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Sample records for osmotic swelling characteristics

  1. 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

  2. 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.

  3. 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)

  4. 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

  5. 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

  6. Topotactic intercalation of a bulky organic anion (thiacalix[4]arene) into LDH through an osmotic swelling/restoration reaction in formamide.

    Science.gov (United States)

    Huang, Gailing; Ma, Shulan; Zhao, Xinhua; Yang, Xiaojing; Ooi, Kenta

    2009-01-21

    Utilizing the osmotic swelling of LDH in formamide, for the first time, the bulky thiacalix[4]arene anion is introduced, leading to the recovery of LDH layers, and the hexagonal prism morphology of the precursor is well retained.

  7. 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

  8. Comparison of osmotic swelling influences on meniscal fibrocartilage and articular cartilage tissue mechanics in compression and shear.

    Science.gov (United States)

    Nguyen, An M; Levenston, Marc E

    2012-01-01

    Although the contribution of the circumferential collagen bundles to the anisotropic tensile stiffness of meniscal tissue has been well described, the implications of interactions between tissue components for other mechanical properties have not been as widely examined. This study compared the effects of the proteoglycan-associated osmotic swelling stress on meniscal fibrocartilage and articular cartilage (AC) mechanics by manipulating the osmotic environment and tissue compressive offset. Cylindrical samples were obtained from the menisci and AC of bovine stifles, equilibrated in phosphate-buffered saline solutions ranging from 0.1× to 10×, and tested in oscillatory torsional shear and unconfined compression. Biochemical analysis indicated that treatments and testing did not substantially alter tissue composition. Mechanical testing revealed tissue-specific responses to both increasing compressive offset and decreasing bath salinity. Most notably, reduced salinity dramatically increased the shear modulus of both axially and circumferentially oriented meniscal tissue explants to a much greater extent than for cartilage samples. Combined with previous studies, these findings suggest that meniscal proteoglycans have a distinct structural role, stabilizing, and stiffening the matrix surrounding the primary circumferential collagen bundles. Copyright © 2011 Orthopaedic Research Society.

  9. Contribution of proteoglycan osmotic swelling pressure to the compressive properties of articular cartilage.

    Science.gov (United States)

    Han, EunHee; Chen, Silvia S; Klisch, Stephen M; Sah, Robert L

    2011-08-17

    The negatively charged proteoglycans (PG) provide compressive resistance to articular cartilage by means of their fixed charge density (FCD) and high osmotic pressure (π(PG)), and the collagen network (CN) provides the restraining forces to counterbalance π(PG). Our objectives in this work were to: 1), account for collagen intrafibrillar water when transforming biochemical measurements into a FCD-π(PG) relationship; 2), compute π(PG) and CN contributions to the compressive behavior of full-thickness cartilage during bovine growth (fetal, calf, and adult) and human adult aging (young and old); and 3), predict the effect of depth from the articular surface on π(PG) in human aging. Extrafibrillar FCD (FCD(EF)) and π(PG) increased with bovine growth due to an increase in CN concentration, whereas PG concentration was steady. This maturation-related increase was amplified by compression. With normal human aging, FCD(EF) and π(PG) decreased. The π(PG)-values were close to equilibrium stress (σ(EQ)) in all bovine and young human cartilage, but were only approximately half of σ(EQ) in old human cartilage. Depth-related variations in the strain, FCD(EF), π(PG), and CN stress profiles in human cartilage suggested a functional deterioration of the superficial layer with aging. These results suggest the utility of the FCD-π(PG) relationship for elucidating the contribution of matrix macromolecules to the biomechanical properties of cartilage. Copyright © 2011 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  10. Modeling osmotic salinity effects on yield characteristics of substrate-grown greenhouse crops

    NARCIS (Netherlands)

    Sonneveld, C.; Bos, van den A.L.; Voogt, W.

    2004-01-01

    In a series of experiments with different osmotic potentials in the root environment, various vegetables, and ornamentals were grown in a substrate system. The osmotic potential was varied by addition of nutrients. Yield characteristics of the crop were related to the osmotic potential of the

  11. 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.

  12. Selection of Sperm Based on Hypo-Osmotic Swelling May Improve ICSI Outcome: A Preliminary Prospective Clinical Trial

    Directory of Open Access Journals (Sweden)

    Nasim Charehjooy

    2014-03-01

    Full Text Available Background: The intra-cytoplasmic sperm injection (ICSI technique selects sperm according to morphology and motility. However, these parameters cannot predict the chromatin integrity of sperm. Considering the detrimental effects of DNA-damaged sperm on reproductive outcomes, novel sperm selection procedures have been proposed to circumvent the possibility of inseminating DNA-damaged sperm. It has been shown that different potential hypo-osmotic swelling test (HOST patterns possess the potential to differentiate between sperm that have intact or damaged chromatin. Therefore, for the first time, this preliminary study evaluates the role of HOST as a sperm selection procedure in a clinical setting. Materials and Methods: In this preliminary prospective clinical trial study, we divided infertile couples diagnosed with male infertility into two groups. In the treatment group (n=39, half of the oocytes were inseminated by sperm selected following density gradient centrifugation (DGC group. The remaining oocytes from the treatment group were inseminated by sperm chosen according to HOST pattern (c, d or e following DGC processing (HOST group. In the control group (n=63, all oocytes were inseminated by sperm chosen after DGC. Results: There was a significantly higher percentage of embryos that had good quality, implantation, and chemical pregnancy rates in the HOST group compared to the DGC group (p≤0.05. Conclusion: This study has shown that selecting sperm according to membrane functionality (HOST pattern rather morphology and viability may open a new window in our approach for determining the appropriate sperm for ICSI, particularly in individuals with severe male infertility (Registration Number: IRCT201307087223N2.

  13. 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.)

  14. 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)

  15. Drying characteristics of osmotically pretreated cranberries : Energy and quality aspects

    Energy Technology Data Exchange (ETDEWEB)

    Grabowski, S.; Marcotte, M. [Agriculture and Agri-Food Canada, St. Hyacinthe, PQ (Canada). Food Research and Development Centre; Poirier, M.; Kudra, T. [Natural Resources Canada, Varennes, PQ (Canada). CANMET Energy Technology Centre

    2002-06-01

    This paper presents the results of a study in which osmotically pretreated cranberries were dried. The osmotic treatment included dehydration and sugar infusion. The process involved pretreating halved cranberries in a standard osmotic solution followed by freeze-drying, vacuum-drying and air-drying in various dryers, such as cabinet-air-through, fluid bed, pulsed fluid bed, and vibrated fluid bed dryers. The intent was to identify the best drying technology. The comparison criteria selected were energy consumption and product quality. Product quality for freeze-dried berries was quantified based on anthocyanins content, rehydration ratio, color, and taste. Unit heat consumption could be used for selecting the drying method, as all other drying methods yielded similar but slightly lower quality products. The highest energy efficiency was obtained with the vibrated fluid bed and the pulsed fluid bed. It was noted that drying rates were reduced during the second drying period when sugar was infused into the cranberries during osmotic pretreatment, but the total energy consumption was reduced by osmotic dehydration. 22 refs., 1 tab., 5 figs.

  16. 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 ...

  17. Sea Water Acidification Affects Osmotic Swelling, Regulatory Volume Decrease and Discharge in Nematocytes of the Jellyfish Pelagia noctiluca

    Directory of Open Access Journals (Sweden)

    Rossana Morabito

    2013-12-01

    Full Text Available Background: Increased acidification/PCO2 of sea water is a threat to the environment and affects the homeostasis of marine animals. In this study, the effect of sea water pH changes on the osmotic phase (OP, regulatory volume decrease (RVD and discharge of the jellyfish Pelagia noctiluca (Cnidaria, Scyphozoa nematocytes, collected from the Strait of Messina (Italy, was assessed. Methods: Isolated nematocytes, suspended in artificial sea water (ASW with pH 7.65, 6.5 and 4.5, were exposed to hyposmotic ASW of the same pH values and their osmotic response and RVD measured optically in a special flow through chamber. Nematocyte discharge was analyzed in situ in ASW at all three pH values. Results: At normal pH (7.65, nematocytes subjected to hyposmotic shock first expanded osmotically and then regulated their cell volume within 15 min. Exposure to hyposmotic ASW pH 6.5 and 4.5 compromised the OP and reduced or totally abrogated the ensuing RVD, respectively. Acidic pH also significantly reduced the nematocyte discharge response. Conclusion: Data indicate that the homeostasis and function of Cnidarians may be altered by environmental changes such as sea water acidification, thereby validating their use as novel bioindicators for the quality of the marine environment.

  18. Sea water acidification affects osmotic swelling, regulatory volume decrease and discharge in nematocytes of the jellyfish Pelagia noctiluca.

    Science.gov (United States)

    Morabito, Rossana; Marino, Angela; Lauf, Peter K; Adragna, Norma C; La Spada, Giuseppa

    2013-01-01

    Increased acidification/PCO2 of sea water is a threat to the environment and affects the homeostasis of marine animals. In this study, the effect of sea water pH changes on the osmotic phase (OP), regulatory volume decrease (RVD) and discharge of the jellyfish Pelagia noctiluca (Cnidaria, Scyphozoa) nematocytes, collected from the Strait of Messina (Italy), was assessed. Isolated nematocytes, suspended in artificial sea water (ASW) with pH 7.65, 6.5 and 4.5, were exposed to hyposmotic ASW of the same pH values and their osmotic response and RVD measured optically in a special flow through chamber. Nematocyte discharge was analyzed in situ in ASW at all three pH values. At normal pH (7.65), nematocytes subjected to hyposmotic shock first expanded osmotically and then regulated their cell volume within 15 min. Exposure to hyposmotic ASW pH 6.5 and 4.5 compromised the OP and reduced or totally abrogated the ensuing RVD, respectively. Acidic pH also significantly reduced the nematocyte discharge response. Data indicate that the homeostasis and function of Cnidarians may be altered by environmental changes such as sea water acidification, thereby validating their use as novel bioindicators for the quality of the marine environment. © 2014 S. Karger AG, Basel.

  19. 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 ...

  20. 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

  1. Physicochemical characteristics of guava “Paluma” submitted to osmotic dehydration

    Directory of Open Access Journals (Sweden)

    Roselene Ferreira Oliveira

    2014-09-01

    Full Text Available The aim of this work was to evaluate the conservation post process osmotic of guava stored temperature at 5oC. Guava (Psidium guajava L., red variety “Paluma” minimally processed by mild osmotic dehydration, were packaged in polyethylene terephthalate (PET and stored temperature at 5ºC. Non-treated guava, packed in PET trays, was used as control. The treatment used was osmotic dehydration in sucrose syrup at 60ºBrix and physicochemical determinations were pH, total soluble solids (TSS, total titratable acidity (TTA, reducing sugars (RS, total sugars (TS and parameters related to colour read (a*, chroma (c*, yellow (b*, luminosity (L* of the fresh and osmotically dehydrated guava slices. The dehydrated fruits lost about 34.45% of water, concentrating contents of soluble solids, total and reducing sugars, when compared to control samples. The pH value remained around 3.76 for the OD fruits and 3.87 for the fresh fruits. The colour of the dehydrated fruits was more intense than the control samples’. The guava slices osmotic dehydration had 21 days of shelf life, showed physicochemical characteristics significantly superior to the control samples’, having a stable and high quality product as a result.

  2. 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”.

  3. 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)

  4. Water absorption, retention and the swelling characteristics of cassava starch grafted with polyacrylic acid.

    Science.gov (United States)

    Witono, J R; Noordergraaf, I W; Heeres, H J; Janssen, L P B M

    2014-03-15

    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. Also, water retention under mechanical strain is usually not reported. Cassava starch was used since it has considerable economic potential in Asia. The gelatinized starch was grafted with acrylic acid and Fenton's initiator and crosslinked with N,N'-methylenebisacrylamide (MBAM). Besides a good initial absorption capacity, the product could retain up to 63 g H2O/g under severe suction. The material thus combines a good absorption capacity with sufficient gel strength. The mathematical analysis of the absorption kinetics shows that at conditions of practical interest, the rate of water penetration into the gel is determined by polymer chain relaxations and not by osmotic driven diffusion. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. 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

    increased from monovalent to divalent cation. For samples prepared with distilled water and inundated with simulated groundwater solutions, the swell potential reduced up to 50% for sample inundated with less saline granitic groundwater and up to 62% for sample inundated with moderately saline groundwater. For the samples prepared with salt solutions and were heated, the reduction in swell potential ranged from 30-42% compared with bentonite sand sample mixed with distilled water and without any heating. Comparing swell potentials of samples heated for similar conditions, the samples prepared with 1000 ppm Na and 1000 ppm K swelled little less (3.5-3.8%) then sample prepared with distilled water. The exchange of adsorbed cation on bentonite to K and heating did not cause collapse of montmorillonite layers. The samples prepared with 1000 ppm Ca and 1000 ppm Mg swelled to 12-20% less than distilled water sample. Presence of divalent cations in pore water and exchangeable cation positions, leads to substantial reduction in swelling ability of bentonite. For the samples prepared with distilled water and heated, and then inundated with simulated ground water solutions, the reduction in swell potential ranged from 11-47% with respect to samples mixed and inundated with distilled water and heated for similar conditions. High swelling ability is the one of the most characteristic property of bentonite and must be retained over a span of several thousand years to fulfill its role as a containment barrier successfully. The results show that heating of compacted bentonite sand mix samples to temperature 50-80 deg. C which is the temperature range expected to prevail in the bentonite buffer in repository for a long time leads to significant reduction in its swelling ability. Increasing the pore water salinity of bentonite with salts of monovalent (Na, K) and divalent cations (Ca, Mg) has the effect of reducing the swelling ability but to different degrees. The inundation of bentonite

  6. 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

  7. Swelling characteristics of acrylic acid polyelectrolyte hydrogel in a dc electric field

    Science.gov (United States)

    Jabbari, Esmaiel; Tavakoli, Javad; Sarvestani, Alireza S.

    2007-10-01

    A novel application of environmentally sensitive polyelectrolytes is in the fabrication of BioMEMS devices as sensors and actuators. Poly(acrylic acid) (PAA) gels are anionic polyelectrolyte networks that exhibit volume expansion in aqueous physiological environments. When an electric field is applied to PAA polyelectrolyte gels, the fixed anionic polyelectrolyte charges and the requirement of electro-neutrality in the network generate an osmotic pressure, above that in the absence of the electric field, to expand the network. The objective of this research was to investigate the effect of an externally applied dc electric field on the volume expansion of the PAA polyelectrolyte gel in a simulated physiological solution of phosphate buffer saline (PBS). For swelling studies in the electric field, two platinum-coated plates, as electrodes, were wrapped in a polyethylene sheet to protect the plates from corrosion and placed vertically in a vessel filled with PBS. The plates were placed on a rail such that the distance between the two plates could be adjusted. The PAA gel was synthesized by free radical crosslinking of acrylic acid monomer with ethylene glycol dimethacrylate (EGDMA) crosslinker. Our results demonstrate that volume expansion depends on the intensity of the electric field, the PAA network density, network homogeneity, and the position of the gel in the field relative to positive/negative electrodes. Our model predictions for PAA volume expansion, based on the dilute electrolyte concentration in the gel network, is in excellent agreement with the experimental findings in the high-electric-field regime (250-300 Newton/Coulomb).

  8. Physicochemical characteristics of guava “Paluma” submitted to osmotic dehydration

    OpenAIRE

    Roselene Ferreira Oliveira; Lia Mara Moterlle; Edmar Clemente

    2014-01-01

    The aim of this work was to evaluate the conservation post process osmotic of guava stored temperature at 5oC. Guava (Psidium guajava L.), red variety “Paluma” minimally processed by mild osmotic dehydration, were packaged in polyethylene terephthalate (PET) and stored temperature at 5ºC. Non-treated guava, packed in PET trays, was used as control. The treatment used was osmotic dehydration in sucrose syrup at 60ºBrix and physicochemical determinations were pH, total soluble solids (TSS), tot...

  9. 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.

  10. 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.

  11. 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.)

  12. 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.

  13. Evaluation for swelling characteristics of buffer and backfill materials for high-level nuclear waste disposal. Influence of sand-bentonite content and cation compositions in bentonite

    International Nuclear Information System (INIS)

    Komine, Hideo; Ogata, Nobuhide

    1999-01-01

    Compacted bentonite and sand-bentonite mixture are attracting greater attention as buffer and backfill materials for disposal pits and access tunnels in the underground facilities for repositories of high-level nuclear waste. Buffer and backfill materials must have the swelling characteristics and are expected to fill up the space between these materials and surrounding ground by swelling. This role is called as 'Self-sealing'. To design the specifications, such as dry density, bentonite content and size, of buffer and backfill materials for the disposal facilities of high-level nuclear wastes described above, we must evaluate the swelling characteristics of compacted bentonite and sand-bentonite mixtures. For this purpose, this study proposed the evaluation formula for swelling characteristics of buffer and backfill materials containing bentonite. This study derived new equations for evaluating the relationship between the swelling deformation of compacted bentonite and sand-bentonite mixtures, and the swelling behavior of montmorillonite minerals, which are swelling clay minerals. This study also proposed new equations for evaluating the ion compositions of bentonite, ion concentration of pore water and the specific surface of bentonite, which significantly influence the swelling characteristics of buffer and backfill materials. The evaluation formula proposed in this study is presented by combining the above-mentioned new equations with theoretical equations, of which are the Gouy-Chapman diffuse double layer theory and the van der Waals force, of repulsive and attractive forces of montmorillonite minerals. (author)

  14. Swelling characteristics of sand-bentonite mixtures under one-dimensional stress

    International Nuclear Information System (INIS)

    Cui, Hongbin; Sun, De'an; Matsuoka, Hajime; Xu Yongfu

    2004-01-01

    Based on the concept that the maximum water volume absorbed by unit volume of montmorillonite is constant, the swelling deformation of sand-bentonite mixtures is uniquely characterized using the void ratio of montmorillonite, which is defined by the ratio of water volume to montomorillonite volume. The relationship between the montmorillonite void ratio and overburden pressure at fully swelling is independent of the initial compaction condition and the sand-bentonite mixture ratio, and is a linear line in their log scale. When overburden pressure is large enough and/or the bentonite ratio of the mixture is small, the measured plots deviate from the line. A method for predicting the limited overburden pressure which is linearly correlated with the montmorillonite void ratio is proposed and verified using the concept of the skeleton void ratio. (author)

  15. Granular MX-80 bentonite as buffer material: a focus on swelling characteristics

    International Nuclear Information System (INIS)

    Rizzi, M.; Laloui, L.; Salager, S.; Marschall, P.

    2010-01-01

    Document available in extended abstract form only. The Swiss High Level Waste (HLW) disposal concept envisages the emplacement of the waste canisters in horizontal tunnels excavated at a depth of several hundred meters in an over-consolidated clay-stone formation. After waste emplacement the disposal tunnels are backfilled with MX-80 granular bentonite. Research activities are presented in this paper, aimed at characterising the geomechanical behaviour of the MX-80 granular bentonite and at providing the theoretical framework for modelling its response to thermo-hydro- mechanical (THM) perturbations. From the experimental point of view, a series of tests has been designed in order to extract constitutive data and to assess the temperature and suction effects on the mechanical behaviour of the bentonite, paying particular attention in the investigation to the swelling behaviour of the material. As for the theoretical framework an elasto-plastic constitutive model has been developed to take into account those coupled processes of stress, capillary pressure, and temperature to which the bentonite will be submitted,. Bentonite is mainly composed of the smectite mineral montmorillonite with a high swelling capacity which may provide sufficient sealing properties to seal the tunnel without gaps and to restore the buffer continuity. In fact, as bentonite hydrates in the repositories it will expand in those areas where it is allowed and will exert a swelling pressure where the material is confined. The results of both confined and free swelling tests are presented. Confined tests are aiming at determining the pressure applied by the material during complete saturation under isochoric conditions, whereas in the free swelling tests the strain on hydration is measured. Some results from confined swelling tests at ambient temperature are presented. The specimen is compacted uniaxially directly in the cells, the initial dry density being chosen in the range between 1.6 and 1

  16. Characteristics of long-period swells measured in the near shore regions of eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Johnson, G.; SanilKumar, V.; Amrutha, M.M.; Singh, J.

    Measured wave data covering two years simultaneously at 3 locations along the eastern Arabian Sea reveals the presence of long-period (peak wave period > 18 s) low-amplitude waves (significant wave height < 1 m) and the characteristics...

  17. Impact of osmotic stress on seedling growth observations, membrane characteristics and antioxidant defense system of different wheat genotypes

    Directory of Open Access Journals (Sweden)

    Bardees M. Mickky

    2017-03-01

    Full Text Available The objective of the present study was to find out a straightforward technique for screening the tolerance of ten wheat genotypes to two levels of osmotic stress at early seedling stage. Data revealed that polyethylene glycol-induced drought had general negative effect on seedling morphological characters indicated by plumule and radicle length, number of adventitious roots as well as seedling biomass and water content. Water deficit could also suppress membrane integrity by stimulating lipid peroxidation with marked increase in membrane leakage and subsequent decrease in its stability index. For all the addressed germination parameters and seedling membrane features, the impact of severe drought was more pronounced than that of moderate drought. Simultaneously, moderate stress could activate peroxidase, polyphenol oxidase and ascorbic peroxidase of the studied genotypes; but these enzymes were inhibited by severe stress. The activity of catalase, superoxide dismutase and glutathione reductase was conversely retarded by drought whether at moderate or severe level. More interestingly, a novel function “Stress Impact Index; SII” was introduced to rank the estimated morpho-physiological traits (SIItrait as well as the considered genotypes (SIIgenotype according to their sensitivity to stress. Values of SIItrait implied that germination parameters were generally affected by drought more intensively than membrane characteristics and finally came the antioxidant enzymes with the least degree of suppression when applying stress. Based on the magnitudes of SIIgenotype, Sids 13 seemed to be the most drought-tolerant wheat cultivar while Shandawel 1 could be the most sensitive one at their juvenile growth stage.

  18. Clinical and Radiographic Characteristics as Predictive Factors of Swelling and Trismus after Mandibular Third Molar Surgery: A Longitudinal Approach

    Directory of Open Access Journals (Sweden)

    José Manuel Pérez-González

    2018-01-01

    Full Text Available Introduction. Factors that contribute to swelling and trismus are complex, and they are originated by surgical trauma. The aim of the present study was to determine whether clinical and radiographic factors could predict the level of swelling and trismus after lower third molar surgery, through longitudinal approach. Methodology. A prospective longitudinal trial was carried out. Forty-five patients of both genders with clinical and radiographic diagnosis of asymptomatic mandibular impacted third molar and with no intake of analgesic or anti-inflammatory drugs 12 h prior to surgery were recruited and evaluated in a 72 h follow-up period. A mixed repeated measures model and backward and restricted maximal likelihood methods were used to analyze the data. Results. Male gender, body mass index (BMI, the relation to the lingual and buccal walls, and age were determinants for predicting postoperative swelling and for exerting a significant influence (P<0.05. Conclusions. This study suggests the association of male gender, the relation to lingual and buccal walls, BMI, and age with measurement of swelling.

  19. Enhancement of gravimetric forced flow through system to determine sorption, swelling, and mass transfer characteristics of liquid sorbents

    Science.gov (United States)

    Dresp, G.; Petermann, M.; Fieback, T. M.

    2018-04-01

    An existing apparatus for forced flow through of liquid sorbents has been enhanced with an optically accessible system including a transparent crucible, high pressure viewing cell, and camera. With this optical system, the active surface area between gas and liquid can be determined in situ for the first time under industrial process conditions while maintaining the accuracy of a magnetic suspension balance. Additionally, occurring swelling and the resulting buoyancy changes can now be corrected, further improving the quality of the data. Validation measurements focusing on the sorption isotherms, swelling, and bubble geometry of 1-butyl-3-methylimidazolium tetrafluoroborate with nitrogen at 303 K and up to 17 MPa, as well as with carbon dioxide at 303 K, 323 K, and 373 K at up to 3.5 MPa were completed. Absorption of nitrogen resulted in no observable volume change, whereas absorption of carbon dioxide resulted in temperature independent swelling of up to 9.8%. The gas bubble's structure and behavior during its ascend through the liquid was optically tracked in situ. Combining these two data sets with the absorption kinetics forms the basis to determine the measuring system independent mass transfer coefficients, which are applicable in other laboratory scale and industrial processes.

  20. 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.)

  1. Influence of dissolution processing of PVA blends on the characteristics of their hydrogels synthesized by radiation—Part I: Gel fraction, swelling, and mechanical properties

    International Nuclear Information System (INIS)

    Alcântara, M.T.S.; Brant, A.J.C.; Giannini, D.R.; Pessoa, J.O.C.P.; Andrade, A.B.; Riella, H.G.; Lugão, A.B.

    2012-01-01

    In this work several hydrogels were obtained with two different poly(vinyl alcohol)s/PVAs as the main polymer in aqueous solutions containing 10% of PVA, 0.6% of agar, and 0.6% of κ-carrageenan (KC), cross-linked by gamma-rays from a 60 Co irradiation source. The PVAs tested have different degrees of hydrolysis and viscosities at 4% with values closed to 30 mPa s. The aqueous polymeric solutions were prepared using two distinct processes: the simple process of heating–stirring and that of making use of an autoclave. The purpose of this study was to evaluate the influence of the dissolution process by means of both methods on the hydrogels’ properties obtained. These were investigated by means of degree of cross-linking/gel fraction, degree of swelling in water, and some mechanical properties. The results that are obtained for hydrogels synthesized from solutions of PVA, agar, KC, and blends thereof prepared by both dissolution processes showed higher degrees of swelling for hydrogels from the autoclaved polymer solutions than those from the solutions prepared by simple heating–stirring process. Furthermore, their hydrogels containing totally hydrolyzed PVA displayed higher tensile strength and lower elongation properties. - Highlights: ► Hydrogels from γ-irradiated PVA and PVA-polysaccharide blends were obtained. ► PVA molar mass and degree of hydrolysis play an important role in their hydrogels. ► Dissolution processes of PVAs have influenced on their hydrogel characteristics. ► Degrees of swelling of hydrogels were lower when prepared from autoclaved solutions.

  2. Effect of non-cross-linked calcium on characteristics, swelling behaviour, drug release and mucoadhesiveness of calcium alginate beads.

    Science.gov (United States)

    Dalaty, Adnan Al; Karam, Ayman; Najlah, Mohammad; Alany, Raid G; Khoder, Mouhamad

    2016-04-20

    In this study, ibuprofen-loaded calcium alginate beads (CABs) with varying amounts of non-cross-linked calcium (NCL-Ca) were prepared using different washing methods. The influence of NCL-Ca on beads properties was investigated. Increasing the number or duration of washes led to significant decreases in the amount of NCL-Ca whereas the impact of the volume of washes was not significant. Approximately 70% of the initial amount of Ca(2+) was NCL-Ca which was removable by washing while only 30% was cross-linked (CL-Ca). Ca(2+) release from the CABs was bimodal; NCL-Ca was burst-released followed by a slower release of CL-Ca. Washing methods and the amount of NCL-Ca had significant influences on the encapsulation efficiency, beads weight, beads swelling, drug release profile and the mucoadhesiveness of CABs. This study highlighted the importance of washing methods and the amount of NCL-Ca to establish CABs properties and understand their behaviour in the simulated intestinal fluids (SIFs). Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Saltstone Osmotic Pressure

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, Ralph L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Dixon, Kenneth L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRN

    2013-09-23

    Recent research into the moisture retention properties of saltstone suggest that osmotic pressure may play a potentially significant role in contaminant transport (Dixon et al., 2009 and Dixon, 2011). The Savannah River Remediation Closure and Disposal Assessments Group requested the Savannah River National Laboratory (SRNL) to conduct a literature search on osmotic potential as it relates to contaminant transport and to develop a conceptual model of saltstone that incorporates osmotic potential. This report presents the findings of the literature review and presents a conceptual model for saltstone that incorporates osmotic potential. The task was requested through Task Technical Request HLW-SSF-TTR- 2013-0004.

  4. Mechanical properties of the collagen network in human articular cartilage as measured by osmotic stress technique

    NARCIS (Netherlands)

    Basser, P.J.; Schneiderman, R.; Bank, R.A.; Wachtel, E.; Maroudas, A.

    1998-01-01

    We have used an isotropic osmotic stress technique to assess the swelling pressures of human articular cartilage over a wide range of hydrations in order to determine from these measurements, for the first time, the tensile stress in the collagen network, P(c), as a function of hydration. Osmotic

  5. 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 ...

  6. Saltstone Osmotic Pressure

    International Nuclear Information System (INIS)

    Nichols, Ralph L.; Dixon, Kenneth L.

    2013-01-01

    Recent research into the moisture retention properties of saltstone suggest that osmotic pressure may play a potentially significant role in contaminant transport (Dixon et al., 2009 and Dixon, 2011). The Savannah River Remediation Closure and Disposal Assessments Group requested the Savannah River National Laboratory (SRNL) to conduct a literature search on osmotic potential as it relates to contaminant transport and to develop a conceptual model of saltstone that incorporates osmotic potential. This report presents the findings of the literature review and presents a conceptual model for saltstone that incorporates osmotic potential. The task was requested through Task Technical Request HLW-SSF-TTR-2013-0004. Simulated saltstone typically has very low permeability (Dixon et al. 2008) and pore water that contains a large concentration of dissolved salts (Flach and Smith 2013). Pore water in simulated saltstone has a high salt concentration relative to pore water in concrete and groundwater. This contrast in salt concentration can generate high osmotic pressures if simulated saltstone has the properties of a semipermeable membrane. Estimates of osmotic pressure using results from the analysis of pore water collected from simulated saltstone show that an osmotic pressure up to 2790 psig could be generated within the saltstone. Most semi-permeable materials are non-ideal and have an osmotic efficiency 3 , KNO 3 , Na 3 PO 4 x12H 2 O, and K 3 PO 4 when exposed to a dilute solution. Typically hydraulic head is considered the only driving force for groundwater in groundwater models. If a low permeability material containing a concentrated salt solution is present in the hydrogeologic sequence large osmotic pressures may develop and lead to misinterpretation of groundwater flow and solute transport. The osmotic pressure in the semi-permeable material can significantly impact groundwater flow in the vicinity of the semi-permeable material. One possible outcome is that

  7. 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

  8. Long-term water absorption and thickness swelling and determine their characteristics in wood flour/polypropylene/Nano SiO2 nanocomposite

    Directory of Open Access Journals (Sweden)

    Saeed Ismaeilimoghadam

    2016-09-01

    Full Text Available The objective of this study was to investigate the effect of nano SiO2 on long-term water absorption and thickness swelling, humidity coefficient diffusion and thickness swelling rate of wood plastic composite. For this purpose, 60% wood flour, 40% polypropylene, 2 per hundred compound (phc MAPP in internal mixer (HAAKE were mixed. Nano SiO2 with 0, 1, 3 and 5 (phc ratios as a reinforcing was used too. Finally test samples were fabricated by using the injection molding machine. Then long-term water absorption and thickness swelling for 1848 hours according to the ASTM standard on the samples were measured. Humidity coefficient diffusion and thickness swelling rate for closer look long-term water absorption and thickness swelling behavior in wood plastic nanocomposite were calculated too. For ensure to the formation of hydrogen bonds between hydroxyl grope of SiO2 nanoparticles with hydroxyl grope of wood flour form Fourier transform infrared (FTIR spectroscopy tests was used. The results showed that water absorption behavior of nanocomposite is according to Fick's law, in addition with increasing to SiO2 nanoparticles, long-term water absorption and thickness swelling and humidity coefficient diffusion in wood plastic nanocomposite decreased. The results of infrared spectroscopy showed that hydrogen bond between the nano SiO2 and wood flour confirmed. Statistical analysis showed that after 1848 hours of immersion, nano SiO2 showed a significant effect at a confidence level of 99% on water absorption and thickness swelling, so the sample with 5% silica nanoparticles was chosen as the best treatment.

  9. 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.

  10. 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.

  11. Fouling in Membrane Distillation, Osmotic Distillation and Osmotic Membrane Distillation

    Directory of Open Access Journals (Sweden)

    Mourad Laqbaqbi

    2017-03-01

    Full Text Available Various membrane separation processes are being used for seawater desalination and treatment of wastewaters in order to deal with the worldwide water shortage problem. Different types of membranes of distinct morphologies, structures and physico-chemical characteristics are employed. Among the considered membrane technologies, membrane distillation (MD, osmotic distillation (OD and osmotic membrane distillation (OMD use porous and hydrophobic membranes for production of distilled water and/or concentration of wastewaters for recovery and recycling of valuable compounds. However, the efficiency of these technologies is hampered by fouling phenomena. This refers to the accumulation of organic/inorganic deposits including biological matter on the membrane surface and/or in the membrane pores. Fouling in MD, OD and OMD differs from that observed in electric and pressure-driven membrane processes such electrodialysis (ED, membrane capacitive deionization (MCD, reverse osmosis (RO, nanofiltration (NF, ultrafiltration (UF, microfiltration (MF, etc. Other than pore blockage, fouling in MD, OD and OMD increases the risk of membrane pores wetting and reduces therefore the quantity and quality of the produced water or the concentration efficiency of the process. This review deals with the observed fouling phenomena in MD, OD and OMD. It highlights different detected fouling types (organic fouling, inorganic fouling and biofouling, fouling characterization techniques as well as various methods of fouling reduction including pretreatment, membrane modification, membrane cleaning and antiscalants application.

  12. Disassembly of actin structures by nanosecond pulsed electric field is a downstream effect of cell swelling.

    Science.gov (United States)

    Pakhomov, Andrei G; Xiao, Shu; Pakhomova, Olga N; Semenov, Iurii; Kuipers, Marjorie A; Ibey, Bennett L

    2014-12-01

    Disruption of the actin cytoskeleton structures was reported as one of the characteristic effects of nanosecond-duration pulsed electric field (nsPEF) in both mammalian and plant cells. We utilized CHO cells that expressed the monomeric fluorescent protein (mApple) tagged to actin to test if nsPEF modifies the cell actin directly or as a consequence of cell membrane permeabilization. A train of four 600-ns pulses at 19.2 kV/cm (2 Hz) caused immediate cell membrane poration manifested by YO-PRO-1 dye uptake, gradual cell rounding and swelling. Concurrently, bright actin features were replaced by dimmer and uniform fluorescence of diffuse actin. To block the nsPEF-induced swelling, the bath buffer was isoosmotically supplemented with an electropore-impermeable solute (sucrose). A similar addition of a smaller, electropore-permeable solute (adonitol) served as a control. We demonstrated that sucrose efficiently blocked disassembly of actin features by nsPEF, whereas adonitol did not. Sucrose also attenuated bleaching of mApple-tagged actin in nsPEF-treated cells (as integrated over the cell volume), although did not fully prevent it. We conclude that disintegration of the actin cytoskeleton was a result of cell swelling, which, in turn, was caused by cell permeabilization by nsPEF and transmembrane diffusion of solutes which led to the osmotic imbalance. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. 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

  14. The rate of hypo-osmotic challenge influences regulatory volume decrease (RVD) and mechanical properties of articular chondrocytes.

    Science.gov (United States)

    Wang, Z; Irianto, J; Kazun, S; Wang, W; Knight, M M

    2015-02-01

    Osteoarthritis (OA) is associated with a gradual reduction in the interstitial osmotic pressure within articular cartilage. The aim of this study was to compare the effects of sudden and gradual hypo-osmotic challenge on chondrocyte morphology and biomechanics. Bovine articular chondrocytes were exposed to a reduction in extracellular osmolality from 327 to 153 mOsmol/kg applied either suddenly (osmotic stress, 66% of chondrocytes exhibited an increase in diameter followed by RVD, whilst 25% showed no RVD. By contrast, cells exposed to gradual hypo-osmotic stress exhibited reduced cell swelling without subsequent RVD. There was an increase in the equilibrium modulus for cells exposed to sudden hypo-osmotic stress. However, gradual hypo-osmotic challenge had no effect on cell mechanical properties. This cell stiffening response to sudden hypo-osmotic challenge was abolished when actin organization was disrupted with cytochalasin D or RVD inhibited with REV5901. Both sudden and gradual hypo-osmotic challenge reduced cortical F-actin distribution and caused chromatin decondensation. Sudden hypo-osmotic challenge increases chondrocyte mechanics by activation of RVD and interaction with the actin cytoskeleton. Moreover, the rate of hypo-osmotic challenge is shown to have a profound effect on chondrocyte morphology and biomechanics. This important phenomenon needs to be considered when studying the response of chondrocytes to pathological hypo-osmotic stress. Copyright © 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  15. Modified swelling pressure apparatus using vapor pressure technique for compacted bentonite

    International Nuclear Information System (INIS)

    Nishimura, Tomoyoshi

    2012-01-01

    Document available in extended abstract form only. bentonite. The compacted bentonite is found in unsaturated conditions before applying of swelling due to absorption. The behaviour of compacted bentonite is not consistent with the principle and concepts of classical, saturated soil mechanics. An unsaturated soil theoretical framework using soil water characteristic curve has been fairly established over the past several decades. The soil-water characteristic curve is a relationship between soil moisture and soil suction obtained by the axis translation technique, vapor pressure technique or osmotic suction control which is a key feature in unsaturated soil mechanics. The soil-water characteristic curve can be used for prediction of the shear strength, volume change and hydraulic conductivity. Cui et al. 2002 indicated soil-water characteristic curve of expansive clay soil in high soil suction ranges using osmotic suction technique. Tripathy et al. 2010 described the soil-water characteristic curve both using the axis translation technique and vapor pressure technique in the entire soil suction ranges. Nishimura and Koseki 2011 measured suction of bentonite applied high soil suction due vapor pressure using a chilled mirror dew point potentiometer (WP4-T of DECAGON Device). The bentonite with gravimetric water content of 18 % indicated soil suction of 2.8 MPa at least. It is predicted that suction efforts to swelling pressure and shear strength of unsaturated compacted bentonite. This study focuses on the influence of suction on both swelling pressure and shear strength of compacted bentonite. The soil-water characteristic curve (SWCC) tests were conducted for compacted bentonite using both axis-translation technique and vapor pressure technique. The SWCC had a range from 0 kPa to 296 MPa in suction. The compacted bentonite having two different soil suctions were prepared for swelling pressure tests. Newly swelling pressure testing apparatus was developed in order

  16. 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.

  17. [Extrapontine osmotic myelinolysis].

    Science.gov (United States)

    Silva, Federico A; Rueda-Clausen, Christian F; Ramírez, Fabián

    2005-06-01

    Extrapontine osmotic myelinolysis is a rare nervous system complication. Symptoms of this malady were presented during the clinical examination of a 49-year-old alcoholic male, who arrived at the hospital emergency room in a state of cardiorespiratory arrest. After resuscitation methods were applied, the patient was found in metabolic acidosis (pH 7.014) and was treated with sodium bicarbonate. Forty-eight hours later, sodium levels in the patient had risen from 142 to 174 mEq/l. During the period of clinical observation, the patient showed signs of cognitive impairment, disartria, bilateral amaurosis, hyporeflexia and right-half body hemiparesias. After 72 hours, computer tomography was applied; this showed a bilateral lenticular hypodensity with internal and external capsule compromise. One month later, when the patient was referred to another institution for rehabilitation, the patient showed cognitive impairment, bilateral optic atrophy, residual disartria, bradikynesia and double hemiparesia.

  18. Characteristic Magnetic Resonance Imaging Findings in Rheumatoid Arthritis of the Temporomandibular Joint: Focus on Abnormal Bone Marrow Signal of the Mandibular Condyle, Pannus, and Lymph Node Swelling in the Parotid Glands.

    Science.gov (United States)

    Hirahara, Naohisa; Kaneda, Takashi; Muraoka, Hirotaka; Fukuda, Taiga; Ito, Kotaro; Kawashima, Yusuke

    2017-04-01

    The purpose of this study was to determine the characteristic magnetic resonance imaging (MRI) findings indicating bone and soft tissue involvement in patients with rheumatoid arthritis (RA) of the temporomandibular joints (TMJs). Twenty-one patients with RA and TMJ pain who underwent MRI examination of the TMJs at the authors' hospital from August 2006 to December 2014 were included in this study. Twenty-two patients with normal TMJs who underwent MRI examination at the authors' hospital from November to December 2014 were included as controls. MRI findings were compared between the 2 groups. MRI findings of RA in the TMJ included 1) abnormal disc position (95.2%), 2) abnormal disc morphology (83.3%), 3) joint effusion (30.9%), 4) osseous changes in the mandibular condyle (83.3%), 5) synovial proliferation (pannus; 85.7%), 6) erosion of the articular eminence and glenoid fossa (9.52%), 7) deformity of the articular eminence and glenoid fossa (16.6%), 8) abnormal bone marrow signal in the mandibular condyle (83.3%), and 9) swelling of lymph nodes in the parotid glands (78.5%). The abnormal bone marrow signal and pannus in the mandibular condyle and lymph node swelling in the parotid glands were markedly more common in patients with RA than in controls. MRI findings of RA of the TMJs were characterized by bone and soft tissue involvement, including abnormal bone marrow signal of the mandibular condyle, pannus, and swelling of lymph nodes in the parotid glands. These characteristic MRI findings could be useful in detecting RA in the TMJ in a clinical situation. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  19. HYPOOSMOTIC SPERM SWELLING TEST DOES NOT ASSESS FERTILIZING-CAPACITY OF HUMAN SPERMATOZOA

    NARCIS (Netherlands)

    JAGER, S; KREMER, J; WIJCHMAN, J

    1991-01-01

    The hypo-osmotic sperm swelling (HOSS) test was performed on semen samples of five normospermic men from couples with prolonged infertility. Previously, the men had negative results of the zona-free hamster oocyte (ZFHO) test on two different ejaculates and the wives subsequently had become pregnant

  20. Osmotic consolidation of suspensions and gels

    International Nuclear Information System (INIS)

    Miller, K.T.; Zukoski, C.F.

    1994-01-01

    An osmotic method for the consolidation of suspensions of ceramic particles is demonstrated. Concentrated solutions of poly(ethylene oxide) are separated from a suspension of ceramic particles by a semipermeable membrane, creating a gradient in solvent chemical potential. Solvent passes from the suspension into the polymer solution, lowering its free energy and consolidating the suspension. Dispersions of stable 8-nm hydrous zirconia particles were consolidated to over 47% by volume. Suspensions of α-alumina in three states of aggregation (dispersed, weakly flocculated, and strongly flocculated) were consolidated to densities greater than or equal to those produced in conventional pressure filtration. Moreover, the as-consolidated alumina bodies were partially drained of fluid during the osmotic consolidation process, producing cohesive partially dried bodies with improved handling characteristics

  1. 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.)

  2. 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.

  3. Osmotic water transport in aquaporins

    DEFF Research Database (Denmark)

    Zeuthen, Thomas; Alsterfjord, Magnus; Beitz, Eric

    2013-01-01

    Abstract  We test a novel, stochastic model of osmotic water transport in aquaporins. A solute molecule present at the pore mouth can either be reflected or permeate the pore. We assume that only reflected solute molecules induce osmotic transport of water through the pore, while permeating solute...... molecules give rise to no water transport. Accordingly, the rate of water transport is proportional to the reflection coefficient σ, while the solute permeability, P(S), is proportional to 1 - σ. The model was tested in aquaporins heterologously expressed in Xenopus oocytes. A variety of aquaporin channel...... sizes and geometries were obtained with the two aquaporins AQP1 and AQP9 and mutant versions of these. Osmotic water transport was generated by adding 20 mM of a range of different-sized osmolytes to the outer solution. The osmotic water permeability and the reflection coefficient were measured...

  4. 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.

  5. Extra pontine osmotic demyelination syndrome.

    Science.gov (United States)

    Zunga, Pervaiz M; Farooq, Omar; Dar, Mohd I; Dar, Ishrat H; Rashid, Samia; Rather, Abdul Q; Basu, Javid A; Ashraf, Mohammed; Bhat, Jahangeer A

    2015-01-01

    The osmotic demyelination syndrome (ODS) has been identified as a complication of the rapid correction of hyponatremia for decades. However, in recent years, a variety of other medical conditions have been associated with the development of ODS, independent of changes in serum sodium which cause a rapid changes in osmolality of the interstitial (extracellular) compartment of the brain leading to dehydration of energy-depleted cells with subsequent axonal damage that occurs in characteristic areas. Slow correction of the serum sodium concentration and additional administration of corticosteroids seems to be a major prevention step in ODS patients. In the current report we aimed to share a rare case which we observed in our hospital. A 65 year old female admitted as altered sensorium with history of vomiting, diarrhea was managed with intravenous fluids for 2 days at a peripheral health centre. Patient was referred to our centre with encephalopathy, evaluated and found to have hyponatremia and hypokalemia rest of biochemical parameters and septic profile were normal. Patient's electrolyte disturbances were managed as per guidelines but encephalopathy persisted. Supportive treatment was continued and patient was discharged after 2 wks of stay in hospital after gaining full sensorium and neurological functions.

  6. 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.

  7. 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...

  8. 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.

  9. Extracellular-matrix-mediated osmotic pressure drives Vibrio cholerae biofilm expansion and cheater exclusion.

    Science.gov (United States)

    Yan, Jing; Nadell, Carey D; Stone, Howard A; Wingreen, Ned S; Bassler, Bonnie L

    2017-08-23

    Biofilms, surface-attached communities of bacteria encased in an extracellular matrix, are a major mode of bacterial life. How the material properties of the matrix contribute to biofilm growth and robustness is largely unexplored, in particular in response to environmental perturbations such as changes in osmotic pressure. Here, using Vibrio cholerae as our model organism, we show that during active cell growth, matrix production enables biofilm-dwelling bacterial cells to establish an osmotic pressure difference between the biofilm and the external environment. This pressure difference promotes biofilm expansion on nutritious surfaces by physically swelling the colony, which enhances nutrient uptake, and enables matrix-producing cells to outcompete non-matrix-producing cheaters via physical exclusion. Osmotic pressure together with crosslinking of the matrix also controls the growth of submerged biofilms and their susceptibility to invasion by planktonic cells. As the basic physicochemical principles of matrix crosslinking and osmotic swelling are universal, our findings may have implications for other biofilm-forming bacterial species.Most bacteria live in biofilms, surface-attached communities encased in an extracellular matrix. Here, Yan et al. show that matrix production in Vibrio cholerae increases the osmotic pressure within the biofilm, promoting biofilm expansion and physical exclusion of non-matrix producing cheaters.

  10. 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

  11. Role of Osmotic Adjustment in Plant Productivity

    Energy Technology Data Exchange (ETDEWEB)

    Gebre, G.M.

    2001-01-11

    Successful implementation of short rotation woody crops requires that the selected species and clones be productive, drought tolerant, and pest resistant. Since water is one of the major limiting factors in poplar (Populus sp.) growth, there is little debate for the need of drought tolerant clones, except on the wettest of sites (e.g., lower Columbia River delta). Whether drought tolerance is compatible with productivity remains a debatable issue. Among the many mechanisms of drought tolerance, dehydration postponement involves the maintenance of high leaf water potential due to, for example, an adequate root system. This trait is compatible with productivity, but requires available soil moisture. When the plant leaf water potential and soil water content decline, the plant must be able to survive drought through dehydration tolerance mechanisms, such as low osmotic potential or osmotic adjustment. Osmotic adjustment and low osmotic potential are considered compatible with growth and yield because they aid in the maintenance of leaf turgor. However, it has been shown that turgor alone does not regulate cell expansion or stomatal conductance and, therefore, the role of osmotic adjustment is debated. Despite this finding, osmotic adjustment has been correlated with grain yield in agronomic crop species, and gene markers responsible for osmotic adjustment are being investigated to improve drought tolerance in productive progenies. Although osmotic adjustment and low osmotic potentials have been investigated in several forest tree species, few studies have investigated the relationship between osmotic adjustment and growth. Most of these studies have been limited to greenhouse or container-grown plants. Osmotic adjustment and rapid growth have been specifically associated in Populus and black spruce (Picea mariuna (Mill.) B.S.P.) progenies. We tested whether these relationships held under field conditions using several poplar clones. In a study of two hybrid poplar

  12. 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.

  13. Self-consistent unstirred layers in osmotically driven flows

    DEFF Research Database (Denmark)

    Jensen, Kåre Hartvig; Bohr, Tomas; Bruus, Henrik

    2010-01-01

    It has long been recognized that the osmotic transport characteristics of membranes may be strongly influenced by the presence of unstirred concentration boundary layers adjacent to the membrane. Previous experimental as well as theoretical works have mainly focused on the case where the solutions...

  14. Benchtop-magnetic resonance imaging (BT-MRI) characterization of push-pull osmotic controlled release systems.

    Science.gov (United States)

    Malaterre, Vincent; Metz, Hendrik; Ogorka, Joerg; Gurny, Robert; Loggia, Nicoletta; Mäder, Karsten

    2009-01-05

    The mechanism of drug release from push-pull osmotic systems (PPOS) has been investigated by Magnetic Resonance Imaging (MRI) using a new benchtop apparatus. The signal intensity profiles of both PPOS layers were monitored non-invasively over time to characterize the hydration and swelling kinetics. The drug release performance was well-correlated to the hydration kinetics. The results show that (i) hydration and swelling critically depend on the tablet core composition, (ii) high osmotic pressure developed by the push layer may lead to bypassing the drug layer and incomplete drug release and (iii) the hydration of both the drug and the push layers needs to be properly balanced to efficiently deliver the drug. MRI is therefore a powerful tool to get insights on the drug delivery mechanism of push-pull osmotic systems, which enable a more efficient optimization of such formulations.

  15. Osmotic effects of polyethylene glycol.

    Science.gov (United States)

    Schiller, L R; Emmett, M; Santa Ana, C A; Fordtran, J S

    1988-04-01

    Polyethylene glycol (PEG) has been used to increase the osmotic pressure of fluids used to cleanse the gastrointestinal tract. However, little is known about its osmotic activity. To investigate this activity systematically, solutions of PEG of differing molecular weights were made and subjected to measurement of osmolality by both freezing point depression and vapor pressure osmometry. Measured osmolality was increasingly greater than predicted from average molecular weight as PEG concentration increased. Measurement of sodium activity in NaCl/PEG solutions by means of an ion-selective electrode suggested that the higher than expected osmolality could be due in part to interactions that, in effect, sequestered water from the solution. Osmolality was consistently greater by freezing point osmometry than by vapor pressure osmometry. To determine which osmometry method reflected biologically relevant osmolality, normal subjects underwent steady-state total gut perfusion with an electrolyte solution containing 105 g/L of PEG 3350. This produced rectal effluent that was hypertonic by freezing point osmometry but isotonic by vapor pressure osmometry. Assuming that luminal fluid reaches osmotic equilibrium with plasma during total gut perfusion, this result suggests that the vapor pressure osmometer accurately reflects the biologically relevant osmolality of intestinal contents. We conclude that PEG exerts more of an osmotic effect than would be predicted from its molecular weight. This phenomenon may reflect interactions between PEG and water molecules that alter the physical chemistry of the solution and sequester water from the solution.

  16. Osmotic Effects in Sludge Dewatering

    DEFF Research Database (Denmark)

    Keiding, Kristian; Rasmussen, Michael R.

    2003-01-01

    A model of filtration dewatering is presented. The model is based on the d’Arcy flow equation in which the resistance to filtration is described by the Corzeny–Carman equation and the driving force is the difference between the external pressure and the osmotic pressure of the filter cake. It has...

  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 effects of osmotic stress on the structure and function of the cell nucleus.

    Science.gov (United States)

    Finan, John D; Guilak, Farshid

    2010-02-15

    Osmotic stress is a potent regulator of the normal function of cells that are exposed to osmotically active environments under physiologic or pathologic conditions. The ability of cells to alter gene expression and metabolic activity in response to changes in the osmotic environment provides an additional regulatory mechanism for a diverse array of tissues and organs in the human body. In addition to the activation of various osmotically- or volume-activated ion channels, osmotic stress may also act on the genome via a direct biophysical pathway. Changes in extracellular osmolality alter cell volume, and therefore, the concentration of intracellular macromolecules. In turn, intracellular macromolecule concentration is a key physical parameter affecting the spatial organization and pressurization of the nucleus. Hyper-osmotic stress shrinks the nucleus and causes it to assume a convoluted shape, whereas hypo-osmotic stress swells the nucleus to a size that is limited by stretch of the nuclear lamina and induces a smooth, round shape of the nucleus. These behaviors are consistent with a model of the nucleus as a charged core/shell structure pressurized by uneven partition of macromolecules between the nucleoplasm and the cytoplasm. These osmotically-induced alterations in the internal structure and arrangement of chromatin, as well as potential changes in the nuclear membrane and pores are hypothesized to influence gene transcription and/or nucleocytoplasmic transport. A further understanding of the biophysical and biochemical mechanisms involved in these processes would have important ramifications for a range of fields including differentiation, migration, mechanotransduction, DNA repair, and tumorigenesis. (c) 2009 Wiley-Liss, Inc.

  19. Direct measurement of osmotic pressure of glycosaminoglycan solutions by membrane osmometry at room temperature.

    Science.gov (United States)

    Chahine, Nadeen O; Chen, Faye H; Hung, Clark T; Ateshian, Gerard A

    2005-09-01

    Articular cartilage is a hydrated soft tissue composed of negatively charged proteoglycans fixed within a collagen matrix. This charge gradient causes the tissue to imbibe water and swell, creating a net osmotic pressure that enhances the tissue's ability to bear load. In this study we designed and utilized an apparatus for directly measuring the osmotic pressure of chondroitin sulfate, the primary glycosaminoglycan found in articular cartilage, in solution with varying bathing ionic strength (0.015 M, 0.15 M, 0.5 M, 1 M, and 2 M NaCl) at room temperature. The osmotic pressure (pi) was found to increase nonlinearly with increasing chondroitin sulfate concentration and decreasing NaCl ionic bath environment. Above 1 M NaCl, pi changes negligibly with further increases in salt concentration, suggesting that Donnan osmotic pressure is negligible above this threshold, and the resulting pressure is attributed to configurational entropy. Results of the current study were also used to estimate the contribution of osmotic pressure to the stiffness of cartilage based on theoretical and experimental considerations. Our findings indicate that the osmotic pressure resulting from configurational entropy is much smaller in cartilage (based on an earlier study on bovine articular cartilage) than in free solution. The rate of change of osmotic pressure with compressive strain is found to contribute approximately one-third of the compressive modulus (H(A)(eff)) of cartilage (Pi approximately H(A)(eff)/3), with the balance contributed by the intrinsic structural modulus of the solid matrix (i.e., H(A) approximately 2H(A)(eff)/3). A strong dependence of this intrinsic modulus on salt concentration was found; therefore, it appears that proteoglycans contribute structurally to the magnitude of H(A), in a manner independent of osmotic pressure.

  20. RBC deformability and amino acid concentrations after hypo-osmotic challenge may reflect chronic cell hydration status in healthy young men

    OpenAIRE

    Stookey, Jodi D; Klein, Alexis; Hamer, Janice; Chi, Christine; Higa, Annie; Ng, Vivian; Arieff, Allen; Kuypers, Frans A; Larkin, Sandra; Perrier, Erica; Lang, Florian

    2013-01-01

    Biomarkers of chronic cell hydration status are needed to determine whether chronic hyperosmotic stress increases chronic disease risk in population-representative samples. In vitro, cells adapt to chronic hyperosmotic stress by upregulating protein breakdown to counter the osmotic gradient with higher intracellular amino acid concentrations. If cells are subsequently exposed to hypo-osmotic conditions, the adaptation results in excess cell swelling and/or efflux of free amino acids. This stu...

  1. Osmotic dehydration of fruit and berry raw materials in the food industry

    Directory of Open Access Journals (Sweden)

    N. A. Gribova

    2017-01-01

    Full Text Available Osmotic dehydration has recently received more attention as an effective method of preserving fruits and berries. Osmosis is a simple process that facilitates the processing of fruits and berries in order to preserve the original characteristics, namely nutritional value and organoleptic properties: color, aroma and texture. Osmotic dehydration has found wide application in the preservation of food products, as the activity of water in fruits and berries decreases, in some of them up to 90% of water is contained. The process of osmotic dehydration with the help of various agents is less energy-intensive than the process of drying or freezing, since it can be processed at ambient temperature. Osmotic dehydration has potential advantages in preserving the quality of food and in maintaining healthy food for the food industry. Treatment includes dehydration of fruits and berries by an osmotic agent followed by dehydration in dry or frozen apparatus where the moisture content decreases and the product becomes more stable. This process is a partial dewatering process to provide improved product quality compared to conventional drying processes or freezing. The purpose of studying osmotic dehydration is to identify the advantages and disadvantages in the treatment of osmotic agents. Various aspects of osmotic dehydration technology are considered, namely the solutions used, the characteristics of solutions, the effect of variable processes and the qualitative characteristics of osmo-dehydrated products. Factors of osmotic dehydration that depend on the osmotic agent, concentration of solute, temperature, time, size, shape and compactness of the material, mixing and the ratio of the solution to the samples.

  2. Influence of microorganisms on swelling behavior of smectites

    International Nuclear Information System (INIS)

    Viefhaus, Hanna; Schanz, Tom

    2012-01-01

    stimulated microbial growth. This is all with respect to the fact that electrolyte concentration has to be unaltered in comparison to the liquid that was used for the reference samples without microbial accumulation. Therefore C 6 H 12 O 6 was added to tap water, with a concentration of 20 g/l, as it acted as the desired energy and carbon source for the microbial growth. Reference samples were treated with tap water as well. The changes measured in COD (chemical oxygen demand), which acted as an indicator for microbial growth, and the microscopic analysis of the samples in ESEM (environmental scanning electron microscope) were utilized to monitor the accumulation during and following the test. In the first series of tests 1-D volume change was measured and in the second series of tests it was added by weight measurement. This was in order to differentiate water adsorption from other volume changing effects, such as gas generation by metabolism processes, which seemed to appear during the first series of tests. Water content was plotted against time for each sample of Calcigel and MX80 mixtures. Both mixtures began to swell with the rapid occurring hydration of the cations and the charged surfaces, within the first 24 hours. This was followed by time intensive osmotic swelling in the case of MX80 smectite occupied with Na + . While hydration depends on the initial condition 'dry' or 'wet', osmotic swelling leads to water adsorption regardless of these conditions. Rapid occurring hydration of the charge carriers remains relatively unaffected by the presence of microorganisms. In comparison osmotic swelling exhibits considerable differences in water adsorption and volume change when samples have been accumulated with microorganisms. Therefore the influence reacts in different fashions, with negligible hydration increase and a significant decrease in osmotic swelling behavior of microbial accumulated samples. Also biological cells appear as charge carriers, and for this purpose

  3. Flow cytometric determination of osmotic behaviour of animal erythrocytes toward their engineering for drug delivery

    Directory of Open Access Journals (Sweden)

    Kostić Ivana T.

    2015-01-01

    Full Text Available Despite the fact that the methods based on the osmotic properties of the cells are the most widely used for loading of drugs in human and animal erythrocytes, data related to the osmotic properties of erythrocytes derived from animal blood are scarce. This work was performed with an aim to investigate the possibility of use the flow cytometry as a tool for determination the osmotic behaviour of porcine and bovine erythrocytes, and thus facilitate the engineering of erythrocytes from animal blood to be drug carriers. The method of flow cytometry successfully provided the information about bovine and porcine erythrocyte osmotic fragility, and made the initial steps in assessment of erythrocyte shape in a large number of erythrocytes. Although this method is not able to confirm the swelling of pig erythrocytes, it indicated to the differences in pig erythrocytes that had basic hematological parameters inside and outside the reference values. In order to apply/use the porcine and bovine erythrocytes as drug carriers, the method of flow cytometry, confirming the presence of osmotically different fractions of red blood cells, indicated that various amounts of the encapsulated drug in porcine and bovine erythrocytes can be expected.

  4. Isolated Extrapontine Myelinolysis of Osmotic Demyelination Syndrome

    Directory of Open Access Journals (Sweden)

    Ömer Yılmaz

    2013-01-01

    Full Text Available The osmotic demyelination syndrome (ODS has been identified as a complication of the rapid correction of hyponatremia for decades (King and Rosner, 2010. However, in recent years, a variety of other medical conditions have been associated with the development of ODS, independent of changes in serum sodium which cause a rapid changes in osmolality of the interstitial (extracellular compartment of the brain leading to dehydration of energy-depleted cells with subsequent axonal damage that occurs in characteristic areas (King and Rosner, 2010. Slow correction of the serum sodium concentration and additional administration of corticosteroids seems to be a major prevention step in ODS patients. In the current report we aimed to share a rare case which we observed in our clinic.

  5. Use of osmotic dehydration to improve fruits and vegetables quality during processing.

    Science.gov (United States)

    Maftoonazad, Neda

    2010-11-01

    Osmotic treatment describes a preparation step to further processing of foods involving simultaneous transient moisture loss and solids gain when immersing in osmotic solutions, resulting in partial drying and improving the overall quality of food products. The different aspects of the osmotic dehydration (OD) technology namely the solutes employed, solutions characteristics used, process variables influence, as well as, the quality characteristics of the osmodehydrated products will be discussed in this review. As the process is carried out at mild temperatures and the moisture is removed by a liquid diffusion process, phase change that would be present in the other drying processes will be avoided, resulting in high quality products and may also lead to substantial energy savings. To optimize this process, modeling of the mass transfer phenomenon can improve high product quality. Several techniques such as microwave heating, vacuum, high pressure, pulsed electric field, etc. may be employed during or after osmotic treatment to enhance performance of the osmotic dehydration. Moreover new technologies used in osmotic dehydration will be discussed. Patents on osmotic dehydration of fruits and vegetables are also discussed in this article.

  6. The physics of osmotic pressure

    Science.gov (United States)

    Bowler, M. G.

    2017-09-01

    Osmosis drives the development of a pressure difference of many atmospheres between a dilute solution and pure solvent with which it is in contact through a semi-permeable membrane. The educational importance of this paper is that it presents a novel treatment in terms of fluid mechanics that is quantitative and exact. It is also simple and intuitive, showing vividly how osmotic pressures are generated and maintained in equilibrium, driven by differential solvent pressures. The present rigorous analysis using the virial theorem seems unknown and can be easily understood—and taught—at various different levels. It should be valuable to undergraduates, graduate students and indeed to the general physicist.

  7. Efficiency of osmotic pipe flows

    DEFF Research Database (Denmark)

    Haaning, Louise Sejling; Jensen, Kaare Hartvig; Helix Nielsen, Claus

    2013-01-01

    efficiency of these flows is limited by the presence of “unstirred” concentration boundary layers near the tube walls, and our primary aim is to understand and quantify these layers and their effect on the flow. We measure the outlet flow rate Qout while varying the inlet flow rate Q*, concentration c......We present experiments and theory for flows of sugar or salt solutions in cylindrical tubes with semipermeable walls (hollow fiber membranes) immersed in water, quantifying the strength of the osmotic driving force in relation to the dimensionless parameters that specify the system. The pumping...

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

    Science.gov (United States)

    Johnson, Lee James

    2001-08-01

    The severity of brain edema resulting from a stroke can determine a patient's survival and the extent of their recovery. Cellular swelling is the microscopic source of a significant part of brain edema. Mitochondrial swelling also appears to be a determining event in the death or survival of the cells that are injured during a stroke. Therapies for reducing brain edema are not effective in many cases and current treatments of stroke do not address mitochondrial swelling at all. This dissertation is motivated by the lack of a complete understanding of cellular swelling resulting from stroke and the lack of a good method to begin to study mitochondrial swelling resulting from stroke in living brain tissue. In this dissertation, a novel method of detecting mitochondrial and cellular swelling in living hippocampal slices is developed and validated. The system is used to obtain spatial and temporal information about cellular and mitochondrial swelling resulting from various models of stroke. The effect of changes in water content on light scatter and absorption are examined in two models of brain edema. The results of this study demonstrate that optical techniques can be used to detect changes in water content. Mie scatter theory, the theoretical basis of the dual- angle scatter ratio imaging system, is presented. Computer simulations based on Mie scatter theory are used to determine the optimal angles for imaging. A detailed account of the early systems is presented to explain the motivations for the system design, especially polarization, wavelength and light path. Mitochondrial sized latex particles are used to determine the system response to changes in scattering particle size and concentration. The dual-angle scatter ratio imaging system is used to distinguish between osmotic and excitotoxic models of stroke injury. Such distinction cannot be achieved using the current techniques to study cellular swelling in hippocampal slices. The change in the scatter ratio is

  9. Osmotic dehydration of fruit and berry raw materials in the food industry

    OpenAIRE

    N. A. Gribova; L. G. Eliseeva

    2017-01-01

    Osmotic dehydration has recently received more attention as an effective method of preserving fruits and berries. Osmosis is a simple process that facilitates the processing of fruits and berries in order to preserve the original characteristics, namely nutritional value and organoleptic properties: color, aroma and texture. Osmotic dehydration has found wide application in the preservation of food products, as the activity of water in fruits and berries decreases, in some of them up to 90% o...

  10. Osmotic homeostasis and NKLy lymphoma cells radiosensitivity

    International Nuclear Information System (INIS)

    Tishchenko, V.V.; Magda, I.N.

    1992-01-01

    In experiments with cells of ascites NKLy lymphoma differing in ploidy and position in the cell cycle, a study was made of the radiosensitivity, osmotic homeostasis peculiarities and thermoradiation changes in potassium content. It was shown that the resistance of osmotic homeostasis of NKLy cells to thermoradiation correlated with their radioresistance

  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. 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

  13. 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 ...

  14. Development of hyper osmotic resistant CHO host cells for enhanced antibody production.

    Science.gov (United States)

    Kamachi, Yasuharu; Omasa, Takeshi

    2018-04-01

    Cell culture platform processes are generally employed to shorten the duration of new product development. A fed-batch process with continuous feeding is a conventional platform process for monoclonal antibody production using Chinese hamster ovary (CHO) cells. To establish a simplified platform process, the feeding method can be changed from continuous feed to bolus feed. However, this change induces a rapid increase of osmolality by the bolus addition of nutrients. The increased osmolality suppresses cell culture growth, and the final product concentration is decreased. In this study, osmotic resistant CHO host cells were developed to attain a high product concentration. To establish hyper osmotic resistant CHO host cells, CHO-S host cells were passaged long-term in a hyper osmotic basal medium. There were marked differences in cell growth of the original and established host cells under iso- (328 mOsm/kg) or hyper-osmolality (over 450 mOsm/kg) conditions. Cell growth of the original CHO host cells was markedly decreased by the induction of osmotic stress, whereas cell growth of the hyper osmotic resistant CHO host cells was not affected. The maximum viable cell concentration of hyper osmotic resistant CHO host cells was 132% of CHO-S host cells after the induction of osmotic stress. Moreover, the hyper osmotic resistant characteristic of established CHO host cells was maintained even after seven passages in iso-osmolality basal medium. The use of hyper osmotic resistance CHO host cells to create a monoclonal antibody production cell line might be a new approach to increase final antibody concentrations with a fed-batch process. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  15. 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...

  16. 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 ...

  17. Downregulation of the taurine transporter TauT during hypo-osmotic stress in NIH3T3 mouse fibroblasts

    DEFF Research Database (Denmark)

    Hansen, Daniel Bloch; Friis, Martin Barfred; Hoffmann, Else Kay

    2012-01-01

    The present work was initiated to investigate regulation of the taurine transporter TauT by reactive oxygen species (ROS) and the tonicity-responsive enhancer binding protein (TonEBP) in NIH3T3 mouse fibroblasts during acute and long-term (4 h) exposure to low-sodium/hypo-osmotic stress. Taurine...... are significantly increased following hyperosmotic exposure. Swelling-induced ROS production in NIH3T3 fibroblasts is generated by NOX4 and by increasing total ROS, by either exogenous application of H(2)O(2) or overexpressing NOX4, we demonstrate that TonEBP activity and taurine influx are regulated negatively...... by ROS under hypo-osmotic, low-sodium conditions, whereas the TauT mRNA level is unaffected. Acute exposure to ROS reduces taurine uptake as a result of modulated TauT transport kinetics. Thus, swelling-induced ROS production could account for the reduced taurine uptake under low...

  18. 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

  19. Osmotic pressure in Ca/Na montmorillonite dispersions: Monte Carlo simulations

    International Nuclear Information System (INIS)

    Joensson, Bo; Aakesson, T.; Segad, M.; Cabane, B.

    2010-01-01

    Document available in extended abstract form only. In the past, clay-water systems have been extensively studied. due to its importance in agricultural as well as technological applications. A more recent use of clay is as sealing material for nuclear waste. The success for such a containment depends on the clay structure and its swelling properties. This means that the clay should be able to sustain considerable changes in the surrounding ground water including salinities of glacial melt water as well as sea water, while still being an effective hydraulic barrier. We have approached this problem using statistical mechanical simulation techniques. The osmotic pressure in Ca/Na montmorillonite dispersions has been calculated via Monte Carlo simulations. For a clay system in equilibrium with pure water, Monte Carlo simulations predict a large swelling when the clay counterions are monovalent, while in presence of divalent counterions a limited swelling is predicted with an aqueous layer between the clay lamellae of about 1 nm - in excellent agreement with SAXS data. Montmorillonite in contact with a salt reservoir with e.g. both Na and Ca counterions will only show a modest swelling unless the Na + concentration in the bulk is several orders of magnitude larger than the Ca 2+ concentration. This is true both for a clay repository surrounded by ground water as well as sea water of high salinity. The limited swelling of clay in presence of divalent counterions is a consequence of ion-ion correlations, which both reduce the entropic repulsion and give rise to an attractive component in the total osmotic pressure. Ion-ion correlations also favour divalent counterions when competing with monovalent ones. This is an important aspect for the retention of radioactive charged species. A more fundamental result of ion-ion correlations is that the osmotic pressure as a function of clay sheet separation becomes non-monotonic - which indicates the possibility of a phase

  20. Osmotic pressure-dependent release profiles of payloads from nanocontainers by co-encapsulation of simple salts

    Science.gov (United States)

    Behzadi, Shahed; Rosenauer, Christine; Kappl, Michael; Mohr, Kristin; Landfester, Katharina; Crespy, Daniel

    2016-06-01

    The encapsulation of payloads in micro- to nano-scale capsules allows protection of the payload from the surrounding environment and control of its release profile. Herein, we program the release of hydrophilic payloads from nanocontainers by co-encapsulating simple inorganic salts for adjusting the osmotic pressure. The latter either leads to a burst release at high concentrations of co-encapsulated salts or a sustained release at lower concentrations. Osmotic pressure causes swelling of the nanocapsule's shell and therefore sustained release profiles can be adjusted by crosslinking it. The approach presented allows for programing the release of payloads by co-encapsulating inexpensive salts inside nanocontainers without the help of stimuli-responsive materials.The encapsulation of payloads in micro- to nano-scale capsules allows protection of the payload from the surrounding environment and control of its release profile. Herein, we program the release of hydrophilic payloads from nanocontainers by co-encapsulating simple inorganic salts for adjusting the osmotic pressure. The latter either leads to a burst release at high concentrations of co-encapsulated salts or a sustained release at lower concentrations. Osmotic pressure causes swelling of the nanocapsule's shell and therefore sustained release profiles can be adjusted by crosslinking it. The approach presented allows for programing the release of payloads by co-encapsulating inexpensive salts inside nanocontainers without the help of stimuli-responsive materials. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr01882c

  1. 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.

  2. The Influence of the Osmotic Dehydration Process on Physicochemical Properties of Osmotic Solution.

    Science.gov (United States)

    Lech, Krzysztof; Michalska, Anna; Wojdyło, Aneta; Nowicka, Paulina; Figiel, Adam

    2017-12-16

    The osmotic dehydration (OD) process consists of the removal of water from a material during which the solids from the osmotic solution are transported to the material by osmosis. This process is commonly performed in sucrose and salt solutions. Taking into account that a relatively high consumption of those substances might have a negative effect on human health, attempts have been made to search for alternatives that can be used for osmotic dehydration. One of these is an application of chokeberry juice with proven beneficial properties to human health. This study aimed to evaluate the physicochemical properties of the OD solution (chokeberry juice concentrate) before and after the osmotic dehydration of carrot and zucchini. The total polyphenolics content, antioxidant capacity (ABTS, FRAP), dynamic viscosity, density, and water activity were examined in relation to the juice concentration used for the osmotic solution before and after the OD process. During the osmotic dehydration process, the concentration of the chokeberry juice decreased. Compounds with lower molecular weight and lower antioxidant capacity present in concentrated chokeberry juice had a stronger influence on the exchange of compounds during the OD process in carrot and zucchini. The water activity of the osmotic solution increased after the osmotic dehydration process. It was concluded that the osmotic solution after the OD process might be successfully re-used as a product with high quality for i.e. juice production.

  3. 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

  4. Osmotic therapies added to antibiotics for acute bacterial meningitis

    Science.gov (United States)

    Wall, Emma Cb; Ajdukiewicz, Katherine Mb; Bergman, Hanna; Heyderman, Robert S; Garner, Paul

    2018-01-01

    children with bacterial meningitis die in high-income countries with much higher rates in low-income settings. The infection causes the brain to swell, and this is thought to contribute to death and to long-term brain damage in survivors. Osmotic therapies increase the concentration of the blood by exerting an osmotic pressure across a semi-permeable membrane (such as a cell wall or blood vessel lining in the brain). This draws water from the brain into the blood, thereby reducing pressure in the brain. Potentially osmotic therapies could increase the rate of survival, or they could do harm. What are the main results of the review? We included five trials that compared glycerol with placebo in a total of 1451 patients with bacterial meningitis. In the studies steroids were often given as well, but this did not appear to modify any of the effects seen with glycerol. This review detected no benefit from glycerol relating to death. There appeared to be marginal protection against deafness and against neurological disability. No effect on epileptic seizures at follow-up was noted. Glycerol was not associated with any severe adverse effects. The number of trials included was small and only two tested a large number of participants. All trials were from different healthcare settings and examined either adults or children. PMID:29405037

  5. Osmocapsules for direct measurement of osmotic strength.

    Science.gov (United States)

    Kim, Shin-Hyun; Lee, Tae Yong; Lee, Sang Seok

    2014-03-26

    Monodisperse microcapsules with ultra-thin membranes are microfluidically designed to be highly sensitive to osmotic pressure, thereby providing a tool for the direct measurement of the osmotic strength. To make such osmocapsules, water-in-oil-in-water double-emulsion drops with ultra-thin shells are prepared as templates through emulsification of core-sheath biphasic flow in a capillary microfluidic device. When photocurable monomers are used as the oil phase, the osmocapsules are prepared by in-situ photopolymerization of the monomers, resulting in semipermeable membranes with a relatively large ratio of membrane thickness to capsule radius, approximately 0.02. These osmocapsules are buckled by the outward flux of water when they are subjected to a positive osmotic pressure difference above 125 kPa. By contrast, evaporation-induced consolidation of middle-phase containing polymers enables the production of osmocapsules with a small ratio of membrane thickness to capsule radius of approximately 0.002. Such an ultra-thin membrane with semi-permeability makes the osmocapsules highly sensitive to osmotic pressure; a positive pressure as small as 12.5 kPa induces buckling of the capsules. By employing a set of distinct osmocapsules confining aqueous solutions with different osmotic strengths, the osmotic strength of unknown solutions can be estimated through observation of the capsules that are selectively buckled. This approach provides the efficient measurement of the osmotic strength using only a very small volume of liquid, thereby providing a useful alternative to other measurement methods which use complex setups. In addition, in-vivo measurement of the osmotic strength can be potentially accomplished by implanting these biocompatible osmocapsules into tissue, which is difficult to achieve using conventional methods. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. 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

  7. 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)

  8. Studies on osmotic concentration of radioactive effluents

    International Nuclear Information System (INIS)

    Thomas, K.C.; Ramachandhran, V.; Misra, B.M.

    1986-01-01

    The potential of direct osmosis for concentrating radioactive effluents is examined on the laboratory scale. Studies were carried out using asymmetric cellulose acetate membranes of a range of porosities under varying salinity gradients. A suitable bench scale osmotic concentrator employing tubular membrane systems has been fabricated and tested. An attempt to understand the mechanism of water permeation under osmotic and hydrostatic gradients has been made based on the irreversible thermodynamic approach. The solute separation of sodium chloride and radionuclides under osmosis is in the range of 85 to 95% for various osmotic sink solutions. The osmotic water flux is observed to be lower than the hydraulic water flux under reverse osmosis conditions. While the solute separation increases with an increase in annealing temperature, water flux decreases for both osmosis and reverse osmosis systems for various feed salinities. The effect of concentration polarization is analysed, and the effect of feed and osmotic sink velocity on the performance of the osmotic concentrator has also been studied. (orig.)

  9. 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.

  10. Controlled release of glaucocalyxin - a self-nanoemulsifying system from osmotic pump tablets with enhanced bioavailability.

    Science.gov (United States)

    Yanfei, Miao; Guoguang, Chen; Lili, Ren; Pingkai, Ouyang

    2017-03-01

    The purpose of this study was to develop a new formulation to enhance the bioavailability simultaneously with controlled release of glaucocalyxin A (GLA). In this study, controlled release of GLA was achieved by the osmotic release strategy taking advantage of the bioavailability enhancing capacity of self-nanoemulsifying drug delivery systems (SNEDDS). The formulation of GLA-SNEDDS was selected by the solubility and pseudoternary-phase diagrams studies. The prepared GLA-SNEDDS formulations were characterized for self-emulsification time, effect of pH and robustness to dilution, droplet size analysis and zeta potential. The optimized GLA-SNEDDS were used to prepare GLA-SNEDDS osmotic pump tablet via direct powder compression method. The effect of formulation variables on the release characteristic was investigated. GLA-SNEDDS osmotic pump tablets were administered to beagle dogs and their pharmacokinetics were compared to GLA and GLA-SNEDDS as a control. In vitro drug release studies indicated that the GLA-SNEDDS osmotic pump tablet showed sustained release profiles with 90% released within 12 h. Pharmacokinetic study showed steady blood GLA with prolonged T max and mean residence time (MRT), and enhanced bioavailability for GLA-SNEDDS osmotic pump tablet. It was concluded that simultaneous controlling on GLA release and enhanced bioavailability had been achieved by a combination of osmotic pump tablet and SNEDDS.

  11. Release and Decay Kinetics of Copeptin vs AVP in Response to Osmotic Alterations in Healthy Volunteers.

    Science.gov (United States)

    Fenske, Wiebke K; Schnyder, Ingeborg; Koch, Gilbert; Walti, Carla; Pfister, Marc; Kopp, Peter; Fassnacht, Martin; Strauss, Konrad; Christ-Crain, Mirjam

    2018-02-01

    Copeptin is the C-terminal fragment of the arginine vasopressin (AVP) prohormone whose measurement is more robust than that of AVP. Similar release and clearance characteristics have been suggested promoting copeptin as a surrogate marker. To characterize the physiology of osmotically regulated copeptin release and its half-life in direct comparison with plasma AVP. Ninety-one healthy volunteers underwent a standardized three-phase test protocol including (1) osmotic stimulation into the hypertonic range by hypertonic-saline infusion followed by osmotic suppression via (2) oral water load and (3) subsequent glucose infusion. Plasma copeptin, AVP, serum sodium, and osmolality levels were measured in regular intervals. In phase 1, an increase in median osmotic pressure [289 (286; 291) to 311 (309; 314) mOsm/kg H2O] caused similar release kinetics of plasma copeptin [4 (3.1; 6) to 29.3 (18.6; 48.2) pmol/L] and AVP [1 (0.7; 1.6) to 10.3 (6.8; 18.8) pg/mL]. Subsequent osmotic suppression to 298 (295; 301) mOsm/kg at the end of phase 3 revealed markedly different decay kinetics between both peptides-an estimated initial half-life of copeptin being approximately 2 times longer than that of AVP (26 vs 12 minutes). Copeptin is released in equimolar amounts with AVP in response to osmotic stimulation, suggesting its high potential as an AVP surrogate for differentiation of osmotic disorders. Furthermore, we here describe the decay kinetics of copeptin in response to osmotic depression enabling to identify a half-life for copeptin in direct comparison with AVP. Copyright © 2017 Endocrine Society

  12. 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...

  13. Quality and sensorial characteristics of osmotically dehydrated mango with syrups of inverted sugar and sucrose Qualidade e características sensoriais de manga osmoticamente desidratada com xaropes de açúcar invertido e a sacarose

    Directory of Open Access Journals (Sweden)

    Sabrina Bernardi

    2009-02-01

    Full Text Available Osmotic dehydration is becoming more popular as a complementary treatment in the processing of dehydrated foods, since it presents some advantages such as minimising heat damage to the colour and flavour, inhibiting enzymatic browning and thus dispensing the addition of sulphite and, mainly, reducing energy costs. The objective of the present study was to evaluate the effect of using inverted sugar and sucrose syrups as osmotic agents in the dehydration of mango. The conditions used in the dehydration process were: syrup/fruit ratio of 3:1 (v/w; temperature of 45ºC and constant stirring. The in natura and osmo-dehydrated fruits were evaluated in relation to pH, moisture content, water activity (a w and soluble solids (ºBrix. Solids incorporation and loss in mass after the dehydration process were also determined. The sensory acceptance of the in natura and osmo-dehydrated fruits was determined for the attributes of aroma, flavour, texture and overall acceptance using a hedonic scale. Osmotic dehydration resulted in a reduction in moisture content and water activity, an increase in Brix and maintenance of the pH. The treatment with inverted sugar syrup resulted in more significant alterations in moisture content, a w, Brix, solids incorporation and loss in mass than the treatment with sucrose syrup. Mangos osmo-dehydrated with inverted sugar (55.3% inversion rate syrup obtained acceptance similar to in natura mangos, this treatment being considered the most adequate for dehydration purposes.A desidratação osmótica tem se tornado uma tecnologia cada vez mais usual no processamento de alimentos desidratados, por apresentar vantagens como a redução nas perdas de cor e sabor durante o tratamento térmico, inibição do escurecimento enzimático, prescindindo da adição de agentes sulfitantes, e principalmente economia no consumo de energia. Este trabalho avaliou o efeito da utilização de xaropes de açúcar invertido e sacarose como agentes

  14. Effect of osmotic predehydration on drying characteristics of banana fruits Efeito da pré-secagem osmótica sobre as características de banana desidratada

    Directory of Open Access Journals (Sweden)

    Vahideh Ranemaye Rabbani Jalali

    2008-06-01

    Full Text Available Osmotic dehydration is considered to be a suitable preprocessing step to reduce the water content of foods. Such products can be dried further by conventional drying processes to lower their water activity and thus extend their shelf life. In this work, banana (Musa sapientum fruits were initially treated by osmosis by varying several parameters of the processing conditions which included, besides the cutting format (longitudinal and round slices of the fruit, temperature (28 and 49 ºC, syrup concentration (50, 60 and 67 ºBrix, treatment time (2, 4, 6, 10, 14, 16 and 18 hours, fruit and syrup ratio (1:1, 1:2, 1:3 and 1:4 and agitation effects. The best quality products were obtained by the use of the 67 ºBrix syrup, for 60 minutes of osmotic treatment, at 28 ºC, having a fruit and syrup ratio of 1:1 and agitation. The experimental data obtained on reduction in moisture content during the osmotic treatment were correlated with the experimental equation of M/Mo = Ae(-Kt, where A and K are the constants which represent the geometry and effective diffusivity of the drying process. This simplified mathematical model correlated well with the experimental results.A desidratação osmótica é considerada como uma etapa de pré-processamento para reduzir o teor da umidade em alimentos. Estes produtos poderão ser desidratados pelo processo de secagem convencional para abaixar o teor de umidade em alimentos, e assim aumentar a vida de prateleira destes produtos. Neste trabalho, a desidratação osmótica de banana prata (Musa sapientum foi estudada. Os ensaios foram realizados nas temperaturas de 28 e 49 ºC, com concentração de xarope de 50, 60 e 67 ºBrix, tempo de tratamento (2, 4, 6, 10, 14, 16 e 18 horas, proporção de frutas/xarope de 1:1, 1:2, 1:3 e 1:4, e o efeito de agitação do xarope. Os melhores resultados foram obtidos para concentração de xarope: 67 ºBrix, tratamento osmótico de 60 minutos, proporção de fruta/xarope: 1

  15. The analysis of creep characteristics of the surrounding rock of the carbonaceous rock tunnel based on Singh-Mitchell model

    Science.gov (United States)

    Luo, Junhui; Mi, Decai; Ye, Qiongyao; Deng, Shengqiang; Zeng, Fuquan; Zeng, Yongjun

    2018-01-01

    Carbonaceous rock has the characteristics of easy disintegration, softening, swelling and environmental sensitivity, which belongs to soft surrounding rock, and the deformation during excavation and long-term stability of the surrounding rock of carbonaceous rock tunnel are common problems in the construction of carbonaceous rock tunnel. According to the above, the Monitor and measure the displacement, temperature and osmotic pressure of the surrounding carbonaceous rock of the tunnel of Guangxi Hebai highway. Then it based on the obtaining data to study the creep mechanism of surrounding rock using Singh-Mitchell model and predict the deformation of surrounding rock before the tunnel is operation. The results show that the Singh-Mitchell creep model can effectively analyse and predict the deformation development law of surrounding rock of tunnel without considering temperature and osmotic pressure, it can provide reference for the construction of carbonaceous rock tunnel and the measures to prevent and reinforce it..

  16. 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.)

  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. Bentonite swelling pressure in strong NaCl solutions. Correlation of model calculations to experimentally determined data

    International Nuclear Information System (INIS)

    Karnland, O.

    1998-01-01

    A number of quite different quantitative models concerning swelling pressure in bentonite clay have been proposed. This report discusses a number of models which possibly can be used also for saline conditions. A discrepancy between calculated and measured values was noticed for all models at brine conditions. In general the models predicted a too low swelling pressure compared to what was experimentally found. An osmotic component in the clay/water system is proposed in order to improve the previous conservative use of the thermodynamic model. Calculations of this osmotic component is proposed to be made by use of the clay cation exchange capacity and Donnan equilibrium. Calculations made by this approach showed considerably better correlation to literature laboratory data, compared to calculations made by the previous conservative use of the thermodynamic model. A few verifying laboratory tests were made and are briefly described in the report. The improved model predicts a substantial bentonite swelling pressure also in a saturated sodium chloride solution if the density of the system is sufficiently high. This means in practice that the buffer in a KBS-3 repository will give rise to an acceptable swelling pressure, but that the positive effects of mixing bentonite into a backfill material will be lost if the system is exposed to brines. (orig.)

  19. Bentonite swelling pressure in strong NaCl solutions. Correlation between model calculations and experimentally determined data

    Energy Technology Data Exchange (ETDEWEB)

    Karnland, O. [Clay Technology, Lund (Sweden)

    1997-12-01

    A number of quite different quantitative models concerning swelling pressure in bentonite clay have been proposed by different researchers over the years. The present report examines some of the models which possibly may be used also for saline conditions. A discrepancy between calculated and measured values was noticed for all models at brine conditions. In general the models predicted a too low swelling pressure compared to what was experimentally found. An osmotic component in the clay/water system is proposed in order to improve the previous conservative use of the thermodynamic model. Calculations of this osmotic component is proposed to be made by use of the clay cation exchange capacity and Donnan equilibrium. Calculations made by this approach showed considerably better correlation to literature laboratory data, compared to calculations made by the previous conservative use of the thermodynamic model. A few verifying laboratory tests were made and are briefly described in the report. The improved thermodynamic model predicts substantial bentonite swelling pressures also in saturated sodium chloride solution if the density of the system is high enough. In practice, the model predicts a substantial swelling pressure for the buffer in a KBS-3 repository if the system is exposed to brines, but the positive effects of mixing bentonite into a backfill material will be lost, since the available compaction technique does not give a sufficiently high bentonite density 37 refs, 15 figs

  20. Bentonite swelling pressure in strong NaCl solutions. Correlation of model calculations to experimentally determined data

    Energy Technology Data Exchange (ETDEWEB)

    Karnland, O. [Clay Technology, Lund (Sweden)

    1998-01-01

    A number of quite different quantitative models concerning swelling pressure in bentonite clay have been proposed. This report discusses a number of models which possibly can be used also for saline conditions. A discrepancy between calculated and measured values was noticed for all models at brine conditions. In general the models predicted a too low swelling pressure compared to what was experimentally found. An osmotic component in the clay/water system is proposed in order to improve the previous conservative use of the thermodynamic model. Calculations of this osmotic component is proposed to be made by use of the clay cation exchange capacity and Donnan equilibrium. Calculations made by this approach showed considerably better correlation to literature laboratory data, compared to calculations made by the previous conservative use of the thermodynamic model. A few verifying laboratory tests were made and are briefly described in the report. The improved model predicts a substantial bentonite swelling pressure also in a saturated sodium chloride solution if the density of the system is sufficiently high. This means in practice that the buffer in a KBS-3 repository will give rise to an acceptable swelling pressure, but that the positive effects of mixing bentonite into a backfill material will be lost if the system is exposed to brines. (orig.). 14 refs.

  1. Bentonite swelling pressure in strong NaCl solutions. Correlation between model calculations and experimentally determined data

    International Nuclear Information System (INIS)

    Karnland, O.

    1997-12-01

    A number of quite different quantitative models concerning swelling pressure in bentonite clay have been proposed by different researchers over the years. The present report examines some of the models which possibly may be used also for saline conditions. A discrepancy between calculated and measured values was noticed for all models at brine conditions. In general the models predicted a too low swelling pressure compared to what was experimentally found. An osmotic component in the clay/water system is proposed in order to improve the previous conservative use of the thermodynamic model. Calculations of this osmotic component is proposed to be made by use of the clay cation exchange capacity and Donnan equilibrium. Calculations made by this approach showed considerably better correlation to literature laboratory data, compared to calculations made by the previous conservative use of the thermodynamic model. A few verifying laboratory tests were made and are briefly described in the report. The improved thermodynamic model predicts substantial bentonite swelling pressures also in saturated sodium chloride solution if the density of the system is high enough. In practice, the model predicts a substantial swelling pressure for the buffer in a KBS-3 repository if the system is exposed to brines, but the positive effects of mixing bentonite into a backfill material will be lost, since the available compaction technique does not give a sufficiently high bentonite density

  2. Casein Micelle Dispersions under Osmotic Stress

    Science.gov (United States)

    Bouchoux, Antoine; Cayemitte, Pierre-Emerson; Jardin, Julien; Gésan-Guiziou, Geneviève; Cabane, Bernard

    2009-01-01

    Abstract Casein micelles dispersions have been concentrated and equilibrated at different osmotic pressures using equilibrium dialysis. This technique measured an equation of state of the dispersions over a wide range of pressures and concentrations and at different ionic strengths. Three regimes were found. i), A dilute regime in which the osmotic pressure is proportional to the casein concentration. In this regime, the casein micelles are well separated and rarely interact, whereas the osmotic pressure is dominated by the contribution from small residual peptides that are dissolved in the aqueous phase. ii), A transition range that starts when the casein micelles begin to interact through their κ-casein brushes and ends when the micelles are forced to get into contact with each other. At the end of this regime, the dispersions behave as coherent solids that do not fully redisperse when osmotic stress is released. iii), A concentrated regime in which compression removes water from within the micelles, and increases the fraction of micelles that are irreversibly linked to each other. In this regime the osmotic pressure profile is a power law of the residual free volume. It is well described by a simple model that considers the micelle to be made of dense regions separated by a continuous phase. The amount of water in the dense regions matches the usual hydration of proteins. PMID:19167314

  3. 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)

  4. Inverse osmotic process for radioactive laundry waste

    Energy Technology Data Exchange (ETDEWEB)

    Ebara, K; Takahashi, S; Sugimoto, Y; Yusa, H; Hyakutake, H

    1977-01-07

    Purpose: To effectively recover the processing amount reduced in a continuous treatment. Method: Laundry waste containing radioactive substances discharged from a nuclear power plant is processed in an inverse osmotic process while adding starch digesting enzymes such as amylase and takadiastase, as well as soft spherical bodies such as sponge balls of a particle diameter capable of flowing in the flow of the liquid wastes along the inverse osmotic membrane pipe and having such a softness and roundness as not to damage the inverse osmotic membrane. This process can remove the floating materials such as thread dusts or hairs deposited on the membrane surface by the action of the soft elastic balls and remove paste or the like through decomposition by the digesting enzymes. Consequently, effective recovery can be attained for the reduced processing amount.

  5. Inverse osmotic process for radioactive laundry waste

    International Nuclear Information System (INIS)

    Ebara, Katsuya; Takahashi, Sankichi; Sugimoto, Yoshikazu; Yusa, Hideo; Hyakutake, Hiroshi.

    1977-01-01

    Purpose: To effectively recover the processing amount reduced in a continuous treatment. Method: Laundry waste containing radioactive substances discharged from a nuclear power plant is processed in an inverse osmotic process while adding starch digesting enzymes such as amylase and takadiastase, as well as soft spherical bodies such as sponge balls of a particle diameter capable of flowing in the flow of the liquid wastes along the inverse osmotic membrane pipe and having such a softness and roundness as not to damage the inverse osmotic membrane. This process can remove the floating materials such as thread dusts or hairs deposited on the membrane surface by the action of the soft elastic balls and remove paste or the like through decomposition by the digesting enzymes. Consequently, effective recovery can be attained for the reduced processing amount. (Furukawa, Y.)

  6. Simulating the swelling and deformation behaviour in soft tissues using a convective thermal analogy

    Directory of Open Access Journals (Sweden)

    Herzog Walter

    2002-12-01

    Full Text Available Abstract Background It is generally accepted that cartilage adaptation and degeneration are mechanically mediated. Investigating the swelling behaviour of cartilage is important because the stress and strain state of cartilage is associated with the swelling and deformation behaviour. It is well accepted that the swelling of soft tissues is associated with mechanical, chemical, and electrical events. Method The purpose of the present study was to implement the triphasic theory into a commercial finite element tool (ABAQUS to solve practical problems in cartilage mechanics. Because of the mathematical identity between thermal and mass diffusion processes, the triphasic model was transferred into a convective thermal diffusion process in the commercial finite element software. The problem was solved using an iterative procedure. Results The proposed approach was validated using the one-dimensional numerical solutions and the experimental results of confined compression of articular cartilage described in the literature. The time-history of the force response of a cartilage specimen in confined compression, which was subjected to swelling caused by a sudden change of saline concentration, was predicted using the proposed approach and compared with the published experimental data. Conclusion The advantage of the proposed thermal analogy technique over previous studies is that it accounts for the convective diffusion of ion concentrations and the Donnan osmotic pressure in the interstitial fluid.

  7. New Osmosis Law and Theory: the New Formula that Replaces van't Hoff Osmotic Pressure Equation

    OpenAIRE

    Huang, Hung-Chung; Xie, Rongqing

    2012-01-01

    This article derived a new abstract concept from the osmotic process and concluded it via "osmotic force" with a new law -- "osmotic law". The "osmotic law" describes that, in an osmotic system, osmolyte moves osmotically from the side with higher "osmotic force" to the side with lower "osmotic force". In addition, it was proved mathematically that the osmotic process could be explained perfectly via "osmotic force" and "osmotic laws", which can prevent the difficulties in using current "osmo...

  8. 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.

  9. 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.

  10. Osmotic dehydration of fish: principal component analysis

    Directory of Open Access Journals (Sweden)

    Lončar Biljana Lj.

    2014-01-01

    Full Text Available Osmotic treatment of the fish Carassius gibelio was studied in two osmotic solutions: ternary aqueous solution - S1, and sugar beet molasses - S2, at three solution temperatures of 10, 20 and 30oC, at atmospheric pressure. The aim was to examine the influence of type and concentration of the used hypertonic agent, temperature and immersion time on the water loss, solid gain, dry mater content, aw and content of minerals (Na, K, Ca and Mg. S2 solution has proven to be the best option according to all output variables.[ Projekat Ministarstva nauke Republike Srbije, br. TR 31055

  11. Dependence of osmotic pressure on solution properties

    International Nuclear Information System (INIS)

    Fritz, S.J.

    1978-01-01

    Hydrostatic pressure, temperature, salt concentration, and the chemical composition of the salt are parameters affecting solution properties. Pressure and temperature have little effect on osmosis, but osmotic pressure variations due to type of dissolved salt may be significant, especially at high concentrations. For a given salt solution, concentration variations cause large differences in osmotic pressure. A representative difference in concentration across a clay layer in a relatively shallow groundwater system might be 100 to 1,000 ppm. When expressed as ppm NaCl, this difference could cause a head difference of 0.8 to 8 meters of water if one of the rock bodies were closed to fluid escape

  12. Quantified Effects of Late Pregnancy and Lactation on the Osmotic ...

    African Journals Online (AJOL)

    Quantified Effects of Late Pregnancy and Lactation on the Osmotic Stability of ... in the composition of erythrocyte membranes associated with the physiologic states. Keywords: Erythrocyteosmotic stability, osmotic fragility, late pregnancy, ...

  13. Increased Resistance to osmotic lysis of sickled erythrocytes ...

    African Journals Online (AJOL)

    treated with CNw had significantly reduced osmotic lysis when compared with the untreated set (P<0.05, respectively) at various hypotonic NaCl concentrations. Various Hb genotypes exhibited a graded increase in osmotic pressure lysis in ...

  14. Osmotic stress upregulates the transcription of thiamine (vitamin B1 ...

    African Journals Online (AJOL)

    Osmotic stress upregulates the transcription of thiamine (vitamin B1) ... Oil palm's responses in terms of the expression profiles of these two thiamine biosynthesis genes to an osmotic stress inducer, polyethylene glycol ... from 32 Countries:.

  15. Augmentation of peristaltic microflows through electro-osmotic mechanisms

    International Nuclear Information System (INIS)

    Chakraborty, Suman

    2006-01-01

    The present work aims to theoretically establish that the employment of an axial electric field can substantially augment the rate of microfluidic transport occurring in peristaltic microtubes. For theoretical analysis, shape evolution of the tube is taken to be arbitrary, except for the fact that the characteristic wavelength is assumed to be significantly greater than the average radius of cross section. First, expressions for the velocity profile within the tube are derived and are subsequently utilized to obtain variations in the net flow rate across the same, as a function of the pertinent system parameters. Subsequently, the modes of interaction between the electro-osmotic and peristaltic mechanisms are established through the variations in the time-averaged flow rates for zero pressure rise and the pressure rise for zero time-averaged flow rates, as expressed in terms of the occlusion number, characteristic electro-osmotic velocity and the peristaltic wave speed. From the simulation predictions, it is suggested that a judicious combination of peristalsis and an axial electrokinetic body force can drastically enhance the time-averaged flow rate, provided that the occlusion number is relatively small

  16. 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

  17. Flux limitation in ultrafiltration: Osmotic pressure model and gel layer model

    NARCIS (Netherlands)

    Wijmans, J.G.; Nakao, S.; Smolders, C.A.

    1984-01-01

    The characteristic permeate flux behaviour in ultrafiltration, i.e., the existence of a limiting flux which is independent of applied pressure and membrane resistance and a linear plot of the limiting flux versus the logarithm of the feed concentration, is explained by the osmotic pressure model. In

  18. Comparative Erythrocytes Osmotic Fragility Test and some ...

    African Journals Online (AJOL)

    Erythrocytes osmotic fragility and haematological parameters of subjects with HbAS (sickle cell trait) and HbSS (sickle cell anaemia) were determined and compared with subjects with HbAA (normal adult haemoglobin), which acted as control. They were divided into three groups of 40 subjects for HbAA, 35 subjects for ...

  19. The plant cuticle is required for osmotic stress regulation of abscisic acid biosynthesis and osmotic stress tolerance in Arabidopsis

    KAUST Repository

    Wang, Zhenyu; Xiong, Liming; Li, Wenbo; Zhu, Jian-Kang; Zhu, Jianhua

    2011-01-01

    Osmotic stress activates the biosynthesis of abscisic acid (ABA). One major step in ABA biosynthesis is the carotenoid cleavage catalyzed by a 9-cis epoxycarotenoid dioxygenase (NCED). To understand the mechanism for osmotic stress activation of ABA

  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. Refinement of elastic, poroelastic, and osmotic tissue properties of intervertebral disks to analyze behavior in compression.

    Science.gov (United States)

    Stokes, Ian A F; Laible, Jeffrey P; Gardner-Morse, Mack G; Costi, John J; Iatridis, James C

    2011-01-01

    Intervertebral disks support compressive forces because of their elastic stiffness as well as the fluid pressures resulting from poroelasticity and the osmotic (swelling) effects. Analytical methods can quantify the relative contributions, but only if correct material properties are used. To identify appropriate tissue properties, an experimental study and finite element analytical simulation of poroelastic and osmotic behavior of intervertebral disks were combined to refine published values of disk and endplate properties to optimize model fit to experimental data. Experimentally, nine human intervertebral disks with adjacent hemi-vertebrae were immersed sequentially in saline baths having concentrations of 0.015, 0.15, and 1.5 M and the loss of compressive force at constant height (force relaxation) was recorded over several hours after equilibration to a 300-N compressive force. Amplitude and time constant terms in exponential force-time curve-fits for experimental and finite element analytical simulations were compared. These experiments and finite element analyses provided data dependent on poroelastic and osmotic properties of the disk tissues. The sensitivities of the model to alterations in tissue material properties were used to obtain refined values of five key material parameters. The relaxation of the force in the three bath concentrations was exponential in form, expressed as mean compressive force loss of 48.7, 55.0, and 140 N, respectively, with time constants of 1.73, 2.78, and 3.40 h. This behavior was analytically well represented by a model having poroelastic and osmotic tissue properties with published tissue properties adjusted by multiplying factors between 0.55 and 2.6. Force relaxation and time constants from the analytical simulations were most sensitive to values of fixed charge density and endplate porosity.

  2. 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...

  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. Charge-regularized swelling kinetics of polyelectrolyte gels: Elasticity and diffusion

    Science.gov (United States)

    Sen, Swati; Kundagrami, Arindam

    2017-11-01

    We apply a recently developed method [S. Sen and A. Kundagrami, J. Chem. Phys. 143, 224904 (2015)], using a phenomenological expression of osmotic stress, as a function of polymer and charge densities, hydrophobicity, and network elasticity for the swelling of spherical polyelectrolyte (PE) gels with fixed and variable charges in a salt-free solvent. This expression of stress is used in the equation of motion of swelling kinetics of spherical PE gels to numerically calculate the spatial profiles for the polymer and free ion densities at different time steps and the time evolution of the size of the gel. We compare the profiles of the same variables obtained from the classical linear theory of elasticity and quantitatively estimate the bulk modulus of the PE gel. Further, we obtain an analytical expression of the elastic modulus from the linearized expression of stress (in the small deformation limit). We find that the estimated bulk modulus of the PE gel decreases with the increase of its effective charge for a fixed degree of deformation during swelling. Finally, we match the gel-front locations with the experimental data, taken from the measurements of charged reversible addition-fragmentation chain transfer gels to show an increase in gel-size with charge and also match the same for PNIPAM (uncharged) and imidazolium-based (charged) minigels, which specifically confirms the decrease of the gel modulus value with the increase of the charge. The agreement between experimental and theoretical results confirms general diffusive behaviour for swelling of PE gels with a decreasing bulk modulus with increasing degree of ionization (charge). The new formalism captures large deformations as well with a significant variation of charge content of the gel. It is found that PE gels with large deformation but same initial size swell faster with a higher charge.

  5. 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...

  6. 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

  7. Plasma osmotic changes during major abdominal surgery.

    Science.gov (United States)

    Malone, R A; McLeavey, C A; Arens, J F

    1977-12-01

    Fluid balance across the capillary membrane is maintained normally by a balance of hydrostatic and colloid osmotic pressures (COP). In 12 patients having major intra-abdominal procedures, the COP was followed during the operative and immediate postoperative periods. The patients' intraoperative fluid management consisted of replacing shed blood with blood and following Shires' concept of crystalloid replacement. Significant decreases in COP to approximately two thirds of the initial value occurred in patients having intra-abdominal procedures versus only a 10 percent decrease in those having peripheral procedures (greater than .001). As a result of this decrease in COP, the balance between hydrostatic and colloid osmotic pressures is lost and risk of pulmonary intersitial edema is increased.

  8. A REVIEW ON OSMOTIC DRUG DELIVERY SYSTEM

    OpenAIRE

    Harnish Patel; Upendra Patel; Hiren Kadikar; Bhavin Bhimani; Dhiren Daslaniya; Ghanshyam Patel

    2012-01-01

    Conventional oral drug delivery systems supply an instantaneous release of drug, which cannot control the release of the drug and effective concentration at the target site. This kind of dosing pattern may result in constantly changing, unpredictable plasma concentrations. Drugs can be delivered in a controlled pattern over a long period of time by the process of osmosis. Osmotic devices are the most promising strategy based systems for controlled drug delivery. They are the most reliable con...

  9. Hydrothermal Carbonization of Spent Osmotic Solution (SOS Generated from Osmotic Dehydration of Blueberries

    Directory of Open Access Journals (Sweden)

    Kaushlendra Singh

    2014-09-01

    Full Text Available Hydrothermal carbonization of spent osmotic solution (SOS, a waste generated from osmotic dehydration of fruits, has the potential of transformation into hydrochars, a value-added product, while reducing cost and overall greenhouse gas emissions associated with waste disposal. Osmotic solution (OS and spent osmotic solution (SOS generated from the osmotic dehydration of blueberries were compared for their thermo-chemical decomposition behavior and hydrothermal carbonization. OS and SOS samples were characterized for total solids, elemental composition, and thermo-gravimetric analysis (TGA. In addition, hydrothermal carbonization was performed at 250 °C and for 30 min to produce hydrochars. The hydrochars were characterized for elemental composition, Brunauer-Emmett-Teller (BET surface area, particle shape and surface morphology. TGA results show that the SOS sample loses more weight in the lower temperature range than the OS sample. Both samples produced, approximately, 40%–42% (wet-feed basis hydrochar during hydrothermal carbonization but with different properties. The OS sample produced hydrochar, which had spherical particles of 1.79 ± 1.30 μm diameter with a very smooth surface. In contrast, the SOS sample produced hydrochar with no definite particle shape but with a raspberry-like surface.

  10. Osmotic and Heat Stress Effects on Segmentation.

    Directory of Open Access Journals (Sweden)

    Julian Weiss

    Full Text Available During vertebrate embryonic development, early skin, muscle, and bone progenitor populations organize into segments known as somites. Defects in this conserved process of segmentation lead to skeletal and muscular deformities, such as congenital scoliosis, a curvature of the spine caused by vertebral defects. Environmental stresses such as hypoxia or heat shock produce segmentation defects, and significantly increase the penetrance and severity of vertebral defects in genetically susceptible individuals. Here we show that a brief exposure to a high osmolarity solution causes reproducible segmentation defects in developing zebrafish (Danio rerio embryos. Both osmotic shock and heat shock produce border defects in a dose-dependent manner, with an increase in both frequency and severity of defects. We also show that osmotic treatment has a delayed effect on somite development, similar to that observed in heat shocked embryos. Our results establish osmotic shock as an alternate experimental model for stress, affecting segmentation in a manner comparable to other known environmental stressors. The similar effects of these two distinct environmental stressors support a model in which a variety of cellular stresses act through a related response pathway that leads to disturbances in the segmentation process.

  11. Electro-osmotic flows inside triangular microchannels

    International Nuclear Information System (INIS)

    Vocale, P; Spiga, M; Geri, M; Morini, G L

    2014-01-01

    This work presents a numerical investigation of both pure electro-osmotic and combined electro-osmotic/pressure-driven flows inside triangular microchannels. A finite element analysis has been adopted to solve the governing equations for the electric potential and the velocity field, accounting for a finite thickness of the electric double layer. The influence of non-dimensional parameters such as the aspect ratio of the cross-section, the electrokinetic diameter and the ratio of the pressure force to the electric force on the flow behavior has been investigated. Numerical results point out that the velocity field is significantly influenced by the aspect ratio of the cross section and the electrokinetic diameter. More specifically, the aspect ratio plays an important role in determining the maximum volumetric flow rate, while the electrokinetic diameter is crucial to establishing the range of pressures that may be sustained by the electro-osmotic flow. Numerical results are also compared with two correlations available in the literature which enable to assess the volumetric flow rate and the pressure head for microchannels featuring a rectangular, a trapezoidal or an elliptical cross-section.

  12. Do osmotic forces play a role in renin secretion?

    DEFF Research Database (Denmark)

    Skøtt, O

    1988-01-01

    Secretory granules swell during exocytosis. Swelling may follow fusion and assist in extrusion of the granular content, or swelling may cause granular fusion with the plasmalemma. A granular proton gradient has been suggested to be involved in such preexocytic granular swelling. Exocytosis of ren...

  13. 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.

  14. Simplified modeling of HM behavior of swelling clays for nuclear waste disposal buffers

    International Nuclear Information System (INIS)

    Hoxha, Dashnor; Belayachi, Naima; Do, Duc-Phi; Poutrel, Adrien; Wendling, Jacques

    2010-01-01

    Document available in extended abstract form only. The swelling clays are extensively studied these last decades in relation with many industrial applications: foundations in civil engineering, sealing of waste disposals., etc. Especially in the case of waste disposals buffers the swelling pressure and its kinetics are of great importance. In the research programme of ANDRA (French National Radioactive Waste Management Agency), a mixing of bentonite MX80 with 30% of sands has been chosen as a buffering material. The modelling of behaviour of this material has been object of several works and several sophisticated models have been proposed. However as the practice of nuclear waste disposals proves, the needs for robust and simple models, able to describe the most important features of buffers, are yet to be meet by engineers and researches. This paper aims at a simplified model for the buffers behaviour based upon an extension of previous works and laboratory results. As discussed and proposed by many authors modeling of swelling clays behavior needs to consider both crystalline and osmotic swelling. While molecular dynamics could be used to understand the relation between the structure of clay minerals and its swelling properties a multiscale approach counting for chemical and hydro-mechanical couplings in various scale is revealed to give insights on the mechanisms governing clayey soil swelling. However in many industrial application large scale problems would be considered for which macroscopic and robust models should be used. From macroscopic point of view, basically two alternative approaches are used: effective stress approach and so called independent stress state variables. For an isotropic material, the volumetric strain of unsaturated media predicted by BBM model, could be written as a function of: the mean stress of applied mechanical stress, the air pressure, the suction (or pore pressure where the media is fully saturated), the drained bulk

  15. 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.

  16. 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

  17. 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

  18. PEG-induced osmotic stress in Mentha x piperita L.: Structural features and metabolic responses.

    Science.gov (United States)

    Búfalo, Jennifer; Rodrigues, Tatiane Maria; de Almeida, Luiz Fernando Rolim; Tozin, Luiz Ricardo Dos Santos; Marques, Marcia Ortiz Mayo; Boaro, Carmen Silvia Fernandes

    2016-08-01

    The present study investigated whether osmotic stress induced by the exposure of peppermint (Mentha x piperita L.) to moderate and severe stress for short periods of time changes the plant's physiological parameters, leaf anatomy and ultrastructure and essential oil. Plants were exposed to two levels of polyethyleneglycol (50 g L(-1) and 100 g L(-1) of PEG) in a hydroponic experiment. The plants exposed to 50 g L(-1) maintained metabolic functions similar to those of the control group (0 g L(-1)) without changes in gas exchange or structural characteristics. The increase in antioxidant enzyme activity reduced the presence of free radicals and protected membranes, including chloroplasts and mitochondria. In contrast, the osmotic stress caused by 100 g L(-1) of PEG inhibited leaf gas exchange, reduced the essential oil content and changed the oil composition, including a decrease in menthone and an increase in menthofuran. These plants also showed an increase in peroxidase activity, but this increase was not sufficient to decrease the lipid peroxidation level responsible for damaging the membranes of organelles. Morphological changes were correlated with the evaluated physiological features: plants exposed to 100 g L(-1) of PEG showed areas with collapsed cells, increases in mesophyll thickness and the area of the intercellular space, cuticle shrinkage, morphological changes in plastids, and lysis of mitochondria. In summary, our results revealed that PEG-induced osmotic stress in M. x piperita depends on the intensity level of the osmotic stress applied; severe osmotic stress changed the structural characteristics, caused damage at the cellular level, and reduced the essential oil content and quality. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  19. 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)

  20. 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.

  1. 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

  2. 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.)

  3. Enhanced monoclonal antibody production by gradual increase of osmotic pressure

    OpenAIRE

    Lin, Jianqiang; Takagi, Mutsumi; Qu, Yinbo; Gao, Peiji; Yoshida, Toshiomi

    1999-01-01

    The time length required for the adaptation of AFP-27 hybridoma cells to high osmotic pressure and the effect of a gradual increase of osmotic pressure on monoclonal antibody production were investigated. When the cells were subjected to an increase of osmotic pressure from 300 mOsmol kg-1 to 366 mOsmol kg- 1, the intracellular content of osmoprotective free amino acids reached a maximum level 6 h after the osmotic pressure was increased to 366 mOsmol kg-1. The same time period of 6 h incubat...

  4. RBC deformability and amino acid concentrations after hypo-osmotic challenge may reflect chronic cell hydration status in healthy young men

    Science.gov (United States)

    Stookey, Jodi D; Klein, Alexis; Hamer, Janice; Chi, Christine; Higa, Annie; Ng, Vivian; Arieff, Allen; Kuypers, Frans A; Larkin, Sandra; Perrier, Erica; Lang, Florian

    2013-01-01

    Biomarkers of chronic cell hydration status are needed to determine whether chronic hyperosmotic stress increases chronic disease risk in population-representative samples. In vitro, cells adapt to chronic hyperosmotic stress by upregulating protein breakdown to counter the osmotic gradient with higher intracellular amino acid concentrations. If cells are subsequently exposed to hypo-osmotic conditions, the adaptation results in excess cell swelling and/or efflux of free amino acids. This study explored whether increased red blood cell (RBC) swelling and/or plasma or urine amino acid concentrations after hypo-osmotic challenge might be informative about relative chronic hyperosmotic stress in free-living men. Five healthy men (20–25 years) with baseline total water intake below 2 L/day participated in an 8-week clinical study: four 2-week periods in a U-shaped A-B-C-A design. Intake of drinking water was increased by +0.8 ± 0.3 L/day in period 2, and +1.5 ± 0.3 L/day in period 3, and returned to baseline intake (0.4 ± 0.2 L/day) in period 4. Each week, fasting blood and urine were collected after a 750 mL bolus of drinking water, following overnight water restriction. The periods of higher water intake were associated with significant decreases in RBC deformability (index of cell swelling), plasma histidine, urine arginine, and urine glutamic acid. After 4 weeks of higher water intake, four out of five participants had ½ maximal RBC deformability below 400 mmol/kg; plasma histidine below 100 μmol/L; and/or undetectable urine arginine and urine glutamic acid concentrations. Work is warranted to pursue RBC deformability and amino acid concentrations after hypo-osmotic challenge as possible biomarkers of chronic cell hydration. PMID:24303184

  5. A Simple Student Laboratory on Osmotic Flow, Osmotic Pressure, and the Reflection Coefficient.

    Science.gov (United States)

    Feher, Joseph J.; Ford, George D.

    1995-01-01

    Describes a laboratory exercise containing a practical series of experiments that novice students can perform within two hours. The exercise provides a confirmation of van't Hoff's law while placing more emphasis on osmotic flow than pressure. Students can determine parameters such as the reflection coefficient which stress the interaction of both…

  6. Oscillatory phase separation in giant lipid vesicles induced by transmembrane osmotic differentials

    Science.gov (United States)

    Oglęcka, Kamila; Rangamani, Padmini; Liedberg, Bo; Kraut, Rachel S; Parikh, Atul N

    2014-01-01

    Giant lipid vesicles are closed compartments consisting of semi-permeable shells, which isolate femto- to pico-liter quantities of aqueous core from the bulk. Although water permeates readily across vesicular walls, passive permeation of solutes is hindered. In this study, we show that, when subject to a hypotonic bath, giant vesicles consisting of phase separating lipid mixtures undergo osmotic relaxation exhibiting damped oscillations in phase behavior, which is synchronized with swell–burst lytic cycles: in the swelled state, osmotic pressure and elevated membrane tension due to the influx of water promote domain formation. During bursting, solute leakage through transient pores relaxes the pressure and tension, replacing the domain texture by a uniform one. This isothermal phase transition—resulting from a well-coordinated sequence of mechanochemical events—suggests a complex emergent behavior allowing synthetic vesicles produced from simple components, namely, water, osmolytes, and lipids to sense and regulate their micro-environment. DOI: http://dx.doi.org/10.7554/eLife.03695.001 PMID:25318069

  7. The plant cuticle is required for osmotic stress regulation of abscisic acid biosynthesis and osmotic stress tolerance in Arabidopsis

    KAUST Repository

    Wang, Zhenyu

    2011-05-01

    Osmotic stress activates the biosynthesis of abscisic acid (ABA). One major step in ABA biosynthesis is the carotenoid cleavage catalyzed by a 9-cis epoxycarotenoid dioxygenase (NCED). To understand the mechanism for osmotic stress activation of ABA biosynthesis, we screened for Arabidopsis thaliana mutants that failed to induce the NCED3 genee xpression in response to osmotic stress treatments. The ced1 (for 9-cis epoxycarotenoid dioxy genase defective 1) mutant isolated in this study showed markedly reduced expression of NCED3 in response to osmotic stress (polyethylene glycol)treatments compared with the wild type. Other ABA biosynthesis genes are also greatly reduced in ced1 under osmotic stress. ced1 mutant plants are very sensitive to even mild osmotic stress. Map-based cloning revealed unexpectedly thatCED1 encodes a putative a/b hydrolase domain-containing protein and is allelic to the BODYGUARD gene that was recently shown to be essential for cuticle biogenesis. Further studies discovered that other cut in biosynthesis mutants are also impaired in osmotic stress induction of ABA biosynthesis genes and are sensitive to osmotic stress. Our work demonstrates that the cuticle functions not merely as a physical barrier to minimize water loss but also mediates osmotic stress signaling and tolerance by regulating ABA biosynthesis and signaling. © 2011 American Society of Plant Biologists. All rights reserved.

  8. 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.

  9. 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 ...

  10. [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.

  11. 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.

  12. 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

  13. Osmotic stress on nitrification in an airlift bioreactor

    International Nuclear Information System (INIS)

    Jin Rencun; Zheng Ping; Mahmood, Qaisar; Hu Baolan

    2007-01-01

    The effect of osmotic pressure on nitrification was studied in a lab-scale internal-loop airlift-nitrifying reactor. The reactor slowly adapted to the escalating osmotic pressure during 270 days operation. The conditions were reversed to the initial stage upon full inhibition of the process. Keeping influent ammonium concentration constant at 420 mg N L -1 and hydraulic retention time at 20.7 h, with gradual increase in osmotic pressure from 4.3 to 18.8 x 10 5 Pa by adding sodium sulphate, the ammonium removal efficiencies of the nitrifying bioreactor were maintained at 93-100%. Further increase in osmotic pressure up to 19.2 x 10 5 Pa resulted in drop of the ammonium conversion to 69.2%. The osmotic pressure caused abrupt inhibition of nitrification without any alarm and the critical osmotic pressure value causing inhibition remained between 18.8 and 19.2 x 10 5 Pa. Nitrite oxidizers were found more sensitive to osmotic stress as compared with ammonia oxidizers, leading to nitrite accumulation up to 61.7% in the reactor. The performance of bioreactor recovered gradually upon lowering the osmotic pressure. Scanning and transmission electron microscopy indicated that osmotic stress resulted in simplification of the nitrifying bacterial populations in the activated sludge as the cellular size reduced; the inner membrane became thinner and some unknown inclusions appeared within the cells. The microbial morphology and cellular structure restored upon relieving the osmotic pressure. Addition of potassium relieved the effect of osmotic pressure upon nitrification. Results demonstrate that the nitrifying reactor possesses the potential to treat ammonium-rich brines after acclimatization

  14. Osmotic stress alters chromatin condensation and nucleocytoplasmic transport

    Energy Technology Data Exchange (ETDEWEB)

    Finan, John D.; Leddy, Holly A. [Department of Orthopaedic Surgery, Duke University Medical Center, Durham, NC (United States); Department of Biomedical Engineering, Duke University, Durham, NC (United States); Guilak, Farshid, E-mail: guilak@duke.edu [Department of Orthopaedic Surgery, Duke University Medical Center, Durham, NC (United States); Department of Biomedical Engineering, Duke University, Durham, NC (United States)

    2011-05-06

    Highlights: {yields} The rate of nucleocytoplasmic transport increases under hyper-osmotic stress. {yields} The mechanism is a change in nuclear geometry, not a change in permeability of the nuclear envelope. {yields} Intracytoplasmic but not intranuclear diffusion is sensitive to osmotic stress. {yields} Pores in the chromatin of the nucleus enlarge under hyper-osmotic stress. -- Abstract: Osmotic stress is a potent regulator of biological function in many cell types, but its mechanism of action is only partially understood. In this study, we examined whether changes in extracellular osmolality can alter chromatin condensation and the rate of nucleocytoplasmic transport, as potential mechanisms by which osmotic stress can act. Transport of 10 kDa dextran was measured both within and between the nucleus and the cytoplasm using two different photobleaching methods. A mathematical model was developed to describe fluorescence recovery via nucleocytoplasmic transport. As osmolality increased, the diffusion coefficient of dextran decreased in the cytoplasm, but not the nucleus. Hyper-osmotic stress decreased nuclear size and increased nuclear lacunarity, indicating that while the nucleus was getting smaller, the pores and channels interdigitating the chromatin had expanded. The rate of nucleocytoplasmic transport was increased under hyper-osmotic stress but was insensitive to hypo-osmotic stress, consistent with the nonlinear osmotic properties of the nucleus. The mechanism of this osmotic sensitivity appears to be a change in the size and geometry of the nucleus, resulting in a shorter effective diffusion distance for the nucleus. These results may explain physical mechanisms by which osmotic stress can influence intracellular signaling pathways that rely on nucleocytoplasmic transport.

  15. 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.

  16. Novel regulation of aquaporins during osmotic stress.

    Science.gov (United States)

    Vera-Estrella, Rosario; Barkla, Bronwyn J; Bohnert, Hans J; Pantoja, Omar

    2004-08-01

    Aquaporin protein regulation and redistribution in response to osmotic stress was investigated. Ice plant (Mesembryanthemum crystallinum) McTIP1;2 (McMIPF) mediated water flux when expressed in Xenopus leavis oocytes. Mannitol-induced water imbalance resulted in increased protein amounts in tonoplast fractions and a shift in protein distribution to other membrane fractions, suggesting aquaporin relocalization. Indirect immunofluorescence labeling also supports a change in membrane distribution for McTIP1;2 and the appearance of a unique compartment where McTIP1;2 is expressed. Mannitol-induced redistribution of McTIP1;2 was arrested by pretreatment with brefeldin A, wortmannin, and cytochalasin D, inhibitors of vesicle trafficking-related processes. Evidence suggests a role for glycosylation and involvement of a cAMP-dependent signaling pathway in McTIP1;2 redistribution. McTIP1;2 redistribution to endosomal compartments may be part of a homeostatic process to restore and maintain cellular osmolarity under osmotic-stress conditions.

  17. Osmotic properties of sulfobutylether and hydroxypropyl cyclodextrins.

    Science.gov (United States)

    Zannou, E A; Streng, W H; Stella, V J

    2001-08-01

    The purpose of this study was to determine the osmolality of sulfobutylether (SBE) and hydroxypropyl (HP) derivatives of cyclodextrins (CDs) via vapor pressure osmometry (VPO) and freezing point depression (FPD). (SBE) and HP-CDs are efficient excipients capable of solubilizing and stabilizing poorly water-soluble drugs in parenteral formulations. (SBE)-CDs have also been used as solubility enhancers and osmotic agents for the sustained release of poorly water-soluble drugs from osmotic pump tablets. The knowledge of the CD's osmolality in solution or inside such tablets would allow one to further characterize the release mechanisms. Experiments were conducted at 37 degrees C with eight types of HP and (SBE)-CDs. The aqueous solutions ranged from 0.005-0.350 mol(-1). Methods were developed to allow the measurement of high osmolalities using a vapor pressure osmometer or a differential scanning calorimeter. The osmolality calculations from the VPO and FPD measurements correlated well. The osmolality of (SBE)-CDs was significantly higher than the osmolality of HP-CDs and increased with the total degree of substitution (TDS). All CDs showed deviations from ideality at high concentrations. Empirical correlations of osmolality with concentration and TDS allowed the prediction of osmolality over a wide concentration range. This study also gave some useful insights into the behavior of CD derivatives in solution.

  18. Approximate Mathematical Modeling of Osmotic Dehydration of Cone-Shaped Fruits and Vegetables in Hypertonic Solutions

    OpenAIRE

    Mohammad Sirousazar

    2017-01-01

    Water loss kinetics in osmotic dehydration of cone-shaped fruits and vegetables was modeled on the basis of diffusion mechanism, using the Fick’s second law. The model was developed by taking into account the influences of the fruit geometrical characteristics, initial water content of fruit, water diffusion coefficient in fruit, and the water concentration in hypertonic solution. Based on the obtained model, it was shown that the water diffusion coefficient and the initial water concentratio...

  19. Sugar beet molasses: Properties and applications in osmotic dehydration of fruits and vegetables

    Directory of Open Access Journals (Sweden)

    Šarić Ljubiša Ć.

    2016-01-01

    Full Text Available Molasses is an important by-product of sugar beet or sugar cane refining industry and it was one of the first sweeteners used in human nutrition. Sugar cane molasses has unique characteristics that can make it suitable for application in food industry, especially in confectionery and bakery products. On the other hand, sugar beet molasses has not had greater application in the human diet, primarily because of its strong smell and taste of the beet, which makes it unattractive for consumption. Since recent investigations showed that sugar beet molasses can be used as a hypertonic solution in osmotic dehydration of different materials of plant and animal origin, the objective of this work was to review recently studied sugar beet molasses in terms of its applications in osmotic dehydrations of fruits and vegetables. Previous studies showed that sugar beet molasses is an excellent medium for osmotic dehydration of fruits and vegetables (apple, carrot, plum, etc. primarily due to a high content of dry matter (80%, w/w and specific nutrient content. An important advantage of using sugar beet molasses as a hypertonic solution is an enrichment of the dehydrated material in minerals and vitamins, which penetrate from molasses into the plant tissue. Concentration of sugar beet molasses solution and immersion time had the biggest influence on the process of osmotic dehydration of fruit and vegetables, while the temperature of the solution was the least influential parameter. The effect of immersion time on the kinetics of osmotic dehydration in sugar beet molasses increases with an increase in concentration of hypertonic solution. Fruit and vegetables dehydrated in sugar beet molasses had a higher dry matter content compared to samples treated in sucrose solutions. Besides, application of sugar beet molasses in osmotic dehydration of fruits and vegetables had some other advantages such as lower cost of molasses compared to sugar and its liquid aggregate

  20. The effects of exogenous proline and osmotic stress on morpho ...

    African Journals Online (AJOL)

    USER

    2010-06-21

    Jun 21, 2010 ... For evaluation of growth parameters of strawberry callus under osmotic stress and exogenous proline, embryonic calli were transferred to Murashige and Skoog (MS) medium containing four sucrose. (osmotic stress) treatments including 3, 6, 9 and 12% and various concentrations of exogenous L- proline ...

  1. The effects of exogenous proline and osmotic stress on morpho ...

    African Journals Online (AJOL)

    For evaluation of growth parameters of strawberry callus under osmotic stress and exogenous proline, embryonic calli were transferred to Murashige and Skoog (MS) medium containing four sucrose (osmotic stress) treatments including 3, 6, 9 and 12% and various concentrations of exogenous Lproline (0, 2.5, 5 and 10 ...

  2. Osmotic Power: A Fresh Look at an Old Experiment

    Science.gov (United States)

    Dugdale, Pam

    2014-01-01

    Electricity from osmotic pressure might seem a far-fetched idea but this article describes a prototype in Norway where the osmotic pressure generated between salt and fresh water drives a turbine. This idea was applied in a student investigation, where they were tasked with researching which alternative materials could be used for the…

  3. 21 CFR 864.6600 - Osmotic fragility test.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Osmotic fragility test. 864.6600 Section 864.6600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Manual Hematology Devices § 864.6600 Osmotic fragility...

  4. Improved Erythrocyte Osmotic Fragility and Packed Cell Volume ...

    African Journals Online (AJOL)

    Improved Erythrocyte Osmotic Fragility and Packed Cell Volume following administration of Aloe barbadensis Juice Extract in Rats. ... Abstract. Aloe barbadensis is a popular house plant that has a long history of a multipurpose folk remedy. ... Keywords: osmotic fragility, packed cell volume, haemoglobin, Aloe vera ...

  5. 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.

  6. 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.

  7. 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.

  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. Xylem diameter changes during osmotic stress, desiccation and freezing in Pinus sylvestris and Populus tremula.

    Science.gov (United States)

    Lintunen, Anna; Lindfors, Lauri; Nikinmaa, Eero; Hölttä, Teemu

    2017-04-01

    Trees experience low apoplastic water potential frequently in most environments. Low apoplastic water potential increases the risk of embolism formation in xylem conduits and creates dehydration stress for the living cells. We studied the magnitude and rate of xylem diameter change in response to decreasing apoplastic water potential and the role of living parenchyma cells in it to better understand xylem diameter changes in different environmental conditions. We compared responses of control and heat-injured xylem of Pinus sylvestris (L.) and Populus tremula (L.) branches to decreasing apoplastic water potential created by osmotic stress, desiccation and freezing. It was shown that xylem in control branches shrank more in response to decreasing apoplastic water potential in comparison with the samples that were preheated to damage living xylem parenchyma. By manipulating the osmotic pressure of the xylem sap, we observed xylem shrinkage due to decreasing apoplastic water potential even in the absence of water tension within the conduits. These results indicate that decreasing apoplastic water potential led to withdrawal of intracellular water from the xylem parenchyma, causing tissue shrinkage. The amount of xylem shrinkage per decrease in apoplastic water potential was higher during osmotic stress or desiccation compared with freezing. During desiccation, xylem diameter shrinkage involved both dehydration-related shrinkage of xylem parenchyma and water tension-induced shrinkage of conduits, whereas dehydration-related shrinkage of xylem parenchyma was accompanied by swelling of apoplastic ice during freezing. It was also shown that the exchange of water between symplast and apoplast within xylem is clearly faster than previously reported between the phloem and the xylem. Time constant of xylem shrinkage was 40 and 2 times higher during osmotic stress than during freezing stress in P. sylvestris and P. tremula, respectively. Finally, it was concluded that the

  10. Osmotic mechanism of the loop extrusion process

    Science.gov (United States)

    Yamamoto, Tetsuya; Schiessel, Helmut

    2017-09-01

    The loop extrusion theory assumes that protein factors, such as cohesin rings, act as molecular motors that extrude chromatin loops. However, recent single molecule experiments have shown that cohesin does not show motor activity. To predict the physical mechanism involved in loop extrusion, we here theoretically analyze the dynamics of cohesin rings on a loop, where a cohesin loader is in the middle and unloaders at the ends. Cohesin monomers bind to the loader rather frequently and cohesin dimers bind to this site only occasionally. Our theory predicts that a cohesin dimer extrudes loops by the osmotic pressure of cohesin monomers on the chromatin fiber between the two connected rings. With this mechanism, the frequency of the interactions between chromatin segments depends on the loading and unloading rates of dimers at the corresponding sites.

  11. 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.

  12. Toward an injectable continuous osmotic glucose sensor.

    Science.gov (United States)

    Johannessen, Erik; Krushinitskaya, Olga; Sokolov, Andrey; Philipp, Häfliger; Hoogerwerf, Arno; Hinderling, Christian; Kautio, Kari; Lenkkeri, Jaakko; Strömmer, Esko; Kondratyev, Vasily; Tønnessen, Tor Inge; Mollnes, Tom Eirik; Jakobsen, Henrik; Zimmer, Even; Akselsen, Bengt

    2010-07-01

    The growing pandemic of diabetes mellitus places a stringent social and economic burden on the society. A tight glycemic control circumvents the detrimental effects, but the prerogative is the development of new more effective tools capable of longterm tracking of blood glucose (BG) in vivo. Such discontinuous sensor technologies will benefit from an unprecedented marked potential as well as reducing the current life expectancy gap of eight years as part of a therapeutic regime. A sensor technology based on osmotic pressure incorporates a reversible competitive affinity assay performing glucose-specific recognition. An absolute change in particles generates a pressure that is proportional to the glucose concentration. An integrated pressure transducer and components developed from the silicon micro- and nanofabrication industry translate this pressure into BG data. An in vitro model based on a 3.6 x 8.7 mm large pill-shaped implant is equipped with a nanoporous membrane holding 4-6 nm large pores. The affinity assay offers a dynamic range of 36-720 mg/dl with a resolution of +/-16 mg/dl. An integrated 1 x 1 mm(2) large control chip samples the sensor signals for data processing and transmission back to the reader at a total power consumption of 76 microW. Current studies have demonstrated the design, layout, and performance of a prototype osmotic sensor in vitro using an affinity assay solution for up to four weeks. The small physical size conforms to an injectable device, forming the basis of a conceptual monitor that offers a tight glycemic control of BG. 2010 Diabetes Technology Society.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. Recognition-Mediated Hydrogel Swelling Controlled by Interaction with a Negative Thermoresponsive LCST Polymer.

    Science.gov (United States)

    Belal, Khaled; Stoffelbach, François; Lyskawa, Joël; Fumagalli, Matthieu; Hourdet, Dominique; Marcellan, Alba; Smet, Lieselot De; de la Rosa, Victor R; Cooke, Graeme; Hoogenboom, Richard; Woisel, Patrice

    2016-11-02

    Most polymeric thermoresponsive hydrogels contract upon heating beyond the lower critical solution temperature (LCST) of the polymers used. Herein, we report a supramolecular hydrogel system that shows the opposite temperature dependence. When the non-thermosesponsive hydrogel NaphtGel, containing dialkoxynaphthalene guest molecules, becomes complexed with the tetra cationic macrocyclic host CBPQT 4+ , swelling occurred as a result of host-guest complex formation leading to charge repulsion between the host units, as well as an osmotic contribution of chloride counter-ions embedded in the network. The immersion of NaphtGel in a solution of poly(N-isopropylacrylamide) with tetrathiafulvalene (TTF) end groups complexed with CBPQT 4+ induced positive thermoresponsive behaviour. The LCST-induced dethreading of the polymer-based pseudorotaxane upon heating led to transfer of the CBPQT 4+ host and a concomitant swelling of NaphtGel. Subsequent cooling led to reformation of the TTF-based host-guest complexes in solution and contraction of the hydrogel. © 2016 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  18. Approximate Mathematical Modeling of Osmotic Dehydration of Cone-Shaped Fruits and Vegetables in Hypertonic Solutions

    Directory of Open Access Journals (Sweden)

    Mohammad Sirousazar

    2017-07-01

    Full Text Available Water loss kinetics in osmotic dehydration of cone-shaped fruits and vegetables was modeled on the basis of diffusion mechanism, using the Fick’s second law. The model was developed by taking into account the influences of the fruit geometrical characteristics, initial water content of fruit, water diffusion coefficient in fruit, and the water concentration in hypertonic solution. Based on the obtained model, it was shown that the water diffusion coefficient and the initial water concentration of fruit have direct effects on the dehydration rate and also inverse influence on the dehydration duration. The geometrical parameters of fruit and water concentration in hypertonic solution showed direct effect on the dehydration duration as well as inverse effect on the dehydration rate. The presented model seems to be useful tool to predict the dehydration kinetics of cone-shaped fruit during osmotic dehydration process and to optimize the process prior to perform the experiments.

  19. Osmotic Edema Rapidly Increases Neuronal Excitability Through Activation of NMDA Receptor-Dependent Slow Inward Currents in Juvenile and Adult Hippocampus

    Directory of Open Access Journals (Sweden)

    Kelli Lauderdale

    2015-09-01

    Full Text Available Cellular edema (cell swelling is a principal component of numerous brain disorders including ischemia, cortical spreading depression, hyponatremia, and epilepsy. Cellular edema increases seizure-like activity in vitro and in vivo, largely through nonsynaptic mechanisms attributable to reduction of the extracellular space. However, the types of excitability changes occurring in individual neurons during the acute phase of cell volume increase remain unclear. Using whole-cell patch clamp techniques, we report that one of the first effects of osmotic edema on excitability of CA1 pyramidal cells is the generation of slow inward currents (SICs, which initiate after approximately 1 min. Frequency of SICs increased as osmolarity decreased in a dose-dependent manner. Imaging of real-time volume changes in astrocytes revealed that neuronal SICs occurred while astrocytes were still in the process of swelling. SICs evoked by cell swelling were mainly nonsynaptic in origin and NMDA receptor-dependent. To better understand the relationship between SICs and changes in neuronal excitability, recordings were performed in increasingly physiological conditions. In the absence of any added pharmacological reagents or imposed voltage clamp, osmotic edema induced excitatory postsynaptic potentials and burst firing over the same timecourse as SICs. Like SICs, action potentials were blocked by NMDAR antagonists. Effects were more pronounced in adult (8–20 weeks old compared with juvenile (P15–P21 mice. Together, our results indicate that cell swelling triggered by reduced osmolarity rapidly increases neuronal excitability through activation of NMDA receptors. Our findings have important implications for understanding nonsynaptic mechanisms of epilepsy in relation to cell swelling and reduction of the extracellular space.

  20. Salt Effect on Osmotic Pressure of Polyelectrolyte Solutions: Simulation Study

    Directory of Open Access Journals (Sweden)

    Jan-Michael Y. Carrillo

    2014-07-01

    Full Text Available Abstract: We present results of the hybrid Monte Carlo/molecular dynamics simulations of the osmotic pressure of salt solutions of polyelectrolytes. In our simulations, we used a coarse-grained representation of polyelectrolyte chains, counterions and salt ions. During simulation runs, we alternate Monte Carlo and molecular dynamics simulation steps. Monte Carlo steps were used to perform small ion exchange between simulation box containing salt ions (salt reservoir and simulation box with polyelectrolyte chains, counterions and salt ions (polyelectrolyte solution. This allowed us to model Donnan equilibrium and partitioning of salt and counterions across membrane impermeable to polyelectrolyte chains. Our simulations have shown that the main contribution to the system osmotic pressure is due to salt ions and osmotically active counterions. The fraction of the condensed (osmotically inactive counterions first increases with decreases in the solution ionic strength then it saturates. The reduced value of the system osmotic coefficient is a universal function of the ratio of the concentration of osmotically active counterions and salt concentration in salt reservoir. Simulation results are in a very good agreement with osmotic pressure measurements in sodium polystyrene sulfonate, DNA, polyacrylic acid, sodium polyanetholesulfonic acid, polyvinylbenzoic acid, and polydiallyldimethylammonium chloride solutions.

  1. 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.

  2. 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

  3. 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

  4. Transformation of oats and its application to improving osmotic stress tolerance.

    Science.gov (United States)

    Maqbool, Shahina B; Zhong, Heng; Oraby, Hesham F; Sticklen, Mariam B

    2009-01-01

    Oat (Avena sativa L.), a worldwide temperate cereal crop, is deficient in tolerance to osmotic stress due to drought and/or salinity. To genetically transform the available commercial oat cultivars, a genotype-independent and efficient regeneration system from shoot apical meristems was developed using four oat cultivars: Prairie, Porter, Ogle, and Pacer. All these oat cultivars generated a genotype-independent in vitro differentiated multiple shoots from shoot apical meristems at a high frequency. Using this system, three oat cultivars were genetically co-transformed with pBY520 (containing hva1 and bar) and pAct1-D (containing gus) using biolistic trade mark bombardment. Transgenic plants were selected and regenerated using herbicide resistance and GUS as a marker. Molecular and biochemical analyses of putative transgenic plants confirmed the co-integration of hva1 and bar genes with a frequency of 100%, and 61.6% of the transgenic plants carried all three genes (hva1, bar and gus). Further analyses of R0, R1, and R2 progenies confirmed stable integration, expression, and Mendalian inheritance for all transgenes. Histochemical analysis of GUS protein in transgenic plants showed a high level of GUS expression in vascular tissues and in the pollen grains of mature flowers. Immunochemical analysis of transgenic plants indicated a constitutive expression of hva1 at all developmental stages. However, the level of HVA1 was higher during the early seedling stages. The characteristic of HVA1 expression for osmotic tolerance in transgenic oat progeny was analyzed in vitro as well as in vivo. Transgenic plants exhibited significantly (Pplants. The symptoms of wilting or death of leaves as observed in 80% of non-transgenic plants due to osmotic stress was delayed and detected only in less than 10% of trans-genic plants. These observations confirmed the characteristic of HVA1 protein as providing or enhancing the osmotic tolerance in transgenic plants against salinity and

  5. 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.

  6. 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.

  7. Self-assembly of silk fibroin under osmotic stress

    Science.gov (United States)

    Sohn, Sungkyun

    The supramolecular self-assembly behavior of silk fibroin was investigated using osmotic stress technique. In Chapter 2, a ternary phase diagram of water-silk-LiBr was constructed based on X-ray results on the osmotically stressed regenerated silk fibroin of Bombyx mori silkworm. Microscopic data indicated that silk I is a hydrated structure and a rough estimate of the number of water molecules lost by the structure upon converting from silk I to silk II has been made, and found to be about 2.2 per [GAGAGS] hexapeptide. In Chapter 3, wet-spinning of osmotically stressed, regenerated silk fibroin was performed, based on the prediction that the enhanced control over structure and phase behavior using osmotic stress method helps improve the physical properties of wet-spun regenerated silk fibroin fibers. The osmotic stress was applied in order to pre-structure the regenerated silk fibroin molecule from its original random coil state to more oriented state, manipulating the phase of the silk solution in the phase diagram before the start of spinning. Monofilament fiber with a diameter of 20 microm was produced. In Chapter 4, we investigated if there is a noticeable synergistic osmotic pressure increase between co-existing polymeric osmolyte and salt when extremely highly concentrated salt molecules are present both at sample subphase and stressing subphase, as is the case of silk fibroin self-assembly. The equilibration method that measures osmotic pressure relative to a reference with known osmotic pressure was introduced. Osmotic pressure of aqueous LiBr solution up to 2.75M was measured and it was found that the synergistic effect was insignificant up to this salt concentration. Solution parameters of stressing solutions and Arrhenius kinetics based on time-temperature relationship for the equilibration process were derived as well. In Chapter 5, self-assembly behavior of natural silk fibroin within the gland of Bombyx mori silkworm was investigated using osmotic

  8. Mechanism of actuation in conducting polymers: Osmotic expansion

    DEFF Research Database (Denmark)

    Bay, Lasse; Jacobsen, Torben; West, Keld

    2001-01-01

    Conducting polymers expand or contract when their redox state is changed. This expansion/contraction effect can be separated in an intrinsic part because of changes of the polymer backbone on reduction/oxidation and a part depending on the surrounding electrolyte phase, because of osmotic expansion...... is compared with measurements on PPy(DBS) films. The experiments show that the expansion decreases as the electrolyte concentration is increased. This means that a considerable part of the total expansion is due to the osmotic effect. The osmotic effect should be taken into account when interpreting...

  9. Effects of osmotic stress on the activity of MAPKs and PDGFR-beta-mediated signal transduction in NIH-3T3 fibroblasts

    DEFF Research Database (Denmark)

    Nielsen, M-B; Christensen, Søren Tvorup; Hoffmann, E K

    2008-01-01

    Signaling in cell proliferation, cell migration, and apoptosis is highly affected by osmotic stress and changes in cell volume, although the mechanisms underlying the significance of cell volume as a signal in cell growth and death are poorly understood. In this study, we used NIH-3T3 fibroblasts...... in a serum- and nutrient-free inorganic medium (300 mosM) to analyze the effects of osmotic stress on MAPK activity and PDGF receptor (PDGFR)-beta-mediated signal transduction. We found that hypoosmolarity (cell swelling at 211 mosM) induced the phosphorylation and nuclear translocation of ERK1/2, most...... likely via a pathway independent of PDGFR-beta and MEK1/2. Conversely, hyperosmolarity (cell shrinkage at 582 mosM) moved nuclear and phosphorylated ERK1/2 to the cytoplasm and induced the phosphorylation and nuclear translocation of p38 and phosphorylation of JNK1/2. In a series of parallel experiments...

  10. 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 ...

  11. Osmotically-driven membrane processes for water reuse and energy recovery

    Science.gov (United States)

    Achilli, Andrea

    the lack of suitable membranes and membrane modules. In this investigation, for the first time, the use of a custom-made laboratory-scale membrane module enabled the collection of experimental PRO data. Results obtained with a flat-sheet cellulose triacetate FO membrane and NaCl feed and draw solutions closely matched model predictions. Power density was substantially reduced due to internal concentration polarization in the asymmetric membrane and, to a lesser degree, to salt passage. External concentration polarization was found to exhibit a relatively small effect on reducing the osmotic pressure driving force. Using the predictive PRO model, optimal membrane characteristics and module configuration can be determined in order to design a system specifically tailored for PRO processes.

  12. 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.)

  13. 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.

  14. 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.

  15. '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...

  16. 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

  17. 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)

  18. 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.

  19. 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.

  20. 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

  1. 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)

  2. Efficiency of Osmotic Dehydration of Apples in Polyols Solutions

    Directory of Open Access Journals (Sweden)

    Joanna Cichowska

    2018-02-01

    Full Text Available The present study aimed to evaluate the influence of selected compounds from the polyol group, as well as other saccharides, on the osmotic dehydration process of apples. The following alternative solutions were examined: erythritol, xylitol, maltitol, inulin and oligofructose. Efficiency of the osmotic dehydration process was evaluated based on the kinetics of the process, and through comparison of the results obtained during the application of a sucrose solution. This innovative research utilizes alternative solutions in osmotic pretreatment, which until now, have not been commonly used in fruit processing by researchers worldwide. Results indicate that erythritol and xylitol show stronger or similar efficiency to sucrose; however, the use of inulin, as well as oligofructose, was not satisfactory due to the insufficient, small osmotic driving forces of the process, and the low values of mass transfer parameters.

  3. Efficiency of Osmotic Dehydration of Apples in Polyols Solutions.

    Science.gov (United States)

    Cichowska, Joanna; Żubernik, Joanna; Czyżewski, Jakub; Kowalska, Hanna; Witrowa-Rajchert, Dorota

    2018-02-17

    The present study aimed to evaluate the influence of selected compounds from the polyol group, as well as other saccharides, on the osmotic dehydration process of apples. The following alternative solutions were examined: erythritol, xylitol, maltitol, inulin and oligofructose. Efficiency of the osmotic dehydration process was evaluated based on the kinetics of the process, and through comparison of the results obtained during the application of a sucrose solution. This innovative research utilizes alternative solutions in osmotic pretreatment, which until now, have not been commonly used in fruit processing by researchers worldwide. Results indicate that erythritol and xylitol show stronger or similar efficiency to sucrose; however, the use of inulin, as well as oligofructose, was not satisfactory due to the insufficient, small osmotic driving forces of the process, and the low values of mass transfer parameters.

  4. Method of osmotic energy harvesting using responsive compounds and molecules

    KAUST Repository

    Hu, Xiao; Cai, Yufeng; Lai, Zhiping; Zhong, Yujiang

    2017-01-01

    The present invention discloses and claims a more efficient and economical method and system for osmotic energy production and capture using responsive compounds and molecules. The present invention is an energy harvest system enabled by stimuli

  5. Plant response to sunflower seeds to osmotic conditioning

    Directory of Open Access Journals (Sweden)

    Camila Santos Barros de Morais

    2014-10-01

    Full Text Available The aim of this study was to evaluate the effect of seeds osmotic conditioning in seedlings emergence and plants performance of sunflower. Three lots of seeds sunflower (Catissol, was submited to osmotic conditioning with polyethylene glycol solution, –2,0 MPa in aerated system, under 15 ºC for 8 hour and then was evaluated for germination tests and vigour. Under filed conditions was conducted emergency evaluations of seedling, plants development as well as the productivity and seeds quality, and the accumulation of nutrients in the seeds. The osmotic conditioning improve the survival of seedling, the dry matter mass to aerial part of plants from 60 days after sowing and oil content, in lots with low seeds physiological quality. The osmotic conditioning not increase the seeds yield but promotes the vigour of seeds produced, regardless of the lot used for sowing seeds.

  6. A physiological evaluation of the enhanced osmotic stress tolerance ...

    African Journals Online (AJOL)

    ELO

    2012-01-05

    Jan 5, 2012 ... SR3 and Jinan 177 were hydroponically subjected to osmotic stress, the accumulation of proline .... hydroponically in half strength Hoagland's solution for three weeks ..... ascrobate specific peroxidase in spinach chloroplasts.

  7. Method of osmotic energy harvesting using responsive compounds and molecules

    KAUST Repository

    Hu, Xiao

    2017-07-27

    The present invention discloses and claims a more efficient and economical method and system for osmotic energy production and capture using responsive compounds and molecules. The present invention is an energy harvest system enabled by stimuli responsive draw solutions that are competent in terms of energy production, geographic location flexibility, and the affordable, efficient and economical production and delivery of osmotic power. Specifically, the present invention is a novel osmotic power system that uses stimuli responsive draw solutions, economically feasible larger permeable membranes, and low grade heat sources to deliver osmotic power more efficiently and economically with less negative environmental impact, greater power output, and located in more geographically diverse areas of the world than previously thought possible for supporting such a power source.

  8. Experimental Support for a Predictive Osmotic Model of Clay Membranes

    International Nuclear Information System (INIS)

    Fritz, S.J.

    2001-01-01

    Osmosis has been cited as a mechanism for explaining anomalously high fluid pressures in the subsurface. Clays and shales act as membranes, and osmotic flux across these units may result in pressures sufficiently high to explain these anomalies. The theoretical osmotic pressures as calculated solely from solution properties can be quite large; however, it is not yet resolved whether these geologic membranes are sufficiently ideal to generate such pressures

  9. Osmotic and stimulant laxatives for the management of childhood constipation

    OpenAIRE

    Gordon, Morris; Macdonald, John; Parker, Claire; Akobeng, Anthony; Thomas, Adrian

    2016-01-01

    Background\\ud \\ud Constipation within childhood is an extremely common problem. Despite the widespread use of osmotic and stimulant laxatives by health professionals to manage constipation in children, there has been a long standing paucity of high quality evidence to support this practice.\\ud \\ud \\ud Objectives\\ud \\ud We set out to evaluate the efficacy and safety of osmotic and stimulant laxatives used to treat functional childhood constipation.\\ud \\ud \\ud Search methods\\ud \\ud We searched ...

  10. 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

  11. Controlling Release of Integral Lipid Nanoparticles Based on Osmotic Pump Technology.

    Science.gov (United States)

    Tian, Zhiqiang; Yu, Qin; Xie, Yunchang; Li, Fengqian; Lu, Yi; Dong, Xiaochun; Zhao, Weili; Qi, Jianping; Wu, Wei

    2016-08-01

    To achieve controlled release of integral nanoparticles by the osmotic pump strategy using nanostructured lipid carriers (NLCs) as model nanoparticles. NLCs was prepared by a hot-homogenization method, transformed into powder by lyophilization, and formulated into osmotic pump tablets (OPTs). Release of integral NLCs was visualized by live imaging after labeling with a water-quenching fluorescent probe. Effects of formulation variables on in vitro release characteristics were evaluated by measuring the model drug fenofibrate. Pharmacokinetics were studied in beagle dogs using the core tablet and a micronized fenofibrate formulation as references. NLCs are released through the release orifices of the OPTs as integral nanoparticles. Near zero-order kinetics can be achieved by optimizing the influencing variables. After oral administration, decreased C max and steady drug levels for as long as over 24 h are observed. NLC-OPTs show an oral bioavailability of the model drug fenofibrate similar to that of the core tablets, which is about 1.75 folds that of a fast-release formulation. Controlled release of integral NLCs is achieved by the osmotic pump strategy.

  12. Osmotic pressure in a bacterial swarm.

    Science.gov (United States)

    Ping, Liyan; Wu, Yilin; Hosu, Basarab G; Tang, Jay X; Berg, Howard C

    2014-08-19

    Using Escherichia coli as a model organism, we studied how water is recruited by a bacterial swarm. A previous analysis of trajectories of small air bubbles revealed a stream of fluid flowing in a clockwise direction ahead of the swarm. A companion study suggested that water moves out of the agar into the swarm in a narrow region centered ∼ 30 μm from the leading edge of the swarm and then back into the agar (at a smaller rate) in a region centered ∼ 120 μm back from the leading edge. Presumably, these flows are driven by changes in osmolarity. Here, we utilized green/red fluorescent liposomes as reporters of osmolarity to verify this hypothesis. The stream of fluid that flows in front of the swarm contains osmolytes. Two distinct regions are observed inside the swarm near its leading edge: an outer high-osmolarity band (∼ 30 mOsm higher than the agar baseline) and an inner low-osmolarity band (isotonic or slightly hypotonic to the agar baseline). This profile supports the fluid-flow model derived from the drift of air bubbles and provides new (to our knowledge) insights into water maintenance in bacterial swarms. High osmotic pressure at the leading edge of the swarm extracts water from the underlying agar and promotes motility. The osmolyte is of high molecular weight and probably is lipopolysaccharide. Copyright © 2014 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  13. 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)

  14. 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.

  15. 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.

  16. 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).

  17. 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.)

  18. Osmotic dehydration of fruits and vegetables: a review.

    Science.gov (United States)

    Yadav, Ashok Kumar; Singh, Satya Vir

    2014-09-01

    The main cause of perishability of fruits and vegetables are their high water content. To increase the shelf life of these fruits and vegetables many methods or combination of methods had been tried. Osmotic dehydration is one of the best and suitable method to increase the shelf life of fruits and vegetables. This process is preferred over others due to their vitamin and minerals, color, flavor and taste retention property. In this review different methods, treatments, optimization and effects of osmotic dehydration have been reviewed. Studied showed that combination of different osmotic agents were more effective than sucrose alone due to combination of properties of solutes. During the experiments it was found that optimum osmosis was found at approximately 40 °C, 40 °B of osmotic agent and in near about 132 min. Pretreatments also leads to increase the osmotic process in fruits and vegetables. Mass transfer kinetics study is an important parameter to study osmosis. Solids diffusivity were found in wide range (5.09-32.77 kl/mol) studied by Fick's laws of diffusion. These values vary depending upon types of fruits and vegetables and osmotic agents.

  19. Mass transfer kinetics during osmotic dehydration of pomegranate arils.

    Science.gov (United States)

    Mundada, Manoj; Hathan, Bahadur Singh; Maske, Swati

    2011-01-01

    The mass transfer kinetics during osmotic dehydration of pomegranate arils in osmotic solution of sucrose was studied to increase palatability and shelf life of arils. The freezing of the whole pomegranate at -18 °C was carried out prior to osmotic dehydration to increase the permeability of the outer cellular layer of the arils. The osmotic solution concentrations used were 40, 50, 60°Bx, osmotic solution temperatures were 35, 45, 55 °C. The fruit to solution ratio was kept 1:4 (w/w) during all the experiments and the process duration varied from 0 to 240 min. Azuara model and Peleg model were the best fitted as compared to other models for water loss and solute gain of pomegranate arils, respectively. Generalized Exponential Model had an excellent fit for water loss ratio and solute gain ratio of pomegranate arils. Effective moisture diffusivity of water as well as solute was estimated using the analytical solution of Fick's law of diffusion. For above conditions of osmotic dehydration, average effective diffusivity of water loss and solute gain varied from 2.718 × 10(-10) to 5.124 × 10(-10) m(2)/s and 1.471 × 10(-10) to 5.147 × 10(-10) m(2)/s, respectively. The final product was successfully utilized in some nutritional formulations such as ice cream and bakery products.

  20. PHOTOMETRIC EVIDENCE FOR THE OSMOTIC BEHAVIOR OF RAT LIVER MICROSOMES

    Science.gov (United States)

    Tedeschi, Henry; James, Joseph M.; Anthony, William

    1963-01-01

    Electron microscope observations are consistent with the interpretation that the elements of the endoplasmic reticulum are osmotically active in situ as well as after isolation. More recently, it has been reported that microsomal suspensions equilibrate almost completely with added C14-sucrose and that no osmotic behavior is evident from photometric data. These findings were considered at variance with the electron microscope data. However, equilibration with added label simply attests to a relatively high permeability, and, in addition, the photometric data need not be critical. Osmotic volume changes, measured photometrically, may be masked by concomitant events (e.g., changes in the refractive index of the test solutions at varying osmotic pressures, breakdown of the particles, and agglutination). For these reasons the photometric experiments were repeated. In this work, the reciprocal of optical density of microsomal suspensions was found to vary linearly with the reciprocal of concentration of the medium at constant refractive index. These changes probably correspond to osmotic volume changes, since the effect was found to be (a) independent of substance used and (b) osmotically reversible. The transmission of the suspension was found to vary with the refractive index of the medium, the concentration of particles, and the wavelength of incident light, according to relationships that are similar to or identical with those obtained for mitochondrial suspensions. PMID:14064105

  1. 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+).

  2. Flow cytometric osmotic fragility test and eosin-5'-maleimide dye-binding tests are better than conventional osmotic fragility tests for the diagnosis of hereditary spherocytosis.

    Science.gov (United States)

    Arora, R D; Dass, J; Maydeo, S; Arya, V; Radhakrishnan, N; Sachdeva, A; Kotwal, J; Bhargava, M

    2018-03-24

    Hereditary spherocytosis (HS) is the most common inherited hemolytic anemia with heterogeneous clinico-laboratory manifestations. We evaluated the flow-cytometric tests: eosin-5'-maleimide (EMA) and flow-cytometric osmotic fragility test (FOFT) and the conventional osmotic fragility tests (OFT) for the diagnosis of hereditary spherocytosis (HS). One hundred two suspected HS patients underwent EMA, FOFT, incubated OFT (IOFT), and room temperature OFT (RT-OFT). In addition, 10 cases of immune hemolytic anemia (IHA) were included, and performance of the above 4 tests was evaluated. For EMA and FOFT, 5 normal controls were assessed together with the patients and cutoffs were calculated using receiver-operator-characteristics curve (ROC) analysis. The best cutoff for %EMA decrease was 12.5%, and for FOFT, %residual red cells (%RRC) was 25.6%. The sensitivity and specificity of RT-OFT was 62.06% and 86.3%, respectively, while that of IOFT was 79.31% and 87.67%, respectively. Both flow cytometric tests performed better. Sensitivity and specificity of EMA was 86.2% and 93.9% respectively, and that of FOFT was 96.6% and 98.63%, respectively. The combination of the FOFT with IOFT or EMA dye-binding test yields a sensitivity of 100%, but with EMA, it had a higher specificity. Hb/MCHC was a predictor of the severity of the disease while %EMA decrease and %RRC did not correlate with severity of the disease. Flow-cytometric osmotic fragility test is the best possible single test followed by EMA for diagnosis of HS. A combination of FOFT and EMA can correctly diagnose 100% patients. These tests are likely to replace conventional OFTs in future. © 2018 John Wiley & Sons Ltd.

  3. 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.))

  4. Osmotic Compounds Enhance Antibiotic Efficacy against Acinetobacter baumannii Biofilm Communities.

    Science.gov (United States)

    Falghoush, Azeza; Beyenal, Haluk; Besser, Thomas E; Omsland, Anders; Call, Douglas R

    2017-10-01

    Biofilm-associated infections are a clinical challenge, in part because a hydrated matrix protects the bacterial community from antibiotics. Herein, we evaluated how different osmotic compounds (maltodextrin, sucrose, and polyethylene glycol [PEG]) enhance antibiotic efficacy against Acinetobacter baumannii biofilm communities. Established (24-h) test tube biofilms (strain ATCC 17978) were treated with osmotic compounds in the presence or absence of 10× the MIC of different antibiotics (50 μg/ml tobramycin, 20 μg/ml ciprofloxacin, 300 μg/ml chloramphenicol, 30 μg/ml nalidixic acid, or 100 μg/ml erythromycin). Combining antibiotics with hypertonic concentrations of the osmotic compounds for 24 h reduced the number of biofilm bacteria by 5 to 7 log ( P baumannii strains were similarly treated with 400-Da PEG and tobramycin, resulting in a mean 2.7-log reduction in recoverable bacteria compared with tobramycin treatment alone. Multivariate regression models with data from different osmotic compounds and nine antibiotics demonstrated that the benefit from combining hypertonic treatments with antibiotics is a function of antibiotic mass and lipophilicity ( r 2 > 0.82; P baumannii and Escherichia coli K-12. Augmenting topical antibiotic therapies with a low-mass hypertonic treatment may enhance the efficacy of antibiotics against wound biofilms, particularly when using low-mass hydrophilic antibiotics. IMPORTANCE Biofilms form a barrier that protects bacteria from environmental insults, including exposure to antibiotics. We demonstrated that multiple osmotic compounds can enhance antibiotic efficacy against Acinetobacter baumannii biofilm communities, but viscosity is a limiting factor, and the most effective compounds have lower molecular mass. The synergism between osmotic compounds and antibiotics is also dependent on the hydrophobicity and mass of the antibiotics. The statistical models presented herein provide a basis for predicting the optimal combination of

  5. 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.

  6. 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)

  7. 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.)

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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.

  13. Structure and osmotic pressure of ionic microgel dispersions

    Energy Technology Data Exchange (ETDEWEB)

    Hedrick, Mary M. [Department of Physics, North Dakota State University, Fargo, North Dakota 58108-6050 (United States); Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108-6050 (United States); Chung, Jun Kyung; Denton, Alan R., E-mail: alan.denton@ndsu.edu [Department of Physics, North Dakota State University, Fargo, North Dakota 58108-6050 (United States)

    2015-01-21

    We investigate structural and thermodynamic properties of aqueous dispersions of ionic microgels—soft colloidal gel particles that exhibit unusual phase behavior. Starting from a coarse-grained model of microgel macroions as charged spheres that are permeable to microions, we perform simulations and theoretical calculations using two complementary implementations of Poisson-Boltzmann (PB) theory. Within a one-component model, based on a linear-screening approximation for effective electrostatic pair interactions, we perform molecular dynamics simulations to compute macroion-macroion radial distribution functions, static structure factors, and macroion contributions to the osmotic pressure. For the same model, using a variational approximation for the free energy, we compute both macroion and microion contributions to the osmotic pressure. Within a spherical cell model, which neglects macroion correlations, we solve the nonlinear PB equation to compute microion distributions and osmotic pressures. By comparing the one-component and cell model implementations of PB theory, we demonstrate that the linear-screening approximation is valid for moderately charged microgels. By further comparing cell model predictions with simulation data for osmotic pressure, we chart the cell model’s limits in predicting osmotic pressures of salty dispersions.

  14. Drying and osmotic conditioning in Hancornia speciosa Gomes seeds

    Directory of Open Access Journals (Sweden)

    Tathiana Elisa Masetto

    Full Text Available Hancornia speciosa is a native tree species of the Brazilian Cerrado whose seeds are desiccation sensitive. In this study, we aimed to evaluate drying and osmotic conditioning in H. speciosa seeds. We used fresh seeds with 48% moisture content, which were slowly dried until they attained contents of 20%, 15%, 10% and 5%. To evaluate osmotic conditioning, the seeds were imbibed in 12 mL osmotic solutions at 0.0; -0.2; -0.4 and -0.6 MPa for two days. After that, they were dehydrated until their original moisture content. The experiments were carried out in a completely randomized design with four repetitions with 50 seeds each. Reduction in moisture content from 20% to 5% decreased the physiological potential of seeds. H. speciosa seeds do not require osmotic priming with PEG solutions, because imbibition of seeds in osmotic solutions of up to -0.6 MPa results in reduction of germination rate and seedling length.

  15. Quantification of osmotic water transport in vivo using fluorescent albumin.

    Science.gov (United States)

    Morelle, Johann; Sow, Amadou; Vertommen, Didier; Jamar, François; Rippe, Bengt; Devuyst, Olivier

    2014-10-15

    Osmotic water transport across the peritoneal membrane is applied during peritoneal dialysis to remove the excess water accumulated in patients with end-stage renal disease. The discovery of aquaporin water channels and the generation of transgenic animals have stressed the need for novel and accurate methods to unravel molecular mechanisms of water permeability in vivo. Here, we describe the use of fluorescently labeled albumin as a reliable indicator of osmotic water transport across the peritoneal membrane in a well-established mouse model of peritoneal dialysis. After detailed evaluation of intraperitoneal tracer mass kinetics, the technique was validated against direct volumetry, considered as the gold standard. The pH-insensitive dye Alexa Fluor 555-albumin was applied to quantify osmotic water transport across the mouse peritoneal membrane resulting from modulating dialysate osmolality and genetic silencing of the water channel aquaporin-1 (AQP1). Quantification of osmotic water transport using Alexa Fluor 555-albumin closely correlated with direct volumetry and with estimations based on radioiodinated ((125)I) serum albumin (RISA). The low intraperitoneal pressure probably accounts for the negligible disappearance of the tracer from the peritoneal cavity in this model. Taken together, these data demonstrate the appropriateness of pH-insensitive Alexa Fluor 555-albumin as a practical and reliable intraperitoneal volume tracer to quantify osmotic water transport in vivo. Copyright © 2014 the American Physiological Society.

  16. Structure and osmotic pressure of ionic microgel dispersions

    International Nuclear Information System (INIS)

    Hedrick, Mary M.; Chung, Jun Kyung; Denton, Alan R.

    2015-01-01

    We investigate structural and thermodynamic properties of aqueous dispersions of ionic microgels—soft colloidal gel particles that exhibit unusual phase behavior. Starting from a coarse-grained model of microgel macroions as charged spheres that are permeable to microions, we perform simulations and theoretical calculations using two complementary implementations of Poisson-Boltzmann (PB) theory. Within a one-component model, based on a linear-screening approximation for effective electrostatic pair interactions, we perform molecular dynamics simulations to compute macroion-macroion radial distribution functions, static structure factors, and macroion contributions to the osmotic pressure. For the same model, using a variational approximation for the free energy, we compute both macroion and microion contributions to the osmotic pressure. Within a spherical cell model, which neglects macroion correlations, we solve the nonlinear PB equation to compute microion distributions and osmotic pressures. By comparing the one-component and cell model implementations of PB theory, we demonstrate that the linear-screening approximation is valid for moderately charged microgels. By further comparing cell model predictions with simulation data for osmotic pressure, we chart the cell model’s limits in predicting osmotic pressures of salty dispersions

  17. Influence of high energy electron irradiation and gamma irradiation on the osmotic resistance of human erythrocyte membranes

    International Nuclear Information System (INIS)

    Catana, D.; Hategan, Alina; Moraru, Rodica; Popescu, Alina; Morariu, V. V.

    1998-01-01

    The effects of 5 MeV electrons and of gamma irradiation at 0 deg. C on the osmotic fragility of human erythrocyte membranes are presented. Both electron and gamma radiation in the range 0-400 Gy induced no hemolysis indicating that the membrane modifications due to radiation interaction do not reach a critical point as to cause swelling of the cells and subsequent lysis. The osmotic stress experiments performed after irradiation showed that the gamma irradiated erythrocytes exhibited an almost similar sigmoidal behavior for all irradiation doses, whereas the electron irradiated samples showed a much larger increase in hemolysis degree and, in the case of a given electron dose (100 Gy), the hemolysis was found much smaller than for the control sample (a similar behavior of the erythrocytes was found in the case of microwave irradiation at temperatures under 0 deg. C). Our experimental data suggest that electron radiation and gamma radiation have different impacts on the erythrocyte membrane fluidity, involving, probably, the different rate of energy deposition in the samples and the direct interaction of electrons with the erythrocyte membranes. (authors)

  18. On the swelling behavior of cationic exchange resins saturated with Na+ ions in a C3S paste

    International Nuclear Information System (INIS)

    Lafond, E.; Cau Dit Coumes, C.; Chartier, D.; Gauffinet, S.; Le Bescop, P.; Stefan, L.

    2015-01-01

    Ion exchange resins (IERs) are widely used in the nuclear industry to decontaminate radioactive effluents. Spent resins are usually encapsulated in cementitious materials. However, the solidified waste form can exhibit strong expansion, possibly leading to cracking, if the appropriate binder is not used. In this work, the interactions between cationic resins in the Na + form and tricalcium silicate are investigated during the early stages of hydration in order to gain a better understanding of the expansion process. It is shown that the IERs exhibit a transient swelling of small magnitude due to the decrease in the osmotic pressure of the external solution. This expansion, which occurs just after setting, is sufficient to damage the material which is poorly consolidated for several reasons: low degree of hydration, precipitation of poorly cohesive sodium-bearing C-S-H, and very heterogeneous microstructure with zones of high porosity. (authors)

  19. 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

  20. Roles of phospholipase A2 isoforms in swelling- and melittin-induced arachidonic acid release and taurine efflux in NIH3T3 fibroblasts

    DEFF Research Database (Denmark)

    Pedersen, Stine Helene Falsig; Poulsen, Kristian Arild; Lambert, Ian H.

    2006-01-01

    Osmotic swelling of NIH3T3 mouse fibroblasts activates a bromoenol lactone (BEL)-sensitive taurine efflux, pointing to the involvement of a Ca2+-independent phospholipase A2 (iPLA2) (Lambert IH. J Membr Biol 192: 19-32, 2003). We report that taurine efflux from NIH3T3 cells was not only increased...... by cell swelling but also decreased by cell shrinkage. Arachidonic acid release to the cell exterior was similarly decreased by shrinkage yet not detectably increased by swelling. NIH3T3 cells were found to express cytosolic calcium-dependent cPLA2-IVA, cPLA2-IVB, cPLA2-IVC, iPLA2-VIA, iPLA2-VIB......, and secretory sPLA2-V. Arachidonic acid release from swollen cells was partially inhibited by BEL and by the sPLA2-inhibitor manoalide. Cell swelling elicited BEL-sensitive arachidonic acid release from the nucleus, to which iPLA2-VIA localized. Exposure to the bee venom peptide melittin, to increase PLA2...

  1. Detection of osmotic damages in GRP boat hulls

    Science.gov (United States)

    Krstulović-Opara, L.; Domazet, Ž.; Garafulić, E.

    2013-09-01

    Infrared thermography as a tool of non-destructive testing is method enabling visualization and estimation of structural anomalies and differences in structure's topography. In presented paper problem of osmotic damage in submerged glass reinforced polymer structures is addressed. The osmotic damage can be detected by a simple humidity gauging, but for proper evaluation and estimation testing methods are restricted and hardly applicable. In this paper it is demonstrated that infrared thermography, based on estimation of heat wave propagation, can be used. Three methods are addressed; Pulsed thermography, Fast Fourier Transform and Continuous Morlet Wavelet. An additional image processing based on gradient approach is applied on all addressed methods. It is shown that the Continuous Morlet Wavelet is the most appropriate method for detection of osmotic damage.

  2. Osmotic stress tolerance in semi-terrestrial tardigrades

    DEFF Research Database (Denmark)

    Heidemann, Nanna W T; Smith, Daniel K.; Hygum, Thomas L.

    2016-01-01

    Little is known about ionic and osmotic stress tolerance in tardigrades. Here, we examine salt stress tolerance in Ramazzottius oberhaeuseri and Echiniscus testudo from Nivå (Denmark) and address whether limno-terrestrial tardigrades can enter a state of quiescence (osmobiosis) in the face of high......-ionic osmolytes as compared to NaCl. Ramazzottius oberhaeuseri furthermore readily regained activity following gradual increases in non-ionic osmolytes and NaCl of up to 2434 ± 28 and 1905 ± 3 mOsm kg−1, respectively, showing that short-term acclimation promoted salt stress tolerance. Our results suggest...... that the limno-terrestrial R. oberhaeuseri enters a state of quiescence in the face of high external osmotic pressure and that it, in this state, is highly tolerant of ionic and osmotic stress....

  3. Solute Transfer in Osmotic Dehydration of Vegetable Foods: A Review.

    Science.gov (United States)

    Muñiz-Becerá, Sahylin; Méndez-Lagunas, Lilia L; Rodríguez-Ramírez, Juan

    2017-10-01

    While various mechanisms have been proposed for the water transfer during osmotic dehydration (OD), little progress has been made to understand the mechanisms of solute transfer during osmotic dehydration. The transfer of solutes has been often described only by the diffusion mechanism; however, numerous evidences suggest the participation of a variety of mechanisms. This review deals with the main issues of solute transfer in the OD of vegetables. In this context, several studies suggest that during OD of fruits and vegetables, the migration of solutes is not influenced by diffusion. Thus, new theories that may explain the solute transport are analyzed, considering the influence of the plant microstructure and its interaction with the physicochemical properties of osmotic liquid media. In particular, the surface adhesion phenomenon is analyzed and discussed, as a possible mechanism present during the transfer of solutes in OD. © 2017 Institute of Food Technologists®.

  4. Studies of Protein Solution Properties Using Osmotic Pressure Measurements

    Science.gov (United States)

    Agena, S.; Bogle, David; Pusey, Marc; Agena, S.

    1998-01-01

    Examination of the protein crystallization process involves investigation of the liquid and solid state and a protein's properties in these states. Liquid state studies such as protein self association in solution by light scattering methods or other methods have been used to examine a protein Is properties and therefore its crystallization process and conditions. Likewise can osmotic pressure data be used to examine protein properties and various published osmotic pressure studies were examined by us to correlate osmotic pressure to protein solution properties. The solution behavior of serum albumin, alpha - chymotrypsin, beta - lactoglobulin and ovalbumin was examined over a range of temperatures, pH values and different salt types and concentrations. Using virial expansion and a local composition model the non ideal solution behavior in form of the activity coefficients (thermodynamic) was described for the systems. This protein activity coefficient data was related to a protein's solubility behavior and this process and the results will be presented.

  5. Folding propensity of intrinsically disordered proteins by osmotic stress

    International Nuclear Information System (INIS)

    Mansouri, Amanda L.; Grese, Laura N.; Rowe, Erica L.

    2016-01-01

    Proteins imparted with intrinsic disorder conduct a range of essential cellular functions. To better understand the folding and hydration properties of intrinsically disordered proteins (IDPs), we used osmotic stress to induce conformational changes in nuclear co-activator binding domain (NCBD) and activator for thyroid hormone and retinoid receptor (ACTR). Osmotic stress was applied by the addition of small and polymeric osmolytes, where we discovered that water contributions to NCBD folding always exceeded those for ACTR. Both NCBD and ACTR were found to gain a-helical structure with increasing osmotic stress, consistent with their folding upon NCBD/ACTR complex formation. Using small-angle neutron scattering (SANS), we further characterized NCBD structural changes with the osmolyte ethylene glycol. Here a large reduction in overall size initially occurred before substantial secondary structural change. In conclusion, by focusing on folding propensity, and linked hydration changes, we uncover new insights that may be important for how IDP folding contributes to binding.

  6. Recycling of osmotic solutions in microwave-osmotic dehydration: product quality and potential for creation of a novel product.

    Science.gov (United States)

    Wray, Derek; Ramaswamy, Hosahalli S

    2016-08-01

    Despite osmotic dehydration being a cost effective process for moisture removal, the cost implications of making, regenerating, and properly disposing of the spent osmotic solutions contributes greatly to the economic feasibility of the drying operation. The potential for recycling of osmotic solutions and their use for creation of a novel product was explored using microwave-osmotic dehydration under continuous flow spray (MWODS) conditions. Identical runs were repeated 10 times to determine the progressive physical and compositional effects of the thermal treatment and leaching from the cranberry samples. The microbiological stability and constant drying performance indicated that MWODS would be well suited for employing recycled solutions. While the anthocyanin content of the solution never approached that of cranberry juice concentrate, it is demonstrated that the spent syrup can infuse these health positive components into another product (apple). This study found that re-using osmotic solutions is a viable option to reduce cost in future MWODS applications, with no detriment to product quality and potential to use the spent solution for novel products. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  7. 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 ...

  8. 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.

  9. 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 ...

  10. 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 ...

  11. 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

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. The safety of osmotically acting cathartics in colonic cleansing

    DEFF Research Database (Denmark)

    Nyberg, Caroline; Hendel, J.; Nielsen, O.H.

    2010-01-01

    Efficient cleansing of the colon before a colonoscopy or a radiological examination is essential. The osmotically acting cathartics (those given the Anatomical Therapeutic Chemical code A06AD) currently used for this purpose comprise products based on three main substances: sodium phosphate...... hyperphosphatemia and irreversible kidney damage owing to acute phosphate nephropathy, have been reported after use of sodium-phosphate-based products. The aim of this Review is to provide an update on the potential safety issues related to the use of osmotically acting cathartics, especially disturbances of renal...

  17. Relation between lowered colloid osmotic pressure, respiratory failure, and death.

    Science.gov (United States)

    Tonnesen, A S; Gabel, J C; McLeavey, C A

    1977-01-01

    Plasma colloid osmotic pressure was measured each day in 84 intensive care unit patients. Probit analysis demonstrated a direct relationship between colloid osmotic pressure (COP) and survival. The COP associated with a 50% survival rate was 15.0 torr. COP was higher in survivors than in nonsurvivors without respiratory failure and in patients who recovered from respiratory failure. We conclude that lowered COP is associated with an elevated mortality rate. However, the relationship to death is not explained by the relationship to respiratory failure.

  18. 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.)

  19. 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

  20. 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)

  1. 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.)

  2. 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.

  3. 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)

  4. Dynamic swelling of tunable full-color block copolymer photonic gels via counterion exchange.

    Science.gov (United States)

    Lim, Ho Sun; Lee, Jae-Hwang; Walish, Joseph J; Thomas, Edwin L

    2012-10-23

    One-dimensionally periodic block copolymer photonic lamellar gels with full-color tunability as a result of a direct exchange of counteranions were fabricated via a two-step procedure comprising the self-assembly of a hydrophobic block-hydrophilic polyelectrolyte block copolymer, polystyrene-b-poly(2-vinyl pyridine) (PS-b-P2VP), followed by sequential quaternization of the P2VP layers in 1-bromoethane solution. Depending on the hydration characteristics of each counteranion, the selective swelling of the block copolymer lamellar structures leads to large tunability of the photonic stop band from blue to red wavelengths. More extensive quaternization of the P2VP block allows the photonic lamellar gels to swell more and red shift to longer wavelength. Here, we investigate the dynamic swelling behavior in the photonic gel films through time-resolved in situ measurement of UV-vis transmission. We model the swelling behavior using the transfer matrix method based on the experimentally observed reflectivity data with substitution of appropriate counterions. These tunable structural color materials may be attractive for numerous applications such as high-contrast displays without using a backlight, color filters, and optical mirrors for flexible lasing.

  5. A cellulose synthase-like protein is required for osmotic stress tolerance in Arabidopsis

    KAUST Repository

    Zhu, Jianhua; Lee, Byeongha; Dellinger, Michael T.; Cui, Xinping; Zhang, Changqing; Wu, Shang; Nothnagel, Eugene A.; Zhu, Jian-Kang

    2010-01-01

    Osmotic stress imposed by soil salinity and drought stress significantly affects plant growth and development, but osmotic stress sensing and tolerance mechanisms are not well understood. Forward genetic screens using a root-bending assay have

  6. Osmotically driven membrane process for the management of urban runoff in coastal regions

    KAUST Repository

    Li, Zhenyu; Valladares Linares, Rodrigo; Abu-Ghdaib, Muhannad; Zhan, Tong; Yangali-Quintanilla, Victor; Amy, Gary L.

    2014-01-01

    An osmotic detention pond was proposed for the management of urban runoff in coastal regions. Forward osmosis was employed as a bridge to utilize natural osmotic energy from seawater for concentrating and reusing urban runoff water, and as a barrier

  7. Alterations in the colonic microbiota in response to osmotic diarrhea.

    Science.gov (United States)

    Gorkiewicz, Gregor; Thallinger, Gerhard G; Trajanoski, Slave; Lackner, Stefan; Stocker, Gernot; Hinterleitner, Thomas; Gülly, Christian; Högenauer, Christoph

    2013-01-01

    Diseases of the human gastrointestinal (GI) tract are often accompanied by diarrhea with profound alterations in the GI microbiota termed dysbiosis. Whether dysbiosis is due to the disease itself or to the accompanying diarrhea remains elusive. With this study we characterized the net effects of osmotic diarrhea on the composition of the GI microbiota in the absence of disease. We induced osmotic diarrhea in four healthy adults by oral administration of polyethylene glycol 4000 (PEG). Stool as well as mucosa specimens were collected before, during and after diarrhea and 16S rDNA-based microbial community profiling was used to assess the microbial community structure. Stool and mucosal microbiotas were strikingly different, with Firmicutes dominating the mucosa and Bacteroidetes the stools. Osmotic diarrhea decreased phylotype richness and showed a strong tendency to equalize the otherwise individualized microbiotas on the mucosa. Moreover, diarrhea led to significant relative shifts in the phyla Bacteroidetes and Firmicutes and to a relative increase in the abundance of Proteobacteria on the mucosa, a phenomenon also noted in several inflammatory and diarrheal GI diseases. Changes in microbial community structure induced by osmotic diarrhea are profound and show similarities to changes observed in other GI diseases including IBD. These effects so must be considered when specimens from diarrheal diseases (i.e. obtained by stratification of samples according to diarrheal status) or conditions wherein bowel preparations like PEG (i.e. specimens obtained during endoscopy) are used.

  8. Alterations in the colonic microbiota in response to osmotic diarrhea.

    Directory of Open Access Journals (Sweden)

    Gregor Gorkiewicz

    Full Text Available BACKGROUND & AIMS: Diseases of the human gastrointestinal (GI tract are often accompanied by diarrhea with profound alterations in the GI microbiota termed dysbiosis. Whether dysbiosis is due to the disease itself or to the accompanying diarrhea remains elusive. With this study we characterized the net effects of osmotic diarrhea on the composition of the GI microbiota in the absence of disease. METHODS: We induced osmotic diarrhea in four healthy adults by oral administration of polyethylene glycol 4000 (PEG. Stool as well as mucosa specimens were collected before, during and after diarrhea and 16S rDNA-based microbial community profiling was used to assess the microbial community structure. RESULTS: Stool and mucosal microbiotas were strikingly different, with Firmicutes dominating the mucosa and Bacteroidetes the stools. Osmotic diarrhea decreased phylotype richness and showed a strong tendency to equalize the otherwise individualized microbiotas on the mucosa. Moreover, diarrhea led to significant relative shifts in the phyla Bacteroidetes and Firmicutes and to a relative increase in the abundance of Proteobacteria on the mucosa, a phenomenon also noted in several inflammatory and diarrheal GI diseases. CONCLUSIONS: Changes in microbial community structure induced by osmotic diarrhea are profound and show similarities to changes observed in other GI diseases including IBD. These effects so must be considered when specimens from diarrheal diseases (i.e. obtained by stratification of samples according to diarrheal status or conditions wherein bowel preparations like PEG (i.e. specimens obtained during endoscopy are used.

  9. Effect of road transport stress on Erthrocyte Osmotic Fragility (EOF ...

    African Journals Online (AJOL)

    After an overnight fast, venous blood was collected from each subject for the determination of serum cortisol, glucose concentration and erythrocyte osmotic fragility. The subjects were then transported at a speed of 65 – 75Km/h covering a distance of 180km. Thereafter venous blood was again collected (within 10 minutes) ...

  10. Compression and reswelling of microgel particles after an osmotic shock

    NARCIS (Netherlands)

    Sleeboom, J.F.; Voudouris, P.; Punter, M.T.J.J.M.; Aangenendt, F.J.; Florea, D.; van der Schoot, P.P.A.M.; Wyss, H.M.

    2016-01-01

    We use dedicated microfluidic devices to expose soft hydrogel particles to a rapid change in the externally applied osmotic pressure and observe a non-monotonic response: After an initial rapid compression the particle slowly reswells to approximately its original size. Using a simple

  11. Drying of carrots in slices with osmotic dehydration

    African Journals Online (AJOL)

    SAM

    2014-07-23

    Jul 23, 2014 ... extend the shelf-life by a few weeks, one year or more. The methods .... drated carrots, this work studied the drying of carrot with pre-osmotic ... e) Weight Loss - obtained directly using balance semi-analytical model BEL ...

  12. Modeling and computational simulation of the osmotic evaporation process

    Directory of Open Access Journals (Sweden)

    Freddy Forero Longas

    2016-09-01

    Conclusions: It was found that for the conditions studied the Knudsen diffusion model is most suitable to describe the transfer of water vapor through the hydrophobic membrane. Simulations developed adequately describe the process of osmotic evaporation, becoming a tool for faster economic development of this technology.

  13. Root water extraction under combined water and osmotic stress

    NARCIS (Netherlands)

    Jong van Lier, de Q.; Dam, van J.C.; Metselaar, K.

    2009-01-01

    Using a numerical implicit model for root water extraction by a single root in a symmetric radial flow problem, based on the Richards equation and the combined convection-dispersion equation, we investigated some aspects of the response of root water uptake to combined water and osmotic stress. The

  14. Osmotic pressure of ring polymer solutions : A Monte Carlo study

    NARCIS (Netherlands)

    Flikkema, Edwin; Brinke, Gerrit ten

    2000-01-01

    Using the wall theorem, the osmotic pressure of ring polymers in solution has been determined using an off-lattice topology conserving Monte Carlo algorithm. The ring polymers are modeled as freely-jointed chains with point-like beads, i.e., under conditions corresponding to θ-conditions for the

  15. Osmotic generation of 'anomalous' fluid pressures in geological environments

    Science.gov (United States)

    Neuzii, C.E.

    2000-01-01

    Osmotic pressures are generated by differences in chemical potential of a solution across a membrane. But whether osmosis can have a significant effect on the pressure of fluids in geological environments has been controversial, because the membrane properties of geological media are poorly understood. 'Anomalous' pressures - large departures from hydrostatic pressure that are not explicable in terms of topographic or fluid-density effects are widely found in geological settings, and are commonly considered to result from processes that alter the pore or fluid volume, which in turn implies crustal changes happening at a rate too slow to observe directly. Yet if osmosis can explain some anomalies, there is no need to invoke such dynamic geological processes in those cases. Here I report results of a nine- year in situ measurement of fluid pressures and solute concentrations in shale that are consistent with the generation of large (up to 20 MPa) osmotic-pressure anomalies which could persist for tens of millions of years. Osmotic pressures of this magnitude and duration can explain many of the pressure anomalies observed in geological settings. The require, however, small shale porosity and large contrasts in the amount of dissolved solids in the pore waters - criteria that may help to distinguish between osmotic and crystal-dynamic origins of anomalous pressures.

  16. An analysis of electro-osmotic and magnetohydrodynamic heat pipes

    International Nuclear Information System (INIS)

    Harrison, M.A.

    1988-01-01

    Mechanically simple methods of improving heat transport in heat pipes are investigated. These methods are electro-osmotic and magnetohydrodynamic augmentation. For the electro-osmotic case, a detailed electrokinetic model is used. The electrokinetic model used includes the effects of pore surface curvature and multiple ion diffusivities. The electrokinetic model is extended to approximate the effects of elevated temperature. When the electro-osmotic model is combined with a suitable heat-pipe model, it is found that the electro-osmotic pump should be a thin membrane. Arguments are provided that support the use of a volatile electrolyte. For the magnetohydrodynamic case, a brief investigation is provided. A quasi-one-dimensional hydromagnetic duct flow model is used. This hydromagnetic model is extended to approximate flow effects unique to heat pipes. When combined with a suitable heat pipe model, it is found that there is no performance gain for the case considered. In fact, there are serious pressure-distribution problems that have not been previously recognized. Potential solutions to these pressure-distribution problems are suggested

  17. Controlled porosity solubility modulated osmotic pump tablets of gliclazide.

    Science.gov (United States)

    Banerjee, Arti; Verma, P R P; Gore, Subhash

    2015-06-01

    A system that can deliver drug at a controlled rate is very important for the treatment of various chronic diseases such as diabetes, asthma, and heart disease. Poorly water-soluble drug with pH-dependent solubility such as gliclazide (GLZ) offers challenges in the controlled-release formulation because of low dissolution rate and poor bioavailability. Solid dispersion (SD) of GLZ consisted of hydroxypropyl cellulose (HPC-SSL) as a polymeric solubilizer was manufactured by hot melt extrusion (HME) technology. Then, controlled porosity osmotic pump (CPOP) tablet of gliclazide was designed to deliver drug in a controlled manner up to 16 h. The developed formulation was optimized for type and level of pore former and coating weight gain. The optimized formulation was found to exhibit zero order kinetics independent of pH and agitation speed but depends on osmotic pressure of dissolution media indicated that mechanism of drug release was osmotic pressure. The in vivo performance prediction of developed formulation using convolution approach revealed that the developed formulation was superior to the existing marketed extended-release formulation in terms of attaining steady state plasma levels and indicated adequate exposure in translating hypoglycemic response. The prototype solubilization method combined with controlled porosity osmotic pump based technique could provide a unique way to increase dissolution rate and bioavailability of many poorly water-soluble, narrow therapeutic index drugs used in diabetes, cardiovascular diseases, etc.

  18. Vocal Fold Epithelial Response to Luminal Osmotic Perturbation

    Science.gov (United States)

    Sivasankar, Mahalakshmi; Fisher, Kimberly V.

    2007-01-01

    Purpose: Dry-air challenges increase the osmolarity of fluid lining the luminal surface of the proximal airway. The homeostasis of surface fluid is thought to be essential for voice production and laryngeal defense. Therefore, the authors hypothesized that viable vocal fold epithelium would generate a water flux to reduce an osmotic challenge (150…

  19. Development of an electro-osmotic heat pump

    NARCIS (Netherlands)

    Stoel, J.P. van der; Oostendorp, P.A.

    1999-01-01

    The majority of heat pumps and refrigerators is driven by a mechanical compressor. Although they usually function very well, the search for new and in some cases better heat pumping concepts continues. One of the topics in this field is the development of an electro-osmotic heat pump. As each

  20. A Simple Membrane Osmometer System & Experiments that Quantitatively Measure Osmotic Pressure

    Science.gov (United States)

    Marvel, Stephen C.; Kepler, Megan V.

    2009-01-01

    It is important for students to be exposed to the concept of osmotic pressure. Understanding this concept lays the foundation for deeper discussions that lead to more theoretical aspects of water movement associated with the concepts of free energy, water potential, osmotic potential, pressure potential, and osmotic adjustment. The concept of…

  1. 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)

  2. 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

  3. 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.

  4. 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.

  5. Modelling the Thin-Layer Drying Kinetics of Untreated and Blanch-Osmotic Pre-treated Tomato Slices

    Directory of Open Access Journals (Sweden)

    Samuel Enahoro Agarry

    2016-10-01

    Full Text Available The objective of this study was to investigate the effect of pre-treatment and drying temperature on the drying kinetics and nutritional quality of tomato (Lycopersicon esculantum L. under hot air drying. Tomato samples were blanched at 80oC and osmotically dehydrated using 20% w/w sodium chloride solutions at 30oC for 20 min. The blanch-osmotic pre-treated and untreated tomato slices were dried at temperature of 40, 50, 60, 70 and 80oC, respectively in a hot air-dryer. The results showed that blanch-osmotic pre-treatment offered a higher drying rate and lower or faster drying time than untreated condition. The tomato drying regime was characteristically in the constant and falling rate period. The tomato drying rate curve showed characteristics of porous hygroscopic solids. The optimum drying temperature for tomato was found to be 60oC. Four semi-empirical drying models of Newton, Page, Henderson and Pabis, and Logarithmic were fitted to the drying data using non-linear regression analysis. The most appropriate model was selected using the coefficient of determination (R2 and root mean square error (RMSE. The Page model has shown a better fit to the drying kinetics data of tomato in comparison with other tested models. Transport of moisture during drying was described by Fick’s diffusion model application and the effective moisture diffusivity (Deff thus estimated. The Deff at 60oC was 4.43 × 10-11m2/s and 6.33 × 10-11m2/s for blanch-osmotic pre-treated and untreated tomato slices, respectively.

  6. 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.)

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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;.

  12. 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

  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. 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+.

  15. 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.)

  16. 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

  17. 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

  18. 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

  19. 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

  20. Plasticity, Swell-Shrink, and Microstructure of Phosphogypsum Admixed Lime Stabilized Expansive Soil

    Directory of Open Access Journals (Sweden)

    Jijo James

    2016-01-01

    Full Text Available The study involved utilization of an industrial waste, Phosphogypsum (PG, as an additive to lime stabilization of an expansive soil. Three lime dosages, namely, initial consumption of lime (ICL, optimum lime content (OLC, and less than ICL (LICL, were identified for the soil under study for stabilizing the soil. Along with lime, varying doses of PG were added to the soil for stabilization. The effect of stabilization was studied by performing index tests, namely, liquid limit, plastic limit, shrinkage limit, and free swell test, on pulverized remains of failed unconfined compression test specimens. The samples were also subjected to a microstructural study by means of scanning electron microscope. Addition of PG to lime resulted in improvement in the plasticity and swell-shrink characteristics. The microstructural study revealed the formation of a dense compact mass of stabilized soil.

  1. In vitro screening of potato genotypes for osmotic stress tolerance

    Directory of Open Access Journals (Sweden)

    Gelmesa Dandena

    2017-02-01

    Full Text Available Potato (Solanum tuberosum L. is a cool season crop which is susceptible to both drought and heat stresses. Lack of suitable varieties of the crop adapted to drought-prone areas of the lowland tropics deprives farmers living in such areas the opportunity to produce and use the crop as a source of food and income. As a step towards developing such varieties, the present research was conducted to evaluate different potato genotypes for osmotic stress tolerance under in vitro conditions and identify drought tolerant genotypes for future field evaluation. The experiment was carried out at the Leibniz University of Hannover, Germany, by inducing osmotic stress using sorbitol at two concentrations (0.1 and 0.2 M in the culture medium. A total of 43 genotypes collected from different sources (27 advanced clones from CIP, nine improved varieties, and seven farmers’ cultivars were used in a completely randomized design with four replications in two rounds. Data were collected on root and shoot growth. The results revealed that the main effects of genotype, sorbitol treatment, and their interactions significantly (P < 0.01 influenced root and shoot growthrelated traits. Under osmotic stress, all the measured root and shoot growth traits were significantly correlated. The dendrogram obtained from the unweighted pair group method with arithmetic mean allowed grouping of the genotypes into tolerant, moderately tolerant, and susceptible ones to a sorbitol concentration of 0.2 M in the culture medium. Five advanced clones (CIP304350.100, CIP304405.47, CIP392745.7, CIP388676.1, and CIP388615.22 produced shoots and rooted earlier than all other genotypes, with higher root numbers, root length, shoot and root mass under osmotic stress conditions induced by sorbitol. Some of these genotypes had been previously identified as drought-tolerant under field conditions, suggesting the capacity of the in vitro evaluation method to predict drought stress tolerant

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

    KAUST Repository

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

    2014-01-01

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

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

    KAUST Repository

    Zhang, Sui

    2014-04-01

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

  4. Osmotic distillation and quality evaluation of sucrose, apple and orange juices in hollow fiber membrane contactor

    Directory of Open Access Journals (Sweden)

    Rehman Waheed Ur

    2017-01-01

    Full Text Available Sucrose solution, apple and orange juices were concentrated through osmotic distillation (OD process using a mini-module Liqui-CelTM hollow fibre membrane contactor. Mass transport characteristics of water molecules from feed to stripping solution were studied. Process parameters such as feed temperature, feed flow rate and concentration of stripping solution (CaCl2 were varied. Sucrose solution was concentrated from 135 to 510 g TSS kg-1 in 340 min using feed-in- -lumen flow configuration at a start-up water flux of 0.250 L m-2 h-1 and a temperature of 30°C. Similarly, it was concentrated up to 510 g TSS kg-1 in 200 min using feed-in-shell flow configuration at a start-up water flux of 0.505 L m-2 hr1 and a temperature of 30°C. In a total recycle time of 340 min, clarified apple and orange juices were concentrated up to 500 g TSS kg-1 using feed-in-lumen flow configuration at a start-up water flux of 0.204 and 0.294 L m-2 hr1, respectively. It was found that quality parameters of fruit juices were well improved after the osmotic distillation process. The process therefore has good potential for application in the fruit processing industry for concentration of fruit juices.

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. Analytical Expressions for Thermo-Osmotic Permeability of Clays

    Science.gov (United States)

    Gonçalvès, J.; Ji Yu, C.; Matray, J.-M.; Tremosa, J.

    2018-01-01

    In this study, a new formulation for the thermo-osmotic permeability of natural pore solutions containing monovalent and divalent cations is proposed. The mathematical formulation proposed here is based on the theoretical framework supporting thermo-osmosis which relies on water structure alteration in the pore space of surface-charged materials caused by solid-fluid electrochemical interactions. The ionic content balancing the surface charge of clay minerals causes a disruption in the hydrogen bond network when more structured water is present at the clay surface. Analytical expressions based on our heuristic model are proposed and compared to the available data for NaCl solutions. It is shown that the introduction of divalent cations reduces the thermo-osmotic permeability by one third compared to the monovalent case. The analytical expressions provided here can be used to advantage for safety calculations in deep underground nuclear waste repositories.

  10. Osmotic pressure of the cutaneous surface fluid of Rana esculenta

    DEFF Research Database (Denmark)

    Hviid Larsen, Erik; Ramløv, Hans

    2012-01-01

    The osmotic pressure of the cutaneous surface fluid (CSF) in vivo was measured for investigating whether evaporative water loss (EWL) derives from water diffusing through the skin or fluid secreted by exocrine subepidermal mucous glands. EWL was stimulated by subjecting R. esculenta to 30–34 °C....../Kg, n = 16. Osmolality of lymph was, 239 ± 4 mosmol/Kg, n = 8. Thus the flow of water across the epidermis would be in the direction from CSF to the interstitial fluid driven by the above osmotic gradients and/or coupled to the inward active Na+ flux via the slightly hyperosmotic paracellular...... compartment [EH Larsen et al. (2009) Acta Physiologica 195: 171–186]. It is concluded that the source of EWL of the frog on land is the fluid secreted by the mucous glands and not water diffusing through the skin. The study supports the hypothesis [EH Larsen (2011) Acta Physiologica 202: 435–464] that volume...

  11. Optimization of the Energy Output of Osmotic Power Plants

    Directory of Open Access Journals (Sweden)

    Florian Dinger

    2013-01-01

    Full Text Available On the way to a completely renewable energy supply, additional alternatives to hydroelectric, wind, and solar power have to be investigated. Osmotic power is such an alternative with a theoretical global annual potential of up to 14400 TWh (70% of the global electricity consumption of 2008 per year. It utilizes the phenomenon that upon the mixing of fresh water and oceanic salt water (e.g., at a river mouth, around 2.88 MJ of energy per 1 m3 of fresh water is released. Here, we describe a new approach to derive operational parameter settings for osmotic power plants using a pressure exchanger for optimal performance, either with respect to maximum generated power or maximum extracted energy. Up to now, only power optimization is discussed in the literature, but when considering the fresh water supply as a limiting factor, the energy optimization appears as the challenging task.

  12. Glucose Monitoring System Based on Osmotic Pressure Measurements

    Directory of Open Access Journals (Sweden)

    Alexandra LEAL

    2011-02-01

    Full Text Available This paper presents the design and development of a prototype sensor unit for implementation in a long-term glucose monitoring system suitable for estimating glucose levels in people suffering from diabetes mellitus. The system utilizes osmotic pressure as the sensing mechanism and consists of a sensor prototype that is integrated together with a pre-amplifier and data acquisition unit for both data recording and processing. The sensor prototype is based on an embedded silicon absolute pressure transducer and a semipermeable nanoporous membrane that is enclosed in the sensor housing. The glucose monitoring system facilitates the integration of a low power microcontroller that is combined with a wireless inductive powered communication link. Experimental verification have proven that the system is capable of tracking osmotic pressure changes using albumin as a model compound, and thereby show a proof of concept for novel long term tracking of blood glucose from remote sensor nodes.

  13. Linear Dispersion Relation and Depth Sensitivity to Swell Parameters: Application to Synthetic Aperture Radar Imaging and Bathymetry

    Directory of Open Access Journals (Sweden)

    Valentina Boccia

    2015-01-01

    Full Text Available Long gravity waves or swell dominating the sea surface is known to be very useful to estimate seabed morphology in coastal areas. The paper reviews the main phenomena related to swell waves propagation that allow seabed morphology to be sensed. The linear dispersion is analysed and an error budget model is developed to assess the achievable depth accuracy when Synthetic Aperture Radar (SAR data are used. The relevant issues and potentials of swell-based bathymetry by SAR are identified and discussed. This technique is of particular interest for characteristic regions of the Mediterranean Sea, such as in gulfs and relatively close areas, where traditional SAR-based bathymetric techniques, relying on strong tidal currents, are of limited practical utility.

  14. Hydro-osmotic Instabilities in Active Membrane Tubes

    Science.gov (United States)

    Al-Izzi, Sami C.; Rowlands, George; Sens, Pierre; Turner, Matthew S.

    2018-03-01

    We study a membrane tube with unidirectional ion pumps driving an osmotic pressure difference. A pressure-driven peristaltic instability is identified, qualitatively distinct from similar tension-driven Rayleigh-type instabilities on membrane tubes. We discuss how this instability could be related to the function and biogenesis of membrane bound organelles, in particular, the contractile vacuole complex. The unusually long natural wavelength of this instability is in agreement with that observed in cells.

  15. Osmotic dehydration of fruits and vegetables: a review

    OpenAIRE

    Yadav, Ashok Kumar; Singh, Satya Vir

    2012-01-01

    The main cause of perishability of fruits and vegetables are their high water content. To increase the shelf life of these fruits and vegetables many methods or combination of methods had been tried. Osmotic dehydration is one of the best and suitable method to increase the shelf life of fruits and vegetables. This process is preferred over others due to their vitamin and minerals, color, flavor and taste retention property. In this review different methods, treatments, optimization and effec...

  16. Does Osmotic Stress Affect Natural Product Expression in Fungi?

    Science.gov (United States)

    Overy, David; Correa, Hebelin; Roullier, Catherine; Chi, Wei-Chiung; Pang, Ka-Lai; Rateb, Mostafa; Ebel, Rainer; Shang, Zhuo; Capon, Rob; Bills, Gerald; Kerr, Russell

    2017-08-13

    The discovery of new natural products from fungi isolated from the marine environment has increased dramatically over the last few decades, leading to the identification of over 1000 new metabolites. However, most of the reported marine-derived species appear to be terrestrial in origin yet at the same time, facultatively halo- or osmotolerant. An unanswered question regarding the apparent chemical productivity of marine-derived fungi is whether the common practice of fermenting strains in seawater contributes to enhanced secondary metabolism? To answer this question, a terrestrial isolate of Aspergillus aculeatus was fermented in osmotic and saline stress conditions in parallel across multiple sites. The ex-type strain of A. aculeatus was obtained from three different culture collections. Site-to-site variations in metabolite expression were observed, suggesting that subculturing of the same strain and subtle variations in experimental protocols can have pronounced effects upon metabolite expression. Replicated experiments at individual sites indicated that secondary metabolite production was divergent between osmotic and saline treatments. Titers of some metabolites increased or decreased in response to increasing osmolite (salt or glycerol) concentrations. Furthermore, in some cases, the expression of some secondary metabolites in relation to osmotic and saline stress was attributed to specific sources of the ex-type strains.

  17. Development and evaluation of microporous osmotic tablets of diltiazem hydrochloride

    Directory of Open Access Journals (Sweden)

    Afifa Bathool

    2012-01-01

    Full Text Available Microporous osmotic tablet of diltiazem hydrochloride was developed for colon targeting. These prepared microporous osmotic pump tablet did not require laser drilling to deliver the drug to the specific site of action. The tablets were prepared by wet granulation method. The prepared tablets were coated with microporous semipermeable membrane and enteric polymer using conventional pan coating process. The incorporation of sodium lauryl sulfate (SLS, a leachable pore-forming agent, could form in situ delivery pores while coming in contact with gastrointestinal medium. The effect of formulation variables was studied by changing the amounts of sodium alginate and NaCMC in the tablet core, osmogen, and that of pore-forming agent (SLS used in the semipermeable coating. As the amount of hydrophilic polymers increased, drug release rate prolonged. It was found that drug release was increased as the concentration of osmogen and pore-former was increased. Fourier transform infrared spectroscopy and Differential scanning calorimetry results showed that there was no interaction between drug and polymers. Scanning electron microscopic studies showed the formation of pores after predetermined time of coming in contact with dissolution medium. The formation of pores was dependent on the amount of pore former used in the semipermeable membrane. in vitro results showed acid-resistant, timed release at an almost zero order up to 24 hours. The developed osmotic tablets could be effectively used for prolonged delivery of Diltiazem HCl.

  18. Active osmotic exchanger for advanced filtration at the nano scale

    Science.gov (United States)

    Marbach, Sophie; Bocquet, Lyderic

    2015-11-01

    One of the main functions of the kidney is to remove the waste products of an organism, mostly by excreting concentrated urea while reabsorbing water and other molecules. The human kidney is capable of recycling about 200 liters of water per day, at the relatively low cost of 0.5 kJ/L (standard dialysis requiring at least 150 kJ/L). Kidneys are constituted of millions of parallel filtration networks called nephrons. The nephrons of all mammalian kidneys present a specific loop geometry, the Loop of Henle, that is believed to play a key role in the urinary concentrating mechanism. One limb of the loop is permeable to water and the other contains sodium pumps that exchange with a common interstitium. In this work, we take inspiration from this osmotic exchanger design to propose new nanofiltration principles. We first establish simple analytical results to derive general operating principles, based on coupled water permeable pores and osmotic pumps. The best filtration geometry, in terms of power required for a given water recycling ratio, is comparable in many ways to the mammalian nephron. It is not only more efficient than traditional reverse osmosis systems, but can also work at much smaller pressures (of the order of the blood pressure, 0.13 bar, as compared to more than 30 bars for pressure-retarded osmosis systems). We anticipate that our proof of principle will be a starting point for the development of new filtration systems relying on the active osmotic exchanger principle.

  19. Osmotic heat engine using thermally responsive ionic liquids

    KAUST Repository

    Zhong, Yujiang

    2017-07-11

    The osmotic heat engine (OHE) is a promising technology for converting low grade heat to electricity. Most of the existing studies have focused on thermolytic salt systems. Herein, for the first time, we proposed to use thermally responsive ionic liquids (TRIL) that have either an upper critical solution temperature (UCST) or lower critical solution temperature (LCST) type of phase behavior as novel thermolytic osmotic agents. Closed-loop TRIL-OHEs were designed based on these unique phase behaviors to convert low grade heat to work or electricity. Experimental studies using two UCST-type TRILs, protonated betaine bis(trifluoromethyl sulfonyl)imide ([Hbet][Tf2N]) and choline bis(trifluoromethylsulfonyl)imide ([Choline][Tf2N]) showed that (1) the specific energy of the TRIL-OHE system could reach as high as 4.0 times that of the seawater and river water system, (2) the power density measured from a commercial FO membrane reached up to 2.3 W/m2, and (3) the overall energy efficiency reached up to 2.6% or 18% of the Carnot efficiency at no heat recovery and up to 10.5% or 71% of the Carnet efficiency at 70% heat recovery. All of these results clearly demonstrated the great potential of using TRILs as novel osmotic agents to design high efficient OHEs for recovery of low grade thermal energy to work or electricity.

  20. Physiologically Based Pharmacokinetic and Absorption Modeling for Osmotic Pump Products.

    Science.gov (United States)

    Ni, Zhanglin; Talattof, Arjang; Fan, Jianghong; Tsakalozou, Eleftheria; Sharan, Satish; Sun, Dajun; Wen, Hong; Zhao, Liang; Zhang, Xinyuan

    2017-07-01

    Physiologically based pharmacokinetic (PBPK) and absorption modeling approaches were employed for oral extended-release (ER) drug products based on an osmotic drug delivery system (osmotic pumps). The purpose was to systemically evaluate the in vivo relevance of in vitro dissolution for this type of formulation. As expected, in vitro dissolution appeared to be generally predictive of in vivo PK profiles, because of the unique feature of this delivery system that the in vitro and in vivo release of osmotic pump drug products is less susceptible to surrounding environment in the gastrointestinal (GI) tract such as pH, hydrodynamic, and food effects. The present study considered BCS (Biopharmaceutics Classification System) class 1, 2, and 3 drug products with half-lives ranging from 2 to greater than 24 h. In some cases, the colonic absorption models needed to be adjusted to account for absorption in the colon. C max (maximum plasma concentration) and AUCt (area under the concentration curve) of the studied drug products were sensitive to changes in colon permeability and segmental GI transit times in a drug product-dependent manner. While improvement of the methodology is still warranted for more precise prediction (e.g., colonic absorption and dynamic movement in the GI tract), the results from the present study further emphasized the advantage of using PBPK modeling in addressing product-specific questions arising from regulatory review and drug development.

  1. Osmotic stress response in the wine yeast Dekkera bruxellensis.

    Science.gov (United States)

    Galafassi, Silvia; Toscano, Marco; Vigentini, Ileana; Piškur, Jure; Compagno, Concetta

    2013-12-01

    Dekkera bruxellensis is mainly associated with lambic beer fermentation and wine production and may contribute in a positive or negative manner to the flavor development. This yeast is able to produce phenolic compounds, such as 4-ethylguaiacol and 4-ethylphenol which could spoil the wine, depending on their concentration. In this work we have investigated how this yeast responds when exposed to conditions causing osmotic stress, as high sorbitol or salt concentrations. We observed that osmotic stress determined the production and accumulation of intracellular glycerol, and the expression of NADH-dependent glycerol-3-phosphate dehydrogenase (GPD) activity was elevated. The involvement of the HOG MAPK pathway in response to this stress condition was also investigated. We show that in D. bruxellensis Hog1 protein is activated by phosphorylation under hyperosmotic conditions, highlighting the conserved role of HOG MAP kinase signaling pathway in the osmotic stress response. Gene Accession numbers in GenBank: DbHOG1: JX65361, DbSTL1: JX965362. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Design of an osmotic pressure sensor for sensing an osmotically active substance

    International Nuclear Information System (INIS)

    Ch, Nagesh; Paily, Roy P

    2015-01-01

    A pressure sensor based on the osmosis principle has been designed and demonstrated successfully for the sensing of the concentration levels of an osmotically active substance. The device is fabricated using the bulk micro-machining technique on a silicon on insulator (SOI) substrate. The substrate has a square cavity on the bottom side to fill with the reference glucose solution and a silicon (Si) membrane on the top side for the actuation. Two sets of devices, having membrane thicknesses of 10 µm and 25 µm, but the same area of 3 mm ×3 mm, are fabricated. The cavity is filled with a glucose solution of 100 mg dL −1 and it is sealed with a semi-permeable membrane made up of cellulose acetate material. The glucose solution is employed to prove the functionality of the device and it is tested for different glucose concentration levels, ranging from 50 mg dL −1 to 450 mg dL −1 . The output voltage obtained for the corresponding glucose concentration levels ranges from −6.7 mV to 22.7 mV for the 10 µm device and from −1.7 mV to 4 mV for the 25 µm device. The device operation was simulated using the finite element method (FEM) and the finite volume method (FVM), and the simulation and experimental results match closely. A response time of 40 min is obtained in the case of the 10 µm device compared to one of 30 min for the 25 µm device. The response times obtained for these devices are found to be small compared to those in similar works based on the osmosis principle. This pressure sensor has the potential to provide controlled drug delivery if it can be integrated with other microfluidic devices. (paper)

  3. Recent experimental data may point to a greater role for osmotic pressures in the subsurface

    Science.gov (United States)

    Neuzil, C.E.; Provost, A.M.

    2009-01-01

    Uncertainty about the origin of anomalous fluid pressures in certain geologic settings has caused researchers to take a second look at osmosis, or flow driven by chemical potential differences, as a pressure‐generating process in the subsurface. Interest in geological osmosis has also increased because of an in situ experiment by Neuzil (2000) suggesting that Pierre Shale could generate large osmotic pressures when highly compacted. In the last few years, additional laboratory and in situ experiments have greatly increased the number of data on osmotic properties of argillaceous formations, but they have not been systematically examined. In this paper we compile these data and explore their implications for osmotic pressure generation in subsurface systems. Rather than base our analysis on osmotic efficiencies, which depend strongly on concentration, we calculated values of a quantity we term osmotic specific surface area (Aso) that, in principle, is a property of the porous medium only. The Aso values are consistent with a surprisingly broad spectrum of osmotic behavior in argillaceous formations, and all the formations tested exhibited at least a modest ability to generate osmotic pressure. It appears possible that under appropriate conditions some formations can be highly effective osmotic membranes able to generate osmotic pressures exceeding 30 MPa (3 km of head) at porosities as high as ∼0.1 and pressures exceeding 10 MPa at porosities as high as ∼0.2. These findings are difficult to reconcile with the lack of compelling field evidence for osmotic pressures, and we propose three explanations for the disparity: (1) Our analysis is flawed and argillaceous formations are less effective osmotic membranes than it suggests; (2) the necessary subsurface conditions, significant salinity differences within intact argillaceous formations, are rare; or (3) osmotic pressures are unlikely to be detected and are not recognized when encountered. The last possibility

  4. SAXS investigations on lipid membranes under osmotic stress

    Energy Technology Data Exchange (ETDEWEB)

    Rubim, R.L.; Vieira, V.; Gerbelli, B.B.; Teixeira da Silva, E.R.; Oliveira, C.L.P.; Oliveira, E.A. [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil)

    2012-07-01

    Full text: In this work we, experimentally, investigate the interactions between lipid bilayers. A structural characterization is performed by small angle x-ray scattering (SAXS) on multilamellar systems under known osmotic pressure. Changes in the composition of membranes can modify their mechanical properties and structural parameters, like the flexibility of these membranes, which plays a key role on the determination of the tridimensional organization of bilayers. The membranes are composed of soya lecithin, where the major component is DPPC (Dipalmitoylphosphatidylcholine), and fatty acids are incorporated to the membrane in different concentrations, in order to turn the membrane more fluid. The membranes are inserted in a solution of PVP [poly(vinyl-pyrrolidone) - 40000] and the polymer will apply an osmotic pressure on them. The osmotic pressure is controlled by preparing PVP solutions of desired composition and, as we know the concentration of polymer in solution, we can obtain the intensity of the osmotic pressure. SAXS experiments were done in order to determine the distance between the bilayer. From the position of the Bragg peaks, the lamellar periodicity (the thickness of the membranes plus their distance of separation) was determined. Using theoretical model for the form and structure factors we fitted those experimental data and determined the thickness of the membranes. The distance between the membranes was controlled by the osmotic pressure (P) applied to the membranes and, for a given pressure, we determine the distance between the bilayers (a) on equilibrium. The experimental curve P(a) is theoretically described by the different contributions from van der Waals, hydration and fluctuation forces. From the fitting of experimental curves, relevant parameters characterizing the strength of the different interactions are obtained, such as Hamaker and rigidity constant [2, 3]. We observe that the separation between the bilayers on equilibrium is

  5. Osmotic phenomena in application for hyperbaric oxygen treatment.

    Science.gov (United States)

    Babchin, A; Levich, E; Melamed M D, Y; Sivashinsky, G

    2011-03-01

    Hyperbaric oxygen (HBO) treatment defines the medical procedure when the patient inhales pure oxygen at elevated pressure conditions. Many diseases and all injuries are associated with a lack of oxygen in tissues, known as hypoxia. HBO provides an effective method for fast oxygen delivery in medical practice. The exact mechanism of the oxygen transport under HBO conditions is not fully identified. The objective of this article is to extend the colloid and surface science basis for the oxygen transport in HBO conditions beyond the molecular diffusion transport mechanism. At a pressure in the hyperbaric chamber of two atmospheres, the partial pressure of oxygen in the blood plasma increases 10 times. The sharp increase of oxygen concentration in the blood plasma creates a considerable concentration gradient between the oxygen dissolved in the plasma and in the tissue. The concentration gradient of oxygen as a non-electrolyte solute causes an osmotic flow of blood plasma with dissolved oxygen. In other words, the molecular diffusion transport of oxygen is supplemented by the convective diffusion raised due to the osmotic flow, accelerating the oxygen delivery from blood to tissue. A non steady state equation for non-electrolyte osmosis is solved asymptotically. The solution clearly demonstrates two modes of osmotic flow: normal osmosis, directed from lower to higher solute concentrations, and anomalous osmosis, directed from higher to lower solute concentrations. The fast delivery of oxygen from blood to tissue is explained on the basis of the strong molecular interaction between the oxygen and the tissue, causing an influx of oxygen into the tissue by convective diffusion in the anomalous osmosis process. The transport of the second gas, nitrogen, dissolved in the blood plasma, is also taken into the consideration. As the patient does not inhale nitrogen during HBO treatment, but exhales it along with oxygen and carbon dioxide, the concentration of nitrogen in blood

  6. 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.)

  7. Preparation and characterization of oil palm frond based cellulose hydrogel and its swelling properties

    Science.gov (United States)

    Selvakumaran, Nesha; Lazim, Mohd Azwani Shah bin Mat

    2016-11-01

    Malaysia is one of the largest producer of palm oil thus the quantity of biomass each year from this industry is very large. The oil palm frond from palm oil industry can be used as a source of cellulose which can be incorporated into hydrogel to be used as adsorbent. This research reported how to disperse 2 % cellulose in a `green-solution' prepared by using urea and sodium hydroxide. Polymerization is carried out between the monomers polyacrylamide and cellulose using microwave to form hydrogel. Hydrogel with 2 % cellulose have a swelling index of 1814 %. Meanwhile, zero hydrogel which is made with only polyacrylamide has swelling index of 15 %. Scanning electron microscope shows that cellulose hydrogel have a rough surface compared with zero hydrogel. This might attribute to the high swelling index for cellulose hydrogel compared with zero hydrogel. Meanwhile, FTIR shows that successful polymerization has occurred between polyacrylamide and cellulose with the characteristic band at 1657.99 cm-1 which is for N-H bond.

  8. Adaptive MscS gating in the osmotic permeability response in E. coli: the question of time.

    Science.gov (United States)

    Boer, Miriam; Anishkin, Andriy; Sukharev, Sergei

    2011-05-17

    Microorganisms adapt to osmotic downshifts by releasing small osmolytes through mechanosensitive (MS) channels. We want to understand how the small mechanosensitive channel's (MscS) activation and inactivation, both driven by membrane tension, optimize survival in varying hypoosmotic shock situations. By measuring light scattering with a stopped-flow device, we estimate bacterial swelling time as 30-50 ms. A partial solute equilibration follows within 150-200 ms, during which optical responses from cells with WT MscS deviate from those lacking MS channels. MscS opening rates estimated in patch clamp show the channels readily respond to tensions below the lytic limit with a time course faster than 20 ms and close promptly upon tension release. To address the role of the tension-insensitive inactivated state in vivo, we applied short, long, and two-step osmotic shock protocols to WT, noninactivating G113A, and fast-inactivating D62N mutants. WT and G113A showed a comparable survival in short 1 min 800 mOsm downshock experiments, but G113A was at a disadvantage under a long 60 min shock. Preshocking cells carrying WT MscS for 15 s to 15 min with a 200 mOsm downshift did not sensitize them to the final 500 mOsm drop in osmolarity of the second step. However, these two-step shocks induced death in D62N more than just a one-step 700 mOsm downshift. We conclude MscS is able to activate and exude osmolytes faster than lytic pressure builds inside the cell under abrupt shock. During prolonged shocks, gradual inactivation prevents continuous channel activity and assists recovery. Slow kinetics of inactivation in WT MscS ensures that mild shocks do not inactivate the entire population, leaving some protection should conditions worsen.

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. 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

  14. Competitive excitation and osmotic-pressure-mediated control of lasing modes in cholesteric liquid crystal microshells

    Science.gov (United States)

    Lin, Ya-Li; Gong, Ling-Li; Che, Kai-Jun; Li, Sen-Sen; Chu, Cheng-Xu; Cai, Zhi-Ping; Yang, Chaoyong James; Chen, Lu-Jian

    2017-05-01

    We examined the end-pumped lasing behaviors of dye doped cholesteric liquid crystal (DDCLC) microshells which were fabricated by glass capillary microfluidics. Several kinds of mode resonances, including distributed feedback, Fabry-Pérot (FP), and whispering gallery (WG) modes, can be robustly constructed in each individual DDCLC microshell by varying the beam diameter, namely, tuning the DDCLC gain area. The FP and WG modes were further confirmed experimentally, and the corresponding lasing mechanisms are clearly revealed from the unique material characteristics of DDCLC and the geometrical structure of the microshell. Additionally, we demonstrated that the osmotic pressure can be used to shrink/expand the microshell, productively tuning the excitation of lasing modes in a controlled manner. We wish our findings can provide a new insight into the design of DDCLC microlasers with tunable optical properties.

  15. The Response Strategy of Maize, Pea and Broad Bean Plants to Different Osmotic Potential Stress

    Directory of Open Access Journals (Sweden)

    Hamdia M. Abd El-Samad

    2013-08-01

    Full Text Available This investigation was conducted to study the tolerance strategy of maize, broad bean and pea plants to salinity stress with exogenous applications of proline or phenylalanine on seed germination and seedlings growth. From the results obtained, it can be observed that osmotic stress affected adversely the rate of germination in maize, broad bean and pea plants. The excessive inhibition was more prominent at higher concentration of NaCl. The seeds and grains tested were exhibited some differential responses to salinity, in a manner that the inhibitory effect of salinity on seed germination ran in the order, maize higher than broad bean and the later was higher than pea plant. Treatment with proline or phenylalanine (100 ppm significantly increased these seed germination and seedlings growth characteristics even at lowest salinity level tested.

  16. 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.

  17. 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)

  18. 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)

  19. 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

  20. 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.

  1. 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...

  2. 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

  3. 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.)

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. Effect of plasma colloid osmotic pressure on intraocular pressure during haemodialysis

    OpenAIRE

    Tokuyama, T.; Ikeda, T.; Sato, K.

    1998-01-01

    BACKGROUND—In a previous case report, it was shown that an increase in plasma colloid osmotic pressure induced by the removal of fluid during haemodialysis was instrumental in decreasing intraocular pressure. The relation between changes in intraocular pressure, plasma osmolarity, plasma colloid osmotic pressure, and body weight before and after haemodialysis is evaluated.
METHODS—Intraocular pressure, plasma osmolarity, plasma colloid osmotic pressure, and body weight were evaluated before a...

  10. Evaluation of rate of swelling and erosion of verapamil (VRP) sustained-release matrix tablets.

    Science.gov (United States)

    Khamanga, Sandile M; Walker, Roderick B

    2006-01-01

    Tablets manufactured in-house were compared to a marketed sustained-release product of verapamil to investigate the rate of hydration, erosion, and drug-release mechanism by measuring the wet and subsequent dry weights of the products. Swelling and erosion rates depended on the polymer and granulating fluid used, which ultimately pointed to their permeability characteristics. Erosion rate of the marketed product was highest, which suggests that the gel layer that formed around these tablets was weak as opposed to the robust and resistant layers of test products. Anomalous and near zero-order transport mechanisms were dominant in tests and commercial product, respectively.

  11. Gene expression analysis in response to osmotic stimuli in the intervertebral disc with DNA microarray.

    Science.gov (United States)

    Zhang, Wenzhi; Li, Xu; Shang, Xifu; Zhao, Qichun; Hu, Yefeng; Xu, Xiang; He, Rui; Duan, Liqun; Zhang, Feng

    2013-12-27

    Intervertebral disc (IVD) cells experience a broad range of physicochemical stimuli under physiologic conditions, including alterations in their osmotic environment. At present, the molecular mechanisms underlying osmotic regulation in IVD cells are poorly understood. This study aims to screen genes affected by changes in osmotic pressure in cells of subjects aged 29 to 63 years old, with top-scoring pair (TSP) method. Gene expression data set GSE1648 was downloaded from Gene Expression Omnibus database, including four hyper-osmotic stimuli samples, four iso-osmotic stimuli samples, and three hypo-osmotic stimuli samples. A novel, simple method, referred to as the TSP, was used in this study. Through this method, there was no need to perform data normalization and transformation before data analysis. A total of five pairs of genes ((CYP2A6, FNTB), (PRPF8, TARDBP), (RPS5, OAZ1), (SLC25A3, NPM1) and (CBX3, SRSF9)) were selected based on the TSP method. We inferred that all these genes might play important roles in response to osmotic stimuli and age in IVD cells. Additionally, hyper-osmotic and iso-osmotic stimuli conditions were adverse factors for IVD cells. We anticipate that our results will provide new thoughts and methods for the study of IVD disease.

  12. Transcriptome Profiling of Watermelon Root in Response to Short-Term Osmotic Stress.

    Science.gov (United States)

    Yang, Yongchao; Mo, Yanling; Yang, Xiaozheng; Zhang, Haifei; Wang, Yongqi; Li, Hao; Wei, Chunhua; Zhang, Xian

    2016-01-01

    Osmotic stress adversely affects the growth, fruit quality and yield of watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai). Increasing the tolerance of watermelon to osmotic stress caused by factors such as high salt and water deficit is an effective way to improve crop survival in osmotic stress environments. Roots are important organs in water absorption and are involved in the initial response to osmosis stress; however, few studies have examined the underlying mechanism of tolerance to osmotic stress in watermelon roots. For better understanding of this mechanism, the inbred watermelon accession M08, which exhibits relatively high tolerance to water deficits, was treated with 20% polyethylene glycol (PEG) 6000. The root samples were harvested at 6 h after PEG treatment and untreated samples were used as controls. Transcriptome analyses were carried out by Illumina RNA sequencing. A total of 5246 differentially expressed genes were identified. Gene ontology enrichment and biochemical pathway analyses of these 5246 genes showed that short-term osmotic stress affected osmotic adjustment, signal transduction, hormone responses, cell division, cell cycle and ribosome, and M08 may repress root growth to adapt osmotic stress. The results of this study describe the watermelon root transcriptome under osmotic stress and propose new insight into watermelon root responses to osmotic stress at the transcriptome level. Accordingly, these results allow us to better understand the molecular mechanisms of watermelon in response to drought stress and will facilitate watermelon breeding projects to improve drought tolerance.

  13. An osmotic model of the growing pollen tube.

    Directory of Open Access Journals (Sweden)

    Adrian E Hill

    Full Text Available Pollen tube growth is central to the sexual reproduction of plants and is a longstanding model for cellular tip growth. For rapid tip growth, cell wall deposition and hardening must balance the rate of osmotic water uptake, and this involves the control of turgor pressure. Pressure contributes directly to both the driving force for water entry and tip expansion causing thinning of wall material. Understanding tip growth requires an analysis of the coordination of these processes and their regulation. Here we develop a quantitative physiological model which includes water entry by osmosis, the incorporation of cell wall material and the spreading of that material as a film at the tip. Parameters of the model have been determined from the literature and from measurements, by light, confocal and electron microscopy, together with results from experiments made on dye entry and plasmolysis in Lilium longiflorum. The model yields values of variables such as osmotic and turgor pressure, growth rates and wall thickness. The model and its predictive capacity were tested by comparing programmed simulations with experimental observations following perturbations of the growth medium. The model explains the role of turgor pressure and its observed constancy during oscillations; the stability of wall thickness under different conditions, without which the cell would burst; and some surprising properties such as the need for restricting osmotic permeability to a constant area near the tip, which was experimentally confirmed. To achieve both constancy of pressure and wall thickness under the range of conditions observed in steady-state growth the model reveals the need for a sensor that detects the driving potential for water entry and controls the deposition rate of wall material at the tip.

  14. Osmotic membrane bioreactor for phenol biodegradation under continuous operation

    Energy Technology Data Exchange (ETDEWEB)

    Praveen, Prashant; Loh, Kai-Chee, E-mail: chelohkc@nus.edu.sg

    2016-03-15

    Highlights: • Osmotic membrane bioreactor was used for phenol biodegradation in continuous mode. • Extractant impregnated membranes were used to alleviate substrate inhibition. • Phenol removal was achieved through both biodegradation and membrane rejection. • Phenol concentrations up to 2500 mg/L were treated at HRT varying in 2.8–14 h. • A biofilm removal strategy was formulated to improve bioreactor sustainability. - Abstract: Continuous phenol biodegradation was accomplished in a two-phase partitioning osmotic membrane bioreactor (TPPOMBR) system, using extractant impregnated membranes (EIM) as the partitioning phase. The EIMs alleviated substrate inhibition during prolonged operation at influent phenol concentrations of 600–2000 mg/L, and also at spiked concentrations of 2500 mg/L phenol restricted to 2 days. Filtration of the effluent through forward osmosis maintained high biomass concentration in the bioreactor and improved effluent quality. Steady state was reached in 5–6 days at removal rates varying between 2000 and 5500 mg/L-day under various conditions. Due to biofouling and salt accumulation, the permeate flux varied from 1.2–7.2 LMH during 54 days of operation, while maintaining an average hydraulic retention time of 7.4 h. A washing cycle, comprising 1 h osmotic backwashing using 0.5 M NaCl and 2 h washing with water, facilitated biofilm removal from the membranes. Characterization of the extracellular polymeric substances (EPS) through FTIR showed peaks between 1700 and 1500 cm{sup −1}, 1450–1450 cm{sup −1} and 1200–1000 cm{sup −1}, indicating the presence of proteins, phenols and polysaccharides, respectively. The carbohydrate to protein ratio in the EPS was estimated to be 0.3. These results indicate that TPPOMBR can be promising in continuous treatment of phenolic wastewater.

  15. Tirilazad mesylate protects stored erythrocytes against osmotic fragility.

    Science.gov (United States)

    Epps, D E; Knechtel, T J; Bacznskyj, O; Decker, D; Guido, D M; Buxser, S E; Mathews, W R; Buffenbarger, S L; Lutzke, B S; McCall, J M

    1994-12-01

    The hypoosmotic lysis curve of freshly collected human erythrocytes is consistent with a single Gaussian error function with a mean of 46.5 +/- 0.25 mM NaCl and a standard deviation of 5.0 +/- 0.4 mM NaCl. After extended storage of RBCs under standard blood bank conditions the lysis curve conforms to the sum of two error functions instead of a possible shift in the mean and a broadening of a single error function. Thus, two distinct sub-populations with different fragilities are present instead of a single, broadly distributed population. One population is identical to the freshly collected erythrocytes, whereas the other population consists of osmotically fragile cells. The rate of generation of the new, osmotically fragile, population of cells was used to probe the hypothesis that lipid peroxidation is responsible for the induction of membrane fragility. If it is so, then the antioxidant, tirilazad mesylate (U-74,006f), should protect against this degradation of stored erythrocytes. We found that tirilazad mesylate, at 17 microM (1.5 mol% with respect to membrane lecithin), retards significantly the formation of the osmotically fragile RBCs. Concomitantly, the concentration of free hemoglobin which accumulates during storage is markedly reduced by the drug. Since the presence of the drug also decreases the amount of F2-isoprostanes formed during the storage period, an antioxidant mechanism must be operative. These results demonstrate that tirilazad mesylate significantly decreases the number of fragile erythrocytes formed during storage in the blood bank.

  16. An Osmotic Model of the Growing Pollen Tube

    Science.gov (United States)

    Hill, Adrian E.; Shachar-Hill, Bruria; Skepper, Jeremy N.; Powell, Janet; Shachar-Hill, Yair

    2012-01-01

    Pollen tube growth is central to the sexual reproduction of plants and is a longstanding model for cellular tip growth. For rapid tip growth, cell wall deposition and hardening must balance the rate of osmotic water uptake, and this involves the control of turgor pressure. Pressure contributes directly to both the driving force for water entry and tip expansion causing thinning of wall material. Understanding tip growth requires an analysis of the coordination of these processes and their regulation. Here we develop a quantitative physiological model which includes water entry by osmosis, the incorporation of cell wall material and the spreading of that material as a film at the tip. Parameters of the model have been determined from the literature and from measurements, by light, confocal and electron microscopy, together with results from experiments made on dye entry and plasmolysis in Lilium longiflorum. The model yields values of variables such as osmotic and turgor pressure, growth rates and wall thickness. The model and its predictive capacity were tested by comparing programmed simulations with experimental observations following perturbations of the growth medium. The model explains the role of turgor pressure and its observed constancy during oscillations; the stability of wall thickness under different conditions, without which the cell would burst; and some surprising properties such as the need for restricting osmotic permeability to a constant area near the tip, which was experimentally confirmed. To achieve both constancy of pressure and wall thickness under the range of conditions observed in steady-state growth the model reveals the need for a sensor that detects the driving potential for water entry and controls the deposition rate of wall material at the tip. PMID:22615784

  17. The use of the rapid osmotic fragility test as an additional test to diagnose canine immune-mediated haemolytic anaemia

    DEFF Research Database (Denmark)

    Paes, Geert; Paepe, Dominique; Meyer, Evelyne

    2013-01-01

    Background: Diagnosing canine immune-mediated haemolytic anaemia (IMHA) is often challenging because all currently available tests have their limitations. Dogs with IMHA often have an increased erythrocyte osmotic fragility (OF), a characteristic that is sometimes used in the diagnosis of IMHA...... hyperlipemic dogs (group 3), 10 dogs with lymphoma (group 4), 8 dogs with an infection (group 5) and 13 healthy dogs (group 6) were included. In all dogs, blood smear examination, in-saline auto-agglutination test, Coombs' test, COFT and ROFT were performed. In the COFT, OF5, OF50 and OF90 were defined...

  18. Suppression of ion conductance by electro-osmotic flow in nano-channels with weakly overlapping electrical double layers

    Directory of Open Access Journals (Sweden)

    Yang Liu

    2016-08-01

    Full Text Available This theoretical study investigates the nonlinear ionic current-voltage characteristics of nano-channels that have weakly overlapping electrical double layers. Numerical simulations as well as a 1-D mathematical model are developed to reveal that the electro-osmotic flow (EOF interplays with the concentration-polarization process and depletes the ion concentration inside the channels, thus significantly suppressing the channel conductance. The conductance may be restored at high electrical biases in the presence of recirculating vortices within the channels. As a result of the EOF-driven ion depletion, a limiting-conductance behavior is identified, which is intrinsically different from the classical limiting-current behavior.

  19. Artificial neural network model of pork meat cubes osmotic dehydration

    OpenAIRE

    Pezo, Lato L.; Ćurčić, Biljana Lj.; Filipović, Vladimir S.; Nićetin, Milica R.; Koprivica, Gordana B.; Mišljenović, Nevena M.; Lević, Ljubinko B.

    2013-01-01

    Mass transfer of pork meat cubes (M. triceps brachii), shaped as 1x1x1 cm, during osmotic dehydration (OD) and under atmospheric pressure was investigated in this paper. The effects of different parameters, such as concentration of sugar beet molasses (60-80%, w/w), temperature (20-50ºC), and immersion time (1-5 h) in terms of water loss (WL), solid gain (SG), final dry matter content (DM), and water activity (aw), were investigated using experimental results. Five artificial neural net...

  20. Compression and Reswelling of Microgel Particles after an Osmotic Shock

    Science.gov (United States)

    Sleeboom, Jelle J. F.; Voudouris, Panayiotis; Punter, Melle T. J. J. M.; Aangenendt, Frank J.; Florea, Daniel; van der Schoot, Paul; Wyss, Hans M.

    2017-09-01

    We use dedicated microfluidic devices to expose soft hydrogel particles to a rapid change in the externally applied osmotic pressure and observe a surprising, nonmonotonic response: After an initial rapid compression, the particle slowly reswells to approximately its original size. We theoretically account for this behavior, enabling us to extract important material properties from a single microfluidic experiment, including the compressive modulus, the gel permeability, and the diffusivity of the osmolyte inside the gel. We expect our approach to be relevant to applications such as controlled release, chromatography, and responsive materials.

  1. Investigation of the swelling behavior of cationic exchange resins saturated with Na{sup +} ions in a C{sub 3}S paste

    Energy Technology Data Exchange (ETDEWEB)

    Lafond, E. [CEA, DEN, DTCD, SPDE, F-30207 Bagnols-sur-Cèze cedex (France); Cau Dit Coumes, C., E-mail: celine.cau-dit-coumes@cea.fr [CEA, DEN, DTCD, SPDE, F-30207 Bagnols-sur-Cèze cedex (France); Gauffinet, S. [UMR5209 Institut Carnot de Bourgogne, Université de Bourgogne Dijon, Faculté des Sciences Mirande, 9 Avenue Alain Savary, BP 47870, 21078 Dijon cedex (France); Chartier, D. [CEA, DEN, DTCD, SPDE, F-30207 Bagnols-sur-Cèze cedex (France); Le Bescop, P. [CEA, DEN, DPC, SECR, F-91192 Gif-sur-Yvette (France); Stefan, L. [AREVA, Back End Business Group, Dismantling & Services, 1 place Jean Millier, 92084 Paris La Défense (France); Nonat, A. [UMR5209 Institut Carnot de Bourgogne, Université de Bourgogne Dijon, Faculté des Sciences Mirande, 9 Avenue Alain Savary, BP 47870, 21078 Dijon cedex (France)

    2015-03-15

    Ion exchange resins (IERs) are widely used by the nuclear industry to decontaminate radioactive effluents. Spent products are usually encapsulated in cementitious materials. However, the solidified waste form can exhibit strong expansion, possibly leading to cracking, if the appropriate binder is not used. In this work, the interactions between cationic resins in the Na{sup +} form and tricalcium silicate are investigated during the early stages of hydration in order to gain a better understanding of the expansion process. It is shown that the IERs exhibit a transient swelling of small magnitude due to the decrease in the osmotic pressure of the external solution. This expansion, which occurs just after setting, is sufficient to damage the material which is poorly consolidated for several reasons: low degree of hydration, precipitation of poorly cohesive sodium-bearing C–S–H, and very heterogeneous microstructure with zones of high porosity.

  2. Cell swelling activates K+ and Cl- channels as well as nonselective, stretch-activated cation channels in ehrlich ascites tumor cells

    DEFF Research Database (Denmark)

    Christensen, Ove; Hoffmann, Else Kay

    1992-01-01

    Cell-attached patch-clamp recordings from Ehrlich ascites tumor cells reveal nonselective cation channels which are activated by mechanical deformation of the membrane. These channels are seen when suction is applied to the patch pipette or after osmotic cell swelling. The channel activation does...... system. In isolated insideout patches a Ca2+-dependent, inwardly rectifying K+ channel is demonstrated. The single-channel conductance recorded with symmetrical 150 mm K+ solutions is for inward current estimated at 40 pS and for outward current at 15 pS. Activation of the K+ channel takes place after...... by membrane stretch (suction). The time-averaged number of open K+ channels during regulatory volume decrease (RVD) can be estimated at 40 per cell. The number of open K+ channels following addition of Ca2+ plus ionophore A23187 was estimated at 250 per cell. Concurrent activation in cell-attached patches...

  3. 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 ...

  4. 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.)

  5. 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)

  6. 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 ...

  7. 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

  8. 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...

  9. 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

  10. 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 ...

  11. 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

  12. 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

  13. 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.

  14. 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

  15. 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.

  16. 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...

  17. Nano-funnels as electro-osmotic ``tweezers and pistons''

    Science.gov (United States)

    Wang, Yanqian; Panyukov, Sergey; Zhou, Jinsheng; Menard, Laurent D.; Ramsey, J. Michael; Rubinstien, Michael

    2014-03-01

    An electric field is used to force a DNA molecule into a nano-channel by compensating the free energy penalty that results from the reduced conformational entropy of the confined macromolecule. Narrow nano-channels require high critical electric fields to achieve DNA translocation, leading to short dwell times of DNA in these channels. We demonstrate that nano-funnels integrated with nano-channels reduce the free energy barrier and lower the critical electric field required for DNA translocation. A focused electric field within the funnel increases the electric force on the DNA, compresses the molecule, and increases the osmotic pressure at the nano-channel entrance. This ``electro-osmotic piston'' forces the molecule into the nano-channel at lower electric fields than those observed without the funnel. Appropirately designed nano-funnels can also function as tweezers that allow manipulation of the position of the DNA molecule. The predictions of our theory describing double-stranded DNA behavior in nano-funnel - nano-channel devices are consistent with experimental results. Thanks for the financial support from NSF (DMR-1309892, DMR-1121107, DMR-1122483), NIH (1-P50-HL107168, 1-P01-HL108808-01A1, R01HG02647), NHGRI and CF Foundation.

  18. Novel Regulation of Aquaporins during Osmotic Stress1

    Science.gov (United States)

    Vera-Estrella, Rosario; Barkla, Bronwyn J.; Bohnert, Hans J.; Pantoja, Omar

    2004-01-01

    Aquaporin protein regulation and redistribution in response to osmotic stress was investigated. Ice plant (Mesembryanthemum crystallinum) McTIP1;2 (McMIPF) mediated water flux when expressed in Xenopus leavis oocytes. Mannitol-induced water imbalance resulted in increased protein amounts in tonoplast fractions and a shift in protein distribution to other membrane fractions, suggesting aquaporin relocalization. Indirect immunofluorescence labeling also supports a change in membrane distribution for McTIP1;2 and the appearance of a unique compartment where McTIP1;2 is expressed. Mannitol-induced redistribution of McTIP1;2 was arrested by pretreatment with brefeldin A, wortmannin, and cytochalasin D, inhibitors of vesicle trafficking-related processes. Evidence suggests a role for glycosylation and involvement of a cAMP-dependent signaling pathway in McTIP1;2 redistribution. McTIP1;2 redistribution to endosomal compartments may be part of a homeostatic process to restore and maintain cellular osmolarity under osmotic-stress conditions. PMID:15299122

  19. Protozoa inhibition by different salts: Osmotic stress or ionic stress?

    Science.gov (United States)

    Li, Changhao; Li, Jingya; Lan, Christopher Q; Liao, Dankui

    2017-09-01

    Cell density and morphology changes were tested to examine the effects of salts including NaHCO 3 , NaCl, KHCO 3 , and KCl at 160 mM on protozoa. It was demonstrated that ionic stress rather than osmotic stress led to protozoa cell death and NaHCO 3 was shown to be the most effective inhibitor. Deformation of cells and cell shrinkage were observed when protozoan cells were exposed to polyethylene glycol (PEG) or any of the salts. However, while PEG treated cells could fully recover in both number and size, only a small portion of the salt-treated cells survive and cell size was 36-58% smaller than the regular. The disappearance of salt-treated protozoa cells was hypothetically attributed to disruption of the cytoplasmic membrane of these cells. It is further hypothesized that the PEG-treated protozoan cells carried out regulatory volume increase (RVI) after the osmotic shock but the RVI of salt-treated protozoa was hurdled to varied extents. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1418-1424, 2017. © 2017 American Institute of Chemical Engineers.

  20. Does osmotic distillation change the isotopic relation of wines?

    Directory of Open Access Journals (Sweden)

    Schmitt Matthias

    2014-01-01

    Full Text Available Currently partial alcohol reduction of wine is in the focus of research worldwide. There are several technologies available to achieve this target. These techniques are either based on distilling or membrane processes. Osmotic distillation, one of the possibilities, is a quite modern membrane process that can be used. During that process, wine is pumped in counter flow to water along a micro porous, hydrophobic membrane. The volatile components of the wine can permeate that membrane and are dissolved in water. The driving force of that process is the vapor pressure difference between the volatiles on the wine and water side of the membrane. The aim of this work was to determine if the alcohol reduction by osmotic distillation can change the isotopic relation in a wine. Can this enological practice change the composition of a wine in a way that an illegal water addition is simulated? Different wines were reduced by 2% alcohol v/v with varying process parameters. The isotopic analysis of the O 16/18 ratio in the wine were performed according to the OIV methods (353/2009 These analyses showed that the isotopic ratio is modified by an alcohol reduction of 2% v/v in a way that corresponds to an addition of 4–5% of external water.

  1. Quorum sensing regulates the osmotic stress response in Vibrio harveyi.

    Science.gov (United States)

    van Kessel, Julia C; Rutherford, Steven T; Cong, Jian-Ping; Quinodoz, Sofia; Healy, James; Bassler, Bonnie L

    2015-01-01

    Bacteria use a chemical communication process called quorum sensing to monitor cell density and to alter behavior in response to fluctuations in population numbers. Previous studies with Vibrio harveyi have shown that LuxR, the master quorum-sensing regulator, activates and represses >600 genes. These include six genes that encode homologs of the Escherichia coli Bet and ProU systems for synthesis and transport, respectively, of glycine betaine, an osmoprotectant used during osmotic stress. Here we show that LuxR activates expression of the glycine betaine operon betIBA-proXWV, which enhances growth recovery under osmotic stress conditions. BetI, an autorepressor of the V. harveyi betIBA-proXWV operon, activates the expression of genes encoding regulatory small RNAs that control quorum-sensing transitions. Connecting quorum-sensing and glycine betaine pathways presumably enables V. harveyi to tune its execution of collective behaviors to its tolerance to stress. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  2. Osmotic and activity coefficients of triorganophosphates in n-octane

    International Nuclear Information System (INIS)

    Sagert, N.H.; Lau, D.W.P.

    1982-01-01

    Vapour pressure osmometry was used to measure osmotic coefficients for tributylphosphate (TBP), tricresylphosphate (TCP), and triethylhexylphosphate (THEP) in n-octane at 30, 40, 50, and 60 0 C and at molalities up to 0.3 mol/kg. Activity coefficients and excess thermodynamic properties (unsymmetrical definition) were calculated from these osmotic coefficients. At 30 0 C, the excess Gibbs free energies for 0.1 mol of solute in 1.0 kg n-octane were -42 J, -66 J, and -20 J for TBP, TCP, and TEHP, respectively. The more ideal behavior of the TEHP-octane system is attributed to the increasing importance of hydrocarbon-hydrocarbon interactions as the chain length is increased. The excess enthalpies for 0.1 mol of solute in 1.0 kg of solvent were -100 J, and -300 J, and -150 J for TBP, TCP, and TEHP, respectively. Thus, association of these solutes arises primarily from entropic effects. Our data could generally be accommodated adequately by postulating association of monomers into dimmers. The exception was TCP at lower temperatures, where more complex models were required

  3. Thermal and Osmotic Tolerance of 'Irukandji' Polyps: Cubozoa; Carukia barnesi.

    Directory of Open Access Journals (Sweden)

    Robert Courtney

    Full Text Available This research explores the thermal and osmotic tolerance of the polyp stage of the Irukandji jellyfish Carukia barnesi, which provides new insights into potential polyp habitat suitability. The research also targets temperature, salinity, feeding frequency, and combinations thereof, as cues for synchronous medusae production. Primary findings revealed 100% survivorship in osmotic treatments between 19 and 46‰, with the highest proliferation at 26‰. As salinity levels of 26‰ do not occur within the waters of the Great Barrier Reef or Coral Sea, we conclude that the polyp stage of C. barnesi is probably found in estuarine environments, where these lower salinity conditions commonly occur, in comparison to the medusa stage, which is oceanic. Population stability was achieved at temperatures between 18 and 31°C, with an optimum temperature of 22.9°C. We surmise that C. barnesi polyps may be restricted to warmer estuarine areas where water temperatures do not drop below 18°C. Asexual reproduction was also positively correlated with feeding frequency. Temperature, salinity, feeding frequency, and combinations thereof did not induce medusae production, suggesting that this species may use a different cue, possibly photoperiod, to initiate medusae production.

  4. Swelling and drug release behavior of poly(2-hydroxyethyl methacrylate/itaconic acid) copolymeric hydrogels obtained by gamma irradiation

    International Nuclear Information System (INIS)

    Tomic, S.Lj.; Micic, M.M.; Filipovic, J.M.; Suljovrujic, E.H.

    2007-01-01

    The new copolymeric hydrogels based on 2-hydroxyethyl methacrylate (HEMA) and itaconic acid (IA) were prepared by gamma irradiation, in order to examine the potential use of these hydrogels in controlled drug release systems. The influence of IA content in the gel on the swelling characteristics and the releasing behavior of hydrogels, and the effect of different drugs, theophylline (TPH) and fenethylline hydrochloride (FE), on the releasing behavior of P(HEMA/IA) matrix were investigated in vitro. The diffusion exponents for swelling and drug release indicate that the mechanisms of buffer uptake and drug release are governed by Fickian diffusion. The swelling kinetics and, therefore, the release rate depends on the matrix swelling degree. The drug release was faster for copolymeric hydrogels with a higher content of itaconic acid. Furthermore, the drug release for TPH as model drug was faster due to a smaller molecular size and a weaker interaction of the TPH molecules with(in) the P(HEMA/IA) copolymeric networks

  5. Spinal cord swelling as a myelographic indicator of prognosis: a retrospective study in dogs with intervertebral disc disease and loss of deep pain perception

    International Nuclear Information System (INIS)

    Duval, J.; Dewey, C.; Roberts, R.; Aron, D.

    1996-01-01

    The association of myelographic spinal cord swelling with neurological outcome was examined in 46 dogs with intervertebral disc disease and absence of deep pain perception (DPP). Spinal cord swelling was measured by calculating a ratio of the length of the loss of the myelographic dye column to the length of the second lumbar vertebra (L2). A positive neurological outcome was defined as return of voluntary motor function. A cut-off value for swelling:L2 of 5.0 was established by the creation of a receiver operator characteristic curve. Using a swelling:L2 ratio of 5.0 as a cutoff for indication of neurological recovery yielded a sensitivity of 74% and a specificity of 61%. Overall neurological recovery rate was 43%. Dogs with spinal cord swelling:L2 ratios less than 5.0 had a recovery rate of 61%, whereas dogs with a ratio greater than or equal to 5.0 had a recovery rate of 26%. Evaluation of these data by chi square analysis confirmed that a ratio less than 5.0 was associated with a positive outcome, and a ratio greater than or equal to 5.0 was associated with a negative outcome, (P < .05). Although other factors, such as duration of neurological signs, affect neurological outcome in dogs with no DPP, evaluation of myelographic spinal cord swelling can assist in establishing a prognosis

  6. The osmotic pressure of 3He-4He mixtures along the phase separation curve

    NARCIS (Netherlands)

    van de Klundert, L.J.M.; Bos, M.R.E.; van der Meij, J.A.M.; Steffens, H.A.

    1977-01-01

    The osmotic pressure of 3He-4He mixtures was measured along the phase separation curve at temperatures up to 500 mK by balancing it with the fountain pressure of pure 4He. The usefullness of the secondary osmotic pressure thermometer was reinvestigated.

  7. The osmotic pressure of 3He-4He mixtures along the phase separation curve

    International Nuclear Information System (INIS)

    Klundert, L.J.M. van de; Bos, M.R.E.; Meij, J.A.M. van der; Steffens, H.A.

    1977-01-01

    The osmotic pressure of 3 He- 4 He mixtures was measured along the phase separation curve at temperatures up to 500 mK by balancing it with the fountain pressure of pure 4 He. The usefullness of the secondary osmotic pressure thermometer was reinvestigated. (Auth.)

  8. Effect of osmotic stress on in vitro propagation of Musa sp. (Malbhog ...

    African Journals Online (AJOL)

    This study demonstrates up to 36% reduced microbial contamination in aseptic culture establishment and subsequent micropropagation due to osmotic stress induction in the banana suckers. Osmotic stress was induced by keeping the freshly collected suckers in shade and measuring fresh weight at 0, 7, 14, 21, and 28 ...

  9. Influence of osmotic pressure changes on the opening of existing cracks in 2 intervertebral disc models

    NARCIS (Netherlands)

    Wognum, Silvia; Huyghe, Jacques M.; Baaijens, Frank P. T.

    2006-01-01

    An experimental hydrogel model and a numerical mixture model were used to investigate why the disc herniates while osmotic pressure is decreasing. To investigate the influence of decreasing osmotic pressure on the opening of cracks in the disc. In the degeneration process, the disc changes structure

  10. The dependence of molecular transmembrane electrotransfer efficiency on medium conductivity and osmotic pressure

    OpenAIRE

    Jakutavičiūtė, Milda; Ruzgys, Paulius; Šatkauskas, Saulius

    2014-01-01

    The electrotransfer efficiency was evaluated for different external medium conductivities, osmotic pressures and electric pulse voltages. It was found that increase in conductivity or decrease in electric pulse strength decreases electrotransfer efficiency. Decrease in osmotic pressure tends to decrease electrotransfer efficiency.

  11. 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.

  12. Hybrid Pressure Retarded Osmosis−Membrane Distillation (PRO−MD) Process for Osmotic Power and Clean Water Generation

    KAUST Repository

    Han, Gang; Zuo, Jian; Wan, Chunfeng; Chung, Neal Tai-Shung

    2015-01-01

    unique advantages of high water recovery rate, huge osmotic power generation, well controlled membrane fouling, and minimal environmental impacts. Experimental results show that the PRO−MD hybrid process is promising that not only can harvest osmotic

  13. Left Ulnar Artery Pseudoaneurysm and Left Hand Swelling Simulated by Elephantiasis in a Patient with Neurofibromatosis Type 1

    Directory of Open Access Journals (Sweden)

    Ta-Pin Lee

    2017-06-01

    Full Text Available Elephantiasis is a condition featured by gross enlargement of body parts to massive proportions. Neurofibromatosis type 1 (NF1 is a multisystem genetic disorder. Vascular anomaly is one among the complications of NF1. We report a case of NF1 who had a left hand vascular pseudoaneurysm with left hand swelling mimicking elephantiasis. The characteristics of sonography make it an excellent imaging modality to investigate this sort of superficial vascular lesion.

  14. Optimum condition of producing crisp osmotic banana using superheated steam puffing.

    Science.gov (United States)

    Tabtiang, Surapit; Prachayawarakorn, Somkiat; Soponronnarit, Somchart

    2017-03-01

    Puffing can improve textural property of snacks. Nevertheless, high temperature puffing accelerates non-enzymatic browning reactions. The osmotic treatment using sucrose solution potentially retards the browning, but the high amount of sucrose gain causes hard texture. The objective of this work was therefore to study the effects of osmotic time, puffing time and puffing temperature on banana qualities such as colour, shrinkage and textural property. The experimental results showed that puffing temperature, puffing time and osmotic time significantly affected colour, shrinkage and textual properties. The optimisation using response surface methodology was used for a trade-off between colour and textural properties. To obtain a good quality product, the puffed osmotic banana should be operated at the osmotic time of 43 min and puffing temperature of 220 °C and puffing time of 2 min. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  15. Fecal osmotic gap and pH in experimental diarrhea of various causes.

    Science.gov (United States)

    Eherer, A J; Fordtran, J S

    1992-08-01

    Although the osmotic gap of fecal fluid is often used to distinguish osmotic diarrhea from secretory diarrhea, there has never been a scientific evaluation of the validity of this concept. Similarly, although a low fecal fluid pH value is used to indicate that diarrhea is mediated by carbohydrate malabsorption, the validity of this method is unproven. Therefore, in the present study, diarrhea was induced in normal subjects by different mechanisms and fecal fluid osmotic gap (using an assumed fecal fluid osmolality of 290 mOsm/kg) and pH were measured. In secretory diarrhea caused by phenolphthalein, the osmotic gap was always less than 50 mOsm/kg, whereas in osmotic diarrhea caused by polyethylene glycol, magnesium hydroxide, lactulose, and sorbitol, the osmotic gap always exceeded 50 mOsm/kg. In osmotic diarrhea caused by sodium sulfate, the fecal fluid osmotic gap was less than 50 mOsm/kg, but phenolphthalein-induced secretory diarrhea could be distinguished from sodium sulfate-induced osmotic diarrhea by the fecal chloride concentration. When diarrhea was caused by carbohydrate malabsorption (lactulose or sorbitol), the fecal fluid pH was always less than 5.6 and usually less than 5.3; by contrast, other causes of diarrhea rarely caused a fecal pH as low as 5.6 and never caused a pH less than 5.3. It is concluded that measurement of fecal fluid osmotic gap and pH can distinguish various mechanisms of experimental diarrhea in normal subjects. The concepts on which these tests are based are therefore verified experimentally.

  16. 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)

  17. 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.

  18. 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

  19. 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

  20. 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.

  1. 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 ...

  2. 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

  3. 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)

  4. 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...

  5. 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

  6. 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...

  7. Swelling kinetics and antimicrobial activity of radiolytically synthesized nano-Ag/PVA hydrogels

    International Nuclear Information System (INIS)

    Krstic, J.; Spasojevic, J.; Krkljes, A.; Kacarevic-Popovic, Z.

    2011-01-01

    Complete text of publication follows. Synthesis of nanocomposite materials for biomedical applications, is being systematically developed. The materials having metal nanoparticles incorporated into polymer network have been widely investigated due to their unique properties induced by the synergy of two different materials. Silver nanoparticles (nano-Ag) have been proved to be effective antimicrobial agent and their enhanced antibacterial properties have been demonstrated both in vitro and in vivo. Recent research efforts are directed towards exploiting the in situ synthesis of nano-Ag within polymeric network architectures and products of these approaches are new hybrid nanocomposite systems. Due to characteristic properties such as swellability in water, hydrophilicity, biocompatibility and lack of toxicity, hydrogels have been utilized in a wide range of biological, medical, pharmaceutical and environmental applications. Among different synthetic methods, γ-irradiation induced synthesis has been recognized as highly suitable tool for production of hydrogel nanocomposites due to formation and sterilization of material in one technological step. In this work, the swelling kinetics of PVA and nano-Ag/PVA hydrogels in distilled water and Kokubo's Simulated Body Fluid (SBF), at 25 and 37 deg C, was investigated. The obtained hydrogel nanocomposites had greater swelling capacity and diffusion coefficient compared to PVA hydrogel. Both hydrogel systems show non-Fickian diffusion and Schott second order kinetics, at early and extensive stage of swelling, respectively. Investigated nano-Ag/PVA hydrogel nanocomposites show continuous release of silver over a long period of time and, as consequence, the test of antimicrobial activity was performed. Antimicrobial efficiency was determined by agar-diffusion test and the obtained results clearly show the formation of inhibition zone towards Escherichia coli and Staphylococcus aureus in the case of higher nano

  8. 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

  9. 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

  10. 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.

  11. 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.)

  12. 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.

  13. Osmotically driven flows in microchannels separated by a semipermeable membrane

    DEFF Research Database (Denmark)

    Jensen, Kåre Hartvig; Lee, J.; Bohr, Tomas

    2009-01-01

    We have fabricated lab-on-a-chip systems with microchannels separated by integrated membranes allowing for osmotically driven microflows. We have investigated these flows experimentally by studying the dynamics and structure of the front of a sugar solution travelling in 200 mu m wide and 50-200 mu...... m deep microchannels. We find that the sugar front travels at a constant speed, and that this speed is proportional to the concentration of the sugar solution and inversely proportional to the depth of the channel. We propose a theoretical model, which, in the limit of low axial flow resistance......, predicts that the sugar front should indeed travel with a constant velocity. The model also predicts an inverse relationship between the depth of the channel and the speed, and a linear relation between the sugar concentration and the speed. We thus find good qualitative agreement between the experimental...

  14. Environmental impacts by running an osmotic power plan

    Energy Technology Data Exchange (ETDEWEB)

    Staalstroem, A.; Gitmark, J.

    2012-07-01

    The possible environmental impact by running an osmotic power plant is assessed by using results from monitoring of the prototype plant at Tofte in the Oslofjord, where a water flow of approximately 13 L/s of freshwater is mixed with 20 L/s of saltwater and discharged at 2 m depth. The results from the biological investigations show no impact of the discharge water on the benthic communities in the area. Eutrophication effects near the discharge point are identified as the main environmental concern in an up-scaled power plant. Water samples from the saltwater intake indicate that the phosphorous concentration often is higher at 35 m depth than in the euphotic layer, and there will be a net supply of phosphorous to this layer. By diving the outlet plume below the euphotic zone, eutrophication effects as well as possible effects from use of chemicals and possible changed temperature and salinity in the surface layer is avoided. (Author)

  15. Solute coupled diffusion in osmotically driven membrane processes.

    Science.gov (United States)

    Hancock, Nathan T; Cath, Tzahi Y

    2009-09-01

    Forward osmosis (FO) is an emerging water treatment technology with potential applications in desalination and wastewater reclamation. In FO, water is extracted from a feed solution using the high osmotic pressure of a hypertonic solution that flows on the opposite side of a semipermeable membrane; however, solutes diffuse simultaneously through the membrane in both directions and may jeopardize the process. In this study, we have comprehensively explored the effects of different operating conditions on the forward diffusion of solutes commonly found in brackish water and seawater, and reverse diffusion of common draw solution solutes. Results show that reverse transport of solutes through commercially available FO membranes range between 80 mg to nearly 3,000 mg per liter of water produced. Divalent feed solutes have low permeation rates (less than 1 mmol/m2-hr) while monovalent ions and uncharged solutes exhibit higher permeation. Findings have significant implications on the performance and sustainability of the FO process.

  16. Osmotic pressure induced tensile forces in tendon collagen.

    Science.gov (United States)

    Masic, Admir; Bertinetti, Luca; Schuetz, Roman; Chang, Shu-Wei; Metzger, Till Hartmut; Buehler, Markus J; Fratzl, Peter

    2015-01-22

    Water is an important component of collagen in tendons, but its role for the function of this load-carrying protein structure is poorly understood. Here we use a combination of multi-scale experimentation and computation to show that water is an integral part of the collagen molecule, which changes conformation upon water removal. The consequence is a shortening of the molecule that translates into tensile stresses in the range of several to almost 100 MPa, largely surpassing those of about 0.3 MPa generated by contractile muscles. Although a complete drying of collagen would be relevant for technical applications, such as the fabrication of leather or parchment, stresses comparable to muscle contraction already occur at small osmotic pressures common in biological environments. We suggest, therefore, that water-generated tensile stresses may play a role in living collagen-based materials such as tendon or bone.

  17. 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' ...

  18. Involvement of both sodium influx and potassium efflux in ciguatoxin-induced nodal swelling of frog myelinated axons.

    Science.gov (United States)

    Mattei, César; Molgó, Jordi; Benoit, Evelyne

    2014-10-01

    Ciguatoxins, mainly produced by benthic dinoflagellate Gambierdiscus species, are responsible for a complex human poisoning known as ciguatera. Previous pharmacological studies revealed that these toxins activate voltage-gated Na+ channels. In frog nodes of Ranvier, ciguatoxins induce spontaneous and repetitive action potentials (APs) and increase axonal volume that may explain alterations of nerve functioning in intoxicated humans. The present study aimed determining the ionic mechanisms involved in Pacific ciguatoxin-1B (P-CTX-1B)-induced membrane hyperexcitability and subsequent volume increase in frog nodes of Ranvier, using electrophysiology and confocal microscopy. The results reveal that P-CTX-1B action is not dependent on external Cl- ions since it was not affected by substituting Cl- by methylsulfate ions. In contrast, substitution of external Na+ by Li+ ions suppressed spontaneous APs and prevented nodal swelling. This suggests that P-CTX-1B-modified Na+ channels are not selective to Li+ ions and/or are blocked by these ions, and that Na+ influx through Na+ channels opened during spontaneous APs is required for axonal swelling. The fact that the K+ channel blocker tetraethylammonium modified, but did not suppress, spontaneous APs and greatly reduced nodal swelling induced by P-CTX-1B indicates that K+ efflux might also be involved. This is supported by the fact that P-CTX-1B, when tested in the presence of both tetraethylammonium and the K+ ionophore valinomycin, produced the characteristic nodal swelling. It is concluded that, during the action of P-CTX-1B, water movements responsible for axonal swelling depend on both Na+ influx and K+ efflux. These results pave the way for further studies regarding ciguatera treatment. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. GABA not only a neurotransmitter: osmotic regulation by GABAAR signalling

    Directory of Open Access Journals (Sweden)

    Tiziana eCesetti

    2012-01-01

    Full Text Available In neurons the anionic channel γ-aminobutyric (GABA A receptor (GABAAR plays a central role in mediating both the neurotrophic and neurotransmitter role of GABA. Activation of this receptor by GABA also affects the function of non-neuronal cells in the central nervous system (CNS, as GABAARs are expressed in mature macroglia and in almost all progenitor types, including neural stem cells. The relevance of GABA signalling in non-neuronal cells has been comparatively less investigated than in neurons. However, it is becoming increasingly evident that these cells are direct targets of GABA regulation. In non-neuronal cells GABAAR activation leads to influx or efflux of chloride (Cl- depending on the electrochemical gradient. Ion transport is indissolubly associated to water fluxes across the plasma membrane and plays a key role in brain physiology. Therefore, GABAAR could affect osmotic tension in the brain by modulating ion gradients. In addition, since water movements also occur through specialized water channels and transporters, GABAAR signalling could affect the movement of water also by regulating the function of the channels and transporters involved, thereby affecting not only the direction of the water fluxes but also their dynamics. This regulation has consequences at the cellular level as it modulates cell volume and activates multiple intracellular signalling mechanisms important for cell proliferation, maturation and survival. It may also have consequences at the systemic level. For example, it may indirectly control neuronal excitability, by regulating the extracellular space and interstitial concentration of Cl-, and contribute to brain water homeostasis. Therefore, GABAergic osmotic regulation should be taken into account during the treatment of pathologies requiring the administration of GABAAR modulators and for the development of therapies for diseases causing water unbalance in the brain.

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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

  6. The Arabidopsis Vacuolar Sorting Receptor1 Is Required for Osmotic Stress-Induced Abscisic Acid Biosynthesis

    KAUST Repository

    Wang, Zhen-Yu

    2014-11-21

    Osmotic stress activates the biosynthesis of the phytohormone abscisic acid (ABA) through a pathway that is rate limited by the carotenoid cleavage enzyme 9-cis-epoxycarotenoid dioxygenase (NCED). To understand the signal transduction mechanism underlying the activation of ABA biosynthesis, we performed a forward genetic screen to isolate mutants defective in osmotic stress regulation of the NCED3 gene. Here, we identified the Arabidopsis (Arabidopsis thaliana) Vacuolar Sorting Receptor1 (VSR1) as a unique regulator of ABA biosynthesis. The vsr1 mutant not only shows increased sensitivity to osmotic stress, but also is defective in the feedback regulation of ABA biosynthesis by ABA. Further analysis revealed that vacuolar trafficking mediated by VSR1 is required for osmotic stress-responsive ABA biosynthesis and osmotic stress tolerance. Moreover, under osmotic stress conditions, the membrane potential, calcium flux, and vacuolar pH changes in the vsr1 mutant differ from those in the wild type. Given that manipulation of the intracellular pH is sufficient to modulate the expression of ABA biosynthesis genes, including NCED3, and ABA accumulation, we propose that intracellular pH changes caused by osmotic stress may play a signaling role in regulating ABA biosynthesis and that this regulation is dependent on functional VSR1.

  7. The Arabidopsis Vacuolar Sorting Receptor1 Is Required for Osmotic Stress-Induced Abscisic Acid Biosynthesis

    KAUST Repository

    Wang, Zhen-Yu; Gehring, Christoph A; Zhu, Jianhua; Li, Feng-Min; Zhu, Jian-Kang; Xiong, Liming

    2014-01-01

    Osmotic stress activates the biosynthesis of the phytohormone abscisic acid (ABA) through a pathway that is rate limited by the carotenoid cleavage enzyme 9-cis-epoxycarotenoid dioxygenase (NCED). To understand the signal transduction mechanism underlying the activation of ABA biosynthesis, we performed a forward genetic screen to isolate mutants defective in osmotic stress regulation of the NCED3 gene. Here, we identified the Arabidopsis (Arabidopsis thaliana) Vacuolar Sorting Receptor1 (VSR1) as a unique regulator of ABA biosynthesis. The vsr1 mutant not only shows increased sensitivity to osmotic stress, but also is defective in the feedback regulation of ABA biosynthesis by ABA. Further analysis revealed that vacuolar trafficking mediated by VSR1 is required for osmotic stress-responsive ABA biosynthesis and osmotic stress tolerance. Moreover, under osmotic stress conditions, the membrane potential, calcium flux, and vacuolar pH changes in the vsr1 mutant differ from those in the wild type. Given that manipulation of the intracellular pH is sufficient to modulate the expression of ABA biosynthesis genes, including NCED3, and ABA accumulation, we propose that intracellular pH changes caused by osmotic stress may play a signaling role in regulating ABA biosynthesis and that this regulation is dependent on functional VSR1.

  8. A cellulose synthase-like protein is required for osmotic stress tolerance in Arabidopsis

    KAUST Repository

    Zhu, Jianhua

    2010-04-16

    Osmotic stress imposed by soil salinity and drought stress significantly affects plant growth and development, but osmotic stress sensing and tolerance mechanisms are not well understood. Forward genetic screens using a root-bending assay have previously identified salt overly sensitive (sos) mutants of Arabidopsis that fall into five loci, SOS1 to SOS5. These loci are required for the regulation of ion homeostasis or cell expansion under salt stress, but do not play a major role in plant tolerance to the osmotic stress component of soil salinity or drought. Here we report an additional sos mutant, sos6-1, which defines a locus essential for osmotic stress tolerance. sos6-1 plants are hypersensitive to salt stress and osmotic stress imposed by mannitol or polyethylene glycol in culture media or by water deficit in the soil. SOS6 encodes a cellulose synthase-like protein, AtCSLD5. Only modest differences in cell wall chemical composition could be detected, but we found that sos6-1 mutant plants accumulate high levels of reactive oxygen species (ROS) under osmotic stress and are hypersensitive to the oxidative stress reagent methyl viologen. The results suggest that SOS6/AtCSLD5 is not required for normal plant growth and development but has a critical role in osmotic stress tolerance and this function likely involves its regulation of ROS under stress. © 2010 Blackwell Publishing Ltd.

  9. The Role of Superoxide Dismutase in Inducing of Wheat Seedlings Tolerance to Osmotic Shock

    Directory of Open Access Journals (Sweden)

    Oboznyi A.I.

    2013-08-01

    Full Text Available Influence of short-term hardening osmotic exposure (immersion in 1 M sucrose solution with subsequent transferring to distilled water for 20 min on the hydrogen peroxide generation and superoxide dismutase activity in wheat (Triticum aestivum L., cv. Elegiya seedlings and their tolerance to osmotic shock were investigated. During the initial 30 min after osmotic exposure, the increasing of hydrogen peroxide amount in roots and shoots (to a lesser extent was observed, but the resistance of the seedlings and superoxide dismutase (SOD activity decreased. Sometime later the decrease in hydrogen peroxide amount and the increase of seedlings tolerance to osmotic shock took place. SOD activity increased in 10 min after hardening osmotic exposure. Transient accumulation of hydrogen peroxide induced in this way was suppressed by the treatment of seedlings with sodium diethyldithiocarbamate (DDC, SOD inhibitor. DDC and hydrogen peroxide scavenger dimethylthiourea decreased positive hardening effect of osmotic exposure on the development of seedlings tolerance. It was concluded that SOD providing the generation of signal hydrogen peroxide pool took part in the induction of seedlings tolerance to osmotic shock development caused by preliminary hardening effect.

  10. Linking natural microstructures with numerical modeling of pinch-and-swell structures

    Science.gov (United States)

    Peters, Max; Berger, Alfons; Herwegh, Marco; Regenauer-Lieb, Klaus

    2016-04-01

    For a variety of geological problems, the change from homogeneous to localized deformation and the establishment of steady-state conditions are equally important. Here, we show that pinch-and-swell structures are ideal candidates for the study of the switch in deformation style and mechanism during ductile creep. We present an interdisciplinary approach to the onset of pinch-and-swell structures and to the flow conditions during pre- to post-localization stages in ductile rocks. For this reason, naturally boudinaged calcite veins, embedded in a calc-mylonite, and their microfabrics were investigated quantitatively. Remnants of slightly deformed calcite hosts build up the swells, showing twinning and minor dislocation glide as crystal plastic deformation mechanisms which are accompanied by subgrain rotation recrystallization (SGR). Towards the pinches, we find a gradient of severe grain size reduction through progressive SGR, developing a characteristic dislocation creep crystallographic preferred orientation (CPO). Along this gradient, the finest recrystallized calcite grains appear randomly oriented, expressed by a "smearing-out" of the CPO and missing systematics of misorientation angles in the most extended areas. We interpret this microstructure as a switch from dislocation dominated creep to grain boundary sliding processes. Further, we show that the onset of boudinage is independent on both the original orientation and grain size of calcite hosts. We implemented these microstructural observations into a layered elasto-visco-plastic finite element framework, tracing variations in grain size (Peters et al., 2015). We base the microstructural evolution on thermo-mechanical-chemical principles and end-member flow laws (Herwegh et al., 2014). The simulated pinch-and-swell structures indicate that low strain rates in the swells favor dislocation creep, whereas accelerated rates provoke continuous grain size reduction allowing strain accommodation by diffusion creep

  11. Combined infragravity wave and sea-swell runup over fringing reefs by super typhoon Haiyan

    Science.gov (United States)

    Shimozono, Takenori; Tajima, Yoshimitsu; Kennedy, Andrew B.; Nobuoka, Hisamichi; Sasaki, Jun; Sato, Shinji

    2015-06-01

    Super typhoon Haiyan struck the Philippines on 8 November 2013, marking one of the strongest typhoons at landfall in recorded history. Extreme storm waves attacked the Pacific coast of Eastern Samar where the violent typhoon first made landfall. Our field survey confirmed that storm overwash heights of 6-14 m above mean sea level were distributed along the southeastern coast and extensive inundation occurred in some coastal villages in spite of natural protection by wide fringing reefs. A wave model based on Boussinesq-type equations is constructed to simulate wave transformation over shallow fringing reefs and validated against existing laboratory data. Wave propagation and runup on the Eastern Samar coast are then reproduced using offshore boundary conditions based on a wave hindcast. The model results suggest that extreme waves on the shore are characterized as a superposition of the infragravity wave and sea-swell components. The balance of the two components is strongly affected by the reef width and beach slope through wave breaking, frictional dissipation, reef-flat resonances, and resonant runup amplification. Therefore, flood characteristics significantly differ from site to site due to a large variation of the two topographic parameters on the hilly coast. Strong coupling of infragravity waves and sea swells produces extreme runup on steep beaches fronted by narrow reefs, whereas the infragravity waves become dominant over wide reefs and they evolve into bores on steep beaches.

  12. Uranium favorability of the San Rafael Swell area, east-central Utah

    International Nuclear Information System (INIS)

    Mickle, D.G.; Jones, C.A.; Gallagher, G.L.; Young, P.; Dubyk, W.S.

    1977-10-01

    The San Rafael Swell project area in east-central Utah is approximately 3,000 sq mi and includes the San Rafael Swell anticline and the northern part of the Waterpocket Fold monocline at Capitol Reef. Rocks in the area are predominantly sedimentary rocks of Pennsylvanian through Cretaceous age. Important deposits of uranium in the project area are restricted to two formations, the Chinle (Triassic) and Morrison (Jurassic) Formations. A third formation, the White Rim Sandstone (Permian), was also studied because of reported exploration activity. The White Rim Sandstone is considered generally unfavorable on the basis of lithologic characteristics, distance from a possible source of uranium, lack of apparent mineralization, and the scarcity of anomalies on gamma-ray logs or in rock, water, and stream-sediment samples. The lower Chinle from the Moss Back Member down to the base of the formation is favorable because it is a known producer. New areas for exploration are all subsurface. Both Salt Wash and Brushy Basin Members of the Morrison Formation are favorable. The Salt Wash Member is favorable because it is a known producer. The Brushy Basin Member is favorable as a low-grade resource

  13. 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.

  14. The approximate entropy of the electromyographic signals of tremor correlates with the osmotic fragility of human erythrocytes

    Directory of Open Access Journals (Sweden)

    Penha-Silva Nilson

    2010-06-01

    Full Text Available Abstract Background The main problem of tremor is the damage caused to the quality of the life of patients, especially those at more advanced ages. There is not a consensus yet about the origins of this disorder, but it can be examined in the correlations between the biological signs of aging and the tremor characteristics. Methods This work sought correlations between the osmotic fragility of erythrocytes and features extracted from electromyographic (EMG activity resulting from physiological tremor in healthy patients (N = 44 at different ages (24-87 years. The osmotic fragility was spectrophotometrically evaluated by the dependence of hemolysis, provided by the absorbance in 540 nm (A54o, on the concentration of NaCl. The data were adjusted to curves of sigmoidal regression and characterized by the half transition point (H50, amplitude of lysis transition (dx and values of A540 in the curve regions that characterize the presence of lysed (A1 and preserved erythrocytes (A2. The approximate entropy was estimated from EMG signals detected from the extensor carpi ulnaris muscle during the movement of the hand of subjects holding up a laser pen towards an Archimedes spiral, fixed in a whiteboard. The evaluations were carried out with the laser pen at rest, at the center of the spiral, and in movement from the center to the outside and from outside to the center. The correlations among the parameters of osmotic fragility, tremor and age were tested. Results Negative correlations with age were found for A1 and dx. With the hand at rest, a positive correlation with H50 was found for the approximate entropy. Negative correlations with H50 were found for the entropy with the hand in movement, as from the center to the outside or from the outside to the center of the spiral. Conclusion In healthy individuals, the increase in the erythrocyte osmotic fragility was associated with a decrease in the approximate entropy for rest tremor and with an increase

  15. 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

  16. 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.

  17. Osmotic coefficients of water for thorium nitrate solutions at 25, 37, and 50oC

    International Nuclear Information System (INIS)

    Lemire, R.J.; Sagert, N.H.; Lau, D.W.P.

    1983-01-01

    Vapor pressure osmometry was used to measure osmotic coefficients of water for thorium nitrate solutions at 25, 37, and 50 o C and at molalities up to 0.2 mol·kg -1 . The data were fitted to three- and four-parameter equations containing limiting-law terms for a 4:1 electrolyte. The variation of the osmotic coefficients as a function of temperature was found to be small. The results are compared to published values for the osmotic coefficients. (author)

  18. A micropuncture study of proximal tubular transport of lithium during osmotic diuresis

    DEFF Research Database (Denmark)

    Leyssac, P P; Holstein-Rathlou, N H; Skøtt, P

    1990-01-01

    Lithium and sodium are normally reabsorbed in parallel with water by the renal proximal tubule whereby their tubular fluid-to-plasma concentration ratios (TF/P) remain close to unity throughout the proximal convoluted segment. During osmotic diuresis, the late proximal (TF/P)Na is known to decrease....... The present experiments were undertaken to study whether the late proximal TF/P for Li decreases like that of Na during osmotic diuresis. Data were obtained in a control period (C) and in two successive periods during mannitol diuresis (P1, P2). Glomerular filtration rate decreased gradually during osmotic...

  19. Neutral lipid production in Dunaliella salina during osmotic stress and adaptation

    DEFF Research Database (Denmark)

    Yao, Shuo; Lu, Jingquan; Sárossy, Zsuzsa

    2016-01-01

    The salt-tolerant green microalga Dunaliella salina can survive both hyper- and hypo-osmotic shock. Upon osmotic shock, the cells transiently and rapidly decreased or increased in size within minutes and slowly over hours acquired their original cell size and volume. Cell size distribution differs...... significantly in the cultures grown in the salinity range from 1.5 to 15 % NaCl. By using Nile Red fluorescence to detect neutral lipids, it became clear that only hyper-osmotic shock on cells induced transient neutral lipid appearance in D. salina, while those transferred from 9 to 15 % NaCl stimulated...

  20. Water swelling, brine soluble imidazole based zwitterionic polymers-synthesis and study of reversible UCST behaviour and gel-sol transitions

    NARCIS (Netherlands)

    Vasantha, Vivek Arjunan; Jana, Satyasankar; Parthiban, Anbanandam; Vancso, Julius G.

    2014-01-01

    New vinylbenzene substituted imidazole based zwitterionic polymers with unique characteristics like swelling in water and solubility in concentrated brine solution in which they exhibited a reversible upper critical solution temperature (UCST) and gel-sol transitions are reported herein. © 2014 The

  1. Swelling and hydrolysis kinetics of Kraft pulp fibers in aqueous 1-butyl-3-methylimidazolium hydrogen sulfate solutions.

    Science.gov (United States)

    Mao, Jia; Abushammala, Hatem; Pereira, Laura Barcellos; Laborie, Marie-Pierre

    2016-11-20

    1Butyl-3-methylimidazolium hydrogen sulfate ([Bmim]HSO4) is efficient at extracting cellulose nanocrystals from pulp fibers. To shed some light on the respective contributions of swelling and hydrolysis of pulp fibers by [Bmim]HSO4, the physical, structural and morphological characteristics of hardwood Kraft pulp fibers were monitored under various conditions of temperature, water content and time. Swelling was largely compounded by hydrolysis at the highest temperatures (120°C) as evidenced by mass loss and reduced degree of polymerization (DPn) at this temperature. At 120°C only, water content appeared to play a significant role on the extent of hydrolysis. At this temperature, a heterogeneous kinetic model involving weak links and amorphous regions best described the experimental data. Hydrolysis rates were maximum at 25% water content in the aqueous ionic liquid. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Stacking fault density as engineering criterion for resistance to radiation swelling of alloys' FCC- and BCC-lattice

    International Nuclear Information System (INIS)

    Zheltov, Yu.V.; Ageev, V.S.; Kolesnikov, Yu.G.

    1990-01-01

    The experimental data on influence of Mn, Cr, Ni, P, B, Ce alloying in austenitic and simultaneously Nb, V, B alloying in ferritic steels and also heat treatment on stacking fault density (SFD) are represented. In all cases besides influence of Cr in austenitic steel the increase of SFD is shown. The decrease of radiation swelling of industrial steels at the increase of their SFD, measured by X-rays, was studied. The tendency of increase of relative radiation swelling change at SFD increase at relative fluence rise is verified. It is shown that SFD may be a perspective proximate characteristics of choice of radiation-resistant steel melts within one steel quality. 14 refs.; 4 figs. (author)

  3. Seminal characteristics and sexual behavior in men of different age groups: is there an aging effect?

    Science.gov (United States)

    Zavos, Panayiotis M; Kaskar, Khalied; Correa, Juan R; Sikka, Suresh C

    2006-05-01

    To assess the seminal characteristics as well as the sexual behavior of men of various age groups to establish the presence of an aging effect on those characteristics. Semen samples were collected from men (n = 792) undergoing in vitro fertilization or intrauterine insemination in cases of female factor infertility only. Samples were collected using a seminal collection device at intercourse and evaluated manually according to World Health Organization (WHO) standards. Men were divided into four groups according to their ages: (i) 20-30, (ii) 31-40, (iii) 41-50 and (iv) 51-60 years, and their seminal characteristics and responses to a sexual behavior questionnaire were compared. The data showed statistically significant differences in the seminal characteristics tested, most notably in the sperm concentration, motility, grade of motility, hypo-osmotic swelling and normal sperm morphology. Furthermore, the decline in normal sperm morphology with age was more pronounced when using strict criteria rather than WHO standards. There were also differences in total sperm count, total motile sperm and total functional sperm fraction (assessed by both WHO and strict criteria). Significant differences were also observed in the sexual behavior patterns in older men in terms of the number of years they have been trying to conceive, sexual frequency and sexual satisfaction. The data clearly illustrate an aging effect on semen characteristics and sexual behavior in men as they age. It is suggested that the aging effect be taken into consideration when proposing normal standard values for semen characteristics in routine semen analysis as outlined by WHO standards.

  4. Exposure of natural rubber to personal lubricants--swelling and stress relaxation as potential indicators of reduced seal integrity of non-lubricated male condoms.

    Science.gov (United States)

    Sarkar Das, Srilekha; Coburn, James C; Tack, Charles; Schwerin, Matthew R; Richardson, D Coleman

    2014-07-01

    Male condoms act as mechanical barriers to prevent passage of body fluids. For effective use of condoms the mechanical seal is also expected to remain intact under reasonable use conditions, including with personal lubricants. Absorption of low molecular weight lubricant components into the material of male condoms may initiate material changes leading to swelling and stress relaxation of the polymer network chains that could affect performance of the sealing function of the device. Swelling indicates both a rubber-solvent interaction and stress relaxation, the latter of which may indicate and/or result in a reduced seal pressure in the current context. Swelling and stress relaxation of natural rubber latex condoms were assessed in a laboratory model in the presence of silicone-, glycol-, and water-based lubricants. Within 15 minutes, significant swelling (≥6 %) and stress reduction (≥12 %) of condoms were observed with 2 out of 4 silicone-based lubricants tested, but neither was observed with glycol- or water-based lubricants tested. Under a given strain, reduction in stress was prominent during the swelling processes, but not after the process was complete. Lubricant induced swelling and stress relaxation may loosen the circumferential stress responsible for the mechanical seal. Swelling and stress relaxation behavior of latex condoms in the presence of personal lubricants may be useful tests to identify lubricant-rooted changes in condom-materials. For non-lubricated latex condoms, material characteristics--which are relevant to failure--may change in the presence of a few silicone-based personal lubricants. These changes may in turn induce a loss of condom seal during use, specifically at low strain conditions. Published by Elsevier Inc.

  5. 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)

  6. 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

  7. Influence of layer charge and charge distribution of smectites on the flow behaviour and swelling of bentonites

    Science.gov (United States)

    Christidis, G.E.; Blum, A.E.; Eberl, D.D.

    2006-01-01

    The influence of layer charge and charge distribution of dioctahedral smectites on the rheological and swelling properties of bentonites is examined. Layer charge and charge distribution were determined by XRD using the LayerCharge program [Christidis, G.E., Eberl, D.D., 2003. Determination of layer charge characteristics of smectites. Clays Clay Miner. 51, 644-655.]. The rheological properties were determined, after sodium exchange using the optimum amount of Na2CO3, from free swelling tests. Rheological properties were determined using 6.42% suspensions according to industrial practice. In smectites with layer charges of - 0.425 to - 0.470 per half formula unit (phfu), layer charge is inversely correlated with free swelling, viscosity, gel strength, yield strength and thixotropic behaviour. In these smectites, the rheological properties are directly associated with the proportion of low charge layers. By contrast, in low charge and high charge smectites there is no systematic relation between layer charge or the proportion of low charge layers and rheological properties. However, low charge smectites yield more viscous suspensions and swell more than high charge smectites. The rheological properties of bentonites also are affected by the proportion of tetrahedral charge (i.e. beidellitic charge), by the existence of fine-grained minerals having clay size, such as opal-CT and to a lesser degree by the ionic strength and the pH of the suspension. A new method for classification of smectites according to the layer charge based on the XRD characteristics of smecites is proposed, that also is consistent with variations in rheological properties. In this classification scheme the term smectites with intermediate layer charge is proposed. ?? 2006 Elsevier B.V. All rights reserved.

  8. 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.)

  9. 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

  10. 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

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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

  19. 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

  20. 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)

  1. Red blood cell phosphate concentration and osmotic resistance during dietary phosphate depletion in dairy cows

    NARCIS (Netherlands)

    Grünberg, W; Mol, J A; Teske, E

    BACKGROUND: Hypophosphatemia in early lactating dairy cows has been implicated as primary cause for postparturient hemoglobinuria in cattle. Decreased availability of phosphorus has been proposed to reduce adenosine triphosphate synthesis of erythrocytes and thereby reduce osmotic resistance of

  2. The osmotic second virial coefficient and the Gibbs-McMillan-Mayer framework

    DEFF Research Database (Denmark)

    Mollerup, J.M.; Breil, Martin Peter

    2009-01-01

    The osmotic second virial coefficient is a key parameter in light scattering, protein crystallisation. self-interaction chromatography, and osmometry. The interpretation of the osmotic second virial coefficient depends on the set of independent variables. This commonly includes the independent...... variables associated with the Kirkwood-Buff, the McMillan-Mayer, and the Lewis-Randall solution theories. In this paper we analyse the osmotic second virial coefficient using a Gibbs-McMillan-Mayer framework which is similar to the McMillan-Mayer framework with the exception that pressure rather than volume...... is an independent variable. A Taylor expansion is applied to the osmotic pressure of a solution where one of the solutes is a small molecule, a salt for instance, that equilibrates between the two phases. Other solutes are retained. Solvents are small molecules that equilibrate between the two phases...

  3. Osmotic actuation for microfluidic components in point-of-care applications

    KAUST Repository

    Chen, Yu-Chih; Ingram, Patrick; Lou, Xia; Yoon, Euisik

    2013-01-01

    at low cost. In this work, we report two key active components actuated by osmotic mechanism for total integrated microfluidic system. For the proof of concept, we have demonstrated valve actuation, which can maintain stable ON/OFF switching operations

  4. On equations for the total suction and its matric and osmotic components

    International Nuclear Information System (INIS)

    Dao, Vinh N.T.; Morris, Peter H.; Dux, Peter F.

    2008-01-01

    A clear fundamental understanding of suctions is crucial for the study of the behaviour of plastic cement mortar and concrete, including plastic shrinkage cracking. In this paper, the expression relating the change in free energy of the pore water with an isothermal change in pressure is first derived. Based upon definitions of suctions, it is then shown that total, matric, and osmotic suctions can all be expressed in the same thermodynamic form. The widely accepted, but not yet satisfactorily validated, assumption that the total suction comprises matric and osmotic components is then confirmed theoretically. The well-known Kelvin equation for matric suction, and Morse and van't Hoff equations for osmotic suction are subsequently derived from the corresponding thermodynamic equations. The applicability of latter two equations in evaluating the osmotic suctions of cement mortar and concrete is highlighted

  5. Cross tolerance of osmotically and ionically adapted cell lines of rice ...

    African Journals Online (AJOL)

    saad

    2012-01-10

    Jan 10, 2012 ... The phenomenon of cross tolerance in osmotically and ionically adapted rice .... the mean values of 5 replicates ± standard error. variance showed .... Education Commission of Pakistan and Pakistan Science. Foundation.

  6. Alleviation of osmotic stress of water and salt in germination and ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-07-04

    Jul 4, 2008 ... ening, osmoconditioning, osmohardening, and hormonal priming have ... germination, emergence and plant growth of wheat (Das and Choudhury .... In the present study, a significant three way interaction. (osmotic agents ...

  7. Ebselen exhibits glycation-inhibiting properties and protects against osmotic fragility of human erythrocytes in vitro.

    Science.gov (United States)

    Soares, Julio C M; Folmer, Vanderlei; Da Rocha, João B T; Nogueira, Cristina W

    2014-05-01

    Diabetic status is associated with an increase on oxidative stress markers in humans and animal models. We have investigated the in vitro effects of high concentrations of glucose on the profile of oxidative stress and osmotic fragility of blood from control and diabetic patients; we considered whether its antioxidant properties could afford some protection against glucose-induced osmotic fragility, and whether ebselen could act as an inhibitor of hemoglobin glycation. Raising blood glucose to 5-100 mmol/L resulted in a concentration-dependent increase of glycated hemoglobin (HbA1c; P Ebselen significantly reduced the glucose-induced increase in osmotic fragility and inhibited HbA1c formation (P < 0.0001). These results indicate that blood from patients with uncontrolled diabetes are more sensitive to osmotic shock than from patients with controlled diabetes and control subjects in relation to increased production of free radicals in vivo. © 2014 International Federation for Cell Biology.

  8. Comparison of the mineralogical composition, physical, swelling and hydraulic properties of untreated sodium bentonites from Canada, the United States and Japan

    International Nuclear Information System (INIS)

    Dixon, D.A.; Miller, S.H.

    1995-11-01

    A large variety of commercial grade sodium bentonite products are available from suppliers in North America and Japan. This report generally characterizes the products available for environmental engineering applications. A compilation of the swelling capacity and hydraulic properties of the available products, together with their basic mineralogical composition, physical and engineering properties is presented. This report identifies the range of materials available commercially and documents the basic physical properties of these products. The geological origins and locations of bentonite-ore deposits are discussed with reference to the availability and variability of this material. The hydraulic and swelling characteristics of 17 different bentonite products from 9 different producers were compared. Considerable variation was noted in the free-swell capacity of these clays but this was not reflected in the swelling pressure or hydraulic conductivity of densely compacted specimens. The density -hydraulic conductivity relationship was found to be independent of product for untreated sodium bentonite clays with hydraulic conductivity decreasing with increasing clay density (for materials tested at high (>500) hydraulic gradients). A large body of hydraulic conductivity data was obtained from the literature to supplement the data generated by this study. The literature values further supported the results of this study. Hydraulic conductivity and swelling pressure performance at high density are consistent when sodium bentonites of similar quality are densely compacted prior to use. (author) 27 refs., 5 tabs., 17 figs

  9. Electrostatic Swelling and Conformational Variation Observed in High-Generation Polyelectrolyte Dendrimers

    International Nuclear Information System (INIS)

    Butler, Paul D.; Chen, Wei-Ren; Herwig, Kenneth W.; Hong, Kunlun; Liu, Yun; Porcar, L.; Shew, Chwen-Yang; Smith, Gregory Scott; Chen, Hsin-Lung; Chen, Chun-Yu; Li, Xin; Liu, Emily

    2010-01-01

    A coordinated study combining small angle neutron scattering (SANS) and small angle x-ray scattering (SAXS) measurements was conducted to investigate the structural characteristics of aqueous (D2O) generation 7 and 8 (G7 and G8) PAMAM dendrimer solutions as a function of molecular protonation at room temperature. The change in intra-molecular conformation was clearly exhibited in the data analysis by separating the variation in the inter-molecular correlation. Our results unambiguously demonstrate an increased molecular size and evolved intra-molecular density profile upon increasing the molecular protonation. This is contrary to the existing understanding that in higher generation polyelectrolyte dendrimers, steric crowding stiffens the local motion of dendrimer segments exploring additional available intra-dendrimer volume and therefore inhibits the electrostatic swelling. Our observation is relevant to elucidation of the general microscopic picture of polyelectrolyte dendrimer structure, as well as the development of dendrimer-based packages with based on the stimuli-responsive principle.

  10. 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.

  11. 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])

  12. 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.

  13. 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.

  14. 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.

  15. Studies of osmotic diarrhea induced in normal subjects by ingestion of polyethylene glycol and lactulose.

    OpenAIRE

    Hammer, H F; Santa Ana, C A; Schiller, L R; Fordtran, J S

    1989-01-01

    The purpose of these studies was to gain insight into the pathophysiology of pure osmotic diarrhea and the osmotic diarrhea caused by carbohydrate malabsorption. Diarrhea was induced in normal volunteers by ingestion of polyethylene glycol (PEG), which is nonabsorbable, not metabolized by colonic bacteria, and carries no electrical charge. In PEG-induced diarrhea, (a) stool weight was directly correlated with the total mass of PEG ingested; (b) PEG contributed 40-60% of the osmolality of the ...

  16. A model of strategic marketing alliances for hospices: vertical, internal, osmotic alliances and the complete model.

    Science.gov (United States)

    Starnes, B J; Self, D R

    1999-01-01

    This article develops two previous research efforts. William J. Winston (1994, 1995) has proposed a set of strategies by which health care organizations can benefit from forging strategic alliances. Raadt and Self (1997) have proposed a classification model of alliances including horizontal, vertical, internal, and osmotic. In the second of two articles, this paper presents a model of vertical, internal, and osmotic alliances. Advantages and disadvantages of each are discussed. Finally, the complete alliance system model is presented.

  17. Screening for Osmotic Stress Responses in Rice Varieties under Drought Condition

    OpenAIRE

    Simon Swapna; Korukkanvilakath Samban Shylaraj

    2017-01-01

    Drought is the major abiotic stress factor that limits rice production worldwide. To evaluate the osmotic stress responses in rice varieties under drought condition, a total of 42 high-yielding rice varieties were collected from various research stations of Kerala Agricultural University in India. The experimental setup comprises of initial hydroponic treatments at different osmotic potentials, artificially induced by desired strengths of polyethylene glycol (PEG6000), and followed by the pot...

  18. Extracellular-matrix-mediated osmotic pressure drives Vibrio cholerae biofilm expansion and cheater exclusion

    OpenAIRE

    Yan, Jing; Nadell, Carey D.; Stone, Howard A.; Wingreen, Ned S.; Bassler, Bonnie L.

    2017-01-01

    Biofilms, surface-attached communities of bacteria encased in an extracellular matrix, are a major mode of bacterial life. How the material properties of the matrix contribute to biofilm growth and robustness is largely unexplored, in particular in response to environmental perturbations such as changes in osmotic pressure. Here, using Vibrio cholerae as our model organism, we show that during active cell growth, matrix production enables biofilm-dwelling bacterial cells to establish an osmot...

  19. Using miniature osmotic infusion pumps to maintain tritiated thymidine exposure to cells in culture

    International Nuclear Information System (INIS)

    Neely, J.E.; Hake, D.A.

    1982-01-01

    To provide a constant level of tracer doses of tritiated thymidine to cultured cells during continuous infusion, miniature osmotic infusion pumps were used to provide replacement thymidine. By determining the loss of isotope from the media during nonreplacement, the rate of constant infusion replacement to maintain thymidine levels was calculated. The replacement rates were similar for the three cell lines examined and allowed a standard osmotic pump infusion

  20. Effect of hydrodynamic slippage on electro-osmotic flow in zeta potential patterned nanochannels

    Energy Technology Data Exchange (ETDEWEB)

    Datta, S; Choudhary, J N, E-mail: subhra-datta@iitd.ac.in [Department of Mechanical Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016 (India)

    2013-10-01

    The effect of hydrodynamic slippage on the electro-osmotic flow in a nanochannel with thick electrical double layers whose wall surface potential has a periodic axial variation is studied. The equations of Stokes flow are solved exactly with the help of the Navier slip boundary condition and the Debye-Huckel linearization of the equation governing the potential of the electrical double layer. Each periodic cell of the flow field consists of four counter-rotating vortices. The cross-channel profile of the axial velocity at the center of the cell exhibits three extrema and a reversed velocity zone near the channel axis of symmetry. The size of the extrema and that of the reversed velocity zone increases with increase in the degree of slippage. In the limit when the wavelength of axial variation in surface potential is much larger than the channel width, the flow characteristics are interpreted in terms of the lubrication approximation. In the limit when the electrical double layer is much thinner than the channel height, the effect of slip is modeled by a Helmholtz-Smoluchowski apparent slip boundary condition that depends on the pattern wavelength. (paper)