WorldWideScience

Sample records for dual-ion swelling experiments

  1. Applications of the theory of cavity growth to dual-ion swelling experiments

    International Nuclear Information System (INIS)

    Hayns, M.R.; Mansur, L.K.

    1980-01-01

    The rate theory of cavity growth is applied to study the effects of helium gas on cavity swelling. The variation of swelling with temperature is emphasized: (1) expressions are derived showing that the primary effect of the helium is in pressurizing cavities and that a secondary effect is in altering the microstructural sink strengths. The expressions simplify in the parameter range of engineering interest such that the temperature regime of swelling is predicted to shift upward in approximately direct proportion to the cavity gas pressure; (2) recent experimental data on swelling of a pure stainless steel type alloy under dual-nickel and helium-ion bombardment is interpreted. Helium-free, helium-coimplanted, and helium-preimplanted swelling results can be explained by the theory. It is necessary to account for the partitioning of the helium to dislocations as well as to cavities in order to explain the experimental results for helium coimplantation; (3) model studies for physically reasonable parameters reveal the importance of the He/dpa ratio

  2. Effects of dual-ion irradiation on the swelling of SiC/SiC composites

    International Nuclear Information System (INIS)

    Kishimoto, Hirotatsu; Kohyama, Akira; Ozawa, Kazumi; Kondo, Sosuke

    2005-01-01

    Silicon carbide (SiC) matrix composites reinforced by SiC fibers is a candidate structural material of fusion gas-cooled blanket system. From the viewpoint of material designs, it is important to investigate the swelling by irradiation, which results from the accumulation of displacement damages. In the fusion environment, (n, α) nuclear reactions are considered to produce helium gas in SiC. For the microstructural evolution, a dual-ion irradiation method is able to simulate the effects of helium. In the present research, 1.7 MeV tandem and 1 MeV single-end accelerators were used for Si self-ion irradiation and helium implantation, respectively. The average helium over displacement per atom (dpa) ratio in SiC was adjusted to 60 appm/dpa. The irradiation temperature ranged from room temperature to 1400degC. The irradiation-induced swelling was measured by the step height method. Helium that was implanted simultaneously with displacement damages in dual-ion irradiated SiC increased the swelling that was larger than that by single-ion irradiated SiC below 800degC. Since this increase was not observed above 1000degC, the interaction of helium and displacement damages was considered to change above 800degC. In this paper, the microstructural behavior and dimensional stability of SiC materials under the fusion relevant environment are discussed. (author)

  3. In-situ observation system for dual ion irradiation damage

    International Nuclear Information System (INIS)

    Furuno, Shigemi; Hojou, Kiichi; Otsu, Hitoshi; Sasaki, T.A.; Izui, Kazuhiko; Tukamoto, Tetsuo; Hata, Takao.

    1992-01-01

    We have developed an in-situ observation and analysis system during dual ion beam irradiation in an electron microscope. This system consists of an analytical electron microscope of JEM-4000FX type equipped with a parallel EELS and an EDS attachments and linked with two sets of ion accelerators of 40 kV. Hydrogen and helium dual-ion beam irradiation experiments were performed for SiC crystals. The result of dual-ion beam irradiation was compared with those of helium and hydrogen single ion irradiations. It is clearly seen that the dual-ion irradiation has the effect of suppressing bubble formation and growth in comparison with the case of single helium ion irradiation. (author)

  4. Comparison of FISGAS swelling and gas release predictions with experiment

    International Nuclear Information System (INIS)

    Ostensen, R.W.

    1979-01-01

    FISGAS calculations were compared to fuel swelling data from the FD1 tests and to gas release data from the FGR39 test. Late swelling and gas release predictions are satisfactory if vacancy depletion effects are added to the code. However, early swelling predictions are not satisfactory, and early gas release predictions are very poor. Explanation of these discrepancies is speculative

  5. Erosion experiments in swelling clays and result evaluation

    International Nuclear Information System (INIS)

    Sane, Petri; Turtiainen, M.; Koskinen, K.

    2012-01-01

    Document available in extended abstract form only. The performance of the bentonite buffer in KBS-3-nuclear waste repository concept relies strongly on the sufficient dry density of the buffer layer surrounding the deposition canister. As the buffer density is essentially fixed during the installation process, erosive mass loss of the buffer material remains as the most significant process reducing the density of the buffer. Most important parameters affecting the mass loss in the erosion process are the groundwater flow rate through the deposition hole from fractures in the surrounding rock and groundwater chemistry. Based on the rock suitability criteria for individual deposition holes in ONKALO, the Finnish spent nuclear fuel repository, the groundwater flow conditions in a single deposition hole/deposition hole tunnel section can be characterized in sufficient certainty in terms of maximum groundwater inflow rate; 0.1 L/min, i.e., deposition holes with larger inflows will not be used. Based on different climate scenarios the evolution of the groundwater chemistry can also be assessed and certain reference bounding salinities can be determined and corresponding fixed laboratory use reference solutions can be defined, most important being the current groundwater composition at deposition depth, which can be defined as 10 g/L reference solution as Total Dissolved Solids (TDS) per a liter of groundwater, relevant salts being NaCl and CaCl 2 . Additional reference salinities relevant to the ONKALO-repository are 1 g/L and 70 g/L, salt composition varying. Based on these fixed environmental parameters, testing of the erosive properties of the buffer can be performed with sufficient reliability. The current material type chosen for the Posiva buffer material in deposition hole is Wyoming MX-80 bentonite with sufficiently high montmorillonite content ensuring sufficient swelling. The dry density and water ratio of the buffer are also currently fixed in the design to

  6. Current status of gas migration and swelling experiments using engineering scale model for immediate depth disposal in Japan

    International Nuclear Information System (INIS)

    Higashihara, Tomohiro; Ono, Makoto; Kawaragi, Chie; Saito, Shigeyuki

    2010-01-01

    In intermediate depth disposal facility of radioactive waste in Japan, waste is surrounded with bentonite layer to retard interaction of the waste and groundwater, because the bentonite layer saturated with the groundwater has very low hydraulic conductivity. On the other hand, it is important to confirm stability of barrier system for stress generated together with swelling of the bentonite and to understand effect of increase of gas pressure because of generation of hydrogen gas by corrosion of metallic waste. To understand and evaluate the swelling behavior of the bentonite layer, JNES carries out the experiment. In the experiments, we carry out the swelling experiment to examine the swelling behavior of the bentonite layer and the gas migration experiment to understand the gas migration behavior in the bentonite layer, using engineering scale model of the disposal facility. The swelling experiment has been in operation since June 2010. After this experiment, the gas migration experiment will start in July 2011. (orig.)

  7. Modeling injected interstitial effects on void swelling in self-ion irradiation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Short, M.P., E-mail: hereiam@mit.edu [Dept. of Nuclear Science and Engineering, Massachusetts Institute of Technology (United States); Gaston, D.R. [Idaho National Laboratory (United States); Jin, M. [Dept. of Nuclear Science and Engineering, Massachusetts Institute of Technology (United States); Shao, L. [Dept. of Nuclear Engineering, Texas A& M University (United States); Garner, F.A. [Radiation Effects Consulting, LLC (United States)

    2016-04-01

    Heavy ion irradiations at high dose rates are often used to simulate slow and expensive neutron irradiation experiments. However, many differences in the resultant modes of damage arise due to unique aspects of heavy ion irradiation. One such difference was recently shown in pure iron to manifest itself as a double peak in void swelling, with both peaks located away from the region of highest displacement damage. In other cases involving a variety of ferritic alloys there is often only a single peak in swelling vs. depth that is located very near the ion-incident surface. We show that these behaviors arise due to a combination of two separate effects: 1) suppression of void swelling due to injected interstitials, and 2) preferential sinking of interstitials to the ion-incident surface, which are very sensitive to the irradiation temperature and displacement rate. Care should therefore be used in collection and interpretation of data from the depth range outside the Bragg peak of ion irradiation experiments, as it is shown to be more complex than previously envisioned. - Highlights: • A model of the spatially dependent point defect kinetics equations with injected interstitials has been implemented. • The results predict a double peak in the void nucleation rate, helping to explain a recent experiment. • The double peak is predicted to be evident within a narrow (+/− 30 °C) temperature window for self-irradiation of pure iron. • The ballistic damage profile may not match the resultant void swelling profile from ion irradiation experiments.

  8. Controlling the extrudate swell in melt extrusion additive manufacturing of 3D scaffolds: a designed experiment.

    Science.gov (United States)

    Yousefi, Azizeh-Mitra; Smucker, Byran; Naber, Alex; Wyrick, Cara; Shaw, Charles; Bennett, Katelyn; Szekely, Sarah; Focke, Carlie; Wood, Katherine A

    2018-02-01

    Tissue engineering using three-dimensional porous scaffolds has shown promise for the restoration of normal function in injured and diseased tissues and organs. Rigorous control over scaffold architecture in melt extrusion additive manufacturing is highly restricted mainly due to pronounced variations in the deposited strand diameter upon any variations in process conditions and polymer viscoelasticity. We have designed an I-optimal, split-plot experiment to study the extrudate swell in melt extrusion additive manufacturing and to control the scaffold architecture. The designed experiment was used to generate data to relate three responses (swell, density, and modulus) to a set of controllable factors (plotting needle diameter, temperature, pressure, and the dispensing speed). The fitted regression relationships were used to optimize the three responses simultaneously. The swell response was constrained to be close to 1 while maximizing the modulus and minimizing the density. Constraining the extrudate swell to 1 generates design-driven scaffolds, with strand diameters equal to the plotting needle diameter, and allows a greater control over scaffold pore size. Hence, the modulus of the scaffolds can be fully controlled by adjusting the in-plane distance between the deposited strands. To the extent of the model's validity, we can eliminate the effect of extrudate swell in designing these scaffolds, while targeting a range of porosity and modulus appropriate for bone tissue engineering. The result of this optimization was a predicted modulus of 14 MPa and a predicted density of 0.29 g/cm 3 (porosity ≈ 75%) using polycaprolactone as scaffold material. These predicted responses corresponded to factor levels of 0.6 μm for the plotting needle diameter, plotting pressure of 2.5 bar, melt temperature of 113.5 °C, and dispensing speed of 2 mm/s. The validation scaffold enabled us to quantify the percentage difference for the predictions, which was 9.5% for the

  9. Microstructural development in multi-pass TIG welded F82H steels under dual-ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ogiwara, H.; Tanigawa, H. [Japan Atomic Energy Agency, Tokai-mura, Naga-gun, Ibaraki-ken (Japan); Kishimoto, H.; Tomohiro, M.; Kohyama, A. [Kyoto Univ., Institute of Advanced Energy (Japan)

    2007-07-01

    Full text of publication follows: Reduced-activation ferritic/martensitic (RAFM) steels are the first candidate materials for blanket structural component. On fabricating blanket components, various joining technologies will be required, and it could be anticipated that some parts of the weldments will suffer from high-dose 14 MeV neutron irradiation. For example, the current Japanese water cooled test blanket module design has the weldment of the first wall and side wall at 25 mm from the surface. This will not be the case for TIER-TBM, but could be the critical issue if the same design is applied for DEMO blanket system. In this study, the effects of displacement damage and helium production on mechanical properties and microstructures of the multi-pass tungsten inert gas (TIG) welding were investigated. The welded joint used in this study is a multi-pass TIG weldment on 15-mm thick plates of F82H-IEA. The post weld heat treatment was carried out at 720 deg. C for 1 h. To obtain systematic and accurate information of the microstructural response under fusion environment, dual-ion irradiation was performed. 15 mm x 20 mm pieces which cover the whole TIG weldment were irradiated at 470 deg. C up to 20 dpa using 6.4 MeV Fe{sup +3} and/or energy-degraded 1.0 MeV He{sup +}. The damage rate was 1.0 x 10{sup -3} dpa/s, and the helium injection rate was 15 x 10{sup -3} appm He/s. After the irradiations, thin film samples were made from various regions of the weldment by focused ion beam (FIB) processor, and transmission electron microscopy (TEM) observation and hardness tests were performed. Microstructure and Vickers hardness profiles across base metal, heat affected zone (HAZ) and fusion zone (FZ) were examined before irradiation experiments. The hardness measurements revealed that the maximum hardness was observed at the last pass region of FZ, and the softest region was in the middle of the FZ and HAZ region near the transformation line. In the microstructure study

  10. The swelling behavior of montmorillonite as affected by the grain size by in situ X-ray diffraction experiments

    International Nuclear Information System (INIS)

    Morodome, S.; Kawamura, K.; Owada, H.; Yahagi, R.; Kobayashi, I.

    2012-01-01

    Document available in extended abstract form only. In many existing researches, the swelling behavior and impermeability of smectitic engineered barrier materials in disposal facilities of radioactive waste was investigated. In the RWMC-project, the effect of smectite content on the mechanical and hydraulic behavior of smectitic materials is investigated and modeled to introduce into THMC analysis. However, since smectite is a natural resource, physical and chemical properties are different with places of production. In order to model the swelling behavior and impermeability of smectitic materials, not only the smectite content but also layer charge and crystal size will be the primary factors. In addition, smectite types and impurity minerals contents or soluble salts affect bentonite characteristic, as well. In this research, in order to focus on the effect of grain size of smectite, the swelling behavior of smectitic materials which are the same place of production but are different grain size were investigated. The smectitic material used in this study was Kunipia-F (Kunimine Industry Co. Ltd., Japan), which is from the Tukinuno Mine, Yamagata prefecture, Japan, and is purified montmorillonite produced by hydraulic elutriation. It is considered that the montmorillonite, Kunipia-F, has large crystal size, and for example Kunipia-F is able to make a sheet when drying weak solution. The grain size was conditioned by jet mill pulverizer. The pulverizing was conducted by making each other collide with high speed. The grain size of the intact and pulverized samples was measured by using of the laser scattering particle distribution analyzer and SEM. The swelling behavior was measured by in situ X-ray diffraction using of a sample chamber which can control the temperature and humidity precisely. The result of the laser scattering analysis denoted that the pulverized sample fined down expressly. The difference of the crystal aspect ratio of the pre- and post

  11. Effect of helium on swelling and microstructural evolution in ion-irradiated V-15Cr-5Ti alloy

    International Nuclear Information System (INIS)

    Loomis, B.A.; Kestel, B.J.; Gerber, S.B.; Ayrault, G.

    1986-03-01

    An investigation was made on the effects of implanted helium on the swelling and microstructural evolution that results from energetic single- and dual-ion irradiation of the V-15Cr-5Ti alloy. Single-ion irradiations were utilized for a simulated production of the irradiation damage that might be expected from neutron irradiation of the alloy in a reactor with a fast neutron energy spectrum (E > 0.1 MeV). Dual-ion irradiations were utilized for a simulated production of the simultaneous creation of helium atoms and irradiation damage in the alloy in the MFR environment. Experimental results are also presented on the radiation-induced segregation of the constituent atoms in the single- and dual-ion irradiated alloy

  12. Effects of pulsed dual-ion irradiation of microstructural development

    International Nuclear Information System (INIS)

    Packan, N.H.

    1981-01-01

    The effect of pulsed irradiation on the development of microstructure during Ni ion bombardment has been investigated in a simple austenitic alloy similar to type 316 stainless steel. Bombardment conditions were 10 dpa, 940 K, pulsing with equal on/off times of either 0.5 or 60 s, and the addition of 20 appM He/dpa to some specimens either by room temperature preimplantation or by dual-beam coimplantation. Particular care was taken to minimize thermal pulses from beam heating (to 0 C). The results show that pulsing has a subtle influence, and the effects on specific cavity parameters are complex. Pulsing produced a small increase in swelling in the helium-free case, but a slight decrease for helium-implanted specimens, and it seems to have counteracted the usual stimulative effects of helium on cavity nucleation

  13. Indium-tin-oxide thin film deposited by a dual ion beam assisted e-beam evaporation system

    International Nuclear Information System (INIS)

    Bae, J.W.; Kim, J.S.; Yeom, G.Y.

    2001-01-01

    Indium-tin-oxide (ITO) thin films were deposited on polycarbonate (PC) substrates at low temperatures (<90 deg. C) by a dual ion beam assisted e-beam evaporation system, where one gun (gun 1) is facing ITO flux and the other gun (gun 2) is facing the substrate. In this experiment, effects of rf power and oxygen flow rate of ion gun 2 on the electrical and optical properties of depositing ITO thin films were investigated. At optimal deposition conditions, ITO thin films deposited on the PC substrates larger than 20 cmx20 cm showed the sheet resistance of less than 40 Ω/sq., the optical transmittance of above 90%, and the uniformity of about 5%

  14. Foot, leg, and ankle swelling

    Science.gov (United States)

    Swelling of the ankles - feet - legs; Ankle swelling; Foot swelling; Leg swelling; Edema - peripheral; Peripheral edema ... Foot, leg, and ankle swelling is common when the person also: Is overweight Has a blood clot in the leg Is older Has ...

  15. Microstructural evolution during dual-ion irradiation of candidate fusion reactor materials

    International Nuclear Information System (INIS)

    Nolfi, F.V. Jr.; Ayrault, G.

    1979-01-01

    Single- and dual-ion (heavy ions + 3 He) irradiations of Fe-20wt.%Ni-15wt.%Cr, V-15wt.%Cr and Ti-6wt.%Al-4wt.%V alloys have been performed over a range of temperatures and doses. Various features of microstructural evolution during irradiation are reported as determined by transmission electron microscopy and Auger spectroscopy investigations

  16. The use of the JEM 1250 high voltage electron microscope (HVEM) of the university of Antwerp (RUCA) as an instrument for void swelling simulation experiments

    International Nuclear Information System (INIS)

    Snijkers, M.; Janssens, C.

    1978-01-01

    The working procedure has been established for the use of the high voltage electron microscope of the University of Antwerp (RUCA) as an apparatus for testing the swelling behavior of ferritic and austenitic stainless steels. The local temperature increase of the specimen due to beam heating was measured. The results are in good agreement with measurements done in other laboratories. The intensity of the transmitted beam has been measured as a function of specimen thickness (for thicknesses smaller than a few μ) The operation conditions are described for carrying out irradiation experiments and for taking stereo pairs. (author)

  17. Microstructural evolution in dual-ion irradiated 316SS under various helium injection schedules

    International Nuclear Information System (INIS)

    Kohyama, A.; Igata, N.; Ayrault, G.; Tokyo Univ.

    1984-01-01

    Dual-ion irradiated 316 SS samples with various helium injection schedules were studied. The intent of using different schedules was to either approximate the MFR condition, mimic the mixed spectrum reactor condition or mimic the fast reactor condition. The objective of this investigation is to study the influence of these different helium injection schedules on the microstructural development under irradiation. The materials for this study was 316 SS (MFE heat) with three thermomechanical pre-irradiation treatments: solution annealed, solution annealed and aged and 20% cold worked. The cavity nucleation and growth stages were investigated using high resolution TEM. (orig.)

  18. Side Effects: Edema (Swelling)

    Science.gov (United States)

    Edema is a condition in which fluid builds up in your body’s tissues. The swelling may be caused by chemotherapy, cancer, and conditions not related to cancer. Learn about signs of edema, including swelling in your feet, ankles, and legs.

  19. Dual ion beam irradiation system for in situ observation with electron microscope

    International Nuclear Information System (INIS)

    Tsukamoto, Tetuo; Hojou, Kiiti; Furuno, Sigemi; Otsu, Hitosi; Izui, Kazuhiko.

    1993-01-01

    We have developed a new in situ observation system for dynamic processes under dual ion beam irradiation. The system consists of a modified 400 keV analytical electron microscope (JEOL, JEM-4000FX) and two 40 kV ion beam accelerators. This system allows evaluation of microscopic changes of structure and chemical bonding state of materials in the dynamic processes under two kinds of ion beam irradiations, that is required for the simulation test of the first wall of nuclear fusion reactors onto which He + , H + , and H 2 + ions are irradiated simultaneously. These two ion accelerators were equipped symmetrically both sides of the electron microscope and individually controlled. Each ion beam extracted from a duo-plasmatron ion gun is bent downward by an angle of 30deg with a mass-separating magnet, and introduced into specimen chamber of the electron microscope. Inside the specimen chamber the beam is deflected again by an angle of 30deg with an electrostatic prism so as to be incident on the specimen surface. Finally, two ion beams from both side are incident on the specimen surface at an angle of 60deg. The maximum ion current density of helium is more than 250μA/cm 2 at the specimen at an ion energy of 17 keV. Images of the electron microscope during dual ion beam irradiation are observed through a TV camera and recorded with a VTR. (author)

  20. Surface modification of M50 steel by dual-ion-beam dynamic mixing

    International Nuclear Information System (INIS)

    Kuang Yuanzhu; Jan Jun; Qin Ouyang

    1994-01-01

    TaN films have many attractive characteristics, and so have been used for electronic and mechanical applications. There are many methods used for deposition of TaN films. Recently, the ion-beam dynamic mixing method has been used for thin film deposition and materials modification. In order to obtain high performance, stoichiometric composition and good adhesion we have deposited TaN films by a dual-ion-beam dynamic mixing method. This paper introduces the deposition and properties of TaN films on M50 steel by dual-ion-beam dynamic mixing. The microstructure of films was analysed by X-ray diffraction and Auger electron spectroscopy (AES). The microhardness, resistance to wear and erosion of these films were determined. The results showed that (1) the TaN films were successfully deposited on M50 steel by this method, (2) the performance, resistance to wear and erosion of M50 steel were improved by ion-beam-mixing deposition of the TaN thin films, (3) AES showed there was a mixed layer on the film interface, (4) the microhardness of the thin film depends on microstructure and thickness and (5) the microstructure and quality of the films depends on the deposition conditions, so it is important to select the proper operational parameters of ion sources. ((orig.))

  1. The swelling hadrons

    International Nuclear Information System (INIS)

    Rho, M.

    1992-01-01

    The notion of a 'swelled world' for strong interactions is introduced, followed by a discussion on some phenomenological consequences of the 'dropping' meson and baryon masses in dense and/or hot nuclear matter. (author) 26 refs

  2. Potassium-Based Dual Ion Battery with Dual-Graphite Electrode.

    Science.gov (United States)

    Fan, Ling; Liu, Qian; Chen, Suhua; Lin, Kairui; Xu, Zhi; Lu, Bingan

    2017-08-01

    A potassium ion battery has potential applications for large scale electric energy storage systems due to the abundance and low cost of potassium resources. Dual graphite batteries, with graphite as both anode and cathode, eliminate the use of transition metal compounds and greatly lower the overall cost. Herein, combining the merits of the potassium ion battery and dual graphite battery, a potassium-based dual ion battery with dual-graphite electrode is developed. It delivers a reversible capacity of 62 mA h g -1 and medium discharge voltage of ≈3.96 V. The intercalation/deintercalation mechanism of K + and PF 6 - into/from graphite is proposed and discussed in detail, with various characterizations to support. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Development of a dual ion beam system with single accelerator for materials studies

    International Nuclear Information System (INIS)

    Suzuki, Kazumichi; Nishimura, Eiichi; Hashimoto, Tsuneyuki

    1986-01-01

    The dual ion beam accelerator system has been developed for simulation studies of neutron radiation damage of structural materials for nuclear fusion and fission reactors. One accelerator is used to accelerate two different kinds of ions, which are generated in the ion source simultaneously. One of these ions is selected alternatively by switching the magnetic field of the analyzing magnet, and is then accelerated to the desired energy value. The system is controlled by a microcomputer. The accelerator used in the system is a conventional 400 kV Cockcroft-Walton accelerator. The performance test by the acceleration of He + and Ar + shows that the system is capable of accelerating two ions alternatively with a switching time of less than 22 s. The beam current obtained with the microcomputer control is more than 98% of the current obtained by manual operation. (orig.)

  4. Optical and tribomechanical stability of optically variable interference security devices prepared by dual ion beam sputtering.

    Science.gov (United States)

    Çetinörgü-Goldenberg, Eda; Baloukas, Bill; Zabeida, Oleg; Klemberg-Sapieha, Jolanta; Martinu, Ludvik

    2011-07-01

    Optical security devices applied to banknotes and other documents are exposed to different types of harsh environments involving the cycling of temperature, humidity, chemical agents, and tribomechanical intrusion. In the present work, we study the stability of optically variable devices, namely metameric interference filters, prepared by dual ion beam sputtering onto polycarbonate and glass substrates. Specifically, we assess the color difference as well as the changes in the mechanical properties and integrity of all-dielectric and metal-dielectric systems due to exposure to bleach, detergent and acetone agents, and heat and humidity. The results underline a significant role of the substrate material, of the interfaces, and of the nature and microstructure of the deposited films in long term stability under everyday application conditions.

  5. Hotspot swells revisited

    Science.gov (United States)

    King, Scott D.; Adam, Claudia

    2014-10-01

    The first attempts to quantify the width and height of hotspot swells were made more than 30 years ago. Since that time, topography, ocean-floor age, and sediment thickness datasets have improved considerably. Swell heights and widths have been used to estimate the heat flow from the core-mantle boundary, constrain numerical models of plumes, and as an indicator of the origin of hotspots. In this paper, we repeat the analysis of swell geometry and buoyancy flux for 54 hotspots, including the 37 considered by Sleep (1990) and the 49 considered by Courtillot et al. (2003), using the latest and most accurate data. We are able to calculate swell geometry for a number of hotspots that Sleep was only able to estimate by comparison with other swells. We find that in spite of the increased resolution in global bathymetry models there is significant uncertainty in our calculation of buoyancy fluxes due to differences in our measurement of the swells’ width and height, the integration method (volume integration or cross-sectional area), and the variations of the plate velocities between HS2-Nuvel1a (Gripp and Gordon, 1990) and HS3-Nuvel1a (Gripp and Gordon, 2002). We also note that the buoyancy flux for Pacific hotspots is in general larger than for Eurasian, North American, African and Antarctic hotspots. Considering that buoyancy flux is linearly related to plate velocity, we speculate that either the calculation of buoyancy flux using plate velocity over-estimates the actual vertical flow of material from the deep mantle or that convection in the Pacific hemisphere is more vigorous than the Atlantic hemisphere.

  6. Nanocrystalline magnetite thin films grown by dual ion-beam sputtering

    International Nuclear Information System (INIS)

    Prieto, Pilar; Ruiz, Patricia; Ferrer, Isabel J.; Figuera, Juan de la; Marco, José F.

    2015-01-01

    Highlights: • We have grown tensile and compressive strained nanocrystalline magnetite thin films by dual ion beam sputtering. • The magnetic and thermoelectric properties can be controlled by the deposition conditions. • The magnetic anisotropy depends on the crystalline grain size. • The thermoelectric properties depend on the type of strain induced in the films. • In plane uniaxial magnetic anisotropy develops in magnetite thin films with grain sizes ⩽20 nm. - Abstract: We have explored the influence of an ion-assisted beam in the thermoelectric and magnetic properties of nanocrystalline magnetite thin films grown by ion-beam sputtering. The microstructure has been investigated by XRD. Tensile and compressive strained thin films have been obtained as a function of the parameters of the ion-assisted beam. The evolution of the in-plane magnetic anisotropy was attributed to crystalline grain size. In some films, magneto-optical Kerr effect measurements reveal the existence of uniaxial magnetic anisotropy induced by the deposition process related with a small grain size (⩽20 nm). Isotropic magnetic properties have observed in nanocrystalline magnetite thin film having larger grain sizes. The largest power factor of all the films prepared (0.47 μW/K 2 cm), obtained from a Seebeck coefficient of −80 μV/K and an electrical resistivity of 13 mΩ cm, is obtained in a nanocrystalline magnetite thin film with an expanded out-of-plane lattice and with a grain size ≈30 nm

  7. Spinal cord swelling and candidiasis

    International Nuclear Information System (INIS)

    Ho, K.; Gronseth, G.; Aldrich, M.; Williams, A.

    1982-01-01

    Fusiform swelling of the spinal cord was noted myelographically in a patient with Hodgkin's disease. Autopsy revealed that the swelling was cauused by Candida infection of the spinal cord. It is suggested that fungal infection be included in the differential diagnosis of spinal cord swelling in the immunsupporessed cancer patient. (orig.)

  8. Spinal cord swelling and candidiasis

    Energy Technology Data Exchange (ETDEWEB)

    Ho, K.; Gronseth, G.; Aldrich, M.; Williams, A.

    1982-11-01

    Fusiform swelling of the spinal cord was noted myelographically in a patient with Hodgkin's disease. Autopsy revealed that the swelling was caused by Candida infection of the spinal cord. It is suggested that fungal infection be included in the differential diagnosis of spinal cord swelling in the immunosuppressed cancer patient.

  9. Mitochondrial Swelling Induced by Glutathione

    Science.gov (United States)

    Lehninger, Albert L.; Schneider, Marion

    1959-01-01

    Reduced glutathione, in concentrations approximating those occurring in intact rat liver, causes swelling of rat liver mitochondria in vitro which is different in kinetics and extent from that yielded by L-thyroxine. The effect is also given by cysteine, which is more active, and reduced coenzyme A, but not by L-ascorbate, cystine, or oxidized glutathione. The optimum pH is 6.5, whereas thyroxine-induced swelling is optimal at pH 7.5. The GSH-induced swelling is not inhibited by DNP or dicumarol, nor by high concentrations of sucrose, serum albumin, or polyvinylpyrrolidone, in contrast to thyroxine-induced swelling. ATP inhibits the GSH swelling, but ADP and AMP are ineffective. Mn-+ is a very potent inhibitor, but Mg++ is ineffective. Ethylenediaminetetraacetate is also an effective inhibitor of GSH-induced swelling. The respiratory inhibitors amytal and antimycin A do not inhibit the swelling action of GSH, but cyanide does; these findings are consistent with the view that the oxidation-reduction state of the respiratory chain between cytochrome c and oxygen is a determinant of GSH-induced swelling. Reversal of GSH-induced swelling by osmotic means or by ATP in KCl media could not be observed. Large losses of nucleotides and protein occur during the swelling by GSH, suggesting that the action is irreversible. The characteristically drastic swelling action of GSH could be prevented if L-thyroxine was also present in the medium. PMID:13630941

  10. Morphing of geometric composites via residual swelling.

    Science.gov (United States)

    Pezzulla, Matteo; Shillig, Steven A; Nardinocchi, Paola; Holmes, Douglas P

    2015-08-07

    Understanding and controlling the shape of thin, soft objects has been the focus of significant research efforts among physicists, biologists, and engineers in the last decade. These studies aim to utilize advanced materials in novel, adaptive ways such as fabricating smart actuators or mimicking living tissues. Here, we present the controlled growth-like morphing of 2D sheets into 3D shapes by preparing geometric composite structures that deform by residual swelling. The morphing of these geometric composites is dictated by both swelling and geometry, with diffusion controlling the swelling-induced actuation, and geometric confinement dictating the structure's deformed shape. Building on a simple mechanical analog, we present an analytical model that quantitatively describes how the Gaussian and mean curvatures of a thin disk are affected by the interplay among geometry, mechanics, and swelling. This model is in excellent agreement with our experiments and numerics. We show that the dynamics of residual swelling is dictated by a competition between two characteristic diffusive length scales governed by geometry. Our results provide the first 2D analog of Timoshenko's classical formula for the thermal bending of bimetallic beams - our generalization explains how the Gaussian curvature of a 2D geometric composite is affected by geometry and elasticity. The understanding conferred by these results suggests that the controlled shaping of geometric composites may provide a simple complement to traditional manufacturing techniques.

  11. Ion beam and dual ion beam sputter deposition of tantalum oxide films

    Science.gov (United States)

    Cevro, Mirza; Carter, George

    1994-11-01

    Ion beam sputter deposition (IBS) and dual ion beam sputter deposition (DIBS) of tantalum oxide films was investigated at room temperature and compared with similar films prepared by e-gun deposition. Optical properties ie refractive index and extinction coefficient of IBS films were determined in the 250 - 1100 nm range by transmission spectrophotometry and at (lambda) equals 632.8 nm by ellipsometry. They were found to be mainly sensitive to the partial pressure of oxygen used as a reactive gas in the deposition process. The maximum value of the refractive index of IBS deposited tantalum oxide films was n equals 2.15 at (lambda) equals 550 nm and the extinction coefficient of order k equals 2 X 10-4. Films deposited by e-gun deposition had refractive index n equals 2.06 at (lambda) equals 550 nm. Films deposited using DIBS ie deposition assisted by low energy Ar and O2 ions (Ea equals 0 - 300 eV) and low current density (Ji equals 0 - 40 (mu) A/cm2) showed no improvement in the optical properties of the films. Preferential sputtering occurred at Ea(Ar) equals 300 eV and Ji equals 20 (mu) A/cm2 and slightly oxygen deficient films were formed. Different bonding states in the tantalum-oxide films were determined by x-ray spectroscopy while composition of the film and contaminants were determined by Rutherford scattering spectroscopy. Tantalum oxide films formed by IBS contained relatively high Ar content (approximately equals 2.5%) originating from the reflected argon neutrals from the sputtering target while assisted deposition slightly increased the Ar content. Stress in the IBS deposited films was measured by the bending technique. IBS deposited films showed compressive stress with a typical value of s equals 3.2 X 109 dyn/cm2. Films deposited by concurrent ion bombardment showed an increase in the stress as a function of applied current density. The maximum was s approximately equals 5.6 X 109 dyn/cm2 for Ea equals 300 eV and Ji equals 35 (mu) A/cm2. All

  12. Ion-beam and dual-ion-beam sputter deposition of tantalum oxide films

    Science.gov (United States)

    Cevro, Mirza; Carter, George

    1995-02-01

    Ion-beam sputter deposition (IBS) and dual-ion-beam sputter deposition (DIBS) of tantalum oxide films was investigated at room temperature and compared with similar films prepared by e-gun deposition. The optical properties, i.e., refractive index and extinction coefficient, of IBS films were determined in the 250- to 1100-nm range by transmission spectrophotometry and at (lambda) equals 632.8 nm by ellipsometry. They were found to be mainly sensitive to the partial pressure of oxygen used as a reactive gas in the deposition process. The maximum value of the refractive index of IBS deposited tantalum oxide films was n equals 2.15 at (lambda) equals 550 nm and the extinction coefficient of order k equals 2 X 10-4. Films deposited by e-gun deposition had refractive index n 2.06 at (lambda) equals 550 nm. Films deposited using DIBS, i.e., deposition assisted by low energy Ar and O2 ions (Ea equals 0 to 300 eV) and low current density (Ji equals 0 to 40 (mu) A/cm2), showed no improvement in the optical properties of the films. Preferential sputtering occurred at Ea(Ar) equals 300 eV and Ji equals 20 (mu) A/cm2 and slightly oxygen deficient films were formed. Different bonding states in the tantalum-oxide films were determined by x-ray spectroscopy, whereas composition of the film and contaminants were determined by Rutherford backscattering spectroscopy (RBS). Tantalum oxide films formed by IBS contained relatively high Ar content (approximately equals 2.5%) originating from the reflected argon neutrals from the sputtering target whereas assisted deposition slightly increased the Ar content. Stress in the IBS-deposited films was measured by the bending technique. IBS-deposited films showed compressive stress with a typical value of s equals 3.2 X 109 dyn/cm2. Films deposited by concurrent ion bombardment showed an increase in the stress as a function of applied current density. The maximum was s approximately equals 5.6 X 109 dyn/cm2 for Ea equals 300 eV and Ji equals

  13. Two Dual Ion Spectrometer Flight Units of the Fast Plasma Instrument Suite (FPI) for the Magnetospheric Multiscale Mission (MMS)

    Science.gov (United States)

    Adams, Mitzi

    2014-01-01

    Two Dual Ion Spectrometer flight units of the Fast Plasma Instrument Suite (FPI) for the Magnetospheric Multiscale Mission (MMS) have returned to MSFC for flight testing. Anticipated to begin on June 30, tests will ensue in the Low Energy Electron and Ion Facility of the Heliophysics and Planetary Science Office (ZP13), managed by Dr. Victoria Coffey of the Natural Environments Branch of the Engineering Directorate (EV44). The MMS mission consists of four identical spacecraft, whose purpose is to study magnetic reconnection in the boundary regions of Earth's magnetosphere.

  14. Swelling characteristics of buffer material

    International Nuclear Information System (INIS)

    Suzuki, Hideaki; Fujita, Tomoo

    1999-12-01

    After emplacement of the engineered barrier system (EBS), it is expected that the near-field environment will be impacted by phenomena such as heat dissipation by conduction and other heat transfer mechanism, infiltration of groundwater from the surrounding rock into the EBS, generation of swelling pressure in the buffer due to water infiltration and the stress imposed by the overburden pressure. These phenomena are not all independent, but can be strongly influenced by, and coupled with, each other. Evaluating these coupled thermo-hydro-mechanical phenomena is important in order to clarify the initial transient behavior of the engineered barrier system within the near-field. This report describes the results on measurement of swelling amount and stress at boundary built up under restraint condition with water uptake. The following results are identified. (1) The swelling stress of buffer material at saturated condition tends to be independent of effects of pore water pressure and synthetic sea water, and to decrease with increasing temperature. The swelling stress can be explained by the effective dry density. (2) The strain due to swelling estimated from the results of the swelling amount of buffer material is proportional to swelling stress. (3) The swelling stress and strain under unsaturated condition increase with water uptake. (author)

  15. Effect of phosphorus on the swelling and precipitation behavior of austenitic stainless steels during irradiation

    International Nuclear Information System (INIS)

    Lee, E.H.; Mansur, L.K.; Rowcliffe, A.F.

    1983-01-01

    It has been observed that increasing the volume fraction of the needle-shaped iron phosphide phase in austenitic stainless steels tends to inhibit void swelling during neutron irradiation. An earlier analysis showed that this effect could not be accounted for in terms of enhanced point defect recombination at particle-matrix interfaces. The behavior of the iron phosphide phase has been further examined using dual ion beam irradiations. It was found that the particle-matrix interface serves as a site for the nucleation of a very fine dispersion of helium bubbles. It is thought that since a high number density of cavities lowers the number of helium atoms per cavity, the irradiation time for the cavities to accumulate the critical number of gas atoms for bias-driven growth is correspondingly increased. Although the phosphide phase nucleates rapidly, it eventually undergoes dissolution if either the G or Laves phase develops with increasing dose

  16. Second order nonlinear optical properties of zinc oxide films deposited by low temperature dual ion beam sputtering

    International Nuclear Information System (INIS)

    Larciprete, M.C.; Passeri, D.; Michelotti, F.; Paoloni, S.; Sibilia, C.; Bertolotti, M.; Belardini, A.; Sarto, F.; Somma, F.; Lo Mastro, S.

    2005-01-01

    We investigated second order optical nonlinearity of zinc oxide thin films, grown on glass substrates by the dual ion beam sputtering technique under different deposition conditions. Linear optical characterization of the films was carried out by spectrophotometric optical transmittance and reflectance measurements, giving the complex refractive index dispersion. Resistivity of the films was determined using the four-point probe sheet resistance method. Second harmonic generation measurements were performed by means of the Maker fringes technique where the fundamental beam was originated by nanosecond laser at λ=1064 nm. We found a relatively high nonlinear optical response, and evidence of a dependence of the nonlinear coefficient on the deposition parameters for each sample. Moreover, the crystalline properties of the films were investigated by x-ray diffraction measurements and correlation with second order nonlinearity were analyzed. Finally, we investigated the influence of the oxygen flow rate during the deposition process on both the second order nonlinearity and the structural properties of the samples

  17. Effects of tensile and compressive stresses on irradiation-induced swelling in AISI 316

    International Nuclear Information System (INIS)

    Lauritzen, T.; Bell, W.L.; Konze, G.M.; Rosa, J.M.; Vaidyanathan, S.; Garner, F.A.

    1985-05-01

    The results of two recent experiments indicate that the current perception of stress-affected swelling needs revision. It appears that compressive stresses do not delay swelling as previously modeled but actually accelerate swelling at a rate comparable to that induced by tensile stresses

  18. Osmotic de-swelling and swelling of latex dispersions

    International Nuclear Information System (INIS)

    Bonnet-Gonnet, Cecile

    1993-01-01

    This research thesis reports the comparison of, on the one hand, direct measurements of de-swelling resistance of latex dispersions obtained by osmotic pressure with, on the other hand, predictions made by models of electrostatic interactions. This resistance is explained in the case of sulphate-stabilised polystyrene particles (direct repulsion between charged particles), and in the case of copolymer (ps-pba) particles covered by an amphiphilic polymer (interactions between surface macromolecules and polymers). The study of de-swelling and swelling cycles highlights the existence of thresholds beyond which the concentrated dispersion has some cohesion. This irreversibility can be modelled by a Van der Waals attraction. The role of hydrophobic forces in latex destabilisation is studied [fr

  19. On the way to high resolution TEM characterization of dual ion beam irradiated ODS steels

    International Nuclear Information System (INIS)

    Hsiung, L.; Tumey, S.; Fluss, M. J.; King, W.; Marian, J.; Kuntz, J.; Dasher, B. El; Serruys, Y.; Willaime, F.; Kimura, A.

    2009-01-01

    Fission and fusion energy application of ODS steels while appearing promising requires that many key science issues be resolved. Among these issues are our incomplete understanding of the effect of irradiation on low-temperature fracture properties, the role of fusion relevant helium and hydrogen transmutation gases on the deformation and fracture of irradiated material at low and high temperatures, radiation-induced solute segregation and phase stability, mechanisms of swelling suppression in ODS steels, and the effects of radiation damage on localized deformation. While planning to focus on all these issues we are particularly interested in the atomic scale mechanism by which helium is mitigated by the nano scale particles. In order to obtain insight we are performing analytical transmission electron microscopy (AEM), high resolution electron microscopy (HRTEM) to investigate micro-structural and micro-compositional changes and property alterations of Fe-Cr ferritic/martensitic and ODS steels driven by temperature and ion-beam irradiation with Fe, H, and He. As a beginning to a collaboration between LLNL and CEA-Saclay, we have carried out an irradiation of four specimens, Fe, Fe14%Cr, and two ODS steels (14% Cr and 16% Cr) using the dual beam facility at CEA-Saclay (JANNuS). An Fe 8+ beam was implanted at 24 MeV and helium was implanted through a degrader wheel with energies between 1.7 MeV and 1.3 MeV. The nominal radiation parameters were 40 to 25 DPA, 10 to 25 appm He/DPA ratio, and specimen temperatures of ∼425 deg. C. Our goal is to compare the evolved microstructure with respect to the accumulation of helium at or near the particle matrix interface. Preparatory to this first study we have made many hi-resolution analyses of the nano-particles in the two ODS steels which serve as a base line for comparison with the TEM post irradiation examination reported here. These base line studies are reported separately at this conference. (author)

  20. Bubble-Sheet-Like Interface Design with an Ultrastable Solid Electrolyte Layer for High-Performance Dual-Ion Batteries.

    Science.gov (United States)

    Qin, Panpan; Wang, Meng; Li, Na; Zhu, Haili; Ding, Xuan; Tang, Yongbing

    2017-05-01

    In this work, a bubble-sheet-like hollow interface design on Al foil anode to improve the cycling stability and rate performance of aluminum anode based dual-ion battery is reported, in which, a carbon-coated hollow aluminum anode is used as both anode materials and current collector. This anode structure can guide the alloying position inside the hollow nanospheres, and also confine the alloy sizes within the hollow nanospheres, resulting in significantly restricted volumetric expansion and ultrastable solid electrolyte interface (SEI). As a result, the battery demonstrates an excellent long-term cycling stability within 1500 cycles with ≈99% capacity retention at 2 C. Moreover, this cell displays an energy density of 169 Wh kg -1 even at high power density of 2113 W kg -1 (10 C, charge and discharge within 6 min), which is much higher than most of conventional lithium ion batteries. The interfacial engineering strategy shown in this work to stabilize SEI layer and control the alloy forming position could be generalized to promote the research development of metal anodes based battery systems. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Room-Temperature Growth of SiC Thin Films by Dual-Ion-Beam Sputtering Deposition

    Directory of Open Access Journals (Sweden)

    C. G. Jin

    2008-01-01

    Full Text Available Silicon carbide (SiC films were prepared by single and dual-ion-beamsputtering deposition at room temperature. An assisted Ar+ ion beam (ion energy Ei = 150 eV was directed to bombard the substrate surface to be helpful for forming SiC films. The microstructure and optical properties of nonirradicated and assisted ion-beam irradicated films have been characterized by transmission electron microscopy (TEM, scanning electron microscopy (SEM, Fourier transform infrared spectroscopy (FTIR, and Raman spectra. TEM result shows that the films are amorphous. The films exposed to a low-energy assisted ion-beam irradicated during sputtering from a-SiC target have exhibited smoother and compacter surface topography than which deposited with nonirradicated. The ion-beam irradicated improves the adhesion between film and substrate and releases the stress between film and substrate. With assisted ion-beam irradicated, the density of the Si–C bond in the film has increased. At the same time, the excess C atoms or the size of the sp2 bonded clusters reduces, and the a-Si phase decreases. These results indicate that the composition of the film is mainly Si–C bond.

  2. A STUDY ON PAROTID SWELLINGS

    Directory of Open Access Journals (Sweden)

    Alli Muthiah

    2017-03-01

    Full Text Available BACKGROUND Swellings of the parotid gland are of special interest to a surgeon’s keen eye. These lesions are not only involved in diseases isolated to the parotid, but can also present as a part of a generalised systemic disorder, medical or surgical. For a surgeon, the interests lie in the probable origin of the swelling, its involvement of the facial nerve, the variability in behaviour, regarding the operability criteria and its postoperative complications. 1 A comprehensive knowledge of the anatomy of the parotid and the prediction of the swelling behaviour can help not only in the diagnosis, but also in ensuring an apt management of the lesion and the patient. 2 This cohort study was conducted to analyse the following in our institution. The incidence of various parotid swellings to discuss accuracy of FNAC in comparison to the histopathological reports. The various surgical modalities of treatment of parotid swellings applied. MATERIALS AND METHODS The cohort study, which included 45 patients was conducted at Kilpauk Medical College Hospital and Government Royapettah Hospital from September 2010 to October 2012. Data was collected from the patients after obtaining an informed consent. The demographic details of the patients and history of their swelling was taken. The patients were examined and basic investigations performed. Details regarding the FNAC report, surgical and nonsurgical management were noted. Postoperative complications were documented. The final histopathological report was analysed and compared with the FNAC report. RESULTS Parotid lesions are commonest cases in our study. Benign tumours are more common than malignant lesions. This study found to correlate with world statistics. Investigations, clinical findings and treatment correlate well with world statistical records. CONCLUSION The analysis of the data of the study conducted at our institution provided us with the following results- Parotid lesions comprised of the

  3. Swelling

    Science.gov (United States)

    ... Liver failure from cirrhosis Nephrotic syndrome Poor nutrition Pregnancy Thyroid disease Too little albumin in the blood (hypoalbuminemia) Too much salt or sodium Use of certain drugs, such as corticosteroids or ...

  4. Cell swelling and volume regulation

    DEFF Research Database (Denmark)

    Hoffmann, Else Kay

    1992-01-01

    The extracellular space in the brain is typically 20% of the tissue volume and is reduced to at least half its size under conditions of neural insult. Whether there is a minimum size to the extracellular space was discussed. A general model for cell volume regulation was presented, followed...... by a discussion on how many of the generally involved mechanisms are identified in neural cells and (or) in astrocytes. There seems to be clear evidence suggesting that parallel K+ and Cl- channels mediate regulatory volume decrease in primary cultures of astrocytes, and a stretch-activated cation channel has...... been reported. The role of the different channels was discussed. A taurine leak pathway is clearly activated after cell swelling both in astrocytes and in neurones. The relations between the effect of glutamate and cell swelling were discussed. Discussion on the clearance of potassium from...

  5. Engineering Significant of Swelling Soils

    OpenAIRE

    Behzad Kalantari

    2012-01-01

    This study describes some of the most important swelling characters of expansive soils when used as foundation materials to support various types of civil engineering structures. Expansive soils are considered among difficult foundation materials and expand upon wetting and shrink upon losing moisture. They are considered problematic soils for architectural and civil engineers. These types of soils may cause minor to major structural damages to pavements as well as buildings. It is therefore ...

  6. Laboratory study of the Flandres clay swelling

    International Nuclear Information System (INIS)

    Khaddaj, Said

    1992-01-01

    The first chapter contains a survey about the swelling of soils, and about the experimental methods used to characterize this phenomenon. A classification of soils in function of their swelling potential is proposed. The second chapter deals with the properties of Flandres clay. Chemical and mineralogical compositions, mechanical properties and free swell index are given. The third chapter contains a presentation of the study of the swelling potential of Flandres clay using the oedometer. Four methods are described and used (free-swell, different pressures, pre-swell and direct-swell). A numerical simulation of free-swell tests is also given. The fourth chapter includes a presentation of the study of the swelling behaviour of Flandres clay using a triaxial cell. Three methods are used: free-swell, pre-swell and different-pressures. The last chapter contains a parametric study of the swelling behaviour of Flandres clay. The influence of some parameters such as sample thickness, initial water content, vertical load and load history is presented. (author) [fr

  7. Electric-field control of tri-state phase transformation with a selective dual-ion switch

    Science.gov (United States)

    Lu, Nianpeng; Zhang, Pengfei; Zhang, Qinghua; Qiao, Ruimin; He, Qing; Li, Hao-Bo; Wang, Yujia; Guo, Jingwen; Zhang, Ding; Duan, Zheng; Li, Zhuolu; Wang, Meng; Yang, Shuzhen; Yan, Mingzhe; Arenholz, Elke; Zhou, Shuyun; Yang, Wanli; Gu, Lin; Nan, Ce-Wen; Wu, Jian; Tokura, Yoshinori; Yu, Pu

    2017-06-01

    Materials can be transformed from one crystalline phase to another by using an electric field to control ion transfer, in a process that can be harnessed in applications such as batteries, smart windows and fuel cells. Increasing the number of transferrable ion species and of accessible crystalline phases could in principle greatly enrich material functionality. However, studies have so far focused mainly on the evolution and control of single ionic species (for example, oxygen, hydrogen or lithium ions). Here we describe the reversible and non-volatile electric-field control of dual-ion (oxygen and hydrogen) phase transformations, with associated electrochromic and magnetoelectric effects. We show that controlling the insertion and extraction of oxygen and hydrogen ions independently of each other can direct reversible phase transformations among three different material phases: the perovskite SrCoO3-δ (ref. 12), the brownmillerite SrCoO2.5 (ref. 13), and a hitherto-unexplored phase, HSrCoO2.5. By analysing the distinct optical absorption properties of these phases, we demonstrate selective manipulation of spectral transparency in the visible-light and infrared regions, revealing a dual-band electrochromic effect that could see application in smart windows. Moreover, the starkly different magnetic and electric properties of the three phases—HSrCoO2.5 is a weakly ferromagnetic insulator, SrCoO3-δ is a ferromagnetic metal, and SrCoO2.5 is an antiferromagnetic insulator—enable an unusual form of magnetoelectric coupling, allowing electric-field control of three different magnetic ground states. These findings open up opportunities for the electric-field control of multistate phase transformations with rich functionalities.

  8. Study of swelling by simulation

    International Nuclear Information System (INIS)

    Gilbon, D.; Le Naour, L.; Didout, G.

    1983-06-01

    Fuel cans and hexagonal tubes containing the pins must withstand high irradiation doses (220 or even 275 dpa) with a low swelling. Qualification of a new alloy for claddings requires several years of irradiation on a reactor. For a fast first selection simulation by 1MeV electron or heavy ions enhance radiation damages. Principles of these techniques are recalled and some examples mainly with steel 316 are given. Results are compared with results obtained in reactor to determine simulation limits. The method is not valid in the case of a structural instability of the irradiated material in a reactor [fr

  9. Counterion-induced swelling of ionic microgels

    Science.gov (United States)

    Denton, Alan R.; Tang, Qiyun

    2016-10-01

    Ionic microgel particles, when dispersed in a solvent, swell to equilibrium sizes that are governed by a balance between electrostatic and elastic forces. Tuning of particle size by varying external stimuli, such as pH, salt concentration, and temperature, has relevance for drug delivery, microfluidics, and filtration. To model swelling of ionic microgels, we derive a statistical mechanical theorem, which proves exact within the cell model, for the electrostatic contribution to the osmotic pressure inside a permeable colloidal macroion. Applying the theorem, we demonstrate how the distribution of counterions within an ionic microgel determines the internal osmotic pressure. By combining the electrostatic pressure, which we compute via both Poisson-Boltzmann theory and molecular dynamics simulation, with the elastic pressure, modeled via the Flory-Rehner theory of swollen polymer networks, we show how deswelling of ionic microgels with increasing concentration of particles can result from a redistribution of counterions that reduces electrostatic pressure. A linearized approximation for the electrostatic pressure, which proves remarkably accurate, provides physical insight and greatly eases numerical calculations for practical applications. Comparing with experiments, we explain why soft particles in deionized suspensions deswell upon increasing concentration and why this effect may be suppressed at higher ionic strength. The failure of the uniform ideal-gas approximation to adequately account for counterion-induced deswelling below close packing of microgels is attributed to neglect of spatial variation of the counterion density profile and the electrostatic pressure of incompletely neutralized macroions.

  10. Effect of metallurgical variables on void swelling

    International Nuclear Information System (INIS)

    Johnston, W.G.; Lauritzen, T.; Rosolowski, J.H.; Turkalo, A.M.

    1976-01-01

    The mechanism of void swelling is reviewed briefly and the anticipated effects of metallurgical variables are described. Experimental results showing the effects of metallurgical variables are reviewed, most of the work being done by simulation methods employing charged particle bombardments to simulate reactor damage. Although the early emphasis was on structural variables such as grain size, cold work and precipitates to control swelling, it now seems that the practical reduction of swelling will be achieved by modifying alloy composition. Void swelling is strongly influenced by the relative amounts of Fe, Cr, and Ni in an alloy; the amount of swelling can be varied by three orders of magnitude by changing the relative amounts of the three elements in an austenitic ternary alloy. The effect of composition on swelling of a simple ferritic alloy will also be described. The swelling of a simple austenitic alloy of Fe, Cr, and Ni can be reduced by certain minor element additions. The most effective swelling inhibitors are Si, Ti, Zr, and Nb, and combinations of Si and Ti are synergetic. Swelling reductions of two orders of magnitude have been achieved with combined additions. Predictions of swelling in commercial solid solution alloys are made on the basis of the present knowledge of the effects of major composition and minor element additions. The predictions agree with experimental results. For more complex commercial alloys, predictions are made for the effects on swelling of heat treatments that cause changes in matrix composition. In some cases, heat treatment is expected to change the peak swelling by more than a factor of ten, and to shift the peak swelling temperature by almost 100 0 C. Sensitivity of swelling to detailed matrix composition places emphasis on the need for developing understanding of the stability of structure and local composition in an irradiation environment

  11. Swelling variability of reference steels in HVEM studies

    International Nuclear Information System (INIS)

    Garner, F.A.; Mastel, B.

    1975-09-01

    A series of low-fluence electron irradiation experiments (0-15 dpa) were conducted on 316 stainless steels to explore the effects of the following variables: heat variations, FTR duct vs tubes, fabrication, annealing, Si content. Conclusions: the swelling rate became constant (max 1.3 percent/dpa) in all irradiations after an incubation period, which is variable. There is no difference in the steady-state swelling rate between various FTR heats, for annealing temperature variations, or for variation of Si content from 0.4 to 2 percent

  12. Radiation-induced void swelling in metals and alloys

    International Nuclear Information System (INIS)

    Zelinskij, V.F.; Neklyudov, I.M.; Ozhigov, L.S.; Reznichenko, Eh.A.; Rozhkov, V.V.; Chernyaeva, T.T.

    1979-01-01

    Main regularities in the development of radiation-induced void swelling are considered. Special attention is paid to consideration of a possibility to obtain information on material behaviour under conditions of reactor irradiation proceeding from the data of simulation experiments and to methods of rate control, for the processes which occur in material during irradiation and further annealing by the way of rationalized alloying, of thermomechanical treatment and programmed change of irradiation conditions under operation. Problems of initiation and growth of voids in irradiated materials are discussed as well as the ways to decrease the rate of radiation-induced void swelling

  13. Laser damage resistance of hafnia thin films deposited by electron beam deposition, reactive low voltage ion plating, and dual ion beam sputtering

    International Nuclear Information System (INIS)

    Gallais, Laurent; Capoulade, Jeremie; Natoli, Jean-Yves; Commandre, Mireille; Cathelinaud, Michel; Koc, Cian; Lequime, Michel

    2008-01-01

    A comparative study is made of the laser damage resistance of hafnia coatings deposited on fused silica substrates with different technologies: electron beam deposition (from Hf or HfO2 starting material), reactive low voltage ion plating, and dual ion beam sputtering.The laser damage thresholds of these coatings are determined at 1064 and 355 nm using a nanosecond pulsed YAG laser and a one-on-one test procedure. The results are associated with a complete characterization of the samples: refractive index n measured by spectrophotometry, extinction coefficient k measured by photothermal deflection, and roughness measured by atomic force microscopy

  14. Experimental evidence for stress enhanced swelling

    International Nuclear Information System (INIS)

    Bates, J.F.; Gilbert, E.R.

    1976-01-01

    Experimental evidence is presented which shows that the application of a biaxial stress during irradiation can increase the magnitude of irradiation-induced swelling observed in tubular specimens. It is shown that this increase in swelling is linear below the proportional elastic limit of the material and decreases above this value of stress. In the linear region a relationship is found between total swelling and stress free swelling. The phenomenon of reduced swelling is evaluated on the basis of increased cold work due to pre-irradiation straining. This analysis yields a relationship of dislocation density proportional to stress to the 3.82 power. Additional analyses using dislocation density proportional to sigma 2 (sigma = hoop stress) yield a similar but sharper decrease in swelling after the proportional elastic limit is reached. (Auth.)

  15. Prediction for swelling characteristics of compacted bentonite

    International Nuclear Information System (INIS)

    Komine, H.; Ogata, N.

    1996-01-01

    Compacted bentonites are attracting greater attention as back-filling (buffer) materials for high-level nuclear waste repositories. For this purpose, it is very important to quantitatively evaluate the swelling characteristics of compacted bentonite. New equations for evaluating the relationship between the swelling deformation of compacted bentonite and the distance between two montmorillonite layers are derived. New equations for evaluating the ion concentration of pore water and the specific surface of bentonite, which significantly influence the swelling characteristics of compacted bentonite, are proposed. Furthermore, a prediction method for the swelling characteristics of compacted bentonite is presented by combining the new equations with the well-known theoretical equations of repulsive and attractive forces between two montmorillonite layers. The applicability of this method was investigated by comparing the predicted results with laboratory test results on the swelling deformation and swelling pressure of compacted bentonites. (author) 31 refs., 8 tabs., 12 figs

  16. Soil shrinkage characteristics in swelling soils

    International Nuclear Information System (INIS)

    Taboada, M.A.

    2004-01-01

    The objectives of this presentation are to understand soil swelling and shrinkage mechanisms, and the development of desiccation cracks, to distinguish between soils having different magnitude of swelling, as well as the consequences on soil structural behaviour, to know methods to characterize soil swell/shrink potential and to construct soil shrinkage curves, and derive shrinkage indices, as well to apply them to assess soil management effects

  17. Recurrent painful calf swelling associated with gout.

    Science.gov (United States)

    Kovarsky, J; Young, M B

    1978-01-01

    A 30-year-old man had a recurrent painful calf swelling associated with gout that mimicked thrombophlebitis and possibly muscle tear. This painful calf swelling occurred in the absence of a subjective history of arthritis of the knee. A constellation of clinical signs was highly suggestive that gout was the cause of the painful calf swellings. Patients with similar conditions, after careful exclusion of thrombophlebitis, might be spared unnecessary and potentially dangerous anticoagulation or surgical intervention by early diagnosis of gout.

  18. Pool swell sub-scale testing and code comparison

    International Nuclear Information System (INIS)

    Elisson, K.

    1981-01-01

    The main objective of the experiment was to investigate the pool swell dynamics in general and the forces on the lowered central part of the diaphragm between drywell and wetwell in particular. Apart from the high speed camera pressure transducers and strain gauges were used to monitor the transient. Data was recorded on a 14 channel FM recorder and then digitalised and plotted. In total more than one hundred tests were performed including parametric variations of for example geometry, break flow, initial drywell pressure and initial water level. In parallel to this experiment pool swell calculations have been performed with the computer codes COPTA and STEALTH. COPTA which is a lumped mass code for pressure suppression containment analysis has a slug pool swell mode. STEALTH which is a general purpose lagrangian hydrodynamics code has been used in a 2-D axisymmetric version. The STEALTH code has been used to calculate the radial variations in the vertical displacement and velocity of the pool surface and to predict the load on the lowered central part of the diaphragm. A comparison between the calculations and the experimental data indicates that both codes are sufficiently correct in their description of the pool swell transient. (orig.)

  19. Investigation of Pre- and Post-Swelling Behavior of Elastomeric Material

    Directory of Open Access Journals (Sweden)

    M Akhtar

    2013-06-01

    Full Text Available In the last ten years, a new type of modern polymer, known as swelling elastomer, has been used extensively as a sealing element in the oil and gas industry. These elastomers have been instrumental in various new applications such as water shut off, zonal isolation, and sidetracking. Though swell packers can significantly reduce costs and increase productivity, their failure can lead to serious losses. The integrity and reliability of swelling elastomer seals under different field conditions is a major concern. The investigation of changes in material behavior over a specified swelling period is a necessary first step for performance evaluation of elastomer seals. The current study is based on experimental analysis of changes in geometric and mechanical behavior (hardness, tensile, compressive, bulk of an elastomeric material due to swelling. Tests were carried out before and after various stages of swelling. Specimens were placed in saline water (0.6% and 12% concentrations at a temperature of 50°C, with the total swelling period being one month. Swelling, hardness, compression, and bulk tests were conducted using disc samples, while ring samples were used for tensile experiments. A small test rig was designed and constructed for determination of bulk modulus. Stress-strain curves under tension and compression, and pressure volumetric-strain curves were obtained for specimens subjected to different swelling periods. Due to the fast-swell nature of the elastomer, there were sharp changes in mechanical properties within the first few days of swelling for both salinities. Elastic modulus derived from tensile and compressive tests showed a 90% decrease in the first few days. Bulk modulus showed fluctuation in its variation with an increasing swelling period. There was a small effect of salinity only during the first 5 or 6 days.

  20. Fuel swelling importance in PCI mechanistic modelling

    International Nuclear Information System (INIS)

    Arimescu, V.I.

    2005-01-01

    Under certain conditions, fuel pellet swelling is the most important factor in determining the intensity of the pellet-to-cladding mechanical interaction (PCMI). This is especially true during power ramps, which lead to a temperature increase to a higher terminal plateau that is maintained for hours. The time-dependent gaseous swelling is proportional to temperature and is also enhanced by the increased gas atom migration to the grain boundary during the power ramp. On the other hand, gaseous swelling is inhibited by a compressive hydrostatic stress in the pellet. Therefore, PCMI is the net result of combining gaseous swelling and pellet thermal expansion with the opposing feedback from the cladding mechanical reaction. The coupling of the thermal and mechanical processes, mentioned above, with various feedback loops is best simulated by a mechanistic fuel code. This paper discusses a mechanistic swelling model that is coupled with a fission gas release model as well as a mechanical model of the fuel pellet. The role of fuel swelling is demonstrated for typical power ramps at different burn-ups. Also, fuel swelling plays a significant role in avoiding the thermal instability for larger gap fuel rods, by limiting the potentially exponentially increasing gap due to the positive feedback loop effect of increasing fission gas release and the associated over-pressure inside the cladding. (author)

  1. Ultrasound-assisted swelling of bacterial cellulose

    OpenAIRE

    Song, J.; Su, Jing; Loureiro, Ana; Sá, M.; Cavaco-Paulo, Artur; Kim, Hye Rim; Silva, Carla

    2017-01-01

    Bacterial cellulose (BC) was obtained by static cultivation using commercial BC gel from scoby. BC membranes (oven dried and freeze-dried) were swelled with 8% NaOH, in absence and in presence of ultrasound (US), for 30, 60 and 90 min. The influence of swelling conditions on both physico-chemical properties and molecules entrapment was evaluated. Considering the highest levels of entrapment, an optimum swelling procedure was established: 8% NaOH for 30 min. at room temperature in the presence...

  2. Hydric transfer in swelling clayey soils: influence of confinement

    International Nuclear Information System (INIS)

    Rolland, S.

    2002-01-01

    Description of imbibition and swelling mechanisms in clayey soils represents an important stake in different scientific domains such as agronomy, geotechnics or petroleum industry. The aim of the present work is to show the effects of hydro-mechanical couplings during imbibition in a swelling clayey medium, under different confinement conditions. Our material is a bentonite-silt mixture, prepared with a known water content and compacted with a double-piston technique. This method allows us to produce uniform soil samples, in terms of humidity and bulk density. Experiments related to bottom imbibition are then carried out for three types of mechanical boundary conditions (free, oedometric, fixed volume). The non-intrusive dual-energy gamma-ray technique is used to assess the local variation of bulk density and humidity. Finally, the three imbibition kinetics are compared for each experiment in terms of hydraulic diffusivity, described in a Lagrangian way. (author)

  3. Managing Chemotherapy Side Effects: Swelling (Fluid Retention)

    Science.gov (United States)

    N ational C ancer I nstitute Managing Chemotherapy Side Effects Swelling (Fluid retention) “My hands and feet were swollen and puffy. My nurse helped me understand why I had to stop eating salty ...

  4. Realization of synaptic learning and memory functions in Y2O3 based memristive device fabricated by dual ion beam sputtering

    Science.gov (United States)

    Das, Mangal; Kumar, Amitesh; Singh, Rohit; Than Htay, Myo; Mukherjee, Shaibal

    2018-02-01

    Single synaptic device with inherent learning and memory functions is demonstrated based on a forming-free amorphous Y2O3 (yttria) memristor fabricated by dual ion beam sputtering system. Synaptic functions such as nonlinear transmission characteristics, long-term plasticity, short-term plasticity and ‘learning behavior (LB)’ are achieved using a single synaptic device based on cost-effective metal-insulator-semiconductor (MIS) structure. An ‘LB’ function is demonstrated, for the first time in the literature, for a yttria based memristor, which bears a resemblance to certain memory functions of biological systems. The realization of key synaptic functions in a cost-effective MIS structure would promote much cheaper synapse for artificial neural network.

  5. Mechanism of swelling suppression in phosphorous-modified Fe-Ni-Cr alloys

    International Nuclear Information System (INIS)

    Lee, E.H.; Mansur, L.K.

    1986-01-01

    Five simple alloys were ion irradiated at 948 0 K in an experiment designed to investigate the mechanism of swelling suppression associated with phosphorous additions. One of the alloys was the simple ternary Fe-15Ni-13Cr, another had 0.05% P added and the other three had further additions of the phosphide precipitate-forming elements Ti and/or Si. Ion irradiations were carried out with heavy ions only (Ni or Fe) or with heavy ions followed by dual heavy ions and helium. The ternary with and without P swelled readily early in dose with or without helium. The other three alloys only showed swelling in the presence of helium and exhibited a long delay in dose prior to the onset of swelling. These displayed fine distributions of Fe 2 P type phosphide precipitates enhanced by irradiation. The phosphide particles gave rise to very high concentrations of stable helium filled cavities at the precipitate matrix interfaces. The results were analyzed in terms of the theory of cavity swelling. The accumulation of the critical number of gas atoms in an individual cavity is required in the theory for point defect driven swelling to begin. It is concluded that the primary mechanism leading to swelling suppression is therefore the dilution of injected helium over a very large number of cavities. It is suggested that this mechanism may offer a key for alloy design for swelling resistance in high helium environments

  6. Relationship between phase development and swelling of AISI 316 during temperature changes

    International Nuclear Information System (INIS)

    Yang, W.J.S.; Garner, F.A.

    1982-04-01

    The effect of temperature changes on radiation-induced swelling and phase development of AISI 316 has been examined for specimens irradiated in two different experiments. The formation of radiation-stable phases at low temperature appears to precede swelling but these phases tend to dissolve when subsequently subjected to higher temperature. Phases which develop at high temperature persist when the temperature is subsequently lowered. Once nucleated at low temperatures, voids tend to persist without reduction in density at higher temperatures. However, a new round of void nucleation occurs when the temperature is decreased during irradiation. If the swelling has entered the steady-state swelling regime prior to the temperature change, there is no effect on the subsequent swelling rate. For temperature changes that occur before the end of the transient swelling regime, substantial changes can occur in the swelling behavior, particularly if the changes occur in the range around 500 0 . The isothermal swelling behavior of AISI 316 is much less sensitive to irradiation temperature than previously envisioned

  7. Molecular accessibility in solvent swelled coals. Quarterly report, [September--November, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Kispert, L.D.

    1993-11-01

    This quarter, experiments were performed on the use of binary swelling solvents in molecular accessibility in coal conversion. These experiments consisted of accessibility measurements of spin probe VII (TEMPAMINE) in Toluene swelled Illinois No. 6 APCS coal. The toluene was spiked with amounts of pyridine which ranged in concentration from 500 ppm to 10%. The experiments were done in triplicate to gain information about the experimental error involved in the procedure. It was shown that oscillations occur in the concentration of spin probe retained as the amount of pyridine that is added to the swelling solvent is increased. These oscillations decrease in intensity as the concentration of pyridine in the solvent solution is increased up to 2% pyridine (0.2mLs pyridine in 10mLs toluene). From a 2% pyridine concentration to a 5% concentration, there is no significant change in the retention of spin probe VII. An increase in retention is observed when the concentration of pyridine is increased to 6% and 7% successively, followed by a large decrease at 8% and 9% pyridine. The largest changes in spin probe retention are observed for concentrations of pyridine less than 0.5%. A three fold increase in spin probe retention is observed upon the addition of 500 ppm pyridine in the toluene swelling solvent, which indicates that small amounts of a strong swelling solvent could be used to improve molecular accessibility 91% in coals swelled in an otherwise weak swelling solvent.

  8. Swell propagation across a wide continental shelf

    OpenAIRE

    Hendrickson, Eric J.

    1996-01-01

    The effects of wave refraction and damping on swell propagation across a wide continental shelf were examined with data from a transect of bottom pressure recorders extending from the beach to the shelf break near Duck, North Carolina. The observations generally show weak variations in swell energy across the shelf during benign conditions, in qualitative agreement with predictions of a spectral refraction model. Although the predicted ray trajectories are quite sensitive to the irregular she...

  9. Swelling behavior of PEMFC during conditioning

    Directory of Open Access Journals (Sweden)

    J. Parrondo

    2007-09-01

    Full Text Available Polymeric cation exchange membranes (PEMFC are used in fuel cell technology. These membranes act as a physical barrier between anode and cathode, but diffusion through the membrane should allow protons to be carried from anode to cathode at a rate sufficient to supply energy requirements. They avoid any direct reaction of oxygen and hydrogen that would diminish fuel cell efficiency. Membranes have to be conditioned before use. This conditioning step changes membrane counterions and modifies their water content, which has an effect on their diffusion coefficients. In order to analyse and quantify the effect of conditioning techniques on membrane performance various experiments with Nafion 117 cation exchange membranes were carried out. Membranes were conditioned using various methods to change the charged cation in the membrane. The reactives used were ultrapure water, nitric acid, hydrochloric acid, hydrogen peroxide, sodium chloride, potassium chloride and ethylene glycol, all at room temperature. Some conditioning methods were carried out using solvents heated to 100 ºC. Water content was indirectly monitored by measuring membrane swelling. Results show that membrane conditioning with strong acids followed by treatment with water increases membrane water content by about 5%. Using high-temperature treatment the water content also increases. Water uptake or release from membranes is analysed in terms of water activity.

  10. Optical scatter imaging of cellular and mitochondrial swelling in brain tissue models of stroke

    Science.gov (United States)

    Johnson, Lee James

    2001-08-01

    then shown to correlate to mitochondrial swelling, as observed with electron microscopy. The system is finally used to study mitochondrial and cellular swelling. Evidence of the susceptibility of certain hippocampal regions, CA1 and the dentate gyrus, to exhibit mitochondrial swelling as the result of oxygen and glucose deprivation is presented. In addition, for the first time, the time course of mitochondrial swelling is seen. Finally, experiments with scatter imaging and measurement of nitric oxide with carbon fiber electrodes demonstrate a clear link between nitric oxide and cellular swelling. A potential mechanism of the action of nitric oxide is evaluated. Nitric oxide appears to act to cause cellular swelling without the release of glutamate. The use of targeted nitric oxide inhibitors may be useful for the reduction of edema.

  11. Swelling kinetics of several residues from Shenhua coal extraction

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Mei-xia; Shui, Heng-fu; Wang, Zhi-cai [Anhui University of Technology, Maanshan (China). School of Chemistry and Chemical Engineering

    2008-08-15

    In order to understand the mechanism of swelling and the relation between swelling behavior and solvent extraction, the swelling kinetics of residues from Shenhua coal extracted by CS{sub 2}/NMP with different mixing ratios were studied in different solvents. The result shows that the swelling rates of extraction residues increase along with swelling temperature. The swelling rate in polar solvent NMP is much higher than that in non-polar solvent THN. Solvent extraction has a great effect on the swelling of extraction residues. The swelling activation energy of extraction residues increases and the swelling rate decreases with the increase of extraction yield. The swelling activation energies of extraction residues in NMP and THN are less than 10 kJ/mol, suggesting that the swelling process is controlled by solvent molecular diffusion in coal structure. 22 refs., 2 figs., 7 tabs.

  12. Swelling, mechanical and friction properties of PVA/PVP hydrogels after swelling in osmotic pressure solution.

    Science.gov (United States)

    Shi, Yan; Xiong, Dangsheng; Liu, Yuntong; Wang, Nan; Zhao, Xiaoduo

    2016-08-01

    The potential of polyvinyl alcohol/polyvinylpyrrolidone (PVA/PVP) hydrogels as articular cartilage replacements was in vitro evaluated by using a macromolecule-based solution to mimic the osmotic environment of cartilage tissue. The effects of osmotic pressure solution on the morphology, crystallinity, swelling, mechanical and friction properties of PVA/PVP hydrogels were investigated by swelling them in non-osmotic and osmotic pressure solutions. The results demonstrated that swelling ratio and equilibrium water content were greatly reduced by swelling in osmotic solution, and the swelling process was found to present pseudo-Fickian diffusion character. The crystallization degree of hydrogels after swelling in osmotic solution increased more significantly when it compared with that in non-osmotic solution. After swelling in osmotic solution for 28days, the compressive tangent modulus and storage modulus of hydrogels were significantly increased, and the low friction coefficient was reduced. However, after swelling in the non-osmotic solution, the compressive tangent modulus and friction coefficient of hydrogels were comparable with those of as-prepared hydrogels. The better material properties of hydrogels in vivo than in vitro evaluation demonstrated their potential application in cartilage replacement. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Swelling and swelling resistance possibilities of austenitic stainless steels in fusion reactors

    International Nuclear Information System (INIS)

    Maziasz, P.J.

    1983-01-01

    Fusion reactor helium generation rates in stainless steels are intermediate to those found in EBR-II and HFIR, and swelling in fusion reactors may differ from the fission swelling behavior. Advanced titanium-modified austenitic stainless steels exhibit much better void swelling resistance than AISI 316 under EBR-II (up to approx. 120 dpa) and HFIR (up to approx. 44 dpa) irradiations. The stability of fine titanium carbide (MC) precipitates plays an important role in void swelling resistance for the cold-worked titanium-modified steels irradiated in EBR-II. Futhermore, increased helium generation in these steels can (a) suppress void conversion, (b) suppress radiation-induced solute segregation (RIS), and (c) stabilize fine MC particles, if sufficient bubble nucleation occurs early in the irradation. The combined effects of helium-enhanced MC stability and helium-suppressed RIS suggest better void swelling resistance in these steels for fusion service than under EBR-II irradiation

  14. Swelling in neutron-irradiated titanium alloys

    International Nuclear Information System (INIS)

    Peterson, D.T.

    1982-04-01

    Immersion density measurements have been performed on a series of titanium alloys irradiated in EBR-II to a fluence of 5 x 10 22 n/cm 2 (E > 0.1 MeV) at 450 and 550 0 C. The materials irradiated were the near-alpha alloys Ti-6242S and Ti-5621S, the alpha-beta alloy Ti-64, and the beta alloy Ti-38644. Swelling was observed in all alloys with the greater swelling being observed at 550 0 C. Microstructural examination revealed the presence of voids in all alloys. Ti-38644 was found to be the most radiation resistant. Ti-6242S and Ti-5621S also displayed good radiation resistance, whereas considerable swelling and precipitation were observed in Ti-64 at 550 0 C

  15. Assessment of void swelling in austenitic stainless steel PWR core internals

    International Nuclear Information System (INIS)

    Chung, H.M.

    2006-01-01

    As many pressurized water reactors (PWRs) age and life extension of the aged plants is considered, void swelling behavior of austenitic stainless steel (SS) core internals has become the subject of increasing attention. In this report, the available database on void swelling and density change of austenitic SSs was critically reviewed. Irradiation conditions, test procedures, and microstructural characteristics were carefully examined, and key factors that are important to determine the relevance of the database to PWR conditions were evaluated. Most swelling data were obtained from steels irradiated in fast breeder reactors at temperatures >385 C and at dose rates that are orders of magnitude higher than PWR dose rates. Even for a given irradiation temperature and given steel, the integral effects of dose and dose rate on void swelling should not be separated. It is incorrect to extrapolate swelling data on the basis of 'progressive compounded multiplication' of separate effects of factors such as dose, dose rate, temperature, steel composition, and fabrication procedure. Therefore, the fast reactor data should not be extrapolated to determine credible void swelling behavior for PWR end-of-life (EOL) or life-extension conditions. Although the void swelling data extracted from fast reactor studies is extensive and conclusive, only limited amounts of swelling data and information have been obtained on microstructural characteristics from discharged PWR internals or steels irradiated at temperatures and at dose rates comparable to those of a PWR. Based on this relatively small amount of information, swelling in thin-walled tubes and baffle bolts in a PWR is not considered a concern. As additional data and relevant research becomes available, the newer results should be integrated with existing data, and the worthiness of this conclusion should continue to be scrutinized. PWR baffle reentrant corners are the most likely location to experience high swelling rates, and

  16. Investigation of voltage swell mitigation using STATCOM

    International Nuclear Information System (INIS)

    Razak, N A Abdul; Jaafar, S; Hussain, I S

    2013-01-01

    STATCOM is one of the best applications of a self commutated FACTS device to control power quality problems in the distribution system. This project proposed a STATCOM model with voltage control mechanism. DQ transformation was implemented in the controller system to achieve better estimation. Then, the model was used to investigate and analyse voltage swell problem in distribution system. The simulation results show that voltage swell could contaminate distribution network with unwanted harmonic frequencies. Negative sequence frequencies give harmful effects to the network. System connected with proposed STATCOM model illustrates that it could mitigate this problems efficiently.

  17. Stress-enhanced swelling of metal during irradiation

    International Nuclear Information System (INIS)

    Garner, F.A.; Gilbert, E.R.; Porter, D.L.

    1980-04-01

    Data are available which show that stress plays a major role in the development of radiation-induced void growth in AISI 316 and many other alloys. Earlier experiments came to the opposite conclusion and are shown to have investigated stress levels which inadvertantly cold-worked the material. Stress-affected swelling spans the entire temperature range in fast reactor irradiations and accelerates with increasing irradiatin temperature. It also appears to operate in all alloy starting conditions investigated. Two major microstructural mechanisms appear to be causing the enhancement of swelling, which for tensile stresses is manifested primarily as a decrease in the incubation period. These mechanisms are stress-induced changes in the interstitial capture efficiency of voids and stress-induced changes in the vacancy emission rate of various microstructural components. There also appears to be an enhancement of intermetallic phase formation with applied stress and this is shown to increase swelling by accelerating the microchemical evolution that precedes void growth at high temperature. This latter consideration complicates the extrapolation of these data to compressive stress states

  18. Unusual presentation of ulcerative postauricular swelling as ...

    African Journals Online (AJOL)

    The swelling became ulcerative and associated with progressive tinnitus and hoarseness of voice. The patient was investigated. Fine‑needle aspiration cytology suggested sebaceous cell carcinoma. Then excision biopsy was done, and histopathological examination of excised tissue confirmed the diagnosis. Extraorbital ...

  19. [A woman with a postoperative lumbar swelling].

    Science.gov (United States)

    Hulshof, Hanna M; Elsenburg, Patric H J M; Frequin, Stephan T F M

    2013-01-01

    A 65-year-old woman had developed a large lumbar swelling in a period of four weeks following lumbar laminectomy. An MRI-scan revealed a large fluid collection, which had formed from the spinal canal. The diagnosis 'liquorcele', a rare complication of spine surgery, was established.

  20. The extrudate swell of HDPE: Rheological effects

    Science.gov (United States)

    Konaganti, Vinod Kumar; Ansari, Mahmoud; Mitsoulis, Evan; Hatzikiriakos, Savvas G.

    2017-05-01

    The extrudate swell of an industrial grade high molecular weight high-density polyethylene (HDPE) in capillary dies is studied experimentally and numerically using the integral K-BKZ constitutive model. The non-linear viscoelastic flow properties of the polymer resin are studied for a broad range of large step shear strains and high shear rates using the cone partitioned plate (CPP) geometry of the stress/strain controlled rotational rheometer. This allowed the determination of the rheological parameters accurately, in particular the damping function, which is proven to be the most important in simulating transient flows such as extrudate swell. A series of simulations performed using the integral K-BKZ Wagner model with different values of the Wagner exponent n, ranging from n=0.15 to 0.5, demonstrates that the extrudate swell predictions are extremely sensitive to the Wagner damping function exponent. Using the correct n-value resulted in extrudate swell predictions that are in excellent agreement with experimental measurements.

  1. PREVENTION OF PHOSPHATE - INDUCED MITOCHONDRIAL SWELLING

    Science.gov (United States)

    Kroll, Arnold J.; Kuwabara, Toichiro

    1962-01-01

    The prevention of phosphate-induced mitochondrial swelling in the whole retina of the rabbit was studied with the electron microscope. It was found that a mixture of ATP, Mg++, and bovine serum albumin protected the mitochondria in vitro. This finding confirmed the results obtained spectrophotometrically with isolated rat liver mitochondria by Lehninger. PMID:13927020

  2. Swell Propagation over Indian Ocean Region

    Directory of Open Access Journals (Sweden)

    Suchandra A. Bhowmick

    2011-06-01

    Full Text Available Swells are the ocean surface gravity waves that have propagated out of their generating fetch to the distant coasts without significant attenuation. Therefore they contain a clear signature of the nature and intensity of wind at the generation location. This makes them a precursor to various atmospheric phenomena like distant storms, tropical cyclones, or even large scale sea breeze like monsoon. Since they are not affected by wind once they propagate out of their generating region, they cannot be described by regional wave models forced by local winds. However, their prediction is important, in particular, for ship routing and off shore structure designing. In the present work, the propagation of swell waves from the Southern Ocean and southern Indian Ocean to the central and northern Indian Ocean has been studied. For this purpose a spectral ocean Wave Model (WAM has been used to simulate significant wave height for 13 years from 1993–2005 using NCEP blended winds at a horizontal spatial resolution of 1° × 1°. It has been observed that Indian Ocean, with average wave height of approximately 2–3 m during July, is mostly dominated by swell waves generated predominantly under the extreme windy conditions prevailing over the Southern Ocean and southern Indian Ocean. In fact the swell waves reaching the Indian Ocean in early or mid May carry unique signatures of monsoon arriving over the Indian Subcontinent. Pre-monsoon month of April contains low swell waves ranging from 0.5–1 m. The amplitudes subsequently increase to approximately 1.5–2 meters around 7–15 days prior to the arrival of monsoon over the Indian Subcontinent. This embedded signature may be utilized as one of the important oceanographic precursor to the monsoon onset over the Indian Ocean.

  3. Influence of nickel and beryllium content on swelling behavior of copper irradiated with fast neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Singh, B.N.; Garner, F.A.; Edwards, D.J. [Pacific Northwest National Lab., Richland, WA (United States); Evans, J.H.

    1996-10-01

    In the 1970`s, the effects of nickel content on the evolution of dislocation microstructures and the formation and growth of voids in Cu-Ni alloys were studied using 1 MeV electrons in a high voltage electron microscope. The swelling rate was found to decrease rapidly with increasing nickel content. The decrease in the swelling rate was associated with a decreasing void growth rate with increasing nickel content at irradiation temperatures up to 450{degrees}C. At 500{degrees}C, both void size and swelling rate were found to peak at 1 and 2% Ni, respectively, and then to decrease rapidly with increasing nickel content. However, recent work has demonstrated that the swelling behavior of Cu-5%Ni irradiated with fission neutrons is very similar for that of pure copper. The present experiments were designed to investigate this apparent discrepancy.

  4. Two-dimensional electron gases in MgZnO/ZnO and ZnO/MgZnO/ZnO heterostructures grown by dual ion beam sputtering

    Science.gov (United States)

    Singh, Rohit; Arif Khan, Md; Sharma, Pankaj; Than Htay, Myo; Kranti, Abhinav; Mukherjee, Shaibal

    2018-04-01

    This work reports on the formation of high-density (~1013-1014 cm-2) two-dimensional electron gas (2DEG) in ZnO-based heterostructures, grown by a dual ion beam sputtering system. We probe 2DEG in bilayer MgZnO/ZnO and capped ZnO/MgZnO/ZnO heterostructures utilizing MgZnO barrier layers with varying thickness and Mg content. The effect of the ZnO cap layer thickness on the ZnO/MgZnO/ZnO heterostructure is also studied. Hall measurements demonstrate that the addition of a 5 nm ZnO cap layer results in an enhancement of the 2DEG density by about 1.5 times compared to 1.11 × 1014 cm-2 for the uncapped bilayer heterostructure with the same 30 nm barrier thickness and 30 at.% Mg composition in the barrier layer. From the low-temperature Hall measurement, the sheet carrier concentration and mobility are both found to be independent of the temperature. The capacitance-voltage measurement suggests a carrier density of ~1020 cm-3, confined in 2DEG at the MgZnO/ZnO heterointerface. The results presented are significant for the optimization of 2DEG for the eventual realization of cost-effective and large-area MgZnO/ZnO-based high-electron-mobility transistors.

  5. Effect of argon ion beam voltages on the microstructure of aluminum nitride films prepared at room temperature by a dual ion beam sputtering system

    International Nuclear Information System (INIS)

    Chen, H.-Y.; Han Sheng; Cheng, C.-H.; Shih, H.C.

    2004-01-01

    Aluminum nitride (AlN) films were successfully deposited at room temperature onto p-type (1 0 0) silicon wafers by manipulating argon ion beam voltages in a dual ion beam sputtering (DIBS). X-ray diffraction spectra showed that aluminum nitride films could be synthesized above 800 V. The (0 0 2) orientation was dominant at 800 V, above which the orientation was random. The atomic force microscope (AFM) images displayed a relatively smooth surface with the root-mean-square roughness of 2-3 nm, where this roughness decreased with argon ion beam voltage. The Al 2p 3/2 and N 1s spectra indicated that both the aluminum-aluminum bond and aluminum-nitrogen bond appeared at 600 V, above which only the aluminum-nitrogen bond was detected. Moreover, the atomic concentration in aluminum nitride films was concentrated in aluminum-rich phases in all cases. Nevertheless, the aluminum concentration markedly increased with argon ion beam voltages below 1000 V, above which the concentration decreased slightly. The correlation between the microstructure of aluminum nitride films and argon ion beam voltages is also discussed

  6. Structural evaluation of fast reactor core restraint with irradiation creep-swelling opposition effects

    International Nuclear Information System (INIS)

    Kalinowski, J.E.

    1979-01-01

    Irradiation creep and swelling correlations are derived from primary loading in-reactor experiments in which irradiation creep and swelling act in the same direction. When correlation uncertainty bands are applied in core restraint evaluations, significant variability in sub-assembly behavior is predicted. For example, sub-assemblies in the outer core region where neutron flux and duct temperature gradients are significant exhibit bowing responses ranging from a creep dominated outward bow to a swelling dominated inward bow. Furthermore, solutions based on upper bound and lower bound correlation uncertainty combinations are observed to cross-over indicating that such combinations are physically unrealistic in the assessment of creep-swelling opposition effects. In order to obtain realistic upper and lower bound sub-assembly responses, judgement must be applied in the selection of creep-swelling equation uncertainty combinations. Experimental programs have been defined which will provide the needed basic as well as prototypic creep-swelling opposition data for reference and advanced sub-assembly duct alloys. The first of these is an irradiation of cylindrical capsules subjected to a through-wall temperature gradient. This test which is presently underway in the EBR-II reactor will provide the data needed to refine irradiation creep and swelling correlations and their associated uncertainties when applied to core restraint evaluations. Restrained pin and duct bowing experiments in FFTF have also been defined. These will provide the prototypic data necessary to verify irradiated duct bowing methodology. The results of this experimental program are expected to reduce creep and swelling uncertainties and permit better definition of the design window for load plane gaps. (orig.)

  7. A simple operational gas release and swelling model. Pt. 1

    International Nuclear Information System (INIS)

    Wood, M.H.; Matthews, J.R.

    1980-01-01

    A new and simple model of fission gas release and swelling has been developed for oxide nuclear fuel under operational conditions. The model, which is to be incorporated into a fuel element behaviour code, is physically based and applicable to fuel at both thermal and fast reactor ratings. In this paper we present that part of the model describing the behaviour of intragranular gas: a future paper will detail the treatment of the grain boundary gas. The results of model calculations are compared with recent experimental observations of intragranular bubble concentrations and sizes, and gas release from fuel irradiated under isothermal conditions. Good agreement is found between experiment and theory. (orig.)

  8. Radiation-induced creep and swelling

    International Nuclear Information System (INIS)

    Heald, P.T.

    1977-01-01

    The physical basis for radiation induced creep and swelling is reviewed. The interactions between the point defects and dislocations are recalled since these interactions are ultimately responsible for the observable deformation phenomena. Both the size misfit interaction and the induced inhomogeneity interaction are considered since the former gives rise to irradiation swelling while the latter, which depends on both internal and external stresses, results in irradiation creep. The defect kinetics leading to the deformation processes are discussed in terms of chemical rate theory. The rate equations for the spatially averaged interstitial and vacancy concentrations are expressed in terms of the microstructural sink strengths and the solution of these equations leads to general expressions for the deformation rates

  9. Effects of the Charge Ions Strength on the Swelling of Organic-Inorganic Nanogels

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Qin; Lu, Xiangguo; Wang, Jing; Guo, Qi; Niu, Liwei [Northeast Petroleum University, Daqing (China)

    2016-07-15

    The swelling behavior and swelling mechanism of hydrogels can be greatly affected by the charge strength of ions in them. To investigate such effects, we prepared two gels: a carboxylic acid gel (CAG) and a poly (2-acrylamide–methyl propane sulfonic acid) gel (SAG) based on starchy polyacrylamide (PAM) nanocomposite gels, both with montmorillonite, which underwent in situ intercalation, and used them as probes in swelling experiments. The equilibrium swelling rates (ESRs) of the hydrogels in both salt water and acidic water strongly depended on the charge strength of the ions in the chains. SAG had a higher ESR than CAG at the same mole ratio of polymer/water, which is attributed to the greater electrostatic repulsion between the strong electrolyte ions of SAG. Both water salinity and hydrogen ion contact of the hydrogels weakened ESR with the enhancement of charge ionic strength. The downward trend of ESR with increasing concentration of salt or hydrogen ions became weaker in SAG compared to CAG, which is attributed to the shielding and deprotonation effects of the strong electrolyte ions. Regarding the swelling mechanism, the chain relaxation occurred in neutral and acidic solutions for SAG and in neutral and weak acidic solutions for CAG, but water diffusion dominated in strong acidic solutions for CAG, leading to different swelling behaviors.

  10. Mechanisms affecting swelling in alloys with precipitates

    International Nuclear Information System (INIS)

    Mansur, L.K.; Haynes, M.R.; Lee, E.H.

    1980-01-01

    In alloys under irradiation many mechanisms exist that couple phase instability to cavity swelling. These are compounded with the more familiar mechanisms associated with point defect behavior and the evolution of microstructure. The mechanisms may be classified according to three modes of operation. Some affect cavity swelling directly by cavity-precipitate particle association, others operate indirectly by precipitate-induced changes in sinks other than cavities and finally there are mechanisms that are mediated by precipitate-induced changes in the host matrix. The physics of one mechanism of each type is developed in detail and the results compared where possible to experimental measurements. In particular, we develop the theory necessary to treat the effects on swelling of precipitation-induced changes in overall sink density; precipitation-induced changes in point defect trapping by solute depletion and creation of precipitate particle-matrix interfacial trap sites; and preciwill come from waste wood available locally requiring minimal energy for recovery and transportation to the site. The applicant is strongly considering the use of a solar preheating unit anium southward as well as to deeper dened al half-lives with experimental ones, over a range of 24 orders of magnitude was obtained. This is a strong argument that the alpha decay could be considered a fission process with very high mass asymmetry and charge density asymmetry

  11. Molecular accessibility in solvent swelled coals

    Energy Technology Data Exchange (ETDEWEB)

    Kispert, L.D.

    1993-02-01

    An EPR technique developed in this lab is being used to determine the pore size and number distribution changes after swelling the coal samples with various solvents. Stable nitroxide radical spin probes of different sizes, shapes and reactivity are dissolved in an appropriate solvent, the coal sample is added to the resulting solution, stirred over night at elevated temperature, filtered, washed with a non swelling solvent to eliminate any spin probes that are not trapped in the pores and the spin concentration is measured. Comparing these spin probe measurements to DRIFT data have shown that the relative number distribution of acidic functionalities can be accurately predicted by the spin probe method. The spin probe method had also been used to predict the increase in elongated voids in Pittsburgh No. 8 (APCS No. 4) upon swelling with pyridine in agreement with independent SANS data. NMR relaxation data show that it is possible to deduce the pore (accessibility) distribution as a function of size (up to 6 mn). It has also been possible by variable temperature and ENDOR measurements to determine the presence of hydrogen bonding as a function of pore shape and size. The advantage of the EPR method is that it permits molecules of selected shape and size to be used as probes of accessible regions of coal, thus providing information on the importance of molecular shape.

  12. Se of polymers to control clay swelling

    Energy Technology Data Exchange (ETDEWEB)

    Slobod, R L; Beiswanger, J P.G.

    1968-01-01

    The injection of water to displace oil is one of the main methods used to increase oil recovery. High injection rates are generally desired, and in some cases the flood will not be economic unless high rates are maintained. The presence of clays which swell in the presence of water offers a complication to the problem of maintaining adequate injectivity. In the course of this study it was observed that certain polymers, when present in dilute concentrations in the water, had the ability to reduce the response of these clays to fresh water. Two polymers, one an anionic and the other nonionic, were found to be very effective in controlling the clays present in Berea cores. Successful control of clay swelling was obtained by use of solutions containing as little as 1.0 ppM of polymer, but at this low concentration appreciable volumes of treating solution were required. These results suggest that some minimum amount of polymer must be adsorbed to prevent clay swelling. In Berea sandstone this minimum amount appeared to be of the order of 0.03 mg per cc of pore space. A series of tests made using 10.0 ppM polymer showed that the polymer could be made through the porous system in which 0.066 per mg of polymer was adsorbed per cc of pore space.

  13. Effect of crosslinker on the swelling and adsorption properties of ...

    Indian Academy of Sciences (India)

    tinence products and as a material for improving the water retention ... showed lower swelling capacity and higher swelling rate than the other ..... The presence of mobile chlo- ...... We thank the Department of Science and Technology for the.

  14. Full length cluster level swell data at pressures from 2 to 40 bar

    International Nuclear Information System (INIS)

    Pearson, K.G.

    1987-11-01

    This paper gives results of level swell experiments at pressures up to 40 bar, performed at Winfrith in 1981 as described elsewhere. The results have been used by a number of workers to develop voidage correlations and to assess safety codes. The experiment and experimental rig used are described. The results are tabulated. (author)

  15. The Darfur Swell, Africa: Gravity constraints on its isostatic compensation

    Science.gov (United States)

    Crough, S. Thomas

    The free-air gravity anomaly observed over the Darfur Swell is explainable by local isostatic balance with a root approximately 50 km deep on average. This root depth is similar to that inferred beneath other African domes and beneath oceanic midplate swells, suggesting that the Darfur Swell is a hotspot uplift created by lithospheric reheating.

  16. Factors which determine the swelling rate of austenitic stainless steels

    International Nuclear Information System (INIS)

    Garner, F.A.; Wolfer, W.G.

    1983-01-01

    Once void nucleation subsides, the swelling rate of many austenitic alloys becomes rather insensitive to variables that control the transient regime of swelling. Models are presented which describe the roles of nickel, chromium and silicon in void nucleation. The relative insensitivity of steady-state swelling to temperature, displacement rate and composition is also discussed

  17. High performance polymer electrolyte fuel cells with ultra-low Pt loading electrodes prepared by dual ion-beam assisted deposition

    International Nuclear Information System (INIS)

    Saha, Madhu Sudan; Gulla, Andrea F.; Allen, Robert J.; Mukerjee, Sanjeev

    2006-01-01

    Ultra-low pure Pt-based electrodes (0.04-0.12 mg Pt /cm 2 ) were prepared by dual ion-beam assisted deposition (dual IBAD) method on the surface of a non-catalyzed gas diffusion layer (GDL) substrate. Film thicknesses ranged between 250 and 750 A, these are compared with a control, a conventional Pt/C (1.0 mg Pt(MEA) /cm 2 , E-TEK). The IBAD electrode constituted a significantly different morphology, where low density Pt deposits (largely amorphous) were formed with varying depths of penetration into the gas diffusion layer, exhibiting a gradual change towards increasing crystalline character (from 250 to 750 A). Mass specific power density of 0.297 g Pt /kW is reported with 250 A IBAD deposit (0.04 mg Pt /cm 2 for a total MEA loading of 0.08 mg Pt /cm 2 ) at 0.65 V. This is contrasted with the commercial MEA with a loading of 1 mg Pt(MEA) /cm 2 where mass specific power density obtained was 1.18 g Pt /kW (at 0.65 V), a value typical of current state of the art commercial electrodes containing Pt/C. The principal shortcoming in this effort is the area specific power density which was in the range of 0.27-0.43 W/cm 2 (for 250-750 A IBAD) at 0.65 V, hence much below the automotive target value of 0.8-0.9 W/cm 2 (at 0.65 V). An attempt to mitigate these losses is reported with the use of patterning. In this context a series of patterns ranging from 45 to 80% Pt coverage were used in conjunction with a hexagonal hole geometry. Up to 30% lowering of mass transport losses were realized

  18. Simulation of high fluence swelling behavior in technological materials

    International Nuclear Information System (INIS)

    Garner, F.A.; Powell, R.W.; Diamond, S.; Lauritzen, T.; Rowcliffe, A.F.; Sprague, J.A.; Keefer, D.

    1977-06-01

    The U.S. Breeder Reactor Program is employing charged particle irradiation experiments at accelerated displacement rates to simulate neutron-induced microstructural changes in materials of technological interest. Applications of the simulation technique range from the study of fundamental microstructural mechanisms to the development of predictions of the high fluence swelling behavior of candidate alloys for breeder reactor ducts and fuel cladding. An exact equivalence probably cannot be established between all facets of the microstructural evolution which occurs in the disparate charged-particle and neutron environments. To aid in the correlation of data developed in the two environments an assessment has been made of the factors influencing the simulation process. A series of intercorrelation programs and analysis activities have been conducted to identify and explore the relevant phenomena. The factors found to exert substantial influence on the correlation process fall into two categories, one which deals with those variables which are atypical of the neutron environment and one which deals with the additional factors which arise due to the large differences in displacement rate of the two irradiation environments. While the various simulation techniques have been invaluable in determining the basic mechanisms and parametric dependencies of swelling, the potential of these tools in the confident prediction of swelling at high neutron fluence has yet to be realized. The basic problem lies in the inability of the simulation technique to reproduce the early microstructural development in the period that precedes and encompasses the incubation of voids. The concepts of temperature shift and dose equivalency have also been found to be more complicated than previously imagined. Preconditioning of metals in a neutron environment prior to simulation testing is now being employed in order to provide more appropriate starting microstructures

  19. The Future of Swelling Elastomers: An Elastomer Manufacturer's View of Swelling Elastomer Developments and Market Trends

    Directory of Open Access Journals (Sweden)

    R Seyger

    2013-06-01

    Full Text Available Swelling elastomers have gained acceptance as very effective products for creating sealing in various industries, including those creating energy from fossil fuels and geothermal resources. This paper outlines the research and development work being conducted not only in the application of these elastomers but also in the development work required to create new generations of elastomers. It touches on fundamental research into the mechanics of swelling with the intent to create a better and more predictable sealing as well as more advanced elastomers. It lifts the veil on the direction of work being done on new elastomers being developed in order to enable a better control of swelling. By doing so, the research is opening up field of applications for new equipment designs and mechanical possibilities in the future. Additionally, it addresses the need for a better and more in-depth dialogue between both chemical and mechanical engineers, and the elastomer companies and their customers on the potential that both swelling and non-swelling elastomers can offer to the industry as a whole.

  20. Swelling pressure in compacted bentonite below 0°C

    International Nuclear Information System (INIS)

    Birgersson, Martin; Karnland, Ola; Nilsson, Ulf

    2010-01-01

    Document available in extended abstract form only. Bentonite is a common component in many concepts for underground storage of high level radioactive waste. During its lifetime, an underground repository will be subject to various ambient temperatures. Backfilled tunnels, shafts and investigation bore holes closest to ground level will experience periods of temperature below 0 deg. C. From a safety assessment perspective, it is therefore essential to investigate and understand the behavior of bentonite below 0 deg. C. A large set of laboratory tests have been performed where fully water saturated samples of bentonites have been exposed to temperatures in the range -10 deg. C - +25 deg. C. The swelling pressure response has been recorded continuously. The samples have been varied with respect to bentonite type (e.g. calcium or sodium dominated), smectite content and density. The general observation is that the pressure of the bentonite lowers in a temperature range between 0 deg. C and a specific (negative) temperature T c , which is strongly correlated to the swelling pressure measured above 0 deg. C. Consequently, Tc decreases (i.e. becomes more negative) with increased density or smectite content. At T c , swelling pressure is completely lost. Furthermore, a very weak pressure dependence is observed at temperatures above 0 deg. C. This dependence is however strictly dependent on sample density. For any type of bentonite at high enough densities above 0 deg. C, the slope of the P-T curve is negative and becomes more negative with increasing density. For Na-dominated bentonites at lower densities, on the other hand, the slope is positive. An important observation is that no pressure increase was observed for any of the tested bentonite samples as the transition to temperatures below 0 deg. C was made. Since water expands as it freezes, this observation indicates that no ice is formed in compacted bentonite as the 0 deg. C level is passed. The observed swelling

  1. Use of double and triple-ion irradiation to study the influence of high levels of helium and hydrogen on void swelling of 8-12% Cr ferritic-martensitic steels

    Science.gov (United States)

    Kupriiyanova, Y. E.; Bryk, V. V.; Borodin, O. V.; Kalchenko, A. S.; Voyevodin, V. N.; Tolstolutskaya, G. D.; Garner, F. A.

    2016-01-01

    In accelerator-driven spallation (ADS) devices, some of the structural materials will be exposed to intense fluxes of very high energy protons and neutrons, producing not only displacement damage, but very high levels of helium and hydrogen. Unlike fission flux-spectra where most helium and hydrogen are generated by transmutation in nickel and only secondarily in iron or chromium, gas production in ADS flux-spectra are rather insensitive to alloy composition, such that Fe-Cr base ferritic alloys also generate very large gas levels. While ferritic alloys are known to swell less than austenitic alloys in fission spectra, there is a concern that high gas levels in fusion and especially ADS facilities may strongly accelerate void swelling in ferritic alloys. In this study of void swelling in response to helium and hydrogen generation, irradiation was conducted on three ferritic-martensitic steels using the Electrostatic Accelerator with External Injector (ESUVI) facility that can easily produce any combination of helium to dpa and/or hydrogen to dpa ratios. Irradiation was conducted under single, dual and triple beam modes using 1.8 MeV Cr+3, 40 keV He+, and 20 keV H+. In the first part of this study we investigated the response of dual-phase EP-450 to variations in He/dpa and H/dpa ratio, focusing first on dual ion studies and then triple ion studies, showing that there is a diminishing influence on swelling with increasing total gas content. In the second part we investigated the relative response of three alloys spanning a range of starting microstructure and composition. In addition to observing various synergisms between He and H, the most important conclusion was that the tempered martensite phase, known to lag behind the ferrite phase in swelling in the absence of gases, loses much of its resistance to void nucleation when irradiated at large gas/dpa levels.

  2. Use of double and triple-ion irradiation to study the influence of high levels of helium and hydrogen on void swelling of 8–12% Cr ferritic-martensitic steels

    Energy Technology Data Exchange (ETDEWEB)

    Kupriiyanova, Y.E., E-mail: fomenkoj@kipt.kharkov.ua [National Science Centre Kharkov Institute of Physics and Technology, 1, Akademicheskaya St., Kharkov, 61108 (Ukraine); Bryk, V.V.; Borodin, O.V.; Kalchenko, A.S.; Voyevodin, V.N.; Tolstolutskaya, G.D. [National Science Centre Kharkov Institute of Physics and Technology, 1, Akademicheskaya St., Kharkov, 61108 (Ukraine); Garner, F.A. [Radiation Effects Consulting, Richland, WA 99354 (United States)

    2016-01-15

    In accelerator-driven spallation (ADS) devices, some of the structural materials will be exposed to intense fluxes of very high energy protons and neutrons, producing not only displacement damage, but very high levels of helium and hydrogen. Unlike fission flux-spectra where most helium and hydrogen are generated by transmutation in nickel and only secondarily in iron or chromium, gas production in ADS flux-spectra are rather insensitive to alloy composition, such that Fe–Cr base ferritic alloys also generate very large gas levels. While ferritic alloys are known to swell less than austenitic alloys in fission spectra, there is a concern that high gas levels in fusion and especially ADS facilities may strongly accelerate void swelling in ferritic alloys. In this study of void swelling in response to helium and hydrogen generation, irradiation was conducted on three ferritic-martensitic steels using the Electrostatic Accelerator with External Injector (ESUVI) facility that can easily produce any combination of helium to dpa and/or hydrogen to dpa ratios. Irradiation was conducted under single, dual and triple beam modes using 1.8 MeV Cr{sup +3}, 40 keV He{sup +}, and 20 keV H{sup +}. In the first part of this study we investigated the response of dual-phase EP-450 to variations in He/dpa and H/dpa ratio, focusing first on dual ion studies and then triple ion studies, showing that there is a diminishing influence on swelling with increasing total gas content. In the second part we investigated the relative response of three alloys spanning a range of starting microstructure and composition. In addition to observing various synergisms between He and H, the most important conclusion was that the tempered martensite phase, known to lag behind the ferrite phase in swelling in the absence of gases, loses much of its resistance to void nucleation when irradiated at large gas/dpa levels.

  3. Void swelling behaviour of austenitic stainless steel during electron irradiation

    International Nuclear Information System (INIS)

    Sheng Zhongqi; Xiao Hong; Peng Feng; Ti Zhongxin

    1994-04-01

    The irradiation swelling behaviour of 00Cr17Ni14Mo2 austenitic stainless steel (AISI 316L) was investigated by means of high voltage electron microscope. Results showed that in solution annealed condition almost no swelling incubation period existed, and the swelling shifted from the transition period to the steady-state one when the displacement damage was around 40 dpa. In cold rolled condition there was evidently incubation period, and when the displacement damage was up to 84 dpa the swelling still remained in the transition period. The average size and density of voids in both conditions were measured, and the factors, which influenced the void swelling, were discussed. (3 figs.)

  4. Swelling Kinetics of Waxy Maize Starch

    Science.gov (United States)

    Desam, Gnana Prasuna Reddy

    Starch pasting behavior greatly influences the texture of a variety of food products such as canned soup, sauces, baby foods, batter mixes etc. The annual consumption of starch in the U.S. is 3 million metric tons. It is important to characterize the relationship between the structure, composition and architecture of the starch granules with its pasting behavior in order to arrive at a rational methodology to design modified starch of desirable digestion rate and texture. In this research, polymer solution theory was applied to predict the evolution of average granule size of starch at different heating temperatures in terms of its molecular weight, second virial coefficient and extent of cross-link. Evolution of granule size distribution of waxy native maize starch when subjected to heating at constant temperatures of 65, 70, 75, 80, 85 and 90 C was characterized using static laser light scattering. As expected, granule swelling was more pronounced at higher temperatures and resulted in a shift of granule size distribution to larger sizes with a corresponding increase in the average size by 100 to 120% from 13 mum to 25-28 mum. Most of the swelling occurred within the first 10 min of heating. Pasting behavior of waxy maize at different temperatures was also characterized from the measurements of G' and G" for different heating times. G' was found to increase with temperature at holding time of 2 min followed by its decrease at larger holding times. This behavior is believed to be due to the predominant effect of swelling at small times. However, G" was insensitive to temperature and holding times. The structure of waxy maize starch was characterized by cryoscanning electron microscopy. Experimental data of average granule size vs time at different temperatures were compared with model predictions. Also the Experimental data of particle size distribution vs particle size at different times and temperatures were compared with model predictions.

  5. Swelling of a Zirconium Oxide Film

    International Nuclear Information System (INIS)

    Henderson, Mark; Hawley, Adrian; White, John; Rennie, Adrian

    2005-01-01

    Full text: The structural changes that cause the change in the interlayer spacing of a surfactanttemplated zirconium oxide film have been studied using neutron diffractometry. We report that the film after drying on a glass substrate swells slightly through the addition of benzene by up to 4 Aangstroem on a lattice parameter of about 36 Aangstroem. The (001) and (002) diffraction peaks positions, widths and areas of a swollen film were then monitored by neutron diffraction as a function of benzene desorption. Disorder of the lamellar mesophase is considered as a cause of the observed effects on the diffraction signals. (authors)

  6. Swelling of a mesostructured zirconium oxide film

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, M.J. [Research School of Chemistry, Australian National University, Canberra, ACT 0200 (Australia); Rennie, A.R. [Uppsala University, Studsvik Neutron Research Laboratory, S-611 82 Nykoeping (Sweden); Hawley, A.M. [Research School of Chemistry, Australian National University, Canberra, ACT 0200 (Australia); White, J.W. [Research School of Chemistry, Australian National University, Canberra, ACT 0200 (Australia)]. E-mail: jww@rsc.anu.edu.au

    2006-11-15

    The structural changes that cause the change in interlayer spacing of a surfactant-templated zirconium oxide film have been studied using neutron diffractometry. We report that the film after drying on a glass substrate swells slightly through the addition of benzene by up to 4 A on a lattice parameter of about 36 A. The (0 0 1) and (0 0 2) diffraction peak widths, positions and areas of a swollen film were monitored as a function of benzene desorption. Disorder of the lamellar mesophase is considered as a cause of the observed effects on the diffraction signals.

  7. Fission product induced swelling of U–Mo alloy fuel

    International Nuclear Information System (INIS)

    Kim, Yeon Soo; Hofman, G.L.

    2011-01-01

    Highlights: ► We measured fuel swelling of U–Mo alloy by fission products at temperatures below 250 °C. ► We quantified the swelling portion of U–Mo by fission gas bubbles. ► We developed an empirical model as a function of fission density. - Abstract: Fuel swelling of U–Mo alloy was modeled using the measured data from samples irradiated up to a fission density of ∼7 × 10 27 fissions/m 3 at temperatures below ∼250 °C. The overall fuel swelling was measured from U–Mo foils with as-fabricated thickness of 250 μm. Volume fractions occupied by fission gas bubbles were measured and fuel swelling caused by the fission gas bubbles was quantified. The portion of fuel swelling by solid fission products including solid and liquid fission products as well as fission gas atoms not enclosed in the fission gas bubbles is estimated by subtracting the portion of fuel swelling by gas bubbles from the overall fuel swelling. Empirical correlations for overall fuel swelling, swelling by gas bubbles, and swelling by solid fission products were obtained in terms of fission density.

  8. Calculation simulation of equivalent irradiation swelling for dispersion nuclear fuel

    International Nuclear Information System (INIS)

    Cai Wei; Zhao Yunmei; Gong Xin; Ding Shurong; Huo Yongzhong

    2015-01-01

    The dispersion nuclear fuel was regarded as a kind of special particle composites. Assuming that the fuel particles are periodically distributed in the dispersion nuclear fuel meat, the finite element model to calculate its equivalent irradiation swelling was developed with the method of computational micro-mechanics. Considering irradiation swelling in the fuel particles and the irradiation hardening effect in the metal matrix, the stress update algorithms were established respectively for the fuel particles and metal matrix. The corresponding user subroutines were programmed, and the finite element simulation of equivalent irradiation swelling for the fuel meat was performed in Abaqus. The effects of the particle size and volume fraction on the equivalent irradiation swelling were investigated, and the fitting formula of equivalent irradiation swelling was obtained. The results indicate that the main factors to influence equivalent irradiation swelling of the fuel meat are the irradiation swelling and volume fraction of fuel particles. (authors)

  9. Swelling of biological and semiflexible polyelectrolytes.

    Science.gov (United States)

    Dobrynin, Andrey V; Carrillo, Jan-Michael Y

    2009-10-21

    We have developed a theoretical model of swelling of semiflexible (biological) polyelectrolytes in salt solutions. Our approach is based on separation of length scales which allowed us to split a chain's electrostatic energy into two parts that describe local and remote electrostatic interactions along the polymer backbone. The local part takes into account interactions between charged monomers that are separated by distances along the polymer backbone shorter than the chain's persistence length. These electrostatic interactions renormalize chain persistence length. The second part includes electrostatic interactions between remote charged pairs along the polymer backbone located at distances larger than the chain persistence length. These interactions are responsible for chain swelling. In the framework of this approach we calculated effective chain persistence length and chain size as a function of the Debye screening length, chain degree of ionization, bare persistence length and chain degree of polymerization. Our crossover expression for the effective chain's persistence length is in good quantitative agreement with the experimental data on DNA. We have been able to fit experimental datasets by using two adjustable parameters: DNA ionization degree (α = 0.15-0.17) and a bare persistence length (l(p) = 40-44 nm).

  10. Critical parameters controlling irradiation swelling in beryllium

    International Nuclear Information System (INIS)

    Dubinko, V.I.

    1995-01-01

    Radiation effects in beryllium can hardly be explained within a framework of the conventional theory based on the bias concept due to elastic interaction difference (EID) between vacancies and self-interstitial atoms (SIAs) since beryllium belongs to hexagonal close-packed metals where diffusion has been shown to be anisotropic. Diffusional anisotropy difference (DAD) between point defects changes the cavity bias for their absorption and leads to dependence of the dislocation bias on the distribution of dislocations over crystallographic directions. On the other hand, the elastic interaction between point defects and cavities gives rise to the size and gas pressure dependencies of the cavity bias, resulting in new critical quantities for bubble-void transition effects at low temperature irradiation. In the present paper, we develop the concept of the critical parameters controlling irradiation swelling with account of both DAD and EID, and take care of thermal effects as well since they are of major importance for beryllium which has an anomalously low self-diffusion activation energy. Experimental data on beryllium swelling are analyzed on the basis of the present theory. (orig.)

  11. Swelling induced by alpha decay in monazite and zirconolite ceramics: A XRD and TEM comparative study

    Science.gov (United States)

    Deschanels, X.; Seydoux-Guillaume, A. M.; Magnin, V.; Mesbah, A.; Tribet, M.; Moloney, M. P.; Serruys, Y.; Peuget, S.

    2014-05-01

    Zirconolite and monazite matrices are potential ceramics for the containment of actinides (Np, Cm, Am, Pu) which are produced over the reprocessing of spent nuclear fuel. Actinides decay mainly through the emission of alpha particles, which in turn causes most ceramics to undergo structural and textural changes (amorphization and/or swelling). In order to study the effects of alpha decays on the above mentioned ceramics two parallel approaches were set up. The first involved the use of an external irradiation source, Au, which allowed the deposited recoil energy to be simulated. The second was based on short-lived actinide doping with 238Pu, (i.e. an internal source), via the incorporation of plutonium oxide into both the monazite and zirconolite structures during synthesis. In both types of irradiation experiments, the zirconolite samples became amorphous at room temperature with damage close to 0.3 dpa; corresponding to a critical dose of 4 × 1018 α g-1 (i.e. ∼1.3 × 1021 keV cm-3). Both zirconolite samples also showed the same degree of macroscopic swelling at saturation (∼6%), with ballistic processes being the predominant damaging effect. In the case of the monazite however, the macroscopic swelling and amorphization were dependent on the nature of the irradiation. Externally, (Au), irradiated samples became amorphous while also demonstrating a saturation swelling of up to 8%. In contrast to this, the swelling of the 238Pu doped samples was much smaller at ∼1%. Also, unlike the externally (Au) irradiated monazite these 238Pu doped samples remained crystalline up to 7.5 × 1018 α g-1 (0.8 dpa). XRD, TEM and swelling measurements were used to fully characterize and interpret this behavior. The low swelling and the conservation of the crystalline state of 238Pu doped monazite samples indicates that alpha annealing took place within this material.

  12. Hysteresis in clay swelling induced by hydrogen bonding: accurate prediction of swelling states

    NARCIS (Netherlands)

    Tambach, T.J.; Bolhuis, P.G.; Hensen, E.J.M.; Smit, B.

    2006-01-01

    We perform grand-canonical molecular simulations to study the molecular mechanism of clay swelling hysteresis as a function of the relative humidity. In particular, we focus on the transition from the one- to the two-layer hydrate and the influence of three types of counterions (Li+, Na+, and K+).

  13. Thickness dependence of magnetic properties and giant magneto-impedance effect in amorphous Co{sub 73}Si{sub 12}B{sub 15} thin films prepared by Dual-Ion beam assisted deposition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yu [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); BISSE/BUAA-SPNEE joint Laboratory Magnetism and Sperconducting technology on Spacecraft, Beihang University, Beijing 100191 (China); Wang, San-sheng, E-mail: wangssh@buaa.edu.cn [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); BISSE/BUAA-SPNEE joint Laboratory Magnetism and Sperconducting technology on Spacecraft, Beihang University, Beijing 100191 (China); Hu, Teng [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); He, Tong-fu [School of Instrumentation Science and Opto-electronics Engineering, Beihang University, Beijing 100191 (China); Chen, Zi-yu [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Yi, Zhong; Meng, Li-Fei [Science and Technology on Reliability and Environmental Engineering Laboratory, Beijing Institute of Spacecraft Environment Engineering, Beijing 100094 (China); BISSE/BUAA-SPNEE joint Laboratory Magnetism and Sperconducting technology on Spacecraft, Beihang University, Beijing 100191 (China)

    2017-03-15

    Dual-Ion Beam Assisted Deposition is a suitable method for the preparation of giant magneto-impedance (GMI) materials. In this paper, Co{sub 73}Si{sub 12}B{sub 15} thin films with different thicknesses were prepared by Dual-Ion Beam Assisted Deposition, and the influences of film thickness on magnetic properties and GMI effect were investigated. It was found that the asymmetric magnetic hysteresis loop in the prepared Co{sub 73}Si{sub 12}B{sub 15} thin films occurs at ambient temperature, and the shift behavior of hysteresis loop associated with film thickness. With the film thickness increasing, the values of shift field and coercive field and other parameters such as remanence and shift ratio appeared complex variation. At a certain frequency, the large GMI effect is only observed in some films, which have good magnetic properties including low coercivity, low remanence ratio and high shift ratio. The results indicated that the thickness dependence of magnetic properties nonlinearly determined the GMI effect in Co{sub 73}Si{sub 12}B{sub 15} thin films. - Highlights: • The relationship between film thickness and ΔZ/Z, ΔR/R, ΔX/X ratio of CoSiB film exhibits a complex behavior as the film thickness increases from 1.33 to 7.34 µm. The maximum value of GMI ratio is observed when the film thickness was 1.56, 2.48, 3.81 or 7.34 µm. • With the increase of film thickness, the peak frequency shifts to lower frequency, but does not decrease following the t-power law. • The above thickness phenomenon is due to the different magnetic properties of thin films. • The Dual-Ion Beam Assisted Deposition is introduced to prepare the GMI materials.

  14. Radiation swelling diagram of chromium-nickel austenitic steels

    Energy Technology Data Exchange (ETDEWEB)

    Gol' tsev, V.P.; Bulyga, V.V.

    1983-01-01

    The diagram of radiation swelling of the gas-cooled reactor core materials is presented. The swelling diagram is built on the basis of the relationships existing between the damaging dose and maximum swelling and takes an account of the temperature corresponding to maximum swelling. The analysis of the estimated data on swelling show that for the same temperatures especially with damaging dose above 30 displ./at., large scattering of swelling absolute values obtained during utilization of different empirical expressions, is observed. The scattering of material swelling values of the fuel elements irradiated under identical conditions results from a variety of gas content in the material of cans in the process of void formation. The displacement of swelling temperature maximum finds explanation in various rates of damaging dose attainment, the temperature swelling maximum being displaced to the side of large values during the increase of the velocity of atomic displacement upon irradiation (displ./atx sec). The suggested characteristic of steel swelling gives the idea about the behaviour of materisls upon neutron irradiation and can be useful for developing of the core elements of the gas-cooled reactors.

  15. Flakeboard thickness swelling. Part I, Stress relaxation in a flakeboard mat

    Science.gov (United States)

    R. L. Geimer; J. H. Kwon; J. Bolton

    1998-01-01

    The steam injection schedule best suited for dimensionally stabilizing a flake mat is one in which steam treatment is initiated before the press is closed and is continued at least until the mat attains target thickness. Experiments showed that resinless mats treated with 20 sec of steam at 600 kPa had maximum thickness swelling of 205% compared to 350% for resinless...

  16. Swelling behaviour of isora/natural rubber composites in oils used

    Indian Academy of Sciences (India)

    Natural rubber/isora fibre composites were cured at various temperatures. The solvent swelling characteristics of natural rubber composites containing both untreated and alkali treated fibres were investigated in aromatic and aliphatic solvents like toluene, and -hexane. The diffusion experiments were conducted by the ...

  17. A contribution to the better understanding of swelling in soils and soft rocks

    Directory of Open Access Journals (Sweden)

    Ana Petkovšek

    2010-12-01

    Full Text Available Swelling and shrinkage of sediments rich with clay belong to geologically conditioned risk factors. Economicloss as the consequence of volume changes in the geological catchment area of buildings and infrastructuralobjects is immense. Untimely detected swelling causes higher prices and unnecessary delays during the construction.In those cases when deep cuts and underground spaces are used as intervention into highly preconsolidatedsoils and soft rock with clay contents, failures of embankments and improperly designed supporting measures dueto swelling are not infrequent. Also periodic appearance of landslides at certain areas can be the consequence ofswelling. Some countries, such as the USA, introduced the guidelines and standards for the detection, assessmentand handling with swellable geological materials decades ago. Due to some other more urgent geologically conditionedrisks, such as landslides, earthquakes and constructions on soft ground, in Slovenia the development ofknowledge in the area of swelling soils was several years behind the knowledge in the rest of the world. With theconstruction of the Slovenian-Hungarian railway connection after 1998, motorways and the introduction of newknowledge about soil suction, also Slovenian experts were introduced to a different dimension of the problem ofswelling soils, as well as some important experiences were learned and new possibilities for the investigation andunderstanding of volume behaviour of swelling soils were opened. This is especially important for the predictedweather extremes, as only adequate knowledge will allow us to adequately explain any new phenomena in theground and prepare appropriate protection.

  18. Swelling kinetics and impregnation of PLA with thymol under supercritical CO2 conditions

    Directory of Open Access Journals (Sweden)

    Milovanović Stoja L.

    2016-01-01

    Full Text Available The present work was aimed to study swelling kinetics of polylactic acid (PLA and its impregnation with thymol in supercritical carbon dioxide (scCO2 medium. The influences of temperature and soaking time on the swelling kinetics and impregnation yield of PLA cylindrical disc and film were investigated. Swelling experiments were performed in a high pressure view cell at 10 MPa and temperatures of 40°C, 60°C and 75°C for 2 to 24 h. On the basis of swelling kinetics, pressure of 10 MPa and temperature of 40°C were chosen for supercritical solvent impregnation (SSI of the PLA samples during 2 to24 h. The highest swelling extent was observed for the PLA monolith after 24 h treatment with pure scCO2 (7.5% and scCO2 with thymol (118.3%. It was shown that sufficiently high amount of thymol can be loaded into both PLA monolith and film using SSI after only 2 h (10.0% and 6.6%, respectively. Monolith and film of PLA impregnated with thymol could be suitable for active food packaging and sterile medical disposables.

  19. Tensile, swelling and morphological properties of bentonite-filled acrylonitrile butadiene rubber composites

    Science.gov (United States)

    Lotfi, Muhamad Nadhli Amin; Ismail, Hanafi; Othman, Nadras

    2017-10-01

    Tensile, swelling and morphological properties of bentonite filled acrylonitrile butadiene rubber (NBR/Bt) composites were studied. The experiments were conducted at room temperature by using two rolled mill, universal testing machine (INSTRON), and American Standard Testing Method (ASTM) D471 for compounding, tensile testing, and swelling test, respectively. Results obtained indicated that a better tensile strength, elongation at break and tensile modulus were recorded as compared to the pure NBR particularly up to 90 phr of Bt loading. However, swelling (%) exhibited the opposite trend where the liquid uptake by the composites was indirectly proportional with the increasing of Bt loading. Scanning electron microscopy (SEM) used on the tensile fractured surface of the NBR/Bt composites have shown that the fillers were well embedded in the NBR matrix, for Bt loading up to 90 phr. The agglomeration of fillers occurred for Bt loading exceeding 90 phr.

  20. Effect of gas atoms on swelling of austenitic stainless steel

    International Nuclear Information System (INIS)

    Igata, N.; Eguchi, N.; Nishibe, E.; Naito, A.

    1994-01-01

    There have been many studies on the effect of He on swelling, however not so many on the effect of nitrogen on swelling. In this study the effect of nitrogen on swelling of 316 steel was investigated under HVEM irradiation for establishing a model of swelling. The nitrogen content was changed from 0.083 to 0.002 wt%, and for the comparison 321 steel containing Ti was used. Irradiation was performed by HVEM at 500 C under 2x10 -3 dpa/s. The dislocation loop number density in the early stage was nearly equal to the cavity number density formed later and both increased with nitrogen content. The swelling increased and decreased through the maximum as the nitrogen content increased. The result was explained by the model of swelling. As for 321 steel, no cavities were found under HVEM until 6 dpa at 500 C. This suggests the effect of scavenging of nitrogen by Ti. ((orig.))

  1. Ethanol-induced swelling in neonatal rat primary astrocyte cultures.

    Science.gov (United States)

    Aschner, M; Allen, J W; Mutkus, L A; Cao, C

    2001-05-11

    We tested the hypothesis that astrocytes swell in response to ethanol (EtOH) exposure. The experimental approach consisted of an electrical impedance method designed to measure cell volume. In chronic experiments, EtOH (100 mM) was added to the culture media for 1, 3, or 7 days. The cells were subsequently exposed for 15 min to isotonic buffer (122 mM NaCl) also containing 100 mM EtOH. Subsequently, the cells were washed and exposed to hypotonic buffer (112 mM NaCl) containing 100 mM mannitol. Chronic exposure to EtOH led to a marked increase in cell volume compared with control cells. Specific anion cotransport blockers, such as SITS, DIDS, furosemide, or bumetanide, when simultaneously added with EtOH to hyponatremic buffer, failed to reverse the EtOH-induced effect on swelling. In acute experiments, confluent neonatal rat primary astrocyte cultures were exposed to isotonic media (122 mM NaCl) for 15 min, followed by 45-min exposure to hypotonic media (112 mM NaCl, mimicking in vivo hyponatremic conditions associated with EtOH withdrawal) in the presence of 0-100 mM EtOH. This exposure led to a concentration-dependent increase in cell volume. Combined, these studies suggest that astrocytes exposed to EtOH accumulate compensatory organic solutes to maintain cell volume, and that in response to hyponatremia and EtOH withdrawal their volume increases to a greater extent than in cells exposed to hyponatremia alone. Furthermore, the changes associated with EtOH are osmotic in nature, and they are not reversed by anion cotransport blockers.

  2. Midface swelling reveals nasofrontal dermal sinus

    International Nuclear Information System (INIS)

    Houneida, Zaghouani Ben Alaya; Manel, Limeme; Latifa, Harzallah; Habib, Amara; Dejla, Bakir; Chekib, Kraiem

    2012-01-01

    Nasofrontal dermal sinuses are very rare and generally occur in children. This congenital malformation can be revealed by midface swelling, which can be complicated by local infection or neuromeningitis. Such complications make the dermal sinus a life-threatening disease. Two cases of nasofrontal dermal sinuses are reported in this work. The first case is an 11-month-old girl who presented with left orbitonasal soft tissue swelling accompanied by inflammation. Physical examination found fever, left orbitonasal thickening, and a puncture hole letting out pus. Computed tomography revealed microabscesses located at the left orbitonasal soft tissues, a frontal bone defect, and an intracranial cyst. Magnetic resonance imaging showed the transosseous tract between the glabella and the brain and affirmed the epidermoid nature of the intracranial cyst. The second case is a 7-year-old girl who presented with a nasofrontal non-progressive mass that intermittently secreted a yellow liquid through an external orifice located at the glabella. MRI revealed a cystic mass located in the deep layer of the glabellar skin related to an epidermoid cyst with a nasofrontal dermal sinus tract. In both cases, surgical excision was performed, and pathological confirmation was made for the diagnoses of dermal sinuses. The postoperative course was favorable. Through these cases, the authors stress the role of imaging methods in confirming the diagnosis and looking for associated cysts (dermoid and epidermoid) to improve recognition of this rare disease. Knowledge of the typical clinical presentations, imaging manifestations, and most common sites of occurrence of this malformation are needed to formulate a differential diagnosis.

  3. Effect of gamma irradiation on nylon 6 films : swelling study

    International Nuclear Information System (INIS)

    Singh, L.P.; Chaudhuri, N.K.

    1980-01-01

    This paper reports on swelling studies of γ-irradiated nylon 6 films undertaken to investigate the effects of γ-irradiation in finer details. Benzyl alcohol has been used as the swelling agent. The kinetics of weight swelling of γ-irradiated nylon 6 films in benzyl alcohol was studied at different irradiation doses in the range 0 - 28.8 Mrad. It is observed that with increasing irradiation dose upto 14.4 Mrad the swelling, and hence the diffusion process are retarded; moreover, the sigmoidal nature of the percentage weight swelling vs (time)sup(1/2) plot is augmented. Above this critical dose the swelling and diffusion processes are accelerated. Besides, the sigmoidal behaviour recedes and is converted into linear behaviour at 28.8 Mrad. This behaviour indicates that a relaxation-controlled non-Fickian diffusion process is at work below 28.8 Mrad while at 28.8 Mrad a Fickian process is established. A significant effect on the equilibrium swelling in benzyl alcohol is observed. The plot of equilibrium weight swelling vs irradiation dose at 23deg C shows an initial decrease of swelling upto 3.6 Mrad at which swelling starts decreasing at accelerated rate in the dose range 3.6 - 7.6 Mrad. The rate slows down appreciably between 7.00 and 14.4 Mrad, above which there is a rapid fall. The results are correlated with scission and crosslinking processes through relative viscosity determination of formic acid solutions of the irradiated samples. It is established by combining viscosity data with kinetics and equilibrium swelling data that, besides scission, crosslinking processes are also at work in nylon 6 in the irradiation dose range 0 - 3.6 Mrad. It has been possible to bring out this point because the swelling technique seems to be preferentially sensitive towards crosslinking. (author)

  4. Effects of stress on swelling in reactor fuel cladding

    International Nuclear Information System (INIS)

    Bates, J.F.; Gilbert, E.R.

    1977-01-01

    The purpose of this report is to describe the effect of stress on swelling in both annealed and 20% cold worked 316 stainless steel. An effect of stress on swelling in irradiated metals has been postulated for some time. Low fluence data confirmed that indeed a tensile stress can increase swelling in irradiated annealed 316 stainless steel and that the maximum swelling occurs at an intermediate stress level which is approximately equal to the proportional elastic limit of the material. The specimens discussed above were examined by transmission electron microscopy and an effect of stress on the microstructure of the annealed and 20% cold worked 316 specimens has been observed. Howver, as yet, copious swelling had not occurred in the 20% cold worked material. Specimens of 20% cold worked 316 fabricated from the same heat of material as those described above have now been irradiated to sufficiently high neutron fluences that swelling has occurred in both the annealed and cold worked conditions. Swelling increases linearly with stress for both materials. However, for solution annealed 316, swelling reaches a maximum at approximately 136 MPa, whereupon further increases in stress result in reduced swelling. It is felt that this reduction in swelling is related to the onset of plastic yielding in the material. The swelling observed in the 20% CW 316 and the solution annealed 316 below the maximum swelling stress can be adequately described by an equation of the form: S = S 0 (1 + Psigma). No strong effect of stress on changing the incubation period associated with void nucleation was found. (Auth.)

  5. Reassessment of the swelling behavior of AISI 304 stainless steel

    International Nuclear Information System (INIS)

    Garner, F.A.; Porter, D.L.

    1982-03-01

    Published swelling data derived from EBR-II irradiations of AISI 304 and 304L have been reanalyzed in light of insights gained from irradiation of AISI 316 and Fe-15Cr-25Ni. The primary influence of temperature, displacement rate and compositional variations in the 300 series stainless steels lies in the duration of the transient regime of swelling and not in the steady-state or constant swelling rate regime

  6. Helium-induced blistering and volume swelling in nickel

    International Nuclear Information System (INIS)

    Fenske, G.R.

    1980-01-01

    The results of an experimental investigation of helium-induced blistering are presented. The goal of the research was to examine the mechanisms involved in blistering by observing the microstructure of the implanted region using transmission electron microscopy (TEM). In particular, the volume swelling was measured as a function of the implant depth, and compared to experimental skin thicknesses in order to determine if the skin separated at the maximum volume swelling, or at the end of the swelling profile

  7. The swelling of nucleons in nuclei and the Roper resonance

    International Nuclear Information System (INIS)

    Desplanques, B.

    1988-01-01

    Conditions where some swelling of the nucleon occurs, and, in particular the relation of this effect with the attractive character of the force acting on it, are studied. It is found that short range repulsive correlations can turn the swelling into a shrinking, in spite of a globally attractive interaction, whereas repulsive velocity dependent forces can lead to some swelling. The role of the Roper resonance in this nucleon change of size is considered in some detail

  8. Swelling behavior of titanium-modified AISI 316 alloys

    International Nuclear Information System (INIS)

    Garner, F.A.; Brager, H.R.; Puigh, R.J.

    1984-01-01

    It appears that titanium additions to stainless steels covering a wide compositional range around the specifications of AISI 316 result only in an increased delay period before neutron-induced void swelling proceeds. Once swelling is initiated the post transient behavior of both annealed and cold-worked titanium-modified steels is quite consistent with that of AISI 316, approaching a relatively temperature-independent swelling rate of approx. 1% per dpa

  9. Tracking the attenuation and nonbreaking dissipation of swells using altimeters

    Science.gov (United States)

    Jiang, Haoyu; Stopa, Justin E.; Wang, He; Husson, Romain; Mouche, Alexis; Chapron, Bertrand; Chen, Ge

    2016-02-01

    A method for systematically tracking swells across oceanic basins is developed by taking advantage of high-quality data from space-borne altimeters and wave model output. The evolution of swells is observed over large distances based on 202 swell events with periods ranging from 12 to 18 s. An empirical attenuation rate of swell energy of about 4 × 10-7 m-1 is estimated using these observations, and the nonbreaking energy dissipation rates of swells far away from their generating areas are also estimated using a point source model. The resulting acceptance range of nonbreaking dissipation rates is -2.5 to 5.0 × 10-7 m-1, which corresponds to a dissipation e-folding scales of at least 2000 km for steep swells, to almost infinite for small-amplitude swells. These resulting rates are consistent with previous studies using in-situ and synthetic aperture radar (SAR) observations. The frequency dispersion and angular spreading effects during swell propagation are discussed by comparing the results with other studies, demonstrating that they are the two dominant processes for swell height attenuation, especially in the near field. The resulting dissipation rates from these observations can be used as a reference for ocean engineering and wave modeling, and for related studies such as air-sea and wind-wave-turbulence interactions.

  10. Intraplate seismicity across the Cape Verde swell

    Science.gov (United States)

    Vales, Dina; Matias, Luís.; Haberland, Christian; Silveira, Graça.; Weber, Michael; Carrilho, Fernando; Dias, Nuno

    2010-05-01

    The Cape Verde Archipelago ((15-17°N, 23-26°W) is located within the African plate, about 500km west of Senegal, in the African coast. The islands are located astride the Cape Verde mid-plate topographic swell, one of the largest features of its type in the world's ocean basins. The origin of this Cape Verde swell is still in debate. Previous determinations of the elastic thickness (Te) reveal a normal Te and a modest heat flow anomaly which suggest that the swell cannot be fully explained by uplift due to thermal reheating of the lithosphere by an underlying ‘‘hot spot'' and that other, deep-seated, mantle processes must be involved. The CV-PLUME (An investigation on the geometry and deep signature of the Cape Verde mantle plume) project intends to shape the geometry and deep origin of the Cape Verde mantle plume, via a combined study of seismic, magnetic, gravimetric and geochemical observations. Through this study we intend to characterize the structure beneath the archipelago from the surface down to the deep mantle. The core of this 3-year project was a temporary deployment of 39 Very Broad Band seismometers, across all the inhabited islands, to recorder local and teleseismic earthquakes. These instruments were operational from November 2007 to September 2008. In this work we report on the preliminary results obtained from the CV-PLUME network on the characterization of the local and regional seismicity. To detect the small magnitude seismic events the continuous data stream was screened using spectrograms. This proved to be a very robust technique in the face of the high short-period noise recorded by many of the stations, particularly during day time. The 10 month observation time showed that the background seismic activity in the Archipelago and surrounding area is low, with only a very few events recorded by the complete network. However, two clusters of earthquakes were detected close to the Brava Island, one to the NW and a second one, more active

  11. Effect of heating and pore water salinity on the swelling characteristics of bentonite buffer

    International Nuclear Information System (INIS)

    Dhawan, Sarita; Rao, M. Sudhakar

    2010-01-01

    Document available in extended abstract form only. Changes in swell potential of bentonite-sand mixture as a function of temperature and pore water salinity were measured. Bentonite dried at 105 deg. C and sand was mixed in 50:50 ratio by weight for study. The bentonite sand mix was compacted to 1.83 Mg/m 3 dry density and 13.8% water content (mixed with distilled water) obtained from Modified proctor compaction test for all test conditions. For the first series, the mix was prepared using distilled water as molding fluid. The compacted samples were dried at temperatures 50 deg. C and 80 deg. C for time periods 2 to 45 days. Dried samples were assembled in oedometer cells and allowed to swell under load of 6.25 kPa. In second series, bentonite sand mixes were prepared with 1000 ppm Na, 1000 ppm K, 1000 ppm Ca and 1000 ppm Mg solutions using chloride salts to achieve water content of 13.8%. The mixes were then compacted and dried at 80 deg. C for 15 days and allowed to swell in oedometer assembly. In third series of experiments, bentonite sand mix were compacted with distilled water as molding fluid and heated at 80 deg. C for 15 days. The dried samples were then swollen inundating with solutions simulating less saline granitic ground water and a moderately saline groundwater. The swell behavior is compared with samples without heating treatment. For samples prepared with distilled water and heated, the swell potential reduced up to 10-28% on heating compared to sample without any heating. The swell reduction varied depending on temperature and time period. The volumetric shrinkage varied from 1.4 to 3.3% of original volume of compacted sample on heating. Addition of sand was found effective in controlling shrinkage caused by heating. For samples prepared with salt solutions with no heating and inundated with distilled water for swell, the swell potential reduced from 12-20% compared to sample mixed and inundated with distilled water. The reduction in swell

  12. Molar Intubation for Intra Oral Swellings:Our Experience

    Directory of Open Access Journals (Sweden)

    Meenoti Potdar

    2008-01-01

    Full Text Available Molar intubation is a technique of laryngoscopy that can be used for anticipated difficult intubation in cases where standard laryngoscopy technique is difficult due to presence of any intraoral mass that anatomically hampers laryngoscopy or that bleeds on touch. This technique is very easy, reliable and rewarding but should be practiced on normal patients for easy application in actual difficult cases.

  13. Irradiation creep and void swelling of two LMR heats of HT9 at ∝400 C and 165 dpa

    International Nuclear Information System (INIS)

    Toloczko, M.B.; Garner, F.A.

    1996-01-01

    Two nominally identical heats of HT9 ferritic-martensitic steel were produced, fabricated into pressurized tubes, and then irradiated in FFTF, using identical procedures. After reaching 165 dpa at ∝400 C, small differences in strains associated with both phase-related changes in lattice parameter and void swelling were observed in comparing the two heats. The creep strains, while different, exhibited the same functional dependence on swelling behavior. The derived creep coefficients, the one associated with creep in the absence of swelling and the one directly responsive to swelling, were essentially identical for the two heats. Even more significantly, the creep coefficients for this bcc ferritic-martensitic steel appear to be very similar and possibly identical to those routinely derived from creep experiments on fcc austenitic steels. (orig.)

  14. Irradiation creep and void swelling of two LMR heat of HT9 at ∼400 degrees C and 165 dpa

    International Nuclear Information System (INIS)

    Toloczko, M.B.; Garner, F.A.

    1996-01-01

    Two nominally identical heats of HT9 ferritic-martensitic steel were produced, fabricated into pressurized tubes, and then irradiated in FFTF, using identical procedures. After reaching 165 dpa at ∼400C, small differences in strains associated with both phase-related change in lattice parameter and void swelling were observed in comparing the two heats. The creep strains, while different, exhibited the same functional relationship to the swelling behavior. The derived creep coefficients, the one associated with creep in the absence of swelling and the one directly responsive to swelling, were essentially identical for the two heats. Even more significantly, the creep coefficients for this bcc ferritic-martensitic steel appear to be very similar and possibly identical to those routinely derived from creep experiments on fcc austenitic steels

  15. Effect of Lime on characteristics of consolidation, strength, swelling and plasticity of fine grained soil

    Science.gov (United States)

    Estabragh, A. R.; Bordbar, A. T.; Parsaee, B.; Eskandari, Gh.

    2009-04-01

    Using Lime as an additive material to clayey soil is one of the best effective technique in building the soil structures to get some purposes such as soil stabilization, soil reinforcement and decreasing soil swelling. In this research the effect of Lime on geotechnical characteristics of a clayey soil was investigated. Soil specimen types used in this study were consisted of clayey soil as the control treatment and clay mixed with different weight fractions of lime, 4, 6, 8 & 10 percent. Some experiments such as CBR, atterburg limits, compaction, consolidation and swelling was conducted on specimens. Results revealed that adding lime to soil would change its physical and mechanical properties. Adding lime increase the compression strength and consolidation coefficient and decrease swelling potential and maximum dry density. According to the results, Atterburg experiments show that presence of lime in soil increase the liquid limit of low plasticity soil and decrease the liquid limit of high plasticity soil, but totally it decreases the plasticity index of soils. Key words: soil stabilization, lime, compression strength, swelling, atterburg limits, compaction

  16. Thermal effects on granules and direct determination of swelling ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-08-04

    Aug 4, 2009 ... DEA. UAA. Abidjan. Côte d'Ivoire, pp. 25-28. Larrigue S, Alvarez G, Cuvelier G, Flick D (2008). Swelling kinetics of waxy maize and starches at high temperatures and heating rates. Carbohydr. Polym. 73: 148-155. Leach HW, MC Cowen LD, Schoch JJ (1959). Structure of the starch granule swelling and ...

  17. Swelling Characteristics and Tensile Properties of Natural Fiber ...

    African Journals Online (AJOL)

    The swelling behavior and tensile strength of natural fiber-reinforced plastic in premium motor spirit (PMS), dual purpose kerosene (DPK) and sea water have been studied. Composite formed by reinforcing polyester resin with Okam fibers was immersed in the selected solvents for 16 weeks (4 months). Swelling ...

  18. Ageing effects on swelling behaviour of compacted GMZ01 bentonite

    Energy Technology Data Exchange (ETDEWEB)

    Ye, W.M., E-mail: ye_tju@tongji.edu.cn [Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092 (China); United Research Center for Urban Environment and Sustainable Development, the Ministry of Education, China, Shanghai 200092 (China); Lai, X.L.; Liu, Y. [Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092 (China); Chen, Y.G. [Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092 (China); United Research Center for Urban Environment and Sustainable Development, the Ministry of Education, China, Shanghai 200092 (China); Cui, Y.J. [Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092 (China); Ecole des Ponts Paris Tech, UR Navier/CERMES (France)

    2013-12-15

    Highlights: • Ageing effects on compacted GMZ01 bentonite are investigated. • Swelling property decreases with ageing and influenced by initial conditions. • Ageing effects are mainly attributed to the bonding effects and the hydration of smectites. - Abstract: Ageing effects on the swelling properties of compacted GMZ01 bentonite are investigated in this paper. Samples were compacted to prescribed dry densities and water contents and kept for ageing under constant volume and K{sub 0} confined conditions for target days of 0, 1, 7, 15, 30 and 90. Then, swelling deformation and swelling pressure tests were performed on the aged samples. Results indicate that both the swelling deformation and swelling pressure decrease with ageing time, with a more significant decrease at the first few days of ageing. Ageing effects are more pronounced for samples with large dry density and high water content. At the same initial dry density and water content, samples aged under constant volume conditions show much smaller decrease of swelling pressure compared to that of samples aged under K{sub 0} confined conditions. The decrease of swelling potential of samples with ageing days is mainly attributed to the bonding effects and the internal redistribution of water within the bentonite, which was confirmed by the changes of microstructure of samples with ageing.

  19. Prediction of Swelling Behavior of Addis Ababa Expansive Soil ...

    African Journals Online (AJOL)

    In this study a simple hyperbolic mathematical model is used to predict the swelling behavior of an expansive soil from Addis Ababa. The main parameters that are needed to run the model are the applied pressure and initial dry density. The other parameters of the model including the initial slope of the swell-time curve, the ...

  20. Neurofibromas as bilateral cystic chest wall swellings. | Ugare ...

    African Journals Online (AJOL)

    A 35 year old male farmer presented with soft bilateral posterior chest wall swellings. He had no similar swellings elsewhere. There were no associated symptoms, except cosmetic deformity and discomfort when he lies on his back. A clinical diagnosis of posterior chest wall lipomata was made. However at surgery, the two ...

  1. Spectral partitioning and swells in the black sea

    NARCIS (Netherlands)

    van Vledder, G.P.; Akpınar, Adem; Lynett, P.

    2016-01-01

    The swell climate of the Black Sea has been determined using a long-term 31-year wave hindcast with the thirdgeneration spectral wave model SWAN in combination with spectral partitioning. This technique enables decomposing wave spectra into individual wave systems representing wind seas or swells

  2. Partial swelling of latex particles by two monomers

    NARCIS (Netherlands)

    Noel, E.F.J.; Maxwell, I.A.; German, A.L.

    1993-01-01

    The swelling of polymeric latex particles with solvent and monomer is of great importance for the emulsion polymn. process in regard to compn. drift and rate of polymn. For the monomer combination, Me acrylate-vinyl acetate, both satn. and partial swelling were detd. exptl. Theories for satn.

  3. Theory of void swelling, irradiation creep and growth

    International Nuclear Information System (INIS)

    Wood, M.H.; Bullough, R.; Hayns, M.R.

    Recent progress in our understanding of the fundamental mechanisms involved in swelling, creep and growth of materials subjected to irradiation is reviewed. The topics discussed are: the sink types and their strengths in the lossy continuum; swelling and void distribution analysis, including recent work on void nucleation; and, irradiation creep and growth of zirconium and zircaloy are taken as an example

  4. Odontogenic facial swelling of unknown origin.

    Science.gov (United States)

    Ranjitkar, S; Cheung, W; Yong, R; Deverell, J; Packianathan, M; Hall, C

    2015-12-01

    Current radiography techniques have limitations in detecting subtle odontogenic anomalies or defects that can lead to dentoalveolar and facial infections. This report examines the application of micro-CT imaging on two extracted teeth to enable detailed visualization of subtle odontogenic defects that had given rise to facial swelling. Two extracted non-carious mandibular left primary canine teeth (73) associated with odontogenic infections were selected from two patients, and an intact contralateral tooth (83) from one of the patients was used as a control. All three teeth were subjected to three-dimensional micro-CT imaging at a resolution of 20 μm. Tooth 73 from the first case displayed dentine pores (channels) that established communication between the pulp chamber and the exposed dentine surface. In comparison, tooth 73 from the second case had a major vertical crack extending from the external enamel surface into the pulp chamber. The control tooth did not display any anomalies or major cracks. The scope of micro-CT imaging can be extended from current in vitro applications to establish post-extraction diagnosis of subtle odontogenic defects, in a manner similar to deriving histopathological diagnoses in extracted teeth. Ongoing technological advancements hold the promise for more widespread translatory applications. © 2015 Australian Dental Association.

  5. Swelling and outgassing of heavily-irradiated lithium hydride

    International Nuclear Information System (INIS)

    Souers, P.C.; Ackerman, F.J.; Biel, T.J.; Bigwood, J.; Brite, V.; Christensen, L.D.; Folkers, C.L.; Gede, V.; Griffith, C.M.; Huss, E.B.; Lindahl, R.; McCreary, T.; Otsuki, H.H.; Pond, R.L.; Snider, G.D.; Stanhope, C.; Stump, R.K.; Vanderhoofven, F.; Tsugawa, R.T.; Anderson, J.L.; Carstens, D.W.H.; Drumhiller, W.L.; Lewis, W.B.; Nasise, J.E.; Pretzel, F.E.; Szklarz, E.G.; Vier, D.T.; Bowman, R.C. Jr.; Attalla, A.

    1988-01-01

    Twenty-two years worth of data on lithium deuteride-tritide (Li(D, T)) from three national laboratories is presented. The percent linear swelling and the outgassing of hydrogen isotopes and 3 He for samples stored at 243 to 438 K are presented in summary tables. In some cases, up to a full half-life of tritium (12 years) has been spent in the study. Initial tritium concentrations range from 2 to 98 at%. The precision of the swelling is considered, and the evidence is ambiguous as to whether temperature cycling and handling affects swelling. The early outgassing is all hydrogen, but it turns to helium at long lines. The outgassing levels out for each sample but the amount outgassed varies wildly from sample to sample. At linear swellings beyond 11%, behavior becomes erratic. A maximum linear swelling of 23% is seen for one sample at 5000 days. (orig.)

  6. Use of additive material to stabilize the soil swelling

    Science.gov (United States)

    Parsaee, B.; Estabragh, A. R.; Bordbar, A. T.; Eskandari, G. H.

    2009-04-01

    Change volume increasing of soil, because of increase in its humidity content causes appearing of swelling phenomenon in the soil. This phenomenon has created a lot of damages in the building which is constructed on this kind of soils. Usage the additive materials which stabilize the swelling, has been the subject of many researches. In this research the Potential expansibility of the expansive soils, which were stabilized by additive materials such as Lime, cement and coal ash, was investigated. To get this purpose, by preparing soil samples mixed with upper additive material, changes of potential swelling of stabilized soils were compared. The results revealed that usage of these stabilizing materials caused the decrease in destructive effects due to swelling of soils to some extent. Keywords: swelling, soil stabilizing, additive material, coal ash

  7. Study of 316 stainless steel swelling due to neutron irradiation

    International Nuclear Information System (INIS)

    Furutani, Gen; Konishi, Takao

    2000-01-01

    Large stresses will be generated in the austenitic stainless steel core internals of pressurized water reactors (PWRs) if excessive swelling occurs after long periods of operation. As a result, deformation or stress corrosion cracking (SCC) could occur in the core internals. However, data on the swelling of irradiated austenitic stainless steel in actual PWRs is limited. In this study, mechanical tests, measurement of produced helium amount and analysis using transmission electron microscopes were carried out on a cold-worked (CW) 316 stainless steel flux thimble tube irradiated up to approximately 35 dpa in a Japanese PWR. The swelling was evaluated to be approximately 0.02%. This level of swelling was much lower than the swelling of the more than several percent that has been observed in fast breeder reactors. (author)

  8. Swelling of the buffer of KBS-3V deposition hole

    International Nuclear Information System (INIS)

    Lempinen, A.

    2006-12-01

    At the time of the installation of spent nuclear fuel canister in the KBS-3V deposition hole, empty space is left around bentonite buffer for technical reasons. The gap between the buffer and the canister is about 10 mm, and the gap between the buffer and the rock is 30 to 35 mm. In this study, the swelling of the buffer to fill the gaps was simulated, when the gaps are initially filled with water and no external water is available. The model used here is a thermodynamical model for swelling clay, with parameters determined for bentonite. The simulations presented here were performed with Freefem++ software, which is a finite element application for partial differential equations. These equations come from the material model. The simulation results show that the swelling fills the outer gaps in few years, but no significant swelling pressure is generated. For swelling pressure, external water supply is required. (orig.)

  9. Thyroid swellings in the art of the Italian Renaissance.

    Science.gov (United States)

    Sterpetti, Antonio V; De Toma, Giorgio; De Cesare, Alessandro

    2015-09-01

    Thyroid swellings in the art of the Italian Renaissance are sporadically reported in the medical literature. Six hundred paintings and sculptures from the Italian Renaissance, randomly selected, were analyzed to determine the prevalence of personages with thyroid swellings and its meaning. The prevalence of personages with thyroid swellings in the art of Italian Renaissance is much higher than previously thought. This phenomenon was probably secondary to iodine deficiency. The presence of personages with thyroid swelling was related to specific meanings the artists wanted to show in their works. Even if the function and the role of the thyroid were discovered only after thyroidectomy was started to be performed, at the beginning of the 19th century, artists of the Italian Renaissance had the intuition that thyroid swellings were related to specific psychological conditions. Artistic intuition and sensibility often comes before scientific demonstration, and it should be a guide for science development. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Study on the saturating and swelling behavior of an engineering bentonite barrier using a test model

    International Nuclear Information System (INIS)

    Nakajima, Makoto; Kobayashi, Ichizo; Toida, Masaru; Fujisaki, Katsutoshi

    2007-01-01

    The conceptual design of a disposal facility with additional buffer depth for radioactive waste is mainly constituted from the multi-barrier system that is constructed around the waste form so that it prevents radionuclide transfer to the biosphere. The engineered bentonite barrier is one of the elements of the multi-barrier system and is constructed with homogeneous bentonite-containing material compacted to a high density so that there are no voids. Due to the swelling characteristics of the bentonite material, the self-sealing function which is an important function of the bentonite barrier can work, but at the same time it mechanically affects the neighboring structures. Therefore, an experimental study was implemented in order to evaluate the mechanical effect of the bentonite swelling behavior throughout the construction, emplacement operations and closure re-saturation phase. In this article, the results of swelling tests to obtain the mechanical properties of the bentonite and three types of test model experiments performed for the event observations in the different saturation processes are described. As a result, the effects of a seepage pattern of ground water and a variation in the density produced by construction on the swelling pressure distribution of the bentonite barrier could be reproduced and validated. It is thought that they will be important events when ground water permeates the bentonite layer of a multiple barrier system. (author)

  11. Swelling of austenitic iron-nickelchromium ternary alloys during fast neutron irradiation

    International Nuclear Information System (INIS)

    Garner, F.A.; Brager, H.R.

    1984-01-01

    Swelling data are now available for 15 iron-nickel-chromium ternary alloys irradiated to exposures as high as 110 displacements per atom (dpa) in Experimental Breeder Reactor-II (EBR-II) between 400 and 650 0 C. These data confirm trends observed at lower exposure levels and extend the generality of earlier conclusions to cover a broader range of composition and temperature. It appears that all austenitic iron-nickel-chromium ternary alloys eventually approach an intrinsic swelling rate of about1%/dpa over a range of temperature even wider than studied in this experiment. The duration of the transient regime that precedes the attainment of this rate is quite sensitive to nickel and chromium content, however. At nickel and chromium levels typical of 300 series steels, swelling does not saturate at engineering-relevant levels. However, there appears to be a tendency toward saturation that increases with declining temperature, increasing nickel and decreasing chromium levels. Comparisons of these results are made with those of similar studies conducted with charged particles. Conclusions are then drawn concerning the validity of charged particle simulation studies to determine the compositional and temperature dependence of swelling

  12. Irradiation creep and swelling of AISI 316 to exposures of 130 dpa at 385?400$deg;C

    Science.gov (United States)

    Garner, F. A.; Porter, D. L.

    1988-07-01

    The creep and swelling of AISI 316 stainless steel have been studied at 385 to 400°C in EBR-II to doses of 130 dpa. Most creep capsules were operated at constant stress and temperature but mid-life changes in these variables were also made. This paper concentrates on the behavior of the 20% cold-worked condition but five other conditions were also studied. Swelling at ⩽ 400° C was found to lose the sensitivity to stress exhibited at higher temperatures while the creep rate was found to retain linear dependencies on both stress and swelling rate. The creep coefficients extracted at 400°C agree with those found in other experiments conducted at higher temperatures. In the temperature range of ⩽ 400° C, swelling is in the recombinationdominated regime and the swelling rate falls strongly away from the ~1%/dpa rate observed at higher temperatures. These lower rates of creep and swelling, coupled with the attainment of high damage levels without failure, encourage the use of AISI 316 in the construction of water-cooled fusion first walls operating at temperatures below 400°C.

  13. Swelling of structural materials in fast neutron reactors

    International Nuclear Information System (INIS)

    Seran, J.L.

    1983-06-01

    The physical origin of swelling in irradiated materials and the main parameters acting on swelling of SS 316 are examined: temperature, neutron dose, dose rate, chemical composition, strain hardening. Results obtained, in Rapsodie and Phenix reactors, with fuel cans and with the hexagonal tube containing the fuel pins are analyzed and compared with results found in litterature. In conclusion hot swelling of SS 316 is too important at high doses and is will be replaced by austenitic steels stabilized by Ti and ferritic steels or high nickel steels with structural hardening [fr

  14. Swelling on the inner aspect of the lower lip

    Directory of Open Access Journals (Sweden)

    Irfan Mohamad

    2014-08-01

    Full Text Available A 14-year-old man presented with 1-month history of swelling on the inner aspect of his lower lip. The swelling was painless; however, it disturbed his speech. There was no contact bleeding but had a positive history of habitual lip biting. Examination showed a single 0.5 × 1 cm2 soft oval-shaped swelling with well-circumscribed margin (Figures 1 and 2. On palpation, the mass was non-tender and had a cystic or fluctuant sensation.

  15. Influence of network topology on the swelling of polyelectrolyte nanogels.

    Science.gov (United States)

    Rizzi, L G; Levin, Y

    2016-03-21

    It is well-known that the swelling behavior of ionic nanogels depends on their cross-link density; however, it is unclear how different topologies should affect the response of the polyelectrolyte network. Here we perform Monte Carlo simulations to obtain the equilibrium properties of ionic nanogels as a function of salt concentration Cs and the fraction f of ionizable groups in a polyelectrolyte network formed by cross-links of functionality z. Our results indicate that the network with cross-links of low connectivity result in nanogel particles with higher swelling ratios. We also confirm a de-swelling effect of salt on nanogel particles.

  16. The rf-power dependences of the deposition rate, the hardness and the corrosion-resistance of the chromium nitride film deposited by using a dual ion beam sputtering system

    International Nuclear Information System (INIS)

    Lim, Jongmin; Lee, Chongmu

    2006-01-01

    The hexavalent chromium used in chromium plating is so toxic that it is very hazardous to human body and possibly causes cancer in humans. Therefore, it is indispensable to develop an alternative deposition technique. Dependences of the deposition rate, the phases, the hardness, the surface roughness and the corrosion-resistance of CrN x deposited on the high speed steel substrate by using a dual ion beam sputtering system on the rf-power were investigated to see the feasibility of sputtering as an alternative technique for chromium plating. The dual ion beam sputtering system used in this study was designed in such a way as the primary argon ion beam and the secondary nitrogen ion beam are injected toward the target and the substrate, respectively so that the chromium atoms at the chromium target surface may not nearly react with nitrogen atoms. The hardness and the surface roughness were measured by a micro-Vicker's hardness tester and an atomic force microscope (AFM), respectively. X-ray diffraction analyses were performed to identify phases in the films. The deposition rate of CrN x depends more strongly upon the rf-power for argon ion beam than that for nitrogen ion beam. The hardness of the CrN x film is highest when the volume percent of the Cr 2 N phase in the film is highest. Amorphous films are obtained when the rf-power for nitrogen ion beam is much higher than that for argon ion beam. The CrN x film deposited by using the sputtering technique under the optimal condition provides corrosion-resistance comparable to that of the electroplated chromium

  17. Nucleon swelling and the Nolen-Schiffer anomaly

    International Nuclear Information System (INIS)

    Epele, L.N.; Garcia Canal, C.A.; Fanchiotti, H.; Mendez Galain, R.

    1987-01-01

    A previously proposed explanation of the Nolen-Schiffer anomaly based on the nucleon swelling inside a nuclei is reanalyzed. We found a clear incompatibility beetween this proposal and the experimental results. (orig.)

  18. Fission induced swelling of U–Mo/Al dispersion fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeon Soo, E-mail: yskim@anl.gov [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Jeong, G.Y. [Ulsan National Institute of Science and Technology, 50 UNIST-gil, Eonyang-eup, Uljoo-gun, Ulsan 689-798 (Korea, Republic of); Park, J.M. [Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Robinson, A.B. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States)

    2015-10-15

    Fission-induced swelling of U–Mo/Al dispersion fuel meat was measured using microscopy images obtained from post-irradiation examination. The data of reduced-size plate-type test samples and rod-type test samples were employed for this work. A model to predict the meat swelling of U–Mo/Al dispersion fuel was developed. This model is composed of several submodels including a model for interaction layer (IL) growth between U–Mo and Al matrix, a model for IL thickness to IL volume conversion, a correlation for the fission-induced swelling of U–Mo alloy particles, a correlation for the fission-induced swelling of IL, and models of U–Mo and Al consumption by IL growth. The model was validated using full-size plate data that were not included in the model development.

  19. Postoperative Submandibular Gland Swelling following Craniotomy under General Anesthesia

    Directory of Open Access Journals (Sweden)

    Haruka Nakanishi

    2015-01-01

    Full Text Available Objective. Reporting of a rare case of postoperative submandibular gland swelling following craniotomy. Case Report. A 33-year-old male underwent resection for a brain tumor under general anesthesia. The tumor was resected via a retrosigmoid suboccipital approach and the patient was placed in a lateral position with his face down and turned to the right. Slight swelling of the right submandibular gland was observed just after the surgery. Seven hours after surgery, edematous change around the submandibular gland worsened and he required emergent reintubation due to airway compromise. The cause of submandibular gland swelling seemed to be an obstruction of the salivary duct due to surgical positioning. Conclusion. Once submandibular swelling and edematous change around the submandibular gland occur, they can worsen and compromise the air way within several hours after operation. Adequate precaution must be taken for any predisposing skull-base surgery that requires strong cervical rotation and flexion.

  20. Splenogonadal fusion: a forgotten cause of testicular swelling in ...

    African Journals Online (AJOL)

    swelling in children. Mohamad ... report describes a 25-month-old male child who presented with left .... conditions such as mumps, malaria, leukemia, trauma, and ... Splenogonadal fusion and testicular cancer: case report and review of.

  1. Mechanism of disintegrant action of polacrilin potassium: Swelling or wicking?

    Directory of Open Access Journals (Sweden)

    Mrudula Hemant Bele

    2012-02-01

    Full Text Available The effect of particle size, pH of medium, and presence of lubricant on the swelling behaviour, water uptake properties and disintegrant performance of polacrilin potassium was examined. Particle size did not affect the bulk swelling of disintegrant particles when measured as settling volume, but increased the water uptake and decreased the disintegration time of tablets containing this disintegrant. An increase in the pH of the medium from acidic to neutral increased the bulk swelling of the particles, whereas it decreased water uptake and disintegrant performance. Addition of lubricant had no effect on settling volume, but decreased the water uptake rate and the disintegrant performance significantly. It is concluded that wicking, i.e. capillary action, rather than swelling, is the major factor that contributes to the disintegration behaviour of polacrilin potassium.

  2. Clozapine- induced recurrent and transient parotid gland swelling

    African Journals Online (AJOL)

    effect of clozapine, may sometimes cause salivary gland swelling. Rarely, the ... side effect of clozapine to the attention of clinicians is to discuss its pathogenesis. Informed ... selective muscarinic M4 receptor agonist. Eur J Pharmacol 1994;.

  3. swelling characteristics and tensile properties of natural fiber rei

    African Journals Online (AJOL)

    USER

    The swelling behavior and tensile strength of natural fiber-reinforced plastic in premium motor spirit (PMS), dual ... with fibers usually of glass fiber, Kevlar and carbon have gained ... NIGERIAN JOURNAL OF TECHNOLOGY, VOL. 27 NO.2 ...

  4. Swelling and microstructure of neutrons irradiated 316 Ti SS

    International Nuclear Information System (INIS)

    Seran, J.L.; Le Naour, L.; Grosjean, P.; Hugon, M.P.; Carteret, Y.; Maillard, A.

    1984-06-01

    The analysis of the behaviour of fuel pins irradiated in the same RAPSODIE subassembly, shows that titanium has a marked beneficial effect on the swelling resistance of CW 316 SS in a large range of temperature. This effect is particularly visible at high temperature since CW 316 Ti SS does not swell above 550 0 C up to a dose of 100 French dpa. The results obtained on samples irradiated in a RAPSODIE experimental rig give us confirmation of the good behaviour of CW 316 Ti SS which swells less and at smaller temperature than the other steels of the 316 series such as SA 316 Ti or aged SA 316 Ti. The swelling differences between some of these materials can be associated to different microstructures which are also very different from the ones obtained on the irradiated steels aged in the same time and temperature conditions

  5. Influence of cold work to increase swelling of pure iron irradiated in the BR-10 reactor to ∼6 and ∼25 dpa at ∼400 deg. C

    International Nuclear Information System (INIS)

    Dvoriashin, A.M.; Porollo, S.I.; Konobeev, Yu.V.; Garner, F.A.

    2000-01-01

    Irradiation of pure iron in several starting conditions at 400 deg. C has been conducted in the BR-10 fast reactor. Contrary to expectations, cold working appears to significantly accelerate the onset of void swelling. When compared to a similar experiment conducted in this reactor at the same time, it appears that iron experiences a rather long transient duration before the onset of steady-state swelling. The transient appears to be shortened by both cold-working and lower atomic displacement rates

  6. Lepromatous leprosy presenting as a swelling in the neck

    Directory of Open Access Journals (Sweden)

    Dogra Devraj

    1999-01-01

    Full Text Available A 25-year-old electrician presented with gradually, asymptomatic swelling on left of the neck since 2 years. The swelling which was initially diagnosed as cervical lymphadenitis by the internist represented the enlarged left great auricular nerve. Cutaneous examination revealed an ill-defined, hypoaesthetic macule with minimal atrophy on the pinna of the left ear. The histopathology of the nerve showed a lepromatous neuritis with bacteriological index (BI of 5+.

  7. Detailed analysis of uranium silicide dispersion fuel swelling

    International Nuclear Information System (INIS)

    Hofmann, G.L.; Ryu, Woo-Seog

    1991-01-01

    Swelling of U 3 Si and U 3 Si 2 is analyzed. The growth of fission gas bubbles appears to be affected by fission rate, fuel loading, and micro structural change taking place in the fuel compounds during irradiation. Several mechanisms are explored to explain the observations. The present work is aimed at a better understanding of the basic swelling phenomenon in order to accurately model irradiation behavior of uranium silicide dispersion fuel. (orig.)

  8. Swelling behavior of manganese-bearing AISI 216 steel

    International Nuclear Information System (INIS)

    Gelles, D.S.; Garner, F.A.

    1984-01-01

    The inclusion of 8.5 wt % manganese in AISI 216 does not appear to alter the swelling behavior from that found to be typical of austenitic alloys with comparable levels of other austentite-stabilizing elements. The swelling in AISI 216 in EBR-II is quite insensitive to irradiation temperature in the range 400-650 0 C. Microscopy reveals that this may arise from the low level of precipitation that occurs in the alloy

  9. Radiation swelling of steels with lath martensite-austenic structure

    International Nuclear Information System (INIS)

    Sagaradze, V.V.; Pavlov, V.A.; Alyab'ev, V.M.; Lapin, S.S.; Ermishkin, V.A.; Antonova, O.V.

    1987-01-01

    Influence of electron radiation in the column of the JEM-1000 electron microscope on radiation swelling of austenite as austenitic fields and thin plates surrounded by α-martensite crystals is investigated. Formation of lath structure of alternating dispersive plates of martensite and invert austenite formed as a result of partial inverse martensite transformation α→γ is shown to restrain radiation swelling and formation of vacancy voids in stainless steels

  10. Stress-affected microstructural development and creep-swelling interrelationship

    International Nuclear Information System (INIS)

    Brager, H.R.; Garner, F.A.; Gilbert, E.R.; Flinn, J.E.; Wolfer, W.G.

    1977-05-01

    Macroscopic measurement of the deformations arising from swelling and creep during neutron irradiation indicate that both processes are dependent on the magnitude and possibly the sign of the applied stress state. Current modeling efforts also indicate that a strong interaction exists between swelling and creep through the stress state. Because the macroscopic distortions arise from the integrated microscopic strains associated with specific microstructural elements, the effect of applied stress on microstructural development has been studied

  11. Detailed analysis of uranium silicide dispersion fuel swelling

    International Nuclear Information System (INIS)

    Hofman, G.L.; Ryu, Woo-Seog.

    1989-01-01

    Swelling of U 3 Si and U 3 Si 2 is analyzed. The growth of fission gas bubbles appears to be affected by fission rate, fuel loading, and microstructural change taking place in the fuel compounds during irradiation. Several mechanisms are explored to explain the observations. The present work is aimed at a better understanding of the basic swelling phenomenon in order to accurately model irradiation behavior of uranium silicide disperson fuel. 5 refs., 10 figs

  12. Mechanical and swelling behaviour of well characterized polybutadiene networks

    Science.gov (United States)

    Mckenna, Gregory B.; Hinkley, Jeffrey A.

    1986-01-01

    Endlinking of hydroxyl-terminated polybutadiene with the appropriate isocyanate has been used to prepare well characterized networks. Two networks have been studied with molecular weights of the prepolymers being 6100 and 2400 g/mole by g.p.c. Cylindrical specimens were prepared and the derivatives of the stored energy function with respect to the stretch invariants were determined by torque and normal force measurements in torsion. From these data the Valanis-Landel (1967) stored energy function derivatives w-prime(lambda) were determined for both networks. The stored energy function for the junction constraint model of Flory (1953, 1977, 1979, 1985) which is a special form of the Valanis-Landel function, has been fitted to that determined from the experiments. The contributions to the stored energy function from the phantom network and from the junction constraints respectively do not agree with predictions from the topologies of the networks. In spite of this, the form of w-prime(lambda) for the junction constraint model gives an excellent 'curve fit' to the data. Comparison is also made with equilibrium swelling.

  13. Research on swelling clays and bitumen as sealing materials for radioactive waste repositories

    International Nuclear Information System (INIS)

    Allison, J.A.; Wilson, J.; Mawditt, J.M.; Hurt, J.C.

    1991-01-01

    This report describes a programme of research to investigate the performance of composite seals incorporating adjacent blocks of swelling clay and bitumen. It is shown that the interaction of the materials can promote a self-sealing mechanism which prevents water penetration, even when defects are present in the bitumen layer. A review of the swelling properties of highly compacted bentonite and magnesium oxide is presented, and the characteristic sealing properties of bituminous materials are described. On the basis of this review, it is concluded that bentonite is the preferred candidate material for use in composite clay/bitumen seals for intermediate-level radioactive waste repositories. However, it is thought that magnesium oxide may have other sealing applications for high-level waste repositories. A programme of laboratory experiments is described in which relevant swelling and intrusion properties of highly compacted bentonite blocks and the annealing characteristics of oxidised and hard-grade industrial bitumens are examined. The results of composite sealing experiments involving different water penetration routes are reported, and factors governing the mechanism of self-sealing are described. The validation of the sealing concept at a laboratory scale indicates that composite bentonite/bitumen seals could form highly effective barriers for the containment of radioactive wastes. Accordingly, recommendations are made concerning the development of the research, including the implementation of full-scale demonstration experiments to simulate conditions in an underground repository. 13 tabs., 41 figs., 62 refs

  14. Swelling and infusion of tea in tea bags.

    Science.gov (United States)

    Yadav, Geeta U; Joshi, Bhushan S; Patwardhan, Ashwin W; Singh, Gurmeet

    2017-07-01

    The present study deals with swelling and infusion kinetics of tea granules in tea bags. The swelling and infusion kinetics of tea bags differing in tea loading and tea bag shapes were compared with loose tea. Increment in temperature and dipping frequency of tea bag in hot water increased the infusion kinetics of tea bags. Reduction in particle size enhanced the swelling and infusion kinetics of tea in a tea bag. The effects of tea particle size, tea bag dipping rate, loading of tea granules in tea bag and tea bag shapes on infusion kinetics were investigated. Increase in tea loading in tea bags resulted in reduced infusion kinetics. Double chambered tea bag showed the highest swelling (30%) and infusion kinetics (8.30% Gallic acid equivalence) while single chambered tea bags showed the lowest kinetics, amongst the various bags studied. The swelling and infusion kinetics of loose tea was always faster and higher than that of tea bags. It was found that overall effect of percentage filling of tea granules and height of tea bed in a tea bag affects tea infusion kinetics the most. Weibull model was found to be in good agreement with the swelling data.

  15. Irradiation swelling in self-ion irradiated niobium

    International Nuclear Information System (INIS)

    Bajaj, R.; Shiels, S.A.; Hall, B.O.; Fenske, G.R.

    1987-01-01

    This paper presents initial results of an investigation of swelling mechanisms in a model body centered cubic (bcc) metal, niobium, irradiated at elevated temperatures (0.3 T/sub m/ to 0.6 T/sub m/) where T/sub m/ = melting point in K. The objective of this work is to achieve an understanding of the elevated temperature swelling in bcc metals, which are the prime candidate alloys and composite matrix materials for space reactor applications. Niobium was irradiated with 5.3 MeV Nb ++ ions, at temperatures ranging from 700 0 C to 1300 0 C, to a nominal dose of 50 dpa at a dose rate of 6 x 10 -3 dpas. Swelling was observed over a temperature range of 700 0 C to 1200 0 C, with a peak swelling of 7% at 900 0 C. The microstructural data, obtained from transmission electron microscopy, were compared to the predictions of the theoretical model developed during this program. A reasonable agreement was obtained between the experimental measurements of swelling and theoretical predictions by adjusting both the niobium-oxygen binding energy and the incubation dose for swelling to realistic values

  16. Kinetics of electrically and chemically induced swelling in polyelectrolyte gels

    Science.gov (United States)

    Grimshaw, P. E.; Nussbaum, J. H.; Grodzinsky, A. J.; Yarmush, M. L.

    1990-09-01

    Controlled swelling and shrinking of polyelectrolyte gels is useful for regulating the transport of solutes into, out of, and through these materials. A macroscopic continuum model is presented to predict the kinetics of swelling in polyelectrolyte gel membranes induced by augmentation of electrostatic swelling forces arising from membrane fixed charge groups. The model accounts for ionic transport within the membrane, electrodiffusion phenomena, dissociation of membrane charge groups, intramembrane fluid flow, and mechanical deformation of the membrane matrix. Model predictions are compared with measurements of chemically and electrically induced swelling and shrinking in crosslinked polymethacrylic acid (PMAA) membranes. Large, reversible changes in PMAA membrane hydration were observed after changing the bath pH or by applying an electric field to modify the intramembrane ionic environment and fixed charge density. A relatively slow swelling process and more rapid shrinking for both chemical and electrical modulation of the intramembrane pH are observed. The model indicates that retardation of membrane swelling is dominated by diffusion-limited reaction of H+ ions with membrane charge groups, and that the more rapid shrinking is limited primarily by mechanical processes.

  17. Helium-induced blistering and volume swelling in nickel

    International Nuclear Information System (INIS)

    Fenske, G.R.

    1979-01-01

    The results of an experimental investigation of He-induced blistering are presented. The mechanisms involved in blistering were examined by observing the microstructure of the implanted region using TEM. The volume swelling was measured as a function of the implant depth. The investigation revealed factors important in understanding the mechanisms involved in blister formation. First, a direct comparison of measured skin-thicknesses with the location of the maximum volume swelling demonstrated that the skin separates at the peak swelling depth, not at the end of the swelling profile. Second, an examination of the assumptions that have been used to predict skin-thicknesses revealed that the differences between predicted and measured skin thicknesses at low energies can be attributed to: failure to account for volume swelling in the skin, using a Gaussian approximation to the range profile, or one generated with a Monte-Carlo code, and uncertainties in the electronic stopping powers. Beyond a certain dose, the density of cavities in the peak-swelling region decreased with increasing dose; indicating that cavity coalescence does occur. A calculation of the He concentration required to fracture the load-bearing cross section between the cavities revealed that a sufficient quantity of He was available to generate the required gas pressures. These observations indicate that models based on coalescence followed by gas-driven deformation provide an accurate description of the mechanisms involved in blistering; and they can accurately predict skin thicknesses at low energies

  18. A study on the enhancement of the reliability in gravure offset roll printing with blanket swelling control

    International Nuclear Information System (INIS)

    Kim, Ga Eul; Woo, Kyoohee; Kang, Dongwoo; Jang, Yunseok; Lee, Taik-Min; Kwon, Sin; Choi, Young-Man; Lee, Moon G

    2016-01-01

    In roll-offset printing (patterning) technology with a PDMS blanket as a transfer medium, one of the major reliability issues is the occurrence of swelling, which involves absorption of the ink solvent in the printing blanket with repeated printing. This study developed a method to resolve blanket swelling in gravure offset roll printing and performed experiments for performance verification. The physical phenomena of mass and heat transfer were applied to fabricate a device based on convection drying. The proposed device managed to effectively control blanket swelling through drying by blowing air and additional temperature control. The experiments verified that printing quality (in particular the variation of the width of printed patterns) was maintained over 500 continuous printing. (paper)

  19. The distinct element analysis for swelling pressure test of bentonite. Discussion on the effects of wall friction force and aspect ratio of specimen

    International Nuclear Information System (INIS)

    Shimizu, Hiroyuki; Kikuchi, Hirohito; Fujita, Tomoo; Tanai, Kenji

    2011-10-01

    For geological isolation systems for radioactive waste, bentonite based material is assumed to be used as a buffer material. The swelling characteristics of the bentonite based material are expected to fill up the void space around the radioactive wastes by swelling. In general, swelling characteristics and properties of bentonite are evaluated by the laboratory tests. However, due to the lack of standardization of testing method for bentonite, the accuracy and reproducibility of the testing results are not sufficiently proved. In this study, bentonite swelling pressure test were simulated by newly developed Distinct Element Method (DEM) code, and the effects of wall friction force and aspect ratio of bentonite specimen were discussed. As a result, the followings were found. In the beginning of the swelling pressure test, since swelling occurs only around the fluid injection side of the specimen, wall friction force acts only in the swelling area and the specimen moves to opposite side from fluid injection side. However, when the entire specimen started swelling, displacement of the specimen prevented by the wall friction force, and the specimen is pressed against the pressure measurement side. Then, the swelling pressure measured on the pressure measurement side increases. Such displacement in the specimen is significantly affected by the decreasing of mechanical properties and the difference of saturation in the bentonite specimen during the fluid infiltration. Moreover, when the aspect ratio of the specimen is large, the displacement of the particle in the specimen becomes large and the area on which the wall frictional force acts is also large. Therefore, measured swelling pressure increases more greatly as the aspect ratio of the specimen increases. To contributes to the standardization of laboratory test methods for bentonite, these effects of wall friction force revealed by the DEM simulation should be verified through laboratory experiments. (author)

  20. Fission gas induced fuel swelling in low and medium burnup fuel during high temperature transients

    International Nuclear Information System (INIS)

    Vinjamuri, K.

    1980-01-01

    The behavior of light water reactor fuel elements under postulated accident conditions is being studied by the EG and G Idaho, Inc., Thermal Fuels Behavior Program for the Nuclear Regulatory Commission. As a part of this program, unirradiated and previously irradiated, pressurized-water-reactor type fuel rods were tested under power-cooling-mismatch (PCM) conditions in the Power Burst Facility (PBF). During these integral in-reactor experiments, film boiling was produced on the fuel rods which created high fuel and cladding temperatures. Fuel rod diameters increased in the film boiling region to a greater extent for irradiated rods than for unirradiated rods. The purpose of the study was to investigate and assess the fuel swelling which caused the fuel rod diameter increases and to evaluate the ability of an analytical code, the Gas Release and Swelling Subroutine - Steady-State and Transient (GRASS-SST), to predict the results

  1. Fission gas induced fuel swelling in low and medium burnup fuel during high temperature transients. [PWR

    Energy Technology Data Exchange (ETDEWEB)

    Vinjamuri, K.

    1980-01-01

    The behavior of light water reactor fuel elements under postulated accident conditions is being studied by the EG and G Idaho, Inc., Thermal Fuels Behavior Program for the Nuclear Regulatory Commission. As a part of this program, unirradiated and previously irradiated, pressurized-water-reactor type fuel rods were tested under power-cooling-mismatch (PCM) conditions in the Power Burst Facility (PBF). During these integral in-reactor experiments, film boiling was produced on the fuel rods which created high fuel and cladding temperatures. Fuel rod diameters increased in the film boiling region to a greater extent for irradiated rods than for unirradiated rods. The purpose of the study was to investigate and assess the fuel swelling which caused the fuel rod diameter increases and to evaluate the ability of an analytical code, the Gas Release and Swelling Subroutine - Steady-State and Transient (GRASS-SST), to predict the results.

  2. Steady-state and transient fission gas release and swelling model for LIFE-4

    International Nuclear Information System (INIS)

    Villalobos, A.; Liu, Y.Y.; Rest, J.

    1984-06-01

    The fuel-pin modeling code LIFE-4 and the mechanistic fission gas behavior model FASTGRASS have been coupled and verified against gas release data from mixed-oxide fuels which were transient tested in the TREAT reactor. Design of the interface between LIFE-4 and FASTGRASS is based on an earlier coupling between an LWR version of LIFE and the GRASS-SST code. Fission gas behavior can significantly affect steady-state and transient fuel performance. FASTGRASS treats fission gas release and swelling in an internally consistent manner and simultaneously includes all major mechanisms thought to influence fission gas behavior. The FASTGRASS steady-state and transient analysis has evolved through comparisons of code predictions with fission-gas release and swelling data from both in- and ex-reactor experiments. FASTGRASS was chosen over other fission-gas behavior models because of its availability, its compatibility with the LIFE-4 calculational framework, and its predictive capability

  3. Swelling characteristics of Gaomiaozi bentonite and its prediction

    Directory of Open Access Journals (Sweden)

    De'an Sun

    2014-04-01

    Full Text Available Gaomiaozi (GMZ bentonite has been chosen as a possible matrix material of buffers/backfills in the deep geological disposal to isolate the high-level radioactive waste (HLRW in China. In the Gaomiaozi deposit area, calcium bentonite in the near surface zone and sodium bentonite in the deeper zone are observed. The swelling characteristics of GMZ sodium and calcium bentonites and their mixtures with sand wetted with distilled water were studied in the present work. The test results show that the relationship between the void ratio and swelling pressure of compacted GMZ bentonite-sand mixtures at full saturation is independent of the initial conditions such as the initial dry density and water content, but dependent on the ratio of bentonite to sand. An empirical method was accordingly proposed allowing the prediction of the swelling deformation and swelling pressure with different initial densities and bentonite-sand ratios when in saturated conditions. Finally, the swelling capacities of GMZ Na- and Ca-bentonites and Kunigel Na-bentonite are compared.

  4. STUDY OF A SOIL WITH SWELLING AND SHRINKING PHENOMENA

    Directory of Open Access Journals (Sweden)

    G. Rogobete

    2012-12-01

    Full Text Available Vertisols are deep clayey soils, with more than 45 % clay, dominated by clay minerals, such as smectites, that expand upon wetting and shrink upon drying. The most important physical characteristics of Vertisols are a low hydraulic conductivity and stickiness when wet and high flow of water through the cracks when dry. They become very hard when dry and in all the time are difficult to work. During the rainy season, the cracks disappear and the soil becomes sticky and plastic with a very slippery surface which makes Vertisols in – trafficable when wet. Water movement in soil that change volume with water content is not well understood and management of swelling soil remains problematic. Swelling or shrinking result in vertical displacement of the wet soil, which involves gravitational work and contributes to an overburden component to the total potential of the soil water. Many swelling soil crack and the network of cracks provides pathways for rapid flow of water which prejudice application of theory based on Darcian flow. One – dimensional flow of water in a swelling system requires material balance equation for both the aqueous and solid phases. The analytical data offers some values particle – size distribution, compression, swelling degree and pressure, plasticity index, elastic modulus, triaxial shear, angle of shear and load carrying capacity in order to realize a foundation study for some constructions.

  5. Scrotal Swelling as a Complication of Hydrochlorothiazide Induced Acute Pancreatitis

    Directory of Open Access Journals (Sweden)

    Ivan Nikiforov

    2015-01-01

    Full Text Available Background. Scrotal swelling is a rare complication of acute pancreatitis with few reported cases in the literature. In this case report, we present a 59-year-old male with hydrochlorothiazide induced pancreatitis who developed scrotal swelling. Case Presentation. A 59-year-old male presented to the emergency department with sharp epigastric abdominal pain that radiated to the back and chest. On physical examination, he had abdominal tenderness and distention with hypoactive bowel sounds. Computed tomography (CT scan of the abdomen showed acute pancreatitis. The patient’s condition deteriorated and he was admitted to the intensive care unit (ICU. After he improved and was transferred out of the ICU, the patient developed swelling of the scrotum and penis. Ultrasound (US of the scrotum showed large hydrocele bilaterally with no varicoceles or testicular masses. Good blood flow was observed for both testicles. The swelling diminished over the next eight days with the addition of Lasix and the patient was discharged home in stable condition. Conclusion. Scrotal swelling is a rare complication of acute pancreatitis. It usually resolves spontaneously with conservative medical management such as diuretics and elevation of the legs.

  6. Swelling of spinel after low-dose neutron irradiation

    International Nuclear Information System (INIS)

    Coghlan, W.A.; Clinard, F.W. Jr.; Itoh, N.; Greenwood, L.R.

    1986-01-01

    Swelling was determined in samples of single-crystal MgAl 2 O 4 spinel, irradiated to doses as high as 8 x 10 22 n/m 2 (E > 0.1 MeV) at approx. =50 0 C in the Omega West Reactor. Swelling effectively saturated at approx. =2 x 10 22 n/m 2 which corresponds to a damage level of only approx. =2 x 10 -3 dpa. In addition subsequent measurements after irradiation have revealed that the samples continued swelling for several weeks. These results imply that irradiation defects begin to interact by recombination and aggregation at low damage levels in this material at 50 0 C and perhaps continue to cluster at room temperature after irradiation. Rate equations have been employed to determine defect concentrations at saturation. Results to date show that the observed swelling is consistent with the number of surviving defects if swelling per Frenkel defect pair is taken to be one atomic volume

  7. Molecular accessibility in solvent swelled coals. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kispert, L.D.

    1994-04-01

    The conversion of coal by an economically feasible catalytic method requires the catalyst to diffuse into the coal sample so that hydrogenation catalysis can occur from within as well as the normal surface catalysis. Thus an estimate of the size, shape, and reactivity, of the pores in the coal before and after the swelling with different solvents is needed so that an optimum sized catalyst will be used. This study characterizes the accessible area found in Argonne Premium Coal Samples (APCS) using a EPR spin probe technique. The properties deduced in this manner correlate well with the findings deduced from SANS, NMR, SEM, SAXS and light scattering measurements. The use of nitroxide spin probes with swelling solvents is a simple way in which to gain an understanding of the pore structure of coals, how it changes in the presence of swelling solvents and the chemistry that occurs at the pore wall. Hydrogen bonding sites occur primarily in low-rank coals and vary in reactive strength as rank is varied. Unswelled coals contain small, spherical pores which disappear when coal is swelled in the presence of polar solvents. Swelling studies of polystyrene-divinyl benzene copolymers implied that coal is polymeric, contains significant quantities of covalent cross-links and the covalent cross-link density increases with rank.

  8. Overview of the swelling behavior of 316 stainless steel

    International Nuclear Information System (INIS)

    Garner, F.A.

    1985-01-01

    The austenitic stainless steel designated as A1S1 316 is currently being used as the major structural material for fast breeder reactors in the United States, Britain and France. Efforts are now underway in each country to optimize the swelling resistance of this alloy for further application to both fission and fusion power generating devices. The optimization effort requires knowledge of the factors which control swelling in order that appropriate compositional and fabricational modifications can be made to the alloy specification. The swelling data for this alloy are reviewed and the conclusion is reached that optimization efforts must focus on the incubation or transient regime of swelling rather than the post-transient or ''steady-state'' regime. Attempts to reduce the swelling of this steel by solute modification have focused on elements such as phosphorous and titanium. It is shown that the action of these solutes is manifested only in their ability to extend the transient regime. It is also shown that irradiation at high helium/dpa ratios does not appear to change the conclusions of this study. Another important conclusion is that small differences in reactor environmental history can have a larger influence than either helium or solutes

  9. Overview of the swelling behavior of 316 stainless steel

    International Nuclear Information System (INIS)

    Garner, F.A.

    1984-01-01

    The austenitic stainless steel designated as AISI 316 is currently being used as the major structural material for fast breeder reactors in the United States, Britain and France. Efforts are now underway in each country to optimize the swelling resistance of this alloy for further application to both fission and fusion power generating devices. The optimization effort requires knowledge of the factors which control swelling in order that appropriate compositional and fabricational modifications can be made to the alloy specification. The swelling data for this alloy are reviewed and the conclusion is reached that optimization efforts must focus on the incubation or transient regime of swelling rather than the post-transient or ''steady-state'' regime. Attempts to reduce the swelling of this steel by solute modification have focused on elements such as phosphorus and titanium. It is shown that the action of these solutes is manifested only in their ability to extend the transient regime. It is also shown that irradiation at high helium/dpa ratios does not appear to change the conclusions of this study. Another important conclusion is that small differences in reactor environmental history can have a larger influence than either helium or solutes. 31 refs., 27 figs., 1 tab

  10. NEUTRON-INDUCED SWELLING OF Fe-Cr BINARY ALLOYS IN FFTF AT ∼400 DEGREES C

    International Nuclear Information System (INIS)

    Garner, Francis A.; Greenwood, Lawrence R.; Okita, Taira; Sekimura, Naoto; Wolfer, W. G.

    2002-01-01

    The purpose of this effort is to determine the influence of dpa rate, He/dpa ratio and composition on the void swelling of simple binary Fe-Cr alloys. Contrary to the behavior of swelling of model fcc Fe-Cr-Ni alloys irradiated in the same FFTF-MOTA experiment, model bcc Fe-Cr alloys do not exhibit a dependence of swelling on dpa rate at approximately 400 degrees C. This is surprising in that an apparent flux-sensitivity was observed in an earlier comparative irradiation of Fe-Cr binaries conducted in EBR-II and FFTF. The difference in behavior is ascribed to the higher helium generation rates of Fe-Cr alloys in EBR-II compared to that of FFTF, and also the fact that lower dpa rates in FFTF are accompanied by progressively lower helium generation rates.

  11. Degradation of Nafion due to contamination from Swelling-Dehydration Cycles

    DEFF Research Database (Denmark)

    Andersen, Shuang Ma; Morgen, Per; Skou, Eivind Morten

    degradation in direct methanol fuel cells (DMFCs), where liquid water has direct contact with the electrolyte. An ex-situ experiment was established with swelling-dehydration cycles on the membrane. However, formation of sulfonic anhydride was not detected during the entire treatment; instead contamination...... from traces calcium in the nominally pure water used in the experiment was found to be the primary reason for the deterioration of the membrane properties. Trace impurities in the liquid methanol feed in DMFC may therefore represent an important contamination source....

  12. Hereditary angioedema: a bradykinin-mediated swelling disorder.

    Science.gov (United States)

    Björkqvist, Jenny; Sala-Cunill, Anna; Renné, Thomas

    2013-03-01

    Edema is tissue swelling and is a common symptom in a variety of diseases. Edema form due to accumulation of fluids, either through reduced drainage or increased vascular permeability. There are multiple vascular signalling pathways that regulate vessel permeability. An important mediator that increases vascular leak is the peptide hormone bradykinin, which is the principal agent in the swelling disorder hereditary angioedema. The disease is autosomal dominant inherited and presents clinically with recurrent episodes of acute swelling that can be life-threatening involving the skin, the oropharyngeal, laryngeal, and gastrointestinal mucosa. Three different types of hereditary angiodema exist in patients. The review summarises current knowledge on the pathophysiology of hereditary angiodema and focuses on recent experimental and pharmacological findings that have led to a better understanding and new treatments for the disease.

  13. Effect of temperature on swelling and bubble growth in metals

    International Nuclear Information System (INIS)

    Tiwari, G.P.

    1982-01-01

    The effect of temperature on the swelling of copper-boron alloys has been studied in the temperature range of 900-1040deg C. It is observed that beyond 1030deg C, swelling as well as the rate of bubble growth decrease. Similar characteristics of the bubble growth have been observed in aluminium-boron alloys also. At 590deg C, the bubble growth in aluminium-boron alloys is faster as compared to that at 640deg C. It thus appears that the swelling as well as the growth of the gas bubble are retarded at temperatures near the melting point in metals. Possible reasons for this kind of behaviour are discussed. (author)

  14. CFD modeling of pool swell during large break LOCA

    International Nuclear Information System (INIS)

    Yan, Jin; Bolger, Francis; Li, Guangjun; Mintz, Saul; Pappone, Daniel

    2009-01-01

    GE had conducted a series of one-third scale three-vent air tests in support the horizontal vent pressure suppression system used in Mark III containment design for General Electric BWR plants. During the test, the air-water interface has been tracked by conductivity probes. There are many pressure monitors inside the test rig. The purpose of the test was to provide a basis for the pool swell load definition for the Mark III containment. In this paper, a transient 3-Dimensional CFD model of the one-third scale Mark III suppression pool swell process is constructed. The Volume of Fluid (VOF) multiphase model is used to explicitly track the interface between the water liquid and the air. The CFD results such as flow velocity, pressure, interface locations are compared to those from the test. Through the comparisons, a technical approach to numerically model the pool swell phenomenon is established and benchmarked. (author)

  15. Spinal-cord swelling in acute multiple sclerosis

    International Nuclear Information System (INIS)

    Kikuchi, Seiji; Tashiro, Kunio; Naganuma, Mutsuo; Hida, Kazutoshi; Iwasaki, Yoshinobu; Abe, Hiroshi; Miyasaka, Kazuo

    1986-01-01

    Despite the frequent involvement of the spinal cord by multiple sclerosis, reports concerning neuroradiological findings regarding these lesions have been limited; most of them have demonstrated a normal or small spinal cord. Two cases of acute paraparesis showed evidence of spinal-cord swelling on myelography and CT myelography, initially suggesting the diagnosis of an intramedullary tumor. Spinal-cord swelling was demonstrated more clearly on CT myelography than on conventional myelography. The diagnosis of multiple sclerosis was made with the aid of the CSF findings, the clinical course, and the contracting-cord sign. The ''contracting-cord sign'' means the diminution of the spinal-cord diameter in the chronic stage. Since acute multiple sclerosis may produce spinal-cord swelling simulating a tumor, careful investigations are necessary to avoid unwarranted surgical interventions. (author)

  16. Generation of continental rifts, basins, and swells by lithosphere instabilities

    Science.gov (United States)

    Fourel, Loïc.; Milelli, Laura; Jaupart, Claude; Limare, Angela

    2013-06-01

    Continents may be affected simultaneously by rifting, uplift, volcanic activity, and basin formation in several different locations, suggesting a common driving mechanism that is intrinsic to continents. We describe a new type of convective instability at the base of the lithosphere that leads to a remarkable spatial pattern at the scale of an entire continent. We carried out fluid mechanics laboratory experiments on buoyant blocks of finite size that became unstable due to cooling from above. Dynamical behavior depends on three dimensionless numbers, a Rayleigh number for the unstable block, a buoyancy number that scales the intrinsic density contrast to the thermal one, and the aspect ratio of the block. Within the block, instability develops in two different ways in an outer annulus and in an interior region. In the outer annulus, upwellings and downwellings take the form of periodically spaced radial spokes. The interior region hosts the more familiar convective pattern of polygonal cells. In geological conditions, such instabilities should manifest themselves as linear rifts striking at a right angle to the continent-ocean boundary and an array of domal uplifts, volcanic swells, and basins in the continental interior. Simple scaling laws for the dimensions and spacings of the convective structures are derived. For the subcontinental lithospheric mantle, these dimensions take values in the 500-1000 km range, close to geological examples. The large intrinsic buoyancy of Archean lithospheric roots prevents this type of instability, which explains why the widespread volcanic activity that currently affects Western Africa is confined to post-Archean domains.

  17. Aqueous suspensions of natural swelling clay minerals. 2. Rheological characterization.

    Science.gov (United States)

    Paineau, Erwan; Michot, Laurent J; Bihannic, Isabelle; Baravian, Christophe

    2011-06-21

    We report in this article a comprehensive investigation of the viscoelastic behavior of different natural colloidal clay minerals in aqueous solution. Rheological experiments were carried out under both dynamic and steady-state conditions, allowing us to derive the elasticity and yield stress. Both parameters can be renormalized for all sizes, ionic strength, and type of clay using in a first approach only the volume of the particles. However, applying such a treatment to various clays of similar shapes and sizes yields differences that can be linked to the repulsion strength and charge location in the swelling clays. The stronger the repulsive interactions, the better the orientation of clay particles in flows. In addition, a master linear relationship between the elasticity and yield stress whose value corresponds to a critical deformation of 0.1 was evidenced. Such a relationship may be general for any colloidal suspension of anisometric particles as revealed by the analysis of various experimental data obtained on either disk-shaped or lath- and rod-shaped particles. The particle size dependence of the sol-gel transition was also investigated in detail. To understand why suspensions of larger particles gel at a higher volume fraction, we propose a very simplified view based on the statistical hydrodynamic trapping of a particle by an another one in its neighborhood upon translation and during a short period of time. We show that the key parameter describing this hydrodynamic trapping varies as the cube of the average diameter and captures most features of the sol-gel transition. Finally, we pointed out that in the high shear limit the suspension viscosity is still closely related to electrostatic interactions and follows the same trends as the viscoelastic properties. © 2011 American Chemical Society

  18. Calcium in the Mechanism of Ammonia-Induced Astrocyte Swelling

    Science.gov (United States)

    Jayakumar, A.R.; Rao, K.V. Rama; Tong, X.Y; Norenberg, M.D.

    2016-01-01

    Brain edema, due largely to astrocyte swelling, is an important clinical problem in patients with acute liver failure. While mechanisms underlying astrocyte swelling in this condition are not fully understood, ammonia and associated oxidative/nitrosative stress (ONS) appear to be involved. Mechanisms responsible for the increase in reactive oxygen/nitrogen species (RONS) and their role in ammonia-induced astrocyte swelling, however, are poorly understood. Recent studies have demonstrated a transient increase in intracellular Ca2+ in cultured astrocytes exposed to ammonia. As Ca2+ is a known inducer of RONS, we investigated potential mechanisms by which Ca2+ may be responsible for the production of RONS and cell swelling in cultured astrocytes after treatment with ammonia. Exposure of cultured astrocytes to ammonia (5 mM) increased the formation of free radicals, including nitric oxide, and such increase was significantly diminished by treatment with the Ca2+ chelator BAPTA-AM. We then examined the activity of Ca2+-dependent enzymes that are known to generate RONS and found that ammonia significantly increased the activities of NADPH oxidase (NOX), constitutive nitric oxide synthase (cNOS) and phospholipase A2 (PLA2) and such increases in activity were significantly diminished by BAPTA. Pretreatment of cultures with 7-nitroindazole, apocyanin and quinacrine, respective inhibitors of cNOS, NOX and PLA2, all significantly diminished RONS production. Additionally, treatment of cultures with BAPTA or with inhibitors of cNOS, NOX and PLA2 reduced ammonia-induced astrocyte swelling. These studies suggest that the ammonia-induced rise in intracellular Ca2+ activates free radical producing enzymes that ultimately contribute to the mechanism of astrocyte swelling. PMID:19393035

  19. Reliability of Arch dams subject to concrete swelling

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, J.M.; Silva, H.S.; Pinho, S. de [Laboratorio Nacional de Engenharia Civil (LNEC), Lisboa (Portugal)] [and others

    1995-12-31

    In this report, results of several studies are presented. The main aim of those studies was to assess the reliability of the three arch dams, in which swelling occurred due to alkali- aggregate reactions in various stages of development and having different effects on their reliability: the Cahora-Bassa dam, in Mozambique, where swelling accumulated up to the moment are very moderate and their development is apparently homogeneous; Santa-Luzia dam, in Portugal, where accumulated swelling have already considerable magnitude, nevertheless, important fissuration has not been observed up to the moment due to the homogeneous development of the swelling process; Alto-Ceira dam, also in Portugal, where accumulated swelling have also considerable magnitude but with a heterogeneous development, causing in conjunction with thermal variations important fissuration. Mention is made of mineralogical, chemical and petrographic analyses carried out for identification of the nature of reactions developed in each case and the back-analysis and other technics used in the assessment of the magnitude and distribution of swelling. Results are presented of measurement tests of the ultrasonic pulse velocity, used both in the assessment of alterations in the physical properties of concretes and in the determination of the depth of fissuration. Results are also presented of tests for characterisation of the rheology of integral concrete. Lastly, considerations are made about the reliability of the works on the basis of studies and the results of analyses of the state of stress, performed by means of the finite element method, by assuming for either visco-elastic or visco-elastic-plastic behaviour.

  20. Mitigation of Voltage Swells by Static Series Compensator

    DEFF Research Database (Denmark)

    Awad, Hilmy; Blaabjerg, Frede

    2004-01-01

    Swells and overvoltages can cause overheating, tripping or even destruction of industrial equipment such as motor drives and control relays. This paper investigates the possibility of employing the Static Series Compensator (SSC) to mitigate voltage swells/overvoltages. In the case of voltage...... is lower than a predetermined voltage level, the active power is employed to charge the ESC to this voltage level; 2) otherwise, the overvoltage protection of the SSC must operate. This paper also applies an overvoltage protection scheme based on a combination of a dc resistor with a chopper and the valves...

  1. Swelling in neutron irradiated nickel-base alloys

    International Nuclear Information System (INIS)

    Brager, H.R.; Bell, W.L.

    1972-01-01

    Inconel 625, Incoloy 800 and Hastelloy X were neutron irradiated at 500 to 700 0 C. It was found that of the three alloys investigated, Inconel 625 offers the greatest swelling resistance. The superior swelling resistance of Inconel 625 relative to that of Hastelloy-X is probably related to differences in the concentrations of the minor rather than major alloy constituents, and can involve (a) enhanced recombination of defects in the Inconel 625 and (b) preferential attraction of vacancies to incoherent precipitates. (U.S.)

  2. Increase of volume swelling by a temperature gradient

    International Nuclear Information System (INIS)

    Herschbach, K.; Schneider, W.; Stober, T.

    1996-11-01

    The temperature gradient in the cladding of a Fast Reactor fuel pin leads to increased dilatation compared to material irradiations. Investigations of a specially designed fuel pin reached the conclusion that the cause is enhanced volume swelling. It is induced by He-bubbles, which migrate upwards the temperature gradient and coalesce. The critical size of nuclei for void swelling is thus reached much faster. Consequently, the p in deformation is larger than expected from materials irradiations, in the present case (DIN 1.4981 sa) by about 50%. (orig.) [de

  3. Encephalocele presenting as lower lid swelling: A rare case report

    Directory of Open Access Journals (Sweden)

    Vaibhav Kumar Jain

    2018-01-01

    Full Text Available Encephalocele is a rare congenital abnormality characterized by abnormal protrusion of brain and meninges through an opening in the skull. We report an 8-year-old girl who presented with a swelling in the right lower lid for the last 6 years. In her infancy, she had undergone surgery for a very small swelling located in the right nasolacrimal area. On further clinicoradiological evaluation, anterior encephalocele was diagnosed. This case highlights the uncommon site of anterior encephalocele; misdiagnosis and mismanagement of which could result in dreaded complications such as meningitis and cerebrospinal fluid leaking fistula formation.

  4. Temporomandibular joint osteochondromatosis: an unusual cause of preauricular swelling.

    LENUS (Irish Health Repository)

    Phelan, Eimear

    2012-02-01

    We report an unusual and rare cause of preauricular swelling and review the most recent literature concerning synovial osteochondromatosis of the temporomandibular joint. We report the clinical and radiologic findings of a case of synovial osteochondromatosis of the temporomandibular joint that presented as preauricular swelling in a female patient. This disease typically affects large joints; fewer than 100 cases reported in the literature affect the temporomandibular joint. This case illustrates that disorders of the temporomandibular joint should also be included in the differential diagnosis of patients who present with a preauricular mass.

  5. Influence of effective stress on swelling pressure of expansive soils

    Directory of Open Access Journals (Sweden)

    Baille Wiebke

    2016-01-01

    Full Text Available The volume change and shear strength behaviour of soils are controlled by the effective stress. Recent advances in unsaturated soil mechanics have shown that the effective stress as applicable to unsaturated soils is equal to the difference between the externally applied stress and the suction stress. The latter can be established based on the soil-water characteristic curve (SWCC of the soil. In the present study, the evolution of swelling pressure in compacted bentonite-sand mixtures was investigated. Comparisons were made between magnitudes of applied suction, suction stress, and swelling pressure.

  6. Swelling and fracturing of borides under neutron irradiation

    International Nuclear Information System (INIS)

    Krainy, A.G.; Ogorodnikov, V.V.; Grinik, E.U.; Chirko, L.I.; Shinakov, A.A.

    1994-01-01

    The neutron irradiation of high temperature borides, which are included in boron-containing reactor materials, results in high internal stresses, leading to considerable swelling and micro- and macro-fracturing. Experimental results over a large range of temperature and fluences, show a change of damage mechanism for borides within 400-530 C: the macro-cracking with formation of annular and radial cracks is observed below this temperature zone. The accumulation of micro-fractures and the process of gas swelling take place at irradiation temperatures above 530 C. The effect of the high internal stresses is compared to external pressure. 12 refs., 4 figs

  7. Use of swelling clays to reduce permeability and its potential application to nuclear waste repository sealing

    International Nuclear Information System (INIS)

    Moore, D.E.; Morrow, C.A.; Byerlee, J.D.

    1982-01-01

    The injection of swelling-clay slurries into joints or faults at a deep-burial nuclear waste disposal site may result in signficant permeability reductions for the effective containment of radioactive wastes. In an experiment conducted to illustrate the permeability change accompanying clay swelling, a coarse stone with interconnected pore spaces was injected with a clay-electrolyte slurry, modelling the pressure-grouting of a fractured repository rock. Subsequently, solutions with lower electroylte concentrations were driven through the clay-filled stone, corresponding to migration of lower salinity ground-waters through the clay-grouted fracture. The initial injection procedure reduced the permeability of the stone from 1--10 darcies to 700 nanodarcies; the changes in solution composition decreased permeability by more than 2 additional orders of magnitude to 3 nanodarcies. For application at a nuclear waste repository, the electrolyte concentration of the injected clay slurry should be made higher than that of the ground-water in the host rock. Subesquent interaction of the ground-water with the clays would initiate swelling and create the additional, post-injection permeability reductions that may be important in preventing the escape of buried radioactive wastes. The measured permeability of the clay filling is considerably lower than that of cement tested for borehole plugging. Clays also have the advantage over cement and chemical grouts in that they are geologically stable at relatively low temperatures and have a high capacity for radionuclide adsorption

  8. Surface depression of glass and surface swelling of ceramics induced by ion implantation

    International Nuclear Information System (INIS)

    Ikeyama, Masami; Saitoh, Kazuo; Nakao, Setsuo; Niwa, Hiroaki; Tanemura, Seita; Miyagawa, Yoshiko; Miyagawa, Souji

    1994-01-01

    By the measurement of the change of the surface shapes of the glass and ceramics in which ion implantation was performed, it was clarified that glass surface was depressed, and ceramic surface swelled. These depression and swelling changed according to the kinds of ions, energy and the amount to be implanted and the temperature of samples. It became clear that the depression of glass surface was nearly proportional to the range of flight of the implanted ions, and the swelling of ceramic surface showed different state in the silicon nitride with strong covalent bond and the alumina and sapphire with strong ionic bond. For the improvement of the mechanical characteristics of solid materials such as hardness, strength, toughness, wear resistance, oxidation resistance and so on, attention has been paid to the surface reforming by high energy ion implantation at MeV level. The change of shapes of base materials due to ion implantation is not always negligible. The experiment was carried out on sintered silicon nitride and alumina, polished sapphire single crystals and quartz glass. The experimental method and the results are reported. (K.I.)

  9. Use of pressurized eccentric tubes to study the effect of hydrostatic stress on swelling

    International Nuclear Information System (INIS)

    Wolfer, W.G.; Reiley, T.C.

    1977-05-01

    A technique for measuring the effect of hydrostatic stress on radiation-induced swelling is presented. This technique is based on the nonuniform hydrostatic stress that arises when an eccentric tube (a tube with inner and outer surfaces having dissimilar centers of revolution) is internally pressurized. The elastic analyses of the thin- and thick-walled eccentric tube are given. The elastic stress state is allowed to relax plastically, based on a constitutive law for deformation during neutron irradiation. In this case, the constitutive law contains a linearly stress-dependent deviatoric strain rate and a dilatation rate that is linearly dependent on hydrostatic stress. Emphasis is placed on the specimen design and experimental procedure for in-reactor experiments in which the coefficient relating hydrostatic stress and swelling is sought. It is shown that, for the 316L stainless steel specimens placed in EBR-II, we may expect that any appreciable effect of hydrostatic stress on swelling will be observable through changes in specimen curvature

  10. Strategies used to inhibit postoperative swelling following removal of impacted lower third molar

    Directory of Open Access Journals (Sweden)

    Francesco Sortino

    2011-01-01

    Full Text Available Postoperative swelling following different surgical strategies is an area of great interest. The main part of literature on the topic deals with swelling after extraction of low impacted third molar. In this review, we have analyzed publications of the last 20 years with a pubmed search using the following key words: impacted third molar, swelling third molar, wisdom tooth, edema jaw, corticosteroids and extraction third molar, antibiotic prophylaxis and tooth extraction. Attention has often been focused on corticosteroid therapy administered by diverse routes (orally, IV, IM, topically and at different time schedules (before or after surgery or both. This investigation revealed how the use of different molecules and dosages makes the obtained results hardly comparable. Similar conclusions can be drawn from studies aimed at evaluating the efficacy of antibiotic therapy administered either before or after surgery. A complete review has also to take into account different surgical strategies used including various flaps, no traumatic osteothomy, and primary or secondary closure. The use of pharmacological therapy and application of an ice pack is critical in the postoperative period and has always provided positive results. However, even if it is difficult to come to definite conclusions, due to the variability of the design of studies analyzed, the postoperative discomfort identified with edema, pain and trismus following wisdom tooth removal is influenced by various factors such as the difficulty of the surgical procedure involved, age and gender of the patient, and experience of the surgeon. The pharmacological therapy when performed with corticosteroids seems to improve control of the postoperative swelling related with this kind of surgeries.

  11. Journal of EEA, Vol. 30, 2013 PREDICTION OF SWELLING ...

    African Journals Online (AJOL)

    dell

    Dakshanamurthy [8] to represent the swelling-time relationship by a hyperbolic equation. A versatile mathematical model presented by. Richard and Abbott [9] has been used to represent the stress-strain spectrum of different types of concrete as well as ...

  12. Effects of solute interstitial elements on swelling of stainless steel

    International Nuclear Information System (INIS)

    Stiegler, J.O.; Leitnaker, J.M.; Bloom, E.E.

    1975-01-01

    High-purity stainless steel (HPS), equivalent to type 316 stainless steel in major alloy elements but with greatly reduced interstitial elements and manganese contents, was irradiated in the temperature range 725 to 875 K to fluences ranging from 1.0 to 3.5 x 10 26 neutrons/m 2 (>0.1 MeV). The HPS swelled 20 to 50 times more than commercial grade 316 stainless steel (316 SS), and about the same as commercial-purity nickel, which has about the same interstitial content as HPS. A fine-grained 316 SS in which interstitial elements but not manganese were precipitated by thermomechanical treatments also showed exaggerated swelling, approaching that of HPS, which suggests that swelling in commercial stainless steels is retarded by small amounts of interstitial elements normally present in them and not by the major alloying elements. Interstitials tend to precipitate from solution during irradiation, and bulk extractions of precipitate particles were made to evaluate the extent of the precipitation reactions. At both 643 and 853 K precipitation was clearly enhanced by irradiation significantly enough to alter the matrix composition, which suggests that swelling may be increased at high fluences over that predicted by extrapolation of lower fluence data. These observations are discussed in terms of potential behaviour of fuel cladding materials and of the validity and interpretation of accelerated schemes for simulating neutron damage. (author)

  13. Grewia Gum 1: Some Mechanical and Swelling Properties of ...

    African Journals Online (AJOL)

    Purpose: To study the mechanical and dynamic swelling properties of grewia gum, evaluate its compression behaviour and determine the effect of drying methods on its properties. Methods: Compacts (500 mg) of both freeze-dried and air-dried grewia gum were separately prepared by compression on a potassium bromide ...

  14. Swelling of cross-linked polymers: interpretations and misinterpretations

    Czech Academy of Sciences Publication Activity Database

    Dušek, Karel; Dušková-Smrčková, Miroslava

    2017-01-01

    Roč. 254, 20 August (2017), s. 102 ISSN 0065-7727. [ACS National Meeting & Exposition /254./. 20.08.2017-24.08.2017, Washington] Institutional support: RVO:61389013 Keywords : swelling * cross-linked polymer Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science

  15. Laboratory tests of hydraulic fracturing and swell healing

    DEFF Research Database (Denmark)

    Thunbo, Christensen Claes; Foged, Christensen Helle; Foged, Niels

    1998-01-01

    New laboratory test set-ups and test procedures are described - for testing the formation of hydraulically induced fractures as well as the potential for subsequent fracture closurefrom the relase of a swelling potential. The main purpose with the tests is to provide information on fracturing str...

  16. Thermodynamics of swelling of latex particles with two monomers

    NARCIS (Netherlands)

    Maxwell, I.A.; Kurja, J.; van Doremaele, G.H.J.; German, A.L.

    1992-01-01

    The partitioning of 2 monomers between the latex particle, monomer droplet, and aq. phases of an emulsion polymer latex are measured at satn. swelling of the latex particle phase (corresponding to intervals I and II of an emulsion polymn.). The monomer (Me acrylate, Bu acrylate, styrene) and polymer

  17. Kimura's disease: A case presentation of postauricular swelling ...

    African Journals Online (AJOL)

    Kimura's disease: A case presentation of postauricular swelling. A Rajesh, T Prasanth, V.C. Naga Sirisha, M.D.S. Azmi. Abstract. Kimura's disease (KD) is a rare chronic inflammatory disease of subcutaneous tissues and occurs predominantly in head and neck region. It is seen primarily in young Asian males. Typical clinical ...

  18. Cell swelling and glycogen metabolism in hepatocytes from fasted rats

    NARCIS (Netherlands)

    Gustafson, L. A.; Jumelle-Laclau, M. N.; van Woerkom, G. M.; van Kuilenburg, A. B.; Meijer, A. J.

    1997-01-01

    Cell swelling is known to increase net glycogen production from glucose in hepatocytes from fasted rats by activating glycogen synthase. Since both active glycogen synthase and phosphorylase are present in hepatocytes, suppression of flux through phosphorylase may also contribute to the net increase

  19. Mechanism of activation of liver glycogen synthase by swelling

    NARCIS (Netherlands)

    Meijer, A. J.; Baquet, A.; Gustafson, L.; van Woerkom, G. M.; Hue, L.

    1992-01-01

    The mechanism linking the stimulation of liver glycogen synthesis to swelling induced either by amino acids or hypotonicity was studied in hepatocytes, in gel-filtered liver extracts, and in purified preparations of particulate glycogen to which glycogen-metabolizing enzymes are bound. High

  20. Ward Round - a boy with multiple joint swellings | Tickell | Malawi ...

    African Journals Online (AJOL)

    Ward Round - a boy with multiple joint swellings. D Tickell. Abstract. No Abstract Malawi Medical Journal Vol. 20 (3) 2008: pp. 99-100. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/mmj.v20i3.10968 · AJOL African Journals Online.

  1. Processing of La(1.8)Sr(0.2)CuO4 and YBa2Cu3O7 superconducting thin films by dual-ion-beam sputtering

    Science.gov (United States)

    Madakson, P.; Cuomo, J. J.; Yee, D. S.; Roy, R. A.; Scilla, G.

    1988-03-01

    High-quality La(1.8)Sr(0.2)CuO4 and YBa2Cu3O7 superconducting thin films, with zero resistance at 88 K, have been made by dual-ion-beam sputtering of metal and oxide targets at elevated temperatures. The films are about 1.0 micron thick and are single phase after annealing. The substrates investigated are Nd-YAP, MgO, SrF2, Si, CaF2, ZrO2-(9 pct)Y2O3, BaF2, Al2O3, and SrTiO3. Characterization of the films was carried out using Rutherford backscattering spectroscopy, resistivity measurements, TEM, X-ray diffraction, and SIMS. Substrate/film interaction was observed in every case. This generally involves diffusion of the substrate into the film, which is accompanied by, for example, the replacement of Ba by Sr in the YBa2Cu2O7 structure, in the case of SrTiO3 substrate. The best substrates were those that did not significantly diffuse into the film and which did not react chemically with the film.

  2. Processing of La/sub 1.8/Sr/sub 0.2/CuO4 and YBa2Cu3O7 superconducting thin films by dual-ion-beam sputtering

    International Nuclear Information System (INIS)

    Madakson, P.; Cuomo, J.J.; Yee, D.S.; Roy, R.A.; Scilla, G.

    1988-01-01

    High quality La/sub 1.8/Sr/sub 0.2/CuO 4 and YBa 2 Cu 3 O 7 superconducting thin films, with zero resistance at 88 K, have been made by dual-ion-beam sputtering of metal and oxide targets at elevated temperatures. The films are about 1.0 μm thick and are single phase after annealing. The substrates investigated are Nd-YAP, MgO, SrF 2 , Si, CaF 2 , ZrO 2 -9% Y 2 O 3 , BaF 2 , Al 2 O 3 , and SrTiO 3 . Characterization of the films was carried out using Rutherford backscattering spectroscopy, resistivity measurements, transmission electron microscopy, x-ray diffraction, and secondary ion mass spectroscopy. Substrate/film interaction was observed in every case. This generally involves diffusion of the substrate into the film, which is accompanied by, for example, the replacement of Ba by Sr in the YBa 2 Cu 2 O 7 structure, in the case of SrTiO 3 substrate. The best substrates were those that did not significantly diffuse into the film and which did not react chemically with the film. In general, the superconducting transition temperature is found to depend on substrate temperature and ion beam energy, film composition, annealing conditions, and the nature and the magnitude of the substrate/film interaction

  3. Mesoporous block-copolymer nanospheres prepared by selective swelling.

    Science.gov (United States)

    Mei, Shilin; Jin, Zhaoxia

    2013-01-28

    Block-copolymer (BCP) nanospheres with hierarchical inner structure are of great interest and importance due to their possible applications in nanotechnology and biomedical engineering. Mesoporous BCP nanospheres with multilayered inner channels are considered as potential drug-delivery systems and templates for multifunctional nanomaterials. Selective swelling is a facile pore-making strategy for BCP materials. Herein, the selective swelling-induced reconstruction of BCP nanospheres is reported. Two poly(styrene-block-2-vinylpyridine) (PS-b-P2VP) samples with different compositions (PS(23600)-b-P2VP(10400) and PS(27700)-b-P2VP(4300)) are used as model systems. The swelling reconstruction of PS-b-P2VP in ethanol, 1-pyrenebutyric acid (PBA)/ethanol, or HCl/ethanol (pH = 2.61) is characterized by scanning electron microscopy and transmission electron microscopy. It is observed that the length of the swellable block in BCP is a critical factor in determining the behavior and nanostructures of mesoporous BCP nanospheres in selective swelling. Moreover, it is demonstrated that the addition of PBA modifies the swelling structure of PS(23600)-b-P2VP(10400) through the interaction between PBA and P2VP blocks, which results in BCP nanospheres with patterned pores of controllable size. The patterned pores can be reversibly closed by annealing the mesoporous BCP nanospheres in different selective solvents. The controllable and reversible open/closed reconstruction of BCP nanospheres can be used to enclose functional nanoparticles or drugs inside the nanospheres. These mesoporous BCP nanospheres are further decorated with gold nanoparticles by UV photoreduction. The enlarged decoration area in mesoporous BCP nanospheres will enhance their activity and sensitivity as a catalyst and electrochemical sensor. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Level-Swell Prediction With RETRAN-3D And Its Application To A BWR Steam-Line-Break Analysis

    International Nuclear Information System (INIS)

    Aounallah, Y.; Hofer, K.

    2003-01-01

    Level-swell experiments have often been simulated using system codes, such as TRAC and RELAP, but only cursory assessments have been performed with the operational-transient code RETRAN-3D, the main system code used within the STARS project. The present study, initiated in the framework of a BWR Steam-Line-Break (SLB) accident scenario, addresses this lacuna by performing RETRAN simulations of the General Electric Level-Swell experiments, and by investigating their implications on power plant accident analyses. Parameters to which the predicted level swell is sensitive have been identified, and recommendations on code options are made. The SLB analysis objective was to determine the amount of steam and liquid discharged through the break under specified boundary conditions, and to gauge the results against reference values. The impact of the nodalization of the upper part of the reactor pressure vessel was investigated and found to play an important role, whereas the level swell induced from flashing was found not to be the predominant factor for these simulations. (author)

  5. Swell impact on wind stress and atmospheric mixing in a regional coupled atmosphere-wave model

    DEFF Research Database (Denmark)

    Wu, Lichuan; Rutgersson, Anna; Sahlée, Erik

    2016-01-01

    Over the ocean, the atmospheric turbulence can be significantly affected by swell waves. Change in the atmospheric turbulence affects the wind stress and atmospheric mixing over swell waves. In this study, the influence of swell on atmospheric mixing and wind stress is introduced into an atmosphere-wave-coupled...... regional climate model, separately and combined. The swell influence on atmospheric mixing is introduced into the atmospheric mixing length formula by adding a swell-induced contribution to the mixing. The swell influence on the wind stress under wind-following swell, moderate-range wind, and near......-neutral and unstable stratification conditions is introduced by changing the roughness length. Five year simulation results indicate that adding the swell influence on atmospheric mixing has limited influence, only slightly increasing the near-surface wind speed; in contrast, adding the swell influence on wind stress...

  6. The effect of radiation dose on the crosslink density of ultra-high molecular weight polyethylene (UHMWPE) measured by a novel swelling method

    International Nuclear Information System (INIS)

    Muratoglu, O.K.; Bragdon, C.R.; O'Connor, D.O.; Jasty, M.; Harris, W.H.

    1998-01-01

    The crosslink density of a polyethylene network structure can be determined by swelling in hot xylene (130 deg C). The Flory's swelling theory is generally used to calculate the crosslink density, dx (ln(l-q -1 )+q -1 +Xq -1 )/(V 1 q -1/3 ), where V 1 is the molar volume of xylene at 130 deg C (136 cc/mol), X is the xylene-polyethylene interaction parameter, and q is the equilibrium volume swelling ratio of cross-linked network in hot xylene. Conventionally, q is measured using gravimetric methods as described in ASTM D2765-95. However, as noted in the ASTM standard, the gravimetric method has a large error factor associated with the measurement of q (as much as 100%). UHMWPE was irradiated (range of 25 to 300 kGy) using an AECL I 10/1 linear electron beam accelerator operated at 1 kW. The irradiated specimens were subsequently melt-annealed at 150 deg C for 2 hours in vacuum. For swelling experiments, 2 mm thin samples were machined using a diamond blade. The sample sizes were kept at around 3x3x2 mm and the bottom and top surfaces were machined parallel to each other. The equilibrium volume swelling ratios were determined using a Perkin-Elmer TMA/DMA 7 (n=3 for each radiation dose level). The samples were placed in a quartz basket-probe assembly and lowered into a xylene/antioxidant bath at room temperature. The xylene was then heated to 130 deg C at 5 deg C/min and held at 130 deg C for 2 hours. The swelling was then recorded with the upward motion of the probe until the equilibrium swelling was achieved. (The experiments were carried out in 3 orthogonal directions which confirmed the isotropy of swelling). (author)

  7. Degradation and contamination of perfluorinated sulfonic acid membrane due to swelling-dehydration cycles

    DEFF Research Database (Denmark)

    Andersen, Shuang Ma; Morgen, Per; Skou, Eivind Morten

    Formation of sulfonic anhydride S-O-S (from the condensation of sulfonic acids) was known one of the important degradation mechanisms [i] for Nafion membrane under hydrothermal aging condition, which is especially critical for hydrogen fuel cells. Similar mechanism would also have be desirable...... to the membrane degradation in direct methanol fuel cells (DMFCs), where liquid water has direct contact with the electrolyte. An ex-situ experiment was established with swelling-dehydration cycles on the membrane. However, formation of sulfonic anhydride was not detected during the entire treatment; instead...

  8. Effect of Rhodococcus sp. on desulfurization, swelling and extraction of coal

    Energy Technology Data Exchange (ETDEWEB)

    Wang De-qiang; Shui Heng-fu [University of Technology of Anhui, Maanshang (China). School of Chemical Engineering

    2006-08-15

    Bio-desulfurization of coal by rhodococcus sp. was studied. Some kinds of coal were swelled with different organic solvents, and then the swelled coals were treated by rhodococcus sp. The results show that the ratios of desulfurization of coals increase after they are swelled, especially swelled with NMP, the ratio is more than 80%. The swelling and extraction of coal were also studied after the coal had been treated by rhodococcus sp. The results show that the ratios of swelling increase more than 65%, but the extraction yield decreases for the coal treated by rhodococcus sp. 11 refs., 5 tabs.

  9. Development of a bentonite free swelling model in an elastoplastic framework

    International Nuclear Information System (INIS)

    Navarro, V.; Asensio, L.; Yustres, A.; Alonso, J.; Pintado, X.

    2012-01-01

    Document available in extended abstract form only. The aim of this work is to develop a Hydro-Chemo-Mechanical (HcM) model able to consistently reproduce the whole swelling process of both unsaturated and saturated bentonites. The Barcelona Expansive Model (BExM) was taken as a starting point, as it has been satisfactorily applied to model the behaviour of compacted bentonites. However, its suitability for the analysis of free swelling has not been proved, namely for the case when porosities reach values close to and over 0.9 and the soil becomes disarranged. These conditions mean pulling BExM further away from the domain for which it was initially conceived. For this reason, a modified formulation of BExM has been developed. It has been named m/BExM. In order to explain the high swelling ability of bentonites, it is assumed that the distortion of the water structure induced by the clay sheets begins to have a significant effect also in macro water structure when the micro void ratio goes beyond a certain threshold value and the confining forces do not exceed the repulsive forces. Accordingly, macro water will experience a decrease in its chemical potential, and the voids in which this phenomenon takes part will act as sinks, increasing their volume and causing an important raise of macro-porosity (disarrangement of the soil macro skeleton). When this phenomenon starts, the micro strain rate is greater than that of the macro disarrangement. Nonetheless, when the micro void ratio reaches high values, the disarrangement becomes more significant. The variation of the micro void ratio with the swelling pressure is described with an exponential law. The developed formulation takes into account the geochemical effects by using a modified swelling pressure, in keeping with the proposal of Karnland et al. (2005) when working with a saline solution of relevant concentration. The presence of sodium and calcium cations, as well as that of a generic polyvalent anion (by

  10. Depleted depletion drives polymer swelling in poor solvent mixtures.

    Science.gov (United States)

    Mukherji, Debashish; Marques, Carlos M; Stuehn, Torsten; Kremer, Kurt

    2017-11-09

    Establishing a link between macromolecular conformation and microscopic interaction is a key to understand properties of polymer solutions and for designing technologically relevant "smart" polymers. Here, polymer solvation in solvent mixtures strike as paradoxical phenomena. For example, when adding polymers to a solvent, such that all particle interactions are repulsive, polymer chains can collapse due to increased monomer-solvent repulsion. This depletion induced monomer-monomer attraction is well known from colloidal stability. A typical example is poly(methyl methacrylate) (PMMA) in water or small alcohols. While polymer collapse in a single poor solvent is well understood, the observed polymer swelling in mixtures of two repulsive solvents is surprising. By combining simulations and theoretical concepts known from polymer physics and colloidal science, we unveil the microscopic, generic origin of this collapse-swelling-collapse behavior. We show that this phenomenon naturally emerges at constant pressure when an appropriate balance of entropically driven depletion interactions is achieved.

  11. Structure and radiation induced swelling of steels and alloys

    International Nuclear Information System (INIS)

    Parshin, A.M.

    1983-01-01

    Regularities of vacancy void formation and radiation induced swelling of austenitic chromium-nickel steels and alloyse ferritic steels as well as titanium α-alloys under radiation by light and heavy ions and neutrons are considered. Possible methods for preparation of alloys with increased resistance to radiation swelling are described. Accounting for investigations into ferritic steels and α-alloys of titanium the basic way of weakening vacancy smelling is development of continuous homogeneous decomposition of solid solution using alloying with vividly expressed incubation period at a certain volumetric dilatation as well as decompositions of the type of ordering, K-state, lamination of solid solutions, etc. Additional alloying of solid solutions is also shown to be necessary for increasing recrystallization temperature of cold-deformed steel

  12. Void swelling and segregation in dilute nickel alloys

    International Nuclear Information System (INIS)

    Potter, D.I.; Rehn, L.E.; Okamoto, P.R.; Wiedersich, H.

    1977-01-01

    Five binary alloys containing 1 at.% of Al, Ti, Mo, Si and Be in nickel were irradiated at temperatures from 525 to 675 0 C with 3.5-MeV 58 Ni + ions. The resultant microstructures were examined by TEM, and void diameters, number densities and swelling are presented for each alloy over the temperature interval investigated. A systematic relation between solute misfit (size factor) and void swelling is established for these alloys. Solute concentration profiles near the irradiated surface were determined and these also exhibited a systematic behavior--undersize solutes segregated to the surface, whereas oversize solutes were depleted. The results are consistent with calculations based on strong interstitial-solute trapping by undersize solutes and vacancy-solute trapping by oversize solutes that are weak interstitial traps

  13. Swell activated chloride channel function in human neutrophils

    Energy Technology Data Exchange (ETDEWEB)

    Salmon, Michael D. [Leukocyte and Ion Channel Research Laboratory, School of Health and Biosciences, University of East London, Stratford Campus, London E15 4LZ (United Kingdom); Ahluwalia, Jatinder, E-mail: j.ahluwalia@uel.ac.uk [Leukocyte and Ion Channel Research Laboratory, School of Health and Biosciences, University of East London, Stratford Campus, London E15 4LZ (United Kingdom)

    2009-04-17

    Non-excitable cells such as neutrophil granulocytes are the archetypal inflammatory immune cell involved in critical functions of the innate immune system. The electron current generated (I{sub e}) by the neutrophil NADPH oxidase is electrogenic and rapidly depolarises the membrane potential. For continuous function of the NADPH oxidase, I{sub e} has to be balanced to preserve electroneutrality, if not; sufficient depolarisation would prevent electrons from leaving the cell and neutrophil function would be abrogated. Subsequently, the depolarisation generated by the neutrophil NADPH oxidase I{sub e} must be counteracted by ion transport. The finding that depolarisation required counter-ions to compensate electron transport was followed by the observation that chloride channels activated by swell can counteract the NADPH oxidase membrane depolarisation. In this mini review, we discuss the research findings that revealed the essential role of swell activated chloride channels in human neutrophil function.

  14. Mid Arm Swelling- A Rare Presentation of Filariasis

    OpenAIRE

    Haren Oza; Jignasa Bhalodia; Ami Shah; Palak Modi

    2014-01-01

    Bancroftian Filariasis is a tropical and subtropical disease caused by Wuchereria bancrofti and transmitted by the Culex mosquitoes. The diagnosis of it is conventionally made by demonstrating microfilariae in the peripheral blood smear. Microfilaria and adult filarial worm have been incidentally detected in fine needle aspirates of various lesions. We here report a rare case presentation of Bancroftian filariasis in 20 years old asymptomatic male coming from an endemic area with swelling in ...

  15. Effect of helium on void swelling in vanadium

    International Nuclear Information System (INIS)

    Brimhall, J.L.; Simonen, E.P.

    1975-01-01

    Little difference in void microstructural swelling of vanadium is observed when helium is injected simultaneously with a 46- or 5-MeV nickel beam as compared to no helium injection, at least at high dose rates. At lower dose rates, a strong helium effect is seen when the helium is injected prior to heavy ion bombardment. The effect of the helium is shown to be a strong function of the overall displacement damage rate

  16. A FACSIMILE code for calculating void swelling, version VS1

    International Nuclear Information System (INIS)

    Windsor, M.; Bullough, R.; Wood, M.H.

    1979-11-01

    VS1 is the first of a series of FACSIMILE codes that are being made available to predict the swelling of materials under irradiation at different temperatures, using chemical rate equations for the point defect losses to voids, interstitial loops, dislocation network, grain boundaries and foil surfaces. In this report the rate equations used in the program are given together with a detailed description of the code and directions for its use. (author)

  17. Atypical Post Kala Azar Dermal Leishmaniasis with ?Muzzle Area? Swelling

    OpenAIRE

    Arora, Sandeep; Bal, Arvinder Singh; Baveja, Sukriti; Sood, Aradhana; Rathi, Khushi Ram; Patil, Pradeep

    2015-01-01

    A 50-year-old male presented with recurrent swelling of the muzzle area of the face with history of low-grade intermittent fever of 3 year duration managed variously with antibiotics, systemic steroids, and antituberculous therapy. Skin biopsy revealed a granulomatous infiltration negative for acid-fast bacilli and leishmania donovan bodies. Immunochromatography test for rK 39 antigen and polymerase chain reaction for leishmania was positive. He was diagnosed as a case of post kala azar derma...

  18. Application of the Group Contribution Approach to Nafion Swelling

    Czech Academy of Sciences Publication Activity Database

    Randová, A.; Bartovská, L.; Hovorka, Š.; Poloncarzová, M.; Kolská, Z.; Izák, Pavel

    2009-01-01

    Roč. 111, č. 4 (2009), s. 1745-1750 ISSN 0021-8995 R&D Projects: GA ČR GA104/08/0600; GA AV ČR IAA400720710 Institutional research plan: CEZ:AV0Z40720504 Keywords : group contribution method * structure-property relations * swelling Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.203, year: 2009

  19. Influence of network topology on the swelling of polyelectrolyte nanogels

    OpenAIRE

    Rizzi, Leandro G.; Levin, Yan

    2016-01-01

    It is well-known that the swelling behavior of ionic nanogels depends on their cross-link density, however it is unclear how different topologies should affect the response of the polyelectrolyte network. Here we perform Monte Carlo simulations to obtain the equilibrium properties of ionic nanogels as a function of salt concentration $C_s$ and the fraction $f$ of ionizable groups in a polyelectrolyte network formed by cross-links of functionality $z$. Our results indicate that the network wit...

  20. SuperLig Ion Exchange Resin Swelling and Buoyancy Study

    International Nuclear Information System (INIS)

    Hassan, N.M.

    2000-01-01

    The objective of this study was to achieve a fundamental understanding of SuperLig resin swelling and shrinking characteristics, which lead to channeling and early breakthrough during loading cycles. The density of salt solution that causes resin floating was also determined to establish a limit for operation. Specific tests performed include (a) pH dependence, (b) ionic strength dependence and (c) buoyancy effect vs. simulant composition

  1. Impurities effect on the swelling of neutron irradiated beryllium

    International Nuclear Information System (INIS)

    Donne, M.D.; Scaffidi-Argentina, F.

    1995-01-01

    An important factor controlling the swelling behaviour of fast neutron irradiated beryllium is the impurity content which can strongly affect both the surface tension and the creep strength of this material. Being the volume swelling of the old beryllium (early sixties) systematically higher than that of the more modem one (end of the seventies), a sensitivity analysis with the aid of the computer code ANFIBE (ANalysis of Fusion Irradiated BEryllium) to investigate the effect of these material properties on the swelling behaviour of neutron irradiated beryllium has been performed. Two sets of experimental data have been selected: the first one named Western refers to quite recently produced Western beryllium, whilst the second one, named Russian refers to relatively old (early sixties) Russian beryllium containing a higher impurity rate than the Western one. The results obtained with the ANFIBE Code were assessed by comparison with experimental data and the used material properties were compared with the data available in the literature. Good agreement between calculated and measured values has been found

  2. Molecular accessibility in solvent swelled coals. Quarterly report

    Energy Technology Data Exchange (ETDEWEB)

    Kispert, L.D.

    1993-02-01

    An EPR technique developed in this lab is being used to determine the pore size and number distribution changes after swelling the coal samples with various solvents. Stable nitroxide radical spin probes of different sizes, shapes and reactivity are dissolved in an appropriate solvent, the coal sample is added to the resulting solution, stirred over night at elevated temperature, filtered, washed with a non swelling solvent to eliminate any spin probes that are not trapped in the pores and the spin concentration is measured. Comparing these spin probe measurements to DRIFT data have shown that the relative number distribution of acidic functionalities can be accurately predicted by the spin probe method. The spin probe method had also been used to predict the increase in elongated voids in Pittsburgh No. 8 (APCS No. 4) upon swelling with pyridine in agreement with independent SANS data. NMR relaxation data show that it is possible to deduce the pore (accessibility) distribution as a function of size (up to 6 mn). It has also been possible by variable temperature and ENDOR measurements to determine the presence of hydrogen bonding as a function of pore shape and size. The advantage of the EPR method is that it permits molecules of selected shape and size to be used as probes of accessible regions of coal, thus providing information on the importance of molecular shape.

  3. Bias factors for radiation creep, growth and swelling

    International Nuclear Information System (INIS)

    Nichols, F.A.

    1980-01-01

    Central to the present concepts of the origin of the radiation-induced creep, growth and swelling phenomena is the relative interaction of interstitials and vacancies with various sinks. Radiation-induced climb of dislocations, which figures in many theories of radiation creep and growth, requires the absorption of an excess of either vacancies or interstitials. On the other hand, radiation swelling requires the absorption of an excess of vacancies to effect void growth. These relative preferences are normally expressed in theoretical models by certain bias factors, or capture efficiencies, usually assumed to be constant. Several attempts have been made to estimate their magnitude theoretically but all are seen to involve errors or physically unrealistic assumptions. We present here a unified treatment in which these various bias factors are estimated in a self-consistent model which incorporates, for the first time, all the essential physics, i.e., defect production, interactions of both vacancies and interstitials with sinks and the presence of two types of sinks. We present quantitative evaluations for the SIPA creep model and for radiation swelling, and compare with previous estimates of these phenomena. (orig.)

  4. Clayey landslide initiation and acceleration strongly modulated by soil swelling

    Science.gov (United States)

    Schulz, William; Smith, Joel B.; Wang, Gonghui; Jiang, Yao; Roering, Joshua J.

    2018-01-01

    Largely unknown mechanisms restrain motion of clay-rich, slow-moving landslides that are widespread worldwide and rarely accelerate catastrophically. We studied a clayey, slow-moving landslide typical of thousands in northern California, USA, to decipher hydrologic-mechanical interactions that modulate landslide dynamics. Similar to some other studies, observed pore-water pressures correlated poorly with landslide reactivation and speed. In situ and laboratory measurements strongly suggested that variable pressure along the landslide's lateral shear boundaries resulting from seasonal soil expansion and contraction modulated its reactivation and speed. Slope-stability modeling suggested that the landslide's observed behavior could be predicted by including transient swell pressure as a resistance term, whereas modeling considering only transient hydrologic conditions predicted movement 5–6 months prior to when it was observed. All clayey soils swell to some degree; hence, our findings suggest that swell pressure likely modulates motion of many landslides and should be considered to improve forecasts of clayey landslide initiation and mobility.

  5. Effect of seawater and high-temperature history on swelling characteristics of bentonite

    International Nuclear Information System (INIS)

    Tanaka, Yukihisa; Nakamura, Kunihiko

    2005-01-01

    In the case of construction of repository for nuclear waste near the coastal area, the effect of seawater on swelling characteristics of bentonite as an engineering as an engineering barrier should be considered. Effects of high-temperature history on swelling characteristics of bentonite should also be considered because nuclear waste generates heat. Thus, in this study, swelling characteristics of bentonite on the conditions of high temperature history and seawater are investigated. The results of this study imply that : (1) Swelling strain of sodium bentonite or transformed sodium bentonite decrease as the salinity of water increases, whereas those of calcium bentonite are not affected by salinity of the water. (2) Quantitative evaluation method for swelling strain and swelling pressure of several kinds of bentonites under brine is proposed. (3) Using distilled water, swelling strain and swelling pressure of sodium bentonite with high-temperature history is less than those without high-temperature history. (author)

  6. Void swelling in fast reactor irradiated high purity binary iron-chromium alloys

    International Nuclear Information System (INIS)

    Little, E.A.; Stow, D.A.

    The void swelling characteristics of a series of high purity binary iron-chromium alloys containing 0 - 615 0 C. The void swelling behaviour can be qualitatively rationalized in terms of point defect trapping and precipitation processes involving chromium atoms

  7. What Causes Ankle Swelling During Pregnancy - And What Can I do About it?

    Science.gov (United States)

    ... the ankles or calves. Some research suggests that foot massage and reflexology, which involves applying pressure to certain areas of the feet, hands and ears, might help decrease foot and ankle swelling during pregnancy. Also, swelling doesn' ...

  8. Swelling Behaviour of Superabsorbent Polymers for Soil Amendment under Different Loads

    Directory of Open Access Journals (Sweden)

    Krzysztof Lejcuś

    2018-03-01

    Full Text Available One of the most important among the numerous applications of superabsorbent polymers (SAPs, also known as hydrogels, is soil improvement and supporting plant vegetation in agriculture and environmental engineering. Currently, when water scarcity involves water stress, they are becoming still more commonly used for water retention in soil. As it turns out, one of the major factors influencing the superabsorbent polymers water retention capacity (WRC is the load of soil. The study presents test results of absorbency under load (AUL of SAPs. The object of the analysis was cross-linked copolymer of acrylamide and potassium acrylate, of a granulation of 0.50–3.15 mm. The authors analysed the water absorption capacity of the superabsorbent polymers under loads characteristic for 3 different densities of soil (1.3 g∙cm−3, 0.9 g∙cm−3, 0.5 g∙cm−3 and three different depths of application (10 cm, 20 cm, and 30 cm. Soil load and bulk densities were simulated by using weights. The experiments were conducted with a Mecmesin Multitest 2.5-xt apparatus. The obtained results demonstrate a very significant reduction in water absorption capacity by SAP under load. For a 30 cm deep layer of soil of bulk density of 1.3 g∙cm−3, after 1 h, this value amounted to 5.0 g∙g−1, and for the control sample without load, this value amounted to more than 200 g∙g−1. For the lowest load in the experiment, which was 0.49 kPa (10 cm deep layer of soil of a bulk density of 0.5 g∙cm−3, this value was 33.0 g∙g−1 after 60 min. Loads do not only limit the volume of the swelling superabsorbent polymer but they also prolong the swelling time. The soil load caused a decrease in the absorption capacity from 338.5 g∙g−1 to 19.3 g∙g−1, as well as a prolongation of the swelling time. The rate parameter (time required to reach 63% of maximum absorption capacity increased from 63 min for the control sample to more than 300 min for the largest analysed

  9. Recovery effects due to the interaction between nuclear and electronic energy losses in SiC irradiated with a dual-ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Thomé, Lionel, E-mail: thome@csnsm.in2p3.fr; Debelle, Aurélien; Garrido, Frédérico; Sattonnay, Gaël; Mylonas, Stamatis [Centre de Sciences Nucléaires et de Sciences de la Matière, CNRS-IN2P3-Université Paris-Sud, Bât. 108, F-91405 Orsay (France); Velisa, Gihan [CEA, DEN, Service de Recherches de Métallurgie Physique, Laboratoire JANNUS, F-91191 Gif-sur-Yvette (France); Horia Hulubei National Institute for Physics and Nuclear Engineering, P.O.B. MG-6, 077125 Magurele (Romania); Miro, Sandrine; Trocellier, Patrick; Serruys, Yves [CEA, DEN, Service de Recherches de Métallurgie Physique, Laboratoire JANNUS, F-91191 Gif-sur-Yvette (France)

    2015-03-14

    Single and dual-beam ion irradiations of silicon carbide (SiC) were performed to study possible Synergetic effects between Nuclear (S{sub n}) and Electronic (S{sub e}) Energy Losses. Results obtained combining Rutherford backscattering in channeling conditions, Raman spectroscopy, and transmission electron microscopy techniques show that dual-beam irradiation of SiC induces a dramatic change in the final sample microstructure with a substantial decrease of radiation damage as compared to single-beam irradiation. Actually, a defective layer containing dislocations is formed upon dual-beam irradiation (S{sub n} and S{sub e}), whereas single low-energy irradiation (S{sub n} alone) or even sequential (S{sub n} + S{sub e}) irradiations lead to full amorphization. The healing process is ascribed to the electronic excitation arising from the electronic energy loss of swift ions. These results shed new light on the long-standing puzzling problem of the existence of a possible synergy between S{sub n} and S{sub e} in ion-irradiation experiments. This work is interesting for both fundamental understanding of the ion-solid interactions and technological applications in the nuclear industry where recovery S{sub n}/S{sub e} effects may preserve the integrity of nuclear devices.

  10. Analysis of the General Electric Company swell tests with RELAP4/MOD7

    International Nuclear Information System (INIS)

    Fischer, S.R.; Hendrix, C.E.

    1979-01-01

    The RELAP4/MOD7 nuclear reactor transient analysis code, presently being developed by EG and G Idaho, Inc., will incorporate several significant improvements over earlier versions of RELAP4. As part of the development of RELAP4/MOD7, a thorough assessment of the capability of the code to simulate water reactor LOCA phenomena is being made. This assessment is accomplished in part by comparing results from code calculations with test data from experimental facilities. Simulations of the General Electric Company (GE) level swell tests were performed as part of the code checkout. In these tests, a pressurized vessel partially filled with nearly saturated water was blown down through a simulated break located near the top of the vessel. Comparison of RELAP4 calculations with data from these experiments indicates that the code has the capability to model the unequal phase velocity flow and resulting density gradients that might occur in a BWR steam line break transient. Comparisons of RELAP4 calculations with data from two level swell experiments are presented

  11. In Situ Swelling Behavior of Chitosan-Polygalacturonic Acid/Hydroxyapatite Nanocomposites in Cell Culture Media

    Directory of Open Access Journals (Sweden)

    Rohit Khanna

    2010-01-01

    Full Text Available The molecular and mechanical characteristics of in situ degradation behavior of chitosan-polygalacturonic acid/hydroxyapatite (Chi-PgA-HAP nanocomposite films is investigated using Fourier Transform Infrared spectroscopy (FTIR, Atomic Force Microscopy (AFM, and modulus mapping techniques for up to 48 days of soaking in cell culture media. The surface molecular structure of media-soaked samples changes over the course of 48 days of soaking, as indicated by significant changes in phosphate vibrations (1200–900 cm−1 indicating apatite formation. Chitosan-Polygalacturonic acid polyelectrolyte complexes (PECs govern structural integrity of Chi-PgA-HAP nanocomposites and FTIR spectra indicate that PECs remain intact until 48 days of soaking. In situ AFM experiments on media-soaked samples indicate that soaking results in a change in topography and swelling proceeds differently at the initial soaking periods of about 8 days than for longer soaking. In situ modulus mapping experiments are done on soaked samples by probing ∼1–3 nm of surface indicating elastic moduli of ∼4 GPa resulting from proteins adsorbed on Chi-PgA-HAP nanocomposites. The elastic modulus decreases by ∼2 GPa over a long exposure to cell culture media (48 days. Thus, as water enters the Chi-PgA-HAP sample, surface molecular interactions in Chi-PgA-HAP structure occur that result in swelling, causing small changes in nanoscale mechanical properties.

  12. New investigations into carbon dioxide flooding by focusing on viscosity and swelling factor changes

    Energy Technology Data Exchange (ETDEWEB)

    Enayati, M.; Mokhtari, B. [Iranian Offshore Oil Co., Tehran (Iran, Islamic Republic of); Heidaryan, E. [Islamic Azad Univ., Tehran (Iran, Islamic Republic of). Masjidosolayman Branch

    2008-07-01

    Carbon dioxide flooding (CO{sub 2}) is an effective method of enhanced oil recovery (EOR). This paper presented an experimental and theoretical investigation to determine the viscosity and swelling factor changes of the oil in the Cheshmeh Khoshk reservoir in southern Iran as well as the minimum miscible pressure. The study involved setting up of a series of slim tube experiments. The purpose of the slim tube experiments were to indicate the microscopic efficiency of the process. A numerical simulator was used to calculate the results on certain conditions. The paper discussed the validity of recombined sample as well as the slim tube tests and its results. Simulator results were also presented. It was concluded that viscosity reduction and oil swelling by CO{sub 2} contribute to oil recovery. The viscosity showed an almost linear decrease with CO{sub 2} concentration. Last, it was shown that the results of the study combined with the results of other gas injection projects could be utilized as a basic input parameter for the economic feasibility study and a decision could then be made whether to implement or abandon the prospective project or which type of injection leads to better performance. 12 refs., 5 tabs., 11 figs.

  13. Characterization of calcium, phosphate and peroxide interactions in activation of mitochondrial swelling using derivative of the swelling curves

    Czech Academy of Sciences Publication Activity Database

    Drahota, Zdeněk; Endlicher, R.; Staňková, P.; Rychtrmoc, D.; Milerová, Marie; Červinková, Z.

    2012-01-01

    Roč. 44, č. 3 (2012), s. 309-315 ISSN 0145-479X R&D Projects: GA MZd(CZ) NT12370 Grant - others:GA ČR(CZ) GP305/09/P145 Institutional support: RVO:67985823 Keywords : mitochondrial swelling * mitochondrial permeability transition pore * Calcium, phosphate and peroxide interactions Subject RIV: FG - Pediatrics Impact factor: 1.604, year: 2012

  14. Recent experimental and theoretical insights on the swelling of austenitic alloys

    International Nuclear Information System (INIS)

    Garner, F.A.; Wolfer, W.G.

    1983-01-01

    Once void nucleation subsides, the swelling rate of many austenitic alloys becomes rather insensitive to the variables that determine the duration of the transient regime of swelling. Models are presented which describe the roles of nickel, chromium and silicon in void nucleation. The relative insensitivity of steady-state swelling to temperature and composition is also discussed

  15. Hydric transfer in swelling clayey soils: influence of confinement; Transfert hydrique dans des sols argileux gonflants: influence du confinement

    Energy Technology Data Exchange (ETDEWEB)

    Rolland, S

    2002-01-01

    Description of imbibition and swelling mechanisms in clayey soils represents an important stake in different scientific domains such as agronomy, geotechnics or petroleum industry. The aim of the present work is to show the effects of hydro-mechanical couplings during imbibition in a swelling clayey medium, under different confinement conditions. Our material is a bentonite-silt mixture, prepared with a known water content and compacted with a double-piston technique. This method allows us to produce uniform soil samples, in terms of humidity and bulk density. Experiments related to bottom imbibition are then carried out for three types of mechanical boundary conditions (free, oedometric, fixed volume). The non-intrusive dual-energy gamma-ray technique is used to assess the local variation of bulk density and humidity. Finally, the three imbibition kinetics are compared for each experiment in terms of hydraulic diffusivity, described in a Lagrangian way. (author)

  16. Production bias and void swelling in the transient regime under cascade damage conditions

    International Nuclear Information System (INIS)

    Singh, B.N.; Foreman, A.J.E.

    1992-01-01

    Molecular dynamics (MD) studies of collision cascades have firmly established that, in addition to clusters of vacancies, clusters of self-interstitial atoms (SIAs) are formed within the cascade volume during the thermal spike phase of a cascade. These clusters are formed in a segregated fashion such that the vacancy-rich core is surrounded by SIA clusters. At temperatures above stage V the vacancies evaporate from the vacancy cluster and diffuse into the medium whereas the SIA clusters remain thermally stable at temperatures even above the peak swelling temperature. This asymmetry in the production of free and mobile vacancies and SIAs gives rise to a production bias. Some of the vacancies evaporating from the vacancy-rich core annihilate at the SIA clusters surrounding it and others escape into the medium. It is this escaping fraction of vacancies which determines the strength of the production bias. Diffusion calculations have been performed to estimate the magnitude of this escaping fraction of vacancies. The necessary cascade parameters for this calculation are obtained from MD simulation experiments. Almost 80% of vacancies retained in the vacancy-rich core of a 20 keV cascade are found to escape the cascade volume containing SIA clusters. We have taken this escape rate to be effective vacancy production rate in the medium and calculated the temporal evolution of SIA clusters, void size and swelling for fully annealed pure copper under neutron irradiation at 523 K. The general trends of the calculated swelling behaviour are found to be in agreement with experimental results. The present calculations provide further validity and support to the concept of production bias. (Author)

  17. Interactive Influence on Void Swelling in 300 Series Stainless Steels of Coupled Gradients in Temperature and DPA Rate

    International Nuclear Information System (INIS)

    Garner, F.

    2007-01-01

    Full text of publication follows: Recently, experimental evidence has accumulated that demonstrates that the dependence of swelling in austenitic steels on dpa rate has been strongly underestimated. In development of swelling correlations for both fusion and fission reactor applications the dpa rate is frequently but inadvertently incorporated into the temperature dependence. This inability to separate the separate dependencies of dpa rate and temperature is closely associated with the coupling of gradients in neutron flux-spectra and irradiation temperature along the axial length of components, especially for relatively small cores. In order to demonstrate the separate action of dpa rate and temperature, previously unpublished swelling data are presented from hexagonal ducts, fuel pins and pressurized tubes irradiated in EBR-II, all possessing both axial and radial gradients in dpa rate. Annealed AISI 304 components were chosen to avoid complications of precipitation found in other alloys such as AISI 316 or PCA. Since this steel never develops multiple-peak swelling behavior and experiences very little precipitation at high dpa rates, it use in this effort is ideal for separation of environmental variables. It is demonstrated that the transient regime of void selling is increased by increasing dpa rate and by decreasing temperature. It is also shown that the combined effect of dpa rate and temperature distribution along the length of any given structural component produces a well defined, scatter-free 'swelling loop' vs. dpa that uniquely allows estimation and separation of the separate dependencies of swelling on temperature and dpa rate. One consequence of the derived flux dependence is that components subject to a dpa rate gradient in general suffer much less distortion than predicted by equations that do not explicitly incorporate a dependence on dpa rate. It is also shown that over a wide range of irradiation conditions the terminal steady-state swelling

  18. Differential Response of Neural Cells to Trauma-Induced Swelling In Vitro.

    Science.gov (United States)

    Jayakumar, A R; Taherian, M; Panickar, K S; Shamaladevi, N; Rodriguez, M E; Price, B G; Norenberg, M D

    2018-02-01

    Brain edema and the associated increase in intracranial pressure are major consequences of traumatic brain injury (TBI) that accounts for most early deaths after TBI. We recently showed that acute severe trauma to cultured astrocytes results in cell swelling. We further examined whether trauma induces cell swelling in neurons and microglia. We found that severe trauma also caused cell swelling in cultured neurons, whereas no swelling was observed in microglia. While severe trauma caused cell swelling in both astrocytes and neurons, mild trauma to astrocytes, neurons, and microglia failed to cell swelling. Since extracellular levels of glutamate are increased in brain post-TBI and microglia are known to release cytokine, and direct exposure of astrocytes to these molecules are known to stimulate cell swelling, we examined whether glutamate or cytokines have any additive effect on trauma-induced cell swelling. Exposure of cultured astrocytes to trauma caused cell swelling, and such swelling was potentiated by the exposure of traumatized astrocytes to glutamate and cytokines. Conditioned medium (CM) from traumatized astrocytes had no effect on neuronal swelling post-trauma, while CM from traumatized neurons and microglia potentiated the effect of trauma on astrocyte swelling. Further, trauma significantly increased the Na-K-Cl co-transporter (NKCC) activity in neurons, and that inhibition of NKCC activity diminished the trauma-induced neuronal swelling. Our results indicate that a differential sensitivity to trauma-induced cell swelling exists in neural cells and that neurons and microglia are likely to be involved in the potentiation of the astrocyte swelling post-trauma.

  19. [Experimental study of acute brain swelling under acute intracranial hypertension (author's transl)].

    Science.gov (United States)

    Shigemori, M; Watanabe, M; Kuramoto, S

    1976-12-01

    There are many problems about the cause, pathophysiology and treatment of acute brain swelling under intracranial hypertension frequently encountered in the neurosurgical clinics. Generally, rapid increase of the cerebral vasoparesis caused by unknown etiology is thought to be the main cause of acute brain swelling under intracranial hypertension. Moreover, disturbance of the cerebral venous circulatory system is discussed recently by many authors. But, research from the point of systemic respiration and hemodynamics is necessary for resolving these problems. This experiment was designed to study the effects of respiration and hemodynamics on the cerebral vasoparesis. Using 22 adult dogs, acute intracranial hypertension was produced by epidural balloon inflation sustained at the level of 300 - 400 mmH2O. Simultaneously with measurement of intracranial pressure at the epidural space, superior sagittal sinus pressure, respirogram, systemic blood pressure (femoral artery), central venous pressure, common carotid blood flow, EKG and bipolar lead EEG were monitored continuously. The experimental group was divided by the respiratory loading into 5 groups as follows: control (6 cases), 10% CO2 hypercapnia (4 cases), 10% O2 hypoxia (4 cases), stenosis of airway (5 cases), 100% O2-controled respiration (3 cases). 1) Cerebral vasoparesis under acute intracranial hypertension took place earlier and showed more rapid progression in groups of stenosis of airway, hypercapnia and hypoxia than control group of spontaneous respiration in room air. No occurrence of cerebral vasoparesis was found out in a group of 100% O2 controlled respiration. It is proved that increased airway resistance or asphyxia, hypercapnia and hypoxia have strictly reference to the occurrence and progression of cerebral vasoparesis and for the prevention of cerebral vasoparesis, correct 100% O2 cont rolled respiration is effective. 2) From the hemodynamic change, the progression of rapid increase of cerebral

  20. Mechanistic modelling of drug release from polymer-coated and swelling and dissolving polymer matrix systems.

    Science.gov (United States)

    Kaunisto, Erik; Marucci, Mariagrazia; Borgquist, Per; Axelsson, Anders

    2011-10-10

    The time required for the design of a new delivery device can be sensibly reduced if the release mechanism is understood and an appropriate mathematical model is used to characterize the system. Once all the model parameters are obtained, in silico experiments can be performed, to provide estimates of the release from devices with different geometries and compositions. In this review coated and matrix systems are considered. For coated formulations, models describing the diffusional drug release, the osmotic pumping drug release, and the lag phase of pellets undergoing cracking in the coating due to the build-up of a hydrostatic pressure are reviewed. For matrix systems, models describing pure polymer dissolution, diffusion in the polymer and drug release from swelling and eroding polymer matrix formulations are reviewed. Importantly, the experiments used to characterize the processes occurring during the release and to validate the models are presented and discussed. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Modeling multidomain hydraulic properties of shrink-swell soils

    Science.gov (United States)

    Stewart, Ryan D.; Abou Najm, Majdi R.; Rupp, David E.; Selker, John S.

    2016-10-01

    Shrink-swell soils crack and become compacted as they dry, changing properties such as bulk density and hydraulic conductivity. Multidomain models divide soil into independent realms that allow soil cracks to be incorporated into classical flow and transport models. Incongruously, most applications of multidomain models assume that the porosity distributions, bulk density, and effective saturated hydraulic conductivity of the soil are constant. This study builds on a recently derived soil shrinkage model to develop a new multidomain, dual-permeability model that can accurately predict variations in soil hydraulic properties due to dynamic changes in crack size and connectivity. The model only requires estimates of soil gravimetric water content and a minimal set of parameters, all of which can be determined using laboratory and/or field measurements. We apply the model to eight clayey soils, and demonstrate its ability to quantify variations in volumetric water content (as can be determined during measurement of a soil water characteristic curve) and transient saturated hydraulic conductivity, Ks (as can be measured using infiltration tests). The proposed model is able to capture observed variations in Ks of one to more than two orders of magnitude. In contrast, other dual-permeability models assume that Ks is constant, resulting in the potential for large error when predicting water movement through shrink-swell soils. Overall, the multidomain model presented here successfully quantifies fluctuations in the hydraulic properties of shrink-swell soil matrices, and are suitable for use in physical flow and transport models based on Darcy's Law, the Richards Equation, and the advection-dispersion equation.

  2. Thermodynamic understanding on swelling pressure of bentonite buffer

    International Nuclear Information System (INIS)

    Sato, Haruo

    2007-01-01

    Smectite (montmorillonite) is a major clay mineral constituent of the bentonite buffer and backfilling materials to be used for the geological disposal of high-level radioactive waste. Swelling pressure of the bentonite buffer occurring in the permeation process of moisture was estimated based on thermodynamic theory and the thermodynamic data of interlayer water in smectite in this study. The relative partial molar Gibbs free energies (ΔG H2O ) of water on the smectite surface were measured as a function of water content (0-83%) in a dry density range of 0.6-0.9 Mg/m 3 . Purified Na-smectite of which interlayer cations were exchanged with Na + ions and soluble salts were completely removed, was used in this study. Obtained ΔG H2O decreased with an increase of water content in the range of water content lower than about 40%, and similar trends were obtained to data of Kunipia-F bentonite (Na-bentonite) of which smectite content was approximately 100 wt.%. From the specific surface area of smectite (ca. 800 m 2 /g) and the correlation between ΔG H2O and water content, water affected from the surface of smectite was estimated to be up to approximately 2 water layers. Swelling pressure versus smectite partial density (montmorillonite partial density) was estimated based on ΔG H2O from the chemical potential balance of water in equilibrium between the free water and moisturized smectite, and compared to data measured for various kinds of bentonites of which smectite contents were respectively different. The estimated swelling pressures were in good agreement with the measured data. (author)

  3. Effect of vacancy loops on swelling of metals under irradiation

    International Nuclear Information System (INIS)

    Golubov, S.I.

    1981-01-01

    Subsequent analysis of vacancy loops formation in metals under irradiation is carried out and effect of vacancy loops on vacancy porosity is studied. Expression for quasistationary function of vacancy loops distribution according to sizes taking into consideration two mechanisms of their initiation-cascade and fluctuational ones - is obtained. It is shown that rate of vacancy absorption and interstitials by vacancy loops in quasiequilibrium state is similar and depends only on summary length of loops, for its calculations the self-coordinated procedure is formulated. For the rate of metal swelling under irradiation obtained is the expression taking into consideration the presence of vacancy loops [ru

  4. Effect of fusion burn cycle on first wall swelling

    International Nuclear Information System (INIS)

    Choi, Y.H.; Bement, A.L.; Russell, K.C.

    1976-01-01

    A mathematical simulation of first wall swelling has been performed for stainless steel under a hypothetical duty cycle of 50 sec burn, 50 sec cool. In most instances steady state nucleation conditions were not established during the burn cycle, thereby necessitating the use of transient nucleation theory. The effects of transmutation helium and of surface active impurities were modelled in an approximate way. Both kinds of impurity were found to give large increases in the void nucleation rate. Suggestions for refining and extending the calculations are also given

  5. Atypical post kala azar dermal leishmaniasis with "muzzle area" swelling.

    Science.gov (United States)

    Arora, Sandeep; Bal, Arvinder Singh; Baveja, Sukriti; Sood, Aradhana; Rathi, Khushi Ram; Patil, Pradeep

    2015-01-01

    A 50-year-old male presented with recurrent swelling of the muzzle area of the face with history of low-grade intermittent fever of 3 year duration managed variously with antibiotics, systemic steroids, and antituberculous therapy. Skin biopsy revealed a granulomatous infiltration negative for acid-fast bacilli and leishmania donovan bodies. Immunochromatography test for rK 39 antigen and polymerase chain reaction for leishmania was positive. He was diagnosed as a case of post kala azar dermal leishmaniasis, managed with injection sodium stibogluconate and followed-up thereafter.

  6. Genital tuberculosis: A rare cause of vulvovaginal discharge and swelling

    Directory of Open Access Journals (Sweden)

    Malak Alhakeem

    2013-09-01

    Full Text Available Herein, we report a patient with vulvovaginal tuberculosis (TB presented with a vulvovaginal mass and vaginal discharge.The diagnosis was made by both histopathological examination of the excised specimen which was clinicallysuspected to be a malignant lesion and cervical smear culture positivity for Mycobacterium tuberculosis. The patientwas prescribed a full course of anti-tuberculous drugs. In this report, we discuss the genital TB and its gynecologicaleffects in the light of medical literature. J Microbiol Infect Dis 2013; 3(3: 140-142Key words: Genital tuberculosis, vulvovaginal swelling

  7. Kimura's Disease: A Rare Cause of Postauricular Swelling

    Directory of Open Access Journals (Sweden)

    Suman Kumar Das

    2017-04-01

    Full Text Available Introduction Kimura’s Disease is a chronic inflammatory disorder of lymph node which is very rare in Indian population. Case Report A 15 year old boy with multiple postauricular swelling for 18 months presenting in OPD and diagnosed having eosinophilia. Then excision biopsy was taken, which indicates Kimura’s Disease. Patient was treated with high dose of corticosteroid. Conclusion Kimura’s disease, though rare should be kept in mind for treating a patient with lymphadenopathy with eosinophilia or high IgE level, because it can spare the patient unnecessary invasive procedure.

  8. A boy with recurrent swelling of the jaw

    Directory of Open Access Journals (Sweden)

    Lien Haverals

    2018-01-01

    Full Text Available We present a 10-year old boy with recurrent swelling of the right mandibular region. Based on the diagnosis of chronic recurrent parotitis, he received only supportive treatment. Because of frequent relapses, the diagnosis was reconsidered. Magnetic resonance imaging, scintigraphy and biopsy were compatible with chronic osteomyelitis. This lead to a diagnosis of mandibular primary chronic osteomyelitis, an uncommon non-suppurative inflammatory disease of unknown origin. After decortication of the mandible, the patient recovered well. Because there were no further complaints, the follow-up was ended 18 months after the operation.

  9. Influence of microorganisms on swelling behavior of smectites

    International Nuclear Information System (INIS)

    Viefhaus, Hanna; Schanz, Tom

    2012-01-01

    Document available in extended abstract form only. Considerable interaction of smectitic clay minerals and water leads to the pronounced seal effect needed for barrier materials in the toxic and nuclear waste storage. Nano-structural processes on the molecular level cause macroscopic material properties such as fluid/ion permeability and volume change/swelling pressure development, that are taken into account when characterizing the barrier material. In situ behavior results from a combination of specific influence factors (e.g. electrolyte concentration, temperature, pH-value) due to the great dependence on the environmental conditions of clay water interaction. Considering this aspect, the origin of change in chemical and physical variables become relevant. Particularly in terms of naturally existing and rapid changing factors such as microbial activity. Due to the biodiversity of microorganisms and their individual diversity of metabolism processes, many species have been studied with respect to the influence on the different soil properties. In this study, the effects created by microbial biocenose have been the object of investigation. This corresponds to natural conditions rather than the isolated species. The present study concerns the swelling behavior of smectitic clay with respect to the influence of induced microbial accumulation. Two types of smectites were studied, Calcigel (Ca 2+ -ions embedded between the silicate layers) and MX80 (Na + -ions embedded). A natural silt was mixed at a ratio of 70:30 for the dry mass with smectites, this provided an amount of microbial portfolio. Using the mixtures, samples were created (20 mm height, 70 mm diameter) with two types of water contents. They exhibited the same dry densities of 1.495 g/cm 3 (Calcigel) and 1.386 g/cm 3 (MX80). Water adsorption was permitted through the contact of the sample with the liquid phase and also unhindered volume change in one dimension. The addition of nutrients to the liquid phase

  10. Evaluation of the swelling behaviour of iota-carrageenan in monolithic matrix tablets.

    Science.gov (United States)

    Kelemen, András; Buchholcz, Gyula; Sovány, Tamás; Pintye-Hódi, Klára

    2015-08-10

    The swelling properties of monolithic matrix tablets containing iota-carrageenan were studied at different pH values, with measurements of the swelling force and characterization of the profile of the swelling curve. The swelling force meter was linked to a PC by an RS232 cable and the measured data were evaluated with self-developed software. The monitor displayed the swelling force vs. time curve with the important parameters, which could be fitted with an Analysis menu. In the case of iota-carrageenan matrix tablets, it was concluded that the pH and the pressure did not influence the swelling process, and the first section of the swelling curve could be fitted by the Korsmeyer-Peppas equation. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Influence of applied stress on swelling behavior in Type 304 stainless steel

    International Nuclear Information System (INIS)

    Igata, N.; Fujihira, T.; Kohno, Y.; Tsunakawa, M.

    1984-01-01

    The swelling behavior of Type 304 stainless steel during stress application was investigated by means of electron irradiation using a high-voltage electron microscope (HVEM). The dose dependence of swelling under stress is similar to the linearafter-incubation swelling scheme of other electron irradiation studies. The effect of applied stress on the swelling characteristics appeared through the control of incubation regime of swelling rather than of the swelling rate. The incubation dose first increases, then decreases, and increases again with increasing applied stress. The prominent finding in this study, based on the advantage of HVEM in situ observation, is that the saturated void density is equal to the number density of interstitial dislocation loops observed in the early stage of irradiation. Essentially, applied stress affects the loop nucleation process. The dislocation loop density then affects the incubation dose of swelling through its control of dislocation behavior and the saturation dose of dislocation density

  12. Influence of solutes on heavy ion induced void-swelling in binary copper alloys

    International Nuclear Information System (INIS)

    Leister, K.H.

    1983-05-01

    As radiation induced swelling of metals depends on their constitution, swelling of copper and copper alloys with low solute concentration is studied. Diffusion coefficients and solubility of solute in copper were used as criteria of selection of the alloys. The samples were irradiated by 200keV copper ions. Swelling and void densities were measured by transmission electron microscopy. The measurements show low dependence of swelling upon the diffusibility of the solute in the solvent and a strong dependence on their concentration. Alloys of 0.1at% solute show more swelling than pure copper, and alloys of 1at% show less swelling under the irradiation conditions. The different swelling behavior in Cu-Ni alloys is due to the different void densities. (orig.) [de

  13. Site-Specific Pre-Swelling-Directed Morphing Structures of Patterned Hydrogels.

    Science.gov (United States)

    Wang, Zhi Jian; Hong, Wei; Wu, Zi Liang; Zheng, Qiang

    2017-12-11

    Morphing materials have promising applications in various fields, yet how to program the self-shaping process for specific configurations remains a challenge. Herein we show a versatile approach to control the buckling of individual domains and thus the outcome configurations of planar-patterned hydrogels. By photolithography, high-swelling disc gels were positioned in a non-swelling gel sheet; the swelling mismatch resulted in out-of-plain buckling of the disc gels. To locally control the buckling direction, masks with holes were used to guide site-specific swelling of the high-swelling gel under the holes, which built a transient through-thickness gradient and thus directed the buckling during the subsequent unmasked swelling process. Therefore, various configurations of an identical patterned hydrogel can be programmed by the pre-swelling step with different masks to encode the buckling directions of separate domains. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Effect of pressure on the transient swelling rate of oxide fuel

    International Nuclear Information System (INIS)

    Gruber, E.E.

    1982-04-01

    An analysis of the transient swelling rate of oxide fuel, based on fission-gas bubble conditions calculated with the FRAS3 code, has been developed and implemented in the code. The need for this capability arises in the coupling of the FRAS3 fission-gas analysis code to the FPIN fuel-pin mechanics code. An efficient means of closely coupling the calculations of swelling strains and stresses between the modules is required. The present analysis provides parameters that allow the FPIN calculation to proceed through a fairly large time step, using estimated swelling rates, to calculate the stresses. These stress values can then be applied in the FRAS3 detailed calculation to refine the swelling calculation, and to provide new values for the parameters to estimate the swelling in the next time step. The swelling rates were calculated for two representative transients and used to estimate swelling over a short time period for various stress levels

  15. Swelling pressures of a potential buffer material for high-level waste repository

    International Nuclear Information System (INIS)

    Lee, Jae Owan; Cho, Won Jin; Chun, Kwan Sik

    1999-01-01

    The swelling pressure of a potential buffer material was measured and the effect of dry density, bentonite content and initial water content on the swelling pressure was investigated to provide the information for the selection of buffer material in a high-level waste repository. Swelling tests were carried out according to Box-Behnken's experimental design. Measured swelling pressures were in the wide range of 0.7 Kg/cm 2 to 190.2 Kg/cm 2 under given experimental conditions. Based upon the experimental data, a 3-factor polynomial swelling model was suggested to analyze the effect of dry density, bentonite content and initial water content on the swelling pressure. The swelling pressure increased with an increase in the dry density and bentonite content, while it decreased with increasing the initial water content and, beyond about 12 wt.% of the initial water content, levelled to nearly constant value. (author). 21 refs., 10 figs., 4 tabs

  16. Development and validation of constitutive equation of HBS irradiation swelling considering hydrostatic pressure

    International Nuclear Information System (INIS)

    Gao Lijun; Jiang Shengyao; Yu Jiyang; Chen Bingde; Xiao Zhong

    2014-01-01

    The mechanism of hydrostatic pressure affecting the irradiation swelling of UO_2 high burnup structure was analyzed. Three basic assumptions used to develop the constitutive equation of irradiation swelling were made accordingly. It is concluded that hydrostatic pressure imposes an important impact on irradiation swelling mainly through compressing the UO_2 high burnup structure pores. Based on the already developed correlation of the irradiation swelling of UO_2 high burnup structure, pore shrinkage due to the application of hydrostatic pressure and thus the reduction of irradiation swelling of UO_2 high burnup structure were determined quantitatively, and the constitutive equation of irradiation swelling of UO_2 high burnup structure considering the hydrostatic pressure was constructed successfully. The constitutive equation is validated using available irradiation swelling data of UO_2 high burnup structure, which demonstrates its reasonability. (authors)

  17. Upper crustal structure of the Hawaiian Swell from seafloor compliance measurements

    Science.gov (United States)

    Doran, A. K.; Laske, G.

    2017-12-01

    We present new constraints on elastic properties of the marine sediments and crust surrounding the Hawaiian Islands derived from seafloor compliance measurements. We analyze long-period seismic and pressure data collected during the Plume-Lithosphere Undersea Mantle Experiment [Laske et al, 2009], a deployment consisting of nearly 70 broadband ocean-bottom seismometers with an array aperture of over 1000 kilometers. Our results are supported by previous reflection & refraction studies and by direct sampling of the crust from regional drilling logs. We demonstrate the importance of simultaneously modeling density, compressional velocity, and shear velocity, the former two of which are often ignored during compliance investigations. We find variable sediment thickness and composition across the Hawaiian Swell, with the thickest sediments located within the Hawaiian Moat. Improved resolution of near-surface structure of the Hawaiian Swell is crucially important to improve tomographic images of the underlying lithosphere and asthenosphere and to address outstanding questions regarding the size, source, and location of the hypothesized mantle plume.

  18. Formation of nanoscale networks: selectively swelling amphiphilic block copolymers with CO2-expanded liquids.

    Science.gov (United States)

    Gong, Jianliang; Zhang, Aijuan; Bai, Hua; Zhang, Qingkun; Du, Can; Li, Lei; Hong, Yanzhen; Li, Jun

    2013-02-07

    Polymeric films with nanoscale networks were prepared by selectively swelling an amphiphilic diblock copolymer, polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP), with the CO(2)-expanded liquid (CXL), CO(2)-methanol. The phase behavior of the CO(2)-methanol system was investigated by both theoretical calculation and experiments, revealing that methanol can be expanded by CO(2), forming homogeneous CXL under the experimental conditions. When treated with the CO(2)-methanol system, the spin cast compact PS-b-P4VP film was transformed into a network with interconnected pores, in a pressure range of 12-20 MPa and a temperature range of 45-60 °C. The formation mechanism of the network, involving plasticization of PS and selective swelling of P4VP, was proposed. Because the diblock copolymer diffusion process is controlled by the activated hopping of individual block copolymer chains with the thermodynamic barrier for moving PVP segments from one to another, the formation of the network structures is achieved in a short time scale and shows "thermodynamically restricted" character. Furthermore, the resulting polymer networks were employed as templates, for the preparation of polypyrrole networks, by an electrochemical polymerization process. The prepared porous polypyrrole film was used to fabricate a chemoresistor-type gas sensor which showed high sensitivity towards ammonia.

  19. Comparison of Swelling and Mechanical Analysis for the Determination of Crosslink Density of Acrylamide Based Hydrogels Prepared by Ionizing Radiation

    International Nuclear Information System (INIS)

    Sen, M.

    2006-01-01

    One of the basic parameters that describes the structure of a hydrogel network is the molecular weight between cross-links or cross-link density of highly swollen network. Several theories have been proposed to calculate the average molecular weight between cross-links. In the highly swollen state, the constrained junction theory indicates that a real network exhibits properties closer to those of the phantom network model and molecular weight between cross-links can be calculated easily by using swelling and polymer-solvent based parameters such as molar volume of the swelling agent, polymer-solvent interaction parameter, functionality, specific volume of the polymer and polymer volume fraction in the relaxed state. Molecular weight between cross-links (M c a ver.) and effective cross-linking density (V e ) of a hydrogel can also be determined from shear modulus data obtained from compression tests. Our previous studies indicated that simple compression analyses and equations derived from Phantom network theory can be used for the determination of effective cross-link density of hydrogels without needing some polymer-solvent based parameters as in the case of swelling based determinations. The M c a ver. and V e values calculated from mechanical tests were found to be very close to the values obtained from swelling experiments. Slight differences observed were attributed to the uncertainty on the value of the χ parameter used in the expression related to swelling data. In this study the uncertainty in the polymer based parameter χ on the M c a ver. was discussed. Poly(acrylamide/methacrylamide) P(AAm/MAAm) and Poly(acrylamide/hydroxyethylmeth acrylate) P(AAm/HEMA) hydrogels were prepared by gamma rays and used as model hydrogel systems. The uniaxial compression was applied to cylindrical samples using the Universal Testing Instrument in the swollen form at pH 7. Stress-strain curves of hydrogels were evaluated to calculate the shear modulus values. The M c a ver

  20. Controlled swelling and adsorption properties of polyacrylate/montmorillonite composites

    Energy Technology Data Exchange (ETDEWEB)

    Natkanski, Piotr [Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow (Poland); Kustrowski, Piotr, E-mail: kustrows@chemia.uj.edu.pl [Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow (Poland); Bialas, Anna; Piwowarska, Zofia [Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow (Poland); Michalik, Marek [Institute of Geological Sciences, Jagiellonian University, Oleandry 2a, 30-063 Krakow (Poland)

    2012-10-15

    A series of novel polyacrylate/montmorillonite composites was synthesized by in situ polymerization in aqueous slurry of clay. Dissociated (obtained by adding ammonium or sodium hydroxide) and undissociated forms of acrylic acid were used as monomers in the hydrogel synthesis. The structure and composition of the samples were studied by powder X-ray diffraction, diffuse reflectance infra-red Fourier transform spectroscopy, thermogravimetry and elemental analysis. It has been found that the kind of monomer influences strongly the location of a polymer chain in the formed composite. Complete intercalation of hydrogel into the interlayer space of montmorillonite was observed for sodium polyacrylate, whereas polyacrylic acid and ammonium polyacrylate mainly occupied the outer surface of the clay. The position of hydrogel determined the swelling and adsorption properties of the studied composites. The important factor influencing the kinetics of Fe(III) cation adsorption was pH. The analysis of adsorption isotherms allowed to propose the mechanism of Fe(III) cation adsorption. Highlights: Black-Right-Pointing-Pointer Polyacrylate hydrogels can be introduced into the interlayers of clay. Black-Right-Pointing-Pointer The position of hydrogel in the composite depends on the polymer type. Black-Right-Pointing-Pointer Ammonium polyacrylate places outside the clay, sodium one is intercalated into it. Black-Right-Pointing-Pointer Swelling and adsorption capacities can be controlled by the polymer position. Black-Right-Pointing-Pointer High adsorption efficiency in Fe(III) removal was observed.

  1. Swelling and tensile properties of neutron-irradiated vanadium alloys

    International Nuclear Information System (INIS)

    Loomis, B.A.; Smith, D.L.

    1990-07-01

    Vanadium-base alloys are candidates for use as structural material in magnetic fusion reactors. In comparison to other candidate structural materials (e.g., Type 316 stainless and HT-9 ferritic steels), vanadium-base alloys such as V-15Cr-5Ti and V-20Ti have intrinsically lower long-term neutron activation, neutron irradiation after-heat, biological hazard potential, and neutron-induced helium and hydrogen transmutation rates. Moreover, vanadium-base alloys can withstand a higher surface-heat, flux than steels because of their lower thermal stress factor. In addition to having these favorable neutronic and physical properties, a candidate alloy for use as structural material in a fusion reactor must have dimensional stability, i.e., swelling resistance, and resistance to embrittlement during the reactor lifetime at a level of structural strength commensurate with the reactor operating temperature and structural loads. In this paper, we present experimental results on the swelling and tensile properties of several vanadium-base alloys after irradiation at 420, 520, and 600 degree C to neutron fluences ranging from 0.3 to 1.9 x 10 27 neutrons/m 2 (17 to 114 atom displacements per atom [dpa])

  2. Industrial tests of rock consolidation for fighting floor swelling

    Energy Technology Data Exchange (ETDEWEB)

    Pirskii, A A; Stovpnik, S N [KPI (USSR)

    1990-04-01

    Reports on investigations into the mechanism of floor swelling in main roadways and into rock mass stabilization by consolidating fluid injection combined with blasting. The principal cause of deterioration in the stability of workings is considered to be the state of stress in the rock mass, rock destruction in side walls where rock blocks are being pressed into the floor while the floor rock is squeezed out into the working space. A case study of fluid injection combined with blasting applied in several mines in the Donbass is presented where holes were drilled 1.5-3 m deep and explosive charges of 0.07-0.1 kg/hole and injection of hardening solutions (0.56-0.83 m{sup 3}/m of workings) were applied. As a result floor swelling rates were reduced by up to about 5 times (e.g. from 2.5 mm/d to 0.5 mm/d.). The period of maintenence free upkeep of workings was extended to 6-8 years. The economic effect in maintenance of 1 m of workings was 11.7 rubles for floor consolidation without sidewall bolting and 51.4 rubles for floor consolidation combined with sidewall bolting. Recommendations that concern the technology of floor consolidation by fluid injection and blasting are made. 4 refs.

  3. The physical properties and compaction characteristics of swelling soils

    International Nuclear Information System (INIS)

    Komine, Hideo; Ogata, Nobuhide

    1990-01-01

    Expansive soils have recently attracted increasing attention as the back filling material for the repositories of high level nuclear wastes or as the material for improving extremely soft grounds. However, since very little has been known concerning the physical and mechanical properties of such materials, it is necessary to clarify the swelling, compaction and thermal characteristics of expansive soils. For this purpose, various kinds of index tests and a series of static compaction tests were performed using several kinds of swelling soils in order to investigate the relationship between the fundamental physical properties and the compaction characteristics. Since the ordinary testing method stipulated in JIS is difficult to perform for such expansive soils, the new method was proposed to obtained the reliable values of specific gravity, grain size distribution and liquid/plastic limits. By this method, some representative values were presented for various kinds of clay including bentonite. As the results of static compaction tests, the compaction characteristics of clay were strongly dependent on the plastic limit of clay. The maximum dry density and optimum water content were strongly dependent on both plastic limit and compaction pressure. (K.I.)

  4. Swelling, Structure, and Phase Stability of Soft, Compressible Microgels

    Science.gov (United States)

    Denton, Alan R.; Urich, Matthew

    Microgels are soft colloidal particles that swell when dispersed in a solvent. The equilibrium particle size is governed by a delicate balance of osmotic pressures, which can be tuned by varying single-particle properties and externally controlled conditions, such as temperature, pH, ionic strength, and concentration. Because of their tunable size and ability to encapsulate dye or drug molecules, microgels have practical relevance for biosensing, drug delivery, carbon capture, and filtration. Using Monte Carlo simulation, we model suspensions of microgels that interact via Hertzian elastic interparticle forces and can expand or contract via trial size changes governed by the Flory-Rehner free energy of cross-linked polymer gels. We analyze the influence of particle compressibility and size fluctuations on bulk structural and thermal properties by computing swelling ratios, radial distribution functions, static structure factors, osmotic pressures, and freezing densities. With increasing density, microgels progressively deswell and their intrinsic polydispersity broadens, while compressibility acts to forestall crystallization. This work was supported by the National Science Foundation under Grant No. DMR- 1106331.

  5. Segmentation of knee injury swelling on infrared images

    Science.gov (United States)

    Puentes, John; Langet, Hélène; Herry, Christophe; Frize, Monique

    2011-03-01

    Interpretation of medical infrared images is complex due to thermal noise, absence of texture, and small temperature differences in pathological zones. Acute inflammatory response is a characteristic symptom of some knee injuries like anterior cruciate ligament sprains, muscle or tendons strains, and meniscus tear. Whereas artificial coloring of the original grey level images may allow to visually assess the extent inflammation in the area, their automated segmentation remains a challenging problem. This paper presents a hybrid segmentation algorithm to evaluate the extent of inflammation after knee injury, in terms of temperature variations and surface shape. It is based on the intersection of rapid color segmentation and homogeneous region segmentation, to which a Laplacian of a Gaussian filter is applied. While rapid color segmentation enables to properly detect the observed core of swollen area, homogeneous region segmentation identifies possible inflammation zones, combining homogeneous grey level and hue area segmentation. The hybrid segmentation algorithm compares the potential inflammation regions partially detected by each method to identify overlapping areas. Noise filtering and edge segmentation are then applied to common zones in order to segment the swelling surfaces of the injury. Experimental results on images of a patient with anterior cruciate ligament sprain show the improved performance of the hybrid algorithm with respect to its separated components. The main contribution of this work is a meaningful automatic segmentation of abnormal skin temperature variations on infrared thermography images of knee injury swelling.

  6. Textureless Macula Swelling Detection with Multiple Retinal Fundus Images

    Energy Technology Data Exchange (ETDEWEB)

    Giancardo, Luca [ORNL; Meriaudeau, Fabrice [ORNL; Karnowski, Thomas Paul [ORNL; Tobin Jr, Kenneth William [ORNL; Grisan, Enrico [University of Padua, Padua, Italy; Favaro, Paolo [Heriot-Watt University, Edinburgh; Ruggeri, Alfredo [University of Padua, Padua, Italy; Chaum, Edward [University of Tennessee, Knoxville (UTK)

    2010-01-01

    Retinal fundus images acquired with non-mydriatic digital fundus cameras are a versatile tool for the diagnosis of various retinal diseases. Because of the ease of use of newer camera models and their relatively low cost, these cameras can be employed by operators with limited training for telemedicine or Point-of-Care applications. We propose a novel technique that uses uncalibrated multiple-view fundus images to analyse the swelling of the macula. This innovation enables the detection and quantitative measurement of swollen areas by remote ophthalmologists. This capability is not available with a single image and prone to error with stereo fundus cameras. We also present automatic algorithms to measure features from the reconstructed image which are useful in Point-of-Care automated diagnosis of early macular edema, e.g., before the appearance of exudation. The technique presented is divided into three parts: first, a preprocessing technique simultaneously enhances the dark microstructures of the macula and equalises the image; second, all available views are registered using non-morphological sparse features; finally, a dense pyramidal optical flow is calculated for all the images and statistically combined to build a naiveheight- map of the macula. Results are presented on three sets of synthetic images and two sets of real world images. These preliminary tests show the ability to infer a minimum swelling of 300 microns and to correlate the reconstruction with the swollen location.

  7. Polymer-Induced Swelling of Solid-Supported Lipid Membranes

    Directory of Open Access Journals (Sweden)

    Martin Kreuzer

    2015-12-01

    Full Text Available In this paper, we study the interaction of charged polymers with solid-supported 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC membranes by in-situ neutron reflectivity. We observe an enormous swelling of the oligolamellar lipid bilayer stacks after incubation in solutions of poly(allylamine hydrochloride (PAH in D2O. The positively charged polyelectrolyte molecules interact with the lipid bilayers and induce a drastic increase in their d-spacing by a factor of ~4. Temperature, time, and pH influence the swollen interfacial lipid linings. From our study, we conclude that electrostatic interactions introduced by the adsorbed PAH are the main cause for the drastic swelling of the lipid coatings. The DMPC membrane stacks do not detach from their solid support at T > Tm. Steric interactions, also introduced by the PAH molecules, are held responsible for the stabilizing effect. We believe that this novel system offers great potential for fundamental studies of biomembrane properties, keeping the membrane’s natural fluidity and freedom, decoupled from a solid support at physiological conditions.

  8. Fuel swelling and interaction layer formation in the SELENIUM Si and ZrN coated U(Mo) dispersion fuel plates irradiated at high power in BR2

    Energy Technology Data Exchange (ETDEWEB)

    Leenaers, A., E-mail: aleenaer@sckcen.be [Nuclear Materials Science Institute, SCK-CEN, Boeretang 200, 2400 Mol (Belgium); Van den Berghe, S.; Koonen, E.; Kuzminov, V. [Nuclear Materials Science Institute, SCK-CEN, Boeretang 200, 2400 Mol (Belgium); Detavernier, C. [Department of Solid State Sciences, Ghent University, Krijgslaan 281/S1, 9000 Ghent (Belgium)

    2015-03-15

    In the framework of the SELENIUM project two full size flat fuel plates were produced with respectively Si and ZrN coated U(Mo) particles and irradiated in the BR2 reactor at SCK• CEN. Non-destructive analysis of the plates showed that the fuel swelling profiles of both SELENIUM plates were very similar to each other and none of the plates showed signs of pillowing or excessive swelling at the end of irradiation at the highest power position (local maximum 70% {sup 235}U). The microstructural analysis showed that the Si coated fuel has less interaction phase formation at low burn-up but at the highest burn-ups, defects start to develop on the IL–matrix interface. The ZrN coated fuel, shows a virtual absence of reaction between the U(Mo) and the Al, up to high fission densities after which the interaction layer formation starts and defects develop in the matrix near the U(Mo) particles. It was found and is confirmed by the SELENIUM (Surface Engineering of Low ENrIched Uranium–Molybdenum) experiment that there are two phenomena at play that need to be controlled: the formation of an interaction layer and swelling of the fuel. As the interaction layer formation occurs at the U(Mo)–matrix interface, applying a diffusion barrier (coating) at that interface should prevent the interaction between U(Mo) and the matrix. The U(Mo) swelling, observed to proceed at an accelerating rate with respect to fission density accumulation, is governed by linear solid state swelling and fission gas bubble swelling due to recrystallization of the fuel. The examination of the SELENIUM fuel plates clearly show that for the U(Mo) dispersion fuel to be qualified, the swelling rate at high burn-up needs to be reduced.

  9. Fuel swelling and interaction layer formation in the SELENIUM Si and ZrN coated U(Mo) dispersion fuel plates irradiated at high power in BR2

    Science.gov (United States)

    Leenaers, A.; Van den Berghe, S.; Koonen, E.; Kuzminov, V.; Detavernier, C.

    2015-03-01

    In the framework of the SELENIUM project two full size flat fuel plates were produced with respectively Si and ZrN coated U(Mo) particles and irradiated in the BR2 reactor at SCK•CEN. Non-destructive analysis of the plates showed that the fuel swelling profiles of both SELENIUM plates were very similar to each other and none of the plates showed signs of pillowing or excessive swelling at the end of irradiation at the highest power position (local maximum 70% 235U). The microstructural analysis showed that the Si coated fuel has less interaction phase formation at low burn-up but at the highest burn-ups, defects start to develop on the IL-matrix interface. The ZrN coated fuel, shows a virtual absence of reaction between the U(Mo) and the Al, up to high fission densities after which the interaction layer formation starts and defects develop in the matrix near the U(Mo) particles. It was found and is confirmed by the SELENIUM (Surface Engineering of Low ENrIched Uranium-Molybdenum) experiment that there are two phenomena at play that need to be controlled: the formation of an interaction layer and swelling of the fuel. As the interaction layer formation occurs at the U(Mo)-matrix interface, applying a diffusion barrier (coating) at that interface should prevent the interaction between U(Mo) and the matrix. The U(Mo) swelling, observed to proceed at an accelerating rate with respect to fission density accumulation, is governed by linear solid state swelling and fission gas bubble swelling due to recrystallization of the fuel. The examination of the SELENIUM fuel plates clearly show that for the U(Mo) dispersion fuel to be qualified, the swelling rate at high burn-up needs to be reduced.

  10. Advanced liquefaction using coal swelling and catalyst dispersion techniques. Volume 2, appendices. Final technical report, October 1, 1991--September 30, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, C.W. [Auburn Univ., AL (United States); Chander, S. [Pennsylvania State Univ., College Park, PA (United States); Gutterman, C.

    1995-04-01

    Liquefaction experiments were undertaken using subbituminous Black Thunder mine coal to observe the effects of aqueous SO{sub 2} coal beneficiation and the introduction of various coal swelling solvents and catalyst precursors. Aqueous SO{sub 2} beneficiation of Black Thunder coal removed alkali metals and alkaline earth metals, increased the sulfur content and increased the catalytic liquefaction conversion to THF solubles compared to untreated Black Thunder coal. The liquefaction solvent had varying effects on coal conversion, depending upon the type of solvent added. The hydrogen donor solvent, dihydroanthracene, was most effective, while a coal-derived Wilsonville solvent promoted more coal conversion than did relatively inert 1-methylnaphthalene. Swelling of coal with hydrogen bonding solvents tetrahydrofuran (THF), isopropanol, and methanol, prior to reaction resulted in increased noncatalytic conversion of both untreated and SO{sub 2} treated Black Thunder coals, while dimethylsulfoxide (DMSO), which was absorbed more into the coal than any other swelling solvent, was detrimental to coal conversion. Swelling of SO{sub 2} treated coal before liquefaction resulted in the highest coal conversions; however, the untreated coal showed the most improvements in catalytic reactions when swelled in either THF, isopropanol, or methanol prior to liquefaction. The aprotic solvent DMSO was detrimental to coal conversion.

  11. Prospective evaluation of pain, swelling, and disability from copperhead envenomation.

    Science.gov (United States)

    Roth, Brett; Sharma, Kapil; Onisko, Nancy; Chen, Tiffany

    2016-03-01

    In light of the existing controversy regarding antivenin treatment for copperhead envenomation, a more detailed analysis of the disability from this species is needed. Our objective was to prospectively determine the duration of pain, swelling, and functional disability, i.e., residual venom effects, in patients with copperhead envenomation. Patients with venomous snakebite reported to the North Texas Poison Center between April 2009 and November 2011 were assessed. Patients with confirmed envenomations were contacted by a specialist in poison information. Day zero was the day of the bite and verbal phone consent for study enrollment was obtained at that time. The patient (or their guardian) was contacted by phone daily thereafter, and asked to rate their pain, edema/swelling, and disability using the modified DASH and LEFS scales. Patients were followed to resolution of all symptoms or return to baseline. About 104 cases of venomous snakebite were followed; of which 17 were excluded due to being a dry bites (5) or for having insufficient data during follow-up (11) or due to coagulopathy (1). Overall, residual venom effects from copperhead bites for most patients last between 7 and 13 days. Median time to complete pain resolution was 7 days (mean = 10.7 days). Median length of time to resolution of swelling was 10 days (mean = 13 days) and median length of time to resolution of functional disability was 9 days (mean = 12.2 days). Residual venom effects from copperhead envenomation in this study had a slightly shorter duration than some other studies. Data are skewed due to outliers where residual venom effects lasted for up to 89 days. Initial reoccurrence of some symptoms may be seen. Antivenom (AV) is currently being used for a large percentage of patients with copperhead envenomation. Finally, no differences in duration of venom effects were seen based on age or location of bite. Our study suggests that residual venom effects from copperhead

  12. Influence of smectite hydration and swelling on atrazine sorption behavior.

    Science.gov (United States)

    Chappell, Mark A; Laird, David A; Thompson, Michael L; Li, Hui; Teppen, Brian J; Aggarwal, Vaneet; Johnston, Cliff T; Boyd, Stephen A

    2005-05-01

    Smectites, clay minerals commonly found in soils and sediments, vary widely in their ability to adsorb organic chemicals. Recent research has demonstrated the importance of surface charge density and properties of exchangeable cations in controlling the affinity of smectites for organic molecules. In this study, we induced hysteresis in the crystalline swelling of smectites to test the hypothesis that the extent of crystalline swelling (or interlayer hydration status) has a large influence on the ability of smectites to adsorb atrazine from aqueous systems. Air-dried K-saturated Panther Creek (PC) smectite swelled less (d(001) = 1.38 nm) than never-dried K-PC (d(001) = 1.7 nm) when rehydrated in 20 mM KCl. Correspondingly, the air-dried-rehydrated K-PC had an order of magnitude greater affinity for atrazine relative to the never-dried K-PC. Both air-dried-rehydrated and never-dried Ca-PC expanded to approximately 2.0 nm in 10 mM CaCl2 and both samples had similar affinities for atrazine that were slightly lower than that of never-dried K-PC. The importance of interlayer hydration status in controlling sorption affinity was confirmed by molecular modeling, which revealed much greater interaction between interlayer water molecules and atrazine in a three-layer hydrate relative to a one-layer hydrate. The entropy change on moving atrazine from a fully hydrated state in the bulk solution to a partially hydrated state in the smectite interlayers is believed to be a major factor influencing sorption affinity. In an application test, choice of background solution (20 mM KCl versus 10 mM CaCl2) and air-drying treatments significantly affected atrazine sorption affinities for three-smectitic soils; however, the trends were not consistent with those observed for the reference smectite. Further, extending the initial rehydration time from 24 to 240 h (prior to adding atrazine) significantly decreased the soil's sorption affinity for atrazine. We conclude that interlayer

  13. Feet swelling in a multistage ultraendurance triathlete: a case study

    Directory of Open Access Journals (Sweden)

    Knechtle B

    2015-10-01

    Full Text Available Beat Knechtle,1 Matthias Alexander Zingg,2 Patrizia Knechtle,1 Thomas Rosemann,2 Christoph Alexander Rüst2 1Gesundheitszentrum St Gallen, St Gallen, 2Institute of Primary Care, University of Zurich, Zurich, Switzerland Abstract: Recent studies investigating ultraendurance athletes showed an association between excessive fluid intake and swelling of the lower limbs such as the feet. To date, this association has been investigated in single-stage ultraendurance races, but not in multistage ultraendurance races. In this case study, we investigated a potential association between fluid intake and feet swelling in a multistage ultraendurance race such as a Deca Iron ultratriathlon with ten Ironman triathlons within 10 consecutive days. A 49-year-old well-experienced ultratriathlete competed in autumn 2013 in the Deca Iron ultratriathlon held in Lonata del Garda, Italy, and finished the race as winner within 129:33 hours:minutes. Changes in body mass (including body fat and lean body mass, foot volume, total body water, and laboratory measurements were assessed. Food and fluid intake during rest and competing were recorded, and energy and fluid turnovers were estimated. During the ten stages, the volume of the feet increased, percentage body fat decreased, creatinine and urea levels increased, hematocrit and hemoglobin values decreased, and plasma [Na+] remained unchanged. The increase in foot volume was significantly and positively related to fluid intake during the stages. The poststage volume of the foot was related to poststage total body water, poststage creatinine, and poststage urea. This case report shows that the volume of the foot increased during the ten stages, and the increase in volume was significantly and positively related to fluid intake during the stages. Furthermore, the poststage volume of the foot was related to poststage total body water, poststage creatinine, and poststage urea. The continuous feet swelling during the race was

  14. Biodestruction of strongly swelling polymer hydrogels and its effect on the water retention capacity of soils

    Science.gov (United States)

    Smagin, A. V.; Sadovnikova, N. B.; Smagina, M. V.

    2014-06-01

    The biodestruction of strongly swelling polymer hydrogels (water adsorbing soil conditioners of the new generation) has been studied at the quantitative level using original mathematical models. In laboratory experiments, a relationship between the hydrogel degradation rate and the temperature has been obtained, and the effect of the biodestruction on the water retention curve of soil compositions with hydrogels (used as an index of their water retention capacity) has been assessed. From the automatic monitoring data of the temperature regime of soils, the potential biodestruction of hydrogels has been predicted for different climatic conditions. The loss of hydrogels during three months of the vegetation period because of destruction can exceed 30% of their initial content in irrigated agriculture under arid climatic conditions and more than 10% under humid climatic conditions. Thus, the biodestruction of hydrogels is one of the most important factors decreasing their efficiency under actual soil conditions.

  15. Void migration, coalescence and swelling in fusion materials

    International Nuclear Information System (INIS)

    Cottrell, G.A.

    2003-01-01

    A recent analysis of the migration of voids and bubbles, produced in neutron irradiated fusion materials, is outlined. The migration, brought about by thermal hopping of atoms on the surface of a void, is normally a random Brownian motion but, in a temperature gradient, can be slightly biassed up the gradient. Two effects of such migrations are the transport of voids and trapped transmutation helium atoms to grain boundaries, where embrittlement may result; and the coalescence of migrating voids, which reduces the number of non-dislocation sites available for the capture of knock-on point defects and thereby enables the dislocation bias process to maintain void swelling. A selection of candidate fusion power plant armour and structural metals have been analysed. The metals most resistant to void migration and its effects are tungsten and molybdenum. Steel and beryllium are least so and vanadium is intermediate

  16. MRI estimation of extraocular muscle swelling in dysthyroid ophthalmopathy

    International Nuclear Information System (INIS)

    Watanabe, Yoshihiro; Kakisu, Yonetsugu; Hatakeyama, Masayuki; Asanagi, Kaoru

    1988-01-01

    The thickness and width of superior, inferior and medial rectus muscles were measured via T1-weighted coronal images using a 0.5 T superconducting MRI (magnetic resonance imaging) system in 10 patients with dysthyroid ophthalmopathy and 27 normal orbits. Lateral rectus muscles were not measured because the partial volume effect obscured their contours. Patients were divided into 3 groups according to the severity of ophthalmopathy. Group A had no ophthalmopathy, group B had corneal involvement or restricted eye movement, group C had optic nerve involvement. Mean muscle thickness increased in the order A, B and C. Mean rectus muscle width was normal in group A, but dramatically increased in group C, results suggesting that swelling of the extraocular muscles is a characteristic pathologic change in dysthyroid ophthalmopathy. It is concluded that MRI is a safe and useful method of evaluating the severity of and prognosing dysthyroid ophthalmopathy. (author)

  17. Global ship accidents and ocean swell-related sea states

    Science.gov (United States)

    Zhang, Zhiwei; Li, Xiao-Ming

    2017-11-01

    With the increased frequency of shipping activities, navigation safety has become a major concern, especially when economic losses, human casualties and environmental issues are considered. As a contributing factor, the sea state plays a significant role in shipping safety. However, the types of dangerous sea states that trigger serious shipping accidents are not well understood. To address this issue, we analyzed the sea state characteristics during ship accidents that occurred in poor weather or heavy seas based on a 10-year ship accident dataset. Sea state parameters of a numerical wave model, i.e., significant wave height, mean wave period and mean wave direction, were analyzed for the selected ship accident cases. The results indicated that complex sea states with the co-occurrence of wind sea and swell conditions represent threats to sailing vessels, especially when these conditions include similar wave periods and oblique wave directions.

  18. Global ship accidents and ocean swell-related sea states

    Directory of Open Access Journals (Sweden)

    Z. Zhang

    2017-11-01

    Full Text Available With the increased frequency of shipping activities, navigation safety has become a major concern, especially when economic losses, human casualties and environmental issues are considered. As a contributing factor, the sea state plays a significant role in shipping safety. However, the types of dangerous sea states that trigger serious shipping accidents are not well understood. To address this issue, we analyzed the sea state characteristics during ship accidents that occurred in poor weather or heavy seas based on a 10-year ship accident dataset. Sea state parameters of a numerical wave model, i.e., significant wave height, mean wave period and mean wave direction, were analyzed for the selected ship accident cases. The results indicated that complex sea states with the co-occurrence of wind sea and swell conditions represent threats to sailing vessels, especially when these conditions include similar wave periods and oblique wave directions.

  19. Magnetic resonance imaging of clays: swelling, sedimentation, dissolution

    Science.gov (United States)

    Dvinskikh, Sergey; Furo, Istvan

    2010-05-01

    measure of clay distribution in extended samples during different physical processes such as swelling, dissolution, and sedimentation on the time scale from minutes to years [1-3]. To characterize the state of colloids that form after/during clay swelling the water self-diffusion coefficient was measured on a spatially resolved manner. Both natural clays and purified and ion-exchanged montmorillonite clays were investigated. The primary variables were clay composition and water ionic strength. These results have a significant impact for engineering barriers for storage of spent nuclear fuel where clay erosion by low salinity water must be addressed. Presented methods were developed under the motivation of using bentonite clays as a buffer medium to build in-ground barriers for the encapsulation of radioactive waste. Nevertheless, the same approaches can be found suitable in other applications in soil and environmental science to study other types of materials as they swell, dissolve, erode, or sediment. Acknowledgements: This work has been supported by the Swedish Nuclear Fuel and Waste Management Co (SKB) and the Swedish Research Council VR. [1] N. Nestle, T. Baumann, R. Niessner, Magnetic resonance imaging in environmental science. Environ. Sci. Techn. 36 154A (2002). [2] S. V. Dvinskikh, K. Szutkowski, I. Furó. MRI profiles over a very wide concentration ranges: application to swelling of a bentonite clay. J. Magn. Reson. 198 146 (2009). [3] S. V. Dvinskikh, I. Furó. Magnetic resonance imaging and nuclear magnetic resonance investigations of bentonite systems. Technical Report, TR-09-27, SKB (2009), www.skb.se.

  20. Influence of pressure on pyrolysis of black liquor: 1. Swelling.

    Science.gov (United States)

    Whitty, Kevin; Backman, Rainer; Hupa, Mikko

    2008-02-01

    This is the first of two papers concerning the behavior of black liquor during pyrolysis under pressurized conditions. Two industrial kraft liquors were pyrolyzed in a laboratory-scale pressurized single particle reactor and a pressurized grid heater at temperatures ranging from 650 to 1100 degrees C and at pressures between 1 and 20 bar. The dimensions of the chars produced were measured and the specific swollen volume was calculated. Swelling decreased roughly logarithmically over the pressure range 1-20 r. An expression is developed to predict the specific swollen volume at elevated pressure when the volume at 1 bar is known. The bulk density of the char increased with pressure, indicating that liquors will be entrained less easily at higher pressures.

  1. Buoy observations of the influence of swell on wind waves in the open ocean

    Energy Technology Data Exchange (ETDEWEB)

    Violante-Carvalho, N.; Robinson, I.S. [University of Southampton (United Kingdom). Oceanography Centre; Ocampo-Torres, F.J. [CICESE, Ensenada (Mexico). Dpto. de Oceanografia Fisica

    2004-04-01

    The influence of longer (swell) on shorter, wind sea waves is examined using an extensive database of directional buoy measurements obtained from a heave-pitch-roll buoy moored in deep water in the South Atlantic. This data set is unique for such an investigation due to the ubiquitous presence of a young swell component propagating closely in direction and frequency with the wind sea, as well as a longer, opposing swell. Our results show, within the statistical limits of the regressions obtained from our analysis when compared to measurements in swell free environments, that there is no obvious influence of swell on wind sea growth. For operational purposes in ocean engineering this means that power-laws from fetch limited situations describing the wind sea growth can be applied in more realistic situations in the open sea when swell is present. (author)

  2. Improved swelling resistance for PCA austenitic stainless steel under HFIR irradiation through microstructural control

    International Nuclear Information System (INIS)

    Maziasz, P.J.; Braski, D.N.

    1983-01-01

    Six microstructural variants of Prime Candidate Alloy (PCA) were evaluated for swelling resistance during HFIR irradiation, together with several heats of type 316 stainless steel (316). Swelling was negligible in all the steels at 300 0 C after approx. 44 dpa. At 500 to 600 0 C 25%-cold-worked PCA showed better void swelling resistance than type 316 at approx. 44 dpa. There was less swelling variability among alloys at 400 0 C, but again 25%-cold-worked PCA was the best. Microstructurally, swelling resistance correlated with development of fine, stable bubbles whereas high swelling was due to coarser distributions of bubbles becoming unstable and converting to voids (bias-driven cavities)

  3. Kinetics of swelling of polyelectrolyte gels: Fixed degree of ionization

    Science.gov (United States)

    Sen, Swati; Kundagrami, Arindam

    2015-12-01

    The swelling kinetics of uncharged and charged polymer (polyelectrolyte) gels in salt-free conditions is studied in one dimension by solving the constitutive equation of motion (Newton's law for the elementary gel volume) of the displacement variable by two theoretical methods: one in which the classical definition of stress is used with the bulk modulus taken as a parameter, and the other in which a phenomenological expression of the osmotic stress as a function of polymer density and degree of ionization is taken as an input to the dynamics. The time-evolution profiles for spatially varying polymer density and stress, along with the location of the gel-solvent interface, are obtained from the two methods. We show that both the polymer density (volume fraction) and stress inside the gel follow expected behaviours of being maximum for the uniformly shrunken gel, and relaxing slowly to the lowest values as the gel approaches equilibrium. We further show that, by comparing the temporal profiles of the gel-solvent interface and other variables between the two methods, one may attempt to assign an effective bulk modulus to the polyelectrolyte gel as a function of the degree of ionization and other parameters of the gel such as hydrophobicity, cross-link density, and the temperature. The major result we get is that the effective bulk modulus of a polyelectrolyte gel increases monotonically with its degree of ionization. In the process of identifying the parameters for a monotonic swelling, we calculated using a well-known expression of the free energy the equilibrium results of two-phase co-existence and the critical point of a polyelectrolyte gel with a fixed degree of ionization.

  4. Swelling of two-dimensional polymer rings by trapped particles.

    Science.gov (United States)

    Haleva, E; Diamant, H

    2006-09-01

    The mean area of a two-dimensional Gaussian ring of N monomers is known to diverge when the ring is subject to a critical pressure differential, p c ~ N -1. In a recent publication (Eur. Phys. J. E 19, 461 (2006)) we have shown that for an inextensible freely jointed ring this divergence turns into a second-order transition from a crumpled state, where the mean area scales as [A]~N-1, to a smooth state with [A]~N(2). In the current work we extend these two models to the case where the swelling of the ring is caused by trapped ideal-gas particles. The Gaussian model is solved exactly, and the freely jointed one is treated using a Flory argument, mean-field theory, and Monte Carlo simulations. For a fixed number Q of trapped particles the criticality disappears in both models through an unusual mechanism, arising from the absence of an area constraint. In the Gaussian case the ring swells to such a mean area, [A]~ NQ, that the pressure exerted by the particles is at p c for any Q. In the freely jointed model the mean area is such that the particle pressure is always higher than p c, and [A] consequently follows a single scaling law, [A]~N(2) f (Q/N), for any Q. By contrast, when the particles are in contact with a reservoir of fixed chemical potential, the criticality is retained. Thus, the two ensembles are manifestly inequivalent in these systems.

  5. Study of swelling behavior in ArF resist during development by the QCM method (3): observations of swelling layer elastic modulus

    Science.gov (United States)

    Sekiguchi, Atsushi

    2013-03-01

    The QCM method allows measurements of impedance, an index of swelling layer viscosity in a photoresist during development. While impedance is sometimes used as a qualitative index of change in the viscosity of the swelling layer, it has to date not been used quantitatively, for data analysis. We explored a method for converting impedance values to elastic modulus (Pa), a coefficient expressing viscosity. Applying this method, we compared changes in the viscosity of the swelling layer in an ArF resist generated during development in a TMAH developing solution and in a TBAH developing solution. This paper reports the results of this comparative study.

  6. Specimen Machining for the Study of the Effect of Swelling on CGR in PWR Environment.

    Energy Technology Data Exchange (ETDEWEB)

    Teysseyre, Sebastien Paul [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-06-01

    This report describes the preparation of ten specimens to be used for the study of the effect of swelling on the propagation of irradiation assisted stress corrosion cracking cracks. Four compact tension specimens, four microscopy plates and two tensile specimens were machined from a AISI 304 material that was irradiated up to 33 dpa. The specimens had been machined such as to represent the behavior of materials with 3.7%swelling and <2% swelling.

  7. Swelling of Fe-Mn and Fe-Cr-Mn alloys at high neutron fluence

    International Nuclear Information System (INIS)

    Garner, F.A.; Brager, H.R.

    1986-06-01

    Swelling data on neutron-irradiated simple Fe-Cr-Mn and Fe-Mn alloys, as well as commercial Fe-Cr-Mn base alloys are now becoming available at exposure levels approaching 50 dpa. The swelling rate decreases from the ∼1%/dpa found at lower exposures, probably due to the extensive formation of ferritic phases. As expected, commercial alloys swell less than the simple alloys

  8. Comparison of swelling for structural materials on neutron and ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Loomis, B.A.

    1986-03-01

    The swelling of V-base alloys, Type 316 stainless steel, Fe-25Ni-15Cr alloys, ferritic steels, Cu, Ni, Nb-1% Zr, and Mo on neutron irradiation is compared with the swelling for these materials on ion irradiation. The results of this comparison show that utilization of the ion-irradiation technique provides for a discriminative assessment of the potential for swelling of candidate materials for fusion reactors.

  9. Relationship between equivalent chromium content and irradiation-induced swelling in 316 stainless steel

    International Nuclear Information System (INIS)

    Bates, J.F.; Guthrie, G.L.

    1974-12-01

    A correlation is noted between equivalent chromium content and resistance to irradiation induced swelling in various 316 stainless steel specimens which have slightly different chemical compositions. Several examples are cited where an increased concentration of an α-stabilizing minor constituent results in decreased swelling. It is shown that the relative swelling resistance of alloys having the same carbon and equivalent nickel contents is higher for those alloys with the higher equivalent chromium content

  10. A SIPA-based theory of irradiation creep in the low swelling rate regime

    International Nuclear Information System (INIS)

    Garner, F.A.; Woo, C.H.

    1991-11-01

    A model is presented which describes the major facets of the relationships between irradiation creep, void swelling and applied stress. The increasing degree of anisotropy in distribution of dislocation Burger's vectors with stress level plays a major role in this model. Although bcc metals are known to creep and swell at lower rates than fcc metals, it is predicted that the creep-swelling coupling coefficient is actually larger

  11. Development of a swelling equation for 20%-CW 316 in a fusion device

    International Nuclear Information System (INIS)

    1980-01-01

    The difficulties involved in the development of swelling correlations for AISI 316 in fusion environments are discussed. A set of void and bubble-swelling correlations has been developed which incorporates the limited available data from EBR-II and HFIR irradiations. It appears that at high fluences helium may play a minor role in the determination of total swelling over a considerable temperature range

  12. A formula for determination of swelling characteristics of buffer material containing bentonite and evaluation of self-sealing performance

    International Nuclear Information System (INIS)

    Komine, Hideo; Ogata, Nobuhide

    1998-01-01

    High level radioactive waste disposal facility is planned to construct in a rock board deeper than some hundreds meter at underground, it is necessary to develop a material to refill the gap between waste container and its circumferential rock board. For this material it is required to have high water sealing and swellability, and bentonite is expected to use such application. Production of soil buffer materials containing bentonite is difficult to obtain required dry density by solidifying due to in situ roll-pressing, so it is, at present, thought to be an effective method to carry a block produced in a factory to a pit for disposal to settle. When supposing to produce and settle such buffer material, a gap forming between the buffer material and circumferential rock board or waste container has a large possibility to make a water path when remaining without treating it. Therefore, the buffer material is required to have a function to fill gap portion by swelling deformation and to proof water. In this study, in order to evaluated self-sealing of bentonite, due to a theoretical examination and a laboratory experiment on swelling behavior of soil materials containing bentonite, a swelling evaluation equation of the buffer materials was proposed. And, an application example for outlined design of an actual high level radioactive waste disposal facility was introduced. (G.K.)

  13. Quantitative evaluation of polymer concentration profile during swelling of hydrophilic matrix tablets using 1H NMR and MRI methods.

    Science.gov (United States)

    Baumgartner, Sasa; Lahajnar, Gojmir; Sepe, Ana; Kristl, Julijana

    2005-02-01

    Many pharmaceutical tablets are based on hydrophilic polymers, which, after exposure to water, form a gel layer around the tablet that limits the dissolution and diffusion of the drug and provides a mechanism for controlled drug release. Our aim was to determine the thickness of the swollen gel layer of matrix tablets and to develop a method for calculating the polymer concentration profile across the gel layer. MR imaging has been used to investigate the in situ swelling behaviour of cellulose ether matrix tablets and NMR spectroscopy experiments were performed on homogeneous hydrogels with known polymer concentration. The MRI results show that the thickest gel layer was observed for hydroxyethylcellulose tablets, followed by definitely thinner but almost equal gel layer for hydroxypropylcellulose and hydroxypropylmethylcellulose of both molecular weights. The water proton NMR relaxation parameters were combined with the MRI data to obtain a quantitative description of the swelling process on the basis of the concentrations and mobilities of water and polymer as functions of time and distance. The different concentration profiles observed after the same swelling time are the consequence of the different polymer characteristics. The procedure developed here could be used as a general method for calculating polymer concentration profiles on other similar polymeric systems.

  14. Hydrogel-forming microneedles prepared from "super swelling" polymers combined with lyophilised wafers for transdermal drug delivery.

    Directory of Open Access Journals (Sweden)

    Ryan F Donnelly

    Full Text Available We describe, for the first time, hydrogel-forming microneedle arrays prepared from "super swelling" polymeric compositions. We produced a microneedle formulation with enhanced swelling capabilities from aqueous blends containing 20% w/w Gantrez S-97, 7.5% w/w PEG 10,000 and 3% w/w Na2CO3 and utilised a drug reservoir of a lyophilised wafer-like design. These microneedle-lyophilised wafer compositions were robust and effectively penetrated skin, swelling extensively, but being removed intact. In in vitro delivery experiments across excised neonatal porcine skin, approximately 44 mg of the model high dose small molecule drug ibuprofen sodium was delivered in 24 h, equating to 37% of the loading in the lyophilised reservoir. The super swelling microneedles delivered approximately 1.24 mg of the model protein ovalbumin over 24 h, equivalent to a delivery efficiency of approximately 49%. The integrated microneedle-lyophilised wafer delivery system produced a progressive increase in plasma concentrations of ibuprofen sodium in rats over 6 h, with a maximal concentration of approximately 179 µg/ml achieved in this time. The plasma concentration had fallen to 71±6.7 µg/ml by 24 h. Ovalbumin levels peaked in rat plasma after only 1 hour at 42.36±17.01 ng/ml. Ovalbumin plasma levels then remained almost constant up to 6 h, dropping somewhat at 24 h, when 23.61±4.84 ng/ml was detected. This work represents a significant advancement on conventional microneedle systems, which are presently only suitable for bolus delivery of very potent drugs and vaccines. Once fully developed, such technology may greatly expand the range of drugs that can be delivered transdermally, to the benefit of patients and industry. Accordingly, we are currently progressing towards clinical evaluations with a range of candidate molecules.

  15. Swelling behavior of γ-ray irradiated elastomers in boiling spray solution

    International Nuclear Information System (INIS)

    Yagi, Toshiaki; Kusama, Yasuo; Ito, Masayuki; Okada, Sohei; Yoshikawa, Masahito; Yoshida, Kenzo

    1983-05-01

    Elastomers swelled significantly by water sorption during a simulated LOCA test, and this phenomenon could cause the deterioration of their mechanical and electrical properties. Many factors like as radiation, heat, the composition of spray solution, types of elastomers and their formulation, related to the phenomenon. A relationship between swelling properties of the formulation-known various elastomers and the pre-aging conditions such as radiation dose and thermal aging period was studied by measuring their swelling behaviors in boiling spray solution (water and chemical solution). All eight elastomers tested showed remarkable swelling with an increase of radiation dose when they irradiated in air. A swelling in boiling water was about twice of in chemical solution. Some types of Neoprene and Hypalons had an optimum swelling dose where they showed the maxima. Over this dose, the swelling ratio decreased with dose. When irradiated under vacuum, its swelling ratio became significantly lower than that of exposed in air. This attributed the swelling phenomena closely related to radiation oxidation degradation. (author)

  16. Improved swelling resistance for PCA austenitic stainless steel under HFIR irradiation through microstructural control

    International Nuclear Information System (INIS)

    Maziasz, P.J.; Braski, D.N.

    1984-01-01

    Swelling evaluation of PCA variants and 20%-cold-worked (N-Lot) type 316 stainless steel (CW 316) at 300 to 600 0 C was extended to 44 dpa. Swelling was negligible in all the steels at 300 0 C after approx. 44 dpa. At 500 to 600 0 C 25%-cold-worked PCA showed better void swelling resistance than type 316 at approx. 44 dpa. There was less swelling variation among alloys at 400 0 C, but again 25%-cold-worked PCA was the best

  17. A volatile tracer-assisted headspace analytical technique for determining the swelling capacity of superabsorbent polymers.

    Science.gov (United States)

    Zhang, Shu-Xin; Jiang, Ran; Chai, Xin-Sheng

    2017-09-01

    This paper reports on a new method for the determination of swelling capacity of superabsorbent polymers by a volatile tracer-assisted headspace gas chromatography (HS-GC). Toluene was used as a tracer and added to the solution for polymers swelling test. Based on the differences of the tracer partitioned between the vapor and hydrogel phase before and after the polymer's swelling capacity, a transition point (corresponding to the material swelling capacity) can be observed when plotting the GC signal of toluene vs. the ratio of solution added to polymers. The present method has good precision (RSDpolymers at the elevated temperatures. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Study on the irradiation swelling of U3Si2-Al dispersion fuel

    International Nuclear Information System (INIS)

    Xing Zhonghu; Ying Shihao

    2001-01-01

    The dominant modeling mechanisms on irradiation swelling of U 3 Si 2 -Al dispersion fuel are introduced. The core of dispersion fuel is looked to as micro-fuel elements of continuous matrix. The formation processes of gas bubbles in the fuel phase are described through the behavior mechanisms of fission gases. The swelling in the fuel phase causes the interaction between fuel particles and metal matrix, and the metal matrix can restrain the irradiation swelling of fuel particles. The developed code can predict irradiation-swelling values according to the parameters of fuel elements and irradiation conditions, and the predicted values are in agreement with the measured results

  19. DART model for irradiation-induced swelling of dispersion fuel elements including aluminum-fuel interaction

    International Nuclear Information System (INIS)

    Rest, J.; Hofman, G.L.

    1997-01-01

    The Dispersion Analysis Research Tool (DART) contains models for fission-gas-induced fuel swelling, interaction of fuel with the matrix aluminum, for the resultant reaction-product swelling, and for the calculation of the stress gradient within the fuel particle. The effects of an aluminide shell on fuel particle swelling are evaluated. Validation of the model is demonstrated by a comparison of DART calculations of fuel swelling of U 3 SiAl-Al and U 3 Si 2 -Al for various dispersion fuel element designs with the data

  20. The imaging diagnosis of diffuse brain swelling due to severe brain trauma

    International Nuclear Information System (INIS)

    Shen Jianqiang; Hu Jiawang

    2008-01-01

    Objective: To discuss the clinical and pathological characteristics and the imaging types of the diffuse brain swelling due to severe brain trauma. Methods: The clinical data and CT and MR images on 48 cases with diffuse brain swelling due to severe brain trauma were analyzed. Results: Among these 48 cases of the diffuse brain swelling due to severe brain trauma, 33 cases were complicated with brain contusions (including 12 cases brain diffuse axonal injury, 1 case infarct of the right basal ganglion), 31 cases were complicated with hematoma (epidural, subdural or intracerebral), 27 cases were complicated with skull base fracture, and 10 cases were complicated with subarachnoid hematoma. The CT and MR imaging of the diffuse brain swelling included as followed: (1) Symmetrically diffuse brain swelling in both cerebral hemispheres with cerebral ventricles decreased or disappeared, without median line shift. (2)Diffuse brain swelling in one side cerebral hemisphere with cerebral ventricles decreased or disappeared at same side, and median line shift to other side. (3) Subarachnoid hematoma or little subcortex intracerebral hematoma were complicated. (4) The CT value of the cerebral could be equal, lower or higher comparing with normal. Conclusion: The pathological reason of diffuse brain swelling was the brain vessel expanding resulting from hypothalamus and brainstem injured in severe brain trauma. There were four CT and MR imaging findings in diffuse brain swelling. The diffuse brain swelling without hematoma may be caused by ischemical reperfusion injury. (authors)

  1. High dose stainless steel swelling data on interior and peripheral oxide fuel pins

    International Nuclear Information System (INIS)

    Boltax, A.; Foster, J.P.; Nayak, U.P.

    1983-01-01

    High dose (2 x 10 23 n/cm 2 , E > 0.1 Mev) swelling data obtained on 20% cold-worked AISI 316 stainless steel (N-lot) cladding from mixed-oxide fuel pins show large differences in swelling incubation dose due to pre-incubation dose temperature changes. Circumferential swelling variations of 1.5 to 4 times were found in peripheral fuel pin cladding which experienced 30 to 60 deg C temperature changes due to movement in a temperature gradient. Consideration is given to the implications of these results to low swelling materials development and core design. (author)

  2. The effect of radiation dose on the crosslink density of ultra-high molecular weight polyethylene (UHMWPE) measured by a novel swelling method

    International Nuclear Information System (INIS)

    Muratoglu, O.K.; Bragdon, C.R.; O'Connor, D.O.; Jasty, M.; Harris, W.H.

    1998-01-01

    The crosslink density of a polyethylene network structure can be determined by swelling in hot xylene (130 deg C). The Flory's swelling theory is generally used to calculate the crosslink density, dx (ln(l-q -1 ) + q -1 + Xq -1 )/(V l q -1/3 ), where V l is the molar volume of xylene at 130 deg C (136 cc/mol), X is the xylene-polyethylene interaction parameter, and q is the equilibrium volume swelling ratio of cross-linked network in hot xylene. Conventionally, q is measured using gravimetric methods as described in ASTM D2765-95. However, as noted in the ASTM standard, the gravimetric method has a large error factor associated with the measurement of q (as much as 100%). UHMWPE was irradiated (range of 25 to 300 kGy) using an AECL I 10/1 linear electron beam accelerator operated at 1 kW. The irradiated specimens were subsequently melt-annealed at 150 deg C for 2 hours in vacuum. For swelling experiments, 2 mm thin samples were machined using a diamond blade. The sample sizes were kept at around 3x3x2 mm and the bottom and top surfaces were machined parallel to each other. The equilibrium volume swelling ratios were determined using a Perkin-Elmer TMA/DMA 7 (n=3 for each radiation dose level). The samples were placed in a quartz basket-probe assembly and lowered into a xylene/antioxidant bath at room temperature. The xylene was then heated to 130 deg C at 5 deg C/min and held at 130 deg C for 2 hours. The swelling was then recorded with the upward motion of the probe until the equilibrium swelling was achieved. (The experiments were carried out in 3 orthogonal directions which confirmed the isotropy of swelling). From this one-dimensional change in height, q was calculated by taking into account the volumetric expansion due to heating and melting. (author)

  3. Swelling analysis of austenitic stainless steels by means of ion irradiation and kinetic modeling

    International Nuclear Information System (INIS)

    Kohyama, Akira; Donomae, Takako

    1999-03-01

    The influences of irradiation environment on the swelling behavior of austenitic stainless steel has been studied, to aid understanding the origin of the difference in swelling response of PNC316 stainless steel in fuel-pin environment and in materials irradiation capsules, in terms of irradiation conditions, damage mechanism and material conditions. This work focused on the theoretical investigation of the influence of temperature variation on microstructural development of austenitic stainless steels during irradiation, using a kinetic rate theory model. A modeling and calculation on non-steady irradiation effects were first carried out. A fully dynamic model of point defect evolution and extended defect development, which accounts for cascade damage, was developed and successfully applied to simulate the interstitial loop evolution in low temperature regimes. The influence of cascade interstitial clustering on dislocation loop formation has also been assessed. The establishment of a basis for general assessment of non-steady irradiation effects in austenitic stainless steels was advanced. The developed model was applied to evaluate the influences of temperature variation in formerly carried out CMIR and FFTF/MFA-1 FBR irradiation experiments. The results suggested the gradual approach of microstructural features to equilibrium states in all the temperature variation conditions and no sign of anomalous behavior was noted. On the other hand, there is the influence of temperature variation on microstructural development under the neutron irradiation, like CMIR. So there are some possibilities of the work of mechanism which is not taken care on this model, for example the effect of the precipitate behavior which is sensitive to irradiation temperature. (author)

  4. On recoil energy dependent void swelling in pure copper: Theoretical treatment

    International Nuclear Information System (INIS)

    Golubov, S.I.; Singh, B.N.; Trinkaus, H.

    2000-06-01

    Over the years, an enormous amount of experimental results have been reported on damage accumulation (e.g. void swelling) in metals and alloys irradiated under vastly different recoil energy conditions. Unfortunately, however, very little is known either experimentally or theoretically about the effect of recoil energy on damage accumulation. Recently, dedicated irradiation experiments using 2.5 MeV electrons, 3.0 MeV protons and fission neutrons have been carried out to determine the effect of recoil energy on the damage accumulation behaviour in pure copper and the results have been reported in Part I of this paper (Singh, Eldrup, Horsewell, Ehrhart and Dworschak 2000). The present paper attempts to provide a theoretical framework within which the effect of recoil energy on damage accumulation behaviour can be understood. The damage accumulation under Frenkel pair production (e.g. 2.5 MeV electron) has been treated in terms of the standard rate theory (SRT) model whereas the evolution of the defect microstructure under cascade damage conditions (e.g. 3.0 MeV protons and fission neutrons) has been calculated within the framework of the production bias model (PBM). Theoretical results, in agreement with experimental results, show that the damage accumulation behaviour is very sensitive to recoil energy and under cascade damage conditions can be treated only within the framework of the PBM. The intracascade clustering of self-interstitial atoms (SIAs) and the properties of SIA clusters such as one-dimensional diffusional transport and thermal stability are found to be the main reasons for the recoil energy dependent vacancy supersaturation. The vacancy supersaturation is the main driving force for the void nucleation and void swelling. In the case of Frenkel pair production, the experimental results are found to be consistent with the SRT model with a dislocation bias value of 2 %. (au)

  5. French Polynesia Hotspot Swells Explained By Dynamic Topography

    Science.gov (United States)

    Adam, C.; Yoshida, M.; Isse, T.; Suetsugu, D.; Shiobara, H.; Sugioka, H.; Kanazawa, T.; Fukao, Y.; Barruol, G.

    2007-12-01

    Situated on the South Pacific Superswell, French Polynesia is a region characterized by numerous geophysical anomalies among which a high volcanism concentration. Seven hotspots are required to explain the observed chains, volcanism ages and geochemical trends. Many open questions still remain on the origin of these hotspot chains: are they created by passive uplift of magma due to discontinuities in the structure of the lithosphere or by the ascent of mantle plumes? In this case, at which depth do these plumes initiate in the mantle? Many geophysical observations (bathymetry, gravity, magnetism, volcanism ages..) are used to understand the unique phenomenon occurring on this region. The most useful information may come from tomography models since they provide a 3D view of the mantle. Until recently, the tomography models over the region were quite inaccurate because of the sparse location of the seismic stations. The deployment of two new seismic stations networks (BBOBS and temporary island stations) has lately remedied this failing. The resulting tomography model obtained through the inversion of Rayleigh waves provides the most accurate view of the shallowest part of the mantle (depths ≤ 240 km) beneath French Polynesia. Indeed, for the first time the accuracy of a tomography model is good enough to provide information about plume phenomenology in this complex region. In order to quantify the plumes effect on the seafloor, we compute the dynamic topography through an instantaneous flow model. The general trend of the observed depths anomalies (highs and lows) is well recovered. For example the amplitude, location and extension of the swells associated with the Society, Macdonald and Rarotonga are accurately described by the dynamic model. We also find that dynamic uplift is associated with the Tuamotu archipelago which means that a part of the observed swell is due to the present day action of plumes. Since no volcanism ages are available over this chain

  6. Swelling pressure and water absorption property of compacted granular bentonite during water absorption

    International Nuclear Information System (INIS)

    Oyamada, T.; Komine, H.; Murakami, S.; Sekiguchi, T.; Sekine, I.

    2012-01-01

    Document available in extended abstract form only. Bentonite is currently planned to be used as buffer materials in engineered barrier of radioactive waste disposal. Granular bentonites are expected as the materials used in constructions as buffer materials by in-situ compaction methods. After applying these buffer materials, it is expected that the condition of the buffer area changes in long-term by the seepage of groundwater into buffer area. Therefore, it is important to understand water movement and swelling behavior of the buffer materials for evaluating the performance of engineered barrier. In this study, we investigated water absorption property and swelling pressure of compacted granular bentonite. Specifically, the process of swelling pressure and amount of water absorption of granular bentonite-GX (Kunigel-GX, produced at the Tsukinuno mine in Japan) were observed by laboratory tests. To discuss the influence of maximum grain size of bentonite particle on swelling pressure and water absorption property, two types of samples were used. One is granular sample which is Bentonite-GX controlled under 2 mm the maximum grain size, the other is milled sample which is Bentonite-GX with the maximum grain size under 0.18 mm by milling with the agate mortar. In addition, the mechanism on the swelling pressure of compacted granular bentonite was considered and discussed. In the cases of granular sample, swelling pressure increases rapidly, then gradually continues to increase up to maximum value. In the cases of milled sample, swelling pressure also increases rapidly at first. However, then its value decreases before progressing of gradual increase continues. Especially, this trend was clearly observed at a relatively low dry density. At the peaks of these curves, the swelling pressure of granular samples is lower than that of milled samples. In addition, the increasing of swelling pressure by the time the peak observed during the process of swelling pressure from

  7. On the swelling of ion exchange resins used in Swedish nuclear power plants

    International Nuclear Information System (INIS)

    Nilsson, A.C.; Hoegfeldt, E.; Muhammed, M.

    1988-03-01

    Ion exchange resins are used in nuclear power plants for purification and decontamination of water. In some of the cases, the spent resins are solidified by drying at elevated temperatures and then molded together with bitumen before final disposal. The objective of the present work is to study the swelling behavior of such resins and describe it with a model that permits calculation of the water uptake into the bituminized resins and the external swelling pressure that might develop by the swelling resins under repository conditions. The experimental part of the study comprises the swelling of ion exchange resins upon their exposure to water vapour before and after thermal treatment under conditions simulating those used in the various solidification processes. Seven different resins were studied in different chemical forms; H + , N + and OH - , So 4 2- for the cation an anion exchangers respectively. For each resin, water uptake, density and volume were measured at different water activities at 25 degrees C. The swelling pressure for all resins studied was calculated. A slight increase in swelling pressure after thermal treatment could be observed, especially for anion exchangers. The apparent molar volume of water in the resin phase has been determined and the swelling free energies of swelling has been calculated from experimental data at 25 degrees C and estimated at 0 degrees C. (authors)

  8. Effect of irradiation damage and helium on the swelling and structure of vanadium-base alloys

    International Nuclear Information System (INIS)

    Chung, H.M.; Loomis, B.A.; Smith, D.L.

    1993-12-01

    Swelling behavior and microstructural evolution of V-Ti, V-Cr-Ti, and V-Ti-Si alloys were investigated after irradiation at 420--600C up to 114 dpa. The alloys exhibited swelling maxima between 30 and 80 dpa and swelling decreased on irradiation to higher dpa. This is in contrast to the monotonically increasing swelling of binary alloys that contain Fe, Ni, Cr, Mo, W, and Si. Precipitation of dense Ti 5 Si 3 promotes good resistance to swelling of the Ti-containing alloys and it was concluded that Ti of >3 wt.% and 400--1000 wppm Si are necessary to effectively suppress swelling. Swelling was minimal in V-4Cr-4Ti, identified as the most promising alloy based on good mechanical properties and superior resistance to irradiation embrittlement. V-20Ti doped with B exhibited somewhat higher swelling because of He generation. Lithium atoms, generated from transmutation of 10 B, formed γ-LiV 2 O 5 precipitates and did not seem to produce undesirable effects on mechanical properties

  9. Effects of swelling forces on the durability of wood adhesive bonds

    Science.gov (United States)

    Blake M. Hofferber; Edward Kolodka; Rishawn Brandon; Robert J. Moon; Charles R. Frihart

    2006-01-01

    The purpose of this study was to investigate the role of wood swelling on performance of wood-adhesive bonds (resorcinol formaldehyde, epoxy, emulsion polymerisocyanate), for untreated and acetylated wood. Effects of these treatments on measured strain anisotropy and swelling stress were measured and then related to compressive shear strength and percentage wood...

  10. Swelling of whey and egg white protein hydrogels with stranded and particulate microstructures.

    Science.gov (United States)

    Li, Hui; Zhao, Lei; Chen, Xiao Dong; Mercadé-Prieto, Ruben

    2016-02-01

    Swelling of protein hydrogels in alkaline conditions strongly depends on the gel microstructure. Stranded transparent gels swell as predicted using a modified Flory-Rehner model with the net protein charge. Particulate opaque gels swell very differently, with a sudden increase at a narrow pH range. Its swelling is not controlled by the protein charge, but by the destruction of the non-covalent interactions. Comparable dissolution thresholds, one with pH and another with the degree of swelling, are observed in both types of microstructures. These conclusions are valid for both whey protein isolate (WPI) gels and egg white gels, suggesting that they are universal for all globular proteins that can form such microscructures. Differences are observed, however, from the prevalent chemical crosslinks in each protein system. Non-covalent interactions dominate WPI gels; when such interactions are destroyed at pH≥11.5 the gels swell extensively and eventually dissolve. In egg white gels, the higher degree of disulphide crosslinking allows extensive swelling when non-covalent interactions are destroyed, but dissolution only occurs at pH≥13 when covalent crosslinks are cleaved. The current study highlights that the microstructure of protein hydrogels, a unique particularity of protein systems compared to other synthetic hydrogels, defines swelling. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. A rare cause of calf swelling: the Morel-Lavallee lesion.

    LENUS (Irish Health Repository)

    Moriarty, J M

    2011-03-01

    Calf swelling is a common clinical presentation with a wide and varied differential diagnosis. The Morel-Lavallee is a rare cause of subcutaneous swelling, caused by post-traumatic shearing of the hypodermis from the underlying fascia. The potential space so created fills with blood, lymph and necrotic fat giving specific findings on MR evaluation.

  12. Effect of pre-swelling of coal on its liquefaction properties

    Energy Technology Data Exchange (ETDEWEB)

    Hengfu Shui; Zhicai Wang; Meixia Cao [Anhui University of Technology, Ma' anshan (China). School of Chemistry & Chemical Engineering

    2007-07-01

    The effects of pre-swelling of Shenhua coal on its liquefaction property were studied in this paper. It was found that pre-swelling treatments of Shenhua coal in three solvents, i.e toluene (TOL), N-methyl-2-pyrrolidinone (NMP) and tetralin (THN) increased its liquefaction conversion, and the liquefied product distributions were also quite different. Removal of the pre-swelling solvent from the swollen coals further increased the liquefaction conversion compared to that of the swollen coals with the swelling solvent existed in them. It was found that oil and gas yields for the liquefaction of swollen coals in NMP and TOL with swelling solvent existed dramatically decreased. Pre-swelling in THN at 120{sup o}C gave the highest liquefaction conversion, however the liquefaction conversion decreased with the increase of pre-swelling temperature in the case of NMP. TG and FTIR analyses of raw coal, the swollen coals and liquefied products were carried out and the mechanism of the effects of pre-swelling of coal on its extraction and liquefaction behaviors were probed in the paper. 12 refs., 6 figs., 3 tabs.

  13. Thermal ramp rate effects on mixed-oxide fuel swelling/gas release

    International Nuclear Information System (INIS)

    Hinman, C.A.; Randklev, E.H.

    1979-01-01

    Macroscopic swelling behavior of PNL-10 was compared to that of PNL-2 fuel and it was found that the swelling-threshold behavior is similar for similar thermal conditions. Transient fission gas release for the PNL-10 fuel is very similar to that observed for the PNL-2 fuel for similar thermal conditions

  14. The temperature dependence of void swelling of fast reactor irradiated 316 stainless steel

    International Nuclear Information System (INIS)

    Bramman, J.I.; Brown, C.

    The swelling versus temperature profile for cold-worked M316 stainless steel irradiated in DFR to fluences around 6.5 x 10 22 n.cm -2 (E > 0.1 MeV) is singly-peaked with maximum swelling at just below 600 0 C. The underlying microstructural features are discussed

  15. Variations in swells along Eastern Arabian Sea during the summer monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Johnson, G.; SanilKumar, V.; Sanjiv, P.C.; Singh, J.; Pednekar, P.S.; AshokKumar, K.; Dora, G.U.; Gowthaman, R.

    A study was carried out to find the variation in wave characteristics along the eastern Arabian Sea and the influence of swells in the nearshore waves at 3 locations during summer monsoon in 2010. Percentage of swells in the measured waves was 75...

  16. Loss of knee-extension strength is related to knee swelling after total knee arthroplasty

    DEFF Research Database (Denmark)

    Holm, Bente; Kristensen, Morten T; Bencke, Jesper

    2010-01-01

    To examine whether changes in knee-extension strength and functional performance are related to knee swelling after total knee arthroplasty (TKA).......To examine whether changes in knee-extension strength and functional performance are related to knee swelling after total knee arthroplasty (TKA)....

  17. Polymerization of alanine in the presence of a non-swelling montmorillonite

    Science.gov (United States)

    Paecht-Horowitz, M.; Lahav, N.

    1977-01-01

    Alanine, starting from alanine-adenylate, has been polymerized in the presence of non-swelling Al-montmorillonite. The yield of polymerization is much lower than that obtained in the presence of swelling Na-montmorillonite. The possibility that the changing interlayer spacing in Na-montmorillonite might be responsible for its catalytic properties, is discussed.

  18. Swelling dynamics of zwitterionic copolymers: The effects of concentration and type of anion and cation

    NARCIS (Netherlands)

    de Grooth, Joris; Ogieglo, Wojciech; de Vos, Wiebe Matthijs; Girones nogue, Miriam; Nijmeijer, Dorothea C.; Benes, Nieck Edwin

    2014-01-01

    The effect of different salts and their concentration on the swelling of zwitterionic copolymers has been investigated for bulk polymer samples as well as for thin films. Relatively low ratios of the zwitterionic monomer already radically change the swelling properties of the copolymer. Increasing

  19. Hawaiian volcanic propagation and Hawaiian swell asymmetry : evidence of northwestward flow of the deep upper mantle

    NARCIS (Netherlands)

    Cox, RT

    1999-01-01

    Bathymetry and the geoid anomaly of the northern flank of the Hawaiian swell is broader and higher than the southern flank, and it is characterized by higher heat flow than the axis or southern flank. It is here proposed that the northern flank of the Hawaiian swell has been augmented by heat

  20. Sea and swell along west coast of India: Study based on measured data

    Digital Repository Service at National Institute of Oceanography (India)

    SanilKumar, V.; AshokKumar, K.; Pednekar, P.; Gowthaman, R.

    Conference on Harbour and Ocean Engineering 12-14, Dec. 2007, at NITK, Surathkal 736 SEA AND SWELL...@nio.org pprem@nio.org rgowtham@nio.org Ocean Engineering Division National Institute of Oceanography Dona Paula, Goa 403 004 India ABSTRACT Separation of sea and swell from the measured data is important for studying the wind wave dynamics...

  1. Characterization of fuel swelling in helium-bonded carbide fuel pins

    International Nuclear Information System (INIS)

    Louie, D.L.Y.

    1987-08-01

    This work is not only the first attempt at characterizing the swelling of (U,Pu)C fuel pellets, but it also represents the only detailed examinations on carbide fuel swelling at high fuel burnups (4 to 16 at. %). This characterization includes the contributions of fission gases, cracks and solid fission products to fuel swelling. Significantly, the contributions of fission gases and cracks were determined by using the image analysis technique (IAT) which allows researchers to take areal measurements of the irradiated fuel porosity and cracks from the photographs of metallographic fuel samples. However, because areal measurements for varying depths in the fuel pellet could not be obtained, the crack areal measurements could not be converted into volumetric quantities. Consequently, in this situation, an areal fuel swelling analysis was used. The macroscopic fission-gas induced fuel swelling (MAS) caused by fission-gas bubbles and pores > 1 μm was determined using the measured irradiated fuel porosity because the measuring range of IAT is limited to bubbles and pores >1 μm. Conversely, for fuel swelling induced by fission-gas bubbles < 1 μm, the microscopic fission-gas induced fuel swelling (MIS) was estimated using an areal fuel swelling model

  2. Experimental study of swelling of irradiated solid methane during annealing

    International Nuclear Information System (INIS)

    Shabalin, E.; Fedorov, A.; Kulagin, E.; Kulikov, S.; Melikhov, V.; Shabalin, D.

    2008-01-01

    Solid methane, notwithstanding its poor radiation properties, is still widely in use at pulsed neutron sources. One of the specific problems is radiolytic hydrogen gas pressure on the walls of a methane chamber during annealing of methane. Results of experimental study of this phenomenon under fast neutron irradiation with the help of a specially made low temperature irradiation rig at the IBR-2 pulsed reactor are presented. Peak pressure on the wall of the experimental capsule during heating of a sample irradiated at 23-35 K appeared to have a maximum of 27 bar at the absorbed dose 20 MGy, and then falls down with higher doses. Pressure always reached its peak value within the temperature range 72-79 K. Generally, three phases of methane swelling during heating can be distinguished, each characterized by proper rate and intensity. Results of this study were accounted for in design of the solid methane moderator of the second target station of the ISIS facility (England)

  3. Internal structure and swelling behaviour of in silico microgel particles

    Science.gov (United States)

    Rovigatti, Lorenzo; Gnan, Nicoletta; Zaccarelli, Emanuela

    2018-01-01

    Microgels are soft colloids that, by virtue of their polymeric nature, can react to external stimuli such as temperature or pH by changing their size. The resulting swelling/deswelling transition can be exploited in fundamental research as well as for many diverse practical applications, ranging from art restoration to medicine. Such an extraordinary versatility stems from the complex internal structure of the individual microgels, each of which is a crosslinked polymer network. Here we employ a recently-introduced computational method to generate realistic microgel configurations and look at their structural properties, both in real and Fourier space, for several temperatures across the volume phase transition as a function of the crosslinker concentration and of the confining radius employed during the ‘in-silico’ synthesis. We find that the chain-length distribution of the resulting networks can be analytically predicted by a simple theoretical argument. In addition, we find that our results are well-fitted to the fuzzy-sphere model, which correctly reproduces the density profile of the microgels under study.

  4. Brain Cell Swelling During Hypocapnia Increases with Hyperglycemia or Ketosis

    Science.gov (United States)

    Glaser, Nicole; Bundros, Angeliki; Anderson, Steve; Tancredi, Daniel; Lo, Weei; Orgain, Myra; O'Donnell, Martha

    2014-01-01

    Severe hypocapnia increases the risk of DKA-related cerebral injury in children, but the reason for this association is unclear. To determine whether the effects of hypocapnia on the brain are altered during hyperglycemia or ketosis, we induced hypocapnia (pCO2 20 ± 3 mmHg) via mechanical ventilation in three groups of juvenile rats: 25 controls, 22 hyperglycemic rats (serum glucose 451± 78 mg/dL) and 15 ketotic rats (beta-hydroxy butyrate 3.0 ± 1.0 mmol/L). We used magnetic resonance imaging to measure cerebral blood flow (CBF) and apparent diffusion coefficient (ADC) values in these groups and in 17 ventilated rats with normal pCO2 (40±3 mmHg). In a subset (n=35), after 2 hrs of hypocapnia, pCO2 levels were normalized (40±3 mmHg) and ADC and CBF measurements repeated. Declines in CBF with hypocapnia occurred in all groups. Normalization of pCO2 after hypocapnia resulted in striatal hyperemia. These effects were not substantially altered by hyperglycemia or ketosis, however, declines in ADC during hypocapnia were greater during both hyperglycemia and ketosis. We conclude that brain cell swelling associated with hypocapnia is increased by both hyperglycemia and ketosis, suggesting that these metabolic conditions may make the brain more vulnerable to injury during hypocapnia. PMID:24443981

  5. Experimental Analysis on Shrinkage and Swelling in Ordinary Concrete

    Directory of Open Access Journals (Sweden)

    Barbara Kucharczyková

    2017-01-01

    Full Text Available The paper deals with the experimental determination of shrinkage development during concrete ageing. Three concrete mixtures were made. They differed in the amount of cement in the fresh mixture, 300, 350, and 400 kg/m3. In order to determine the influence of plasticiser on the progress of volume changes, another three concrete mixtures were prepared with plasticiser in the amount of 0.25% by cement mass. Measurements were performed with the goal of observing the influence of cement and plasticiser content on the overall development of volume changes in the concrete. Changes in length and mass losses of the concrete during ageing were measured simultaneously. The continuous measurement of concrete mass losses caused by drying of the specimen’s surface proved useful during the interpretation of results obtained from the concrete shrinkage measurement. During the first 24 hours of ageing, all the concrete mixtures exhibited swelling. Its magnitude and progress were influenced by cement, water, and plasticiser content. However, a loss of mass caused by water evaporation from the surface of the specimens was also recorded in this stage. The measured progress of shrinkage corresponded well to the progress of mass loss.

  6. Measurements and observations on microscopic swelling in MX-type fuels

    International Nuclear Information System (INIS)

    Ronchi, C.; Ray, I.L.F.; Thiele, H.; Laar, J. van de.

    1978-01-01

    Microscopic swelling has been investigated by electron microscopy in several MX-type fuels, irradiated in fast and thermal neutron flux. The results show that fission gas bubbles in these compounds grow to large sizes if the in-pile fuel temperature rises above a critical value (swelling critical temperature Tsub(C)). A comparison has been made of the swelling rates in fuels of different composition, showing that Tsub(C) increases from carbides to nitrides. In fuels subjected to in-pile restructuring (highly rated) He-bonded pins microscopic swelling is affected by pore and grain boundary migration. The influence of these phenomena on the fuel swelling performance has been discussed

  7. Water-Triggered Dimensional Swelling of Cellulose Nanofibril Films: Instant Observation Using Optical Microscope

    International Nuclear Information System (INIS)

    Qing, Y.; Wu, Y.; Li, X.; Qing, Y.; Cai, Z.

    2013-01-01

    To understand the swelling behavior of cellulose nano fibril (CNF) films, the dimensional variation of untreated and phenol formaldehyde modified CNF (CNF/PF) films soaked in distilled water was examined in situ with microscopic image recording combined with pixel calculation. Results showed that a dramatic thickness increase exhibited in both CNF and CNF/PF films, despite being at different swelling levels. Compared to thickness swelling, however, the width expansion for these films is negligible. Such significant difference in dimensional swelling for CNF and PF modified films is mainly caused by nano fibril deposition and their meso structure. However, addition of PF modifier has a positive effect on the constraint of water absorption and thickness swelling, which is strongly dependent on PF loadings

  8. Cell swelling activates separate taurine and chloride channels in Ehrlich mouse ascites tumor cells

    DEFF Research Database (Denmark)

    Lambert, Ian Henry; Hoffmann, Else Kay

    1994-01-01

    The taurine efflux from Ehrlich ascites tumor cells is stimulated by hypotonic cell swelling. The swelling-activated taurine efflux is unaffected by substitution of gluconate for extracellular Cl– but inhibited by addition of MK196 (anion channel blocker) and 4,4 -diisothiocyanostilbene-2......,2 -disulfonic acid (DIDS; anion channel and anion exchange blocker) and by depolarization of the cell membrane. This is taken to indicate that taurine does not leave the osmotically swollen Ehrlich cells in exchange for extracellular Cl–, i.e., via the anion exchanger but via a MK196- and DIDS-sensitive channel...... that is potential dependent. An additional stimulation of the swelling-activated taurine efflux is seen after addition of arachidonic acid and oleic acid. Cell swelling also activates a Mini Cl– channel. The Cl– efflux via this Cl– channel, in contrast to the swelling-activated taurine efflux, is unaffected by DIDS...

  9. Swelling/shrinkage of compacted and natural clayey soils

    International Nuclear Information System (INIS)

    Nowamooz, H.

    2007-12-01

    This thesis presents an experimental study performed on compacted loose and natural dense expansive soils using osmotic odometers. Several successive cycles were applied under three different low constant vertical net stresses. The loose soil presents a significant shrinkage accumulation while the dense one produces the swelling accumulation during the suction cycles. The suction cycles induced an equilibrium stage which indicates an elastic behaviour of the samples. At the end of suction cycles, a loading/unloading test was performed at the constant suctions for both materials. The mechanical parameters, i.e. the virgin compression index lambda(s), the apparent pre-consolidation stress p0(s) and the elastic compression index values lambda are completely dependent on the followed stress paths. The whole experimental results made it possible to define the yielding surfaces: suction limit between micro and macrostructure (Lm/M), loading collapse (LC) and saturation curve (SCS). The suction limit (Lm/M) depends completely to the soil fabrics and to the diameter separating the micro- and macrostructure. The pre-consolidation stress variation with suction is represented by the LC surface. The compression curves at different imposed suctions converge towards the saturated state for the high applied vertical stresses. We consider the saturation pressure (Psat) as the necessary pressure to reach the saturated state for an imposed suction. The higher the suction, the higher the saturation pressure. The yielding surface representing this pressure as a function of suction is called the saturation curve (SCS). Generally we can state that the suction cycles unified the LC and SC surfaces and increased the (Lm/M) up to a higher value. (author)

  10. Cell swelling and ion redistribution assessed with intrinsic optical signals

    Directory of Open Access Journals (Sweden)

    WITTE OTTO W.

    2001-01-01

    Full Text Available Cell volume changes are associated with alterations of intrinsic optical signals (IOS. In submerged brain slices in vitro, afferent stimulation induces an increase in light transmission. As assessed by measurement of the largely membrane impermeant ion tetramethylammonium (TMA in the extracellular space, these IOS correlate with the extent and time course of the change of the extracellular space size. They have a high signal to noise ratio and allow measurements of IOS changes in the order of a few percent. Under conditions of reduced net KCl uptake (low Cl solution a directed spatial buffer mechanism (K syphoning can be demonstrated in the neocortex with widening of the extracellular space in superficial layers associated with a reduced light transmission and an increase of extracellular K concentration. The nature of the IOS under pathophysiological conditions is less clear. Spreading depressions first cause an increase of light transmission, then a decrease. Such a decrease has also been observed following application of NMDA where it was associated with structural damage. Pharmacological analyses suggest that under physiological conditions changes of extracellular space size are mainly caused by astrocytic volume changes while with strong stimuli and under pathophysiological conditions also neuronal swelling occurs. With reflected light usually signals opposite to those observed with transmitted light are seen. Recording of IOS from interface slices gives very complex signals since under these conditions an increase of light transmission has been reported to be superimposed by a decrease of the signal due to mechanical lensing effects of the slice surface. Depending on the method of measurement and the exact conditions, several mechanisms may contribute to IOS. Under well defined conditions IOS are a useful supplementary tool to monitor changes of extracellular volume both in space and time.

  11. Effect of seawater on consistency, infiltration rate and swelling characteristics of montmorillonite clay

    Directory of Open Access Journals (Sweden)

    Mohie Eldin Elmashad

    2016-08-01

    Full Text Available This paper presents the results of an experimental investigation performed to quantify the effect of mixing clayey soils with saltwater on consistency and swelling characteristics of clays. Massive natural clay deposits and compacted clay backfills either exist or are used in certain important and sensitive applications such as dams, liners, barriers and buffers in waste disposal facilities. In many cases, the clay deposits in these applications are subjected to saltwater. However, in standard laboratory classification tests, distilled or potable water are usually used in mixing test samples. This may lead to faulty interpretation of the actual in-situ consistency and volume change behaviors. In this research, an attempt is made to quantify the changes in consistency and swelling of clay soils from various locations around the Nile valley and possessing a wide range of consistency, when mixed with natural seawater with different salt concentrations. The results showed that the increase of the salt concentration of the mixing water may result in major decrease in the liquid limit and swelling characteristics of high plasticity montmorillonite clays. The reduction in the swelling of the clay soils is also proportional to the rate of saltwater infiltration. In an attempt to correlate the swelling of clays to the rate of water infiltration, a new simplified laboratory apparatus is proposed where swelling and infiltration are measured in one simple test “the swelling infiltrometer”.

  12. The wind sea and swell waves climate in the Nordic seas

    Science.gov (United States)

    Semedo, Alvaro; Vettor, Roberto; Breivik, Øyvind; Sterl, Andreas; Reistad, Magnar; Soares, Carlos Guedes; Lima, Daniela

    2015-02-01

    A detailed climatology of wind sea and swell waves in the Nordic Seas (North Sea, Norwegian Sea, and Barents Sea), based on the high-resolution reanalysis NORA10, developed by the Norwegian Meteorological Institute, is presented. The higher resolution of the wind forcing fields, and the wave model (10 km in both cases), along with the inclusion of the bottom effect, allowed a better description of the wind sea and swell features, compared to previous global studies. The spatial patterns of the swell-dominated regional wave fields are shown to be different from the open ocean, due to coastal geometry, fetch dimensions, and island sheltering. Nevertheless, swell waves are still more prevalent and carry more energy in the Nordic Seas, with the exception of the North Sea. The influence of the North Atlantic Oscillation on the winter regional wind sea and swell patterns is also presented. The analysis of the decadal trends of wind sea and swell heights during the NORA10 period (1958-2001) shows that the long-term trends of the total significant wave height (SWH) in the Nordic Seas are mostly due to swell and to the wave propagation effect.

  13. Effect of pre-swelling of coal on its solvent extraction and liquefaction properties

    Energy Technology Data Exchange (ETDEWEB)

    Hengfu Shui; Zhicai Wang; Meixia Cao [Anhui University of Technology, Ma' anshan (China). School of Chemistry and Chemical Engineering

    2008-10-15

    Effects of pre-swelling of coal on solvent extraction and liquefaction properties were studied with Shenhua coal. It was found that pre-swelling treatments of the coal in three solvents, i.e., toluene (TOL), N-methyl-2-pyrrolidinone (NMP) and tetralin (THN) increased its extraction yield and liquefaction conversion, and differed the liquefied product distributions. The pre-swollen coals after removing the swelling solvents showed increased conversion in liquefaction compared with that of the swollen coals in the presence of swelling solvents. It was also found that the yields of (oil + gas) in liquefaction of the pre-swollen coals with NMP and TOL dramatically decreased in the presence of swelling solvent. TG and FTIR analyses of the raw coal, the swollen coals and the liquefied products were carried out in order to investigate the mechanism governing the effects of pre-swelling treatment on coal extraction and liquefaction. The results showed that the swelling pre-treatment could disrupt some non-covalent interactions of the coal molecules, relax its network structure and loosened the coal structure. It would thus benefit diffusion of a hydrogen donor solvent into the coal structure during liquefaction, and also enhance the hydrogen donating ability of the hydrogen-rich species derived from the coal. 21 refs., 4 figs., 3 tabs.

  14. Episodic swell growth inferred from variable uplift of the Cape Verde hotspot islands

    Science.gov (United States)

    Ramalho, R.; Helffrich, G.; Cosca, M.; Vance, D.; Hoffmann, D.; Schmidt, D.N.

    2010-01-01

    On the Beagle voyage, Charles Darwin first noted the creation and subsidence of ocean islands, establishing in geology's infancy that island freeboard changes with time. Hotspot ocean islands have an obvious mechanism for freeboard change through the growth of the bathymetric anomaly, or swell, on which the islands rest. Models for swell development indicate that flexural, thermal or dynamic pressure contributions, as well as spreading of melt residue from the hotspot, can all contribute to island uplift. Here we test various models for swell development using the uplift histories for the islands of the Cape Verde hotspot, derived from isotopic dating of marine terraces and subaerial to submarine lava-flow morphologies. The island uplift histories, in conjunction with inter-island spacing, uplift rate and timing differences, rule out flexural, thermal or dynamic pressure contributions. We also find that uplift cannot be reconciled with models that advocate the spreading of melt residue in swell development unless swell growth is episodic. Instead, we infer from the uplift histories that two processes have acted to raise the islands during the past 6 Myr. During an initial phase, mantle processes acted to build the swell. Subsequently, magmatic intrusions at the island edifice caused 350 m of local uplift at the scale of individual islands. Finally, swell-wide uplift contributed a further 100 m of surface rise.

  15. Fractional cable equation for general geometry: A model of axons with swellings and anomalous diffusion

    Science.gov (United States)

    López-Sánchez, Erick J.; Romero, Juan M.; Yépez-Martínez, Huitzilin

    2017-09-01

    Different experimental studies have reported anomalous diffusion in brain tissues and notably this anomalous diffusion is expressed through fractional derivatives. Axons are important to understand neurodegenerative diseases such as multiple sclerosis, Alzheimer's disease, and Parkinson's disease. Indeed, abnormal accumulation of proteins and organelles in axons is a hallmark of these diseases. The diffusion in the axons can become anomalous as a result of this abnormality. In this case the voltage propagation in axons is affected. Another hallmark of different neurodegenerative diseases is given by discrete swellings along the axon. In order to model the voltage propagation in axons with anomalous diffusion and swellings, in this paper we propose a fractional cable equation for a general geometry. This generalized equation depends on fractional parameters and geometric quantities such as the curvature and torsion of the cable. For a cable with a constant radius we show that the voltage decreases when the fractional effect increases. In cables with swellings we find that when the fractional effect or the swelling radius increases, the voltage decreases. Similar behavior is obtained when the number of swellings and the fractional effect increase. Moreover, we find that when the radius swelling (or the number of swellings) and the fractional effect increase at the same time, the voltage dramatically decreases.

  16. Deformation mechanisms in a coal mine roadway in extremely swelling soft rock.

    Science.gov (United States)

    Li, Qinghai; Shi, Weiping; Yang, Renshu

    2016-01-01

    The problem of roadway support in swelling soft rock was one of the challenging problems during mining. For most geological conditions, combinations of two or more supporting approaches could meet the requirements of most roadways; however, in extremely swelling soft rock, combined approaches even could not control large deformations. The purpose of this work was to probe the roadway deformation mechanisms in extremely swelling soft rock. Based on the main return air-way in a coal mine, deformation monitoring and geomechanical analysis were conducted, as well as plastic zone mechanical model was analysed. Results indicated that this soft rock was potentially very swelling. When the ground stress acted alone, the support strength needed in situ was not too large and combined supporting approaches could meet this requirement; however, when this potential released, the roadway would undergo permanent deformation. When the loose zone reached 3 m within surrounding rock, remote stress p ∞ and supporting stress P presented a linear relationship. Namely, the greater the swelling stress, the more difficult it would be in roadway supporting. So in this extremely swelling soft rock, a better way to control roadway deformation was to control the releasing of surrounding rock's swelling potential.

  17. Effect of synthesis parameters on polymethacrylic acid xerogel structures and equilibrium swelling

    Science.gov (United States)

    Panić, V.; Jovanović, J.; Adnadjević, B.; Velicković, S.

    2009-09-01

    Hydrogels based on crosslinked polymethacrylic acid were synthesized via free-radical polymerization in aqueous solution, using N,N'-methylene bisacrylamide as a crosslinking agent and 2,2'-azobis-[2-(2-imidazolin-2-yl)propane] dihydrochloride as an initiator. The influence of the reaction parameters (the neutralization degree of methacrylic acid and the initial monomer concentration) on the equilibrium swelling degree, the swelling kinetic parameters and the basic structural properties of xerogels was investigated. The change of synthesis parameters leads to the change of the basic structural parameters of xerogel, as well as the equilibrium swelling degree and the initial swelling rate of the hydrogels. It is found that there are power form relationships between the equilibrium swelling degree, the initial swelling rate and the structural xerogel’s properties and the change of the neutralization degree of monomer, i.e. the monomer concentration. The examined correlations proved that the crosslinking density is the crucial parameter which determines all the other investigated structural and swelling parameters.

  18. Molecular Dynamics Study of Crystalline Swelling of Montmorillonite as Affected by Interlayer Cation Hydration

    Science.gov (United States)

    Li, Hongliang; Song, Shaoxian; Dong, Xianshu; Min, Fanfei; Zhao, Yunliang; Peng, Chenliang; Nahmad, Yuri

    2018-04-01

    Swelling of montmorillonite (Mt) is an important factor for many industrial applications. In this study, crystalline swelling of alkali-metal- and alkaline-earth-metal-Mt has been studied through energy optimization and molecular dynamics simulations using the clay force field by Materials Studio 8.0. The delamination and exfoliation of Mt are primarily realized by crystalline swelling caused by the enhanced interlayer cation hydration. The initial position of the interlayer cations and water molecules is the dominated factor for the accuracy of the Mt simulations. Crystalline swelling can be carried out in alkali-metal-Mt and Mg-Mt but with difficulty in Ca-Mt, Sr-Mt and Ba-Mt. The crystalline swelling capacity values are in the order Na-Mt > K-Mt > Cs-Mt > Mg-Mt. This order of crystalline swelling of Mt in the same group can be attributed to the differences between the interlayer cation hydration strengths. In addition, the differences in the crystalline swelling between the alkali-metal-Mt and alkaline-earth-metal-Mt can be primarily attributed to the valence of the interlayer cations.

  19. Investigating the swelling pressure of compacted crushed-Callovo-Oxfordian clay-stone

    International Nuclear Information System (INIS)

    Tang, C. S.; Tang, A. M.; Cui, Y. J.; Delage, P.; Schroeder, C.; De Laure, E.

    2011-01-01

    This paper presents an experimental study on the swelling pressure of heavily compacted crushed Callovo-Oxfordian (COx) clay-stone at a dry unit mass ρ d =2.0 Mg/m 3 using four different methods: constant-volume, swell-reload, zero-swell and adjusted constant-volume method. Results show that the swelling pressure varies in the range of 1-5 MPa and depends significantly on the test method. From the constant-volume tests, it is observed that the swelling behavior during wetting is a function of the suction and depends on both the hydration paths and wetting conditions (e.g. vapor-wetting or liquid-wetting). The swelling pressure decreases significantly with saturation time. To identify the microstructure changes of specimens before and after wetting, mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM) tests were performed. It is observed that, after wetting, the large inter-aggregate pores observed in the as-compacted specimen are no longer apparent; the whole pattern is characterized by a general swell of hydrated clay particles, rendering the soil more homogenous. Results from MIP indicated that wetting caused a significant reduction of the entrance diameter of the dominant inter-aggregate pores from 2.1 to 0.5μm whereas intra-aggregate pores were not significantly influenced. (authors)

  20. On grain size dependent void swelling in pure copper irradiated with fission neutrons

    International Nuclear Information System (INIS)

    Singh, B.N.; Eldrup, M.; Golubov, S.I.; Zinkle, S.J.

    2001-03-01

    The effect of grain size on void swelling has its origin in the intrinsic property of grain boundaries as neutral and unsaturable sinks for both vacancies and self-interstitial atoms (SIAs). The phenomenon was investigated already in the 1970s and it was demonstrated that the grain size dependent void swelling measured under irradiation producing only Frenkel pairs could be satisfactorily explained in terms of the standard rate theory (SRT) and dislocation bias. Experimental results reported in the 1980s demonstrated, on the other hand, that the effect of grain boundaries on void swelling under cascade damage conditions was radically different and could not be explained in terms of the SRT. In an effort to understand the source of this significant difference, the effect of grain size on void swelling under cascade damage conditions has been investigated both experimentally and theoretically in pure copper irradiated with fission neutrons at 623K to a dose level of ∼0.3 dpa (displacement per atom). The post-irradiation defect microstructure including voids was investigated using transmission electron microscopy and positron annihilation spectroscopy. The evolution of void swelling was calculated within the framework of the production bias model (PBM) and the SRT. The grain size dependent void swelling measured experimentally is in good accord with the theoretical results obtained using PMB. Implications of these results on modeling of void swelling under cascade damage conditions are discussed. (au)

  1. Calculations of void swelling in Type 316 stainless steel after a temperature change using the VS8 code

    International Nuclear Information System (INIS)

    Windsor, M.E.; Matthews, J.R.

    1985-06-01

    The report compares measurements made by Norris and Buswell of void swelling in irradiated Type 316 steel after a temperature change from 475 to 575 C, and vice versa, with calculated swelling using the VS8 FACSIMILE code. (author)

  2. Swelling behavior of several bituminous coals and their thermally treated coals

    Energy Technology Data Exchange (ETDEWEB)

    Shui, Heng-fu; Cao, Mei-xia; Wang, Zhi-cai [Anhui University of Technology, Maanshan (China). School of Chemistry & Chemical Engineering

    2007-07-01

    The swelling behavior in different solvents of 4 bituminous coals with different ranks and their residues from extraction by CS{sub 2}/NMP mixed solvent (l:1 in volume) were measured. The change in swelling property of the four coals thermally treated at different temperature was observed. The results show that the swelling ratio decreases with increasing rank of coal. For lower rank bituminous coals the swelling ratios in polar solvent are higher than those in non-polar solvent, and this difference decreases with increasing rank. The cross-linking densities of the four residues decrease, and the swelling ratios increase compared with those of raw coals. The swelling ratios of the four thermally treated coals under 150{sup o}C in CS{sub 2} increase, suggesting the decrease in crosslinking density of them. When the thermal treatment temperature increases to 240{sup o}C, the swelling rations of the other three coals in NMP and CS{sub 2} increase again except gas coal, demonstrating the further decrease in crosslinking density. This result is coincident with the extraction yield change in the mixed solvent of the thermally treated coal. For example, the extraction yield of lean coal treated at 240{sup o}C increases from 6.9% to 17.3%. FT-IR results show the removal of oxygen group of the thermally treated coals. This may explain the increase in swelling ratio and extraction yield in the mixed solvent of coal after thermal treatment. The cross-linking density of the thermally treated coal decreases because of the break of hydrogen bonds due to removal of C = 0 and -OH oxygen groups during the thermal treatment, resulting in the increases of swelling ratio and extraction yield in the mixed solvent of thermally treated coal compared with those of raw coal. 15 refs., 3 figs., 6 tabs.

  3. Modelling of U-Mo/Al Dispersion fuel fission induced swelling and creep

    International Nuclear Information System (INIS)

    Jeong, Gwan Yoon; Sohn, Dong Seong; Kim, Yeon Soo

    2014-01-01

    In a Dispersion fuel which U-Mo particles are dispersed in Al metal matrix, a similar phenomenon forming a bulge region was observed but it is difficult to quantify and construct a model for explaining creep and swelling because of its complex microstructure change during irradiation including interaction layer (IL) and porosity formation. In a Dispersion fuel meat, fission product induces fuel particles swelling and it has to be accommodated by the deformation of the Al matrix and newly formed IL during irradiation. Then, it is reasonable that stress from fuel swelling in the complex structure should be relaxed by local adjustments of particles, Al matrix, and IL. For analysis of U-Mo/Al Dispersion fuel creep, the creep of U-Mo particle, Al matrix, and IL should be considered. Moreover, not only fuel particle swelling and IL growth, but also fuel and Al matrix consumptions due to IL formation are accounted in terms of their volume fraction changes during irradiation. In this work, fuel particles, Al matrix and IL are treated in a way of homogenized constituents: Fuel particles, Al matrix and IL consist of an equivalent meat during irradiation. Meat volume swelling of two representative plates was measured: One (Plate A) was a pure Al matrix with 6g/cc uranium loading, the other (Plate B) a silicon added Al matrix with 8g/cc uranium loading. The meat swelling of calculated as a function of burnup. The meat swelling of calculation and measurement was compared and the creep rate coefficients for Al and IL were estimated by repetitions. Based on assumption that only the continuous phase of Al-IL combined matrix accommodated the stress from fuel particle swelling and it was allowed to have creep deformation, the homogenization modeling was performed. The meat swelling of two U-Mo/Al Dispersion fuel plates was modeled by using homogenization model

  4. Modelling of U-Mo/Al Dispersion fuel fission induced swelling and creep

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Gwan Yoon; Sohn, Dong Seong [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of); Kim, Yeon Soo [Argonne National Laboratory, Argonne (United States)

    2014-05-15

    In a Dispersion fuel which U-Mo particles are dispersed in Al metal matrix, a similar phenomenon forming a bulge region was observed but it is difficult to quantify and construct a model for explaining creep and swelling because of its complex microstructure change during irradiation including interaction layer (IL) and porosity formation. In a Dispersion fuel meat, fission product induces fuel particles swelling and it has to be accommodated by the deformation of the Al matrix and newly formed IL during irradiation. Then, it is reasonable that stress from fuel swelling in the complex structure should be relaxed by local adjustments of particles, Al matrix, and IL. For analysis of U-Mo/Al Dispersion fuel creep, the creep of U-Mo particle, Al matrix, and IL should be considered. Moreover, not only fuel particle swelling and IL growth, but also fuel and Al matrix consumptions due to IL formation are accounted in terms of their volume fraction changes during irradiation. In this work, fuel particles, Al matrix and IL are treated in a way of homogenized constituents: Fuel particles, Al matrix and IL consist of an equivalent meat during irradiation. Meat volume swelling of two representative plates was measured: One (Plate A) was a pure Al matrix with 6g/cc uranium loading, the other (Plate B) a silicon added Al matrix with 8g/cc uranium loading. The meat swelling of calculated as a function of burnup. The meat swelling of calculation and measurement was compared and the creep rate coefficients for Al and IL were estimated by repetitions. Based on assumption that only the continuous phase of Al-IL combined matrix accommodated the stress from fuel particle swelling and it was allowed to have creep deformation, the homogenization modeling was performed. The meat swelling of two U-Mo/Al Dispersion fuel plates was modeled by using homogenization model.

  5. Estimates of the eigenvalues of operator arising in swelling pressure model

    International Nuclear Information System (INIS)

    Kanguzhin, Baltabek; Zhapsarbayeva, Lyailya

    2016-01-01

    Swelling pressures from materials confined by structures can cause structural deformations and instability. Due to the complexity of interactions between expansive solid and solid-liquid equilibrium, the forces exerting on retaining structures from swelling are highly nonlinear. This work is our initial attempt to study a simplistic spectral problem based on the Euler-elastic beam theory and some simplistic swelling pressure model. In this work estimates of the eigenvalues of some initial/boundary value problem for nonlinear Euler-elastic beam equation are obtained.

  6. Evaluation on therapeutic effect of de-compressive craniectomies for patients with diffuse brain swelling

    International Nuclear Information System (INIS)

    Xiao Sanchao; Zhang Changrong; Zuo Yi; Zhou Xiaowei; Li Jian

    2000-01-01

    Objective: To evaluate the therapeutic effect of de-compressive craniectomies in acute traumatic patients with diffuse brain swelling. Methods: 23 patients with acute posttraumatic diffuse brain swelling admitted and confirmed by X-CT were randomly treated by surgical de-compressive craniectomies (operative group). Their treated results were compared with those of another 11 patients treated conservatively (non-operative group) at the same period. Results: The mortality rate was similar in both operative and nonoperative groups. Conclusion: The de-compressive craniectomy operation has no value and not valid for treatment of acute posttraumatic diffuse brain swelling

  7. Interaction of irradiation creep and swelling in the creep disappearance regime

    International Nuclear Information System (INIS)

    Garner, F.A.; Toloczko, M.B.

    1992-01-01

    The objective of this effort is to determine the relationship between applied stresses and irradiation-induced dimensional changes in structural metals for fusion applications. Reanalysis of an earlier data set derived from irradiation of long creep tubes in EBR-II at 550 C has shown that the creep-swelling coupling coefficient is relatively independent of temperature at ∼0.6 x 10 -2 MPa -1 , but falls with increases in the swelling rate, especially at high stress levels. The action of stress-affected swelling and carbide precipitation exert different influences on the derivation of this coefficient

  8. Alloys of nickel-iron and nickel-silicon do not swell under fast neutron irradiation

    International Nuclear Information System (INIS)

    Silvestre, G.; Silvent, A.; Regnard, C.; Sainfort, G.

    1975-01-01

    This research is concerned with the effect of fast-neutron irradiation on the swelling of nickel and nickel alloys. Ni-Fe (0-60at%Fe) and Ni-Si (0-8at%Si) were studied, and the fluences were in the range 10 20 -4.3x10 22 n/cm 2 . In dilute alloys, the added elements are dissolved and reduce swelling, silicon being particularly effective. In more concentrated alloys, irradiation of Ni-Fe and Ni-Si alloys brings about the formation of plate-shaped precipitates of Ni 3 X and these alloys do not swell. (Auth.)

  9. On grain-size-dependent void swelling in pure copper irradiated with fission neutrons

    DEFF Research Database (Denmark)

    Singh, Bachu Narain; Eldrup, Morten Mostgaard; Zinkle, S.J.

    2002-01-01

    The effect of grain size on void swelling has its origin in the intrinsic property of grain boundaries as neutral and unsaturable sinks for both vacancies and self-interstitial atoms. The phenomenon had already been investigated in the 1970s and it was demonstrated that the grain......-size-dependent void swelling measured under irradiation producing only Frenkel pairs could be satisfactorily explained in terms of the standard rate theory (SRT) and dislocation bias. Experimental results reported in the 1980s demonstrated, on the other hand, that the effect of grain boundaries on void swelling under...

  10. Anesthetic concerns in a huge congenital sublingual swelling obscuring airway access

    Directory of Open Access Journals (Sweden)

    Nilesh Kumar

    2015-01-01

    Full Text Available Presence of intraoral pathology poses a great challenge during management of pediatric airway. We report management of big intraoral cystic swelling physically occupying the entire oral cavity restricting access to airway. Preintubation aspiration of swelling was done to decrease its size and make room for airway manipulation, followed by laryngoscopy and intubation in lateral position. Airway patency is at risk in postoperative period also, in this case, though the swelling decreased in size postoperatively but presence of significant edema required placement of tongue stitch and modified nasopharyngeal airway. Case report highlights simple maneuvers to manage a difficult case.

  11. Evolution of swelling pressure of cohesive-frictional, rough and elasto-plastic granulates

    OpenAIRE

    Luding, Stefan; Bauer, Erich; Jiang, Mingjing; Liu, Fang; Bolton, Malcolm

    2010-01-01

    The subject of this study is the modeling of the evolution of the swell-ing pressure of granulates with cohesive-frictional, rough and elasto-plastic “mi-croscopic” contact properties. The spherical particles are randomly arranged in a periodic cubic space with a fixed volume so that an increase of the particle size – i.e. swelling that can be caused by intake of some fluid – is accompanied by a de-crease of the void space. An analytical function is proposed that properly de-scribes the (macr...

  12. Three-dimensional Electromagnetic Modeling of the Hawaiian Swell

    Science.gov (United States)

    Avdeev, D.; Utada, H.; Kuvshinov, A.; Koyama, T.

    2004-12-01

    An anomalous behavior of the geomagnetic deep sounding (GDS) responses at the Honolulu geomagnetic observatory has been reported by many researchers. Kuvshinov et al (2004) found that the predicted GDS Dst C-response does not match the experimental data -- 10-20% disagreement occurs for all periods of 2 to 30 days, qualitatively implying a more resistive, rather than conductive, structure beneath the Hawaiian Islands. Simpson et al. (2000) found that the GDS Sq C-response at the Honolulu observatory is about 4 times larger than that at a Hawaii island site, again suggesting a more resistive (than elsewhere around) structure beneath the observatory. Constable and Heinson (2004, http://mahi.ucsd.edu/Steve/swell.pdf), presenting a 2-D interpretation of the magnetotelluric (MT) and GDS responses recently obtained at 7 seafloor sites to the south of the Hawaii Islands, concluded that the dataset require the presence of a narrow conducting plume just beneath the islands. The main motivation of our work is to reveal the reason of the anomalous behavior of the Honolulu response. Obviously, the cause may be due to heterogeneity of either the conductivity or the source field. We examine this problem in some detail with reference to the Constable and Heinson's seafloor dataset, as well as the available dataset from the Honolulu observatory. To address the problem we apply numerical modeling using the three-dimensional (3-D) forward modeling code of Avdeev et al. (1997, 2002). With this code we simulate various regional 3-D conductivity models that may produce EM responses that better fit the experimental datasets, at least qualitatively. Also, to explain some features of the experimental long-period GDS responses we numerically studied a possible effect in the responses caused by the equatorial electrojet. Our 3-D modeling results show that, in particular: (1) The GDS responses are better explained by models with a resistive lithosphere whereas the MT data are better fit by

  13. Effects of Swelling Processes on the Particle Morphology of Porous P(MMA-EGDMA) Particles via Seeded Two-step Swelling Method

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1 Results Porous functional polymer particles have been drawing great interest for their applications in many fields such as ion exchange,polymeric carrier,biomedicine,biochemistry,cosmetics,plastic pigments,and were first prepared by suspension polymerization in 1 950 s.Since 1990's,some approaches such as seeded emulsion polymerization method,dynamic monomer swelling method,activated swelling method and multi-step seeded method[1-4] have been used by many researchers to synthesize this kind of polymer...

  14. Production bias: A proposed modification of the driving force for void swelling under cascade damage conditions

    International Nuclear Information System (INIS)

    Woo, C.H.; Garner, F.A.

    1991-11-01

    A new concept of point-defect production as the main driving force for void swelling under cascade damage conditions is proposed. This concept takes into account the recombination and formation of immobile clusters and loops of vacancies and interstitials in the cascade region. The life times of the clusters and loops due to desolution are strong functions of the temperature, as well as their vacancy and interstitial nature. The resulting biased production of free point defects from the internal sources is shown to be a strong driving force for void swelling. The characteristics of void swelling due to production bias are described and compared with experimental results. We conclude that the production bias concept provides a good description of void swelling under cascade damage conditions

  15. Production bias: A proposed modification of the driving force for void swelling under cascade damage conditions

    International Nuclear Information System (INIS)

    Woo, C.H.; Singh, B.N.; Garner, F.A.

    1992-01-01

    A new concept of point defect production as the main driving force for void swelling under cascade damage conditions is proposed. This concept takes into account the recombination and formation of immobile clusters and loops of vacancies and interstitials in the cascade region. The lifetimes of the clusters and loops due to desolution are strong functions of the temperature, as well as their vacancy and interstitial nature. The resulting biased production of free point defects from the internal sources is shown to be a strong driving force for void swelling. The characteristics of void swelling due to production bias are described and compared with experimental results. We conclude that the production bias concept provides a good description of void swelling under cascade damage conditions. (orig.)

  16. Numerical studies of temperature effect on the extrusion fracture and swell of plastic micro-pipe

    Science.gov (United States)

    Ren, Zhong; Huang, Xingyuan; Xiong, Zhihua

    2018-03-01

    Temperature is a key factor that impacts extrusion forming quality of plastic micro-pipe. In this study, the effect of temperature on extrusion fracture and swell of plastic micro-pipe was investigated by numerical method. Under a certain of the melt’s flow volume, the extrusion pattern, extrusion swelling ratio of melt are obtained under different temperatures. Results show that the extrusion swelling ratio of plastic micro-pipe decreases with increasing of temperature. In order to study the reason of temperature effect, the physical distributions of plastic micro-pipe are gotten. Numerical results show that the viscosity, pressure, stress value of melt are all decreased with the increasing of temperature, which leads to decrease the extrusion swell and fracture phenomenon for the plastic micro-pipe.

  17. Cell Swelling Activates Phospholipase A2 in Ehrlich Ascites Tumor Cells

    DEFF Research Database (Denmark)

    Thoroed, S.M.; Lauritzen, L.; Lambert, I.H.

    1997-01-01

    Ehrlich ascites tumor cells! loaded with H-labeled arachidonic acid and C-labeled stearic acid for two hours, were washed and transferred to either isotonic or hypotonic media containing BSA to scavenge the labeled fatty acids released from the cells. During the first two minutes of hypo......-osmotic exposure the rate of H-labeled arachidonic acid release is 3.3 times higher than that observed at normal osmolality. Cell swelling also causes an increase in the production of C-stearic acid-labeled lysophosphatidylcholine. This indicates that a phospholipase A is activated by cell swelling in the Ehrlich...... cells. Within the same time frame there is no swelling-induced increase in C-labeled stearic acid release nor in the synthesis of phosphatidyl C-butanol in the presence of C-butanol. Furthermore, U7312, an inhibitor of phospholipase C, does not affect the swelling induced release of C...

  18. The effect of swelling agent on the pore characteristics of mesoporous hydroxyapatite nanoparticles

    Directory of Open Access Journals (Sweden)

    L. Bakhtiari

    2015-06-01

    Full Text Available The effect of swelling agent on the physicochemical properties of mesoporous hydroxyapatite particles synthesized by self-assembly process has been investigated. Cetyl trimethylammonium bromide (CTAB and 1-dodecanethiol were used as soft template and swelling agent respectively. The results of the field emission scanning electron microscopy (FESEM, X-ray diffraction (XRD, simultaneous thermal analysis (STA, Brunauer-Emmett-Teller (BET surface area, small-angle X-ray diffraction and Fourier transform infrared spectroscopy (FTIR assessments revealed that in the case of low concentration, 1-dodecanethiol performed as swelling agent and caused an increase in the pore size. However, at higher concentrations it led to the formation of microemulsion and foamy structures. The optimum swelling agent: surfactant mass ratio in synthesis of mesoporous hydroxyapatite particles with high pore volume was determined to be around 2.1 in this study.

  19. Network Modelling of the Influence of Swelling on the Transport Behaviour of Bentonite

    Directory of Open Access Journals (Sweden)

    Ignatios Athanasiadis

    2016-12-01

    Full Text Available Wetting of bentonite is a complex hydro-mechanical process that involves swelling and, if confined, significant structural changes in its void structure. A coupled structural transport network model is proposed to investigate the effect of wetting of bentonite on retention conductivity and swelling pressure response. The transport network of spheres and pipes, representing voids and throats, respectively, relies on Laplace–Young’s equation to model the wetting process. The structural network uses a simple elasto-plastic approach without hardening to model the rearrangement of the fabric. Swelling is introduced in the form of an eigenstrain in the structural elements, which are adjacent to water filled spheres. For a constrained cell, swelling is shown to produce plastic strains, which result in a reduction of pipe and sphere spaces and, therefore, influence the conductivity and retention behaviour.

  20. Swelling/deswelling of polyacrylamide gels in aqueous NaCl solution

    Indian Academy of Sciences (India)

    Swelling kinetics of water-swollen polyacrylamide (PAAm) hydrogels (WSG) was investigated in various ... parameter, χ, were calculated and found to decrease with increase in [NaCl]. Collective ..... in other words, increase in hydrophilicity.

  1. The effect of swelling agent on the pore characteristics of mesoporous hydroxyapatite nanoparticles

    Institute of Scientific and Technical Information of China (English)

    L. Bakhtiari; J. Javadpour; H.R. Rezaie; M. Erfan; M.A. Shokrgozar

    2015-01-01

    The effect of swelling agent on the physicochemical properties of mesoporous hydroxyapatite particles synthesized by self-assembly process has been investigated. Cetyl trimethylammonium bromide (CTAB) and 1-dodecanethiol were used as soft template and swelling agent respectively. The results of the field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), simultaneous thermal analysis (STA), Brunauer-Emmett-Teller (BET) surface area, small-angle X-ray diffraction and Fourier transform infrared spectroscopy (FTIR) assessments revealed that in the case of low concentration, 1-dodecanethiol performed as swelling agent and caused an increase in the pore size. However, at higher concentrations it led to the formation of microemulsion and foamy structures. The optimum swelling agent:surfactant mass ratio in synthesis of mesoporous hydroxyapatite particles with high pore volume was determined to be around 2.1 in this study.

  2. BILATERAL CYSTIC SWELLING OVER SCAPULA-An Unusual Presentation of Filariasis

    Directory of Open Access Journals (Sweden)

    Deepak Kumar

    2018-05-01

    Full Text Available Lymphatic filariasis is a parasitic infection commonly known as elephantiasis. Filariasis presents as hydrocele, genital/scrotal swelling, adenolymphangitis (ADL, swelling of limbs, and genitalia. The causative agent resides in lymphatic channels and causes its obstructions leading to lymphedema. In India, males commonly present with hydrocele and females with lymphedema. Filariasis presenting as bilateral cystic swelling over the scapula is very rare even in endemic areas like India. Wuchereria bancrofti is the common causative agent of filarial infections in India. Here, we present a rare case of filariasis presenting as bilateral cystic swelling over the scapula. The imaging findings are discussed in the case report, which leads us to the diagnosis with further confirmation on microscopy by the presence of microfilariae within the cyst.No such case has been reported in the literature.

  3. Effect of Ti additions on the swelling of electron irradiated austenitic steels and Ni alloys

    International Nuclear Information System (INIS)

    Gilbon, D.; Didout, G.; Le Naour, L.; Levy, V.

    1979-01-01

    It has been shown that titanium is a beneficial additive for the swelling of austenitic steels. The amplitude of the effects observed depends much on the nature and concentration of the other additives in the austenitic matrix [fr

  4. Effect of compression therapy on knee swelling and pain after total knee arthroplasty

    DEFF Research Database (Denmark)

    Munk, Stig; Jensen, Niels J. F.; Andersen, Ida Bøgh

    2013-01-01

    PURPOSE: Knee swelling after total knee arthroplasty may impair postoperative mobilisation and training, and as medical elastic compression stockings are well tolerated and effective to prevent oedema, haematoma and postoperative pain after venous surgery, we wanted to study whether this effect...... could be transferred to total knee arthroplasty surgery reducing postoperative swelling and pain and thereby facilitating mobilisation and improving patient-reported knee function. METHODS: In a randomised controlled study, 88 patients were randomised to use either a medical elastic compression stocking...... or no stocking from the first postoperative day and the following 4 weeks after total knee arthroplasty. Outcome measures were knee, calf and ankle swelling, knee flexion, pain and patient-reported knee function. RESULTS: Seventy per cent of the swelling had occurred before application of the stocking the day...

  5. Swelling and irradiation creep of neutron irradiated 316Ti and 15-15Ti steels

    International Nuclear Information System (INIS)

    Maillard, A.; Touron, H.; Seran, J.L.; Chalony, A.

    1992-01-01

    The global behavior, the swelling and irradiation creep resistances of cold worked 316Ti and 15-15Ti, two variants of austenitic steels in use as core component materials of the French fast reactors, are compared. The 15-15Ti leads to a significant improvement due to an increase in the incubation dose swelling. The same phenomena observed on 316Ti are found on 15-15Ti. All species without fuel like samples, wrappers or empty clad swell and creep less than fuel pin cladding irradiated in the same conditions. To explain the swelling difference, as for 316Ti, thermal gradient is also invoked but the irradiation creep difference is not yet clearly understood. To predict the behavior of clads it is indispensable to study the species themselves and to use specific rules. All results confirm the good behavior of 15-15Ti, the best behavior being obtained with the 1% Si doped version irradiated up to 115 dpa

  6. Decreased STAT3 Phosphorylation Mediates Cell Swelling in Ammonia-Treated Astrocyte Cultures

    Directory of Open Access Journals (Sweden)

    Arumugam R. Jayakumar

    2016-12-01

    Full Text Available Brain edema, due largely to astrocyte swelling, and the subsequent increase in intracranial pressure and brain herniation, are major complications of acute liver failure (ALF. Elevated level of brain ammonia has been strongly implicated in the development of astrocyte swelling associated with ALF. The means by which ammonia brings about astrocyte swelling, however, is incompletely understood. Recently, oxidative/nitrosative stress and associated signaling events, including activation of mitogen-activated protein kinases (MAPKs, as well as activation of the transcription factor, nuclear factor-kappaB (NF-κB, have been implicated in the mechanism of ammonia-induced astrocyte swelling. Since these signaling events are known to be regulated by the transcription factor, signal transducer and activator of transcription 3 (STAT3, we examined the state of STAT3 activation in ammonia-treated cultured astrocytes, and determined whether altered STAT3 activation and/or protein expression contribute to the ammonia-induced astrocyte swelling. STAT3 was found to be dephosphorylated (inactivated at Tyrosine705 in ammonia-treated cultured astrocytes. Total STAT3 protein level was also reduced in ammonia-treated astrocytes. We also found a significant increase in protein tyrosine phosphatase receptor type-1 (PTPRT-1 protein expression in ammonia-treated cultured astrocytes, and that inhibition of PTPRT-1 enhanced the phosphorylation of STAT3 after ammonia treatment. Additionally, exposure of cultured astrocytes to inhibitors of protein tyrosine phosphatases diminished the ammonia-induced cell swelling, while cultured astrocytes over-expressing STAT3 showed a reduction in the astrocyte swelling induced by ammonia. Collectively, these studies strongly suggest that inactivation of STAT3 represents a critical event in the mechanism of the astrocyte swelling associated with acute liver failure.

  7. Relationship between swelling and elastic properties in neutron-irradiated 316 stainless steel

    International Nuclear Information System (INIS)

    Bates, J.F.

    1976-04-01

    The results encompass elastic property measurements on several alloys, which differ in silicon, molybdenum and phosphorus contents but have a nominal 316 stainless steel composition. It is shown that there is a good correlation between the initial shear modulus of the material and the resultant swelling rate of that material. It is also shown that the bias factor concept does not satisfactorily account for the observed compositional sensitivity of swelling in the alloys investigated. 6 fig

  8. Preparation of high water-swelling agricultural starch hydrogels by 60Co γ-radiation grafting

    International Nuclear Information System (INIS)

    Wang Qingjun; Quan Yiwu; Chen Qingmin

    2003-01-01

    The starch grafted acrylic acid was used to synthesize water-swelling hydrogels by 60 Co γ-radiation grafting technique. With radiation dose of about 7 kGy, the crosslinking reagent amount of 0.001%-0.1%, the pH value 5-8 and the starch amount of 10%-30%, we can produce 600 times water-swelling hydrogels which are of high performance, low cost and suitable for agriculture

  9. Muzzle size, paranasal swelling size and body mass in Mandrillus leucophaeus.

    Science.gov (United States)

    Elton, Sarah; Morgan, Bethan J

    2006-04-01

    The drill (Mandrillus leucophaeus), a forest-living Old World monkey, is highly sexually dimorphic, with males exhibiting extreme secondary sexual characteristics, including growth of paranasal swellings on the muzzle. In this study, the size of the secondary bone that forms the paranasal swellings on the muzzles of drills was assessed in relation to body mass proxies. The relationship between the overall size of the muzzle and surrogate measures of body mass was also examined. In female drills, muzzle breadth was positively correlated with two proxies of overall body mass, greatest skull length and upper M1 area. However, there was no such correlation in males. Paranasal swellings in males also appeared to have no significant relationship to body mass proxies. This suggests that secondary bone growth on the muzzles of male drills is independent of overall body size. Furthermore, this secondary bone appears to be vermiculate, probably developing rapidly and in an irregular manner, with no correlation in the sizes of paranasal swelling height and breadth. However, various paranasal swelling dimensions were related to the size of the muzzle. It is suggested that the growth of the paranasal swellings and possibly the muzzle could be influenced by androgen production and reflect testes size and sperm motility. The size and appearance of the paranasal swellings may thus be an indicator of reproductive quality both to potential mates and male competitors. Further work is required to investigate the importance of the paranasal swellings as secondary sexual characteristics in Mandrillus and the relationship between body size and secondary sexual characteristics. Attention should also be paid to the mechanisms and trajectories of facial growth in Mandrillus.

  10. A Simple Optical Model for the Swelling Evaluation in Polymer Nanocomposites

    Directory of Open Access Journals (Sweden)

    Anna De Girolamo Del Mauro

    2009-01-01

    In particular, the behavior of poly(2-hydroxyethyl methacrylate (PHEMA and of carbon black/PHEMA nanocomposite layers, used for volatile organic compounds (VOCs detection, was investigated and measured under ethanol vapors exposure (max 1%. The method is very sensitive and the swelling in the range of only few nanometers can be measured. Interestingly, we have found that the nanocomposite undergoes a more pronounced swelling process with respect to pristine polymer. Ethanol diffusion coefficients in the nanocomposite were evaluated.

  11. Transitory spinal cord swelling in a 6-year-old boy with Guillain-Barre syndrome

    International Nuclear Information System (INIS)

    Delhaas, T.; Kamphuis, D.J.; Witkamp, T.D.

    1998-01-01

    A 6-year-old boy developed progressive motor weakness and areflexia. The clinical picture, combined with electrophysiological findings, indicated a diagnosis of Guillain-Barre syndrome (GBS). MRI on admission revealed spinal cord swelling and increased signal intensity within the cord. It is concluded that, since a degree of central nervous system involvement can occasionally be part of the spectrum of GBS, swelling of the spinal cord without contrast enhancement does not exclude a diagnosis of GBS. (orig.)

  12. The prevention of curcumin against rat liver mitochondrial swelling induced by tert-butylhydroperoxide

    Directory of Open Access Journals (Sweden)

    S. Susilowati

    2006-09-01

    Full Text Available Liver diseases have been a medical problem which is difficult to manage. Some of the problems in the treatment of these diseases lie in the lack of reliable drug available. Curcumin, an active ingredient of the rhizomes of plant Curcuma has been investigated in the treatment of various disorders incuding liver diseases. The therapeutic effects of curcumin on liver diseases have been thought to be associated to its antioxidative properties. In the present study, we investigated the effects of curcumin on mitochondrial swelling in vitro induced by tert-butylhydroperoxide (t-BuOOH. Liver mitochondria were homogeneously isolated from Sprague-Dawley rats (the relative specific activity of succinate dehydrogenase was 35.73 ± 2.78. Addition of 90 µM of t-BuOOH caused a typical 2-phase swelling of the mitochondria. The pattern of swelling was influenced by various factors such as buffer composition, concentrations of t-BuOOH, amount of isolation buffer and mitochondrial proteins and incubation temperature.The swelling could be reduced by as much as 85 ± 3% by 2.50 µM of curcumin. At lower (1.25 µM or higher (5.00 µM concentrations, the protection against swelling by curcumin were less effective (respectively were 41 ± 3% and 77 ± 6%. Swelling might occur due to the opening of mitochondrial transition pore and could be an initial indication in the cascade process leading to cell death. The inhibition of t-BuOOH-induced mitochondrial swelling by curcumin might be because of the antioxidant effects of the compound. (Med J Indones 2006; 15:131-6 Keywords: mitochondria, swelling, tert-butylhydroperoxide, curcumin

  13. Spinal Cord Swelling and Alterations in Hydrostatic Pressure After Acute Injury

    Science.gov (United States)

    2016-10-01

    management ! of! such! patients.! However,! this! swelling! has! largely! been! neglected! in! SCI,! despite! being! consistently!observed.!!Even!after... management !of!acute!SCI.!As!an!example!of!how!swelling,!increased!intraparenchymal! pressure,! and! its! effects! on! perfusion! are! factored! into! clinical...Yucatan! 22=Jul=15! 2014! 18.5! duraplasty! Completed! 7743! Football ! Yucatan! 22=Jul=15! 3482! 18.5! SCI!only! Completed! 7730! Golf! Yucatan! 29=Jul=15

  14. Enhanced transduction of photonic crystal dye lasers for gas sensing via swelling polymer film

    DEFF Research Database (Denmark)

    Smith, Cameron; Lind, Johan Ulrik; Christiansen, Mads Brøkner

    2011-01-01

    We present the enhanced transduction of a photonic crystal dye laser for gas sensing via deposition of an additional swelling polymer film. Device operation involves swelling of the polymer film during exposure to specific gases, leading to a change in total effective refractive index. Experimental...... in its application to other intracavity-based detection schemes to enable gas sensing. © 2011 Optical Society of America....

  15. Altered osmotic swelling behavior of proteoglycan-depleted bovine articular cartilage using high frequency ultrasound

    International Nuclear Information System (INIS)

    Wang, Q; Zheng, Y P; Leung, G; Mak, A F T; Lam, W L; Guo, X; Lu, H B; Qin, L

    2008-01-01

    Swelling behavior is an electrochemical mechanical property of articular cartilage. It plays an important role in weight bearing and joint lubrication. In this study, the altered transient and inhomogeneous swelling behavior of the degenerated articular cartilage was observed and quantified in situ using ultrasound. Three groups of bovine patellar articular cartilage samples (n = 10 x 3) were obtained and digested by trypsin for 10, 20 and 30 min respectively to mimic different levels of degeneration. The osmotic-free shrinkage and swelling behavior induced by changing the concentration of the bathing saline solution from 0.15 M to 2 M and then back to 0.15 M were characterized using high-frequency ultrasound (central frequency = 35 MHz) before and after digestion. It was found that the degenerated cartilage specimens showed a weaker shrinkage-swelling behavior compared with the normal cartilage samples. However, no significant differences in the peak shrinkage or swelling strains were observed between different groups. The absolute values of the peak shrinkage strain significantly (p < 0.05) decreased by 45.4%, 42.1% and 50.6% respectively after the trypsin digestion for 10, 20 and 30 min, but such significance was not demonstrated for the peak swelling strains. Due to the potential alterations in the collagen-PG matrix during trypsin digestion, the correlation between the swelling strain and the shrinkage strain of the degenerated samples changed slightly in comparison with the normal samples. The proposed ultrasound method has been successfully used to measure the transient and inhomogeneous swelling behavior of the degenerated articular cartilage and has the potential for the characterization of osteoarthritis

  16. Penis swelling due to foreign body reaction after injection of silicone.

    Science.gov (United States)

    Plaza, Tobias; Lautenschlager, Stephan

    2010-09-01

    A 19-year-old man presented with phimosis and painful swelling of the penis four weeks after augmentation with silicone in Thailand. Histology revealed a foreign body reaction to silicone. Infectious causes were ruled out. Granulomatous foreign body reactions to silicone are common, but there are few case reports on reactions following silicone injection for penis enlargement. Foreign body reactions should be included in the differential diagnosis of penis swelling.

  17. The Compressibility and Swell of Mixtures for Sand-Clay Liners

    Directory of Open Access Journals (Sweden)

    Muawia A. Dafalla

    2017-01-01

    Full Text Available Sand-clay liners utilize expansive clay to act as a filler to occupy the voids in the sand and thus reduce the hydraulic conductivity of the mixture. The hydraulic conductivity and transfer of water and other substances through sand-clay mixtures are of prime concern in the design of liners and hydraulic barriers. Many successful research studies have been undertaken to achieve appropriate mixtures that satisfy hydraulic conductivity requirements. This study investigates compressibility and swelling properties of mixtures to ensure that they were acceptable for light structures, roads, and slabs on grade. A range of sand-expansive clay mixtures were investigated for swell and compression properties. The swelling and compressibility indices were found to increase with increasing clay content. The use of highly expansive material can result in large volume changes due to swell and shrinkage. The inclusion of less expansive soil material as partial replacement of bentonite by one-third to two-thirds is found to reduce the compressibility by 60% to 70% for 10% and 15% clay content, respectively. The swelling pressure and swell percent were also found significantly reduced. Adding less expansive natural clay to bentonite can produce liners that are still sufficiently impervious and at the same time less problematic.

  18. Mathematical modelling of liquid transport in swelling pharmaceutical immediate release tablets.

    Science.gov (United States)

    Markl, Daniel; Yassin, Samy; Wilson, D Ian; Goodwin, Daniel J; Anderson, Andrew; Zeitler, J Axel

    2017-06-30

    Oral dosage forms are an integral part of modern health care and account for the majority of drug delivery systems. Traditionally the analysis of the dissolution behaviour of a dosage form is used as the key parameter to assess the performance of a drug product. However, understanding the mechanisms of disintegration is of critical importance to improve the quality of drug delivery systems. The disintegration performance is primarily impacted by the hydration and subsequent swelling of the powder compact. Here we compare liquid ingress and swelling data obtained using terahertz pulsed imaging (TPI) to a set of mathematical models. The interlink between hydration kinetics and swelling is described by a model based on Darcy's law and a modified swelling model based on that of Schott. Our new model includes the evolution of porosity, pore size and permeability as a function of hydration time. Results obtained from two sets of samples prepared from pure micro-crystalline cellulose (MCC) indicate a clear difference in hydration and swelling for samples of different porosities and particle sizes, which are captured by the model. Coupling a novel imaging technique, such as TPI, and mathematical models allows better understanding of hydration and swelling and eventually tablet disintegration. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  19. Fission-induced recrystallization effect on intergranular bubble-driven swelling in U-Mo fuel

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Linyun; Mei, Zhi-Gang; Yacout, Abdellatif M.

    2017-10-01

    We have developed a mesoscale phase-field model for studying the effect of recrystallization on the gas-bubble-driven swelling in irradiated U-Mo alloy fuel. The model can simulate the microstructural evolution of the intergranular gas bubbles on the grain boundaries as well as the recrystallization process. Our simulation results show that the intergranular gas-bubble-induced fuel swelling exhibits two stages: slow swelling kinetics before recrystallization and rapid swelling kinetics with recrystallization. We observe that the recrystallization can significantly expedite the formation and growth of gas bubbles at high fission densities. The reason is that the recrystallization process increases the nucleation probability of gas bubbles and reduces the diffusion time of fission gases from grain interior to grain boundaries by increasing the grain boundary area and decreasing the diffusion distance. The simulated gas bubble shape, size distribution, and density on the grain boundaries are consistent with experimental measurements. We investigate the effect of the recrystallization on the gas-bubble-driven fuel swelling in UMo through varying the initial grain size and grain aspect ratio. We conclude that the initial microstructure of fuel, such as grain size and grain aspect ratio, can be used to effectively control the recrystallization and therefore reduce the swelling in U-Mo fuel.

  20. GRSIS program to predict fission gas release and swelling behavior of metallic fast reactor fuel

    International Nuclear Information System (INIS)

    Lee, Chan Bock; Lee, Byung Ho; Nam, Cheol; Sohn, Dong Seong

    1999-03-01

    A mechanistic model of fission gas release and swelling for the U-(Pu)-Zr metallic fuel in the fast reactor, GRSIS (Gas Release and Swelling in ISotropic fuel matrix) was developed. Fission gas bubbles are assumed to nucleate isotropically from the gas atoms in the metallic fuel matrix since they can nucleate at both the grain boundaries and the phase boundaries which are randomly distributed inside the grain. Bubbles can grow to larger size by gas diffusion and coalition with other bubbles so that they are classified as three classes depending upon their sizes. When bubble swelling reaches the threshold value, bubbles become interconnected each other to make the open channel to the external free space, that is, the open bubbles and then fission gases inside the interconnected open bubbles are released instantaneously. During the irradiation, fission gases are released through the open bubbles. GRSIS model can take into account the fuel gap closure by fuel bubble swelling. When the fuel gap is closed by fuel swelling, the contact pressure between fuel and cladding in relation to the bubble swelling and temperature is calculated. GRSIS model was validated by comparison with the irradiation test results of U-(Pu)-Zr fuels in ANL as well as the parametric studies of the key variable in the model. (author). 13 refs., 1 tab., 22 figs

  1. GRSIS program to predict fission gas release and swelling behavior of metallic fast reactor fuel

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chan Bock; Lee, Byung Ho; Nam, Cheol; Sohn, Dong Seong

    1999-03-01

    A mechanistic model of fission gas release and swelling for the U-(Pu)-Zr metallic fuel in the fast reactor, GRSIS (Gas Release and Swelling in ISotropic fuel matrix) was developed. Fission gas bubbles are assumed to nucleate isotropically from the gas atoms in the metallic fuel matrix since they can nucleate at both the grain boundaries and the phase boundaries which are randomly distributed inside the grain. Bubbles can grow to larger size by gas diffusion and coalition with other bubbles so that they are classified as three classes depending upon their sizes. When bubble swelling reaches the threshold value, bubbles become interconnected each other to make the open channel to the external free space, that is, the open bubbles and then fission gases inside the interconnected open bubbles are released instantaneously. During the irradiation, fission gases are released through the open bubbles. GRSIS model can take into account the fuel gap closure by fuel bubble swelling. When the fuel gap is closed by fuel swelling, the contact pressure between fuel and cladding in relation to the bubble swelling and temperature is calculated. GRSIS model was validated by comparison with the irradiation test results of U-(Pu)-Zr fuels in ANL as well as the parametric studies of the key variable in the model. (author). 13 refs., 1 tab., 22 figs.

  2. How Much Do Ultrathin Polymers with Intrinsic Microporosity Swell in Liquids?

    KAUST Repository

    Ogieglo, Wojciech

    2016-09-13

    As synthetic membrane materials, polymers with intrinsic microporosity (PIMs) have demonstrated unprecedented permeation and molecular-separation properties. Here, we report the swelling characteristics of submicron-thick supported films of spirobisindane-based PIMs, PIM-1 and PIM-6FDA-OH, for six organic solvents and water using in situ spectroscopic ellipsometry. Surprisingly, PIMs swell significantly in most organic solvents, with swelling factors (SF = h/h) as high as 2.5. This leads to the loss of the ultrarigid character of the polymer and produces equilibrated liquid-like swollen films. Filling of the excess frozen-in fractional free volume with liquid was discovered next to swelling-induced polymer matrix dilation. Water hardly swells the polymer matrix, but it penetrates into the intrinsic microporous structure. This study is the first to provide fundamental swelling data for PIMs, leading to better comprehension of their permeation properties. Such an understanding is indispensable for applications such as solvent filtration, natural-gas separation, and ion retention in flow batteries.

  3. How Much Do Ultrathin Polymers with Intrinsic Microporosity Swell in Liquids?

    Science.gov (United States)

    Ogieglo, Wojciech; Ghanem, Bader; Ma, Xiaohua; Pinnau, Ingo; Wessling, Matthias

    2016-10-06

    As synthetic membrane materials, polymers with intrinsic microporosity (PIMs) have demonstrated unprecedented permeation and molecular-separation properties. Here, we report the swelling characteristics of submicron-thick supported films of spirobisindane-based PIMs, PIM-1 and PIM-6FDA-OH, for six organic solvents and water using in situ spectroscopic ellipsometry. Surprisingly, PIMs swell significantly in most organic solvents, with swelling factors (SF = h swollen /h dry ) as high as 2.5. This leads to the loss of the ultrarigid character of the polymer and produces equilibrated liquid-like swollen films. Filling of the excess frozen-in fractional free volume with liquid was discovered next to swelling-induced polymer matrix dilation. Water hardly swells the polymer matrix, but it penetrates into the intrinsic microporous structure. This study is the first to provide fundamental swelling data for PIMs, leading to better comprehension of their permeation properties. Such an understanding is indispensable for applications such as solvent filtration, natural-gas separation, and ion retention in flow batteries.

  4. Hygroscopic Swelling Determination of Cellulose Nanocrystal (CNC) Films by Polarized Light Microscopy Digital Image Correlation.

    Science.gov (United States)

    Shrestha, Shikha; Diaz, Jairo A; Ghanbari, Siavash; Youngblood, Jeffrey P

    2017-05-08

    The coefficient of hygroscopic swelling (CHS) of self-organized and shear-oriented cellulose nanocrystal (CNC) films was determined by capturing hygroscopic strains produced as result of isothermal water vapor intake in equilibrium. Contrast enhanced microscopy digital image correlation enabled the characterization of dimensional changes induced by the hygroscopic swelling of the films. The distinct microstructure and birefringence of CNC films served in exploring the in-plane hygroscopic swelling at relative humidity values ranging from 0% to 97%. Water vapor intake in CNC films was measured using dynamic vapor sorption (DVS) at constant temperature. The obtained experimental moisture sorption and kinetic profiles were analyzed by fitting with Guggenheim, Anderson, and deBoer (GAB) and Parallel Exponential Kinetics (PEK) models, respectively. Self-organized CNC films showed isotropic swelling, CHS ∼0.040 %strain/%C. By contrast, shear-oriented CNC films exhibited an anisotropic swelling, resulting in CHS ∼0.02 and ∼0.30 %strain/%C, parallel and perpendicular to CNC alignment, respectively. Finite element analysis (FEA) further predicted moisture diffusion as the predominant mechanism for swelling of CNC films.

  5. Swelling-induced chloride current in glioblastoma proliferation, migration, and invasion.

    Science.gov (United States)

    Wong, Raymond; Chen, Wenliang; Zhong, Xiao; Rutka, James T; Feng, Zhong-Ping; Sun, Hong-Shuo

    2018-01-01

    Glioblastoma (GBM) remains as the most common and aggressive brain tumor. The survival of GBM has been linked to the aberrant activation of swelling-induced chloride current I Cl,swell . In this study, we investigated the effects of I Cl,swell on cell viability, proliferation, and migration in the human GBM cell lines, U251 and U87, using a combination of patch clamp electrophysiology, MTT, colony formation, wound healing assays and Western immunoblotting. First, we showed that the specific inhibitor of I Cl,swell , DCPIB, potently reduced the I Cl,swell in U87 cells. Next, in both U87 and U251 cells, we found that DCPIB reduced GBM viability, proliferation, colony formation, migration, and invasion. In addition, our Western immunoblot assay showed that DCPIB-treated U251 cells had a reduction in JAK2, STAT3, and Akt phosphorylation, thus, suggesting that DCPIB potentially suppresses GBM functions through inhibition of the JAK2/STAT3 and PI3K/Akt signaling pathways. Therefore, the I Cl,swell may be a potential drug target for GBM. © 2017 Wiley Periodicals, Inc.

  6. How Much Do Ultrathin Polymers with Intrinsic Microporosity Swell in Liquids?

    KAUST Repository

    Ogieglo, Wojciech; Ghanem, Bader; Ma, Xiaohua; Pinnau, Ingo; Wessling, Matthias

    2016-01-01

    As synthetic membrane materials, polymers with intrinsic microporosity (PIMs) have demonstrated unprecedented permeation and molecular-separation properties. Here, we report the swelling characteristics of submicron-thick supported films of spirobisindane-based PIMs, PIM-1 and PIM-6FDA-OH, for six organic solvents and water using in situ spectroscopic ellipsometry. Surprisingly, PIMs swell significantly in most organic solvents, with swelling factors (SF = h/h) as high as 2.5. This leads to the loss of the ultrarigid character of the polymer and produces equilibrated liquid-like swollen films. Filling of the excess frozen-in fractional free volume with liquid was discovered next to swelling-induced polymer matrix dilation. Water hardly swells the polymer matrix, but it penetrates into the intrinsic microporous structure. This study is the first to provide fundamental swelling data for PIMs, leading to better comprehension of their permeation properties. Such an understanding is indispensable for applications such as solvent filtration, natural-gas separation, and ion retention in flow batteries.

  7. Children presenting in delayed fashion after minor head trauma with scalp swelling: do they require further workup?

    Science.gov (United States)

    Sellin, Jonathan N; Moreno, Amee; Ryan, Sheila L; Lam, Sandi K; Donaruma-Kwoh, Marcella; Luerssen, Thomas G; Jea, Andrew

    2017-04-01

    It is common to evaluate children who have sustained minor head trauma with computed tomography (CT) of the head. Scalp swelling, in particular, has been associated with intracranial injury. A subset of patients, however, present in delayed fashion, often days after the head trauma, as soft tissue edema progresses and their caregiver notices scalp swelling. We explore the value of further workup in this setting. We conducted a retrospective review of a prospectively collected cohort of children ≤24 months of age presenting to the Texas Children's Hospital with scalp swelling more than 24 h following a head trauma. Cases were collected over a 2-year study period from June 1, 2014 to May 31, 2016. Seventy-six patients comprising 78 patient encounters were included in our study. The mean age at presentation was 8.8 months (range 3 days-24 months). All patients had noncontrast CT of the head as part of their evaluation by emergency medicine, as well as screening for nonaccidental trauma (NAT) by the Child Protection Team. The most common finding on CT head was a linear/nondisplaced skull fracture (SF) with associated extra-axial hemorrhage (epidural or subdural hematoma), which was found in 31/78 patient encounters (40%). Of all 78 patient encounters, 43 patients (55%) were discharged from the emergency room (ER), 17 patients (22%) were admitted for neurologic monitoring, and 18 patients (23%) were admitted solely to allow further NAT evaluation. Of those patients admitted, none experienced a neurologic decline and all had nonfocal neurologic exams on discharge. No patient returned to the ER in delayed fashion for a neurologic decline. Of all the patient encounters, no patient required surgery. Pediatric patients ≤24 months of age presenting to the ER in delayed fashion with scalp swelling after minor head trauma-who were otherwise nonfocal on examination-did not require surgical intervention and did not experience any neurologic decline. Further radiographic

  8. A study on the swelling characteristics of a potential buffer material : Effect of ionic strength and temperature on the swelling pressure

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Owan; Cho, Won Jin; Chun, Kwan Sik [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-04-01

    This study is intended to investigate the effect of ionic strength and temperature on the swelling pressure of bentonite. The dry density for compacted bentonite was adjusted between 1.4 Mg/m{sup 3} - 1.8 Mg/m{sup 3}. The effect of temperature was tested at 20 deg C, 40 deg C, 60 deg C, 80 deg C, and the effect of ionic strength with distilled water, synthetic ground water, and 0.01 M - 0.1 M NaCl solution. The swelling pressure decreased with increasing ionic strength, and its dependency got lower at high dry density. Temperature had negligible effect on the swelling pressure of compacted bentonite, which could be explained by the change in hydration pressure, osmotic pressure, and pore water pressure in accordance with temperature. The swelling pressure of compacted bentonite with low dry density was dominated mainly by osmosis. However, hydration was thought to become important at higher dry density, compared with the osmosis. 32 refs., 11 figs., 4 tabs. (Author)

  9. The effect of low dose rate irradiation on the swelling of 12% cold-worked 316 stainless steel

    International Nuclear Information System (INIS)

    Allen, T. R.

    1999-01-01

    In pressurized water reactors (PWRs), stainless steel components are irradiated at temperatures that may reach 400 C due to gamma heating. If large amounts of swelling (>10%) occur in these reactor internals, significant swelling related embrittlement may occur. Although fast reactor studies indicate that swelling should be insignificant at PWR temperatures, the low dose rate conditions experienced by PWR components may possibly lead to significant swelling. To address these issues, JNC and ANL have collaborated to analyze swelling in 316 stainless steel, irradiated in the EBR-II reactor at temperatures from 376-444 C, at dose rates between 4.9 x 10 -8 and 5.8 x 10 -7 dpa/s, and to doses of 56 dpa. For these irradiation conditions, the swelling decreases markedly at temperatures less than approximately 386 C, with the extrapolated swelling at 100 dpa being around 3%. For temperatures greater than 386 C, the swelling extrapolated to 100 dpa is around 9%. For a factor of two difference in dose rate, no statistically significant effect of dose rate on swelling was seen. For the range of dose rates analyzed, the swelling measurements do not support significant (>10%) swelling of 316 stainless steel in PWRs

  10. A coupled THC model of the FEBEX in situ test with bentonite swelling and chemical and thermal osmosis

    International Nuclear Information System (INIS)

    Zheng, L.; Samper, J.; Montenegro, L.

    2011-01-01

    The performance assessment of a geological repository for radioactive waste requires quantifying the geochemical evolution of the bentonite engineered barrier. This barrier will be exposed to coupled thermal (T), hydrodynamic (H), mechanical (M) and chemical (C) processes. This paper presents a coupled THC model of the FEBEX (Full-scale Engineered Barrier EXperiment) in situ test which accounts for bentonite swelling and chemical and thermal osmosis. Model results attest the relevance of thermal osmosis and bentonite swelling for the geochemical evolution of the bentonite barrier while chemical osmosis is found to be almost irrelevant. The model has been tested with data collected after the dismantling of heater 1 of the in situ test. The model reproduces reasonably well the measured temperature, relative humidity, water content and inferred geochemical data. However, it fails to mimic the solute concentrations at the heater-bentonite and bentonite-granite interfaces because the model does not account for the volume change of bentonite, the CO 2 (g) degassing and the transport of vapor from the bentonite into the granite. The inferred HCO 3 - and pH data cannot be explained solely by solute transport, calcite dissolution and protonation/deprotonation by surface complexation, suggesting that such data may be affected also by other reactions.

  11. Comparison of immersion density and improved microstructural characterization methods for measuring swelling in small irradiated disk specimens

    International Nuclear Information System (INIS)

    Sawai, T.; Suzuki, M.; Hishinuma, A.; Maziasz, P.J.

    1992-01-01

    The procedure of obtaining microstructural data from reactor-irradiated specimens has been carefully checked for accuracy by comparison of swelling data obtained from transmission electron microscopy (TEM) observations of cavities with density-change data measured using the Precision Densitometer at Oak Ridge National Laboratory (ORNL). Comparison of data measured by both methods on duplicate or, in some cases, on the same specimen has shown some appreciable discrepancies for US/Japan collaborative experiments irradiated in the High Flux Isotope Reactor (HFIR). The contamination spot separation (CSS) method was used in the past to determine the thickness of a TEM foil. Recent work has revealed an appreciable error in this method that can result in an overestimation of the foil thickness. This error causes lower swelling values to be measured by TEM microstructural observation relative to the Precision Densitometer. An improved method is proposed for determining the foil thickness by the CSS method, which includes a correction for the systematic overestimation of foil thickness. (orig.)

  12. A coupled THC model of the FEBEX in situ test with bentonite swelling and chemical and thermal osmosis

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, L.; Samper, J.; Montenegro, L.

    2011-04-01

    The performance assessment of a geological repository for radioactive waste requires quantifying the geochemical evolution of the bentonite engineered barrier. This barrier will be exposed to coupled thermal (T), hydrodynamic (H), mechanical (M) and chemical (C) processes. This paper presents a coupled THC model of the FEBEX (Full-scale Engineered Barrier EXperiment) in situ test which accounts for bentonite swelling and chemical and thermal osmosis. Model results attest the relevance of thermal osmosis and bentonite swelling for the geochemical evolution of the bentonite barrier while chemical osmosis is found to be almost irrelevant. The model has been tested with data collected after the dismantling of heater 1 of the in situ test. The model reproduces reasonably well the measured temperature, relative humidity, water content and inferred geochemical data. However, it fails to mimic the solute concentrations at the heater-bentonite and bentonite-granite interfaces because the model does not account for the volume change of bentonite, the CO{sub 2}(g) degassing and the transport of vapor from the bentonite into the granite. The inferred HCO{sub 3}{sup -} and pH data cannot be explained solely by solute transport, calcite dissolution and protonation/deprotonation by surface complexation, suggesting that such data may be affected also by other reactions.

  13. Influence of Silicon on Swelling and Microstructure in Russian Austenitic Stainless Steels Irradiated to High Neutron Doses

    International Nuclear Information System (INIS)

    Porollo, S.I.; Shulepin, S.V.; Konobeev, Y.V.; Garner, F.

    2007-01-01

    Full text of publication follows: For some applications in fusion devices austenitic stainless steels are still considered to be candidates for use as structural components, but high neutron exposures must be endured by the steels. Operational experience of fast reactors in Western Europe, USA and Japan provides evidence of the possible use of austenitic steels up to ∼ 150 dpa. Studies aimed at improvement of existing Russian austenitic steels are being carried out in Russia. For improvement of irradiation resistance of Russian steels it is necessary to understand the basic mechanisms responsible for deterioration of steel properties. This understanding can be achieved by continuing detailed investigations of the microstructure of cladding steels after irradiation to high doses. By investigating the evolution of radiation-induced microstructure in neutron irradiated steels of different chemical composition one can study the effect of chemical variations on steel properties. Silicon is one of the most important chemical elements that strongly influence the behavior of austenitic steel properties under irradiation. In this paper results are presented of investigations of the effect of silicon additions on void swelling and microstructure of base austenitic stainless steel EI-847 (0.06C-16Cr-15Ni- 3Mo-Nb) irradiated as fuel pin cladding of both regular and experimental assemblies in the BOR-60, BN-350 and BN-600 fast reactors to neutron doses up to 49 dpa. The possible mechanisms of silicon's effect on void swelling in austenitic stainless steels are presented and analyzed. (authors)

  14. Role of Defects in Swelling and Creep of Irradiated SiC

    Energy Technology Data Exchange (ETDEWEB)

    Szlufarska, Izabela [Univ. of Wisconsin, Madison, WI (United States); Voyles, Paul [Univ. of Wisconsin, Madison, WI (United States); Sridharan, Kumar [Univ. of Wisconsin, Madison, WI (United States); Katoh, Yutai [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-01-16

    Silicon carbide is a promising cladding material because of its high strength and relatively good corrosion resistance. However, SiC is brittle and therefore SiC-based components need to be carefully designed to avoid cracking and failure by fracture. In design of SiC-based composites for nuclear reactor applications it is essential to take into account how mechanical properties are affected by radiation and temperature, or in other words, what strains and stresses develop in this material due to environmental conditions. While thermal strains in SiC can be predicted using classical theories, radiation-induced strains are much less understood. In particular, it is critical to correctly account for radiation swelling and radiation creep, which contribute significantly to dimensional instability of SiC under radiation. Swelling typically increases logarithmically with radiation dose and saturates at relatively low doses (damage levels of a few dpa). Consequently, swelling-induced stresses are likely to develop within a few months of operation of a reactor. Radiation-induced volume swelling in SiC can be as high as 2%, which is significantly higher than the cracking strain of 0.1% in SiC. Swelling-induced strains will lead to enormous stresses and fracture, unless these stresses can be relaxed via some other mechanism. An effective way to achieve stress relaxation is via radiation creep. Although it has been hypothesized that both radiation swelling and radiation creep are driven by formation of defect clusters, existing models for swelling and creep in SiC are limited by the lack of understanding of specific defects that form due to radiation in the range of temperatures relevant to fuel cladding in light water reactors (LWRs) (<1000°C). For example, defects that can be detected with traditional transmission electron microscopy (TEM) techniques account only for 10-45% of the swelling measured in irradiated SiC. Here, we have undertaken an integrated experimental and

  15. The Swelling of Rat Liver Mitochondria by Thyroxine and its Reversal

    Science.gov (United States)

    Lehninger, Albert L.; Ray, Betty Lou; Schneider, Marion

    1959-01-01

    The in vitro swelling action of L-thyroxine on rat liver mitochondria as examined photometrically represents an acceleration of a process which the mitochondria are already inherently capable of undergoing spontaneously, as indicated by the identical kinetic characteristics and the extent of thyroxine-induced and spontaneous swelling, the nearly identical pH dependence, and the fact that sucrose has a specific inhibitory action on both types of swelling. However, thyroxine does not appear to be a "catalyst" or coenzyme since it does not decrease the temperature coefficient of spontaneous swelling. The temperature coefficient is very high, approximately 6.0 near 20°. Aging of mitochondria at 0° causes loss of thyroxine sensitivity which correlates closely with the loss of bound DPN from the mitochondria, but not with loss of activity of the respiratory chain or with the efficiency of oxidative phosphorylation. Tests with various respiratory chain inhibitors showed that the oxidation state of bound DPN may be a major determinant of thyroxine sensitivity; the oxidation state of the other respiratory carriers does not appear to influence sensitivity to thyroxine. These facts and other considerations suggest that a bound form of mitochondrial DPN is the "target" of the action of thyroxine. The thyroxine-induced swelling is not reversed by increasing the osmolar concentration of external sucrose, but can be "passively" or osmotically reversed by adding the high-particle weight solute polyvinylpyrrolidone. The mitochondrial membrane becomes more permeable to sucrose during the swelling reaction. On the other hand, thyroxine-induced swelling can be "actively" reversed by ATP in a medium of 0.15 M KCl or NaCl but not in a 0.30 M sucrose medium. The action of ATP is specific; ADP, Mn++, and ethylenediaminetetraacetate are not active. It is concluded that sucrose is an inhibitor of the enzymatic relationship between oxidative phosphorylation and the contractility and

  16. Role of Defects in Swelling and Creep of Irradiated SiC

    International Nuclear Information System (INIS)

    Szlufarska, Izabela; Voyles, Paul; Sridharan, Kumar; Katoh, Yutai

    2016-01-01

    Silicon carbide is a promising cladding material because of its high strength and relatively good corrosion resistance. However, SiC is brittle and therefore SiC-based components need to be carefully designed to avoid cracking and failure by fracture. In design of SiC-based composites for nuclear reactor applications it is essential to take into account how mechanical properties are affected by radiation and temperature, or in other words, what strains and stresses develop in this material due to environmental conditions. While thermal strains in SiC can be predicted using classical theories, radiation-induced strains are much less understood. In particular, it is critical to correctly account for radiation swelling and radiation creep, which contribute significantly to dimensional instability of SiC under radiation. Swelling typically increases logarithmically with radiation dose and saturates at relatively low doses (damage levels of a few dpa). Consequently, swelling-induced stresses are likely to develop within a few months of operation of a reactor. Radiation-induced volume swelling in SiC can be as high as 2%, which is significantly higher than the cracking strain of 0.1% in SiC. Swelling-induced strains will lead to enormous stresses and fracture, unless these stresses can be relaxed via some other mechanism. An effective way to achieve stress relaxation is via radiation creep. Although it has been hypothesized that both radiation swelling and radiation creep are driven by formation of defect clusters, existing models for swelling and creep in SiC are limited by the lack of understanding of specific defects that form due to radiation in the range of temperatures relevant to fuel cladding in light water reactors (LWRs) (<1000°C). For example, defects that can be detected with traditional transmission electron microscopy (TEM) techniques account only for 10-45% of the swelling measured in irradiated SiC. Here, we have undertaken an integrated experimental and

  17. Boron carbide in pile behaviour Rapsodie experience

    International Nuclear Information System (INIS)

    Kryger, B.; Colin, M.

    1983-04-01

    Results concerning boron carbide irradiation experiments performed in RAPSODIE up to 10 22 .cm - 3 capture density in the temperature range 600-1100 0 lead to the following main conclusions: initial density and grain size lowering contribute to swelling decrease but density is the major parameter for swelling limitation; swelling rate can vary in a wide range (ratio 1 to 3) according to combinations of density (1.8 to 2.3) and grain size (10 to 50 μm) values; a swelling balance reveals that the most important contribution to swelling should be a high density of helium small bubbles (<400 A); helium retention increases with density and grain size and decreases with temperature elevation. A diffusion law is proposed to describe the rate of helium release

  18. Overnight corneal swelling with high and low powered silicone hydrogel lenses.

    Science.gov (United States)

    Moezzi, Amir M; Fonn, Desmond; Varikooty, Jalaiah; Simpson, Trefford L

    2015-01-01

    To compare central corneal swelling after eight hours of sleep in eyes wearing four different silicone hydrogel lenses with three different powers. Twenty-nine neophyte subjects wore lotrafilcon A (Dk, 140), balafilcon A (Dk, 91), galyfilcon A (Dk, 60) and senofilcon A (Dk, 103) lenses in powers -3.00, -10.00 and +6.00 D on separate nights, in random order, and on one eye only. The contra-lateral eye (no lens) served as the control. Central corneal thickness was measured using a digital optical pachometer before lens insertion and immediately after lens removal on waking. For the +6.00 D and -10.00 D, lotrafilcon A induced the least swelling and galyfilcon A the most. The +6.00 D power, averaged across lens materials, induced significantly greater central swelling than the -10.00 and -3.00 D (Re-ANOVA, p<0.001), (7.7±2.9% vs. 6.8±2.8% and 6.5±2.5% respectively) but there was no difference between -10.00 and -3.00 D. Averaged for power, lotrafilcon A induced the least (6.2±2.8%) and galyfilcon A the most (7.6±3.0%) swelling at the center (Re-ANOVA, p<0.001). Central corneal swelling with +6.00 D was significantly greater than -10.00 D lens power despite similar levels of average lens transmissibility of these two lens powers. The differences in corneal swelling of the lens wearing eyes are consistent with the differences in oxygen transmission of the silicone hydrogel lenses. In silicone hydrogel lenses central corneal swelling is mainly driven by central lens oxygen transmissibility. Copyright © 2013 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

  19. Modeling the controllable pH-responsive swelling and pore size of networked alginate based biomaterials.

    Science.gov (United States)

    Chan, Ariel W; Neufeld, Ronald J

    2009-10-01

    Semisynthetic network alginate polymer (SNAP), synthesized by acetalization of linear alginate with di-aldehyde, is a pH-responsive tetrafunctionally linked 3D gel network, and has potential application in oral delivery of protein therapeutics and active biologicals, and as tissue bioscaffold for regenerative medicine. A constitutive polyelectrolyte gel model based on non-Gaussian polymer elasticity, Flory-Huggins liquid lattice theory, and non-ideal Donnan membrane equilibria was derived, to describe SNAP gel swelling in dilute and ionic solutions containing uni-univalent, uni-bivalent, bi-univalent or bi-bi-valent electrolyte solutions. Flory-Huggins interaction parameters as a function of ionic strength and characteristic ratio of alginates of various molecular weights were determined experimentally to numerically predict SNAP hydrogel swelling. SNAP hydrogel swells pronouncedly to 1000 times in dilute solution, compared to its compact polymer volume, while behaving as a neutral polymer with limited swelling in high ionic strength or low pH solutions. The derived model accurately describes the pH-responsive swelling of SNAP hydrogel in acid and alkaline solutions of wide range of ionic strength. The pore sizes of the synthesized SNAP hydrogels of various crosslink densities were estimated from the derived model to be in the range of 30-450 nm which were comparable to that measured by thermoporometry, and diffusion of bovine serum albumin. The derived equilibrium swelling model can characterize hydrogel structure such as molecular weight between crosslinks and crosslinking density, or can be used as predictive model for swelling, pore size and mechanical properties if gel structural information is known, and can potentially be applied to other point-link network polyelectrolytes such as hyaluronic acid gel.

  20. Porewater salinity and the development of swelling pressure in bentonite-based buffer and backfill materials

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, D.A. [Atomic Energy of Canada Limited (Canada)

    2000-06-01

    At the depths proposed for a nuclear fuel waste repository, it is likely that saline groundwater conditions will be encountered in the granitic rocks of Finland and Canada. The potential for saline groundwater to influence of the ability of bentonite-based buffer and backfilling materials to swell and thereby generate swelling pressure has been reviewed. Based on the data collected from existing literature, it would appear that porewater salinities as high as 100 g/l will not compromise the ability of confined, bentonite-based materials to develop a swelling pressure of at least 100 kPa on its confinement, provided the effective clay dry density (ECDD), exceeds approximately 0.9 Mg/m{sup 3}. At densities less than approximately 0.9 Mg/m{sup 3} the swelling pressure of bentonite-based materials may be reduced and become sensitive to salt concentration. The influence of porewater salinity on swelling pressure can be compared on the basis of the ECDD required to develop 100 kPa of swelling pressure. In order to generate 100 kPa of swelling pressure an ECDD of approximately 0.7 Mg/m{sup 3} is required to be present under fresh water or brackish porewater conditions. This density would need to be increased to approximately 0.9 Mg/m{sup 3} where the groundwater conditions were saline. The impact that groundwater salinity will have on density specifications for buffer and backfilling materials are discussed with reference to the nuclear fuel waste disposal concepts of Finland and Canada. (orig.)

  1. Hydration of swelling clays: multi-scale sequence of hydration and determination of macroscopic energies from microscopic properties

    International Nuclear Information System (INIS)

    Salles, F.

    2006-10-01

    Smectites have interesting properties which make them potential candidates for engineered barriers in deep geological nuclear waste repository: low permeability, swelling and cations retention. The subject of this thesis consists in the determination of the relationship between hydration properties, swelling properties and cations mobility in relation with confinement properties of clayey materials. The aim is to understand and to predict the behaviour of water in smectites, following two research orientations: the mechanistic aspects and the energetic aspects of the hydration of smectites. We worked on the Na-Ca montmorillonite contained in the MX80 bentonite, with the exchanged homo ionic structure (saturated with alkaline cations and calcium cations). The approach crosses the various scales (microscopic, mesoscopic and macroscopic) and implied the study of the various components of the system (layer-cation-water), by using original experimental methods (thermo-poro-metry and electric conductivity for various relative humidities (RH) and electrostatic calculations. Initially, the dry state is defined by SCTA (scanning calorimetry thermal analysis). Then a classical characterization of the smectite porosity for the dry state is carried out using mercury intrusion and nitrogen adsorption. We evidenced the existence of a meso-porosity which radius varies from 2 to 10 nm depending on the compensating cation. The thermo-poro-metry and conductivity experiments performed at various hydration states made it possible to follow the increase in the pore sizes and the cations mobility as a function of the hydration state. We highlight in particular the existence of an osmotic mesoscopic swelling for low RH (approximately 50-60%RH for Li and Na). By combining the results of thermo-poro-metry, X-ray diffraction and electric conductivity, we are able to propose a complete hydration sequence for each cation, showing the crucial role of the compensating cation in the hydration of

  2. Shrinkage and swelling properties of flocculated mature fine tailings

    NARCIS (Netherlands)

    Yao, Y.; Van Tol, A.F.; Van Paassen, L.A.; Vardon, P.J.

    2014-01-01

    In the atmospheric fines drying technique, mature fine tailings (MFT) are treated with polymers and deposited in thin layers on a sloped surface for sub-aerial drying. During the whole drying period, the tailings deposits can experience rewetting during periods of rainy weather or as result of the

  3. Release of Water Soluble Drugs from Dynamically Swelling POLY(2-HYDROXYETHYL Methacrylate - CO - Methacrylic Acid) Hydrogels.

    Science.gov (United States)

    Kou, Jim Hwai-Cher

    In this study, ionizable copolymers of HEMA and methacrylic acid (MA) are investigated for their potential use in developing pH dependent oral delivery systems. Because of the MA units, these gels swell extensively at high pH. Since solute diffusion in the hydrophilic polymers depends highly on the water content of the matrix, it is anticipated that the release rate will be modulated by this pH induced swelling. From a practical point of view, the advantage of the present system is that one can minimize drug loss in the stomach and achieve a programmed release in intestine. This approach is expected to improve delivery of acid labile drugs or drugs that cause severe gastrointestinal side effects. This work mainly focuses on the basic understanding of the mechanism involved in drug release from the poly(HEMA -co- MA) gels, especially under dynamic swelling conditions. Equilibrium swelling is first characterized since water content is the major determinant of transport properties in these gels. Phenylpropanolamine (PPA) is chosen as the model drug for the release study and its diffusion characteristics in the gel matrix determined. The data obtained show that the PPA diffusivity follows the free volume theory of Yasuda, which explains the accelerating effect of swelling on drug release. A mathematical model based on a diffusion mechanism has been developed to describe PPA release from the swelling gels. Based on this model, several significant conclusions can be drawn. First, the release rate can be modulated by the aspect ratio of the cylindrical geometry, and this has a practical implication in dosage form design. Second, the release rate can be lowered quite considerably if the dimensional increase due to swelling is significant. Consequently, it is the balance between the drug diffusivity increase and the gel dimensional growth that determines the release rate from the swelling matrix. Third, quasi-steady release kinetics, which are characteristic of swelling

  4. Dermal collagen and lipid deposition correlate with tissue swelling and hydraulic conductivity in murine primary lymphedema.

    Science.gov (United States)

    Rutkowski, Joseph M; Markhus, Carl Erik; Gyenge, Christina C; Alitalo, Kari; Wiig, Helge; Swartz, Melody A

    2010-03-01

    Primary lymphedema is a congenital pathology of dysfunctional lymphatic drainage characterized by swelling of the limbs, thickening of the dermis, and fluid and lipid accumulation in the underlying tissue. Two mouse models of primary lymphedema, the Chy mouse and the K14-VEGFR-3-Ig mouse, both lack dermal lymphatic capillaries and exhibit a lymphedematous phenotype attributable to disrupted VEGFR-3 signaling. Here we show that the differences in edematous tissue composition between these two models correlated with drastic differences in hydraulic conductivity. The skin of Chy mice possessed significantly higher levels of collagen and fat, whereas K14-VEGFR-3-Ig mouse skin composition was relatively normal, as compared with their respective wild-type controls. Functionally, this resulted in a greatly increased dermal hydraulic conductivity in K14-VEGFR3-Ig, but not Chy, mice. Our data suggest that lymphedema associated with increased collagen and lipid accumulation counteracts an increased hydraulic conductivity associated with dermal swelling, which in turn further limits interstitial transport and swelling. Without lipid and collagen accumulation, hydraulic conductivity is increased and overall swelling is minimized. These opposing tissue responses to primary lymphedema imply that tissue remodeling--predominantly collagen and fat deposition--may dictate tissue swelling and govern interstitial transport in lymphedema.

  5. Black liquor devolatilization and swelling - a detailed droplet model and experimental validation

    International Nuclear Information System (INIS)

    Jaervinen, M.; Zevenhoven, R.; Vakkilainen, E.; Forssen, M.

    2003-01-01

    In this paper, we present results from a new detailed physical model for single black liquor droplet pyrolysis and swelling, and validate them against experimental data from a non-oxidizing environment using two different reactor configurations. In the detailed model, we solve for the heat transfer and gas phase mass transfer in the droplet and thereby, the intra-particle gas-char and gas-gas interactions during drying and devolatilization can be studied. In the experimental part, the mass change, the swelling behaviour, and the volume fraction of larger voids, i.e. cenospheres in the droplets were determined in a non-oxidizing environment. The model gave a good correlation with experimental swelling and mass loss data. Calculations suggest that a considerable amount of the char can be consumed before the entire droplet has experienced the devolatilization and drying stages of combustion. Char formed at the droplet surface layer is generally consumed by gasification with H 2 O flowing outwards from the droplet interior. The extent of char conversion during devolatilization and the rate of devolatilization are greatly affected by swelling and the formation of larger voids in the particle. The more the particle swells and the more homogeneous the particle structure is, the larger is the conversion of char at the end of devolatilization

  6. Ion irradiation-induced swelling and hardening effect of Hastelloy N alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, S.J. [Key Laboratory of Artificial Micro-and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Li, D.H.; Chen, H.C.; Lei, G.H.; Huang, H.F.; Zhang, W.; Wang, C.B. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Yan, L., E-mail: yanlong@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Fu, D.J. [Key Laboratory of Artificial Micro-and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Tang, M. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2017-06-15

    The volumetric swelling and hardening effect of irradiated Hastelloy N alloy were investigated in this paper. 7 MeV and 1 MeV Xe ions irradiations were performed at room temperature (RT) with irradiation dose ranging from 0.5 to 27 dpa. The volumetric swelling increases with increasing irradiation dose, and reaches up to 3.2% at 27 dpa. And the irradiation induced lattice expansion is also observed. The irradiation induced hardening initiates at low ion dose (≤1dpa) then saturates with higher ion dose. The irradiation induced volumetric swelling may be ascribed to excess atomic volume of defects. The irradiation induced hardening may be explained by the pinning effect where the defects can act as obstacles for the free movement of dislocation lines. And the evolution of the defects' size and number density could be responsible for the saturation of hardness. - Highlights: •Irradiation Swelling: The irradiation induced volumetric swelling increases with ion dose. •Irradiation Hardening: The irradiation hardening initiates below 1 dpa, then saturates with higher ion dose (1–10 dpa). •Irradiation Mechanism: The irradiation phenomena are ascribed to the microstructural evolution of the irradiation defects.

  7. Water swelling properties of the electron beam irradiated PVA-g-AAc hydrogels

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qingguo, E-mail: qwang@qust.edu.cn [Key Laboratory of Rubber-Plastics of Ministry of Education, Qingdao University of Science and Technology, Qingdao 266042 (China); Shandong Provincial Key Laboratory of Rubber-Plastics, Qingdao 266042 (China); Zhou, Xue; Zeng, Jinxia; Wang, Jizeng [Key Laboratory of Rubber-Plastics of Ministry of Education, Qingdao University of Science and Technology, Qingdao 266042 (China)

    2016-02-01

    In this paper, the electron beam irradiation technology being more suitable for the industry application is explored to fabricate the acrylic acid (AAc) monomer-grafted polyvinyl alcohol (PVA-g-AAc) hydrogels. ATR-IR spectra of the PVA-g-AAc hydrogels shows an obvious absorption peak of the −C=O group at 1701 cm{sup −1}, indicating that the AAc monomers were grafted onto the PVA macromolecules. This paper also studied some effects of the mass ratio of PVA/AAc, pH of buffer solution and irradiation dosage on the water swelling properties of the electron beam irradiated PVA-g-AAc hydrogels. The water swelling ratio of PVA-g-AAc hydrogels decreases with increased irradiation dosage and mass ratio of PVA/AAc, whereas swelling ratio increases with increased pH of buffer solution and soaking time. The water-swelling behavior of PVA-g-AAc hydrogels occurred easily in an alkaline environment, particularly in a buffer solution with pH 9.2. Both PVA-g-AAc hydrogels (PVA/AAc = 1/5, w/w) irradiated with 5 kilogray (kGy) and PVA-g-AAc hydrogels (PVA/AAc = 1/1, w/w) irradiated with 15 kGy could easily absorb water and lead to high water swelling ratios (up to about 600%), which are potential candidates to meet the requirements for some biomedical applications.

  8. Characterization and swelling-deswelling properties of wheat straw cellulose based semi-IPNs hydrogel.

    Science.gov (United States)

    Liu, Jia; Li, Qian; Su, Yuan; Yue, Qinyan; Gao, Baoyu

    2014-07-17

    A novel wheat straw cellulose-g-poly(potassium acrylate)/polyvinyl alcohol (WSC-g-PKA/PVA) semi-interpenetrating polymer networks (semi-IPNs) hydrogel was prepared by polymerizing wheat straw and an aqueous solution of acrylic acid (AA), and further semi-interpenetrating with PVA occurred during the chemosynthesis. The swelling and deswelling properties of WSC-g-PKA/PVA semi-IPNs hydrogel and WSC-g-PKA hydrogel were studied and compared in various pH solutions, salt solutions, temperatures, particle sizes and ionic strength. The results indicated that both hydrogels had the largest swelling capacity at pH=6, and the effect of ions on the swelling of hydrogels was in the order: Na(+)>K(+)>Mg(2+)>Ca(2+). The Schott's pseudo second order model can be effectively used to evaluate swelling kinetics of hydrogels. Moreover, the semi-IPNs hydrogel had improved swelling-deswelling properties compared with that of WSC-g-PKA hydrogel. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Evaluation of permeability and swelling pressure of compacted bentonite using a calcium hydroxide solution

    International Nuclear Information System (INIS)

    Aoyagi, Takayoshi; Maeda, Munehiro; Mihara, Morihiro; Tanaka, Masuhiro

    1998-12-01

    Tests to determine the swelling pressure, permeability, compressive strength and elastic modulus of Ca-Na exchanged bentonite, Na-bentonite and Ca-bentonite at the Power Reactor and Nuclear Fuel Development Corporation have mainly used distilled water. However, disposal facilities for TRU waste will use cementateous material for packaging, backfill as well as structural support. In this case, a large amount of calcium will dissolve in groundwater flowing through the cementateous material. Therefore, it is important to investigate the mechanical properties of bentonite in calcium-rich water as part of the disposal research program for TRU waste. In order to understand the effect of the chemical composition of water on the basic mechanical properties of bentonite - part of evaluating the disposal concepts for TRU waste disposal - we tested the permeability of compacted bentonite under saturated conditions using a calcium hydroxide solution. The aqueous solution represents water dominated by the calcium component. Na-bentonite, Ca-Na exchanged bentonite and Ca-bentonite were used for swelling pressure measurement tests and permeability testing. Measures of the maximum and equilibrium swelling pressure as well as permeability we obtained. The dry density of bentonite was varied between tests. Results show that swelling pressure and permeability are dependent on dry density. In separate tests using Ca-bentonite, the bentonite-mixing rate was varied as an independent parameter. Results show that there is little change in the swelling pressure and permeability between tests using calcium hydroxide solution and distilled water for all bentonite types. (author)

  10. Effect of Guci powder on toe swelling induced by egg white in rats

    Science.gov (United States)

    Xie, Guoqi; Hao, Shaojun; Shen, Huiling; Ma, Zhenzhen; Zhang, Xuehui; Zhang, Zhengchen

    2018-04-01

    To observe the effect of Guci Powder on foot swelling induced by egg white in rats. 50 male rats were randomly divided into normal saline group (n=10), white vinegar group (n=10) and Guning lotion group (n=10). There were 10 rats in the high-dose group and 10 in the low-dose group. The rats in each group were treated with the drug on the left and right feet of the rats. 0.5 hours after the last administration, the rats in each group were inflamed. The left hindsole plantar volume was measured respectively, so that the difference of the posterior toe volume before inflammation was taken as the swelling degree, and the swelling degree of each group was calculated. Compared with physiological saline group, the rats' egg white toe swelling (Pegg white toe in rats was inhibited at 0.5˜2h (Pegg white in rats, and the external application of bone spur powder has anti-inflammatory and swelling effect.

  11. Development of advanced austenitic stainless steels resistant to void swelling under irradiation

    International Nuclear Information System (INIS)

    Rouxel, Baptiste

    2016-01-01

    In the framework of studies about Sodium Fast Reactors (SFR) of generation IV, the CEA is developing new austenitic steel grades for the fuel cladding. These steels demonstrate very good mechanical properties but their use is limited because of the void swelling under irradiation. Beyond a high irradiation dose, cavities appear in the alloys and weaken the material. The reference material in France is a 15Cr/15Ni steel, named AIM1, stabilized with titanium. This study try to understand the role played by various chemical elements and microstructural parameters on the formation of the cavities under irradiation, and contribute to the development of a new grade AIM2 more resistant to swelling. In an analytical approach, model materials were elaborated with various chemical compositions and microstructures. Ten grades were cast with chemical variations in Ti, Nb, Ni and P. Four specific microstructures for each alloy highlighted the effect of dislocations, solutes or nano-precipitates on the void swelling. These materials were characterized using TEM and SANS, before irradiation with Fe"2"+ (2 MeV) ions in the order to simulate the damages caused by neutrons. Comparing the irradiated microstructures, it is demonstrated that the solutes have a dominating effect on the formation of cavities. Specifically titanium in solid solution reduces the swelling whereas niobium does not show this effect. Finally, a matrix enriched by 15% to 25% of nickel is still favorable to limit swelling in these advanced austenitic stainless steels. (author) [fr

  12. Effect of light impurities on the early stage of swelling in austenitic stainless steel

    International Nuclear Information System (INIS)

    Igata, N.

    1998-01-01

    The objective of this study is to analyse the early stage of swelling and clarify the role of light impurities (nitrogen) in swelling of austenitic stainless steel. Recent results show that light impurities affect the swelling of 316 stainless steel under HVEM irradiation up to 10 dpa. At low concentration of light impurities the radiation swelling increases then decreases through the maximum as the concentration of light impurities increases. In the present paper the theoretical model is presented for the explanation of this effect. The model is based on the two factors: the influence of absorbed impurities on the voids caused by the production of an additional gas pressure in voids for their stabilization and the effect of impurities segregated around the surface of voids by the lowering of surface tension. These two affects are taken into account in the calculations of the critical size and the growth rate of cavities. The theoretical predictions on the radiation swelling rate dependent on the impurity concentration and temperature coincided with the experimental results on 316 stainless steel irradiated by HVEM. (orig.)

  13. Molecular accessibility in solvent swelled coals. Quarterly report, [April--June 1993

    Energy Technology Data Exchange (ETDEWEB)

    Kispert, L.D.

    1993-08-01

    The effect of weathering (oxidation and dehydration upon exposure to air) on the molecular accessibility of potential catalysts was studied by the EPR spin probe technique. Fresh samples of all 8 APCS coals were exposed to air for periods up to 36 days. Weathering produced significant effects on the retention of spin probes in most of the APCS coals under 91 % carbon (dmmf). It was determined that the lower ranked coal (Beulah Zap and Wyodak) under went a structural collapse which precluded retention of even spin probe VIII. However, medium ranked coals exhibited improved retention upon weathering when swelled in toluene. Swelling with pyridine opened up small pores for 81--86% carbon which is not observed for swelling with toluene. Changes in coal structure were successfully followed by the EPR spin probe method. A detailed analysis of the data collected from the swelling of coals oxidized in a moisture free environment was completed to differentiate between weathering and oxidation. Eight vacuum dried APCS coals were oxidized in an enclosed, pure oxygen, moisture free environment, and the effects of oxidation alone on coal structure were studied by the intercalation of EPR spin probes. The data shows a factor of 5 increase in spin probe retention for some coals oxidized in O{sub 2} versus air., suggesting a large increase in oxidized material. Particular care was taken during the swelling procedures to avoid exposure of the coal samples to air or moisture. EPR spectra were then obtained for these 300 samples.

  14. Swelling, Mechanics, and Thermal/Chemical Stability of Hydrogels Containing Phenylboronic Acid Side Chains

    Directory of Open Access Journals (Sweden)

    Arum Kim

    2017-12-01

    Full Text Available We report here studies of swelling, mechanics, and thermal stability of hydrogels consisting of 20 mol % methacrylamidophenylboronic acid (MPBA and 80 mol % acrylamide (AAm, lightly crosslinked with methylenebisacrylamide (Bis. Swelling was measured in solutions of fixed ionic strength, but with varying pH values and fructose concentrations. Mechanics was studied by compression and hold. In the absence of sugar or in the presence of fructose, the modulus was mostly maintained during the hold period, while a significant stress relaxation was seen in the presence of glucose, consistent with reversible, dynamic crosslinks provided by glucose, but not fructose. Thermal stability was determined by incubating hydrogels at pH 7.4 at room temperature, and 37, 50, and 65 °C, and monitoring swelling. In PBS (phosphate buffered saline solutions containing 9 mM fructose, swelling remained essentially complete for 50 days at room temperature, but decreased substantially with time at the higher temperatures, with accelerated reduction of swelling with increasing temperature. Controls indicated that over long time periods, both the MPBA and AAm units were experiencing conversion to different species.

  15. A novel multiphysic model for simulation of swelling equilibrium of ionized thermal-stimulus responsive hydrogels

    Science.gov (United States)

    Li, Hua; Wang, Xiaogui; Yan, Guoping; Lam, K. Y.; Cheng, Sixue; Zou, Tao; Zhuo, Renxi

    2005-03-01

    In this paper, a novel multiphysic mathematical model is developed for simulation of swelling equilibrium of ionized temperature sensitive hydrogels with the volume phase transition, and it is termed the multi-effect-coupling thermal-stimulus (MECtherm) model. This model consists of the steady-state Nernst-Planck equation, Poisson equation and swelling equilibrium governing equation based on the Flory's mean field theory, in which two types of polymer-solvent interaction parameters, as the functions of temperature and polymer-network volume fraction, are specified with or without consideration of the hydrogen bond interaction. In order to examine the MECtherm model consisting of nonlinear partial differential equations, a meshless Hermite-Cloud method is used for numerical solution of one-dimensional swelling equilibrium of thermal-stimulus responsive hydrogels immersed in a bathing solution. The computed results are in very good agreements with experimental data for the variation of volume swelling ratio with temperature. The influences of the salt concentration and initial fixed-charge density are discussed in detail on the variations of volume swelling ratio of hydrogels, mobile ion concentrations and electric potential of both interior hydrogels and exterior bathing solution.

  16. Multipurpose Compensation Scheme for Voltage Sag/Swell and Selective Harmonics Elimination in Distribution Systems

    Directory of Open Access Journals (Sweden)

    Mustafa Inci

    2018-01-01

    Full Text Available Voltage harmonics, sag, and swell are the most harmful disturbances in distribution systems. This paper introduces a novel effective controller method for simultaneous compensation of both voltage sag/swell and voltage harmonics by using multifunctional dynamic voltage restorer. In proposed controller method called FFT with integrated ISRF, ISRF detects the magnitudes of voltage sag/swell quickly and precisely, and FFT extracts the selective components of voltage harmonics very effectively. The proposed method integrates the superior properties of ISRF and FFT methods. FFT integrated ISRF is applied for the first time to provide the compensation of both sag/swell and selective harmonics together. The proposed system has ability to compensate symmetrical/asymmetrical sag/swell and symmetrical/asymmetrical selective harmonics which are 5th, 7th, 11th and 13th. The controlled system is modelled in PSCAD/EMDTC and compared with conventional methods. The performance results verify that the proposed method compensates voltage disturbances effectively in the system.

  17. Correlation of creep and swelling with fuel pin performance

    International Nuclear Information System (INIS)

    Jackson, R.J.; Washburn, D.F.; Garner, F.A.; Gilbert, E.R.

    1975-09-01

    The HEDL PNL-11 experiment described was one in a series of fueled subassemblies irradiated in EBR-II to demonstrate the adequacy of the FFTF fuel pin design. The cladding material, dimensions, and fuel density are prototypic of FFTF. Because neutron flux in EBR-II is lower than in FFTF, the uranium enrichment is higher in these experimental fuel pins, irradiated in EBR-II, than the FFTF enrichment for comparable linear heat rates. Some pertinent oprating conditions for the center fuel pin in this experiment are listed. This 37-pin subassembly represents, at 110,000 MWd/MTM, the highest burnup yet attained by a prototypic FFTF subassembly. Similarly, this is the highest fluence presently attained by prototypic fuel pins. A cladding breach occurred in one fuel pin which is presently being examined. Results are presented and discussed

  18. Erythrocyte swelling and membrane hole formation in hypotonic media as studied by conductometry.

    Science.gov (United States)

    Pribush, A; Meyerstein, D; Hatskelzon, L; Kozlov, V; Levi, I; Meyerstein, N

    2013-02-01

    Hypoosmotic swelling of erythrocytes and the formation of membrane holes were studied by measuring the dc conductance (G). In accordance with the theoretical predictions, these processes are manifested by a decrease in G followed by its increase. Thus, unlike the conventional osmotic fragility test, the proposed methodological approach allows investigations of both the kinetics of swelling and the erythrocyte fragility. It is shown that the initial rate of swelling and the equilibrium size of the cells are affected by the tonicity of a hypotonic solution and the membrane rheological properties. Because the rupture of biological membranes is a stochastic process, a time-dependent increase in the conductance follows an integral distribution function of the membrane lifetime. The main conclusion which stems from reported results is that information about rheological properties of red blood cell (RBC) membranes and the resistivity of RBCs to a certain osmotic shock may be extracted from conductance signals.

  19. Water uptake, migration and swelling characteristics of unsaturated and saturated, highly compacted bentonite

    International Nuclear Information System (INIS)

    Pusch, R.

    1980-09-01

    The report presents the results of a number of laboratory tests and field observations to form the basis of a physical and mathematical model that can be used for predicting water uptake and swelling in highly compacted bentonite components of an actual deposition plant. The clay buffer masses have been suggested as barriers in the Swedish KBS concepts. Two commercially available bentonites were used for the production of samples. The rate of water uptake suggests a mathematical model based on a simple diffusion equation. The rate is determined by the access of water and thousands of years may pass before saturation is obtained. The rate of swelling is governed by the negative pore pressure and the permeability. There is reasonable agreement with field observations. The observed swelling potential of old smectite-rich clays has offered the evidence. (G.B.)

  20. Hypoosmotic cell swelling as a novel mechanism for modulation of cloned HCN2 channels

    DEFF Research Database (Denmark)

    Calloe, Kirstine; Elmedyb, Pernille; Olesen, Søren-Peter

    2005-01-01

    This work demonstrates cell swelling as a new regulatory mechanism for the cloned hyperpolarization-activated, cyclic nucleotide-gated channel 2 (HCN2). HCN2 channels were coexpressed with aquaporin1 in Xenopus laevis oocytes and currents were monitored using a two-electrode voltage-clamp. HCN2...... channels were activated by hyperpolarization to -100 mV and the currents were measured before and during hypoosmotic cell swelling. Cell swelling increased HCN2 currents by 30% without changing the kinetics of the currents. Injection of 50 nl intracellular solution resulted in a current increase of 20......%, indicating that an increase in cell volume also under isoosmotic conditions may lead to activation of HCN2. In the absence of aquaporin1 only negligible changes in oocyte cell volume occur during exposure to hypoosmotic media and no significant change in HCN2 channel activity was observed during perfusion...

  1. Swelling of uranium dioxide and deformation behavior of the fuel element at high temperature irradiation

    International Nuclear Information System (INIS)

    Gontar, A.S.; Gutnik, V.S.; Nelidov, M.V.; Nikolaev, Yu.V.

    1993-01-01

    As post-reactor investigations showed, significant difference of swelling rates is connected with the fact that swelling of UO 2 with the equiaxial structure is mainly the result of fission gas bubbles accumulation along grain boundaries, and, in the case of the column structure, with formation of fine bubbles inside grains. The data given testify to usefulness of such investigations to predict TFE lifetime. As proven in this study one can see rates of radial deformation of fuel element cladding of a multi-cell TFE as a result of UO 2 swelling. They were calculated using the code SDS. Typical sizes were taken for calculation: cladding diameter--20 mm, cladding temperature at the central section of the fuel element--1,900 K, energy generation rate--145 W/cm 3 . These parameters provide output electric power of the TFE 600 W at the active zone length--400 mm

  2. Ion-induced swelling of ODS ferritic alloy MA957 tubing to 500 dpa

    Energy Technology Data Exchange (ETDEWEB)

    Toloczko, M.B., E-mail: mychailo.toloczko@pnnl.gov [Pacific Northwest National Laboratory, Richland, WA 99354 (United States); Garner, F.A. [Radiation Effects Consulting, Richland, WA 99354 (United States); Voyevodin, V.N.; Bryk, V.V.; Borodin, O.V.; Mel’nychenko, V.V.; Kalchenko, A.S. [Kharkov Institute of Physics and Technology, Kharkov (Ukraine)

    2014-10-15

    In order to study the potential swelling behavior of the ODS ferritic alloy MA957 at very high dpa levels, specimens were prepared from pressurized tubes that were unirradiated archives of tubes previously irradiated in FFTF to doses as high as 110 dpa. These unirradiated specimens were irradiated with 1.8 MeV Cr{sup +} ions to doses ranging from 100 to 500 dpa and examined by transmission electron microscopy. No co-injection of helium or hydrogen was employed. It was shown that compared to several tempered ferritic/martensitic steels irradiated in the same facility, these tubes were rather resistant to void swelling, reaching a maximum value of only 4.5% at 500 dpa and 450 °C. In this fine-grained material, the distribution of swelling was strongly influenced by the presence of void denuded zones along the grain boundaries.

  3. Bearing and Swelling Properties of Randomly Distributed Waste Jute Reinforced Soil

    Directory of Open Access Journals (Sweden)

    Murat Ozturk

    2017-10-01

    Full Text Available In this study, waste jute, which was provided from textile companies, was investigated to define effect of waste jute on swelling and bearing behavior of the sand used. Three different water content (17, 19 and 21% and four different waste jute addition amount at different percentages (0, 1, 2, and 3 by mass of dry soil were selected as design variables. With defined variables Swelling Ratio and California Bearing Ratio (CBR tests were conducted. According to test results it is concluded that minimum swelling ratio was observed in the test containing 3% jute with 19% water content and the highest value of CBR was observed in the sample containing 2% jute with 16% water content. In addition to that, CBR values of unreinforced samples were decreased when water content increased from 16% to 21%. However, CBR values of reinforced samples increased with increasing water content from 19% to 21%.

  4. Swelling of radiation crosslinked acrylamide-based microgels and their potential applications

    Energy Technology Data Exchange (ETDEWEB)

    Abd El-Rehim, H.A. [National Center for Radiation Research and Technology, Atomic Energy Authority, P.O. Box 29 Nasr City, Cairo (Egypt)]. E-mail: ha_rehim@hotmail.com

    2005-10-01

    Crosslinked polyacrylamide PAAm and acrylamide-Na-acrylate P(AAm-Na-AAc) microgels were prepared by electron beam irradiation. It was found that the dose required for crosslinking depends on the polymer moisture content, so that the dose to obtain PAAm of maximum gel fraction was over 40 and 20 kGy for dry and moist PAAm, respectively. The structural changes in irradiated PAAm were investigated using FTIR and SEM. The swelling property of such microgels in distilled water and real urine solution was determined and crosslinked polymers reached their equilibrium swelling state in a few minutes. As the gel content and crosslinking density decrease, the swelling of the microgels increases. The ability of the microgels to absorb and retain large amount of solutions suggested their possible uses in horticulture and in hygienic products such as disposable diapers.

  5. Swelling of radiation crosslinked acrylamide-based microgels and their potential applications

    International Nuclear Information System (INIS)

    Abd El-Rehim, H.A.

    2005-01-01

    Crosslinked polyacrylamide PAAm and acrylamide-Na-acrylate P(AAm-Na-AAc) microgels were prepared by electron beam irradiation. It was found that the dose required for crosslinking depends on the polymer moisture content, so that the dose to obtain PAAm of maximum gel fraction was over 40 and 20 kGy for dry and moist PAAm, respectively. The structural changes in irradiated PAAm were investigated using FTIR and SEM. The swelling property of such microgels in distilled water and real urine solution was determined and crosslinked polymers reached their equilibrium swelling state in a few minutes. As the gel content and crosslinking density decrease, the swelling of the microgels increases. The ability of the microgels to absorb and retain large amount of solutions suggested their possible uses in horticulture and in hygienic products such as disposable diapers

  6. Mark II pressure suppression containment systems: an analytical model of the pool swell phenomenon

    International Nuclear Information System (INIS)

    Ernst, R.J.; Ward, M.G.

    1976-12-01

    A one-dimensional pool swell model of the dynamic and thermodynamic conditions in the suppression chamber following a postulated loss-of-coolant accident (LOCA) is described. The pool swell phenomena is approximated by a constant thickness water slug, which is accelerated upward by the difference between the air bubble pressure acting below the pool and the wetwell air space pressure acting above the pool surface. The transient bubble pressure is computed using the known drywell pressure history and a quasi-steady compressible vent flow model. Comparisons of model predictions with pool swell experimental data are favorable and show the model is based on a conservative interpretation of the physical phenomena involved

  7. Effects of tunneling on groundwater flow and swelling of clay-sulfate rocks

    Science.gov (United States)

    Butscher, Christoph; Einstein, Herbert H.; Huggenberger, Peter

    2011-11-01

    Swelling of clay-sulfate rocks is a major threat in tunneling. It is triggered by the transformation of the sulfate mineral anhydrite into gypsum as a result of water inflow in anhydrite-containing layers after tunnel excavation. The present study investigates the hydraulic effects of tunneling on groundwater flow and analyzes how hydraulic changes caused by excavation lead to water inflow into anhydrite-containing layers in the tunnel area. Numerical groundwater models are used to conduct scenario simulations that allow one to relate hydrogeological conditions to rock swelling. The influence of the topographic setting, the excavation-damaged zone around the tunnel, the sealing effect of the tunnel liner, and the geological configuration are analyzed separately. The analysis is performed for synthetic situations and is complemented by a case study from a tunnel in Switzerland. The results illustrate the importance of geological and hydraulic information when assessing the risk of swelling at an actual site.

  8. Swelling and hydraulic properties of Ca-bentonite for the buffer of a waste repository

    International Nuclear Information System (INIS)

    Lee, J.O.; Cho, W.J.; Kang, C.H.; Chun, K.S.

    2001-01-01

    Swelling and hydraulic tests were carried out to provide the information for the selection of buffer material in a radioactive waste repository. Ca-bentonite and de-ionized water were used for the tests. The swelling pressures of compacted bentonite were in the wide range of 0.7 Kg/cm 2 to 190.2 Kg/cm 2 , and they largely increased with an increase in the dry density and bentonite content. However, the swelling pressures decreased with increasing the initial water content and beyond about 12 wt.% of the initial water content, leveled off to a nearly constant value. The hydraulic conductivities were lower than 10 -11 m/s for the compacted bentonite with the dry density higher than 1.4 Mg/m 3 . They increased with increasing temperature in the range of 20 deg. C to 150 deg. C. (author)

  9. Extracranial soft-tissue swelling: a normal postmortem radiographic finding or a sign of trauma?

    International Nuclear Information System (INIS)

    Strouse, P.J.; Caplan, M.; Owings, C.L.

    1998-01-01

    Objective. To determine if extracranial soft-tissue swelling is an expected postmortem finding or a sign of trauma. Materials and methods. Extracranial soft-tissue thickness was measured at 5 standardized locations on postmortem skull films obtained of 18 infants with no evidence of trauma on autopsy. The same measurements were performed on the skull films of 100 living children, all less than 3 years old and without clinical history of trauma. Results. Extracranial soft tissues measured only slightly greater in the postmortem group than on films of living children; however, the difference did achieve statistical significance. Conclusion. Minimal extracranial soft-tissue swelling is a normal finding on a postmortem skeletal survey. The presence of substantial or asymmetric extracranial soft-tissue swelling should be viewed with suspicion for trauma. (orig.)

  10. [Octanol preconditioning alleviates mouse cardiomyocyte swelling induced by simulated ischemia/reperfusion challenge in vitro].

    Science.gov (United States)

    Luo, Yukun; Fang, Jun; Fan, Lin; Lin, Chaogui; Chen, Zhaoyang; Chen, Lianglong

    2012-10-01

    To investigate the role of connexin 43-formed hemichannels in cell volume regulation induced by simulated ischemia/reperfusion (SI/R). Mouse cardiomyocytes isolated on a Langendorff apparatus with enzyme solution were aliquoted into control, SI/R and SI/R +octanol groups. Calcein-AM was used to stain the cells and the cell volume was measured with confocal microscope by stack scanning. Trypan blue was used to measure the cell viability after the treatments. Calcein-AM staining and cofocal microscopy yielded stable and reproducible results for cell volume measurement. Mouse cardiomyocytes subjected to simulated SI/R showed obvious cell swelling as compared with the control cells [(126∓6)% vs 100%, Poctanol preconditioning significantly attenuated the cell swelling [(113∓6)%, Poctanol preconditioning obviously reduced the viability of the cells with SI/R challenge [(31∓2)%, Poctanol can alleviate the cell swelling to enhance the viability of the cardiomyocytes following SI/R.

  11. Technical and economic assessment of losses caused by rock swelling in mines of the Western Donbass

    Energy Technology Data Exchange (ETDEWEB)

    Pirskii, A A; Stovpnik, S N; Shmigol' , A V

    1988-07-01

    Describes mining geologic conditions in mines of the Pavlovgradugol' association where production increased by 1.7 times during the last 10 years. Floor swelling of 1.1 m/a occurs at depths over 300 m and with rock strength in side walls below 20 MPa. Annually 22 km of workings must undergo repair and 10.4% of crews does the repair work. Technical and economic consequences of floor swelling are analyzed. Annual outlays on maintenance of 1 m of roadways increased to 160-200 rubles. Annual losses on maintenance of workings per coal mining association lie within 300,000-500,000 rubles. At the im. Geroev Kosmosa and im. Leninskogo Komsomola Ukrainy mines these losses amount to 520,000-730,000 and 840,000-845,000 rubles respectively. A comprehensive analysis of production losses and delays in development workings caused by floor swelling is presented. Formulae for loss calculation are given.

  12. Extracranial soft-tissue swelling: a normal postmortem radiographic finding or a sign of trauma?

    Energy Technology Data Exchange (ETDEWEB)

    Strouse, P.J. [Section of Pediatric Radiology, University of Michigan Medical Center, Ann Arbor (United States); Caplan, M. [Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan (United States); Owings, C.L. [Department of Pediatrics and Communicable Diseases, C. S. Mott Children`s Hospital, Ann Arbor, Michigan (United States)

    1998-08-01

    Objective. To determine if extracranial soft-tissue swelling is an expected postmortem finding or a sign of trauma. Materials and methods. Extracranial soft-tissue thickness was measured at 5 standardized locations on postmortem skull films obtained of 18 infants with no evidence of trauma on autopsy. The same measurements were performed on the skull films of 100 living children, all less than 3 years old and without clinical history of trauma. Results. Extracranial soft tissues measured only slightly greater in the postmortem group than on films of living children; however, the difference did achieve statistical significance. Conclusion. Minimal extracranial soft-tissue swelling is a normal finding on a postmortem skeletal survey. The presence of substantial or asymmetric extracranial soft-tissue swelling should be viewed with suspicion for trauma. (orig.) With 2 tabs., 5 refs.

  13. Quantitative analysis of swelling on annealing of hydrogen ion implanted diamond single crystals

    International Nuclear Information System (INIS)

    Kuznetsov, G.F.

    2006-01-01

    Local swelling observed upon high-temperature annealing of natural diamond single crystals implanted by 350-keV hydrogen ions with a dose of 12 10 16 cm 2 is studied. Based on room-temperature measurements, Griffith cracking criterion in combination with gas law, model quantitative calculations of the swelling size and the amount of hydrogen molecules in a swelling have been carried out for the first time. At room temperature, T 1 293 K, the amount of local elastic stresses in the upper layer of the diamond is counterbalanced by inner hydrogen pressure. Behavior of the gas bubbles with the annealing temperature increase up to 1693 K and repeated annealing at a temperature of 1743 K has been calculated [ru

  14. Leukoencephalopathy with swelling in children and adolescents: MRI patterns and differential diagnosis

    International Nuclear Information System (INIS)

    Knaap, M.S. van der; Valk, J.; Barth, P.G.; Smit, L.M.E.; Engelen, B.G.M. van; Tortori Donati, P.

    1995-01-01

    In children, several neurological disorders are characterised by spongiform leukoencephalopathy. MRI of the brain typically shows white matter swelling, but does not enable differentiation of the various underlying disorders. The aim of this article is optimisation of the diagnostic value of MRI in leukoencephalopathy accompanied by swelling. MRI-based inclusion criteria were met by 20 patients in our database. The images were analysed using a detailed scoring list. In 13 of the 20 patients the clinical diagnosis was known (11 definite and 2 probable diagnoses). Characteristic MRI abnormalities could be defined in these patients. Of the 7 patients without a diagnosis, 5 had identical MRI abnormalities: diffuse hemisphere swelling and typical cysts in frontoparietal subcortical white matter and the tips of the temporal lobes. The clinical picture was also similar in these patients, suggesting a similar disease. (orig.). With 10 figs., 2 tabs

  15. Irradiation creep and swelling of various austenitic alloys irradiated in PFR and FFTF

    Energy Technology Data Exchange (ETDEWEB)

    Garner, F.A.; Toloczko, M.B. [Pacific Northwest National Lab., Richland, WA (United States)] [and others

    1996-10-01

    In order to use data from surrogate neutron spectra for fusion applications, it is necessary to analyze the impact of environmental differences on property development. This is of particular importance in the study of irradiation creep and its interactions with void swelling, especially with respect to the difficulty of separation of creep strains from various non-creep strains. As part of an on-going creep data rescue and analysis effort, the current study focuses on comparative irradiations conducted on identical gas-pressurized tubes produced and constructed in the United States from austenitic steels (20% CW 316 and 20% CW D9), but irradiated in either the Prototype Fast Reactor (PFR) in the United Kingdom or the Fast Flux Test Facility in the United States. In PFR, Demountable Subassemblies (DMSA) serving as heat pipes were used without active temperature control. In FFTF the specimens were irradiated with active ({+-}{degrees}5C) temperature control. Whereas the FFTF irradiations involved a series of successive side-by-side irradiation, measurement and reinsertion of the same series of tubes, the PFR experiment utilized simultaneous irradiation at two axial positions in the heat pipe to achieve different fluences at different flux levels. The smaller size of the DMSA also necessitated a separation of the tubes at a given flux level into two groups (low-stress and high-stress) at slightly different axial positions, where the flux between the two groups varied {le}10%. Of particular interest in this study was the potential impact of the two types of separation on the derivation of creep coefficients.

  16. The Time Course of Knee Swelling Post Total Knee Arthroplasty and Its Associations with Quadriceps Strength and Gait Speed.

    Science.gov (United States)

    Pua, Yong-Hao

    2015-07-01

    This study examines the time course of knee swelling post total knee arthroplasty (TKA) and its associations with quadriceps strength and gait speed. Eighty-five patients with unilateral TKA participated. Preoperatively and on post-operative days (PODs) 1, 4, 14, and 90, knee swelling was measured using bioimpedance spectrometry. Preoperatively and on PODs 14 and 90, quadriceps strength was measured using isokinetic dynamometry while fast gait speed was measured using the timed 10-meter walk. On POD1, knee swelling increased ~35% from preoperative levels after which, knee swelling reduced but remained at ~11% above preoperative levels on POD90. In longitudinal, multivariable analyses, knee swelling was associated with quadriceps weakness (P<0.01) and slower gait speed (P=0.03). Interventions to reduce post-TKA knee swelling may be indicated to improve quadriceps strength and gait speed. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Effects of minor alloying additions on the strength and swelling behavior of an austenitic stainless steel

    International Nuclear Information System (INIS)

    Gessel, G.R.

    1978-06-01

    A set of 32 alloys consisting of various additions of the elements Mo, W, Al, Ti, Nb, C and Si to an Fe-7.5 Cr-20 Ni alloy were made in order to investigate the effects of these solute additions on alloy swelling and strength. Both single and multiple additions were examined. The influence of various solute elements on the swelling behavior in the range 500 to 730 0 C was investigated using 4 MeV Ni ion bombardment to a dose 170 dpa. It was found that on an atomic percent basis, the elements may be arranged in order of decreasing effectiveness in reducing peak temperature swelling as follows: Ti, C, Nb, Si, and Mo. Small amounts of aluminum enhance swelling. Additions of Si, Ti, or Nb truncate the high temperature swelling regime of the ternary alloy. Mo, W, and C do not have a strong effect on the temperature dependence of swelling. The results may be interpreted in terms of the effect of point defect trapping on void growth rates, and it is suggested that the changes in peak temperature are the result of small changes in the free vacancy formation energy. A method for treating certain multiple additions is proposed. The effect of these alloying additions on short time high temperature strength properties was estimated using hot hardness measurements over the temperature range 22 to 850 0 C. On an atom percent basis Nb and Ti were most effective in conferring solid solution strengthening and Si the least effective. In the regime 22 to approximately 650 0 C, the hardness data was found to fit an equation of the form: H = H 0 + b/T; where H is the hardness, T is the temperature, and H 0 and b are constants for a given alloy. An empirical method was devised to estimate the hot hardness of alloys containing more than one solute addition

  18. Kinesio Taping does not decrease swelling in acute, lateral ankle sprain of athletes: a randomised trial

    Directory of Open Access Journals (Sweden)

    Guilherme S Nunes

    2015-01-01

    Full Text Available Question: Does Kinesio Taping reduce swelling in athletes who have suffered an acute, lateral ankle sprain? Design: Randomised controlled trial with concealed allocation, intention-to-treat analysis and blinded assessment. Participants: Thirty-six athletes who participated regularly in one of seven different sports modalities and suffered an acute ankle sprain. Intervention: The experimental group received Kinesio Taping application for 3 days, which was designed to treat swelling. The control group received an inert Kinesio Taping application. Outcome measures: For the comparison between groups, the swelling was measured via volumetry, perimetry, relative volumetry and two analyses of the difference in volume and perimetry between ankles of each participant. Data were collected immediately after the 3 days of intervention and at follow-up, which was 15 days post intervention. Results: At 3 days after intervention, there were no differences between groups for swelling in volumetry (MD –2 ml, 95% CI –28 to 32; perimetry (MD 0.2 cm, 95% CI –0.6 to 1.0; relative volumetry (MD 0.0 cm, 95% CI –0.1 to 0.1; and the other analyses. At day 15 follow-up, there were no significant between-group differences in outcomes. Conclusion: The application of Kinesio Taping, with the aim of stimulating the lymphatic system, is ineffective in decreasing acute swelling after an ankle sprain in athletes. Trial registration: Brazilian Registry of Clinical Trials, RBR-32sctf. [Nunes GS, Vargas VZ, Wageck B, dos Santos Hauphental DP, da Luz CM, de Noronha M (2015 Kinesio Taping does not decrease swelling in acute, lateral ankle sprain of athletes: a randomised trial. Journal of Physiotherapy 61: 28–33

  19. Mechanisms of astrocytic K(+) clearance and swelling under high extracellular K(+) concentrations.

    Science.gov (United States)

    Murakami, Shingo; Kurachi, Yoshihisa

    2016-03-01

    In response to the elevation of extracellular K(+) concentration ([K(+)]out), astrocytes clear excessive K(+) to maintain conditions necessary for neural activity. K(+) clearance in astrocytes occurs via two processes: K(+) uptake and K(+) spatial buffering. High [K(+)]out also induces swelling in astrocytes, leading to edema and cell death in the brain. Despite the importance of astrocytic K(+) clearance and swelling, the underlying mechanisms remain unclear. Here, we report results from a simulation analysis of astrocytic K(+) clearance and swelling. Astrocyte models were constructed by incorporating various mechanisms such as intra/extracellular ion concentrations of Na(+), K(+), and Cl(-), cell volume, and models of Na,K-ATPase, Na-K-Cl cotransporter (NKCC), K-Cl cotransporter, inwardly-rectifying K(+) (KIR) channel, passive Cl(-) current, and aquaporin channel. The simulated response of astrocyte models under the uniform distribution of high [K(+)]out revealed significant contributions of NKCC and Na,K-ATPase to increases of intracellular K(+) and Cl(-) concentrations, and swelling. Moreover, we found that, under the non-uniform distribution of high [K(+)]out, KIR channels localized at synaptic clefts absorbed excess K(+) by depolarizing the equivalent potential of K(+) (E K) above membrane potential, while K(+) released through perivascular KIR channels was enhanced by hyperpolarizing E K and depolarizing membrane potential. Further analysis of simulated drug effects revealed that astrocyte swelling was modulated by blocking each of the ion channels and transporters. Our simulation analysis revealed controversial mechanisms of astrocytic K(+) clearance and swelling resulting from complex interactions among ion channels and transporters.

  20. Swelling behaviour of stones and its interest in conservation. An appraisal

    Directory of Open Access Journals (Sweden)

    Delgado Rodrigues, J.

    2001-12-01

    Full Text Available Swelling can be defined as the volume increase experienced by any solid body when wetted. Many lithotypes (carbonate rocks, sandstones, igneous rocks have expansive components in their composition; anhydrite and clay minerals are the two best-known expansive components in stone materials. Swelling strain can be easily quantified and swelling pressure determination is accessible in many geotechnical laboratories. This paper deals with the decay of stone due to swelling of clays and discusses the ways to take the swelling behaviour into account when the assessment of stone durability is concerned. It analyses the role of swelling in stone conservation and reviews some cases where this decay mechanism has a relevant role, explicit or implicitly.

    La expansibilidad puede ser definida como el incremento de volumen que un cuerpo sólido experimenta cuando es humedecido. Muchos tipos litológicos (rocas carbonatadas, areniscas, rocas ígneas tienen componentes expansivos en su composición; la anhidrita y los minerales arcillosos son los dos componentes expansivos más conocidos. La expansibilidad puede ser medida con facilidad y la determinación de la presión de hinchamiento se puede efectuar en muchos laboratorios de geotecnia. Este trabajo trata del problema de la degradación de los materiales rocosos debida a la expansión de las arcillas y discute las formas de tenerla en cuenta cuando interesa evaluar la durabilidad de esos materiales. Se analiza el papel de la expansibilidad en la conservación de la piedra y se hace una revisión de algunos casos en los que la degradación por expansión tiene un papel relevante, explícito o implícito.

  1. Progression of asymptomatic optic disc swelling to non-arteritic anterior ischaemic optic neuropathy.

    Science.gov (United States)

    Subramanian, Prem S; Gordon, Lynn K; Bonelli, Laura; Arnold, Anthony C

    2017-05-01

    The time of onset of optic disc swelling in non-arteritic anterior ischaemic optic neuropathy (NAION) is not known, and it is commonly assumed to arise simultaneously with vision loss. Our goal is to report the presence and persistence of optic disc swelling without initial vision loss and its subsequent evolution to typical, symptomatic NAION. Clinical case series of patients with optic disc swelling and normal visual acuity and visual fields at initial presentation who progressed to have vision loss typical of NAION. All subjects underwent automated perimetry, disc photography and optic coherence tomography and/or fluorescein angiography to evaluate optic nerve function and perfusion. Four patients were found to have sectoral or diffuse optic disc swelling without visual acuity or visual field loss; the fellow eye of all four had either current or prior NAION or a 'disc at risk' configuration. Over several weeks of clinical surveillance, each patient experienced sudden onset of visual field and/or visual acuity loss typical for NAION. Current treatment options for NAION once vision loss occurs are limited and may not alter the natural history of the disorder. Subjects with NAION may have disc swelling for 2-10 weeks prior to the occurrence of visual loss, and with the development of new therapeutic agents, treatment at the time of observed disc swelling could prevent vision loss from NAION. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  2. Numerical Simulation Of The Treatment Of Soil Swelling Using Grid Geocell Columns

    Directory of Open Access Journals (Sweden)

    Fattah Mohammed Y.

    2015-06-01

    Full Text Available In this paper, a method for the treatment of the swelling of expansive soil is numerically simulated. The method is simply based on the embedment of a geogrid (or a geomesh in the soil. The geogrid is extended continuously inside the volume of the soil where the swell is needed to be controlled and orientated towards the direction of the swell. Soils with different swelling potentials are employed: bentonite base-Na and bentonite base-Ca samples in addition to kaolinite mixed with bentonite. A numerical analysis was carried out by the finite element method to study the swelling soil's behavior and investigate the distribution of the stresses and pore water pressures around the geocells beneath the shallow footings. The ABAQUS computer program was used as a finite element tool, and the soil is represented by the modified Drucker-Prager/cap model. The geogrid surrounding the geocell is assumed to be a linear elastic material throughout the analysis. The soil properties used in the modeling were experimentally obtained. It is concluded that the degree of saturation and the matric suction (the negative pore water pressure decrease as the angle of friction of the geocell column material increases due to the activity of the sand fill in the dissipation of the pore water pressure and the acceleration of the drainage through its function as a drain. When the plasticity index and the active depth (the active zone is considered to be equal to the overall depth of the clay model increase, the axial movement (swelling movement and matric suction, as a result of the increase in the axial forces, vary between this maximum value at the top of the layer and the minimum value in the last third of the active depth and then return to a consolidation at the end of the depth layer.

  3. Microstructure and anisotropic swelling behaviour of compacted bentonite/sand mixture

    Directory of Open Access Journals (Sweden)

    Simona Saba

    2014-04-01

    Full Text Available Pre-compacted elements (disks, torus of bentonite/sand mixture are candidate materials for sealing plugs of radioactive waste disposal. Choice of this material is mainly based on its swelling capacity allowing all gaps in the system to be sealed, and on its low permeability. When emplaced in the gallery, these elements will start to absorb water from the host rock and swell. Thereby, a swelling pressure will develop in the radial direction against the host rock and in the axial direction against the support structure. In this work, the swelling pressure of a small scale compacted disk of bentonite and sand was experimentally studied in both radial and axial directions. Different swelling kinetics were identified for different dry densities and along different directions. As a rule, the swelling pressure starts increasing quickly, reaches a peak value, decreases a little and finally stabilises. For some dry densities, higher peaks were observed in the radial direction than in the axial direction. The presence of peaks is related to the microstructure change and to the collapse of macro-pores. In parallel to the mechanical tests, microstructure investigation at the sample scale was conducted using microfocus X-ray computed tomography (μCT. Image observation showed a denser structure in the centre and a looser one in the border, which was also confirmed by image analysis. This structure heterogeneity in the radial direction and the occurrence of macro-pores close to the radial boundary of the sample can explain the large peaks observed in the radial swelling pressure evolution. Another interesting result is the higher anisotropy found at lower bentonite dry densities, which was also analysed by means of μCT observation of a sample at low bentonite dry density after the end of test. It was found that the macro-pores, especially those between sand grains, were not filled by swelled bentonite, which preserved the anisotropic microstructure caused by

  4. Swelling behaviour of Early Jurassic shales when exposed to water vapour

    Science.gov (United States)

    Houben, Maartje; Barnhoorn, Auke; Peach, Colin; Drury, Martyn

    2017-04-01

    The presence of water in mudrocks has a largely negative impact on production of gas, due to the fact that water causes swelling of the rock. Removing the water from the mudrock on the other hand could potentially shrink the rock and increase the matrix permeability. Investigation of the swelling/shrinkage behaviour of the rock during exposure to water vapour is of key importance in designing and optimizing unconventional production strategies. We have used outcrop samples of the Whitby Mudstone and the Posidonia shale [1], potential unconventional sources for gas in North-western Europe, to measure the swelling and shrinkage behaviour. Subsamples, 1 mm cubes, were prepared by the Glass Workshop at Utrecht University using a high precision digitally controlled diamond wafering saw cooled by air. The mm cubes were then exposed to atmospheres with different relative humidities either in an Environmental Scanning Electron Microscope (ESEM) or in a 3D dilatometer. So that the sample responses to exposure of water vapour could be measured. Parallel to the bedding we found a swelling strain between 0.5 and 1.5 %, perpendicular to the bedding though swelling strain varied between 1 and 3.5%. Volumetric swelling strain varied between 1 and 2% at a maximum relative humidity of 95%. Volumetric swelling strains measured in the Early Toarcian Shales are similar to the ones found in coal [2], where the results suggest that it might be possible to increase permeability in the reservoir by decreasing the in-situ water activity due to shrinkage of the matrix. [1] M.E. Houben, A. Barnhoorn, L. Wasch, J. Trabucho-Alexandre, C. J. Peach, M.R. Drury (2016). Microstructures of Early Jurassic (Toarcian) shales of Northern Europe, International Journal of Coal Geology, 165, 76-89. [2] Jinfeng Liu, Colin J. Peach, Christopher J. Spiers (2016). Anisotropic swelling behaviour of coal matrix cubes exposed to water vapour: Effects of relative humidity and sample size, International Journal of

  5. Sonographic and MRI appearance of tensor fasciae suralis muscle, an uncommon cause of popliteal swelling

    International Nuclear Information System (INIS)

    Montet, Xavier; Mauget, Denis; Sandoz, Alain; Martinoli, Carlo; Bianchi, Stefano

    2002-01-01

    A 20-year-old white man presented with a localized unilateral swelling in the popliteal fossa. Ultrasound (US) showed the presence of an accessory muscle, the tensor fasciae suralis. The muscle was located in the proximal portion of the popliteal fossa, superficial to the medial head of the gastrocnemius. Its long tendon extended inferiorly to join the Achilles tendon. Magnetic resonance images correlated well with the US findings, confirming the diagnosis. Tensor fasciae suralis muscle is a rare cause of popliteal swelling and must be differentiated from other masses. Both US and magnetic resonance imaging can diagnose it but we suggest US as the first-line technique in its evaluation. (orig.)

  6. Water Vapor Sensors Based on the Swelling of Relief Gelatin Gratings

    Directory of Open Access Journals (Sweden)

    Sergio Calixto

    2015-01-01

    Full Text Available We report on a novel device to measure relative humidity. The sensor is based on surface diffraction gratings made of gelatin. This material swells and shrinks according to the content of water vapor in air. By sending a light beam to the grating, diffracted orders appear. Due to the gelatin swelling or shrinking, first order intensity changes according to the relative humidity. Calibration curves relating intensity versus relative humidity have been found. The fabrication process of diffraction gratings and the testing of the prototype sensing devices are described.

  7. Transitory spinal cord swelling in a 6-year-old boy with Guillain-Barre syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Delhaas, T. [Section of Child Neurology, Wilhelmina Children`s Hospital, University Hospital for Children and Youth, Utrecht (Netherlands)]|[Department of Pediatrics, University Hospital Maastricht, P0 Box 5800, 6202 AZ Maastricht (Netherlands); Kamphuis, D.J. [Section of Child Neurology, Wilhelmina Children`s Hospital, University Hospital for Children and Youth, Utrecht (Netherlands); Witkamp, T.D. [Department of Radiology, University Hospital Utrecht, Utrecht (Netherlands)

    1998-07-01

    A 6-year-old boy developed progressive motor weakness and areflexia. The clinical picture, combined with electrophysiological findings, indicated a diagnosis of Guillain-Barre syndrome (GBS). MRI on admission revealed spinal cord swelling and increased signal intensity within the cord. It is concluded that, since a degree of central nervous system involvement can occasionally be part of the spectrum of GBS, swelling of the spinal cord without contrast enhancement does not exclude a diagnosis of GBS. (orig.) With 2 figs., 8 refs.

  8. Swelling and eicosanoid metabolites differentially gate TRPV4 channels in retinal neurons and glia

    DEFF Research Database (Denmark)

    Ryskamp, Daniel A; Jo, Andrew O; Frye, Amber M

    2014-01-01

    that were inhibited by TRPV4 antagonists and absent in TRPV4(-/-) Müller cells. Glial TRPV4 signals were phospholipase A2- and cytochrome P450-dependent, characterized by slow-onset and Ca(2+) waves, and, in excess, were sufficient to induce reactive gliosis. In contrast, neurons responded to TRPV4 agonists...... and swelling with fast, inactivating Ca(2+) signals that were independent of phospholipase A2. Our results support a model whereby swelling and proinflammatory signals associated with arachidonic acid metabolites differentially gate TRPV4 in retinal neurons and glia, with potentially significant consequences...

  9. Bowing-reactivity trends in EBR-II assuming zero-swelling ducts

    International Nuclear Information System (INIS)

    Meneghetti, D.

    1994-01-01

    Predicted trends of duct-bowing reactivities for the Experimental Breeder Reactor II (EBR-II) are correlated with predicted row-wise duct deflections assuming use of idealized zero-void-swelling subassembly ducts. These assume no irradiation induced swellings of ducts but include estimates of the effects of irradiation-creep relaxation of thermally induced bowing stresses. The results illustrate the manners in which at-power creeps may affect subsequent duct deflections at zero power and thereby the trends of the bowing component of a subsequent power reactivity decrement

  10. Swelling in several commercial alloys irradiated to very high neutron fluence

    International Nuclear Information System (INIS)

    Gelles, D.S.; Pintler, J.S.

    1984-01-01

    Swelling values have been obtained from a set of commercial alloys irradiated in EBR-II to a peak fluence of 2.5 x 10 23 n/cm 2 (E > 0.1 MeV) or approx. 125 dpa covering the range 400 to 650 0 C. The alloys can be ranked for swelling resistance from highest to lowest as follows: the martensitic and ferritic alloys, the niobium based alloys, the precipitation strengthened iron and nickel based alloys, the molybdenum alloys and the austenitic alloys

  11. 'Shamal' swells in the Arabian Sea and their influence along the west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Aboobacker, V.M.; Vethamony, P.; Rashmi, R.

    on the meteorological and oceanographic conditions of the Arabian Sea, and this has not been studied so far. Rapid changes in wind patterns during these shamal events can alter the wave characteristics of the Arabian Sea. This has motivated us to take up the present... generated in the Gulf of Oman and the east coast of Oman propagate in the NW direction. Another swell system formed off Salalah coast (Figure 4a) propagates in the NNW direction. Since the present study aims at understanding the influence of shamal swells...

  12. Swelling of AISI 304L in response to simultaneous variations in stress and displacement rate

    International Nuclear Information System (INIS)

    Porter, D.L.; Garner, F.A.

    1984-01-01

    The duration of the transient regime of neutron-induced swelling in annealed AISI 304L at 400 0 C is sensitive to both stress and displacement rate variations. The simultaneous application of both variables exerts a synergistic effect on the transient regime. The duration of this regime cannot be reduced below a required intrinsic exposure of approx. 10 dpa, however, which has been found to be characteristic of all Fe-Ni-Cr austenitic alloys. This is four times larger than that currently assumed in the stress-affected swelling equation for 20% cold-worked AISI 316

  13. Effect of laser and/or electron beam irradiation on void swelling in SUS316L austenitic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Subing [School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Yang, Zhanbing, E-mail: yangzhanbing@ustb.edu.cn [School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083 (China); State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083 (China); Wang, Hui [School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Watanabe, Seiichi; Shibayama, Tamaki [Center for Advanced Research of Energy and Materials, Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628 (Japan)

    2017-05-15

    Large amounts of void swelling still limit the application of austenitic stainless steels in nuclear reactors due to radiation-induced lattice point defects. In this study, laser and/or beam irradiation was conducted in a temperature range of 573–773 K to explore the suppression of void swelling. The results show that during sequential laser-electron beam irradiation, the void nucleation is enhanced because of the vacancy clusters and void nuclei formed under pre-laser irradiation, causing greater void swelling than single electron beam irradiation. However, simultaneous laser-electron dual-beam irradiation exhibits an obvious suppression effect on void swelling due to the enhanced recombination between interstitials and vacancies in the temperature range of 573–773 K; especially at 723 K, the swelling under simultaneous dual-beam irradiation is 0.031% which is only 22% of the swelling under electron beam irradiation (0.137%). These results provide new insight into the suppression of void swelling during irradiation. - Highlights: •The temperature dependence of void swelling under simultaneous laser-electron dual-beam irradiation has been investigated. •Pre-laser irradiation enhances void nucleation at temperatures from 573 K to 773 K. •Simultaneous laser-electron dual-beam irradiation suppresses void swelling in the temperature range of 573–773 K.

  14. Swelling of copper-aluminum and copper-nickel alloys in FFTF-MOTA at approximately 4500C

    International Nuclear Information System (INIS)

    Garner, F.A.; Brager, H.R.

    1986-06-01

    Pure copper appears to swell with an S-shaped behavior at 450 0 C, tending to saturate at higher fluence levels. The addition of solutes such as aluminum and nickel at 5 wt % leads to an extended transient regime and thereby a reduction in swelling at low to moderate fast neutron exposures. The addition of these elements also leads to an increase in the saturation level of swelling, however, resulting in an increase in swelling relative to that of pure copper at high fluence

  15. Inhibition of VEGF Signaling Reduces Diabetes-Exacerbated Brain Swelling, but Not Infarct Size, in Large Cerebral Infarction in Mice.

    Science.gov (United States)

    Kim, Eunhee; Yang, Jiwon; Park, Keun Woo; Cho, Sunghee

    2017-12-30

    In light of repeated translational failures with preclinical neuroprotection-based strategies, this preclinical study reevaluates brain swelling as an important pathological event in diabetic stroke and investigates underlying mechanism of the comorbidity-enhanced brain edema formation. Type 2 (mild), type 1 (moderate), and mixed type 1/2 (severe) diabetic mice were subjected to transient focal ischemia. Infarct volume, brain swelling, and IgG extravasation were assessed at 3 days post-stroke. Expression of vascular endothelial growth factor (VEGF)-A, endothelial-specific molecule-1 (Esm1), and the VEGF receptor 2 (VEGFR2) was determined in the ischemic brain. Additionally, SU5416, a VEGFR2 inhibitor, was treated in the type 1/2 diabetic mice, and stroke outcomes were determined. All diabetic groups displayed bigger infarct volume and brain swelling compared to nondiabetic mice, and the increased swelling was disproportionately larger relative to infarct enlargement. Diabetic conditions significantly increased VEGF-A, Esm1, and VEGFR2 expressions in the ischemic brain compared to nondiabetic mice. Notably, in diabetic mice, VEGFR2 mRNA levels were positively correlated with brain swelling, but not with infarct volume. Treatment with SU5416 in diabetic mice significantly reduced brain swelling. The study shows that brain swelling is a predominant pathological event in diabetic stroke and that an underlying event for diabetes-enhanced brain swelling includes the activation of VEGF signaling. This study suggests consideration of stroke therapies aiming at primarily reducing brain swelling for subjects with diabetes.

  16. Two-phase mixture level swell and liquid entrainment/off-take in a vessel during rapid depressurization

    International Nuclear Information System (INIS)

    Kim, Chang Hyun

    2004-02-01

    An experimental study has been performed to analyze the two-phase mixture level swell and the liquid entrainment/off-take through the break in a vessel, which are important phenomena to determine the bleed capacity of the Safety Depressurization System (SDS) of Korea Advanced Power Reactor 1400 (APR1400). Three separate experiments are performed in this study: (a) the depressurization and two-phase mixture level swell experiment: (b) the two-phase mixture level measurement experiment: (c) the liquid entrainment and off-take experiment. A series of experiments has been performed using a scaled pressurized vessel in various depressurization conditions to analyze the two-phase mixture level swell and the liquid entrainment/off-take phenomena from the two-phase mixture surface in the first experiment. The test parameters are the initial pressure (10 - 38.75bars), the initial water level (43.7% - 80.0% of full height), the orifice inner diameter (10mm, 17.5mm, and 20mm). The liquid off-take takes place in certain experimental conditions. The measured parameters in the present experiments are axial void fraction distributions, pressures, temperatures in the test vessel, and the mixture density and mass flowrate through the discharge pipe. An assessment of RELAP5/MOD3 code with the present experimental data has been performed. With appropriate nodalization and time step, RELAP5/MOD3 showed reasonable agreement with the present experimental data for the gradual depressurization without liquid off-take. In the case that the off-take takes place, however, RELAP5/MOD3 under-predicts the amount of liquid entrainment/off-take during depressurization. In the second experiment, an assessment of an ultrasonic sensor and a two-wire type capacitance probe for the two-phase mixture level measurement has been performed under the same experimental conditions to adopt an appropriate measurement method for the two-phase mixture level swell and to investigate pool void fraction by the

  17. A new approach combining different MRI methods to provide detailed view on swelling dynamics of xanthan tablets influencing drug release at different pH and ionic strength.

    Science.gov (United States)

    Mikac, Ursa; Sepe, Ana; Kristl, Julijana; Baumgartner, Sasa

    2010-08-03

    release kinetics. The slowest release of pentoxifylline was observed in water where the thickest gel was formed, whereas the fastest release was observed in HCl pH 1.2, in which the gel layer was thinnest. Moreover, experiments simulating physiological conditions showed that changes of pH and ionic strength influence the xanthan gel structure relatively quickly, and consequently the drug release kinetics. It is therefore concluded that drug release is greatly influenced by changes in the xanthan molecular conformation, as reflected in changed thickness of the gel layer. A new method utilizing combination of SPI, multi-echo MRI and T(2) mapping eliminates the limitations of standard methods used in previous studies for determining moving fronts and improves current understanding of the dynamic processes involved in polymer swelling. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  18. Ion irradiation studies on the void swelling behavior of a titanium modified D9 alloy

    Science.gov (United States)

    Balaji, S.; Mohan, Sruthi; Amirthapandian, S.; Chinnathambi, S.; David, C.; Panigrahi, B. K.

    2015-12-01

    The sensitivity of Positron Annihilation Spectroscopy (PAS) for probing vacancy defects and their environment is well known. Its applicability in determination of swelling and the peak swelling temperature was put to test in our earlier work on ion irradiated D9 alloys [1]. Upon comparison with the peak swelling temperature determined by conventional step height measurements it was found that the peak swelling temperature determined using PAS was 50 K higher. It was conjectured that the positrons trapping in the irradiation induced TiC precipitation could have caused the shift. In the present work, D9 alloys have been implanted with 100 appm helium ions and subsequently implanted with 2.5 MeV Ni ions up to peak damage of 100 dpa. The nickel implantations have been carried out through a range of temperatures between 450 °C and 650 °C. The evolution of cavities and TiC precipitates at various temperatures has been followed by TEM and this report provides an experimental verification of the conjecture.

  19. Second toe swelling: Nora's lesion or glomus tumour, case report and literature review.

    LENUS (Irish Health Repository)

    Mohammad, A

    2012-09-01

    We report a rare case of bizarre parosteal osteochondromatous proliferation (BPOP, Nora\\'s lesion) of the right second toe in a 60-year-old man who presented with painful, bluish and bulbous swelling of the right second toe without any break in the skin.

  20. A brief review of cavity swelling and hardening in irradiated copper and copper alloys

    International Nuclear Information System (INIS)

    Zinkle, S.J.

    1990-01-01

    The literature on radiation-induced swelling and hardening in copper and its alloy is reviewed. Void formation does not occur during irradiation of copper unless suitable impurity atoms such as oxygen or helium are present. Void formation occurs for neutron irradiation temperatures of 180 to 550 degree C, with peak swelling occurring at ∼320 degree C for irradiation at a damage rate of 2 x 10 -7 dpa/s. The post-transient swelling rate has been measured to be ∼0.5%/dpa at temperatures near 400 degree C. Dispersion-strengthened copper has been found to be very resistant to void swelling due to the high sink density associated with the dispersion-stabilized dislocation structure. Irradiation of copper at temperatures below 400 degree C generally causes an increase in strength due to the formation of defect clusters which inhibit dislocation motion. The radiation hardening can be adequately described by Seeger's dispersed barrier model, with a barrier strength for small defect clusters of α ∼ 0.2. The radiation hardening apparently saturates for fluences greater than ∼10 24 n/m 2 during irradiation at room temperature due to a saturation of the defect cluster density. Grain boundaries can modify the hardening behavior by blocking the transmission of dislocation slip bands, leading to a radiation- modified Hall-Petch relation between yield strength and grain size. Radiation-enhanced recrystallization can lead to softening of cold-worked copper alloys at temperatures above 300 degree C

  1. A purple swelling on the tongue | Panta | Pan African Medical Journal

    African Journals Online (AJOL)

    Hemangiomas are benign hamartomatous lesions that are slow growing, sessile or pedunculated, smooth or lobulated, red swellings which sometimes exhibit a bluish hue. Hemangiomas of the tongue need special attention due to their susceptability to trauma from masticatory forces. Pan African Medical Journal 2015; 21 ...

  2. Microcystic adnexal carcinoma: an unusual cause of swelling and paraesthesia of the lower lip.

    Science.gov (United States)

    Hodgson, T A; Haricharan, A K; Barrett, A W; Porter, S R

    2003-02-01

    Microcystic adnexal carcinoma (MAC) is an uncommon, recently described, cutaneous adnexal malignant neoplasm, associated with significant morbidity as a consequence of its propensity for perineural invasion. The present report details the clinical and histological features of MAC in a young female presenting with lower labial swelling and paraesthesia. Copyright 2002 Published by Elsevier Science Ltd.

  3. Constrained swelling of polymer networks: characterization of vapor-deposited cross-linked polymer thin films

    Czech Academy of Sciences Publication Activity Database

    Dušek, Karel; Choukourov, A.; Dušková-Smrčková, Miroslava; Biederman, H.

    2014-01-01

    Roč. 47, č. 13 (2014), s. 4417-4427 ISSN 0024-9297 R&D Projects: GA ČR GAP101/12/1306 Institutional support: RVO:61389013 Keywords : swelling * cross-linked polymer * elasticity Subject RIV: CD - Macromolecular Chemistry Impact factor: 5.800, year: 2014

  4. Activity-dependent astrocyte swelling is mediated by pH-regulating mechanisms

    DEFF Research Database (Denmark)

    Larsen, Brian Roland; MacAulay, Nanna

    2017-01-01

    affecting the K(+) transients, pointing to NBCe1 as a key contributor to the stimulus-induced astrocytic cell swelling. Inhibition of the monocarboxylate cotransporters (MCT), like-wise, reduced the ECS shrinkage by ∼25% without compromising the K(+) transients. Isosmotic reduction of extracellular Cl...

  5. Recent studies on wind seas and swells in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Vethamony, P.; Rashmi, R.; Samiksha, S.V.; Aboobacker, V.M.

    generated waves from NW with the pre-existing swell from SW. This leads to an obvious increase in wave height; the superimposition of two wave systems with completely different dominant frequencies lead to a formal decrease of the mean wave period (Fig. 6a...

  6. Lipophilic Super-Absorbent Swelling Gels as Cleaners for Use on Weapons Systems and Platforms

    Science.gov (United States)

    2014-02-01

    Tetrahydrofuran (THF), isopropa- nol, acetonitrile, and dichloromethane were obtained from Acros Organics (Morris Plains, NJ). Dimethylsulfoxide ( DMSO ) and 1...1. In the following solvents , swelling degree did not change in both heating and cooling processes: water, DMSO , methanol, ethanol, isopropanol...available alkylstyrene copolymer (imbiber beads). The cleaning ability of the gels was compared with the standard solvent cleaner trichloroethylene

  7. Water absorption, retention and the swelling characteristics of cassava starch grafted with polyacrylic acid

    NARCIS (Netherlands)

    Witono, J. R.; Noordergraaf, Inge; Heeres, H. J.; Janssen, L. P. B. M.; Heeres, Hero

    2014-01-01

    An important application of starch grafted with copolymers from unsaturated organic acids is the use as water absorbent. Although much research has been published in recent years, the kinetics of water absorption and the swelling behavior of starch based superabsorbents are relatively unexplored.

  8. Swelling, stiffness, and stress in gel material - as related to moisture sorption

    DEFF Research Database (Denmark)

    Nielsen, Lauge Fuglsang

    1996-01-01

    A method is presented by which estimates can be made on swelling, bulk modulus, and internal stresses in gel materials as related to water sorption. Porous gel materials are considered as gel materials made porous by capillary pores large enough not to create capillary condensation and capillary...

  9. Propagation of Atlantic Ocean swells in the north Indian Ocean: A case study

    Digital Repository Service at National Institute of Oceanography (India)

    Samiksha, S.V.; Vethamony, P.; Aboobacker, V.M.; Rashmi, R.

    An analysis of altimeter significant wave height data of May 2007 revealed the occurrence of an extreme weather event off southern tip of South Africa in the Atlantic Ocean, and generation of a series of very high swells at 40 degrees S...

  10. NFkappaB in the mechanism of ammonia-induced astrocyte swelling in culture.

    NARCIS (Netherlands)

    Sinke, A.P.; Jayakumar, A.R.; Panickar, K.S.; Moriyama, M.; Reddy, P.V.; Norenberg, M.D.

    2008-01-01

    Astrocyte swelling and brain edema are major neuropathological findings in the acute form of hepatic encephalopathy (fulminant hepatic failure), and substantial evidence supports the view that elevated brain ammonia level is an important etiological factor in this condition. Although the mechanism

  11. Propionate induces cell swelling and K+ accumulation in shark rectal gland

    International Nuclear Information System (INIS)

    Feldman, G.M.; Ziyadeh, F.N.; Mills, J.W.; Booz, G.W.; Kleinzeller, A.

    1989-01-01

    Small organic anions have been reported to induce cell solute accumulation and swelling. To investigate the mechanism of swelling, we utilized preparations of rectal gland cells from Squalus acanthias incubated in medium containing propionate. Propionate causes cells to swell by diffusing across membranes in its nonionic form, acidifying cell contents, and activating the Na+-H+ antiporter. The Na+-H+ exchange process tends to correct intracellular pH (pHi), and thus it maintains a favorable gradient for propionic acid diffusion and allows propionate to accumulate. Activation of the Na+-H+ antiport also facilitates Na+ entry into the cell and Nai accumulation. At the same time Na+-K+-ATPase activity, unaffected by propionate, replaces Nai with Ki, whereas the K+ leak rate, decreased by propionate, allows Ki to accumulate. As judged by 86 Rb+ efflux, the reduction in K+ leak was not due to propionate-induced cell acidification or reduction in Cli concentration. Despite inducing cell swelling, propionate did not disrupt cell structural elements and F actin distribution along cell membranes

  12. Propionate induces cell swelling and K+ accumulation in shark rectal gland

    Energy Technology Data Exchange (ETDEWEB)

    Feldman, G.M.; Ziyadeh, F.N.; Mills, J.W.; Booz, G.W.; Kleinzeller, A. (Mount Desert Island Biological Laboratory, Salsbury Cove, ME (USA))

    1989-08-01

    Small organic anions have been reported to induce cell solute accumulation and swelling. To investigate the mechanism of swelling, we utilized preparations of rectal gland cells from Squalus acanthias incubated in medium containing propionate. Propionate causes cells to swell by diffusing across membranes in its nonionic form, acidifying cell contents, and activating the Na+-H+ antiporter. The Na+-H+ exchange process tends to correct intracellular pH (pHi), and thus it maintains a favorable gradient for propionic acid diffusion and allows propionate to accumulate. Activation of the Na+-H+ antiport also facilitates Na+ entry into the cell and Nai accumulation. At the same time Na+-K+-ATPase activity, unaffected by propionate, replaces Nai with Ki, whereas the K+ leak rate, decreased by propionate, allows Ki to accumulate. As judged by {sup 86}Rb+ efflux, the reduction in K+ leak was not due to propionate-induced cell acidification or reduction in Cli concentration. Despite inducing cell swelling, propionate did not disrupt cell structural elements and F actin distribution along cell membranes.

  13. The effect of solvent swelling for the production of ashless coal

    Energy Technology Data Exchange (ETDEWEB)

    Aylin Kurman; Sultan Giray; Ozgur Sonmez [Cukurova University, Adana (Turkey). Chemistry Department, Art& Science Faculty

    2005-07-01

    Two Turkish coal (a bituminous and a brown coal) were extracted with NMP-CS2 (1:1 v/v) and NMP-EDA (1:17, v/v) at room conditions and with NMP and NMP/EDA under reflux. To obtain any effect of solvent swelling on extraction yield coals were also extracted at same conditions after swelling with NMP and EDA. The extraction yield was maximum in the NMP-CS2 mixed solvent for higher ranked coal, suggesting a synergistic effect of the system. It was possible to extract over 35 % of sub-bituminous coal by using NMP- CS2. The extraction of same coal with NMP under reflux gave an extraction yield of 33% suggesting the useful effect of solvent swelling and heat during the reflux period. A positive effect of pre-swelling with NMP and EDA on extraction yield and recovery of solid extracts were observed , especially for brown coal sample. Following the extraction, solid extracts were produced with less than 0.12 % in ash content for almost all extraction conditions.

  14. Swelling and tribological properties of melt-mixed fluoroelastomer/nitrile rubber blends under crude oil

    Science.gov (United States)

    Tagelsir, Yasin; Li, San-Xi; Lv, Xiaoren; Wang, Shijie; Wang, Song; Osman, Zeinab

    2018-01-01

    The melt-mixed fluoroelastomer (FKM)/ nitrile rubber (NBR) blends of (90/10, 80/20, 70/30, 60/40 and 50/50) ratios with same hardness were prepared, and their swelling and tribological properties under crude oil were investigated for the purpose of developing high performance cost-effective elastomers meeting requirement of oil extraction progressive cavity pump stator. Differential scanning calorimetry confirmed compatible blend system for all blends. Field emission scanning electron microscopy (FE-SEM) showed co-continuous morphology of 200-400 nm phase size for all blends, expect FKM/NBR (90/10) which exhibited partially continuous phase morphology of 100-250 nm phase size. The results of swelling and linear wear tests under crude oil indicated that swelling percentage, coefficient of friction and specific wear rate of FKM/NBR blends were much better than NBR, with FKM/NBR (90/10 and 80/20) showing swelling percentage and specific wear rate very close to FKM. Attenuated total reflectance-Fourier transform infrared spectroscopy disclosed that fracture of macromolecular chains was the main mechanochemical effect of unswollen and swollen worn surfaces, in addition to oxygenated degradation detected with increasing NBR ratio in the blends. The fracture of macromolecular chains resulted in slight fatigue wear mechanism, which was also confirmed by FE-SEM of the worn surfaces.

  15. Methodology for determining void swelling at very high damage under ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Getto, E., E-mail: embecket@umich.edu [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Sun, K. [Department of Materials Science Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Taller, S.; Monterrosa, A.M.; Jiao, Z. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Was, G.S. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Department of Materials Science Engineering, University of Michigan, Ann Arbor, MI 48109 (United States)

    2016-08-15

    At very high damage levels in ion irradiated samples, the decrease in effective density of the irradiated material due to void swelling can lead to errors in quantifying swelling. HT9 was pre-implanted with 10 appm He and subjected to a raster-scanned beam with a damage rate of ∼1 × 10{sup −3} dpa/s at 460{sup o}C. Voids were characterized from 0 to 1300 nm. Fixed damage rate and fixed depth methods were developed to account for damage-dependent porosity increase and resulting dependence on depth. The fixed depth method was more appropriate as it limits undue effects from the injected interstitial while maintaining a usable void distribution. By keeping the depth fixed and accounting for the change in damage rate due to reduced density, the steady state swelling rate was 10% higher than calculation of swelling from raw data. This method is easily translatable to other materials, ion types and energies and limits the impact of the injected interstitial.

  16. The SWELLS survey - III. Disfavouring 'heavy' initial mass functions for spiral lens galaxies

    NARCIS (Netherlands)

    Brewer, Brendon J.; Dutton, Aaron A.; Treu, Tommaso; Auger, Matthew W.; Marshall, Philip J.; Barnabè, Matteo; Bolton, Adam S.; Koo, David C.; Koopmans, Léon V. E.

    We present gravitational lens models for 20 strong gravitational lens systems observed as part of the Sloan WFC Edge-on Late-type Lens Survey (SWELLS) project. 15 of the lenses are taken from Paper I, while five are newly discovered systems. The systems are galaxy-galaxy lenses where the foreground

  17. Comparison study of thickness swell performance of commercial oriented strandboard flooring products

    Science.gov (United States)

    Hongmei Gu; Siqun Wang; Trairat Neimsuwan; Sunguo Wang

    2005-01-01

    The multiple layer structure of oriented strandboard (OSB) has a significant influence on its performance, including thickness swell (TS). TS is recognized as an important performance property for OSB products. Optimization of TS through layer property ma- nipulation to achieve the lowest total TS while maintaining acceptable mechanical properties is attainable if the...

  18. Development of swelling strain in smectite clays through exposure to carbon dioxide

    NARCIS (Netherlands)

    de Jong, S.M.; Spiers, C.J.; Busch, A.

    2014-01-01

    Smectites are common constituents of claystones, mudstones and shales and are often present in the caprocks and faults that seal potential CO2 storage reservoirs at depths up to 2 or even 3 km. Whilst the marked swelling behaviour of smectites caused by hydration through interlayer sorption of water

  19. How Do Organic Vapors Swell Ultra-Thin PIM-1 Films?

    KAUST Repository

    Ogieglo, Wojciech; Rahimi, Khosrow; Rauer, Sebastian Bernhard; Ghanem, Bader; Ma, Xiao-Hua; Pinnau, Ingo; Wessling, Matthias

    2017-01-01

    Dynamic sorption of ethanol and toluene vapor into ultra-thin supported PIM-1 films down to 6 nm are studied with a combination of in-situ spectroscopic ellipsometry and in-situ X-ray reflectivity. Both ethanol and toluene significantly swell

  20. Throat ache ans swelling of the neck: first symptoms of Lemierre's syndrome

    NARCIS (Netherlands)

    de Lange, J.; Ybema, A; Baas, E. M.

    2014-01-01

    Lemierre's syndrome, a thrombophlebitis of the internal jugular vein, is a rare disorder, usually caused by the microorganism Fusobacterium necrophorum. Throat ache and swelling of the neck are often the first symptoms. Without adequate treatment, Lemierre's syndrome may result in thrombosis of the