during loading/unloading played a dominant role on the strength, strain and modulus behavior of CNT.

Bituminization of simulated waste, spent resins, evaporator concentrates and animal ashes by extrusion process

International Nuclear Information System (INIS)

Grosche Filho, C.E.; Chandra, U.

1986-01-01

The results of the study of simulated radwaste, spent ion-exchange resins, borates/evaporator-concentrates and animal ashes, in bituminized form, are presented and discussed. Distilled and oxidized bitumen were used for characterizing the crude material and simulated wastes-bitumen mixtures of varying weight composition 30, 40, 50, 60% by weight the dry waste material. The asphaltine and parafin contents in the bitumens were determined. Some additives and clays were used aiming best characteristics of solidified wastes. For leaching studies, granular ion-exchange resins were loaded with Cs 134 and mixtures of resins-bitumens were prepared. The leaching studies were executed using the IAEA recommendation and the ISO method. It was used a conventional screw-extruder, used in plastic industry, to determine operational conditions and process difficulties. Mixtures resins-bitumen and concentrate-bitumen in differents operational condition were prepared and analysed. (Author) [pt

Preparation of minor actinides targets or blankets by the means of Ionic Exchange Resin

Energy Technology Data Exchange (ETDEWEB)

Picart, S.; Mokhtari, H.; Ramiere, I.; Jobelin, I. [CEA, Nuclear Energy Division, RadioChemistry and Process Department, Actinides Chemistry Laboratory, BP17171, Bagnols-sur-Ceze, 30207 (France)

2009-06-15

The objective of our R and D work is the elaboration by the use of ionic exchange resin of minor actinide precursors for target or blanket dedicated to their transmutation in sodium fast reactor. From the beginning, the resin process called WAR (acronym of Weak Acid Resin) was developed in the 70's at the ORNL for the making of uranium carbide kernels for the high temperature gas reactor [1] [2]. By now, our aim is to extend this concept to the manufacturing of minor actinides oxide mixed with uranium oxides [3]. More precisely, this process can be divided in two major steps: the loading of the resin and the thermal treatment of the fully loaded resin driving either to oxide or carbide phases depending on the gas atmosphere. The difficulty stems from the preparation of the loading solutions which must fulfill precise conditions of pH in presence of actinides cations prone to hydrolysis. Furthermore, the proportions of uranium and minor actinides in solutions must be adjusted to fit the right ratio in the solid. The study presented here will then focus on the experiments and tests which enable us to optimize the fixing of minor actinides on ionic exchange resin and their carbonization in oxide. [1] G. W. Weber, R. L. Beatty et V. J. Tennery, Nuclear Technology, 35, 217-226, (1977), 'Processing and composition control of weak-acid-resin derived fuel microspheres'. [2] K. J. Notz, P. A. Haas, J. H. Shaffer, Radiochimica Acta, 25, 153-160, (1978). 'The preparation of HTGR Fissile Fuel Kernels by Uranium Loading of Ion Exchange Resin'. [3] S. Picart, H. Mokhtari, I. Ramiere, 'Plutonium Futures, The Science 2008', 7-11 july 2008, Dijon, France. 'Modelling of the ionic Exchange between a weak acid resin in its ammonium form and a minor actinide'. (authors)

A method for producing a hydrocarbon resin

Energy Technology Data Exchange (ETDEWEB)

Tsachev, A B; Andonov, K S; Igliyev, S P

1980-11-25

Rock coal resin (KS), for instance, with a relative density of 1,150 to 1,190 kilograms per cubic meter, which contains 8 to 10 percent naphthaline, 1.5 to 2.8 percent phenol and 6 to 15 percent substances insoluble in toluene, or its mixture with rock coal or oil fractions of resin are subjected to distillation (Ds) in a pipe furnace with two evaporators (Is) and a distillation tower with a temperature mode in the second stage of 320 to 360 degrees and 290 to 340 degrees in the pitch compartment. A hydrocarbon resin is produced with a high carbon content, especially for the production of resin and dolomite refractory materials, as well as fuel mixtures for blast furnace and open hearth industry.

Parallel Atomistic Simulations

Energy Technology Data Exchange (ETDEWEB)

HEFFELFINGER,GRANT S.

2000-01-18

Algorithms developed to enable the use of atomistic molecular simulation methods with parallel computers are reviewed. Methods appropriate for bonded as well as non-bonded (and charged) interactions are included. While strategies for obtaining parallel molecular simulations have been developed for the full variety of atomistic simulation methods, molecular dynamics and Monte Carlo have received the most attention. Three main types of parallel molecular dynamics simulations have been developed, the replicated data decomposition, the spatial decomposition, and the force decomposition. For Monte Carlo simulations, parallel algorithms have been developed which can be divided into two categories, those which require a modified Markov chain and those which do not. Parallel algorithms developed for other simulation methods such as Gibbs ensemble Monte Carlo, grand canonical molecular dynamics, and Monte Carlo methods for protein structure determination are also reviewed and issues such as how to measure parallel efficiency, especially in the case of parallel Monte Carlo algorithms with modified Markov chains are discussed.

Modification of bifunctional epoxy resin using CO2 fixation process and nanoclay

International Nuclear Information System (INIS)

Khoshkish, Morteza; Bouhendi, Hosein; Vafayan, Mehdi

2014-01-01

A bifunctional epoxy resin was modified by using a CO 2 fixation solution process in the presence of tetra n-butyl ammonium bromide (TBAB) as catalyst and the modified treated resin was treated by cloisite 30B as nano additive. The Unmodified epoxy resin (UME), CO 2 fixated modified epoxy resin (CFME), and CFME/clay nano composite (CFMEN), were cured by diethylenetriamine (DETA). A cycloaliphatic compound as a reactive diluent was used to control the viscosity of high viscose CFME. The exfoliation of organoclay in UME and CFME was investigated by X-ray diffraction and activation energy was computed using the advanced integral isoconversional method. The activation energy dependency demonstrated that the mechanism of UME curing did not change in the presence of nanoclay. In contrast, the CO 2 fixation results showed a significant change in the activation energy dependency. The Thermal stability parameters include the initial degradation temperature (IDT), the temperature at the maximum rate of weight loss (T max ), and the decomposition activation energy (E d ) were determined by thermal gravimetry analysis. Dynamic mechanical thermal analysis measurements showed that the presence of organoclay in CFME increases the T g of nano composite in contrast to UME. The fracture roughness of UME, CFME and CFNE were determined by scanning electron microscope. The exfoliated UME/1%clay nanocomposite was confirmed by TEM image. - Highlights: • A new epoxy resin was synthesized using CO 2 fixation reaction. • The synthesized epoxy resin was modified by an organo nano-clay. • CO 2 fixation noticeably changed the curing mechanism. • CO 2 fixation reaction consumes CO 2 which is a harmful greenhouse gas

Preparation of carbon dioxide adsorbents from the chemical activation of urea-formaldehyde and melamine-formaldehyde resins

Energy Technology Data Exchange (ETDEWEB)

T.C. Drage; A. Arenillas; K.M. Smith; C. Pevida; S. Piippo; C.E. Snape [University of Nottingham, Nottingham (United Kingdom). Nottingham Fuel and Energy Centre, School of Chemical, Environmental and Mining Engineering

2007-01-15

Adsorption is considered to be one of the more promising technologies for the capture of CO{sub 2} from flue gases. In general, nitrogen enrichment is reported to be effective in enhancing the specific adsorbent-adsorbate interaction for CO{sub 2}. Nitrogen enriched carbons were produced from urea-formaldehyde and melamine-formaldehyde resins polymerised in the presence of K{sub 2}CO{sub 3} as a chemical activation agent, with activation undertaken over a range of temperatures. CO{sub 2} adsorption capacity was determined to be dependent upon both textural properties and more importantly nitrogen functionality. Adsorbents capable of capturing above 8 wt.% CO{sub 2} at 25{sup o}C were produced from the chemical activation of urea-formaldehyde resin at 500{sup o}C. Chemical activation seems to produce more effective adsorbents than CO{sub 2} activation. 29 refs., 4 figs., 3 tabs.

Radiation processing for carbon fiber-reinforced polytetrafluoroethylene composite materials

International Nuclear Information System (INIS)

Oshima, Akihiro; Udagawa, Akira; Morita, Yousuke

2001-01-01

The present work is an attempt to evaluate the performance of the fiber composites with crosslinked polytetrafluoroethylene (PTFE) as a polymer matrix by radiation. The uni-directional carbon fiber-reinforced composites were fabricated with PTFE fine powder impregnation method and then crosslinked by electron beams irradiation under selective conditions. The carbon fiber-reinforced crosslinked PTFE composites show good mechanical properties compared with crosslinked PTFE. The radiation resistance of crosslinked PTFE composites is improved more than that of crosslinked resin without fiber. (author)

Potential contribution of exposed resin to ecosystem emissions of monoterpenes

Science.gov (United States)

Eller, Allyson S. D.; Harley, Peter; Monson, Russell K.

2013-10-01

Conifers, especially pines, produce and store under pressure monoterpene-laden resin in canals located throughout the plant. When the plants are damaged and resin canals punctured, the resin is exuded and the monoterpenes are released into the atmosphere, a process that has been shown to influence ecosystem-level monoterpene emissions. Less attention has been paid to the small amounts of resin that are exuded from branches, expanding needles, developing pollen cones, and terminal buds in the absence of any damage. The goal of this study was to provide the first estimate of the potential of this naturally-exposed resin to influence emissions of monoterpenes from ponderosa pine (Pinus ponderosa) ecosystems. When resin is first exuded as small spherical beads from undamaged tissues it emits monoterpenes to the atmosphere at a rate that is four orders of magnitude greater than needle tissue with an equivalent exposed surface area and the emissions from exuded beads decline exponentially as the resin dries. We made measurements of resin beads on the branches of ponderosa pine trees in the middle of the growing season and found, on average, 0.15 cm2 of exposed resin bead surface area and 1250 cm2 of total needle surface area per branch tip. If the resin emerged over the course of 10 days, resin emissions would make up 10% of the ecosystem emissions each day. Since we only accounted for exposed resin at a single point in time, this is probably an underestimate of how much total resin is exuded from undamaged pine tissues over the course of a growing season. Our observations, however, reveal the importance of this previously unrecognized source of monoterpenes emitted from pine forests and its potential to influence regional atmospheric chemistry dynamics.

Flexural Strength of Acrylic Resin Denture Bases Processed by Two Different Methods

Directory of Open Access Journals (Sweden)

Jafar Gharechahi

2014-09-01

Full Text Available Background and aims. The aim of this study was to compare flexural strength of specimens processed by conventional and injection-molding techniques. Materials and methods. Conventional pressure-packed PMMA was used for conventional pressure-packed and injection-molded PMMA was used for injection-molding techniques. After processing, 15 specimens were stored in distilled water at room temperature until measured. Three-point flexural strength test was carried out. Statistical analysis was carried out by SPSS using t-test. Statistical significance was defined at P<0.05. Results. Flexural strength of injection-polymerized acrylic resin specimens was higher than that of theconventional method (P=0.006. This difference was statistically significant (P=0.006. Conclusion. Within the limitations of this study, flexural strength of acrylic resin specimens was influenced by the mold-ing technique.

Bituminization of simulated waste, spent resins, evaporator concentrates and animal ashes by extrusion process

International Nuclear Information System (INIS)

Grosche Filho, C.E.; Chandra, U.

1987-01-01

The results of the study of bituminization of simulated radwaste - spennt ion-exchange resins, borate evaporator/concentrates and animal ashes, are presented and discussed. Distilled and oxidizer bitumen were used. Characterization of the crude material and simulated wastes-bitumen mixtures of varying weigt composition (30, 40, 50, 60% by weight of dry waste material) was carried out. The asphaltene and parafin contents in the bitumens were also determined. Some additives and were used with an aim to improve the characteristcs of solidified wastes. For leaching studies, granular ion-exchange resins were with Cs - 134 and mixtures of resin-bitumen were prepared. The leaching studies were executed using the IAEA recommendation and the ISO method. A conventional screw-extruder, common in plastic industry, was used determine operational parameters and process difficulties. Mixtures of resin-bitumen and evaporator concentrate-bitumen obtained from differents operational conditions were characterized. (Author) [pt

Chromatographic separation process with pellicular ion exchange resins that can be used for ion or isotope separation and resins used in this process

International Nuclear Information System (INIS)

Carles, M.; Neige, R.; Niemann, C.; Michel, A.; Bert, M.; Bodrero, S.; Guyot, A.

1989-01-01

For separation of uranium, boron or nitrogen isotopes, an isotopic exchange is carried out betwen an isotope fixed on an ion exchange resin and another isotope of the same element in the liquid phase contacting the resin. Pellicular resins are used comprising composite particulates with an inert polymeric core and a surface layer with ion exchange groups [fr

Atomistic computer simulations a practical guide

CERN Document Server

Brazdova, Veronika

2013-01-01

Many books explain the theory of atomistic computer simulations; this book teaches you how to run them This introductory ""how to"" title enables readers to understand, plan, run, and analyze their own independent atomistic simulations, and decide which method to use and which questions to ask in their research project. It is written in a clear and precise language, focusing on a thorough understanding of the concepts behind the equations and how these are used in the simulations. As a result, readers will learn how to design the computational model and which parameters o

Ionic diffusion in quartz studied by transport measurements, SIMS and atomistic simulations

International Nuclear Information System (INIS)

Sartbaeva, Asel; Wells, Stephen A; Redfern, Simon A T; Hinton, Richard W; Reed, Stephen J B

2005-01-01

Ionic diffusion in the quartz-β-eucryptite system is studied by DC transport measurements, SIMS and atomistic simulations. Transport data show a large transient increase in ionic current at the α-β phase transition of quartz (the Hedvall effect). The SIMS data indicate two diffusion processes, one involving rapid Li + motion and the other involving penetration of Al and Li atoms into quartz at the phase transition. Atomistic simulations explain why the fine microstructure of twin domain walls in quartz near the transition does not hinder Li + diffusion

[Investigation on the process of sapindus saponin purified with macroporous adsorption resin and screening of its bacteriostasis].

Science.gov (United States)

Fu, Yong; Lei, Peng; Han, Yu-mei; Yan, Dan

2010-02-01

To study the technological parameters of the purification process of saponins with macroporous adsorption resin. The adsorptive characteristics and elutive parameters of the process were studied by taking the elutive and purified ratio of saponins as markers. Bacteriostasis activity of each parts eluted was evaluated by the mean of cup-plate method. 13.6 mL of the extraction of sapindus saponin (crude drugs 0.01 g/mL) was purified with a column of macroporous adsorption resin (phi15 mm x H90 mm, dry weight 2.5 g) and washed with 3BV of distilled water, then eluted with 3BV of 30% ethanol and 3BV of 70% ethanol, most of saponins were collected in the 70% ethanol. With macroporous adsorption resin adsorbing and purifying, the elutive ratio of saponins was 93.8% and the purity reached 250.1%. So this process of applying macroporous adsorption resin to adsorb and purify saponins is feasible, and supplies reference to the purification of other types of saponin.

Contact allergy to epoxy resin

DEFF Research Database (Denmark)

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

2012-01-01

Background. Epoxy resin monomers are strong skin sensitizers that are widely used in industrial sectors. In Denmark, the law stipulates that workers must undergo a course on safe handling of epoxy resins prior to occupational exposure, but the effectiveness of this initiative is largely unknown...... in an educational programme. Conclusion. The 1% prevalence of epoxy resin contact allergy is equivalent to reports from other countries. The high occurrence of epoxy resin exposure at work, and the limited use of protective measures, indicate that reinforcement of the law is required....

Assessment of the impact strength of the denture base resin polymerized by various processing techniques

Directory of Open Access Journals (Sweden)

Rajashree Jadhav

2013-01-01

Full Text Available Aim : To measure the impact strength of denture base resins polymerized using short and long curing cycles by water bath, pressure cooker and microwave techniques. Materials and Methods: For impact strength testing, 60 samples were made. The sample dimensions were 60 mm × 12 mm × 3 mm, as standardized by the American Standards for Testing and Materials (ASTM. A digital caliper was used to locate the midpoint of sample. The impact strength was measured in IZOD type of impact tester using CEAST Impact tester. The pendulum struck the sample and it broke. The energy required to break the sample was measured in Joules. Data were analyzed using Student′s " t" test. Results: There was statistically significant difference in the impact strength of denture base resins polymerized by long curing cycle and short curing cycle in each technique, with the long curing processing being the best. Conclusion: The polymerization technique plays an important role in the influence of impact strength in the denture base resin. This research demonstrates that the denture base resin polymerized by microwave processing technique possessed the highest impact strength.

Optimal Composite Material for Low Cost Fabrication of Large Composite Aerospace Structures using NASA Resins or POSS Nanoparticle Modifications

Science.gov (United States)

Lamontia, Mark A.; Gruber, Mark B.; Jensen, Brian J.

2006-01-01

Thermoplastic laminates in situ consolidated via tape or tow placement require full mechanical properties. Realizing full properties requires resin crystallinity to be controlled - partial crystallinity leads to unacceptably low laminate compression properties. There are two approaches: utilize an amorphous matrix resin; or place material made from a semi-crystalline resin featuring kinetics faster than the process. In this paper, a matrix resin evaluation and trade study was completed with commercial and NASA amorphous polyimides on the one hand, and with PEKK mixed with POSS nanoparticles for accelerated crystallinity growth on the other. A new thermoplastic impregnated material, 6 mm wide (0.25-in) AS-4 carbon/LaRC(TradeMark)8515 dry polyimide tow, was fabricated. Since LaRC(TradeMark)8515 is fully amorphous, it attains full properties following in situ consolidation, with no post processing required to build crystallinity. The tow in situ processing was demonstrated via in situ thermoplastic filament winding it into rings.

Synthesis of resorcinol resin as a polymer adsorbent, and study of its usability in uranium sorption process

International Nuclear Information System (INIS)

Aslani, M. A. A.; Yusan, S.; Goek, C.; Akyil, S.; Aytas, S.

2009-01-01

Uranium is one of the most important elements in nuclear fuel technology. In order to obtain purified of this element at uranium mining and processing the use of synthetic resins is significant at column and/or batch process. The synthesis of resorcinol resin polymer was carried out with a modified microwave oven instead of the conventional heater due to the some advantage properties such as very rapid reaction, rapid bulk heat, short reaction duration and high yield etc. To characterization of synthesized resin FT-IR, TG-DTA and SEM techniques were used. In order to obtain the optimum uranium adsorption conditions the effective sorption parameters such as solution pH, uranium concentration, reaction time and temperature were investigated.

Preliminary Research on Granulation Process of Dust Waste from Reclamation Process of Moulding Sands with Furan Resin

Directory of Open Access Journals (Sweden)

Kamińska J.

2012-09-01

Full Text Available The results of investigations of the granulation process of foundry dusts generated in the dry mechanical reclamation process of used sands, where furan resins were binders are presented in the paper. Investigations concerned producing of granules of the determined dimensions and strength parameters.

Influence of carbon nanotubes coatings onto carbon fiber by oxidative treatments combined with electrophoretic deposition on interfacial properties of carbon fiber composite

International Nuclear Information System (INIS)

Deng, Chao; Jiang, Jianjun; Liu, Fa; Fang, Liangchao; Wang, Junbiao; Li, Dejia; Wu, Jianjun

2015-01-01

Graphical abstract: Carbon nanotube/carbon fiber hybrid fiber was proposed by the treatment with hydrogen peroxide and concentrated nitric acid combined with electrophoretic deposition process. - Highlights: • Carbon nanotube coated carbon fiber was prepared by two methods. • Uniform and dense CNTs network formed by oxidative treatments combined with EPD. • Pretreatment of the CF is beneficial to EPD of CNTs on carbon fiber surface. • CNTs enhanced the surface activity and wettability of carbon fibers. • CNTs have contributed to the interfacial properties of composite. - Abstract: To improve the interfacial performance of carbon fiber (CF) and epoxy resin, carbon nanotubes (CNTs) coatings were utilized to achieve this purpose through coating onto CF by the treatment with hydrogen peroxide and concentrated nitric acid combined with electrophoretic deposition (EPD) process. The influence of electrophoretically deposited CNTs coatings on the surface properties of CFs were investigated by Fourier transform infrared spectrometer, atomic force microscopy, scanning electron microscopy and dynamic contact angle analysis. The results indicated that the deposition of carbon nanotubes introduced some polar groups to carbon fiber surfaces, enhanced surface roughness and changed surface morphologies of carbon fibers. Surface wettability of carbon fibers may be significantly improved by increasing surface free energy of the fibers due to the deposition of CNTs. The thickness and density of the coatings increases with the introduction of pretreatment of the CF during the EPD process. Short beam shear test was performed to examine the effect of carbon fiber functionalization on mechanical properties of the carbon fiber/epoxy resin composites. The interfacial adhesion of CNTs/CF reinforced epoxy composites showed obvious enhancement of interlaminar shear strength by 60.2% and scanning electron microscope photographs showed that the failure mode of composites was changed

Three-dimensional numerical simulation during laser processing of CFRP

Science.gov (United States)

Ohkubo, Tomomasa; Sato, Yuji; Matsunaga, Ei-ichi; Tsukamoto, Masahiro

2017-09-01

We performed three-dimensional numerical simulation about laser processing of carbon-fiber-reinforced plastic (CFRP) using OpenFOAM as libraries of finite volume method (FVM). Although a little theoretical or numerical studies about heat affected zone (HAZ) formation were performed, there is no research discussing how HAZ is generated considering time development about removal of each material. It is important to understand difference of removal speed of carbon fiber and resin in order to improve quality of cut surface of CFRP. We demonstrated how the carbon fiber and resin are removed by heat of ablation plume by our simulation. We found that carbon fiber is removed faster than resin at first stage because of the difference of thermal conductivity, and after that, the resin is removed faster because of its low combustion temperature. This result suggests the existence of optimal contacting time of the laser ablation and kerf of the target.

Multifunctional multiscale composites: Processing, modeling and characterization

Science.gov (United States)

Qiu, Jingjing

Carbon nanotubes (CNTs) demonstrate extraordinary properties and show great promise in enhancing out-of-plane properties of traditional polymer/fiber composites and enabling functionality. However, current manufacturing challenges hinder the realization of their potential. In the dissertation research, both experimental and computational efforts have been conducted to investigate effective manufacturing techniques of CNT integrated multiscale composites. The fabricated composites demonstrated significant improvements in physical properties, such as tensile strength, tensile modulus, inter-laminar shear strength, thermal dimension stability and electrical conductivity. Such multiscale composites were truly multifunctional with the addition of CNTs. Furthermore, a novel hierarchical multiscale modeling method was developed in this research. Molecular dynamic (MD) simulation offered reasonable explanation of CNTs dispersion and their motion in polymer solution. Bi-mode finite-extensible-nonlinear-elastic (FENE) dumbbell simulation was used to analyze the influence of CNT length distribution on the stress tensor and shear-rate-dependent viscosity. Based on the simulated viscosity profile and empirical equations from experiments, a macroscale flow simulation model on the finite element method (FEM) method was developed and validated to predict resin flow behavior in the processing of CNT-enhanced multiscale composites. The proposed multiscale modeling method provided a comprehensive understanding of micro/nano flow in both atomistic details and mesoscale. The simulation model can be used to optimize process design and control of the mold-filling process in multiscale composite manufacturing. This research provided systematic investigations into the CNT-based multiscale composites. The results from this study may be used to leverage the benefits of CNTs and open up new application opportunities for high-performance multifunctional multiscale composites. Keywords. Carbon

Atomistically informed solute drag in Al–Mg

International Nuclear Information System (INIS)

Zhang, F; Curtin, W A

2008-01-01

Solute drag in solute-strengthened alloys, caused by diffusion of solute atoms around moving dislocations, controls the stress at deformation rates and temperatures useful for plastic forming processes. In the technologically important Al–Mg alloys, the solute drag stresses predicted by classical theories are much larger than experiments, which is resolved in general by eliminating the singularity of the dislocation core via Peierls–Nabarro-type models. Here, the drag stress versus dislocation velocity is computed numerically using a realistic dislocation core structure obtained from an atomistic model to investigate the role of the core and obtain quantitative stresses for comparison with experiment. The model solves a discrete diffusion equation in a reference frame moving with the dislocation, with input solute enthalpies and diffusion activation barriers in the core computed by or estimated from atomistic studies. At low dislocation velocities, the solute drag stress is controlled by bulk solute diffusion because the core diffusion occurs too quickly. In this regime, the drag stress can be obtained using a Peierls–Nabarro model with a core spreading parameter tuned to best match the atomistic models. At intermediate velocities, both bulk and core diffusion can contribute to the drag, leading to a complex stress–velocity relationship showing two peaks in stress. At high velocities, the drag stress is controlled solely by diffusion within and across the core. Like the continuum models, the drag stress is nearly linear in solute concentration. The Orowan relationship is used to connect dislocation velocity to deformation strain rate. Accounting for the dependence of mobile dislocation density on stress, the simulations are in good agreement with experiments on Al–Mg alloys over a range of concentrations and temperatures

Adsorption behaviour of uranium on immobilized tannin resin

International Nuclear Information System (INIS)

Olivares, Susana; Preval, Ivon; Santana, Jorge L.; Martinez, Francisco; Vargas, Luis M.

1995-01-01

The sorption of uranium by Eucalyptus Saligna Sm. tannin resin was investigated. This resin resulted a suitable adsorbent for the concentration of uranium from aqueous systems. The sorption of uranium is pH dependent. The presence of appreciable quantities of sodium chloride does not have any effect on uranium removal. Carbonate and calcium ions in concentrations similar to these found in seawater and other natural water do not decrease the uranium uptake. TANNsorb resin can be used several times without an appreciable decay of their sorption capacity. (author). 8 refs., 4 figs., 1 tab

Cleanup of TMI-2 demineralizer resins

International Nuclear Information System (INIS)

Bond, W.D.; King, L.J.; Knauer, J.B.; Hofstetter, K.J.; Thompson, J.D.

1985-01-01

Radiocesium is being removed from Demineralizers A and B (DA and DB by a process that was developed from laboratory tests on small samples of resin from the demineralizers. The process was designed to elute the radiocesium from the demineralizer resins and then to resorb it onto the zeolite ion exchangers contained in the Submerged Demineralizer System (SDS). The process was also required to limit the maximum cesium activities in the resin eluates (SDS feeds) so that the radiation field surrounding the pipelines would not be excessive. The process consists of 17 stages of batch elution. In the initial stage, the resin is contacted with 0.18 M boric acid. Subsequent stages subject the resin to increasing concentrations of sodium in NaH 2 BO 3 -H 3 BO 3 solution (total B = 0.35 M) and then 1 M sodium hydroxide in the final stages. Results on the performance of the process in the cleanup of the demineralizers at TMI-2 are compared to those obtained from laboratory tests with small samples of the DA and DB resins. To date, 15 stages of batch elution have been completed on the demineralizers at TMI-2 which resulted in the removal of about 750 Ci of radiocesium from DA and about 3300 Ci from DB

A genetic-neural artificial intelligence approach to resins optimization

International Nuclear Information System (INIS)

Cabral, Denise C.; Barros, Marcio P.; Lapa, Celso M.F.; Pereira, Claudio M.N.A.

2005-01-01

This work presents a preliminary study about the viability and adequacy of a new methodology for the definition of one of the main properties of ion exchange resins used for isotopic separation. Basically, the main problem is the definition of pelicule diameter in case of pelicular ion exchange resins, in order to achieve the best performance in the shortest time. In order to achieve this, a methodology was developed, based in two classic techniques of Artificial Intelligence (AI). At first, an artificial neural network (NN) was trained to map the existing relations between the nucleus radius and the resin's efficiency associated with the exchange time. Later on, a genetic algorithm (GA) was developed in order to find the best pelicule dimension. Preliminary results seem to confirm the potential of the method, and this can be used in any chemical process employing ion exchange resins. (author)

Importance of resin ducts in reducing ponderosa pine mortality from bark beetle attack.

Science.gov (United States)

Kane, Jeffrey M; Kolb, Thomas E

2010-11-01

The relative importance of growth and defense to tree mortality during drought and bark beetle attacks is poorly understood. We addressed this issue by comparing growth and defense characteristics between 25 pairs of ponderosa pine (Pinus ponderosa) trees that survived and trees that died from drought-associated bark beetle attacks in forests of northern Arizona, USA. The three major findings of our research were: (1) xylem resin ducts in live trees were >10% larger (diameter), >25% denser (no. of resin ducts mm(-2)), and composed >50% more area per unit ring growth than dead trees; (2) measures of defense, such as resin duct production (no. of resin ducts year(-1)) and the proportion of xylem ring area to resin ducts, not growth, were the best model parameters of ponderosa pine mortality; and (3) most correlations between annual variation in growth and resin duct characteristics were positive suggesting that conditions conducive to growth also increase resin duct production. Our results suggest that trees that survive drought and subsequent bark beetle attacks invest more carbon in resin defense than trees that die, and that carbon allocation to resin ducts is a more important determinant of tree mortality than allocation to radial growth.

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 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 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.

Fiber reinforced silicon-containing arylacetylene resin composites

Directory of Open Access Journals (Sweden)

2007-12-01

Full Text Available A silicon-containing arylacetylene resin (SAR, a poly(dimethylsilyleneethynylene phenyleneethynylene (PMSEPE, was synthesized. The PMSEPE is a solid resin at ambient temperature with a softening temperature about 60°C and soluble in some solvents like tetrahydrofuran. The melt viscosity of the PMSEPE resin is less than 1 Pa•s. The resin could cure at the temperature of lower than 200°C. Fiber reinforced PMSEPE composites were prepared from prepregs which were made by the impregnation of fibers in PMSEPE resin solution. The composites exhibit good mechanical properties at room temperature and 250°C. The observation on fracture surfaces of the composites reinforced by glass fibers and carbon fibers demonstrates that the adhesion between the fibers and resin is good. The results from an oxyacetylene flame test show that the composites have good ablation performance and XRD analyses indicate that SiC forms in the residues during the ablation of the composites.

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

Catalyst design for carbon nanotube growth using atomistic modeling

International Nuclear Information System (INIS)

Pint, Cary L; Bozzolo, Guillermo; Hauge, Robert

2008-01-01

The formation and stability of bimetallic catalyst particles, in the framework of carbon nanotube growth, is studied using the Bozzolo-Ferrante-Smith (BFS) method for alloys. Monte Carlo-Metropolis simulations with the BFS method are utilized in order to predict and study equilibrium configurations for nanoscale catalyst particles which are directly relevant to the catalyst state prior to growth of carbon nanotubes. At the forefront of possible catalyst combinations is the popular Fe-Mo bimetallic catalyst, which we have recently studied experimentally. We explain our experimental results, which indicate that the growth observed is dependent on the order of co-catalyst deposition, in the straightforward interpretation of BFS strain and chemical energy contributions toward the formation of Fe-Mo catalyst prior to growth. We find that the competition between the formation of metastable inner Mo cores and clusters of surface-segregated Mo atoms in Fe-Mo catalyst particles influences catalyst formation, and we investigate the role of Mo concentration and catalyst particle size in this process. Finally, we apply the same modeling approach to other prominent bimetallic catalysts and suggest that this technique can be a powerful tool to understand and manipulate catalyst design for highly efficient carbon nanotube growth

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

Novel simple process for tocopherols selective recovery from vegetable oils by adsorption and desorption with an anion-exchange resin.

Science.gov (United States)

Hiromori, Kousuke; Shibasaki-Kitakawa, Naomi; Nakashima, Kazunori; Yonemoto, Toshikuni

2016-03-01

A novel and simple low-temperature process was used to recover tocopherols from a deodorizer distillate, which is a by-product of edible oil refining. The process consists of three operations: the esterification of free fatty acids with a cation-exchange resin catalyst, the adsorption of tocopherols onto an anion-exchange resin, and tocopherol desorption from the resin. No degradation of tocopherols occurred during these processes. In the tocopherol-rich fraction, no impurities such as sterols or glycerides were present. These impurities are commonly found in the product of the conventional process. This novel process improves the overall recovery ratio and the mass fraction of the product (75.9% and 51.0wt%) compared with those in the conventional process (50% and 35wt%). Copyright © 2015 Elsevier Ltd. All rights reserved.

A novel fabrication method of carbon electrodes using 3D printing and chemical modification process.

Science.gov (United States)

Tian, Pan; Chen, Chaoyang; Hu, Jie; Qi, Jin; Wang, Qianghua; Chen, Jimmy Ching-Ming; Cavanaugh, John; Peng, Yinghong; Cheng, Mark Ming-Cheng

2017-11-23

Three-dimensional (3D) printing is an emerging technique in the field of biomedical engineering and electronics. This paper presents a novel biofabrication method of implantable carbon electrodes with several advantages including fast prototyping, patient-specific and miniaturization without expensive cleanroom. The method combines stereolithography in additive manufacturing and chemical modification processes to fabricate electrically conductive carbon electrodes. The stereolithography allows the structures to be 3D printed with very fine resolution and desired shapes. The resin is then chemically modified to carbon using pyrolysis to enhance electrochemical performance. The electrochemical characteristics of 3D printing carbon electrodes are assessed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The specific capacitance of 3D printing carbon electrodes is much higher than the same sized platinum (Pt) electrode. In-vivo electromyography (EMG) recording, 3D printing carbon electrodes exhibit much higher signal-to-noise ratio (40.63 ± 7.73) than Pt electrodes (14.26 ± 6.83). The proposed biofabrication method is envisioned to enable 3D printing in many emerging applications in biomedical engineering and electronics.

Ultrafiltration Membrane Fouling and the Effect of Ion Exchange Resins

KAUST Repository

Jamaly, Sanaa

2011-01-01

resins. Two advanced organic characterization methods are compared in terms of concentration of dissolved organic carbons: The liquid chromatography with organic carbon (LC-OCD) and Shimadzu total organic carbon (TOC). In this study, two secondary

Biodiesel purification methodology produced in the RECOPE experimental plant, using ion exchange resins

International Nuclear Information System (INIS)

Calderon Hernandez, Teresita

2016-01-01

A methodology was proposed for the biodisel purification of crude palm oil produced in a plant located on the Refinadora Costarricense de Petroleo (RECOPE) campus in Alto de Ochomogo, using ion exchange resins. A comparison between two resins was carried out: the USF C-211H, which had been acquired together with the RECOPE experimental plant and the PD206 resin, which was in the process of being acquired at the time of starting the project. The biodisel was eluted by glass columns packed with each resin, to determine the saturation of the same. The percentage of free and bound glycerin and the presence of soaps were analyzed as response variables. With the results obtained, it was determined that the PD206 resin is more efficient in the removal of glycerin, soaps and methanol than the resin USF C-211H. However, neither of the two resins diminishes the acidity of the biodisel. A biodisel sample was eluted by the PD206 resin and the quality of the obtained product was analyzed. A flash point of 145 degrees was obtained. A total acid number of 0.82 mg KOH / G was shown, no presence of water or sediment was observed. The percentage value of carbon residue was 0.01% m / m, the cloud point was 12 degrees, the density at 15 degrees was 0.8713 g / cm 3 , the viscosity at 40 degrees was 2.75 mm 2 /s; the stability to oxidation was 14.5 h, the percentage of free glycerin was 0.01% m / m and the percentage of total glycerin was 0.06% m / m, finally a percentage of Fatty Acids Methyl Esters (FAME) of 98,6%. Of the analyzed parameters, all are within the limits established in the Reglamento Tecnico Centroamericano except the acidity value, which exceeds the maximum value of 0.05 mg KOH / g sample. An economic analysis was carried out to evaluate which resin provides the best option to complete the purification process of the biodisel produced. The PD206, despite being more expensive, purifies a larger volume of biodiesel, so for a better negotiation in the purchase price, this

No-Oven, No-Autoclave Composite Processing

Science.gov (United States)

Rauscher, Michael D.

2015-01-01

Very large composite structures, such as those used in NASA's Space Launch System, push the boundaries imposed by current autoclaves. New technology is needed to maintain composite performance and free manufacturing engineers from the restraints of curing equipment size limitations. Recent efforts on a Phase II project by Cornerstone Research Group, Inc. (CRG), have advanced the technology and manufacturing readiness levels of a unique two-part epoxy resin system. Designed for room-temperature infusion of a dry carbon preform, the system includes a no-heat-added cure that delivers 350 F composite performance in a matter of hours. This no-oven, no-autoclave (NONA) composite processing eliminates part-size constraints imposed by infrastructure and lowers costs by increasing throughput and reducing capital-specific, process-flow bottlenecks. As a result of the Phase II activity, NONA materials and processes were used to make high-temperature composite tooling suitable for further production of carbon-epoxy laminates and honeycomb/ sandwich-structure composites with an aluminum core. The technology platform involves tooling design, resin infusion processing, composite part design, and resin chemistry. The various technology elements are combined to achieve a fully cured part. The individual elements are not unusual, but they are combined in such a way that enables proper management of the heat generated by the epoxy resin during cure. The result is a self-cured carbon/ epoxy composite part that is mechanically and chemically stable at temperatures up to 350 F. As a result of the successful SBIR effort, CRG has launched NONA Composites as a spinoff subsidiary. The company sells resin to end users, fabricates finished goods for customers, and sells composite tooling made with NONA materials and processes to composite manufacturers.

Destruction of Ion-Exchange Resin In Waste From the HFIR, T1 and T2 Tanks Using Fenton's Reagent

International Nuclear Information System (INIS)

Taylor, P.A.

2002-01-01

The use of Fenton's reagent (hydrogen peroxide and a ferrous iron catalyst) has been tested as a method for destroying ion-exchange resin in radioactive waste from three underground storage tanks at the Oak Ridge National Laboratory. The resin in these wastes must be destroyed before they can be transferred to the Melton Valley Storage Tanks (MVSTs) prior to solidification and disposal at the Waste Isolation Pilot Plant. The reaction with ion-exchange resin requires a dilute acidic solution (pH = 3 to 5) and moderate temperatures (T = 60 to 100 C). Laboratory-scale tests of the process have been successfully completed using both simulants and actual waste samples. The ion-exchange resin is oxidized to carbon dioxide and inorganic salts. The reaction rate is quite slow for temperatures below 70 C but increases almost linearly as the temperature of the slurry increases from 70 to 90 C. Pilot-scale tests have demonstrated the process using larger samples of actual waste slurries. A sample from the High Flux Isotope Reactor (HFIR) tank, containing 500 mL of settled solids (resin and inorganic sludge) in a total volume of 1800 mL, was successfully treated to meet MVST waste acceptance requirements in 9 h of processing time, using 1650 mL of 50 wt% hydrogen peroxide. A composite sample from the T1 and T2 tanks, which contained 1000 mL of settled solids in a total volume of 2000 mL required 8 h of treatment, using 1540 mL of 50 wt% peroxide, to meet waste acceptance requirements. Hydrogen peroxide reaction rates were 0.71 to 0.74 g H 2 O 2 /L/min, with very low (<2000 mg/L) concentrations of peroxide in the slurry. The reaction produces mostly carbon dioxide gas during the early part of the treatment, when organic carbon concentrations in the slurry are high, and then produces increasing amounts of oxygen as the organic carbon concentration drops. Small amounts (<3 vol%) of carbon monoxide are also generated. The off-gas from the pilot-scale tests, which was 81 vol

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)

Autoclave processing for composite material fabrication. 1: An analysis of resin flows and fiber compactions for thin laminate

Science.gov (United States)

Hou, T. H.

1985-01-01

High quality long fiber reinforced composites, such as those used in aerospace and industrial applications, are commonly processed in autoclaves. An adequate resin flow model for the entire system (laminate/bleeder/breather), which provides a description of the time-dependent laminate consolidation process, is useful in predicting the loss of resin, heat transfer characteristics, fiber volume fraction and part dimension, etc., under a specified set of processing conditions. This could be accomplished by properly analyzing the flow patterns and pressure profiles inside the laminate during processing. A newly formulated resin flow model for composite prepreg lamination process is reported. This model considers viscous resin flows in both directions perpendicular and parallel to the composite plane. In the horizontal direction, a squeezing flow between two nonporous parallel plates is analyzed, while in the vertical direction, a poiseuille type pressure flow through porous media is assumed. Proper force and mass balances have been made and solved for the whole system. The effects of fiber-fiber interactions during lamination are included as well. The unique features of this analysis are: (1) the pressure gradient inside the laminate is assumed to be generated from squeezing action between two adjacent approaching fiber layers, and (2) the behavior of fiber bundles is simulated by a Finitely Extendable Nonlinear Elastic (FENE) spring.

Cure Behavior and Thermal Properties of Diepoxidized Cardanol Resin Cured by Electron Beam Process

International Nuclear Information System (INIS)

Cho, Donghwan; Cheon, Jinsil

2013-01-01

Thermal curing of epoxy resin requires high temperature, time-consuming process and the volatilization of hardener. It has known that electron beam curing of epoxy resin is a fast process and occurs at low or room temperature that help reduce residual mechanical stresses in thermosetting polymers. Diepoxidized cardanol (DEC) can be synthesized by an enzymatic method from cashew nut shell liquid (CNSL), that constitutes nearly one-third of the total nut weight. A large amount of CNSL can be formed as a byproduct of the mechanical processes used to render the cashew kerneledible and its total production approaches one million tons annually, which can be bio-degradable and replace the industrial thermosetting plastics. It is expected that DEC may be cured as in an epoxy resin, which was constituted on two epoxide group and long alkyl chain, and two-types of onium salts (cationic initiator) were used as a photo-initiator. The experimental variables of this study are type and concentration of photo-initiators and electron beam dosage. In this study, the effects of initiator type and concentration on the cure behavior and the thermal properties of DEC resin processed by using electron beam technology were studied using FT-IR, TGA, TMA, DSC, and DMA. Figure 1 is the FT-IR results, showing the change of chemical structure of pure DEC and electron beam cured DEC. The characteristic absorption peak of epoxide group appeared at 850cm -1 . The shape and the height were reduced when the sample was irradiated with electron beam. From this result, the epoxide groups is DEC were opened by electron beam and cured. After then, electron beam cured DEC was investigated the effect of forming 3-dimensional network

Cure Behavior and Thermal Properties of Diepoxidized Cardanol Resin Cured by Electron Beam Process

Energy Technology Data Exchange (ETDEWEB)

Cho, Donghwan; Cheon, Jinsil [Kumoh National Institute of Technology, Gumi (Korea, Republic of)

2013-07-01

Thermal curing of epoxy resin requires high temperature, time-consuming process and the volatilization of hardener. It has known that electron beam curing of epoxy resin is a fast process and occurs at low or room temperature that help reduce residual mechanical stresses in thermosetting polymers. Diepoxidized cardanol (DEC) can be synthesized by an enzymatic method from cashew nut shell liquid (CNSL), that constitutes nearly one-third of the total nut weight. A large amount of CNSL can be formed as a byproduct of the mechanical processes used to render the cashew kerneledible and its total production approaches one million tons annually, which can be bio-degradable and replace the industrial thermosetting plastics. It is expected that DEC may be cured as in an epoxy resin, which was constituted on two epoxide group and long alkyl chain, and two-types of onium salts (cationic initiator) were used as a photo-initiator. The experimental variables of this study are type and concentration of photo-initiators and electron beam dosage. In this study, the effects of initiator type and concentration on the cure behavior and the thermal properties of DEC resin processed by using electron beam technology were studied using FT-IR, TGA, TMA, DSC, and DMA. Figure 1 is the FT-IR results, showing the change of chemical structure of pure DEC and electron beam cured DEC. The characteristic absorption peak of epoxide group appeared at 850cm{sup -1}. The shape and the height were reduced when the sample was irradiated with electron beam. From this result, the epoxide groups is DEC were opened by electron beam and cured. After then, electron beam cured DEC was investigated the effect of forming 3-dimensional network.

Preparation of Polymeric Resin Beads Using Gamma Irradiation and Chemical Processes for Use in the Recovery of Some Alkali Metal Ions

International Nuclear Information System (INIS)

El-Nahas, H. H.; Khalil, F. H.; Ibrahim, G. M.; El-Gammal, B.

2007-01-01

Syntheses of resin beads from unsaturated polyester and urea-formaldehyde were carried out by dispersion polymerization. The reaction was performed through gamma irradiation and chemical processing. Factors affecting the reaction and syntheses parameters that are the type and viscosity of dispersant, irradiation dose and agitation rate on the resin beads size were thoroughly investigated. The resulting resin beads were smooth on their spherical surface and the beads diameters were in the range 2-200μm. Some measurements such as beads diameter, surface hardness and scanning electron microscopy were studied. The bead diameter was generally decreased with increasing concentration and viscosity of the dispersant and agitation rate. A comparison study between irradiation and chemical processes for resin beads synthesis was discussed to identify the suitable process for preparing a resin beads in a pilot scale. The different methods of preparation were tried to be applied in the recovery of Li + , Na+, k + and Cs + ions from acidic media.

Experimental Studies on the Synthesis and Performance of Boron-containing High Temperature Resistant Resin Modified by Hydroxylated Tung Oil

Science.gov (United States)

Zhang, J. X.; Y Ren, Z.; Zheng, G.; Wang, H. F.; Jiang, L.; Fu, Y.; Yang, W. Q.; He, H. H.

2017-12-01

In this work, hydroxylated tung oil (HTO) modified high temperature resistant resin containing boron and benzoxazine was synthesized. HTO and ethylenediamine was used to toughen the boron phenolic resin with specific reaction. The structure of product was studied by Fourier-transform infrared spectroscopy(FTIR), and the heat resistance was tested by Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis(TGA). The results indicated that the conjugated triene structure of HTO was involved in the crosslinking of the heating curing progress, and in addition, the open-loop polymerization reaction of benzoxazine resin during heating can effectively reduce the curing temperature of the resin and reduce the release of small molecule volatiles, which is advantageous to follow-up processing. DSC data showed that the initial decomposition temperature of the resin is 350-400 °C, the carbon residue rate under 800 °C was 65%. It indicated that the resin has better heat resistance than normal boron phenolic resin. The resin can be used as an excellent ablative material and anti-friction material and has a huge application market in many fields.

Thermosetting resins for nuclear track detection

International Nuclear Information System (INIS)

Fujii, M.; Yokota, R.

1986-01-01

Several new thermosetting resins with a three dimensional network structure similar to that of CR-39 were polymerized to study their characteristics as nuclear track detectors. The comparison of the molecular structures of these resins gives us an important clue to develop highly sensitive polymeric track detectors. For example, butanediol bis allylcarbonate (BuAC) shows the sensitivity about ten times higher than diallyl and adipate (DAA). This suggests the carbonate groups in the BuAC molecule provide a much higher sensitivity than the ester groups in the DAA. During the course of this study, thermosetting resins with good etching properties and various sensitivities have been developed. Though the sensitivity of DAA is low, it will be useful for observations of ultra heavy cosmic rays and heavily ionizing particles at low energies. (author)

Ion Exchange Temperature Testing with SRF Resin - 12088

Energy Technology Data Exchange (ETDEWEB)

Russell, R.L.; Rinehart, D.E.; Brown, G.N.; Peterson, R.A. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States)

2012-07-01

Ion exchange using the Spherical Resorcinol-Formaldehyde (SRF) resin has been selected by the U.S. Department of Energy's Office of River Protection for use in the Pretreatment Facility of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) and for potential application in an at-tank deployment for removing Cs-137. Recent proposed changes to the WTP ion exchange process baseline indicate that higher temperatures (50 deg. C) to alleviate post-filtration precipitation issues prior to reaching the ion exchange columns may be required. Therefore, it is important to understand the behavior of SRF resin performance under the conditions expected with the new equipment and process changes. This research examined the impact of elevated temperature on resin loading and resin degradation during extended solution flow at elevated temperature (45 deg., 50 deg., 55 deg., 60 deg., 65 deg., 75 deg. C). Testing for extended times at elevated temperatures showed that the resin does degrade and loading capacity is reduced at and above 45 deg. C. Above 60 deg. C the resin appears to not load at all. It was observed that the resin disintegrated at 75 deg. C until not much was left and partially disintegrated at 65 deg. C, which caused the column to plug in both tests after ∼336 hours. The results indicate that WTP will lose resin loading capacity if the ion exchange process is performed above 25 deg. C, and the resin will disintegrate above 65 deg. C. Therefore, WTP will have a restricted operating range of temperatures to perform the ion exchange process with this resin. PNNL and WTP are currently evaluating the operating limits of the resin in further detail. Aging in 0.5 M HNO{sub 3} also caused the resin to lose capacity above 25 deg. C and to completely dissolve at 55 deg. C. Again, WTP will have a restricted operating range of temperatures when eluting the resin with nitric acid in order to maintain resin loading capacity and avoid disintegration of the resin

Color change in acrylic resin processed in three ways after immersion in water, cola, coffee, mate and wine.

Science.gov (United States)

Waldemarin, Renato Fa; Terra, Priscila C; Pinto, Luciana R; Faot, Fernanda; Camacho, Guilherme B

2013-01-01

Denture bases may undergo color change over time induced by pigment accumulation within their body; however there is a lack of information regarding the role of yerba mate tea in this process. This work evaluated the effect of five common beverages, including yerba mate tea, on color changes of acrylic denture base resins processed in three different ways. Three different processing techniques were used (P1--microwave irradiation/microwave activated resin; P2--heat polymerization/conventional heat activated resin and P3--microwave irradiation/conventional heat polymerized resin) to make twenty five resin discs each (3.0 mm thick x 20 mm diameter), totaling seventy-five resin discs. The discs made with each technique were randomly divided into five groups (n = 5) and placed in the following solutions: G1-water; G2-cola; G3-coffee; G4-yerba mate tea; G5-red wine, for 30 days at 37 degrees C. The solutions were renewed every 3 days. Color change on the CIE-L*a*b* scale was measured with a Konica-Minolta CR-10 colorimeter and compared with original L* a* and b* values of each specimen prior to immersion. Data were analyzed using 2-way ANOVA, and showed no difference among techniques and significant statistical differences among solutions (p < 0.05). Tukey's post-hoc test showed that the lowest color changes were for water and cola, which were undistinguishable from each other; coffee produced the second lowest color change; yerba mate tea produced second greatest color change, while the greatest color change was produced by red wine. Within the limitations of this study, it was concluded that almost all the solutions used can change color in acrylic resin, especially yerba mate tea, considered distinguishable by professionals, and red wine, considered distinguishable by patients and clinically unacceptable.

Preparation of High Surface Area Activated Carbon from Spent Phenolic Resin by Microwave Heating and KOH Activation

Science.gov (United States)

Cheng, Song; Zhang, Libo; Zhang, Shengzhou; Xia, Hongying; Peng, Jinhui

2018-01-01

The spent phenolic resin is as raw material for preparing high surface area activated carbon (HSAAC) by microwave-assisted KOH activation. The effects of microwave power, activation duration and impregnation ratio (IR) on the iodine adsorption capability and yield of HSAAC were investigated. The surface characteristics of HSAAC were characterized by nitrogen adsorption isotherms, FTIR, SEM and TEM. The operating variables were optimized utilizing the response surface methodology (RSM) and were identified to be microwave power of 700 W, activation duration of 15 min and IR of 4, corresponding to a yield of 51.25 % and an iodine number of 2,384 mg/g. The pore structure parameters of the HSAAC, i. e., Brunauer-Emmett-Teller (BET) surface area, total pore volume, and average pore diameter were estimated to be 4,269 m2/g, 2.396 ml/g and 2.25 nm, respectively, under optimum conditions. The findings strongly support the feasibility of microwave-assisted KOH activation for preparation of HSAAC from spent phenolic resin.

Modification of bifunctional epoxy resin using CO{sub 2} fixation process and nanoclay

Energy Technology Data Exchange (ETDEWEB)

Khoshkish, Morteza; Bouhendi, Hosein, E-mail: H.boohendi@ippi.ac.ir; Vafayan, Mehdi

2014-10-15

A bifunctional epoxy resin was modified by using a CO{sub 2} fixation solution process in the presence of tetra n-butyl ammonium bromide (TBAB) as catalyst and the modified treated resin was treated by cloisite 30B as nano additive. The Unmodified epoxy resin (UME), CO{sub 2} fixated modified epoxy resin (CFME), and CFME/clay nano composite (CFMEN), were cured by diethylenetriamine (DETA). A cycloaliphatic compound as a reactive diluent was used to control the viscosity of high viscose CFME. The exfoliation of organoclay in UME and CFME was investigated by X-ray diffraction and activation energy was computed using the advanced integral isoconversional method. The activation energy dependency demonstrated that the mechanism of UME curing did not change in the presence of nanoclay. In contrast, the CO{sub 2} fixation results showed a significant change in the activation energy dependency. The Thermal stability parameters include the initial degradation temperature (IDT), the temperature at the maximum rate of weight loss (T{sub max}), and the decomposition activation energy (E{sub d}) were determined by thermal gravimetry analysis. Dynamic mechanical thermal analysis measurements showed that the presence of organoclay in CFME increases the T{sub g} of nano composite in contrast to UME. The fracture roughness of UME, CFME and CFNE were determined by scanning electron microscope. The exfoliated UME/1%clay nanocomposite was confirmed by TEM image. - Highlights: • A new epoxy resin was synthesized using CO{sub 2} fixation reaction. • The synthesized epoxy resin was modified by an organo nano-clay. • CO{sub 2} fixation noticeably changed the curing mechanism. • CO{sub 2} fixation reaction consumes CO{sub 2} which is a harmful greenhouse gas.

Synthesis and Characterization of Bio-Oil Phenol Formaldehyde Resin Used to Fabricate Phenolic Based Materials.

Science.gov (United States)

Cui, Yong; Hou, Xiaopeng; Wang, Wenliang; Chang, Jianmin

2017-06-18

In this study, bio-oil from the fast pyrolysis of renewable biomass was used as the raw material to synthesize bio-oil phenol formaldehyde (BPF) resin-a desirable resin for fabricating phenolic-based material. During the synthesis process, paraformaldehyde was used to achieve the requirement of high solid content and low viscosity. The properties of BPF resins were tested. Results indicated that BPF resin with the bio-oil addition of 20% had good performance on oxygen index and bending strength, indicating that adding bio-oil could modify the fire resistance and brittleness of PF resin. The thermal curing behavior and heat resistance of BPF resins were investigated by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Results showed that adding bio-oil had an impact on curing characteristics and thermal degradation process of PF resin, but the influence was insignificant when the addition was relatively low. The chemical structure and surface characteristics of BPF resins were determined by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The analysis demonstrated that adding bio-oil in the amount of 20% was able to improve the crosslinking degree and form more hydrocarbon chains in PF resin.

Radiation processed composite materials of wood and elastic polyester resins

International Nuclear Information System (INIS)

Tapolcai, I.; Czvikovszky, T.

1983-01-01

The radiation polymerization of multifunctional unsaturated polyester-monomer mixtures in wood forms interpenetrating network system. The mechanical resistance (compression, abrasion, hardness, etc.) of these composite materials are generally well over the original wood, however the impact strength is almost the same or even reduced, in comparison to the wood itself. An attempt is made using elastic polyester resins to produced wood-polyester composite materials with improved modulus of elasticity and impact properties. For the impregnation of European beech wood two types of elastic unsaturated polyester resins were used. The exothermic effect of radiation copolymerization of these resins in wood has been measured and the dose rate effects as well as hardening dose was determined. Felxural strength and impact properties were examined. Elastic unsaturated polyester resins improved the impact strength of wood composite materials. (author)

Production and characterization of composite material based on ablative phenolic resin and carbon fibers

International Nuclear Information System (INIS)

Srebrenkoska, Vineta

2002-01-01

The optimisation of technology for production of moulding compound based on short carbon fibers and ablative phenolic resin is carried out. The characterisation of the starting raw materials is performed and moulding compounds With different fiber/matrix ratios and different fiber lengths are prepared. From the different samples, mouldings are produced by thermal compression. All physical, mechanical and thermal properties of the composites are tested. From the obtained results the optimal fiber/matrix ratio, for high temperature moulding compounds production are determined. Also, in order to meet the request for high thermal and mechanics properties of the composite, optimization is carded out on the moulding process itself. The optimization is fulfilled by a planned experiment. The full factorial experimental design is applied in which the following parameters are varied: fiber length, temperature and time of the press cycle. Regression equations for the influence of the parameters to the impact resistance, compression strength, flexural strength and the modulus of elasticity of the molding, are obtained. The obtained mechanical properties of the composite rate this material for potential application in the automotive, leisure, military and other industries.(Author)

Experimental and Numerical Study of the Interfacial Shear Strength in Carbon Fiber/Epoxy Resin Composite under Thermal Loads

Directory of Open Access Journals (Sweden)

Hongxiao Wang

2018-01-01

Full Text Available This study examined the influence mechanism of temperature on the interfacial shear strength (IFSS between carbon fiber (CF and epoxy resin (EP matrices under various thermal loads using experimental and numerical simulation methods. To evaluate the change in IFSS as a function of the increase in temperature, a microbond test was performed under controlled temperature environment from 23°C to 150°C. The experimental results showed that IFSS values of CF/EP reduce significantly when the temperature reaches near glass transition temperature. To interpret the effect of thermal loads on IFSS, a thermal-mechanical coupling finite element model was used to simulate the process of fiber pull-out from EP. The results revealed that temperature dependence of IFSS is linked to modulus of the matrix as well as to the coefficients of thermal expansion of the fiber and matrix.

Hierarchical Approach to 'Atomistic' 3-D MOSFET Simulation

Science.gov (United States)

Asenov, Asen; Brown, Andrew R.; Davies, John H.; Saini, Subhash

1999-01-01

We present a hierarchical approach to the 'atomistic' simulation of aggressively scaled sub-0.1 micron MOSFET's. These devices are so small that their characteristics depend on the precise location of dopant atoms within them, not just on their average density. A full-scale three-dimensional drift-diffusion atomistic simulation approach is first described and used to verify more economical, but restricted, options. To reduce processor time and memory requirements at high drain voltage, we have developed a self-consistent option based on a solution of the current continuity equation restricted to a thin slab of the channel. This is coupled to the solution of the Poisson equation in the whole simulation domain in the Gummel iteration cycles. The accuracy of this approach is investigated in comparison to the full self-consistent solution. At low drain voltage, a single solution of the nonlinear Poisson equation is sufficient to extract the current with satisfactory accuracy. In this case, the current is calculated by solving the current continuity equation in a drift approximation only, also in a thin slab containing the MOSFET channel. The regions of applicability for the different components of this hierarchical approach are illustrated in example simulations covering the random dopant-induced threshold voltage fluctuations, threshold voltage lowering, threshold voltage asymmetry, and drain current fluctuations.

The removal of toxic metals from liquid effluents by ion exchange resins. Part VI: Manganese(II/H+/Lewatit K2621

Directory of Open Access Journals (Sweden)

Francisco J. Alguacil

2018-05-01

Full Text Available In this sixth part of the series, Manganese(II was removed from aqueous solutions by the cationic exchange resin Lewatit K2621. The investigation was performed under various experimental conditions such as the stirring speed associated with the system, aqueous pH, temperature, resin dosage and the ionic strength of the solution. The performance of the resin against the loading of metals from metal-binary solutions as well as the removal of Manganese(II from the solutions using multiwalled carbon nanotubes and functionalized (carboxylic groups multiwalled carbon nanotubes, were also investigated. Experimental results fit well with the pseudo-first kinetic order model, whereas fit of the data show that at 20 °C the process responded well to the diffusion controlled model, and that at 60 °C, the system is controlled by the moving boundary model. Adsorption data is better related to the Freundlich isotherm. Elution of the Manganese(II loaded onto the resin was investigated using acidic (H2SO4 or HCl solutions.

Atomistic Kinetic Monte Carlo studies of microchemical evolutions driven by diffusion processes under irradiation

Science.gov (United States)

Soisson, F.; Becquart, C. S.; Castin, N.; Domain, C.; Malerba, L.; Vincent, E.

2010-11-01

Atomistic Kinetic Monte Carlo (AKMC) simulations are a powerful tool to study the microstructural and microchemical evolution of alloys controlled by diffusion processes, under irradiation and during thermal ageing. In the framework of the FP6 Perfect program, two main approaches have been applied to binary and multicomponent iron based alloys. The first one is based on a diffusion model which takes into account vacancy and self-interstitial jumps, using simple rigid lattice approximation and broken-bond models to compute the point-defect jump frequencies. The corresponding parameters are fitted on ab initio calculations of a few typical configurations and migration barriers. The second method uses empirical potentials to compute a much larger number of migration barriers, including atomic relaxations, and Artificial Intelligence regression methods to predict the other ones. It is somewhat less rapid than the first one, but significantly more than simulations using "on-the-fly" calculations of all the barriers. We review here the recent advances and perspectives concerning these techniques.

Atomistic Kinetic Monte Carlo studies of microchemical evolutions driven by diffusion processes under irradiation

International Nuclear Information System (INIS)

Soisson, F.; Becquart, C.S.; Castin, N.; Domain, C.; Malerba, L.; Vincent, E.

2010-01-01

Atomistic Kinetic Monte Carlo (AKMC) simulations are a powerful tool to study the microstructural and microchemical evolution of alloys controlled by diffusion processes, under irradiation and during thermal ageing. In the framework of the FP6 Perfect program, two main approaches have been applied to binary and multicomponent iron based alloys. The first one is based on a diffusion model which takes into account vacancy and self-interstitial jumps, using simple rigid lattice approximation and broken-bond models to compute the point-defect jump frequencies. The corresponding parameters are fitted on ab initio calculations of a few typical configurations and migration barriers. The second method uses empirical potentials to compute a much larger number of migration barriers, including atomic relaxations, and Artificial Intelligence regression methods to predict the other ones. It is somewhat less rapid than the first one, but significantly more than simulations using 'on-the-fly' calculations of all the barriers. We review here the recent advances and perspectives concerning these techniques.

Method of processing decontaminating liquid waste

International Nuclear Information System (INIS)

Kusaka, Ken-ichi

1989-01-01

When decontaminating liquid wastes are processed by ion exchange resins, radioactive nuclides, metals, decontaminating agents in the liquid wastes are captured in the ion exchange resins. When the exchange resins are oxidatively deomposed, most of the ingredients are decomposed into water and gaseous carbonic acid and discharged, while sulfur ingredient in the resins is converted into sulfuric acid. In this case, even less oxidizable ingredients in the decontaminating agent made easily decomposable by oxidative decomposition together with the resins. The radioactive nuclides and a great amount of iron dissolved upon decontamination in the liquid wastes are dissolved in sulfuric acid formed. When the sulfuric acid wastes are nuetralized with sodium hydroxide, since they are formed into sodium sulfate, which is most popular as wastes from nuclear facilities, they can be condensated and solidified by existent waste processing systms to thereby facilitate the waste processing. (K.M.)

Double Vacuum Bag Process for Resin Matrix Composite Manufacturing

Science.gov (United States)

Hou, Tan-Hung (Inventor); Jensen, Brian J. (Inventor)

2007-01-01

A double vacuum bag molding assembly with improved void management and laminate net shape control which provides a double vacuum enviromnent for use in fabricating composites from prepregs containing air and/or volatiles such as reactive resin matrix composites or composites from solvent containing prepregs with non-reactive resins matrices. By using two vacuum environments during the curing process, a vacuum can be drawn during a B-stage of a two-step cycle without placing the composite under significant relative pressure. During the final cure stage, a significant pressure can be applied by releasing the vacuum in one of the two environments. Inner and outer bags are useful for creating the two vacuum environments with a perforated tool intermediate the two. The composite is placed intermediate a tool plate and a caul plate in the first environment with the inner bag and tool plate defining the first environment. The second environment is characterized by the outer bag which is placed over the inner bag and the tool plate.

Fabrication of micro-dot arrays and micro-walls of acrylic acid/melamine resin on aluminum by AFM probe processing and electrophoretic coating

International Nuclear Information System (INIS)

Kurokawa, S.; Kikuchi, T.; Sakairi, M.; Takahashi, H.

2008-01-01

Micro-dot arrays and micro-walls of acrylic acid/melamine resin were fabricated on aluminum by anodizing, atomic force microscope (AFM) probe processing, and electrophoretic deposition. Barrier type anodic oxide films of 15 nm thickness were formed on aluminum and then the specimen was scratched with an AFM probe in a solution containing acrylic acid/melamine resin nano-particles to remove the anodic oxide film locally. After scratching, the specimen was anodically polarized to deposit acrylic acid/melamine resin electrophoretically at the film-removed area. The resin deposited on the specimen was finally cured by heating. It was found that scratching with the AFM probe on open circuit leads to the contamination of the probe with resin, due to positive shifts in the potential during scratching. Scratching of the specimen under potentiostatic conditions at -1.0 V, however, resulted in successful resin deposition at the film-removed area without probe contamination. The rate of resin deposition increased as the specimen potential becomes more positive during electrophoretic deposition. Arrays of resin dots with a few to several tens μm diameter and 100-1000 nm height, and resin walls with 100-1000 nm height and 1 μm width were obtained on specimens by successive anodizing, probe processing, and electrophoretic deposition

Fabrication of micro-dot arrays and micro-walls of acrylic acid/melamine resin on aluminum by AFM probe processing and electrophoretic coating

Energy Technology Data Exchange (ETDEWEB)

Kurokawa, S.; Kikuchi, T.; Sakairi, M. [Graduate School of Engineering, Hokkaido University, N-13, W-8, Kita-Ku, Sapporo 060-8628 (Japan); Takahashi, H. [Graduate School of Engineering, Hokkaido University, N-13, W-8, Kita-Ku, Sapporo 060-8628 (Japan)], E-mail: takahasi@elechem1-mc.eng.hokudai.ac.jp

2008-11-30

Micro-dot arrays and micro-walls of acrylic acid/melamine resin were fabricated on aluminum by anodizing, atomic force microscope (AFM) probe processing, and electrophoretic deposition. Barrier type anodic oxide films of 15 nm thickness were formed on aluminum and then the specimen was scratched with an AFM probe in a solution containing acrylic acid/melamine resin nano-particles to remove the anodic oxide film locally. After scratching, the specimen was anodically polarized to deposit acrylic acid/melamine resin electrophoretically at the film-removed area. The resin deposited on the specimen was finally cured by heating. It was found that scratching with the AFM probe on open circuit leads to the contamination of the probe with resin, due to positive shifts in the potential during scratching. Scratching of the specimen under potentiostatic conditions at -1.0 V, however, resulted in successful resin deposition at the film-removed area without probe contamination. The rate of resin deposition increased as the specimen potential becomes more positive during electrophoretic deposition. Arrays of resin dots with a few to several tens {mu}m diameter and 100-1000 nm height, and resin walls with 100-1000 nm height and 1 {mu}m width were obtained on specimens by successive anodizing, probe processing, and electrophoretic deposition.

Feasibility of vitrifying EPICOR II organic resins

International Nuclear Information System (INIS)

Buelt, J.L.

1981-11-01

Two laboratory-scale runs have recently been completed to test the feasibility of a single-step incineration/vitrification process for Three Mile Island EPICOR II resins. The process utilizes vitrification equipment, specifically a 15-cm-dia in-can melter, and a specially designed feed technique. Two process tests, each conducted with 1.2 kg of EPICOR II resins loaded with nonradioactive cesium and strontium, showed excellent operational characteristics. Less than 0.8 wt% of the resins were entrained with the gaseous effluents in the second test. Cesium and strontium losses were controlled to 0.71 wt% and less. In addition, all the carbonaceous resins were converted completely to CO 2 with no detectable CO. Future activities are being directed to longer-term tests in laboratory-scale equipment to determine attainable volume reduction, process rates, and material conformance to processing conditions

Aspects of the Fracture Toughness of Carbon Nanotube Modified Epoxy Polymer Composites

Science.gov (United States)

Mirjalili, Vahid

Epoxy resins used in fibre reinforced composites exhibit a brittle fracture behaviour, because they show no sign of damage prior to a catastrophic failure. Rubbery materials and micro-particles have been added to epoxy resins to improve their fracture toughness, which reduces strength and elastic properties. In this research, carbon nanotubes (CNTs) are investigated as a potential toughening agent for epoxy resins and carbon fibre reinforced composites, which can also enhance strength and elastic properties. More specifically, the toughening mechanisms of CNTs are investigated theoretically and experimentally. The effect of aligned and randomly oriented carbon nanotubes (CNTs) on the fracture toughness of polymers was modelled using Elastic Plastic Fracture Mechanics. Toughening from CNT pull-out and rupture were considered, depending on the CNTs critical length. The model was used to identify the effect of CNTs geometrical and mechanical properties on the fracture toughness of CNT-modified epoxies. The modelling results showed that a uniform dispersion and alignment of a high volume fraction of CNTs normal to the crack growth plane would lead to the maximum fracture toughness enhancement. To achieve a uniform dispersion, the effect of processing on the dispersion of single walled and multi walled CNTs in epoxy resins was investigated. An instrumented optical microscope with a hot stage was used to quantify the evolution of the CNT dispersion during cure. The results showed that the reduction of the resin viscosity at temperatures greater than 100 °C caused an irreversible re-agglomeration of the CNTs in the matrix. The dispersion quality was then directly correlated to the fracture toughness of the modified resin. It was shown that the fine tuning of the ratio of epoxy resin, curing agent and CNT content was paramount to the improvement of the base resin fracture toughness. For the epoxy resin (MY0510 from Hexcel), an improvement of 38% was achieved with 0.3 wt

Processing of indium (III solutions via ion exchange with Lewatit K-2621 resin

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López Díaz-Pavón, Adrián

2014-06-01

Full Text Available The processing of indium(III-hydrochloric acid solutions by the cationic ion exchange Lewatit K-2621 resin has been investigated. The influence of several variables such as the hydrochloric acid and metal concentrations in the aqueous solution and the variation of the amount of resin added has been studied. Moreover, a kinetic study performed in the uptake of indium(III by Lewatit K-2621, shows that either the film-diffusion and the particle-diffusion models fit the ion exchange process onto the resin, depending upon the initial metal concentration in the aqueous solution. The loaded resin could be eluted by HCl solutions at 20 °C.Se ha investigado el tratamiento de disoluciones de ácido clorhídrico conteniendo indio(III mediante la resina de cambio catiónico Lewatit K-2621. Las variables ensayadas han sido las concentraciones de ácido y de metal en la disolución acuosa y la cantidad de resina empleada en el tratamiento de dichas disoluciones. Asimismo, se ha llevado a cabo un estudio cinético del proceso de intercambio catiónico entre el indio(III y la resina Lewatit K-2621. Este estudio muestra que el proceso de intercambio responde a un mecanismo de difusión en la disolución o en la partícula de resina dependiendo de la concentración inicial del metal en el medio acuoso. El metal cargado en la resina puede ser eluido con disoluciones de ácido clorhídrico a 20 °C.

Plasma arc pyrolysis of radioactive ion exchange resin

International Nuclear Information System (INIS)

Pickles, C.A.; Toguri, J.M.

1992-01-01

This paper reports on two ion exchange resins (IRN 77 and IRN 78) which were pyrolysed in a plasma-arc furnace. Both continuous and batch tests were performed. Volume reduction ratios of 10 to 1 and 10 to 3.5 were achieved for IRN 78 and IRN 77 respectively. The product of the resin pyrolysis was a char which contained the radioactive elements such as cobalt. The off-gases consisted of mainly hydrogen and carbon monoxide. There was a relatively small amount of dust in the off-gases. At the present time radioactive ion exchange resign is being kept in storage. The volume of this waste is increasing and it is important that the volume be reduce. The volume reduction ratio should be of the order of ten-to-one. Also, it is required that the radioactive elements can be collected or fixed in a form which could easily be disposed of. Plasma arc treatment offers considerable potential for the processing of the waste

The mechanism of uranium adsorption on Resin 508 and isoelectric point of the resin

International Nuclear Information System (INIS)

Han Qingping; Lu Weichang; Su Huijuan; Hu Jinbo; Zhang Liqin; Chen Banglin

1990-01-01

The adsorption process of uranium by Resin 508 at the solid-liquid interface was investigated and the mechanism of uranium adsorption including adsorption dynamics, adsorption thermodynamics and isoelectric point of resin was studied. The results are as follows: The maximum of uranium adsorption is attained at pH5-7; Uranium adsorption isotherm by Resin 508 in experimental conditions agrees with Langmuir's adsorption isotherm, the maximum of uranium adsorbed (Vm) is 716 mg U/g-dried resin; The adsorption of uranium by Resin 508 is an endothermic reaction and ΔH = 16.87 kJ/mol; The exchange-adsorption rate is mainly controlled by liquid film diffusion; The isoelectric points of Resin 508 before and after uranium adsorption are found to be pH7.5 and pH5.7 respectively. It is a specific adsorption for uranium

Treatment of aqueous diethyl phthalate by adsorption using a functional polymer resin.

Science.gov (United States)

Xu, Zhengwen; Zhang, Weiming; Pan, Bingcai; Lv, Lu; Jiang, Zhengmao

2011-01-01

To study the adsorptive separation efficiency, adsorption and desorption performances of diethyl phthalate (DEP) were investigated with a functional polymer resin (NDA-702). A macroporous polymer resin (XAD-4) and a coal-based granular activated carbon (AC-750) were chosen for comparison. The kinetic adsorption data obeyed the pseudo-second-order rate model, and the adsorption processes were limited by both film and intraparticle diffusions. Adsorption equilibrium data were well fitted by the Freundlich equation, and the larger uptake and higher selection of NDA-702 than AC-750 and XAD-4 was probably due to the microporous structure, phenyl rings and polar groups on NDA-702. Thermodynamic adsorption studies indicated that the test adsorbents spontaneously adsorbed DEP, driven mainly by enthalpy change. Continuous fixed-bed runs demonstrated that there no significant loss of the resin's adsorption capacity and there was complete regeneration of NDA-702. The results suggest that NDA-702 has excellent potential as an adsorption material for water treatment.

Resin-based preparation of HTGR fuels: operation of an engineering-scale uranium loading system

International Nuclear Information System (INIS)

Haas, P.A.

1977-10-01

The fuel particles for recycle of 233 U to High-Temperature Gas-Cooled Reactors are prepared from uranium-loaded carboxylic acid ion exchange resins which are subsequently carbonized, converted, and refabricated. The development and operation of individual items of equipment and of an integrated system are described for the resin-loading part of the process. This engineering-scale system was full scale with respect to a hot demonstration facility, but was operated with natural uranium. The feed uranium, which consisted of uranyl nitrate solution containing excess nitric acid, was loaded by exchange with resin in the hydrogen form. In order to obtain high loadings, the uranyl nitrate must be acid deficient; therefore, nitric acid was extracted by a liquid organic amine which was regenerated to discharge a NaNO 3 or NH 4 NO 3 solution waste. Water was removed from the uranyl nitrate solution by an evaporator that yielded condensate containing less than 0.5 ppM of uranium. The uranium-loaded resin was washed with condensate and dried to a controlled water content via microwave heating. The loading process was controlled via in-line measurements of the pH and density of the uranyl nitrate. The demonstrated capacity was 1 kg of uranium per hour for either batch loading contractors or a continuous column as the resin loading contractor. Fifty-four batch loading runs were made without a single failure of the process outlined in the chemical flowsheet or any evidence of inability to control the conditions dictated by the flowsheet

Structure-to-property relationships in addition cured polymers. II - Resin Tg and composite initial mechanical properties of norbornenyl cured polyimide resins

Science.gov (United States)

Alston, William B.

1986-01-01

PRM (polymerization of monomeric reactants) methodology was used to prepare thirty different polyimide oligomeric resins. Monomeric composition as well as chain length between sites of crosslinks were varied to examine their effects on glass transition temperature (Tg) of the cured/postcured resins. An almost linear correlation of Tg versus molecular distance between the crosslinks was observed. An attempt was made to correlate Tg with initial mechanical properties (flexural strength and interlaminar shear strength) of unidirectional graphite fiber composites prepared with these resins. However, the scatter in mechanical strength data prevented obtaining as clear a correlation as was observed for the structural modification/crosslink distance versus Tg. Instead, only a range of composite mechanical properties was obtained at the test temperatures studied (room temperature, 288 and 316 C). Perhaps more importantly, what did become apparent during the attempted correlation study was: (1) that PMR methodology could be used to prepare composites from resins that contain a wide variety of monomer modifications, and (2) that these composites almost invariably provided satisfactory initial mechanical properties as long as the resins selected were melt processable.

Safety evaluation of cation-exchange resins

International Nuclear Information System (INIS)

Kalkwarf, D.R.

1977-08-01

Results are presented of a study to evaluate whether sufficient information is available to establish conservative limits for the safe use of cation-exchange resins in separating radionuclides and, if not, to recommend what new data should be acquired. The study was also an attempt to identify in-line analytical techniques for the evaluation of resin degradation during radionuclide processing. The report is based upon a review of the published literature and upon discussions with many people engaged in the use of these resins. It was concluded that the chief hazard in the use of cation-exchange resins for separating radionuclides is a thermal explosion if nitric acid or other strong oxidants are present in the process solution. Thermal explosions can be avoided by limiting process parameters so that the rates of heat and gas generation in the system do not exceed the rates for their transfer to the surroundings. Such parameters include temperature, oxidant concentration, the amounts of possible catalysts, the radiation dose absorbed by the resin and the diameter of the resin column. Current information is not sufficient to define safe upper limits for these parameters. They can be evaluated, however, from equations derived from the Frank-Kamenetskii theory of thermal explosions provided the heat capacities, thermal conductivities and rates of heat evolution in the relevant resin-oxidant mixtures are known. It is recommended that such measurements be made and the appropriate limits be evaluated. A list of additional safety precautions are also presented to aid in the application of these limits and to provide additional margins of safety. In-line evaluation of resin degradation to assess its safety hazard is considered impractical. Rather, it is recommended that the resin be removed from use before it has received the limiting radiation dose, evaluated as described above

Synthesis and Characterization of Bio-Oil Phenol Formaldehyde Resin Used to Fabricate Phenolic Based Materials

Directory of Open Access Journals (Sweden)

Yong Cui

2017-06-01

Full Text Available In this study, bio-oil from the fast pyrolysis of renewable biomass was used as the raw material to synthesize bio-oil phenol formaldehyde (BPF resin—a desirable resin for fabricating phenolic-based material. During the synthesis process, paraformaldehyde was used to achieve the requirement of high solid content and low viscosity. The properties of BPF resins were tested. Results indicated that BPF resin with the bio-oil addition of 20% had good performance on oxygen index and bending strength, indicating that adding bio-oil could modify the fire resistance and brittleness of PF resin. The thermal curing behavior and heat resistance of BPF resins were investigated by differential scanning calorimetry (DSC and thermal gravimetric analysis (TGA. Results showed that adding bio-oil had an impact on curing characteristics and thermal degradation process of PF resin, but the influence was insignificant when the addition was relatively low. The chemical structure and surface characteristics of BPF resins were determined by Fourier transform infrared (FTIR spectroscopy and scanning electron microscopy (SEM. The analysis demonstrated that adding bio-oil in the amount of 20% was able to improve the crosslinking degree and form more hydrocarbon chains in PF resin.

Optimization of mixing process and effect of multi-walled carbon nanotubes on tensile properties of unsaturated polyester resin in composite materials

Energy Technology Data Exchange (ETDEWEB)

Hoang, Van-Tho; Yum, Young-Jin [University of Ulsan, Ulsan (Korea, Republic of)

2017-04-15

Multi-walled carbon nanotubes (MWCNTs) were mixed with Unsaturated polyester resin (UPR) using the stir method at high temperatures. The mixing temperature and hardener ratio were optimized based on compression properties and the exothermic temperature. In the experiment, 60 °C and 1 wt.% of Methyl ethyl ketone peroxide (MEKP) were chosen for the mixing condition and catalyst concentration, respectively. MWCNTs with different weight fractions (0.05, 0.1, 0.2 and 0.3 wt.%) were dispersed to investigate the effect of MWCNTs on tensile properties of the UPR, and it was found that 0.1 wt.% of MWCNTs showed the best performance in this range of fiber weight fraction due to a higher strength (42.14 %), modulus (14.33 %) and fracture strain (37.17 %) than pure UPR. The state of dispersion and arrangement of fibers were examined by a Field emission Scanning electron microscope (FE-SEM) according to fracture surfaces. Similarly, the FE-SEM also showed better results with 0.1 wt.% of MWCNTs mixed in the UPR.

Correlations of norbornenyl crosslinked polyimide resin structures with resin thermo-oxidative stability, resin glass transition temperature and composite initial mechanical properties

Science.gov (United States)

Alston, William B.

1988-01-01

PMR (polymerization of monomeric reactants) methodology was used to prepare 70 different polyimide oligomeric resins and 30 different unidirectional graphite fiber/polyimide composites. Monomeric composition as well as chain length between sites of crosslinks were varied to examine their effects on resin thermo-oxidative stability and glass transition temperature (Tg) of the cured/postcured resins. A linear correlation of decreasing 316 C resin weight loss/surface area versus (1) decreasing aliphatic content, or (2) increasing benzylic/aliphatic content stoichiometry ratio over a wide range of resin compositions was observed. An almost linear correlation of Tg versus molecular distance between the crosslinks was also observed. An attempt was made to correlate Tg with initial composite mechanical properties (flexural strength and interlaminar shear strength). However, the scatter in mechanical strength data prevented obtaining a clear correlation. Instead, only a range of composite mechanical properties was obtained at 25, 288, and 316 C. Perhaps more importantly, what did become apparent during the correlation study was (1) the PMR methodology could be used to prepare composites from resins containing a wide variety of monomer modifications, (2) that these composites almost invariably provided satisfactory initial mechanical properties as long as the resins formulated exhibited satisfactory processing flow, and (3) that PMR resins exhibited predictable rates of 316 C weight loss/surface area based on their benzylic/aliphatic stoichiometery ratio.

4-META opaque resin--a new resin strongly adhesive to nickel-chromium alloy.

Science.gov (United States)

Tanaka, T; Nagata, K; Takeyama, M; Atsuta, M; Nakabayashi, N; Masuhara, E

1981-09-01

1) A new adhesive opaque resin containing a reactive monomer, 4-methacryloxy-ethyl trimellitate anhydride (4-META), was prepared, and its application to thermosetting acrylic resin veneer crowns was studied. 2) The 4-META opaque resin was applied to a variety of nickel-chromium dental alloy specimens which had undergone different treatment, and endurance tests were conducted to evaluate the durability of adhesion. 3) Stable adhesion against water penetration was achieved with metal surfaces first etched with HCl and then oxidized with HNO3. A bond strength of 250 kg/cm2 was maintained even after immersion in water at 37 degrees C for 30 wk or at 80 degrees C for ten wk. Furthermore, this value did not decrease even after the specimens were subjected to 500 thermal cycles. 4) The 4-META opaque resin studied can eliminate the necessity for retention devices on metal castings. 5) The smooth 4-META opaque resin should have no adverse effects on gingivae.

Method of solidifying radioactive ion exchange resin

International Nuclear Information System (INIS)

Minami, Yuji; Tomita, Toshihide

1989-01-01

Spent anion exchange resin formed in nuclear power plants, etc. generally catch only a portion of anions in view of the ion exchange resins capacity and most of the anions are sent while possessing activities to radioactive waste processing systems. Then, the anion exchange resins increase the specific gravity by the capture of the anions. Accordingly, anions are caused to be captured on the anion exchange resin wastes such that the specific gravity of the anion exchange resin wastes is greater than that of the thermosetting resins to be mixed. This enables satisfactory mixing with the thermosetting resins and, in addition, enables to form integral solidification products in which anion exchange resins and cation exchange resins are not locallized separately and which are homogenous and free from cracks. (T.M.)

Influence of composite processing on the properties of CNT grown on carbon surfaces

Science.gov (United States)

Guignier, Claire; Bueno, Marie-Ange; Camillieri, Brigitte; Durand, Bernard

2018-01-01

Carbon nanotubes (CNT) grafted on carbon fibres (CF) are the subject of more and more studies on the reinforcement of composite materials thanks to the CNT' mechanical properties. This study concerns the growth of CNT directly on CF by the flame method, which is an assembly-line process. However the industrial-scale use of this method and of the composite processing leads to stresses on the CNT-grafted fabrics, such as friction and pulling-out. The aim of this study is to determine the behaviour of the CNT under these kinds of stresses and to study theirs consequences in composite processing. For this purpose, adhesion tests and friction tests were performed as well as analysis of the surface by Scanning Electron Microscopy (SEM), Raman spectroscopy, and energy-dispersive X-ray spectroscopy (EDX). In friction tests, CNT formed a transfer film, and its effect on the wettability of the fabric with epoxy resin is determined. Finally, the wear of the CNT does not influence the wettability of the fabric. Furthermore, it is proven that the nature of the catalyst needed to grow the CNT modifies the behaviour of the surface.

High performance thermoplastics - A review of neat resin and composite properties

Science.gov (United States)

Johnston, Norman J.; Hergenrother, Paul M.

1987-01-01

A review was made of the principal thermoplastics used to fabricate high performance composites. Neat resin tensile and fracture toughness properties, glass transition temperatures (Tg), crystalline melt temperatures (Tm) and approximate processing conditions are presented. Mechanical properties of carbon fiber composites made from many of these thermoplastics are given, including flexural, longitudinal tensile, transverse tensile and in-plane shear properties as well as short beam shear and compressive strengths and interlaminar fracture toughness.

Reduced toxicity polyester resins and microvascular pre-preg tapes for advanced composites manufacturing

Science.gov (United States)

Poillucci, Richard

Advanced composites manufacturing broadly encapsulates topics ranging from matrix chemistries to automated machines that lay-up fiber-reinforced materials. Environmental regulations are stimulating research to reduce matrix resin formulation toxicity. At present, composites fabricated with polyester resins expose workers to the risk of contact with and inhalation of styrene monomer, which is a potential carcinogen, neurotoxin, and respiratory irritant. The first primary goal of this thesis is to reduce the toxicity associated with polyester resins by: (1) identification of potential monomers to replace styrene, (2) determination of monomer solubility within the polyester, and (3) investigation of approaches to rapidly screen a large resin composition parameter space. Monomers are identified based on their ability to react with polyester and their toxicity as determined by the Globally Harmonized System (GHS) and a green screen method. Solubilities were determined by the Hoftyzer -- Van Krevelen method, Hansen solubility parameter database, and experimental mixing of monomers. A combinatorial microfluidic mixing device is designed and tested to obtain distinct resin compositions from two input chemistries. The push for safer materials is complemented by a thrust for multifunctional composites. The second primary goal of this thesis is to design and implement the manufacture of sacrificial fiber materials suitable for use in automated fiber placement of microvascaular multifunctional composites. Two key advancements are required to achieve this goal: (1) development of a roll-to-roll method to place sacrificial fibers onto carbon fiber pre-preg tape; and (2) demonstration of feasible manufacture of microvascular carbon fiber plates with automated fiber placement. An automated method for placing sacrificial fibers onto carbon fiber tapes is designed and a prototype implemented. Carbon fiber tows with manual placement of sacrificial fibers is implemented within an

Study on dehydrochlorination of waste poly (vinyl chloride) resins by microwave irradiation

Science.gov (United States)

Moriwaki, Saburo; Qian, Qingrong; Sunohara, Satoshi; Machida, Motoi; Tatsumoto, Hideki

Waste poly (vinyl chloride: PVC) resins are experimentally dehydrochlorinated by microwave irradiation. The following unique results are obtained: (1) plasticizer in PVC resin absorbs microwave power more effectively than PVC polymer. The higher the plasticizer content in PVC resin, the higher is the dehydrochlorination reaction (2) low PVC polymer content materials such as cushion floor require high microwave irradiation power to secure a high dehydrochlorination yield, (3) calcium carbonate in PVC resin reacts with released hydrochloric acid gas and results calcium chloride during microwave irradiation, (4) additives in PVC resin strongly influence dehydrochlorination yield, (5) it is evidenced that the PVC copolymer is also dehydrochlorinated by microwave irradiation.

Changes to Electrical Conductivity in Irradiated Carbon-Nickel Nanocomposites

Science.gov (United States)

2010-03-01

10 Figure 4. Radiation tolerances of some thermoset resins. Light shaded region is moderate damage and dark shaded...for all types of engineering applications include a diverse range of materials from plastics and ceramics to exotic alloys and carbon composites...Figure 4. Radiation tolerances of some thermoset resins. Light shaded region is moderate damage and dark shaded region is severe damage [17]. 18

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.

Atomistic materials modeling of complex systems: Carbynes, carbon nanotube devices and bulk metallic glasses

Science.gov (United States)

Luo, Weiqi

The key to understanding and predicting the behavior of materials is the knowledge of their structures. Many properties of materials samples are not solely determined by their average chemical compositions which one may easily control. Instead, they are profoundly influenced by structural features of different characteristic length scales. Starting in the last century, metallurgical engineering has mostly been microstructure engineering. With the further evolution of materials science, structural features of smaller length scales down to the atomic structure, have become of interest for the purpose of properties engineering and functionalizing materials and are, therefore, subjected to study. As computer modeling is becoming more powerful due to the dramatic increase of computational resources and software over the recent decades, there is an increasing demand for atomistic simulations with the goal of better understanding materials behavior on the atomic scale. Density functional theory (DFT) is a quantum mechanics based approach to calculate electron distribution, total energy and interatomic forces with high accuracy. From these, atomic structures and thermal effects can be predicted. However, DFT is mostly applied to relatively simple systems because it is computationally very demanding. In this thesis, the current limits of DFT applications are explored by studying relatively complex systems, namely, carbynes, carbon nanotube (CNT) devices and bulk metallic glasses (BMGs). Special care is taken to overcome the limitations set by small system sizes and time scales that often prohibit DFT from being applied to realistic systems under realistic external conditions. In the first study, we examine the possible existence of a third solid phase of carbon with linear bonding called carbyne, which has been suggested in the literature and whose formation has been suggested to be detrimental to high-temperature carbon materials. We have suggested potential structures for

Gamma irradiation-induced modifications of resins found in nuclear waste embedding processes; Modifications induites par irradiation gamma dans les differentes resines rencontrees dans le traitement des dechets nucleaires

Energy Technology Data Exchange (ETDEWEB)

Allali, H [Faculte des Science et Techniques, Settat (Morocco); Debre, O; Lambert, M; Nsouli, B; Thomas, J P [Inst. de Physique Nucleaire, Lyon-1 Univ., 69 - Villeurbanne (France); Collaboration: IPN-Lyon, Laboratoire d` Etude des Materiaux Plastiques et des Biomateriaux, URA 507, UCBL, Agence Nationale pour la Gestion des Dechets Radiactifs

1999-12-31

The various resins involved in nuclear waste disposal are subject to gamma irradiation-induced modifications. From Time-of-Flight Mass Spectrometry of Secondary ions emitted under High Energy Projectiles bombardment (HSF-SIMS) of such materials the following results are obtained: the embedding epoxy resin DGEBA-DDM does not exhibit significant bulk changes in chemical structure, whatever the dose rate and irradiation medium (air or water), at least up to 2 MGy. However, oxidation processes are well observed at the very surface. Under the same conditions Ion exchange resins to be embedded are subjected to scissions of their functional sites, leading to fixed ion release. Dehydration under irradiation is observed pointing out the crucial role of water in ion transport outside of the material. (authors)

Atomistic and holistic understanding in physics

International Nuclear Information System (INIS)

Bohm, A.

1992-01-01

Understanding means always reduction to the simpler. In the atomistic understanding the reduction is to the simpler objects. One asks the question: what does it consist of? For instance, one asks: What does the molecule consist of? and the answer is: The molecule consists of electrons and nuclei. Or: what does the nucleus consist of? And the answer is: The nucleus consists of protons and neutrons. The parts in the atomistic understanding are the constituents. In the holistic understanding, the reduction is to the simpler functions, the simpler motions. One asks the question: What does it do? What does the molecule do? What does the nucleus do? And the answer is: The molecule rotates and oscillates. The nucleus rotates and oscillates

A coupled atomistics and discrete dislocation plasticity simulation of nanoindentation into single crystal thin films

International Nuclear Information System (INIS)

Miller, Ronald E.; Shilkrot, L.E.; Curtin, William A.

2004-01-01

The phenomenon of 2D nanoindentation of circular 'Brinell' indenter into a single crystal metal thin film bonded to a rigid substrate is investigated. The simulation method is the coupled atomistics and discrete dislocation (CADD) model recently developed by the authors. The CADD model couples a continuum region containing any number of discrete dislocations to an atomistic region, and permits accurate, automatic detection and passing of dislocations between the atomistic and continuum regions. The CADD model allows for a detailed study of nanoindentation to large penetration depths (up to 60 A here) using only a small region of atoms just underneath the indenter where dislocation nucleation, cross-slip, and annihilation occur. Indentation of a model hexagonal aluminum crystal shows: (i) the onset of homogeneous dislocation nucleation at points away from the points of maximum resolved shear stress; (ii) size-dependence of the material hardness, (iii) the role of dislocation dissociation on deformation; (iv) reverse plasticity, including nucleation of dislocations on unloading and annihilation; (v) permanent deformation, including surface uplift, after full unloading; (vi) the effects of film thickness on the load-displacement response; and (vii) the differences between displacement and force controlled loading. This application demonstrates the power of the CADD method in capturing both long-range dislocation plasticity and short-range atomistic phenomena. The use of CADD permits for a clear study of the physical and mechanical influence of both complex plastic flow and non-continuum atomistic-level processes on the macroscopic response of material under indentation loading

Disposal of bead ion exchange resin wastes

International Nuclear Information System (INIS)

Gay, R.L.; Granthan, L.F.

1985-01-01

Bead ion exchange resin wastes are disposed of by a process which involves spray-drying a bead ion exchange resin waste in order to remove substantially all of the water present in such waste, including the water on the surface of the ion exchange resin beads and the water inside the ion exchange resin beads. The resulting dried ion exchange resin beads can then be solidified in a suitable solid matrix-forming material, such as a polymer, which solidifies to contain the dried ion exchange resin beads in a solid monolith suitable for disposal by burial or other conventional means

Nanocomposites with Liquid-Like Multiwalled Carbon Nanotubes Dispersed in Epoxy Resin without Solvent Process

Directory of Open Access Journals (Sweden)

Xi Zhang

2014-01-01

Full Text Available Liquid-like multiwall carbon nanotubes (MWNTs were prepared with as-received carboxylic MWNTs-COOH and poly(ethylene oxide-block-poly(propylene oxide-block-poly(ethylene oxide (PEO-b-PPO-b-PEO through hydrogen bonding. The sample has liquid-like behavior above 58°C. The MWNTs content is 26.6 wt%. The liquid-like MWNTs nanofluids were incorporated into epoxy matrix with solvent-free process and dispersed well. When the liquid-like MWNTs nanofluids content is up to 1 wt%, the impact toughness of the nanocomposite is 153% higher than the pure epoxy matrix.

Peridynamics as a rigorous coarse-graining of atomistics for multiscale materials design

International Nuclear Information System (INIS)

Lehoucq, Richard B.; Aidun, John Bahram; Silling, Stewart Andrew; Sears, Mark P.; Kamm, James R.; Parks, Michael L.

2010-01-01

This report summarizes activities undertaken during FY08-FY10 for the LDRD Peridynamics as a Rigorous Coarse-Graining of Atomistics for Multiscale Materials Design. The goal of our project was to develop a coarse-graining of finite temperature molecular dynamics (MD) that successfully transitions from statistical mechanics to continuum mechanics. The goal of our project is to develop a coarse-graining of finite temperature molecular dynamics (MD) that successfully transitions from statistical mechanics to continuum mechanics. Our coarse-graining overcomes the intrinsic limitation of coupling atomistics with classical continuum mechanics via the FEM (finite element method), SPH (smoothed particle hydrodynamics), or MPM (material point method); namely, that classical continuum mechanics assumes a local force interaction that is incompatible with the nonlocal force model of atomistic methods. Therefore FEM, SPH, and MPM inherit this limitation. This seemingly innocuous dichotomy has far reaching consequences; for example, classical continuum mechanics cannot resolve the short wavelength behavior associated with atomistics. Other consequences include spurious forces, invalid phonon dispersion relationships, and irreconcilable descriptions/treatments of temperature. We propose a statistically based coarse-graining of atomistics via peridynamics and so develop a first of a kind mesoscopic capability to enable consistent, thermodynamically sound, atomistic-to-continuum (AtC) multiscale material simulation. Peridynamics (PD) is a microcontinuum theory that assumes nonlocal forces for describing long-range material interaction. The force interactions occurring at finite distances are naturally accounted for in PD. Moreover, PDs nonlocal force model is entirely consistent with those used by atomistics methods, in stark contrast to classical continuum mechanics. Hence, PD can be employed for mesoscopic phenomena that are beyond the realms of classical continuum mechanics and

Characterization of Composite Fan Case Resins

Science.gov (United States)

Dvoracek, Charlene M.

2004-01-01

The majority of commercial turbine engines that power today s aircraft use a large fan driven by the engine core to generate thrust which dramatically increases the engine s efficiency. However, if one of these fan blades fails during flight, it becomes high energy shrapnel, potentially impacting the engine or puncturing the aircraft itself and thus risking the lives of passengers. To solve this problem, the fan case must be capable of containing a fan blade should it break off during flight. Currently, all commercial fan cases are made of either just a thick metal barrier or a thinner metal wall surrounded by Kevlar-an ultra strong fiber that elastically catches the blade. My summer 2004 project was to characterize the resins for a composite fan case that will be lighter and more efficient than the current metal. The composite fan case is created by braiding carbon fibers and injecting a polymer resin into the braid. The resin holds the fibers together, so at first using the strongest polymer appears to logically lead to the strongest fan case. Unfortunately, the stronger polymers are too viscous when melted. This makes the manufacturing process more difficult because the polymer does not flow as freely through the braid, and the final product is less dense. With all of this in mind, it is important to remember that the strength of the polymer is still imperative; the case must still contain blades with high impact energy. The research identified which polymer had the right balance of properties, including ease of fabrication, toughness, and ability to transfer the load to the carbon fibers. Resin deformation was studied to better understand the composite response during high speed impact. My role in this research was the testing of polymers using dynamic mechanical analysis and tensile, compression, and torsion testing. Dynamic mechanical analysis examines the response of materials under cyclic loading. Two techniques were used for dynamic mechanical analysis

The Resin-Embedded Cornea Prepared Via Rapid Processing Protocol : A Good Histomorphometric Target for Clinical Investigation in Ophthalmology and Optometry

Science.gov (United States)

Cheah, Pike See; Mohidin, Norhani; Mohd Ali, Bariah; Maung, Myint; Latif, Azian Abdul

2008-01-01

This study illustrates and quantifies the changes on corneal tissue between the paraffin-embedded and resin-embedded blocks and thus, selects a better target in investigational ophthalmology and optometry via light microscopy. Corneas of two cynomolgus monkeys (Macaca fascicularis) were used in this study. The formalin-fixed cornea was prepared in paraffin block via the conventional tissue processing protocol (4-day protocol) and stained with haematoxylin and eosin. The glutaraldehyde-fixed cornea was prepared in resin block via the rapid and modified tissue processing procedure (1.2-day protocol) and stained with toluidine blue. The paraffin-embedded sample exhibits various undesired tissue damage and artifact such as thinner epithelium (due to the substantial volumic extraction from the tissue), thicker stroma layer (due to the separation of lamellae and the presence of voids) and the distorted endothelium. In contrast, the resin-embedded corneal tissue has demonstrated satisfactory corneal ultrastructural preservation. The rapid and modified tissue processing method for preparing the resin-embedded is particularly beneficial to accelerate the microscopic evaluation in ophthalmology and optometry. PMID:22570589

A Novel Approach to Mineral Carbonation: Enhancing Carbonation While Avoiding Mineral Pretreatment Process Cost

Energy Technology Data Exchange (ETDEWEB)

Andrew V. G. Chizmeshya; Michael J. McKelvy; Kyle Squires; Ray W. Carpenter; Hamdallah Bearat

2007-06-21

Known fossil fuel reserves, especially coal, can support global energy demands for centuries to come, if the environmental problems associated with CO{sub 2} emissions can be overcome. Unlike other CO{sub 2} sequestration candidate technologies that propose long-term storage, mineral sequestration provides permanent disposal by forming geologically stable mineral carbonates. Carbonation of the widely occurring mineral olivine (e.g., forsterite, Mg{sub 2}SiO{sub 4}) is a large-scale sequestration process candidate for regional implementation, which converts CO{sub 2} into the environmentally benign mineral magnesite (MgCO{sub 3}). The primary goal is cost-competitive process development. As the process is exothermic, it inherently offers low-cost potential. Enhancing carbonation reactivity is key to economic viability. Recent studies at the U.S. DOE Albany Research Center have established that aqueous-solution carbonation using supercritical CO{sub 2} is a promising process; even without olivine activation, 30-50% carbonation has been achieved in an hour. Mechanical activation (e.g., attrition) has accelerated the carbonation process to an industrial timescale (i.e., near completion in less than an hour), at reduced pressure and temperature. However, the activation cost is too high to be economical and lower cost pretreatment options are needed. We have discovered that robust silica-rich passivating layers form on the olivine surface during carbonation. As carbonation proceeds, these passivating layers thicken, fracture and eventually exfoliate, exposing fresh olivine surfaces during rapidly-stirred/circulating carbonation. We are exploring the mechanisms that govern carbonation reactivity and the impact that (1) modeling/controlling the slurry fluid-flow conditions, (2) varying the aqueous ion species/size and concentration (e.g., Li+, Na+, K+, Rb+, Cl-, HCO{sub 3}{sup -}), and (3) incorporating select sonication offer to enhance exfoliation and carbonation. Thus

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

Damage analysis of fiber reinforced resin matrix composites irradiated by CW laser

International Nuclear Information System (INIS)

Wan Hong; Hu Kaiwei; Mu Jingyang; Bai Shuxin

2008-01-01

In this paper, the damage modes of the carbon fiber and the glass fiber reinforced epoxy or bakelite resin matrix composites irradiated by CW laser under different power densities were analyzed, and the changes of the microstructure and the tensile strength of the composites were also researched. When the resin matrix composites were radiated at a power density more than 0.1 kW/cm 2 , the matrix would be decomposed and the tensile properties of the radiated samples were lost over 30% while the carbon fiber hardly damaged and the glass fiber melted. When the power density of the laser was raised to 1 kW/cm 2 , the matrix burned violently and the carbon fiber cloth began to split with some carbon fiber being fractured, therefore, the fracture strength of the radiated sample lost over 80%. The higher the power density of radiation was, the more serious the damage of the sample was. It was also found that the difference of the matrixes had little effect on the damage extent of the composites. The influence of the radiation density on the temperature of the radiated surface of the carbon/resin composite was numerically calculated by ANSYS finite element software and the calculation results coincided with the damage mode of the radiated composites. (authors)

Atomistic Monte Carlo simulation of lipid membranes

DEFF Research Database (Denmark)

Wüstner, Daniel; Sklenar, Heinz

2014-01-01

Biological membranes are complex assemblies of many different molecules of which analysis demands a variety of experimental and computational approaches. In this article, we explain challenges and advantages of atomistic Monte Carlo (MC) simulation of lipid membranes. We provide an introduction...... into the various move sets that are implemented in current MC methods for efficient conformational sampling of lipids and other molecules. In the second part, we demonstrate for a concrete example, how an atomistic local-move set can be implemented for MC simulations of phospholipid monomers and bilayer patches...

Dislocation climb models from atomistic scheme to dislocation dynamics

OpenAIRE

Niu, Xiaohua; Luo, Tao; Lu, Jianfeng; Xiang, Yang

2016-01-01

We develop a mesoscopic dislocation dynamics model for vacancy-assisted dislocation climb by upscalings from a stochastic model on the atomistic scale. Our models incorporate microscopic mechanisms of (i) bulk diffusion of vacancies, (ii) vacancy exchange dynamics between bulk and dislocation core, (iii) vacancy pipe diffusion along the dislocation core, and (iv) vacancy attachment-detachment kinetics at jogs leading to the motion of jogs. Our mesoscopic model consists of the vacancy bulk dif...

Adsorption of CO2 on KOH activated, N-enriched carbon derived from urea formaldehyde resin: kinetics, isotherm and thermodynamic studies

Science.gov (United States)

Tiwari, Deepak; Bhunia, Haripada; Bajpai, Pramod K.

2018-05-01

High surface area nitrogen enriched carbon adsorbents were prepared from a low cost and widely available urea-formaldehyde resin using a standard chemical activation with KOH and characterized using different characterization techniques for their porous structure and surface functional groups. Maximum surface area and total pore volume of 4547 m2 g-1 and 4.50 cm3 g-1 were found by controlling the activation conditions. Nitrogen content of this sample was found to be 5.62%. Adsorption of CO2 uptake for the prepared carbon adsorbents was studied using a dynamic fixed bed adsorption system at different adsorption temperatures (30-100 °C) and at different CO2 concentrations (5-12.5%), relevant from the flue gas point application. Maximum CO2 uptake of 1.40 mmol g-1 for UFA-3-700 at 30 °C under 12.5% CO2 flow was obtained. Complete regenerability of the adsorbents over multiple adsorption-desorption cycles was obtained. Fractional order kinetic model provided best description over all adsorption temperatures and CO2 concentrations. Heterogeneity of the adsorbent surface was confirmed from Temkin adsorption isotherm model fit and isosteric heat of adsorption values. Negative value of ΔG° and ΔH° confirms spontaneous, feasible nature and exothermic nature of adsorption process. Overall, very high surface area of carbon adsorbent makes this adsorbent a new promising carbon material for CO2 capture from power plant flue gas and for other relevant applications.

Study on spraying water soluble resin to reduce pollution for Fukushima daiichi NPP accident

International Nuclear Information System (INIS)

Zhang Qiong; Guo Ruiping; Zhang Chunming; Han Fujuan; Hua Jie; Zhang Jiankui

2012-01-01

After Fukushima nuclear accident, Tokyo electric power company used the method of spraying water soluble resin synthesis at the scene of the accident, to restrain and control the spread of the radioactive dust, by forming consolidation layer in pollution area surface. This paper briefly introduced the accident, motivation of spraying water soluble resin, spraying range and implementation process. According to the relevant report on Fukushima nuclear accident, the effect of spraying water soluble resin for reducing pollution was analyzed. The mechanism of reducing pollution for water soluble resin and the application prospect were discussed. Spraying water soluble resin for fixing radioactive dust has reasonable reducing pollution effect. It is worth to use as reference and study in China. (authors)

EB treatment of carbon nanotube-reinforced polymer composites

International Nuclear Information System (INIS)

Szebényi, G.; Romhány, G.; Vajna, B.; Czvikovszky, T.

2012-01-01

A small amount — less than 0.5% — carbon nanotube reinforcement may improve the mechanical properties of epoxy based composite materials significantly. The basic technical problem on one side is the dispersion of the nanotubes into the viscous matrix resin, namely, the fine powder-like — less than 100 nanometer diameter — nanotubes are prone to form aggregates. On the other side, the good connection between the nanofiber and matrix, which is determining the success of the reinforcement, requires some efficient adhesion promoting treatment. The goal of our research was to give one such treatment capable of industrial size application. A two step curing epoxy/vinylester resin process technology has been developed where the epoxy component has been cured conventionally, while the vinylester has been cured by electron treatment afterwards. The sufficient irradiation dose has been selected according to Raman spectroscopy characterization. Using the developed hybrid resin system hybrid composites containing carbon fibers and multiwalled carbon nanotubes have been prepared. The effect of the electron beam induced curing of the vinylester resin on the mechanical properties of the composites has been characterized by three point bending and interlaminar shear tests, which showed clearly the superiority of the developed resin system. The results of the mechanical tests have been supported by AFM studies of the samples, which showed that the difference in the viscoelastic properties of the matrix constituents decreased significantly by the electron beam treatment.

Multiscale modeling of dislocation processes in BCC tantalum: bridging atomistic and mesoscale simulations

International Nuclear Information System (INIS)

Yang, L H; Tang, M; Moriarty, J A

2001-01-01

Plastic deformation in bcc metals at low temperatures and high-strain rates is controlled by the motion of a/2 screw dislocations, and understanding the fundamental atomistic processes of this motion is essential to develop predictive multiscale models of crystal plasticity. The multiscale modeling approach presented here for bcc Ta is based on information passing, where results of simulations at the atomic scale are used in simulations of plastic deformation at mesoscopic length scales via dislocation dynamics (DD). The relevant core properties of a/2 screw dislocations in Ta have been obtained using quantum-based interatomic potentials derived from model generalized pseudopotential theory and an ab-initio data base together with an accurate Green's-function simulation method that implements flexible boundary conditions. In particular, the stress-dependent activation enthalpy for the lowest-energy kink-pair mechanism has been calculated and fitted to a revealing analytic form. This is the critical quantity determining dislocation mobility in the DD simulations, and the present activation enthalpy is found to be in good agreement with the previous empirical form used to explain the temperature dependence of the yield stress

Flow Characteristics of a Thermoset Fiber Composite Photopolymer Resin in a Vat Polymerization Additive Manufacturing Process

DEFF Research Database (Denmark)

Hofstätter, Thomas; Spangenberg, Jon; Pedersen, David B.

Additive manufacturing vat polymerization has become a leading technology and gained a massive amount of attention in industrial applications such as injection molding inserts. By the use of the thermoset polymerization process inserts have increased their market share. For most industrial...... understood. Research indicates an orientation within the manufacturing layer and efforts have been made to achieve a more uniform orientation within the part. A vat polymerization machine consisting of a resin vat and a moving build plate has been simulated using the fluid flow module of Comsol Multiphysics...... photopolymer resin. The prediction can be used to identify potential clusters or misalignment of fibers and in the future allow for optimization of the machine design and manufacturing process....

Evaluation of off-gas characteristics in vitrification process of ion-exchange resin

International Nuclear Information System (INIS)

Park, S. C.; Kim, H. S.; Yang, K. H.; Yun, C. H.; Hwang, T. W.; Shin, S. W.

2001-01-01

The properties of off-gas generated from vitrification process of ion-exchange resin were characterized. Theoretical composition and flow rate of the off-gas were calculated based on chemical composition of resin and it's burning condition inside CCM. The calculated off-gas flow rate was 67.9 Nm 3 /h at the burning rate of 40 kg/h. And the composition of off-gas was evaluated as CO 2 (41.4%), Steam (40.0%), O 2 (13.3%), NO (3.6%), and SO 2 (1.6%) in order. Then, actual flow rate and composition of off-gas were measured during pilot-scale demonstration tests and the results were compared with theoretical values. The actual flow rate of off-gas was about 1.6 times higher than theoretical one. The difference between theoretical and actual flow rates was caused by the in-leakage of air to the system, and the in-leakage rate was evaluated as 36.3 Nm 3 /h. Because of continuous change in the combustion parameters inside CCM, during demonstration tests, the concentration of toxic gases showed wide fluctuation. However, the concentration of CO, a barometer of incompleteness of combustion inside CCM, was stabilized soon. The result showed quasi-equilibrium state was achieved two hours after feeding of resin. (author)

An object oriented Python interface for atomistic simulations

Science.gov (United States)

Hynninen, T.; Himanen, L.; Parkkinen, V.; Musso, T.; Corander, J.; Foster, A. S.

2016-01-01

Programmable simulation environments allow one to monitor and control calculations efficiently and automatically before, during, and after runtime. Environments directly accessible in a programming environment can be interfaced with powerful external analysis tools and extensions to enhance the functionality of the core program, and by incorporating a flexible object based structure, the environments make building and analysing computational setups intuitive. In this work, we present a classical atomistic force field with an interface written in Python language. The program is an extension for an existing object based atomistic simulation environment.

Hydrogen storage enhanced in Li-doped carbon replica of zeolites: a possible route to achieve fuel cell demand.

Science.gov (United States)

Roussel, Thomas; Bichara, Christophe; Gubbins, Keith E; Pellenq, Roland J-M

2009-05-07

We first report the atomistic grand canonical Monte Carlo simulations of the synthesis of two realistic ordered microporous carbon replica in two siliceous forms of faujasite zeolite (cubic Y-FAU and hexagonal EMT). Atomistic simulations of hydrogen adsorption isotherms in these two carbon structures and their Li-doped composites were carried out to determine their storage capacities at 77 and 298 K. We found that these new forms of carbon solids and their Li-doped versions show very attractive hydrogen storage capacities at 77 and 298 K, respectively. However, for a filling pressure of 300 bars and at room temperature, bare carbons do not show advantageous performances compared to a classical gas cylinder despite of their crystalline micropore network. In comparison, Li-doped nanostructures provide reversible gravimetric and volumetric hydrogen storage capacities twice larger (3.75 wt % and 33.7 kg/m(3)). The extreme lattice stiffness of their skeleton will prevent them from collapsing under large external applied pressure, an interesting skill compared to bundle of carbon nanotubes, and metal organic frameworks (MOFs). These new ordered composites are thus very promising materials for hydrogen storage issues by contrast with MOFs.

Processing and properties of carbon nanofibers reinforced epoxy powder composites

International Nuclear Information System (INIS)

Palencia, C.; Mazo, M. A.; Nistal, A.; Rubio, F.; Rubio, J.; Oteo, J. L.

2011-01-01

Commercially available CNFs (diameter 30–300 nm) have been used to develop both bulk and coating epoxy nanocomposites by using a solvent-free epoxy matrix powder. Processing of both types of materials has been carried out by a double-step process consisting in an initial physical premix of all components followed by three consecutive extrusions. The extruded pellets were grinded into powder and sieved. Carbon nanofibers powder coatings were obtained by electrostatic painting of the extruded powder followed by a curing process based in a thermal treatment at 200 °C for 25 min. On the other hand, for obtaining bulk carbon nanofibers epoxy composites, a thermal curing process involving several steps was needed. Gloss and mechanical properties of both nanocomposite coatings and bulk nanocomposites were improved as a result of the processing process. FE-SEM fracture surface microphotographs corroborate these results. It has been assessed the key role played by the dispersion of CNFs in the matrix, and the highly important step that is the processing and curing of the nanocomposites. A processing stage consisted in three consecutive extrusions has reached to nanocomposites free of entanglements neither agglomerates. This process leads to nanocomposite coatings of enhanced properties, as it has been evidenced through gloss and mechanical properties. A dispersion limit of 1% has been determined for the studied system in which a given dispersion has been achieved, as the bending mechanical properties have been increased around 25% compared with the pristine epoxy resin. It has been also demonstrated the importance of the thickness in the nanocomposite, as it involves the curing stage. The complex curing treatment carried out in the case of bulk nanocomposites has reached to reagglomeration of CNFs.

Processing and properties of carbon nanofibers reinforced epoxy powder composites

Science.gov (United States)

Palencia, C.; Mazo, M. A.; Nistal, A.; Rubio, F.; Rubio, J.; Oteo, J. L.

2011-11-01

Commercially available CNFs (diameter 30-300 nm) have been used to develop both bulk and coating epoxy nanocomposites by using a solvent-free epoxy matrix powder. Processing of both types of materials has been carried out by a double-step process consisting in an initial physical premix of all components followed by three consecutive extrusions. The extruded pellets were grinded into powder and sieved. Carbon nanofibers powder coatings were obtained by electrostatic painting of the extruded powder followed by a curing process based in a thermal treatment at 200 °C for 25 min. On the other hand, for obtaining bulk carbon nanofibers epoxy composites, a thermal curing process involving several steps was needed. Gloss and mechanical properties of both nanocomposite coatings and bulk nanocomposites were improved as a result of the processing process. FE-SEM fracture surface microphotographs corroborate these results. It has been assessed the key role played by the dispersion of CNFs in the matrix, and the highly important step that is the processing and curing of the nanocomposites. A processing stage consisted in three consecutive extrusions has reached to nanocomposites free of entanglements neither agglomerates. This process leads to nanocomposite coatings of enhanced properties, as it has been evidenced through gloss and mechanical properties. A dispersion limit of 1% has been determined for the studied system in which a given dispersion has been achieved, as the bending mechanical properties have been increased around 25% compared with the pristine epoxy resin. It has been also demonstrated the importance of the thickness in the nanocomposite, as it involves the curing stage. The complex curing treatment carried out in the case of bulk nanocomposites has reached to reagglomeration of CNFs.

Raman spectroscopic study of the aging and nitration of actinide processing anion-exchange resins in concentrated nitric acid

International Nuclear Information System (INIS)

Buscher, C. T.; Donohoe, R. J.; Mecklenburg, S. L.; Berg, J. M.; Tait, C. D.; Huchton, K. M.; Morris, D. E.

1999-01-01

Degradation of two types of anion exchange resins, Dowex 11 and Reillex HPQ, from the action of concentrated nitric acid (4 to 12 M) and radiolysis [from depleted uranium as UO 2 2+ nitrate species and 239 Pu as Pu(IV) nitrate species] was followed as a function of time with Raman vibrational spectroscopy. Elevated temperatures (∼50 degree sign C) were used in the absence of actinide metal loading to simulate longer exposures of the resin to a HNO 3 process stream and waste storage conditions. In the absence of actinide loading, only minor changes in the Dowex resin at acid concentrations ≤10 M were observed, while at 12 M acid concentration, the emergence of a Raman peak at 1345 cm-1 indicates the addition of nitro functional groups to the resin. Similar studies with the Reillex resin show it to be more resistant to nitric acid attack at all acid concentrations. Incorporation of weakly radioactive depleted uranium as the UO 2 2+ nitrate species to the ion-exchange sites of Dowex 11 under differing nitric acid concentrations (6 to 12 M) at room temperature showed no Raman evidence of resin degradation or nitration, even after several hundred days of contact. In contrast, Raman spectra for Dowex 11 in the presence of 239 Pu as Pu(IV) nitrate species reveal numerous changes indicating resin alterations, including a new mode at 1345 cm-1 consistent with a Pu(IV)-nitrate catalyzed addition of nitro groups to the resin backbone. (c) 2000 Society for Applied Spectroscopy

[Studies on purification of total glycosides of paeony (TGP) from Paeonia lactiflora by ethanol gradient combined with resin processing].

Science.gov (United States)

Shu, Xin-Ying; Meng, Xian-Sheng; Pan, Ying; Han, Ling; Bao, Yong-Rui; Guo, Xiao-Rui

2010-11-01

To study the purification technology of TGP from Paeonia lactiflora by ethanol gradient combined with resin processing and determine the optimum technological conditions and parameters. Using orthogonal test design to investigate the effect of ethanol gradient treatment on the content of TGP. Moreover, from the static and dynamic adsorption nine types of macroporous adsorption resin were evaluated to select the best resin type and the optimum separation and purification conditions. The best technology of Paeonia lactiflora ethanol precipitation was concentration of 1 g crude drug/mL precipitated by 95% ethanol to 90% concentration and then frozen for 10 h. HPD300 resin was the optimal model for the separation and purification of TGP from Paeonia lactiflora, with 5BV of 50% ethanol eluenting and the ratio of herb to resin was 2:1 . This technology is suitable and advanced for industry production and it is simple and convenient, rapid, accurate, etc.

Characterization of Thermo-Elastic Properties and Microcracking Behaviors of CFRP Laminates Using Cup-Stacked Carbon Nanotubes (CSCNT) Dispersed Resin

Science.gov (United States)

Yokozeki, Tomohiro; Iwahori, Yutaka; Ishiwata, Shin

This study investigated the thermo-elastic properties and microscopic ply cracking behaviors in carbon fiber reinforced nanotube-dispersed epoxy laminates. The nanocomposite laminates used in this study consisted of traditional carbon fibers and epoxy resin filled with cup-stacked carbon nanotubes (CSCNTs). Thermo-mechanical properties of unidirectional nanocomposite laminates were evaluated, and quasi-static and fatigue tension tests of cross-ply laminates were carried out in order to observe the damage accumulation behaviors of matrix cracks. Clear retardation of matrix crack onset and accumulation was found in composite laminates with CSCNT compared to those without CSCNT. Fracture toughness associated with matrix cracking was evaluated based on the analytical model using the experimental results. It was concluded that the dispersion of CSCNT resulted in fracture toughness improvement and residual thermal strain decrease, and specifically, the former was the main contribution to the retardation of matrix crack formation.

Elastic dipoles of point defects from atomistic simulations

Science.gov (United States)

Varvenne, Céline; Clouet, Emmanuel

2017-12-01

The interaction of point defects with an external stress field or with other structural defects is usually well described within continuum elasticity by the elastic dipole approximation. Extraction of the elastic dipoles from atomistic simulations is therefore a fundamental step to connect an atomistic description of the defect with continuum models. This can be done either by a fitting of the point-defect displacement field, by a summation of the Kanzaki forces, or by a linking equation to the residual stress. We perform here a detailed comparison of these different available methods to extract elastic dipoles, and show that they all lead to the same values when the supercell of the atomistic simulations is large enough and when the anharmonic region around the point defect is correctly handled. But, for small simulation cells compatible with ab initio calculations, only the definition through the residual stress appears tractable. The approach is illustrated by considering various point defects (vacancy, self-interstitial, and hydrogen solute atom) in zirconium, using both empirical potentials and ab initio calculations.

Characterization of monolith block of spent resin cementation

International Nuclear Information System (INIS)

Prayitno; Endro-Kismolo; Isman MT

1996-01-01

Spent resin immobilization process with cement was done to prevent release of radionuclide in the ultimate storage or disposal. The varied Composition of water/cement ratio in the cementation process were 0.3; 0.4; 0.5 and the various weight of resin waste are 25 g, 37.5 g and 50 gram. The compressive strength of the various water/cement ratio without spent resin was bigger than 0.3. This investigation proved that the compressive strength of Tiga Roda cement was bigger than those of Gresik cement or Nusantara cement. The compressive of the cement block of were the spent resin cementation was influenced by the water/cement ratio and the total spent resin addition. The best condition reached at the water/cement ratio of 0.3 and 25 gram spent resin, was compressive strength of 17.86 N/mm 2 . Leaching rate of the various weight composition of spent resin cementation for 91 days were between 10 -2 - 10 -4 gram.cm -2 .day -1

Amp: A modular approach to machine learning in atomistic simulations

Science.gov (United States)

Khorshidi, Alireza; Peterson, Andrew A.

2016-10-01

Electronic structure calculations, such as those employing Kohn-Sham density functional theory or ab initio wavefunction theories, have allowed for atomistic-level understandings of a wide variety of phenomena and properties of matter at small scales. However, the computational cost of electronic structure methods drastically increases with length and time scales, which makes these methods difficult for long time-scale molecular dynamics simulations or large-sized systems. Machine-learning techniques can provide accurate potentials that can match the quality of electronic structure calculations, provided sufficient training data. These potentials can then be used to rapidly simulate large and long time-scale phenomena at similar quality to the parent electronic structure approach. Machine-learning potentials usually take a bias-free mathematical form and can be readily developed for a wide variety of systems. Electronic structure calculations have favorable properties-namely that they are noiseless and targeted training data can be produced on-demand-that make them particularly well-suited for machine learning. This paper discusses our modular approach to atomistic machine learning through the development of the open-source Atomistic Machine-learning Package (Amp), which allows for representations of both the total and atom-centered potential energy surface, in both periodic and non-periodic systems. Potentials developed through the atom-centered approach are simultaneously applicable for systems with various sizes. Interpolation can be enhanced by introducing custom descriptors of the local environment. We demonstrate this in the current work for Gaussian-type, bispectrum, and Zernike-type descriptors. Amp has an intuitive and modular structure with an interface through the python scripting language yet has parallelizable fortran components for demanding tasks; it is designed to integrate closely with the widely used Atomic Simulation Environment (ASE), which

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

Resin bleed improvement on surface mount semiconductor device

Science.gov (United States)

Rajoo, Indra Kumar; Tahir, Suraya Mohd; Aziz, Faieza Abdul; Shamsul Anuar, Mohd

2018-04-01

Resin bleed is a transparent layer of epoxy compound which occurs during molding process but is difficult to be detected after the molding process. Resin bleed on the lead on the unit from the focused package, SOD123, can cause solderability failure at end customer. This failed unit from the customer will be considered as a customer complaint. Generally, the semiconductor company has to perform visual inspection after the plating process to detect resin bleed. Mold chase with excess hole, split cavity & stepped design ejector pin hole have been found to be the major root cause of resin bleed in this company. The modifications of the mold chase, changing of split cavity to solid cavity and re-design of the ejector pin proposed were derived after a detailed study & analysis conducted to arrive at these solutions. The solutions proposed have yield good results during the pilot run with zero (0) occurrence of resin bleed for 3 consecutive months.