WorldWideScience

Sample records for coextrusion

  1. Finite element analysis of multilayer coextrusion.

    Energy Technology Data Exchange (ETDEWEB)

    Hopkins, Matthew Morgan; Schunk, Peter Randall; Baer, Thomas A. (Proctor & Gamble Company, West Chester, OH); Mrozek, Randy A. (Army Research Laboratory, Adelphi, MD); Lenhart, Joseph Ludlow (Army Research Laboratory, Adelphi, MD); Rao, Rekha Ranjana; Collins, Robert (Oak Ridge National Laboratory); Mondy, Lisa Ann

    2011-09-01

    Multilayer coextrusion has become a popular commercial process for producing complex polymeric products from soda bottles to reflective coatings. A numerical model of a multilayer coextrusion process is developed based on a finite element discretization and two different free-surface methods, an arbitrary-Lagrangian-Eulerian (ALE) moving mesh implementation and an Eulerian level set method, to understand the moving boundary problem associated with the polymer-polymer interface. The goal of this work is to have a numerical capability suitable for optimizing and troubleshooting the coextrusion process, circumventing flow instabilities such as ribbing and barring, and reducing variability in layer thickness. Though these instabilities can be both viscous and elastic in nature, for this work a generalized Newtonian description of the fluid is used. Models of varying degrees of complexity are investigated including stability analysis and direct three-dimensional finite element free surface approaches. The results of this work show how critical modeling can be to reduce build test cycles, improve material choices, and guide mold design.

  2. Ceramic core–shell composites with modified mechanical properties prepared by thermoplastic co-extrusion

    Czech Academy of Sciences Publication Activity Database

    Kaštyl, J.; Chlup, Zdeněk; Clemens, F.; Trunec, M.

    2015-01-01

    Roč. 35, č. 10 (2015), s. 2873-2881 ISSN 0955-2219 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 Keywords : Alumina * Zirconia toughened alumina * Co-extrusion * Composite * Mechanical properties1 Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 2.933, year: 2015

  3. Co-Extrusion: Advanced Manufacturing for Energy Devices

    Energy Technology Data Exchange (ETDEWEB)

    Cobb, Corie Lynn [PARC, Palo Alto, CA (United States)

    2016-11-18

    The development of mass markets for large-format batteries, including electric vehicles (EVs) and grid support, depends on both cost reductions and performance enhancements to improve their economic viability. Palo Alto Research Center (PARC) has developed a multi-material, advanced manufacturing process called co-extrusion (CoEx) to remove multiple steps in a conventional battery coating process with the potential to simultaneously increase battery energy and power density. CoEx can revolutionize battery manufacturing across most chemistries, significantly lowering end-product cost and shifting the underlying economics to make EVs and other battery applications a reality. PARC’s scale-up of CoEx for electric vehicle (EV) batteries builds on a solid base of experience in applying CoEx to solar cell manufacturing, deposition of viscous ceramic pastes, and Li-ion battery chemistries. In the solar application, CoEx has been deployed commercially at production scale where multi-channel CoEx printheads are used to print viscous silver gridline pastes at full production speeds (>40 ft/min). This operational scale-up provided invaluable experience with the nuances of speed, yield, and maintenance inherent in taking a new technology to the factory floor. PARC has leveraged this experience, adapting the CoEx process for Lithium-ion (Li-ion) battery manufacturing. To date, PARC has worked with Li-ion battery materials and structured cathodes with high-density Li-ion regions and low-density conduction regions, documenting both energy and power performance. Modeling results for a CoEx cathode show a path towards a 10-20% improvement in capacity for an EV pouch cell. Experimentally, we have realized a co-extruded battery structure with a Lithium Nickel Manganese Cobalt (NMC) cathode at print speeds equivalent to conventional roll coating processes. The heterogeneous CoEx cathode enables improved capacity in thick electrodes at higher C-rates. The proof-of-principle coin cells

  4. Numerical investigations on the lateral angular co-extrusion of aluminium and steel

    Science.gov (United States)

    Behrens, B.-A.; Klose, C.; Chugreev, A.; Thürer, S. E.; Uhe, J.

    2018-05-01

    In order to save weight and costs, different materials can be combined within one component. In the novel process chain being developed within the Collaborative Research Centre (CRC) 1153, joined semi-finished workpieces are used to produce hybrid solid components with locally adapted properties. Different materials are joined in an initial step before the forming process takes place. Hereby, the quality of the joining zone is improved by means of the thermo-mechanical treatment during the forming and machining processes. The lateral angular co-extrusion (LACE) approach is used to produce semi-finished workpieces because it allows for the production of coaxial semi-finished products consisting of aluminium and steel. In the further process chain, these semi-finished products are processed into hybrid bearing bushings with locally adapted properties by die forging. In the scope of this work, numerical investigations of the co-extrusion of aluminium-steel compounds were carried out using finite element (FE) simulation in order to examine the influence of the process parameters on the co-extrusion process. For this purpose, the relevant material properties of the aluminium alloy EN AW-6082 were determined experimentally and subsequently implemented in the numerical model. The obtained numerical model was used to study the impact of different ram speeds, press ratios and billet temperatures on the resulting extrusion forces and the material flow. The numerical results have been validated using force-time curves obtained from experimental extrusion tests carried out on a 2.5 MN laboratory extrusion press.

  5. Mathematical model of a current of two plastic environments in the forming channel extruders at coextrusion

    Directory of Open Access Journals (Sweden)

    V. N. Vasilenko

    2012-01-01

    Full Text Available On the basis of the classical equations of an isothermal pressure head current of two rheology the various not mixing up viscou- plastic environments in the cylindrical channel, Ostvald-de-Vil submitting to the law, the model of a current of two viscous-plastic environments in the moulding channel extruder is synthesised at co-extrusion on which basis the technique of a choice of diameter of a dosing out branch pipe on the demanded value of the ratio of volume expenditures of two viscous-plastic environments (extrudat and stuffings is offered.

  6. Mechanical properties of zirconia core-shell rods with porous core and dense shell prepared by thermoplastic co-extrusion

    Czech Academy of Sciences Publication Activity Database

    Kaštyl, J.; Chlup, Zdeněk; Clemen, F.; Trunec, M.

    2017-01-01

    Roč. 37, č. 6 (2017), s. 2439-2447 ISSN 0955-2219 R&D Projects: GA MŠk(CZ) LQ1601 Institutional support: RVO:68081723 Keywords : ceramic injection moldings * oxide fuel -cells * electrophoretic deposition * large pores * alumina * fabrication * behavior * tubes * bioceramics * composites * Zirconia * Co-extrusion * Core-shell * Porous structure * Mechanical properties Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass OBOR OECD: Ceramics Impact factor: 3.411, year: 2016

  7. Co-extrusion as a processing technique to manufacture a dual sustained release fixed-dose combination product.

    Science.gov (United States)

    Vynckier, An-Katrien; Voorspoels, Jody; Remon, Jean Paul; Vervaet, Chris

    2016-05-01

    This study aimed to design a fixed-dose combination dosage form which provides a sustained release profile for both the freely water-soluble metformin HCl and the poorly soluble gliclazide, two antidiabetic compounds used to treat diabetes mellitus. Hot-melt co-extrusion was used as an innovative manufacturing technique for a pharmaceutical fixed-dose combination product. In this way, a matrix formulation that sustained metformin release could be developed, despite the high drug load in the formulation and the freely soluble nature of the drug. It was clear that co-extrusion was perfectly suited to produce a fixed-dose combination product with adequate properties for each of the incorporated APIs. A coat layer, containing at least 30% CAPA(®) 6506 as a hydrophobic polymer, was necessary to adequately sustain the release of the highly dosed freely soluble drug from the 70% metformin HCl-loaded CAPA(®) 6506 core of the co-extrudate. To obtain a complete gliclazide release over 24-h solubilization in Kollidon(®) VA, added as a second polymer to the CAPA(®) 6506 in the coat, was needed. Both active pharmaceutical ingredients (APIs), which have different physicochemical characteristics, were formulated in a single dosage form, using co-extrusion. © 2016 Royal Pharmaceutical Society, Journal of Pharmacy and Pharmacology.

  8. Coextrusion of 60 to 80 wt % U3O8 nuclear fuel elements

    International Nuclear Information System (INIS)

    Peacock, H.B.

    1980-01-01

    Aluminum-clad billets with up to 80 wt % U 3 O 8 in U 3 O 8 -Al cores have been coextruded at SRP. However, above 70 wt % U 3 O 8 , yields are low because of core-cracking. Proper selection of materials and extrusion parameters will give process conditions for successful fabrication. Studies were begun of the effects of these parameters on the flow of metal during coextrusion. In coextruded tubes, cracks are formed in large uranium oxide particles. Cracking is caused by the high tensile deformation of these particles that occurs as the cermet material flows through the die. Lower extrusion ratios and larger die angles appear to reduce severe particle cracking and increase fabrication yields. The particle size distribution of the ceramic fuel phase also influences fabricability. Six P/M assemblies with up to 57 wt % U 3 O 8 in U 3 O 8 -Al cores were successfully irradiated to 1.6 x 10 21 fissions per cm 3 of core. No swelling or blistering of the tubes occurred

  9. Development of sustained and dual drug release co-extrusion formulations for individual dosing.

    Science.gov (United States)

    Laukamp, Eva Julia; Vynckier, An-Katrien; Voorspoels, Jody; Thommes, Markus; Breitkreutz, Joerg

    2015-01-01

    In personalized medicine and patient-centered medical treatment individual dosing of medicines is crucial. The Solid Dosage Pen (SDP) allows for an individual dosing of solid drug carriers by cutting them into tablet-like slices. The aim of the present study was the development of sustained release and dual release formulations with carbamazepine (CBZ) via hot-melt co-extrusion for the use in the SDP. The selection of appropriate coat- and core-formulations was performed by adapting the mechanical properties (like tensile strength and E-modulus) for example. By using different excipients (polyethyleneglycols, poloxamers, white wax, stearic acid, and carnauba wax) and drug loadings (30-50%) tailored dissolution kinetics was achieved showing cube root or zero order release mechanisms. Besides a biphasic drug release, the dose-dependent dissolution characteristics of sustained release formulations were minimized by a co-extruded wax-coated formulation. The dissolution profiles of the co-extrudates were confirmed during short term stability study (six months at 21.0 ± 0.2 °C, 45%r.h.). Due to a good layer adhesion of core and coat and adequate mechanical properties (maximum cutting force of 35.8 ± 2.0 N and 26.4 ± 2.8 N and E-modulus of 118.1 ± 8.4 and 33.9 ± 4.5 MPa for the dual drug release and the wax-coated co-extrudates, respectively) cutting off doses via the SDP was precise. While differences of the process parameters (like the barrel temperature) between the core- and the coat-layer resulted in unsatisfying content uniformities for the wax-coated co-extrudates, the content uniformity of the dual drug release co-extrudates was found to be in compliance with pharmacopoeial specification. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Concept Feasibility Report for Using Co-Extrusion to Bond Metals to Complex Shapes of U-10Mo

    Energy Technology Data Exchange (ETDEWEB)

    Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Paxton, Dean M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Smith, Mark T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Soulami, Ayoub [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Joshi, Vineet V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Burkes, Douglas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-12-01

    In support of the Convert Program of the U.S. Department of Energy’s National Nuclear Security Administration (DOE/NNSA) Global Threat Reduction Initiative (GTRI), Pacific Northwest National Laboratory (PNNL) has been investigating manufacturing processes for the uranium-10% molybdenum (U-10Mo) alloy plate fuel for the U.S. high-performance research reactors (USHPRR). This report documents the results of PNNL’s efforts to develop the extrusion process for this concept. The approach to the development of a co-extruded complex-shaped fuel has been described and an extrusion of DU-10Mo was made. The initial findings suggest that given the extrusion forces required for processing U-10Mo, the co-extrusion process can meet the production demands of the USHPRR fuel and may be a viable production method. The development activity is in the early stages and has just begun to identify technical challenges to address details such as dimensional tolerances and shape control. New extrusion dies and roll groove profiles have been developed and will be assessed by extrusion and rolling of U-10Mo during the next fiscal year. Progress on the development and demonstration of the co-extrusion process for flat and shaped fuel is reported in this document

  11. Structure and Barrier Properties of Multinanolayered Biodegradable PLA/PBSA Films: Confinement Effect via Forced Assembly Coextrusion.

    Science.gov (United States)

    Messin, Tiphaine; Follain, Nadège; Guinault, Alain; Sollogoub, Cyrille; Gaucher, Valérie; Delpouve, Nicolas; Marais, Stéphane

    2017-08-30

    Multilayer coextrusion processing was applied to produce 2049-layer film of poly(butylene succinate-co-butylene adipate) (PBSA) confined against poly(lactic acid) (PLA) using forced assembly, where the PBSA layer thickness was about 60 nm. This unique technology allowed to process semicrystalline PBSA as confined polymer and amorphous PLA as confining polymer in a continuous manner. The continuity of PBSA layers within the 80/20 wt % PLA/PBSA layered films was clearly evidenced by atomic force microscopy (AFM). Similar thermal events to the reference films were revealed by thermal studies; indicating no diffusion of polymers during the melt-processing. Mechanical properties were measured for the multilayer film and the obtained results were those expected considering the fraction of each polymer, revealing the absence of delamination in the PLA/PBSA multinanolayer film. The confinement effect induced by PLA led to a slight orientation of the crystals, an increase of the rigid amorphous fraction (RAF) in PBSA with a densification of this fraction without changing film crystallinity. These structural changes allowed to strongly improve the water vapor and gas barrier properties of the PBSA layer into the multilayer film up to two decades in the case of CO 2 gas. By confining the PBSA structure in very thin and continuous layers, it was then possible to improve the barrier performances of a biodegradable system and the resulting barrier properties were successfully correlated to the effect of confinement on the microstructure and the chain segment mobility of the amorphous phase. Such investigation on these multinanolayers of PLA/PBSA with the aim of evidencing relationships between microstructure implying RAF and barrier performances has never been performed yet. Besides, gas and water permeation results have shown that the barrier improvement obtained from the multilayer was mainly due to the reduction of solubility linked to the reduction of the free volume while

  12. Influences of layer thickness on the compatibility and physical properties of polycarbonate/polystyrene multilayered film via nanolayer coextrusion

    Science.gov (United States)

    Cheng, Junfeng; Chen, Zhiru; Zhou, Jiaqi; Cao, Zheng; Wu, Dun; Liu, Chunlin; Pu, Hongting

    2018-05-01

    The effects of layer thickness on the compatibility between polycarbonate (PC) and polystyrene (PS) and physical properties of PC/PS multilayered film via nanolayer coextrusion are studied. The morphology of multilayered structure is observed using a scanning electron microscope. This multilayered structure may have a negative impact on the transparency, but it can improve the water resistance and heat resistance of film. To characterize the compatibility between PC and PS, differential scanning calorimetry is used to measure the glass transition temperature. The compatibility is found to be improved with the decrease of layer thickness. Therefore, the viscosity of multilayered film is also reduced with the decrease of layer thickness. In addition, the multilayered structure can improve the tensile strength with the increase of layer numbers. Because of the complete and continuous layer structure of PC, the PC/PS multilayered film can retain its mechanical strength at the temperature above Tg of PS.

  13. Facile fabrication of multilayer separators for lithium-ion battery via multilayer coextrusion and thermal induced phase separation

    Science.gov (United States)

    Li, Yajie; Pu, Hongting

    2018-04-01

    Polypropylene (PP)/polyethylene (PE) multilayer separators with cellular-like submicron pore structure for lithium-ion battery are efficiently fabricated by the combination of multilayer coextrusion (MC) and thermal induced phase separation (TIPS). The as-prepared separators, referred to as MC-TIPS PP/PE, not only show efficacious thermal shutdown function and wider shutdown temperature window, but also exhibit higher thermal stability than the commercial separator with trilayer construction of PP and PE (Celgard® 2325). The dimensional shrinkage of MC-TIPS PP/PE can be negligible until 160 °C. In addition, compared to the commercial separator, MC-TIPS PP/PE exhibits higher porosity and electrolyte uptake, leading to higher ionic conductivity and better battery performances. The above-mentioned fascinating characteristics with the convenient preparation process make MC-TIPS PP/PE a promising candidate for the application as high performance lithium-ion battery separators.

  14. Rheology at the Interface and the Role of the Interphase in Reactive Functionalized Multilayer Polymers in Coextrusion Process

    Science.gov (United States)

    Lamnawar, Khalid; Maazouz, Abderrahim

    2008-07-01

    Coextrusion technologies are commonly used to produce multilayered composite sheets or films for a large range of applications from food packaging to optics. The contrast of rheological properties between layers can lead to interfacial instabilities during flow. Important theoretical and experimental advances regarding the stability of compatible and incompatible polymers have, during the last decades, been made using a mechanical approach. However, few research efforts have been dedicated to the physicochemical affinity between the neighboring layers. The present study deals with the influence of this affinity on interfacial instabilities for functionalized incompatible polymers. Polyamide (PA6)/polyethylene grafted with glycidyl methacrylate (PE-GMA) was used as a reactive system and PE/PA6 as a non reactive one. Two grades of polyamide (PA6) were used in order to change the viscosity and elasticity ratios between PE (or PE-GMA) and PA6. It was experimentally confirmed, in this case, that weak disturbance can be predicted by considering an interphase of non-zero thickness (corresponding to an interdiffusion/reaction zone) instead of a purely geometrical interface between the two reactive layers. According to the rheological investigations from previous work which the interphase effect can be probed, an experimental strategy was here formulated to optimize the process by listing the parameters that controlled the stability of the reactive multilayer flows. Hence, based on this analysis, guidelines for a stable coextrusion of reactive functionalized polymers can be provided coupling the classical parameters (viscosity, elasticity and layer ratios) and the physicochemical affinity at the polymer/polymer interface.

  15. Fluoride adsorption from aqueous solution by magnetic core-shell Fe_3O_4@alginate-La particles fabricated via electro-coextrusion

    International Nuclear Information System (INIS)

    Zhang, Yahui; Lin, Xiaoyan; Zhou, Quisheng; Luo, Xuegang

    2016-01-01

    Graphical abstract: The magnetic core-shell Fe_3O_4@Alg-La particles were fabricated successfully by a simple method of electro-coextrusion, and employed as an adsorbent for separation of fluoride from aqueous solution. - Highlights: • Magnetic core-shell Fe_3O_4@Alg-La particles were prepared by electro-coextrusion. • The maximum adsorption capacity for fluoride at 298.15 K was 45.230 mg/g. • The adsorbent has a good saturation magnetization value. • The adsorbent has a great potential in removing the fluoride. - Abstract: The magnetic core-shell Fe_3O_4@Alg-La particles were fabricated successfully by a simple method of electro-coextrusion, and employed as an adsorbent for separation of fluoride from aqueous solution. Main factors affecting the removal of fluoride, including pH, adsorbent dosage, initial concentration, temperature and contact time were investigated. The adsorption isotherm and adsorption kinetics were studied to understand the adsorption process in detail. The experimental data were fitted well by the non-linear Freundlich isotherm and linear pseudo-second-order model, the maximum fluoride adsorption capacity was 45.230 mg/g at pH 4, 298.15 K. Thermodynamic parameters indicated that the fluoride adsorption process was feasible and spontaneous. The presence of other anions like Cl"−, SO_4"2"−, HCO_3"− and PO_4"3"− had almost no effect on the fluoride adsorption. The adsorbent can be easily separated from the solution by a magnet. The magnetic core-shell Fe_3O_4@Alg-La particles before and after fluoride adsorption were studied by SEM, FTIR, EDX and XPS, which indicated that the adsorption mechanism may be related to electrostatic attraction and Lewis acid-base interaction.

  16. Fluoride adsorption from aqueous solution by magnetic core-shell Fe{sub 3}O{sub 4}@alginate-La particles fabricated via electro-coextrusion

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yahui [School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, Sichuan (China); Engineering Research Center of Biomass Materials, Ministry of Education, Mianyang 621010, Sichuan (China); Lin, Xiaoyan, E-mail: lxy20100205@163.com [School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, Sichuan (China); Engineering Research Center of Biomass Materials, Ministry of Education, Mianyang 621010, Sichuan (China); Zhou, Quisheng [A State Key Laboratory of Pulp & Paper Engineering, South China University of Technology, Guangzhou 510640 (China); Luo, Xuegang [Engineering Research Center of Biomass Materials, Ministry of Education, Mianyang 621010, Sichuan (China)

    2016-12-15

    Graphical abstract: The magnetic core-shell Fe{sub 3}O{sub 4}@Alg-La particles were fabricated successfully by a simple method of electro-coextrusion, and employed as an adsorbent for separation of fluoride from aqueous solution. - Highlights: • Magnetic core-shell Fe{sub 3}O{sub 4}@Alg-La particles were prepared by electro-coextrusion. • The maximum adsorption capacity for fluoride at 298.15 K was 45.230 mg/g. • The adsorbent has a good saturation magnetization value. • The adsorbent has a great potential in removing the fluoride. - Abstract: The magnetic core-shell Fe{sub 3}O{sub 4}@Alg-La particles were fabricated successfully by a simple method of electro-coextrusion, and employed as an adsorbent for separation of fluoride from aqueous solution. Main factors affecting the removal of fluoride, including pH, adsorbent dosage, initial concentration, temperature and contact time were investigated. The adsorption isotherm and adsorption kinetics were studied to understand the adsorption process in detail. The experimental data were fitted well by the non-linear Freundlich isotherm and linear pseudo-second-order model, the maximum fluoride adsorption capacity was 45.230 mg/g at pH 4, 298.15 K. Thermodynamic parameters indicated that the fluoride adsorption process was feasible and spontaneous. The presence of other anions like Cl{sup −}, SO{sub 4}{sup 2−}, HCO{sub 3}{sup −} and PO{sub 4}{sup 3−} had almost no effect on the fluoride adsorption. The adsorbent can be easily separated from the solution by a magnet. The magnetic core-shell Fe{sub 3}O{sub 4}@Alg-La particles before and after fluoride adsorption were studied by SEM, FTIR, EDX and XPS, which indicated that the adsorption mechanism may be related to electrostatic attraction and Lewis acid-base interaction.

  17. Microcapsules loaded with the probiotic Lactobacillus paracasei BGP-1 produced by co-extrusion technology using alginate/shellac as wall material: Characterization and evaluation of drying processes.

    Science.gov (United States)

    Silva, Marluci P; Tulini, Fabricio L; Ribas, Marcela M; Penning, Manfred; Fávaro-Trindade, Carmen S; Poncelet, Denis

    2016-11-01

    Microcapsules containing Lactobacillus paracasei BGP-1 were produced by co-extrusion technology using alginate and alginate-shellac blend as wall materials. Sunflower oil and coconut fat were used as vehicles to incorporate BGP-1 into the microcapsules. The microcapsules were evaluated with regard the particle size, morphology, water activity and survival of probiotics after 60days of storage at room temperature. Fluidized bed and lyophilization were used to dry the microcapsules and the effect of these processes on probiotic viability was also evaluated. Next, dried microcapsules were exposed to simulated gastrointestinal fluids to verify the survival of BGP-1. Microcapsules dried by fluidized bed had spherical shape and robust structures, whereas lyophilized microcapsules had porous and fragile structures. Dried microcapsules presented a medium size of 0.71-0.86mm and a w ranging from 0.14 to 0.36, depending on the drying process. When comparing the effects of drying processes on BGP-1 viability, the fluidized bed was less aggressive than lyophilization. The alginate-shellac blend combined with coconut fat as core effectively protected the encapsulated probiotic under simulated gastrointestinal conditions. Thus, the production of microcapsules by co-extrusion followed by drying using the fluidized bed is a promising strategy for protection of probiotic cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Comparison between PCL/hydroxyapatite (HA) and PCL/halloysite nanotube (HNT) composite scaffolds prepared by co-extrusion and gas foaming.

    Science.gov (United States)

    Jing, Xin; Mi, Hao-Yang; Turng, Lih-Sheng

    2017-03-01

    In this work, three-dimensional poly(caprolactone) (PCL) tissue engineering scaffolds were prepared by co-extrusion and gas foaming. Biocompatible hydroxyapatite (HA) and halloysite nanotubes (HNT) were added to the polymer matrix to enhance the mechanical properties and bioactivity of the composite scaffolds. The effects of HA and HNT on the rheological behavior, microstructure, and mechanical properties of the composite scaffolds were systematically compared. It was found that the HNT improved viscosity more significantly than HA, and reduced the pore size of scaffolds, while the mechanical performance of PCL/HNT scaffolds was higher than PCL/HA scaffolds with the same filler content. Human mesenchymal stem cells (hMSCs) were used as the cell model to compare the biological properties of two composite scaffolds. The results demonstrated that cells could survive on all scaffolds, and showed a more flourishing living state on the composite scaffolds. The cell differentiation for 5% HA and 1% HNT scaffolds were significantly higher than other scaffolds, while the differentiation of 5% HNT scaffolds was lower than that of 1% HNT scaffolds mainly because of the reduced pore size and pore interconnectivity. Therefore, this study suggested that, with proper filler content and control of microstructure through processing, HNT could be a suitable substitute for HA for bone tissue engineering to reduce the cost and improve mechanical performance. Copyright © 2016. Published by Elsevier B.V.

  19. Co-extrusion of electrolyte/anode functional layer/anode triple-layer ceramic hollow fibres for micro-tubular solid oxide fuel cells-electrochemical performance study

    Science.gov (United States)

    Li, Tao; Wu, Zhentao; Li, K.

    2015-01-01

    In this study, the effects of an anode functional layer (AFL) with controlled thickness on physical and electrochemical properties of a micro-tubular SOFC have been systematically studied. A series of electrolyte/AFL/anode triple-layer hollow fibres with controllable AFL thicknesses (16.9-52.7 μm) have been fabricated via a single-step phase-inversion assisted co-extrusion technique. Both robustness of the cell and gas-tightness of the electrolyte layer are considerably improved by introducing the AFL of this type. The fracture force of the sample with the thickest AFL (9.67 N) almost doubles when compared to the electrolyte/anode dual-layer counterpart (5.24 N). Gas-tightness of the electrolyte layer is also considerably increased as AFL contributes to better-matched sintering behaviours between different components. Moreover, the formation of an AFL simultaneously with electrolyte and anode significantly improves the cell performances. The sample with the thinnest AFL (approximately 16.9 μm, 6% of the total anode thickness) leads to a 30% (from 0.89 to 1.21 W cm-2) increase in maximum power density, due to increased triple-phase boundaries (TPB). However, further increase in TPB from a thicker AFL is less effective for improving the cell performance, due to the substantially increased fuel diffusion resistance and subsequently higher concentration polarization. This indicates that the control over the AFL thickness is critically important in avoiding offsetting the benefits of extended TPB and consequently decreased cell performances.

  20. Fuel elements (uranium clad with zirconium) produced by co-extrusion; Les elements combustibles uranium gaine de zirconium obtenus par coextrusion

    Energy Technology Data Exchange (ETDEWEB)

    Montagne, R.; Winogradzki, A.; Sauve, C.; Buffet, J. [Commissariat a l' energie atomique et aux energies alternatives - CEA, Departement de Metallurgie et de Chimie Appliquee (France)

    1959-07-01

    In this paper a description is given of a process for making fuel elements for atomic reactors. Contact of the most intimate possible kind is achieved between the fuel and the sheath by the simultaneous extrusion of the two elements. Genuine welding between the two metals is thus effected. This can be subsequently improved by a heat-treatment which causes diffusion. Tests made on these co-extruded elements are described in the paper. Reprint of a paper published in Revue de Metallurgie, LV, no. 11, 1958.

  1. Coextrusion applied to the construction of fuel elements in solid or powder form; Coextrusion appliquee a la realisation d'elements combustibles massifs ou disperses

    Energy Technology Data Exchange (ETDEWEB)

    Montagne, R; Meny, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    In this issue is described, in the first part, a realisation process of fuel elements for nuclear reactors. A contact as good as possible is achieved between the fuel and the can by both elements simultaneous extrusion. In this way a real weld is work out between the two metals. This weld can be improved by a thermic treatment that bring a diffusion. In this article are described the test carried out on these co extruded elements. In the second part, the fabrication of dispersed fuel elements studied: a 30 per cent weight U uranium-aluminium alloy is used, valuable with 20 per cent enriched uranium. The dimensions of the fuel element have been fixed at: external diameter: 30 mm, internal diameter: 24 mm, length of the core: 300 mm, thickness of the can: 0,4 mm. The method of fabrication is pressing of the mixed uranium and aluminium powders in an aluminium can, and extrusion at 500 deg. C.; one end is directly canned by extrusion and the other by welding of an aluminium plug. The results of the first test are described. (author) [French] Dans ce memoire est decrit, en premiere partie, un procede d'obtention d'elements combustibles pour reacteurs atomiques. Un contact aussi bon que possible est realise entre le combustible et la gaine grace au filage simultane des deux elements. Une veritable soudure est ainsi realisee entre les deux metaux. Celle-ci peut ensuite etre amelioree par un traitement thermique provoquant une diffusion. Les essais effectues sur ces elements coextrudes sont decrits dans cet article. Dans une deuxieme partie, la fabrication d'elements combustibles disperses est etudiee, avec un alliage uranium-aluminium a 30 pour cent en poids d'uranium, valable pour un enrichissement de l'uranium de 20 pour cent. Les dimensions des elements combustibles ont ete fixees a: diametre exterieur: 30 mm, diametre interieur: 24 mm, longueur du noyau: 300 mm, epaisseur de la gaine: 0,4 mm. La methode de fabrication est le pressage dans un pot en aluminium du melange de poudres d'uranium et d'aluminium et l'extrusion a 500 deg. C. Une extremite est gainee directement par extrusion, l'autre par soudure d'un bouchon. Les resultats des premiers essais sont decrits. (auteur)

  2. Co-extrusion of food grains-banana pulp for nutritious snacks: optimization of process variables.

    Science.gov (United States)

    Mridula, D; Sethi, Swati; Tushir, Surya; Bhadwal, Sheetal; Gupta, R K; Nanda, S K

    2017-08-01

    Present study was undertaken to optimize the process conditions for development of food grains (maize, defatted soy flour, sesame seed)-banana based nutritious expanded snacks using extrusion processing. Experiments were designed using Box-Behnken design with banana pulp (8-24 g), screw speed (300-350 rpm) and feed moisture (14-16% w.b.). Seven responses viz. expansion ratio (ER), bulk density (BD), water absorption index (WAI), protein, minerals, iron and sensory acceptability were considered for optimizing independent parameters. ER, BD, WAI, protein content, total minerals, iron content, and overall acceptability ranged 2.69-3.36, 153.43-238.83 kg/m 3 , 4.56-4.88 g/g, 15.19-15.52%, 2.06-2.27%, 4.39-4.67 mg/100 g (w.b.) and 6.76-7.36, respectively. ER was significantly affected by all three process variables while BD was influenced by banana pulp and screw speed only. Studied process variables did not affected colour quality except 'a' value with banana pulp and screw speed. Banana pulp had positive correlation with water solubility index, total minerals and iron content and negative with WAI, protein and overall acceptability. Based upon multiple response analysis, optimized conditions were 8 g banana pulp, 350 rpm screw speed and 14% feed moisture indicating the protein, calorie, iron content and overall sensory acceptability in sample as 15.46%, 401 kcal/100 g, 4.48 mg/100 g and 7.6 respectively.

  3. Ductile mandrel and parting compound facilitate tube drawing

    Science.gov (United States)

    Burt, W. R., Jr.; Mayfield, R. M.; Polakowski, N. H.

    1966-01-01

    Refractory tubing is warm drawn over a solid ductile mandrel with a powder parting compound packed between mandrel and the tubes inner surface. This method applies also to the coextrusion of a billet and a ductile mandrel.

  4. Tailoring the porosity and shrinkage of extruded MgO support tubes for oxygen separation membranes by thermoplastic feedstock development

    DEFF Research Database (Denmark)

    Kothanda Ramachandran, Dhavanesan; Kaiser, Andreas; Glasscock, Julie

    for co-extrusion and co-sintering of a porous Magnesium oxide (MgO) support with a thin film of cerium gadolinium oxide (Ce0.9Gd0.1O1.95-δ, CGO) as active oxygen transport membrane layer has been developed using a thermoplastic ceramic system and graphite as pore former. The feedstocks have been...

  5. Proving the viability of manufacturing of multi-layer steel/vanadium alloy/steel composite tubes by numerical simulations and experiment

    Science.gov (United States)

    Nechaykina, T.; Nikulin, S.; Rozhnov, A.; Molotnikov, A.; Zavodchikov, S.; Estrin, Y.

    2018-05-01

    Vanadium alloys are promising structural materials for fuel cladding tubes for fast-neutron reactors. However, high solubility of oxygen and nitrogen in vanadium alloys at operating temperatures of 700 °C limits their application. In this work, we present a novel composite structure consisting of vanadium alloy V-4Ti-4Cr (provides high long-term strength of the material) and stainless steel Fe-0.2C-13Cr (as a corrosion resistant protective layer). It is produced by co-extrusion of these materials forming a three-layered tube. Finite element simulations were utilised to explore the influence of the various co-extrusion parameters on manufacturability of multi-layered tubes. Experimental verification of the numerical modelling was performed using co-extrusion with the process parameters suggested by the numerical simulations. Scanning electron microscopy and microhardness measurements revealed a defect-free diffusion layer at the interfaces between both materials indicating a good quality bonding for these co-extrusion conditions.

  6. JPRS Report, Soviet Union, International Affairs.

    Science.gov (United States)

    1987-08-10

    centers to help maintain sold equipment; organize joint-stock companies ; open technical-commercial buros, etc. We plan to reorganize our patent...systematically. The successes of the CEMA countries are especially tangible against the background of the economic situation which has taken shape in the...the Unilever Fleysgrup firm they showed us a kielbasa and sausage production line which uses the process of coextrusion. It can produce one and a

  7. Experimental Design for Evaluation of Co-extruded Refractory Metal/Nickel Base Superalloy Joints

    International Nuclear Information System (INIS)

    ME Petrichek

    2005-01-01

    Prior to the restructuring of the Prometheus Program, the NRPCT was tasked with delivering a nuclear space reactor. Potential NRPCT nuclear space reactor designs for the Prometheus Project required dissimilar materials to be in contact with each other while operating at extreme temperatures under irradiation. As a result of the high reactor core temperatures, refractory metals were the primary candidates for many of the reactor structural and cladding components. They included the tantalum-base alloys ASTAR-811C and Ta-10W, the niobium-base alloy FS-85, and the molybdenum base alloys Moly 41-47.5 Rhenium. The refractory metals were to be joined to candidate nickel base alloys such as Haynes 230, Alloy 617, or Nimonic PE 16 either within the core if the nickel-base alloys were ultimately selected to form the outer core barrel, or at a location exterior to the core if the nickel-base alloys were limited to components exterior to the core. To support the need for dissimilar metal joints in the Prometheus Project, a co-extrusion experiment was proposed. There are several potential methods for the formation of dissimilar metal joints, including explosive bonding, friction stir welding, plasma spray, inertia welding, HIP, and co-extrusion. Most of these joining methods are not viable options because they result in the immediate formation of brittle intermetallics. Upon cooling, intermetallics form in the weld fusion zone between the joined metals. Because brittle intermetallics do not form during the initial bonding process associated with HIP, co-extrusion, and explosive bonding, these three joining procedures are preferred for forming dissimilar metal joints. In reference to a Westinghouse Astronuclear Laboratory report done under a NASA sponsored program, joints that were fabricated between similar materials via explosive bonding had strengths that were directly affected by the width of the diffusion barrier. It was determined that the diffusion zone should not exceed

  8. NASA, We Have a Challenge and It's Food Packaging

    Science.gov (United States)

    Perchonok, Michele

    2014-01-01

    Current Packaging: Freeze Dried Foods Packaging ? The thermoformed base is fabricated from Combitherm PAXX230 [a coextrusion of nylon/medium-density polyethylene (MDPE)/nylon/ethylene-vinyl alcohol (EVOH)/nylon/MDPE/linear low-density polyethylene (LLDPE)]. ? The lid is fabricated from Combitherm PAXX115 (a coextrusion of nylon/EVOH/nylon/LF adhesive/HV polyethylene/LLDPE) ? Natural form (Bite size) foods ? The bite-size food package is fabricated from Combitherm PAXX115, a coextrusion of nylon/EVOH/nylon/LF adhesive/HV polyethylene/LLDPE. ? Overwrap ? Packages are wrapped in a white pouch,.003-mm thick, fabricated from a laminate of polyester/polyethylene/aluminum foil/Surlyn®. This overwrap is removed before the food is prepared and heated. Requirements ? High barrier packaging - low oxygen and water vapor transmission rates ? No aluminum layer ? Mass - Retortable, microwavable, high pressure use. Small Business Innovative Research Program - 7 years ? 8 Phase I contracts ? 4 Phase II contracts ? Two workshops to bring together food packaging experts ? Three internal research tasks ? Public Outreach - average of 3 presentations/yr. for 8 years describing NASA's challenges ? Department of Defense Collaboration - Combat Feeding Program No significant improvement in food packaging capabilities after these efforts. It was unlikely that a food packaging solution could be found within the food science community ? There was a need to go outside to other industries such as pharmaceutical or electrical ? Although a positive result was preferred, a negative result would also be useful ? Two Innovation Techniques were used as a comparison ? InnoCentive - Theoretical Challenge to identify new technologies ? Yet2.com - A matchmaker between NASA and commercial packaging manufacturers

  9. Forging of eccentric co-extruded Al-Mg compounds and analysis of the interface strength

    International Nuclear Information System (INIS)

    Förster, W; Binotsch, C; Awiszus, B; Lehmann, T; Müller, J; Kirbach, C; Stockmann, M; Ihlemann, J

    2016-01-01

    Within the subproject B3 of the Collaborative Research Center 692 it has been shown that Al-Mg compounds with a good bonding quality can be produced by hydrostatic coextrusion. During processing by forging, the aluminum sleeve is thinned in areas of high strains depending on the component geometry. To solve this problem an eccentric core arrangement during co-extrusion was investigated. Based on the results of FE-simulations, the experimental validation is presented in this work. Rods with an offset of 0.25, 0.5 and 0.75 mm were produced by eccentric hydrostatic co-extrusion. Ultrasonic testing was used to evaluate the bonding quality across the entire rods. For the forging investigations the basic process Rising was chosen. The still good bonding quality after forging was examined by dye penetrant testing and optical microscopy. For an optimal stress transfer between the materials across the entire component, a sufficient bonding between the materials is essential. To evaluate the interface strength, a special bending test was developed. For the conception of the bending specimens it was required to analyze the Rising specimens geometry. These analyses were performed using a reconstruction of the geometrical data based on computer tomography (CT) investigations. The comparison with the numerically deter-mined Rising specimen geometry shows good correlation. Parametric Finite Element Analyses of the bending test were used to develop the load case and the specimen geometry. By means of iterative adaption of load application, bearing and specimen geometry parameters, an advantageous stress state and experimentally applicable configuration were found. Based on this conception, the experimental setup was configured and bending tests were performed. The interface strength was deter-mined by the calculation of the maximum interlaminar interfacial tension stress using the experimental interface failure force and the bending FE model. (paper)

  10. Aluminium stabilized Nb$-3$/Sn superconductors

    International Nuclear Information System (INIS)

    Thoener, M.; Krauth, H.; Rudolph, J.; Szulczyk, A.

    1988-01-01

    Composite superconductors made of reacted Nb 3 Sn stabilized with high purity Al were produced. Two methods were tested. The first involved soft soldering a Cu clad aluminum tape to the Nb 3 Sn conductor. In the second method the conductor, cable or monolith, was coextruded with the aluminum. Results obtained from using both methods indicated that mechanically reinforcing materials can be easily introduced into superconductors. Tests were conducted to determine magnetoresistance, electric contact resistance, yield strength, Young modulus, critical current, and other properties of the composites. Strengthening with Duratherm during coextrusion was also evaluated

  11. Recent progress in online ultrasonic process monitoring

    Science.gov (United States)

    Wen, Szu-Sheng L.; Chen, Tzu-Fang; Ramos-Franca, Demartonne; Nguyen, Ky T.; Jen, Cheng-Kuei; Ihara, Ikuo; Derdouri, A.; Garcia-Rejon, Andres

    1998-03-01

    On-line ultrasonic monitoring of polymer co-extrusion and gas-assisted injection molding are presented. During the co- extrusion of high density polyethylene and Santoprene ultrasonic sensors consisting of piezoelectric transducers and clad ultrasonic buffer rods are used to detect the interface between these two polymers and the stability of the extrusion. The same ultrasonic sensor also measures the surface temperature of the extruded polymer. The results indicate that temperature measurements using ultrasound have a faster response time than those obtained by conventional thermocouple. In gas-assisted injection molding the polymer and gas flow front positions are monitored simultaneously. This information may be used to control the plunger movement.

  12. Shape memory polymer cellular solid design for medical applications

    International Nuclear Information System (INIS)

    De Nardo, L; Bertoldi, S; Tanzi, M C; Farè, S; Haugen, H J

    2011-01-01

    Shape memory polymers (SMPs) are an emerging class of active materials whose response can be easily tailored via modifications of the molecular parameters and optimization of the transformation processes. In this work, we originally demonstrated that a correct coupling of polymer transformation processes (co-extrusion with chemical blowing agents, salt co-extrusion/particulate leaching, solvent casting/particulate leaching) and SMPs allows one to obtain porous structures with a broad spectrum of morphological properties resulting in tunable thermo-mechanical and shape recovery properties. Such a wide range of properties could fulfil the specifications of medical applications in which the use of SMP-based foams can be envisaged

  13. Food packaging materials and radiation processing of food: a brief review

    International Nuclear Information System (INIS)

    Chuaqui-Offermanns, N.

    1989-01-01

    Food is usually packaged to prevent microbial contamination and spoilage. Ionizing radiation can be applied to food-packaging materials in two ways: (i) sterilization of packaging materials for aseptic packaging, and (ii) radiation processing of prepackaged food. In aseptic packaging, a sterile package is filled with a sterile product in a microbiologically controlled environment. In irradiation of prepackaged food, the food and the packaging material are irradiated simultaneously. For both applications, the radiation stability of the packaging material is a key consideration if the technology is to be used successfully. To demonstrate the radiation stability of the packaging material, it must be shown that irradiation does not significantly alter the physical and chemical properties of the material. The irradiated material must protect the food from environmental contamination while maintaining its organoleptic and toxicological properties. Single-layer plastics cannot meet the requirements of either application. Multilayered structures produced by coextrusion would likely satisfy the demands of radiation processing prepackaged food. In aseptic packaging, the package is irradiated prior to filling, making demands on toxicological safety less stringent. Therefore, multilayered structures produced by coextrusion, lamination or co-injection moulding could satisfy the requirements. (author)

  14. Mechanical properties of a co-extruded Metallic Glass/Alloy (MeGA) rod-Effect of the metallic glass volume fraction

    International Nuclear Information System (INIS)

    Gravier, S.; Blandin, J.J.; Suery, M.

    2010-01-01

    A Metallic Glass/Alloy (MeGA) rod with a core in zirconium-based bulk metallic glass and a sleeve in aluminium alloy has been successfully elaborated by co-extrusion. SEM observations of the cross-section of the rod show that the interface between the glass and the alloy is defect-free. Compression tests are carried out at room temperature on the MeGA rods containing various glass volume fractions. The yield stress is well described by the rule of mixtures which combines the strength of the glass and that of the alloy, suggesting isostrain behaviour as could be expected. During compression, a good mechanical bonding is observed in the MeGA-rod even after the first fracture of the metallic glass. Finally, push-out tests are performed to evaluate the bonding quality between the two materials. Large values of the shear strength are measured which confirms that co-extrusion leads to good bonding between the glass and the aluminium alloy.

  15. Transport, mechanical and global migration data of multilayer copolyamide nanocomposite films with different layouts.

    Science.gov (United States)

    Scarfato, P; Garofalo, E; Di Maio, L; Incarnato, L

    2017-06-01

    Transport, mechanical and global migration data concern multilayer food packaging films with different layouts, all incorporating a layered silicate/polyamide nanocomposite as oxygen barrier layer, and a low-density polyethylene (LDPE) as moisture resistant layer in direct contact with food. The data are related to "Tuning of co-extrusion processing conditions and film layout to optimize the performances of PA/PE multilayer nanocomposite films for food packaging" by Garofalo et al. (2017) [1]. Nanocomposite multilayer films, with different relative layer thicknesses and clay types, were produced using a laboratory scale co-extrusion blown-film equipment and were analyzed in terms of transport to oxygen and water vapor, mechanical properties and overall migration. The results have shown that all the multilayer hybrid films, based on the copolyamide layer filled with Cloisite 30B, displayed the most significant oxygen barrier improvements and the best mechanical properties compared to the unfilled films. No significant alteration of the overall migration values was observed, as expectable [2], [3], [4]. The performance improvement was more relevant in the case of the film with the thinner nanocomposite layer.

  16. Numerical simulation of viscoelastic layer rearrangement in polymer melts using OpenFOAM®

    Energy Technology Data Exchange (ETDEWEB)

    Köpplmayr, Thomas, E-mail: tkoepplmayr@gmail.com; Mayrhofer, Elias [Institute of Polymer Extrusion and Compounding, Johannes Kepler University Linz, Altenberger Str. 69, 4040 Linz (Austria)

    2015-05-22

    In addition to their shear-thinning behavior, polymer melts are characterized by first and second normal stress differences, which cause secondary motions. Polymer coextrusion processes involve viscoelastic two-phase flows that influence layer formation. Using polymer melts with different pigmentation makes visible the layers deformed by second normal stress differences. We used a new solver for the OpenFOAM CFD toolbox which handles viscoelastic two-phase flows. A derivative of the volume-of-fluid (VoF) methodology was employed to describe the interface. Different types of polymer melt, such as polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET) were investigated. In a coextrusion process, the less viscous phase usually tends to encapsulate the more viscous one. However, the different viscoelastic properties of the melts also influence interface deformation. The materials were characterized by small-amplitude oscillatory-shear rheometry, and a multimode Giesekus model was used to fit shear viscosity, storage and loss modulus. Our simulations also took interfacial tension into account. Experimental observations and corresponding numerical simulations were found to be in good accordance.

  17. Numerical simulation of viscoelastic layer rearrangement in polymer melts using OpenFOAM®

    International Nuclear Information System (INIS)

    Köpplmayr, Thomas; Mayrhofer, Elias

    2015-01-01

    In addition to their shear-thinning behavior, polymer melts are characterized by first and second normal stress differences, which cause secondary motions. Polymer coextrusion processes involve viscoelastic two-phase flows that influence layer formation. Using polymer melts with different pigmentation makes visible the layers deformed by second normal stress differences. We used a new solver for the OpenFOAM CFD toolbox which handles viscoelastic two-phase flows. A derivative of the volume-of-fluid (VoF) methodology was employed to describe the interface. Different types of polymer melt, such as polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET) were investigated. In a coextrusion process, the less viscous phase usually tends to encapsulate the more viscous one. However, the different viscoelastic properties of the melts also influence interface deformation. The materials were characterized by small-amplitude oscillatory-shear rheometry, and a multimode Giesekus model was used to fit shear viscosity, storage and loss modulus. Our simulations also took interfacial tension into account. Experimental observations and corresponding numerical simulations were found to be in good accordance

  18. Design and performance of the Savannah River Site Billet Active Well Coincidence Counter

    International Nuclear Information System (INIS)

    Griffin, J.C.; Sadowski, E.T.

    1991-01-01

    The Savannah River Site (SRS) has acquired, installed, and tested a custom-built Billet Active Well (neutron) Coincidence Counter (BAWCC). The BAWCC is used to make accountability measurements of the 235 U content of U-Al coextrusion billets in the SRS fuel fabrication facility. The instrument design incorporates a unique center-source configuration, with two moderated americium-lithium (AmLi) neutron sources located in a central spindle that inserts through the center hole of the U-Al billets. This configuration, a result of earlier experimental studies at SRS, yields improved response and precision for billet assay when compared to the standard AWCC source arrangement. Initial tests of the BAWCC at SRS have yielded one-sigma uncertainties of 0.8--1.0% for a fifteen-minute assay. This paper will describe the design, testing program and performance characteristics of the BAWCC

  19. Using thermoforming capacity of metallic glasses to produce multimaterials

    International Nuclear Information System (INIS)

    Ragani, J.; Volland, A.; Valque, S.; Liu, Y.; Gravier, S.; Blandin, J.J.; Suery, M.

    2010-01-01

    In addition to casting, thermoforming is a particularly interesting way to produce components in bulk metallic glasses since large strains can be achieved when the BMGs are deformed in their supercooled liquid region. The experimental window (temperature, time) in which high temperature forming can be carried out is directly related to the crystallization resistance of the glass. Such forming windows have been identified for zirconium based bulk metallic glasses thanks to thermal analysis and compression tests in the supercooled liquid region. Based on this identification, the thermoforming capacity of the studied glasses was used to produce multimaterials associating metallic glasses with conventional metallic alloys. Two processes have been preferentially investigated (co-extrusion and co-pressing) and the interface quality of the elaborated multi materials was studied.

  20. Optimization of the Refractive-Index Distribution of Graded-Index Polymer Optical Fiber by the Diffusion-Assisted Fabrication Process

    Science.gov (United States)

    Mukawa, Yoshiki; Kondo, Atsushi; Koike, Yasuhiro

    2012-04-01

    Graded-index polymer optical fiber (GI-POF) is a promising high-speed communication medium for very-short-reach networks, such as home or office networks. The refractive-index distribution of GI-POF needs to be accurately controlled to maximize the bandwidth. We attempted to control the refractive-index distribution by developing a simulation for dopant diffusion. In the rod-in-tube method, GI-POF with an optimal refractive-index distribution was obtained by adjusting the diffusion temperature and the diffusion time, whereas in the coextrusion process, GI-POF with an optimal refractive-index distribution was fabricated by controlling the length of the diffusion tube and the rate of discharge of polymer.

  1. Porous double-layer polymer tubing for the potential use in heterogeneous continuous flow reactions.

    Science.gov (United States)

    Herwig, Gordon; Hornung, Christian H; Peeters, Gary; Ebdon, Nicholas; Savage, G Paul

    2014-12-24

    Functional polymer tubing with an OD of 1/16 or 1/8 in. was fabricated by a simple polymer coextrusion process. The tubing was made of an outer impervious polypropylene layer and an inner layer, consisting of a blend of a functional polymer, polyethylene-co-methacrylic acid, and a sacrificial polymer, polystyrene. After a simple solvent leaching step using common organic solvents, the polystyrene was removed, leaving behind a porous inner layer that contains functional carboxylic acid groups, which could then be used for the immobilization of target molecules. Solution-phase reactions using amines or isocyanates have proven successful for the immobilization of a series of small molecules and polymers. This flexible multilayered functional tubing can be easily cut to the desired length and connected via standard microfluidic fittings.

  2. Deformation of confined poly(ethylene oxide) in multilayer films.

    Science.gov (United States)

    Lai, Chuan-Yar; Hiltner, Anne; Baer, Eric; Korley, LaShanda T J

    2012-04-01

    The effect of confinement on the deformation behavior of poly(ethylene oxide) (PEO) was studied using melt processed coextruded poly(ethylene-co-acrylic acid) (EAA) and PEO multilayer films with varying PEO layer thicknesses from 3600 to 25 nm. The deformation mechanism was found to shift as layer thickness was decreased between 510 and 125 nm, from typical axial alignment of the crystalline fraction, as seen in bulk materials, to nonuniform micronecking mechanisms found in solution-grown single crystals. This change was evaluated via tensile testing, wide-angle X-ray diffraction (WAXD), atomic force microscopy (AFM), and differential scanning calorimetry (DSC). With the commercially relevant method of melt coextrusion, we were able to overcome the limitations to the testing of solution-grown single crystals, and the artifacts that occur from their handling, and bridged the gap in knowledge between thick bulk materials and thin single crystals.

  3. Irradiated multilayer film for primal meat packaging

    International Nuclear Information System (INIS)

    Lustig, S.; Schuetz, J.M.; Vicik, S.J.

    1987-01-01

    This patent deals with a heat-shrinkable, multilayer film suitable for use in fabricating bags for packaging primal and sub-primal meat cuts and processed meats. The multilayer film has a first outer layer of a first ethylene-vinyl acetate copolymer, a core layer of a polyvinylidene chloride-vinyl chloride copolymer containing between about 70 weight percent and about 90 weight percent vinylidene chloride as a barrier film, and a second outer layer of a second ethylene-vinyl acetate copolymer. The multilayer film is preferably made by co-extrusion of the layers, and then it is biaxially stretched. After biaxial stretching, the entire multilayer film is substantially uniformly irradiated to a dosage level of between about 2 megarads and about 3 megarads and heat-sealed in the form of a bag. The film is not significantly discoloured by the irradiation and the bag has improved toughness properties and heat-sealing characteristics

  4. Irradiated multilayer film for primal meat packaging

    International Nuclear Information System (INIS)

    Lustig, S.; Schuetz, J.M.; Vicik, S.J.

    1987-01-01

    This patent deals with a heat-shrinkable, multilayer film suitable for use in fabricating bags for packaging primal and sub-primal meat cuts and processed meats. The multilayer film has a first outer layer of an ethylene-vinyl acetate copolymer, a core layer of a barrier film comprising vinylidene chloride-methyl acrylate copolymer, and a second outer layer of an ethylene-vinyl acetate copolymer. The multilayer film is preferably made by co-extrusion of the layers, and then it is biaxially stretched. After biaxial stretching, the multilayer film is irradiated to a dosage level of between 1 megarad and 5 megarads and heat-sealed in the form of a bag. The bag has improved storage stability characteristics

  5. Bond quality control of aluminium stabilised superconductors with ultrasonic phased-array technology

    International Nuclear Information System (INIS)

    Neuenschwander, J.; Luethi, T.; Horvath, I.L.

    2001-01-01

    Novel aluminium stabilised superconductors are currently being produced for the Large Hadron Collider detectors ATLAS and CMS. For a satisfying service of the conductor an intact bonding between the different constituents must be guaranteed. We have shown previously that ultrasonics is a powerful tool for checking the bond quality. However, up to now the full width of the bond could be inspected only on short samples with a mechanical scanner. The essence of this presentation is the introduction of the phased-array technique which allows a continuous analysis of the complete bond over km-long conductor units during their manufacture. For now, more than 50 km of conductor have been tested during co-extrusion. Disbondings are detected as regions with enhanced echo-amplitudes. We are about to set-up a second system for the control of an electron beam welding process which is used for the reinforcement of the CMS conductor. (orig.)

  6. Twin-screw extrusion for hemicellulose recovery: influence on extract purity and purification performance.

    Science.gov (United States)

    Zeitoun, Rawan; Pontalier, Pierre Yves; Marechal, Philippe; Rigal, Luc

    2010-12-01

    A twin-screw extruder was used for the extraction of wheat bran hemicelluloses by the co-extrusion of wheat straw and bran. As compared with a stirred reactor extraction, a twin-screw extruder resulted in a lower extraction rate (only about 24% of hemicelluloses in the wheat bran), but it has the advantages of a shorter residence time for the vegetable matter and a lower chemical and water consumption. Hemicellulose powder production is usually effected via an expensive alcoholic precipitation step after concentration. Ultrafiltration was investigated as a means to reduce the alcohol consumption. Trials were made with hollow fiber polyethersulfone membranes with a molecular weight cut-off of 30 kDa. Ultrafiltration mainly concentrated the extract and removed small molecules such as monosaccharides and minerals. The combination of the anion-exchange chromatography and ultrafiltration allowed for the removal of colored compounds. 2010 Elsevier Ltd. All rights reserved.

  7. Phase formation at bonded vanadium and stainless steel interfaces

    International Nuclear Information System (INIS)

    Summers, T.S.E.

    1992-01-01

    The interface between vanadium bonded to stainless steel was studies to determine whether a brittle phase formed during three joining operations. Inertia friction welds between V and 21-6-9 stainless steel were examined using TEM. In the as-welded condition, a continuous, polygranular intermetallic layer about 0.25 μm thick was present at the interface. This layer grew to about 50 μm thick during heat treatment at 1000 degrees C for two hours. Analysis of electron diffraction patterns confirmed that this intermetallic was the ω phase. The interface between vanadium and type 304, SANDVIK SAF 2205, and 21-6-9 stainless steel bonded by a co-extrusion process had intermetallic particles at the interface in the as-extruded condition. Heat treatment at 1000 degrees C for two hours caused these particles to grow into continuous layers in all three cases. Based on the appearance, composition and hardness of this interfacial intermetallic, it was also concluded to be ω phase. Bonding V to type 430 stainless steel by co-extrusion caused V-rich carbides to form at the interface due to the higher concentration of C in the type 430 than in the other stainless steels investigated. The carbide particles initially present grew into a continuous layer during a two-hour heat treatment at 1000 degrees C. Co-hipping 21-6-9 stainless steel tubing with V rod resulted in slightly more concentric specimens than the co-extruded ones, but a continuous layer of the ω phase formed during the hipping operation. This brittle layer could initiate failure during subsequent forming operations. The vanadium near the stainless steel interface in the co-extruded and co-hipped tubing in some cases was harder than before heat treatment. It was concluded that this hardening was due to thermal straining during cooling following heat treatment and that thermal strains might present a greater problem than seen here when longer tubes are used in actual applications

  8. Design of robust hollow fiber membranes with high power density for osmotic energy production

    KAUST Repository

    Zhang, Sui; Sukitpaneenit, Panu; Chung, Neal Tai-Shung

    2014-01-01

    This study highlights the design strategy of highly asymmetric hollow fiber membranes that possess both characteristics of high flux and high mechanical strength to effectively reap the osmotic energy from seawater brine with an ultrahigh power density. An advanced co-extrusion technology was employed to fabricate the polyethersulfone (PES) hollow fiber supports with diversified structures from macrovoid to sponge-like. The microstructure of the supports is found critical for the stability and water permeability of the thin film composite (TFC) membranes. A high porosity in the porous layer is needed to reduce internal concentration polarization, while a thick and relatively dense skin layer underneath the TFC layer is required to maintain good mechanical stability and stress dissipation. The pore size of the supporting layer underneath the TFC layer must be small with a narrow pore size distribution to ensure the formation of a less-defective, highly permeable and mechanically stable TFC layer. The newly developed hollow fiber comprising high asymmetry, high porosity, and a thick skin layer with a small and narrow pore size distribution underneath the TFC layer produces a maximum power density of 24.3W/m2 at 20.0bar by using 1M NaCl as the concentrated brine and deionized (DI) water as the feed. The proposed design strategy for ultrahigh power density membranes clearly advances the osmotic energy production close to commercialization with a quite cost-effective and practicable approach. © 2013 Elsevier B.V.

  9. Compatibilization of recycled polymers through radiation treatment

    International Nuclear Information System (INIS)

    Czvikovszky, T.; Hargitai, H.

    1998-01-01

    Complete text of publication follows. The use of compatibilizers is crucial in composites of apolar, synthetic matrix such as PP and fibrous, polar, natural reinforcement. Radiation treatment using small EB- or gamma dose of about 8 kGy - may enhance the effect of reactive compatibilizer, involving both matrix and reinforcement into a chemically attached system. In the present work we applied byproducts of textile- and woodworking industry as reinforcing additives for polypropylene (PP), reprocessed from waste car-bumpers and recollected bottle-caps. Hemp fibers and waste-wood fibers can be mixed into the PP on a continuously operating twin-screw extruder. Various additives have been tries out in our laboratory including maleic acid anhydride, acrylic-acid grafted compatibilizers, unsaturated oligomers and vinylsilanes. The effect of different compatibilizing methods have been evaluated by comparing mechanical properties (tensile- and flexural strength, modulus of elasticity etc.), dynamic mechanical analysis (DMA) and rheological properties. The ensemble of properties is clearly enhanced by the efficient compatibilization. The reinforced - recycled products can be applied in advanced sandwich molding processing technologies of coextrusion and co-injection molding, where the dark coloured, recycled product forms the inner core of the product, covered on both side with virgin thermoplastic

  10. Design of robust hollow fiber membranes with high power density for osmotic energy production

    KAUST Repository

    Zhang, Sui

    2014-04-01

    This study highlights the design strategy of highly asymmetric hollow fiber membranes that possess both characteristics of high flux and high mechanical strength to effectively reap the osmotic energy from seawater brine with an ultrahigh power density. An advanced co-extrusion technology was employed to fabricate the polyethersulfone (PES) hollow fiber supports with diversified structures from macrovoid to sponge-like. The microstructure of the supports is found critical for the stability and water permeability of the thin film composite (TFC) membranes. A high porosity in the porous layer is needed to reduce internal concentration polarization, while a thick and relatively dense skin layer underneath the TFC layer is required to maintain good mechanical stability and stress dissipation. The pore size of the supporting layer underneath the TFC layer must be small with a narrow pore size distribution to ensure the formation of a less-defective, highly permeable and mechanically stable TFC layer. The newly developed hollow fiber comprising high asymmetry, high porosity, and a thick skin layer with a small and narrow pore size distribution underneath the TFC layer produces a maximum power density of 24.3W/m2 at 20.0bar by using 1M NaCl as the concentrated brine and deionized (DI) water as the feed. The proposed design strategy for ultrahigh power density membranes clearly advances the osmotic energy production close to commercialization with a quite cost-effective and practicable approach. © 2013 Elsevier B.V.

  11. Protein and Bacterial Antifouling Behavior of Melt-Coextruded Nanofiber Mats.

    Science.gov (United States)

    Kim, Si-Eun; Zhang, Cong; Advincula, Abigail A; Baer, Eric; Pokorski, Jonathan K

    2016-04-13

    Antifouling surfaces are important for biomedical devices to prevent secondary infections and mitigate the effects of the foreign body response. Herein, we describe melt-coextruded poly(ε-caprolactone) (PCL) nanofiber mats grafted with antifouling polymers. Nonwoven PCL fiber mats are produced using a multilayered melt coextrusion process followed by high-pressure hydroentanglement to yield porous patches. The resulting fiber mats show submicrometer cross-sectional fiber dimensions and yield pore sizes that were nearly uniform, with a mean pore size of 1.6 ± 0.9 μm. Several antifouling polymers, including hydrophilic, zwitterionic, and amphipathic molecules, are grafted to the surface of the mats using a two-step procedure that includes photochemistry followed by the copper-catalyzed azide-alkyne cycloaddition reaction. Fiber mats are evaluated using separate adsorption tests for serum proteins and E. coli. The results indicate that poly(oligo(ethylene glycol) methyl ether methacrylate)-co-(trifluoroethyl methacrylate) (poly(OEGMEMA-co-TFEMA)) grafted mats exhibit approximately 85% less protein adhesion and 97% less E. coli adsorption when compared to unmodified PCL fibermats. In dynamic antifouling testing, the amphiphilic fluorous polymer surface shows the highest flux and highest rejection value of foulants. The work presented within has implications on the high-throughput production of antifouling microporous patches for medical applications.

  12. Electrical characterization of S/C conductor for the CMS solenoid

    CERN Document Server

    Fabbricatore, P; Farinon, S; Greco, Michela; Kircher, F; Musenich, R

    2005-01-01

    The Compact Muon Solenoid (CMS) is one of the general-purpose detectors to be provided for the LHC project at CERN. The design field of the CMS superconducting magnet is 4 T, the magnetic length is 12.5 m and the free bore is 6 m. The coil is wound from 20 high purity aluminum-stabilized NbTi conductors with a total length of 45 km. The main peculiarity of the CMS magnet among other existing thin detector solenoids is its sandwich-type aluminum-stabilized superconductor. This special feature was chosen in order to have a mechanically self-supporting winding structure. We measured the critical current of all the 21 finished conductors in fields up to 6 T using the Ma.Ri.S.A. test facility at INFN-Genova. We compare these results with the critical current of single strands measured by CEA- Saclay, extracted from the conductor after the co-extrusion. A comparison among the measurements provides information about the possible critical current degradation and assures an accurate quality control of the conductor pr...

  13. Powder metallurgy development at SRL

    International Nuclear Information System (INIS)

    Peacock, H.B.

    1993-01-01

    The Savannah River Laboratory (SRL) is developing a powder metallury (P/M) process for manufacturing reactor-grade fuel tubes containing high wt % U 3 O 8 -Al cores clad with 8001 aluminum. The P/M cores are made by isostatic compaction. They are assembled in billets, outgassed, and hot-extruded using conventional coextrusion techniques. Cores have been compacted with up to 100% U 3 O 8 and tubes extruded with 80 wt % oxide cores. Irradiation tests have been made using P/M core tubes in the Savannah River reactors. These tubes contained U 3 O 8 concentrations up to 59 wt % and no significant swelling or blistering occurred. The tubes were irradiated to ∼40% burnup or 1.6x10 21 fissions/cc of core. This report discusses both small-scale and production tests for high- density P/M fuel development. The purpose of the P/M development program at SRL is to: (1) determine the maximum U 3 O 8 content that can be fabricated into thin wall tubes, (2) irradiate high-density tubes to high burnup and assess irradiation and dimensional stability, (3) continue metal forming studies for extrusion and drawing, and (4) evaluate hydrostatic extrusion and hydrostatically assisted drawing of P/M core tubes

  14. Canning by the diffusion caused by a heated die

    International Nuclear Information System (INIS)

    Gauthron, M.

    1959-01-01

    In this process, the uranium fuel is clad with a zirconium can by passing the element through a die. The operation takes place at a temperature varying between 500 and 1000 deg. C. The heating is obtained by passing low voltage electric current through the can. This process differs from the co-extrusion process in that the uranium is not deformed. The uranium is therefore machined to the final dimensions before canning, it can also be hollow. Two types of processes can be adopted for the extrusion: a) Process in which the binding of the can to the uranium is obtained without diffusion (here the can is at high temperature - subsequently cooled - and the uranium is at a low temperature); b) Process in which uranium-zirconium diffusion is initiated. No matter which process is adopted the element is subsequently heat treated in an over at 800 deg. C in order to obtain the final diffusion. The quality of this diffusion is dependent on the initial state of the surfaces and on the degree of vacuum maintained during the operation. (author) [fr

  15. Performance properties, lactic acid specific migration and swelling by simulant of biodegradable poly(lactic acid)/nanoclay multilayer films for food packaging.

    Science.gov (United States)

    Scarfato, Paola; Di Maio, Luciano; Milana, Maria Rosaria; Giamberardini, Silvia; Denaro, Massimo; Incarnato, Loredana

    2017-10-01

    The aim of the study was the development of a multifunctional, high-performance, fully biodegradable multilayer polylactic acid (PLA) film for food packaging applications. In particular, sealable multilayer PLA-clay nanocomposite systems with different layouts in terms of composition and relative thickness of the layers, all consisting of a PLA-clay nanocomposite layer between two pure PLA layers for direct food contact, were designed and produced by blown film co-extrusion. The films obtained were analysed for their morphology, functional properties and lactic acid (LA)-specific migration in 50% ethanol. The results showed that, with respect to the unfilled multilayer system, taken as a reference, the nanocomposite films had significant improvements, up to about 40%, in their barriers to oxygen and tensile strengths, and resulted in being more easily sealable over a wide heat-sealing temperature range (80-100°C) with higher seal strength. Moreover, all films had LA migrations always well below the former generic overall migration limit of 60 mg kg -1 food (10 mg dm - 2 ) of European Union Regulation No. 10/2011 (deleted by the amending Regulation No. 2016/1416), even if their morphology was strongly modified during the migration tests due to the strong swelling action of the used simulant (simulant D1 = 50% ethanol (aq.) (v/v)) towards PLA.

  16. Preliminary Characterization and Analysis of the Designs and Research-Manufacturing Approaches

    Energy Technology Data Exchange (ETDEWEB)

    Scott Swartz; Gwendolyn Cheney; Williams Dawson; Michael Cobb; Kirby Meacham; James Stephan; Bob Remick; Harlan Anderson; Wayne Huebner; Aaron Crumm; John Holloran; Tim Armstrong

    2000-10-30

    This report summarizes the results of Phase I of a study entitled, Low-Cost Manufacturing Of Multilayer Ceramic Fuel Cells. The work was carried out by a group called the Multilayer Fuel Cell Alliance (MLFCA) led by NexTech Materials and including Adaptive Materials, Advanced Materials Technologies (AMT), Cobb & Co., Edison Materials Technology Center, Iowa State University, Gas Technology Institute (GTI), Northwestern University, Oak Ridge National Laboratory (ORNL), Ohio State University, University of Missouri-Rolla (UMR), and Wright-Patterson Air Force Base. The objective of the program is to develop advanced manufacturing technologies for making solid oxide fuel cell components that are more economical and reliable for a variety of applications. In the Phase I effort, five approaches were considered: two based on NexTech's planar approach using anode and cathode supported variations, one based on UMR's ultra-thin electrolyte approach, and two based on AMI's co-extrusion technology. Based on a detailed manufacturing cost analysis, all of the approaches are projected to result in a significantly reduced production cost. Projected costs range from $139/kW to $179/kW for planar designs. Development risks were assessed for each approach and it was determined that the NexTech and UMR approaches carried the least risk for successful development. Using advanced manufacturing methods and a proprietary high power density design, the team estimated that production costs could be reduced to $94/kW.

  17. In-situ polymerized cellulose nanocrystals (CNC)-poly(l-lactide) (PLLA) nanomaterials and applications in nanocomposite processing.

    Science.gov (United States)

    Miao, Chuanwei; Hamad, Wadood Y

    2016-11-20

    CNC-PLLA nanomaterials were synthesized via in-situ ring-opening polymerization of l-lactide in the presence of CNC, resulting in hydrophobic, homogeneous mixture of PLLA-grafted-CNC and free PLLA homopolymer. The free PLLA serves two useful functions: as barrier to further prevent PLLA-g-CNC from forming aggregates, and in creating improved interfacial properties when these nanomaterials are blended with other polymers, hence enhancing their performance. CNC-PLLA nanomaterials can be used for medical or engineering applications as-they-are or by compounding with suitable biopolymers using versatile techniques, such as solution casting, co-extrusion or injection molding, to form hybrid nanocomposites of tunable mechanical properties. When compounded with commercial-grade PLA, the resulting CNC-PLA nanocomposites appear transparent and have tailored (dynamic and static) mechanical and barrier properties, approaching those of poly(ethylene terephthalate), PET. The effect of reaction conditions on the properties of CNC-PLLA nanomaterials have been carefully studied and detailed throughout the paper. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Dual layer hollow fiber sorbents: Concept, fabrication and characterization

    KAUST Repository

    Bhandari, Dhaval

    2013-02-01

    Hollow fiber sorbents are pseudo-monolithic separations materials created with fiber spinning technology using a polymer \\'binder\\', impregnated with high loadings of sorbent \\'fillers\\' [1]. To increase purified gas recovery during the sorption step and to ensure consistent sorption capacity over repeated cycles, a dense, thin polymer barrier layer on the fiber sorbents is needed to allow only thermal interactions between the sorbate loaded layer and the thermal regeneration fluid. This paper considers materials and methods to create delamination-free dual layer fiber sorbents, with a porous core and a barrier sheath layer formed using a simultaneous co-extrusion process. Low permeability polymers were screened for sheath layer creation, with the core layer comprising cellulose acetate polymer as binder and zeolite NaY as sorbent fillers. Appropriate core and sheath layer dope compositions were determined by the cloud-point method and rheology measurements. The morphology of the as-spun fibers was characterized in detail by SEM, EDX and gas permeation analysis. A simplified qualitative model is described to explain the observed fiber morphology. The effects of core, sheath spin dope and bore fluid compositions, spinning process parameters such as air-gap height, spin dope and coagulation bath temperatures, and elongation draw ratio are examined in detail. © 2012 Elsevier B.V. All rights reserved.

  19. Design of multi materials combining crystalline and amorphous metallic alloys

    International Nuclear Information System (INIS)

    Volland, A.; Ragani, J.; Liu, Y.; Gravier, S.; Suéry, M.; Blandin, J.J.

    2012-01-01

    Highlights: ► Elaboration of multi materials associating metallic glasses and conventional crystalline alloys by co-deformation performed at temperatures close to the glass transition temperature of the metallic glasses. ► Elaboration of filamentary metal matrix composites with a core in metallic glass by co extrusion. ► Sandwich structures produced by co-pressing. ► Detection of atomic diffusion from the glass to the crystalline alloys during the processes. ► Good interfaces between the metallic glasses and the crystalline alloys, as confirmed by mechanical characterisation. - Abstract: Multi materials, associating zirconium based bulk metallic glasses and crystalline metallic alloys like magnesium alloys or copper are elaborated by co-deformation processing performed in the supercooled liquid regions (SLR) of the bulk metallic glasses. Two processes are investigated: co-extrusion and co-pressing. In the first case, filamentary composites with various designs can be produced whereas in the second case sandwich structures are obtained. The experimental window (temperature, time) in which processing can be carried out is directly related to the crystallisation resistance of the glass which requires getting information about the crystallisation conditions in the selected metallic glasses. Thermoforming windows are identified for the studied BMGs by thermal analysis and compression tests in their SLR. The mechanical properties of the produced multi materials are investigated thanks to specifically developed mechanical devices and the interfaces between the amorphous and the crystalline alloys are characterised.

  20. Effect of thermo-mechanical processing on the material properties at low temperature of a large size Al-Ni stabilized Nb-Ti/Cu superconducting cable

    Science.gov (United States)

    Langeslag, S. A. E.; Curé, B.; Sgobba, S.; Dudarev, A.; ten Kate, H. H. J.; Neuenschwander, J.; Jerjen, I.

    2014-01-01

    For future high-resolution particle experiments, a prototype for a 60 kA at 5 T, 4.2 K class conductor is realized by co-extrusion of a large, 40-strand Nb-Ti/Cu superconducting cable with a precipitation type Al-0.1wt.%Ni stabilizer. Microalloying with nickel contributes to the strength of the stabilizer, and avoids significant degradation in residual resistivity ratio, owing to its low solid solubility in aluminum. Sections of the conductor are work hardened to increase the mechanical properties of the as-extruded temper. Mechanical and resistivity characteristics are assessed as function of the amount of work hardening, at room temperature as well as at 4.2 K. Thermal treatments, like resin curing after coil winding, can cause partial annealing of the cold-worked material and reverse the strengthening effect. However, targeted thermal treatments, applied at relatively low temperature can result in precipitation hardening. The depletion of nickel in the aluminum-rich matrix around the precipitates results in an increased strength and a decreased effect of nickel on the thermal and electrical resistivity of the material. The present work aims at identifying an optimal work hardening sequence, and an optimal thermal treatment, possibly coinciding with a suitable coil resin curing cycle, for the Al-Ni stabilized superconductor.

  1. The CMS conductor

    CERN Document Server

    Horváth, I L; Marti, H P; Neuenschwander, J; Smith, R P; Fabbricatore, P; Musenich, R; Calvo, A; Campi, D; Curé, B; Desirelli, Alberto; Favre, G; Riboni, P L; Sgobba, Stefano; Tardy, T; Sequeira-Lopes-Tavares, S

    2000-01-01

    The Compact Muon Solenoid (CMS) is one of the experiments, which are being designed in the framework of the Large Hadron Collider (LHC) project at CERN, the design field of the CMS magnet is 4 T, the magnetic length is 13 m and the aperture is 6 m. This high magnetic field is achieved by means of a 4 layer, 5 modules superconducting coil. The coil is wound from an Al-stabilized Rutherford type conductor. The nominal current of the magnet is 20 kA at 4.5 K. In the CMS coil the structural function is ensured, unlike in other existing Al-stabilized thin solenoids, both by the Al-alloy reinforced conductor and the external former. In this paper the retained manufacturing process of the 50-km long reinforced conductor is described. In general the Rutherford type cable is surrounded by high purity aluminium in a continuous co-extrusion process to produce the Insert. Thereafter the reinforcement is joined by Electron Beam Welding to the pure Al of the insert, before being machined to the final dimensions. During the...

  2. Strength analysis of welded corners of PVC window profiles

    Science.gov (United States)

    Postawa, P.; Stachowiak, T.; Gnatowski, A.

    2017-08-01

    The article presents the results of researches which main purpose was to define the influence of welding parameters on strength of welded corners of PVC window profile. PVC profiles of a branded name GENEO® produced by Rehau Company were used for this research. The profiles were made by using a co-extrusion method. The surface of the profile was made of PVC mixture with no additives. Its main task was to get a smooth surface resistant to a smudge. The use of an unfilled polyester provides an aesthetic look and improves the resistance of extrudate to water getting into inner layers. The profile's inner layers have been filled up with glass fibre in order to improve its stiffness and mechanical properties. Window frames with cut corners used for this research, were produced on technological line of EUROCOLOR Company based in Pyskowice (Poland). The main goal of this analysis was to evaluate the influence of the main welding parameter (temperature upsetting) on hardness of welds we received in whole process. A universal testing machine was used for the research.

  3. INFLUENCE OF THE SHELL MATERIAL IN THE MICROCAPSULES FORMATION BY SPRAY DRYING

    Directory of Open Access Journals (Sweden)

    FERRÁNDIZ Marcela

    2015-05-01

    Full Text Available Microencapsulation is a process of entrapment, packaging or immobilizing an active (core material, which can be in the state of solid, liquid or gas, within a more stable, protective secondary (wall material that can be released at controlled rates under specific conditions. There are several microencapsulation techniques such as: spray drying, spray cooling/chilling, freeze drying, extrusion, fluidized bed coating, coacervation, liposome entrapment, coextrusion, interfacial polymerization, radical polymerization, molecular inclusion in cyclodextrins, etc. Spray drying has been commonly applied due to their simplicity process, wide availability of equipment facilities, significant merits in terms of reductions in product volume, easy of handling, etc. In the spray drying process the wall materials (shells and their properties are parameters to be considered to achieve proper encapsulation of the active ingredients (core materials. Some commonly used wall materials and their properties related to spray drying encapsulation, including proteins, carbohydrates, and other materials, or mixtures of some of them. Proper encapsulation of the active ingredient (core is essential to achieve this active material protecting the outer. The aim of this work is encapsulated an essential oil, sage oil, using two differet wall materials in order to determine which is the best wall material. Scanning electron microscopy (SEM has been used in order to know the microcapsules morphology. Core, Shell, Gum Arabic, Alginate, Sage oil, Scanning Electron Microscopy (SEM

  4. Bioinspired adaptive gradient refractive index distribution lens

    Science.gov (United States)

    Yin, Kezhen; Lai, Chuan-Yar; Wang, Jia; Ji, Shanzuo; Aldridge, James; Feng, Jingxing; Olah, Andrew; Baer, Eric; Ponting, Michael

    2018-02-01

    Inspired by the soft, deformable human eye lens, a synthetic polymer gradient refractive index distribution (GRIN) lens with an adaptive geometry and focal power has been demonstrated via multilayer coextrusion and thermoforming of nanolayered elastomeric polymer films. A set of 30 polymer nanolayered films comprised of two thermoplastic polyurethanes having a refractive index difference of 0.05 were coextruded via forced-assembly technique. The set of 30 nanolayered polymer films exhibited transmission near 90% with each film varying in refractive index by 0.0017. An adaptive GRIN lens was fabricated from a laminated stack of the variable refractive index films with a 0.05 spherical GRIN. This lens was subsequently deformed by mechanical ring compression of the lens. Variation in the optical properties of the deformable GRIN lens was determined, including 20% variation in focal length and reduced spherical aberration. These properties were measured and compared to simulated results by placido-cone topography and ANSYS methods. The demonstration of a solid-state, dynamic focal length, GRIN lens with improved aberration correction was discussed relative to the potential future use in implantable devices.

  5. Ultrastrong exciton-photon coupling in single and coupled organic microcavities

    Science.gov (United States)

    Liu, Bin; Bramante, Rosemary; Valle, Brent; Singer, Kenneth; Khattab, Tawfik; Williams, Jarrod; Twieg, Robert

    2015-03-01

    We have demonstrated ultrastrong light-matter coupling in organic planar microcavities composed of a neat glassy organic dye film between two metallic (aluminum) mirrors in a half-cavity configuration. Such cavities are characterized by Q factors around 10. Tuning the thickness of the organic layer enables the observation of the ultrastrong coupling regime. Via reflectivity measurements, we observe a very large Rabi splitting around 1.227 eV between upper and lower polariton branches at room temperature, and we detect polariton emission from the lower polariton branch via photoluminescence measurements. The large splitting is due to the large oscillator strength of the neat dye glass, and to the match of the low-Q cavity spectral width to the broad absorption width of the dye film material. We also study the interaction between excitonic states of neat glassy organic dye and cavity modes within coupled microcavity structures. The high-reflectivity mirrors are formed from distributed Bragg reflectors (DBR), which are multilayer films fabricated using the coextrusion process, containing alternating layers of high (SAN25, n =1.57) and low (Dyneon THV 220G, n =1.37) refractive index dielectric polymers. Nonlinear optical measurements will be discussed. This research was supported by the National Science Foundation Center for Layered Polymer Systems (CLiPS) under Grant Number DMR-0423914.

  6. Mechanical and microstructural behaviour of alumina-zirconia ceramic filaments for high temperature applications; Comportement mecanique et microstructure de filaments ceramiques alumine-zircone pour applications a haute temperature

    Energy Technology Data Exchange (ETDEWEB)

    Poulon-Quintin, A

    2002-04-01

    This thesis is a contribution to the development and to the study of two-phase alumina-zirconia ceramic filaments resistant to creep and chemical and microstructural degradation. The materials studied are experimental two-phase filaments (diameter of few millimeters) with a fibrillary structure obtained by coextrusion of sol-gels or of powder pastes and a nanocrystalline fiber of thin diameter (11{mu}m) with a homogeneous structure. They have been respectively perfected and chosen for their very promising microstructures and compositions concerning the creep resistance. This study is concentrated on the mechanical characterization at high temperature of these materials and especially on the understanding of the deformation and rupture mechanisms in relation with the microstructural evolution. The commercial fiber (Nextel 650) is a {alpha} alumina (grain size {>=}0.1{mu}m) in which the grains of the second phase zirconia are dispersed in a homogeneous way in intra (5-10 nm) as in inter-granular (20-30 nm). After a heat treatment at temperatures superior to 1200 C, it can be noted a strong grains growth preferentially to the axis of the fiber. The tensile properties decrease to a considerable extent with high temperatures ({>=}1000 C). The creep behaviour has been determined between 1000 and 1300 C (value of 2.5 for the stress exponent and of 850 kJ/mol for the activation energy). The evolution of the microstructure to a long grains microstructure is favourable for the creep resistance. A comparison with other fibers of compositions near the Nextel 650 fiber show that the Nextel 650 fiber has interesting properties for being used at high temperatures (until 1200 C). The study of co-extruded alumina-zirconia filaments with a fibrillary structure has at first required those of filaments which composition are each of the phases obtained from pastes (powder-thermoplastics or sol-gels). The composition of each of the phases has been optimized in order to adapt the

  7. Final Technical Report - High-Performance, Oxide-Dispersion-Strengthened Tubes for Production of Ethylene adn Other Industrial Chemicals

    Energy Technology Data Exchange (ETDEWEB)

    McKimpson, Marvin G.

    2006-04-06

    strengthened materials produced using mechanical alloying technology. To minimize cost, the bimetallic tube is produced by direct powder co-extrusion. This technology has potential for domestic energy savings of up to 4.1 trillion BTU/year (4.3 x 1015J/year) and a reduction of 370,000 tons (340,000 tonnes) of CO2 emissions in short-residence-time ethylene furnaces. This represents an energy savings and CO2 emissions reduction of about 3.3%. If the technology is also applied to other types of ethylene pyrolysis furnaces, total energy savings and CO2 emissions reductions could increase by up to five times. The work involved: Developing powder and consolidation processing protocols to produce an oxide-dispersion strengthened variant of Alloy 803 exhibiting creep strength comparable to Incoloy? Alloy MA956, Developing a direct powder co-extrusion protocol for fabricating co-extruded bimetallic Incoloy? Alloy MA956 / ODS Alloy 803 tubes, Characterizing the properties of the ODS Alloy 803 material, the welding characteristics of the bimetallic tubes, and the coking characteristics of the Incoloy? MA956 alloy, and Documenting the potential energy savings and user requirements for these bimetallic pyrolysis furnace tubes. The project demonstrated that oxide dispersion strengthened Alloy 803 can be produced successfully using conventional mechanical alloying technology. The oxide dispersion strengthened bimetallic radiant coil technology explored under this program has significant potential for energy savings and productivity improvements for domestic ethylene producers. In today's competitive market, however, domestic furnace manufacturers and ethylene producers appear reluctant to pay any cost premium for higher-performance coil materials offering either higher temperature capabilities or longer service life. Interest in oxide dispersion strengthened radiant coils is likely to increase if furnace and ethylene producers begin to focus more on increasing tube wall temperatures to

  8. Development in the manufacture of fuel assembly components at Nuclear Fuel Complex

    International Nuclear Information System (INIS)

    Saibaba, N.

    2012-01-01

    The integrity of the fuel bundle and pellet-clad mechanical and chemical interaction (PCMCI) is the major limiting factor in achieving high burn up in thermal as well as fast reactors. Zircaloy based fuel bundle used for Indian pressurized heavy water reactor consists of number of components such as fuel clad tube, end cap bearing pad and spacer pad. These tubular, bar and sheet components are manufactured at Nuclear Fuel Complex using a series of thermomechanical processes involving hot and cold working with intermediate heat treatment. This paper is aimed at bringing out recent advances in NFC in the manufacture of fuel assembly components. Zircaloy based double clad tube adopting co-extrusion route followed by cold pilgering was successfully produced for its potential usage for high burnup in advance thermal reactors such as Advanced Heavy Water Reactors, This paper also includes process modifications carried out in the manufacture of clad tube and end cap components based on in-depth metallurgical studies. A radial forging process was established for primary breakdown of arc melted ingot which allows for better soundness and homogeneous microstructure. Manufacturing route of bar components for end caps was suitably modified by adopting only barrel straightening to minimize the residual stress and thereby increasing the recovery appreciably. NFC also supplies clad tube for fast breeder reactors where limiting factor for burn up are void swelling and fuel-clad interaction. In view of this, advance claddings such as P/M based 9Cr - Oxide Dispersion strengthened (ODS) steel clad and Zirconium lined T91 (9Cr-1 Mo) steel double clad have been successfully produced. Zirconium lined T91 (9Cr-1 Mo) double clad tubes required was successfully produced by adopting the method of co-pilgering, as a candidate material for clad tubes of Fast Breeder Reactors. (author)

  9. Development of nuclear fuel materials for research reactor

    International Nuclear Information System (INIS)

    Kim, Chang Kyu; Park, H. D.; Kim, K. H.; Lee, J. T.; Ryu, W. S.; Hwang, W.; Kim, H. N.; Kim, H. I.; Kwon, H. I.; Park, C.; Lee, B. C.; Park, J. M.; Lee, C. S.; Chae, H. T.; Im, N. J.; Cho, M. S.; Im, I. C.; Nam, C.; Lee, D. B.; Goh, Y. M.; Kim, J. D.; Ahn, H. S.; Woo, Y. M.; Chang, S. J.; Cho, H. D.

    1997-09-01

    This project has aimed at the development of U 3 Si dispersion fuel for the localization of HANARO fuel and the application of atomization process to advanced RERTR fuel development. The design criteria were established through the modified computer codes. Design documents were prepared and issued. The acceptable co-extrusion cladding was achieved. The electron beam welding technology has been developed and the sealing of the end plug and cladding was accomplished without defects. The atomization fuel meats have about 200% higher elongation and about 20% higher than comminution fuel meats. The thermal compatibility test showed that atomization fuel have about 30% higher stability that the comminution fuel. The pressure drops of 18 rods fuel assembly and 36 rods fuel assembly were measured to have 213 kPa and 205 kPa respectively. Apparent wear was not found in endurance test. The irradiation fuel was designed and fabricated by using low enriched uranium metal following the developed Q/A system. The safety analysis of irradiation fuel assembly was performed through linear power calculation by using MCNP4A code and centerline temperature calculation by using DIFAIR code. The quality assurance system has been established. The quality inspection technologies were developed. By acquiring the license, low enriched uranium of 100 kg as well as depleted uranium can be used. U 3 Si 2 -Al fuel swelled less than comminution fuel irrespective of temperature and fuel fraction in a compatibility test. The atomized U-10wt.%Mo powder were found to have gamma phase of isotropic structure. Gamma structure remained with a little swelling without any structure change at 400 deg C for 100 hours. Irradiation miniplate and test rig were designed preliminary manufactured. Thermal hydraulic and linear power calculations were performed by using PLTEMP and MCNP4A computer codes respectively. The hydraulic test showed that the pressure drop met the HANARO requirement. The vibration

  10. Characterization of the morphology of co-extruded, thermoplastic/rubber multi-layer tapes

    International Nuclear Information System (INIS)

    L'Abee, R.M.A.; Vissers, A.M.J.T.; Goossens, J.G.P.; Spoelstra, A.B.; Duin, M. van

    2009-01-01

    Tapes with alternating semi-crystalline thermoplastic/rubber layers with thicknesses varying from 100 nm up to several μm were prepared by multi-layer co-extrusion. The variation in layer thickness was obtained by varying the thermoplastic/rubber feed ratio. A systematic study on the use of various microscopy techniques to visualize the morphology of the layered systems is presented. The relatively large length scales and the sample preparation make optical microscopy (OM) unsuitable to study the morphology of the multi-layer tapes. Although excellent contrast between the thermoplastic and rubber layers can be obtained, the usually applied, relatively large magnifications limit the use of transmission electron microscopy (TEM) and atomic force microscopy (AFM) to small sample areas. The large range of applicable magnifications makes scanning electron microscopy (SEM) the most suitable technique to study the morphology of the multi-layer tapes. The sample preparation for SEM with a secondary electron (SE) detector is often based on the removal of one of the components, which may induce changes in the morphology. SEM with a back-scattered electron (BSE) detector is a very convenient method to study the morphology over a wide range of length scales, where the contrast between the different layers can be enhanced by chemical staining. Finally, the nucleation behavior (homogeneous versus heterogeneous) of the semi-crystalline layers, as probed by differential scanning calorimetry (DSC), provides valuable information on the layered morphology. The use of relatively straightforward DSC measurements shows a clear advantage with respect to the discussed microscopy techniques, since no sample preparation is required and relatively large samples can be studied, which are more representative for the bulk.

  11. A Eutectic Melting Study of Double Wall Cladding Tubes of FeCrAl and Zircaloy-4

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Woojin; Son, Seongmin; Lee, You Ho; Lee, Jeong Ik; Ryu, Ho Jin [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Jeong, Eun [Kyunghee University, Yongin (Korea, Republic of)

    2015-10-15

    The eutectic melting behavior of FeCrAl/Zircaloy-4 double wall cladding tubes was investigated by annealing at various temperatures ranging from 900 .deg. C to 1300 .deg. C. It was found that significant eutectic melting occurred after annealing at temperatures equal to or higher than 1150 .deg. C. It means that an additional diffusion barrier layer is necessary to limit the eutectic melting between FeCrAl and Zircaloy-4 alloy cladding tubes. Coating of FeCrAl layers on the Zr alloy cladding tube is being investigated for the development of accident tolerant fuel by exploiting of both the oxidation resistance of FeCrAl alloys and the neutronic advantages of Zr alloys. Coating of FeCrAl alloys on Zr alloy cladding tubes can be performed by various techniques including thermal spray, laser cladding, and co-extrusion. Son et al. also reported the fabrication of FeCrAl/Zr ally double wall cladding by the shrink fit method. For the double layered cladding tubes, the thermal expansion mismatch between the dissimilar materials, severe deformation or mechanical failure due to the evolution of thermal stresses can occur when there is a thermal cycling. In addition to the thermal stress problems, chemical compatibilities between the two different alloys should be investigated in order to check the stability and thermal margin of the double wall cladding at a high temperature. Generally, it is considered that Zr alloy cladding will maintain its mechanical integrity up to 1204 .deg. C (2200 .deg. F) to satisfy the acceptance criteria for emergency core cooling systems.

  12. Fabrication of U-10wt.%Zr Fuel slug for SFR by Injection Casting

    International Nuclear Information System (INIS)

    Kim, Jong Hwan; Song, Hoon; Kim, Hyung Tae; Ko, Young Mo; Kim, Ki Hwan; Lee, Chan B.

    2013-01-01

    The fabrication technology of metal fuel has been developed by various methods such as rolling, swaging, wire drawing, and co-extrusion, but each of these methods had process limitations requiring an additional subsequent process, and needing the fabrication equipment is complex, which is not favorable for remote use. A practical process of metallic fuel fabrication for an SFR needs to be cost efficient, suitable for remote operation, and capable of mass production while reducing the amount of radioactive waste. Injection casting was chosen as the most promising technique, in the early 1950s, and this technique has been applied to fuel slug fabrication for the Experimental Breeder Reactor-II (EBR-II) driver and the Fast Flux Test Facility (FFTF) fuel pins. Because of the simplistic nature of the process and equipment, compared to other processes examined, this process has been successfully used in a remote operation environment for fueling of the EBR-II reactor. In this study, vacuum injection casting suitable for remote operation has been developed to fabricate metallic fuel for an SFR. Vacuum injection casting technique was developed to fabricate metallic fuel for an SFR. The appearance of the fabricated U-10wt.%Zr fuel was generally sound and the internal integrity was found to be satisfactory through gamma-ray radiography. Minimum fuel losses after casting relative to the initial charge amount of U-10wt.%Zr fuel slugs met the proposed goal of less than 0.1% fuel losses during fabrication. Modifications of the current facility system and advanced casting techniques are underway to produce higher quality fuel slugs

  13. Fabrication of U-10wt.%Zr Fuel slug for SFR by Injection Casting

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Hwan; Song, Hoon; Kim, Hyung Tae; Ko, Young Mo; Kim, Ki Hwan; Lee, Chan B. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    The fabrication technology of metal fuel has been developed by various methods such as rolling, swaging, wire drawing, and co-extrusion, but each of these methods had process limitations requiring an additional subsequent process, and needing the fabrication equipment is complex, which is not favorable for remote use. A practical process of metallic fuel fabrication for an SFR needs to be cost efficient, suitable for remote operation, and capable of mass production while reducing the amount of radioactive waste. Injection casting was chosen as the most promising technique, in the early 1950s, and this technique has been applied to fuel slug fabrication for the Experimental Breeder Reactor-II (EBR-II) driver and the Fast Flux Test Facility (FFTF) fuel pins. Because of the simplistic nature of the process and equipment, compared to other processes examined, this process has been successfully used in a remote operation environment for fueling of the EBR-II reactor. In this study, vacuum injection casting suitable for remote operation has been developed to fabricate metallic fuel for an SFR. Vacuum injection casting technique was developed to fabricate metallic fuel for an SFR. The appearance of the fabricated U-10wt.%Zr fuel was generally sound and the internal integrity was found to be satisfactory through gamma-ray radiography. Minimum fuel losses after casting relative to the initial charge amount of U-10wt.%Zr fuel slugs met the proposed goal of less than 0.1% fuel losses during fabrication. Modifications of the current facility system and advanced casting techniques are underway to produce higher quality fuel slugs.

  14. Ni/Ni-YSZ current collector/anode dual layer hollow fibers for micro-tubular solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Kanawka, K.; Othman, M.H.D.; Droushiotis, N.; Wu, Z.; Kelsall, G.; Li, K. [Department of Chemical Engineering and Chemical Technology, Imperial College London, London SW7 2AZ (United Kingdom)

    2011-10-15

    A co-extrusion technique was employed to fabricate a novel dual layer NiO/NiO-YSZ hollow fiber (HF) precursor which was then co-sintered at 1,400 C and reduced at 700 C to form, respectively, a meshed porous inner Ni current collector and outer Ni-YSZ anode layers for SOFC applications. The inner thin and highly porous ''mesh-like'' pure Ni layer of approximately 50 {mu}m in thickness functions as a current collector in micro-tubular solid oxide fuel cell (SOFC), aiming at highly efficient current collection with low fuel diffusion resistance, while the thicker outer Ni-YSZ layer of 260 {mu}m acts as an anode, providing also major mechanical strength to the dual-layer HF. Achieved morphology consisted of short finger-like voids originating from the inner lumen of the HF, and a sponge-like structure filling most of the Ni-YSZ anode layer, which is considered to be suitable macrostructure for anode SOFC system. The electrical conductivity of the meshed porous inner Ni layer is measured to be 77.5 x 10{sup 5} S m{sup -1}. This result is significantly higher than previous reported results on single layer Ni-YSZ HFs, which performs not only as a catalyst for the oxidation reaction, but also as a current collector. These results highlight the advantages of this novel dual-layer HF design as a new and highly efficient way of collecting current from the lumen of micro-tubular SOFC. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Conceptual design for muon detectors using resistive plastic tubes. Final technical report

    International Nuclear Information System (INIS)

    Border, P.; Courant, H.; Heller, K.; Jones, A.; Lin, J.; Maxam, D.; Ruddick, K.

    1998-01-01

    Reliable low cost detectors which can be built in quantity require a simple design consisting of as few separate pieces as possible using inexpensive materials. For example, ordinary insulating plastics with good structural strength, such as polyethylene or polystyrene, have about 1/3 the cost of aluminum per unit weight. Since plastic is also about 1/3 the density of aluminum, the material cost for a drift tube would be reduced by an order of magnitude. This substitution of plastic for aluminum alone would save the muon system for the SDC more than $2M. Additional savings of greater magnitude can be expected since an entire drift tube, including a field shaping electrode structure, can be manufactured as a single piece by the technique of co-extrusion. A symmetric design with all walls far from the wire will also eliminate critical tolerances in the relative position of the electrodes with respect to the wire. Furthermore, module assembly and mounting costs will surely be reduced if the muon detectors were light weight and, as far as possible, had the same shape and size. With the 8 cm diameter plastic tube of the design, the electric drift field is nearly uniform as shown. This field is determined by a simple symmetric electrode structure, so that the necessary drift/position relationship can be achieved without precisely controlling the position of the electrode structure with respect to the wire. If the positioning of the electrode structure relative to the wire is not a critical dimension, the structural support for the tube need not be maintained to a high tolerance reducing the cost of the structure. Using a resistive plastic to shape the potential gives a simple electrode structure that will require a minimum number of electronic connections. The basic element of this design is the cylindrical plastic drift tube constructed from co-extruded plastics of different conductivity

  16. Biomimetic porous high-density polyethylene/polyethylene- grafted-maleic anhydride scaffold with improved in vitro cytocompatibility.

    Science.gov (United States)

    Sharma, Swati; Bhaskar, Nitu; Bose, Surjasarathi; Basu, Bikaramjit

    2018-05-01

    A major challenge for tissue engineering is to design and to develop a porous biocompatible scaffold, which can mimic the properties of natural tissue. As a first step towards this endeavour, we here demonstrate a distinct methodology in biomimetically synthesized porous high-density polyethylene scaffolds. Co-extrusion approach was adopted, whereby high-density polyethylene was melt mixed with polyethylene oxide to form an immiscible binary blend. Selective dissolution of polyethylene oxide from the biphasic system revealed droplet-matrix-type morphology. An attempt to stabilize such morphology against thermal and shear effects was made by the addition of polyethylene- grafted-maleic anhydride as a compatibilizer. A maximum ultimate tensile strength of 7 MPa and elastic modulus of 370 MPa were displayed by the high-density polyethylene/polyethylene oxide binary blend with 5% maleated polyethylene during uniaxial tensile loading. The cell culture experiments with murine myoblast C2C12 cell line indicated that compared to neat high-density polyethylene and high-density polyethylene/polyethylene oxide, the high-density polyethylene/polyethylene oxide with 5% polyethylene- grafted-maleic anhydride scaffold significantly increased muscle cell attachment and proliferation with distinct elongated threadlike appearance and highly stained nuclei, in vitro. This has been partly attributed to the change in surface wettability property with a reduced contact angle (∼72°) for 5% PE- g-MA blends. These findings suggest that the high-density polyethylene/polyethylene oxide with 5% polyethylene- grafted-maleic anhydride can be treated as a cell growth substrate in bioengineering applications.

  17. Materials considerations in accelerator targets

    International Nuclear Information System (INIS)

    Peacock, H. B. Jr.; Iyer, N. C.; Louthan, M. R. Jr.

    1995-01-01

    Future nuclear materials production and/or the burn-up of long lived radioisotopes may be accomplished through the capture of spallation produced neutrons in accelerators. Aluminum clad-lead and/or lead alloys has been proposed as a spallation target. Aluminum was the cladding choice because of the low neutron absorption cross section, fast radioactivity decay, high thermal conductivity, and excellent fabricability. Metallic lead and lead oxide powders were considered for the target core with the fabrication options being casting or powder metallurgy (PM). Scoping tests to evaluate gravity casting, squeeze casting, and casting and swaging processes showed that, based on fabricability and heat transfer considerations, squeeze casting was the preferred option for manufacture of targets with initial core cladding contact. Thousands of aluminum clad aluminum-lithium alloy core targets and control rods for tritium production have been fabricated by coextrusion processes and successfully irradiated in the SRS reactors. Tritium retention in, and release from, the coextruded product was modeled from experimental and operational data. The model assumed that tritium atoms, formed by the 6Li(n,a)3He reaction, were produced in solid solution in the Al-Li alloy. Because of the low solubility of hydrogen isotopes in aluminum alloys, the irradiated Al-Li rapidly became supersaturated in tritium. Newly produced tritium atoms were trapped by lithium atoms to form a lithium tritide. The effective tritium pressure required for trap or tritide stability was the equilibrium decomposition pressure of tritium over a lithium tritide-aluminum mixture. The temperature dependence of tritium release was determined by the permeability of the cladding to tritium and the local equilibrium at the trap sites. The model can be used to calculate tritium release from aluminum clad, aluminum-lithium alloy targets during postulated accelerator operational and accident conditions. This paper describes

  18. Materials considerations in accelerator targets

    International Nuclear Information System (INIS)

    Peacock, H.B. Jr.; Iyer, N.C.; Louthan, M.R. Jr.

    1994-01-01

    Future nuclear materials production and/or the burn-up of long lived radioisotopes may be accomplished through the capture of spallation produced neutrons in accelerators. Aluminum clad-lead and/or lead alloys has been proposed as a spallation target. Aluminum was the cladding choice because of the low neutron absorption cross section, fast radioactivity decay, high thermal conductivity, and excellent fabricability. Metallic lead and lead oxide powders were considered for the target core with the fabrication options being casting or powder metallurgy (PM). Scoping tests to evaluate gravity casting, squeeze casting, and casting and swaging processes showed that, based on fabricability and heat transfer considerations, squeeze casting was the preferred option for manufacture of targets with initial core cladding contact. Thousands of aluminum clad aluminum-lithium alloy core targets and control rods for tritium production have been fabricated by coextrusion processes and successfully irradiated in the SRS reactors. Tritium retention in, and release from the coextruded product was modeled from experimental and operational data. Newly produced tritium atoms were trapped by lithium atoms to form a lithium tritide. The effective tritium pressure required for trap or tritide stability was the equilibrium decomposition pressure of tritium over a lithium tritide-aluminum mixture. The temperature dependence of tritium release was determined by the permeability of the cladding to tritium and the local equilibrium at the trap sites. The model can be used to calculate tritium release from aluminum clad, aluminum-lithium alloy targets during postulated accelerator operational and accident conditions. This paper describes the manufacturing technologies evaluated and presents the model for tritium retention in aluminum clad, aluminum-lithium alloy tritium production targets

  19. Extrusion and drawing of zircaloy 2. Production of pressure tubes for EL-4

    International Nuclear Information System (INIS)

    Thevenet, J.

    1964-01-01

    The authors give briefly the physical mechanical and chemical properties of zircaloy 2, as far as the transformation of this alloy is concerned. Extrusion: After a few general remarks concerning the extrusion and co-extrusion, including a comparison of the deformation resistance of canning metals and of zircaloy 2, the following points are considered: - the difficulties occurring because of the use of this alloy: - atmosphere protection - adjustment on to the machine tools - low thermal conductivity - economy of the metal (price) - the factors affecting the quality of the extruded products extrusion under a copper can and under lubricant glass - fine grain structure - temperature homogeneity - working temperature The transformation cycle - '550 kg ingot - preliminary shape 'for drawing of EL-4 tubes (112 x 120 L 12 m)' - is described in detail (extrusion or forging of the φ = 340 ingot into φ = 220 billets, cutting into lengths and hot drilling at φ = 125, fixing into a copper can and rough extrusion). Drawing: The main difficulties are due to seizing of the tools and to the necessity of protecting the alloy from the atmosphere during annealings. A brief description is given of drawing out on a short mandrel, on a long mandrel, of laminating on a reducing machine and of the carrying out of an annealing, as well as of the production of EL-4 tubes (φ =107 x 113 L 430 m) by drawing out shapes having a size of 112 x 120 on long mandrels. Conclusion: It is possible by extrusion and drawing to produce zircaloy 2 tubes similar to those which may be obtained normally using stainless steel. (authors) [fr

  20. Application of a powder sintering-extrusion process to the fabrication of U-Al and UO{sub 2}-stainless steel dispersed fuel elements; Application de frittage-filage de poudres a la fabrication d'elements combustibles disperses U-Al et UO{sub 2} inox

    Energy Technology Data Exchange (ETDEWEB)

    Meny, L.; Buffet, J.; Sauve, Ch.

    1962-07-01

    Within the scope of an investigation of dispersion-type fuel elements, the fabrication by extrusion and sintering of cladded bars and tubes with core of either uranium-aluminum or uranium oxide-stainless steel fuel was investigated. The powder mixtures are first pre-densified in a 'pot', whereupon the sheathed compact is degassed and sealed in a vacuum by electron-beam welding. The subsequent co-extrusion is performed at low temperature and with slow pressure application in the case of U-Al dispersions; and at high temperature with rapid pressure application, using the Ugine-Sejournet process, in the case of UO{sub 2}-stainless steel dispersions. The procedure permits the production of practically fully dense bars and tubes more than 1 m. in length and 10-30 mm in diameter, the wall thickness of the tubes ranging from 2-5 mm. The physical and mechanical characteristics of the dispersion, as well as the mechanical characteristics of the cladded elements, were investigated as a function of the uranium content and the temperature. (authors) [French] Dans le cadre de l'etude des elements combustibles disperses, nous avons etudie la fabrication par frittage-filage de barreaux et de tubes gaines renfermant un noyau combustible soit en uranium-aluminium, soit en UO{sub 2}-inox. Les melanges de poudres sont comprimes dans un 'pot'. La billette composite ainsi obtenue est degazee, fermee et soudee sous vide par bombardement electronique. Le cofilage est ensuite effectue, a basse temperature et sur presse lente pour les disperses U-Al, a haute temperature et sur presse rapide par le procede Ugine-Sejournet pour les disperses UO{sub 2}-inox. Nous avons ainsi obtenu des barres et des tubes de porosite pratiquement nulle de plus de 1 metre de longueur et de 10 a 30 mm de diametre; les epaisseurs des tubes sont comprises entre 2 et 5 mm. Les proprietes physiques et mecaniques des disperses ainsi que les proprietes mecaniques des ensembles gaines, ont ete etudiees en fonction de

  1. Confined crystallization, crystalline phase deformation and their effects on the properties of crystalline polymers

    Science.gov (United States)

    Wang, Haopeng

    With the recent advances in processing and catalyst technology, novel morphologies have been created in crystalline polymers and they are expected to substantially impact the properties. To reveal the structure-property relationships of some of these novel polymeric systems becomes the primary focus of this work. In the first part, using an innovative layer-multiplying coextrusion process to obtain assemblies with thousands of polymer nanolayers, dominating "in-plane" lamellar crystals were created when the confined poly(ethylene oxide) (PEO) layers were made progressively thinner. When the thickness was confined to 25 nanometers, the PEO crystallized as single, high-aspect-ratio lamellae that resembled single crystals. This crystallization habit imparted more than two orders of magnitude reduction in the gas permeability. The dramatic decrease in gas permeability was attributed to the reduced diffusion coefficient, because of the increase in gas diffusion path length through the in-plane lamellae. The temperature dependence of lamellar orientation and the crystallization kinetics in the confined nanolayers were also investigated. The novel olefinic block copolymer (OBC) studied in the second part consisted of long crystallizable sequences with low comonomer content alternating with rubbery amorphous blocks with high comonomer content. The crystallizable blocks formed lamellae that organized into space-filling spherulites even when the fraction of crystallizable block was so low that the crystallinity was only 7%. These unusual spherulites were highly elastic and recovered from strains as high as 300%. These "elastic spherulites" imparted higher strain recovery and temperature resistance than the conventional random copolymers that depend on isolated, fringed micellar-like crystals to provide the junctions for the elastomeric network. In the third part, positron annihilation lifetime spectroscopy (PALS) was used to obtain the temperature dependence of the free

  2. Powder metallurgy development at SRL

    International Nuclear Information System (INIS)

    Peacock, H.B.

    1993-01-01

    The Savannah River Laboratory (SRL) is developing a powder metallurgy (P/M) process for manufacturing reactor-grade fuel tubes containing high wt % U 3 O 8 -Al cores clad with 8001 aluminum. The P/M cores are made by isostatic compaction. They are assembled in billets, outgassed, and hot-extruded using conventional coextrusion techniques. Cores have been compacted with up to 100% U3O 8 and tubes extruded with 80 wt % oxide cores. Irradiation tests have been made using P/M core tubes in the Savannah River reactors. These tubes contained U 3 O 8 concentrations up to 59 wt % and no significant swelling or blistering occurred. The tubes were irradiated to ∼ 40% burnup or 1.6x10 21 fissions/cc of core. This report discusses both small-scale and production tests for high-density P/M fuel development. The purpose of the P/M development program at SRL is to: determine the maximum U 3 O 8 content that can be fabricated into thin wall tubes, irradiate high-density tubes to high burnup and assess irradiation and dimensional stability, continue metal forming studies for extrusion and drawing, and evaluate hydrostatic extrusion and hydrostatically assisted drawing of P/M core tubes. Experimental results of testing the fuel assemblies performance so far indicate that: cores containing fine (-325 mesh) U 3 O 8 and aluminum powders can be made practically free of high-density areas using the outlined P/M pre blending and sieving techniques. U 3 O 8 -Al cores can be isostatically compacted with up to 100 wt U 3 O 8 and tubes successfully extruded with up to 80 wt oxide; fission gas blistering of U 3 O 8 -Al P/M tubes as indicated by the blister tests is a function of fissions/cc of U 3 O 8 in the core; Decreasing the fission density of oxide increases the threshold temperature for blister formation; U 3 O 8 -Al P/M fuel tubes with up to 59 wt U 3 O 8 have been successfully irradiated in SRP reactor to 1.6 x 10 21 fissions/cc of core or 7 x 10 20 fissions/cc of U 3 O 8 small

  3. Measurement station for interim inspections of Lightbridge metallic fuel rods at the Halden Boiling Water Reactor

    Science.gov (United States)

    Hartmann, C.; Totemeier, A.; Holcombe, S.; Liverud, J.; Limi, M.; Hansen, J. E.; Navestad, E. AB(; )

    2018-01-01

    Lightbridge Corporation has developed a new Uranium-Zirconium based metallic fuel. The fuel rods aremanufactured via a co-extrusion process, and are characterized by their multi-lobed (cruciform-shaped) cross section. The fuel rods are also helically-twisted in the axial direction. Two experimental fuel assemblies, each containing four Lightbridge fuel rods, are scheduled to be irradiated in the Halden Boiling Water Reactor (HBWR) starting in 2018. In addition to on-line monitoring of fuel rod elongation and critical assembly conditions (e.g. power, flow rates, coolant temperatures, etc.) during the irradiation, several key parameters of the fuel will be measured out-of-core during interim inspections. An inspection measurement station for use in the irradiated fuel handling compartment at the HBWR has therefore been developed for this purpose. The multi-lobed cladding cross section combined with the spiral shape of the Lightbridge metallic fuel rods requires a high-precision guiding system to ensure good position repeatability combined with low-friction guiding. The measurement station is equipped with a combination of instruments and equipment supplied from third-party vendors and instruments and equipment developed at Institute for Energy Technology (IFE). Two sets of floating linear voltage differential transformer (LVDT) pairs are used to measure swelling and diameter changes between the lobes and the valleys over the length of the fuel rods. Eddy current probes are used to measure the thickness of oxide layers in the valleys and on the lobe tips and also to detect possible surface cracks/pores. The measurement station also accommodates gamma scans. Additionally, an eddy-current probe has been developed at IFE specifically to detect potential gaps or discontinuities in the bonding layer between the metallic fuel and the Zirconium alloy cladding. Potential gaps in the bonding layer will be hidden behind a 0.5-1.0 mm thick cladding wall. It has therefore been

  4. Canning by the diffusion caused by a heated die; Gainage par diffusion par filiere chauffante

    Energy Technology Data Exchange (ETDEWEB)

    Gauthron, M [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    In this process, the uranium fuel is clad with a zirconium can by passing the element through a die. The operation takes place at a temperature varying between 500 and 1000 deg. C. The heating is obtained by passing low voltage electric current through the can. This process differs from the co-extrusion process in that the uranium is not deformed. The uranium is therefore machined to the final dimensions before canning, it can also be hollow. Two types of processes can be adopted for the extrusion: a) Process in which the binding of the can to the uranium is obtained without diffusion (here the can is at high temperature - subsequently cooled - and the uranium is at a low temperature); b) Process in which uranium-zirconium diffusion is initiated. No matter which process is adopted the element is subsequently heat treated in an over at 800 deg. C in order to obtain the final diffusion. The quality of this diffusion is dependent on the initial state of the surfaces and on the degree of vacuum maintained during the operation. (author) [French] Dans ce procede, la gaine zirconium est plaquee sur le combustible uranium par passage dans une filiere. L'operation a lieu a chaud, a une temperature variant entre 500 et 1000 deg. C. Le chauffage est assure par passage d'un courant basse tension dans la gaine. A la difference du procede de cofilage, l'uranium ne subit pas de deformation durant l'operation. Il est donc prealablement usine aux cotes definitives et peut etre creux. Deux processus sont possibles pendant le passage dans la filiere: a) Obtention d'un frettage de la gaine sur l'uranium sans diffusion (avec une gaine a haute temperature et un tube d'uranium a basse temperature, eventuellement refroidi); b) Obtention d'un commencement de diffusion uranium-zirconium. Quelque soit le processus adopte, la cartouche est ensuite traitee dans un four a 800 deg. C pour obtenir la diffusion definitive. La qualite de celle-ci depend essentiellement des etats de surface initiaux

  5. Fuel location, homogeneity and amount in flat and tubular configurations; Repartition, Homogeneite et Quantite du Combustible dans les Elements a Configuration Plate ou Tubulaire; Polozhenie, gomogennost' i kolichestvo topliva v ploskikh i trubchatykh konfiguratsiyakh; Disposicion, Homogeneidad y Cantidad de Combustibles en Configuraciones Planas y Tubulares

    Energy Technology Data Exchange (ETDEWEB)

    Meester, P. de [Studiecentrum voor Kernenergie, Mol (Belgium)

    1965-10-15

    The fuel elements tor tne materials testing reactor BR-2 can be assembled either with plates obtained by the picture-frame process, or with tubes obtained by co-extrusion. In the course of the fabrication and before reactor loading the fuel disposition, the homogeneity and the absolute amount have to be checked or measured. The fuel disposition should be known for positioning of the core in plates and tubes and as a first quality evaluation of the product with regard to the geometrical specifications. Radiography at about 80-90 keV, autoradiography and gammagraphy with a thulium-170 source have been done. By radiographing the fuel tubes a lead mandrel with the X-ray film fixed to it was placed inside the tube and subsequent X-ray shots at different angles were taken. A radioactive source scanning the fuel tube along its centre line in combination with a film around the tube showed records with a high resolution. The fuel homogeneity is to be controlled in view of a safe reactor operation, i. e. on the one hand to avoid exaggerated fuel concentrations that could give rise to vapour formation in the operating PWR, and on the other hand to guarantee a sufficient and evenly spread fuel load. Radiographs can be used for a visual check. However, if a quantitative analysis is needed, a better device is a scintillation gamma spectrometer measuring the proper radiation emitted by the U{sup 235}. An analysis of the results on some 400 fuel plates and on a first batch of fuel tubes is given. Forming characteristics and typical end-forms can be controlled. Absorption measurements with an activated source gave less good results. Digital results from static measurements and continuous recording are discussed. The fuel amount as an absolute quantity should be known per zone for actual reactor-operation calculations and per complete element for reasons of fuel accounting and for comparison with post-irradiation bum-up evaluation. The fabrication and the use of the different

  6. Conservação refrigerada de cherimóia embalada em filme plástico com zeolite Cold storage of cherimoya packed with zeolit film

    Directory of Open Access Journals (Sweden)

    Marcelo Rosa Melo

    2002-04-01

    Full Text Available Com o objetivo de avaliar a eficiência da embalagem plástica "zeolite" no retardamento da maturação de cherimóias, mantidas sob armazenamento refrigerado, colheram-se frutos de cherimóia (Annona cherimola Mill., cv. Fino de Jete, de pomar comercial de Conceição dos Ouros (MG, no início de março de 2000. Selecionaram-se frutos de boa qualidade, os quais foram submetidos a dois tratamentos: a embalados com filme de polietileno coextrusado com incorporação de mineral tipo zeólito (zeolite e b controle (sem filme plástico. Os frutos foram colocados em caixas de papelão e submetidos ao armazenamento refrigerado (12 ± 1 ºC; 90% a 95% de umidade relativa - UR no Instituto Agronômico, em Campinas (SP. Avaliaram-se nos frutos: a perda de massa, a coloração externa, a aparência e a firmeza. Determinaram-se na polpa, o teor de sólidos solúveis totais (SST, o pH, o teor de acidez total titulável (ATT e a relação SST/ATT, ao longo de quatro semanas. Observou-se que os frutos do controle começaram a apresentar alterações físicas e químicas a partir do intervalo entre a segunda e a terceira semana de avaliação, apresentando-se consideravelmente depreciados na terceira semana, enquanto o tratamento com "zeolite" proporcionou melhor conservação dos frutos, até a quarta e última avaliação, tanto no aspecto estético, quanto nos atributos internos. Concluiu-se que os frutos não embalados podem ser conservados até por duas semanas em câmara a 12 ºC e 90% a 95% de UR e os embalados em "zeolite", mantidos sob essa temperatura até por quatro semanas.Fruits of cherimoya (Annona cherimola Mill. cv. Fino of Jete were harvested from an orchard situated in Conceição dos Ouros - MG, Brazil, in March 2000. The purpose of this experiment was to evaluate the post harvest conservation of fruits packed with zeolite films. Fruits with better quality were selected and divided into two treatments: a packed with polyethylene coextrused

  7. Extrusion and drawing of zircaloy 2. Production of pressure tubes for EL-4; Filage et etirage du zircaloy 2. Realisation des tubes de force pour EL-4

    Energy Technology Data Exchange (ETDEWEB)

    Thevenet, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Buffet, J [Cefilac (France)

    1964-07-01

    The authors give briefly the physical mechanical and chemical properties of zircaloy 2, as far as the transformation of this alloy is concerned. Extrusion: After a few general remarks concerning the extrusion and co-extrusion, including a comparison of the deformation resistance of canning metals and of zircaloy 2, the following points are considered: - the difficulties occurring because of the use of this alloy: - atmosphere protection - adjustment on to the machine tools - low thermal conductivity - economy of the metal (price) - the factors affecting the quality of the extruded products extrusion under a copper can and under lubricant glass - fine grain structure - temperature homogeneity - working temperature The transformation cycle - '550 kg ingot - preliminary shape 'for drawing of EL-4 tubes (112 x 120 L 12 m)' - is described in detail (extrusion or forging of the {phi} = 340 ingot into {phi} = 220 billets, cutting into lengths and hot drilling at {phi} = 125, fixing into a copper can and rough extrusion). Drawing: The main difficulties are due to seizing of the tools and to the necessity of protecting the alloy from the atmosphere during annealings. A brief description is given of drawing out on a short mandrel, on a long mandrel, of laminating on a reducing machine and of the carrying out of an annealing, as well as of the production of EL-4 tubes ({phi} =107 x 113 L 430 m) by drawing out shapes having a size of 112 x 120 on long mandrels. Conclusion: It is possible by extrusion and drawing to produce zircaloy 2 tubes similar to those which may be obtained normally using stainless steel. (authors) [French] Les auteurs donnent un resume succint des proprietes physiques mecaniques et chimiques du zircaloy 2 en ce qui concerne la transformation de cet alliage. Filage: Apres quelques generalites sur le filage et le cofilage, dont une comparaison entre les resistances a la deformation des metaux de gainage et du zircaloy 2, on etudie successivement: - les